JP2005148415A - El display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that there is dispersion of output current and occurrence of display variations in an EL (electroluminescence) display panel caused by displacement of a threshold in a source driver circuit with respect to a light emission display panel such as an EL display panel (a display device) or the like using organic or inorganic EL element. <P>SOLUTION: An electronic volume 501 which generates a precharge voltage is incorporated in a source driver IC14 that outputs a program current. A zero-th gradation precharge voltage is outputted by the operation of an S1 switch. The zero-th gradation precharge voltage is set by an externally attached resistor Ra. Moreover, the range of the precharge voltage is set by externally attached resistors Rb and Rc. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a self-luminous display panel such as an EL display panel (display device) using an organic or inorganic electroluminescence (EL) element. The present invention also relates to a drive circuit (IC) such as these display panels. The present invention relates to a driving method and a driving circuit of an EL display panel (display device) and the like, an information display device using them, and the like.

  In general, in an active matrix display device, an image is displayed by arranging a large number of pixels in a matrix and controlling the light intensity for each pixel in accordance with a given video signal. For example, when liquid crystal is used as the electro-optical material, the transmittance of the pixel changes according to the voltage written to each pixel.

In an active matrix image display device using an organic electroluminescence (EL) material as an electro-optic conversion substance, light emission luminance changes according to a current written to a pixel.
In the liquid crystal display panel, each pixel operates as a shutter, and an image is displayed by turning on and off light from a backlight with a shutter that is a pixel. The organic EL display panel is a self-luminous type having a light emitting element in each pixel. Therefore, the organic EL display panel has advantages such as higher image visibility than the liquid crystal display panel, no backlight, and high response speed.

  In the organic EL display panel, the luminance of each light emitting element (pixel) is controlled by the amount of current. That is, it is greatly different from the liquid crystal display panel in that the light emitting element is a current drive type or a current control type.

  The organic EL display panel can also be configured in a simple matrix system and an active matrix system. Although the former has a simple structure, it is difficult to realize a large and high-definition display panel. However, it is cheap. The latter can realize a large, high-definition display panel. However, there is a problem that the control method is technically difficult and relatively expensive. At present, active matrix systems are actively developed. In the active matrix system, a current flowing through a light emitting element provided in each pixel is controlled by a thin film transistor (transistor) provided in the pixel.

  An equivalent circuit for one pixel of an active matrix organic EL display panel is shown in FIG. 2 (see, for example, Patent Document 1). The pixel 16 includes an EL element 15 that is a light emitting element, a first transistor (driving transistor) 11 a, a second transistor (switching transistor) 11 b, and a storage capacitor (capacitor) 19. The light emitting element 15 is an organic electroluminescence (EL) element. In this specification, the transistor 11 a that supplies (controls) current to the EL element 15 is referred to as a driving transistor 11. A transistor that operates as a switch, such as the transistor 11b in FIG.

  Since the organic EL element 15 often has a rectifying property, it is sometimes called an OLED (organic light emitting diode). In FIG. 1, FIG. 2, etc., the symbol of a diode is used as the light emitting element 15.

  The light-emitting element 15 in the present invention is not limited to the OLED, and any element can be used as long as the luminance is controlled by the amount of current flowing through the element 15. For example, an inorganic EL element is illustrated. In addition, a white light emitting diode made of a semiconductor is exemplified. Further, a light emitting transistor may be used. In addition, the light emitting element 15 is not necessarily required to have rectification. A bidirectional element may be used.

  In the example of FIG. 2, the source terminal (S) of the P-channel transistor 11a is the anode Vdd, and the cathode (cathode) of the EL element 15 is connected to the ground potential (Vss). The gate terminal (G) of the N-channel transistor 11a is connected to one terminal of the transistor 11b, the source terminal (S) is connected to the EL element 15, and the drain terminal (D) is connected to the cathode electrode.

In order to operate the pixel 16, first, the gate signal line 17 is selected, and a video signal having a voltage representing luminance information is applied to the source signal line 18. The transistor 11 a is turned on, and the video signal is charged in the storage capacitor 19. When the gate signal line 17 is not selected, the transistor 11a is turned off and the transistor 11b is electrically disconnected from the source signal line 18. However, the gate terminal potential of the transistor 11 a is stably held by the storage capacitor (capacitor) 19. The current flowing through the transistor 11a to the light emitting element 15 has a value corresponding to the gate / drain terminal voltage Vgd of the transistor 11a, and the light emitting element 15 emits light with luminance corresponding to the amount of current supplied through the transistor 11a. to continue.
JP-A-8-234683

  Since the liquid crystal display panel is not a self-luminous device, there is a problem that an image cannot be displayed unless a backlight is used. Since a predetermined thickness is required to configure the backlight, there is a problem that the thickness of the display panel is increased. In order to perform color display on the liquid crystal display panel, it is necessary to use a color filter. Therefore, there is a problem that the light utilization efficiency is low. There is also a problem that the color reproduction range is narrow.

  The organic EL display panel is configured by using a low-temperature polysilicon transistor array. However, since the organic EL element emits light by current, there is a problem that display unevenness occurs when the transistor characteristics vary.

  In the pixel configuration shown in FIG. 2, the voltage video signal is converted into a current signal by the transistor 11a. Therefore, if the transistor 11a has a characteristic variation, the current signal to be converted also varies. Normally, the transistor 11a has a characteristic variation of 50% or more. Therefore, display unevenness occurs in the configuration of FIG.

  Display unevenness can be reduced by adopting a current programming system for the pixels. In order to implement the current program, a current drive type driver circuit is required. However, variation also occurs in the transistor elements constituting the current output stage in the current drive type driver circuit. For this reason, there is a problem in that the gradation output current from each output terminal varies and a good image display cannot be performed.

The present invention includes a display area in which pixels are arranged in a matrix,
A source driver circuit for applying a current as a video signal to the pixels;
An electronic volume circuit for generating a precharge voltage configured in the source driver circuit;
A gate driver circuit for controlling the writing timing of the pixel,
The output voltage range of the electronic volume is an EL display device defined by a resistor connected to the outside of the source driver circuit.

  In order to achieve this object, the driver circuit of the EL display panel (EL display device) of the present invention comprises a plurality of transistors that mainly output unit currents, and the output current is changed by changing the number of these transistors. Output. Further, the current flowing through the pixel 16 is controlled (adjusted) by manipulating or controlling the duty ratio control and the reference current.

  The source driver circuit of the present invention has a reference current source, and realizes current control and luminance control by controlling the gate driver circuit. Further, the pixel has a plurality of or single drive transistors, and is driven so as not to cause variation in current flowing in the EL element. Therefore, variation in output current due to threshold shift is small, and occurrence of display unevenness in the EL display panel can be suppressed. Moreover, an image display with a wide dynamic range can be realized, and the practical effect is great.

  In addition, the display panel, the display device, and the like of the present invention exhibit distinctive effects according to their respective configurations such as high image quality, good moving image display performance, low power consumption, low cost, and high luminance.

  Note that if the present invention is used, a low power consumption information display device or the like can be configured, so that power is not consumed. Moreover, since it can be reduced in size and weight, resources are not consumed. Therefore, it is friendly to the global environment and space environment.

  In the present specification, each drawing is omitted or / and enlarged or reduced for easy understanding and / or drawing. For example, in the cross-sectional view of the display panel shown in FIG. 4, the thin film sealing film 41 and the like are shown to be sufficiently thick. On the other hand, in FIG. 3, the sealing lid 40 is shown thinly. Also, there are some omitted parts. For example, in the display panel of the present invention, a phase film (38, 39) such as a circularly polarizing plate is necessary for preventing reflection. However, it is omitted in each drawing of this specification. The same applies to the following drawings. Moreover, the part which attached | subjected the same number or the symbol etc. has the same or similar form, material, function, or operation | movement.

  Note that the contents described in the drawings and the like can be combined with other embodiments and the like without particular notice. For example, a touch panel or the like is added to the display panels of the present invention shown in FIGS. 3 and 4 so that the information display device shown in FIGS. 154 to 157 can be obtained. For example, as an example, FIGS. 19, 21, 22, 24, 27, 32, 39, 40, 85, 89, 93, 98, 108, 116, 117, The driving method or apparatus (circuit) of the present invention described with reference to FIGS. 128, 149 (a), (b), and 163 can be applied to any display device or display panel of the present invention.

  Note that in this specification, the driving transistor 11 and the switching transistor 11 are described as thin film transistors, but the present invention is not limited thereto. A thin film diode (TFD), a ring diode, or the like can also be used. The transistor is not limited to a thin film element, and may be a transistor formed on a silicon wafer. Of course, an FET, a MOS-FET, a MOS transistor, or a bipolar transistor may be used. These are also basically thin film transistors. In addition, it goes without saying that varistors, thyristors, ring diodes, photodiodes, phototransistors, PLZT elements may be used. That is, any of these can be used for the transistor element 11, the gate driver circuit 12, the source driver circuit 14, and the like of the present invention. In FIGS. 3 and 4, the substrate 30 may be formed of a silicon wafer.

  Hereinafter, the EL display panel of the present invention will be described with reference to the drawings. As shown in FIG. 3, the organic EL display panel includes at least an electron transport layer, a light emitting layer, a hole transport layer, and the like on a glass plate 30 (array substrate 30) on which a transparent electrode 35 as a pixel electrode is formed. One organic functional layer (EL layer) 29 and a metal electrode (reflective film) (cathode) 36 are laminated. By applying a positive voltage to the anode (anode) which is the transparent electrode (pixel electrode) 35 and a negative voltage to the cathode (cathode) of the metal electrode (reflection electrode) 36, and applying a direct current between the transparent electrode 35 and the metal electrode 36. The organic functional layer (EL film) 29 emits light.

  The metal electrode 36 is preferably made of a material having a small work function such as lithium, silver, aluminum, magnesium, indium, copper, or an alloy thereof. In particular, for example, an Al—Li alloy is preferably used. The transparent electrode 35 can be made of a conductive material having a high work function such as ITO or gold. When gold is used as an electrode material, the electrode is in a semitransparent state. ITO may be other materials such as IZO. The same applies to the other pixel electrodes 35.

  A desiccant 37 is disposed in the space between the sealing lid 40 and the array substrate 30. This is because the organic EL film 29 is vulnerable to humidity. The desiccant 37 absorbs moisture penetrating the sealing agent and prevents the organic EL film 29 from deteriorating. Further, as shown in FIG. 251, the sealing lid 40 and the array substrate 30 have their peripheral portions sealed with a sealing resin 2511.

  As illustrated in FIG. 251, a thin speaker 2512 may be disposed or formed between the sealing lid 40 and the array substrate 30. The speaker is a thin film type used in mobile devices. Since there is a space 2514 in the recess of the sealing lid 40, the space 2514 can be used effectively by disposing the speaker 2512 in this space 2514. Further, since the speaker 2512 vibrates in the space 2514, sound can be generated from the surface of the panel. The speaker 2512 is fixed at the same time as the desiccant 37 or attached to the sealing lid 40 at a place other than the desiccant 37 and fixed. Alternatively, the speaker 2512 may be formed directly on the sealing lid 40. Further, a temperature sensor is formed or arranged in the space 2514 of the sealing lid 40 or the surface of the sealing lid 40, and the duty ratio control, the reference current ratio control, and the lighting rate control, which will be described later, are performed based on the output result of the temperature sensor. Etc. may be implemented.

  Terminal wiring from the speaker is formed of an aluminum vapor deposition film, and is drawn out of the sealing lid 40 and connected to a power source or a signal source. Note that a thin microphone may be arranged or formed instead of the speaker 2512. A piezoelectric vibrator may be used as a speaker. Needless to say, drive circuits such as speakers and microphones may be directly formed or arranged on the array 30 using polysilicon technology.

  Note that the surface of the speaker 2512 or the microphone is a gas generated from the speaker 2512 or the like by depositing or applying a thin film or thick film 2513 made of one or more kinds of inorganic material, organic material, or metal material and sealing the surface. Deterioration of the organic EL film and the like due to.

  A problem of an EL display panel (EL display device) is a reduction in contrast caused by halation occurring inside the panel. It is generated because light generated from the EL element 15 (EL film 29) is confined inside the panel and diffusely reflected.

  In order to solve this problem, in the EL display panel of the present invention, a light absorption film (light absorption means) is formed or arranged in a display area (ineffective area) ineffective for image display. By forming the light absorption film, it is possible to suppress a decrease in display contrast due to halation that occurs when light generated from the pixels 16 is diffusely reflected by the substrate 30 or the like.

  The invalid region is exemplified by the side surface of the substrate 30 or the sealing lid 40. Moreover, the entire surface of the lid 40 (in the case of taking out the bottom), etc., other than the substrate 30 and the display region (for example, the region where the gate driver circuit 12 and the source driver circuit 14 are formed and the vicinity thereof) are exemplified.

  Needless to say, sapphire glass or the like may be used for the lid 40 and the substrate 30 to improve heat dissipation.

  Substances that make up the light absorption film include organic materials such as acrylic resins containing carbon, black pigments or pigments dispersed in organic resins, and gelatin or casein as a color filter. What was dye | stained with the acid dye is illustrated. In addition, a single black fluoran dye may be used, and a color scheme black obtained by mixing a green dye and a red dye may also be used. Examples thereof include a PrMnO3 film formed by sputtering and a phthalocyanine film formed by plasma polymerization.

  The above materials are all black materials, but as the light absorption film, a material having a complementary color with respect to the light color generated by the display element may be used. For example, a light-absorbing material for a color filter may be used so as to obtain desired light absorption characteristics. Basically, a material obtained by dyeing a natural resin with a pigment may be used in the same manner as the black absorbing material described above.

  Further, a material in which a pigment is dispersed in a synthetic resin can be used. The selection range of the pigment is wider than the black pigment, and may be one suitable from azo dye, anthraquinone dye, phthalocyanine dye, triphenylmethane dye, or a combination of two or more thereof.

  Further, a metal material may be used as the light absorption film. For example, hexavalent chromium is exemplified. Hexavalent chromium is black and functions as a light absorbing film. In addition, light scattering materials such as opal glass and titanium oxide may be used. This is because scattering the light is equivalent to absorbing the light as a result.

  Needless to say, the above items can also be applied to the configuration of FIG.

  The organic EL display panel of the present invention shown in FIG. 3 is configured to be sealed using a glass lid 40. However, the present invention is not limited to this. For example, as shown in FIG. 4, a sealing structure using a film 41 (which may be a thin film, that is, a thin film sealing film 41) 41 may be used.

  Examples of the sealing film (thin film sealing film) 41 include a film of an electrolytic capacitor on which DLC (diamond-like carbon) is vapor-deposited. This film has extremely poor moisture permeability (high moisture resistance). This film is used as the sealing film 41. Needless to say, a structure in which a DLC (diamond-like carbon) film or the like is directly deposited on the surface of the electrode 36 is preferable. In addition, a thin film sealing film may be configured by laminating a resin thin film and a metal thin film in multiple layers.

  The film thickness of the thin film 41 is calculated by n · d (n is the refractive index of the thin film, and when a plurality of thin films are stacked, the refractive indexes thereof are combined (calculating n · d of each thin film). When the thickness of the thin film and a plurality of thin films are stacked, the refractive index of the thin films is calculated to be equal to or less than the emission main wavelength λ of the EL element 15. By satisfying this condition, the light extraction efficiency from the EL element 15 becomes twice or more as compared with the case of sealing with a glass substrate. Further, an alloy or a mixture or a laminate of aluminum and silver may be formed.

  Note that the thickness of the thin film 41 or the film forming the sealing structure is not limited to the thickness of the interference region. Needless to say, the thickness may be 5 to 10 μm or more, or 100 μm or more. In addition, when the sealed thin film 41 or the like has transparency, the A side in FIG. 4 is the light emission side, and when it has an opaque or light reflective function or structure, the B side is the light emission side. .

  Of course, you may comprise so that light may be radiate | emitted from both A side and B side. In the case of adopting this configuration, the image is reversed horizontally when viewing the image of the EL display panel from the A side and when viewing the image of the EL display panel from the B side. Therefore, when viewing the image of the EL display panel from the A side and when viewing the image of the EL display panel from the B side, a function of inverting the left and right of the image manually or automatically is added. This function can be realized by storing one pixel row or a plurality of pixel rows of the video signal in the line memory and inverting the reading direction of the line memory.

  A configuration in which the sealing lid 40 is not used as shown in FIG. 4 and the sealing film 41 is sealed is called thin film sealing. The thin film sealing 41 in the case of “lower extraction (see FIG. 3; the light extraction direction is the direction indicated by the arrow B in FIG. 3)” for extracting light from the substrate 30 side is the EL film after forming the EL film. An aluminum electrode to be a cathode is formed. Next, a resin layer as a buffer layer is formed on the aluminum film. Examples of the buffer layer include organic materials such as acrylic and epoxy. Further, the film thickness is suitably 1 μm or more and 10 μm or less. More preferably, the film thickness is 2 μm or more and 6 μm or less. A sealing film 74 on the buffer film is formed.

  Without the buffer film, the structure of the EL film collapses due to the stress, and a line-like defect occurs. As described above, the sealing film 41 is exemplified by DLC (Diamond Like Carbon) or a layer structure of an electric field capacitor (a structure in which dielectric thin films and aluminum thin films are alternately deposited).

  Thin film sealing in the case of “upward extraction (see FIG. 4, the light extraction direction is the direction of arrow A in FIG. 4)” for extracting light from the organic EL film 29 side is as follows: An Ag—Mg film serving as a cathode (or anode) is formed on the organic EL film 29 with a film thickness of 20 angstroms or more and 300 angstroms. A transparent electrode such as ITO is formed thereon to reduce the resistance. Next, a resin layer as a buffer layer is preferably formed on this electrode film. A sealing film 41 is formed on the buffer film.

  In FIG. 3 and the like, half of the light generated from the organic EL film 29 is reflected by the reflective film (cathode electrode) 36 and transmitted through the array substrate 30 to be emitted. However, external light is reflected on the reflective film (cathode electrode) 36, and reflection occurs to reduce display contrast. For this measure, a λ / 4 plate (phase film) 38 and a polarizing plate (polarizing film) 39 are arranged on the array substrate 30. What united the polarizing plate 39 and the phase film 38 is called a circularly-polarizing plate (circularly polarizing sheet).

  When the pixel is a reflective electrode, light generated from the EL film 29 is emitted upward (light is emitted in the direction A in FIG. 4). Therefore, it goes without saying that the phase plate 38 and the polarizing plate 39 are arranged on the light emitting side.

  The reflective pixel is obtained by configuring the pixel electrode 35 with aluminum, chromium, silver, or the like. Further, by providing a convex portion (or a concave-convex portion) on the surface of the pixel electrode 35, the interface with the organic EL film 29 is widened, the light emission area is increased, and the light emission efficiency is improved. Note that the circularly polarizing plate is not necessary when the reflective film to be the cathode 36 (anode 35) is formed on the transparent electrode, or when the reflectance can be reduced to 30% or less. This is because the reflection is greatly reduced. It is also desirable to reduce light interference. Protruding portions (or uneven portions) having a diffraction grating is effective for light extraction. The diffraction grating has a two-dimensional or three-dimensional structure. The pitch of the diffraction grating is preferably 0.2 μm or more and 2 μm or less. In this range, a result with good light efficiency can be obtained. In particular, the pitch of the diffraction grating is preferably 0.3 μm or more and 0.8 μm or less. Further, the shape of the diffraction grating is preferably a sine curve.

  In FIG. 1 and the like, the transistor 11 preferably adopts an LDD (lightly doped drain) structure.

  EL display panels often have different luminous efficiencies for R, G, and B. Therefore, the currents flowing through the driving transistor 11a are different for R, G, and B. For example, as shown in FIG. 235, when the driving transistor 11a for driving the B pixel 16 is a dotted line, the driving transistor 11a for driving the G pixel 16 is a solid line. The vertical axis in FIG. 235 is the current (SD current) (μA) that the driving transistor 11a flows, that is, the program current Iw, and the horizontal axis is the gate terminal voltage of the driving transistor 11a.

  However, as shown in FIG. 235, the current (voltage) programming accuracy decreases when the S-D current magnitude with respect to the gate terminal voltage differs between R, G, and B (in FIG. 235, the accuracy of the characteristic of the solid line is lost). ). To solve this problem, the transistor 11a is designed by adjusting the WL ratio composed of the channel width (W) and the channel length (L) of the driving transistor 11a, and R, G, and B for the same gate terminal voltage. It is preferable that the difference between the S-D currents output from the driving transistor 11a is within twice.

  In this specification, an organic EL element (described in various abbreviations such as OEL, PEL, PLED, and OLED) is described as an example of the EL element 15, but the present invention is not limited to this, and an inorganic EL element is not limited thereto. Needless to say, this also applies.

  First, the active matrix method used for the organic EL display panel is to select a specific pixel and provide necessary display information. Two conditions must be satisfied that current can flow through the EL element throughout one frame period.

  In order to satisfy these two conditions, in the pixel configuration of the conventional organic EL shown in FIG. 2, the first transistor 11b functions as a switching transistor for selecting a pixel. Further, the second transistor 11 a functions as a driving transistor for supplying current to the EL element 15.

  In the case of displaying gradation using this configuration, it is necessary to apply a voltage corresponding to the gradation as the gate voltage of the driving transistor 11a. Therefore, the variation in the on-state current of the driving transistor 11a appears in the display as it is.

  The on-current of a transistor is very uniform if it is a transistor formed of a single crystal, but in a low-temperature polycrystalline transistor formed by low-temperature polysilicon technology that can be formed on an inexpensive glass substrate with a formation temperature of 450 degrees or less. The threshold value varies in the range of ± 0.2V to 0.5V. For this reason, the on-current flowing through the driving transistor 11a varies correspondingly, and the display is uneven. These irregularities are caused not only by variations in threshold voltage, but also by transistor mobility, gate insulating film thickness, and the like. The characteristics also change due to deterioration of the transistor 11.

  This phenomenon is not limited to low-temperature polysilicon technology, and transistors and the like are formed using solid-phase (CGS) grown semiconductor films even in high-temperature polysilicon technology with a process temperature of 450 degrees Celsius or higher. Even things can occur. In addition, it occurs in organic transistors. It also occurs in amorphous silicon transistors.

  The present invention described below is a configuration or method that can cope with these techniques. In this specification, a transistor formed by low-temperature polysilicon technology will be mainly described.

  Therefore, as shown in FIG. 2, in the method of displaying gradation by writing a voltage, it is necessary to strictly control the device characteristics in order to obtain a uniform display. However, the current low-temperature polycrystalline polysilicon transistor and the like cannot satisfy the specification of suppressing this variation within a predetermined range.

  The EL display device is colored by mask vapor deposition, but the present invention is not limited to this. For example, for EL colorization, a blue light emitting EL layer is formed, and the emitted blue light is converted into R, G, B light by an R, G, B color conversion layer (CCM: Color Change Mediums). May be. For example, in FIG. 4, a color filter is disposed on or below the thin film sealing film 41. Of course, an RGB organic material (EL material) placement method using a precision shadow mask may be employed. Any of these methods may be used for the color EL display panel of the present invention.

  Specifically, as shown in FIG. 1 and the like, the pixel structure of the EL display device of the present invention is formed by a plurality of transistors 11 and EL elements 15 each having at least four pixels. The pixel electrode 35 is configured to overlap the source signal line 18. That is, a planarization film 32 made of an insulating film or an acrylic material is formed on the source signal line 18 for insulation, and a pixel electrode 35 is formed on the planarization film 32. A configuration in which the pixel electrode 35 is overlaid on at least a part of the source signal line 18 in this way is called a high aperture (HA) structure. Unnecessary interference light and the like are reduced, and a good light emission state can be expected. The planarizing film 32 also functions as an interlayer insulating film. The planarizing film 32 is configured or formed with a film thickness of 0.4 μm or more and 2.0 μm or less. If the thickness of the planarization film 32 is 0.4 μm or less, the interlayer insulation tends to be defective (yield reduction). If the thickness is 2.0 μm or more, formation of the contact connecting portion 34 becomes difficult, and contact failure is likely to occur (decrease in yield).

  The transistor 11 constituting the active matrix is preferably a p-channel polysilicon thin film transistor, and preferably has a multi-gate structure in which the transistor 11b has a dual gate or more. Since the transistor 11b functions as a switch between the source and drain of the transistor 11a, the transistor 11b is required to have as high a ON / OFF ratio as possible. By setting the gate structure of the transistor 11b to a multi-gate structure that is equal to or higher than the dual gate structure, a characteristic with a high ON / OFF ratio can be realized.

  The semiconductor film constituting the transistor 11 of the pixel 16 is generally formed by laser annealing in the low temperature polysilicon technology. Variations in the laser annealing conditions result in variations in transistor 11 characteristics. However, if the characteristics of the transistors 11 in one pixel 16 match, the current programming method can drive the EL element 15 so that a predetermined current flows. This is an advantage not found in voltage programming. An excimer laser is preferably used as the laser.

  In the present invention, the formation of the semiconductor film is not limited to the laser annealing method, but may be a thermal annealing method or a method by solid phase (CGS) growth. In addition, the present invention is not limited to the low temperature polysilicon technology, and it goes without saying that the high temperature polysilicon technology may be used. Further, it may be a semiconductor film formed using amorphous silicon technology.

  In order to deal with this problem, in the present invention, a laser irradiation spot (laser irradiation range) at the time of annealing is irradiated in parallel to the source signal line 18. Further, the laser irradiation spot is moved so as to coincide with one pixel column. Of course, the present invention is not limited to one pixel column, and for example, the laser beam may be irradiated in units of one RGB pixel (in this case, it is a three pixel column). In addition, a plurality of pixels may be irradiated simultaneously. It goes without saying that the movement of the laser irradiation range may overlap (usually, the irradiation range of the moving laser light is usually overlapped).

  The pixels are made of three pixels of RGB and have a square shape. Accordingly, each of the R, G, and B pixels has a vertically long pixel shape. Therefore, by annealing the laser irradiation spot in a vertically long shape, the characteristic variation of the transistor 11 can be prevented from occurring within one pixel.

  Further, the characteristics (mobility, Vt, S value, etc.) of the transistor 11 connected to one source signal line 18 can be made uniform (that is, the characteristics are different from those of the transistor 11 of the adjacent source signal line 18). However, the characteristics of the transistor 11 connected to one source signal line can be made substantially equal).

  The pixel configuration of the EL display panel of the present invention shown in FIG. 1 will be described. The gate signal line (first scanning line) 17a is activated (ON voltage is applied). At the same time, the current value Iw to be supplied to the EL element 15 is supplied from the source driver circuit 14 to the driving transistor 11a through the switching transistor 11c. Further, the transistor 11b operates so as to short-circuit the gate terminal (G) and the drain terminal (D) of the driving transistor 11a. At the same time, the gate voltage (or drain voltage) of the transistor 11a is stored in the capacitor (capacitor, storage capacitor, additional capacitor) 19 connected between the gate terminal (G) and the source terminal (S) of the transistor 11a (FIG. 5 ( see a)).

  Note that the size of the capacitor (storage capacitor) 19 is preferably 0.2 pF or more and 2 pF or less, and in particular, the size of the capacitor (storage capacitor) 19 is preferably 0.4 pF or more and 1.2 pF or less. . Preferably, the capacitance of the capacitor 19 is determined in consideration of the pixel size. The capacity required for one pixel is Cs (pF), and the area occupied by one pixel is Sp. Note that Sp is not an aperture ratio. The area occupied by one pixel of each RGB. For example, if the R pixel is 200 μm × 67 μm, then Sp = 13400 square μm.

  Assuming that Sp (square μm), 1500 / Sp ≦ Cs ≦ 30000 / Sp, and more preferably 3000 / Sp ≦ Cs ≦ 15000 / Sp. Since the gate capacity of the transistor 11 is small, Q here is the capacity of the storage capacitor (capacitor) 19 alone. When Cs is smaller than 1500 / Sp, the influence of the punch-through voltage of the gate signal line 17 becomes large, the voltage holding characteristic is lowered, and a luminance gradient is generated. In addition, the compensation performance of the TFT is degraded. When Cs is larger than 30000 / Sp, the aperture ratio of the pixel 16 decreases. Therefore, the electric field density of the EL element 15 is increased, and adverse effects such as a reduction in the life of the EL element 15 occur. In addition, due to the capacitor capacity, the write time of the current program becomes long, and insufficient writing occurs in the low gradation region.

  The object of the invention of this patent is to propose a circuit configuration in which variations in transistor characteristics do not affect display, and for that purpose four or more transistors are required. When circuit constants are determined based on these transistor characteristics, it is difficult to obtain appropriate circuit constants if the characteristics of the four transistors do not match. When the channel direction is horizontal and vertical with respect to the major axis direction of laser irradiation, the threshold value and mobility of transistor characteristics are different. In both cases, the degree of variation is the same. The average value of mobility and threshold value differs between the horizontal direction and the vertical direction. Therefore, it is desirable that the channel directions of all the transistors constituting the pixel are the same.

  Further, when the capacitance value of the storage capacitor 19 is Cs and the off-current value of the second transistor 11b is Ioff, it is preferable to satisfy the following equation.

3 <Cs / Ioff <24
More preferably, it is preferable to satisfy the following formula.

6 <Cs / Ioff <18
By setting the off-state current of the transistor 11b to 5 pA or less, the change in the current value flowing through the EL can be suppressed to 2% or less. This is because when the leakage current increases, the electric charge stored between the gate and the source (both ends of the capacitor) cannot be held for one field in the voltage non-writing state. Therefore, if the storage capacity of the capacitor 19 is large, the allowable amount of off-current is also large. By satisfying the above equation, the fluctuation of the current value between adjacent pixels can be suppressed to 2% or less.

  Needless to say, the above-described matters relating to the storage capacitor Cs are not limited to the pixel configuration of FIG. 1 but can be applied to other current programming pixel configurations. For example, FIG. 6 to FIG. 13, FIG. 31 to FIG.

  In the light emission period of the EL element 15, the gate signal line 17a is inactive (OFF voltage is applied), the gate signal line 17b is active, the path through which the current Iw = Ie flows, and the transistor 11d connected to the EL element 15 and Switching to the path including the EL element 15 causes the stored current Iw to flow through the EL element 15 (see FIG. 5B).

  The pixel circuit in FIG. 1 has four transistors 11 in one pixel. The gate terminal of the driving transistor 11a is connected to the source terminal of the transistor 11b. The gate terminals of the transistors 11b and 11c are connected to the gate signal line 17a. The drain terminal of the transistor 11 b is connected to the source terminal of the transistor 11 c and the source terminal of the transistor 11 d, and the drain terminal of the transistor 11 c is connected to the source signal line 18. The gate terminal of the transistor 11d is connected to the gate signal line 17b, and the drain terminal of the transistor 11d is connected to the anode electrode of the EL element 15.

  In FIG. 1, all the transistors are P-channel. The P channel has a lower mobility than an N channel transistor, but is preferable because it has a high breakdown voltage and is less likely to deteriorate. However, the present invention is not limited to the configuration of the EL element with the P channel. You may comprise only N channel. Moreover, you may comprise using both N channel and P channel. For example, the pixel configurations of FIGS. 9 to 13 are exemplified.

  Preferably, all of the transistors 11 constituting the pixel are formed with a P channel, and the built-in gate driver circuit 12 is also formed with a P channel. By forming the array with only P-channel transistors in this way, the number of masks becomes five, and cost reduction and high yield can be realized.

  Needless to say, the above items are not limited to the pixel configuration of FIG. 1 and can be applied to other current programming pixel configurations. For example, FIG. 6 to FIG. 13, FIG. 31 to FIG.

  Hereinafter, in order to facilitate understanding of the present invention, the EL element configuration of the present invention will be described with reference to FIG. The EL device configuration of the present invention is controlled by two timings. The first timing is a timing for storing a necessary current value. When the transistor 11b and the transistor 11c are turned on at this timing, an equivalent circuit is shown in FIG. Here, a predetermined current Iw is written from the signal line. As a result, the gate and drain of the transistor 11a are connected, and a current Iw flows through the transistor 11a and the transistor 11c. Therefore, the gate-source voltage of the transistor 11a is a voltage at which I1 flows.

  The second timing is a timing at which the transistor 11a and the transistor 11c are closed and the transistor 11d is opened, and the equivalent circuit at that time is shown in FIG. The voltage between the source and gate of the transistor 11a remains held. In this case, since the transistor 11a always operates in the saturation region, the current Iw is constant.

  The above operation is illustrated in FIG. Reference numeral 191a in FIG. 19A denotes a pixel (row) (write pixel row) in which current is programmed at a certain time on the display screen 144. The pixel (row) 191a is not lit (non-display pixel (row)) as illustrated in FIG.

  In the case of the pixel configuration of FIG. 1, as shown in FIG. 5A, the program current Iw flows through the source signal line 18 during current programming. The voltage is set (programmed) in the capacitor 19 so that the current Iw flows through the driving transistor 11a and the current through which the program current Iw flows is held. At this time, the transistor 11d is in an open state (off state).

  Next, during a period in which a current flows through the EL element 15, the transistors 11c and 11b are turned off and the transistor 11d is operated as shown in FIG. That is, the off voltage (Vgh) is applied to the gate signal line 17a, and the transistors 11b and 11c are turned off. On the other hand, an on voltage (Vgl) is applied to the gate signal line 17b, and the transistor 11d is turned on.

  This timing chart is shown in FIG. In FIG. 21 and the like, subscripts in parentheses (for example, (1) and the like) indicate pixel row numbers. That is, the gate signal line 17a (1) indicates the gate signal line 17a of the pixel row (1). Also, * H in the upper part of FIG. 4 (an arbitrary symbol or numerical value is applied to “*” and indicates a horizontal scanning line number) indicates a horizontal scanning period. That is, 1H is the first horizontal scanning period. The above items are for ease of explanation and are not limited (1H number, 1H cycle, order of pixel row numbers, etc.).

  As can be seen from FIG. 21, when a turn-on voltage is applied to the gate signal line 17a in each selected pixel row (selection period is 1H), a turn-off voltage is applied to the gate signal line 17b. Yes. During this period, no current flows through the EL element 15 (non-lighting state). In an unselected pixel row, an off voltage is applied to the gate signal line 17a, and an on voltage is applied to the gate signal line 17b.

  Note that the gate of the transistor 11a and the gate of the transistor 11c are connected to the same gate signal line 11a. However, the gate of the transistor 11a and the gate of the transistor 11c may be connected to different gate signal lines 11 (see FIG. 6). In FIG. 6, one pixel has three gate signal lines (the configuration in FIG. 1 is two).

  In the pixel configuration of FIG. 6, the ON / OFF timing of the gate of the transistor 11b and the ON / OFF timing of the gate of the transistor 11c are individually controlled, thereby further reducing the current value variation of the EL element 15 due to variations in the transistor 11a. be able to.

  In the pixel configuration of FIG. 6, when current programming is performed on the pixel 16, the gate signal lines 17a1 and 17a2 are simultaneously selected to turn on the transistors 11b and 11c. Note that a turn-off voltage is applied to the gate signal line 17b of the pixel 16 that is executing the current program to turn off the transistor 11d.

  When the current program period (usually one horizontal scanning period) in the selected pixel row is completed, first, the off voltage (Vgh) is applied to the gate signal line 17a1 to turn off the transistor 11b. At this time, an ON voltage (Vgl) is applied to the gate signal line 17a2, and the transistor 11c is in an ON state. Next, an off voltage is applied to the gate signal line 17a2 to turn off the transistor 11c. As described above, when both the transistors 11b and 11c are turned on and the transistors 11b and 11c are turned off (when the current program period of the corresponding pixel row is ended), the transistor 11b is first turned off and driven. The gate terminal (G) and the drain terminal (D) of the transistor 11a are opened (off voltage (Vgh) is applied to the gate signal line 17a1). Next, the transistor 11c is turned off, and the source signal line 18 and the drain terminal (D) of the driving transistor 11a are disconnected (an off voltage (Vgh) is also applied to the gate signal line 17a2).

  The period Tw from when the off voltage is applied to the gate signal line 17a1 to when the off voltage is applied to the gate signal line 17a2 is preferably 0.1 μsec or more and 10 μsec or less. It is preferable that the period be 0.1 μsec or more and 10 μsec or less. Alternatively, when the period of 1H is Th, Tw is preferably set to Th / 500 or more and Th / 10 or less. In particular, Tw is preferably set to Th / 200 or more and Th / 50 or less.

  The above items are not limited to the pixel configuration of FIG. For example, the present invention is also applied to the pixel configuration of FIG. In the pixel configuration of FIG. 12, when current programming is performed on the pixel 16, the gate signal lines 17a1 and 17a2 are simultaneously selected to turn on the transistors 11d and 11c. Note that a turn-off voltage is applied to the gate signal line 17b of the pixel 16 that is executing the current program to turn off the transistor 11e.

  When the current program period (usually one horizontal scanning period) in the selected pixel row is completed, first, the off voltage (Vgh) is applied to the gate signal line 17a1 to turn off the transistor 11d. At this time, an ON voltage (Vgl) is applied to the gate signal line 17a2, and the transistor 11c is in an ON state. Next, an off voltage is applied to the gate signal line 17a2 to turn off the transistor 11c. As described above, when both the transistors 11d and 11c are turned on and the transistors 11d and 11c are turned off (when the current program period of the pixel row is ended), the transistor 11d is first turned off. The gate terminal (G) and the drain terminal (D) of 11a are opened (off voltage (Vgh) is applied to the gate signal line 17a1). Next, the transistor 11c is turned off to disconnect the source signal line 18 from the drain terminal (D) of the transistor 11a (an off voltage (Vgh) is also applied to the gate signal line 17a2).

  In FIG. 12, similarly to FIG. 6, the period Tw from when the off voltage is applied to the gate signal line 17a1 to when the off voltage is applied to the gate signal line 17a2 is 0.1 μsec or more and 10 μsec or less. preferable. It is preferable that the period be 0.1 μsec or more and 10 μsec or less. Alternatively, when the period of 1H is Th, Tw is preferably set to Th / 500 or more and Th / 10 or less. In particular, Tw is preferably set to Th / 200 or more and Th / 50 or less.

  Needless to say, the above matters can be applied to the pixel configuration shown in FIG. In FIG. 12, the switching transistor 11e is arranged between the driving transistor 11b and the EL element 15, but it goes without saying that the switching transistor 11e may be omitted as shown in FIG.

  Note that the pixel configuration of the present invention is not limited to the configurations of FIGS. For example, you may comprise as FIG. 7 does not have the switching transistor 11d as compared with the configuration of FIG. Instead, a changeover switch 71 is formed or arranged. The switch 11d in FIG. 1 has a function of controlling on / off (flow or not flow) of a current flowing from the driving transistor 11a to the EL element 15. As will be described in the following embodiments, the on / off control function of the transistor 11d is an important component of the present invention. The configuration in FIG. 7 realizes the on / off function without forming the transistor 11d.

  In FIG. 7, the terminal a of the changeover switch 71 is connected to the anode voltage Vdd. The voltage applied to the terminal a is not limited to the anode voltage Vdd, and any voltage that can turn off the current flowing through the EL element 15 may be used.

  The b terminal of the changeover switch 71 is connected to the cathode voltage (shown as ground in FIG. 7). The voltage applied to the b terminal is not limited to the cathode voltage, and any voltage that can turn on the current flowing through the EL element 15 may be used.

  The cathode terminal of the EL element 15 is connected to the c terminal of the changeover switch 71. Note that the change-over switch 71 may be any as long as it has a function of turning on and off the current flowing through the EL element 15. Therefore, it is not limited to the formation position of FIG. 7, and any path may be used as long as the current of the EL element 15 flows. Further, the function of the switch is not limited, and any function may be used as long as the current flowing through the EL element 15 can be turned on and off. In other words, in the present invention, any pixel configuration may be used as long as switching means capable of turning on and off the current flowing through the EL element 15 is provided in the current path of the EL element 15.

  In this specification, “off” does not mean a state in which no current flows completely. Any current can be used as long as the current flowing through the EL element 15 can be reduced more than usual. The above matters are the same in other configurations of the present invention. That is, the transistor 11d may pass a leakage current that is emitted from the EL element 15.

  Since the change-over switch 71 can be easily realized by combining P-channel and N-channel transistors, description thereof will not be necessary. Of course, since the switch 71 only turns on and off the current flowing through the EL element 15, it is needless to say that the switch 71 can be formed of a P-channel transistor or an N-channel transistor.

  When the switch 71 is connected to the terminal a, the anode voltage Vdd is applied to the cathode terminal of the EL element 15. Therefore, no current flows through the EL element 15 regardless of the voltage holding state of the gate terminal G of the driving transistor 11a. Therefore, the EL element 15 is not turned on. Of course, the voltage at the a terminal of the switching circuit 71 may be set so that the voltage between the source terminal (S) and the drain terminal (D) of the driving transistor 11a can be cut off or in the vicinity thereof.

  When the switch 71 is connected to the b terminal, the cathode voltage Vss is applied to the cathode terminal of the EL element 15. Therefore, a current flows through the EL element 15 in accordance with the voltage state held at the gate terminal G of the driving transistor 11a. Therefore, the EL element 15 is turned on.

  From the above, in the pixel configuration of FIG. 7, the switching transistor 11 d is not formed between the driving transistor 11 a and the EL element 15. However, the lighting control of the EL element 15 can be performed by controlling the switch 71.

  Note that the switching transistor 11 or the like may be a phototransistor. For example, the luminance of the display panel can be changed by turning on / off the phototransistor 11 according to the intensity of external light and controlling the current flowing through the EL element 15.

  In the pixel configurations of FIGS. 1, 2, 6, 11, and 12, the number of driving transistors 11a or 11b is one per pixel. The present invention is not limited to this, and a plurality of driving transistors 11a may be formed or arranged in one pixel.

  FIG. 8 shows an embodiment in which a plurality of driving transistors 11 a are formed or configured in one pixel 16. In FIG. 8, two drive transistor elements 11 a 1 and 11 a 2 are formed in one pixel, and the gate terminals of the two drive transistors 11 a 1 and 11 a 2 are connected to a common capacitor 19. By forming a plurality of driving transistors 11a, there is an effect that variation in programmed current is reduced. Other configurations are the same as those in FIG. In FIG. 8, it goes without saying that the drive transistor 11a may be configured (formed) with three or more transistors. The plurality of driving transistors 11a may be configured (formed) using both the N channel and the P channel.

  1 and 2, the current output from the driving transistor 11a is supplied to the EL element 15, and the current is on / off controlled by the switching element 11d disposed between the driving transistor 11a and the EL element 15. In FIG. However, the present invention is not limited to this. For example, the configuration of FIG. 9 is illustrated.

  In the embodiment of FIG. 9, the current flowing through the EL element 15 is controlled by the driving transistor 11a. Switching on and off the current flowing through the EL element 15 is controlled by the switching element 11 d disposed between the Vdd terminal and the EL element 15. Therefore, in the present invention, the arrangement of the switching element 11d may be anywhere, and any arrangement can be used as long as the current flowing through the EL element 15 can be controlled. The operation is the same as or similar to that shown in FIG.

  Further, in the pixel configuration of FIG. 10, all the transistors are configured with N channels. However, the present invention is not limited to the configuration of the EL element composed of N channels. You may comprise using both N channel and P channel.

  The pixel configuration in FIG. 10 is controlled by two timings. The first timing is a timing for storing a necessary current value. At the first timing, an ON voltage (Vgh) is applied to the gate signal lines 17a1 and 17a2, so that the transistor 11b and the transistor 11c are turned on. Further, an off voltage (Vgl) is applied to the gate signal line 17b, and the transistor 11d is turned off. Therefore, a predetermined current Iw is written from the source signal line 18. As a result, the gate and drain of the transistor 11a are short-circuited, and a program current flows through the transistor 11c through the transistor 11c.

  When the current program period (usually one horizontal scanning period) in the selected pixel row is completed, first, the off voltage (Vgh) is applied to the gate signal line 17a1 to turn off the transistor 11b. At this time, an ON voltage (Vgl) is applied to the gate signal line 17a2, and the transistor 11c is in an ON state. Next, an off voltage is applied to the gate signal line 17a2 to turn off the transistor 11c. As described above, when both the transistors 11b and 11c are turned on and the transistors 11b and 11c are turned off (when the current program period of the pixel row is ended), the transistor 11b is first turned off. The gate terminal (G) and the drain terminal (D) of 11a are opened (off voltage (Vgh) is applied to the gate signal line 17a1). Next, the transistor 11c is turned off to disconnect the source signal line 18 from the drain terminal (D) of the transistor 11a (an off voltage (Vgh) is also applied to the gate signal line 17a2).

  In the second timing, an off voltage is applied to the gate signal lines 17a1 and 17a2, and an on voltage is applied to the gate signal line 17b. Therefore, the transistor 11b and the transistor 11c are turned off, and the transistor 11d is turned on. In this case, since the transistor 11a always operates in the saturation region, the current Iw is constant.

  In current-programmed pixels (FIGS. 1, 6 to 13, FIG. 31 to FIG. 36, etc.), variations in characteristics of the driving transistor 11a (transistor 11b in FIGS. 11, 12, etc.) are correlated with the transistor size. . In order to reduce the characteristic variation, the channel length L of the driving transistor 11 is preferably set to 5 μm or more and 100 μm or less. More preferably, the channel length L of the driving transistor 11 is 10 μm or more and 50 μm or less. This is considered to be because when the channel length L is increased, the grain boundary included in the channel increases, the electric field is relaxed, and the kink effect is suppressed to a low level.

  As described above, the present invention controls the current flowing through the EL element 15 in the path through which current flows into the EL element 15 or the path through which current flows from the EL element 15 (that is, the current path of the EL element 15). The circuit means is configured, formed or arranged.

  Even in the current mirror method which is one of current programming methods, as shown in FIG. 11, an EL element is formed by forming or arranging a transistor 11e as a switching element between the driving transistor 11b and the EL element 15. The current flowing through 15 can be turned on and off (can be controlled). Of course, the transistor 11e may be replaced with the switching circuit 71 of FIG.

  The switching transistors 11d and 11c in FIG. 11 are connected to one gate signal line 17a. As shown in FIG. 12, the transistor 11c is controlled by the gate signal line 17a2, and the transistor 11d is controlled by the gate signal line 17a1. You may comprise so that it may control by. As described above, the pixel configuration shown in FIG. 12 is more versatile in controlling the pixel 16, and the characteristic compensation performance of the driving transistor 11b is improved.

  Next, the EL display panel or EL display device of the present invention will be described. FIG. 14 is an explanatory diagram focusing on the circuit of the EL display device. The pixels 16 are arranged or formed in a matrix. Each pixel 16 is connected to a source driver circuit 14 that outputs a program current for performing current programming of each pixel. A current mirror circuit corresponding to the number of bits of the video signal is formed at the output stage of the source driver circuit 14 (described later). For example, in the case of 64 gradations, 63 current mirror circuits are formed in each source signal line, and a desired current can be applied to the source signal line 18 by selecting the number of these current mirror circuits. (See FIGS. 15, 57, 58, 59, etc.).

  The minimum output current of the unit transistor 154 is 5 nA or more and 100 nA. In particular, the minimum output current of the unit transistor 154 is preferably 15 nA or more and 50 nA. This is to ensure the accuracy of the unit transistors 154 constituting the unit transistor group 431 c in the driver IC 14.

  In addition, a precharge circuit for forcibly releasing or charging the source signal line 18 is incorporated (see FIG. 16 and the like). The voltage (current) output value of the precharge or discharge circuit that forcibly releases or charges the source signal line 18 is preferably configured to be set independently by R, G, and B. This is because the threshold value of the EL element 15 differs between RGB.

  Note that the precharge voltage can be considered as a method of applying a rising voltage or a voltage equal to or lower than the rising voltage to the gate (G) terminal of the driving transistor 11a. That is, even when a state in which the program current Iw becomes 0 is generated by turning off the driving transistor 11a, the current is prevented from flowing through the EL element 15. Charge / discharge of the charge of the source signal line 18 is secondary.

  In the present invention, the source driver circuit 14 is formed of a semiconductor silicon chip, and is connected to the terminal of the source signal line 18 of the substrate 30 by a glass-on-chip (COG) technique. On the other hand, the gate driver circuit 12 is formed by low-temperature polysilicon technology. That is, it is formed by the same process as the pixel transistor. This is because the internal structure is easier and the operating frequency is lower than that of the source driver circuit 14. Therefore, even if it is formed by low-temperature polysilicon technology, it can be formed easily, and a narrow frame of the display panel can be realized. Of course, it goes without saying that the gate driver circuit 12 may be formed of a silicon chip and mounted on the substrate 30 using COG technology or the like. Further, the drivers 12 and 14 may be mounted by COF or TAB technology. In addition, switching elements such as pixel transistors, gate drivers, and the like may be formed by high-temperature polysilicon technology or organic materials (organic transistors).

  The gate driver circuit 12 includes a shift register circuit 141a for the gate signal line 17a and a shift register circuit 141b for the gate signal line 17b. For ease of explanation, the pixel configuration will be described using FIG. 1 as an example. 6 and 12, when the gate signal line 17a is composed of the gate signal lines 17a1 and 17a2, the shift register circuit 141 is formed independently or when the output signal of the shift register circuit 141 is logic The circuit generates control signals for the gate signal lines 17a1 and 17a2.

  Each shift register circuit 141 is controlled by positive-phase and negative-phase clock signals (CLKxP, CLKxN) and a start pulse (STx) (see FIG. 14). In addition, it is preferable to add an enable (ENABL) signal for controlling the output and non-output of the gate signal line and an up / down (UPDWM) signal for reversing the shift direction up and down. In addition, it is preferable to provide an output terminal for confirming that the start pulse is shifted to the shift register circuit 141 and output. Note that the shift timing of the shift register circuit 141 is controlled by a control signal from a control IC 760 (described later). Further, a level shift circuit 141 that performs level shift of external data is incorporated. Note that the clock signal may have only a positive phase. By using only positive phase clock signals, the number of signal lines can be reduced, and a narrow frame can be realized.

  Since the buffer capacity of the shift register circuit 141 is small, the gate signal line 17 cannot be driven directly. Therefore, at least two or more inverter circuits 142 are formed between the output of the shift register circuit 141 and the output gate 143 that drives the gate signal line 17.

  The same applies to the case where the source driver circuit 14 is directly formed on the substrate 30 by a polysilicon technique such as low-temperature polysilicon, and between the gate of an analog switch such as a transfer gate that drives the source signal line 18 and the shift register of the source driver circuit 14. A plurality of inverter circuits are formed. The following items (the output of the shift register and the output stage that drives the signal line (items related to the inverter circuit arranged between the output stages such as the output gate or transfer gate) are common to the source drive and gate driver circuits. is there.

  In the EL display panel of the present invention, the colors of each pixel are the three primary colors of R, G, and B, but are not limited to this, and may be three colors such as cyan, yellow, and magenta. Also, two colors such as B and yellow may be used. If B and yellow (Y) are used, black and white display is possible. Of course, it may be a single color. Also, six colors such as R, G, B, cyan, yellow, and magenta may be used. Five colors such as R, G, B, cyan, and magenta may be used. These are natural colors, and the color reproduction range is expanded to achieve a good display. As described above, the EL display device of the present invention is not limited to one that performs color display with the three primary colors RGB.

  There are mainly three methods for colorizing organic EL display panels. Of these, the color conversion method is one of them. It is only necessary to form the pixel 16 of only blue as the light emitting layer, and the remaining green and red necessary for full color are generated from the blue light by color conversion. Therefore, there is an advantage that it is not necessary to separately coat each layer of RGB, and it is not necessary to prepare organic EL materials of each color of RGB. The color conversion method does not cause a decrease in yield unlike the color separation method. The EL display panel of the present invention may be any type. Moreover, you may form by an inkjet system.

  Even in the case of forming a set of pixels for three primary colors such as RGB, it is preferable that the areas of the pixel electrodes of the respective colors are different. Of course, if the luminous efficiency of each color is well balanced and the color purity is well balanced, the same area may be used. However, if the balance of one or more colors is bad, it is preferable to adjust the pixel electrode (light emitting area). The electrode area of each color may be determined based on the current density. Further, the size of the driving transistor 11a of the pixel 16 constituting R, G, and B may be changed. The driving transistor 11a having the least efficient pixel color is configured to be large.

  The color temperature of the EL display panel is set so that the difference in current density of each color is within ± 30% when the white balance is adjusted in the range of 7000 K (Kelvin) to 12000 K. More preferably, it is within ± 15%. For example, if the current density is 100 A / square meter, the three primary colors are all set to 70 A / square meter or more and 130 A / square meter or less. More preferably, the three primary colors are all set to 85 A / square meter or more and 115 A / square meter or less.

  The organic EL element 15 is a self-light emitting element. When light emitted by this light emission enters a transistor as a switching element, a photoconductor phenomenon (photoconversion) occurs. “Photocon” refers to a phenomenon in which leakage (off leak) increases when a switching element such as a transistor is turned off by photoexcitation.

  In order to cope with this problem, the present invention forms a light shielding film under the gate driver circuit 12 (or the source driver circuit 14 in some cases) and under the pixel transistor 11. In particular, it is preferable to shield light from the transistor 11b disposed between the potential position (shown by c) of the gate terminal and the drain terminal (shown by a) of the driving transistor 11a. This configuration is shown in FIGS. 314 (a) and (b). In particular, when the display panel displays black, the potential at the potential position b of the anode terminal of the EL element 15 in FIGS. 314 (a) and 314 (b) is close to the cathode potential. Therefore, when the TFT 17b is in the on state, the potential “a” is also lowered. Therefore, the potential between the source terminal and the drain terminal of the transistor 11b (between the c potential and the a potential) is increased, and the transistor 11b is likely to leak. For this problem, it is effective to form a light shielding film 3141 as shown in FIGS.

  The light-shielding film 3141 is formed using a metal thin film such as chromium, and the thickness thereof is 50 nm or more and 150 nm or less. When the film thickness 3141 is thin, the light shielding effect is poor, and when it is thick, unevenness is generated and patterning of the upper transistor 11 becomes difficult.

  The driver circuit 12 and the like should suppress light from not only the back surface but also the front surface. This is because malfunction occurs due to the influence of the photocon. Therefore, in the present invention, when the cathode electrode is a metal film, the cathode electrode is also formed on the surface of the driver circuit 12 and the like, and this electrode is used as a light shielding film.

  However, when a cathode electrode is formed on the driver circuit 12, a malfunction of the driver due to an electric field from the cathode electrode or an electrical contact between the cathode electrode and the driver circuit may occur. In order to cope with this problem, in the present invention, an organic EL film of at least one layer, preferably a plurality of layers, is formed simultaneously with the formation of the organic EL film on the pixel electrode on the driver circuit 12 or the like.

  Hereinafter, the driving method of the present invention will be described. As shown in FIG. 1, the gate signal line 17a becomes conductive during the row selection period (here, since the transistor 11 of FIG. 1 is a P-channel transistor, it becomes conductive at a low level), and the gate signal line 17b remains in the non-selection period. Sometimes an on-voltage is applied.

  The source signal line 18 has a parasitic capacitance (not shown). The parasitic capacitance is generated by the capacitance at the intersection of the source signal line 18 and the gate signal line 17, the channel capacitance of the transistors 11b and 11c, and the like.

  The parasitic capacitance is generated not only in the source signal line 18 but also in the source driver IC 14. As shown in FIG. 17, the protection diode 171 is the main cause. The protection diode 171 has a purpose of protecting the IC 14 from static electricity, but becomes a capacitor and also becomes a parasitic capacitance. The capacity of a general protection diode is 3 to 5 pF.

  In the source driver IC of the present invention (which will be described in detail later), a surge reduction resistor 172 is formed or arranged between the connection terminal 155 and the current output circuit 164 as shown in FIG. The resistor 172 is formed of polysilicon or a diffused resistor. The resistance value of the resistor 172 is 1 KΩ to 1 MΩ. The resistor 172 suppresses static electricity from the outside. Therefore, the size of the protection diode 171 may be small. If the protective diode 171 is small, the parasitic capacitance due to the protective diode is also small.

  In FIG. 17, the resistor 172 is illustrated or formed in the source driver IC 14. However, the present invention is not limited to this, and the resistor 172 may be formed or disposed in the array 30. Needless to say. The same applies to the diode 171 (including a transistor having a diode configuration).

  The diode 171 is regarded as the resistor 171. The resistors 171a and 171b are preferably configured so that the resistance value can be adjusted by trimming. By trimming, the resistance values of the resistance values 171a and 171b can be adjusted, and the leakage current flowing through the source signal line 18 can be eliminated. It is also possible to adjust the resistance value other than trimming. For example, the resistance value can be adjusted by heating by forming the resistor 171 as a diffused resistor. For example, the resistance value can be changed by irradiating the resistor with laser light and heating it. Further, by heating the IC chip entirely or partially, the resistance value formed or configured in the IC chip can be adjusted or changed in whole or in part. Further, by forming a plurality of resistors 171a and the like and cutting the connection between the one or more resistors 171a and the source signal line 18, it is possible to adjust the resistance value as a whole and to eliminate a leakage current. Needless to say, the above-described matters relating to trimming, adjustment, and the like apply to the resistor 172.

  The time t required to change the current value of the source signal line 18 is t = C · V / I where C is the magnitude of the stray capacitance, V is the voltage of the source signal line, and I is the current flowing through the source signal line. For example, if the program current is increased 10 times, the time required for the current value change can be shortened to 1/10. Therefore, it is effective to increase the current value in order to write a predetermined current value within a short horizontal scanning period.

  When the program current is increased N times, the current flowing through the EL element 15 is also increased N times. Therefore, the luminance of the EL element 15 is also N times. Therefore, in order to obtain a predetermined luminance, for example, the conduction period of the transistor 17d in FIG. 1 is set to 1 / N.

  As described above, a relatively large current is output from the source driver circuit 14 in order to sufficiently charge and discharge the parasitic capacitance of the source signal line 18 and to perform a current program to the transistor 11a of the pixel 16 with a predetermined current value. There is a need to. However, if a program current of N times is passed through the source signal line 18, this program current value is programmed in the pixel 16, and a current N times as large as a predetermined current flows through the EL element 15. For example, if programming is performed with 10 times the current, naturally, 10 times the current flows through the EL element 15, and the EL element 15 emits light with 10 times the luminance. In order to obtain a predetermined light emission luminance, the time required to flow through the EL element 15 may be reduced to 1/10. By driving in this way, the parasitic capacitance of the source signal line 18 can be sufficiently charged and discharged, and a predetermined light emission luminance can be obtained.

  It should be noted that although 10 times the current value is written in the pixel transistor 11a (more precisely, the terminal voltage of the capacitor 19 is set) and the on-time of the EL element 15 is reduced to 1/10, this is merely an example. In some cases, a 10 times larger current value may be written in the pixel transistor 11a, and the on-time of the EL element 15 may be reduced to 1/5. On the contrary, there may be a case where a 10 times larger current value is written in the pixel transistor 11a and the on-time of the EL element 15 is halved. Alternatively, a one-time current value may be written to the pixel transistor 11a, and the on-time of the EL element 15 may be reduced to 1/5.

  The present invention is characterized in that the pixel write current is set to a value other than a predetermined value and the current flowing through the EL element 15 is driven intermittently. In this specification, for ease of explanation, it is assumed that the current value of N times is written in the driving transistor 11 of the pixel 16 and the ON time of the EL element 15 is 1 / N times. However, the present invention is not limited to this, and a current value of N1 times (N1 is not limited to 1 or more) is written to the driving transistor 11 of the pixel 16, and the ON time of the EL element 15 is 1 / (N2) times ( Needless to say, N2 may be equal to or greater than 1. N1 may be different from N2.

  In the driving method of the present invention, for example, when white raster display is used and the average luminance in one field (frame) period of the display screen 144 is assumed to be B0, the luminance B1 of each pixel 16 is higher than the average luminance B0. This is a driving method for performing current programming. In addition, the non-display area 192 is generated in at least one field (frame) period. Therefore, in the driving method of the present invention, the average luminance in one field (frame) period is lower than B1.

  In addition, the current program is performed on the pixel 16 with normal luminance in one field (frame) period, and the non-display area 192 is generated. In this method, the average luminance during one field (frame) period is lower than that of a normal driving method (conventional driving method). However, the effect of improving the moving image display performance is exhibited.

  In the present invention, the pixel configuration is not limited to the current program method. For example, the present invention can be applied to a voltage-programmed pixel configuration as shown in FIG. This is because displaying a predetermined period of one frame (field) with high luminance and turning off the other period is effective in improving the moving image display performance even in the voltage driving method. Even in the voltage drive system, the influence of the parasitic capacitance of the source signal line 18 cannot be ignored. Particularly in a large EL display panel, since the parasitic capacitance is large, it is effective to implement the driving method of the present invention.

  As shown in FIG. 23, the intermittent interval (non-display area 192 / display area 193) is not limited to an equal interval. For example, it may be random (as a whole, the display period or the non-display period may be a predetermined value (a constant ratio)). Also, it may be different for RGB. That is, it is only necessary to adjust (set) the R, G, B display period or the non-display period to a predetermined value (a constant ratio) so that the white balance is optimal.

  The non-display area 192 is a pixel 16 area of the non-lighting EL element 15 at a certain time. The display area 193 is the pixel 16 area of the lighting EL element 15 at a certain time. The positions of the non-display area 192 and the display area 193 are shifted by one pixel row in synchronization with the horizontal synchronization signal.

  In order to facilitate the description of the driving method of the present invention, 1 / N is described on the assumption that 1F is set to 1 / N on the basis of 1F (one field or one frame). However, there is a time during which one pixel row is selected and the current value is programmed (usually, one horizontal scanning period (1H)), and it goes without saying that an error may occur depending on the scanning state. Of course, it changes from the ideal state also by the penetration voltage from the gate signal line 17a. Here, in order to facilitate the description, the description will be made in an ideal state.

  The liquid crystal display panel holds the current (voltage) written to the pixel for a period of 1F (one field or one frame). For this reason, when a moving image is displayed, there is a problem that the outline of the display image is blurred.

  The organic (inorganic) EL display panel (display device) also holds the current (voltage) written in the pixel during the period of 1F (one field or one frame). Therefore, the same problem as the liquid crystal display panel occurs. On the other hand, a display that displays an image as a set of line displays with an electron gun, such as a CRT, displays an image using the afterimage characteristics of the human eye, so that the outline blur of a moving image display image does not occur.

  In the driving method of the present invention, current is passed through the EL element 15 only during the period of 1F / N, and no current is passed during the other period (1F (N-1) / N). Consider a case where the driving method of the present invention is implemented and one point on the screen is observed. In this display state, image data display and black display (non-lighting) are repeatedly displayed every 1F. That is, the image data display state is intermittently displayed over time. When the moving image data display is viewed in the intermittent display state, the outline of the image is not blurred and a good display state can be realized. That is, a moving image display close to a CRT can be realized.

  In the driving method of the present invention, intermittent display is realized. However, when performing intermittent display, the transistor 11d only needs to be on / off controlled at a maximum of 1H period. Therefore, the main clock of the circuit is not different from the conventional one, and the power consumption of the circuit does not increase. In the liquid crystal display panel, an image memory is necessary to realize intermittent display. In the present invention, image data is held in each pixel 16. Therefore, in the driving method of the present invention, an image memory for performing intermittent display is unnecessary.

  The driving method of the present invention controls the current flowing through the EL element 15 only by turning on and off the switching transistor 11d or the transistor 11e (FIG. 12 and the like). That is, even if the current Iw flowing through the EL element 15 is turned off, the image data is held in the capacitor 19 of the pixel 16 as it is. Therefore, if the switching element 11d and the like are turned on at the next timing and a current flows through the EL element 15, the flowing current is the same as the previously flowing current value.

  In the present invention, it is not necessary to increase the main clock of the circuit even when black insertion (intermittent display such as black display) is realized. Further, there is no need for an image memory because it is not necessary to perform time axis expansion. Further, the organic EL element 15 has a short time from application of current to light emission, and responds at high speed. Therefore, it is suitable for moving image display and can solve the problem of moving image display, which is a problem of conventional data retention type display panels (liquid crystal display panel, EL display panel, etc.) by performing intermittent display.

  Further, when the wiring length of the source signal line 18 is increased and the parasitic capacitance of the source signal line 18 is increased in a large display device, it is possible to cope with the problem by increasing the N value. When the program current value applied to the source signal line 18 is increased N times, the conduction period of the gate signal line 17b (transistor 11d) may be set to 1 F / N. Accordingly, the present invention can be applied to large display devices such as televisions and monitors.

  In current driving, it is necessary to program the capacitor 19 of the pixel with a very small current of 20 nA or less, particularly for black level image display. Therefore, if the parasitic capacitance is generated with a magnitude greater than or equal to a predetermined value, the time for programming to one pixel row (basically within 1H. However, it is limited to within 1H since two pixel rows may be written simultaneously. The parasitic capacitance cannot be charged or discharged within. If charging / discharging is not possible in the 1H period, writing into the pixel is insufficient and the resolution is not high.

  In the pixel configuration of FIG. 1, as shown in FIG. 6A, the program current Iw flows through the source signal line 18 during current programming. The voltage is set (programmed) in the capacitor 19 so that the current Iw flows through the transistor 11a and the current flowing through Iw is maintained. At this time, the transistor 11d is in an open state (off state).

  Next, during a period in which a current flows through the EL element 15, the transistors 11c and 11b are turned off and the transistor 11d operates as shown in FIG. 6B. That is, the off voltage (Vgh) is applied to the gate signal line 17a, and the transistors 11b and 11c are turned off. On the other hand, an on voltage (Vgl) is applied to the gate signal line 17b, and the transistor 11d is turned on.

  Assuming that the program current Iw is N times the current (predetermined value) that flows originally, the current Ie that flows through the EL element 15 in FIG. Therefore, the EL element 15 emits light with a luminance 10 times the predetermined value. That is, as shown in FIG. 18, as the magnification N is increased, the instantaneous display brightness B of the pixel 16 is also increased. Basically, the magnification N and the luminance of the pixel 16 are in a proportional relationship.

  Therefore, if the transistor 11d is turned on only for a period of 1 / N of the time for which the transistor 11d is originally turned on (about 1F) and is turned off for the other periods (N-1) / N, the average brightness of the entire 1F becomes a predetermined brightness. Become. This display state approximates that the CRT is scanning the screen with an electron gun. The difference is that the range in which the image is displayed is 1 / N of the entire screen (the whole screen is 1) is lit (in CRT, the lit range is one pixel row (strictly Is one pixel).

  In the present invention, the 1F / N display (lighting) area 193 moves from the top to the bottom of the display screen 144 as shown in FIG. Note that the scanning direction of the display area 193 may be from the bottom to the top of the display screen 144. Further, it may be random.

  In the present invention, current flows through the EL element 15 only during the period of 1F / N, and no current flows through the EL element 15 in the corresponding pixel row during the other period (1F · (N−1) / N). Accordingly, each pixel 16 is intermittently displayed. However, since the image is retained by the afterimage to the human eye, the entire screen appears to be displayed uniformly.

  Note that, as illustrated in FIG. 19, the writing pixel row 191 a is a non-lighting display region 192. However, this is the case of the pixel configuration shown in FIGS. In the pixel configuration of the current mirror illustrated in FIGS. 11 and 12, the writing pixel row 191 may be lit. However, in this specification, for ease of explanation, the pixel configuration in FIG.

  As described above, the driving method in which the program is programmed with a current larger than the predetermined drive current Iw and is intermittently driven as shown in FIGS. 19 and 23 is called N-fold pulse drive. In the driving method of FIG. 19, image data display and black display (non-lighting) are repeatedly displayed every 1F. That is, the image data display state is a temporal display (intermittent display) state.

  In a liquid crystal display panel (an EL display panel other than the present invention), since data is held in pixels for a period of 1F, even if image data changes in the case of moving image display, the change cannot be followed. The video was blurred (outline blur in the image). However, since the image is intermittently displayed in the present invention, the outline of the image is not blurred and a good display state can be realized. That is, a moving image display close to a CRT can be realized.

  As shown in FIG. 19, in order to drive, the current programming period of the pixel 16 (period in which the on-voltage Vgl of the gate signal line 17a is applied in the pixel configuration of FIG. 1), and the EL element 15 It is necessary to be able to control independently the period during which the off or on control is performed (in the pixel configuration of FIG. 1, the period during which the on voltage Vgl or the off voltage Vgh of the gate signal line 17b is applied). Therefore, the gate signal line 17a and the gate signal line 17b need to be separated.

  For example, when there is one gate signal line 17 wired from the gate driver circuit 12 to the pixel 16, the logic (Vgh or Vgl) applied to the gate signal line 17 is applied to the transistor 11 b, and the gate signal line 17 is applied. The driving method of the present invention cannot be implemented in a configuration in which the applied logic is converted (Vgl or Vgh) by an inverter and applied to the transistor 11d. Therefore, the present invention requires the gate driver circuit 12a for operating the gate signal line 17a and the gate driver circuit 12b for operating the gate signal line 17b.

  FIG. 20 shows a timing chart of the driving method of FIG. In the present invention and the like, the pixel configuration when there is no particular notice is assumed to be FIG. 1 for ease of explanation. As can be seen from FIG. 20, when an on-voltage (Vgl) is applied to the gate signal line 17a in each selected pixel row (selection period is 1H) (see FIG. 20A). In FIG. 20, an off voltage (Vgh) is applied to the gate signal line 17b (see FIG. 20B). During this period, no current flows through the EL element 15 (non-lighting state).

  In an unselected pixel row, an off voltage (Vgh) is applied to the gate signal line 17a, and an on voltage (Vgl) is applied to the gate signal line 17b. Further, during this period, a current flows through the EL element 15 (lighting state). In the lighting state, the EL element 15 is lit with a predetermined N times luminance (N · B), and the lighting period is 1 F / N. Therefore, the display luminance of the display panel that averages 1F is (N · B) × (1 / N) = B (predetermined luminance). N may be any value as long as N is 1 or more.

  FIG. 21 shows an embodiment in which the operation of FIG. 20 is applied to each pixel row. A voltage waveform applied to the gate signal line 17 is shown. In the voltage waveform, the off voltage is Vgh (H level) and the on voltage is Vgl (L level). Subscripts such as (1) and (2) indicate the selected pixel row number.

  In FIG. 21, the gate signal line 17 a (1) is selected (Vgl voltage), and a program current flows from the transistor 11 a in the selected pixel row to the source driver circuit 14 through the source signal line 18. This program current is N times a predetermined value. However, since the predetermined value is a data current for displaying an image, it is not a fixed value unless white raster display or the like is used. Capacitor 19 is programmed so that N times the current flows through transistor 11a. When the pixel row (1) is selected, in the pixel configuration of FIG. 1, the gate signal line 17b (1) is applied with the off voltage (Vgh), and no current flows through the EL element 15.

  After 1H, the gate signal line 17a (2) is selected (Vgl voltage), and a program current flows through the source signal line 18 from the transistor 11a in the selected pixel row toward the source driver circuit. This program current is N times a predetermined value. Therefore, the capacitor 19 is programmed so that N times the current flows through the transistor 11a. When the pixel row (2) is selected, the gate signal line 17b (2) is applied with the off voltage (Vgh) in the pixel configuration of FIG. 1, and no current flows through the EL element 15. However, the off voltage (Vgh) is applied to the gate signal line 17a (1) of the previous pixel row (1), and the on voltage (Vgl) is applied to the gate signal line 17b (1). It has become.

  After the next 1H, the gate signal line 17a (3) is selected, the off voltage (Vgh) is applied to the gate signal line 17b (3), and no current flows through the EL elements 15 in the pixel row (3). However, the off voltage (Vgh) is applied to the gate signal lines 17a (1) (2) of the previous pixel rows (1) (2), and the on voltage (Vgl) is applied to the gate signal lines 17b (1) (2). ) Is applied, and is in a lighting state.

  The above operation is displayed in synchronization with the 1H synchronization signal. However, in the driving method of FIG. 21, N times the current flows through the EL element 15. Therefore, the display screen 144 is displayed with N times the luminance. Of course, in order to perform a predetermined luminance display in this state, it is needless to say that the program current may be set to 1 / N. If the current is 1 / N, writing shortage occurs due to parasitic capacitance or the like. Therefore, programming with a high current and obtaining a predetermined luminance by inserting a black screen (non-lighting display area) 192 is a basic feature of the present invention. The main point.

  However, when the influence of the parasitic capacitance is negligible or the influence is slight, it is needless to say that the driving method of the present invention may be implemented with N = 1. This driving method will be described later with reference to FIGS.

  In the driving method of the present invention, the concept is that a current higher than a predetermined current flows in the EL element 15 and the parasitic capacitance of the source signal line 18 is sufficiently charged and discharged. That is, it is not necessary to flow N times the current through the EL element 15. For example, a current path is formed in parallel with the EL element 15 (a dummy EL element is formed, and this EL element does not emit light by forming a light-shielding film), and the program current is shunted between the dummy EL element and the EL element 15. May be used. For example, the program current written to the pixel 16 to be programmed is 0.2 μA. The program current output from the source driver circuit 14 is 2.0 μA. Therefore, N = 2.0 / 0.2 = 10 when viewed from the source driver circuit 14. Of the program current output from the source driver circuit 14, 1.8 μA (2.0−0.2) is passed through the dummy pixel. The remaining 0.2 μA is passed through the driving transistor 11 a of the target pixel 16. The dummy pixel row is configured not to emit light, or to form a light shielding film or the like so that it cannot be visually seen even if it emits light.

  With the configuration as described above, the current flowing through the source signal line 18 is increased N times, so that the driving transistor 11a can be programmed to flow N times as much current. In addition, a current sufficiently smaller than N times can be supplied to the EL element 15.

  FIG. 19A illustrates a writing state on the display screen 144. In FIG. 19A, 191a is a writing pixel row. A program current is supplied from the source driver IC 14 to each source signal line 18. Note that in FIG. 19 and the like, one pixel row is written in the 1H period. However, it is not limited to 1H at all, and it may be 0.5H period or 2H period. Although the program current is written to the source signal line 18, the present invention is not limited to the current program method, and a voltage program method (such as FIG. 28) in which the voltage is written to the source signal line 18 may be used. .

  In FIG. 19A, when the gate signal line 17a is selected, the current flowing through the source signal line 18 is programmed into the transistor 11a. At this time, an off voltage is applied to the gate signal line 17 b and no current flows through the EL element 15. This is because, when the transistor 11d is in the ON state on the EL element 15 side, the capacitance component of the EL element 15 can be seen from the source signal line 18, and the capacitor 19 cannot be sufficiently accurately programmed due to the capacitance. It is. Therefore, taking the configuration of FIG. 1 as an example, a pixel row in which current is written becomes a non-lighting region 192 as shown in FIG.

  Now, if the current is programmed with N times (N = 10 as described above), the screen brightness will be 10 times. Therefore, a 90% range of the display screen 144 may be the non-lighting area 192. If the horizontal scanning lines of the display screen 144 of the display panel are 220 QCIF (S = 220), 22 lines may be the display area 193 and 220-22 = 198 lines may be the non-display area 192. Generally speaking, if the horizontal scanning line (number of pixel rows) is S, the S / N area is the display area 193, and the display area 193 emits light with N times the luminance (N is a value of 1 or more). Is). The display area 193 is scanned in the vertical direction of the screen. Therefore, the S (N−1) / N region is a non-lighting region 192. This non-lighting area is black display (non-light emitting). The non-light emitting portion 192 is realized by turning off the transistor 11d. Although it is assumed that the light is lit at N times the luminance, it goes without saying that the N times value changes due to the brightness adjustment and the gamma adjustment.

  Further, in the previous embodiment, if programming was performed with 10 times the current, the brightness of the screen would be 10 times, and the 90% range of the display screen 144 should be the non-lighting area 192. However, this is not limited to the common use of the RGB pixels as the non-lighting region 192. For example, the R pixel has 1/8 as the non-lighting area 192, the G pixel has 1/6 as the non-lighting area 192, and the B pixel has 1/10 as the non-lighting area 192. You may change by. Further, the non-lighting area 192 (or the lighting area 193) may be individually adjusted with RGB colors. In order to realize these, separate gate signal lines 17b are required for R, G, and B. However, by enabling individual adjustment of RGB as described above, it is possible to adjust white balance, and color balance adjustment is facilitated at each gradation. This embodiment is shown in FIG.

  As shown in FIG. 19B, the pixel row including the writing pixel row 191a is a non-lighting region 192, and the S / N (1F / N in terms of time) range of the upper screen from the writing pixel row 191a is set. Display area 193 (when the writing scan is from the top to the bottom of the screen, the opposite is true when the screen is scanned from the bottom to the top). In the image display state, the display area 193 has a band shape and moves from the top to the bottom of the screen.

  In the display of FIG. 19, one display area 193 moves downward from the top of the screen. When the frame rate is low, it is visually recognized that the display area 193 moves. In particular, it becomes easier to recognize when the eyelid is closed or when the face is moved up and down.

  To solve this problem, the display area 193 may be divided into a plurality of parts as shown in FIG. If the divided sum is an area of S (N-1) / N, it is equivalent to the brightness of FIG. Note that the divided display areas 193 do not have to be equal (equally divided). Further, the divided non-display areas 192 need not be equal.

  As described above, screen flickering is reduced by dividing display area 193 into a plurality of parts. Therefore, no flicker occurs and a good image display can be realized. The division may be made finer. However, the moving image display performance decreases as it is divided.

  FIG. 24 shows the voltage waveform of the gate signal line 17 and the light emission luminance of EL. As is apparent from FIG. 24, the period (1F / N) during which the gate signal line 17b is set to Vgl is divided into a plurality of numbers (the number of divisions K). That is, a period of 1 gl / (K · N) is performed K times for the period of Vgl. By controlling in this way, the occurrence of flicker can be suppressed and an image display with a low frame rate can be realized.

  It is preferable that the number of image divisions is variable. For example, this change may be detected and the value of K may be changed by the user pressing a brightness adjustment switch or turning the brightness adjustment volume. Moreover, you may comprise so that a user may adjust a brightness | luminance. You may comprise so that it may change manually or automatically by the content and data of the image to display.

  In FIG. 24 and the like, the period (1F / N) in which the gate signal line 17b is set to Vgl is divided into a plurality (number of divisions K), and the period of 1F / (K · N) is executed K times in the period to set Vgl. However, this is not a limitation. The period of 1F / (K · N) may be performed L (L ≠ K) times. In other words, the present invention displays the display screen 144 by controlling the period (time) flowing through the EL element 15. Therefore, it is included in the technical idea of the present invention to execute the period of 1F / (K · N) L (L ≠ K) times. Further, by changing the value of L, the luminance of the display screen 144 can be changed digitally. For example, when L = 2 and L = 3, the luminance (contrast) changes by 50%. Further, when the image display region 193 is divided, the period during which the gate signal line 17b is set to Vgl is not limited to the same period.

  In the above embodiment, the current flowing through the EL element 15 is cut off by the transistor 11d or the switching circuit 71, and the display screen 144 is turned on / off (lit or not lit) by forming a path flowing through the EL element 15. It was a thing. That is, substantially the same current is caused to flow through the driving transistor 11a a plurality of times by the electric charge held in the capacitor 19. The present invention is not limited to this. For example, the display screen 144 may be turned on / off (lighted or not lighted) by charging / discharging the charge held in the capacitor 19.

  FIG. 25 shows voltage waveforms applied to the gate signal line 17 for realizing the image display state of FIG. The difference between FIG. 25 and FIG. 21 is the operation of the gate signal line 17b. The gate signal lines 17b are turned on / off (Vgl and Vgh) corresponding to the number of divided screens. The other points are the same as in FIG.

  In the specification of the present invention, the ratio of the display area 193 and the total display area 144 on the display screen 144 may be referred to as a duty ratio. That is, the duty ratio is the area of the display area 193 / the area of the entire display area 144. Alternatively, the duty ratio is also the number of gate signal lines 17b to which an ON voltage is applied / the number of all gate signal lines 17b. Further, the ON voltage is applied to the gate signal line 17b, and the number of selected pixel rows connected to the gate signal line 17b / the total number of pixel rows in the display region 144 is also obtained.

  If the inverse of the duty ratio (the total number of pixel rows / the number of selected pixel rows) is not less than a certain value, flicker occurs. This relationship is illustrated in FIG. In FIG. 266, the horizontal axis represents the total number of pixel rows / the number of selected pixel rows, that is, the reciprocal of the duty ratio. The vertical axis represents the flicker generation ratio. It is shown that flicker is more prominent as 1 is smallest and larger.

  According to the result of FIG. 266, it is appropriate that the total number of pixel rows / the number of selected pixel rows is 8 or less. That is, the duty ratio is preferably 1/8 or more. In addition, when some flicker may occur (a practically acceptable range), it is appropriate to set the total number of pixel rows / number of selected pixel rows to 10 or less. That is, the duty ratio is preferably 1/10 or more.

  271 and 272 show an embodiment of a driving method for selecting two pixel rows at the same time. In FIG. 271, when the writing pixel row is the (1) pixel row, (1) and (2) are selected for the gate signal line 17a (see FIG. 272). That is, the switching transistors 11b and the transistors 11c in the pixel rows (1) and (2) are on. Further, when a turn-on voltage is applied to the gate signal line 17a of each pixel row, a turn-off voltage is applied to the gate signal line 17b.

  Therefore, in the 1H and 2H-th periods, the switching transistors 11d in the pixel rows (1) and (2) are in the off state, and no current flows through the EL elements 15 in the corresponding pixel rows. That is, the non-lighting state 192. In FIG. 271, the display area 193 is divided into five parts in order to reduce the occurrence of flicker.

  Ideally, the transistors 11a of two pixels (rows) each have Iw × 5 (N = 10. That is, since K = 2, the current flowing through the source signal line 18 is Iw × K × 5 = Iw × 10) is passed through the source signal line 18. Then, the capacitor 19 of each pixel 16 is programmed and held with 5 times the current.

  Since two pixel rows (K = 2) are selected at the same time, the two driving transistors 11a operate. That is, a current of 10/2 = 5 times flows through the transistor 11a per pixel. A current obtained by adding the program currents of the two transistors 11a flows through the source signal line 18.

  For example, the write current Id is originally written in the write pixel row 191 a, and a current of Iw × 10 is passed through the source signal line 18. There is no problem in the writing pixel row 191b because normal image data is written later. The pixel row 191b has the same display as that of 191a during the 1H period. Therefore, at least the non-display state 192 is set for the writing pixel row 191a and the pixel row 191b selected to increase the current.

  After the next 1H, the gate signal line 17a (1) is not selected, and the ON voltage (Vgl) is applied to the gate signal line 17b. At the same time, the gate signal line 17 a (3) is selected (Vgl voltage), and a program current flows from the transistor 11 a of the selected pixel row (3) toward the source driver 14 through the source signal line 18. By operating in this way, regular image data is held in the pixel row (1).

  After the next 1H, the gate signal line 17a (2) is not selected, and the ON voltage (Vgl) is applied to the gate signal line 17b. At the same time, the gate signal line 17 a (4) is selected (Vgl voltage), and a program current flows from the transistor 11 a of the selected pixel row (4) toward the source driver 14 through the source signal line 18. By operating in this way, regular image data is held in the pixel row (2). The above operation and shift by one pixel row (of course, multiple pixel rows may be shifted. For example, if pseudo-interlace driving is used, the shift will be performed by two rows. One screen is rewritten by scanning while the same image may be written in the pixel row.

  In the driving method of FIG. 271, since each pixel is programmed with a current (voltage) five times that of the pixel, the light emission luminance of the EL element 15 of each pixel is ideally five times. Therefore, the brightness of the display area 193 is five times higher than the predetermined value. In order to set this to a predetermined luminance, the non-display area 192 may be set so as to include the writing pixel row 191 and the 1/5 range of the display screen 1 as described above.

  As shown in FIGS. 274 (a) and 274 (b), two write pixel rows 191 (191a and 191b) are selected and sequentially selected from the upper side to the lower side of the screen 144 (see also FIG. 273). In FIG. 273, the pixel rows 16a and 16b are selected). However, as shown in FIG. 274 (b), when reaching the lower side of the screen, the writing pixel row 191a exists, but 191b disappears. That is, only one pixel row is selected. Therefore, all the current applied to the source signal line 18 is written in the pixel row 191a. Therefore, twice as much current is programmed in the pixel as compared with the pixel row 191a.

  In response to this problem, the present invention forms (places) a dummy pixel row 2741 on the lower side of the screen 144 as shown in FIG. 274 (b). Therefore, when the selected pixel row is selected up to the lower side of the screen 144, the last pixel row and the dummy pixel row 2741 on the screen 144 are selected. Therefore, a prescribed current is written into the writing pixel row in FIG. 274 (b). Although the dummy pixel row 2741 is illustrated as being formed adjacent to the upper end or the lower end of the display region 144, the present invention is not limited to this. It may be formed at a position away from the display area 144. Further, it is not necessary to form the switching transistor 11d, the EL element 15 and the like in FIG. By not forming the panel, the size of the dummy pixel row 2741 is reduced, so that the frame of the panel can be shortened.

  FIG. 275 shows the state of FIG. 274 (b). As is clear from FIG. 275, when the selected pixel row is selected up to the pixel 16c row on the lower side of the screen 144, the last pixel row 2741 of the screen 144 is selected. The dummy pixel row 2741 is arranged outside the display area 144. That is, the dummy pixel row 2741 is configured not to be lit, not to be lit, or not to be displayed as a display even when lit. For example, the contact hole between the pixel electrode and the transistor 11 is eliminated, or the EL element 15 is not formed in the dummy pixel row. The dummy pixel row 2741 in FIG. 275 illustrates the EL element 15, the transistor 11d, and the gate signal line 17b, but is not necessary for the implementation of the driving method. In the actually developed display panel of the present invention, the EL element 15, the transistor 11d, and the gate signal line 17b are not formed in the dummy pixel row 2741. However, it is preferable to form a pixel electrode. This is because the parasitic capacitance in the pixel is not the same as that of the other pixels 16 and a difference may occur in the retained program current.

  In FIGS. 274 (a) and 274 (b), dummy pixels (rows) 2741 are provided (formed or arranged) on the lower side of the screen 144, but the present invention is not limited to this. For example, as shown in FIG. 276 (a), scanning is performed from the lower side to the upper side of the screen. In the case of scanning upside down, a dummy pixel row 2741 should be formed on the upper side of the screen 144 as shown in FIG. 276 (b). That is, the dummy pixel row 2741 is formed (arranged) on the upper side and the lower side of the screen 144, respectively. With the configuration described above, it is possible to cope with upside down scanning of the screen.

  In the above embodiment, two pixel rows are selected simultaneously. The present invention is not limited to this. For example, a method of simultaneously selecting five pixel rows may be used. That is, in the case of simultaneous driving of five pixel rows, four dummy pixel rows 2741 may be formed.

  The number of dummy pixel rows 2741 may be formed as many as M-1 pixel rows to be selected simultaneously. For example, if the pixel rows to be selected simultaneously are 5 pixel rows, the write pixel row 191 is 4 pixel rows. If the simultaneously selected pixel rows are 10 pixel rows, 10-1 = 9 pixel rows.

  FIGS. 274 and 276 are explanatory diagrams of the arrangement positions of the dummy pixel rows when the dummy pixel row 2741 is formed. Basically, the display panel is driven upside down, and dummy pixel rows 2741 are arranged above and below the screen 144.

  Since the black display in the EL display device is completely unlit, there is no reduction in contrast as in the case of intermittent display of the liquid crystal display panel. 1, 6, 7, 8, 9, 10, 11, 12, 12, 28, 271, etc., the transistor 11d, the transistor 11e, or the switching circuit 71 is turned on / off. Intermittent display can be achieved with just This is because the image data is stored in the capacitor 19 (the number of gradations is infinite because it is an analog value). That is, the image data is held in each pixel 16 during the period of 1F. Whether or not a current corresponding to the stored image data is supplied to the EL element 15 is realized by controlling the transistors 11d and 11e.

  Therefore, the above driving method is not limited to the current driving method, but can also be applied to the voltage driving method. That is, in the configuration in which the current flowing through the EL element 15 is stored in each pixel, the driving transistor 11 is intermittently driven by turning on and off the current path between the EL elements 15.

  Maintaining the terminal voltage of the capacitor 19 is important for reducing flicker and reducing power consumption. This is because if the terminal voltage of the capacitor 19 changes (charges / discharges) in one field (frame) period, the screen brightness changes, and flickering (flicker or the like) occurs when the frame rate decreases. It is necessary that the current that the transistor 11a passes through the EL element 15 in one frame (one field) period does not decrease to at least 65% or less. This 65% means that when the current written to the pixel 16 and the current flowing to the EL element 15 is 100%, the current flowing to the EL element 15 immediately before writing to the pixel 16 in the next frame (field) is 65% or more. It is to do.

  In the pixel configuration of FIG. 1, there is no change in the number of transistors 11 that constitute one pixel, in the case where intermittent display is realized or not. That is, the current configuration is realized by removing the influence of the parasitic capacitance of the source signal line 18 without changing the pixel configuration. In addition, a moving image display close to a CRT is realized.

  Further, since the operation clock of the gate driver circuit 12 is sufficiently slower than the operation clock of the source driver circuit 14, the main clock of the circuit does not increase. Further, it is easy to change the value of N.

  The image display direction (image writing direction) may be from the top to the bottom in the first field (one frame) and from the bottom to the top in the second field (frame). In other words, the top-to-bottom direction and the bottom-to-top direction are alternately repeated.

  In the first field (one frame), the screen is directed downward from the top. Once the entire screen is displayed in black (not displayed), the second field (frame) is oriented upward from the bottom of the screen. Also good. Alternatively, the entire screen may be displayed black (not displayed) once. Further, scanning may be performed from the center of the screen. Further, the scan start position may be randomized.

  In the above description of the driving method, the screen writing method is set from the top to the bottom or from the bottom to the top, but the present invention is not limited to this. The screen writing direction is constantly fixed from top to bottom or from bottom to top, and the non-display area 192 moves from top to bottom in the first field and in the second field, the bottom of the screen. It is good also as an upward direction. Further, one frame may be divided into three fields, and R is formed in the first field, G is formed in the second field, and B is formed in the third field. In addition, R, G, and B may be switched and displayed for each horizontal scanning period (1H) (see FIGS. 25 to 39 and the description thereof). The above matters are the same in other embodiments of the present invention.

  The non-display area 192 does not need to be completely non-lighted. Even if there is weak light emission or low luminance image display, there is no practical problem. That is, it should be interpreted that the display luminance is lower than that of the display (lighting) region 193. In addition, the non-display area 192 includes a case where only one or two colors of the R, G, and B image display are in the non-display state. In addition, the case where only one or two colors of the R, G, and B image displays are in a low luminance image display state is also included.

  Basically, when the luminance (brightness) of the display area 193 is maintained at a predetermined value, the luminance of the display screen 144 increases as the area of the display area 193 increases. For example, when the luminance of the display area 193 is 100 (nt), if the ratio of the display area 193 to the entire display screen 144 is changed from 10% to 20%, the luminance of the screen is doubled. Therefore, the display brightness of the screen can be changed by changing the area of the display area 193 occupying the entire display screen 144. The display brightness of the display screen 144 is proportional to the proportion of the display area 193 occupying the display screen 144.

  The area of the display region 193 can be arbitrarily set by controlling the data pulse (ST2) to the shift register circuit 141 shown in FIG. Further, the display state of FIG. 23 and the display state of FIG. 19 can be switched by changing the input timing and period of the data pulse. If the number of data pulses in the 1F cycle is increased, the display screen 144 is brightened, and if it is decreased, the display screen 144 is darkened. If the data pulse is continuously applied, the display state shown in FIG. 19 is obtained, and if the data pulse is input intermittently, the display state shown in FIG. 23 is obtained.

  In the conventional brightness adjustment of the screen, when the brightness of the display screen 144 is low, the gradation performance is degraded. That is, even when 64 gradation display can be realized during high brightness display, only half or less of the number of gradations can be displayed during low brightness display. Compared to this, the driving method of the present invention can realize the highest 64 gradation display without depending on the display brightness of the screen.

  The above embodiments are mainly embodiments in which N = 2 times, 4 times, and the like. However, it goes without saying that the present invention is not limited to integer multiples. Moreover, it is not limited to being larger than N = 1. For example, an area less than half of the display screen 144 at a certain time may be set as the non-lighting area 192. If the current is programmed with a current Iw that is 5/4 times the predetermined value and the light is turned on for 4/5 of 1F, a predetermined luminance can be realized.

  The present invention is not limited to this. As an example, there is a method in which current programming is performed with a current Iw that is 10/4 times, and lighting is performed for a 4/5 period of 1F. In this case, it is lit at twice the predetermined luminance. There is also a method in which current programming is performed with a current Iw that is 5/4 times, and lighting is performed for a period of 2/5 of 1F. In this case, the light is lit at half the predetermined luminance. There is also a method in which current programming is performed with a current Iw that is 5/4 times, and lighting is performed for a 1/1 period of 1F. In this case, it is lit at 5/4 times the predetermined luminance. There is also a method in which current programming is performed with a current Iw that is 1 times and lighting is performed for a quarter period of 1F. In this case, it is lit at 1/4 times the predetermined luminance.

  That is, the present invention is a method for controlling the luminance of the display screen by controlling the magnitude of the program current and the lighting period of 1F. By lighting for a period shorter than the 1F period, the black screen 192 can be inserted, and the moving image display performance can be improved. On the contrary, a bright screen can be displayed by setting N to 1 or more and always lighting it for a period of 1F.

Preferably, the current written to the pixel (program current output from the source driver circuit 14) is set such that when the pixel size is A square mm and the white raster display predetermined luminance is B (nt), the program current I (μA) is
(A × B) / 20 ≦ I ≦ (A × B)
It is preferable to set it as the range. Luminous efficiency is improved and insufficient current writing is eliminated.

Further preferably, the program current I (μA) is
(A × B) / 10 ≦ I ≦ (A × B)
It is preferable to set it as the range.

  20 and 24, the operation timing of the gate signal line 17a and the write timing of the gate signal line 17b are not mentioned. However, when a certain pixel is selected (when a turn-on voltage is applied to the gate signal line 17a to which the pixel is connected), the 1H period (one horizontal scanning period) before and after that is the gate signal line. An off voltage is applied to 17b (a gate signal line for controlling the EL-side transistor 11d). By setting the off voltage to the gate signal line 17b during the 1H period before and after, a crosstalk does not occur in the panel, and a stable image display can be realized.

  A timing chart of this driving method is shown in FIG. In FIG. 26, an on-voltage (Vgl) is applied to the gate signal line 17a during 1H (selection period). The off voltage (Vgh) is applied to the gate signal line 17b during the 1H period (total 3H period) before and after the 1H period in which the pixel row is selected.

  In the above embodiment, the off voltage is applied to the gate signal line 17b during the 1H period before and after the selection period. However, the present invention is not limited to this. For example, as shown in FIG. 27, the off voltage may be applied to the gate signal line 17b in the 1H period before the selection period and in the 2H period after the selection period. It goes without saying that the above embodiment can be applied to other embodiments of the present invention.

  The cycle for turning on and off the EL element 15 needs to be 0.5 msec or more. When this period is short, the image is not completely displayed due to the afterimage characteristics of the human eye, and the image becomes blurred, as if the resolution is lowered. Further, the display state of the data holding type display panel is set. However, when the on / off cycle is 100 msec or more, it appears to blink. Therefore, the on / off cycle of the EL element should be 0.5 μsec or more and 100 msec or less. More preferably, the on / off cycle should be 2 msec or more and 30 msec or less. More preferably, the on / off cycle should be 3 msec or more and 20 msec or less.

  As described above, if the number of divisions of the black screen 192 is 1, good moving image display can be realized, but the flickering of the screen can be easily seen. Therefore, it is preferable to divide the black insertion portion into a plurality. However, if the number of divisions is too large, motion blur will occur. The number of divisions should be between 1 and 8. More preferably, it is 1 or more and 5 or less.

  It should be noted that the number of black screen divisions is preferably configured so that it can be changed between a still image and a moving image. With N = 4, 75% is a black screen and 25% is an image display. At this time, the division number is 1 to scan the 75% black display portion in the vertical direction of the screen in the 75% black belt state. The number of divisions is 3 for scanning with 3 blocks of a 25% black screen and a 25/3% display screen. Increase the number of divisions for still images. Reduce the number of divisions for movies. Switching may be performed automatically (moving image detection or the like) according to the input image, or may be performed manually by the user. Further, it may be configured to switch the video of the display device in accordance with the input outlet.

  For example, in a mobile phone or the like, the number of divisions is set to 10 or more on the wallpaper display and input screen (extremely, it may be turned on / off every 1H). When displaying NTSC moving images, the number of divisions is set to 1 or more and 5 or less. It should be noted that the number of divisions is preferably configured so that it can be switched to multiple stages of 3 or more. For example, no division number, 2, 4, 8, etc.

  The ratio of the black screen to the entire display screen is preferably 0.2 or more and 0.9 or less (1.2 or more and 9 or less if displayed in N) when the area of the entire screen 144 is 1. In particular, it is preferably 0.25 or more and 0.6 or less (in the case of N, it is 1.25 or more and 6 or less). If it is 0.20 or less, the improvement effect in moving image display is low. If it is 0.9 or more, the luminance of the display portion increases, and it is easy to visually recognize that the display portion moves up and down.

  The number of frames per second is preferably 10 or more and 100 or less (10 Hz or more and 100 Hz or less). Furthermore, 12 or more and 65 or less (12 Hz or more and 65 Hz or less) are preferable. If the number of frames is small, the flickering of the screen becomes conspicuous. If the number of frames is too large, writing from the source driver circuit 14 becomes difficult and the resolution deteriorates.

  The time to set Vgl only during the period of 1F / N of the gate signal line 17b may be any time in the period of 1F (not limited to 1F; it may be a unit period). This is because a predetermined average luminance is obtained by turning on the EL element 15 for a predetermined period of time in the unit time. However, it is better to set the gate signal line 17b to Vgl immediately after the current program period (1H) and cause the EL element 15 to emit light. This is because it is less susceptible to the retention characteristics of the capacitor 19 of FIG.

  The driving voltage of the gate signal line 17a for driving the transistors 11b and 11c and the gate signal line 17b for driving the transistor 11d may be changed. The amplitude value of the gate signal line 17a (difference between the on voltage and the off voltage) is made smaller than the amplitude value of the gate signal line 17b.

  If the amplitude value of the gate signal line 17a is large, the punch-through voltage between the gate signal line 17a and the pixel 16 increases, and black floating occurs. The amplitude of the gate signal line 17 a may be controlled so that the potential of the source signal line 18 is applied to the pixel 16. Since the potential fluctuation of the source signal line 18 is small, the amplitude value of the gate signal line 17a can be reduced.

  On the other hand, the gate signal line 17b needs to perform on / off control of the EL element 15. Therefore, the amplitude value becomes large. To cope with this, the output voltages of the shift register circuits 141a and 141b in FIG. 6 are changed. When the pixel is formed of a P-channel transistor, Vgh (off voltage) of the shift register circuits 141a and 141b is made substantially the same, and Vgl (on voltage) of the shift register circuit 141a is set to Vgl (on voltage) of the shift register circuit 141b. ).

  In the above embodiment, one selected pixel row is arranged (formed) for each pixel row. The present invention is not limited to this, and one gate signal line 17a may be arranged (formed) in a plurality of pixel rows.

  FIG. 22 shows the embodiment. In order to facilitate the description, the pixel configuration will be described mainly using the case of FIG. In FIG. 22, the gate signal line 17a simultaneously selects three pixels (16R, 16G, 16B). The symbol “R” means a red pixel relationship, the symbol “G” means a green pixel relationship, and the symbol “B” means a blue pixel relationship.

  By selecting the gate signal line 17a, the pixel 16R, the pixel 16G, and the pixel 16B are simultaneously selected to enter a data writing state. The pixel 16R writes video data from the source signal line 18R to the capacitor 19R, and the pixel 16G writes video data from the source signal line 18G to the capacitor 19G. The pixel 16B writes video data from the source signal line 18B to the capacitor 19B.

  The transistor 11d of the pixel 16R is connected to the gate signal line 17bR. The transistor 11d of the pixel 16G is connected to the gate signal line 17bG, and the transistor 11d of the pixel 16B is connected to the gate signal line 17bB. The EL element 15R of the pixel 16R, the EL element 15G of the pixel 16G, and the EL element 15B of the pixel 16B can be separately controlled on and off. That is, the EL element 15R, the EL element 15G, and the EL element 15B can individually control the lighting time and the lighting cycle by controlling the gate signal lines 17bR, 17bG, and 17bB.

  In order to realize this operation, in the configuration of FIG. 6, a shift register circuit 141 that scans the gate signal line 17a, a shift register circuit 141R (not shown) that scans the gate signal line 17bR, and a gate signal line 17bG It is appropriate to form (place) four shift register circuits 141G (not shown) that scan the gate signal lines and shift register circuits 141B (not shown) that scan the gate signal lines 17bB.

  A current N times the predetermined current is passed through the source signal line 18 and a current N times the predetermined current is passed through the EL element 15 for a period of 1 / N. This is an ideal state. This is because the signal pulse applied to the gate signal line 17 actually penetrates the capacitor 19 and a desired voltage value (current value) cannot be set in the capacitor 19. Generally, a voltage value (current value) lower than a desired voltage value (current value) is set for the capacitor 19. For example, even if it is driven to set a current value 10 times, only a current 10 times or less is set in the capacitor 19. For example, even if N = 10, the current that actually flows through the EL element 15 is the same as when N = 10.

  However, in this specification, in order to facilitate the description, the description is made in an ideal state without the influence of the punch-through voltage or the like. In practice, the present invention is a method of setting a current value N times and driving the EL element 15 so that a current proportional to or corresponding to the N times flows.

  Further, the present invention applies a current larger than a desired value (a current that is higher than a desired luminance when a current is continuously passed through the EL element 15 as it is) to the driving transistor 11a (in the case of FIG. 1). (Voltage) programming is performed, and the current flowing through the EL element 15 is made intermittent to obtain the desired light emission luminance of the EL element.

  It is also effective to make the black display better by causing the switching transistors 11b and 11c of FIG. When the P-channel transistor 11b is turned off, the voltage becomes Vgh. Therefore, the terminal voltage of the capacitor 19 is slightly shifted to the Vdd side. For this reason, the gate (G) terminal voltage of the transistor 11a rises, resulting in a black display. In addition, since the current value for the first gradation display can be increased (a constant base current can be made to flow until gradation 1), a shortage of write current can be reduced by the current programming method.

  The transistor 11b in FIG. 1 operates to hold the current flowing in the driving transistor 11a in the capacitor 19. That is, it has a function of shorting between the gate terminal (G) and the drain terminal (D) or the source terminal (S) of the driving transistor 11a at the time of programming.

  The transistor 11b has a source terminal or drain terminal connected to the holding capacitor 19. The transistor 11b is ON / OFF controlled by the voltage applied to the gate signal line 17a. The problem is that the voltage of the gate signal line 17a penetrates the capacitor 19 when the off-voltage is applied. Due to this punch-through voltage, the potential of the capacitor 19 (= the potential of the gate terminal (G) of the driving transistor 11a) varies. Therefore, it becomes impossible to compensate the characteristics of the transistor 11a by current programming. Therefore, it is necessary to reduce the punch-through voltage.

  In order to reduce the penetration voltage, the size of the transistor 11b may be reduced. Now, the transistor size Scc is defined as channel width W (μm) and channel length L (μm), and Scc = W · L (square μm). When a plurality of transistors are connected in series, Scc is the sum of the connected transistor sizes. For example, if W = 5 (μm) and L = 6 (μm) of one transistor and the number (n = 4) is connected, Scc = 5 × 6 × 4 = 120 (square μm) It is.

  There is a correlation between transistor size and punch-through voltage. This relationship is shown in FIG. Note that the transistor is a P-channel transistor. However, even an N-channel transistor can be applied.

  In FIG. 29, the horizontal axis is Scc / n. Scc is the sum of the transistor sizes as described above. n is the number of connected transistors. In FIG. 29, the horizontal axis represents n pieces of Scc. That is, the size per transistor is.

  In the first embodiment, if the transistor size Scc is the channel width W (μm) and the channel length L (μm) and the number of transistors is n = 4, then Scc / n = 5 × 6 × 4/4 = 30 ( Square μm). In FIG. 29, the vertical axis represents the penetration voltage (V).

  If the punch-through voltage is not within 0.3 (V), laser shot unevenness occurs and is not visually acceptable. Therefore, the size of each transistor needs to be 25 (square μm) or less. On the other hand, unless the transistor is set to 5 (square μm) or more, the processing accuracy of the transistor cannot be achieved, and the variation becomes large. There is also a problem with drive capability. Thus, the transistor 11b needs to be 5 (square μm) or more and 25 (square μm) or less. More preferably, the transistor 11b needs to be 5 (square μm) or more and 20 (square μm) or less.

  The punch-through voltage by the transistor is also correlated with the amplitude value (Vgh−Vgl) of the voltage (Vgh, Vgl) for driving the transistor. The larger the amplitude value, the larger the punch-through voltage. This relationship is illustrated in FIG. In FIG. 30, the horizontal axis represents the amplitude value (Vgh−Vhl) (V). The vertical axis represents the penetration voltage. As described with reference to FIG. 29, the punch-through voltage needs to be 0.3 (V) or less.

  In other words, the permissible voltage 0.3 (V) of the penetration voltage is 1/5 or less (20% or less) of the amplitude value of the source signal line 18. The source signal line 18 is 1.5 (V) when the program current is white, and 3.0 (V) when the program current is black. Therefore, (3.0−1.5) /5=0.3 (V).

  On the other hand, if the amplitude value (Vgh−Vhl) of the gate signal line is 4 (V) or more, the pixel 16 cannot be sufficiently written. From the above, the amplitude value (Vgh−Vgl) of the gate signal line needs to satisfy the condition of 4 (V) or more and 15 (V) or less. More preferably, the amplitude value (Vgh−Vgl) of the gate signal line needs to satisfy the condition of 5 (V) or more and 12 (V) or less.

  When the transistor 11b is formed by connecting a plurality of transistors in series, it is preferable to increase the channel length L of a transistor (referred to as a transistor 11bx) close to the gate terminal (G) of the driving transistor 11a. When the gate signal line 17a is changed from the on voltage (Vgl) to the off voltage (Vgh), the transistor 11bx is turned off faster than the other transistors 11b. Therefore, the influence of the punch-through voltage is reduced. For example, if the channel width W of the plurality of transistors 11b and 11bx is 3 μm, the channel length L of the plurality of transistors 11b (other than the transistor 11bx) is 5 μm, and the channel length Lx of the transistor 11bx is 10 μm. The transistor 11b is disposed from the transistor 11c side, and the transistor 11bx is disposed on the gate terminal (G) side of the driving transistor 11a.

  Note that the channel length Lx of the transistor 11bx is preferably 1.4 to 4 times the channel length L of the transistor 11b. More preferably, the channel length Lx of the transistor 11bx is 1.5 to 3 times the channel length L of the transistor 11b.

  The punch-through voltage depends on the voltage amplitude of the gate driver circuit 12a that selects the pixel 16. In other words, the pixel configuration in FIG. 1 depends on the potential difference between the on voltage (Vgl1) and the off voltage (Vgh1). When this potential difference is smaller, the penetration voltage to the capacitor 19 is reduced, and the potential shift of the gate terminal of the transistor 11a is also reduced.

  Therefore, a smaller potential difference between Vgl1 and Vgh1 is effective in reducing the “push-through voltage”. However, if the potential difference is small, the transistor 11c is not completely turned on. For example, taking the pixel configuration of FIG. 1 as an example, when the voltage applied to the source signal line 18 is in the range of 5 (V) to 0 (V), the voltage applied to the gate signal line 17a is Vgh1 = + 6 (V) or higher and Vgl1 = −2 (V) or lower. By applying this voltage to the gate signal line 17a, the transistor 11c operating as a selection switch can maintain a good on / off state.

  On the other hand, almost no current flows through the transistor 11b that performs current programming in the driving transistor 11a. Therefore, the transistor 11b may not be operated as a switch. That is, the ON may not be relatively sufficient. The transistor 11b functions sufficiently even when the on-voltage (Vgl1) is high.

  From the above, the gate signal line 17a does not operate the transistor 11b and the transistor 11c simultaneously as shown in FIG. 1, but the gate signal line 17a1 for controlling the transistor 11b and the transistor as shown in FIG. It is preferable to separate the gate signal line 17a2 for operating 11c.

  The gate driver circuit (IC) 12a1 controls the gate signal line 17a1, and the gate driver circuit (IC) 12a2 controls the gate signal line 17a2. The gate signal line 17a1 controls the on / off state of the transistor 11b. The voltages to be controlled are an on voltage Vgh1a and an off voltage Vgl1a. The gate signal line 17a2 controls the on / off state of the transistor 11c. The voltages to be controlled are an on voltage Vgh1b and an off voltage Vgl1b.

  By reducing the voltage amplitude | Vgh1a-Vgl1a | of the gate signal line 17a1, the penetration voltage to the capacitor 19 due to the parasitic capacitance of the transistor 11b is reduced. By increasing the voltage amplitude | Vgh1b−Vgl1b | of the gate signal line 17a2, the transistor 11c is completely turned on and off, and operates as a good switch. The relationship between | Vgh1a-Vgl1a | and | Vgh1a-Vgl1a | is set or configured so that the relationship | Vgh1a-Vgl1a | <| Vgh1a-Vgl1a | is maintained.

  The off voltage Vgh1 and the off voltage Vgh2 are preferably the same. This is because the number of power supplies is reduced and the circuit cost can be reduced. Further, the off voltage Vgh1 is based on the anode voltage Vdd, so that the operation of the transistor 11 is stabilized. On the other hand, the ON voltage Vgl1 of the gate driver circuit 12a1 preferably maintains a relationship of +1 (V) or less and −6 (V) or more with respect to the ground voltage (GND) of the source driver circuit (IC) 14. This is because the punch-through voltage is reduced and good uniform display can be realized. The on-voltage Vgl2 of the gate driver circuit 12a2 preferably maintains a relationship of 0 (V) or less and −10 (V) or more with respect to the ground voltage (GND) of the source driver circuit (IC) 14. This is because the transistor 11c can be completely turned on and a good current (voltage) program can be realized. Moreover, it is preferable that the voltage setting is performed so that Vgl2 has a relationship of −1 (V) or less than Vgl1.

  It is preferable that the on-voltage is applied to the gate signal line 17a to select a pixel row and the off-voltage is subsequently applied to the gate signal line 17a as follows. That is, after the off voltage (Vgh1a) is applied to the gate signal line 17a1, the off voltage (Vgh1b) is applied to the gate signal line 17a2 after 0.05 μsec to 10 μsec (or from 1/400 to 1/10 of 1H time). Apply. This is because the influence of the punch-through voltage is greatly reduced by turning off the transistor 11b before the transistor 11c.

  In FIG. 281, two gate driver circuits 12a1 and 12a2 are shown, but the present invention is not limited to this and may be integrated. The above items also apply to the relationship between the gate driver circuit 12a and the gate driver circuit 12b. For example, the gate driver circuit 12 may be integrated as shown in FIG. Needless to say, the above matters can be applied to other embodiments of the present invention.

  The matters described in the above embodiments are not limited to the pixel configuration in FIG. For example, FIGS. 6, 7, 8, 9, 10, 11, 12, 12, 13, 28, 31, 36, 193, 194, 215, 314 (a) ( Needless to say, the present invention can also be applied to the pixel configuration b). That is, the voltage variation of the gate terminal (the gate terminal of the transistor 1b in FIG. 1) is connected to one terminal of the voltage holding capacitor 19 to operate the transistor, and the gate terminal of the pixel selection transistor (the transistor 11c in FIG. 1) is operated. Different from the voltage fluctuation. Although the above embodiment describes the transistor operation of the pixel 16, it is needless to say that the present invention is not limited to the pixel configuration and can be applied to the holding circuit 2280 described with reference to FIG. This is because the configuration is the same or similar, and the technical idea is the same.

  In the above embodiment, the driving transistor 11a is described as a P-channel transistor. In the case where the driving transistor 11a is an N-channel, the on-voltage potential and the off-voltage potential may be read so that description thereof is omitted.

  In the pixel configuration described with reference to FIG. 1 and the like, the driving transistor 11 a has one configuration for each pixel 16. However, in the present invention, the driving transistor 11a is not limited to one. For example, the pixel configuration of FIG. 31 is illustrated.

  In FIG. 31, the number of transistors constituting the pixel 16 is six, and the program transistor 11an is configured to be connected to the source signal line 18 via two transistors 11b2 and 11c. 11a1 is an embodiment configured to be connected to the source signal line 18 via two transistors 11b1 and 11c.

  In FIG. 31, the gate terminal of the driving transistor 11a1 and the gate terminal of the programming transistor 11an are made common. The transistor 11b1 operates so as to short-circuit the drain terminal and the gate terminal of the driving transistor 11a1 during current programming. The transistor 11b2 operates so as to short-circuit the drain terminal and the gate terminal of the programming transistor 11an during current programming.

  The transistor 11c is connected to the gate terminal of the driving transistor 11a1, and the transistor 11d is formed or arranged between the driving transistor 11a1 and the EL element 15, and controls the current flowing through the EL element 15. An additional capacitor 19 is formed or disposed between the gate terminal and the anode (Vdd) terminal of the driving transistor 11a1, and the source terminals of the driving transistor 11a1 and the programming transistor 11an are connected to the anode (Vdd) terminal. ing.

  As described above, by configuring the driving transistor 11a1 and the programming transistor 11an to pass through the same number of transistors, the accuracy can be improved. That is, the current flowing through the driving transistor 11a1 flows to the source signal line 18 through the transistors 11b1 and 11c. The current flowing through the programming transistor 11an flows to the source signal line 18 through the transistor 11b2 and the transistor 11c. Therefore, the current of the driving transistor 11a1 and the current of the programming transistor 11an pass through the same number of two transistors and flow to the source signal line 18.

  In FIG. 31, the driving transistor 11an is illustrated as one transistor, but the present invention is not limited to this. The driving transistor 11an may be composed of a plurality of transistors having the same channel width W, the same channel length L, or the same WL ratio. Further, it is preferable that the drive transistor 11an of the drive transistor 11a1 has the same channel width W, the same channel length L, or the same WL ratio. It is preferable to form a plurality of transistors having the same WL or WL ratio because the output variation of each transistor 11a is reduced and the variation between the pixels 16 is reduced.

  When a selection voltage (ON voltage) is applied to the gate signal line 17a, a combination of currents from the transistors 11an and 11a1 becomes the program current Iw. The program current Iw is set to a predetermined magnification of the current Ie flowing from the driving transistor 11a1 to the EL element 15.

Iw = n · Ie (n is a natural number of 1 or more)
In the above formula, the display brightness B (nt) at the maximum white raster of the display panel, the pixel area S (square millimeter) of the display panel (the pixel area is treated with RGB as one unit. Therefore, each of R, G, B If the picture element is 0.1 mm long and 0.05 mm wide, S = 0.1 × (0.05 × 3) (square millimeter)), one pixel row selection period (one horizontal scanning ( 1H) When the period) is H (milliseconds), the following conditions are satisfied. Note that the display brightness B is the maximum displayable brightness specified in the panel specification.

5 ≦ (B · S) / (n · H) ≦ 150
More preferably, the following conditions are satisfied.

10 ≦ (B · S) / (n · H) ≦ 100
Iw is a program current output from the source driver IC (circuit) 14, and a voltage corresponding to this program current is held in the capacitor 19 of the pixel 16. Ie is a current that the driving transistor 11a1 passes through the EL element 15.

  The output variations of the transistors 11a1 and 11an can be improved by forming or arranging the transistors 11an and the driving transistor 11a1 close to each other. Further, the characteristics of the transistor 11an and the transistor 11a1 may differ depending on the formation direction. Therefore, it is preferable to form in the same direction.

  When the gate signal line 17a is selected, both the driving transistor 11a1 and the programming transistor 11an are turned on. It is preferable that the current Iw1 flowing through the driving transistor 11a1 and the current Iw2 flowing through the programming transistor 11a1 are substantially matched. Most preferably, the sizes (W, L) of the programming transistor 11an and the driving transistor 11a1 are matched. That is, it is preferable to satisfy the relationship of Iw1 = Iw2 and Iw = 2Ie. Of course, satisfying the relationship of Iw1 = Iw2 is not limited to matching the transistor sizes (W, L), but may be matched by changing the size. This can be easily realized by adjusting the WL of the transistor. If approximately Iw2 / Iw1 = 1, the sizes of the transistors 11b1 and 11b1 can be configured or formed to be substantially the same.

  It should be noted that Iw2 / Iw1 preferably satisfies the relationship of 1 or more and 10 or less. Iw2 / Iw1 preferably satisfies a relationship of 1 or more and 10 or less. More preferably, the relationship of 1.5 to 5 is preferably satisfied.

  When Iw2 / Iw1 is 1 or less, the effect of improving the influence of the parasitic capacitance of the source signal line 18 is hardly expected. On the other hand, if Iw2 / Iw is 10 or more, the relationship between Ie and Iw varies from pixel to pixel, and a uniform image display cannot be realized. In addition, the transistor 11b is greatly affected by the on-resistance, and pixel design becomes difficult.

  When the current Iw2 flowing through the programming transistor 11an is larger than the current Iw1 flowing through the driving transistor 11a1 (Iw2> Iw1), the on-resistance of the switching transistor 11b2 is set higher than the on-resistance of the switching transistor 11b1. Need to be smaller. This is because the switching transistor 11b2 needs to be configured so that a current larger than that of the transistor 11b1 flows to the voltage of the same gate signal line 17a.

  That is, it is necessary to match the magnitude of the transistor 11b1 with respect to the magnitude of the output current of the driving transistor 11a1 and the magnitude of the transistor 11b2 with respect to the magnitude of the output current of the programming transistor 11an.

  In other words, it is necessary to change the on-resistance of the transistor 11b with respect to the program current Iw2 and the program current Iw1. Further, it is necessary to change the sizes of the transistors 11b1 and 11b2 with respect to the program current Iw2 and the program current Iw1.

  If the program current Iw2 is larger than the program current Iw1, the on-resistance of the transistor 11b2 needs to be smaller than the on-resistance of the transistor 11b1 (in the case where the gate terminal voltages of the transistor 11b1 and the transistor 11b2 are the same). If the program current Iw2 is larger than the program current Iw1, the on-current (Iw2) of the transistor 11b2 needs to be larger than the on-current (Iw1) of the transistor 11b1 (when the gate terminal voltages of the transistor 11b1 and the transistor 11b2 are the same) Is).

  When Iw2: Iw1 = n: 1, an on-voltage is applied to the gate signal line 17a, and when the transistor 11b1 and the transistor 11b2 are turned on, the on-resistance of the transistor 11b2 is R2, and the on-resistance of the transistor 11b1 is R1. At this time, R2 is configured to satisfy the relationship of R1 / (n + 5) or more and R1 / (n) or less. To configure means to form, arrange or operate the transistor 11b in a predetermined size. However, n is a value larger than 1.

  Note that the above item is an explanation of the on-resistance R or the program current Iw of the transistors 11b1 and 11b2. Accordingly, any configuration is possible as long as the pixel configuration is realized so as to satisfy the above-described conditions. For example, when the gate signal line 17 connected to the gate terminal of the transistor 11b1 and the gate signal line 17 connected to the gate terminal of the transistor 11b2 are different signal lines, the voltage applied to each gate signal line is changed. As a result, the on-resistance and the like can be changed, and the conditions of the present invention can be satisfied.

  FIG. 32 is an explanatory diagram of the operation of the pixel configuration of FIG. FIG. 32A shows a current program state, and FIG. 31B shows a state where a current is supplied to the EL element 15. Needless to say, intermittent display may be performed by turning on and off the transistor 11d in the state of FIG.

  In FIG. 32A, an ON voltage is applied to the gate signal line 17a, and the transistors 11b1, 11b2, and 11c are turned on. The transistor 11a1 supplies a current Ie, the transistor 11an supplies a current Iw-Ie, and the combined current Iw becomes a program current for the source driver Ic. With the above operation, a voltage corresponding to the program current Iw is held in the capacitor 19. During current programming, the transistor 11d is held in the off state (the off voltage is applied to the gate signal line 17b).

  The case where a current is passed through the EL element 15 is set to the operation state shown in FIG. An off voltage is applied to the gate signal line 17a, and an on voltage is applied to the gate signal line 17b. In this state, the transistors 11b1, 11b2, and 11c are turned off, and the transistor 11d is turned on. An Ie current is supplied to the EL element 15.

  FIG. 33 is a modification of FIG. In FIG. 33, the transistor 11c is arranged between the source signal line 18 and the drain terminal of the transistor 11a1. As described above, a large number of modifications can be illustrated in FIG.

  In FIG. 31, the transistors 11b1, 11b2, and 11c are controlled by applying an on / off voltage to the gate signal line 17a. However, when the transistors 11b1 and 11b2 and the transistor 11c are turned off at the same time when the current program state is changed to a state other than the current program state, the transistor 11c is turned off before the transistors 11b1 and 11b2. The voltage held at 19 may change from a specified value. Due to the change, an error occurs in the current Ie supplied from the driving transistor 11a to the EL element 15.

  For this problem, a configuration as shown in FIG. 34 is preferable. In FIG. 34, the gate terminals of the transistors 11b1 and 11b2 of the gate signal line 17a1 are connected. The gate terminal of the transistor 11c is connected to the gate signal line 17a2. Therefore, the transistors 11b1 and 11b2 are on / off controlled by applying an on / off voltage to the gate signal line 17a1. Further, the transistor 11c is on / off controlled by applying an on / off voltage to the gate signal line 17a2.

  When changing from the current programming state to a state other than the current programming state (when changing from the state in which the on-voltage is applied to the gate signal lines 17a1 and 17a2 to the state in which the off-voltage is applied to the gate signal lines 17a1 and 17a2) The applied voltage of the gate signal line 17a1 is changed from the on voltage to the off voltage. Accordingly, the transistors 11b1 and 11b2 are turned off. Next, the gate signal line 17a2 is changed from the on-voltage applied state to the off-voltage applied state. Accordingly, the transistor 11c is turned off.

  As described above, by turning off the transistors 11b1 and 11b2 and then turning off the transistor 11c, the influence of the punch-through voltage is reduced and the amount of leakage current is also reduced. The voltage is as specified. Note that it is preferable that the difference in timing of applying the off voltage to the gate signal line 17a1 and the gate signal line 17a2 is 0.1 μsec or more and 5 μsec or less.

  In FIG. 34, the number of driving transistors 11a is one, but the present invention is not limited to this, and two or more may be used as shown in FIG. FIG. 193 includes two transistors 11a (driving transistors 11a1 and 11a2) for driving the EL element 15, and two transistors 11an (11an1 and 11an2) for programming. With the configuration as shown in FIG. 193, pixel characteristic variation can be further reduced. It should be noted that the layout arrangement may be performed so that the driving transistor 11a and the programming transistor 11an are arranged alternately.

  As shown in FIG. 194, a pixel configuration is also effective. FIG. 194 has two driving transistors 11a (11a1, 11a2). Both of the two driving transistors 11a (11a1, 11a2) supply a current Ie to the EL element 15, and the EL element emits light with luminance B by this current.

  FIG. 195 is a timing chart for explaining the operation of the pixel in FIG. Hereinafter, the operation of FIG. 194 will be described. Note that the pixels in FIG. 194 are arranged in a matrix, and the corresponding pixels are selected by sequentially selecting the gate signal lines. Here, for ease of explanation, one pixel will be explained as in FIG.

  First, when the gate signal line 17a is selected and the Vgl voltage is applied, the transistors 11b2, 11b1, and 11c are turned on and become conductive. In this state, the program current applied to the source signal line 18 flows to the transistors 11a2 and 11a1, and the voltage is held in the capacitor 19 so that the program current Iw flows (see the column of the gate signal line 17a in FIG. 195). See This completes the current program. An ON voltage (Vgl) is applied to the gate signal line 17a in the 1H period, and an OFF voltage (Vgh) is applied after the selection period has elapsed. The above is the basic operation, and it goes without saying that FIG. 26, FIG. 27, and the like are actually applied to the on / off timing of the gate signal line.

  Next, during a period in which the current Ie1 of the driving transistor 11a1 flows through the EL element 15, the gate signal line 17b1 is selected (Vgl voltage is applied). Further, an off voltage (Vgh voltage) is applied to the gate signal line 17b1 during a period in which no current flows through the EL element 15. The EL element 15 emits light by repeating the above state regularly or periodically or randomly. In FIG. 195, the light emission of the EL element 15 is indicated by luminance B. Note that a timing chart of the gate signal line 17b1 is indicated by a gate signal line 17b1 in FIG.

  During the period in which the current Ie2 of the driving transistor 11a2 flows through the EL element 15, the gate signal line 17b2 is selected (the Vgl voltage is applied). Further, an off voltage (Vgh voltage) is applied to the gate signal line 17b2 during a period in which no current flows through the EL element 15. The EL element 15 emits light by repeating the above state regularly or periodically or randomly (in FIG. 195, the light emission of the EL element 15 is indicated by luminance B. Note that the gate signal line 17b2 A timing chart is shown by a gate signal line 17b2 in FIG.

  In the embodiment shown in FIGS. 194 and 195, it has been described that there are two drive transistors 11a and these two are switched. However, the present invention is not limited to this, and three or more drive transistors 11a are formed or arranged. The current Ie may be supplied to the EL element 15 by switching three or more driving transistors 11a. Two or more driving transistors 11a may simultaneously supply the current Ie to the EL element. The current Ie1 supplied from the driving transistor 11a1 to the EL element 15 may be different from the current Ie2 supplied from the driving transistor 11a2 to the EL element 15.

  The plurality of driving transistors 11a may be different in size. Further, the time for the plurality of driving transistors 11a to flow current to the EL element 15 does not need to be the same and may be different. For example, the driving transistor 11a1 supplies current to the EL element 15 for a time of 10 μsec (10 μsec), and the driving transistor 11a2 supplies current to the EL element 15 for a time of 20 μsec (20 μsec). You may comprise. In FIG. 194, in the driving transistor 194, the gate terminal of the driving transistor 11a1 and the gate terminal of the driving transistor 11a2 are connected in common. However, the present invention is not limited to this. Needless to say, the potential may be set. The above embodiments can also be applied to the pixel configurations of FIGS. In this case, the present invention is applied to a program transistor and a drive transistor.

  The above embodiment is mainly an embodiment of the modification of FIG. The present invention is not limited to this, and can be applied to a pixel configuration of a current mirror as shown in FIG.

  FIG. 35 shows an embodiment of the present invention. FIG. 35 shows an embodiment in which a pixel is constituted by one driving transistor 11b and four programming transistors 11an. Other configurations are the same as those of the embodiment of FIG.

  In the embodiment of FIG. 35, when the gate signal lines 17a1 and 17a2 are selected, the transistors 11c and 11d are activated, and a current path between the programming transistor 11an and the source signal line 18 is formed. The four programming transistors 11an are preferably formed with the same size (the same channel width W and the same channel length L). However, in the present invention, the programming transistor 11an may be composed of one. In this case, it is preferable to realize a predetermined program current Iw in consideration of the shape or WL ratio of one program transistor 11an.

  In the embodiment of FIG. 35, the program current Iw is a combination of the currents of the four program transistors 11an. For ease of explanation, it is assumed that the currents flowing through the programming transistors 11a are equal. For ease of explanation, the transistor 11a that supplies current to the EL element 15 is referred to as a driving transistor 11b, and the transistor 11an that operates during current programming is referred to as a programming transistor 11an.

  In FIG. 35, the driving transistor 11b and one programming transistor 11an have the same output current (when the voltages applied to the gate terminals of the driving transistor and the programming transistor are the same). In order to make the output currents equal, the transistors 11an and 11b have the same WL (channel width W and channel length L). It is preferable to form a plurality of transistors 11a having the same WL or WL ratio because the output variation of each transistor 11a is reduced and the variation between the pixels 16 is reduced.

  When a selection voltage (ON voltage) is applied to the gate signal lines 17a1 and 17a2, a combination of currents from the plurality of programming transistors 11an becomes the programming current Iw. The program current Iw is set to a predetermined magnification of the current Ie flowing from the driving transistor 11b to the EL element 15.

Iw = n · Ie (n is a natural number greater than 1)
In the above equation, the display brightness B (nt) at the maximum white raster of the display panel, the pixel area S (square millimeter) of the display panel (the pixel area is handled with RGB as one unit. If 0.1 mm and 0.05 mm in width, S = 0.1 × (0.05 × 3) (square millimeter)), one pixel row selection period (one horizontal scanning (1H) period) of the display panel When H is H (milliseconds), the following conditions are satisfied. Note that the display brightness B is the maximum displayable brightness specified in the panel specification.

5 ≦ (B · S) / (n · H) ≦ 150
More preferably, the following conditions are satisfied.

10 ≦ (B · S) / (n · H) ≦ 100
Iw is a program current output from the source driver IC (circuit) 14, and a voltage corresponding to this program current is held in the capacitor 19 of the pixel 16. Ie is a current that the driving transistor 11a passes through the EL element 15.

  Therefore, the WL or size (shape) of the driving transistor 11b and the programming transistor 11a and the output current are configured or formed so as to satisfy the above relational expression. For ease of explanation, in the configuration of FIG. 35, if the size or supply current of the driving transistor 11b is equal to the size (shape) of the programming transistor 11an or the supply current per one, n−1. The relationship of the above equation can be satisfied by forming the programming transistors 11a. In particular, in the pixel configuration of FIG. 35, the current of the driving transistor 11a can also be set to the program current, and the aperture ratio of the pixel 16 can be increased as compared with the pixel configuration of the current mirror.

  By configuring the pixel 16 as described above, the program current Iw becomes n times as large as Ie. Therefore, even if parasitic capacitance exists in the source signal line 18, there is no shortage of writing.

  The output variations of the transistors 11b and 11an can be improved by forming or arranging the programming transistor 11an and the driving transistor 11b close to each other. Further, the characteristics of the transistors 11an and 11b may differ depending on the formation direction. Therefore, it is preferable to unify the channel formation direction of the transistors in the horizontal direction or the vertical direction.

  In the EL display panel, the RGB EL elements are made of different materials. Therefore, the luminous efficiency is often different for each color. Therefore, each RGB program current Iw is also different. The parasitic capacitance of the source signal line 18 generally does not change with respect to RGB and is often the same. If the RGB program currents Iw are different and the parasitic capacitances of the source signal lines 18 are the same in RGB, the program current write time constants are different.

  Regarding the pixel configuration of FIG. 35, the number of RGB programming transistors 11an may be changed. Needless to say, the size (WL or the like) or the magnitude of the supply current of each of the RGB programming transistors 11an may be changed. Further, the number or size of the driving transistor 11b may be changed.

  Needless to say, the above matters can be similarly applied to the pixel configurations of FIG. 31, FIG. 33, FIG. The number of the RGB programming transistors 11an may be changed. Needless to say, the size (WL or the like) or the magnitude of the supply current of each of the RGB programming transistors 11an may be changed. Further, the number or size of the driving transistor 11a may be changed.

  In FIG. 35, the transistor 11c is controlled by the gate signal line 17a2, and the transistor 11d is controlled by the gate signal line 17a1. When the current programming state changes to a state other than the current programming state, it is possible to suppress the transistor 11c and the transistor 11d from being turned off simultaneously.

  When changing from the current programming state to a state other than the current programming state (when changing from the state in which the on-voltage is applied to the gate signal lines 17a1 and 17a2 to the state in which the off-voltage is applied to the gate signal lines 17a1 and 17a2) The applied voltage of the gate signal line 17a2 is changed from the on voltage to the off voltage. Accordingly, the transistor 11d is turned off. Next, the gate signal line 17a1 is changed from the on-voltage applied state to the off-voltage applied state. Accordingly, the transistor 11c is turned off.

  As described above, when the transistor 11d is turned off and then the transistor 11c is turned off, the influence of the punch-through voltage is reduced and the amount of leakage current is also reduced. Is as specified. Note that it is preferable that the difference in timing of applying the off voltage to the gate signal line 17a1 and the gate signal line 17a2 is 0.1 μsec or more and 5 μsec or less.

  FIG. 36 shows a configuration in which the transistor 11c and the transistor 11d can be controlled by a voltage applied to the gate signal line 17a. In the configuration shown in FIG. 36, only one gate signal line 17 is required to drive the pixel 16, so the number of wiring signal lines can be reduced. In the pixel configuration of FIG. 36, the non-display area 192 cannot be generated. However, the control of the pixel is easy and the aperture ratio of the pixel can be improved.

  The above embodiment has a pixel configuration for current programming. The present invention is not limited to this, and a pixel configuration of voltage driving and current driving may be combined. FIG. 211 shows a pixel configuration capable of performing both voltage driving and current driving. In current driving, current writing occurs in the lowered gradation region. On the other hand, in voltage driving, there is no shortage of writing even at a low gradation. However, in the voltage drive, since the characteristic variation of the driving transistor 11a formed on the display screen cannot be absorbed, the unevenness of laser annealing is displayed. Current drive does not have this problem. Therefore, as shown in FIG. 213, voltage driving is performed in the low gradation region, current driving is performed in the high gradation region, and voltage driving is performed in the intermediate gradation region, and then current driving is performed. The problems of both current driving and voltage driving can be solved.

  FIG. 211 shows a pixel configuration in which both voltage driving and current driving can be performed. However, for ease of explanation, only one pixel is shown as in FIG. The driver circuit 12 and the like are also conceptually described.

  When the transistor 11e is deleted in FIG. 211, a pixel configuration of voltage offset cancel driving is obtained. The pixel configuration of FIG. 211 is basically a voltage offset canceling configuration in which a transistor 11e that shorts the capacitor 19b is formed or arranged.

  FIG. 212 is an explanatory diagram illustrating the pixel configuration of FIG. FIG. 212A shows a pixel state at the time of programming in the current driving method. FIG. 212 (b) shows a state at the time of programming in the voltage drive system.

  First, the current program state of FIG. 212 (a) will be described. In FIG. 212 (a), the transistor 11e is turned on. Therefore, both ends of the capacitor 19b are short-circuited. Further, the gate driver circuits 12d and 12a perform the same operation (in FIG. 212 (a), they are shown as gate driver circuits 12a + 12d). That is, when each pixel row is selected, the ON voltage is applied from the gate driver circuits 12a + 12d to the gate signal lines 17b and 17a. Accordingly, the transistors 11e, 11c, and 11b are simultaneously turned on. That is, FIG. 212A is the same as the pixel configuration of FIG. Therefore, the program current Iw output from the source driver circuit 14 is written in the driving transistor 11a. Subsequent operations (selection state and operation of the gate signal line 17b) are the same as those in FIG. In FIG. 212 (a), it goes without saying that any of the driving methods corresponding to FIG. 1 described in the present invention can be applied.

  Next, in FIG. 212 (b), the gate signal line 17a and the gate signal line 17c operate separately. Since this pixel configuration is known as a voltage offset canceller, description of the operation is omitted.

  As shown in FIG. 213, the present invention operates with the pixel circuit configuration of FIG. 212 (b) in the low gradation region and operates with the pixel circuit configuration of FIG. 212 (a) in the high gradation region. In the intermediate gradation region between the high gradation region and the low gradation region, it is preferable to perform the first 1H in the circuit configuration of FIG. 212 (b) and then perform the circuit configuration of FIG. 212 (a). The switching range of FIG. 212 (a) and FIG. 212 (b) needs to be determined by evaluation. According to the result of the examination, in any one of the gradation range, the lowest gradation (gradation 0) to 1/10 or more and ¼ of the whole gradation is not shown in FIG. 212 (b). It is preferable that only voltage driving is performed, and the current program shown in FIG. 212 (a) is performed from any range from 1/6 to 1/3 of all gradations to the highest gradation.

  It should be noted that the current program shown in FIG. 212A is executed after the voltage program shown in FIG. 212B is executed outside the gradation range where only the current drive or voltage drive is executed. Even in the high gradation region, the current program shown in FIG. 212A may be executed after the voltage program shown in FIG. 212B is executed. In the low gradation region, the current program shown in FIG. 212A may be executed after the voltage program shown in FIG. 212B is executed. This is because the voltage program state is dominant in the low gradation region, and even if the current program is executed after the voltage program, the current program state does not affect the program state of the pixel 16.

  As described above, according to the present invention, in the low gradation region, first, at least the voltage program is implemented by realizing the pixel configuration of the voltage program at the beginning of 1H, and at the end of 1H in the high gradation region. A pixel configuration is implemented and at least a current program is implemented. Note that the program for the pixel 16 by a combination of the current program and the voltage program has been described with reference to FIGS. Needless to say, FIGS. 211 and 212 may be combined with the drive systems shown in FIGS. 127 to 143.

  1 and the like have been described as having a pixel configuration for current programming. However, it goes without saying that the following method can also be applied to the pixel configurations of FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. Needless to say, the above items can be similarly applied to other embodiments of the present invention.

  FIG. 214 shows an example in which voltage programming is performed with a current-driven pixel configuration. FIG. 214A shows a state in which voltage programming is being performed, and FIG. 214B shows a state in which light emission is caused by flowing a program current Iw through the EL element 15.

  In FIG. 214A, an on-voltage is applied to the gate signal line 17a to turn on the transistor 11b and the transistor 11c. In this state, a program voltage V is applied to the source signal line 18 and this voltage V is held in the capacitor 19 of the pixel 16. At this time, a turn-off voltage is applied to the gate signal line 17b to turn off the transistor 17d.

  FIG. 214B shows the state of the transistor when the EL element 15 is caused to emit light. An off voltage is applied to the gate signal line 17a, and the transistors 11b and 11c are opened. An ON voltage is applied to the gate signal line 17b, and the transistor 11d is short-circuited (ON state).

  A voltage program can be implemented by driving as described above. That is, in the low gradation region, the program voltage V is applied to the source signal line at the beginning of at least 1H, and in the high gradation region, the program current Iw is applied at least at the end of 1H.

  Note that switching timing between voltage driving and current driving has been described with reference to FIGS. 212, 127 to 143, and the like, and thus description thereof will be omitted. The above matters are the same in other embodiments of the present invention.

  FIG. 215 is a modification of FIG. It can also be considered as a combination of FIG. 1 and FIG. This is because the pixel configuration is obtained by adding the transistor 11e to FIG. A gate signal line 17c for controlling the transistor 11e is added, and a gate driver circuit 12c for sequentially applying an ON / OFF voltage to the gate signal line 17c in a scanning state is provided.

  216 (a) and 216 (b) are explanatory diagrams of the operation of FIG. FIG. 216 (a) shows the driving state of the current program. FIG. 216 (b) shows the driving state of the voltage program.

  In FIG. 216 (a), a turn-off voltage is applied to the gate signal line 17c, and the transistor 11e is turned off (open state). This state is the same as the pixel configuration in FIG. Therefore, the driving method described with reference to FIG. 1 can be realized by driving the gate signal line 17c with the off-voltage constantly applied, and the current program can be implemented.

  In FIG. 216 (b), the off voltage is always applied to the gate signal line 17. Therefore, the transistors 11b and 11c connected to the gate signal line 17a are always turned off (open state). In this state, an ON voltage is sequentially applied to the gate signal line 17c in the scanning state by the gate driver circuit 12c. The transistor 11e in the selected pixel row is turned on, and the program voltage V applied to the source signal line 18 is applied to the capacitor 19. In the driving method shown in FIG. 216 (b), the transistor 11d is not necessarily turned off (open) during voltage programming, and may be either on or off as shown in FIG. 216 (b). . However, it goes without saying that the transistor 11d needs to be turned on when a current is passed through the EL element 15. Other operations and the like are the same as those in the previous embodiment, and the description thereof is omitted.

  FIG. 217 is a modification of FIG. 212 or 215. In FIG. 217, the transistor 11e is formed or arranged between the driving transistor 11a and the transistor 11d. The transistor 11e is on / off controlled by a gate signal line 17c connected to the gate driver circuit 12c.

  FIG. 218 is an explanatory diagram of the operation of FIG. FIG. 218 (a) shows the state of the current program, and FIG. 218 (b) shows the state of the voltage program.

  In FIG. 218 (a), an on-voltage is always applied to the gate signal line 17c (similar to FIG. 212, it goes without saying that the transistor 11e may be turned on when a pixel row is selected. The same applies to FIG. 215.) On-voltage is applied to the gate signal line 17a of the selected pixel row. Therefore, the transistor 11b and the transistor 11c are turned on. In this state, a program current Iw is applied to the source signal line 18, and this program current Iw is written into the capacitor 19 of the selected pixel 16.

  FIG. 218 (b) illustrates a pixel writing state during voltage programming. Basically, the voltage program state of FIG. A turn-off voltage is applied to the gate signal line 17c, and the transistor 11e is turned off (open state). Similarly to FIG. 28A, a turn-off voltage is applied to the gate signal line 17b, and the transistor 11d is turned off. In this state, the program voltage V applied to the source signal line 18 is written to the capacitor 19 of the selected pixel 16. Other operations and the like are the same as those in the previous embodiment, and the description thereof is omitted.

  In the pixel configuration of FIG. 2, a particularly problematic item is that a transient current flows to the EL element 15 when a power source (a cathode voltage or an anode voltage supplied to the panel) is turned on / off. That is, the on / off state of the transistor 11b is determined, and the power supply is turned on while the potential state of the capacitor 19 is indefinite. This problem occurs even when the power is turned off.

  To deal with this problem, as shown in FIG. 219, a switching transistor 219a is disposed or formed between the anode and the transistor 11a, and a transistor 219b is formed or disposed between the driving transistor 11a and the EL element 15 or the cathode. Can be solved.

  When the power is turned off, the transistor 2191 is turned off by the controller before the power is turned off as shown in FIG. As shown in FIG. 220 (a), the transistor 2191 may be turned off by either turning off either 2191a or 2191b, or both the transistor 2191a and the transistor 2191b as shown in FIG. 220 (b). After turning off, the power supply circuit may be turned off.

  When the power is turned on, the transistor 2191 is turned off by the controller. After that, the transistor 2191 is preferably turned on after the power supply circuit is turned on.

  Needless to say, the items described above with reference to FIGS. 219 and 220 can be applied to other pixel configurations of the present invention. Needless to say, the effect can be obtained by disposing or forming either the transistor 219a or the transistor 219b in FIG.

  In FIG. 219, the switching transistor 2191 is formed or arranged in each pixel 16. However, the present invention is not limited to this. One switch 2191a is arranged at the anode terminal, and one switch 2191b is arranged at the cathode terminal. You may arrange. In FIG. 219, 2191 is a transistor. However, the present invention is not limited to this, and it goes without saying that another element such as a thyristor, a photodiode, a relay element, or the like may be used.

  In the above embodiment, the pixels 16 formed or arranged in the display area have a current driving type pixel or a voltage driving type pixel configuration, or can be switched between voltage driving and current driving. However, the present invention is not limited to this. For example, it may be configured as shown in FIG.

  FIG. 221 shows a configuration in which a current-driven pixel (such as FIG. 1) 16 b and a voltage-driven pixel (such as FIG. 2) 16 a are connected to one source signal line 18. The current-driven pixel 16 b is disposed or formed at one end of the source signal line 18, and the formation position is disposed or formed at a position far from the source driver circuit (IC) 14. The WL of the driving transistor 11a of the current-driven pixel 16b and the WL of the driving transistor 11a of the voltage-driven pixel 16a are matched.

  The current-driven pixel 16b is turned on according to the case of the magnitude of the program current (voltage), supplies current to the source signal line 18, and performs charge / discharge of the source signal line 18, thereby the pixel 16 Write program to.

  222 shows a configuration in which the relationship between the voltage pixel 16a and the current pixel 16b in FIG. 221 is switched. As described above, the present invention forms or arranges both the voltage pixel 16a and the current pixel 16b in the display area.

  According to the pixel configuration of the present invention, RGB images can be sequentially displayed by controlling switching means such as the transistor 11d (in the case of FIG. 1) (see also the configuration of FIG. 22). In FIG. 37A, the R display area 193R, the G display area 193G, and the B display area 193B are scanned from the top to the bottom (or from the bottom to the top) in one frame (one field) period. An area other than the RGB display area is a non-display area 52. That is, intermittent driving is performed. R, G, and B display areas 193 are intermittently displayed individually.

  FIG. 37B shows an example in which a plurality of R, G, and B display areas 193 are generated in one field (one frame) period. This driving method is similar to the driving method of FIG. Therefore, no explanation will be required. By dividing the display area 193 into a plurality of parts in FIG. 37B, the occurrence of flicker is eliminated even at a lower frame rate.

  FIG. 38A shows the display area 193 with different areas in the RGB display area 193. Needless to say, the area of the display region 193 is proportional to the lighting period. In FIG. 38A, the R display area 193R and the G display area 193G have the same area. The area of the B display area 193B is larger than that of the G display area 193G.

  In organic EL display panels, the light emission efficiency of B is often poor. As shown in FIG. 38A, by making the B display area 193B larger than the display areas 193 of other colors, white balance can be efficiently achieved. Further, by changing the area of the R, G, B display region 193, white balance adjustment and color temperature adjustment can be easily realized.

  FIG. 38B shows an example in which the B display period 193B is plural (193B1, 193B2) in one field (frame) period. FIG. 38A shows a method of changing one B display area 193B. By changing it, the white balance can be adjusted well. In FIG. 38B, white balance adjustment (correction) is improved by displaying a plurality of B display regions 193B having the same area. In addition, color temperature correction (adjustment) is improved. For example, it is effective to change the color temperature outdoors and indoors. For example, the color temperature is decreased indoors and the color temperature is increased outdoors.

  The drive system of the present invention is not limited to either FIG. 37 or FIG. R, G, and B display areas 193 are generated and intermittently displayed. As a result, the moving image blur is dealt with, and insufficient writing to the pixel 16 is improved. In the driving method shown in FIG. 23, the display area 193 independent of R, G, and B is not generated. RGB is displayed simultaneously (should be expressed when the W display area 193 is displayed). Needless to say, FIG. 38 (a) and FIG. 38 (b) may be combined. For example, a drive method is implemented in which the RGB display area 193 in FIG. 38A is changed and a plurality of RGB display areas 193 in FIG. 38B are generated.

  37 to 38, as long as the current flowing in the EL element 15 (EL element 15R, EL element 15G, EL element 15B) can be controlled for each RGB as shown in FIG. Needless to say, the driving method of FIG. 38 can be easily implemented.

  In the configuration of the display panel of FIG. 22, the R pixel 16R can be controlled to be turned on / off by applying an on / off voltage to the gate signal line 17bR. By applying an on / off voltage to the gate signal line 17bG, the G pixel 16G can be on / off controlled. By applying an on / off voltage to the gate signal line 17bB, the B pixel 16B can be on / off controlled.

  In order to realize the above driving, as shown in FIG. 39, the gate driver circuit 12bR for controlling the gate signal line 17bR, the gate driver circuit 12bG for controlling the gate signal line 17bG, and the gate signal line 17bB are controlled. The gate driver circuit 12bB to be formed may be formed or arranged.

  The gate driver circuits 12bR, 12bG, and 12bB in FIG. 39 are driven by the method described in FIG. 19, FIG. 20, and the like, thereby realizing the driving method in FIGS. Of course, it is needless to say that the driving method shown in FIG. 23 can be realized with the configuration of the display panel shown in FIG.

  In FIG. 20, FIG. 24, FIG. 26, FIG. 27, etc., the gate signal line 17b (EL-side selection signal line) applies an on voltage (Vgl) and an off voltage (Vgh) in units of one horizontal scanning period (1H). I explained as you do. However, the light emission amount of the EL element 15 is proportional to the flow time when the flow current is a constant current. Therefore, it is not necessary to limit the flowing time to 1H unit. The following matters also apply to the gate signal lines 17a (17a1, 17a2).

First, in order to introduce the concept of output enable (OEV), it is defined as follows. By performing the OEV control, an on / off voltage (Vgl voltage, Vgh voltage) can be applied to the pixel 16 to the gate signal lines 17a and 17b within one horizontal scanning period (1H).
For ease of explanation, the display panel of the present invention will be described on the assumption that it is the gate signal line 17a (in the case of FIG. 1) for selecting a pixel row for current programming. The output of the gate driver circuit 12a that controls the gate signal line 17a is called a WR-side selection signal line. The description will be made assuming that the gate signal line 17b (in the case of FIG. 1) for selecting the EL element 15 is used. The output of the gate driver circuit 12b that controls the gate signal line 17b is called an EL-side selection signal line.

  The gate driver circuit 12 receives a start pulse, and the input start pulse sequentially shifts in the shift register as retained data. Data held in the shift register of the gate driver circuit 12a determines whether the voltage output to the WR side selection signal line is the on voltage (Vgl) or the off voltage (Vgh). Further, an OEV1 circuit (not shown) that forcibly turns off the output is formed or arranged at the output stage of the gate driver circuit 12a. When the OEV1 circuit is at the L level, the WR side selection signal that is the output of the gate driver circuit 12a is output to the gate signal line 17a as it is.

  If the above relationship is illustrated logically, it becomes an OR circuit relationship (see FIG. 40B). The on-voltage is a logic level L (0), and the off-voltage is a logic voltage H (1). When the gate driver circuit 12a outputs an off voltage, the off voltage is applied to the gate signal line 17a. When the gate driver circuit 12a outputs an on-voltage (logic L level), the OR circuit takes an OR with the output of the OEV1 circuit and outputs it to the gate signal line 17a. When the OEV1 circuit is at the H level, the voltage output to the gate driver signal line 17a is set to the off voltage (Vgh) (see the timing chart example in FIG. 40A).

  Data held in the shift register of the gate driver circuit 12b determines whether the voltage output to the gate signal line 17b (EL-side selection signal line) is the on voltage (Vgl) or the off voltage (Vgh). Further, an OEV2 circuit (not shown) for forcibly turning off the output is formed or arranged at the output stage of the gate driver circuit 12b. When the OEV2 circuit is at L level, the output of the gate driver circuit 12b is output as it is to the gate signal line 17b. If the above relation is illustrated logically, the relation shown in FIG. The on-voltage is a logic level L (0), and the off-voltage is a logic voltage H (1).

  When the gate driver circuit 12b outputs the off voltage (the EL side selection signal is the off voltage), the off voltage is applied to the gate signal line 17b. When the gate driver circuit 12b outputs an ON voltage (logic L level), the OR circuit takes an OR with the output of the OEV2 circuit and outputs it to the gate signal line 17b. That is, the OEV2 circuit sets the voltage output to the gate driver signal line 17b to the off voltage (Vgh) when the input signal is at the H level. Therefore, even if the EL side selection signal of the OEV2 circuit is in the ON voltage output state, the signal forcibly output to the gate signal line 17b becomes the OFF voltage (Vgh). If the input of the OEV2 circuit is L, the EL side selection signal is output through to the gate signal line 17b (see the example of the timing chart in FIG. 40A).

  The luminance of the display screen 144 can be linearly adjusted by adjusting the period during which the ON voltage is applied to the gate signal line 17b (EL-side selection signal line). This can be easily realized by controlling the OEV2 circuit. For example, in FIG. 41, the display brightness is lower in FIG. 41 (b) than in FIG. 41 (a). In addition, the display luminance is lower in FIG. 41C than in FIG.

  Further, as illustrated in FIG. 42, a set of a period for applying the on-voltage and a period for applying the off-voltage may be provided a plurality of times in the 1H period. FIG. 42A shows an embodiment provided six times. FIG. 42B shows an embodiment provided three times. FIG.42 (c) is the Example provided once. In FIG. 42, the display brightness is lower in FIG. 42B than in FIG. Also, the display brightness is lower in FIG. 42C than in FIG. Therefore, the display luminance can be easily adjusted (controlled) by controlling the number of ON periods.

  Hereinafter, the current driver type source driver IC (circuit) 14 of the present invention will be described. The source driver IC of the present invention is used to realize the driving method and driving circuit of the present invention described above. Further, it is used in combination with the driving method, driving circuit, and display device of the present invention. Although the description will be made on an IC chip, the present invention is not limited to this, and it is fabricated on the substrate 30 of the display panel using a high-temperature engraved silicon technology, a low-temperature polysilicon technology, a CGS technology, an amorphous silicon technology, or the like. Needless to say. Further, the source driver circuit 14 formed on a silicon wafer or the like may be transferred to the substrate 30.

  FIG. 43 is a structural diagram of one output stage of the source driver IC (circuit) 14. That is, the output unit is connected to one source signal line 18. It is composed of a plurality of unit transistors 154 (one unit) of the same size, the number of which is bit-weighted corresponding to the bits of the image data. FIG. 43 shows an example of 64-gradation display as an example. The transistor group 431c corresponding to one output stage includes 63 unit transistors 154.

  The transistor or transistor group constituting the source driver IC (circuit) 14 of the present invention is not limited to the MOS type, but may be a bipolar type. Moreover, it is not limited to a silicon semiconductor, and a gallium arsenide semiconductor may be used. Further, a germanium semiconductor may be used.

  FIG. 43 shows a case of 6-bit digital input as one embodiment of the present invention. That is, since it is 2 6, it is a 64 gradation display. By mounting this source driver IC 14 on the array substrate, red (R), green (G), and blue (B) have 64 gradations, so that 64 × 64 × 64 = about 260,000 colors can be displayed. Become.

  In the case of 64 gradations, there are one D0 bit unit transistor 154, two D1 bit unit transistors 154, four D2 bit unit transistors 154, eight D3 bit unit transistors 154, and D4 bit units. Since there are 16 unit transistors 154 and 32 D5-bit unit transistors 154, the total number of unit transistors 154 is 63. That is, the present invention configures (forms) one unit transistor 154 with the number of gradations expressed (in this example, 64 gradations) minus one unit transistor 154.

  Even when one unit transistor is divided into a plurality of sub-unit transistors, the unit transistor is simply divided into sub-unit transistors. For example, a case where one unit transistor 154 includes four sub-unit transistors is illustrated. Therefore, there is no difference (synonymous) in that the present invention is composed of unit transistors with the number of grayscale representations minus one.

  In FIG. 43, 32 unit transistors 154 of the D5th bit are illustrated as being densely arranged (formed), but the present invention is not limited to this. For example, it may be divided into a group of eight unit transistors 154 (that is, a group of eight transistors is four sets), and the divided transistor groups may be dispersed (arranged). This reduces the variation in output current.

  In FIG. 43, D0 indicates an LSB input, and D5 indicates an MSB input. When the D0 input terminal is at the H level (positive logic), the switch 151a (on / off means. Of course, it may be constituted by a single transistor or an analog switch combining a P-channel transistor and an N-channel transistor). ) Turns on. Then, a current flows toward the unit transistor 154 constituting the current mirror. This current flows through the internal wiring 153 in the IC 14. Since the internal wiring 153 is connected to the source signal line 18 via the terminal electrode of the IC 14, the current flowing through the internal wiring 153 becomes the program current of the pixel 16.

  For example, when the D1 input terminal is at the H level (positive logic), the switch 151 is turned on. Then, a current flows toward the two unit transistors 154 constituting the current mirror. This current flows through the internal wiring 153 in the IC 14. Since the internal wiring 153 is connected to the source signal line 18 via the terminal electrode of the IC 14, the current flowing through the internal wiring 153 becomes the program current of the pixel 16.

  The same applies to the other switches 151. When the D2 input terminal is at the H level (positive logic), the switch 151c is turned on. Then, a current flows toward the four unit transistors 154 constituting the current mirror. When the D5 input terminal is at the H level (positive logic), the switch 151f is turned on. Then, a current flows toward the 32 unit transistors 154 constituting the current mirror.

  As described above, according to data (D0 to D5) from the outside, a current flows toward the corresponding unit transistor. Therefore, the current flows through the unit transistors from 0 to 63 according to the data.

  In the present invention, for ease of explanation, the number of current sources is 63, which is 6 bits. However, the present invention is not limited to this. In the case of 8 bits, 255 unit transistors 154 may be formed (arranged). In the case of 4 bits, 15 unit transistors 154 may be formed (arranged). Of course, in the case of 8 bits, 255 × 2 unit transistors 154 may be formed (arranged). Two unit transistors 154 output one unit current. The unit transistors 154 constituting the unit current source have the same channel width W and channel width L. By configuring with the same transistor in this way, an output stage with little variation can be configured.

  Further, all the unit transistors 154 are not limited to flowing the same current. For example, each unit transistor 154 may be weighted. For example, the current output circuit may be configured by mixing one unit unit transistor 154, two times unit transistor 154, four times unit transistor 154, and the like.

  However, if the unit transistors 154 are weighted, the weighted current sources do not have a weighted ratio and may vary. Therefore, even in the case of weighting, each current source is preferably configured by forming a plurality of transistors serving as one unit of current source.

  The program current Iw is output to the source signal line through the switch controlled by the 6-bit image data D0, D1, D2,..., D5 (current is drawn). Therefore, according to ON / OFF of 6-bit image data D0, D1, D2,..., D5, the current is added to the output line by 1 time, 2 times, 4 times,. Is output. That is, a program current is output from the output line 153 by 6-bit image data D0, D1, D2,..., D5 (current is drawn from the source signal line 18).

  In order to realize full color display on an EL display panel, it is necessary to form (create) a reference current for each of RGB. White balance can be adjusted by the ratio of RGB reference currents. The reference current determines a current value that the unit transistor 154 flows. Therefore, if the magnitude of the reference current is determined, the current flowing through the unit transistor 154 can be determined. For this reason, if R, G, and B reference currents are set, white balance can be obtained in all gradations. The above items are the effects that are exhibited because the source driver circuit 14 has a current step output (current drive).

  The gate terminal (G) of the unit transistor 154 in the transistor group 431 c is connected to the common gate wiring 153. The source terminal (S) of the unit transistor 154 is connected to the common internal wiring 150, and a terminal 155 is configured at one end of the internal wiring 150. The drain terminal (D) of the unit transistor 154 is grounded to the ground potential (GND).

  One transistor group 431 c is configured (formed) corresponding to one source signal line 18. Further, as shown in FIG. 47, the unit transistor 154 forms a current mirror circuit with the transistor 158b1 or 158b2. A reference current Ic flows through the transistor 158b, and an output current of the unit transistor 154 is determined by the reference current Ic.

As shown in FIG. 47, the gate terminal (G) of the transistor 158b and the gate terminal (G) of the unit transistor are connected by a common gate wiring 153. Therefore, the transistor 158b and each transistor group 431c form a current mirror circuit.
As illustrated in FIG. 47, the potential gradient of the gate wiring 153 is reduced by disposing the transistors 158b1 and 158b2 on both sides of the transistor group 431c. Therefore, the magnitudes of the output currents of the left and right transistor groups (431c1, 431cn) are equal (at the same gradation). Further, the potential gradient of the gate wiring 153 can be changed by adjusting the magnitudes of the reference currents Ic1 and Ic2. By adjusting the magnitudes of the reference currents Ic1 and Ic2, the magnitudes of the output currents of the left and right transistor groups (431c1 and 431cn) can be adjusted.

  In FIG. 47, the transistor group 431c and the transistor 158b constitute a current mirror circuit, but actually, the transistor 158b is composed of a plurality of transistors. That is, the transistor group 431b including the plurality of transistors 158b and the transistor group 431c constitute a current mirror circuit. That is, the gate terminals of the plurality of transistors 158 b and the gate terminals of the plurality of unit transistors 154 are connected by the common gate wiring 153.

  FIG. 48 shows an arrangement configuration of the transistors 483b of the transistor group 431b. In one transistor group 431b, 63 transistors 158b having the same number as the unit transistors 154 of the transistor group 431c are formed.

  Of course, the number of transistors 158b in one transistor group 431b is not limited to 63. When the number of unit transistors 154 in the unit transistor group 431c is configured with the number of gradations −1, the number of transistors 158b in the transistor group 431b is the number of gradations −1 or the same or similar number. Further, the configuration is not limited to that shown in FIG. 48, and may be formed or arranged in a matrix as shown in FIG.

  The above configuration is schematically shown in FIG. The unit transistor groups 431c are arranged in parallel by the number of output terminals. A plurality of transistor groups 431b are formed on both sides of the unit transistor group 431c. A gate wiring 153 connects the gate terminal of the transistor 158b of the transistor group 431b and the gate terminal of the unit transistor 154 of the unit transistor group 431c.

  In the above description, for the sake of simplicity, the description has been made for the single-color source driver IC 14, but it is originally configured as shown in FIG. 45. That is, in the transistor group 431b and the unit transistor group 431c, red (R), green (G), and blue (B) transistor groups are alternately arranged (in FIG. 45, the transistor group to which the subscript R is added is red. (R) is shown, the transistor group to which the subscript G is added indicates green (G), and the transistor group to which the subscript B is added indicates blue (B)). As described above, output variations between RGB are reduced by alternately arranging RGB transistor groups. This configuration is also an important requirement for the layout in the source driver IC 14.

  In FIG. 47, transistors 158b (158b1, 158b2) are formed or arranged on both sides of each of the transistor groups 431c1 and 431cn. The present invention is not limited to this. As illustrated in FIG. 46, the transistor 158b may be on one side.

  The reference current Ic is preferably generated by an electronic volume 501 and an operational amplifier 502 as shown in FIG. The electronic volume 501 and the operational amplifier 502 are built in the source driver IC 14. A ladder resistor R is configured (formed) inside the electronic volume 501, and the ladder resistor R divides the reference voltage Vs (or IC power supply voltage). The voltage divided by the ladder resistor is selected by the switch S and applied to the positive terminal of the operational amplifier 502. The reference current Ic is generated by the applied voltage and the external resistor R1 of the source driver IC14. By externally attaching the resistor R1, the value of the reference current can be easily adjusted by the value of R1, and white balance can be easily achieved by adjusting the external resistor of the RGB circuit.

  50, the electronic volume 501a and the electronic volume 501b can be operated independently. Therefore, the value of the current flowing through the transistor 158a1 and the transistor 158a2 can be changed. Therefore, the current flowing through the left and right transistors 158b (158b1, 158b2) of the chip can be adjusted, and the potential gradient of the gate wiring 153 can be adjusted.

  The size of the transistor constituting the unit transistor 154 needs to be a certain size or more. The smaller the transistor size, the greater the variation in output current. The size of the unit transistor 154 is a size obtained by multiplying the channel length L and the channel width W. For example, if the channel width W = 3 μm and the channel length L = 4 μm, the size of the unit transistor 154 constituting one unit current source is W × L = 12 square μm.

  The reason why the variation increases as the transistor size decreases is considered to be due to the influence of the crystal interface state of the silicon wafer. Therefore, when one transistor is formed across a plurality of crystal interfaces, the output current variation of the transistor is reduced.

  44 and 48, the total area of the transistors 158b in the transistor group 431b (the number of the transistor groups 431b × the WL size of the transistors 158b in the transistor group 431b × the number of transistors 158b) is Sb. Needless to say, when the transistor group 431b includes one transistor 158b, Sb is the number of the transistor group 431b × the WL size of the transistor 158b. As described above, the total area of the transistor 158b is Sb.

  The total area of the unit transistors 154 in the transistor group 431c (WL size of the unit transistors 154 in the transistor group 431c × number of unit transistors 154) is Sc (square μm). The number of transistor groups 431c is n (n is an integer). n is 176 in the case of the QCIF + panel (when a reference current circuit is formed for each RGB). Therefore, n × Sc (square μm) is the total area of the unit transistors 154 that form a current mirror circuit with the transistor 158b of the transistor group 431b (the transistor 158b and the gate wiring 153 are shared).

  As Sc × n / Sb increases, the swing of the gate wiring 153 increases. An increase in Sc × n / Sb indicates that the total area of the unit transistors 154 in the transistor group 431c is larger than the total area of the transistors 158b in the transistor group 431b when the number of output terminals n is constant. The swing of the gate wiring 153 increases. As it increases, the swing of the gate wiring 153 increases.

  The smaller Sc × n / Sb indicates that the total area of the unit transistors 154 in the transistor group 431c is smaller than the total area of the transistors 158b in the transistor group 431b when the number of output terminals n is constant. In this case, the swing of the gate wiring 153 is reduced.

  As for the allowable range of the swing of the gate wiring 153, Sc × n / Sb is 50 or less. If Sc × n / Sb is 50 or less, the variation ratio is within an allowable range, and the potential variation of the gate wiring 153 becomes extremely small. Accordingly, there is no occurrence of lateral crosstalk, and output variation is within an allowable range, so that a good image display can be realized.

  FIG. 67 illustrates the relationship between the IC withstand voltage and the output variation of the unit transistor 154. With respect to the variation ratio of the vertical axis, the variation of the unit transistor 154 is set to 1 by the 1.8 (V) breakdown voltage process.

  FIG. 67 shows the output variation of the unit transistor 154 manufactured by each withstand voltage process when the shape L / W of the unit transistor 154 is 12 (μm) / 6 (μm). In addition, a plurality of unit transistors are formed in each IC withstand voltage process, and output current variation is obtained. However, the breakdown voltage process is 1.8 (V) breakdown voltage, 2.5 (V) breakdown voltage, 3.3 (V) breakdown voltage, 5 (V) breakdown voltage, 8 (V) breakdown voltage, 10 (V) breakdown voltage, 15 ( V) Breakdown such as withstand voltage. However, for ease of explanation, the variation of the transistors formed at each breakdown voltage is entered in a graph and connected by a straight line.

  The reason why there is a correlation between the breakdown voltage and the output variation is presumed to be related to the gate insulating film of the transistor. When the breakdown voltage is high, the gate insulating film is thick. If the gate insulating film is thick, the mobility is lowered and the variation with respect to the film thickness is also increased.

  From FIG. 67, until the IC withstand voltage is about 13 (V), the increase ratio of the variation ratio (output current variation of the unit transistor 154) with respect to the IC process is small. However, when the IC breakdown voltage is 15 (V) or more, the slope of the variation ratio with respect to the IC breakdown voltage increases.

  In FIG. 67, the variation ratio within 3 is the variation allowable range in the 64 gradation to 256 gradation display. However, this variation ratio varies depending on the area of the unit transistor 154 and L / W. However, even if the shape of the unit transistor 154 is changed, there is almost no difference in the variation tendency of the variation ratio with respect to the IC breakdown voltage. When the IC withstand voltage is 13 to 15 (V) or more, the variation ratio tends to increase.

  On the other hand, the potential of the output terminal 155 of the source driver IC (circuit) 14 changes according to the program current of the driving transistor 11 a of the pixel 16. The gate terminal potential Vw when the driving transistor 11a of the pixel 16 passes white raster (maximum white display) current is used. A gate terminal potential Vb when the driving transistor 11a of the pixel 16 passes a black raster (full black display) current is used. The absolute value of Vw−Vb needs to be 2 (V) or more. When the Vw voltage is applied to the output terminal 155, the voltage between the channels of the unit transistor 154 needs to be 0.5 (V).

  Therefore, the output terminal 155 (the terminal 155 is connected to the source signal line 18 and the gate terminal voltage of the driving transistor 11a of the pixel 16 is applied during current programming) from 0.5 (V) to ((Vw A voltage of −Vb) +0.5) (V) is applied. Since Vw−Vb is 2 (V), a maximum of 2 (V) +0.5 (V) = 2.5 (V) is applied to the terminal 155. Therefore, even if the output voltage (current) of the source driver IC 14 is a rail-to-rail output, the IC withstand voltage needs to be 2.5 (V). The required amplitude range of the output terminal 155 needs to be 2.5 (V) or more.

  From the above, it is preferable to use a process with a breakdown voltage of the source driver IC 14 of 2.5 (V) to 15 (V). More preferably, the source driver IC 14 has a withstand voltage of 3 (V) or more and 12 (V) or less. More preferably, the minimum breakdown voltage is 4.5 (V) or more from the viewpoint of relatively increasing the amplitude value of the driving transistor 11a, increasing the gate terminal voltage change of the transistor 11a with respect to the program current, and improving the program accuracy. It is preferable to make it. The IC withstand voltage is equivalent to the maximum power supply voltage that can be used. The power supply voltage that can be used is a voltage that can be used at all times and is not an instantaneous withstand voltage.

  In the above explanation, the withstand voltage process of the source driver IC 12 is assumed to be a process of 2.5 (V) or more and 13 (V) or less. However, this withstand voltage is also applied to an embodiment (such as a low-temperature polysilicon process) in which the source driver circuit 14 is formed directly on the array substrate 30. The use withstand voltage of the source driver circuit 14 formed on the array substrate 30 may be as high as 15 (V) or more. In this case, the power supply voltage used for the source driver circuit 14 may be replaced with the IC withstand voltage shown in FIG. Even in the source driver IC 14, the IC withstand voltage may be replaced with the power supply voltage to be used.

  The reason why the unit transistor 154 needs to have a constant transistor size is that the wafer has a mobility characteristic distribution.

  The channel width W of the unit transistor 154 correlates with variations in output current. FIG. 51 is a graph when the area of the unit transistor 154 is constant and the transistor width W of the unit transistor 154 is changed. In FIG. 51, the variation of the channel width W = 2 (μm) of the unit transistor 154 is 1.

As shown in FIG. 51, the variation ratio of the unit transistor gradually increases from 2 (μm) to 9 to 10 (μm), and the increase of the variation ratio tends to increase when it is 10 (μm) or more. Also, the variation ratio tends to increase when the channel width W = 2 (μm) or less.
In FIG. 51, the variation ratio within 3 is a variation allowable range in 64 gradation to 256 gradation display. However, this variation ratio varies depending on the area of the unit transistor 154. However, even if the area of the unit transistor 154 is changed, there is almost no difference in the variation tendency of the variation ratio with respect to the IC breakdown voltage.

  From the above, the channel width W of the unit transistor 154 is preferably 2 (μm) or more and 10 (μm) or less. More preferably, the channel width W of the unit transistor 154 is 2 (μm) or more and 9 (μm) or less. Further, the channel width W of the unit transistor 154 is preferably formed in the above range in order to prevent linking of the gate wiring 153 in FIG.

  53 is a graph of L / W of the unit transistor 154 and a deviation (variation) from the target value. When the L / W ratio of the unit transistor 154 is 2 or less, the deviation from the target value is large (the slope of the straight line is large). However, as L / W increases, the deviation of the target value tends to decrease. When the L / W of the unit transistor 154 is 2 or more, the change in deviation from the target value is small. The deviation (variation) from the target value is L / W = 2 or more and 0.5% or less. Therefore, it can be adopted in the source driver circuit 14 as transistor accuracy.

  From the above, it is preferable that the L / W of the unit transistor 154 is 2 or more. However, large L / W means that L becomes long, so that the transistor size becomes large. Therefore, L / W is preferably 40 or less. More preferably, L / W is preferably 3 or more and 12 or less.

  The reason why the output variation becomes small when L / W is a relatively large value is considered to be that the gate voltage of the corresponding unit transistor 154 becomes high and the change in the output current with respect to the change in the gate voltage becomes small.

  The magnitude of L / W also depends on the number of gradations. When the number of gradations is small, there is no problem even if the output current of the unit transistor 154 varies due to the kink because the difference between the gradations is large. However, in a display panel having a large number of gradations, since the difference between gradations is small, the number of gradations is reduced if the output current of the unit transistor 154 varies even slightly due to the influence of kink.

In consideration of the above, the driver circuit 14 according to the present invention has the number of gradations as K and L / W of the unit transistor 154 (L is the channel length of the unit transistor 154 and W is the channel width of the unit transistor). ,
(√ (K / 16)) ≦ L / W ≦ (√ (K / 16)) × 20
It is configured (formed) to satisfy this relationship.

  In the case of 64 gradations (6 bits for each of RGB), 63 unit transistors 154 are formed. Therefore, in the case of 256 gradations (8 bits for each of RGB), 255 unit transistors 154 are required.

  The current driving method has a characteristic effect that current can be added. Further, in the unit transistor 154, if the channel length L is made constant and the channel width W is halved, there is a characteristic effect that the current flowing through the unit transistor 154 becomes about ½ (there is a characteristic configuration). ). Similarly, if the channel length L is made constant and the channel width W is made 1/4, there is a characteristic effect that the current flowing through the unit transistor 154 becomes about 1/4.

  FIG. 55B shows a configuration of a transistor group 431c in which unit transistors 154 having the same size are arranged for each bit. For ease of explanation, it is assumed that FIG. 55A includes 63 unit transistors 154 and configures (forms) a 6-bit transistor group 431c. FIG. 55 (b) is 8 bits.

  In FIG. 55 (b), the lower 2 bits (indicated by A) are composed of transistors having a size smaller than that of the unit transistor 154. The 0th bit of the minimum bit is formed by 1/4 of the channel width W of the unit transistor 154 (indicated by the unit transistor 154b). The first bit is formed with a half of the channel width W of the unit transistor 154 (indicated by the unit transistor 154a).

  As described above, the lower 2 bits are formed by unit transistors (154a, 154b) having a size smaller than that of the upper unit transistor 154. Further, the number of regular unit transistors 154 is 63, which is not changed. Therefore, even if the bit size is changed from 6 bits to 8 bits, the formation area of the transistor group 431c is not significantly different between FIG. 55A and FIG.

  As shown in FIG. 55B, the size of the output stage transistor group 431c does not increase even when the 6-bit specification is changed to the 8-bit specification because the current can be added. This is because if the length L is constant and the channel width W is 1 / n, the current flowing through the unit transistor 154 is approximately 1 / n.

  As shown in FIG. 55B, when the transistor size is reduced as in the unit transistors 154a and 154b, the output current variation is also increased. However, no matter how large the variations are, the output currents of the unit transistors 154a or 154b are added. Therefore, the 8-bit specification of FIG. 55 (b) can realize higher gradation output than the 6-bit specification of FIG. 55 (a). Of course, since the output variations of the unit transistors 154a and 154b are large, there is a possibility that accurate 8-bit display cannot be realized. However, it is possible to realize a high-definition display as compared with FIG.

  Actually, even if the channel width W is halved, the output current is not exactly halved. Some correction is required. In the correction, a correction coefficient can be easily grasped by forming a test transistor and measuring it.

  In the present invention, in order to produce (configure) a lower bit, a small unit transistor smaller than the unit transistor 154 of the upper bit is formed or arranged. This concept of small means that it is smaller than the output current of the unit transistor 154 constituting the upper bit. Therefore, not only the channel width W is smaller than that of the unit transistor 154, but also the case where the channel length L is also small is included. Other shapes are also included.

  FIG. 55 shows a plurality of types of unit transistors 154 constituting the transistor group 431c. In FIG. 55, there are two types. The reason for the two types is that if the size of the unit transistor 154 is different, the magnitude of the output current is not proportional to the shape, which makes it difficult to design. Therefore, the size of the unit transistor 154 included in the transistor 431c is preferably two types for low gradation and high gradation. However, the present invention is not limited to this. Needless to say, there may be three or more types.

  As shown in FIG. 43, the gate terminals of the unit transistors 154 constituting the transistor group 431 c are connected by one gate wiring 153. The output current of the unit transistor 154 is determined by the voltage applied to the gate wiring 153. Therefore, if the unit transistors 154 in the transistor group 431c have the same shape, each unit transistor 154 outputs the same unit current.

  The present invention is not limited to the common gate wiring 153 of the unit transistors 154 constituting the transistor group 431c. For example, it may be configured as shown in FIG. In FIG. 56A, a unit transistor 154 that forms a current mirror with the transistor 158b1, and a unit transistor 154 that forms a current mirror with the transistor 158b2.

  The transistor 158b1 is connected to the gate wiring 153a. The transistor 158b2 is connected to the gate wiring 153b. In FIG. 56A, the uppermost unit transistor 154 is LSB (0th bit), and the second stage two unit transistors 154 are the first bit and the third stage four unit transistors. 154 is the second bit. The eight unit transistors 154 in the fourth set are the third bit.

  In FIG. 56A, by changing the applied voltage of the gate wiring 153a and the gate wiring 153b, the output current of each unit transistor 154 is changed to the current of the gate wiring 153 even if the size and shape of each unit transistor 154 are the same. It can be changed (changed) by the applied voltage.

  56A, the unit transistors 154 have the same size and the like, and the voltages of the gate wirings 153a and 153b are different. However, the present invention is not limited to this. The unit transistors 154 may have different sizes and the like, and by adjusting the voltages of the gate wirings 153a and 153b to be applied, the output currents of the unit transistors 154 having different shapes may be made the same.

  In FIG. 55, the size of the unit transistor 154 constituting the low gradation bit is made smaller than the unit transistor 154 constituting the high gradation. As the size of the unit transistor 154 decreases, the output variation increases. In order to solve this problem, in practice, the unit transistor 154 having a low gradation has a channel length L larger than that of the high gradation, so that the area of the unit transistor 154 is not reduced, thereby suppressing variations.

  As shown in FIG. 57, when the size of the unit transistor 154 in the range of the low gradation region A is different from the size of the unit transistor 154 in the range of the high gradation region B, the output variation is a combination of two curves. Become. However, there is no problem in practical use. On the contrary, it is preferable that the size of the unit transistor 154 in the low gradation part is larger than the size of the unit transistor 154 in the high gradation part, so that the output variation per unit transistor 154 can be reduced.

  With the configuration as shown in FIG. 56, the output current of the unit transistor 154 can be made the same by adjusting the voltage applied to the gate wiring 153 regardless of the size of the unit transistor 154 of low gradation and high gradation.

  In the present invention, the gate wiring 153 is described as two types of 153a and 153b, but is not limited thereto. There may be three or more types. Also, the unit transistor 154 may have three or more shapes.

  FIG. 56B shows an embodiment in which the unit transistors 154 have the same size and are constituted by two gate wirings 153. The top two unit transistors 154 in FIG. 56B are LSB (0th bit), and the four unit transistors 154 in the second stage are the eight unit transistors in the first bit and the third stage. The group of 154 is the second bit. The fourth set of eight unit transistors 154 connected to the gate wiring 153b is the third bit.

  In FIG. 56B as well, by changing the applied voltage of the gate wiring 153a and the gate wiring 153b, the output current of each unit transistor 154 is changed to the gate wiring 153 even if the size and shape of each unit transistor 154 are the same. It can be changed (changed) by the applied voltage.

  In FIG. 56B, one output current of the unit transistor 154a connected to the gate wiring 153a corresponding to the low gradation part is the output current of the unit transistor 154 connected to the gate wiring 153b corresponding to the high gradation part. It is configured to be 1/2. The unit transistor 154a and the unit transistor 154 have the same shape.

  In order to make the output current of the unit transistor 154a ½ that of the unit transistor 154, the voltage applied to the gate wiring 153a is set lower than that of the gate wiring 153b. By adjusting the voltage applied to the gate wiring 153, the output current can be changed or adjusted even when the unit transistor 154a and the unit transistor 154 have substantially the same shape.

  In the embodiment of FIG. 56, it has been described that the voltage applied to the gate wiring 153 is changed. It goes without saying that the voltage applied to the gate wiring 153 can also be applied from outside the source driver IC (circuit) 14. However, in general, the voltage or voltage of the gate wiring 153 can be adjusted or changed by changing or designing or configuring the configuration or size of the transistor 158b (transistor group 431b) forming a current mirror pair with the unit transistor 154. . It goes without saying that the current Ic flowing through the transistor 158b (transistor group 431b) forming a current mirror pair with the unit transistor 154 can be changed or adjusted.

  In FIG. 58, unit multipliers 154a (D2, D3, D4,...) On the high gradation side are arranged with a multiplier of 2. On the other hand, unit transistors 154b (D1, D2) on the low gradation side are also arranged with a multiplier of 2. The unit transistor 154a and the unit transistor 154b have different unit output currents (the unit current of 154b is smaller than 154a. For example, the unit transistor W is narrower on the low gradation side). The low gradation side and high gradation side unit transistors 154 are connected by a common gate wiring 153, and are controlled by a reference current Ic flowing in the transistor 158b constituting the current mirror circuit.

  In FIG. 59, unit transistors 154a (D2, D3, D4,...) On the high gradation side are arranged with a multiplier of 2. On the other hand, unit transistors 154b (D1, D2) on the low gradation side are also arranged with a multiplier of 2. The unit transistor 154a on the high gradation side forms a current mirror circuit with the transistor 158bh. The reference current flowing through the transistor 158bh is Ich. On the other hand, the unit transistor 154b on the low gradation side forms a current mirror circuit with the transistor 158bl. The reference current flowing through the transistor 158bl is Icl.

  With the above configuration, the unit output currents of the unit transistor 154a and the unit transistor 154b are made different (the unit current of 154b is smaller than 154a). The low gradation side and high gradation side unit transistors 154 are connected by different gate wirings 153.

  As described above, there are many modified embodiments in the present invention. For example, the combination of FIG. 58 and FIG. 59 is also illustrated. It goes without saying that the above matters can be applied to other embodiments of the present invention. Further, some unit transistors 154 may be made larger or smaller.

  The unit transistors 154 constituting the unit transistor group 431c and the transistors 158b constituting the transistor group 431b are preferably constituted (formed) by N-channel transistors. This is because the N channel transistor has less output variation per unit transistor area than the P channel transistor. Therefore, the source driver IC size can be reduced by configuring the unit transistors 154 and the like with N channels.

  Note that forming the unit transistor 154 with an N channel makes the source driver IC 14 a sink type (sink current method). Therefore, the driving transistor 11a of the pixel 16 is preferably composed of a P-channel transistor.

  The graph of FIG. 159 shows the output variation when the size (WL) of the P-channel transistor and the N-channel transistor are the same and the output current is the same. The horizontal axis represents the area ratio of the total area Sc of the transistor group 431c constituting one output. The larger the area Sc, the smaller the output variation.

  The vertical axis represents the output variation ratio. In FIG. 159, the output variation is 1 when the total area Sc of the N-channel transistors is 1.

  As shown in FIG. 159, when the total area Sc of the N-channel transistors is quadrupled, the output variation becomes 0.5. When the total area Sc of the N-channel transistor is 8 times, the output variation becomes 0.25. That is, the output variation is proportional to 1 / √Sc from the result of the present invention.

  When the total area Sc of the N-channel transistor and the total area Sc of the P-channel transistor are the same, the output variation is 1.4 times. When the total area Sc of the P-channel transistor is twice the total area Sc of the N-channel transistor, the output variation is the same. That is, the output variation has a relationship of the total area Sc / 2 of the N-channel transistor = the total area Sc of the P-channel transistor.

  From the above results, the unit transistor 154 constituting the unit transistor group 431c and the transistor 158b constituting the transistor group 431b are preferably constituted (formed) by N-channel transistors.

  The output stage is formed of unit transistors 154 and the like, and the transistor group 431c and the transistor group including the transistor 158b or the transistor 158b constitute a current mirror circuit. By bringing the transistor 154c and the transistor 158b close to each other, the current mirror ratio becomes almost a constant value. However, it may vary within the range of variation. In this case, as shown in FIG. 160, it is effective to cut off the transistor 158b and adjust the current mirror ratio within a predetermined range by trimming (laser trimming, sandblast trimming, etc.).

  Trimming is performed at point A in FIG. 160, and the transistor 158b2 is disconnected. A large number of transistors 158b are formed, and one or more of the plurality of transistors 158b are swept away, whereby the current mirror ratio can be increased.

  Note that preferably, a transistor 158 b is formed or arranged on both sides of the wiring 153 as illustrated in FIG. 161. By cutting the trimming point, A1 or A2, the difference in output current from the output terminals 155a and 115n of the IC chip is made uniform.

  In order to adjust the output variation of the transistor 431c in each output stage, it is effective to configure as shown in FIG. In FIG. 162, a high resistance 1623 is formed or disposed between each output transistor group 431 c (not limited to a transistor group; any configuration is acceptable as long as it is a current output circuit) and a gate wiring 153. Since the resistance is high, even if the output current from the output stage is very small, the voltage drops at the resistor 1623. The output current can be changed by the voltage drop.

  The trimming of the resistor 1623 is performed with a laser beam 1622 from the trimming device 1621. The resistor 1623 is trimmed and adjusted to a high resistance value.

  In the embodiment of the present invention, the transistor group 431c is composed of the unit transistors 154, but the present invention is not limited to this. A single transistor or a current holding circuit (described later) may be used. Alternatively, a voltage-current conversion (VI conversion) circuit may be used. That is, in this specification, the output stage is described as being configured by the transistor group 431c, but the present invention is not limited to this, and any configuration may be used as long as it is a current output circuit.

  In FIG. 163, the transistor 157b and the plurality of transistors 158a constitute a current mirror circuit, and the transistor 158a and the transistor 158b constitute a current mirror circuit. The transistors 158b and 431c also form a current mirror circuit.

  The configuration as shown in FIG. 163 is also within the scope of the present invention. Adjustment by trimming may be performed on the transistor 158b or the transistor group 431c in each output stage.

  As another configuration, the configuration in FIG. 164 is also exemplified. FIG. 164 conceptually shows the output stage of the source driver IC of the present invention. The potential of the gate wiring 153a is determined (adjusted) by the reference voltage (or IC (circuit) 14 power supply voltage) Vs and the external resistors Ra and Rb.

  Each output stage forms a current circuit with a resistor Rn and transistors 158a and 158b. The current flowing through the current circuit is determined by the resistor Rn. The transistor 158b and the transistor group 431c constitute a current mirror circuit. The current output from the output terminal 155 of the transistor group 431c is performed by trimming the resistor Rn. By laser trimming the resistor Rn, the current flowing through the current mirror circuit (the transistor 158b and the transistor group 431c) can be adjusted. Of course, the transistors 158a and 158b may constitute a transistor group.

  In order to adjust the slopes of the output currents on the left and right of the IC chip (in order to make the output terminals 155a to 155n the same (so that there is no output variation), the configuration of Fig. 165 is also exemplified. Current Ic1 path of the transistor 158b The resistor Ra and the resistor Rb are arranged in the current Ic2 path of the transistor 158b, and the resistors Ra and Rb may be built-in or externally connected to the gate by trimming Ra or Rb or both Ra and Rb. The current Id flowing through the wiring 153 changes, so that the voltage drop of the gate wiring 153 changes the potential of the gate signal line of the unit transistor 154 in the output stage 431. Accordingly, the slope distribution of the output currents in the output stages 431a to 431n. Can be corrected.

  Note that the concept of trimming includes volume. For example, in FIG. 165, the magnitudes of the current Id can be adjusted by forming (arranging) the resistors Ra and Rb with volume and adjusting the volume. Further, when the resistance is a diffusion resistance, the resistance value can be adjusted or changed by heating. For example, the resistance value can be changed by irradiating the resistor with laser light and heating it. Further, by heating the IC chip entirely or partially, the resistance value formed or configured in the IC chip can be adjusted or changed in whole or in part.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. Trimming means element trimming for changing resistance values or function trimming for changing functions, cutting trimming for separating elements such as transistors from wiring, divided trimming for dividing one resistance element into a plurality of parts, and laser light at non-connected portions. Trimming for short-circuiting and connecting by irradiating and adjusting trimming for adjusting the resistance value of a volume or the like. In the case of a transistor, examples include changing the S value, changing μ, changing the WL ratio to change the magnitude of the output current, and changing the rising voltage position. In addition, changing the oscillation frequency and changing the cutoff position are also included. That is, trimming is a concept of processing, adjustment, and change. The above matters are the same in other embodiments of the present invention.

  As another configuration, the configuration in FIG. 166 is also exemplified. FIG. 166 conceptually shows the output stage of the source driver IC of the present invention. The potential of the gate wiring 152a is determined (adjusted) by the electronic volume circuit 501 and the operational amplifier 502. The operational amplifier 502, the resistor R1, and the transistor 158a constitute a constant current circuit. A reference current Ic flows through the resistor R1. The value of the current flowing through R1 is determined by the voltage applied to the positive terminal of the operational amplifier 502 and the resistance value R1. Therefore, the magnitude of the reference current Ic can be changed by trimming the resistor R1. The magnitude of the output current from the output terminal 155 can be changed or adjusted by the change. The resistor R1 may be an external resistor and may be a volume. Also, an electronic volume circuit may be used. Moreover, you may input in analog.

  The output voltage from the operational amplifier 502 is applied to the gate terminals of the plurality of transistors 158a, and a current Ic flows through the resistor R1. This current Ic is divided and flows to the transistor 158b. With this current, the gate wiring 153b is set to a predetermined potential. The potential is fixed by the transistor 158b in which the gate wiring 153b is arranged at a plurality of locations. Therefore, a potential gradient is hardly generated in the gate wiring 153b, and output variation from the output terminal 155 is reduced.

  In the above embodiment, as shown in FIG. 43, unit transistors 154 are formed corresponding to gradation bits, and output is performed by changing the number of unit transistors 154 that are turned on (output current to the terminal 155). The current is changed. For example, in FIG. 43, 32 unit transistors 154 are arranged in the D5 bit, one unit transistor 154 is arranged (formed) in the D0 bit, and two unit transistors are arranged in the D1 bit. 154 is arranged (formed).

  However, the present invention is not limited to this. For example, as shown in FIG. 167, each bit may be composed of transistors having different sizes. In FIG. 167, the transistor 154b outputs approximately twice the current of the transistor 154a, and the transistor 154f outputs approximately twice the current of the transistor 154e. As described above, the present invention is not limited to the case where the output stage 431c includes the unit transistor 154.

  FIG. 165 shows a structure in which both ends of the gate wiring 153 are held by the transistors 158b, and FIG. 166 shows a structure in which potentials are held by the plurality of transistors 158b in the gate wiring 153. The present invention is not limited to this. For example, as illustrated in FIG. 168, one end of the gate wiring 153 may be held by a transistor 1681, and the potential gradient of the gate wiring 153 may be adjusted by a current Id flowing through the transistor 1681. In the transistor 1681, the current flowing by the divided voltage of the resistors Ra and Rb connected to the gate terminal is adjusted. The resistor Rb is configured as a volume, or the resistance value is adjusted by trimming. Basically, the current flowing through the transistor 1681 is very small. However, as a special operation method, a method in which the potential of the gate wiring 153 is lowered to near the ground voltage by completing the transistor 1681 is exemplified. By reducing the gate wiring 153 to near the ground voltage, the unit transistors 154 of the transistor group 431c can be turned off. In other words, the output current of the output terminal 155 can be on / off controlled by the operation of the transistor 1681.

  In the above embodiment, the output current or the like is changed, changed, or adjusted by trimming or adjusting the transistors (158, 154, etc.). Specifically, the transistor to be adjusted is preferably configured as shown in FIG. FIG. 169 conceptually illustrates the structure of the transistor 1694 to be adjusted. The transistor 1694 includes a gate terminal 1692, a source terminal 1691, and a drain terminal 1693. The drain terminal 1693 is divided into a plurality of pieces (drain terminals 1693a, 1693b, 1693c,...) So as to be easily trimmed. By cutting along line A in FIG. 169 (a), the drain terminal 1693e is cut and the output current of the transistor 1693 can be reduced.

  FIG. 169 (b) shows an example in which the trimming interval of the drain terminal 1693 is changed. In accordance with the magnitude of the current to be reduced, one or more drain terminals 1693 are trimmed to adjust the output current. In FIG. 169 (b), the line B is trimmed.

  FIG. 170 is a modification of FIG. FIG. 170A shows an example in which the gate terminal 1692 is divided into 1692a and 1692b. FIG. 170B shows an example in which trimming portions (C line and D line) are provided in the drain terminal 1693 and the source terminal 1691.

  In the above embodiments, the drain terminal 1693 or the source terminal 1691 is trimmed at one place or a plurality of places, but the present invention is not limited to this. For example, the gate terminal 1692 may be trimmed. Further, the invention is not limited to trimming. Needless to say, output current or the like may be adjusted by irradiating the semiconductor film of the transistor 1694 with laser light or thermal energy to degrade the transistor 1694. Further, it is needless to say that the embodiments of FIGS. 169 and 170 are not limited to transistors, but may be applied to diodes, crystals, thyristors, capacitors, resistors, and the like.

  As shown in FIG. 167, when the transistor size is different for each bit (such as when proportional to the bit size), the trimming length (such as the drain length) is also proportional to the bit size. It is preferable to configure as described above. This embodiment is shown in FIGS. 175 (a) (b) (c).

  In FIGS. 175 (a) (b) (c), FIG. 175 (a) is the lower bit and FIG. 175 (c) is the upper bit. FIG. 175 (b) shows the state (configuration) of the intermediate bits in FIGS. 175 (a) and 175 (c). The lower bit trimming length A is configured to be shorter than the upper bit trimming length C. The trimming length is proportional to the current change amount of the transistor. Therefore, the upper bit transistor is configured to have a larger trimming change amount. As described above, it goes without saying that the present invention may be changed according to the size of the transistor, the bit position, and the like. That is, it is not limited to making it uniform for each bit.

  FIG. 43 shows an example in which the required number of unit transistors 154 are formed or arranged for each bit. However, the unit transistor 154 has a variation in formation. For this reason, the output from the output terminal 155 varies. In order to reduce this variation, it is necessary to adjust the output current of each bit. To adjust the output current, an extra unit transistor 154 is formed in advance, and the extra unit transistor 154 may be adjusted by disconnecting from the output terminal 155. The extra unit transistors 154 need not have the same size as the other unit transistors 154. It is preferable that the extra unit transistor 154 is formed smaller (ie, the shared output current is reduced).

  FIG. 171 shows the embodiment described above. Three unit transistors 154 are formed in the D0 bit. Of the three, one is a regular unit transistor 154, and the other two are unit transistors 154 that are adjusted by trimming and are disconnected when necessary (referred to as adjustment transistors rather than unit transistors 154). .

  Similarly, four unit transistors 154 are formed in the D1 bit. Of the four, two are regular unit transistors 154, and the other two are unit transistors 154 that are adjusted by trimming and are disconnected when necessary (adjustment transistors rather than unit transistors 154). . Similarly, eight unit transistors 154 are formed in the D2 bit. Of the eight, four are regular unit transistors 154 and the other four are unit transistors 154 that are adjusted by trimming and are disconnected when necessary (adjustment transistors rather than unit transistors 154). .

  As described above, the adjustment transistor 154 (indicated by B in FIG. 171) is trimmed to adjust the output current. The transistor indicated by B is arranged on the line indicated by the arrow A. Therefore, when scanning with a laser beam or the like, the adjustment transistor can be trimmed only by moving the scanning direction in one direction. Therefore, high-speed trimming can be performed.

  In the above embodiment, the output stage is configured by the unit transistor 154 and the like. However, the method of adjusting the output current by trimming or the like is not limited to this. As shown in FIG. 172, the present invention can also be applied to an embodiment in which an output stage connected to each output terminal 155 is formed by an operational amplifier 502, a transistor 158b, and a resistor R1.

  In each output stage illustrated in FIG. 172, an operational amplifier 502, a transistor 158b, and a resistor R1 form a current circuit. The magnitude of the current is adjusted by the resistor R1, and the gradation is expressed by a gradation voltage output from the circuit 862.

  Each output stage illustrated in FIG. 172 is trimmed by being irradiated with laser light 1622 or the like by a laser device 1621 or the like. By sequentially trimming the resistor R1 corresponding to each output stage, variations in output current can be prevented.

  Note that in FIG. 172, the output current is determined by the analog voltage output from the circuit 862. However, the present invention is not limited to this, and it goes without saying that digital 8-bit digital data may be converted into an analog voltage by the DA circuit 661 and applied to the operational amplifier 502a as shown in FIG. .

  In addition, as illustrated in FIG. 209, the output stage may be configured by a current mirror circuit including a transistor 154 configured to have a one-to-one relationship with a transistor 158b that supplies a current Ic corresponding to video data. Each output stage includes a current circuit including a DA circuit 501, an operational amplifier 502, a built-in resistor R1, a transistor 158a, and the like. The output variation can be made extremely small by trimming the resistor R1.

  FIG. 210 is a configuration similar to that of FIG. A current Ic corresponding to the video data is supplied from the sampling circuit 862 to the transistor 158b. The transistor 158b and the transistor 154 constitute an N-fold current mirror circuit.

  In FIG. 172, the resistor R1 is sequentially trimmed as necessary, but the present invention is not limited to this. For example, as shown in FIG. 173, it goes without saying that the output stage 431c may be trimmed as necessary. In determining the necessity of trimming, the terminal 155 is brought into contact with the inspection terminal 1734 and the like, and connected to an ammeter (current measuring means) 1733 via the selection switch 1731 and the common line 1732. The selection switch 1731 is sequentially turned on, and the current from the output stage 431 c is applied to the ammeter 1733. The trimming means 1632 trims unit transistors, resistors, and the like based on the measured current value of the ammeter 1733 and adjusts them to a predetermined value.

  In the above embodiment, the output current variation or the like is changed or adjusted by trimming the current output stage or the like. However, the present invention is not limited to this. For example, as shown in FIG. 176, it is needless to say that the reference current Ic may be adjusted and the output current may be changed or adjusted by trimming resistors Ra and Rb that generate the reference current or set a predetermined value. .

  In the circuit configuration shown in FIG. 60 and the like, white balance adjustment is easy. First, the RGB electronic volume 501 is adjusted to the same set value. Next, the white balance is adjusted by adjusting the external resistors R1r, R1g, and R1b.

  The current driver IC (circuit) 14 is characterized in that if white balance is achieved with any electronic volume setting value, the luminance of the display screen 144 can be adjusted while maintaining the white balance if the value of the electronic volume 501 is the same. There is. Reference numeral 601 denotes a reference current circuit.

  FIG. 60 shows a configuration in which power is supplied from both sides of the transistor group 431c, but the above items are not limited to this. As shown in FIG. 61, the same applies to the one-side power feeding configuration. First, the R, G, B electronic controls 501 are set to the same setting value, and the external resistors R1r, R1g, R1b are adjusted to achieve white balance. Generally, white balance is achieved by setting Icr of the R circuit, Icg of the G circuit, and Icb of the B circuit to a predetermined ratio in consideration of the light emission efficiency of each RGB EL element.

  The current driver IC (circuit) 14 is characterized in that if the white balance is set at a set value of some electronic volume, the luminance of the display screen 144 can be adjusted while maintaining the white balance if the value of the electronic volume 501 is made the same. There is. In addition, although it is preferable to form or arrange | position R, G, and B independently, the electronic volume of RGB is not limited to this. For example, it is possible to adjust the screen brightness while maintaining white balance even with one electronic volume 501 for R, G, and B.

  In the present invention, by forming or arranging an electronic volume inside the source driver IC (circuit) 14, the reference current can be varied or changed by digital data control from the outside of the source driver IC (circuit) 14. . This matter is an important matter in the current drive driver. In current driving, video data is proportional to the current flowing through the EL element 15. Therefore, the current flowing through all the EL elements can be controlled by performing logic processing on the video data. Since the reference current is also proportional to the current flowing through the EL elements 15, the current flowing through all the EL elements 15 can be controlled by digitally controlling the reference current. From the above, by performing the reference current control based on the video data, it is possible to easily realize the expansion of the dynamic range of display luminance.

  By changing or changing the reference current, the output current of the unit transistor 154 can be changed. For example, when the reference current Ic is 100 μA, the output current when one unit transistor 154 is on is 1 μA. In this state, if the reference current Ic is 50 μA, the output current of one unit transistor 154 is 0.5 μA. Similarly, if the reference current Ic is 200 μA, the output current of one unit transistor 154 is 2.0 μA. That is, it is preferable that the reference current Ic and the output current Id of the unit transistor 154 satisfy a proportional relationship (see a solid line a in FIG. 62).

  The setting data for setting the reference current Ic and the reference current Ic are preferably configured to have a proportional relationship. For example, when the setting data is 1, the reference current Ic is 100 μA, and if this is the base, the reference current Ic is 200 μA when the setting data is 100. That is, it is preferable that the reference current Ic increase by 1 μA when the setting data increases by one.

  With the configuration described above, the RGB reference currents (Icr, Icg, Icb) can be changed while maintaining a linear relationship according to the setting data of the electronic volume 501. Accordingly, since the linear relationship is maintained, if the white balance is adjusted at any setting data, the white balance is maintained at any setting data. In this configuration, it is important to configure the white balance by adjusting the external resistors R1r, R1g, and R1b described above (this is a characteristic configuration).

  In the above embodiment, the white balance is adjusted by an external resistor, but it goes without saying that the resistor R1 may be built in the IC chip.

  Further, as shown in FIG. 63, a switch S for adjusting or controlling the resistance value may be added. For example, in FIG. 63 (a), the external resistor is R1 due to the selection of the switch S1. Further, the external resistor becomes R2 depending on the selection of the switch S2. Further, by selecting both the switches S1 and S2, the external resistance becomes a resistance value in which R1 and R2 are connected in parallel.

  FIG. 63B shows a configuration in which resistors R1 and R2 are connected in series, and an external resistor can be set to R1 + R2 or R1 by the control of the switch S.

  With the configuration as shown in FIG. 63, the change range of the reference current Ic can be expanded. That is, the reference current can be adjusted not only by the setting data of the electronic volume 501 but also by the control of the switch S. Therefore, the luminance adjustment range (dynamic range) of the EL display panel of the present invention can be expanded.

  In the present invention, the change in the reference current due to the one-step change in the electronic volume 501 is set to about 3%. For example, if the reference current changes from 1 to 3 times and the number of steps of the electronic volume is 64 steps of 6 bits, (3-1) /64=0.03, which is about 3%.

  If the change in the reference current per step is large, the change in luminance of the display screen 144 when the electronic volume is changed is large, and the change is recognized as flicker. Conversely, if the change in the reference current per step is small, the change in luminance of the display screen 144 is small and the dynamic change in luminance adjustment is poor. In addition, increasing the number of steps is directly connected to increasing the size of the electronic volume 501, which increases the size of the source driver IC 14 and increases the cost.

  From the above, it is preferable that the change in the reference current per step is in increments of 1% or more and 8% or less (although it is based on the base). Furthermore, it is preferable to make a unit of 1% or more and 5% or less. For example, if the electronic volume 501 is 8 bits (256 steps) and the change in the reference current is from 1 to 10 times, (10-1) /256=3.5% increments, and the condition is 1% or more and 5% or less. Is satisfied.

  In the above embodiment, the change in the reference current per step has been described. However, since the change in the reference current is a change in screen luminance, the change in the display screen 144 luminance per step of the electronic volume 501 or the anode (or cathode). It goes without saying that it can be rephrased as a change in current.

  In the above embodiment, as shown by the solid line a in FIG. 62, it is preferable that the reference current Ic and the output current Id of the unit transistor 154 satisfy the proportional relationship, but the present invention is not limited to this. For example, as indicated by a dotted line b in FIG. 62, non-linearity (preferably in the range of 1.8 to 2.8) may be used. By making it non-linear (preferably in the range of 1.8 to 2.8), the change in the reference current with respect to the design data of the electronic volume 501 approaches the square curve of human visual characteristics, so the gradation characteristics are good It becomes.

  In the above embodiment, the reference current is changed by the setting data of the electronic volume 501. However, the present invention is not limited to this. Needless to say, the reference current may be changed, adjusted, or controlled by the voltage input / output terminal 643 as shown in FIGS.

  The electronic volume 501 shown in FIGS. 50, 60, 61 and the like may be configured as shown in FIG. In FIG. 64, a ladder resistor 641 (resistance array or transistor array) and a switch 642 correspond to the electronic volume 501. Note that the ladder resistor 641 may be any means that generates a voltage at a constant interval or a predetermined interval. For example, it goes without saying that the transistor may be diode-connected, or may be configured or formed by the on-resistance of the transistor.

  Needless to say, the configuration and method including the ladder resistor 641 and the switch circuit 642 described above or the configuration and method of the voltage input / output terminal 643 can be applied to the precharge configuration shown in FIG. Further, the present invention can be applied to the color management processing configuration shown in FIGS. 146 and 147. Needless to say, the present invention can also be applied to the voltage program configuration shown in FIGS. 140, 141, 143, and the like.

  The configurations of FIGS. 64 and 65 can also be applied to the configurations of FIGS. 56 and 57. Further, the present invention can also be applied to a configuration in which a reference current is applied from both sides of a source driver IC (circuit) 14 as shown in FIG. Needless to say, the present invention can also be applied to FIGS.

  In FIG. 64, a transistor 158ar generates a reference current Icr for the R circuit, and a transistor 158ag generates a reference current Icg for the G circuit. The transistor 158ab generates a reference current Icb for the B circuit.

  In FIG. 64, the ladder resistor 641 is shared by the three RGB switch circuits (642r, 642g, 642b). Therefore, the formation area of the ladder resistor 641 in the source driver IC (circuit) 14 can be reduced.

  Also in FIGS. 64 and 65, the RGB reference currents (Icr, Icg, Icb) can be changed while maintaining the linear relationship according to the setting data of the switch circuit 642. Accordingly, since the linear relationship is maintained, if the white balance is adjusted at any setting data, the white balance is maintained at any setting data. In this configuration, white balance can be achieved by adjusting the external resistors R1r, R1g, and R1b described above.

  In FIG. 64, a voltage input / output terminal 643 is a terminal for inputting an analog voltage from the outside of the driver IC (circuit) 14. The reference current Ic can be changed or adjusted by the analog voltage. Therefore, white balance adjustment and display screen 144 brightness adjustment can be performed without using the switch circuit 642.

  FIG. 346 is a modification of FIG. In FIG. 346, the electronic volume 501 is shared by the reference current generation circuit (RGB circuit) for red, green, and blue, and the reference current of RGB is set to a built-in or external resistor R (red R1, green R2, and blue R3). ) Or the white balance is maintained by adjusting the internal resistance of the source driver circuit (IC) 14. When the resistor R is built-in, the white balance is adjusted by trimming or the like. Of course, it goes without saying that the external resistor R may be a volume.

  The resistor R may have any configuration as long as it is a means for adjusting or setting the reference current. Nonlinear elements such as Zener diodes, transistors, and thyristors may be used. Further, it may be a circuit or an element such as a constant voltage regulator or a switching power supply. Instead of the resistor R, an element such as a posistor or thermistor may be used. The temperature compensation can be performed simultaneously with the adjustment or setting of the reference current. In addition, a constant current circuit that generates a reference current may be used.

  In FIG. 346, the internal switch of the electronic volume 501 is designated by IDATA (data for setting the reference current), and the Vx voltage (voltage for setting the reference current) is output from the electronic volume 501. The Vx voltage is applied to the positive terminal of the operational amplifier 502 (red 502R, green 502R, blue 502R). Therefore, the red reference current Icr = Vx / R1, the green reference current Icr = Vx / R2, and the blue reference current Icr = Vx / R3. A white balance is obtained with these reference currents. Also, the magnitudes of the RGB program currents are determined based on these reference currents (see FIGS. 60 and 61). The reference current need only be set at a relatively long period, such as every frame (one field). This is because it is sufficient to set corresponding to the changing screen (image).

  Although the magnitude of the RGB reference current varies with IDATA, the magnitude of IDATA and the RGB reference current Ic vary in a linear relationship. Therefore, white balance is maintained even if IDATA changes. In addition, the brightness of the screen 144 changes in proportion to the size of IDATA (when the duty ratio is fixed). In other words, the screen brightness 144 can be controlled by IDATA while maintaining the linear and white balance. Since it changes linearly, the combination control with the duty ratio control becomes very easy (see FIGS. 93 to 116, etc.). This is an effective feature of the present invention. The other points are the same as in FIG. 64, FIG.

  In FIG. 64, FIG. 65, etc., the switch circuit 642 is configured such that when the setting data is 0, all the switches are open. Therefore, the setting data of the switch circuit 642 is 0 and the input voltage of the voltage input / output terminal 642 is controlled to be valid. Conversely, when the setting data of the switch circuit 642 is other than 0, the voltage from the ladder resistor 641 is input to the positive terminal of the operational amplifier 502.

  The voltage input / output terminal 643 also functions as a monitor terminal for the output voltage from the switch circuit 642. That is, the selection voltage of the ladder resistor 641 is selected by the switch circuit 642, and it can be monitored which selected voltage is input to the operational amplifier 502.

  In FIG. 64, since there are many wirings between the ladder resistor 641 (step voltage output means) and the RGB switch circuit 642, a chip area is required. FIG. 65 shows an embodiment in which one switch circuit 642 is used for RGB. Even with the above configuration, white balance adjustment and the like can be realized without any problem in practice.

  In the above embodiment, the electronic volume 501 and the switch circuit 642 are changed by digital setting data. However, the present invention is not limited to this. For example, as shown in FIGS. 66 (a) and 66 (b), the digital-analog conversion circuit (D / A circuit) 661 changes (changes) the input voltage (indicated by point c) of the operational amplifier 502 to change the reference current. It goes without saying that Ic may be controlled.

  In the source driver circuit 14 as shown in FIG. 44, particularly when an image is displayed on the display panel, the potential of the source signal line 18 varies depending on the current applied to the source signal line 18. There is a problem that the gate wiring 153 of the source driver IC 14 which is good against this potential fluctuation is swayed (see FIG. 52). As shown in FIG. 52, linking occurs in the gate wiring 153 at the point where the video signal applied to the source signal line 18 changes. Since the potential of the gate wiring 153 changes due to linking, the gate potential of the unit transistor 154 changes and the output current fluctuates. In particular, the potential fluctuation of the gate wiring 153 becomes crosstalk (lateral crosstalk) along the gate signal line 14.

  This fluctuation (linking of the gate wiring 153 (see FIG. 52)) is influenced by the power supply voltage of the source driver IC 14. This is because the peak value of linking increases as the power supply voltage increases. Worst, the power supply voltage also swings. The voltage of the gate wiring 153 has a steady value of 0.55 to 0.65 (V). Therefore, even if slight linking occurs, the fluctuation value of the magnitude of the output current is large.

  FIG. 67 shows the potential fluctuation ratio of the gate wiring with reference to the time when the power supply voltage of the source driver IC 14 is 1.8 (V). The variation ratio increases as the power supply voltage of the source driver IC 14 increases. The allowable range of the fluctuation ratio is about 3. If the fluctuation ratio is larger than this, lateral crosstalk occurs. The variation ratio tends to increase with respect to the power supply voltage when the IC power supply voltage is 13 to 15 (V) or higher. Therefore, the power supply voltage of the source driver IC 14 needs to be 13 (V) or less.

  On the other hand, in order for the driving transistor 11a to pass a current from white display to black display, the potential of the source signal line 18 needs to be changed by a constant amplitude. This required amplitude range is 2.5 (V) or more. The required amplitude range is below the power supply voltage. This is because the output voltage of the source signal line 18 cannot exceed the power supply voltage of the IC.

  From the above, the power supply voltage of the source driver IC 14 needs to be 2.5 (V) or more and 13 (V) or less. More preferably, the power supply voltage (voltage used) of the IC 14 is preferably 6 (V) or more and 10 (V) or less. By setting it within this range, fluctuations in the gate wiring 153 are suppressed within a specified range, and horizontal crosstalk does not occur, and a good image display can be realized.

  The wiring resistance of the gate wiring 153 is also a problem. In FIG. 47, the wiring resistance R (Ω) of the gate wiring 153 is the resistance value of the total wiring length from the transistor 158b1 to the transistor 158b2. Alternatively, the resistance is the total length of the gate wiring. In FIG. 46, the resistance value is the total wiring length from the transistor 158b (transistor group 431b) to the transistor group 431cn.

  The magnitude of the transient phenomenon of the gate wiring 153 also depends on one horizontal scanning period (1H). This is because if the 1H period is short, the influence of the transient phenomenon is large. The higher the wiring resistance R (Ω), the more likely the transient phenomenon occurs. This phenomenon becomes a problem particularly in the source driver circuit (IC) 14 having the configuration of the one-stage current mirror connection shown in FIGS. This is because the gate wiring 153 is long and the number of unit transistors 154 connected to one gate wiring 153 is large.

  FIG. 68 is a graph in which the horizontal axis represents the multiplication (R · T) of the wiring resistance R (Ω) of the gate wiring 153 and one horizontal scanning period (1H period) T (sec), and the vertical axis represents the variation ratio. is there. The fluctuation ratio of 1 is based on R · T = 100. As can be seen from FIG. 68, when R · T is 5 or less, the variation ratio tends to increase. Further, when R · T is 1000 or more, the variation ratio tends to increase. Therefore, R · T is preferably 5 or more and 1000 or less. More preferably, R · T satisfies the condition of 10 or more and 500 or less.

  The duty ratio is also a problem. This is because the fluctuation of the source signal line 18 also increases due to the duty ratio. The duty ratio will be described later. Here, it is assumed that the duty ratio is a ratio of intermittent driving. The total area of the unit transistors 154 in the transistor group 431c (WL size of the unit transistors 154 in the transistor group 431c × number of unit transistors 154) is Sc (square μm).

  In FIG. 69, the horizontal axis represents the Sc × duty ratio, and the vertical axis represents the variation ratio. As can be seen from FIG. 69, when the Sc × duty ratio is 500 or more, the variation ratio tends to increase. Further, the fluctuation allowable range is when the fluctuation ratio is 3 or less. Therefore, it is preferable to control so that the Sc × duty ratio can be driven at 500 or less.

  As for the allowable range of variation, the Sc × duty ratio is 500 or less. If the Sc × duty ratio is 500 or less, the variation ratio is within an allowable range, and the potential variation of the gate wiring 153 becomes extremely small. Accordingly, there is no occurrence of lateral crosstalk, and output variation is within an allowable range, so that a good image display can be realized. If the Sc × duty ratio is 500 or less, the tolerance is acceptable, but even if the Sc × duty ratio is 50 or less, there is almost no effect. Conversely, the chip area of the source driver IC 14 increases. Therefore, the Sc × duty ratio is preferably 50 or more and 500 or less.

  In the source driver IC (circuit) 14 of the present invention, the transistor group 431b forming the current mirror circuit with the unit transistor group 431c or the transistor group 431b constituting the transistor 158b (see FIGS. 48 and 49) has the relationship of FIG. Is preferably satisfied.

  The current supplied to the transistor 158b or the transistor group 431b constituting the transistor 158b (see FIGS. 48 and 49) is Ic, and the current output from one unit transistor group 431c is Id. Id is a program current (suction or discharge current) output to the source signal line 18, and is a current when all the unit transistors 154 constituting the transistor group 431c are in a selected state. Therefore, Id is the current at the maximum gradation applied to the pixel 16.

  Note that when there is one 158b as shown in FIG. 46, it may be used as Ic as it is. However, when there are a plurality of transistors 158 (a plurality of groups) as shown in FIG. 47, the sum is used as Ic. That is, in FIG. 47, Ic = Ic1 + Ic2. As described above, the current Ic is the sum of the currents Ic flowing through the transistor group 431c and the transistor group 431b constituting the current mirror circuit.

  The ratio (Ic / Id) of the currents Id and Ic needs to be 5 or more. In FIG. 70, the vertical axis represents the crosstalk ratio. Crosstalk is a phenomenon in which a potential change of the source signal line 18 due to image display propagates through the gate wiring 153 of the source driver IC (circuit) 14 and horizontal pulling (crosstalk) occurs on the display screen 144. Crosstalk is likely to occur at a point where an image changes from white display to black display and from a black display to white display (for example, an upper edge portion and a lower edge portion of a white window display). When Ic / Id is 5 or less, the occurrence of crosstalk suddenly increases (crosstalk ratio increases), but when it is 5 or more, the slope of the curve decreases.

  As can be understood from FIG. 70, Ic / Id needs to be 5 or more. However, when the number is 100 or more, the size of the transistor group 431b constituting the transistor 158b is large and not practical. Therefore, Ic / Id needs to be 5 or more and 100 or less. More preferably, it is preferably 8 or more and 50 or less.

  For Ic / Id, it is necessary to consider the horizontal scanning time. This is because the shorter the one horizontal scanning period H, the smaller the time constant of the gate wiring 153 is. Note that one horizontal scanning period may be considered as a period during which a program current (program voltage) is written in a pixel row. That is, this is a period in which each pixel is selected and current (voltage) is written to each pixel 16. Therefore, in the driving method in which two pixel rows are simultaneously selected, two horizontal scanning periods correspond.

  When the horizontal scanning period H is H (milliseconds) (time for selecting one pixel row), it is preferable to satisfy the following relationship. The unit of Ic and Id is μA.

0.3 ≦ (Ic · H) /Id≦6.0
More preferably, it is preferable to satisfy the following relationship.

0.5 ≦ (Ic · H) /Id≦5.0
More preferably, the following relationship is satisfied.

0.6 ≦ (Ic · H) /Id≦3.0
By setting the Ic and Id currents so as to satisfy the above relationship and designing the transistor group 431 or the unit transistors 154 and 158, the occurrence of crosstalk is extremely reduced.

  For example, in the case of a QVGA panel, approximately H = 1000 (milliseconds) / (60 (Hz) · 240 pixel rows) = 0.07 (milliseconds). If Ic = 18 (μA) and the maximum program current Id = 1 (μA), then (Ic · H) / Id = (18 · 0.07) /1=1.3, which satisfies the above equation.

  In the case of the XGA panel, H = 0.025 (milliseconds). If Ic = 18 (μA) and the maximum program current Id = 1 (μA), then (Ic · H) / Id = (60 · 0.025) /1=1.5, which satisfies the above equation.

  H is a fixed value in terms of the number of pixel rows in the panel, and Id is the maximum value of the program current. Therefore, it is a fixed value if the efficiency and display luminance of the EL element of the display panel are determined. Therefore, Ic may be determined so as to satisfy the above equation. For example, if H = 0.07 (milliseconds) and Id = 1 (μA), Ic satisfying 0.3 ≦ (Ic · H) /Id≦6.0 is 4 (μA) or more and 86 ( μA) or less. If H = 0.025 (milliseconds) and Id = 1 (μA), Ic satisfying 0.3 ≦ (Ic · H) /Id≦8.0 is 12 (μA) or more and 240 ( μA) or less.

  In the above embodiment, the output stage is described as the transistor group 431c including the unit transistors 154, but the present invention is not limited to this. Needless to say, the present invention can be applied to the configurations shown in FIGS. 160 to 176 later. The above matters can be similarly applied to the present invention described below.

  The magnitude of the output current of the transistor group 431c has a correlation with the output variation. The larger the output current, the smaller the output variation. The above relationship is shown in FIG. When the output current becomes 10 times, the output variation becomes about 1/2 (= 0.5), and when the output current becomes 100 times, it becomes about 1/4 (= 0.25).

  Also, the variation in output current is the area (WL or the total area Sc of all the transistors that generate one output current) of the transistor area Sc of one output stage (in the case of the unit transistor 154, the transistor group 431c). There is a correlation. This relationship is illustrated in FIG. FIG. 183 shows the relationship between the transistor area Sc and the output current for obtaining this output variation when the output variation is constant. The larger the output current, the smaller the transistor area Sc for obtaining a certain output variation. If the output current is increased 10 times, the transistor area Sc may be about ½ (= 0.5). If the output current becomes 100 times, the transistor area Sc for obtaining a predetermined output variation may be about 1/4 (= 0.25).

  According to the result of the study of the present invention, the magnitude of the maximum output current of one terminal output current is preferably 0.2 μA or more and 20 μA or less. If it is 0.2 μA or less, the output variation is large and it is not practical. If it is 20 μA or more, the gate terminal voltage of the transistor in the output stage increases and the source terminal voltage also decreases, and it is necessary to increase the breakdown voltage of the IC. Therefore, the output variation becomes large, which is not preferable. The maximum output current is an output current at the maximum gradation. For example, if there are 256 gradations, it is the 255th gradation, and if it is 64 gradations, it is the 63rd gradation.

  Further, from the relationship between FIG. 182 and FIG. 183 which is the result of the study of the present invention, the maximum output current of one output is Id (μA), and the transistor constituting the output stage ( When the area of the group 431c) (WL or the total area of all the transistors generating one output current) is Sc (square μm), it is preferable to satisfy the following conditions.

500 ≦ Sc × Id ≦ 10000
More preferably, it is preferable to satisfy the following conditions.

800 ≦ Sc × Id ≦ 8000
More preferably, it is preferable to satisfy the following conditions.

1000 ≦ Sc × Id ≦ 5000
By satisfying the above conditions, the variation between adjacent currents output from the output terminal 155 can be 1% or less, and practically sufficient performance can be obtained.

  In the above embodiment, the output stage is described as the transistor group 431c including the unit transistors 154, but the present invention is not limited to this. Needless to say, the present invention can also be applied to the configurations shown in FIGS. 160 to 176. The above matters can be similarly applied to the present invention described below.

  As described above, the description of the present invention can be applied to or combined with other embodiments. Since it is impossible to describe all of a plurality of combinations, they are not described.

  47, adjusting the reference current Ic1 that flows through the transistor 158b1 and the reference current Ic2 that flows through the transistor 158b2 in FIG. 47 demonstrates that the cascade connection between the source driver ICs 14a and 14b can be satisfactorily performed as illustrated in FIG. did.

  In the cascade, as shown in FIG. 208, the source driver ICs 14 are connected by a cascade wiring 2081. The cascade wiring 2081 is performed on the array 30.

  Note that the cascade wiring 2081 for applying or outputting the reference current may be individually input to the source driver circuit (IC) 14 as illustrated in FIG. Further, as shown in FIG. 249 (b), it may be configured to pass between the source driver circuit (IC) 14a and the source driver circuit (IC) 14b. When the reference current corresponding to each bit (see FIGS. 199, 230, and 246) is passed through the cascade wiring 2081 as shown in FIG. 249 (b), the cascade wirings 2081 do not intersect. Terminals (illustrated by I0 to I5) are arranged as described above.

  When the reference current needs to be adjusted, a trimming adjustment unit 2501 including a transistor or the like is formed or arranged between the cascade wirings 2081a and 2081b. The trimming adjustment unit 2501 adjusts the magnitude of the reference current by adjusting the laser light 1622 using a laser 1621 or the like.

  The reference current passed in cascade requires accuracy. Therefore, in the present invention, the current source unit that outputs the reference current in the cascade unit performs trimming and adjusts so that a predetermined reference current is output. Trimming is performed by laser trimming.

  In order to perform the cascade connection satisfactorily, it may be necessary to measure the characteristics of the manufactured source driver IC 14. If the characteristics can be measured, adjustment or processing can be performed by trimming or the like. The characteristic measurement method of the source driver IC (circuit) 14 of the present invention will be described below. Moreover, the output current variation between the adjacent source signal lines 18 can be measured (can be grasped).

  As shown in FIG. 299 (a), a terminal 155 for cascade connection is provided. A reference current IcR (for red) for cascade connection is output to the terminal 155a. A reference current IcG (for green) for cascade connection is output to the terminal 155b. A reference current IcB (for blue) for cascade connection is output to the terminal 155c. The reference current Ic indicates the characteristics of the source driver IC. If the reference current Ic is small, the program current Iw is small. On the other hand, if the reference current Ic is large, the program current Iw is large.

  From the above, it is possible to grasp the identification of the source driver IC 14 by connecting the resistor R having a known resistance value to the terminal 155 and measuring the voltage of each terminal 155 as shown in FIG. 299 (b). it can. The reference current Ic may be measured by connecting an ammeter directly to the terminal 155.

  In the above embodiment, the characteristics of the source driver circuit (IC) 14 are measured at the output terminal of the cascade current. However, the present invention is not limited to this, and a dedicated terminal 155 for measuring characteristics may be formed, configured, or arranged as shown in FIG.

  In FIG. 300, a transistor group 431c (431cR (red), 431cG (green) 431cB (blue)) for characteristic measurement is provided adjacent to the transistor group 431c that outputs the program current Iw to the source signal line 18. Since the transistor group 431cR, the transistor group 431cG, the transistor group 431cB, and the transistor group 431c are formed adjacent to each other, the characteristics are almost the same. Therefore, as shown in FIG. 301A, a resistor R having a known resistance value is connected to the terminal 155, and the voltage of each terminal 155 (a, b, c) is measured, whereby the source driver IC 14 is connected. You can grasp the specific. The reference current Ic may be measured by connecting an ammeter directly to the terminal 155.

  Needless to say, the resistor R may be built in the IC chip 14 as shown in FIG. However, when the resistor R is built-in, trimming is preferably performed in order to obtain a known resistance value. With the configuration shown in FIG. 301B, the voltage can be measured at the terminals 155a, 155b, and 155c by setting the terminal 155d to a predetermined potential (the ground potential in FIG. 301). Therefore, the characteristics of the transistor group 431c connected to each terminal 155 of the source driver IC 14 can be measured or predicted. In addition, it is possible to assume, predict, or measure the cascaded characteristics.

  In the example of FIG. 301, the transistor group 431c and the like connected to the terminal 155 are measured. Cascade connection performance or characteristics or evaluation can be realized with the same configuration. FIG. 302 shows an example. In FIG. 302, the resistor R is built in the chip 14. R is trimmed to a predetermined resistance value. The reference current Ic flows into the resistor R by closing the switch S (Sa, Sb, Sc). Therefore, the value of the reference current Ic can be measured from the output voltage of the terminal 155. After the measurement, trimming or the like is performed to adjust the reference current Ic (IcR, IcG, IcB) to a predetermined value.

  The source driver IC (circuit) 14 of the present invention can define the white balance of RGB by setting the reference current Ic to a predetermined value, and can set it to the predetermined value. In addition, since the program current Iw can be set to a predetermined value, the display brightness of the image can also be set to a low value. Therefore, the importance of setting the reference current Ic to a low value is large.

  As shown in FIG. 303, the present invention includes an electronic volume circuit 501 that adjusts the reference current for each of RGB. Further, a flash memory 3031 is provided to adjust the reference value Ic to a predetermined value by adjusting and fixing the value of the electronic volume 501. By rewriting the flash memory 3031 with FDATA (FDATAAR, FDATAAG, FDATAB), the value of the electronic volume 501 (501R, 501G, 501B) can be fixed or temporarily held. Therefore, the reference current Ic (IcR, IcG, IcB) can be easily adjusted to a predetermined value. This adjustment may be performed by directly measuring the Ic current (FIGS. 299, 302, etc.) to obtain a target adjustment value, but by measuring the display brightness of the panel screen 144 as shown in FIG. Also good.

  In FIG. 303, the value of the electronic volume 501 is set to a low value by the flash memory 3031 to obtain the target reference current Ic, but the present invention is not limited to this. For example, as shown in FIG. 304, it is needless to say that the reference current Ic may be adjusted by an external volume VR (VR1 for red, VR2 for green, VR3 for blue). Further, as shown in FIG. 305, a reference current Ic (IcR, IcG, IcB) flowing in the transistor 158b (see FIGS. 58, 59, 60, etc.) is supplied to a current source I (Ia, Ib, Ic). Needless to say, you can adjust it.

  In FIG. 47, reference currents Ic1 and Ic2 are adjusted. However, if the gate wiring 153 has a resistance value greater than or equal to a predetermined value, even if the reference current Ic1 flowing through the transistor 158b1 and the reference current Ic2 flowing through the transistor 158b2 are the same, the output current of FIG. The tilt is corrected.

  In order to facilitate understanding, specific numerical values will be described. Ic1 = Ic2 = 10 (μA). At this time, the gate terminal voltage V1 of the transistor 158b1 = 0.60 (V) and the gate terminal voltage V2 of the transistor 158b2 = 0.61 (V). Since the difference between the reference current flowing through the transistor 158b2 and the reference current flowing through the transistor 158b1 needs to be within 1%, 1% of the reference current = 10 (μA) is 0.1 (μA). Therefore, (V2−V1) /0.1 (μA) = (0.61−0.60) (V) /0.1 (μA) = 100 (KΩ). Therefore, by setting the resistance value of the gate wiring 153 to 100 (KΩ), the slope of the output current is adjusted, and the difference between the output currents of the ICs 14 arranged adjacent to each other is kept within 1%.

  The higher the resistance of the gate wiring 153, the smaller the magnitude of the correction current Id. However, if the resistance value of the gate wiring 153 is too high, the peak value of linking in FIG. 52 also increases, and the occurrence of lateral crosstalk becomes significant. Therefore, an appropriate range exists for the resistance value of the gate wiring 153.

  The present invention is characterized in that all of the gate wiring 153 or at least a part of the gate wiring 153 is formed of a wiring made of polysilicon. Preferably, the portion other than the contact portion with or near the gate terminal of the unit transistor 154 is formed of polysilicon. The gate wiring 153 is formed or configured to have a target resistance value by adjusting the wiring width or meandering.

  The suppression of the occurrence of linking of the gate wiring can be achieved by setting the gate wiring 153 to have a resistance value equal to or lower than a predetermined value. Further, this can be achieved by increasing the total area Sb of the transistor 158b (total area Sb of the transistor group 431b). Further, this can be achieved by increasing the reference current Ic.

  When the area of one output unit transistor 154 (total area of unit transistors 154 in one transistor group 431c) is S0, the total area Sb of transistors 158b of the transistor group 431b (when there are a plurality of transistor groups 431b as shown in FIG. 44) Is the total area of the transistors 158b of the plurality of transistor groups 431b).

  FIG. 71 shows the relationship when Sb / S0 is on the horizontal axis and allowable gate wiring resistance (KΩ) is on the vertical axis. The range below the solid line in FIG. 71 is an allowable range (a range that is not affected by the occurrence of linking). In other words, lateral crosstalk is practically acceptable.

  The horizontal axis of FIG. 71 is the size S0 of the unit transistor 154 per output with respect to the size Sb of the total transistor group 431b (in the case of 64 gradations, 63 unit transistors 154). Assuming that S0 is a fixed value, the resistance value that the gate wiring 153 can tolerate increases as Sb increases. This is because as Sb increases, the impedance with respect to the gate wiring 153 decreases and the stability increases.

  Since S0 generates an output current (program current), and the output variation needs to be a certain value or less, the size of S0 has a narrow design change range. On the other hand, there are design restrictions in order to set the resistance value of the gate wiring 153 to a predetermined value.

  In order to increase the resistance of the gate wiring 153, there are a problem that the wiring becomes thin and disconnection occurs, and a problem of stability. Further, increasing Sb increases the chip area and the cost. Therefore, it is preferable to set Sb / S0 to 50 or less from the problem of the chip size of the IC 14, and Sb / S0 should be set to 5 or more because of restrictions such as stable design of the gate wiring 153 and linking problems. preferable. Therefore, it is necessary to satisfy the condition of 5 ≦ Sb / S0 ≦ 50.

  From the graph (solid line) in FIG. 71, the slope of the solid line curve becomes gentler as Sb / S0 becomes smaller. Further, when Sb / S0 is 15 or more, the inclination tends to be constant. Therefore, when Sb / S0 is 5 or more and 15 or less, the resistance value of the gate wiring 153 needs to be 400 (KΩ) or less. Further, when Sb / S0 is 15 or more and 50 or less, it is necessary to set Sb / S0 × 24 (KΩ) or less. For example, when Sb / S0 = 50, it is necessary to set it to 50 × 24 = 1200 (KΩ) or less.

  There is a correlation between the reference current Ic flowing through the transistor 158b and the allowable gate wiring resistance. This is because the larger the reference current Ic, the lower the impedance when the gate wiring 153 is viewed from the transistor 158b. FIG. 72 shows the relationship. FIG. 72 shows the reference current Ic (μA) flowing through the transistor 158b (or transistor group 431b) on the horizontal axis. The vertical axis represents allowable gate wiring resistance (KΩ). The range below the solid line in FIG. 72 is the allowable range (the range not affected by the occurrence of linking). In other words, lateral crosstalk is practically acceptable.

  If the reference current Ic is increased, the stability of the gate wiring 153 is improved. However, the reactive current consumed by the source driver IC 14 increases, and the potential of the gate wiring 153 increases. For this reason, the reference current Ic needs to be 50 (μA) or less.

  If the reference current Ic is reduced, the stability of the gate wiring 153 is lowered, so that the resistance value of the gate wiring 153 needs to be lowered. However, when the reference current is lowered below a certain value, the variation in output current from the unit transistor 431c increases. That is, the stability of the output current is lost. Therefore, the reference current Ic needs to be 2 (μA) or more. From the above, the reference current Ic flowing through the transistor 158b needs to be 2 (μA) or more and 50 (μA) or less.

  The graph (solid line) in FIG. 72 can be approximated by two straight lines. When Ic is 2 (μA) or more and 15 (μA) or less, the resistance value (MΩ) of the gate wiring 153 needs to be 0.04 × Ic (MΩ) or less. For example, if Ic = 15 (μA), the resistance value of the gate wiring 153 needs to satisfy the condition of 0.04 × 15 = 0.6 (MΩ) or less.

  When Ic is 15 (μA) or more and 50 (μA) or less, the resistance value (MΩ) of the gate wiring 153 needs to be 0.025 × Ic (MΩ) or less. For example, if Ic = 50 (μA), the resistance value of the gate wiring 153 needs to satisfy the condition of 0.025 × 50 = 1.25 (MΩ) or less.

  There is a correlation between a period in which one pixel row is selected (one horizontal scanning period (1H)) and the resistance R (KΩ) of the gate wiring 153 × the length D (m) of the gate wiring 153. This is because the shorter the period of 1H, the shorter the period required for the potential of the gate wiring 153 to return to the normal value. Further, as shown in FIG. 47, when the gate wiring 153 length D (= chip length of the driver IC) becomes longer, the potential fluctuation of the unit transistor group 431c farthest from the transistor 158b exceeds the allowable range. This phenomenon is presumed to be caused by the parasitic capacitance between the unit transistor 154 and the source signal line 18. That is, when the chip length D of the driver IC 14 is increased, it is necessary to consider not only the simple resistance value of the gate wiring 153 but also the potential fluctuation of the gate wiring 153 due to parasitic capacitance.

  In FIG. 73, the horizontal axis represents one horizontal scanning period (μ seconds). The vertical axis represents the product of gate wiring resistance (KΩ) and chip length D (m). The range below the solid line in FIG. 73 is the allowable range. As for R · D, 9 (KΩ · m) is the production limit of the source driver IC. Above this, the cost increases and is not practical. On the other hand, when R · D is 0.05 or less, the current Id in FIG. 191 becomes too large, and the deviation of the adjacent output current becomes too large. Therefore, R · D (KΩ · m) needs to be 0.05 or more and 9 or less.

  When the transistor 11 constituting the pixel 16 is configured by a P channel, the program current flows in the direction from the pixel 16 to the source signal line 18. Therefore, the unit transistor 154 (see FIGS. 15, 57, 58, 59, etc.) of the source driver circuit needs to be formed of an N-channel transistor. In other words, the source driver circuit 14 needs to be configured to draw the program current Iw.

  When the driving transistor 11a (in the case of FIG. 1) of the pixel 16 is a P-channel transistor, the unit transistor 154 is configured by an N-channel transistor so that the source driver circuit 14 always draws the program current Iw.

  In order to form the source driver circuit 14 on the array substrate 30, it is necessary to use both an N channel mask (process) and a P channel mask (process). Describing conceptually, the display panel (display device) of the present invention comprises the pixel 16 and the gate driver circuit 12 by P-channel transistors, and the source current source transistor of the source driver by N-channel.

  In one embodiment of the present invention, the transistor 11 of the pixel 16 is formed by a P-channel transistor, and the gate driver circuit 12 is formed by a P-channel transistor. Thus, by forming both the transistor 11 and the gate driver circuit 12 of the pixel 16 with P-channel transistors, the cost of the substrate 30 can be reduced.

  The source driver circuit 14 needs to form the unit transistor 154 with an N-channel transistor. However, the source driver circuit 14 cannot be formed directly on the substrate 30 in the process of only the P channel. Therefore, the source driver circuit 14 is separately manufactured using a silicon chip or the like and mounted on the substrate 30. That is, the present invention has a configuration in which a source driver IC 14 (means for outputting a program current as a video signal) is externally attached.

  When the area of the unit transistor 154 is the same, the variation of the unit transistor 154 formed by the N channel is 70% compared to the variation of the unit transistor formed by the P channel. That is, when the unit transistor 154 is formed with the N channel, the variation can be reduced with the same transistor formation area. According to the result of the examination, in order to make the variation of the P-channel unit transistor the same as that of the N-channel unit transistor, a double formation area is required (see FIG. 159).

  Although the source driver circuit 14 is composed of a silicon chip, it is not limited to this. For example, a large number of glass substrates may be simultaneously formed by low-temperature polysilicon technology, cut into chips, and loaded on the substrate 30.

  Further, although it has been described that the source driver circuit is mounted on the substrate 30, it is not limited to stacking. Any form may be used as long as the output terminal 431 of the source driver circuit 14 is connected to the source signal line 18 of the substrate 30. For example, a method of connecting the source driver circuit 14 to the source signal line 18 by TAB technology is exemplified. By separately forming the source driver circuit 14 on a silicon chip or the like, variation in output current can be reduced and a good image display can be realized. Moreover, cost reduction is possible.

  Further, the configuration in which the selection transistor of the pixel 16 is configured by a P channel and the gate driver circuit is configured by a P channel transistor is not limited to a self-luminous device (display panel or display device) such as an organic EL. For example, the present invention can be applied to a liquid crystal display device and FED (field emission display).

  When the switching transistors 11b and 11c of the pixel 16 are formed of P-channel transistors, the pixel 16 is selected by Vgh. The pixel 16 is in a non-selected state by Vgl. As described before, the voltage penetrates when the gate signal line 17a changes from on (Vgl) to off (Vgh) (penetration voltage). When the driving transistor 11a of the pixel 16 is formed of a P-channel transistor, the current does not flow through the transistor 11a due to the punch-through voltage in the black display state. Therefore, good black display can be realized. It is difficult to realize black display, which is a problem of the current driving method.

  In the present invention, the on-voltage is Vgh by configuring the gate driver circuit 12 with a P-channel transistor. Therefore, matching with the pixel 16 formed by the P channel transistor is good. Further, in order to exert the effect of improving the black display, the driving transistor 11a and the source signal are generated from the anode voltage Vdd as in the configuration of the pixel 16 in FIGS. 1, 2, 6, 7, and 8. It is important to configure the program current Iw to flow into the unit transistor 154 of the source driver circuit 14 via the line 18.

  Therefore, it is excellent synergistic effect that the gate driver circuit 12 and the pixel 16 are configured by P-channel transistors, the source driver circuit 14 is mounted on the substrate, and the unit transistors 154 of the source driver circuit 14 are configured by N-channel transistors. Demonstrate.

  Further, the unit transistor 154 formed by the N channel has less variation in output current than the unit transistor 154 formed by the P channel. When compared with the unit transistors 154 of the same area (W · L), the N-channel unit transistor 154 has a variation in output current from 1 / 1.5 to 1/2 compared to the P-channel unit transistor 154. Become. For this reason, the unit transistor 154 of the source driver IC 14 is preferably formed of an N channel.

  The same applies to FIG. 42B. In FIG. 42B, current does not flow into the unit transistor 154 of the source driver circuit 14 via the driving transistor 11b. However, the configuration is such that the program current Iw flows from the anode voltage Vdd into the unit transistor 154 of the source driver circuit 14 via the programming transistor 11 a and the source signal line 18. Therefore, as in FIG. 1, the gate driver circuit 12 and the pixel 16 are configured by P-channel transistors, the source driver circuit 14 is mounted on the substrate, and the unit transistors 154 of the source driver circuit 14 are configured by N-channel transistors. Exerts an excellent synergistic effect.

  In the present invention, the driving transistor 11a of the pixel 16 is configured by a P channel, and the switching transistors 11b and 11c are configured by a P channel. Further, the unit transistor 154 in the output stage of the source driver IC 14 is configured by N channels. Preferably, the gate driver circuit 12 is composed of a P-channel transistor.

  Needless to say, the above-described reverse configuration is effective. The driving transistor 11a of the pixel 16 is configured with an N channel, and the switching transistors 11b and 11c are configured with an N channel. Further, the unit transistor 154 in the output stage of the source driver IC 14 is configured as a P channel. Preferably, the gate driver circuit 12 is composed of an N channel transistor. This configuration is also a configuration of the present invention.

  Next, the precharge circuit will be described. As described above, in the current driving method, the current written to the pixel is small during black display. For this reason, if the source signal line 18 or the like has a parasitic capacitance, there is a problem that a sufficient current cannot be written to the pixel 16 in one horizontal scanning period (1H). In general, a current-driven light-emitting element has a weak black level current value of about several nA, and thus it is difficult to drive a parasitic capacitance (wiring load capacitance) that seems to be about several tens of pF in its signal value. .

  In order to solve this problem, a precharge voltage (synonymous with or similar to the program voltage) is applied before image data is written to the source signal line 18, and the potential level of the source signal line 18 is set to the black level of the transistor 11a of the pixel. It is effective to set the display current (basically, the transistor 11a is off). For the formation (creation) of this precharge voltage (synonymous with or similar to the program voltage), it is effective to output a black level constant voltage by decoding the upper bits of the image data.

  The precharge is a method for forcibly applying a voltage to the source signal line 18 at the beginning of 1H. The voltage is used to turn off the driving transistor 11a (illustrated in the case of FIG. 1, but is not limited thereto, and may be a voltage-driven pixel configuration). When the driving transistor 11a is a P channel, a voltage close to the anode voltage is applied. That is, a voltage for turning off is applied. In the case of the N channel, a voltage close to the cathode voltage is applied.

  The precharge is to apply a voltage in the vicinity of the driving transistor 11a in an off state (a state below the rising current) or in the vicinity thereof. Alternatively, when a plurality of precharge voltages (synonymous with or similar to the program voltage) are used as shown in FIGS. 135 to 139 (low gradation precharge drive), a voltage is applied to the gate terminal (G) of the drive transistor 11a. The output current of the driving transistor 11a is changed (controlled) according to the applied voltage. In the precharge drive, a black voltage is written to the pixel transistor 11a. In addition, this is a driving method in which the pixel transistor 11a is cut off. Further, the voltage at which the transistor 11a is turned off is written as the terminal voltage of the capacitor 11a.

  Applying a precharge voltage (synonymous with or similar to the program voltage) as described above is a method of applying a voltage for forcibly turning off the driving transistor 11a. Further, it means that a voltage is applied to the source signal line 18 to forcibly charge and discharge.

  Also, a precharge voltage (synonymous with or similar to the program voltage) is applied. However, in order to change the potential of the source signal line 18, not only the voltage but also the current (charge or discharge) is applied to the source. The potential of the signal line 18 can be changed. Therefore, the technical idea of applying a precharge voltage (synonymous with or similar to the program voltage) includes applying a precharge current.

  Further, the precharge voltage (synonymous with or similar to the program voltage) (current) is not limited to being applied once in one horizontal scanning period, and may be applied by being divided into a plurality of times in one horizontal scanning period. Further, it may be controlled so as to be applied once in a plurality of horizontal scanning periods. Needless to say, it may be applied once or more in one frame or one field period, or may be applied multiple times or once in a plurality of fields or one frame. In addition, when applying a plurality of times in one horizontal scanning period or one frame, the magnitude of the precharge voltage (synonymous with or similar to the program voltage) may be changed within a plurality of times. Needless to say, it may be changed. Further, the application position (such as both ends and the center of the source signal line 18) may be changed. The application position may be changed in a frame or a horizontal scanning period.

  The present invention is characterized in that the driving transistor is a P-channel and the precharge voltage (synonymous with or similar to the program voltage) is equal to or lower than the anode voltage Vdd (anode voltage Vdd-1.5 (V)). , R, G, and B, at least one of the other precharge voltages (synonymous with or similar to the program voltage) can be made different, for example, for each of R, G, and B 75 is configured or formed in the source driver IC 14.

  Although the present invention has been described as including R, G, and B output circuits (program current (voltage) output circuits, etc.) in one source driver IC (circuit) 14, the present invention is not limited to this. is not. For example, three source driver ICs (circuits) 14 that output individual outputs of R, G, and B may be provided and mounted on one array substrate 30 or the like. The precharge circuit configuration described with reference to FIG. 75 and the like is arranged in each R, G, B IC chip (circuit) 14. Further, the present invention is not limited to arranging three R, G, and B precharge circuits in one source driver IC (circuit) 14. One or more precharge circuits among R, G, and B may be arranged or formed. This is because there is an EL element 15 of a color that can perform black display well without precharging all of RGB.

  FIG. 186 is an explanatory diagram of precharge driving. FIG. 186 (a) shows a case where the driving transistor 11a is a P channel. Although the pixel configuration has been described with reference to FIG. 1, the present invention is not limited to this. Needless to say, the present invention can also be applied to EL display panels or EL display devices having other pixel configurations such as those shown in FIGS. 2, 7, 11, 12, 13, 28, and 31.

  A precharge voltage (synonymous with or similar to the program voltage) is generated by the source driver circuit 14. This point is also a feature of the present invention. The source driver circuit 14 is a silicon chip IC. Further, the precharge voltage (synonymous with or similar to the program voltage) is a voltage equal to or lower than the Vdd voltage and equal to or higher than Vdd−5.0 (V) when the driving transistor 11a is a P channel. A precharge voltage (synonymous with or similar to the program voltage) Vp is applied to the gate terminal and the drain terminal of the driving transistor 11a when the pixel selection transistor 11c is turned on. Alternatively, it is applied to the gate terminal. The precharge voltage (synonymous with or similar to the program voltage) is a voltage that turns the driving transistor 11a off (voltage that prevents current from flowing). The transistor 11d of the pixel to which the precharge voltage (synonymous or similar to the program voltage) is applied is turned off, and the EL element 15 is controlled so that the precharge voltage (synonymous or similar to the program voltage) is not applied. . Therefore, the EL element 15 does not perform unnecessary light emission due to the precharge voltage (synonymous with or similar to the program voltage).

  FIG. 186 (b) shows the case where the driving transistor 11a is an N channel. A precharge voltage (synonymous with or similar to the program voltage) is generated by the source driver circuit 14. The precharge voltage (synonymous with or similar to the program voltage) is a voltage not lower than Vss voltage and not higher than Vss + 5.0 (V) when the driving transistor 11a is an N channel. A precharge voltage (synonymous with or similar to the program voltage) Vp is applied to the gate terminal and the drain terminal of the driving transistor 11a when the pixel selection transistor 11c is turned on. Alternatively, it is applied to the gate terminal. The precharge voltage (synonymous with or similar to the program voltage) is a voltage that turns the driving transistor 11a off (voltage that prevents current from flowing). The transistor 11d of the pixel to which the precharge voltage (synonymous or similar to the program voltage) is applied is turned off, and the EL element 15 is controlled so that the precharge voltage (synonymous or similar to the program voltage) is not applied. . Therefore, the EL element 15 does not perform unnecessary light emission due to the precharge voltage (synonymous with or similar to the program voltage).

  FIG. 187 (a) shows a case where the pixel configuration is a current mirror configuration as shown in FIG. This is a case where the driving transistor 11b is a P channel. A precharge voltage (synonymous with or similar to the program voltage) is generated by the source driver circuit 14. The precharge voltage (synonymous with or similar to the program voltage) is a voltage equal to or lower than the Vdd voltage and equal to or higher than Vdd−5.0 (V) when the driving transistor 11a is a P channel. A precharge voltage (synonymous with or similar to the program voltage) Vp is applied to the gate terminal and the drain terminal of the driving transistor 11a when the pixel selection transistor 11c is turned on. Alternatively, it is applied to the gate terminal. The precharge voltage (synonymous with or similar to the program voltage) is a voltage that turns the driving transistor 11a off (voltage that prevents current from flowing). The transistor 11 d of the pixel to which the precharge voltage is applied is turned off, and the EL element 15 is controlled so that the precharge voltage is not applied. Therefore, the EL element 15 does not emit unnecessary light due to the precharge voltage.

  Note that the transistor 11d is not necessarily required as illustrated in FIG. In particular, it is not necessary in the current mirror circuit configuration as shown in FIG. Further, as shown in FIG. 186 (b), it goes without saying that the driving transistor 11b can also be constituted by an N channel in FIG. 187.

  FIG. 75 shows an example of a current output type source driver IC (circuit) 14 having a precharge function of the present invention. FIG. 75 shows a case where a precharge function is mounted on the output stage of the 6-bit constant current output circuit 164.

  In FIG. 75, when the precharge voltage is applied, the precharge voltage is applied to the point B of the internal wiring 150. Therefore, the precharge voltage is also applied to the current output stage 164. However, since the current output stage 164 is a constant current circuit, it has a high impedance. Therefore, even if a precharge voltage is applied to the constant current circuit 164, there is no problem in circuit operation.

  The precharge may be performed in the entire gradation range, but preferably, the gradation for precharging should be limited to the black display region. That is, the writing image data is determined, and the black region gradation (low luminance, that is, the writing current is small (small) in the current driving method) is selected and precharged (referred to as selective precharging). When pre-charging is performed on all gradation data, this time, a decrease in luminance (not reaching the target luminance) occurs in the white display area. Moreover, the subject that a vertical stripe is displayed on an image may generate | occur | produce.

  Preferably, selective precharge is performed in a gradation region from gradation 0 to 1/8 of all gradations of gradation data (for example, in the case of 64 gradations, the 0th to 7th gradations are performed). In the case of image data up to, after precharging, the image data is written). Further, it is preferable that selective precharge is performed with gradations in a region of gradations 0 to 1/16 of gradation data (for example, in the case of 64 gradations, images from the 0th gradation to the 3rd gradation are used. Data and time, precharge and then write image data).

  In particular, in order to increase the contrast in black display, it is also effective to detect only the gradation 0 and precharge. The black display is extremely good. The method of precharging only the gradation 0 has less adverse effects on image display. Therefore, it is preferable to adopt as the most precharge technology.

  It is also effective to vary the precharge voltage and gradation range for R, G, and B. This is because the EL display element 15 has different emission start voltages and emission luminances for R, G, and B. For example, R is a selective precharge with the gradation in the range of gradations 0 to 1/8 of the gradation data (for example, in the case of 64 gradations, the images from the 0th gradation to the 7th gradation are used. When data, pre-charge and then write image data). Other colors (G, B) are selectively precharged with gradations in the range of gradations 0 to 1/16 of gradation data (for example, in the case of 64 gradations, the 3rd floor from the 0th gradation) The image data up to the time of the adjustment and the control such as writing the image data after precharging are performed. As for the precharge voltage, if R is 7 (V), a voltage of 7.5 (V) is written to the source signal line 18 for the other colors (G, B).

  The optimum precharge voltage is often different depending on the production lot of the EL display panel. Therefore, it is preferable that the precharge voltage is configured to be adjustable with an external volume or the like. This adjustment circuit can also be easily realized by using an electronic volume circuit.

  Note that the precharge voltage is preferably not more than the anode voltage Vdd-0.5 (V) and not less than the anode voltage Vdd-2.5 (V) in FIG.

  Even in the method of precharging only gradation 0, a method of precharging by selecting one or two colors of R, G, B is also effective. Less harmful to image display. It is also effective to precharge when the screen brightness is less than or equal to a predetermined brightness. In particular, when the brightness of the display screen 144 is low, black display is difficult. By performing precharge driving such as 0 gradation precharge when the luminance is low, the contrast of the image is improved.

  In addition, the 0th mode in which no precharge is performed, the first mode in which only the gradation 0 is precharged, the second mode in which the precharge is performed in the range from the gradation 0 to the gradation 3, and the precharging is performed in the range from the gradation 0 to the gradation 7. It is preferable that a third mode to be charged, a fourth mode to be precharged in a range of all gradations, and the like are set, and these are switched by a command. These can be easily realized by configuring (designing) a logic circuit in the source driver IC (circuit) 14.

  The switch 151a is controlled to be turned on / off by the application state of the above signal, and the precharge voltage PV is applied to the source signal line 18 when the switch 151a is turned on. The time for applying the precharge voltage PV is set by a separately formed counter (not shown). This counter is configured to be set by a command. The precharge voltage application time is preferably set to 1/100 or more and 1/5 or less of one horizontal scanning period (1H). For example, if 1H is 100 μsec, it is 1 μsec or more and 20 μsec (1/100 of 1H or more and 1/5 or less of 1H). More preferably, it is 2 μsec or more and 10 μsec (2/100 of 1H or more and 1/10 or less of 1H).

  The output of the coincidence circuit 161 and the output of the counter circuit 162 are ANDed by an AND circuit 163, and the black level voltage Vp is output for a certain period.

FIG. 75 shows an embodiment in which the precharge voltage can be changed according to the gradation. In FIG. 75, it is possible to easily change the precharge voltage in accordance with the applied image data. The precharge voltage can be changed by the electronic volume 501 according to the image data (D3 to D0). In FIG. 75, since the D3 to D0 bits are connected to the electronic volume, it can be seen that the low gradation precharge voltage can be changed. This is because the black display write current is very small and the white display write current is large. Therefore, the precharge voltage is increased as the low gradation region is reached. Since the driving transistor 11a of the pixel 16 is a P channel, the anode voltage (Vdd) is a black display voltage. As the high gradation region is reached, the precharge voltage is lowered (when the pixel transistor 11a is in the P channel). That is, the voltage programming method is implemented in the low gradation display, and the current programming method is implemented in the high gradation display (white display). Of course, in FIG. 75, not only the precharge voltage is changed according to the gradation, but the precharge voltage may be changed or controlled according to the temperature or the lighting rate, the reference current ratio, and the duty ratio. In addition, the precharge voltage application time may be changed or controlled according to temperature, lighting rate, reference current ratio, or duty ratio. In the precharge circuit of FIG. It is possible to select whether to precharge in the range of 0 to gradation 7. Also, the precharge voltage for each gradation can be changed by the electronic volume 501.

  Good results can also be obtained by varying the precharge voltage PV application time according to the image data applied to the source signal line 18. For example, the application time is lengthened in gradation 0 for full black display, and shorter than that in gradation 4. It is also possible to obtain a good result by setting the application time in consideration of the difference between the image data before 1H and the image data to be applied next.

  For example, when writing a current to display a pixel in white on the source signal line 1H before and writing a current to display a black in the pixel to the next 1H, the precharge time is lengthened. This is because the black display current is very small. On the other hand, when writing the current to make the pixel display black on the source signal line 1H before, and writing the current to make the black display on white next 1H, shorten the precharge time or precharge the current. Stop (do not do). This is because the white display write current is large.

  It is also effective to change the precharge voltage according to the image data to be applied. This is because the writing current for black display is very small and the writing current for white display is large. Therefore, the precharge voltage is increased (with respect to Vdd when the pixel transistor 11a is in the P channel) as the low gradation region is reached, and the precharge voltage is decreased (pixel) as the high gradation region is obtained. A control method in which the transistor 11a is in the P channel) is also effective.

  The screen has a white display area (area with a certain luminance) area (white area) and a black display area (area with a luminance below a certain level) (black area). It is effective to add a function of stopping the precharge when in a certain range (appropriate precharge). This is because vertical stripes occur in the image within this certain range. Of course, conversely, precharging may be performed within a certain range. Also, when the image moves, the image becomes noise-like. Appropriate precharging can be easily realized by counting (calculating) data of pixels corresponding to the white area and the black area with an arithmetic circuit.

  It is also effective to make the precharge control different for R, G, and B. This is because the EL display element 15 has different emission start voltages and emission luminances for R, G, and B. For example, R is the ratio of the white area of the predetermined luminance: the black area of the predetermined luminance is stopped or started when the ratio is 1:20 or more, and G and B are the ratio of the white area of the predetermined luminance: the black area of the predetermined luminance. Is a method of stopping or starting the precharge at 1:16 or more. According to the experiment and examination results, in the case of the organic EL display panel, the pre-processing is performed when the ratio of the white area with the predetermined luminance to the black area with the predetermined luminance is 1: 100 or more (that is, the black area is 100 times or more of the white area). It is preferable to stop charging. Furthermore, it is preferable to stop the precharge when the ratio of the white area with the predetermined luminance to the black area with the predetermined luminance is 1: 200 or more (that is, the black area is 200 times or more of the white area).

  As described before, as shown in FIG. 76, RGB image data (RDATA, GDATA, and BDATA) are each 8 bits. The RGB 8-bit image data is gamma-converted by the gamma circuit 764 to become a 10-bit signal. The signal subjected to gamma conversion is subjected to FRC processing by a frame rate control (FRC) circuit 765 and converted to 6-bit image data. A precharge control circuit (PC) 761 generates a precharge control signal (set to H level when precharging and set to L level when not precharging) from the converted 6-bit image data. A method for generating this precharge will be described later.

  Note that it is preferable for the FRC to process a 10-bit signal for 8 bits or 6 bits without image failure.

  FIG. 77 is a block diagram centering on the precharge circuit 773 of the source driver IC (circuit) 14. The precharge circuit 773 outputs a precharge control signal PC signal (red (RPC), green (GPC), blue (BPC)) by the precharge control circuit 761. The PC signal is generated by the precharge control circuit 761 of the control IC 81 shown in FIG. 76, and the PC signal is input to the selector circuit 772 of the source driver IC 14 shown in FIG.

  The selector circuit 772 sequentially latches in the latch circuit 771 corresponding to the output stage in synchronization with the main clock. The latch circuit 771 has a two-stage configuration of a latch circuit 771a and a latch circuit 771b. The latch circuit 771b sends data to the precharge circuit 773 in synchronization with the horizontal scanning clock (1H). That is, the selector sequentially latches image data and PC data for one pixel row, and stores the data in the latch circuit 771b in synchronization with the horizontal scanning clock (1H).

  In FIG. 77, R, G, and B in the latch circuit 771 are RGB image data 6-bit latch circuits, and P is a latch circuit that latches 3 bits of the precharge signals (RPC, GPC, and BPC). .

  The precharge circuit 773 turns on the switch 151a and outputs a precharge voltage to the source signal line 18 when the output of the latch circuit 771b is at the H level. The current output circuit 164 outputs a program current to the source signal line 18 according to the image data.

  76 and 77 schematically shows the configuration of FIG. 78. 78 and 79 show a configuration in which a plurality of source driver ICs (circuits) 14 are stacked on one display panel (cathode connection of source driver ICs). In addition, CSEL1 and CSEL2 in FIGS. 78 and 79 are select signals for the IC chip. The IC chip is selected by the CSEL signal to determine which image data and PC signal are input.

  77 and 78, a precharge control (PC) signal is generated corresponding to each RGB image data. The precharge is preferably applied for each RGB as described above. However, in moving image display and natural image display, it is often unnecessary to determine whether or not to precharge for each RGB. That is, RGB may be converted (converted) into a luminance signal, and it may be determined whether or not to precharge based on the luminance. This is the configuration of FIG. 79.

  In the configuration of FIG. 78, the PC signal requires 3 bits (RPC, GPC, BPC), but in the configuration of FIG. 79, the PC signal may be 1 bit of RGBPC. Therefore, in the latch circuit 771 of FIG. 77, P may be a 1-bit latch. In the following description, the description will be made without considering RGB from the viewpoint of facilitating the explanation and drawing.

  In the configuration of the present invention described above, the controller 760 generates the PC signal (precharge control signal) based on the image data, and the source driver IC 14 latches the PC signal and synchronizes with the 1H synchronization signal in the source signal line 18. It is characterized in that it is applied to. Further, as shown in FIG. 76, the controller 81 can easily change the generation of the precharge signal by a precharge mode (PMODE) signal.

  For example, PMODE is a mode in which only gradation 0 is precharged, a mode in which a certain gradation range such as gradation 0-7 is precharged, and precharge when image data changes from bright image data to dark image data. Examples include a mode for precharging when low gradation display is continuously performed in a certain frame.

  Note that the present invention is not limited to determining whether or not to precharge one pixel data. For example, the precharge determination may be performed based on the image data of a plurality of pixel rows. In addition, the precharge determination may be performed in consideration of the image data of the surrounding pixels to be precharged (for example, weighting processing). Further, a method of changing the precharge judgment between a moving image and a still image is also exemplified. The above matter is important in that good versatility is exhibited when the controller generates a precharge signal based on image data. Hereinafter, the precharge determination and the precharge mode will be mainly described.

  Note that whether or not to precharge may be determined based on the image data of the previous pixel row (or the image data applied to the source signal line immediately before). For example, if the image data applied to a certain source signal line 18 is white-> black-> black, a precharge voltage is applied when changing from white to black. This is because black gradation is difficult to write. In the case of black to black, no precharge voltage is applied. This is because the potential of the source signal line 18 in the black display first is the black display potential to be written next. The above operation can be realized more easily by forming (arranging) a line memory for one pixel row (requires two lines of memory for FIFO) in the controller 81.

  In the present invention, the precharge drive is described as outputting a precharge voltage, but the present invention is not limited to this. A method of writing a current shorter than one horizontal scanning period and larger than the program current to the source signal line 18 may be used. That is, a method of writing the precharge current to the source signal line 18 and then writing the program current to the source signal line 18 may be used. There is no difference in that the precharge current also physically causes a voltage change. A method of performing precharge with a precharge current is also within the category of precharge driving of the present invention.

  For example, in FIG. 75, the precharge voltage changes by switching the electronic volume 501. This electronic volume 501 may be changed to an electronic volume with current output. The change can be easily realized by combining a plurality of current mirror circuits. In the present invention, for ease of explanation, it is assumed that precharge driving is performed with a precharge voltage.

  The application of the precharge voltage (current) is not limited to the application of a constant precharge voltage (current). For example, a plurality of precharge voltages may be applied to the source signal line. For example, after applying the first precharge voltage 5 (V) for 5 (μsec), the second precharge voltage 4.5 (V) is applied for 5 (μsec). Thereafter, the program current Iw is applied to the source signal line 18.

  Alternatively, the precharge voltage may be changed in a sawtooth shape. A rectangular wave may be applied. Further, a precharge voltage (current) may be superimposed on a regular program current (voltage). Further, the magnitude of the precharge voltage (current) and the application period of the precharge voltage (current) may be changed according to the image data. Further, the type of applied waveform, the value of the precharge voltage, and the like may be changed according to the value of the image data.

  Although the present invention will be described assuming that a precharge voltage (current) is applied in the current drive method, the precharge drive is also effective in the voltage drive method. In the voltage driving method, the size of the driving transistor for driving the EL element 15 is large, so that the gate capacitance is large. Therefore, there is a problem that it is difficult to write a regular program voltage. In response to this problem, by performing precharge before applying the program voltage, the driving transistor can be reset, and good writing can be realized.

  Therefore, the precharge driving method of the present invention is not limited to current program driving. In the embodiments of the present invention, for ease of explanation, the current program driving pixel configuration (see FIG. 1 and the like) will be described as an example.

  In the embodiment of the present invention, the precharge driving method does not act only on the driving transistor 11a. For example, in the pixel configurations shown in FIGS. 11, 12, and 13, the transistor 11a that forms the current mirror circuit is also acted to exert the effect. The precharge drive system of the present invention is intended to charge and discharge the parasitic capacitance of the source signal line 18 as viewed from the source driver IC (circuit) 14, but of course, in the source driver IC (circuit) 14. The purpose is to charge and discharge the parasitic capacitance.

  The precharge voltage (current) is intended to improve black display, but is not limited thereto. If a white write precharge voltage (current) that makes white display easy to write is applied, good white display can be realized. In other words, the precharge driving of the present invention applies pre-charging by applying a predetermined voltage (current) for facilitating writing of the program current (program voltage) before writing the program current (program voltage). It is.

  Although the present invention is described as precharging with black display, this is basically a case where the current is sucked from the driving transistor 11a into the source driver IC (circuit) 14 by a sink current. When the driving transistor 11a or the like is an N-channel transistor, the source driver IC (circuit) 14 is programmed with a discharge current. In this case, a pixel configuration that is white and difficult to write may occur. Therefore, the precharge driving method of the present invention changes the source signal line 18 and the like to a predetermined potential, and precharging with white display or precharging with black display is merely an embodiment. Therefore, it is not limited to these.

  The application timing of the precharge voltage (current) is preferably written while the pixel row to which the program voltage (current) is written is selected. However, the precharge voltage (current) is not limited to this. In a selected state, a precharge voltage (current) may be applied to the source signal line 18 to perform precharge, and then a pixel row in which a program current (voltage) is written may be selected.

  The precharge voltage is applied to the source signal line 18, but other methods are also exemplified. For example, the applied voltage (Vdd) to the anode terminal or the applied voltage (Vss) to the cathode terminal may be changed (a precharge voltage is applied). By changing the anode voltage or the cathode voltage, the writing capability of the driving transistor 11a is expanded. Therefore, the precharge effect is exhibited. In particular, the effect of implementing a method of changing the anode voltage (Vdd) in a pulse manner is high.

  Further, as shown in FIG. 236, the anode voltage and the precharge voltage may be changed with respect to the lighting rate. Further, as shown in FIG. 238, the magnitude of the precharge reference voltage (Vbv) may be changed with respect to the reference current ratio. As shown in FIG. 239 (see FIGS. 127 to 143 and the description thereof), the precharge reference voltage (Vbv) can be generated by the IV conversion circuit 2391 using the reference current Ic.

  The on-voltage (Vgl) and off-voltage (Vgh) of the gate driver circuit 12 may be changed with respect to the lighting rate, the reference current, and the anode (cathode) current of the anode (cathode) terminal. In particular, when the anode voltage Vdd is increased, it is preferable to increase the Vgh voltage in conjunction with the increase.

  In the embodiment of the present invention, the duty ratio, the reference current ratio, etc. are variable or controlled according to the lighting rate or the anode (cathode) current of the anode (cathode) terminal. In the current driving method, it is proportional to the program current Iw. Therefore, the reference current ratio (including pre-charge control or the like before or after the pre-charge control, etc., including the program current Iw, the sum of the program currents, or the sum of the predetermined periods is included. It is obvious that the control of the above and the like is also a technical category of the present invention.

  In FIG. 75 and the like, it is also effective to change the precharge voltage (or precharge current) every horizontal scanning period (1H) (illustrated in FIG. 257 (a)). In addition, as shown in FIG. 257 (b), it may be changed in a plurality of horizontal scanning periods. Alternatively, a precharge voltage may be applied at random so that the average effective voltage becomes the target precharge voltage. Also, the image data of the pixel row to which the precharge voltage is applied is calculated (addition or the like), and control is performed so that the precharge voltage (current) is applied, particularly when the ratio of low gradation image (video) data is large. It may be configured. The precharge voltage (current) can be changed depending on the calculation result. This is because, when the gradation is relatively high, halation occurs in the EL display panel, and a certain low gradation pixel has a high brightness. Therefore, by applying a precharge voltage to the pixels 16 having a certain low gradation or lower, a more complete black display can be realized and the contrast of the image can be increased.

  Further, the precharge voltage to be applied may be a constant voltage applied to a pixel having a certain low gradation (a pixel having a certain low gradation is blacked out), or the precharge in FIG. The value of the voltage change data D may be controlled to change the precharge voltage according to the image data applied to the pixel.

  As described above, the precharge voltage (current) can be changed depending on the case, as shown in FIG. 75, because the electronic volume 501 is incorporated in the source driver IC (circuit) 14. Is big. That is, the precharge voltage and the like can be changed digitally from the outside of the source driver circuit (IC) 14. Digital data D for realizing this change is generated by a controller IC (circuit) 760. Therefore, the source driver circuit (IC) 14 and the controller IC (circuit) 76 are functionally separated and can be easily designed or changed.

Although the precharge voltage and the like are changed within the 1H period as described above, the present invention is not limited to this. Image (video) data in a plurality of pixel rows (for example, 10 pixel rows) may be calculated, change data D may be set, and a precharge voltage (current) may be applied (see FIG. 257 (b)). ). Further, image (video) data in one frame (field) or a plurality of frames (field) may be calculated and a precharge voltage (current) may be applied.
Note that the precharge voltage (current) is changed or applied as a predetermined voltage by calculating image (video) data to the pixel 16 or the pixel row. However, the present invention is not limited to this. For example, a precharge voltage (current) to be applied may be fixed in advance, and this precharge voltage may be applied, or a plurality of precharge voltages may be selected in advance, and the precharge voltage, etc. It is needless to say that control may be applied to pixels, pixel rows, or the entire screen sequentially or randomly. Needless to say, the precharge voltage may not be applied depending on the calculation result.

  Further, the precharge voltage (current) or the like may be implemented using a frame rate control (FRC) technique. That is, gradation is applied to a plurality of frames (fields) by applying or not applying a precharge voltage or the like in a plurality of frames (fields) to a pixel or pixel row to which a precharge voltage is applied. (In this case, gradation is displayed by applying a precharge voltage or the like). By performing FRC as described above, appropriate black display or gradation display can be realized with a small number of precharge voltages (currents).

  The precharge voltage Vpc is generated via the operational amplifier circuit 502 by applying the output of the electronic volume 501 to the operational amplifier circuit 502 as shown in FIG. The power supply voltage (reference voltage) Vs of the electronic volume 501 and the source terminal potential (anode terminal voltage) Vdd of the driving transistor 11a are preferably made common. This is because the precharge voltage Vpc is based on the anode potential of the driving transistor 11a.

  In the above embodiment, the precharge voltage or the like is calculated and applied to the pixel 16 or the like. The application is not performed immediately after the calculation, but may be performed with a delay time. Further, when changing the precharge voltage or the like sequentially or randomly, it is preferable to perform the change gradually or slowly or with hysteresis. The technical idea such as delay time, which is because steep changes in the precharge voltage cause streaky display in the image and flicker may occur in the image display, will be described in FIG. 98 or other embodiments. Therefore, since this idea may be applied directly or similarly, the description is omitted.

  Needless to say, the FRC operation may also be changed according to the lighting rate. The change includes control of whether or not to perform FRC, control of which gradation FRC is performed, and control of the number of FRC conversion bits.

For example, when the lighting rate is high, the display is close to a white raster. Therefore, the entire screen is whitish and it is often unnecessary to perform FRC. On the other hand, when the lighting rate is low, there are many black display portions on the entire screen. In this case, it is necessary to perform FRC and improve the reproducibility of gradation.
The above is described as changing the FRC according to the lighting rate, but the present invention is not limited to this. For example, when the reference current is increased, the entire surface is whitish and there is often no need for FRC. On the other hand, when the reference current is low, there are many black display portions on the entire screen. In this case, it is necessary to perform FRC and improve the reproducibility of gradation. The above items can also be applied to duty ratio control. It goes without saying that the FRC change may be performed in response to the change in the anode (cathode) current.

  It is also effective to change the FRC in accordance with the lighting rate as shown in FIG. In FIG. 259, 8FRC (FRC for gradation display using 8 frames or 8 fields) is performed at a lighting rate of 0 to 25%. Therefore, the gradation display number is improved. At a lighting rate of 25 to 50%, 4FRC (FRC for gradation display using 4 frames or 4 fields) is performed. Similarly, when the lighting rate is 50 to 75%, 2FRC (FRC that performs gradation display using two frames or two fields) is performed, and when the lighting rate is 75 to 100%, FRC is not performed. That is, optimal FRC control is performed according to the lighting rate. In general, at a low lighting rate, there are many dark images, so it is necessary to improve the gradation expression by reducing the gamma coefficient and increasing the number of FRC frames.

  In the above embodiment, the precharge voltage, FRC, and the like are changed or controlled by image (video) data or the like, but the present invention is not limited to this. For example, the magnitude of the precharge voltage (current) may be changed according to the lighting rate, the current flowing through the anode (cathode) terminal, the reference current, the duty ratio, the panel temperature, or a combination thereof. Further, the application time of the precharge voltage may be changed.

  For example, it is preferable to change the magnitude of the precharge voltage since the magnitude of the program current changes according to the magnitude of the reference current and the current flowing through the driving transistor 11a changes. Further, when the lighting rate is high, the screen is close to white display, and halation is generated on the entire screen, so that black floating occurs. Therefore, applying a precharge voltage or the like to the pixel 16 has no effect. In this case, power consumption can be reduced by stopping application of the precharge voltage or the like. On the other hand, when the lighting rate is low, there are many black display portions on the screen and little halation is generated. Therefore, it is necessary to sufficiently precharge the pixels 16 to improve the contrast.

  Similarly, when the anode (cathode) current is large, halation is likely to occur because there are many white display portions on the screen. In this case, it is often unnecessary to apply a precharge voltage or the like. Conversely, when the anode (cathode) current is small, it is often necessary to apply a precharge voltage or the like.

  In the above embodiment, the magnitude of FRC or precharge voltage (current) is determined by image (video) data, lighting rate, current flowing through the anode (cathode) terminal, reference current, duty ratio, panel temperature, or a combination thereof. However, the present invention is not limited to this. Image (video) data, lighting rate, current flowing through anode (cathode) terminal, anode (cathode) terminal voltage (such as FIG. 122), potential difference between anode terminal voltage and cathode terminal voltage (such as FIG. 280), duty ratio, panel temperature It goes without saying that control of FRC, precharge voltage, etc. may be performed by predicting the rate of change or the change.

  As described above, according to the present invention, according to pixel (video) data or the like, the FRC or lighting rate, the current flowing through the anode (cathode) terminal, the reference current, the duty ratio, the panel temperature, or a combination thereof can be used to obtain the result. Correspondingly, this is a driving method for controlling the magnitude of the precharge voltage (current), the presence / absence of application of the precharge voltage, the FRC control of the precharge voltage, the change state of the precharge voltage, the precharge application period, etc. . It should be noted that the change or change is preferably carried out slowly or with a delay as described with reference to FIG.

  As described above, according to the present invention, in the first lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the first FRC or lighting rate or anode ( The current flowing through the cathode terminal is changed as a reference current, a duty ratio, a panel temperature, or a combination thereof. Further, in the second lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the current flowing through the second FRC, the lighting rate, or the anode (cathode) terminal. Alternatively, it is changed as a reference current, a duty ratio, a panel temperature, or a combination thereof. Or, depending on the lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal) (adapted), it flows to the FRC or the lighting rate or the anode (cathode) terminal. The current, the reference current, the duty ratio, the panel temperature, or the like or a combination thereof is changed. It goes without saying that the above matters can be applied to other embodiments of the present invention.

  As described above, according to the present invention, in the first lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the first FRC or lighting rate or anode ( The current flowing through the cathode terminal is changed as a reference current, a duty ratio, a panel temperature, or a combination thereof. Further, in the second lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the current flowing through the second FRC, the lighting rate, or the anode (cathode) terminal. Alternatively, the reference current, the duty ratio, the panel temperature, or the like is changed or a combination thereof, but the present invention is not limited to this. For example, the on-voltage and / or off-voltage of the gate driver circuit 12 may be changed depending on the lighting rate.

  In the above description, the lighting rate indicates an image display state. A low lighting rate indicates an image with many black displays (pixels or images with many low gradations), and a high lighting rate indicates an image with many white displays (pixels or images with many high gradations). Yes. The lighting rate indicates the magnitude of current flowing into the anode terminal (current flowing out from the cathode terminal). When the lighting rate is low, an image with a lot of black display is present, so the current flowing into the anode terminal (current flowing out from the cathode terminal) is small. When the lighting rate is high, an image with many white displays, the current flowing into the anode terminal (current flowing out from the cathode terminal) is large. In the present invention, the duty ratio, the panel temperature, the FRC, the reference current, and the like are changed using the above items.

  A low lighting rate indicates an image with many black displays (pixels or images with many low gradations). In an image with a lot of black display, a bright spot is generated due to leakage of the transistor 11 or black floating occurs. For this countermeasure, it is effective to manipulate the on / off voltage of the gate driver circuit 12. Hereinafter, the embodiment will be described.

  The organic EL element 15 is a self-light emitting element. When light emitted by this light emission enters a transistor as a switching element, a photoconductor phenomenon (photoconversion) occurs. “Photocon” refers to a phenomenon in which leakage (off leak) increases when a switching element such as a transistor is turned off by photoexcitation.

  In order to cope with this problem, the present invention forms a light shielding film under the gate driver circuit 12 (or the source driver circuit 14 in some cases) and under the pixel transistor 11. In particular, it is preferable to shield light from the transistor 11b disposed between the potential position (shown by c) of the gate terminal and the drain terminal (shown by a) of the driving transistor 11a. This configuration is shown in FIGS. 314 (a) and (b). In particular, when the display panel displays black, the potential at the potential position b of the anode terminal of the EL element 15 in FIGS. 314 (a) and 314 (b) is close to the cathode potential. Therefore, when the TFT 17b is in the on state, the potential “a” is also lowered. Therefore, the potential between the source terminal and the drain terminal of the transistor 11b (between the c potential and the a potential) is increased, and the transistor 11b is likely to leak. For this problem, it is effective to form a light shielding film 3141 as shown in FIGS. Note that the light-shielding film 3141 is formed of a metal thin film such as chromium and has a thickness of 50 nm to 150 nm. When the film thickness 3141 is thin, the light shielding effect is poor, and when it is thick, unevenness is generated and patterning of the upper transistor 11 becomes difficult.

  Since the potential between the source terminal and the drain terminal of the transistor 11b (between the c potential and the a potential) is increased and the transistor 11b is likely to leak, if the voltage between the c potential and the a potential is lowered, leakage occurs. Becomes smaller. In order to lower the voltage, it is effective to increase the ON voltage (Vgl2) of the transistor 11d. Vgl2 is the ON voltage of the gate driver circuit 12b.

  If leakage is conspicuous in black display, the on-voltage Vgl2 may be increased when the lighting rate is low. When the on voltage Vgl2 is increased, the transistor 11d is not completely turned on. This is because the on-resistance of the transistor 11d is high. Therefore, the voltage at point a does not decrease. Therefore, leakage of the transistor 11b does not occur. On the other hand, when the lighting rate is high, the terminal voltage of the EL element 15 is increased. Therefore, the transistor 11d needs to have low on-resistance.

  The above embodiment is shown in FIG. When the lighting rate is high as illustrated by the dotted line in FIG. 315, the on-voltage Vgl2 is decreased (in the negative direction), and as the lighting rate decreases, the on-voltage Vgl2 is increased to increase the on-resistance of the transistor 11d. Needless to say, the lighting rate can be replaced with the current of the anode (cathode) terminal. In addition, it goes without saying that the lighting rate control may be performed not only in the case shown in FIG.

  In FIG. 315, the Vgl2 voltage is changed in accordance with the lighting rate. As a method for reducing the leakage current of the transistor 11b, the cathode voltage Vss may be changed as shown in FIG. If leakage is conspicuous in black display, the cathode voltage Vss may be increased when the lighting rate is low. When the cathode voltage Vss is increased, the transistor 11d is not completely turned on. This is because the on-resistance of the transistor 11d is high. Therefore, leakage of the transistor 11b does not occur. On the other hand, when the lighting rate is high, the terminal voltage of the EL element 15 is increased. Therefore, since the transistor 11d needs to have low on-resistance, the on-resistance needs to be low. Therefore, the cathode voltage Vss is lowered. Needless to say, the lighting rate can be replaced with the current of the anode (cathode) terminal. In addition, it goes without saying that the lighting rate control may be performed not only in the case shown in FIG.

  Vgl2 is also preferably changed in the duty ratio control. The duty ratio is often implemented simultaneously with the change of the reference current. For example, in FIG. 116, in the range where the lighting rate is 20% or less, the duty ratio is decreased (the ratio of the non-lighting area 192 in the screen 144 is increased), and the reference current ratio is increased (1). The program current Iw per gradation is increased). By controlling the duty ratio (FIG. 116 (a)) and the reference current ratio (FIG. 116 (b)) simultaneously (duty ratio × reference current ratio = constant), the display luminance (FIG. 116 (c)) is not changed. The problem of current-driven crosstalk or black floating can be solved.

  In the driving method of Fig. 116, the duty ratio x reference current ratio = constant driving method, so the current flowing through the anode terminal increases as the duty ratio decreases. Therefore, if the anode and cathode voltages are fixed and fixed, the transistor 11d needs to have a low on-resistance. Therefore, it is necessary to lower Vgl2 to lower the on-resistance.

  From the above, as shown in FIG. 318, it is preferable to change the Vgl2 voltage in response to the change in the duty ratio. In FIG. 318, Vgl2 = 0V in the range where the duty ratio is 1/1 to 1/2. Therefore, the on-resistance of the transistor 11d is relatively high, and the transistor 11b is unlikely to leak. Therefore, the occurrence of black float can be suppressed. In a range where the duty ratio is ¼ or less, Vgl2 = −8V. Therefore, the on-resistance of the transistor 11d is low, a sufficient program current can be supplied to the driving transistor 11a, and the EL element 15 can be well lit in the saturation region. When the duty ratio is in the range of 1/4 to 1/2, Vgl2 is changed in the range of -8 to 0V in accordance with the duty ratio or the reference current ratio.

Needless to say, the above-described matters can be similarly applied to other embodiments of the present invention. Needless to say, it can be combined with other embodiments.
In FIG. 78 and the like, pixel data R, G, B data and precharge data (PRC, PGC, PBC) are applied in parallel to the source driver circuit 14, but the present invention is not limited to this. When configured to apply in parallel as described above, the number of wires connecting the controller 81 and the source driver IC 14 increases. Therefore, there is a problem that the number of pins of the controller 81 increases and the controller size increases.

As shown in FIG. 80, the present invention is composed of 6 bits of image data (DAT) and 4 bits of control data (DCTL), and 10 bits control image data and precharge data. The voltage is applied from 81 to the source driver circuit 14.
Specifically, image transfer is performed serially using a four-times clock of one clock in the conventional case (when RGB data is transferred in parallel). That is, as shown in FIG. 80 (refer to DAT), R data 6 bits, G data 6 bits, B data 6 bits, and control data 6 bits are transferred in one conventional clock period. Image data and control data are handled as setting data.

  R, G, B, and data identification data (D) are identified by 4 bits of DCTL. As described above, image data and control data are serially transferred (four phases), so that the number of wires connecting the controller and the source driver circuit 14 is reduced, and the control IC can be downsized.

  FIG. 80 shows a system in which 6 bits of image data (DAT) and 4 bits of control data (DCTL) are applied, and image data, precharge data, etc. are applied from the controller 81 to the source driver circuit 14 in 10 bits. Further, in this embodiment, image transfer is performed serially using a 4 × clock. However, the present invention is not limited to this. For example, RGB data that is image data and control data D may be serially transmitted, and the image data and control data may be identified by an ID signal. When the ID data is at the H level, it means image data, and when the ID data is at the L level, it means control data.

  Alternatively, image data may be transferred in RGB serial and whether or not each image data is precharged may be determined by a precharge identification signal PRC. When the PRC signal is at the H level, the corresponding image data is controlled to be applied to the source signal line 18 after being precharged, and when the PRC signal is at the L level, it is controlled not to be precharged.

  Needless to say, the image data and the control data may be serially transmitted as illustrated. Of course, the image data may be serially transmitted and the control data may be transmitted in parallel.

  In the above embodiment, input data to the source driver IC (circuit) 14 is serially transmitted. The present invention is not limited to this. For example, as illustrated in FIG. 81, a differential signal may be transmitted. Examples of means for making a differential signal include LVDS, CMADS, RSDS, mini-LVDS, and a self-transfer method.

  In FIG. 82, serial video data or the like is converted into a higher-frequency differential signal and transmitted, and the differential signal is returned to the serial video data and input to the source driver circuit (IC) 14 or In this embodiment, the data is further converted into parallel data and input to the source driver circuit (IC) 14. That is, video data is converted into serial data and differential signals and transmitted. Needless to say, in transmission, some sections, all sections, or some data signals may be transmitted in parallel.

  As shown in FIG. 81, serial data from the video signal processing circuit of the main body circuit (for example, 1561 in FIG. 156) is converted into a differential signal by a transceiver (transmitter) (T) 811a as a differential circuit. Is done. By converting to a differential signal, the amplitude of the signal is reduced, it is less susceptible to noise, and unnecessary radiation is also reduced. Therefore, the distance between the transceiver (T) 811a and the receiver (R) 811b can be increased. In addition, the number of signal lines can be reduced.

  The differential signal is converted into serial data by a receiver (R) 811b as a differential circuit. Of course, it goes without saying that the function of the controller IC 821 in FIG. 82 may be taken in and converted into parallel data. The receiver (R) 811b restores the serial data before differential signal conversion by the transceiver 811a.

  FIG. 82 shows a configuration example in which a serial-parallel conversion circuit 821 is arranged or formed at the next stage of the receiver (R) 811b. This corresponds to a serial-parallel conversion circuit 821 (specifically, a controller IC (circuit) (control means) composed of an ASIC. Serial data is converted into parallel data by the serial-parallel conversion circuit 821, and the converted parallel data is the source. It is input to a driver IC (circuit) 14.

  190, a differential circuit and a decoder circuit are formed (configured) in the source driver IC 16, and the differential signal 1901 is directly supplied to the source driver IC 16 from the outside of the panel module 1264 via the connector 1801. Needless to say, it may be configured to allow input.

  Examples of the control data include a variety of control data such as precharge control data such as FIGS. 16 and 75 and electronic volume data such as FIGS. 50, 60, 64, and 65.

  Further, as shown in FIG. 319, in addition to video data (RGB), an OSD (on-screen display) signal and an S / D signal (a determination signal between a moving image and a still image) are also sourced as differential signals by the controller 760. You may apply to driver circuit (IC) 14. The OSD signal is used to display a menu screen in a video camera or the like. Also, when the S / D signal is H, it is determined that the transmitted RGB video signal is a moving image, and the driving shown in FIGS. 54 (a1), (a2), (a3), and (a4) is performed to display a moving image. The driving method is performed. When the S / D signal is L, it is determined that the transmitted RGB video signal is a still image, and FIG. 54 (c1) (c2) (c3) (c4) or FIG. 54 (b1) (b2) (b3 ) A driving method corresponding to still display is performed by performing the division driving of (b4).

  In FIG. 251, the embodiment in which the speaker 2512 is arranged or formed in the display device (display panel) of the present invention has been described. The audio signal (AD) of the speaker 2512 may also be applied to the source driver circuit (IC) 14 as a differential signal by the controller 760 as shown in FIG.

  FIG. 83 shows a connection configuration of the control IC 81, the source driver circuit 14, and the gate driver circuit 12. Connection wiring can be omitted by serially transferring image data, electronic volume data, and precharge data as DCTL and DAT. Note that by performing serial-parallel conversion at the input stage of the source driver circuit 14, the precharge data and image data latch or holding circuit becomes the same as in FIG. The 4 bits of GCTL are clock, start pulse, up / down switching, and enable signal.

  FIG. 180 is an external view of a display panel of the present invention. A source driver IC 14 is COG mounted on the panel 1264, and the gate driver circuit 12 is made of polysilicon. A flexible substrate 1802 is connected from a terminal of the panel 1264. A controller IC 760 is mounted on the flexible substrate 1802. A signal from the controller IC 760 is input from the terminal 1801, and similarly, a signal from the gate driver circuit 12 is input from the terminal 1801.

  FIG. 181 is a more detailed display panel of the present invention. A cathode voltage is applied to the cathode wiring 1811, and the cathode wiring 1811 is connected to the cathode electrode at the cathode connection position 1812. A gate driver signal 1813 from the controller IC 760 is applied to the gate driver circuit 12. The source driver signal 1814 is also applied from the controller 760 to the source driver IC 14. The anode wiring 1815 is formed on the back surface (the array surface) of the source driver IC. The anode wiring 1815 is formed near the display area of the display panel.

  The EL display device has a cathode wiring and an anode wiring which are not found in the liquid crystal display device, and two gate driver circuits 12a and 12b are necessary as shown in FIG. 831. Therefore, the number of wires is large and the connection is complicated. Therefore, the frame of the panel 1264 becomes large due to the wiring. The size of the flexible substrate 1802 for inputting signal lines to the panel 1264 is increased, which directly leads to higher costs.

  FIG. 282 is an explanatory diagram of a configuration for solving this problem. For ease of explanation, in FIG. 282 and the like, the control signal line of the gate driver circuit 12 is ST (signal line for applying or transmitting a start pulse), CLK (signal line for applying or transmitting a clock (shift) pulse. ), Only ENBL (signal line for applying or transmitting an enable pulse). In practice, it goes without saying that there are UD (signal lines for applying or transmitting signals in the up / down direction), signal lines for transmitting or supplying Vgh voltage or Vgl voltage, and the like.

  For ease of explanation, ST (signal line for applying or transmitting a start pulse), CLK (signal line for applying or transmitting a clock (shift) pulse), ENBL (signal line for applying or transmitting an enable pulse) , A signal line for transmitting a control signal such as UD (signal line for applying or transmitting a signal in an up / down direction) is called a control signal line, and a signal line for transmitting or supplying a Vgh voltage or a Vgl voltage is a voltage signal line. Call it.

  In FIG. 282, the source driver IC 14 is formed or configured by a silicon chip, and is mounted on the array substrate 30 by the COG (chip on glass) technology. On the other hand, the gate driver circuit 12 is directly formed on the array substrate 30 by polysilicon technology such as low-temperature polysilicon, high-temperature polysilicon, or CGS.

  In FIG. 282, the control signal line (or the power signal line) is connected to the gate driver circuit 12 or the like via the back surface of the source driver IC 14 or the wiring pattern of the source driver IC 14. As described above, the control signal line and the power signal line are supplied via the source driver IC 14, so that the width of the flexible substrate 2911 (1802) to which the signal lines and the like are connected is set to about the chip width ± of the source driver IC 14. it can. Therefore, the cost can be reduced (see FIG. 291).

  In order to realize the configuration of FIG. 282, the source driver IC 14 of the present invention is configured (formed) as shown in FIG. FIG. 288 is a view of the source driver IC 14 of the present invention as seen from the back side. Wiring 2885 and the like are formed at both ends of the chip 14. In FIG. 288, the wiring is a normal aluminum wiring and is formed in the IC manufacturing process. However, the formation method of the wiring 2885 and the like is not limited to this, and may be formed by a screen printing technique after the IC 14 is completed. Needless to say, the wiring 2885 and the like may be formed only on one side of the chip 14.

  The IC 14 is formed with an input terminal 2883 such as a control signal line and a terminal 2884 connected to the source signal line 18. A terminal 2881 a for connecting a control signal line is formed or arranged at the end of the chip 14. In addition, a wiring 2885 is connected to the terminal 2881a, and the other end of the wiring 2885 is connected to the terminal 2881b. Therefore, the control signal line connected to the range of G1a is connected to the terminal 2881b on the side of the chip. The power signal line connected to the terminal 2882a is connected to the terminal 2882b through the wiring 2885. It is assumed that the terminal 2882 is connected to an anode or a cathode wiring. Therefore, the power signal line bridges the IC chip and is output to the output side of the IC 14 (the connection side with the source signal line 18).

  The reason why the IC 14 is bridged by the wiring 2885 in this way is that the anode wiring 1815 and the like are often formed on the back surface of the IC 14 as a light shielding film of the IC 14 as shown in FIG. 208 (FIG. 290 also). See By forming the anode wiring 1815 on the back surface of the IC as a light shielding film, the IC does not operate due to the photoconductor phenomenon. By connecting the control signal line or the power signal line with the wiring 2885, it is not necessary to cross the wiring on the array substrate 30, and a short circuit or the like at the crossing portion can be reduced and the manufacturing yield can be improved.

  In the embodiment of FIG. 288, the wiring 2885 and the like are formed on the back surface of the IC chip 14 (the surface facing the array substrate 30 when mounted), but the present invention is not limited to this. The wiring 2885 and the like may be formed or arranged on the surface of the IC chip 14. Needless to say, flexible 2911 (1802) in which wiring 2885 and the like are formed may be disposed in the gap between the IC chip 14 and the array substrate 30.

  In the above embodiment, the wiring 2885 and the like are formed in the source driver IC 14 and the signal line is bridged. However, the present invention is not limited to this, and it goes without saying that the gate driver circuit 12 may be formed of a silicon chip (gate driver IC 12) or the like, and the wiring 2885 or the like may be formed on the back surface of the gate driver IC 12 or the like. .

  A thin film (thick film) made of an inorganic material or an organic material is preferably formed over the wiring 2885. The thickness of the thin film (thick film) needs to be at least 0.1 μm or more. However, it is preferably 3 μm or less. By forming a thin film (thick film), the wiring 2885 is protected, and problems such as corrosion do not occur. The relative dielectric constant of the thin film (thick film) is preferably 3.5 or more and 6.0 or less.

  FIG. 289 shows a state in which the source driver IC 14 of the present invention is mounted on the array substrate 30. The power signal line (the anode wiring in the embodiment) is output to the terminal 2882b via the wiring 2885 and branched to the pixel 16 portion of the display area 144. It is output from the terminal 2882b at the right end of the IC chip of the cathode wiring and connected to the cathode electrode 36 at the cathode connection point. The control signal line is also output from the terminal 2881 b via the wiring 2885 of the IC 14 and input to the gate driver circuit 12.

  FIG. 290 is a cross-sectional view when the IC 14 is mounted on the array substrate 30. A wiring 2885 is formed on the back surface of the IC chip 14 to connect between the terminals 2882a and 2882b. A gold bump 2904 is formed on the terminal 2882. The gold bump 2904 connects the terminal 2902 of the array substrate 30 and the terminal 2882 of the IC 14. Therefore, since the signal applied to the signal line 2901 is electrically connected to the signal line 2852 via the wiring 2885 of the IC 14, the signal lines 2901 intersect even if conductor lines such as the anode wiring 2903 are formed on the array substrate 30. There is nothing.

  As shown in FIG. 347, the output terminal position is set so that the wiring 2852 delivered from the source driver circuit (IC) 14 to the gate driver circuit (IC) 12 does not intersect. Other contents are described in FIG.

  Further, as shown in FIG. 358, the power supply wiring (for example, supply wiring for Vgh voltage, Vgl voltage, etc.) 2852b of the gate driver 12 is formed on the surface of the array substrate 30, and is formed on the lower surface of the source driver IC 14 constituted by a chip. Arrangement (arrangement or formation). The anode wiring is also formed or arranged on the surface of the array 30 on the back surface of the IC chip 14. The control signal line of the gate driver circuit 12 is connected via a wiring 2885 formed or arranged in the source driver IC 14.

  By configuring as described above, the back surface portion of the IC chip 14 can be effectively used, and the panel can be narrowed.

  As described above, by bridging the power signal line or the control signal line via the wiring 2885 of the IC 14, the effect that it does not intersect with the wiring formed on the substrate 30 is exhibited. As another great effect, as shown in FIG. 291, an effect that the size of the flexible substrate 2911 for applying a signal line or the like to the panel can be reduced is also exhibited. Since the flexible substrate 2911 is generally expensive, the smaller the size, the greater the cost merit.

  As shown in FIG. 291, signals and the like are input straight from the flexible substrate 2911 to the input signal lines 2901 and 2852 to the IC 14. If the wiring 1485 of the IC 14 is not provided, the control signal line needs to be bent at the input surface of the substrate 30 while avoiding the IC 14. If it bends, the frame of a panel will become large. By connecting through the wiring 2885 of the IC chip 14 as in the present invention, the frame can be reduced.

  In the embodiment described with reference to FIG. 288 and the like, the terminal 2881a and the terminal 2881b are connected by a wiring 2885 or the like. That is, the signal input from the terminal 2881a is output to the terminal 2881b as it is. However, the present invention is not limited to this. For example, it goes without saying that a circuit or wiring for branching, delaying, or changing an input signal may be formed or arranged between the terminals 2881.

  FIG. 283 shows a structure in which a conversion circuit 2831 is formed or arranged between the terminals 2881a and 2881b as an example. The conversion circuit 2831 in the embodiment of FIG. 283 is an inverted output generation circuit. An inverted output generation circuit 2831 generates an inverted signal of the input signal. For example, if it is an ST signal, a negative ST signal is generated. This negative ST signal is referred to as NST. More specifically, if ST is 1V in the period of one frame and becomes 3V, and the other periods are 0V, the NST signal becomes 0V in the period of 1H in one frame period and 3V in the other periods. Become. The above items also apply to the CLK and ENBL signals.

  That is, in FIG. 283, the signal input to the terminal 2881a is converted into a positive signal and a negative signal by the inverting output circuit 2831 and output from the terminal 2831b. Therefore, input signals can be reduced in the source driver IC 14.

  Although FIG. 283 shows a circuit for generating an inverted output, the present invention is not limited to this. In FIG. 284, a delay circuit 2841 composed of a flip-flop circuit (FF circuit) is formed in the source driver IC.

  In FIG. 284, as an example, the FF circuit 2841 is disposed between the terminal 2881a and the terminal 2881b. The ST signal and the like are delayed by the FF circuit 2841. The control signals (ST, CLK, etc.) of the gate driver circuit 12 are synchronized with the latch circuit 862 of the source driver circuit 14, and the timing of the program current applied to the source signal line 18 and the ON voltage to the gate signal line 17a. It is necessary to adjust the application timing. This timing adjustment is performed by the FF circuit 2841 or the like. With the configuration described above, the timing adjustment of the control signal output from the controller 760 is facilitated.

  In addition to the above embodiments, as shown in FIG. 285, control signals (ST, CLK, ENBL, etc.) may be generated from HD (horizontal scanning signal) and VD (vertical scanning signal). That is, the signal generation circuit 2851 is formed or arranged in the source driver circuit 14. The signal generation circuit 2851 generates control signals (ST, CLK, ENBL, etc.) from HD (horizontal scanning signal), VD (vertical scanning signal), and the like. With the above configuration, the number of signal lines to the source driver IC 14 can be further reduced.

  In FIG. 190, the embodiment in which the signal to the source driver IC 14 is input as a differential signal has been described. Similarly, in FIG. 81 and FIG. 82, the embodiment in which signals are supplied as differential signals has been described. Similarly, as shown in FIG. 292, a gate signal (control signal (ST, ENBL, etc.) of the gate driver circuit 12) may be applied to the source driver IC 14 as a differential signal. The differential signal is converted into a parallel signal by a differential-parallel signal conversion circuit 2921.

  In the embodiment of FIG. 292, the anode voltage and cathode voltage as power signals are input to the terminal 2882a, and the gate signal (differential) for controlling the gate driver circuit 12 is input to the terminal 2881a. The video signal (differential) and the control signal (differential) are input to the terminal 2883. Needless to say, the gate signal, the video signal, and the control signal may be a single twisted pair differential signal.

  Needless to say, the above embodiment can be applied to other terminals (2883, 2884, 2882, etc.).

  In addition, the number of signal lines is reduced by applying a differential signal to FIG. 292, and the configuration in which signal lines are not crossed by forming the wiring 2885 in the IC 14 as shown in FIGS. 288, 290, etc. This is an effect that can be exhibited by forming the gate driver circuit 12 or the like on the array substrate 30 by polysilicon technology and forming the source driver IC 14 by a silicon chip or the like and mounting it on the array substrate 30 using COG technology.

  The above embodiment is an embodiment in which one IC 14 is used for the panel 1264. However, the present invention is not limited to this. For example, as shown in FIG. 316, two (plural) IC chips 14 may be mounted on the array substrate 30 to constitute the display panel 1264. A power signal line or a control signal line or both signal lines are formed or arranged at both ends of the IC 14, and a differential-parallel signal conversion circuit 2921 is formed or disposed at both ends of the IC 14. Has been placed. Which differential-parallel signal conversion circuit 2921 is operated is switched by a selector signal GSEL. In FIG. 316, the differential-parallel signal conversion circuit 2921a1 operates in the IC chip 14a, and a control signal for the gate driver circuit 12a is output from the differential-parallel signal conversion circuit 2921a1. In the IC chip 14b, the differential-parallel signal conversion circuit 2921b2 operates, and a control signal for the gate driver circuit 12b is output from the differential-parallel signal conversion circuit 2921b2.

  In FIG. 316, the differential-parallel signal conversion circuit 2921 is arranged at both ends of the IC chip 14, but the present invention is not limited to this. One differential-parallel signal conversion circuit 2921 may be provided, and a control signal line or the like may be branched to both ends of the chip 14 by a wiring 2851. What is important is that a power signal line or a control signal line can be output at both ends of the IC chip 14, and when a plurality of IC chips 14 are mounted on the array substrate 30 as shown in FIG. It is possible to switch whether or not the output of the signal line or the control signal line is output (or to prevent the image display from being affected even if a signal or the like is output from both). Switching is performed by a GESL signal. Accordingly, the same source driver IC 14 can be used regardless of whether one source driver IC 14 of the present invention is mounted on the array 30 or a plurality of source driver ICs 14 are mounted. In addition, the case where one gate driver circuit 12 is used and the gate driver circuit 12 is formed or arranged at one end of the screen 144 can be applied.

  In some cases, the direction may be the input direction. For example, the output pulse of the start pulse (ST) from the gate driver circuit 12 may be input to the terminal 2821b and output from the terminal 2821a. This output pulse is input to the control IC 760. With this output pulse, the control IC 760 can monitor the operation of the gate driver circuit 12 or determine its normality. In the present invention, the source driver IC 14 is formed of silicon or the like and mounted on the substrate 30 using COG technology or the like. However, the present invention is not limited to this. You may mount using TAB or COF technology. The circuit 14 of the source driver IC may be directly formed on the array substrate 30 using polysilicon technology. This is particularly effective for the configuration shown in FIG. In addition, the IC chip 14 is mounted on the array substrate 30 (the substrate on which the pixel electrode or the like is formed). However, the present invention is not limited to this. The source signal is formed on the counter substrate side and formed on the array substrate 30 or the like. You may connect with the line 18 etc. It goes without saying that the above matters can be applied to other embodiments of the present invention.

  FIG. 191 is a cross-sectional view of the flexible substrate 1802 portion. A power supply module 1912 is connected to the flexible substrate 1802 via a terminal 1914 on the flexible substrate 1802. A coil (transformer) 1913 is mounted on the power supply module 1912, and the coil 1913 is inserted into a hole formed in the flexible board 1802. By constituting as described above, a thin panel module as a whole can be obtained.

  As shown in FIG. 1, when the driving transistor 11a and the selection transistors (11b, 11c) of the pixel 16 are P-channel transistors, a punch-through voltage is generated. This is because the potential fluctuation of the gate signal line 17a penetrates to the terminal of the capacitor 19 through the GS capacitance (parasitic capacitance) of the selection transistors (11b, 11c). When the P-channel transistor 11b is turned off, the voltage becomes Vgh. Therefore, the terminal voltage of the capacitor 19 is slightly shifted to the Vdd side. For this reason, the gate (G) terminal voltage of the transistor 11a rises, resulting in a black display. Therefore, good black display can be realized.

  However, complete black display of the 0th gradation can be realized, but it is difficult to display the 1st gradation. Alternatively, a large gradation jump occurs from the 0th gradation to the first gradation, or blackout occurs in a specific gradation range.

  The configuration for solving this problem is the configuration shown in FIG. It has a function of raising the output current value. The main purpose of the raising circuit 841 is to compensate for the punch-through voltage. Further, even when the image data has a black level of 0, a certain amount of current (several tens of nA) flows, and can be used for black level adjustment.

  Basically, FIG. 84 is obtained by adding a raising circuit 841 (portion surrounded by a dotted line in FIG. 84) to the output stage of FIG. FIG. 84 assumes that the current value raising control signal is 3 bits (K0, K1, K2), and outputs a current value 0 to 7 times the current value of the grandchild current source by this 3-bit control signal. It is possible to add to the current. Although the current raising control signal is 3 bits, it is needless to say that the current raising control signal is not limited to this and may be 4 bits or more.

  The above is the basic outline of the source driver IC (circuit) 14 of the present invention. Hereinafter, the source driver IC (circuit) 14 of the present invention will be described in more detail.

  There is a linear relationship between the current I (A) flowing through the EL element 15 and the light emission luminance B (nt). That is, the current I (A) flowing through the EL element 15 is proportional to the light emission luminance B (nt). In the current driving method, one step (gradation step) is a current (unit transistor 154 (one unit)).

  Human vision of brightness has a square characteristic. That is, when changing with a square curve, the brightness is recognized as changing linearly. However, as shown by a solid line a in FIG. 62, the current I (A) flowing through the EL element 15 and the light emission luminance B (nt) are proportional to each other in both the low luminance region and the high luminance region.

  Therefore, if the step is changed step by step (one gradation), the luminance change for one step is large (black skip occurs) in the low gradation portion (black region). Since the high gradation portion (white region) substantially coincides with the linear region of the square curve, the luminance change for one step is recognized as changing at equal intervals. From the above, in the current driving method (when one step is in increments of current) (in the current driving source driver IC (circuit) 14), the display of the black display region becomes a particular problem.

  To solve this problem, the slope of the current output in the low gradation region (gradation 0 (full black display) to gradation (R1)) is reduced, and the maximum gradation (R) from the high gradation region (gradation (R1)). )) Increase the current output slope. In other words, in the low gradation region, the current amount is increased with a small amount (one step) per gradation. In the high gradation region, the current amount increases with one gradation (one step). By making the amount of current changing per step different between the high gradation region and the low gradation region, the gradation characteristic becomes close to a square curve, and blackout does not occur in the low gradation region.

  In the above embodiment, the current gradient has two steps of the low gradation region and the high gradation region. However, the present invention is not limited to this. Needless to say, there may be three or more stages. However, it is needless to say that the case of two stages is preferable because the circuit configuration is simplified. Preferably, the gamma circuit is preferably configured so as to generate a gradient of five or more steps.

  The technical idea of the present invention is a circuit for performing gradation display by current output in a current-driven source driver IC (circuit), etc. Therefore, the display panel is limited to an active matrix type. (Instead, a simple matrix type is also included.) This means that a plurality of current increase amounts per gradation step exist.

  In a current-driven display panel such as an EL, display luminance changes in proportion to the amount of current applied. Therefore, in the source driver IC (circuit) 14 of the present invention, the luminance of the display panel can be easily adjusted by adjusting the reference current that causes the current source (one unit transistor) 154 to flow. .

  In the EL display panel, the luminous efficiency is different between R, G, and B, and the color purity with respect to the NTSC standard is shifted. Therefore, in order to optimize the white balance, it is necessary to appropriately adjust the RGB ratio. Adjustment is performed by adjusting the respective reference currents of RGB. For example, the R reference current is set to 2 μA, the G reference current is set to 1.5 μA, and the B reference current is set to 3.5 μA. As described above, it is preferable that at least one color reference current among at least a plurality of display color reference currents can be changed, adjusted, or controlled.

  As shown in FIG. 184, the white balance is realized by adjusting the reference current Ic (the red reference current is Icr, the green reference current is Icg, and the blue reference current is Icb). However, there are variations in the characteristics of the transistor 158 and white balance deviation occurs. This may vary from IC chip to IC chip. For this problem, the trimming technique described in FIG. 164 and the like is used for the inside of the reference current circuit 601r (for red), the reference current circuit 601g (for green), and the reference current circuit 601b (for blue) in FIG. To achieve white balance. In particular, in the current driving method, since the relationship between the current I flowing through the EL and the luminance has a linear relationship, this adjustment is very easy.

  In the current driving method, the relationship between the current I flowing through the EL and the luminance has a linear relationship. Therefore, the white balance adjustment by mixing RGB only needs to adjust the RGB reference current at one point of predetermined luminance. That is, if the RGB reference current is adjusted at one point with a predetermined luminance and the white balance is adjusted, the white balance is basically achieved over all gradations. Therefore, the present invention is characterized in that it includes an adjusting unit that can adjust the RGB reference currents, and includes a one-point bent or multi-point bent gamma curve generating circuit (generating unit). The above items are circuit systems peculiar to the current control EL display panel.

  The generation of the reference current is not limited to the configuration shown in FIGS. 60 to 66 (a) and 66 (b). For example, the configuration of FIG. 198 is illustrated. In FIG. 198, 8-bit data is converted into a voltage by a DA (digital analog) conversion circuit 661. This voltage becomes the power supply voltage (Vs in FIG. 60) of the electronic regulator 501. The electronic volume 501 is controlled by voltage data (VDATA), and a Vt voltage is output. The output Vt data is input to the operational amplifier 502, and a predetermined reference current Ic is output by the current circuit including the resistor R1 and the transistor 158a. If configured as described above, the variable range of the Vt voltage can be controlled widely by 8-bit DATA and 8-bit VDATA.

  FIG. 197 shows a structure including a plurality of current circuits (composed of an operational amplifier 502, a resistor R *, and a transistor 158a). The magnitude Ic of the reference current output by each current circuit differs depending on the magnitude of the resistance. The constant current circuit composed of the operational amplifier 502a has R1 = 1 MΩ, and flows the reference current Ic1. The constant current circuit composed of the operational amplifier 502b has R2 = 500 KΩ, and flows the reference current Ic2. The constant current circuit composed of the operational amplifier 502c has R3 = 250 KΩ, and flows the reference current Ic3.

  The selection switch S determines which current circuit's reference current Ic is used. Selection of the switch S is performed by an external input signal. When the switch S1 is turned on and the switches S2 and S3 are turned off, the reference current Ic1 is applied to the transistor group 431b. When the switch S2 is turned on and the switches S1 and S3 are turned off, the reference current Ic2 is applied to the transistor group 431b. Similarly, when the switch S3 is turned on and the switches S2 and S1 are turned off, the reference current Ic is applied to the transistor group 431b.

  Since the reference currents Ic1, Ic2, and Ic3 are configured to be different from each other, the output currents from the output terminal 155 can be simultaneously changed by switching the switches S to be selected. Further, by changing the selection switch S at a constant cycle such as one field or one frame, the magnitude of the program current applied to the panel can be changed for each frame or the like, and the image brightness or the like can be changed in a plurality of frames or fields. An averaged image display with good uniformity can be obtained.

  In the above embodiment, the switch S selected for each field or frame is changed to change the magnitude of the program current. However, the present invention is not limited to this. For example, it may be changed every several fields or frames, and the switch S may be switched every 1H (one horizontal scanning period) or every plural H (scanning periods). Alternatively, the operation may be performed so that a predetermined reference current Ic is applied to the transistor group 431b as a whole by changing the random.

  The driving method of changing the magnitude of the reference current periodically or randomly to obtain a predetermined reference current as an average at a fixed period is not limited to that shown in FIG. For example, the present invention can be applied to a reference current generating circuit shown in FIGS. 60 to 66 (a) and 66 (b). The reference current of each circuit can be changed by changing or changing the electronic volume 501 and the power supply voltage Vs.

  In the above embodiment, one of the reference currents Ic1 to Ic3 is selected and applied to the transistor 431b. However, the present invention is not limited to this, and the currents of a plurality of current circuits are added to form a transistor group 431b. You may apply to. In this case, a plurality of switches S may be turned on. Further, the reference current applied to the transistor group 431b can be set to 0 A by turning off all the switches S. If 0A is set, the program current output from each terminal 155 becomes 0A. Therefore, the source driver IC 14 can be in an output open state. That is, the source driver IC 14 can be disconnected from the source signal line 18.

  FIG. 198 shows a configuration in which the reference currents from a plurality of reference current generation circuits are added and applied to the transistor 431b. In the current circuit composed of the operational amplifier 502a, the output current Ic1 changes with 8-bit data composed of DATA1. In the current circuit composed of the operational amplifier 502b, the output current Ic2 changes with 8-bit data composed of DATA2. A reference current Ic1 or Ic2 or both reference currents are applied to the transistor group 431b.

  FIG. 199 shows another embodiment of the reference current generating circuit. Transistors 158b1 and 158b2 are arranged on both sides of the gate wiring 153. A current of any one of I, 2I, 4I, and 8I or a combined current is applied to the transistor 158b1 according to the D1 data. That is, the switch S * a is selected by the D1 data. 2I means a current twice as large as I, and 4I means a current four times as large as I. The same applies hereinafter. A current of any one of I, 2I, 4I, and 8I or a combined current is applied to the transistor 158b2 according to the D2 data. That is, the switch S * b is selected by the D2 data. Even with the configuration described above, the reference current can be dynamically varied.

  FIG. 200 shows an example in which the transistor group 431c is divided into a plurality of blocks (431c1, 431c2, 431c3). The output terminal 155 outputs a tradition from a plurality of blocks of transistor groups 431c.

  Even if the unit transistor 154 has the same size in the transistor group 431c, the magnitude of the program current output from the output terminal 155 differs if the current flowing through each unit transistor 154 differs. As shown in FIG. 201, when the reference current is small, the increase rate of the program current with respect to the gradation is small (see 0 to Ka in FIG. 201). When the reference current is large, the increase rate of the program current with respect to the gradation is large (see the range of Kb or more in FIG. 201). That is, the transistor group 431c is divided into a plurality of blocks, and the magnitude of the reference current supplied to the unit transistors 154 in each block is changed. Since this configuration is also described in FIG. 56, see the embodiment in FIG.

  In FIG. 200, one transistor group 431c is divided into three blocks. The potential of the gate wiring 153a is set to the transistor 431c1 of the transistor 431c by the reference current I1 applied to the transistor 158b1. The output current of the unit transistor 154 of the transistor group 431c1 is determined by the potential of the gate wiring 153a. Further, it is assumed that I1 is smaller than I2, and the low gradation range (0 to Ka) in FIG.

  The potential of the gate wiring 153b is set to the transistor 431c2 of the transistor 431c by the reference current I2 applied to the transistor 158b2. The output current of the unit transistor 154 of the transistor group 431c2 is determined by the potential of the gate wiring 153b. Further, it is assumed that I2 is smaller than I3, and the middle gradation range (Ka to Kb) in FIG. Similarly, the potential of the gate wiring 153c is set to the transistor 431c3 of the transistor 431c by the reference current I3 applied to the transistor 158b3. The output current of the unit transistor 154 of the transistor group 431c3 is determined by the potential of the gate wiring 153c. Further, it is assumed that I3 is the largest and the high gradation range (Kb or more) in FIG. 201 corresponds.

  As described above, the plurality of transistor groups 431c are divided into a plurality of blocks, and the magnitude of the reference current is different for each of the divided blocks, whereby a polygonal line gamma curve can be easily generated as shown in FIG. Further, a multi-line broken gamma curve can be obtained by increasing the number of reference currents.

  In the above embodiment, the transistor group 431c is divided into a plurality of blocks, and the unit transistors 154 in the divided blocks are the same. However, the present invention is not limited to this. As illustrated in FIG. 55 and the like, the unit transistors 154 may have different sizes. Further, the unit transistor 154 may not be used as shown in FIG. The generation of the reference current may be any configuration such as FIGS. 161 to 168.

  In the above embodiment, as described with reference to FIG. 43, the output stage basically includes the transistor group 431c. In the transistor group 431c, the unit transistor 154 is one at the D0 bit, the two unit transistors 154 are at the D1 bit, the four unit transistors 154 are at the D2 bit, and the unit transistor is at the Dn bit. 154 is arranged or formed with 2 n powers. This configuration is conceptually illustrated in FIG.

  In FIG. 240, trb (transistor block) 32 indicates that 32 unit transistors 154 are provided. Similarly, trb (transistor block) 1 indicates that one unit transistor 154 is provided, and trb (transistor block) 2 indicates that two unit transistors 154 are included. Further, trb (transistor block) 4 indicates that four unit transistors 154 are provided. The same applies hereinafter.

  However, the unit transistor 154 has different characteristics at the formation position in the IC wafer. In particular, a periodic characteristic distribution occurs before and after the diffusion configuration. As an example, the strength of the characteristics of the unit transistor 154 occurs with a period of 3 to 4 mm. For this reason, when the transistor group 431c is formed at the pitch of the terminals 155 as shown in FIG. 240, the intensity cycle of the current output from the terminals 155 (when the output gradation is the same for all the terminals 155) occurs. There is.

  To deal with this problem, the present invention further subdivides trb (transistor block) having many unit transistors 154 as shown in FIG. In FIG. 241, as an example, trb32 is divided into four blocks (trb32a, trb32b, trb32c, trb32d). Basically, the number of divided unit transistors 154 is the same. Of course, the number of unit transistors 154 to be divided may be different.

  In FIG. 241, trb 32a, trb 32b, trb 32c, and trb 32d are each composed of eight unit transistors 154. Needless to say, trb16 may be divided into small blocks each including eight unit transistors 154, trb16a and trb16b. Here, for ease of explanation, it is assumed that only trb 32 is divided.

  In order to eliminate the period of the output current from the output terminal 155, it is effective to configure one output stage 431c with unit transistors 154 formed at a wider position from within the IC (circuit) chip. This embodiment has the configuration shown in FIG. However, FIG. 242 is conceptually illustrated. Actually, the trb at a far position is connected by the horizontal wiring to constitute the output stage 431c of one terminal 155.

  In FIG. 242, the D5th bit of the terminal 155a includes trb32a1, trb32a2, trb32c1, and trb32c21. In other words, the output stage of the terminal 155a is originally configured by using unit transistor groups of the adjacent output terminals 155b. Similarly, the D5th bit of the terminal 155b is composed of trb32b2, trb32b3, trb32d2, trb32d3. That is, the output stage of the terminal 155b is originally configured by using unit transistor groups of the adjacent output terminals 155c. Further, the D5th bit of the terminal 155c is composed of trb32a3, trb32a4, trb32c3, trb32c4. That is, the output stage of the terminal 155c is originally configured by using unit transistor groups of the adjacent output terminal 155d. The same applies hereinafter.

  More actually, the small transistor group trb is connected as shown in FIG. FIG. 243 illustrates a connection state of only the trb 32 of the terminal 155a (other bits and other terminals 155 are similarly connected). In FIG. 243, trb32 includes trb32a1, trb32b6 adjacent to the 6th terminal, trb32c11 adjacent to the 11th terminal, and trb32d16 adjacent to the 16th terminal. That is, the trb 32 is configured (formed) by connecting (connecting) the trb 32 having different vertical and horizontal positions. As described above, the unit transistor 154 composing each bit of the unit transistor group 431 is composed of the unit transistors 154 at a distant position, so that the periodicity of output variation can be eliminated.

  However, when connection is performed as shown in FIG. 243, there is no trb to be connected to the terminal 155n (the last terminal). This problem can be solved by using the unit transistor 158b (see FIGS. 48 and 49) of the transistor group 431b that flows a reference current that forms a current mirror pair with the transistor group 431c. The unit transistor 158b and the unit transistor 154 are configured to have the same size and the same shape. The transistor group 431b is arranged on one end or both sides of the IC (circuit) 14. It should be noted that when a trb that can be connected also at the terminal 155n is formed, it is obvious that it is not necessary to adopt the configuration described below.

  A transistor group having the same function as trb (32) configured by the unit transistors 158b configuring the transistor group 431b is denoted by tb (see FIG. 244). Therefore, tb and trb are connected to the same gate wiring 153. Therefore, the trb32 of the terminal 155n may be constituted by trb32n1, tb32b6 adjacent to the 6th terminal, tb32c11 adjacent to the 11th terminal, and tb32d16 adjacent to the 16th terminal.

  Of course, as shown in FIG. 245, if tb and trb are dispersed and arranged or arranged in the IC (circuit) 14, it goes without saying that complicated wiring as shown in FIG.

  According to the result of the examination, the unit transistor 154 is preferably composed of the unit transistor 154 in a range of at least 0.05 square mm or more. More preferably, the unit transistor 154 is in the range of 0.1 square mm or more. More preferably, the unit transistor 154 is in the range of 0.2 mm 2 or more. The area (square mm) is calculated from a straight line connecting the four unit transistors 154 located at the farthest position.

  The deviation of the program current output to the source signal line 18 often has periodicity as shown in FIG. In FIG. 286, the horizontal axis indicates the output terminal position of one chip. That is, from the terminal 1 to the n terminal position. The vertical axis indicates the deviation from the average value of the output program current of the 32nd gradation in%. As shown in FIG. 286, the deviation of the output program current often has periodicity. This is due to the diffusion process of the IC manufacturing process.

  When there is a deviation in output program current as indicated by the solid line, correction (compensation) can be performed by applying reverse correction as indicated by the dotted line. Correction (compensation) is easy. When the program current is a sink (sink) current, the discharge current may be added within a range of 0 to 5%. That is, a discharge current circuit composed of a P-channel unit transistor 154 (see the configuration and description of FIG. 43 and the like) is formed in the source driver circuit (IC) 14, and the discharge current of this circuit is supplied to each terminal 155. It is good to add (compensate) the output program current. Further, adjustment, configuration, or formation may be performed using the trimming technique described in FIGS. 162 to 176 and the like.

  In order to determine the magnitude of the current to be corrected (compensated), the output program current from the terminal 155 is measured as shown in FIG. The video data (RDATA, GDATA, BDATA) is set to a predetermined value (generally, each bit of the unit transistor group 431c), and the program current Iw is output from the terminal 155. This output current Iw is connected to a current measuring circuit 2872 by a probe 2873 connected to a terminal 155 and measured. It goes without saying that the current for each terminal may be connected to the switching current measuring circuit 2872 with a switch formed inside the source driver circuit (IC) 14.

  The current measurement circuit 2872 outputs the measured current to the correction data calculation circuit 2872, and the correction data calculation circuit 2872 calculates (calculates or converts) the correction data and outputs the correction data to the correction circuit (data conversion circuit) 2874. The correction circuit (data conversion circuit) 2874 is formed of a flash memory or the like, and adds the discharge current to the terminal 155 in the range of 0 to 5%.

  However, when the output program current has periodicity as shown in FIG. 286, all terminals are measured by measuring the output program current of some terminals (one period or more) without measuring all terminals. The deviation of the output program current can be predicted. Therefore, the output program current of some terminals (one cycle or more) may be measured.

  The allowable range of the variation in output current is determined by the pixel pitch P (mm), the period (number of terminals N in one period), and the luminance change rate b (%) of the screen 144. For example, even if the luminance change between certain terminals is 5%, when the number of terminals between the terminals is 10 terminals and 100 terminals, it is natural that the allowable limit is lower when the terminals are 10 terminals (at 5%). Unacceptable).

  FIG. 298 shows the result of studying the above relationship. The horizontal axis is b / (P · N). Since P is the pixel pitch (mm) and N is the number of terminals between the terminals of the source driver IC 14, P · N indicates the length (distance) of the corresponding period. Therefore, b / (P · N) represents the luminance change rate per (P · N). The vertical axis indicates the relative recognition ratio of the luminance change of the screen 144 when b / (P · N) is 1 (the luminance and the program current are proportional to each other, so the output current Deviation ratio). A larger output current deviation ratio indicates that it is not acceptable.

  As can be seen from FIG. 298, the slope of the curve suddenly increases when b / (P · N) is 0.5 or more. Therefore, b / (P · N) is preferably 0.5 or less.

  Note that the luminance change rate is measured by a luminance meter 3051 as shown in FIG. Control is performed by a control circuit 3053 that controls the gradation of the source driver IC 14. A compensation amount of the luminance measured by the luminance meter 3051 is calculated by the calculator 3052. The calculated data is written in the correction circuit 2874 as shown in FIG.

  In the above embodiment, the output variation of the source driver circuit (IC) 14 has been described. However, it is obvious that this technical idea can be applied to the gate driver circuit (IC) 12 as well. The gate driver circuit (IC) 12 also varies in ON voltage or OFF voltage. Therefore, by applying the matters described in the source driver circuit (IC) 14 of the present invention to the gate driver circuit (IC) 12, a good gate driver circuit (IC) 14 can be configured or formed. Needless to say, the matter to be explained can be applied to the gate driver circuit (IC) 12.

  In addition, the matters described in the driver circuit (IC) of the present invention can be applied to the gate driver circuit (IC) 12 and the source driver circuit (IC) 14, and an organic (inorganic) EL display panel (display device) ) As well as liquid crystal display panels (display devices). The technical idea of the present invention may be used not only for an active matrix display panel but also for a simple matrix display panel.

  Hereinafter, another embodiment of the source driver circuit (IC) 14 of the present invention will be described. In addition, it cannot be overemphasized that the matter demonstrated previously or described in this specification is applicable except the matter demonstrated below. Needless to say, they can be combined in a timely manner. Conversely, it goes without saying that the items described in the following embodiments can be applied to other embodiments of the present invention or can be adopted in a timely manner. It goes without saying that a display panel or a display device (FIG. 126, FIGS. 154 to 157, etc.) can be configured using the source driver circuit (IC) 14 described below.

  FIG. 188 is an example of the source driver circuit (IC) 14 of the present invention. However, only the portions necessary for explanation are shown. Also in the configuration of FIG. 188, as in the other embodiments of the present invention, the circuit is configured with CMOS transistors made of silicon (note that the circuit 14 may be formed directly on the array substrate 30. ).

  In FIG. 188, the data (IRD, IGD, IBD) for controlling the electronic volume 501 is determined in synchronism with the clock (CLK) signal, and the switch of the electronic volume 501 is controlled by this value. Is applied to the + terminal of the operational amplifier 502.

  The operational amplifier 502, the resistor R1, and the transistor 158a constitute a constant current circuit, and a reference current Ic is generated. The magnitude of the program current output from the terminal 155 changes in proportion to the magnitude of the reference current Ic. The program current generation circuit 1884 has a current mirror circuit and a DATA decoder section inside. More specifically, the program current generation circuit 1884 is exemplified by the relationship between the transistor 158b and the transistor group 431c in FIG. 60, the relationship between the transistor 158b and the transistor 154 in FIGS. 209 and 210, or a similar configuration.

  The program current generation circuit generates a program current Ip corresponding to the magnitude of DATA (DATAR, DATAG, DATAB) which is video (image) data with reference to the magnitude of the reference current Ic.

  The generated program current Ip is held in the current holding circuit 1881. The current holding circuit 1881 includes transistors 11a, 11b, 11c, and 11d and a capacitor 19. The configuration is a configuration in which the P-channel transistor is changed to an N-channel transistor in the pixel configuration of FIG. The program current Ip applied to the gradation current wiring 1882 is held as a voltage in the capacitor 19.

  The holding operation of the current Ip is performed by the dot sequential operation of the sampling circuit 862. That is, in the sampling circuit 862, the gradation holding circuit 1881 that holds the program current Ip is selected by an address signal (ADRS) of 10 bits (selectable up to 1024 terminals). Selection is performed by outputting a selection voltage (voltage for turning on the transistors 11b and 11c) to the selection signal line 1885. Therefore, the program current Ip can be randomly stored in the gradation holding circuit 1881. However, generally, the address signal ADRS is sequentially counted up, and the current holding circuits 1881a to 1881n are sequentially selected.

  The program current Ip is held in the capacitor 19, and the driving transistor 11a outputs the program current Ip from the terminal 155 by the held voltage. In the current holding circuit 1881, the function of the driving transistor 11a is the same as the operation of the transistor 11a in FIG. Also, the transistors 11c and 11b in FIG. 188 have the same functions or operations as the transistors 11b and 11c in FIG. That is, the selection voltage is sequentially applied to the selection signal line 1885, the transistors 11b and 11c of the current holding circuit 1881 are turned on, and the program current Ip is held in the transistor 11a (the capacitor 19 connected to the gate terminal of the transistor 11a). The

  When writing of the program current Ip to all the current holding circuits 1881 is completed, an on-voltage is applied to the output control terminal 1883, and the program current Ip held in each current holding circuit 1881 is output to the terminals 155a to 155n (source The program current Ip is input from the signal line 18 to the terminal 155). The timing of the ON voltage applied to the output control terminal 1883 is synchronized with one horizontal scanning clock. That is, it is synchronized with the one pixel row selection (or one pixel row shift) clock.

  FIG. 189 schematically shows FIG. 188. The program current Ip flowing through the gradation current wiring 1882 is controlled by the sampling circuit 862 by the switches 11b and 11c (transistors 11b and 11c), and the program current Ip is input to the current holding circuit 1881. Further, the switch 11b (transistor 11b) is controlled by the output control terminal 1883 and is turned on all at once, and the program current Ip is output.

  In FIGS. 188 and 189, the current holding circuit 1881 is for one pixel row, but actually, two pixel rows are required. One pixel row (first holding circuit) is used to output the program current Ip to the source signal line 18, and the other pixel row (second holding circuit) uses the current sampled by the sampling circuit 862. Used for holding in the voltage holding circuit 1881. The first holding circuit and the second holding circuit are operated by switching alternately.

  FIG. 228 shows an output stage configuration including a first holding circuit 2280a and a second holding circuit 2280b. The relationship between FIGS. 188 and 228 is that the current holding circuit 1881 is an output circuit 2280, the grayscale current wiring 1882 is a current signal line 2283, the output control terminal 1883 is a gate signal line 2282, the selection signal line 1885 is a gate signal line 2284, The transistor 11a corresponds to the transistor 2281a, the transistor 11b corresponds to the transistor 2281b, the transistor 11c corresponds to the transistor 2281c, the transistor 11d corresponds to the transistor 2281d, and the capacitor 19 corresponds to the capacitor 2289.

  When the program current Ip is sampled and input to the output circuit 2280a, the output circuit 2280b outputs the program current Ip held in the source signal line 18. On the contrary, when the output circuit 2280a outputs the program current Ip held in the source signal line 18, the output circuit 2280b holds the sampled program current Ip sequentially. The period during which the output circuit 2280a and the output circuit 2280b output (input) the program current Ip to the source signal line 18b is switched every 1H. This output switching is performed at the c1 and c2 terminals.

  Note that a switch Sc for applying the reset voltage Vcp is formed or embedded in the current signal line 2283. The reset voltage Vcp is applied to the current signal line 2283 by turning on the switch Sc. The reset voltage Vcp is a voltage close to the GND voltage. When applying the reset voltage, an on-voltage is applied to the gate signal line 2284 to turn on the transistors 2281b and 2281c. By turning on the transistors 2281b and 2281c, the charge of the capacitor 2289 can be discharged, and the transistor 2281a can be in a state in which no current is output. That is, the reset voltage Vcp is a voltage that turns the transistor 2281a off or close to an off state. Needless to say, the reset voltage Vcp may be configured such that the transistor 2281a outputs an intermediate level voltage.

  FIG. 229 is an operation timing chart of the circuit of FIG. In FIG. 229, Sig is a signal from the program current generation circuit 1884. A current corresponding to the video signal is continuously applied. Sc represents the operation of the reset switch. When it is at the H level, the switch Sc is in an on state, and the reset voltage Vcp is applied to the current wiring 2283. As can be seen from FIG. 229, the reset voltage Vcp is applied at the beginning of 1H. That is, first, after the reset voltage Vcp is applied to the current holding circuit (output circuit) 2280a or 2280b, the program current Ip is sampled and held in the output circuit 2280. The reset voltage Vcp is not limited to once per 1H, and may be applied every sampling of the one output circuit 2280, or the reset voltage Vcp may be applied every sampling of the plurality of output circuits 2280. . Further, the reset voltage may be applied every frame or every plurality of frames.

  c1 and c2 are switching signals. When the logic voltage of c1 is at the H level, the output circuit 2280a is selected, and when the logic voltage of c2 is at the H level, the output circuit 2280b is selected and the program current Ip is output to the source signal line 18.

  In order to select the output circuit 2280a or 2280b and sequentially apply (hold) the program current Ip as described above, two sampling circuits 862 may be provided as shown in FIG. The sampling circuit 862a sequentially selects the output circuit 2280a and causes the output circuit 2280a to hold the program current Ip. The sampling circuit 862b sequentially selects the output circuit 2280b and causes the output circuit 2280b to hold the program current Ip.

  As shown in FIG. 75, the reset voltage Vcp may be configured to change the precharge voltage. Note that the items described in the items related to the precharge voltage can also be applied to the reset voltage Vcp. The precharge circuit as shown in FIG. 75 may be replaced with the reset circuit 2301 in FIG. Similarly, the reference current circuit 1884 may have the configuration described previously.

  A problem with the output circuit 2280 is that the gate terminal potential of the holding transistor 2281a may change due to a signal applied to the gate signal line 2284, and may change from the held program current Ip. This occurs when the voltage waveform applied to the gate signal line 2284 penetrates due to parasitic capacitance and changes the gate terminal potential. When the holding transistor 2281a is an N-channel transistor due to this punch-through voltage, the held program current Ip is reduced. When the holding transistor 2281a is a P-channel, the held program current increases in the configuration of FIG.

  A configuration for solving this problem is shown in FIG. In the output circuit 2280 of FIG. 231, a transistor 2311 is formed or arranged between the switching transistor 2281b and the capacitor 2289. The transistor 2311 has a function of opening a wiring.

  The transistor 2311 operates (turns off) before the program current Ip sampled in the output circuit 2280 is held and the off voltage is applied to the gate signal line 2284 (the output circuit 2280 is disconnected from the current signal line 2283). . That is, first, after the off voltage is applied to the gate signal line 2284, the off voltage is applied to the gate signal line 2284 with a delay. Therefore, after the transistor 2311 is turned off, the output circuit 2280 is disconnected from the current signal line 2283.

  FIG. 232 is a timing chart of the gate signal lines 2284 and 2285. As can be seen from FIG. 232, after the off voltage is applied to the gate signal line 2285, the off voltage is applied to the gate signal line 2284.

  As described above, first, the transistor 2311 is turned off. By turning off the transistor 2311, the penetration voltage of the gate signal line 2284 can be reduced. Note that the time t in FIG. 232 is preferably 0.5 μsec or more. Furthermore, it is more preferable to set it to 1 microsecond or more.

  The holding transistor 2281a preferably has a constant WL ratio in order to prevent or suppress the influence of kink (Early effect). FIG. 233 is a graph showing the generation ratio of the Early effect. As illustrated in FIG. 233, when the L / W ratio is 2 or less, the influence of the Early effect becomes large. Conversely, when L (transistor 2281a channel length (μm) / W (channel width (μm) of transistor 2281a) is 2 or more, the effect of the Early effect is drastically reduced. The W ratio is preferably 2 or more, more preferably 4 or more.

  In addition, the channel-to-channel voltage (source-drain voltage Vsd in the IC) of the holding transistor 2281a is also related to the Early effect. This relationship is illustrated in FIG. Note that the Vsd voltage is a maximum voltage applied to the holding transistor 2281a and is a voltage applied to the terminal 155 in FIG.

  As shown in the graph of FIG. 234, when the Vsd voltage is 9 V or more, the effect of Early drop tends to become significant. Therefore, it is preferable that the voltage applied to the terminal 155, that is, the voltage applied to the source signal line 18, be 9V or less and within 0V (GND). More preferably, the voltage applied to the source signal line 18 needs to be 8V or less and 0V or more.

  In the above embodiment, two stages of output circuits 2280 are provided. However, the present invention is not limited to this, and a plurality may be formed as shown in FIG. In FIG. 237, the output circuit 2280a is composed of two output circuits 2280ah and 2280al, and similarly, the output circuit 2280b is composed of two output circuits 2280bh and 2280bl. The output circuits 2280ah and 2280bh are circuits that output a relatively large program current Iph, and the output circuits 2280al and 2280bl output a relatively small program current Ipl.

  As described above, by dividing the output circuits 2280a and 2280b into a plurality of parts, the gradations shared by the output circuits 2281 can be separated or added and output. Therefore, it is possible to output the program current Ip with high accuracy.

  The output stage of the source driver circuit (Ic) 14 of the present invention may be configured as shown in FIG. In FIG. 246, one output stage is an output stage circuit 2280a that outputs a current having a magnitude of 1, an output stage circuit 2280b that outputs a current having a magnitude of 2, and an output stage circuit 2280c that outputs a current having a magnitude of 4. , Output stage circuit 2280d for outputting a current having a magnitude of 8, output stage circuit 2280e for outputting a current having a magnitude of 16, and output stage circuit 2280f for outputting a current having a magnitude of 32. The output stage circuits 2280a to 2280f operate corresponding to each bit of the video data. The corresponding output stage circuits 2280a to 2280f that have been operated are added and output from the terminal 155. By configuring as shown in FIG. 246, current output can be realized with higher accuracy.

  In the above embodiment, the source driver circuit 14 is composed of an IC mainly composed of a silicon chip. However, the present invention is not limited to this, and the output stage circuit 2280 (polysilicon current holding) using the polysilicon technology (CGS technology, low temperature polysilicon technology, high temperature polysilicon technology, etc.) directly on the array substrate 30. Circuit 2471) may be formed or configured.

  FIG. 247 shows an example. An output stage circuit 2280 for R, G, and B (2280R for R, 2280G for G, and 2280B for B) and a switch S that selects the RGB output stage circuit 2280 are formed (configured) by polysilicon technology. Yes. The switch S operates by time-sharing the 1H period. Basically, the switch S is connected to the R output stage circuit 2280R in the 1/3 period of 1H, connected to the G output stage circuit 2280G in the 1H period of 1H, and the remaining 1/3 of the 1H period. The period is connected to the output stage circuit 2280B of B. Since the display or driving method has been described with reference to FIGS. 37 and 38, description thereof will be omitted.

  As illustrated in FIG. 247, the source driver (circuit) 14 having a shift register circuit, a sampling circuit, and the like is connected to the source signal line 18 at a terminal 155. The switch S made of polysilicon is switched in a time division manner and connected to the output stage circuit 2280RGB. The output stage circuit 2280RGB holds a current made up of RGB video data, and outputs a program current Iw to the source signal line 18RGB by the configuration or control method described in FIGS. 228 to 234 and the like. In FIG. 247, only one stage of the polysilicon current holding circuit 2471 is shown, but it is needless to say that it is actually composed of two stages (see the description of FIGS. 228 to 234).

  In FIG. 247, the switch S is connected to the R output stage circuit 2280R during the 1/3 period of 1H, the 1/3 period of 1H is connected to the G output stage circuit 2280G, and the remaining 1/3 period of 1H. Is connected to the B output stage circuit 2280B, but the present invention is not limited to this. For example, as illustrated in FIG. 255, the periods for selecting R, G, and B may be different. This is because the R, G, and B program currents Iw are different in magnitude. Since the efficiency of the EL element 15 differs between R, G, and B, the magnitude of the program current differs between R, G, and B. If the magnitude of the program current is small, it is likely to be affected by the parasitic capacitance of the source signal line 18. Therefore, it is necessary to lengthen the application period of the program current and sufficiently ensure the charge / discharge period of the parasitic capacitance of the source signal line 18. is there. On the other hand, the parasitic capacitance of the source signal line 18 is often the same for R, G, and B.

  FIG. 255 assumes that the efficiency of the R EL element 15 is good and the program current is the smallest. Further, it is assumed that the efficiency of the G EL element 15 is low and the program current is the largest. B is an intermediate level of efficiency between R and G. Therefore, in FIG. 255, in the 1H period, the R data selection period (the period in which 2280R in FIG. 247 is selected) is the longest, and the G data selection period (the period in which 2280G in FIG. 247 is selected). The B data selection period (a period in which 2280B in FIG. 247 is selected) is set to the intermediate period.

  Note that the mobility of the holding transistor 2281a is preferably 400 or less and 100 or more. More preferably, the mobility is preferably 300 or less and 150 or more. In order to satisfy this condition, the gate insulating film included in the transistor 2281a is thickened. An example of the thickening method is an example in which the gate insulating film has a multilayer structure such as two-layer deposition.

  The display panel inspection method of the present invention will be described below. FIG. 202 shows a state before the display panel of the present invention is completed. One end of the source signal line 18 is short-circuited by a short wiring 2021. After the inspection, the shorted portion is completed by cutting along the AA 'line. The inspection voltage can be applied to all the source signal lines 18 by probing the short wiring 2021 and applying the inspection voltage.

  When the short wiring 2021 is not formed (separated state), a voltage or current is applied from the COG terminal of the source signal line 18. FIG. 203 shows an example in which a test short chip 2032 is mounted on a COG terminal (source signal line terminal) 2034. The short chip 2032 is made of a metal or a conductor. Alternatively, an electrical signal such as a voltage can be applied to at least the source signal line terminal 2034.

  A DC or AC voltage (current) is applied to the short chip 2032 and the anode terminal wiring 2031 as shown in FIG. The short chip 2032 is connected to the source signal line 18 through a terminal 2033. Therefore, a voltage can be applied to the source signal line 18 and the anode of the pixel 16. For example, a voltage can be applied to the Vdd terminal and the source signal line 18 in FIG. In this state, a power supply voltage is applied to the gate driver 12 and a clock or the like is applied (see FIG. 14 or the like) for operation. The pixels 16 are sequentially selected for each pixel row, and the voltage applied to the source signal line 18 is applied to the gate terminal of the driving transistor 11a. A current flows from the driving transistor 11a to the source signal line 18 by applying a voltage to the gate terminal. Alternatively, current flows through the EL element 15 and the EL element 15 emits light.

  In the above operation, the EL element 15 sequentially emits light by scanning and operating the gate driver circuit 12, and the EL display panel can be inspected by optically detecting the blinking state or lighting state of the light emission. .

  Inspection is performed optically. Examples of optical include judgment by human vision, photographing by a CCD camera, and detection by image recognition. The detection is that the pixel always becomes a bright spot, always becomes a black spot, a line defect, a blinking defect, or the like. Also, display streaks, shading unevenness, etc. are detected. Further, the flicker occurrence state is detected.

  In FIG. 203, the short chip 203 is used; however, a conductive liquid or the like may be dropped onto the source signal line 2034. A direct or alternating voltage (current) is applied between the dropped liquid and the anode terminal wiring 2031. In the current programming method, the applied current is as small as about μA. Therefore, even if the conductive liquid has a high resistance, it is sufficient for the inspection. Examples of the conductive liquid or gel include sodium hydroxide, hydrochloric acid, nitric acid, sodium chloride solution, silver paste, and copper paste.

  In the above embodiment, the gate driver circuit 12 is operated, the gate driver circuit 12 is set in the scanning state, the EL element 15 is turned on for each pixel row, and the panel or the array is inspected. However, the present invention is not limited to this. For example, the display screens may be turned on collectively for inspection.

  FIG. 205 is an explanatory diagram of the batch inspection of the screen. For ease of explanation, the screen is described as being collectively inspected, but the present invention is not limited to this. The inspection may be performed by dividing the screen into blocks, or the inspection may be performed by sequentially lighting a plurality of pixel rows. That is, it is a concept of lighting a large number of pixels simultaneously. Needless to say, the inspection may be performed by lighting one pixel at a time.

  For ease of explanation, it is assumed that the anode voltage Vdd is set to 6 (V) and the driving transistor 11a is set to 5 (V) or less so that a current for sufficiently lighting the EL element 15 can be supplied. In addition, it is assumed that a voltage is applied to all source signal lines 17 from the outside. As described above, the inspection method of the present invention is configured such that when the driving transistor 11a of the pixel 16 is a P channel, a voltage equal to or lower than the rising voltage of the driving transistor 11a can be applied to the source signal line 18. This rising voltage is set to 5 (V) for easy explanation. The voltage applied to the source signal line will be described as being in the range of the anode voltage Vdd to the anode voltage Vdd-8 (V), and preferably in the range of the anode voltage Vdd to the anode -6 (V).

  In FIG. 205, it is assumed that an inspection voltage of 0 to 5 (V) is applied to the source signal line 18. Therefore, when this voltage is applied to the gate terminal of the driving transistor 11a, the driving transistor 11a can pass a current.

  In the inspection method, first, the potential of the source signal line 18 is changed by changing the gate signal line 17a from the off voltage (Vgh) to the on voltage (Vgl) in a state where the off voltage Vgh voltage is applied to all the gate signal lines 17b. Is written into the pixel 16. If the potential of the source signal line 18 is equal to or lower than the rising voltage of the driving transistor 11a (5 (V) or lower), the programming is performed so that the voltage flows through the driving transistor 11a.

  Next, the on voltage Vgl is applied to all the gate signal lines 17b, and the gate signal line 17a is changed from the on voltage (Vgh) to the off voltage (Vgl) at the same time or earlier. Then, if the driving transistor 11a and the like are normal, current is supplied from the driving transistor 11a to the EL element 15, and the EL element 15 is turned on.

  Further, when the ON voltage and the OFF voltage are alternately applied to the gate signal line 17b while the EL element 15 is lit, the EL element 15 blinks. Therefore, the quality of the switching transistor 11d can be determined.

  In FIG. 205, the voltage applied to the source signal line 18 is periodically between the rising voltage and the following voltage of the driving transistor 11a with the on-voltage applied to both the gate signal line 17a and the gate signal line 17b. It may be changed to. By periodically changing, the EL element 15 emits light corresponding to the periodic change. In this case, the light emission current It of the EL element 15 is supplied from the source signal line 18. In some cases, the voltage is supplied from the driving transistor 11a.

  By operating as described above, the performance and defects of the driving transistor 11a and the switching transistors 11c, 11b, and 11d can be detected. Further, the performance and characteristics of the driving transistor 11a and the EL element 15 can be evaluated.

  In the above embodiment, the EL element is controlled to emit light in accordance with the potential of the source signal line 18 by changing the potential of the source signal line 18. However, the present invention is not limited to this. For example, as shown in FIG. 206, the anode voltage Vdd may be changed.

  In the inspection method, first, the potential of the source signal line 18 is changed by changing the gate signal line 17a from the off voltage (Vgh) to the on voltage (Vgl) in a state where the off voltage Vgh voltage is applied to all the gate signal lines 17b. Is written into the pixel 16. If the potential of the source signal line 18 is equal to or lower than the rising voltage of the driving transistor 11a (5 (V) or lower), the programming is performed so that the voltage flows through the driving transistor 11a.

  Next, the on voltage Vgl is applied to all the gate signal lines 17b, and the gate signal line 17a is changed from the on voltage (Vgh) to the off voltage (Vgl) at the same time or earlier. Then, if the driving transistor 11a and the like are normal, the current It is supplied from the driving transistor 11a to the EL element 15, and the EL element 15 is turned on. Further, when the ON voltage and the OFF voltage are alternately applied to the gate signal line 17b while the EL element 15 is lit, the EL element 15 blinks. Therefore, the quality of the switching transistor 11d can be determined.

  Further, with the off voltage applied to the gate signal line 17a and the on voltage applied to the gate signal line 17b, the Vdd voltage is periodically applied to the anode terminal (Vdd voltage), and the voltage equal to or lower than the rising voltage of the driving transistor 11a is periodically generated. To change. By periodically changing, the EL element 15 emits light corresponding to the periodic change. In this case, the light emission current of the EL element 15 is supplied from the driving transistor 11a. By operating as described above, the performance and defects of the driving transistor 11a and the switching transistors 11c, 11b, and 11d can be detected. Further, the performance and characteristics of the driving transistor 11a and the EL element 15 can be evaluated.

  In the above embodiment, the pixel configuration is described as FIG. 1, but the pixel configuration is not limited to this, and other pixels such as FIG. 2, FIG. 7, FIG. 11, FIG. Needless to say, the present invention can also be applied to an EL display panel or an EL display device having a configuration.

  In the above embodiment, the case where the pixel configuration is the current program method is illustrated. However, the present invention is not limited to this, and it is needless to say that the inspection can be performed even with the voltage program method as shown in FIG.

  FIG. 207 is an explanatory diagram of an inspection method in the pixel configuration of the voltage program method. In the inspection method, first, the potential of the source signal line 18 is written in the pixel 16 by changing all the gate signal lines 17a from the off voltage (Vgh) to the on voltage (Vgl). If the potential of the source signal line 18 is equal to or lower than the rising voltage of the driving transistor 11a (5 (V) or lower), the programming is performed so that the voltage flows through the driving transistor 11a.

  Next, the gate signal line 17a is changed from the on voltage (Vgh) to the off voltage (Vgl). Then, if the driving transistor 11a and the like are normal, the current It is supplied from the driving transistor 11a to the EL element 15, and the EL element 15 is turned on.

  Further, an off voltage is applied to the gate signal line 17a, the Vdd voltage is periodically changed to the anode terminal (Vdd voltage), and a voltage equal to or lower than the rising voltage of the driving transistor 11a is periodically changed. By periodically changing, the EL element 15 emits light corresponding to the periodic change. In this case, the light emission current of the EL element 15 is supplied from the driving transistor 11a. By operating as described above, the performance and defects of the driving transistor 11a and the switching transistor 11c can be detected. Further, the performance and characteristics of the driving transistor 11a and the EL element 15 can be evaluated.

  Hereinafter, an inspection method according to another embodiment of the present invention will be described with reference to the drawings. FIG. 202 shows a method of cutting the short wiring 2021 after the inspection. FIG. 223 shows a configuration in which a transistor 2232 as an inspection switch is formed or arranged at one end of the source signal line 18. By applying a voltage to the gate terminal of the transistor 2232, the transistor 2232 is turned on, and a test voltage (Vtest) is applied to the source signal line 18. On / off control of the transistor 2232 is performed by the on / off control means 2231.

  The on / off control means 2231 controls on / off of the transistor 2232, and the control is performed in synchronization with the gate driver circuit 12. Specifically, the inspection method described in FIGS. 203 to 207 is performed.

  For example, the inspection is performed as illustrated in FIG. When the transistor 2232 is turned on, the Vtest voltage is applied to the source signal line 18 via the transistor 2232 as illustrated in FIG. At this time, an off voltage is applied to the gate signal line 17b, and the transistor 11d is in an open state. If the ON voltage is applied to the gate signal line 17a of the pixel 16 to be inspected, the Vtest voltage is applied to the gate terminal of the driving transistor 11a as shown in FIG. This voltage is equal to or higher than the rising voltage of the driving transistor 11a.

  Next, as shown in FIG. 224 (b), an off voltage is applied to the gate signal line 17a, and an on voltage is applied to the gate signal line 17b. Therefore, the current It flows from the driving transistor 11a to the EL element 15, and the EL element 15 emits light.

  Further, in the configuration of FIG. 223, if the on / off control means 2231 is controlled and the transistors 2232 are controlled to be on / off, the EL elements 15 are blinked even when the on voltage is applied to the gate signal lines 17a of all the pixels 16. be able to. That is, the characteristics of the EL element 15 and the like can be evaluated or inspected by the transistor 2232.

  In FIG. 223, current or voltage is applied to the source signal line 18 by controlling the transistor 2232, and the EL display panel or the EL display panel array is inspected or evaluated.

  FIG. 225 applies a voltage or current necessary for inspection to the source signal line 18 by using the protection diode 2251 formed on the source signal line 18. The protection diode 2251 is formed on each source signal line 18 using polysilicon technology for electrostatic protection. Note that the diode 2251 is formed by diode-connecting transistors.

  As shown in FIG. 225, protection diodes 2251 a and 2251 b are connected to each source signal line 18. In a normal voltage (VL, VH) setting state, the protection diode is turned off. That is, a reverse voltage is applied to each protection diode 2251 by VL or VH, and the protection diode 2251 is in an off state.

  At the time of inspection, the VL voltage or the VH voltage or both voltages are set (operated) so that the protective diode is turned on. For example, by setting the VL voltage to a high voltage, the inspection voltage (the high voltage: Vdd to Vdd-6 (V)) can be applied to the source signal line 18 from the voltage wiring 2252a via the protection diode 2251b. . Further, by setting the VH voltage to a low voltage, an inspection voltage (the low voltage) can be applied to the source signal line 18 from the voltage wiring 2252b via the protection diode 2251a.

  FIG. 226 is an explanatory diagram of the inspection state. The protection diode 2251 can be regarded as a resistance when in a leak state. As in the present invention, the inspection voltage (current) can be applied to the source signal line by putting the protection diode in a leak state, and the EL display panel or array can be inspected because the picture 16 is a current program system. Big to do. In the current programming method, the current to be programmed is as small as about μA. Therefore, even if the protection diode 2251 has a high resistance such as a leak state, application or discharge of a minute current is not affected.

  The inspection may be performed by lighting all the pixels 16 in the display area 144 at the same time. However, as shown in FIGS. 227 (a) and (b), the pixel rows are sequentially selected and scanned to perform the inspection. May be. In FIGS. 227 (a) and (b), reference numeral 191 denotes a pixel row in which an inspection current is written. Reference numeral 193 denotes a region in which the EL element 15 is turned on and optically inspected. Reference numeral 192 denotes a non-lighting area. As described above, the optical inspection is facilitated by simultaneously performing the lighting region 193 and the non-lighting region on the display region 144. This is because the inspection can be realized at the same time or in the scanning state (sequential) in the defect state of black display and white display. The above control can be easily realized by controlling the gate driver circuit 12 as described with reference to FIG. Since the scanning or selection method has been described previously, a description thereof will be omitted.

  As described above, the inspection can be realized by applying a current or a voltage from the voltage wiring 2252 to the source signal line 18 so that the protective diode 2251 is turned on or leaking with the potential of the voltage wiring 2252. Since the inspection method is the same as that described previously, the description is omitted.

  As described above, the present invention is an inspection method for an array or a display panel having a pixel configuration such as a current programming method. The protection diode 2251 is leaked to the source signal line 18 and this leakage current is written into the pixel, and the EL element is caused to emit light by this written current. The characteristics and defects of the EL element 15 are detected in this light emitting state, lighting state or blinking state. At the same time, a signal is applied to the gate driver circuit 12 and scanned, and the gate signal line 17 to be selected is moved or always selected to perform inspection. Defect detection of the transistor 11 of the pixel 16 is realized by the above scanning or control.

  In the current program driving method, the program current applied to the source signal line 18 is on the order of μA. Therefore, the current program of the pixel 16 can be sufficiently realized by the current applied through the diode 2251. Therefore, inspection is realized. On the other hand, in the voltage program method, it is necessary to write voltage data to the source signal line 18. Therefore, inspection is difficult to realize.

  In FIG. 225, the protective diode 2251 is formed. However, the present invention is not limited to this, and it goes without saying that a switch element, a relay circuit, and the like may be formed or arranged as in FIG.

  Further, the inspection methods of FIGS. 225 and 223 are methods (methods) for realizing the inspection by applying a voltage or current from the outside. However, the present invention is not limited to this. For example, in the pixel configuration of FIG. 1 and the like, by turning on the switching transistors 11b and 11c (the transistor 11d is in an off (open) state), the current flowing from the anode Vdd through the driving transistor 11a is transmitted via the source signal line 18. , Can be taken out of the array (display panel). By measuring or evaluating the magnitude and direction of current flow, inspection or evaluation of the array or the like can be realized. Similarly, the current flowing through the cathode Vss and the EL element 15 can be taken out from the source signal line 18. Accordingly, it is possible to similarly inspect the EL element 15 and the like.

  In FIG. 223, FIG. 225, etc., a predetermined voltage is applied to all the source signal lines 18 at one time, but the present invention is not limited to this. A current may be used instead of a voltage. For example, in FIG. 225, a low current or a constant current is applied to the voltage wiring 2252. By utilizing this current as a program current and scanning the gate driver circuit 12, current programming can be performed on the pixel 16.

  Also, a plurality of on / off control means are provided, one on / off control means applies a voltage or current to the odd-numbered source signal line 18, and the other on / off control means applies a voltage or current to the even-numbered source signal line 18. You may comprise. The transistor 2232 may be an external element such as a relay. Moreover, what can be turned on / off by light irradiation, such as a photodiode, may be used.

  In the above embodiment, the voltage or current necessary for the inspection is applied to the source signal line 18 from the outside of the panel. However, the present invention is not limited to this. The substrate 30 or the like may be incorporated using polysilicon technology or the like. In addition to applying current, a method of absorbing current (sink method) may be used. Further, the current flowing through the EL element 15 or the driving transistor 11 a may be detected or measured via the source signal line 18.

  Hereinafter, a high-quality display method using a current driving method (current programming method) will be described with reference to the drawings. In the current programming method, a current signal is applied to the pixel 16 to cause the pixel 16 to hold the current signal. Then, a current held in the EL element 15 is applied.

  The EL element 15 emits light in proportion to the magnitude of the applied current. That is, the light emission luminance of the EL element 15 has a linear relationship with the value of the current to be programmed. On the other hand, in the voltage programming method, the applied voltage is converted into current by the pixel 16. This voltage-current conversion is non-linear. Non-linear conversion complicates the control method.

  In the current driving method, the value of video data is linearly converted into a program current as it is. As a simple example, in the case of 64 gradation display, 0 of the video data is set to the program current Iw = 0 μA, and the video data 63 is set to the program current Iw = 6.3 μA (having a proportional relationship). Similarly, the video data 32 has a program current Iw = 3.2 μA, and the video data 10 has a program current Iw = 1.0 μA. That is, the video data is directly converted into the program current Iw in a proportional relationship.

  In order to facilitate understanding, description will be made assuming that the video data and the program current are converted in a proportional relationship. Actually, video data and program current can be converted more easily. This is because the unit current of the unit transistor 154 corresponds to 1 of video data as shown in FIG. Furthermore, the unit current can be easily adjusted to an arbitrary value by adjusting the reference current circuit. This is because the reference current is provided for each of the R, G, and B circuits, and white balance can be achieved over the entire gradation range by adjusting the reference current circuit to the RGB circuit. This is a synergistic effect of the current program method and the configuration of the source driver circuit 14 and the display panel of the present invention.

  The EL display panel is characterized in that the program current and the light emission luminance of the EL element 15 have a linear relationship. This is a major feature of the current programming method. That is, the emission luminance of the EL element 15 can be adjusted linearly by controlling the magnitude of the program current.

  In the driving transistor 11a, the voltage applied to the gate terminal and the current flowing through the driving transistor 11a are nonlinear (often a square curve). Therefore, in the voltage program method, the program voltage and the light emission luminance are in a non-linear relationship, and the light emission control is extremely difficult. Compared with the voltage program, the light emission control is extremely easy in the current program method.

  In particular, in the pixel configuration of FIG. 1, the program current and the current flowing through the EL element 15 are theoretically equal. Therefore, emission control is very easy. The N-fold pulse driving according to the present invention is also excellent in that it is easy to control light emission since the light emission luminance can be grasped by calculating with the program current set to 1 / N.

  When the pixel configuration shown in FIGS. 11, 12, and 13 is a current mirror configuration, the driving transistor 11b and the programming transistor 11a are different from each other, and the current mirror magnification is shifted. . However, the pixel configuration in FIG. 1 does not have this problem because the driving transistor and the programming transistor are the same.

  In the EL element 15, the light emission luminance changes in proportion to the input current amount. The voltage (anode voltage) applied to the EL element 15 is a fixed value. Therefore, the light emission luminance of the EL display panel is proportional to the power consumption.

  From the above, the video data and the program current are proportional, the program current and the light emission luminance of the EL element 15 are proportional, and the light emission luminance and the power consumption of the EL element 15 are proportional. Therefore, if the video data is subjected to logic processing, the current consumption (power) of the EL display panel, the light emission luminance of the EL display panel, and the power consumption of the EL display panel can be controlled. That is, the luminance and power consumption of the EL display panel can be grasped by performing logic processing (addition or the like) on the video data. Therefore, processing such as preventing the peak current from exceeding the set value is extremely easy.

  In particular, the EL display panel of the present invention is a current drive system. In addition, image display control with a characteristic configuration is easier. There are two distinct image display control methods. One is control of the reference current. The other is duty ratio control. By combining the reference current control and the ratio control singly or in combination, a wide dynamic range, high image quality display, and high contrast can be realized.

  In the reference current control, as shown in FIGS. 60, 61, 64, 65, 66 (a) and 66 (b), the source driver IC (circuit) 14 includes a circuit for adjusting the reference current of each RGB. doing. The program current Iw from the source driver circuit 14 is determined by the number of unit transistors 154.

  The current output from one unit transistor 154 is proportional to the magnitude of the reference current. Therefore, by adjusting the reference current, the current output by one unit transistor 154 is determined, and the magnitude of the program current is determined. Since the reference current and the output current of the unit transistor 154 have a linear relationship, and the program current and the luminance have a linear relationship, if the white balance is adjusted by adjusting the reference current of each RGB in white raster display , White balance is maintained in all gradations.

  FIG. 54 shows a duty ratio control method. 54 (a1), (a2), (a3), and (a4) are methods in which the non-display area 192 is continuously inserted. Suitable for video display. Further, FIG. 54 (a1) is the darkest image, and FIG. 54 (a4) is the brightest. The duty ratio can be freely changed by controlling the gate signal line 17b. 54 (c1), (c2), (c3), and (c4) show a method of inserting the non-display area 192 by dividing it into a large number. Particularly suitable for still image display. Further, FIG. 54 (c1) is the darkest image, and FIG. 54 (c4) is the brightest. The duty ratio can be freely changed by controlling the gate signal line 17b. 54 (b1) (b2) (b3) (b4) are intermediate states between FIGS. 54 (a1) to (a4) and FIGS. 54 (c1) to (c4). Similarly in FIGS. 54 (b1), (b2), (b3), and (b4), the duty ratio can be freely changed by controlling the gate signal line 17b. That is, the transistor 11d is turned on / off by controlling the gate signal line 17b and the like, and the current flowing through the EL element 15 is controlled.

  11 and 12, the transistor 11e is on / off controlled, and in FIG. 7, the changeover switch 71 is on / off controlled. In the pixel configuration of FIG. 28, the transistor 11d is controlled to control the current flowing through the EL element 15.

  As described above, the duty ratio control is a method for realizing brightness control of the screen 144 by controlling the current flowing through the EL element 15 without changing the program current Iw applied to the source signal line 18. is there. That is, this is a method for realizing brightness control of the screen 144 in a state where the reference current is constant (without changing).

  In addition, the brightness of the screen 144 can be controlled without changing the current flowing through the driving transistor 11a. In addition, the brightness of the screen 144 can be controlled without changing the gate terminal (G) voltage of the driving transistor 11a. In addition, by changing the scanning state of the gate driver 12b, the gate signal line 17b and the like are controlled, and brightness control of the screen 144 is realized.

  The dispersion of the display area 193 is 220/4 = 55 when the number of pixel rows of the display panel is 220 and the 1/4 duty ratio is 1 to 55 (from 1 brightness to 55 times the brightness). Can be adjusted). Further, if the number of pixel rows of the display panel is 220 and the 1/2 duty ratio is 220/2 = 110, 1 to 110 (the brightness can be adjusted from 1 brightness to 110 times the brightness). Therefore, the adjustment range of the brightness of the screen brightness 144 is very wide (the dynamic range of image display is wide). Further, there is a feature that the number of gradations that can be expressed can be maintained regardless of the brightness. For example, in the case of 64-gradation display, 64-gradation display can be realized regardless of whether the brightness of the display screen 144 in white raster is 300 nt or 3 nt.

  As described before, the duty ratio can be easily changed by controlling the start pulse to the gate driver circuit 12b. Therefore, various duty ratios such as 1/2 duty ratio, 1/4 duty ratio, 3/4 duty ratio, and 3/8 duty ratio can be easily changed.

  The duty ratio driving in units of one horizontal scanning period (1H) may be performed by applying an on / off signal of the gate signal line 17b in synchronization with the horizontal synchronizing signal. Furthermore, the duty ratio can be controlled even in units of 1H or less. It is the drive method of FIG.40, FIG.41, FIG.42. By performing OEV2 control within 1H period, it is possible to perform brightness control (duty ratio control) in minute steps.

  The duty ratio control within 1H is performed when the duty ratio is equal to or less than ¼ duty ratio. If the number of pixel rows is 220 pixel rows, the ratio is 55/220 duty ratio or less. That is, it is performed in the range of 1/220 to 55/220 duty ratio. This is performed when a change in one step changes from 1/20 (5%) or more after change to after change. More preferably, it is desirable to perform minute duty ratio drive control by performing OEV2 control even with a change of 1/50 (2%) or less. That is, in the duty ratio control by the gate signal line 17b, when the brightness change after the change from before the change becomes 5% or more, the change amount is 5 by performing the control by the OEV2 (see FIG. 40 and the like). Change gradually so that it becomes less than%. For this change, it is preferable to introduce the Wait function described in FIG.

  The duty ratio control within 1H when the duty ratio is equal to or less than ¼ duty ratio is due to the large amount of change per step, but the image is halftone, so even small changes are visually recognized. It is also because it is easy to be done. Human vision has a low ability to detect changes in brightness on dark screens above a certain level. In addition, even on a bright screen above a certain level, the detection capability for brightness change is low. This seems to be because human vision depends on the square characteristic.

  If there are 200 pixel rows on the panel, OEV2 control is performed at a 50/200 duty ratio or less (1/200 or more and 50/200 or less), and a duty ratio control is performed for a period of 1H or less. When the 1/200 duty ratio is changed to the 2/200 duty ratio, the difference between the 1/200 duty ratio and the 2/200 duty ratio is 1/200, which is a change of 100%. This change is completely visually recognized as flicker. Therefore, OEV2 control (see FIG. 40 and the like) is performed, and current supply to the EL element 15 is controlled in a period of 1H (one horizontal scanning period) or less. Although the duty ratio control is performed in the 1H period or less (within 1H period), the present invention is not limited to this. As can be seen from FIG. 19, the non-display area 192 is continuous. That is, control such as the 10.5H period is also within the scope of the present invention. In other words, the present invention is not limited to the 1H period (a decimal part is generated), and performs duty ratio driving.

  When the 40/200 duty ratio is changed to the 41/200 duty ratio, the difference between the 40/200 duty ratio and the 41/200 duty ratio is 1/200, and the change is 2.5% at (1/200) / (40/200). It becomes. Whether or not this change is visually recognized as flicker is likely to depend on the screen brightness 144. However, since the 40/200 duty ratio is halftone display, it is visually sensitive. Therefore, it is desirable to perform OEV2 control (see FIG. 40 and the like) and to control current supply to the EL element 15 in a period of 1H (one horizontal scanning period) or less.

  As described above, the driving method and the display device according to the present invention can store the current value flowing through the EL element 15 in the pixel 16 (corresponding to the capacitor 19 in FIG. 1), the driving transistor 11a, and the light emitting element (EL Configurations that can turn on and off the current path to and from the element 15 (such as FIG. 1, FIG. 6, FIG. 7, FIG. 8, FIG. 9, FIG. 10, FIG. 11, FIG. 12, FIG. 28, FIG. 19 is generated at least in the display state of the display image (the pixel configuration is applicable) (the display screen 144 has a display area 193 (duty ratio 1/1) depending on the luminance of the image). If the duty ratio driving (the driving method or driving state in which at least a part of the display screen 144 becomes the non-display area 193) is equal to or less than a predetermined duty ratio, one horizontal scanning period is possible. By controlling the current passed through the EL element 15 to be limited to the (1H period) within or 1H period unit, and performs brightness control of the display screen 144.

  The predetermined duty ratio for performing duty ratio control within 1H unit is implemented when the duty ratio is equal to or less than ¼ duty ratio. Conversely, if the duty ratio is equal to or higher than the predetermined duty ratio, duty ratio control is performed in units of 1H. Or, OEV2 control is not performed. The duty ratio control other than the 1H period is performed when the change of one step changes from before the change to 1/20 (5%) or more after the change. More preferably, it is desirable to perform minute duty ratio drive control by performing OEV2 control even with a change of 1/50 (2%) or less. Alternatively, it is carried out with a luminance of 1/4 or less of the maximum luminance of the white raster.

  According to the duty ratio control drive of the present invention, as shown in FIG. 74, if the number of gradation representations of the EL display panel is 64 gradations, the display luminance (nt) of the display screen 144 is any luminance (luminance). 64 gradation display is maintained even if it is low or high. For example, even when the number of pixel rows is 220 and only one pixel row is in the display region 193 (display state) (duty ratio 1/220), 64-gradation display can be realized. This is because an image is sequentially written in each pixel row by the program current Iw of the source driver circuit 14, and this one pixel row is sequentially displayed by the gate signal line 17b. Even when all the pixel rows are in the display region 193 (display state) (duty ratio 1/1), 64-gradation display can be realized.

  Of course, even when 20 pixel rows are in the display region 193 (display state) (duty ratio 20/220 = duty ratio 1/11), 64-gradation display can be realized. This is because images are sequentially written to the pixel rows by the program current Iw of the source driver circuit 14, and all the pixel rows are simultaneously displayed by the gate signal lines 17b. Further, even when only 20 pixel rows are in the display region 193 (display state) (duty ratio 20/220 = duty ratio 1/11), 64-gradation display can be realized. This is because an image is sequentially written in each pixel row by the program current Iw of the source driver circuit 14, and the 20 pixel rows are sequentially scanned and displayed by the gate signal line 17b.

  The same applies to the reference current control of the present invention (see the circuit configuration in FIG. 50 and the like), and 64-gradation display can be realized regardless of whether the reference current is small or large.

  Since the duty ratio control drive of the present invention is the control of the lighting time of the EL element 15, the brightness of the display screen 144 with respect to the duty ratio has a linear relationship. Therefore, it is very easy to control the brightness of the image, the signal processing circuit is simple, and the cost can be reduced. As shown in FIG. 60, the RGB reference current is adjusted to achieve white balance. In the duty ratio control, white balance is maintained at any gradation and brightness of the display screen 144 in order to simultaneously control the brightness of R, G, and B.

  In the duty ratio control, the luminance of the display screen 144 is changed by changing the area of the display area 193 with respect to the display screen 144. Naturally, the current flowing through the EL display panel changes in proportion to the display area 193. Therefore, by obtaining the sum total of the video data, it is possible to calculate the total consumption current flowing through the EL element 15 of the display screen 144. Since the anode voltage Vdd of the EL element 15 is a DC voltage and is a fixed value, if the total current consumption can be calculated, the total power consumption can be calculated in real time according to the image data. If the calculated total power consumption is predicted to exceed the prescribed maximum power, the reference current Ic in FIG. 60 may be adjusted by an adjustment circuit such as an electronic volume to suppress and control the RGB reference current.

  In addition, a predetermined luminance in white raster display is set, and this time is set so as to minimize the duty ratio. For example, the duty ratio is 1/8. For natural images, the duty ratio is increased. The maximum duty ratio is 1/1. For example, a natural image in which an image is displayed only 1/100 of the display screen 144 is set to a duty ratio 1/1. The duty ratio 1/1 to the duty ratio 1/8 is smoothly changed depending on the display state of the natural image on the display screen 144.

  As described above, as an example, in white raster display (all pixels are 100% lit in a natural image), the duty ratio is 1/8, and 1/100 pixel of the display screen 144 is lit. The duty ratio is 1/1. The approximate power consumption can be calculated by the number of pixels × the ratio of the number of lit pixels × duty ratio.

  For ease of explanation, assuming that the number of pixels is 100, the power consumption in white raster display is 100 × 1 (100%) × duty ratio 1/8 = 80. On the other hand, the power consumption of a natural image in which 1/100 is lit is 100 × (1/100) (1%) × duty ratio 1/1 = 1. The duty ratio 1/1 to the duty ratio 1/8 is a smooth duty ratio control so that flicker does not occur according to the number of lighting pixels of the image (actually, the total current of the lighting pixels = the sum of the program currents of one frame). Is implemented.

  As described above, the power consumption ratio of white raster is 80, and the power consumption ratio of a natural image in which 1/100 is lit is 1. Therefore, the maximum current can be suppressed by setting a predetermined luminance in white raster display and setting this time so as to minimize the duty ratio.

  In the present invention, the sum of the program currents for one screen is S, the duty ratio is D, and drive control is performed with S × D. In addition, the total program current in the white raster display is Sw, the maximum duty ratio is Dmax (usually the duty ratio 1/1 is the maximum), the minimum duty ratio is Dmin, and any natural This is a driving method and a display device that realizes the driving method in which the relationship of Sw × Dmin ≧ Ss × Dmax is maintained when the sum of program currents in the image is Ss.

  Note that the maximum duty ratio is 1/1. The minimum is preferably a duty ratio of 1/16 or more (such as 1/8). That is, the duty ratio is set to 1/16 or more and 1/1 or less. Needless to say, the use of 1/1 is not restricted. Preferably, the minimum duty ratio is 1/10 or more. This is because if the duty ratio is too small, the occurrence of flicker is conspicuous, and the change in screen brightness due to the image content becomes too large, making it difficult to see the image.

  As described above, the program current is proportional to the video data. Therefore, the sum of program currents is synonymous with the sum of video data. Although the sum of program currents for one frame (one field) period is obtained, the present invention is not limited to this. Pixels to which program current is added at a predetermined interval or a predetermined period in one frame (one field) May be sampled to obtain the sum of program currents (video data). Further, the sum data before and after the frame (field) to be controlled may be used, or the duty ratio control may be performed using the sum data by estimation or prediction.

  FIG. 85 is a block diagram of the drive circuit of the present invention. Hereinafter, the drive circuit of the present invention will be described. In FIG. 85, a Y / UV video signal and a composite (COMP) video signal can be input from the outside. The switch circuit 851 selects which video signal is input.

  The video signal selected by the switch circuit 851 is decoded and AD converted by a decoder and an A / D circuit, and converted into digital RGB image data. RGB image data is 8 bits each. The RGB image data is subjected to gamma processing by a gamma circuit 854. At the same time, a luminance (Y) signal is obtained. The RGB image data is converted into 10-bit image data by gamma processing.

  After the gamma processing, the image data is subjected to FRC processing or error diffusion processing by the processing circuit 855. RGB image data is converted into 6 bits by FRC processing or error diffusion processing. This image data is subjected to AI processing or peak current processing by an AI processing circuit 856. The moving image detection circuit 857 performs moving image detection. At the same time, color management processing is performed by the color management circuit 858.

  The processing results of the AI processing circuit 856, the moving image detection circuit 857, and the color management circuit 858 are sent to the arithmetic circuit 859. The arithmetic processing circuit 859 converts the results into control arithmetic, duty ratio control, and reference current control data. The data is sent to the source driver circuit 14 and the gate driver circuit 12 as control data.

  It is preferable that the duty ratio control, the reference current ratio control, the peak current control, and the like are not applied to the OSD (On Screen Display). In OSD, a menu screen is displayed on a video camera or the like. Even in OSD, when peak current control or the like is performed, the screen becomes darker or brighter depending on the display state of the menu, and a visual defect occurs.

  To deal with this problem, OSD data (OSDDATA) and video data (moving image data) are processed by another control circuit 856 as shown in FIG. Basically, OSD data is not subjected to luminance modulation.

  Note that the controller IC 760 is not limited to being made into one chip. For example, as shown in FIG. 248, a controller IC 760G that controls the gate driver circuit 12 and a controller IC 760S that controls the source driver circuit 14 may be separated. The processing contents become clear by the separation, and the controller IC can be reduced in size.

  The duty ratio control data is sent to the gate driver circuit 12b, and duty ratio control is performed. On the other hand, the reference current control data is sent to the source driver circuit 14 and the reference current control is performed. Image data that has been subjected to gamma correction and subjected to FRC or error diffusion processing is also sent to the source driver circuit 14.

  The image data conversion in FIG. 62 needs to be performed by gamma processing of the gamma circuit 854. The gamma circuit 854 performs gradation conversion using a multipoint broken gamma curve. The 256-gradation image data is converted to 1024 gradations by a multipoint broken gamma curve. The gamma circuit 854 performs gamma conversion with a multipoint broken gamma curve, but the present invention is not limited to this.

  In the above description, the control is performed with the duty ratio D. However, the duty ratio is a predetermined period (usually one field or one frame. In other words, in general, a cycle in which image data of an arbitrary pixel is rewritten. Or the time during which the EL element 15 is turned on. That is, a duty ratio of 1/8 means that the EL element 15 is lit during a 1/8 period (1F / 8) of one frame. Therefore, the duty ratio can be read as duty ratio = Ta / Tf, where Tf is the period when the pixel 16 is rewritten and the lighting period Ta of the pixel.

  In addition, although the period time in which the pixel 16 is rewritten is Tf and is based on Tf, the present invention is not limited to this. The duty ratio control drive of the present invention does not need to complete the operation in one frame or one field. That is, the duty ratio control may be performed with several fields or several frame periods as one cycle. Therefore, Tf is not limited to the cycle of rewriting pixels, and may be one frame or one field or more. For example, if the lighting period Ta is different for each field or frame, the repetition period (period) may be Tf and the total lighting period Ta of this period may be employed. That is, Ta may be the average lighting time of several fields or several frame periods. The same applies to the duty ratio. When the duty ratio differs for each frame (field), an average duty ratio of a plurality of frames (fields) may be calculated and used.

  Therefore, the sum of program currents in white raster display is Sw, the sum of program currents in an arbitrary natural image is Ss, the minimum lighting period is Tas, and the maximum lighting period is Tam (usually Tam = Tf). To Tam / Tf = 1), a driving method for maintaining the relationship of Sw × (Tas / Tf) ≧ Ss × (Tam / Tf) and a display device that realizes the driving method.

  As shown in FIGS. 60, 61, 64, and 65, the program current can be linearly adjusted by controlling the reference current. This is because the output current of one unit transistor 154 changes. When the output current of the unit transistor 154 is changed, the program current Iw is also changed. The larger the current programmed in the pixel capacitor 19 (actually, the voltage corresponding to the program current) is, the larger the current flowing through the EL element 15 is. The current flowing through the EL element 15 and the light emission luminance are linearly proportional. Therefore, the light emission luminance of the EL element 15 can be linearly changed by changing the reference current.

  The source driver circuit (IC) 14 of the present invention changes the program current Iw by controlling the number of unit transistors 154 connected to the terminal 155. The program current Iw is realized by changing the reference current Ic as described with reference to FIGS.

  However, the reference current control or the like of the present invention is not limited, and a constant reference (voltage, current, setting data, etc.) can be changed, and the current Iw output from the terminal 155 can be changed by this change. Any may be used. However, it is important that the program current Iw of each output terminal 155 is changed at the same rate due to a change in the reference. Note that the present invention is not limited to changes in the program current Iw. It may be a program voltage. This is because the luminance of the display screen 144 can be adjusted by changing the program voltage of each terminal 155 at the same rate. Further, the white balance can be adjusted by changing the RGB terminal.

  FIG. 86 shows an embodiment of the present invention that does not include an adjustment circuit for the reference current Ic. The terminal 155 is supplied with the program current Iw from the operational amplifier 502 through the transistor 156. The program current Iw is determined by the voltage applied to the operational amplifier 522 by the sampling circuit 862.

  The 8-bit video data is converted into analog data by the D / A circuit 661, and the analog data is gain-adjusted by the variable amplifier circuit 861. The gain-adjusted analog data is sampled by the horizontal scanning clock in the sampling circuit 862 and held in each capacitor C. Note that the gain of the variable amplifier circuit 861 is set by 8-bit data.

  As an example of the variable amplifier circuit 861, the configuration of FIG. 87 is exemplified. In FIG. 87, the analog data of the DA circuit 661 is applied to the Vin terminal. The gain is set by a switch Sx connected in series with the resistor Rx. The switch Sx is controlled by gain setting data at 8 bits. The gain setting data can be changed in units of one frame or one field.

  With the above configuration, the output current from the terminal 155 can be changed in proportion (correlation) to the control data by controlling the gain data in FIG.

  That is, the gain is set by closing one of the switches Sx. The control of the switch Sx corresponds to the switch circuit 642 in FIG. 64 and the electronic volume 501 in FIG. That is, the program current Iw can be changed or adjusted by controlling the switch Sx.

  Therefore, in FIG. 86, analog data is sampled and held at C, and the program current Iw is applied to the source signal line 18 by the sampled and held voltage. The program current Iw is changed (controlled) by the gain data of the variable amplifier 861.

  Also in the configuration of FIG. 86, the luminance of the display screen 144 can be adjusted (variable) all at once by the gain setting data. Therefore, the n-fold pulse driving, the duty ratio driving, and the like of the present invention can be realized. In the configuration of FIG. 86 and the like, the unit transistor 154 is not formed. That is, the present invention is characterized in that the reference current can be adjusted by an electronic volume or the like, and the current output from all the output terminals 155 of the IC 14 can be changed proportionally by adjusting the reference current. is there. As will be described later, the reference current is obtained from the video data. That is, this is a configuration or method in which feedback is applied from video data or the like to change the magnitude of the current from the output terminal 155. In the embodiment, the signal output from the terminal is a current, but it may be a voltage. This is because the current flowing through the EL element 15 can be controlled by the voltage signal (after all, the current flowing from the video data to the cathode (anode) terminal can be controlled). In other words, the configuration is characterized in that the voltage output from all the output terminals 155 of the IC 14 can be proportionally changed by obtaining the magnitude or amount of change of the reference current from the video data and adjusting the reference current.

  Further, by providing the variable amplifier 861 for each RGB, white balance adjustment and color management control can be realized (see FIGS. 145 to 153). That is, in the display panel or device of the present invention, the driving method and configuration of the present invention can be realized even if the source driver circuit (IC) 14 having the configuration of FIG. 86 is used.

  The present invention uses at least one of the reference current control method described in FIG. 60 and the like and the duty ratio control method described in FIGS. 54A, 54B, 54C, etc. This is to control such as. Preferably, the reference current control method and the duty ratio control method are combined and implemented.

  Further, the driving method of the present invention will be described. One object of the driving method of the present invention is to limit the upper limit of current consumption consumed by the EL display panel. In the EL display panel, the luminance is proportional to the current flowing through the EL element 15. Therefore, if the current flowing through the EL element 15 is increased, the luminance of the EL display panel can be increased. The current consumed (= power consumption) increases in proportion to the luminance.

  When used for a mobile device such as a portable device, the capacity of a battery or the like is limited. Further, the scale of the power supply circuit increases as the current consumed increases. Therefore, it is necessary to provide a limit for the consumed current. Providing this limit (peak current suppression) is one object of the present invention.

  Further, the display is improved by increasing the contrast of the image. Display is improved by converting an image (such as a wide dynamic range, a high contrast ratio, and a large gradation expression power) so that the image is displayed with an edge. The second object of the present invention is to improve the image display as described above. The present invention that achieves the above object will be referred to as AI driving.

  First, for ease of explanation, it is assumed that the IC chip 14 of the present invention has a 64-gradation display. In order to realize AI driving, it is desirable to expand the gradation expression range. For ease of explanation, the source driver IC (circuit) 14 according to the present invention has 64 gradation display and the image data has 256 gradation. This image data is subjected to gamma conversion so as to match the gamma characteristic of the EL display device. The gamma conversion is performed by expanding the input 256 gradations to 1024 gradations. The gamma-converted image data is subjected to error diffusion processing or frame rate control (FRC) processing so as to conform to the 64 gradations of the source driver IC 14 and is applied to the source driver IC 14.

  When the image data of one screen is large as a whole, the total sum of the image data becomes large. For example, since the white raster has 63 grayscale image data, the number of pixels of the display screen 144 × 63 is the sum of the image data. In the white window display of 1/100 and the white display portion displaying white with the maximum luminance, the number of pixels of the display screen 144 × (1/100) × 63 is the sum of the image data.

  In the present invention, a value capable of predicting the total sum of image data or the current consumption amount of the screen is obtained, and the duty ratio control or the reference current control is performed based on this sum or value.

  Although the sum of the image data is obtained, the present invention is not limited to this. For example, an average level of one frame of image data may be obtained and used. In the case of an analog signal, the average level can be obtained by filtering the analog image signal with a capacitor. A direct current level may be extracted from an analog video signal through a filter, and the direct current level may be AD converted to be a sum of image data. In this case, the image data can also be referred to as an APL level.

  It is also preferable to obtain data that can estimate the sum of image data or the sum of image data from 30 frames to 300 frames, and perform duty ratio control based on the size of the data. The total data changes slowly according to image changes. The longer the frame period for obtaining the total data, the slower the brightness change of the image.

  Further, it is not necessary to add all the data of the image constituting the display screen 144, and 1 / W (W is a value greater than 1) of the display screen 144 is picked up and extracted, and the sum of the picked up data is obtained. Also good. For example, a method of sampling video data by skipping one pixel and obtaining the sum from the sampled video data is exemplified. Further, there is exemplified a method of sampling video data of one or a plurality of pixels for each pixel row and obtaining a sum from the sampled video data.

  In order to facilitate the description, the description will be made assuming that the sum of the image data is also obtained in the above case. In many cases, the sum of the image data coincides with the determination of the APL level of the image. The sum total of image data includes means for digital addition, but the method for obtaining the sum total of digital and analog image data is hereinafter referred to as an APL level for ease of explanation.

  Since the APL level is 6 bits for each of RGB in the white raster, 63 (indicated by 63 as data representation because it is the 63rd gradation) × number of pixels (176 × RGB × for the QCIF panel) 220). Therefore, the APL level is maximized. However, since the current consumed by the RGB EL elements 15 is different, it is preferable to calculate the image data separately for RGB.

For this problem, the arithmetic circuit shown in FIG. 88 is used. In FIG. 88, there are 881 and 882 multipliers. Reference numeral 881 denotes a multiplier for weighting the emission luminance. R, G, and B have different visibility. The visibility in NTSC is R: G: B = 3: 6: 1. Therefore, the R multiplier 881R multiplies the R image data (Rdata) by a factor of three. The G multiplier 881G multiplies G image data (Gdata) by 6 times. Further, the B multiplier 881B performs multiplication of 1 time on the B image data (Bdata). However, this description is conceptual. This is because EL elements have different efficiencies in RGB.
The EL element 15 has different luminous efficiencies for RGB. Usually, the luminous efficiency of B is the worst. Next, G is bad. R has the best luminous efficiency. Therefore, the multiplier 882 weights the light emission efficiency. The R multiplier 882R multiplies the R image data (Rdata) by the R luminous efficiency. The G multiplier 882G multiplies the G image data (Gdata) by the G light emission efficiency. The B multiplier 882B multiplies the B image data (Bdata) by the B light emission efficiency.

  The results of multipliers 881 and 882 are added by adder 883 and accumulated in summation circuit 884. Based on the result of the summing circuit 884, duty ratio control and reference current control are performed.

  In the embodiment described above, data is obtained by multiplying video data by a predetermined value in consideration of the efficiency of the EL element 15 and the like. The present invention obtains the current flowing from the video data to the anode or cathode terminal of the display panel.

  Usually, the RGB EL element 15 has a known luminous efficiency for each EL material, and the relationship between current and luminance is known. In addition, the target color temperature when the EL display panel is produced is determined. Therefore, if the display size and the target luminance of the EL display panel are determined, the ratio and the magnitude of the RGB current that flows through the EL display panel to obtain the target color temperature can be known. Therefore, the target luminance and color temperature can be obtained by setting the current flowing through the anode terminal or cathode terminal of the EL display panel to a predetermined value.

  The current flowing through the anode terminal or the cathode terminal is proportional to the sum of the video data. From the above, the anode current (cathode current) can be obtained from the sum of the video data. The anode current is a current that flows into the anode terminal connected to the display area. The cathode current is a current that flows out from the cathode terminal connected to the display area. Since the anode voltage or the cathode voltage is a fixed value, the power consumption of the EL display panel can be controlled from the video data.

  That is, by monitoring (calculating) the size of the video data (total) or a change in the size in real time, the cathode (anode) current required by the EL display panel can be obtained. If it is known to which magnitude should be suppressed, the magnitude of the current can be controlled by reference current control and duty ratio control. Of course, by converting the magnitude of the anode current or cathode current from analog to digital (AD), the magnitude of the current can be controlled from the converted digital data by reference current control and duty ratio control. Further, by performing feedback control of amplification factor by using an operational amplifier directly using analog data, the magnitude of current can be controlled by reference current control and duty ratio control. That is, the control may be digital or analog.

  As described above, the present invention calculates or controls the power (current) consumed by the EL display panel from the size (or data that can be estimated) of the video data (or data proportional thereto), and controls the duty ratio. Reference current control is performed.

  Note that the calculation of the power (current) consumed by the EL display panel from the size (or data that can be estimated) of the video data (or data proportional thereto) is limited to being performed for each frame (one field). Needless to say, it may be performed for each of a plurality of frames (fields), or may be performed a plurality of times in one frame (one field). Needless to say, the reference current control and the duty ratio control are not limited to being performed in real time, and may be performed with delay, hysteresis, or skipping.

  The magnitude of the anode current or cathode current of the EL display panel is controlled by reference current control and duty ratio control. However, the present invention is not limited to this, and EL display can also be controlled by controlling the anode voltage or cathode voltage. Needless to say, the power consumption of the panel can be controlled.

  If control is performed as shown in FIG. 88, duty ratio control and reference current control for the luminance signal (Y signal) can be performed. However, when a luminance signal (Y signal) is obtained and duty ratio control is performed, a problem may occur. For example, a blue back display. In the blue back display, the current consumed by the EL display panel is relatively large. However, the display brightness is low. This is because the visibility of blue (B) is low. Therefore, the sum (APL level) of the luminance signal (Y signal) is calculated to be small, and the duty ratio control becomes a high duty ratio. Accordingly, flicker occurs.

  For this problem, the multiplier 881 may be used as through. This is because the sum (APL level) with respect to the current consumption is obtained. It is desirable to obtain the total APL level by taking both the sum (APL level) based on the luminance signal (Y signal) and the sum (APL level) based on the current consumption into consideration. Depending on the total APL level, duty ratio control, reference current control, precharge control, etc. are performed.

  Since the black raster is the 0th gradation in the case of the 64 gradation display, the APL level is 0 and becomes the minimum value. In the current driving method, power consumption (current consumption) is proportional to image data. The image data does not need to count all bits of the data constituting the display screen 144. For example, when the image is represented by 6 bits, only the upper bits (MSB) may be counted. In this case, the number of gradations is 32 or more and one count is made. Therefore, the APL level changes depending on the image data constituting the display screen 144. In other words, the sum total of video data is not a complete sum but may be any method that can estimate the sum.

  Initially, the term “APL level” is used as an index similar to the sum of video data or the sum from the analog concept. However, later, it demonstrates as a lighting rate. The lighting rate will be described later.

  In order to facilitate understanding, specific numerical values will be exemplified. However, this is virtual, and it is actually necessary to determine control data and a control method by experiment and image evaluation.

  The maximum current that can be passed through the EL display panel is 100 (mA). In the case of white raster display, the total (APL level) is assumed to be 200 (no unit). When the APL level is 200, it is assumed that 200 (mA) flows in the EL display panel when applied to the panel as it is. When the APL level is 0, the current flowing through the EL display panel is 0 (mA). When the APL level is 100, the duty ratio is ½.

  Therefore, when the APL is 100 or more, it is necessary to make the limit 100 (mA) or less. Most simply, when the APL level is 200, the duty ratio is (1/2) × (1/2) = 1/4, and when the APL level is 100, the duty ratio is 1/2. When the APL level is 100 or more and 200 or less, the duty ratio is controlled to be between 1/4 and 1/2. The duty ratio of 1/4 to 1/2 can be realized by controlling the number of gate signal lines 17b to be simultaneously selected by the gate driver circuit 12b on the EL selection side.

  However, if the duty ratio control is performed considering only the APL level, the luminance of the display screen 144 changes according to the average luminance (APL) of the display screen 144 according to the image, and flicker occurs. In order to solve this problem, the APL level to be obtained is held for a period of at least 2 frames, preferably 10 frames, more preferably 60 frames or more, and calculation is performed during this period, and the duty ratio by duty ratio control is calculated based on the APL level. calculate. It is also preferable to perform duty ratio control by extracting image features such as maximum luminance (MAX), minimum luminance (MIN), and luminance distribution state (SGM) of the display screen 144. Needless to say, the above items also apply to the reference current control.

  It is also important to perform black stretching and white stretching by extracting image features. This may be performed in consideration of maximum luminance (MAX), minimum luminance (MIN), luminance distribution state (SGM), and scene change state. That is, it is preferable to correct the total (APL level or lighting rate) in consideration of not only the addition of video data but also the distribution state of the image display. Examples of the circuit configuration include a configuration for adding correction amounts of a correction circuit (not shown) of the adder 883c in FIG.

  The gamma circuit 854 performs gamma conversion with a multipoint broken gamma curve, but the present invention is not limited to this. As shown in FIG. 89, gamma conversion may be performed using a one-point broken gamma curve. Since the hardware scale constituting the one-point broken gamma curve is small, the cost of the control IC can be reduced.

  In FIG. 89, a is a polygonal line gamma conversion at the 32nd gradation. b is a polygonal line gamma conversion at the 64th gradation. c is a polygonal line gamma conversion at the 96th gradation. d is a polygonal line gamma conversion at the 128th gradation. When the image data is concentrated at high gradations, the gamma curve d in FIG. 89 is selected to increase the number of gradations at high gradations. When the image data is concentrated in the low gradation, the gamma curve of a in FIG. 89 is selected to increase the number of gradations in the low gradation. If the distribution of the image data is dispersed, gamma curves such as b and c in FIG. 89 are selected. In the above embodiment, the gamma curve is selected. However, actually, the gamma curve is not selected because it is generated by calculation.

  The gamma curve is selected in consideration of the APL level, maximum luminance (MAX), minimum luminance (MIN), and luminance distribution state (SGM). Further, duty ratio control and reference current control are also taken into consideration.

FIG. 90 shows an example of a multipoint broken gamma curve. When the image data is concentrated in high gradations, the n gamma curve in FIG. 89 is selected to increase the number of gradations in the high gradations. When the image data is concentrated in the low gradation, the gamma curve of a in FIG. 89 is selected to increase the number of gradations in the low gradation. If the distribution of the image data is dispersed, an n-1 gamma curve is selected from b in FIG. The gamma curve is selected in consideration of the APL level, maximum luminance (MAX), minimum luminance (MIN), luminance distribution state (SGM), scene change rate, scene change amount, and scene contents. Further, duty ratio control and reference current control are also taken into consideration.
It is also effective to change the gamma curve selected in accordance with the environment used by the display panel (display device). In particular, in an EL display panel, a good image display can be realized indoors, but a low gradation portion cannot be seen outdoors. The EL display panel is for self light emission. Therefore, as shown in FIG. 91, the gamma curve may be changed. The gamma curve a is an indoor gamma curve. The gamma curve b is an outdoor gamma curve. The gamma curves a and b are switched by the user operating the switch. Alternatively, the brightness of outside light may be detected by a photo sensor and automatically switched. Although the gamma curve is switched, the present invention is not limited to this. It goes without saying that a gamma curve may be generated by calculation. In the case of outdoors, the low gradation display portion cannot be seen because the outside light is bright. Therefore, it is effective to select the gamma curve b that crushes the low gradation part.

  In the outdoors, it is also effective to generate a gamma curve as shown in FIG. In the gamma curve a, the output gradation is set to 0 until the 128th gradation. Gamma conversion is performed from 128 gradations. As described above, power consumption can be reduced by performing gamma conversion so that the low gradation portion is not displayed at all. Also, gamma conversion may be performed as shown in the gamma curve b in FIG. The gamma curve in FIG. 92 sets the output gradation to 0 up to the 128th gradation. For 128 or more, the output gradation is 512 or more. In the gamma curve b of FIG. 92, a high gradation part is displayed and the number of output gradations is reduced, so that the image display can be easily seen even outdoors.

  In the drive system of the present invention, image luminance is controlled by duty ratio control and reference current control, and the dynamic range is expanded. In addition, high contrast display is realized.

In the liquid crystal display panel, white display and black display are determined by the transmittance from the backlight. Even when the non-display area 192 is generated on the display screen 144 as in the duty ratio driving of the present invention, the transmittance in black display is constant. On the contrary, by generating the non-display area 192, the white display luminance in one frame period is lowered, so that the display contrast is lowered.
The EL display panel is in a state where the current flowing through the EL element 15 is zero (no current flows or is minute) in black display. Therefore, even when the non-display area 192 is generated on the display screen 144 as in the duty ratio drive of the present invention, the luminance of black display is zero. When the area of the non-display area 192 is increased, the white display luminance is lowered. However, since the luminance of black display is 0, the contrast is infinite. Therefore, the duty ratio driving is an optimal driving method for the EL display panel. The same applies to the reference current control. Even if the magnitude of the reference current is changed, the luminance of black display is zero. Increasing the reference current increases the white display luminance. Therefore, a good image display can be realized even in the reference current control.

  In the duty ratio control, the number of gradations is maintained in the entire gradation range, and the white balance is maintained in the entire gradation range. Further, the luminance change of the display screen 144 can be changed by nearly 10 times by the duty ratio control. Further, since the change has a linear relationship with the duty ratio, the control is easy. However, since the duty ratio control is N-fold pulse driving, the current flowing through the EL element 15 is large, and the current flowing through the EL element is always large regardless of the brightness of the display screen 144. There is a problem that the EL element 15 is easily deteriorated.

  In the reference current control, when the screen brightness 144 is increased, the reference current amount is increased. Therefore, the current flowing through the EL element 15 is increased only when the display screen 144 is high. Therefore, the EL element 15 is not easily deteriorated. The problem tends to be that it is difficult to maintain white balance when the reference current is changed.

  In the present invention, both reference current control and duty ratio control are used. However, it goes without saying that there is also a control in which one is fixed and the other is variable. When the display screen 144 is close to white raster display, the reference current is fixed to a constant value, and only the duty ratio is controlled to change the display brightness. When the display screen 144 is close to black raster display, the duty ratio is fixed to a constant value, and only the reference current is controlled to change the display brightness. Of course, the duty ratio may be reduced, the reference current may be increased, and the program current Iw may be increased while maintaining the display luminance constant.

  As an example, the duty ratio control is performed in a range where the lighting rate is 1/10 or more and 1/1. If the duty ratio is 1/1 and white raster display is used, the lighting rate is 100% (at the time of maximum white raster display). If it is a black raster, the lighting rate is 0% (when a full black raster is displayed).

  The lighting rate is also a ratio to the maximum current flowing through the anode or cathode of the panel (however, the duty ratio is 1/1). For example, if the maximum current flowing through the cathode is 100 mA, the lighting rate is 30/100 = 30% (0.3) when a current of 30 mA flows at a duty ratio of 1/1. In the case of the pixel configuration shown in FIG. 1 and the like, since a program current is added to the anode, it is necessary to consider the calculation of the lighting rate. The cathode is only the current consumed by the EL element. Therefore, the current consumed by all the EL elements 15 of the EL display panel is preferably measured by the current flowing through the cathode terminal.

  If the maximum current flowing through the cathode is 100 mA, and the maximum value of the total sum of the video data at this time, the lighting rate is synonymous with SUM control or APL control. If the lighting rate is expressed as 50%, it means that the current flowing through the cathode (anode) is 50%, and if the lighting rate is expressed as 20%, it means that the current flowing through the cathode is maximum 20%. In the future, the term lighting rate will be mainly used. However, the maximum value of the current flowing through the cathode (anode) terminal is the maximum current flowing through the terminal by design and is a relative magnitude. For example, if the design value is small, the maximum value is small.

  Although the lighting rate is a ratio with respect to the maximum current flowing through the anode or cathode of the panel, it is needless to say that it can be rephrased as a ratio of the maximum current flowing through all the EL elements of the panel.

  In this specification, when the lighting rate is described without any notice, the duty ratio is 1/1. If a current of 20 mA flows at a duty ratio of 1/3, the lighting rate is (20 mA × 3) / 100 mA = 60% (0.6). That is, even if the lighting rate is 100%, if the duty ratio is ½, the current flowing through the anode (cathode) terminal is ½ of the maximum value. If the lighting rate is 50%, the anode current is 20 mA, and the duty ratio is 1/1, the anode current is 10 mA when the duty ratio is 1/2. If the anode current is 100 mA, the lighting rate is 40%, and the duty ratio is 1/1, if the anode current is changed to 200 mA, it means that the lighting rate is changed to 80%. As described above, the lighting rate indicates the ratio to the size of the video data constituting one screen, the current consumption (power) of the EL display panel, or the ratio.

  The above matters are not limited to the EL display panel or EL display device having the pixel configuration of FIG. 1, but other pixel configurations such as FIGS. 2, 7, 11, 12, 13, 28, and 31. Needless to say, the present invention can also be applied to an EL display panel or an EL display device.

  Further, it goes without saying that the reference current control and duty ratio control based on the lighting rate are not applied only to the EL display panel, but can be applied to any self-luminous display panel. For example, an FED display panel is exemplified.

  As an example, the lighting rate (lighting rate) is obtained from the sum of video data. That is, it is calculated from the video data. When the input video signal is Y, U, or V, it may be obtained from a Y (luminance) signal. However, in the case of an EL display panel, since the light emission efficiency differs between R, G, and B, the value obtained from the Y signal does not become power consumption. Therefore, in the case of Y, U, and V signals, the current consumption (power consumption) can be obtained by converting the signals into R, G, and B signals and multiplying them by a coefficient that converts the current into R, G, and B. preferable. However, simply obtaining the current consumption from the Y signal may be considered to facilitate circuit processing.

  It is assumed that the lighting rate is converted by the current flowing through the panel. This is because, in the EL display panel, the light emission efficiency of B is poor, and thus when the display of the sea is displayed, the power consumption increases at a stretch. Therefore, the maximum value is the maximum value of the power supply capacity. The data sum is not a simple addition value of video data, but video data converted into current consumption. Therefore, the lighting rate is also obtained from the current used for each image with respect to the maximum current.

  Here, for ease of explanation, the maximum duty ratio is assumed to be 1/1. The reference current is changed from 1 to 3 times. Further, the data sum means the sum of the data on the display screen 144, and the maximum value (of the data sum) is the sum of the image data in the white raster display at the maximum luminance. Needless to say, it is not necessary to use a duty ratio of 1/1. The duty ratio 1/1 is described as the maximum value. Needless to say, in the driving method of the present invention, the maximum duty ratio may be set to 210/220 or the like.

  When the duty ratio = 1/1, the meaning of setting the lighting rate to 0% means that N-times pulse driving is not performed. This is because 1/1 is the maximum luminance display, and the program current writing is not improved by N-fold pulse driving. As the lighting rate becomes 100%, setting the duty ratio to 1 / n and increasing n does not contribute to the improvement of programming current writing. However, it is only implemented to reduce the power consumption of the panel. This can be easily understood because N-fold pulse driving does not include implementing a duty ratio of 1/1. According to the present invention, when the lighting rate is low (duty ratio approaches 1/1), the reference current is set to 1 or more, and the screen is brightened. This operation does not correspond to the implementation of N-fold pulse driving.

  The maximum duty ratio is preferably set to 1/1, and the minimum is preferably set to within 1/16. More preferably, the duty ratio is within 1/10. This is because the occurrence of flicker can be suppressed. The change range of the reference current is preferably within 4 times. More preferably, it is within 2.5 times. This is because if the multiple of the reference current is too large, the linearity of the reference current generating circuit is lost and white balance deviation occurs.

  The lighting rate of 1% is, for example, 1/100 white window display (duty 1/1). In a natural image, it means a state in which the data sum of pixels for image display can be converted to 1/100 of white raster display. Therefore, the display rate of one bright spot per 100 pixels is 1%.

  In the following description, the maximum value is an added value of white raster image data, but this is for ease of description. The maximum value is the maximum value generated in the image data addition processing or APL processing. Therefore, the lighting rate is a ratio with respect to the maximum value of the image data of the screen to be processed.

  Note that the data sum may be calculated based on current consumption or luminance. Here, for ease of explanation, it is assumed that luminance (image data) is added. In general, the method of adding luminance (image data) is easy to process, and the hardware scale of the controller IC can be reduced. In addition, it is preferable because a dynamic range can be widened without occurrence of flicker due to duty ratio control.

  FIG. 93 shows an example in which the reference current control and the duty ratio control of the present invention are implemented. In FIG. 93, when the lighting rate is 1/100 or less, the magnification of the reference current is changed to 3 times. The duty ratio is changed from 1/1 to 1/8 at a lighting rate of 1% or more. Further, the reference current is changed from 1 to 3 times at a lighting rate of 1% or less. Therefore, since the duty ratio control is 8 times and the reference current control is 3 times, a change of 8 × 3 = 24 times is performed depending on the lighting rate value. Since both the reference current control and the duty ratio control change the screen brightness, a dynamic range of 24 times is realized.

  In FIG. 93, when the lighting rate is 100%, the duty ratio is 1/8. Therefore, the display brightness is 1/8 of the maximum value. Since the lighting rate is 100%, it is a white raster display. That is, in white raster display, the display brightness is reduced to 1/8, the maximum. 1/8 of the display screen 144 is a display (lighting) area 193, and the non-display area 192 occupies 7/8. In an image with a lighting rate close to 100%, most of the pixels 16 are high gradation display. In terms of a histogram, the majority of data is distributed in the high gradation area of the histogram. In this image display, the image is crushed white and there is no sharpness. For this reason, the gamma curve n in FIG. 90 or the like close to n is selected. That is, the gamma curve is dynamically changed according to the lighting rate value.

  When the lighting rate is 1%, the duty ratio is 1/1. The entire display screen 144 is a display area 193. Therefore, screen brightness control by duty ratio control is not performed. The light emission luminance of the EL element 15 becomes the display luminance of the display screen 144 as it is. Most of the image display is black display, and an image is partially displayed. Expressed in terms of images, an image display with a lighting rate of 1% is an image in which stars appear in a dark night sky. Setting the duty ratio to 1/1 in this image means that the star portion is displayed with a brightness that is eight times the brightness of a white raster with a lighting rate of 100%. Therefore, an image display with a wide dynamic range can be realized. Since the image is displayed in the 1/100 area, even if the luminance of the 1/100 area is increased by 8 times, the increase in power consumption is slight. When the lighting rate is 1% or less, the reference current is increased. For example, the reference current ratio is 2 when the lighting rate is 0.1%. Therefore, it is displayed with twice the luminance as compared with the lighting rate of 1%. That is, the star portion is displayed with a brightness 8 × 2 times that of a white raster having a lighting rate of 100%.

  As described above, the luminance of the display pixel can be increased by increasing the reference current at a low lighting rate. By this process, the image is glossy and an image display deep in depth can be realized.

  In the case of an image with a lighting rate close to 1% and most of the pixels 16 displaying a low gradation, if expressed in a histogram, the majority of data is distributed in the low gradation region of the histogram. In this image display, the image is blacked out and there is no sharpness. Therefore, the gamma curve b or b close to b in FIG. 90 or the like is selected.

  As described above, the driving method of the present invention is a driving method that increases the x multiplier of gamma as the duty ratio increases. In this driving method, the x multiplier of gamma is decreased as the duty ratio is decreased.

  In FIG. 93, when the lighting rate is 1% or less, the magnification of the reference current is changed to 3 times. When the lighting rate is 1% or less, the duty ratio is 1/1, and the screen brightness is increased by the duty ratio. As the lighting rate becomes smaller than 1%, the magnification of the reference current is increased. Therefore, the light emitting pixel 16 emits light with higher luminance. For example, a lighting rate of 0.1% is an image in which stars appear in a dark night sky when expressed in terms of an image. Setting the duty ratio to 1/1 in this image means that the star portion is displayed with a brightness 8 × 2 = 16 times the brightness of the white raster. Therefore, an image display with a wide dynamic range can be realized. Since the image is displayed in the 0.1% region, even if the luminance in the 0.1% region is increased 16 times, the increase in power consumption is slight.

  The control of the reference current is that it is difficult to maintain white balance. However, in the image in which stars appear in the dark night sky, even if the white balance is shifted, the white balance shift is not visually recognized. From the above, the present invention in which the reference current control is performed in a range where the lighting rate is very small is an appropriate driving method.

  In FIG. 93, the change in the reference current and the change in the duty ratio control are illustrated linearly. However, the present invention is not limited to this. The reference current magnification control and duty ratio control may be curved. In FIG. 94, since the lighting rate on the horizontal axis is logarithmic, it is natural that the lines of the reference current control and the duty ratio control become curves. The relationship between the lighting rate and the reference current magnification and the relationship between the lighting rate and the duty ratio control are preferably set according to the content of the image data, the image display state, and the external environment.

  93 and 94 show an embodiment in which the RGB duty ratio control and the reference current control are made the same. The present invention is not limited to this. As shown in FIG. 95, the slope of the reference current magnification may be changed in RGB. In FIG. 95, the slope of the change in the reference current magnification for blue (B) is the largest, the slope of the change in the reference current magnification for green (G) is the next largest, and the change in the reference current magnification for red (R) is increased. The inclination is minimized. When the reference current is increased, the current flowing through the EL element 15 is also increased. EL elements have different luminous efficiencies for RGB. Further, when the current flowing through the EL element 15 is increased, the light emission efficiency with respect to the applied current is deteriorated. In particular, the tendency is remarkable in B. Therefore, white balance cannot be achieved unless the reference current amount is adjusted in RGB. Therefore, as shown in FIG. 95, when the reference current magnification is increased (region where the current flowing through each RGB EL element 15 is large), it is effective to vary the RGB reference current magnification so that white balance can be maintained. is there. The relationship between the lighting rate and the reference current magnification and the relationship between the lighting rate and the duty ratio control are preferably set according to the content of the image data, the image display state, and the external environment.

  FIG. 95 shows an example in which the reference current magnification is varied between RGB. In FIG. 96, the duty ratio control is also different. The lighting rate is 1% or more, the slopes of B and G are made the same, and the slope of R is made small. G and R are 1% or less and the duty ratio is 1/1, while B is 1% or less and the duty ratio is 1/2. In FIG. 96, the reference currents are also different. When the lighting rate is 1% or less, the gradient of B is maximized and the gradient of R is minimized. When driven (controlled) as described above, RGB white balance adjustment can be optimized. The relationship between the lighting rate and the reference current magnification and the relationship between the lighting rate and the duty ratio control are preferably set according to the content of the image data, the image display state, and the external environment. Further, it is preferable that the user can set or adjust freely.

  93 to 96 show a method of changing the reference current magnification and the duty ratio with a lighting rate of 1% as an example. The reference current magnification and the duty ratio are changed with the lighting rate as a boundary, so that the region where the reference current magnification changes and the region where the duty ratio changes do not overlap. With this configuration, it is easy to maintain white balance. That is, the duty ratio is changed when the lighting rate is 1% or more, and the reference current is changed when the lighting rate is 1% or less. The region where the reference current magnification is changed is not overlapped with the region where the duty ratio is changed. This method is a characteristic method of the present invention.

  Although the duty ratio was changed when the lighting rate was 1% or more and the reference current was changed when the lighting rate was 1% or less, the reverse relationship may be used. For example, the duty ratio may be changed when the lighting rate is 1% or less, and the reference current may be changed when the lighting rate is 1% or more. Further, the duty ratio is changed when the lighting rate is 1% or more, the reference current is changed when the lighting rate is 1% or less, and the reference current magnification and the duty ratio are constant values when the lighting rate is 1% or more and 10% or less. Good.

  In some cases, the present invention is not limited to the above method. As shown in FIG. 97, the duty ratio may be changed when the lighting rate is 1% or more, and the B reference current may be changed when the lighting rate is 10% or less. The reference current change of B and the duty ratio of RGB are overlapped with each other.

  When a bright screen and a dark screen are alternately repeated at a high speed, flicker occurs when the duty ratio is changed according to the change. Therefore, when changing from a certain duty ratio to another duty ratio, it is preferable to provide a hysteresis (time delay). For example, if the hysteresis period is 1 sec, the previous duty ratio is maintained even if the screen brightness is bright and dark but is repeated a plurality of times within the 1 sec period. That is, the duty ratio does not change. This hysteresis (time delay) time is called Wait time. Also, the duty ratio before the change is called the pre-change duty ratio, and the duty ratio after the change is called the post-change duty ratio.

  When the duty ratio before change is small and changes to another duty ratio, flicker is likely to occur due to the change. The state where the duty ratio before change is small is a state where the data sum of the display screen 144 is small or a state where the display screen 144 has many black display portions. Therefore, it is considered that the display screen 144 is a halftone display and has high visibility. In addition, in a region where the duty ratio is small, the difference from the change duty ratio tends to increase. Of course, when the difference in duty ratio becomes large, control is performed using the OEV2 terminal. However, OEV2 control also has a limit. From the above, when the duty ratio before change is small, it is necessary to lengthen the wait time.

  When the pre-change duty ratio is changed to a different duty ratio, flicker due to the change is less likely to occur. A state in which the duty ratio before change is large is a state in which the data sum of the display screen 144 is large or a state in which the display screen 144 has many white display portions. Therefore, it seems that the entire display screen 144 is white and has low visibility. From the above, when the duty ratio before change is large, the wait time may be short.

  The above relationship is illustrated in FIG. The horizontal axis is the duty ratio before change. The vertical axis represents the wait time (seconds). When the duty ratio is 1/16 or less, the wait time is increased to 3 seconds (sec). When the duty ratio is 1/16 or more and the duty ratio is 8/16 (= 1/2), the wait time is changed from 3 seconds to 2 seconds in accordance with the duty ratio. When the duty ratio is 8/16 or more and the duty ratio is 16/16 = 1/1, the time is changed from 2 seconds to 0 seconds according to the duty ratio.

  As described above, the duty ratio control of the present invention changes the wait time in accordance with the duty ratio. When the duty ratio is small, the wait time is lengthened, and when the duty ratio is large, the wait time is shortened. That is, in the driving method that varies at least the duty ratio, the duty ratio before the first change is smaller than the duty ratio before the second change, and the wait time of the first before-change duty ratio is the second The duty ratio is set to be longer than the wait time of the duty ratio before change.

  In the above embodiment, the wait time is controlled or specified based on the duty ratio before change. However, the difference between the pre-change duty ratio and the post-change duty ratio is slight. Therefore, in the above-described embodiment, the duty ratio before change may be read as the duty ratio after change.

  In the above embodiment, the pre-change duty ratio and the post-change duty ratio have been described. Needless to say, when the difference between the pre-change duty ratio and the post-change duty ratio is large, it is necessary to increase the wait time. Needless to say, when the duty ratio difference is large, it is preferable to change the duty ratio to the post-change duty ratio via the intermediate duty ratio.

  The duty ratio control method of the present invention is a driving method that takes a longer wait time when the difference between the pre-change duty ratio and the post-change duty ratio is large. That is, this is a driving method in which the wait time is changed according to the difference in duty ratio. Further, this is a driving method in which the wait time is lengthened when the difference in duty ratio is large.

  The duty ratio method of the present invention is a driving method characterized in that when the difference in duty ratio is large, the duty ratio is changed to the post-change duty ratio via the duty ratio in the intermediate state.

  In the embodiments of FIGS. 93 and 94, the wait time with respect to the duty ratio is assumed to be the same for R (red), G (green), and B (blue). However, it goes without saying that in the present invention, the wait time may be changed in RGB as shown in FIG. This is because the visibility is different between RGB. By setting the wait time according to the visibility, a better image display can be realized.

  In the following description, the maximum value is an added value of white raster image data, but this is for ease of description. The maximum value is the maximum value generated in the image data addition processing or APL processing. Therefore, the lighting rate is a ratio with respect to the maximum value of the image data of the screen to be processed.

  However, the sum of data does not require accurate addition of data for one screen. An addition value of one screen may be estimated (predicted) from an addition value of pixel data obtained by sampling one screen. The same applies to the maximum value. Also, predicted values or estimated values from a plurality of fields or a plurality of frames may be used. In addition to the addition of image data, the APL level of video data may be obtained by a low-pass filter circuit, and this APL level may be used as the data sum. The maximum value at this time is the maximum value of the APL level when video data having the maximum amplitude is input.

  Note that the data sum may be calculated based on the current consumption of the display panel or the luminance. Here, for ease of explanation, it is assumed that luminance (image data) is added. In general, the process of adding luminance (image data) is easy.

  In FIG. 99, the horizontal axis represents the lighting rate. The maximum value is 100%. The vertical axis represents the duty ratio. The lighting rate = 100% is the maximum white display state in all pixel rows. When the lighting rate is small, the screen is dark or has a small display (lighting) area. At this time, the duty ratio is increased. Therefore, the luminance of the pixel displaying the image is high. For this reason, the dynamic range of the image is expanded and high-quality display is performed. When the lighting rate is high (the maximum value is 100%), the screen is a bright screen or a wide display (lighting) area. At this time, the duty ratio is reduced. Therefore, the luminance of the pixel displaying the image is low. Therefore, power consumption can be reduced. Since the amount of light emitted from the screen is large, the image does not feel dark.

  In FIG. 99, the duty ratio value reached when the lighting rate is 100% is changed. For example, when the duty ratio is 1/2, 1/2 of the screen is in the image display state. Therefore, the image is bright. When the duty ratio is 1/8, 1/8 of the screen is in the image display state. Therefore, the brightness is 1/4 compared to the duty ratio = 1/2.

  In the drive system of the present invention, the image brightness is controlled by the lighting rate, duty ratio, reference current, data sum, etc., and the dynamic range is expanded. In addition, high contrast display is realized.

  In the liquid crystal display panel, white display and black display are determined by the transmittance from the backlight. Even when a non-display area is generated on the screen as in the driving method of the present invention, the transmittance in black display is constant. On the contrary, when the non-display area is generated, the white display luminance in one frame period is lowered, so that the display contrast is lowered.

  In the EL display panel, black display is a state in which the current flowing through the EL element is zero. Therefore, even when a non-display area is generated on the screen as in the driving method of the present invention, the luminance of black display is zero. When the area of the non-display area is increased, the white display luminance is lowered. However, since the luminance of black display is 0, the contrast is infinite. Therefore, a good image display can be realized.

  In the driving method of the present invention, the number of gradations is maintained over the entire gradation range, and white balance is maintained over the entire gradation range. Further, the luminance change of the screen can be changed nearly 10 times by the duty ratio control. Further, since the change has a linear relationship with the duty ratio, the control is easy. Further, R, G, and B can be changed at the same ratio. Therefore, the white balance is maintained at any duty ratio.

  The relationship between the lighting rate and the duty ratio is preferably set according to the content of the image data, the image display state, and the external environment. Further, it is preferable that the user can set or adjust freely.

  The above switching operation displays the display screen very brightly when the power of a mobile phone, a monitor, etc. is turned on. After a certain period of time, the display brightness is reduced to save power. Use. In order to reduce the display luminance, the duty ratio is reduced or the reference current is reduced. Alternatively, either the duty ratio or the reference current is reduced. The power consumption of the EL display panel can be reduced by reducing the reference current or the duty ratio. The above control can also be used as a function for setting the brightness desired by the user. For example, when outdoors, the screen is very bright. This is because the surroundings are bright outdoors and the screen cannot be seen at all. That is, outdoors, the curve a in FIG. 99 is selected. However, if display is continued with high luminance, the EL element deteriorates rapidly. For this reason, when it is very bright, it is configured to return to normal luminance in a short time. For example, normally, the curve of c is selected. Furthermore, when displaying with high brightness, the display brightness can be increased by the user pressing the button.

  Therefore, it is preferable that the user can be switched with a button, can be automatically changed in a setting mode, or can be switched automatically by detecting the brightness of external light. Further, it is preferable that the display brightness is set to 50%, 60%, and 80% and can be set by the user. Further, it is preferable that the duty ratio curve, inclination, etc. are rewritten by an external microcomputer or the like. Further, it is preferable that one can be selected from a plurality of stored duty ratio curves.

  Needless to say, the selection of the duty ratio curve or the like is preferably performed in consideration of one or more of the APL level, maximum luminance (MAX), minimum luminance (MIN), and luminance distribution state (SGM).

  As described above, for example, a is an outdoor curve. c is an indoor curve. b is a curve for an intermediate state between indoor and outdoor. Switching between the curves a, b, and c is performed by the user operating the switch. Alternatively, the brightness of outside light may be detected by a photo sensor and automatically switched. Although the gamma curve is switched, the present invention is not limited to this. It goes without saying that a gamma curve may be generated by calculation.

  Although the duty ratio in FIG. 99 is a straight line, it is not limited to this. As shown in FIG. 100, a single-point folding curve may be used. That is, the slope of the duty ratio is changed according to the lighting rate. Of course, the duty ratio curve may be a curved line or a multipoint broken curve. Further, the duty ratio curve may be changed in real time depending on the external light or the type of image. The above matters are the same in the reference current change control.

  When the power consumption of the display panel needs to be reduced, the c curve in FIG. 100 is selected. The effect of reducing power consumption is exhibited. Although the display brightness decreases, there is no decrease in image display such as the number of gradations. When high display luminance is required, the a curve in FIG. 100 is selected. The image display becomes brighter and the occurrence of flicker is reduced. Although power consumption increases, there is no decrease in image display such as the number of gradations.

  In another embodiment of the present invention, the duty ratio is changed in a range where the lighting rate is 1/10 or more (see FIG. 101). This is because the occurrence of an image with a lighting rate close to 1 is small, and when the driving is performed so that the duty ratio changes until the lighting rate is 100 as shown in FIG. 99, the image display is felt dark. More preferably, the duty ratio is changed in the range where the lighting rate is 8/10 or more.

  In addition, many natural images have a lighting rate of 20% to 40%. Therefore, it is preferable that the duty ratio is large in this range. On the other hand, when the lighting rate is high (60% or more), the power consumption is large and the EL display panel tends to generate heat and deteriorate. Therefore, the duty ratio is controlled to be 1/1 or in the vicinity when the lighting rate is in the range of 20% to 40% or in the vicinity thereof, and the duty ratio is controlled to be smaller than 1/1 when the lighting rate is 60% or in the vicinity thereof. It is preferable.

  In FIG. 101, when the lighting rate is 0.9 or less, the duty ratio is changed from 1/1 to 1/5. Therefore, a dynamic range of 5 times is realized. In FIG. 101, when the lighting rate is 0.9 or more, the duty ratio is 1/5. Therefore, the display luminance is 1/5 of the maximum luminance. A lighting rate of 100% is a white raster display. That is, in white raster display, the display brightness is reduced to 1/5 of the maximum brightness.

  When the lighting rate is 10% or less, the duty ratio is 1/1. 1/10 of the screen is a display area (in the case of a white window or the like). Of course, natural images are images with many dark areas. When the duty ratio is 1/1, since there is no non-lighting area 192, the light emission luminance of the EL element becomes the display luminance of the pixel as it is. The lighting rate of 10% is a state where most of the image display is black display and an image is displayed in part. For example, an image display with a lighting rate of 10% or less is an image in which the moon appears in a dark night sky (this is a reference image example for explanation. In a white window, a 1/10 white window is displayed. ). Setting the duty ratio to 1/1 in this image means that the moon portion is displayed with a luminance five times the luminance of the white raster (the luminance at the lighting rate of 100% in FIG. 101). Therefore, an image display with a wide dynamic range can be realized. Since the image is displayed in the 1/10 area, even if the brightness of the 1/10 area is increased 5 times, the increase in power consumption is slight.

  As described above, in the present invention, the duty ratio is 1/1 or relatively large for an image with a low lighting rate. At a duty ratio of 1/1, a current always flows through a pixel that emits light. Therefore, the current consumption is large when viewed from one pixel. However, since there are few pixels emitting light in the EL display panel, there is almost no increase in power consumption when viewed from the entire EL display panel. In the EL display panel, the black portion is completely black (non-light emitting). Therefore, if the maximum luminance can be displayed with a duty ratio of 1/1, the dynamic range can be expanded, and a good and clear image display can be realized.

  On the other hand, in the present invention, in an image with a high lighting rate, the duty ratio is relatively small, such as 1/5. Further, control is performed so that the duty ratio becomes small in accordance with the lighting rate. When the duty ratio is small, intermittent current flows through the light-emitting pixels. Therefore, the current consumption of one pixel is small. In an EL display panel, many pixels emit light, but since current consumption per pixel is small, an increase in power consumption is small when viewed from the entire EL display panel. As described above, the driving method of the present invention for controlling the duty ratio with respect to the lighting rate is an optimal driving method for a self-luminous display panel such as an EL display panel. If the duty ratio decreases, the image brightness decreases. However, since the generated light flux is large on the entire screen, the impression that it has become dark cannot be felt.

  As described above, by performing one or both of duty ratio control and reference current control, the contrast ratio of the image can be expanded, the dynamic range can be expanded, and low power consumption can be realized.

  The above control is performed using the lighting rate. As described above, the lighting rate is the magnitude of the current that flows into (flows out) the anode or cathode in normal driving (duty ratio 1/1). As the lighting rate increases, the current at the anode or cathode terminal increases in proportion. The current increases / decreases in proportion to the magnitude of the reference current, and increases / decreases in proportion to the duty ratio. The present invention is characterized in that the duty ratio and the reference current are changed depending on the lighting rate. That is, the duty ratio and the reference current are not fixed. The state is changed to at least a plurality of states according to the display state of the image.

  In an image with a lighting rate close to 0, most pixels are in low gradation display. In terms of a histogram, the majority of data is distributed in the low gradation area of the histogram. In this image display, the image is blacked out and there is no sharpness. Therefore, the dynamic range of the black display part is widened by controlling the gamma curve.

  In the above embodiment, when the lighting rate is 0, the duty ratio is set to 1/1, but the present invention is not limited to this. Needless to say, the duty ratio may be smaller than 1 as shown in FIG. In FIG. 102, the solid line has a lighting rate of 0 and a duty ratio = 0.8, and the dotted line has a lighting rate of 0 and a duty ratio = 0.6.

  Further, the duty ratio curve may be a curve as shown in FIG. Examples of the curve include a sine curve shape, an arc shape, and a triangular shape.

  In the case where the maximum value is provided for the duty ratio, it is preferable that the maximum value is set at any position within the range of at least the lighting rate of 20% to 50%. This range often appears in image display. Therefore, by making the duty ratio larger than other lighting rate ranges such as 1/1, it is recognized that the image is displayed with high brightness. For example, a control method in which the duty ratio is 1/1 at a lighting rate of 35%, and the duty ratio is 1/2 at a lighting rate of 20% and 60% is exemplified.

  Moreover, you may control in step shape according to a lighting rate. For example, when the lighting rate is 0% to 20%, the duty ratio is 1/1, and when the lighting rate is greater than 20% and 60% or less, the duty ratio is 1/2 and the lighting rate is When it is greater than 60% and less than or equal to 100%, it refers to a control method in which the duty ratio is ¼.

  As shown in FIG. 104, the duty ratio curve may be changed for red (R), green (G), and blue (B) pixels. In FIG. 104, the slope of the change in the duty ratio of blue (B) is the largest, the slope of the change in the duty ratio of green (G) is the next largest, and the slope of the change in the duty ratio of red (R) is the largest. It is small. If driven as described above, RGB white balance adjustment can be optimized. Of course, one color may be constant (not changed even when the lighting rate changes), and the other two colors may be controlled to change according to the lighting rate.

  The relationship between the lighting rate and the duty ratio is preferably set according to the content of the image data, the image display state, and the external environment. Further, it is preferable that the user can set or adjust freely. Further, it is preferable that the duty ratio, the reference current ratio, etc. can be automatically adjusted by the output from the photo sensor or the temperature sensor. For example, when the ambient temperature (panel temperature) is high, by reducing the duty ratio (1/4, etc.), current consumption flowing into the panel can be suppressed, and the panel's self-heating is reduced. The temperature can be lowered. Therefore, it is possible to prevent the panel from being thermally deteriorated. FIG. 252 (a) shows an embodiment in which the reference current ratio is changed according to the ambient temperature. As the ambient temperature increases, the reference current is suppressed (decreased), and the panel current consumption is reduced to suppress self-heating. FIG. 252 (b) shows an embodiment in which the duty ratio is changed depending on the ambient temperature. As the ambient temperature increases, the duty ratio is reduced, the panel current consumption is reduced, and self-heating is suppressed. Needless to say, the reference current ratio control in FIG. 252 (a) may be combined with the duty ratio control in FIG. 252 (b).

  When a bright screen and a dark screen are alternately repeated at a high speed, flicker occurs when the duty ratio, the reference current, and the like are changed according to the change. Therefore, when the duty ratio is changed from one duty ratio to another, it is preferable to provide a hysteresis (time delay) as shown in FIG. For example, if the hysteresis period is 1 sec, the previous duty ratio is maintained even if the screen brightness is bright and dark but is repeated a plurality of times within the 1 sec period. That is, the duty ratio does not change. Needless to say, the above items can also be applied to reference current control and the like. As shown in FIG. 98, the change may be different between R, G, and B.

  This hysteresis (time delay) time is called Wait time. Also, the duty ratio before the change is called the pre-change duty ratio, and the duty ratio after the change is called the post-change duty ratio. In addition, although called hysteresis (time delay), the meaning of performing a change slowly is also included in hysteresis. For example, when the duty ratio is changed from 1/1 to 1/2, an example in which the duty ratio is changed slowly over a time of 2 seconds is exemplified (almost, control is this method). This embodiment is shown in FIG. The controller IC 760 is controlled so that the duty ratio changes slowly as shown in FIG. 253 (b) in response to the change in the panel temperature in FIG. 253 (a).

  The same applies to the reference current ratio control. This embodiment is shown in FIG. As illustrated in FIG. 254 (b), the controller IC 760 is controlled so that the reference current ratio is slowly changed with respect to the change in the panel temperature in FIG. 254 (a).

  When the duty ratio before change is small and changes to another duty ratio, flicker is likely to occur due to the change. The state where the duty ratio before change is small is a state where the data sum of the screen is small or a state where there are many black display portions on the screen.

  In particular, when the halftone or lighting rate is around the median, the change is slow. This is probably because the screen is halftone and the visibility is high. Further, in a region where the duty ratio is small, the difference from the change duty ratio tends to increase. Of course, when the difference in duty ratio increases, control is performed using OEV. However, OEV control also has a limit. From the above, when the duty ratio before change is small, it is necessary to lengthen the wait time.

  When the pre-change duty ratio is changed to a different duty ratio, flicker due to the change is less likely to occur. The state where the duty ratio before change is large is a state where the data sum of the screen is large or a state where there are many white display portions on the screen. Therefore, it seems that the entire screen is white and the visibility is low. From the above, when the duty ratio before change is large, the wait time may be short.

  The above relationship is illustrated in FIG. The horizontal axis is the duty ratio before change. The vertical axis represents the wait time (seconds). When the duty ratio is 1/16 or less, the wait time is increased to 3 seconds (sec). For example, in B (blue), when the duty ratio is 1/16 or more and the duty ratio is 8/16 (= 1/2), the wait time is changed from 3 seconds to 2 seconds according to the duty ratio. When the duty ratio is 8/16 or more and the duty ratio is 16/16 = 1/1, the duty ratio is changed from 2 seconds to around 0 seconds according to the duty ratio.

  As described above, the duty ratio control of the present invention changes the wait time in accordance with the duty ratio. When the duty ratio is small, the wait time is lengthened, and when the duty ratio is large, the wait time is shortened. That is, in the driving method that varies at least the duty ratio, the duty ratio before the first change is smaller than the duty ratio before the second change, and the wait time of the first before-change duty ratio is the second The duty ratio is set to be longer than the wait time of the duty ratio before change.

  In the above embodiment, the wait time is controlled or specified based on the duty ratio before change. However, the difference between the pre-change duty ratio and the post-change duty ratio is slight. Therefore, in the above-described embodiment, the duty ratio before change may be read as the duty ratio after change.

  In the above embodiment, the pre-change duty ratio and the post-change duty ratio have been described. Needless to say, when the difference between the pre-change duty ratio and the post-change duty ratio is large, it is necessary to increase the wait time. Needless to say, when the duty ratio difference is large, it is preferable to change the duty ratio to the post-change duty ratio via the intermediate duty ratio.

  The duty ratio control method of the present invention is a driving method that takes a longer wait time when the difference between the pre-change duty ratio and the post-change duty ratio is large. That is, this is a driving method in which the wait time is changed according to the difference in duty ratio. Further, this is a driving method in which the wait time is lengthened when the difference in duty ratio is large. As described above, the wait time or hysteresis means to change slowly. Of course, in a broad sense, it goes without saying that it also means delaying the start of change.

  The duty ratio method of the present invention is a driving method characterized in that when the difference in duty ratio is large, the duty ratio is changed to the post-change duty ratio via the duty ratio in the intermediate state.

  In the above embodiment, the Wait time with respect to the duty ratio has been described as different for R (red), G (green), and B (blue). However, needless to say, the present invention may change the wait time by R, G, and B. This is because the visibility is different between RGB. By setting the wait time according to the visibility, a better image display can be realized.

  The above embodiment is an embodiment related to duty ratio control. It is preferable to set the wait time for the reference current control.

  As described above, in the driving method of the present invention, the duty ratio and the reference current are not changed rapidly. This is because the change state is recognized as flicker if it is suddenly changed. Usually, it is changed with a delay time of 0.2 seconds or more and 10 seconds or less. Needless to say, the above items can also be applied to anode voltage change control, precharge voltage change control, change control based on ambient temperature (to change the duty ratio and reference current depending on the panel temperature), and the like.

  When the reference current is small, the display screen 144 is dark, and when the reference current is large, the display screen 144 is bright. That is, when the reference current magnification is small, it can be rephrased as a halftone display state. When the reference current magnification is high, the image display state is high brightness. Therefore, when the reference current magnification is low, the wait time needs to be increased because the visibility to changes is high. On the other hand, when the reference current magnification is high, the wait time may be short because the visibility to the change is low.

  The duty ratio control as described above need not be completed in one frame or one field. The duty ratio control may be performed in a period of several fields (several frames). In this case, the duty ratio is an average value of several fields (several frames) as the duty ratio. Even when the duty ratio control is performed in several fields (several frames), the number field (several frames) period is preferably 6 fields (six frames) or less. This is because flicker may occur when the value exceeds this value. Also, the number field (several frames) is not an integer, and may be 2.5 frames (2.5 fields). That is, it is not limited to a field (frame) unit.

  The above matters are not limited to the EL display panel or EL display device having the pixel configuration shown in FIG. 1, but are also shown in FIGS. 2, 7, 8, 9, 11, 12, 13, 28, and 31. Needless to say, the present invention can also be applied to EL display panels or EL display devices having other pixel configurations such as FIG.

  The duty ratio pattern is changed between the moving image and the still image. When the duty ratio pattern is suddenly changed, an image change may be recognized. Also, flicker may occur. This problem occurs due to the difference between the duty ratio of the moving image and the duty ratio of the still image. The moving image uses a duty ratio pattern in which the non-display area 192 is inserted at once. The still image uses a duty ratio pattern in which the non-display area 192 is dispersedly inserted. The ratio of the area of the non-display area 192 / the screen area 144 is the duty ratio. However, even if the duty ratio is the same, human visibility varies depending on the dispersion state of the non-display area 192. This is thought to be due to the dependence on human video response.

  In the intermediate moving image, the non-display area 192 has a distributed state that is intermediate between the distributed state of the moving image and the distributed state of the still image. Note that a plurality of intermediate moving images may be prepared, and selected from a plurality of intermediate moving images corresponding to the moving image state or the still image state before the change. Examples of the plurality of intermediate moving image states include a configuration in which the non-display area is distributed in a manner similar to the moving image display, and the non-display area 192 is divided into three parts. On the contrary, a state in which the non-display area is dispersed in a large number like a still image is illustrated.

  Some still images are bright and some are dark. The same applies to videos. Therefore, it is only necessary to determine which intermediate moving image state is to be changed according to the state before the change. In some cases, a moving image may be transferred to a still image without going through an intermediate moving image. You may transfer from a still image to a moving image without going through an intermediate moving image. For example, when the display screen 144 has a low luminance, there is no sense of incongruity even if the moving image display and the still image display are moved directly. Further, the display state may be shifted via a plurality of intermediate moving image displays. For example, the duty ratio state of the moving image display may be shifted to the duty ratio state of the intermediate moving image display 1, and may be further shifted to the duty ratio state of the intermediate moving image display 2 and then the duty ratio state of the still image display.

  When moving from the movie display to the still image display, the intermediate movie state is passed. Also, the display is shifted from the still image display to the moving image display via the intermediate moving image display. It is preferable to set a wait time for the transition time of each state. Further, when shifting from a still image to a moving image or an intermediate moving image, the non-display area 192 changes slowly.

  The precharge drive has been described with reference to FIGS. The application of the precharge voltage is preferably linked to the lighting rate or the duty ratio. It is preferable not to apply the precharge voltage to a place where it is not necessary. This is because a decrease in brightness of white display may occur. Therefore, it is preferable that application of the precharge voltage is limited.

  The precharge drive is performed in order to eliminate the phenomenon of crosstalk under the white display portion, particularly in the current drive method. Therefore, this crosstalk is conspicuous in an image having a lot of black display portions on the screen and partly displaying white. In terms of the lighting rate, precharge is necessary in a region where the lighting rate is small. This is because if the entire display screen 144 is white, it will not be visually recognized even if crosstalk occurs. Therefore, it is not necessary to perform precharge driving.

  The present invention reduces the duty ratio when the lighting rate is high (the display screen 144 has many white display portions as a whole). That is, n of the duty ratio 1 / n is increased. When the lighting rate is low (the display screen 144 has a large number of black display portions as a whole), the duty ratio is increased. That is, the duty ratio approaches 1/1. Therefore, there is a correlation between the duty ratio and the lighting rate. Naturally, the lighting rate (lighting rate) is obtained from the video data, and the duty ratio control is performed from the lighting rate. The lighting rate is also related to the precharge control.

  As shown in FIG. 105A, it is assumed that there is a relationship between the duty ratio and the lighting rate (%). FIG. 105B shows the precharge on / off state. In FIG. 105 (b), precharge driving is set at a duty ratio of 20% or less. However, even if the precharge drive is used, the precharge drive of the present invention includes an all precharge mode, an adaptive precharge mode, a 0 grayscale precharge mode, and a selective grayscale precharge mode. Therefore, in FIG. 105 (b), the point is that the precharge drive is set to be performed, and the drive state differs depending on which precharge is performed. What is important is to change whether or not to perform precharge driving depending on the duty ratio or the lighting rate.

  There is also a correlation between the duty ratio or lighting rate (%) and gamma control. FIG. 106 is an explanatory diagram thereof. In an image with a high lighting rate, there are many images with high overall brightness. Therefore, the image becomes whitish. Therefore, it is preferable to increase the coefficient of the gamma constant (usually the coefficient is 2.2) to increase the area of the black gradation region. By increasing the area of the black gradation area, the image is sharpened.

  FIG. 107 shows the duty ratio with respect to the lighting rate. In the control of FIG. 107, when the lighting rate of the display image is close to 100%, the duty ratio is set to almost ¼. The gradation is proportional to the luminance. In an image with a high lighting rate, the gradation display of the image is crushed and the image has no resolution, so it is necessary to change the gamma curve. That is, it is necessary to increase the coefficient, which is a multiplier of the gamma curve, to make the gamma curve steep.

  From the above, in the present invention, the coefficient of the gamma curve is changed according to the lighting rate or the duty ratio. FIG. 106 is an explanatory diagram thereof.

The present invention reduces the duty ratio when the lighting rate is high (the entire display screen 144 has many white display portions). That is, n of the duty ratio 1 / n is increased. When the lighting rate is low (the display screen 144 has a large number of black display portions as a whole), the duty ratio is increased. That is, the duty ratio approaches 1/1. Therefore, there is a correlation between the duty ratio and the lighting rate. Naturally, the lighting rate (lighting rate) is obtained from the video data, and the duty ratio control is performed from the lighting rate.
As shown in FIG. 106A, it is assumed that there is a relationship between the duty ratio and the lighting rate (%). In the graph of FIG. 106B, the vertical axis indicates the coefficient of the gamma curve. In FIG. 106B, the gamma curve coefficient is set to be large when the duty ratio is 70% or more. That is, the gradation expression is increased in the high gradation region so that the gamma curve becomes steep. Therefore, the whiteout image is improved.

  As shown in FIGS. 108A and 108B, increasing the gamma coefficient in a small region where the duty ratio is a certain value or more may improve the image display. As described above, a sharp image display can be realized by changing the gamma curve in accordance with the lighting rate (image data sum). FIG. 256 shows an embodiment in which the comma coefficient is changed with respect to the lighting rate.

  There is a close relationship between duty ratio control and power supply capacity. The power supply size increases as the maximum power supply capacity increases. In particular, when the display device is mobile, a large power source becomes a serious problem. EL has a proportional relationship between current and luminance. In black display, no current flows. The maximum current flows in the white raster display. Therefore, the change in current due to the image is large. When the change in current is large, the power supply size increases and the power consumption increases.

  In the present invention, when the lighting rate is high, 1 / n of duty ratio control is increased to reduce current consumption (power consumption). Conversely, when the lighting rate is low, the duty ratio is set to 1/1 = 1 or close to 1/1 so that the maximum luminance is displayed. This control method will be described below.

  First, the relationship between the lighting rate (lighting rate) and the duty ratio is shown in FIG. It is assumed that the lighting rate is converted by the current flowing through the panel as described above. This is because, in the EL display panel, the light emission efficiency of B is poor, and thus when the display of the sea is displayed, the power consumption increases at a stretch. Therefore, the maximum value is the maximum value of the power supply capacity. The data sum is not a simple addition value of video data, but video data converted into current consumption. Therefore, the lighting rate is also obtained from the current used for each image with respect to the maximum current.

  FIG. 107 shows an example in which the duty ratio is 1/1 when the lighting rate is 0%, and the lowest duty ratio is 1/4 when the lighting rate is 100%. FIG. 109 shows the result of multiplication of power and lighting rate. If the lighting rate is 0 to 100% in FIG. 107 and the duty ratio is constantly 1/1, a curve indicated by a in FIG. 109 is obtained. The vertical axis in FIG. 109 is the ratio of power used to the power supply capacity (power ratio). That is, in the curve a, the lighting rate and the power consumption are in a proportional relationship. Therefore, when the lighting rate is 0%, the power consumption is 0 (power ratio 0), and when the lighting rate is 100%, the power consumption is 100 (power ratio 100%).

  A curve b in FIG. 109 is an example in which power limitation is performed using the duty ratio curve in FIG. Since the duty ratio is 1/4 when the lighting rate is 100%, the power ratio is 25% of 1/4 compared to the curve a. The curve b is operating in a range smaller than the electric power 1/3. Therefore, when duty ratio control is performed as shown in FIG. 107, 1/3 of the power supply capacity is sufficient as compared with the conventional case (curve a). That is, in the present invention, the power supply size can be reduced as compared with the conventional one.

  Further, if the lighting rate continues to be high in the prior art (curve a), the current flowing through the panel is large, and the panel is deteriorated due to heat generation. However, in the present invention in which the duty ratio control is performed, an average current flows through the panel regardless of the lighting rate, as can be seen from the curve b. Therefore, there is little heat generation and the panel does not deteriorate.

  In the duty ratio curve of FIG. 107, an example in which the lowest duty ratio is halved is a curve c. Further, the curve d is an example in which the minimum duty ratio is 1/3. Similarly, the example is curve e with a minimum duty ratio of 1/8.

  In FIG. 107, the duty ratio curve is a straight line. However, the duty ratio curve can be generated by a wide variety of straight lines or curves. For example, FIG. 110 (a1) is a duty ratio control curve such that the power ratio is 30% or less (see FIG. 110 (a2)). 110 (b1) is a duty ratio control curve so that the power ratio is 20% or less (see FIG. 110 (b2)). As described above, the duty ratio curve or the reference current ratio curve is preferably configured to be variable by programming such as a microcomputer or external control.

  The duty ratio control curve allows the user to freely switch between FIGS. 110A and 110B with a button according to the external environment. When the external environment is bright, the duty ratio curve shown in FIG. 110 (a1) is selected. When the external environment is dark, the duty ratio curve shown in FIG. 110 (b1) is selected. Further, it is preferable that the duty ratio control curve is configured to be freely changed.

  In the above embodiments, the case where the reference current is 1 has been described as a reference, and the maximum duty ratio has been described as 1/1. However, the present invention is not limited to this. For example, as shown in FIG. 111, the reference current may be changed to 1 or 1/3 with 1/2 being the center. The maximum may be set to 0.5. The duty ratio may also be changed to 0.5 or less around 0.25. The maximum may be 0.5.

  Further, as shown in FIG. 112, the minimum value of the reference current may be set to 1 and the maximum value may be set to 3 so as to be changed into a plurality of values. Also, as shown in FIG. 113, the duty ratio may be controlled to be the lowest at 80% of the lighting rate and to be increased at 100% or 60%.

  114 (a) and 114 (b), the reference current may be changed to 3 or 1 with 2 as the center. The maximum may be 3. Needless to say, the duty ratio may be changed to 0.25 or the like with 0.5 being the maximum. The same applies to FIGS. 115 (a) and 115 (b).

  Also, as shown in FIG. 116, the duty ratio is decreased in the low lighting rate region (lighting rate of 20% or less in FIG. 116) (FIG. 116 (a)), and the reference current ratio is set in accordance with the decrease in the duty ratio. It may be raised (FIG. 116 (b)). As described above, by performing the duty ratio control and the reference current ratio control at the same time, the luminance does not change as illustrated in FIG.

  In FIG. 116, in the region where the lighting rate is high (40% or more in FIG. 116), the duty ratio is decreased, but the reference current ratio remains constant at 1. Therefore, since the luminance decreases as the duty ratio decreases, the power consumption of the panel can be controlled (basically reduced). In the driving method in which the maximum duty ratio is 1/1, it is preferable to insert the non-display area 192 in a lump.

  Moreover, it is preferable that the relationship between the reference current ratio, the duty ratio, and the lighting rate is kept constant as described below. This is because the increase in flicker generation or the panel deterioration due to self-heating is accelerated. FIG. 267 is an example. In FIG. 267 (c), A on the vertical axis indicates duty ratio × reference current ratio. In a region where the lighting rate is basically low, it is preferable to control A to be in the vicinity of 1. Further, it is preferable to control A to be smaller than 1 in a region where the lighting rate is high.

  According to the result of the study, it is preferable that the duty ratio × reference current ratio (A) is 0.7 or more and 1.4 or less in a region where the lighting rate is 30% or less. More preferably, it is 0.8 or more and 1.2 or less. In the region where the lighting rate is 80% or less, it is preferable to control or set the duty ratio × reference current ratio (A) to be 0.1 or more and 0.8 or less. Further, it is preferable to control or set so as to be 0.2 or more and 0.6 or less.

  Alternatively, when the duty ratio × reference current ratio when the lighting rate is 50% is A, the duty ratio × reference current ratio × A is set to 0.7 or more and 1.4 or less in the region where the lighting rate is 30% or less. Or it is preferable to control. More preferably, it is set or controlled at 0.8 or more and 1.2 or less. Further, in a region where the lighting rate is 80% or less, it is preferable that duty ratio × reference current ratio × A is set or controlled to be 0.1 or more and 0.8 or less. More preferably, it is set or controlled to be 0.2 or more and 0.6 or less.

  In the embodiment of FIG. 267, the duty ratio is decreased in the low lighting rate region (lighting rate of 25% or less in FIG. 267), and the reference current ratio is increased in inverse proportion. Therefore, the relationship of substantially 1 is maintained for A which is duty ratio × reference current ratio. For this reason, there is no change in the brightness of the screen 144, the magnitude of the program current is increased, and insufficient writing of the current program is improved.

  In the high lighting rate region (lighting rate of 75% or more in FIG. 267), the duty ratio is reduced, while the reference current ratio is also reduced. Therefore, A which is duty ratio × reference current ratio is controlled so as to approach 0.25 as the lighting rate increases. Therefore, as the lighting rate increases, the brightness of the screen 144 decreases and the current consumption also decreases. Therefore, the self-heating amount of the panel decreases in proportion to A × lighting rate.

  In general, when the EL display panel is a medium or small size of 15 inches or less, it is preferable to drive according to the relationship shown by the dotted line in FIG. 269 (to reduce the duty ratio × reference current ratio when the lighting rate is high). . When the EL display panel is 15 inches or larger, it is preferable to drive according to the relationship shown by the solid line in FIG. 269 (when the lighting ratio is high, the duty ratio × reference current ratio is reduced and the lighting ratio is low). To increase the duty ratio × reference current ratio).

  Note that an efficiency graph of the power supply circuit of the present invention is shown in FIG. 268 (a). Efficiency is good when the output current is higher than the middle. Therefore, it is preferable to use an output having an output current of a certain level or more on average.

  When control is performed as indicated by the dotted line in FIG. 269, the relative change rate (power ratio) of the power is as indicated by the dotted line in FIG. 268 (b). When the control is performed as indicated by the solid line in FIG. 269, the relative change rate (power ratio) of the power is as indicated by the solid line in FIG. 268 (a). In the solid line, the power increases at a low lighting rate. However, since the lighting rate is low, power consumption hardly increases. The advantage of improving the shortage of writing is greater.

  When the duty ratio is 1/6 or more, or preferably 1/4 or more, the non-display area 192 is preferably inserted all at once (FIGS. 54A1 to 54A4, etc.). Further, when the duty ratio is 1/6 or less or preferably smaller than 1/4, the non-display area 192 is divided and inserted (FIGS. 54 (b1) to (b4), FIGS. 54 (c1) to (c4), etc. ) Is preferable.

  In the present invention, the first lighting rate (the anode current of the anode terminal, the ratio to the sum of the data may be described previously) or the lighting rate range (the anode current range of the anode terminal, the range of the ratio to the sum of the data) In the first FRC, the lighting rate, the current flowing through the anode (cathode) terminal, the reference current, the duty ratio, the panel temperature, the product of the reference current ratio and the duty ratio, or the like. These are changed as a combination. Further, in the second lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the current flowing through the second FRC, the lighting rate, or the anode (cathode) terminal. Alternatively, the reference current or the duty ratio, the panel temperature, the product of the reference current ratio and the duty ratio, or a combination thereof is changed. Or, depending on the lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal) (adapted), it flows to the FRC or the lighting rate or the anode (cathode) terminal. The current, the reference current, the duty ratio, the panel temperature, the product of the reference current ratio and the duty ratio, or a combination thereof is changed. Also, when changing, the hysteresis is changed, delayed or changed slowly.

  In the present invention, the precharge driving method has been described. The concept of lighting rate was also explained. It is also effective to change the precharge voltage depending on the lighting rate. Note that the lighting rate is synonymous with current consumption when duty ratio control is not performed. That is, the lighting rate is derived by adding image data. This is because in the case of current driving, image data and power consumption are proportional, and the lighting rate is derived from the image data.

  Precharge drive is similar to voltage drive. This is because a voltage is applied to the source signal line 18 and a precharge voltage is applied to the gate voltage of the driving transistor 11a to prevent the driving transistor 11a from flowing a current to the EL element 15. Therefore, the reference origin of the precharge voltage is the anode potential (Vdd). Of course, when the driving transistor is an N channel, the origin of the precharge voltage is the cathode. In the present specification, for ease of explanation, the driving transistor 11a is described as a P-channel as shown in FIG.

  When the anode potential changes, it is necessary to change the precharge voltage. The resistance of the anode wiring 2155 is lowered so that the anode potential (Vdd) does not change. However, when the lighting rate is high, the amount of current flowing through the anode wiring (terminal) is large, so that a voltage drop occurs. The voltage drop is proportional to the current consumption. Therefore, the voltage drop of the anode voltage is proportional to the lighting rate.

  From the above, it is preferable to change the precharge voltage in correlation with the lighting rate. Alternatively, it is preferable to change the precharge voltage corresponding to the current flowing through the anode (cathode) terminal (or the current flowing through the EL display panel).

  The source driver circuit of the present invention includes an electronic volume 501 as shown in FIG. Therefore, the precharge voltage can be easily changed by controlling the electronic regulator 501. Needless to say, the precharge voltage may be generated and applied not only by the electronic volume control 501 but also by a DA circuit outside the source driver IC (circuit) 14.

  The voltage drop generated at the anode terminal can be grasped by the following processing. First, the resistance value from the anode voltage source to each pixel is known at the stage of design. This is because the resistance value is determined from the sheet resistance value of the metal thin film of the anode wiring (resistance from the anode terminal to the driving transistor 11a of the pixel 16). The current consumption flowing through the anode terminal can be determined by processing the video data. In the current driving method, the sum of video data may be obtained. The above has been described as derivation of duty ratio, data sum, lighting rate (= lighting rate), etc. in FIGS. 85, 88, 98, 103, 205, 107, 109, and the like. The ability to easily derive the current flowing through the anode is a major feature of the current programming method.

  Therefore, if the resistance value of the anode wiring and the current flowing through the anode wiring (panel consumption current) are known, the voltage drop generated at the anode terminal can be known. The current consumption is derived in real time by processing one frame of image data. Therefore, the voltage drop of the anode terminal in the pixel 16 is also determined in real time.

  From the above, the anode voltage at the pixel 16 (in consideration of the voltage drop) is derived in real time, and the precharge voltage is determined in consideration of this voltage drop. Note that the determination of the precharge voltage is not limited to being performed in real time. It goes without saying that it may be performed intermittently. In addition, when performing duty ratio control, the electric current which flows into an anode changes with duty ratio. Therefore, it is necessary to consider current consumption by duty ratio control. When the duty ratio is 1/1, the lighting rate is the same as the current consumption (power).

  Further, in the present invention, controlling the reference current ratio (or the magnitude of the reference current) to be small (for example, changing from the reference current ratio 4 to 1) means that the current flowing through the cathode terminal or the anode terminal This is synonymous or similar to controlling the current flowing or the current flowing to the EL element 15 of the pixel 16 to be small. Similarly, controlling the duty ratio (or the magnitude of the duty) to be small (for example, changing the duty ratio from 1/1 to 1/4) means that the current flowing in the cathode terminal or the current flowing in the anode terminal Or it is synonymous or similar to controlling so that the electric current which flows into the EL element 15 of the pixel 16 may be decreased.

  Therefore, controlling the current flowing through the cathode terminal, the current flowing through the anode terminal, or the current flowing through the EL element 15 of the pixel 16 so that it decreases or increases controls the gate driver circuit (IC) 12. (For example, by controlling the start signal (ST) in FIG. 14). Alternatively, the gate driver circuit 12 can easily change, adjust, or operate the control state (number of gate signal lines 17 to be selected) of the gate signal line 17b (signal line or control means for controlling the current flowing through the EL element 15). realizable. In addition, controlling the source driver circuit (IC) 14 to control the current flowing in the cathode terminal, the current flowing in the anode terminal, or the current flowing in the EL element 15 of the pixel 16 so as to decrease or increase it. (For example, by controlling the reference current Ic in FIG. 46, FIG. 50, FIG. 60, etc.). Alternatively, it can be realized by changing or controlling the anode voltage Vdd.

  In order to facilitate the description in this specification, the description will be basically made assuming that the duty ratio is 1/1 in FIG. That is, it is assumed that the lighting rate is proportional to the current flowing through the anode.

  In the description, the anode current and the lighting rate are assumed to be proportional. However, in the pixel configuration of FIG. 1 and the like, a program current flowing into the source driver IC is also added to the anode terminal (the source terminal of the driving transistor 11a). Therefore, the reality is somewhat different. Further, the current flowing through the anode wiring is mainly described, but it goes without saying that the current flowing through the cathode wiring may be replaced.

  FIG. 117 (a) illustrates that the voltage drop of the anode voltage of the pixel 16 from Vdd (lighting rate 0%) to Vr (lighting rate 100%) occurs according to the lighting rate. FIG. 117B shows the precharge voltage output to the terminal 155 with respect to the lighting rate. The rising position of the driving transistor 11a is at a position that is lowered by D (V) from Vdd. Therefore, a voltage that is lowered by D (V) from Vd becomes a precharge voltage at a lighting rate of 0%. The solid line in FIG. 117 (b) uses the voltage drop Vr (V) at the anode terminal in FIG. 117 (a) as it is. Therefore, the precharge voltage with a lighting rate of 100% is Vdd-D-Vr.

  The dotted line in FIG. 117 (b) is obtained by changing the precharge voltage at a lighting rate of 40% or more and below. The precharge voltage is Vdd-D (V) up to a lighting rate of 40%, and the precharge voltage is Vdd-D-Vr (V) above 40%. By controlling as indicated by the dotted line, the circuit for deriving the precharge voltage is simplified.

  The anode voltage Vdd depends on the magnitude of the program current Iw. The pixel configuration in FIG. 1 will be described as an example. As shown in FIG. 118A, during current programming, the programming current Iw flows from the driving transistor 11a into the source signal line 18. When the program current Iw is large, the channel-to-channel voltage of the driving transistor 11a increases. FIG. 118 (b) is a graph of FIG. 118 (a). When the channel voltage is V1 (actually 0 on the horizontal axis is the Vdd voltage), the program current I1 flows. When the channel voltage is V2 (actually 0 on the horizontal axis is the Vdd voltage), the program current I2 flows. In order to pass a large program current Iw, it is necessary to increase the anode voltage Vdd.

  In the above embodiment, it is necessary to increase the anode voltage Vdd when the program current Iw is large. Conversely, when the program current Iw is small, it means that the anode voltage Vdd may be low. If the anode voltage Vdd is lowered, the power consumption of the panel can be reduced, and the power consumed by the driving transistor 11a can also be reduced, so that heat generation can be reduced and the life of the EL element 15 can be extended. .

  The program current Iw also changes with a change in the reference current. If the reference current Ic is increased, the program current Iw is also relatively increased (discussed on the raster screen when the gradation data of the screen is constant). If the reference current Ic decreases, the program current Iw also becomes relatively small. Here, for ease of explanation, an increase or decrease in the program current Iw is described as being synonymous with an increase or decrease in the reference current Ic.

  FIG. 119 is a block diagram of the power supply circuit of the present invention. Vin is an unregulator voltage from a battery (not shown) of the main body. The DCDC converter 1191a uses the GND voltage as a reference and boosts it from the Vin voltage to generate an anode voltage Vdd. For ease of explanation, it is assumed that the power supply voltage Vs and the anode voltage Vdd of the source driver IC are the same. By setting Vdd = Vs, the number of power supplies is reduced and the circuit configuration is facilitated. Further, no overvoltage is applied to the source driver IC. The DCDC converter 1191b generates a base voltage Vdw by boosting from the Vin voltage with reference to the GND voltage.

  The regulator 1193 generates the cathode voltage Vss from the Vdw voltage and the Vdd voltage using the Vdd voltage as a ground voltage. With the above configuration, if the Vdd voltage increases, the Vss voltage also increases in proportion.

  As can be understood from FIG. 1, a constant current Iw is generated by the driving transistor 11 a, and a program current Iw flows through the EL element 15. Therefore, power consumption is a potential difference between Vdd and Vss. In the configuration of FIG. 119, the Vss voltage is also shifted in the same direction due to the shift of the Vdd voltage. Therefore, even if the anode voltage changes, the voltage applied between the EL element 15 and the driving transistor 11a is constant.

  As described with reference to FIG. 118, the anode voltage needs to be increased as the program current Iw (reference current Ic) increases. This is because the GND potential is fixed. The IC voltage Vs is also changed simultaneously with the change of the anode voltage (Vdd = Vs). When Vdd−Vss is a constant voltage and Vdd increases, the voltage applied to the EL element 15 decreases. Therefore, the EL element 15 does not operate in the saturation region. However, the region where Iw (Ic) has to be increased is a region with a low lighting rate, and the pixel is subjected to high luminance control. Therefore, even if the luminance of the pixel 16 with a low lighting rate and high luminance display is lowered, the image display is hardly affected. The power consumption, which is an advantage, is greater.

  If Vdd = Vs is not satisfied, it is only necessary to be generated by dividing resistance (R1, R2) between the anode voltage vdd and GND as shown in FIG. This is because the Vs voltage is used for generating a precharge voltage inside the IC. Since the precharge voltage is based on Vdd, Vs and Vdd need to be linked. As shown in FIG. 120, an electrolytic capacitor C is inserted.

FIG. 121 illustrates the relationship between the gate-off voltage (Vgh) and the gate-on voltage (Vgl) (see also FIG. 180 and its description). In FIG. 121 (a), the Vgh voltage is made larger than the anode voltage Vdd. The Vgl voltage is higher than the Vss voltage.
FIG. 121 (b) shows a state in which the anode voltage Vdd is shifted to be higher than the reference voltage Vdd (indicated by voltage Vdd1). In FIG. 121 (b), the Vgh voltage is increased in conjunction with the change in Vdd. The Vgl voltage is not changed from FIG. 121 (a).

  FIG. 121 (b) shows a state in which the anode voltage Vdd is shifted to be higher than the reference voltage Vdd (indicated by voltage Vdd1). In FIG. 121 (b), the Vgh voltage is not interlocked with the change in Vdd. The Vgl voltage is not changed from FIG. 121 (a). As described above, the gate signal line voltages Vgh and Vgl may be either.

  The anode voltage Vdd and the power supply voltage Vs (or reference voltage) of the IC (circuit) 14 are preferably the same. Further, as shown in FIG. 75, it is preferable that the reference voltage Vs of the electronic volume 501 for generating the precharge voltage is also the anode voltage Vdd. That is, the circuit power supply voltage for generating precharge, the power supply voltage (reference voltage) Vs of the IC (circuit) 14 and the anode voltage Vdd are substantially matched. Note that “substantially coincide” means a range within ± 0.2 (V). Of course, it is needless to say that it is preferable to make it completely coincide.

  The reference voltage Vs, the anode voltage Vdd, and the power supply voltage Vs of the circuit (IC) 14 are linked to generate the precharge voltage. For example, when the anode voltage Vdd increases, the reference voltage Vs of the electronic volume 501 that generates the precharge voltage is also increased. Also, the power supply voltage of the circuit (IC) 14 is increased. Conversely, if the anode voltage Vdd drops, the reference voltage Vs of the electronic regulator 501 that generates the precharge voltage is also dropped. Further, the power supply voltage of the circuit (IC) 14 is also lowered.

  The reason for interlocking as described above is that the precharge voltage is preferably generated with reference to Vdd of the driving transistor 11a (that is, the source terminal potential of the driving transistor 11a). That is, if the anode voltage Vdd increases, it is preferable to increase the precharge voltage in conjunction with it. Therefore, the reference voltage of the electronic volume 501 (power supply voltage of the IC (circuit) 14) Vs is also increased. On the other hand, since the electronic volume 501 is built in the source driver circuit (IC) 14, the electronic volume 501 cannot naturally exceed the power supply voltage (withstand voltage) of the IC.

  Actually, the precharge voltage that can be output from the source driver circuit (IC) 14 is about the power supply voltage −0.2 (V) of the IC (circuit) 14. Therefore, if the precharge voltage increases, the target precharge voltage cannot be output from the IC (circuit) 14 unless the power supply voltage of the IC (circuit) 14 is also increased.

  75. Since the precharge voltage has a digital variable (variable from outside the IC) configuration such as an electronic volume 501 as shown in FIG. 75, changes in the anode voltage Vdd (for example, see FIGS. 123, 125, 124, etc.) )) And the switch S of the electronic volume 501 is changed, whereby the precharge voltage can be changed. Therefore, the configuration of FIG. 75 is a characteristic feature of the IC (circuit) 14 of the present invention. The precharge voltage may be generated outside the IC (circuit) 14 and applied to the source signal line 18 or the like via the IC (circuit) 14. In this case as well, the power supply voltage Vs of the IC (circuit) 14 needs to be 0.2 (V) higher than the maximum value of the precharge voltage.

  In the above embodiments, the precharge voltage has been described. However, the present invention is not limited to the precharge voltage, and it goes without saying that the present invention can also be applied to the reset voltage described with reference to FIG.

  Further, the anode voltage Vdd and the power supply voltage of the driver IC (circuit) 14 are linked. However, when the driving transistor 11a is an N channel as shown in FIGS. 10 and 9, the cathode voltage Vss is the reference. It becomes. Therefore, it goes without saying that the reference voltage Vs and cathode voltage Vss of the electronic volume 501 for generating the precharge voltage and the power supply voltage Vs (or GND level) of the circuit (IC) 14 need to be linked. Accordingly, the contents described above may be replaced.

  Needless to say, the above items can be applied to other embodiments of the present invention, such as a display panel, a display device, and a driving method.

  FIG. 122 shows a relationship between the lighting rate and the anode voltage as an example. Vdd + 2 and Vdd + 4 do not indicate absolute voltages, but are relatively illustrated for ease of explanation.

  In FIG. 122, the reference current (program current) is increased when the lighting rate is 25% or less. In this state, since the anode voltage needs to be increased, the anode voltage is increased as the reference current increases. The reference current is increased when the lighting rate is 75% or more. As the reference current increases, the anode voltage increases.

  FIG. 122 shows a relationship between the lighting rate and the anode voltage as an example. The present invention is not limited to this. For example, as shown in FIG. 280, it goes without saying that the potential difference between the anode terminal voltage and the cathode terminal voltage may be changed according to the lighting rate or the like. For example, if the anode terminal voltage is 6 (V) and the cathode terminal voltage is −9 (V), the potential difference is 6 − (− 9) = 15 (V). That is, the absolute value of the anode voltage and the cathode voltage is changed according to the lighting rate, the reference current, the current flowing through the anode terminal, or the like.

  A solid line A in FIG. 280 indicates a potential difference between the first anode terminal voltage and the cathode terminal voltage in the first lighting rate or lighting rate range, and the second anode terminal voltage and the cathode in the second lighting rate or lighting rate range. In addition, the anode terminal voltage and the cathode terminal voltage are changed according to the lighting rate from the first lighting rate or lighting rate range to the second lighting rate or lighting rate range. A dotted line B in FIG. 280 indicates a potential difference between the first anode terminal voltage and the cathode terminal voltage in the first lighting rate or lighting rate range, and the second anode terminal voltage and the cathode in the second lighting rate or lighting rate range. The potential difference from the terminal voltage is changed in steps.

  In FIG. 123, the reference current (program current) is changed stepwise according to the lighting rate. As the reference current changes, the anode voltage also changes.

  In FIGS. 119 to 123, 280, etc., the anode voltage is changed by changing the reference current (program current). However, this is a case where the driving transistor 11a is the P channel, and it goes without saying that the cathode voltage is changed when the driving transistor 11a is the N channel.

Note that the anode voltage with respect to the magnitude of the program current (the magnitude of the reference current) may be changed as shown in FIG. A solid line a in FIG. 124 is an example in which the anode voltage is changed in proportion to the program current (reference current). A dotted line b in FIG. 124 is an embodiment in which the anode voltage is changed when the current is equal to or higher than a predetermined program current (reference current). In the dotted line b, since the change point of the anode voltage with respect to the reference current is one point, the circuit configuration is easy.
In FIGS. 119 and 120, it goes without saying that a booster circuit or the like may be formed or configured using a transformer (single winding transformer, multiple winding transformer) or a coil instead of the DCDC converter or the regulator.

  In the above embodiment, the anode voltage is changed according to the magnitude of the reference current or the program current. However, a change in the magnitude of the reference current or the program current is synonymous with changing the potential of the source signal line 18. In the case where the driving transistor 11a shown in FIG. 1 is a P channel, increasing the program current Iw or the reference current is to lower the potential of the source signal line 18 (close to the GND potential). Conversely, to reduce the program current Iw or the reference current is to increase the potential of the source signal line 18 (closer to the anode Vdd).

  From the above, control may be performed as shown in FIG. That is, when the potential of the source signal line 18 is 0 (GND), the anode voltage is set highest (the reference current and the program current are the maximum values). When the potential of the source signal line 18 is the Vdd potential, the anode voltage is made the lowest (the reference current and the program current are the minimum values). By configuring or controlling as described above, the period during which a high voltage is applied to the EL element 15 can be shortened, and the life of the EL element 15 can be extended.

  Hereinafter, the power supply circuit (voltage generation circuit) of the EL display panel (EL display device) of the present invention will be further described. First, the power supply (voltage) used in the EL display panel of the present invention will be described with reference to FIG. As described with reference to FIG. 14, the gate driver circuit 12 includes a buffer circuit 142 and a shift register circuit 141. The buffer circuit 142 uses the off voltage (Vgh) and the on voltage (Vgl) as power supply voltages. On the other hand, the shift register circuit 141 uses a power supply VGDD and a grant (GND) voltage of the shift register, and also uses a VREF voltage for generating an inverted signal of the input signals (CLK, UD, ST). The source driver circuit 14 uses a power supply voltage Vs and a ground (GND) voltage.

  Here, in order to facilitate understanding, a voltage value is defined. First, the anode voltage Vdd is set to 6 (V), and the cathode voltage Vss is set to −9 (V) (see FIG. 1 and the like). The GND voltage is 0 (V), and the Vs voltage of the source driver circuit is 6 (V), which is the same as the Vdd voltage. The Vgh1 and Vgh2 voltages are preferably 0.5 (V) or more and 3.0 (V) or less from Vdd. Here, Vgh1 = Vgh2 = 8 (V).

  Vgh1 of the gate driver circuit 12 needs to be lowered in order to sufficiently reduce the on-resistance of the transistor 11c in FIG. Here, in order to facilitate the circuit configuration of FIG. 261, Vgl1 = −8 (V) whose absolute value is opposite to Vgh1 is set. The VGDD voltage needs to be lower than Vgh and higher than the GND voltage. Here, in order to facilitate the generated voltage circuit and reduce the circuit cost as shown in FIG. 261, it is set to 4 (V) which is 1/2 of the Vgh voltage. On the other hand, if the Vgl2 voltage is too low, there is a risk of leakage of the transistor 11b. Therefore, it is preferable that the Vgl2 voltage be an intermediate voltage between the VGDD voltage and the VHL1 voltage. Here, in order to facilitate the generated voltage circuit and reduce the circuit cost as shown in FIG. 261, the VGDD voltage is set to -4 (V) which is equal in absolute value and opposite in polarity.

  FIG. 261 shows a circuit configuration of the present invention for generating the voltage set as described above. Hereinafter, FIG. 261 will be described.

  Voltages V1 to V2 from the battery are input to a regulator circuit 2611 having a charge pump circuit. Specifically, V1 = 3.6 (V) and V2 = 4.2 (V). The regulator circuit 2611 converts the input voltage into a constant voltage Va of 4 (V) by the charge pump circuit 2612a. This voltage becomes the VGDD voltage. Of course, as shown in FIG. 261, a charge pump circuit (without regulator function) 2612a that generates a positive voltage and a negative voltage generates 4 (V) that is + V and −4 (V) that is −V. Also good. This -4 (V) is the Vgl2 voltage. Since the charge pump circuit 2612a only generates the positive and negative voltages of Va, the configuration is very easy. Therefore, cost reduction can be realized.

  The output voltage Va from the regulator circuit 2611 is input to the charge pump circuit 2612b. As shown in FIG. 261, a charge pump circuit (without regulator function) 2612b that generates positive and negative voltages may generate + 2V, 8 (V), and −2V, −8 (V). . This -8 (V) becomes the Vgh1 and Vgh2 voltages. The −2V voltage becomes the Vgl1 voltage. Since the charge pump circuit 2612b only generates a positive voltage twice as large as Va and a negative voltage twice as large as Va, the configuration is very easy. Therefore, cost reduction can be realized.

  As described above, the present invention is characterized in that the Vgh voltage or the like is generated by multiplying the reference voltage Va by a fixed multiple (two times, three times, etc.).

  A circuit for generating the Vdd and Vss voltages is shown in FIG. The circuit for generating the Vdd voltage and the Vss voltage has also been described with reference to FIG. FIG. 262 shows a configuration using a transformer circuit. Voltages V1 to V2 from the battery are input to a regulator circuit 2611 having a charge pump circuit. The regulator circuit 2611 converts the input voltage into a constant voltage Va of 4 (V) by the charge pump circuit 2612a. The Va voltage (common to FIG. 261) is switched by the switching circuit 2621 and converted into an alternating current. The AC signal is converted in potential by a circuit including a transformer 2622, and the voltage subjected to the potential conversion is converted into a DC voltage by a smoothing circuit 2623. The converted voltages become Vdd and Vss (since the potential shift can be performed by the transformer).

  FIG. 263 shows the output voltage of the power supply circuit of the display panel of the present invention. The precharge voltage Vpc is generated by an electronic volume 501 that operates between the Vs voltage and the GND voltage. The VREF voltage is generated by resistors (R1, R2) arranged between the VGDD voltage and GND. Note that a capacitor C is provided for the VREF voltage to stabilize it.

  This voltage becomes the VGDD voltage. Of course, as shown in FIG. 261, a charge pump circuit (without regulator function) 2612a that generates a positive voltage and a negative voltage generates 4 (V) that is + V and −4 (V) that is −V. Also good. This -4 (V) is the Vgl2 voltage. Since the charge pump circuit 2612a only generates the positive and negative voltages of Va, the configuration is very easy. Therefore, cost reduction can be realized.

  In the precharge drive of the present invention, a predetermined voltage is applied to the source signal line 18. The source driver IC outputs a program current. However, in the present invention, the output voltage may be changed in accordance with the gradation in the precharge driving. That is, the precharge voltage output to the source signal line 18 is a program voltage. FIG. 127 shows a circuit configuration in which the program voltage circuit 1271 of the precharge voltage is introduced into the source driver IC.

  FIG. 127 is a one-output circuit block diagram corresponding to one source signal line 18. A current gradation circuit 164 and a voltage gradation circuit 1271 that outputs gradation output by precharging are configured. Video data is applied to the current gradation circuit 164 and the voltage gradation circuit 1271. The output of the voltage gradation circuit 1271 is applied to a terminal 155 that outputs to the source signal line 18 when the switch 151 is turned on / off. The switch 151 is controlled by a precharge enable (precharge ENBL) signal and a precharge signal (precharge SIG). The switch 151 is controlled to close when the precharge enable (precharge ENBL) signal is at the H level and the precharge signal (precharge SIG) is at the H level.

  The voltage gradation circuit 1271 includes a sample hold circuit, a DA circuit, and the like. Based on the digital video data, the voltage is converted by the DA circuit. The converted voltage is sampled and held by a sample and hold circuit, and is applied to one terminal of the switch 151 via an operational amplifier. The DA circuit does not need to be configured or formed for each voltage gradation circuit 1271, and a DA circuit may be configured outside, and the output of the DA circuit may be sampled and held in the voltage gradation circuit 1271.

  The output of the voltage gradation circuit 1271 is applied at the beginning of 1H (indicated by symbol A) as shown in FIG. Thereafter, a program current is supplied to the source signal line by the current output circuit 164 (indicated by symbol B). That is, the voltage is set to the approximate source signal line potential by the voltage. Therefore, the driving transistor is set at a high speed up to a value close to the target current. Thereafter, the current is set up to a target current that compensates for variations in the driving transistor. The period A during which the voltage signal is applied is preferably 1/100 to 1/5 of 1H. Alternatively, it is preferably set to a period of 0.2 μsec to 10 μsec. Therefore, the period other than the A period is the current application period of the B period. If the A period is short, charge and discharge of the source signal line 18 are not sufficiently performed, and thus insufficient writing occurs. On the other hand, if it is too long, the current application period (B) is shortened, and the program current cannot be sufficiently applied. Therefore, the current correction of the driving transistor 11a is insufficient.

  The voltage application period (A period) is preferably implemented from the beginning of 1H, but is not limited thereto. For example, the blanking period at the end of 1H may be started. Moreover, you may implement A period in the middle of 1H. That is, the voltage application period may be performed in any period of 1H. However, it is preferable that the voltage application period be implemented within a period of 1 / 4H (0.25H) from the beginning of 1H.

  In the embodiment of FIG. 128, the current is applied (B period) after the voltage precharge (A) period, but the present invention is not limited to this. For example, as shown in FIG. 129 (a), the entire 1H period (or the majority or the majority) may be the voltage precharge (* A) period.

  In the period of * A in FIG. 129 (a), the voltage program is executed in the period of 1H. * A period is a low gradation area. Even if the current program is executed in the low gradation region, the current to be programmed is very small. Therefore, the potential of the source signal line 18 cannot be changed due to the parasitic capacitance of the source signal line 18. That is, the characteristic compensation of the TFT 11a (driving transistor) cannot be performed. In the current programming method, the programming current I and the brightness B are in a linear relationship. Therefore, the luminance change for one gradation is too large in the low gradation area. Therefore, gradation skip is likely to occur in the low gradation region.

  In order to solve this problem, in the present invention, as shown in FIG. 129 (a), a voltage program is executed over a period of 1H in the low gradation region (indicated by * A). The voltage step increment of the voltage program is reduced in the low gradation region. When the voltage applied to the TFT 11a of the pixel 16 is set to a certain step, the output current of the TFT 11a to the EL element 15 has a substantially square characteristic. Therefore, the luminance B with respect to the applied voltage (the luminance B is proportional to the output current to the EL element 15) has a linear human visual sensitivity (the human visual sensitivity changes in a low step when it has a square characteristic. For recognizing

  In the voltage program method, the characteristic compensation of the TFT 11a cannot be performed satisfactorily. However, since the display brightness of the display screen 144 is low in the low gradation region, even if display unevenness due to insufficient characteristic compensation occurs, it is not visually recognized. On the other hand, in the voltage program method, the source signal line 18 can be charged and discharged satisfactorily. Therefore, the source signal line 18 can be sufficiently charged / discharged even in the low gradation region, and appropriate gradation display can be realized.

  As can be understood from FIG. 129 (a), when the potential of the source signal line 18 is close to the anode potential (Vdd), the voltage is applied to all (most) of the period of 1H. When the potential of the source signal line 18 becomes close to 0 (V), the voltage program (A period) and the current program (B) are executed within the period of 1H. Note that in the case where the potential of the source signal line 18 is close to 0 (V) (high gradation region), the current program may be executed over the entire period of 1H.

  In a period other than * A in FIG. 129 (a), a voltage according to a voltage program is applied to the source signal line 18 during a fixed period of 1H (indicated by A), and then a current according to a current program is applied during a period B Yes. As described above, a predetermined voltage is applied to the gate potential of the TFT 11a of the pixel 16 by applying the voltage during the period A so that the current flowing through the EL element 15 is approximately the desired value. Thereafter, the current flowing through the EL element 15 is set to a predetermined value by the program current during the B period. * In the period A, the voltage program is executed throughout the period of 1H (voltage is applied).

  FIG. 129A shows a signal waveform applied to the source signal line 18 when the TFT 11a (driving transistor) of the pixel 16 is a P channel. However, the present invention is not limited to this. The TFT 11a of the pixel 16 may be an N channel (see, for example, FIG. 1). In this case, as shown in FIG. 129 (b), when the potential of the source signal line 18 is close to 0 (V), the voltage is applied to all (most) of the 1H period. When the potential of the source signal line 18 becomes close to the anode voltage (Vdd), the voltage program (A period) and the current program (B) are executed during the 1H period.

  Note that in the case where the potential of the source signal line 18 is close to Vdd (high gradation region), the current program may be executed over the entire period of 1H.

  In the present invention, the driving transistor 11a is described as a P-channel, but the present invention is not limited to this, and it goes without saying that the driving transistor 11a may be an N-channel. For ease of explanation, the explanation is made only assuming that the driving transistor 11a is a P-channel transistor.

  In the embodiments of the present invention such as FIG. 128 and FIG. 129, the voltage program is mainly written in the low gradation region, and the pixel is written. In the middle / high gradation region, the current program is mainly used for writing. In other words, it is possible to realize a good fusion of both current and voltage driving. This is because the low gradation region is displayed with a predetermined gradation by the voltage. This is because the write current is very small in current drive, and the voltage applied first for 1H (by voltage drive or precharge drive. Precharge drive and voltage drive are conceptually the same. If greatly differentiated, This is because precharge driving has a relatively small number of types of applied voltage, and voltage driving has a large number of types of applied voltage).

  In the middle gradation area, after writing by voltage, the amount of voltage deviation is compensated by the program current. That is, the program current is dominant (current drive is dominant). The high gradation region is written with a program current. No program voltage application is required. This is because the applied voltage is rewritten by the program current. That is, current driving is overwhelmingly dominant (see FIGS. 130B and 131). Of course, it goes without saying that a voltage may be applied.

  In FIG. 127, the output of the voltage gradation circuit and the output of the current gradation circuit (including the precharge circuit) can be short-circuited at the terminal 155 because the current gradation circuit has high impedance. . In other words, since the current gray scale circuit has high impedance, even if the voltage from the voltage gray scale circuit is applied to the current gray scale circuit, a problem (such as an overcurrent flowing due to a short circuit) does not occur in the circuit. Therefore, although the voltage output and the current output state are switched in the present invention, the present invention is not limited to this. Needless to say, the voltage of the voltage gradation circuit 1271 may be applied to the terminal 155 by turning on the switch 151 (see FIG. 127) while the program current is output from the current gradation circuit 164.

  Alternatively, the program current may be output from the current gradation circuit 164 with the switch 151 closed and a voltage applied to the terminal 155. Since the current gradation circuit 164 has a high impedance, there is no problem in the circuit. The above state is also an operation category in which the present invention switches between the voltage drive state and the current drive state. The present invention takes advantage of the nature of current and voltage circuits. This is a characteristic configuration not found in other driver circuits.

  Further, as shown in FIG. 130, it goes without saying that the program applied in the 1H period may be either voltage or current. In FIG. 130, the period * A is a 1H period in which the voltage program is implemented, and the period B is a 1H period in which the current program is implemented. The voltage program is implemented mainly in the low gradation region (indicated by * A), and the current program is implemented in the region of halftone or higher (indicated by B). As described above, switching between voltage driving and current driving may be switched according to the gradation or the magnitude of the program current.

  In the embodiment of the present invention shown in FIG. 127, the same video data is input to the voltage gradation circuit 1271 and the current gradation circuit 164. Therefore, the latch circuit for the video data may be common to the voltage gradation circuit 1271 and the current gradation circuit 164. That is, it is not necessary to provide the latch circuit for the video data in the voltage gradation circuit 1271 and the current gradation circuit 164 independently. Based on the data from the common video data latch circuit, the current gradation circuit 164 and / or the voltage gradation circuit 1271 outputs the data to the terminal 155.

  FIG. 132 is a timing chart of the driving method of the present invention. In FIG. 132, DATA in (a) is image data. CLK in (b) is a circuit clock. Pcntl in (c) is a precharge control signal. When the Pcntl signal is at the H level, only the voltage driving mode is set, and when it is at the L level, the current + voltage driving mode is set. Ptc in (d) is a precharge voltage or output switching signal from the voltage gradation circuit 1271. When the Ptc signal is at the H level, a voltage output such as a precharge voltage is applied to the source signal line 18. When the Ptc signal is at the L level, the program current from the current gradation circuit 164 is output to the source signal line.

  For example, when the data is D (2), D (3), and D (8), the Pcntl signal is at the H level, and thus the voltage is output from the voltage gradation circuit 1271 to the source signal line 18 (A period). . When Pcntl is at L level, a voltage is first output to the source signal line 18 and then a program current is output. A period in which the voltage is output is indicated by A, and a period in which the current is output is indicated by B. The period A during which the voltage is output is controlled by the Ptc signal. The Ptc signal is a signal for controlling on / off of the switch 151 in FIG. 127.

  In FIG. 132, the voltage output period A and the current output period B are switched. However, the present invention is not limited to this. Needless to say, the voltage of the voltage gradation circuit 1271 may be applied to the terminal 155 by turning on the switch 151 (see FIG. 127) in a state where the program current is output. Alternatively, the program current may be output from the current gradation circuit 164 with the switch 151 closed and a voltage applied to the terminal 155. The switch 151 is opened after the period A. As described above, since the current gradation circuit 164 has a high impedance, there is no problem in terms of the circuit even if it is short-circuited with the voltage circuit.

  FIG. 133 changes the period during which the voltage is output to the source signal line 18 by changing the H period of the Ptc signal. The H period is changed depending on the gradation number. For example, in D (7), the Ptc signal is at the L level during the 1H period. Therefore, the switch 151 in FIG. 127 is in an open state for a period of 1H. Therefore, no voltage is applied during the 1H period, and the current programming state is always maintained. In D (5), the Ptc period is longer than the other 1H periods. Therefore, the period A during which the voltage is applied is set to be long.

  In the above embodiment, the current drive state and the voltage drive state are switched. However, the present invention is not limited to this. In the embodiment of FIG. 134, there is no Ptc signal. Therefore, it is controlled by the Pcntl signal. Therefore, voltage driving is performed during the H period, and current driving is performed during the L period.

  The voltage program needs to change the voltage value output to the source signal line 18 depending on the light emission efficiency of the RGB EL elements 15. This is because the voltage (program voltage) applied to the gate terminal of the driving transistor 11a varies depending on the current output from the driving transistor 11a in the pixel configuration of FIG. The output current of the driving transistor 11 a needs to be different depending on the light emission efficiency of the EL element 15. In order to make the source driver IC 14 of the present invention versatile, even if the pixel size of the EL display panel is different or the luminous efficiency of the EL element 15 is different, it is necessary to cope with the setting or adjustment. There is.

  The voltage gradation circuit 1271 outputs a voltage with the anode voltage (Vdd) as the origin. This state is shown in FIG. The anode voltage (Vdd) is the operation origin of the driving transistor 11a. For ease of explanation, it is assumed that the driving transistor 11a as shown in FIG. 1 has a P-channel configuration. Also in the case where the driving transistor 11a is an N-channel, only the origin position changes, so that the description is omitted. Therefore, for ease of explanation, the case where the driving transistor 11a is a P channel will be described as an example.

  In FIG. 135, the horizontal axis represents gradation. In the present invention, the output gradation of the voltage gradation circuit 1271 will be described as 256 (8 bits) gradation. The vertical axis represents the output voltage to the source signal line 18. In FIG. 135, the potential of the source signal line 18 decreases in proportion to the gradation number.

  The voltage of the source signal line 18 is the gate terminal voltage of the driving transistor 11a. The output current of the driving transistor 11a changes nonlinearly with the gate terminal voltage. In general, when a voltage is applied to the source signal line 18 as shown in FIG. 135, the output current of the driving transistor 11a changes with a square characteristic with respect to the applied voltage. That is, in FIG. 135, the potential of the source signal line 18 is proportional to the gradation, but the output current of the driving transistor 11a (current flowing through the EL element 15) has a substantially square characteristic.

  The circuit configuration in FIG. 135 is easy to configure. However, the current flowing through the EL element 15 is not proportional to the gradation number. This is because when a linearly changing voltage is applied to the driving transistor 11a (such as in the case of the embodiment in FIG. 135), the output current is output in proportion to the square of the applied voltage due to the square characteristic of the transistor 11a. . Therefore, when the gradation number is small, the change in the output current of the transistor 11a is small, and increases rapidly as the gradation number increases. Therefore, the accuracy of the output current with respect to the gradation number changes.

  FIG. 136 shows a configuration for solving this problem. In FIG. 136, when the gradation number is small, the change in the output voltage to the source signal line 18 is large. Further, the smaller the gradation number, the greater the voltage change rate to the source signal line 18. On the other hand, when the gradation number increases (approaching 256th), the change in the output voltage to the source signal line 18 is reduced. Therefore, the relationship between the source signal line output current and the gradation number is non-linear. This non-linear characteristic is made linear by combining with the output current characteristic to the EL element 15 with respect to the gate terminal voltage of the driving transistor 11a. That is, the output current to the EL element 15 of the driving transistor 11a with respect to the change of the gradation number is adjusted to be linear.

  In the current programming method, the current flowing through the EL element 15 with respect to the gradation number has a linear relationship. The configuration (method) in FIG. 136 is a voltage program method. In FIG. 136, the voltage programming method is used, but the current flowing through the EL element 15 with respect to the gradation number has a linear relationship. Therefore, matching is good in the configuration (method) in which the current program method and the voltage program method are combined as shown in FIGS. 127 and 128.

  In FIG. 136, the output current Ie of the driving transistor 11a with respect to the gradation number changes substantially linearly. Therefore, the relationship of the source signal line output voltage with respect to the gradation number is not small when the gradation number is small, but is finely changed as the gradation number increases. When the gradation number is K and the source signal line is Vs, the change curve equation is such that the source signal line voltage Vs = A / (K · K) as shown in FIG. A is a proportionality constant. Alternatively, the source signal line voltage Vs = A / (B · K · K + C · K + D) or Vs = A / (B · K · K + C). D, B, C, and A are constants.

  As described above, by forming the change curve equation, when the change curve equation is multiplied by the output current Ie of the driving transistor with respect to the source signal line voltage Vs, Ie with respect to Vs can be in a linear relationship.

  In FIG. 136, the change curve equation is a curve. Therefore, it is relatively difficult to create a change curve. For this problem, it is appropriate to form a change curve equation with a plurality of straight lines as shown in FIG. That is, a change curve is formed by two or more straight lines having an inclination.

  In FIG. 136, the increment of the output voltage of the source signal line 18 is increased (indicated by A) in the range where the gradation number is small, and the increment of the output voltage of the source signal line 18 is decreased in the range where the gradation number is large. (Indicated by B). In the change curve of FIG. 136, the output current Ie of the driving transistor 11a with respect to the gradation number K has a non-linear relationship, and a plurality of non-linear outputs are combined. However, the relationship between the output current Ie and the gradation number K increases in a nearly linear range. Therefore, the combination with current program driving is also easy.

  In FIG. 136, the voltage gradation circuit 1271 and the current gradation circuit 164 are illustrated as being formed in one source driver circuit (IC) 14, but the present invention is not limited to this. The present invention is characterized by having a voltage gradation circuit 1271 and a current gradation circuit 164. Therefore, a voltage gradation circuit (IC) 1271 is arranged or formed or mounted at one end of one source signal 18, and a current gradation circuit (use IC) 164 is arranged or formed at the other end of the source signal line. May be implemented. In other words, the present invention may have any configuration as long as it is a configuration or method capable of executing current programming and voltage programming on an arbitrary pixel.

  Further, the driver circuit (IC) 14 that executes the voltage program has a gamma characteristic of 1.5 to 3.0 power. That is, the current increase at equal intervals can be realized corresponding to the step of changing the gate voltage of the driving transistor 11a. This is because the VI characteristic of the driving transistor 11a is a substantially square characteristic (because the output current I changes with a substantially square characteristic with respect to a change in voltage V). Furthermore, it is preferable that the gamma characteristic of the driver circuit (IC) for executing the voltage program is a reverse gamma characteristic of 1.8 to 2.4. The gamma characteristic of the driver circuit (IC) that executes the voltage program is preferably configured to be programmable. When the driving transistor 11a is a P-channel transistor, the origin of the gamma characteristic curve is the anode voltage Vdd or near Vdd. When the driving transistor 11a is an N-channel transistor, the origin of the gamma characteristic curve is the cathode voltage Vss, the ground of the circuit 14, or a potential near them.

  Needless to say, the above items can be applied to FIGS. 127 to 143, 293, 311, 312, and 339 to 344. That is, even in the precharge circuit, the precharge circuit (IC for use) is formed or arranged at one end of the source signal line 18, and the current program type source driver circuit (IC) 14 is connected to the other end of the source signal line 18. Needless to say, they may be arranged or formed. Needless to say, the above matters can be applied to other embodiments of the present invention.

  Further, the change in the voltage gradation circuit 1271 (precharge circuit) and the current gradation circuit 164 are synchronized. In other words, the voltage gradation circuit 1271 (precharge circuit) is changed so as to correspond to the change of the current gradation circuit 164. If the target value (expected value) of the output current of the driving transistor 11a of the pixel 16 by the voltage gradation circuit 1271 is 1 μA, the target value (expected value) of the driving transistor 11a of the pixel 16 by the current gradation circuit 164 is The gradation is controlled so as to be 1 μA. Therefore, it is preferable that the gradation data value of the current gradation circuit 164 and the gradation data of the voltage gradation circuit (precharge circuit) 1271 coincide with each other. Needless to say, the above matters can be applied to other embodiments of the present invention. Moreover, it is preferable to synchronize.

  Note that the present invention is not limited to performing both voltage programming (precharge) and current programming on all source signal lines 18. Any one of them may be implemented. For example, a voltage program (precharge) may be implemented for odd pixel columns and a current program may be implemented for even pixel columns. Even with such a configuration, there is almost no deterioration in image quality. Needless to say, the above matters can be applied to other embodiments of the present invention.

  In the example of FIG. 135, when the gradation number is 0, the potential of the source signal line 18 is not the anode potential (Vdd). The output current of the driving transistor 11a is 0 or almost 0 until the rising voltage. The range up to this rising voltage is the C region. Accordingly, since the region C is blank, when the number of gradation numbers is constant, the output voltage step of the source signal line can be made relatively finer than in FIG.

  138 (the relationship where the potential of the source signal line 18 is not the origin (anode potential) when the gradation number is 0), the non-linear relationship of FIG. 136, and the relationship combining the plurality of relational expressions of FIG. Needless to say, the straight line relationships 135 may be combined with each other.

  The voltage program needs to change the voltage value output to the source signal line 18 depending on the light emission efficiency of the R, G, and B EL elements 15. This is because the voltage (program voltage) applied to the gate terminal of the driving transistor 11a varies depending on the current output from the driving transistor 11a in the pixel configuration of FIG. The output current of the driving transistor 11 a needs to be different depending on the light emission efficiency of the EL element 15. In order to make the source driver IC 14 of the present invention versatile, even if the pixel size of the EL display panel is different or the luminous efficiency of the EL element 15 is different, it is necessary to cope with the setting or adjustment. There is.

  FIG. 131 shows a circuit configuration utilizing the point that the voltage reference is Vdd in voltage driving. 135 to 138, the voltage magnitude Vdd, which is the vertical axis, is fixed and changed. Therefore, even when the gradation number range (256 gradations = 256 increments) is made constant, the magnitude of the voltage on the vertical axis can be adjusted, and the source driver circuit (IC) 14 can be generalized. it can.

  In FIG. 131, the voltage range of the electronic volume 501 is from Vdd to Vbv. Therefore, the output voltage Vad of the operational amplifier 502a is output from Vdd to Vbv. Vbv is input from the outside of the source driver IC (circuit) 14. Further, it may be generated inside the IC (circuit) 14. The switch S of the electronic volume 501 decodes 8-bit control data (gradation number) by the decoder circuit 532, the corresponding switch S is closed, and the voltage between the voltage Vdd and Vbv is output from Vad. The voltage Vad is the voltage that is the vertical axis of FIGS. 135 to 138. Therefore, Vad can be easily changed or adjusted by changing Vbv. That is, as shown in FIG. 139, the vertical axis represents the Vdd voltage and the Vbv voltage range. The circuit configuration shown in FIG. 131 is provided for each RGB as shown in FIG. If the light emission efficiency of the RGB EL elements 15 is balanced and the white balance can be obtained when the RGB current Ic is Icr: Icg: Icb = 1: 1: 1, one circuit configuration common to RGB (see FIG. It goes without saying that 131) may be used. Also, a plurality of Ic current generation circuits such as R and G, G and B, and B and R may be shared. It goes without saying that Vbv and the like may be changed according to the lighting rate, the reference current ratio, and the duty ratio.

  77 and 78 have a two-stage latch circuit 771 for the current program circuit. The source driver IC (circuit) 14 of the present invention includes both a current program circuit and a voltage program circuit.

  131 and the like have the anode voltage vdd as the origin. FIG. 141 makes it possible to adjust the voltage corresponding to the anode potential. The voltage from the operational amplifier 502 c is applied to the terminal Vdd of the electronic volume 501. The applied voltage is Vbvh. The lower limit voltage of the electronic regulator 501 is Vbvl. Therefore, the voltage range applied to the source signal line 18 is Vbvh or less and Vbvl or more as shown in FIG. Since other matters are the same as or similar to those of the other embodiments, description thereof will be omitted.

  As described in FIG. 138, the driving transistor 11a and the like have a rising voltage indicated by C. Below the rising voltage is black display (the driving transistor 11a does not supply current to the EL element 15). FIG. 143 is a circuit for generating the C blank of FIG. 138. The voltage range of C blank is adjusted by Pk data. The Pk data is 8 bits. The Pk data and the gradation number data Data are added by the adding circuit 3731. The added data becomes 9 bits, is input to the decoder circuit 532, is output, and closes the corresponding switch S of the electronic volume 501.

  FIG. 293 shows another embodiment of the circuit for generating the precharge voltage (synonymous with or similar to the program voltage). The resistor is a diffused resistor or a polysilicon resistor. However, if the resistance value also varies, trimming or the like is performed so as to obtain a predetermined resistance value. Since the trimming has been described with reference to FIGS. 162 to 173, the description thereof will be omitted.

  In the embodiment, six resistors R1 to R6 are included in the resistor array 2931. However, the number is not limited to this, and may be six or more or six or less. However, the number of precharge voltages (synonymous with or similar to the program voltage) Vpc generated by a resistor or the like is preferably a multiplier of 2 or a multiplier of 2. As shown in FIG. 293, “−1” is for designating an open state (a mode in which a precharge voltage (synonymous with or similar to a program voltage) is not applied). That is, for example, when the VSEL data specifying the precharge voltage (synonymous or similar to the program voltage) in FIG. 296 is 0, Vpc0 (open: precharge voltage (synonymous or similar to the program voltage) is not applied). . By specifying Vpc0, it is possible to realize driving only during the period B in FIG. 128 (there is no period during which the voltage shown in A is not applied). In other words, the precharge voltage (synonymous with or similar to the program voltage) (synonymous with the program voltage) is not applied to the corresponding pixel 16 (corresponding source signal line 18) (no voltage programming is performed), and only current programming is performed. ).

Among the squares of 2−1, −1 is Vpc0 (open mode) described above. The other is a mode in which a precharge voltage (synonymous with or similar to a program voltage) generated outside the source driver IC (circuit) 14 is taken in from the terminal of the source driver IC (circuit) 14 and used. Note that the externally input precharge voltage (synonymous with or similar to the program voltage) is not limited to fixed. Needless to say, it may be changed in synchronization with the dot clock of the panel circuit (corresponding to each pixel 16). The same applies to the internal precharge voltage (synonymous with or similar to the program voltage). For example, it goes without saying that the precharge voltage (synonymous with or similar to the program voltage) Vpc1 may change in synchronization with the dot clock of the panel circuit (corresponding to each pixel 16). For example, VSEL is 4 bits. If so, there are eight possible numbers. Therefore, in the case of a multiplier-one-2 configuration, seven precharge voltages (synonymous with or similar to the program voltage) can be designated, and the remaining one is an open mode. In the case of the multiplier-2-2 configuration, six precharge voltages (synonymous with or similar to the program voltage) can be designated, the remaining one is in the open mode, and the other one is the precharge voltage of the external input ( The same or similar to the program voltage can be specified. Further, if the VSEL for specifying the precharge voltage (voltage program driving) is 8 bits, the number that can be specified is 256. Therefore, in the case of a multiplier-two-1 configuration, 255 precharge voltages (synonymous with or similar to the program voltage) can be designated, and the remaining one is an open mode. In the case of the multiplier-2-2 configuration, 254 precharge voltages (synonymous with or similar to the program voltage) can be designated, the remaining one is in the open mode, and the other one is the precharge voltage of the external input ( The same or similar to the program voltage can be specified.

  In the above embodiment, if the multiplier is 2-1, the -1 is the open mode. However, the present invention is not limited to this, and -1 is the same as the precharge voltage of the external input (synonymous with the program voltage). Or similar) may be set as the designation mode. Further, the precharge voltage (synonymous with or similar to the program voltage) of the external input is not limited to one type, and may be plural. In that case, the precharge voltage (synonymous with or similar to the program voltage) generated inside decreases. Further, it is not limited to designating different precharge voltages (synonymous with or similar to the program voltage) Vpc for all designations other than -1 or -2. It goes without saying that the same precharge voltage (synonymous with or similar to the program voltage) may be output with a plurality of designated data. Further, it goes without saying that it may be configured, formed or manufactured so that a precharge voltage (synonymous or similar to the program voltage) in the open mode or the external input mode is output with a plurality of designated data. It goes without saying that the above embodiment can be applied to the embodiments of FIGS. 127 to 143. Needless to say, the present invention can be applied to other embodiments of the present specification.

  In the above embodiment, a 2 multiplier-3 configuration may be used. One may be an open mode, the other may be an external input precharge voltage (synonymous with or similar to a program voltage) as a designated mode, and the remaining one as an anode voltage. Good black display can be realized by applying the anode voltage Vdd.

  Note that in FIG. 293, by extending the application period of the precharge voltage (synonymous with or similar to the program voltage) (maximum 1H period), a voltage program can be realized as shown in FIGS. A state in which current data is not applied to the source signal line 18 or the pixel 16). That is, by controlling the selection period or selection timing of VSEL (see FIG. 296), either the voltage programming method or the current programming method is selected, or both programming methods are set to a predetermined ratio period. Can be combined. It is also easy to change the ratio of combining both programming methods according to the size of the video data (gradation data) applied to the pixels 16. It is also easy to change the ratio of combining both program methods in accordance with the size or change state of video data (gradation data) continuous with the 16-column method. Further, only one of the programming methods can be performed. When combining both programming methods, the voltage programming method is performed first.

  Further, the precharge period (voltage application period of the voltage gradation circuit 1271) may be changed in accordance with the magnitude of the gradation data. When the gradation is low, the precharge period (voltage application period of the voltage gradation circuit 1271) is lengthened, and as the intermediate gradation is reached, the precharge period (voltage application period of the voltage gradation circuit 1271) is shortened.

  As described above, according to the present invention, a precharge voltage (synonymous or similar to a program voltage) can be set by a digital signal, and at least one designation can be input from the outside. A mode in which a precharge voltage (synonymous with or similar to a program voltage) is not applied can be selected.

  In addition, the change of the precharge circuit (including the electronic volume 501 or the like, or the voltage gradation circuit 1271 in FIG. 136) and the change of the current gradation circuit 431c are synchronized. That is, the precharge circuit is changed so as to correspond to the change in the current gradation circuit 431c. If the target value (expected value) of the output current of the driving transistor 11a of the pixel 16 by the precharge circuit is 1 μA, the target value (expected value) of the driving transistor 11a of the pixel 16 by the precharge circuit is 1 μA. Tone control. Accordingly, it is preferable that the gradation data value of the precharge circuit matches the gradation data of the current gradation circuit 431c. Needless to say, the above matters can be applied to other embodiments of the present invention. The precharge circuit and the current gradation circuit 431c are preferably synchronized.

  The determination of whether or not to apply the program voltage may be made based on the image data of the previous pixel row (or the image data applied to the source signal line immediately before). For example, when 64 gradations, 63rd gradation is maximum white display, and 0th gradation is completely black display, image data applied to a certain source signal line 18 is 63rd gradation → 10th gradation → If it is the 10th gradation, the program voltage is applied when the 63rd gradation changes to the 10th gradation. This is because the low gradation is difficult to write.

  As a basic operation, a program voltage is applied and then a program current is applied to correct the current. When changing from the same gradation to the same gradation (for example, 10th to 10th gradation) or from a certain gradation to a nearby gradation (for example, 10th to 9th gradation) Only the program current is applied without applying the program voltage. This is because when a program voltage is applied, laser shot unevenness occurs due to characteristic variations of the driving transistor 11a. This is because if the drive is performed only with the program current, the change in gradation is small, and therefore, even with a very small program current, it is possible to follow the characteristic variation of the drive transistor 11a.

  In the driving method or the display panel (display device) of the present invention, the array 30 is formed or configured so that the long side direction of the annealing (ELA) shot by excimer laser coincides with the formation direction of the source signal line 18 (laser of the laser). Needless to say, it is preferable that the scan direction is orthogonal to the formation direction of the source signal line 18. This is because the characteristic change of the driving transistor 11a of the pixel 16 matches the characteristic within one shot of laser annealing (ELA) (that is, the driving transistor in the pixel column in the formation direction of the source signal line 18). 11a characteristics (mobility (μ), S value, etc.) match).

  In the embodiment of the present invention, the program voltage is applied. However, the program voltage may be replaced with a precharge voltage. That is, when the precharge voltage has plural kinds of voltages, the program voltage is synonymous with the operation.

  When the image (video) data to be applied to the next pixel row (pixel) is the same as the image (video) data applied to the previous pixel row (pixel) or the change amount is small, the program voltage is not applied and the program Apply current only. This is because the potential of the source signal line 18 becomes the potential of the program current to be written next by the program current applied to the previous pixel row (the shift amount is only the characteristic variation of the driving transistor 11a). Therefore, in the case of raster display, the program voltage is not applied (although it may be applied). The above operation can be more easily realized by forming (arranging) a line memory for one pixel row (requires two lines of memory for the FIFO) in the controller 760. However, since there is a problem of the vertical blanking period in the first pixel row, it is preferable to apply a program voltage.

  In the present invention, in the case of the program voltage + program current drive, it is described that the program voltage is applied, but the present invention is not limited to this. A method of writing a current shorter than one horizontal scanning period and larger than the program current to the source signal line 18 may be used. That is, a method of writing the precharge current to the source signal line 18 and then writing the program current to the source signal line 18 may be used. There is no difference in that the precharge current also physically causes a voltage change.

  As described above, the method of performing the operation of applying the program voltage with the precharge current or the precharge voltage is also within the category of the program voltage + program current driving of the present invention. For example, in FIGS. 131, 140, 141, 143, 293, 297, 311, 312, and 339 to 344, the program voltage is changed by switching the electronic volume 501. This electronic volume 501 may be changed to an electronic volume with current output. The change can be easily realized by combining a plurality of current mirror circuits. In the present invention, for ease of explanation, it is assumed that the program voltage + program current drive program voltage is applied by voltage.

  The program voltage application is not limited to applying a constant program voltage. For example, a plurality of program voltages may be applied to the source signal line. For example, after applying the first program voltage 5 (V) for 5 (μsec), the second program voltage 4.5 (V) is applied for 5 (μsec). Thereafter, the program current Iw is applied to the source signal line 18. Further, the program voltage may be changed in a sawtooth shape. Further, a rectangular wave, a triangular wave, a sine curve voltage, or the like may be applied. Further, the program voltage (current) may be superimposed on the regular program current (voltage). Further, the magnitude of the program voltage (current) and the application period of the program voltage (current) may be changed corresponding to the image data. Further, the type of applied waveform, the value of the program voltage, etc. may be changed according to the value of the image data.

  The program voltage may be applied from one end of the upper side of the source signal line 18 and the program current may be applied from one end of the lower side of the source signal line 18. Further, the driver circuit 14 of the display panel may be arranged or configured in this way.

  The program current and the program voltage may be applied simultaneously. This is because the constant current (variable current) circuit that generates the program current is a high impedance circuit, so that no problem occurs in operation even if the voltage circuit that generates the program voltage is short-circuited. However, when both the program voltage and the program current are applied to the source signal line 18, the application of the program current is terminated after the application of the program voltage is terminated. In other words, 1H (horizontal scanning period), a plurality of H, or the end of a predetermined period is terminated with the application state of the program current.

  In the current driving method, the present invention will be described on the assumption that a program current is applied after a program voltage of a predetermined voltage is applied. However, the technical idea of the present invention is effective even with a voltage drive system. In the voltage driving method, the size of the driving transistor for driving the EL element 15 is large, so that the gate capacitance is large. Therefore, there is a problem that it is difficult to write a regular program voltage. In response to this problem, by performing an operation of applying a voltage of a predetermined voltage before applying a normal program voltage, the driving transistor can be reset, and good writing can be realized ( The voltage to be applied is preferably a voltage at which the transistor 11a is turned off or in the vicinity thereof. Therefore, the program voltage + program current driving method of the present invention is not limited to current program driving. In the embodiments of the present invention, for ease of explanation, the current program driving pixel configuration (see FIG. 1 and the like) will be described as an example.

  In the embodiment of the present invention, the program voltage + program current driving method (see also FIGS. 127 to 143, etc.) does not affect only the driving transistor 11a. For example, in the pixel configurations shown in FIGS. 11, 12, and 13 and the like, the transistor 11a constituting the current mirror circuit is also exerted and the effect is exhibited. The program voltage + program current drive system of the present invention is intended to charge and discharge the parasitic capacitance of the source signal line 18 as viewed from the source driver IC (circuit) 14, but of course, the source driver IC (circuit) ) It is also intended that the parasitic capacitance in 14 is charged and discharged.

  The operation of applying the program voltage is intended to improve black display, but is not limited to this. If a white writing program voltage (current) that makes white display easy to write is applied, good white display can be realized. In other words, the program voltage + program current drive according to the present invention corresponds to the gradation data written in the pixel 16 to facilitate writing of the program current (program voltage) before writing the program current (program voltage). ) A predetermined voltage is applied to pre-charge the source signal line 18 and the like. In addition, a program voltage is applied in advance in order to make it easy to write a program current corresponding to the gradation. Therefore, if the potential of the source signal line 18 or the like is maintained at a predetermined potential or within a predetermined range, it is not necessary to apply the program voltage.

  However, the operation of the driving transistor 11a of the pixel 16 changing from the white display state (high gradation display state) to the black display state (low gradation display state) is relatively fast. However, the operation of the driving transistor 11a changing from the black display state to the white display state is relatively slow. Therefore, it is preferable that the program voltage be applied larger (high gradation display direction) than the value of the video (image) data and operated so as to be corrected in the black display direction by the program current. Therefore, it is preferable to satisfy the relationship of video data specifying program voltage> video data specifying program current.

  The above is the case where the driving transistor 11a of the pixel 16 is a P-channel transistor and the current program is executed with the sink current (current sucked into the source driver IC (circuit) 14). When the driving transistor 11a of the pixel 16 is an N-channel transistor or when the current program is executed with the discharging current (current discharged from the source driver IC 14) from the driving transistor 11a, the relation is reversed. That is, when the driving transistor 11a of the pixel 16 is N-channel, the operation for changing from the black display state (low gradation display state) to the white display state (high gradation display state) is relatively fast. However, the operation of the driving transistor 11a changing from the white display state to the black display state is relatively slow. Therefore, it is preferable that the program voltage is applied smaller than the value of the video (image) data (low gradation display direction) and is operated so as to correct in the white display direction with the program current. Therefore, it is preferable to satisfy the relationship of video data specifying the program voltage <video data specifying the program current. Needless to say, the above items can be applied (replaced) in other embodiments of the present invention.

  In order to facilitate the description of the present invention, the driving transistor (the transistor that supplies current to the EL element 15) is a P-channel, and the source driver circuit (IC) 14 is operated with a sink (sink) current. A display panel (display device) will be described as an example.

  The program voltage application timing is preferably such that the program voltage is written in a state in which the pixel row to which the program current is to be written is selected. However, the present invention is not limited to this. May be applied to perform preliminary charging, and then a pixel row into which a program current is written may be selected.

  The program voltage is applied to the source signal line 18, but other methods are also exemplified. For example, the applied voltage (Vdd) to the anode terminal or the applied voltage (Vss) to the cathode terminal may be changed (program voltage is applied). By changing the anode voltage or the cathode voltage, the writing capability of the driving transistor 11a is expanded. Therefore, the program voltage application (discharge) effect is exhibited. In particular, the effect of implementing a method of changing the anode voltage (Vdd) in a pulse manner is high. That is, it goes without saying that the program voltage may be applied to any signal line or terminal (anode terminal, cathode terminal, source signal line, etc.) as long as the driving transistor 11a is turned off or configured. Yes.

  FIG. 332 (a) is an explanatory diagram when a program voltage is applied only at gradation 0. FIG. Application of a program voltage with only gradation 0 is a preferable method because there is no gradation skip and good black display can be realized. In FIG. 332, the row number indicates the pixel row number. In the pixel row, image data is sequentially rewritten from the first pixel row to the n pixel row, and when current programming is performed up to the final pixel row n, current programming is started from the first pixel row.

  As an example, the image data is 64-tone image data. The image data takes a value from 0 to 63. Of course, when the gradation is 256, values from 0 to 255 are taken. PSL is a program voltage application select signal, which permits the output of the program voltage when it is at the H level (symbol H). When it is at L level, the program voltage is not output. PEN is a program voltage application enable signal. This PEN is a signal output by the determination of the controller 81. That is, the controller sets the PEN signal to the H or L level based on the image data. When PEN is at the H level, it is a determination signal that the program voltage is applied, and when it is at the L level, it is a determination signal that the program voltage is not applied. Needless to say, the program voltage is preferably changed according to the video data. A specific configuration method will be described with reference to FIGS. 127 to 143, FIGS. 293 to 297, and the like.

  In FIG. 332, the PEN signal is at the H level only at gradation 0. The P output is an on / off state of the switch 151a (see Si in FIGS. 16, 75, and 308). In the table, ◯ indicates that the switch 151a is on (the program voltage Vp is applied to the source signal line 18). X indicates that the switch 151a is in an off state (a state in which no program voltage is applied to the source signal line 18).

  In FIG. 332 (a), the PEN signal is H at locations corresponding to pixel row number 3 and pixel row number 8. At the same time, in the pixel row number 3 and the pixel row number 8, since the PSL signal is also at the H level, the P output is in the state where the program voltage Vp is output (in FIG. 332 (b), the PEN signal is 332 (a), but the PSL signal is at the L level, so that the P output does not continue and the state is x (the program voltage Vp is not output). It is output from the controller 81. However, the PEN signal is preferably made adjustable by the user.

  The period during which the program voltage Vp is output can be set by the counter 162 in FIG. This counter is a programmable counter and operates based on a set value from a controller or a set value of a user. The counter 651 is configured to operate in synchronization with the main clock (CLK).

  FIG. 333 (a) is an explanatory diagram when a program voltage is applied only to gradations 0 to 7. FIG. The method of applying the program voltage only to the low gradation region is effective as a measure for solving the problem that current driving is difficult to write the black display region. It should be noted that to which range the program voltage is applied can be set by the controller 81.

  In FIG. 333, the PEN signal is at the H level only at the gradation 0-7. The P output is an on / off state of the switch 151a. In FIG. 333 (a), the image data is 7 or less at the locations corresponding to the pixel row numbers 3, 5, 6, 7, 11, 12, and 13, and therefore the PEN signal is H. At the same time, since the PSL signal is also at the H level, the P output is ◯ (the state where the program voltage Vp is output). In FIG. 333 (b), since the PSL signal is at the L level, all the P outputs are x (a state where no program voltage is applied).

  FIG. 334 is an explanatory diagram of a driving method for applying a program voltage when the luminance of the pixel 16 is lowered. In the current program method, the program current Iw when the luminance of the pixel 16 is increased (white display) is large. Therefore, even if the source signal line 18 has a parasitic capacitance, the parasitic capacitance can be charged and discharged sufficiently. However, when a program voltage is applied so that the pixel 16 displays black, the program current is small and the parasitic capacitance of the source signal line 18 cannot be sufficiently charged / discharged. Therefore, when the program current written to the pixel 16 becomes large, it is often unnecessary to apply the program voltage. Conversely, when the current written to the pixel 16 is small (when black display is performed), it is necessary to apply a program voltage.

  FIG. 334 is an explanatory diagram of a driving method for applying a program voltage when the luminance of the pixel 16 is lowered. The image data of the first pixel row is 39. Therefore, the source signal line 18 holds a potential for current-programming the pixel 16 to the image data 39. The image data of the second pixel row is 12. Therefore, the source signal line 18 needs to have a potential corresponding to the image data 12. However, the program current decreases from gradation 39 to gradation 12. Therefore, a state where the source signal line 18 cannot be sufficiently charged / discharged may occur. In order to cope with this problem, a program voltage is applied (PEN signal becomes H level). Similar determination results are obtained for pixel rows 3, 5, 6, 8, 11, 12, 13, and 15.

  The image data in the third pixel row is zero. Therefore, the source signal line 18 holds a potential for current-programming the pixel 16 to the image data 0. The image data in the fourth pixel row is 21. Therefore, the source signal line 18 needs to have a potential corresponding to the image data 21. The program current increases from gradation 0 to gradation 21. Therefore, the source signal line 18 can be sufficiently charged / discharged. Therefore, it is not necessary to apply the program voltage in the fourth pixel row.

  The above determination is performed by the controller 81. As a result of the implementation, the PEN signal becomes H level in the pixel rows 2, 3, 5, 6, 8, 11, 12, 13, 15 as illustrated in FIG. That is, the program voltage is applied to the pixel row. In FIG. 334 (a), since the PSL signal is also at the H level, as can be seen from the P output column, the P output is ◯ in the pixel rows 2, 3, 5, 6, 8, 11, 12, 13, and 15. (Program voltage is applied). Note that no program voltage is applied to other pixel rows.

  In FIG. 334 (b), the PEN signal is the same as FIG. 334 (a), but the PSL signal is at the L level. Therefore, the P output is constantly maintained, and the state is x (the program voltage Vp is not output). Basically, the PEN signal is also output from the controller 81. However, the PEN signal is preferably adjustable by the user.

  FIG. 335 is a combination of the program voltage application methods of FIG. 333 and FIG. 334. In this method, the program voltage is applied when the luminance of the pixel 16 is lowered, and the program voltage is applied when the program current of the pixel 16 has a low luminance of 0-7 gradation. It can be changed by the setting value of the controller IC 81 at which gradation the program voltage is applied or not. Also, the user can change it. The change is made to the table inside the controller from the microcomputer via the serial interface.

  The image data is the same as in the embodiment of FIG. However, in FIG. 335, since the image data is 12 in the second pixel row and the image data is 12 in the 15th pixel row, the PEN signal is an L level determination result. As described above, the parasitic capacitance of the source signal line 18 can be charged / discharged if the program current Iw is larger than a certain level. Therefore, it is not necessary to apply the program voltage. Conversely, when the program voltage is applied, the potential of the source signal line 18 changes to the black display potential, and it takes time to return to the halftone display potential.

  The above determination is performed by the controller 81. As a result of the implementation, as shown in FIG. 335 (a), the PEN signal becomes H level in the pixel rows 3, 5, 6, 8, 11, 12, and 13. That is, the program voltage is applied to the pixel row. In FIG. 335 (a), since the PSL signal is also at the H level, as can be seen from the P output column, the P output is indicated by ○ (program voltage applied) in the pixel rows 3, 5, 6, 8, 11, 12, and 13. Will be). Note that no program voltage is applied to other pixel rows. In FIG. 335 (b), the PEN signal is the same as FIG. 335 (a), but the PSL signal is at the L level. Therefore, the P output is constantly maintained, and the state is x (the program voltage Vp is not output).

  In the above embodiment, the application of the program voltage for each RGB is not described, but it is needless to say that the program voltage application determination is preferably performed for each RGB as shown in FIG. This is because image data is different for each RGB.

  FIG. 336 shows a driving method in which the program voltage is applied in the range of gradation 0-7 as in FIG. The controller 81 determines whether to apply the program voltage for each RGB. As a result of the implementation, as illustrated in FIG. 336, in the R image data, the PEN signal becomes H level in the pixel rows 3, 5, 6, 7, 8, 11, 12, and 13. That is, the program voltage is applied to the pixel row. In the G image data, the PEN signal becomes H level in the pixel rows 3, 7, 9, 11, 12, 13, and 14. That is, the program voltage is applied to the pixel row. In the B image data, the PEN signal becomes H level in the pixel rows 1, 2, 3, 6, 7, 8, 9, and 15. That is, the program voltage is applied to the pixel row.

  In the above embodiment, it is determined whether or not the program voltage is applied corresponding to the pixel row. However, the present invention is not limited to this. It goes without saying that the size or change of image data applied to each pixel in units of frames (fields) may be determined to determine whether or not to apply a program voltage. FIG. 337 shows an example.

  FIG. 337 shows changes in image data focusing on a certain pixel 16. The first row of the table in FIG. 337 indicates the frame number. The second row of the table shows changes in image data programmed in a certain pixel 16. FIG. 337 shows a modified example of the driving method in which the program voltage is applied at the gradation 0 as in FIG. In FIG. 332, the program voltage is always applied at gradation 0. In FIG. 337, a program voltage is applied when gradation 0 continues for a certain frame. Continuation is indicated by a counter.

  In FIG. 337 (a), tone is 0 in frames 3, 4, 5, 6, 11, and 12. Therefore, the count value is sequentially counted from the third frame to the sixth frame. In addition, it is counted in frames 11 and 12. In FIG. 337 (a), control is performed so that the program voltage is applied when gradation 0 continues for three frames. Therefore, in frames 5 and 6, the P output becomes ◯ (the program voltage is output). In frames 11 and 12, gradation 0 continues for only two frames, and therefore no program voltage is applied.

  In FIG. 337 (b), the count control is performed by the PSL signal. When the PSL signal is at H level, the count value is increased. In FIG. 337 (b), since the PSL signal is at the L level in the frames 5 and 12, it is not counted up. Therefore, the program voltage is output only in the frame 6.

  In FIG. 337, the program voltage is applied when gradation 0 continues for a certain frame. However, the present invention is not limited to this, and as described in FIG. 333, a certain gradation range (for example, gradation The program voltage may be controlled to be applied when 0-7) continues. Moreover, it is not limited to continuous frames, and may be discrete. Alternatively, the program voltage may be controlled to be applied when a certain gradation range (for example, only gradation 0, gradation 0-7, etc.) continues in successive pixel rows.

  As described above, in the program voltage + program current drive system of the present invention, whether or not the program voltage is applied depends on the value of the image data, the change state of the image data, or the image data value near the pixel to which the program voltage is applied and the change thereof. The program voltage (current) is applied. Information about whether or not to apply the program voltage is held in the source driver IC (circuit). Therefore, since the source driver IC (circuit) 14 only includes a latch circuit 2361 (holding circuit or storage means (memory)) that latches the program voltage application signal, the configuration is easy. In addition, any program voltage application method can be dealt with by changing the program of the controller IC 760 (see FIGS. 83, 85, 181, 319, 320, 327, etc.) or simply changing the set value. Versatile.

  The above is the case of a method for bringing a pixel into a black display or a state close to black display by applying a program voltage. However, white display may be obtained by applying a program voltage. Therefore, the program voltage application is not limited to the black display voltage. In this method, a voltage is applied to the source signal line 18 so that the source signal line 18 has a constant potential.

  In addition, when the driving transistor 11a of the pixel 16 is a P channel as in FIG. 1, it is important that the switching transistor 11b is also formed of a P channel. This is because black display is facilitated by the punch-through voltage when the switching element 11b changes from the on state to the off state. Therefore, when the driving transistor 11a of the pixel 16 has an N channel, it is important to form the switching transistor 11b also with an N channel. This is because black display is facilitated by the punch-through voltage when the switching element 11b changes from the on state to the off state.

  The lower part illustrates the source signal line potential when the program voltage (PRV) is applied to the source signal line 18. The position of the arrow indicates the application position of the program voltage (PRV). The program voltage application position is not limited to the beginning of 1H. What is necessary is just to apply a program voltage in the period to 1 / 2H. When a program voltage is applied to the source signal line 18, it is preferable to operate the OEV terminal of the gate driver 12a on the selection side so that no gate signal line 17a is selected.

  Note that whether or not to apply the program voltage may be determined based on the image data of the previous pixel row (or the image data applied to the source signal line immediately before). In the image data applied to a certain source signal line 18, the application data of the pixel row (pixel) (final pixel row) immediately before the first pixel row is the 63rd gradation, and the first pixel row (pixel) is the first pixel row (pixel). When it is the 10th gradation and there is no change in the image data thereafter (the 10th gradation is continuous), the program voltage corresponding to the 10th gradation or the vicinity thereof is applied to the first pixel row (pixel). However, the program voltage is not applied from the second pixel row to the last pixel row.

  FIG. 338 shows the relationship between program current data (red IR, green IG, blue IB) and program voltage data (red VR, green VG, blue VB). Program current data and program voltage data are generated by a controller IC (circuit) 760 based on video (image) data (see FIGS. 127 to 143, etc.).

  FIG. 338 (a) shows an example in which the program current data (red IR, green IG, blue IB) and program voltage data (red VR, green VG, blue VB) have the same number. That is, it has a case where program voltage data (red VR, green VG, blue VB) corresponding to arbitrary program current data (red IR, green IG, blue IB) is included. Therefore, if a program voltage is applied, a corresponding program current can be applied.

  FIG. 338 (b) shows an embodiment in which program voltage data (VR for red, VG for green, VB for blue) is smaller than program current data (IR for red, IG for green, and IB for blue). There is no lower 2 bits of program voltage data (VR for red, VG for green, VB for blue). Generally, the gradation display may be rough at a low gradation. In the example of FIG. 338 (b), for example, program voltage data of gradation 0 is applied before application of program current data of gradations 0 to 3. Before applying program current data of gradations 4 to 7, program voltage data of gradation 1 (there is actually gradation 2 because there are no lower 2 bits) is applied.

  FIG. 338 (c) is also an example in which the program voltage data (VR for red, VG for green, and VB for blue) is smaller than the program current data (IR for red, IG for green, and IB for blue). There are no upper and lower 2 bits of program voltage data (VR for red, VG for green, VB for blue). Generally, the gradation display may be rough at a low gradation. In the embodiment of FIG. 338 (c), for example, program voltage data of gradation 0 is applied before application of program current data of gradations 0 to 3. Before applying program current data of gradations 4 to 7, program voltage data of gradation 1 (there is actually gradation 2 because there are no lower 2 bits) is applied. In the high gradation region, since the program current is dominant, it is not necessary to apply the program voltage. Therefore, when the program voltage is applied in the high gradation region, the maximum value of the program voltage data (VR for red, VG for green, and VB for blue) is applied to the source signal line 18 and the like.

  In FIG. 293, the c potential of the resistor array 2931 is determined by the output of the electronic volume 501a. The d potential of the resistance array 2931 is determined by the output of the electronic volume 501b. The resistance array 2931 is formed with a ratio of resistance values of 1, 3, 5, 7,... (2n-1). Adding from point c results in 1, 4, 9, 16, 25, ... (n · n). That is, it has a square characteristic. Therefore, the precharge voltage (synonymous with or similar to the program voltage) Vpc has a difference in potential between points c and d of the resistor array 2931 in the form of approximately square characteristics. In addition, it is not limited to a square step, and may be in the range of 1.5 to the 3rd power. In addition, it is preferable that this range can be changed. The change may be made by forming the resistance R * of the resistance array 2931 with a plurality of resistance values and switching according to the purpose. Note that the reason why the gamma characteristic is changed depending on the image is to change the gamma characteristic in the range from the 1.5th power to the third power. This is also because the precharge voltage (synonymous with or similar to the program voltage) needs to change due to a change in gamma. The above has been described with reference to FIG. 106, FIG.

  By configuring as in FIG. 293, the origin (c point = Vcp1) of the precharge voltage (synonymous with or similar to the program voltage) and the final point (d point = Vpc7) of the precharge voltage (synonymous with or similar to the program voltage). ) Can be changed. Further, by outputting the voltages Vcp1 and Vcp7 in approximately square steps, an optimum precharge voltage (synonymous with or similar to the program voltage) can be output according to the gradation (description of FIGS. 135 to 142). See also). Needless to say, when the gradation output method is linear, the resistance of the resistor array 293 may be set to an equal resistance interval. Particularly when combined with the current programming method, it is preferable that the precharge driving (voltage programming method) in FIG.

  Vpc0 in FIG. 293 is open. That is, when Vpc0 is selected, no voltage is applied. Therefore, the precharge voltage (synonymous with or similar to the program voltage) is not applied to the source signal line 18.

  Note that FIG. 293 shows a configuration in which the voltages at both the points c and d are changed. However, as shown in FIG. 297, only the point d may be changed. Further, the precharge voltage (synonymous with or similar to the program voltage) is not limited to eight as shown in FIG. Further, FIG. 297 shows a configuration using the DA circuit 503, but as shown in FIG. 311, the d voltage may be changed or varied in an analog manner using a volume (VR) or the like.

  Further, the Vs voltage that is the origin of the precharge voltage (synonymous with or similar to the program voltage) shown in FIG. 297 may be a voltage generated outside the source driver IC (circuit) 14. In FIG. 324, a voltage V0 is generated by the volume VR, and is applied to the electronic volume 501 as a voltage common to each source driver IC (circuit) 14. That is, the V0 voltage is used as the Vs voltage in FIGS. 131, 143, 308, 311, 312 and the like. By making the Vs voltage the same as the anode voltage Vdd, the number of power supplies can be reduced.

  In the above embodiments, the precharge voltage (synonymous with or similar to the program voltage) has been described as being a voltage close to the anode voltage. However, depending on the pixel configuration, the precharge voltage (synonymous with or similar to the program voltage) is described. May be close to the cathode voltage. For example, when the driving transistor 11a is formed of an N channel transistor, the current transistor is executed by the driving transistor 11a being discharged by the P channel transistor (the pixel configuration in FIG. 1 is a sink (sink) current). It is.

  In this case, the precharge voltage (synonymous with or similar to the program voltage) needs to be a voltage close to the cathode voltage. For example, in FIG. 297, the point d needs to be the reference position. In FIG. 293, it is necessary to use the output voltage of the operational amplifier 502b as a reference. Further, it is necessary to use the Vbv voltage in FIG. 131 as a reference, and in FIGS. 141 and 143, it is necessary to use Vbvl as a reference. Needless to say, it is necessary to change the reference position when the pixel configuration changes as described above.

  Alternatively, a voltage selector circuit 2951 may be used as shown in FIG. The voltage selector circuit a terminal is applied with a change (change) of the precharge voltage (synonymous or similar to the program voltage) Vpc by the electronic volume 501, and the fixed precharge voltage (synonymous with the program voltage) is applied to the b terminal. (Or similar) Vc is applied.

  FIG. 339 shows another embodiment of the present invention. As the precharge voltage (program voltage) V0 corresponding to the 0th gradation of the electronic volume, a fixed voltage is applied in RGB as shown in FIG. Of course, you may change by RGB. In the CCM system, generally RGB may be common. The resistance R may be external to the electronic volume 501 as shown in the figure. By changing or replacing the resistor R, each Vpc voltage can be changed freely. In addition, it comprises so that the relationship of resistance value R1> R2> ...> Rn may be maintained. Further, at least the relationship of R1> Rn is maintained (Rn is a resistor that determines the Vpc voltage output from the last switch. R1 is on the low gradation side and Rn is on the high gradation side. R1 is for generating a voltage in the vicinity of the rising voltage of the driving transistor 11a, and Rn is for generating a white display voltage). In particular, it is preferable to maintain the relationship of R1> R2 (voltage between terminals of R1> voltage between terminals of R2). This is because, due to the characteristics of the driving transistor 11a, the difference between the V0 voltage and the voltage of the next first gradation is large between the voltages of the first gradation and the second gradation.

  Switch S is specified by decoding VDATA. Note that the number of selectable Vpc voltages is preferably 1/8 or more of the number of gradations of the display device when the display device is 6 inches or more (32 gradations or more in the case of 256 gradations). . In particular, it is preferably 1/4 or more (in the case of 256 gradations, 64 gradations or more). This is because the program current is insufficiently written to a relatively high gradation region. In a relatively small display panel (display device) of 6 inches or less, the number of selectable Vpc voltages is preferably 2 or more. This is because even if Vpc is one of V0, good black display can be realized, but it may be difficult to perform gradation display in a low gradation region. If Vpc is 2 or more, a plurality of gradations can be generated by FRC control, and good image display can be realized.

  SDATA that determines the potential at the point b correlates with the reference current Ic. Preferably, control is performed so that Ic is proportional to 1 / 1.5 or higher and 1/3. When the reference current Ic is large, the b-point potential is controlled to drop, and when the reference current Ic is small, the b-point potential is high. Therefore, when the reference current Ic is large, the potential difference between the resistors R is large, and the difference between the Vpc is large (the step change of the program voltage is large). Conversely, when the reference current Ic is small, the potential difference between the resistors R is small, and the difference between the Vpc is small. For example, as shown in FIG. 344, the potential at the b terminal is changed by the reference current Ic, and the potential difference between the resistance terminals of the electronic volume 501 is changed in proportion to the potential difference from the voltage V0.

  In FIG. 344, the potential of the b terminal is directly changed by the reference current Ic, but the present invention is not limited to this. A current obtained by converting the reference current Ic (Icr, Icg, Icb) in FIG. 188 with a current shunt circuit or a conversion circuit may be used. The current obtained by conversion or the like is configured to be in the vicinity of the 1/2 power of the reference current. Needless to say, the reference current Ic in the electronic volume 501 for each RGB is preferably configured to be different for each RGB.

  For example, in FIG. 343, the reference current Ic (or a current proportional to or correlated with the reference current) is introduced into a current mirror circuit composed of the transistors 158b and 158c, and the voltage V1 generated at one end of the resistor R0 is passed through the amplifier 502a. Thus, the voltage is applied to the b terminal. With this configuration, the precharge voltage (in accordance with the change of the reference current (in the lighting rate control of the present invention, the display brightness or the current consumption control is performed by changing the reference current) or in correlation with the change is applied. (Program voltage) can be changed. Note that flicker occurs in the image unless the voltage change at the b terminal is moderated. For this measure, in the embodiment of FIG. 343, a capacitor C is arranged or formed at the b terminal.

  As described above, the change in the voltage at the b terminal (the change in the precharge voltage (program voltage) Vpc) in accordance with the change in the reference current (change due to the lighting rate control) is implemented. It goes without saying that the same applies to the embodiment (see also FIG. 343, FIG. 339, etc.).

  The embodiment shown in FIG. 345 is also exemplified as a configuration for changing or changing the precharge voltage (program voltage) in accordance with or in correlation with the reference current Ic. In the embodiment of FIG. 345, a reference mirror Ic (or a current proportional to or correlated with the reference current Ic) constitutes a current mirror circuit (comprising a transistor 158b, a transistor 158c, etc.). The resistor R0 is attached (arranged or formed) outside the source driver circuit (IC) 14. By replacing or changing the resistor R0, the voltage at the terminal b of the electronic controls 501a and 501b can be changed or varied.

  The resistor R0 is not limited to a fixed resistor, volume, or the like. Nonlinear elements such as Zener diodes, transistors, and thyristors may be used. Further, it may be a circuit or an element such as a constant voltage regulator or a switching power supply. Further, instead of the resistor R0, an element such as a posistor or thermistor may be used. Along with the potential adjustment of the terminal b, temperature compensation can be performed simultaneously. The resistance of the source driver circuit (IC) 14 can be similarly replaced.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. For example, the resistor R1 in FIGS. 188 and 209, the resistors R1 to R3 in FIGS. 197 and 346, the VR in FIG. 311, the VR in FIG. 324, the R1 to R8 in FIG. 339, the R1 and R2 in FIG. 341, and the R0 in FIG. , Ra, Rb, Rc in FIG. 351, Ra, Rb in FIG. 354, etc. are exemplified. Needless to say, the present invention can also be applied to the built-in resistors shown in FIGS. 351, 352, and 353.

  In the configuration of FIG. 345, the electronic volume 501a selects the first precharge voltage (program voltage) Va according to the value of VDATA1, and the electronic volume 501b selects the second precharge voltage (program voltage) Vb according to the value of VDATA2. Is done. Vpc applied to the display panel (display device) is obtained by adding the Va voltage and the Vb voltage by an adder circuit 3451 including an operational amplifier. As described above, by using a plurality of electronic regulators 501 (operation means), a Vpc voltage corresponding to the purpose can be generated flexibly.

  In the embodiment of FIG. 345, the Vpc voltage is generated by adding the Va voltage and the Vb voltage. However, the present invention is not limited to this. You may subtract Va voltage and Vb voltage. Moreover, you may multiply. Further, the voltage is not limited to two voltages, Va voltage and Vb voltage, and the Vpc voltage may be generated by three or more voltages. Moreover, it is not limited to a voltage, The object which generate | occur | produces like Ia current and Ib current may be an electric current. Any method may be used as long as this current is finally changed to Vpc which is a voltage.

  As described above, the precharge voltage (program voltage) may be generated by converting, combining, or manipulating a plurality of voltages. The above matters also apply to other embodiments of the present invention (for example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and FIGS. 349 to 354 are exemplified). Needless to say, it can be applied.

  In FIG. 342, the magnitude of the resistance Ra or Rb of the electronic volume 501 is changed. Ra1> Ra2 and Ra> Rb. With the configuration as shown in FIG. 342, the voltage difference is large in the first step of the precharge voltage, and the step of the precharge voltage becomes smaller as the gradation becomes higher (on the higher gradation side). This is because on the high gradation side, a large output current (= program current) can be obtained by slightly changing the gate terminal voltage of the driving transistor 11a.

  The resistors Rb above the intermediate portion may have the same resistance (Rb1 = Rb2) value. Further, Ra> Rb may be set, and Ra1 = Ra2 =..., Rb1 = Rb2 =. That is, the change of the precharge voltage Vpc with respect to VDATA becomes a one-point broken line curve. Of course, as shown in FIG. 339 and the like, all the resistors R may have the same resistance value. In this case, the change of the precharge voltage Vpc with respect to VDATA is linear. Even in the linear case, it is preferable to maintain the relationship Ra1> Ra2. This is because the step between the rising voltage V0 and the next precharge voltage Vpc = V1 voltage is large.

  It goes without saying that the resistance value of the resistor built in the source driver circuit (IC) 14 may be adjusted or processed by trimming or heating so that the resistance value becomes a predetermined value.

  The value of SDATA is converted into a voltage by the DA circuit 503 and applied to the terminal b of the electronic volume 501. Needless to say, instead of the generation of SADTA, it may be changed in an analog manner as shown in FIG. In FIG. 339 and the like, the b terminal voltage is changed according to the magnitude of the reference current, but the present invention is not limited to this, and a fixed voltage may be used.

  The generation of the voltage Vpc is not limited to being generated by the electronic regulator 501. For example, it can also be generated by an adding circuit composed of an operational amplifier. It can also be configured by a switch circuit that selects a plurality of voltages with a switch.

  FIG. 348 shows an embodiment in which the voltage (V1c, Vc2, Vc3) generated outside the source driver IC (circuit) 14 can be selected by operating the switch S as the potential at the b terminal.

  In the present invention, the V0 terminal (the terminal for applying the voltage at the 0th gradation or the terminal for applying a voltage equal to or lower than the rising voltage of the transistor 11a) may be shared by the RGB precharge circuit (program voltage generation circuit). . However, it is preferable that the voltage at the b terminal can be set independently for RGB. This embodiment is shown in FIG.

  In FIG. 349, the R precharge circuit (program voltage generation circuit) 501R, the G precharge circuit (program voltage generation circuit) 501G, and the B precharge circuit (program voltage generation circuit) 501B are used to set the V0 voltage at the a terminal. Commonly applied. However, at the b terminal, the V1R voltage can be applied to the R precharge circuit (program voltage generation circuit) 501R. Similarly, a V1G voltage can be applied to the G precharge circuit (program voltage generation circuit) 501G. Further, the B precharge circuit (program voltage generation circuit) 501B is configured to be able to apply the V1B voltage.

  The embodiment of FIG. 340 is an embodiment in which at least one DA circuit 503 is formed, configured, or arranged in the electronic volume 501. Each DA circuit 503 has two voltages (for example, DA circuit 503a has voltages V0 and V1, DA circuit 503b has voltages V1 and V2, DA circuit 503c has voltages V2 and V3, DA circuit 503d has voltages V3 and V4), DA It is controlled by VDATA (5: 0) for setting data and a selection bit S for selecting which DA circuit 503 is operated.

  Each DA circuit 503 is controlled by VDATA (5: 0) and the S terminal, and outputs a voltage between two voltages. For example, the DA circuit 503a generates the Vpc voltage when the S1 terminal is selected. A signal for selecting the S1 terminal controls the switch S1 to be turned on. Further, the DA circuit 503a outputs a voltage corresponding to the value of VDATA (5: 0) between the voltage V0 and the voltage V1 according to the value of VDATA (5: 0). In the embodiment of FIG. 340, since VDATA is 6 bits, the V0-V1 voltage is divided into 64, and the divided unit voltage × the value of VDATA (5: 0) + V1 voltage is output.

  Similarly, the DA circuit 503b generates a Vpc voltage when the S2 terminal is selected. A signal for selecting the S2 terminal controls the ON state of the switch S2. Further, the DA circuit 503b outputs a voltage corresponding to the value of VDATA (5: 0) between the V1 voltage and the V2 voltage according to the value of VDATA (5: 0). In the embodiment of FIG. 340, the V1-V2 voltage is divided into 64, and the divided unit voltage × the value of VDATA (5: 0) + V2 voltage is output. The above matters also apply to the DA circuits 503c and 503d.

  If configured as shown in FIG. 340, it is possible to easily change the curve of Vpc generated only by changing the voltages V0, V1,. That is, the voltages V1, V2, and V3 in FIG. 340 control the bent position of Vpc with respect to the gradation data (VDATA (5: 0), S1, S2, S3, and S4) (in the configuration of FIG. 340, 3 It is a broken point gamma curve). By changing the voltages V1, V2, and V3, it is possible to easily change the magnitude or inclination of the precharge voltage (program voltage) with respect to the gradation data. Further, the position of the precharge voltage (program voltage) applied at the 0th gradation can be changed by changing the V0 voltage. Moreover, the maximum value to which the precharge voltage (program voltage) is applied can be changed by changing the V4 voltage. Further, it is possible to set a more flexible precharge voltage (program voltage) or gamma curve by increasing the number of DA circuits 503 and increasing the number of input voltages (V0 to V4).

  In the embodiment of FIG. 340, the voltages V1 to V4 are supplied from the outside of the source driver circuit (IC) 14, but the present invention is not limited to this. It may be generated inside the source driver circuit (IC) 14. Further, as shown in FIG. 341, two voltages (V0 voltage, V2 voltage) may be divided by resistors (R1, R2) to generate the V1 voltage.

  The DA circuit 503b generates a Vpc voltage when the S1 terminal is selected. A signal for selecting the S1 terminal controls the ON state of the switch S1. Further, the DA circuit 503b outputs a voltage corresponding to the value of VDATA (2: 0) between the V0 voltage and the V1 voltage according to the value of VDATA (2: 0). In the embodiment of FIG. 341, the V0−V1 voltage is divided into eight, and the divided unit voltage × the value of VDATA (2: 0) + V1 voltage is output.

  The DA circuit 503c generates a Vpc voltage when the S2 terminal is selected. A signal for selecting the S2 terminal controls the ON state of the switch S2. Further, the DA circuit 503c outputs a voltage corresponding to the value of VDATA (4: 0) between the V1 voltage and the V2 voltage according to the value of VDATA (4: 0). In the embodiment of FIG. 341, the V1-V2 voltage is divided into 32, and the divided unit voltage × the value of VDATA (4: 0) + V2 voltage is output.

  The resistor R 1, the resistor R 2, or both resistors R may be built in the source driver circuit (IC) 14. One or both of the resistors may be variable resistors. Needless to say, the resistors R1 and R2 may be adjusted by performing trimming or the like. Needless to say, the above matters also apply to other embodiments of the present invention.

  FIG. 351 shows an embodiment in which the V0 voltage and the V1 voltage are generated using three resistors (Ra, Rb, Rc) outside the source driver circuit (IC) 14. The resistor is connected to a terminal 2883 of the source driver circuit (IC) 14. Resistors Ra, Rb, and Rc are connected in series between the anode voltage and the ground (GND). A Va voltage (Vdd−Va = V0) is generated at both ends of the resistor Ra, a Vb voltage is generated between the resistors Rb, and a Vc voltage (Vc = V1) is generated between the resistors Rc.

  With the configuration described above, the voltages V0 and V1 can be freely set by adjusting the resistors Ra, Rb, and Rc. In the configuration of FIG. 351, the V0 voltage, the V1 voltage, and the like are generated based on the anode terminal voltage Vdd. Therefore, even when the anode voltage Vdd varies or when the voltage variation of the Vdd voltage generated in the power supply module occurs, the V0 voltage and the V1 voltage change in conjunction with each other. Since this change coincides with the operation origin (anode terminal) of the driving transistor 11a of the pixel 16, a satisfactory operation can be realized.

  In FIG. 339 and FIG. 341, the potential at the point b can be varied. It is necessary to vary the potential at point b because the reference current is varied in the driving method of the present invention (as a method for changing or controlling the reference current, FIGS. 61, 63, 64, 93 to 97, FIG. 111-116, 122, 145-153, 188, 252, 254, 267, 269, 277, 278, 279 and the like and the description thereof). FIG. 350 illustrates the relationship between the gate terminal voltage (horizontal axis) and the output current (vertical axis) of the driving transistor 11a. The vertical axis represents the program current Iw. The program current Iw is proportional to the reference current. The gate terminal voltage on the horizontal axis indicates the potential of the source signal line 18. The potential of the source signal line 18 is the same as the precharge voltage (program voltage).

  From the above, in FIG. 350, when the reference current Ic is I1 and the maximum program current (at the maximum gradation) from the source signal line 18, the precharge voltage (V1) is set so that the potential of the source signal line 18 becomes V1. (Program voltage) must be applied. Similarly, when the reference current Ic is I2 and the maximum program current (at the maximum gradation) from the source signal line 18, a precharge voltage (program voltage) is applied so that the potential of the source signal line 18 becomes V2. Indicates that it is necessary. When the reference current Ic is I3 and the source signal line 18 is at the maximum program current (at the maximum gradation), it is necessary to apply a precharge voltage (program voltage) so that the potential of the source signal line 18 becomes V3. It shows that there is.

  Here, it is assumed that the reference current Ic changes three times from I1 to I3. That is, I3: I2: I1 = 3: 2: 1. At this time, the optimum values of V3, V2, and V1 are V3: V2: V1 = 11.5: 11: 10 according to the examination result. That is, even if the change in the reference current is three times, the change in the precharge voltage Vpc is slight. From the above, the change in Vpc may be small. It is preferable that the change of the precharge voltage Kv (V3 / V1 in FIG. 350) maintains the relationship of the reference current change Ki (I3 / I1 in FIG. 350) of 2 <Ki / Kv <3.5. .

  From FIG. 350, even when the value of the reference current I is largely changed, the change in the precharge voltage is small. Therefore, the amount of change in the V1 voltage in FIGS. 339, 341, etc. can be small even if the reference current changes greatly. For this reason, the output change of the DA circuit 503 is small and sufficient. In FIG. 339 and FIG. 341, the V1 voltage is changed in accordance with the reference current. However, there is no practical problem even if the voltage of the terminal 2883c is fixed as in the embodiment of FIG. Conversely, the variable range of the maximum precharge voltage (program voltage) is small, and the circuit configuration can be simplified. In addition, highly accurate output is possible.

  In the current driving method, insufficient current writing occurs in the low gradation region. Further, the region where insufficient writing occurs is the A section from V0 voltage (0th gradation: rising voltage of the driving transistor 11a) to Vx in FIG. This range shows a linear change as described by the dotted line. In FIG. 350, the section indicated by A represents a small inclination. In practice, such a slope is sufficiently smaller than the solid curve. In the method in which the program current is applied after the voltage application (precharge voltage (program voltage) application) described with reference to FIGS. 127 to 143 and the like is performed, the completely corrected source signal line 18 potential and the precharge voltage application are applied. This is because even if there is a difference from the potential of the source signal line due to (appears as a current difference between the solid line and the dotted line in FIG. 350), complete correction can be realized by the program current.

  What is important is that a precharge voltage (program voltage) is applied to the source signal line 18, and ideally a short time (1H) to the vicinity of the potential of the source signal line 18 (the gate terminal potential at which the driving transistor 11 a is realized by the program current). Setting / adjustment in 1/200 or more and 1/20 or less). By this operation, the potential difference to be changed from the ideal (compensated) source signal line 18 potential to the source signal line 18 realized by the program current is reduced. Therefore, an ideal state can be realized even with a relatively small program current (program current in a low gradation region) (a current program that compensates for the characteristics of the driving transistor 11a can be realized). Since the magnitude of the program current is large in the high gradation region, an ideal state can be achieved (implemented) only with the program current without applying a precharge voltage (program voltage).

  From the above, the range in which insufficient writing occurs is limited to the low gradation region. Further, a precharge voltage (program voltage) is not required in the high gradation region (of course, a precharge voltage may be applied). The region to which the precharge voltage (program voltage) is to be applied is not necessary for the entire gradation range, and the region below the halftone is sufficient. By limiting the range to which the precharge voltage is applied to the intermediate gradation or less, the number of taps of the electronic volume in FIGS. 131, 135 to 142, 339 to 341, 351, and 353 can be reduced. . Therefore, the circuit can be simplified and the cost can be reduced.

  If it is configured to generate (output) a precharge voltage (program voltage) corresponding to the dotted line shown in FIG. 350, each resistor of the electronic volume 501 may be configured with the same resistance value. it can. Therefore, the circuit configuration of the electronic volume 501 is preferable because it is simple.

  However, as shown in FIG. 359, ideally, it is preferable that the output currents I by application of the precharge voltage (program voltage) are equally spaced (equal steps). The differences between voltage 0 and voltage V0, and voltage V0 and voltage V1 are large. The difference between the voltage V4 and the voltage V5 is small. In order to realize such steps (steps), the magnitude of the resistance of the electronic volume 501 may be changed.

  The voltage gradation data for setting (designating) the precharge voltage (program voltage) is preferably matched with the current gradation data for setting (designating) the program current. If the video data is gradation 128, the voltage gradation data is also 128, and the current gradation data is also 128. That is, the number of video data after gamma conversion or the like = the number of voltage gradation data = the current gradation data (the number of the video data is the switch S of the electronic volume 501 in FIGS. 131, 339, 351, etc. 15 is applied to apply the precharge voltage (program voltage) Vpc to the source signal line 18. Also, the on / off state of the switch 151 shown in FIG. The group 431c is operated.

  Whether or not to apply a precharge voltage (program voltage) to each video data is controlled by a control IC 760 and controlled by a precharge bit (see FIGS. 75 to 79 and its description). Depending on the potential state of the source signal line 18 (application state of the previous precharge voltage (program voltage) written to each pixel) or the size of the video data (precharge voltage (program voltage) is applied in the low gradation region) To determine whether or not to apply a precharge voltage (program voltage). Therefore, the precharge voltage (program voltage) may not be applied even for video data in a low gradation region. In addition, a precharge voltage (program voltage) may be applied even to video data in a high gradation region. In the present invention, a bit for determining a precharge voltage (program voltage) is incorporated in a source driver, whether or not a precharge voltage (program voltage) is applied, or a precharge voltage (program voltage) is converted into video data ( It has a feature in that it has a control method or technical idea corresponding to (gradation).

  The configuration or control as described above facilitates the configuration of the source driver circuit (IC) 14 and reduces data transmitted from the controller IC (circuit) 760 to the source driver circuit (IC) 14 (voltage). Since the gradation data number and current gradation data are not necessary and only the video data is required, the frequency of the transmission data can be reduced.

  The number of Vpc voltages that can be selected is preferably 1/8 or more of the number of gradations of the display device when the display device is 6 inches or more (32 gradations or more for 256 gradations). In particular, it is preferably 1/4 or more (in the case of 256 gradations, 64 gradations or more). This is because the program current is insufficiently written to a relatively high gradation region. However, as described above, it is not necessary to configure or form such that a precharge voltage (program voltage) can be applied in the entire gradation range.

  In a relatively small display panel (display device) of 6 inches or less, the number of selectable Vpc voltages is preferably 2 or more. This is because even if Vpc is one of V0, good black display can be realized, but it may be difficult to perform gradation display in a low gradation region. If Vpc is 2 or more, a plurality of gradations can be generated by FRC control, and good image display can be realized.

  The precharge voltage (program voltage) is preferably changed by voltages (Vgh1, Vgl1) for controlling the gate signal line 17a. In particular, the precharge voltage (program voltage) is changed by the Vgl1 voltage. This is because the gate terminal potential of the driving transistor 11a varies depending on the parasitic capacitance of the gate terminal of the driving transistor 11a and the amplitude of the Vgl1 voltage.

  As shown in FIG. 355, the rising voltage of the driving transistor 11a changes as the Vgl1 voltage decreases. For example, when Vgl1 = 0V, the rising voltage (the precharge voltage (program voltage) applied as the 0th gradation) is V2, but when Vgl1 = −4V, the rising voltage (applied as the 0th gradation). When the precharge voltage (program voltage) is V1 and Vgl1 = −9V, the rising voltage (precharge voltage (program voltage) applied as the 0th gradation) is V0 and the anode potential (0V in FIG. 355). Get closer. Therefore, it is preferable to change the V0 voltage in FIG. 339 or the like in conjunction with the Vgl1 voltage. It is also preferable to change the V1 voltage.

  Needless to say, the above items can be applied to other embodiments of the present invention. It goes without saying that the above technical idea can be applied to the display device, display panel, display method and the like of the present invention.

  FIG. 352 is a modification of FIG. In FIG. 352, the resistor Ra and the resistor Rb are built in the source driver circuit (IC) 14. A voltage Vdd is applied to the terminal 2883b, and a resistor Rc is connected between the terminal 2883c and the ground. By configuring as shown in FIG. 352, one external resistor is provided. However, it is preferable to configure so that the value of the resistor Rc can be set individually for each of RGB. Needless to say, a voltage may be directly input to the terminal 2883c. Also, the resistor Rc may be built in the source driver circuit (IC) 14.

  The resistor Ra may be adjusted by trimming or the like. In addition, when the resistor is formed of a diffused resistor, the resistance value can be adjusted by heating. Further, it may be set or adjusted to a predetermined resistance value by constituting an electronic volume or a resistance switch circuit. Needless to say, the above items can be applied to other embodiments such as FIGS. 352 and 353. In FIG. 352, adjusting the resistance Ra is described as an example. FIG. 353 describes an example of adjusting the resistance Rb.

  In FIG. 353, the Vdd voltage is applied to the terminal 2883b, and the external resistor Rc is connected to the terminal 2883c. The potential difference between the potential at point a and the potential at point b is set by adjusting resistance Rb. Further, the potential of the b terminal is adjusted by adjusting the value of the resistor Rc.

  As an example of adjusting the V1 voltage by the reference current Ic, the configuration of FIG. 354 is illustrated. In FIG. 354, the reference current Ic (or the current Ic that is correlated or proportional to the reference current Ic) flows into the external resistor Rb. Therefore, the voltage Vb of the terminal 2883b is the resistance Rb × Ic. This voltage becomes the gate terminal voltage of the transistor 158b. In the transistor 158b, an inter-channel voltage (SD voltage) is generated by the voltage Vb, and an Ib current flows through the external resistor Ra. The voltage V1 of the terminal 2883a is Vdd−Ra × Ib. Therefore, a change in the magnitude of the reference current Ic becomes a change in the V1 voltage. Since the operation of the electronic volume 501 has been described previously, a description thereof will be omitted.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. For example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354 are exemplified. Needless to say, the contents described in each embodiment can be selected, combined, or combined with each embodiment.

  It goes without saying that the resistance value of the resistor built in the source driver circuit (IC) 14 may be adjusted or processed by trimming or heating so that the resistance value becomes a predetermined value. The same applies to the external resistor.

  In FIG. 293 and the like (which may be other embodiments), the resistor array 2931 (resistor R) and the like are incorporated in the IC chip 14 or the source driver circuit 14, but the present invention is not limited to this. Needless to say, the IC (circuit) 14 may be externally connected with discrete components. Further, the precharge voltage (synonymous with or similar to the program voltage) Vpc is not limited to being generated by using the resistor R or the like, but needless to say, it may be constituted by other components such as an operational amplifier or a transistor. The precharge voltage (synonymous with or similar to the program voltage) Vpc is generated, pulsed or generated by a PWM modulation or the like, and smoothed by a capacitor to obtain a predetermined program voltage. Needless to say. Further, the precharge voltage (synonymous with or similar to the program voltage) Vpc is not limited to being generated in the IC (circuit) 14, but is generated outside the IC (circuit) 14, and the terminal of the IC (circuit) 14 The IC (circuit) 14 may be configured to select a precharge voltage (synonymous with or similar to the program voltage) Vpc adapted by a switch or the like. Further, a precharge voltage (synonymous with or similar to the program voltage) Vpc is generated outside the IC (circuit) 14 by the control data of the controller 760, and is taken into the IC (circuit) 14 and applied to the source signal line 18 and the like. Needless to say, it may be configured as described above. The items described above can be applied to other embodiments of the present invention such as FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354. Needless to say.

  127 to 143, 293 to 297, 308 to 313, 338 to 345, 349 to 354, etc., the precharge voltage (synonymous with or similar to the program voltage) is used in the present invention. ) (Voltage data) is applied, and then a program current is applied. The program current Iw uses FRC technology in order to increase the gradation. Generally, 10-bit data is expressed by 8 bits of 4FRC.

  In the present invention, the precharge voltage is also made FRC as shown in FIG. For example, FIG. 313 (b) shows a 4FRC driving method. In FIG. 313 (b), a white circle (white circle) indicates that the precharge voltage (synonymous with or similar to the program voltage) is applied (output), and a black circle (black circle) indicates the precharge voltage (program voltage and (Synonymous or similar) is not applied. That is, FIG. 313 (b) (1) shows that the precharge voltage (synonymous with or similar to the program voltage) is applied only once in 4 frames (fields). Similarly, FIGS. 313 (b) (2) show that the precharge voltage (synonymous with or similar to the program voltage) is applied only twice in 4 frames (fields), and FIGS. 313 (b) (3) This shows that the precharge voltage (synonymous with or similar to the program voltage) is applied three times in four frames (fields). 313 (b) and (4) show that a precharge voltage (synonymous with or similar to the program voltage) is applied to all four frames (fields).

  By performing the above operation (method), gradation display can be increased with a precharge voltage (synonymous with or similar to the program voltage). Therefore, the number of gradations is increased and better image display can be realized. That is, gradation display is realized mainly by a precharge voltage (synonymous with or similar to the program voltage) in the low gradation area, and gradation display is realized by the program current in the high gradation area.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. For example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354 are exemplified.

  It should be noted that the application of the precharge voltage (synonymous or similar to the program voltage) applies the precharge voltage (synonymous or similar to the program voltage twice) shown in FIG. 313 (c) in order to prevent the occurrence of flicker. As in the embodiment, it is preferable to change the timing of applying the precharge voltage (synonymous with or similar to the program voltage).

  In the low gradation region, voltage data (VDATA) such as a precharge voltage (synonymous with or similar to the program voltage) can charge and discharge the source signal line 18 in a short time. On the other hand, current data (IDATA) such as the program current Iw requires time to charge and discharge the source signal line 18 up to a target voltage (current). Therefore, the current program needs to be stronger in the operation for obtaining the current of the EL element 15 which is the same target. Therefore, as shown in FIG. 313 (a), the current data (IDATA) in gradation 1 is data with a higher gradation (for example, IDATA = 1 in gradation 1 is originally, 4 and 4 times as much current). The precharge voltage (synonymous with or similar to the program voltage) (VDATA) is set to 1 (the original value). Similarly, the current data (IDATA) in gradation 2 is data with higher gradation (for example, in gradation 2, IDATA = 2 is originally set to 6, but three times as much current is passed). The precharge voltage (synonymous with or similar to the program voltage) (VDATA) is 2 (which is the original value). As described above, by setting the current data to a large value, the program can be realized with higher accuracy. Note that at halftone or higher, the current data and the voltage data are the same (IDATA = VDATA = k for gradation k), or no voltage data is applied.

  Needless to say, the c potential or the d potential may be changed according to the lighting rate, the anode current, the duty ratio, or the like. Needless to say, the same applies to the technical idea of FRC shown in FIG. Needless to say, the above items can be applied to other embodiments of the present invention. For example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354 are exemplified.

  FIG. 294 is an explanatory diagram focusing on a circuit portion for selecting a precharge voltage (synonymous with or similar to a program voltage) Vpc. The output of the resistor array 2931 is input to the voltage selector circuit 2941. The voltage selector circuit 2941 includes an analog switch and a decoder circuit, and one precharge voltage (synonymous with or similar to the program voltage) is applied by a 3-bit signal of the selection signal VSEL (see FIG. 296). The selected precharge voltage (synonymous with or similar to the program voltage) is output from the terminal 155 via the wiring 150.

  The precharge voltage (synonymous with or similar to the program voltage) output from the terminal 155 is held in Cs which is a parasitic capacitance of the source signal line 18. Therefore, the output of the precharge voltage (synonymous with or similar to the program voltage) may be dot-sequential. However, in the dot sequential operation, the application time of the precharge voltage (synonymous with or similar to the program voltage) differs between the terminal 1 and the terminal n (final terminal). To deal with this problem, two voltage selector circuits 2941 are formed or configured as shown in FIG. In the first H, the voltage selector circuit 2941a outputs the precharge voltage (synonymous with or similar to the program voltage) held in C1 by selecting the switch S1 of the selector circuit 2951 so that the selected precharge voltage (program Vpc is output from terminal 155 (synonymous or similar to voltage). During this period (first H period), the voltage selector circuit 2941a2 sequentially operates, and the selected precharge voltage (synonymous with or similar to the program voltage) Vpc is held at C2. Further, the switch S2 of the selector circuit 2951 is open.

  In the second H period following the first H period, the voltage selector circuit 2941b outputs, and the precharge voltage (synonymous or similar to the program voltage) held in C2 is output from the terminal 155 via the switch S1 of the selector circuit 2951. . During this period (second H period), the voltage selector circuit 2941a1 sequentially operates, and the selected precharge voltage (synonymous with or similar to the program voltage) Vpc is held at C1. The switch S1 of the selector circuit 2951 is open.

  Similarly, in the third H period following the second H period, the voltage selector circuit 2941a outputs, and the precharge voltage (synonymous or similar to the program voltage) held in C1 selects the switch S1 of the selector circuit 2951. Thus, the selected precharge voltage (synonymous with or similar to the program voltage) Vpc is output from the terminal 155. During this period (third H period), the voltage selector circuit 2941a2 sequentially operates, and the selected precharge voltage (synonymous with or similar to the program voltage) Vpc is held at C2. Further, the switch S2 of the selector circuit 2951 is open. In the 4H period following the 3H period, the voltage selector circuit 2941b outputs, and the precharge voltage (synonymous or similar to the program voltage) held in C2 is output from the terminal 155 via the switch S1 of the selector circuit 2951. . During this period (fourth H period), the voltage selector circuit 2941a1 sequentially operates, and the selected precharge voltage (synonymous with or similar to the program voltage) Vpc is held at C1. The switch S1 of the selector circuit 2951 is open. The above operations are sequentially repeated.

  FIG. 308 shows another embodiment of the present invention that outputs a precharge voltage (synonymous with or similar to a program voltage). A switch of the electronic volume 501 is operated by PDATA that selects or determines a precharge voltage (synonymous with or similar to the program voltage), and the corresponding precharge voltage (synonymous or similar to the program voltage) Vpc is held in the capacitor Cc. The held precharge voltage (synonymous with or similar to the program voltage) Vpc is held by the sampling circuit 862 and held in the output Ca to Cn selected by the address data PADRS of the source signal line 18 to be output. Note that the PADRS designation data changes in synchronization with the dot clock CLK. Also, PDATA is changed corresponding to the video data (see the description of FIGS. 127 to 143, etc.).

  Therefore, the precharge voltage (synonymous with or similar to the program voltage) Vpc is held in the holding capacitors Ca to Cn corresponding to each output terminal in the period of 1H. When a precharge voltage (synonymous with or similar to the program voltage) is applied to the source signal line 18, the switches Sp are simultaneously closed for a certain period. At this time, the switch Si is set in an open state, and the backflow of the precharge voltage (synonymous with or similar to the program voltage) Vpc to the current circuit 431c is suppressed. A voltage selector circuit 2941 in FIG. 295 selects a precharge voltage (synonymous with or similar to the program voltage) Vpc. The selection data may be performed by the latch circuit 771. This also applies to the embodiment of FIG. In FIG. 308, it is needless to say that a two-stage configuration is preferable as shown in FIG.

  FIG. 308 shows a circuit configuration for sampling and holding a precharge voltage (synonymous with or similar to the program voltage), but the present invention is not limited to this. As shown in FIG. 309, a plurality of precharge voltages (synonymous with or similar to the program voltage) may be generated and selected.

  In FIG. 309, fixed Vpa, Vpb and Vpc that can be arbitrarily changed by a volume (VR) or the like can be selected as the precharge voltage (synonymous with or similar to the program voltage). The precharge voltage (synonymous with or similar to the program voltage) is selected by a 2-bit selector signal (SEL). A switch Sp for selecting a precharge voltage (synonymous with or similar to the program voltage) is selected by the SEL signal. As shown in the table of FIG. 309, when SEL is 0, no precharge voltage (synonymous with or similar to the program voltage) is selected. That is, the precharge voltage (synonymous with or similar to the program voltage) is not applied to the source signal line 18. When SEL is 1, the switch Sp 1 is selected and a precharge voltage (synonymous with or similar to the program voltage) Vpa is applied to the source signal line 18. When SEL is 2, the switch Sp2 is selected and a precharge voltage (synonymous with or similar to the program voltage) Vpb is applied to the source signal line 18. When SEL is 3, the switch Sp3 is selected and a precharge voltage (synonymous with or similar to the program voltage) Vpc is applied to the source signal line 18.

  In FIG. 309, the current program data (DATAa, DATAb) of the current output circuit is held by the latch circuit 771 and switched every 1H. That is, the latch circuit 771a is selected in the first 1H, and data is sequentially held in the latch circuit 771b in synchronization with the dot clock during this period. In the second H, the latch circuit 771b is selected, and data is sequentially held in the latch circuit 771a in synchronization with the dot clock during this period. The retained data is switched by the switch Sa (Saa, Sab) in synchronization with the horizontal synchronization signal, and the output current (program current, etc.) of the transistor group 431c is determined.

  FIG. 310 mainly illustrates the configuration of FIG. 309 more specifically. Precharge voltage (synonymous with or similar to program voltage) Vp (Vpa, Vpb, Vpc, open) precharge voltage (synonymous with or similar to program voltage) wiring PS (PSa, PSb, PSc, PSd) is a source signal line 18 is wired so as to be orthogonal to 18. The precharge voltage (synonymous with or similar to the program voltage) wiring PS and the internal wiring 150 are orthogonal to each other, and a switch Sp is disposed at each intersection. The switch Sp is switched by a SEL signal as shown in FIG. Note that the precharge voltage (synonymous with or similar to the program voltage) is applied to all the source signal lines 18 simultaneously in the first period of 1H. Therefore, it is necessary to latch and hold the SEL signal.

  In the above embodiment, the precharge voltage (synonymous with or similar to the program voltage) is applied via the source driver IC 14, but the present invention is not limited to this. For example, a precharge voltage (synonymous or similar to program voltage) transistor element formed on the array 30 substrate is formed, and this transistor element is turned on / off to be applied to a precharge voltage (synonymous or similar to program voltage) line. It goes without saying that the precharge voltage (synonymous with or similar to the program voltage) applied may be applied to the source signal line 18.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. For example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354 are exemplified.

  77 and 78 show the configuration or formation of the latch circuit 771 for latching the precharge bit in the current driver IC 14 (circuit or IC for outputting a program current) or the like, but the present invention is not limited to this. Absent. For example, the present invention can be applied to a source driver circuit or an IC that outputs a program voltage. By arranging or configuring a precharge function or a latch circuit for latching a precharge signal or a precharge selection signal line in the source driver circuit 14, the potential of the source signal line is written before the program voltage is written to the source signal line 18. Can be set to a predetermined value, and the writing stability can be improved.

  In FIG. 77, FIG. 78, etc., one precharge signal line (RPC, GPC, BPC) has been described and the corresponding latch circuit has been described as one bit in two stages, but the present invention is limited to this. It is not a thing. For example, when the precharge signal is composed of 4 bits as shown in FIG. 75, four precharge signal lines are required. Therefore, it is needless to say that the precharge signal latch circuit requires four bits for two stages. Further, the latch circuit 771 is not limited to two stages as shown in FIG. Needless to say, it may be composed of three or more stages. For example, a four-stage configuration is preferable because a current signal written to the source signal line 18 can be secured twice as long. Needless to say, it is not necessary to provide the precharge signal lines individually for R, G, and B. A common signal line may be used for RGB.

  As described above, the source driver circuit 14 or the like of the present invention holds a determination bit for selecting whether or not to apply a precharge signal when writing a program current or a program voltage to the source signal line 18 in the source driver circuit. And a signal input terminal for transmitting a signal held in the determination bit or an assumed signal.

  Note that the precharge voltage (synonymous with or similar to the program voltage) applied to the source signal line may be changed or changed according to the lighting rate. For example, the value of the selection signal D in FIG. 75 is changed with respect to the lighting rate, the electronic volume 501 is controlled, and the precharge signal output from the terminal 155 is changed. Since the current flowing through the driving transistor 11a changes according to the lighting rate, the magnitude of the optimum precharge voltage (synonymous with or similar to the program voltage) (especially when gradation display is performed by voltage driving) changes. Gray scale display or the like can be realized by controlling the electronic volume 501 so as to obtain an optimal gray scale display according to the lighting rate.

  In the above embodiments, the precharge voltage (synonymous with or similar to the program voltage) is changed according to the lighting rate, but the present invention is not limited to this. The precharge voltage (synonymous with or similar to the program voltage) may be changed according to the reference current ratio. The current flowing through the driving transistor 11a also changes depending on the magnitude of the reference current, and the optimum precharge voltage (synonymous with or similar to the program voltage) (the voltage applied to the gate terminal of the driving transistor 11a) changes. is there. Also, the precharge voltage (synonymous with or similar to the program voltage) may be changed depending on the magnitude of the current at the anode (cathode) terminal.

  It goes without saying that the above matters can be applied to other embodiments of the present invention. For example, FIGS. 127 to 143, FIGS. 293 to 297, FIGS. 308 to 313, FIGS. 338 to 345, and 349 to 354 are exemplified.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments employing an EL display panel, an EL display device, or a driving method of the present invention will be described below with reference to the drawings. The EL display panel has a problem that the chromaticity of B is particularly bad, while the chromaticity of R is very good. Therefore, when an image is displayed, the display color may be different from the original image. In the XY coordinates of the chromaticity in FIG. 144, the solid line is the NTSC color range. The dotted line is the color range of the organic EL. Since the color reproduction range of NTSC and the color reproduction range of organic EL are shifted, there is a problem that leaves become a dead leaf color particularly in an image display with many trees.

  A method for solving this problem is color management processing. In this method, image color correction is performed by signal processing. A measure for improving the chromaticity of an image by using a color filter is also exemplified.

  In order to improve the color purity of the EL display panel using the color filter, the color filter may be arranged, configured, or formed on the light exit side of the display panel 30. The color filter may be disposed or formed between the polarizing film 39 and the panel 30. The chromaticity of B can be improved by using a color filter that cuts cyan. As the color filter, in addition to a filter made of resin, an interference filter made of an optical interference multilayer film may be used. In addition, you may form or arrange | position a color filter on a polarizing film.

  In order to realize color management (color correction processing) in a circuit, it is preferable to change the output ratio of the RGB unit transistors 154 output from each transistor group 431. In order to suppress the phenomenon that the chromaticity of B is poor in organic EL (on the other hand, the chromaticity of R is good) and the leaves of the tree become dead leaves, the current of B should be increased or the current of R should be decreased. .

  In order to adjust the output current of the transistor group 431c, the current Ic in FIG. 46 or the like may be adjusted (in RGB). In addition, it cannot be overemphasized that the matter, structure, method, and apparatus which were demonstrated in this specification in the Example of this invention are applicable.

  A configuration for adjusting the current Ic is illustrated in FIG. FIG. 145 (a) shows a configuration in which 8-bit data is converted into an analog signal by the DA circuit 661, input to the operational amplifier 502a, and the current Ic is changed (adjusted). The basic current magnitude is externally attached or built-in resistor R1.

  FIG. 145 (b) shows a configuration in which 8-bit data is converted into an analog signal by the DA circuit 661, and the current Ic is changed (adjusted). The basic current magnitude is externally attached or built-in resistor R1. However, in the configuration of FIG. 145 (b), the change in the current Ic with respect to the output voltage of the DA circuit 661 is nonlinear.

  FIG. 145 (c) shows a configuration in which 8-bit data is converted into an analog signal by the DA circuit 661, and the current Ic is changed (adjusted) via the transistor 157b. The basic current magnitude is externally attached or built-in resistor R1. However, in the configuration of FIG. 145 (b), the change in the current Ic with respect to the output voltage of the DA circuit 661 is nonlinear.

  FIG. 146 shows a circuit configuration using the electronic volume circuit 501. The output of the DA circuit 661 is connected to the terminal voltage Vs of the electronic volume circuit 501 in FIG. Other configurations are the same as or similar to those shown in FIGS. That is, the current Ic is switched by the electronic volume 501 and can also be adjusted by the output of the DA circuit 661 for color management processing. Needless to say, the configurations of FIGS. 145 and 146 may be combined. Further, it goes without saying that the color management processing may be performed by controlling the electronic volume 501 in FIG.

  FIG. 147 is a modification of FIG. The voltage Vc can be directly input to the input terminal c of the operational amplifier 502a. When Vc is input, the electronic volume 501 is controlled to be open without selecting any switch S. The current Ic can be easily controlled or adjusted by applying the Vc voltage from the outside of the IC 14.

  In FIG. 148, the input terminal voltage of the operational amplifier 502a is changed by changing the power supply voltage Vda of the DA circuit 661a by the DA circuit 661b. The output current Ic changes linearly with the input terminal voltage.

  In FIG. 148, the output voltage of the DA circuit 661a changes linearly with 8-bit digital data, and the output voltage of the DA circuit 661a changes linearly with the output voltage of the DA circuit 661b. In the circuit configuration shown in FIG. 148, the change width of the current Ic is large, and the change is linear.

  The color management process is controlled by each RGB current. Note that the RGB current can be expressed by a lighting rate (duty ratio is 1/1). When the duty ratio is 1/1, the lighting rate can be calculated from the sum of image data and the maximum value. When the color management process is performed, the lighting rate is obtained individually for RGB. That is, the lighting rate of R, the lighting rate of G, and the lighting rate of B are obtained (the current consumption of R, the current consumption of G, and the current consumption of B are obtained), and the range and size of a certain ratio Perform color management processing at. This is because, when there are many white displays on the screen, the white balance is achieved and color management processing is unnecessary.

  149 (a) and 149 (b) are explanatory diagrams of the color management processing method. The duty ratio control is performed in order to average the current consumption of the EL display panel as described above. The color management process is performed by adjusting the reference current Ic. In FIGS. 149 (a) and (b), the R reference current Icr is decreased and the B reference current Icb is increased in a range where the lighting rate is high. Further, the B reference current Icb is adjusted by increasing the lighting rate even in the range of the intermediate level (30% to 60%). With the above processing, the color management processing of the EL display device can be satisfactorily realized.

  In FIG. 150, the RGB reference current Ic is increased in a region where the lighting rate is low. This is to increase the dynamic range of the image at a low lighting rate. The point that the reference current Icb of B is increased in the region where the lighting rate of B is high is color management processing. As described above, the present invention can realize both dynamic image processing and color management processing by reference current control.

  FIG. 151 shows a method of controlling the R reference current Icr to a plurality of levels. As described above, according to the present invention, color management processing can be performed by freely adjusting the reference current.

  FIG. 152 shows a method of controlling the reference current from the RGB lighting rates. However, the color management processing of the EL display panel may be controlled by the ratio of R and B currents (Icr, Icb). FIG. 152 is an explanatory diagram of this embodiment. 149 (a) and (b), the B lighting rate / R lighting rate (B consumption current / R consumption current) is used instead of the lighting rate on the horizontal axis. The B reference current Icr is changed when the B lighting rate / R lighting rate (B consumption current / R consumption current) exceeds a certain level.

  Similarly, FIG. 152 shows B lighting rate / R lighting rate (B consumption current / R consumption current) instead of the lighting rate on the horizontal axis in FIGS. 149 (a) and (b). In FIG. 153, the B reference current Icr is changed when the B lighting rate / (R lighting rate + G lighting rate) (B consumption current / (R consumption current + G lighting rate)) becomes equal to or higher than a certain value.

  Note that the configurations in FIGS. 145 to 148 described above are configurations for adjusting or controlling the current Ic. The output current of the transistor group 431c can be changed by changing the current Ic. Therefore, it goes without saying that this configuration can be used not only for color management processing but also for gradation control, output current control for the transistor 431c, etc., and a white balance adjustment circuit.

  In the above embodiment, the color management process is performed by adjusting the reference current Ic. However, the present invention is not limited to this. The RGB brightness can be individually adjusted by adjusting the duty ratio or changing, controlling, or adjusting the ratio of the non-display area 51 of each RGB. Therefore, it goes without saying that the color management processing may be performed using these configurations or methods.

  The above embodiment is a method or configuration (apparatus) for performing color management mainly because the chromaticity of the RGB EL elements 15 is different from that of NTSC. However, the necessity of color management is required not only by these embodiments but also by the luminous efficiency of the EL element 15.

  FIG. 321 is a graph showing the relationship between the EL current and luminance of the RGB EL elements. As shown in FIG. 321, G has a relationship in which the luminance increases proportionally even when the EL current increases. However, the luminance of R increases more slowly than the EL current I0 (not proportional = light emission efficiency decreases). In B, the increase in luminance becomes moderate when the EL current is I1 or more (not proportional = light emission efficiency decreases).

  From the above, when the EL current is I1 or more, the brightness of B is relatively lowered and white balance cannot be achieved. Furthermore, the luminance of R equal to or higher than I0 is also relatively lowered and white balance cannot be achieved. In order to solve the above problems and maintain the white balance with respect to the change in the EL current, the relationship of the EL current with respect to the gradation is made nonlinear as illustrated in the dotted lines (R ′, B ′) in FIG. There is a need. In FIG. 322, the EL current of R is increased at the gradation K2 or higher (R ′). Further, the EL current of R is increased at the gradation K1 or higher (B ′).

  The above control can be easily realized by changing the RGB reference current according to the gradation. For example, for R, the reference current may be changed as shown in FIG. That is, the reference current ratio of R is increased in inverse proportion to the efficiency of the EL element of 1 to R at gradation K2 or higher. For B, the reference current is changed as shown in FIG. That is, the reference current ratio of B is increased in inverse proportion to the efficiency of the EL elements of 1 to B at the gradation K1 or higher.

  As in the organic EL display panel, the self-luminous device has a problem of image printing at the time of displaying a fixed pattern. Baking refers to a phenomenon in which an organic EL material or the like deteriorates due to light emission or the like, and the light emission intensity decreases. In order to prevent this burn-in, it is advantageous to move the display position of the display image in time when the fixed pattern is displayed. For example, the screen position is moved at 1 minute intervals. The movement is preferably about one pixel or two pixels. With three or more pixels, it is visually recognized that the display image has moved.

  The display image 1264 is moved to a position 193a or a position 193b as shown in FIG. 177. The movement is one pixel or two pixels vertically and horizontally.

  The movement timing is determined by the lighting rate. Screen movement control is performed when the lighting rate changes suddenly. A sudden change in lighting rate means that the screen is dark to bright (for example, a change from a night scene to a daytime sea scene), the screen is bright to dark, or a drama scene to CM. Such as a change of the scene.

  In the state where the lighting rate changes suddenly, the scene (screen) changes suddenly. Since the screen state changes suddenly, it is not visually recognized even if the display position of the image changes. This is because the content of the image (the display state of the image) is almost completely changed. By utilizing this sudden change in the lighting rate, it is possible to change the display position of the image and suppress the burning of the fixed pattern.

  The sudden change in the lighting rate is a case where the change has changed twice or 1/2 or more. For example, if the lighting rate at a certain time is 10%, the lighting rate changes to 20% or more or the lighting rate changes to 5% or less. As described above, when the lighting rate changes, the display position of the screen is changed. The display position on the screen is changed by delaying the horizontal or vertical start pulse by one clock or two clocks. This operation can be realized by changing the comparison value of the counter.

  Note that the time when the lighting rate changes suddenly is synonymous with the time when the anode current or cathode current changes suddenly. Therefore, the sudden change in the lighting rate is a case where the anode current or the cathode current changes twice or 1/2 or more. In this case, the screen position is changed. For example, if the anode current or cathode current is 50 mA, the screen position is changed when the anode current or cathode current changes to 100 mA or more or 25 mA or less.

  In the present invention, the lighting rate, the anode current, or the cathode current is linked with the duty ratio. Therefore, a sudden change in the lighting rate is synonymous with a state in which the duty ratio has changed twice or 1/2 or more. That is, when the duty ratio is changed or changed, the screen position is changed in conjunction with the duty ratio. For example, as shown in FIG. 178, when the duty ratio is changed to 0.5 as shown by an arrow when the lighting rate is 1 to 25% (duty ratio 1.0), the display position of the screen is changed. Let

  In the above embodiment, when the lighting rate or the like changes, the display position of the screen is changed. However, the present invention is not limited to this. For example, when the display panel is turned on (for example, when the power is turned on), the screen display position may be changed from the previous display position. That is, the display position of the screen is changed every time the power is turned on / off.

  It is also effective to blur the edges of the image in order to prevent burn-in. That is, by integrating (low-pass filter) the image data, the edge of the image is blurred (differentiation is the opposite process). In particular, when the lighting rate is low, an image is displayed in black display, and when the lighting rate is low, the duty ratio is lowered, so that the luminance of the pixel is high. Therefore, baking becomes easy. That is, the edge of the image is blurred (integration processing) when the lighting rate is low. That is, according to the present invention, the image integration process is changed according to the lighting rate. When the lighting rate is low, the integration process is increased, and when the lighting rate is high, the integration process is decreased (normal display).

  The above embodiment is illustrated in FIG. An integration processing ratio of 1 is a state where no integration processing is performed. As this ratio increases, integration processing becomes stronger and pixel edges are blurred. In FIG. 179, the normal display is performed when the lighting rate is 50% or more, and the integration processing ratio is changed to 4 to 1 when the lighting rate is 25 to 50%. When the lighting rate is 25% or less, the integration processing ratio is fixed to 4. By controlling as described above, image edge burn-in can be reduced.

  The lighting rate is basically synonymous with the magnitude of the anode current or the cathode current. Therefore, the integration processing ratio may be changed according to the magnitude of the anode current or the cathode current. The anode current or the cathode current is linked with the duty ratio. Therefore, the integration processing ratio may be changed in conjunction with the duty ratio.

  In addition, the screen position is changed in conjunction with the duty ratio. For example, as shown in FIG. 178, when the duty ratio is changed to 0.5 as shown by an arrow when the lighting rate is 1 to 25% (duty ratio 1.0), the display position of the screen is changed. Let

  In the above embodiment, when the lighting rate or the like changes, the display position of the screen is changed. However, the present invention is not limited to this. For example, when the display panel is turned on (for example, when the power is turned on), the screen display position may be changed from the previous display position. That is, the display position of the screen is changed every time the power is turned on / off.

  As shown in FIG. 192, when a wide display such as 16: 9 is performed on a 4: 3 screen, one pixel row or two pixels as shown in FIGS. 192 (a) and 192 (b). You may shift the line. As described above, this control is preferably performed in synchronization with the lighting rate control, the reference current control, the duty ratio control, the anode (cathode) current control, and the on / off control.

  In the present specification, the reference current has been described as being changed. Changing the reference current means changing the program current Iw flowing through the source signal line. Therefore, it goes without saying that changing or controlling or adjusting the reference current can be replaced by changing, controlling or adjusting the program current Iw flowing through the source signal line 18.

  Note that the present invention changes, adjusts, or changes the current output from the terminal 155 of the source driver circuit 14 proportionally, at a constant rate, or while maintaining a predetermined relationship by changing the reference current. Or it can be controlled.

  In the driving method of the present invention, the program current Iw and the current Ie flowing through the EL element 15 are substantially the same. Accordingly, it goes without saying that changing or controlling or adjusting the reference current can be replaced by changing or controlling or adjusting the current Ie (Iw) flowing through the driving transistor or EL element 15. However, in the pixel configuration shown in FIGS. 31 and 36, the currents Ie and Iw flowing through the EL element 15 do not match. However, changing, controlling, or adjusting the reference current can be said to change, control, or adjust the program current Iw that flows through the source signal line 18. The current that flows through the EL element 15 can be varied, controlled, or adjusted approximately proportionally. Needless to say, it can be replaced.

  In addition, as described with reference to FIGS. 128, 129, 130, etc., changing the reference current means changing the potential of the source signal line 18. For example, when the reference current is increased, the program current Iw is increased proportionally (correlated), and the potential of the source signal line 18 is decreased (when the driving transistor is a P channel). On the contrary, when the reference current is reduced, the program current Iw is reduced proportionally (correlatedly), and the potential of the source signal line 18 is increased (when the driving transistor is a P channel). Therefore, the reference current can be varied, controlled, or adjusted when the potential of the source signal line 18 can be changed, adjusted, varied, or controlled proportionally, at a constant rate, or while maintaining a predetermined relationship. Can be replaced.

  In the driving method of the present invention described with reference to FIGS. 271 to 276, a plurality of pixel rows are simultaneously selected, and the program current Iw is divided into the selected pixel rows and applied (averaged). For example, if four pixel rows are simultaneously selected and the program current is Iw, the program current Ip written to one pixel row is ideally Iw / 4. If two pixel rows are selected simultaneously and the program current is Iw, the program current Ip written to one pixel row is ideally Iw / 2.

  When driven as described above, the program current Ip divided by the selected number of pixels is written in one pixel row. Therefore, the display luminance of the pixel 16 is one for the divided pixel rows. Therefore, the display brightness is dark. In order to prevent this, the reference current may be increased. For example, as shown in FIG. 171, when two pixel rows are simultaneously selected, the luminance is not lowered by doubling the reference current. In other words, the driving method of the present invention is to drive by increasing the reference current by the number of selected pixels.

  Note that the reference current to be increased need not be double the number of pixels selected completely. According to the evaluation result, when the number of selected pixels is N and the magnification of the reference current to be increased is C, N · C may be controlled to 0.8 or more and 1.2 or less. Within this range, flicker or the like does not occur and a good image display can be realized.

  The present invention is not limited to the above embodiments. The number of pixel rows to be selected (number of selection signal lines: vertical axes in FIGS. 277 (a) and (b) to 279 (a) and 279) may be changed depending on the lighting rate. In FIGS. 277 (a) and (b), the number of selection signal lines (number of pixel rows) is 2 pixel rows when the lighting rate is 25% or less (the driving method of FIG. 271), and the selection signal lines are used when the lighting rate is 25% or more. The number (number of pixel rows) is one pixel row (the driving method in FIG. 23 is used). Further, when the lighting rate is 25% or less, the reference current (reference current ratio) is also doubled (with respect to a range where the lighting rate is 25% or more) so that the luminance of the pixel 16 does not decrease.

  As described above, the number of pixel rows to be selected is changed according to the lighting rate, and the reference current ratio is changed because the black display region is large on the screen 144 in the low lighting rate region and crosstalk is easily noticeable. It is. Crosstalk is eliminated as the program current Iw is increased. The program current Iw is proportional to the magnitude of the reference current Ic. Therefore, by increasing the reference current Ic (reference current ratio), the program current Iw increases and crosstalk is eliminated. However, as the program current Iw increases, the luminance of the pixel also increases in proportion. In order to solve this problem, the driving method described with reference to FIG. 271 is performed to increase the number of selections, and the programming current Iw is set to 1 Ip for the selected pixel row, thereby preventing the luminance from increasing.

  In FIGS. 277 (a) and (b), the lighting rate is 25% or less, the number of selection signal lines (number of pixel rows) is two pixel rows, and the reference current ratio is doubled. Therefore, the luminance of the pixel 16 is the same as when the number of selection signal lines (number of pixel rows) is one pixel row and the reference current ratio is one. When the lighting rate is 25% or more, the driving method is the same as that in FIG. 23, the number of selection signal lines (number of pixel rows) is one pixel row, and the reference current (reference current ratio) is also one.

  The present invention is not limited to this. You may drive like FIG. 278 (a) (b). 278 (a) and 278 (b), the lighting rate is 25% or less, the number of selection signal lines (number of pixel rows) is two pixel rows, and the reference current ratio is four times. Therefore, the luminance of the pixel 16 is twice that of the prior art. However, since the reference current ratio is four times, the occurrence of crosstalk can be completely prevented. In order to suppress the luminance from doubling, the duty ratio may be halved in an area where the lighting rate is 25% or less. That is, the selection signal line number (pixel row number), the reference current ratio, and the duty ratio may be linked.

  In FIGS. 278 (a) and 278 (b), when the lighting rate is 25% or more and 75% or less, the number of selection signal lines (number of pixel rows) is one pixel row and the reference current ratio is doubled. Therefore, the luminance of the pixel 16 is twice that of the prior art. In order to suppress the luminance from doubling, the duty ratio may be halved. Similarly, when the lighting rate is 75% or more, the number of selection signal lines (number of pixel rows) is one pixel row, and the reference current ratio is 1 time. Therefore, the luminance of the pixel 16 is the same as that of the prior art when the duty ratio is 1/1. In this lighting rate region and the like, by setting the duty ratio to less than 1/1, the luminance of the screen 144 can be suppressed and the power consumption of the panel can be suppressed.

  279 (a) and 279 (b) show another embodiment of the present invention. 279 (a) and 279 (b), the lighting rate is 25% or less, the number of selection signal lines (number of pixel rows) is four pixel rows, and the reference current ratio is quadrupled. Therefore, the luminance of the pixel 16 is the same as the conventional one. Since the reference current ratio is four times, the occurrence of crosstalk can be completely prevented. When the lighting rate is 25% or more and 50% or less, the number of selection signal lines (number of pixel rows) is two pixel rows, and the reference current ratio is doubled. Therefore, the luminance of the pixel 16 is the same as the conventional one. When the lighting rate is 50% to 75%, the number of selection signal lines (number of pixel rows) is one pixel row, and the reference current ratio is doubled. Therefore, the luminance of the pixel 16 is twice that of the conventional one. When the lighting rate is 75% or more, the number of selection signal lines (number of pixel rows) is one pixel row, and the reference current ratio is one. Therefore, the luminance of the pixel 16 is the same as the conventional one.

  As described above, the driving method of the present invention controls the number of selected signal lines (number of pixel rows), the reference current ratio, the duty ratio, or a combination thereof to suppress the occurrence of crosstalk. is there.

  As described above, it is described that the reference current is changed based on the lighting rate. However, the program current Iw flowing through the source signal line is changed based on the lighting rate, and the source signal line 18 is changed. The program current Iw flowing through the circuit is variable, controlled, or adjusted. In addition, the current output from the terminal 155 of the source driver circuit 14 is changed, adjusted, changed, or controlled proportionally, at a constant rate, or in a state where a predetermined relationship is maintained. Also, based on the lighting rate or data sum, the potential of the source signal line 18 or the gate terminal potential of the driving transistor is changed or adjusted proportionally, at a constant rate, or in a state where a predetermined relationship is maintained. Or it can be variable or controlled.

Needless to say, based on the lighting rate, it can be replaced based on the data sum of video signals. In particular, in the case of current drive, the magnitude of the video signal is proportional to the current flowing through the pixel 16. The lighting rate is proportional to or correlated with the current flowing through the anode terminal (cathode terminal). Therefore, it goes without saying that the replacement based on the lighting rate can be based on the magnitude of the current flowing through the anode terminal (cathode terminal).
The present invention flows to the first FRC or the lighting rate or the anode (cathode) terminal in the first lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal). The current, the reference current, the duty ratio, the panel temperature, or the like is changed. Further, in the second lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the current flowing through the second FRC, the lighting rate, or the anode (cathode) terminal. Alternatively, it is changed as a reference current, a duty ratio, a panel temperature, or a combination thereof. Or, depending on the lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal) (adapted), it flows to the FRC or the lighting rate or the anode (cathode) terminal. The current, the reference current, the duty ratio, the panel temperature, or the like or a combination thereof is changed. It goes without saying that the above matters can be applied to other embodiments of the present invention.

  Hereinafter, an EL display panel or an EL display device of the present invention or a device using the driving method thereof will be described. The following apparatus implements the previously described apparatus or method of the present invention. FIG. 126 is a plan view of a mobile phone as an example of an information terminal device. An antenna 1261, a numeric keypad 1262, and the like are attached to the housing 1263. 1262 and the like are display color switching keys, power on / off, and frame rate switching keys.

  When the key 1262 is pressed once, the display color is set to the 8-color mode, then when the same key 1262 is pressed, the display color is set to the 4096 color mode, and when the key 1262 is pressed, the display color is set to the 260,000 color mode. But you can. The key is a toggle switch that changes the display color mode each time it is pressed. In addition, you may provide the change key with respect to a display color separately. In this case, there are three (or more) keys 1262.

  The key 1262 may be a push switch, a mechanical switch such as a slide switch, or may be switched by voice recognition or the like. For example, when 4096 colors are input to the receiver by voice input, for example, “high quality display”, “4096 color mode” or “low display color mode” is input to the receiver, the display screen 144 of the display panel is displayed. The display color is changed. This can be easily realized by adopting the current speech recognition technology.

  Further, the display color may be switched electrically, or a touch panel that is selected by touching a menu displayed on the display unit 144 of the display panel. Further, it may be configured to be switched by the number of times the switch is pressed, or to be switched by rotation or direction like a click ball.

  Although 1262 is a display color switching key, it may be a key for switching the frame rate. Moreover, it is good also as a key etc. which switch a moving image and a still image. A plurality of requirements such as a moving image, a still image, and a frame rate may be switched at the same time. Alternatively, the frame rate may be changed gradually (continuously) as long as the pressure is kept pressed. This case can be realized by making the resistor R of the capacitor C and the resistor R constituting the oscillator a variable resistor or an electronic volume. The capacitor can be realized by using a trimmer capacitor. Alternatively, a plurality of capacitors may be formed on the semiconductor chip, one or more capacitors may be selected, and these may be connected in parallel in a circuit.

  An important function of the display panel is that images of a plurality of formats can be displayed. For example, a digital video camera (DVC) needs to be able to display NTSC and PAL images. Hereinafter, a method for displaying images of a plurality of formats on one panel will be described. For ease of explanation, it is assumed that the display panel is a QVGA panel of horizontal 320 RGB × vertical 240 dots, and an NTSC image and a PAL image are displayed on the panel having the number of pixels of QVGA.

  FIG. 154 is a cross-sectional view of the viewfinder in the embodiment of the present invention. However, it is schematically drawn for easy explanation. In addition, there are parts that are partially enlarged or reduced, and some parts are omitted. For example, in FIG. 154, the eyepiece cover is omitted. The above also applies to other drawings.

  The back surface of the body 1263 is dark or black. This is because stray light emitted from the EL display panel (display device) 1264 is diffusely reflected on the inner surface of the body 1263 to prevent a decrease in display contrast. Further, a phase plate (λ / 4 plate or the like) 38, a polarizing plate 39, or the like is disposed on the light emission side of the display panel. This is also explained in FIG. 3 and FIG.

  A magnifying lens 1542 is attached to the eyepiece ring 1541. The observer adjusts the eyepiece ring 1541 so that the display screen 144 of the display panel 1264 is in focus by changing the insertion position of the eyepiece ring 1541 in the body 1263.

  Further, if the positive lens 1543 is disposed on the light exit side of the display panel 1264 as necessary, the principal ray incident on the magnifying lens 1542 can be converged. Therefore, the lens diameter of the magnifying lens 1542 can be reduced, and the viewfinder can be downsized.

  FIG. 155 is a perspective view of the video camera. The video camera includes a photographing (imaging) lens unit 1552 and a video camera main body 1263, and the photographing lens unit 1552 and the viewfinder unit 1263 are back to back. An eyepiece cover is attached to the viewfinder (see also FIG. 154) 1263. An observer (user) observes the display screen 144 of the display panel 1264 from the eyepiece cover portion.

  On the other hand, the EL display panel of the present invention is also used as a display monitor. The display portion 144 can freely adjust the angle at a fulcrum 1551. When the display unit 144 is not used, it is stored in the storage unit 1553.

  The switch 1554 is a changeover or control switch that performs the following functions. A switch 1554 is a display mode switching switch. The switch 1554 is preferably attached to a mobile phone or the like. The display mode changeover switch 1554 will be described.

  As one of the driving methods of the present invention, there is a method in which an N-fold current is supplied to the EL element 15 to light it for a period of 1 / M of 1F. The brightness can be changed digitally by changing the lighting period. For example, assuming that N = 4, a current that is four times as large as the EL element 15 is passed. If the lighting period is set to 1 / M and M = 1, 2, 3, and 4 are switched, the brightness can be switched from 1 to 4 times. In addition, you may comprise so that it can change with M = 1, 1.5, 2, 3, 4, 5, 6, etc.

  The above switching operation is configured to display the display screen 144 very brightly when a power source of a mobile phone, a monitor, etc. is turned on, and to reduce the display brightness in order to save power after a certain period of time. Used for. It can also be used as a function for setting the brightness desired by the user. For example, when outdoors, the screen is very bright. This is because the surroundings are bright outdoors and the screen cannot be seen at all. However, if the display is continued with high luminance, the EL element 15 deteriorates rapidly. For this reason, when it is very bright, it is configured to return to normal luminance in a short time. Further, in the case of displaying with high brightness, the display brightness can be increased by the user pressing the button.

  Therefore, it is preferable that the user can be switched with the button 1554, can be automatically changed in the setting mode, or can be automatically switched by detecting the brightness of external light. Further, it is preferable that the display brightness is set to 50%, 60%, and 80% and can be set by the user.

  The display screen 144 is preferably a Gaussian distribution display. The Gaussian distribution display is a method in which the brightness at the center is bright and the periphery is relatively dark. Visually, if the central part is bright, it is felt bright even if the peripheral part is dark. According to the subjective evaluation, if the peripheral part keeps 70% of brightness compared to the central part, it is visually inferior. Even if the brightness is further reduced to 50% luminance, there is almost no problem. In the self-luminous display panel of the present invention, the above-described N-fold pulse driving (a method in which an N-fold current is supplied to the EL element 15 and the light is lit for 1 / M of 1F) is used from the top to the bottom of the screen. A Gaussian distribution is generated in the direction.

  Specifically, the value of M is increased at the top and bottom of the screen, and the value of M is decreased at the center. This is realized by modulating the operation speed of the shift register of the gate driver circuit 12 or the like. The left and right brightness modulation of the screen is generated by multiplying the table data and the video data. With the above operation, when the peripheral luminance (angle of view 0.9) is 50%, the power consumption can be reduced by about 20% compared to the case of 100% luminance. When the peripheral luminance (angle of view 0.9) is 70%, the power consumption can be reduced by about 15% compared to the case of 100% luminance.

  It is preferable to provide a changeover switch or the like so that the Gaussian distribution display can be turned on and off. This is because, for example, when the Gaussian display is used outdoors, the periphery of the screen cannot be seen at all. Therefore, it is preferable that the user can be switched with a button, can be automatically changed in a setting mode, or can be switched automatically by detecting the brightness of external light. In addition, it is preferable that the peripheral brightness is set to 50%, 60%, and 80% so that the user can set it.

  In a liquid crystal display panel, a fixed Gaussian distribution is generated by a backlight. Therefore, the Gaussian distribution cannot be turned on / off. The fact that the Gaussian distribution can be turned on / off is an effect peculiar to a self-luminous display device.

  As described with reference to FIG. 3, the cathode electrode 36 is formed or constituted by a thin film made of aluminum. A thin film made of aluminum has specularity and high reflectivity, so that it can be used as a mirror. Therefore, the front surface of the EL display panel can be used for image display as the screen 144, and the back surface can be used as a mirror. However, the desiccant 37 is disposed in the periphery of the use region so as not to shield the mirror surface from the cathode 36.

  FIG. 325 is a cross-sectional view of the display device of the present invention. FIG. 325 shows a display device of the present invention configured so that the surface can be used as an image display screen 144 (viewed from the B direction) and used as a mirror when viewed from the A direction. The display panel 1264 is configured to be rotatable at a fulcrum 1551. Therefore, depending on the holding angle of the panel 1264, it can be easily used as a mirror or as a monitor.

  FIG. 326 shows a second embodiment of a display device that can be used as a mirror or a monitor. FIG. 326 (a) shows a state where the EL display panel is used as a monitor, and FIG. 326 (c) shows a state where the EL display panel is used as a mirror. FIG. 326 (b) shows a change state from the monitor use state to the mirror use state or from the mirror use state to the monitor use state.

  In FIG. 326 (a), the panel 1264 is stored in the storage unit 1561 of the panel 1264. When used as a mirror, as shown in FIG. 326 (b), the panel 1264 is taken out of the storage portion 1561, rotated at a fulcrum 1551, and the panel 1264 is turned upside down. Thereafter, the display panel 1264 is stored in the storage unit 1564 with the mirror surface (cathode 36 surface) facing upward (FIG. 326 (c)). When used as a monitor, as shown in FIG. 326 (b), the panel 1264 is taken out of the storage portion 1561 and rotated around a fulcrum 1551 so that the front and back of the panel 1264 are turned over. Thereafter, the image is stored in the storage portion 1564 with the pixel electrode 35 of the display panel 1264 facing upward (FIG. 326 (a)). The above embodiment is a case where light is extracted from the B direction as shown in FIG. Needless to say, when the light is extracted from the A side as shown in FIG.

  When the frame rate is predetermined, flicker may occur due to interference with the lighting state of an indoor fluorescent lamp or the like. That is, when the fluorescent lamp is lit at an alternating current of 60 Hz, if the EL display element 15 operates at a frame rate of 60 Hz, a slight interference occurs and the screen feels slowly blinking. There is. To avoid this, change the frame rate. The present invention adds a frame rate changing function. Further, the N or M value can be changed in N-fold pulse driving (a method in which an N-fold current is supplied to the EL element 15 and lighted only for a period of 1 / M of 1F) (FIG. 23). (See also FIGS. 54A to 54C).

  Further, as shown in FIG. 317, it is preferable that the number of screen divisions can be varied in accordance with the frame rate. When the frame rate is low, as shown in FIG. 54C, the number of divisions (the non-lighting area 192 is divided into a plurality of parts to configure the screen 144) is increased. When the frame rate is high, as shown in FIG. 54A, the non-lighting area 192 is inserted into the screen 144 in a lump.

  For example, the transmission frame rate of a terrestrial digital mobile television is 15 Hz. At this time, since the frame rate is low, it is necessary to divide the non-lighting area 192 into a plurality of parts as shown in FIG. However, the transmission frame rate of the current terrestrial analog television is 60 Hz. At this time, since the frame rate is high, it is preferable to insert a non-lighting area 192 at a time as shown in FIG. That is, the number of divisions is changed or varied depending on the application or the received signal.

  In FIG. 317, the division number is 1 (one non-display area 192 (state shown in FIG. 54A)) at a frame rate of 60 to 45 Hz. In this embodiment, the number of divisions is 10 (the non-display area 192 has 10 states) at a frame rate of 45 or less. In addition to the frame rate, the number of divisions depends on the surrounding brightness (brightness), image content (still images, moving images, etc.), device usage (mobile, stationary, etc.), etc. It is preferable to be configured so that it can be changed, changed or set to be programmable. Needless to say, the above matters also apply to other embodiments of the present invention.

  The above functions can be realized by the switch 1554. The switch 1554 switches and realizes the functions described above by holding down a plurality of times according to the menu of the display screen 144.

  Needless to say, the above items are not limited to mobile phones but can be used for televisions, monitors, and the like. In addition, it is preferable to display an icon on the display screen so that the user can immediately recognize the display state. The above matters are the same for the following items.

  The EL display device and the like of this embodiment can be applied not only to a video camera but also to an electronic camera, a still camera, or the like as shown in FIG. The display device is used as a monitor 144 attached to the camera body 1561. In addition to the shutter 1563, a switch 1554 is attached to the camera body 1561.

  The above is the case where the display area of the display panel is relatively small, but the display screen 144 tends to bend when the display area is larger than 30 inches. As a countermeasure, in the present invention, as shown in FIG. 157, an outer frame 1571 is attached to the display panel, and the outer frame 1571 is attached by a fixing member 1574 so that it can be suspended. The fixing member 1574 is used to attach to a wall or the like.

  However, as the screen size of the display panel increases, the weight increases. Therefore, a leg attachment portion 1573 is disposed on the lower side of the display panel so that the plurality of legs 1572 can hold the weight of the display panel.

  The leg 1572 can move left and right as shown in A, and the leg 1572 can be contracted as shown in B. Therefore, the display device can be easily installed even in a narrow place.

  In the television shown in FIG. 157, the surface of the screen is covered with a protective film (or a protective plate). This is for the purpose of preventing an object from hitting the surface of the display panel and damaging it. An AIR coat is formed on the surface of the protective film, and the surface is embossed to prevent external conditions (external light) from appearing on the display panel.

  A certain space is arranged by spreading beads or the like between the protective film and the display panel. Moreover, a fine convex part is formed in the back surface of a protective film, and space is hold | maintained between a display panel and a protective film with this convex part. By holding the space in this way, the impact from the protective film is suppressed from being transmitted to the display panel.

  It is also effective to place or inject an optical binder such as a liquid such as alcohol or ethylene glycol or a solid resin such as an epoxy resin between the protective film and the display panel. This is because interface reflection can be prevented and the optical binder functions as a buffer material.

  Examples of the protective film include a polycarbonate film (plate), a polypropylene film (plate), an acrylic film (plate), a polyester film (plate), and a PVA film (plate). Needless to say, other engineering resin films (ABS and the like) can be used. Moreover, what consists of inorganic materials, such as tempered glass, may be used. The same effect can be obtained by coating the surface of the display panel with an epoxy resin, a phenol resin, or an acrylic resin with a thickness of 0.5 mm or more and 2.0 mm or less instead of disposing the protective film. It is also effective to emboss the surface of these resins.

  It is also effective to coat the surface of the protective film or coating material with fluorine. This is because the dirt on the surface can be easily wiped off with a detergent or the like. Further, the protective film may be formed thick and may also be used as a front light.

  When the display panel becomes large, the parasitic capacitance of the source signal line 18 also increases. Therefore, current programming tends to be difficult. To solve this problem, the source driver circuit 12 is arranged above and below the screen 144 as shown in FIG. The number of source signal lines 18 is also doubled (18a, 18b). With the above configuration, the source driver IC (circuit) 14a applies the program current to the odd pixel rows, and the source driver IC (circuit) 14b applies the program current to the even pixel rows. it can. Therefore, in the past, one pixel was selected and the program current was applied for a period of 1H. However, in the configuration of FIG. 264, two pixel rows can be simultaneously selected and the program current can be applied. The period during which the program current Iw can be applied to the row can be a 2H period. Therefore, a sufficient program current writing period can be ensured, and a good current program can be realized even when the panel size is increased. Needless to say, the above items can also be applied to the voltage programming method.

  Even when driving as shown in FIG. 264, the duty ratio control of the present invention can be applied. For example, in FIG. 265, the gate driver circuit 12a on the pixel writing side selects two gate signal lines 17a, and scans the selected position two by two. On the other hand, the gate driver circuit 12b on the EL selection side sequentially selects one pixel row (that is, sequentially selects one gate signal line 17b). Therefore, the current program side selects the plurality of gate signal lines 17a to execute the current program, and the duty control side controls the single gate signal line 17b as in the conventional case to realize the duty ratio control. Needless to say, the above items can also be applied to the reference current ratio control.

  When the display panel displays a 4: 3 screen on the 16: 9 wide type screen 144, the 4: 3 screen 144a is displayed at the end of the 16: 9 screen as shown in FIG. 270 (a). The remaining screen 144b displays an OSD (On Screen Display). The display 144b on the on-screen display and the display on the screen 144a are preferably combined in advance as a video signal.

  Further, as shown in FIG. 270 (b), a 4: 3 screen 144a is displayed at the center of the 16: 9 screen. The remaining screens 144b1 and 144b2 display an OSD (On Screen Display). The display 144b on the on-screen display and the display on the screen 144a are preferably combined in advance as a video signal.

  As shown in FIG. 327, the controller IC (circuit) 760 controls the power supply module 3272, the source driver circuit (IC) 14 and the like arranged or configured in the panel module. Note that the configuration and operation of the power supply module 3272 have been described with reference to FIGS. 119, 120, 121, 122, 123, 124, 125, 251, 252, 263, 268, 280, and the like. Therefore, explanation is omitted. Further, since the configuration and operation of the panel and the like have been described before, the description thereof is omitted.

  The power supply module 3272 is supplied with power from the lithium battery 3271. The power supply module 3272 generates a Vgh voltage, a Vgl voltage, a Vdd voltage, a Vss voltage, and the like (hereinafter, these voltages are referred to as panel voltages). The panel voltage generation timing is controlled by an ON / OFF signal from the controller 760. On the other hand, power for the control circuit 760 is supplied from the main circuit. Therefore, the device having the display device of the present invention operates by first supplying a power supply voltage to the control IC 760. After the control IC 760 is started, the power supply module 3272 generates a panel voltage by an ON / OFF signal from the control IC 760. To do. The generated panel voltage is applied as the Vdd and Vss voltages of the gate driver circuit 12, the source driver circuit 14, and the panel. By configuring as described above, the number of wires between the main circuit and the panel module can be reduced.

  The device of the present invention has at least a controller 760 and a battery 3271 in the main circuit. Therefore, the panel module and the main circuit control on / off control of two differential signal lines for transmitting RGB video signals, two Vcc and GND lines for supplying the voltage of the panel module 3272, and the power supply module 3272. There are a total of 5 (or more) signal lines.

  FIG. 367 is a modification of FIG. The control IC 760 includes a PLL circuit 3611a and synchronizes differential signals. Red, green and blue (RGB) and RGBD as control data (D) are transmitted as a differential signal through a pair of pair signal lines (see FIGS. 80 to 82, 292, 327 to 331, etc.). . Similarly, the sync signal of the RGBD signal is transmitted as a CLK differential signal through a pair of pair signal lines. Further, in order to indicate the start (the first position of one set) in the RGBD signal, the St signal of the differential signal is transmitted through a pair of pair signal lines. The St signal need not be a differential signal, and may be transmitted as a CMOS or TTL logic signal.

  Power is applied to the power supply circuit 3271 from a battery (not shown) through two lines of GND with the Vcc voltage, and an on / off signal (ON / OFF) of the power supply circuit 3271 is applied from the controller IC 760.

  Although FIG. 367 is configured to transmit RGBD as a pair of differential signals, the present invention is not limited to this, and red video data (RDATA) is transmitted as a pair as shown in FIG. A differential signal may be used, green video data (GDATA) may be a pair of differential signals, and blue video data (BDATA) may be a pair of differential signals.

  As shown in FIG. 371, CLK synchronized with DATA (RDATA, GDATA, etc.) is set to have the same frequency. That is, the DATA contents are identified by the rising edge and falling edge of CLK. By maintaining such a relationship between DATA and CLK, the frequency is made steady and unnecessary radiation is reduced.

  FIG. 357 describes the relationship with the St signal in addition to FIG. CLK, ST, RGB (RGBD) of the video signal (see FIGS. 80 to 82, 292, 327 to 331, etc.) are also transmitted (transmitted) with the amplitude of the Diff voltage centered on 0 V (GND). Is done. Note that the Diff voltage as the amplitude is set, variable, or adjusted by the circuit configurations of FIGS. 368 to 370.

  As shown in FIG. 357, CLK that synchronizes with RGB as the video signal has the same frequency. That is, the DATA contents are identified by the rising edge and falling edge of CLK. By maintaining such a relationship between DATA and CLK, the frequency is made steady and unnecessary radiation is reduced. On the other hand, the St signal has twice the width of CLK and is detected at the rising or falling edge of CLK. The phase of CLK is controlled by the PLL circuit 3611. As described above, the differential signal is transmitted and transmitted / received.

  A characteristic feature of the differential signal or signal transmission of the present invention is that it has a precharge judgment bit in addition to the RGB video signal. This has been described with reference to FIGS. Therefore, as shown in FIG. 359, R, G, B data has a precharge bit (Pr).

  FIG. 359 (a) shows a case where the video data is 10 bits. In addition to 10 bits (D9 to D0) of the video data, there is a precharge bit (Rr). The most significant bit has a D / C bit for identifying whether it is a command or video data. When the D / C bit is 1, it indicates that the following data area bits are commands. The command is normally transmitted in the horizontal blanking period or the vertical blanking period. Since this command has been described with reference to FIGS. 329 and 331, the description thereof will be omitted. When the D / C bit is 0, it indicates video data, and video data (8 bits or 10 bits) and a precharge voltage (program voltage) judgment bit (Pr) are transmitted as data.

  FIG. 359 (b) shows the case of 8 bits (D7 to D0) of video data. Similar to FIG. 359 (a), there is a precharge bit (Rr) in addition to the video data. Further, it is the same as FIG. 359 (a) in that the most significant bit has a D / C bit for identifying whether it is a command or video data. When the D / C bit is 0, it indicates video data, and video data (8 bits) and a judgment bit (Pr) of a precharge voltage (program voltage) are transmitted as data.

  The data of FIG. 359 is transmitted in synchronization with the CLK of FIG. In addition, the ST signal is transmitted in a cycle of RGB video data corresponding to one pixel or RGB video data corresponding to one pixel + control data D.

  FIG. 364 shows an embodiment in which an ST signal is transmitted with R pixel Pr bit + R video data, G pixel Pr bit + G video data, B pixel Pr bit + B video data, and control data as one set.

  FIG. 365 shows an embodiment in which an ST signal is transmitted for each 11-bit control data. The control data is composed of 2-bit address data (A1, A2), precharge bit (Pr), and 8-bit data (D7 to D0). When the address data (A1, A2) A (1: 0) is 0, the data (7: 0) is control data (the description is omitted because it is described in FIG. 329, FIG. 331, etc.). Indicates that there is. Further, when A (1: 0) is 1, it indicates that the data (7: 0) is R video data. When A (1: 0) is 2, it indicates that the data (7: 0) is G video data. When A (1: 0) is 3, it indicates that the data (7: 0) is B video data. Needless to say, the Pr bit may be transmitted as part of control data or video data.

  FIG. 366 is similar to FIG. FIG. 366 (b) shows a configuration in which video data (including precharge bits) RGB is transmitted as R, G, B, R, G, B, R, G, B,. FIG. 366 (a) shows a configuration for transmitting the control data D as necessary. Therefore, when the image data is transmitted just during the image transmission period as shown in FIG. 366 (b), the control data is inserted as shown in FIG. Will be transmitted. However, the transmission efficiency of FIG. 366 (a) is high because it is not necessary to secure the control data period in advance as in FIG. 364 and the horizontal blanking period is effectively used.

  FIG. 362 shows a method in which video data is bit-expanded and transmitted (in FIG. 364 and the like, video data is transmitted in units of one pixel). In FIG. 362, as indicated by the data start position A, the R precharge bit PrR, the G precharge bit PrG, the B precharge bit PrB, the seventh bit (most significant bit) of the R video data, G 7th bit (most significant bit) of B video data, 7th bit (most significant bit) of B video data, 6th bit of R video data, 6th bit of G video data, B video data 6th bit, 5th bit of R video data, 5th bit of G video data, 5th bit of B video data, ... 0th bit of R video data (most The lower bit), the 0th bit (the least significant bit) of the G video data, the 0th bit (the least significant bit) of the B video data, the R precharge bit PrR of the next pixel, the G precharge bit PrG, B 7th bit (most significant bit) of video data of charge bits PrB and R, 7th bit (most significant bit) of G video data, 7th bit (most significant bit) of B video data, ... ... and transmitted.

  FIG. 363 shows a system in which video data is sequentially transmitted as control data D and image data. The RGB precharge bit Pr, image data, and control data are transmitted. First, R Pr and 8-bit image data (R (7: 0)), G Pr and 8-bit image data (G (7: 0)), B Pr and 8-bit image data (B ( 7: 0)) and control data D (9: 0) as one cycle. Next, R Pr of the next pixel and 8-bit image data (R (7: 0)), G Pr and 8-bit image data (G (7: 0)), B Pr and 8-bit image data Image data (B (7: 0)) and control data D (9: 0) are transmitted as one cycle.

  As described above, the present invention has various embodiments. The common point is that Pr data is transmitted. Needless to say, the Pr data may be included as a bit in the control command.

  In the embodiments shown in FIGS. 367 and 361, the PLL circuit 3611 is arranged or configured on the differential signal transmission side. However, the present invention is not limited to this. As shown in FIG. 360, a PLL circuit 3611b may be arranged or formed also on the receiving side (source driver circuit (IC) 14 in FIG. 360). If PLL circuits 3611 are arranged on the transmission side and the reception side, and the number of DATA cycles (number of sets) as a differential signal is set on the transmission / reception side, high-speed differential signal data can be obtained with fewer signal lines. Can be transmitted.

  In FIG. 360, the PLL 3611b oscillates the number of data within one cycle of the differential signal DATA using the CLK indicating the DATA cycle (start position), decodes the DATA as the differential signal, and converts it into a parallel signal. To do.

  In the present invention, it is fair that the impedance can be changed or adjusted on the transmission side and the reception side of the differential signal. As the amplitude of the differential signal increases, the transmission distance can be increased. However, the transmission power increases when the amplitude is large. When a differential signal is output at a constant current, the amplitude can be increased by increasing the impedance when receiving the differential signal. Therefore, it is possible to receive a differential signal even if the current to be transmitted is small. However, it is vulnerable to noise.

  From the above, it is preferable that the differential signal amplitude and impedance can be set or adjusted from the distance for transmitting the differential signal and the power required for transmission. FIG. 368 to FIG. 370 are examples thereof.

  FIG. 368 shows a circuit configuration of the differential signal receiving side. The source driver circuit (IC) 14 has an impedance setting circuit 3682. The impedance setting circuit 3682 is composed of R (R1, R2, R3, R4 in FIG. 368) having different resistance values (impedance values) and a switch S (S1, S2, S3, S4 in FIG. 368) for selecting R. Yes. One or more switches S are turned on by the signal or voltage applied to the signal input terminal RSEL of the source driver circuit (IC) 14, and the resistor R is selected. The selected resistor R is connected to the differential signal input terminal 2883.

  In the present invention, a constant current is passed through the differential signal wiring. Therefore, the amplitude value of the differential signal generated between the terminals 2883a and 2883b can be changed by the value of the resistor R. That is, the amplitude of the differential signal can be adjusted according to the transmission distance.

  FIG. 369 shows another embodiment. The built-in resistor Rx is configured to be variable. The electronic volume 501 etc. which were demonstrated previously are illustrated as a structure which performs variable. In addition, it can also be adjusted by trimming.

  FIG. 370 is a configuration example on the transmission side. A variable voltage source or a fixed voltage is input between the terminals 2884c and 2884d. The current output of the constant current circuit in the controller 760 can be changed by the voltage input to the terminals 2884c and 2884d. By this operation, the current of the differential signal output from the terminals 2884a and 2884b can be changed.

  As shown in FIG. 328, the differential signal is output in synchronization with H and L of the A signal (discrimination signal) of the main circuit. When the A signal is L, the program voltage (VR, VG, VB) is output, and when the A signal is H, the program current (IR, IG, IB) is output. Note that the program voltage, program current output operation, and the like are described in FIGS.

  In addition, program currents (IR, IG, IB) and program voltages (VR, VG, VB) as data signals and data signals DM, DS are transmitted. That is, the differential signal is multiplexed in four phases of R video signal, G video signal, B video signal, and D data signal (VR, IR, VG, IG, VB, IB, DM, DS, VR, IR,・ ・ ・ ・ ・ ・). It should be noted that during the video blanking period, DM and DS signals are continuously transmitted as shown in FIG.

  The 8 or 10 bit data of DM which is data is a command. The 8-bit or 10-bit data of DS, which is data, is control data. FIG. 329 is an example of DM. DM represents a horizontal synchronizing signal (HD), a vertical synchronizing signal (VD), or the like. As an example, DM = 1 is an HD signal. When DM = 2, it is a VD signal. DM = 3 is a UD signal that inverts the image on the screen. DM = 4 is an RL signal that inverts the left and right of the video on the screen 144.

  Similarly, DM = 5 indicates the R precharge time (PR-time), DM = 6 indicates the G precharge time (PG-time), and DM = 7 indicates the B precharge time ( PB-time). DM = 8 indicates an R reference current (reference IR), DM = 9 indicates an R reference current (reference IG), and DM = 10 indicates an R reference current (reference IB). ). DM = 10 indicates the output timing of the gate driver circuit 12 such as a start pulse. As described above, DM is data specified as a command.

  FIG. 331 shows an example of the contents of the DS signal. When DM = 9, it is a control signal for the gate driver circuit 12. The 8 bits of DS are ex. As shown in FIG. 1, the arrangement of each bit is determined. bit0 is an enable signal (ENBL1) of the gate driver circuit 12a. bit1 is a clock signal (CLK1) of the gate driver circuit 12a. Bit2 is a start signal (ST1) of the gate driver circuit 12a. Bit4 is an enable signal (ENBL2) for the gate driver circuit 12b. Bit5 is a clock signal (CLK2) of the gate driver circuit 12b. Bit 6 is a start signal (ST2) of the gate driver circuit 12b. In addition, ex. As shown in FIG. 3, when DM = 8, the DS signal indicates the magnitude of the R reference current as data. As described above, DS is data designated by DM.

  It goes without saying that the display panel according to the embodiment of the present invention can be effectively combined with a three-side free configuration. In particular, the three-side free configuration is effective when the pixel is manufactured using amorphous silicon technology. In addition, in a panel formed by amorphous silicon technology, process control of the variation in characteristics of transistor elements is impossible. Therefore, the N-fold pulse driving, reset driving, reference current ratio control, duty ratio control, dummy pixel driving of the present invention ( It is preferable to implement FIG. That is, the transistor 11 and the like in the present invention are not limited to those using polysilicon technology, but may be those using amorphous silicon. That is, the transistor 11 and the like constituting the pixel 16 in the display panel of the present invention may be a transistor formed by using amorphous silicon technology. Needless to say, the gate driver circuit 12 and the source driver circuit 14 may also be formed or configured using amorphous silicon technology. Needless to say, the transistor may be an organic transistor. Further, the driving circuit such as the speaker 2512 in FIG. 251 is not limited to the one using the polysilicon technology, and may be one using amorphous silicon.

  Note that the N-fold pulse driving (FIGS. 13, 16, 19, 20, 22, 24, 30, 30, 271, 274, etc.) of the present invention forms the transistor 11 by using a low-temperature polysilicon technology. Thus, the display panel is more effective than the display panel in which the transistor 11 is formed by amorphous silicon technology. This is because the characteristics of adjacent transistors in the amorphous silicon transistor 11 are substantially the same. Therefore, even if driving with the added current, the driving current of each transistor is almost the target value (in particular, N-fold pulse driving in FIGS. 22, 24, 30, 271, and 274 is amorphous silicon). This is effective in the pixel structure of the transistor formed in (1). It goes without saying that the present invention can be applied not only to a low-temperature polysilicon display panel, but also to an amorphous silicon display panel and a display panel constituted by CGS technology.

  The drive method and drive circuit of the present invention described in this specification, such as duty ratio control drive, reference current control, N-fold pulse drive, source driver IC (circuit), gate driver configuration, etc. It is not limited to a drive circuit or the like. Needless to say, the present invention can be applied to other displays such as a field emission display (FED) as shown in FIG.

  In the FED of FIG. 158, electron emission protrusions 1583 (corresponding to the pixel electrode 35 in FIG. 3) that emit electrons in a matrix are formed on the substrate 30. A holding circuit 1584 that holds image data from the video signal circuit 1582 (corresponding to the source driver circuit 14 in FIG. 1) is formed in the pixel (corresponding to a capacitor in FIG. 1). In addition, a control electrode 1581 is disposed on the front surface of the electron emission protrusion 1583. A voltage signal is applied to the control electrode 1581 by an on / off control circuit 1585 (which corresponds to the gate driver circuit 12 in FIG. 1).

  If the peripheral circuit is configured as shown in FIG. 174 with the pixel configuration of FIG. 158, duty ratio control driving or N-fold pulse driving can be performed. An image data signal is applied from the video signal circuit 1582 to the source signal line 18. The pixel 16 selection signal is applied from the on / off control circuit 1585a to the selection signal line 2173, the pixels 16 are sequentially selected, and image data is written. Further, an on / off signal is applied from the on / off control circuit 1585b to the on / off signal line 1742, and the FED of the pixel is subjected to on / off control (duty ratio control).

  158 and the like also include the duty ratio control, reference current control, precharge control, lighting rate control, AI control, peak current suppression control, panel wiring routing, gate driver circuit configuration, trimming method, and program voltage of the present invention. It goes without saying that various configurations, methods, and configurations described in the specification of the present invention, such as a + program current driving method, can be applied. Needless to say, the above items can be similarly applied to other embodiments of the present invention.

  The output stage (for example, the transistor group 431c) of the driver circuit (IC) 14 of the present invention is mainly described as outputting current (outputting a program current), but is not limited to this. The output stage may output a program voltage (FIG. 2 corresponds to the pixel configuration). The voltage output stage is exemplified by a voltage output stage converted into a voltage by an operational amplifier or the like so as to correspond to the reference current Ic. Moreover, the output current Id is converted into a voltage by an operational amplifier or the like and output. Other examples include converting video data into voltage data, performing gamma processing on the voltage data, and outputting the voltage data from the output terminal 155. As described above, the output of the source driver circuit (IC) 14 of the present invention is not limited to the program current, but may be a program voltage. 77, 78, 75, and the like have been described on the assumption that the precharge signal applied to the source signal line 18 is a voltage, but the present invention is not limited to this, and may be a current.

  The present invention changes the reference current, duty ratio, precharge voltage (synonymous with or similar to the program voltage), gamma curve, etc. according to image (video) data, lighting rate, current flowing through the anode (cathode) terminal, panel temperature, etc. Alternatively, the adjustment, change, or variable may be used, but the present invention is not limited to this. For example, by predicting or predicting image (video) data, lighting rate, current flowing through the anode (cathode) terminal, panel temperature change rate or change, reference current, duty ratio, precharge voltage (synonymous or similar to program voltage) Needless to say, the gamma curve or the like may be changed, adjusted, changed, changed, or controlled. Needless to say, the frame rate may be changed or changed.

  The present invention flows to the first FRC or the lighting rate or the anode (cathode) terminal in the first lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal). The current, the reference current, the duty ratio, the panel temperature, or the like is changed. Further, in the second lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal), the current flowing through the second FRC, the lighting rate, or the anode (cathode) terminal. Alternatively, it is changed as a reference current, a duty ratio, a panel temperature, or a combination thereof. Or, depending on the lighting rate (which may be the anode current of the anode terminal) or the lighting rate range (which may be the anode current range of the anode terminal) (adapted), it flows to the FRC or the lighting rate or the anode (cathode) terminal. The current, the reference current, the duty ratio, the panel temperature, or the like, or a combination thereof is changed. Also, when changing, the hysteresis is changed, delayed or changed slowly.

  The matters described in the driver circuit (IC) of the present invention can be applied to the gate driver circuit (IC) 12 and the source driver circuit (IC) 14, and only the organic (inorganic) EL display panel (display device). In addition, the present invention can be applied to a liquid crystal display panel (display device).

  Embodiments of the present invention (configuration, operation, driving method, control method, inspection method, formation or arrangement, display panel and display device using the same, etc.) have mainly been described with reference to the pixel configuration of FIG. However, the matters described such as the pixel configuration in FIG. 1 are not limited to those in FIG. For example, the pixel configurations shown in FIGS. 6, 7, 8, 9, 10, 11, 12, 13, 28, 31, 36, 193, 194, 215, and 314 are used. It goes without saying that is also applicable. Needless to say, the present invention is not limited to the pixel configuration and can be applied to the holding circuit 2280 described with reference to FIG. This is because the configuration is the same or similar, and the technical idea is the same.

  1 to 14, 22, 31, 31, 32, 33, 34, 35, 36, 39, 83, 85, 119, 120, 121, 126, 154 to 158, 180, 181, 187, 190, 191, 192, 193, 194, 195, 208, 248, 249, 250, 251, 258, 260 265, 270, 319, 320, 324, 325, 326, 327, etc. The pixel configuration or display panel (display device) of the present invention described or described, or its control method or technical idea Can be combined with each other. Further, they can be applied to each other or configured or formed.

  18, 19, 20, 21, 21, 23, 24, 25, 26, 27, 28, 37, 38, 40, 41, 42, 54, and 89 -118, 122-125, 128, 129, 130, 132, 133, 134, 149-153, 177, 178, 179, 211-222, 227, 252 253, 257, 259, 266 to 269, 280, 281, 282, 289, 290, 291, 307, 313, 314, 315, 316, FIG. 317, 318, 321, 322, 333, 328, 329, 330, 331, 332 to 337, 355 to 371, etc. Device driving method The properly control method or technical idea can be combined with one another. Further, they can be applied to each other or configured or formed.

  15, 16, 17, 29, 30, 43 to 53, 55, 56, 57, 58, 59, 60, 61, 62, 63 to 82, FIG. 84, 86, 87, 88, 127, 131, 135-148, 159-176, 182-185, 186, 188, 196, 197, 198, 199, 200, 201, 209, 210, 228 to 245, 246, 247, 283 to 288, 292 to 305, 308 to 313, 338 to 354, etc. The described source driver IC (circuit) or driver circuit of the present invention and its adjustment or control method (including gate driver circuit) or technical idea can be combined with each other. Further, they can be applied to each other or configured or formed.

  Further, the technical idea of the inspection apparatus and the inspection method or adjustment method of the present invention described or explained in FIGS. 202, 203, 204, 205, 206, 207, 223 to 226, 306, etc. Can be combined with each other. In addition, the present invention can be applied to, configured, or formed mutually on the display panel (display device), source driver circuit (IC), driving method, and the like of the present invention.

  Furthermore, the pixel configuration, the display panel (display device) or the control method or technical idea thereof, the drive method or control method or technical idea of the display panel or display device, the source driver IC (circuit) or the driver circuit described above. And its adjustment or control method (including gate driver circuit) or technical ideas can be combined with each other. Needless to say, they can be applied to each other or configured or formed. Needless to say, the technical idea of the inspection apparatus and the inspection method or adjustment method of the present invention can be applied to the display panel or display apparatus of the present invention.

  The technical ideas such as the display device and the driving method described in the embodiments of the present invention can be applied to a video camera, a projector, a stereoscopic television, a projection television, and the like. The present invention can also be applied to a viewfinder, a main monitor and a sub monitor of a mobile phone, a PHS, a portable information terminal and its monitor, a digital camera, a satellite TV, a satellite mobile TV and a monitor thereof. The present invention can also be applied to an electrophotographic system, a head mounted display, a direct view monitor display, a notebook personal computer, a video camera, and an electronic still camera. Further, the present invention can be applied to a monitor of an automatic cash drawer, a public telephone, a videophone, a personal computer, a wristwatch and a display device thereof.

  Furthermore, it goes without saying that the present invention can be applied or applied to display monitors for home appliances, pocket game devices and their monitors, backlights for display panels, or lighting devices for home use or business use. The lighting device is preferably configured so that the color temperature can be varied. In this case, the color temperature can be changed by forming RGB pixels in a stripe or dot matrix and adjusting the current flowing through them. It can also be applied to display devices such as advertisements or posters, RGB traffic lights, warning indicator lights, and the like.

  Further, the self-luminous element, the display device or the organic EL display panel of the present invention is also effective as a light source for the scanner. Using an RGB dot matrix as a light source, the object is irradiated with light to read an image. Of course, it goes without saying that it may be monochromatic. Moreover, it is not limited to an active matrix, A simple matrix may be sufficient. If the color temperature can be adjusted, the image reading accuracy can be improved.

  The organic EL display device is also effective for the backlight of the liquid crystal display device of the present invention. The RGB pixels of the EL display device (backlight) are formed in a stripe shape or a dot matrix shape, and the color temperature can be changed by adjusting the current passed through them, and the brightness can be easily adjusted. In addition, since it is a surface light source, a Gaussian distribution that brightens the central part of the screen and darkens the peripheral part can be easily configured. It is also effective as a backlight for a field sequential type liquid crystal display panel that alternately scans R, G, and B light. Of course, it is needless to say that the technical idea of the present invention may be used as a white or single color backlight or flon and light without forming the pixel 16 or the like. The technical idea of the present invention may be used not only for an active matrix display panel but also for a simple matrix display panel. Further, even if the backlight blinks, it can be used as a backlight of a liquid crystal display panel for displaying moving images by inserting black. In addition, the apparatus or method of the present invention can realize white light emission and can be used as a backlight of a liquid crystal display device or the like.

  The EL display device according to the present invention has a small variation in output current due to a threshold shift, and can suppress the occurrence of display unevenness in the EL display panel, which is useful.

It is a block diagram of the display panel of this invention. It is a block diagram of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 10 is an explanatory diagram representing a driving method of a display device of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. 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It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the source driver IC (circuit) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the inspection method of the display panel (array) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. FIG. 46 is an explanatory diagram of a display panel of the present invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the drive method of the display panel of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the source driver circuit (IC) of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention. It is explanatory drawing of the display apparatus of this invention.

Explanation of symbols

11 Transistor (TFT, thin film transistor)
12 Gate driver IC (circuit)
14 Source driver IC (circuit)
15 EL (element) (light emitting element)
16 pixel 17 gate signal line 18 source signal line 19 storage capacity (additional capacitor, additional capacity)
29 EL film 30 Array substrate 31 Bank (rib)
32 Interlayer insulating film 34 Contact 35 Pixel electrode 36 Cathode electrode 37 Desiccant 38 λ / 4 plate (λ / 4 film, phase plate, phase film)
39 Polarizing plate 40 Sealing lid 41 Thin film sealing film 71 Switching circuit (analog switch)
141 Shift register 142 Inverter 143 Output buffer 144 Display area (display screen)
150 Internal wiring (Output wiring)
151 switch (on / off means)
153 Gate wiring 154 Current source (unit transistor)
157, 158 Transistor 161 Matching circuit 162 Counter 163 AND
164 Current output circuit 171 Protection diode 172 Surge reduction resistor 191 Write pixel row 192 Non-display (non-lighting) region 193 Display (lighting) region 431 Transistor group 501 Electronic volume (voltage variable means)
502 operational amplifier 601 reference current circuit 641 ladder resistor 642 switch circuit 643 voltage input / output circuit 661 DA conversion circuit 760 control circuit (IC) (control means)
761 Precharge control circuit 764 Gamma conversion circuit 765 Frame rate control (FRC) circuit 771 Latch circuit (holding circuit, holding means, data storage circuit)
772 Selector circuit (selection means, switching means)
773 Precharge circuit 811 Differential circuit 821 Serial-parallel conversion circuit (control IC)
831 Control IC (circuit) (control means)
842 Raising circuit 851 Switch circuit (switching means)
852 Decoder circuit 853 AI processing circuit (peak current suppression, dynamic range expansion processing, etc.)
854 Video detection process (ID process)
856 Color management processing circuit (color compensation / correction, color temperature correction circuit)
859 Arithmetic circuit (MPU, CPU)
861 Variable amplifier 867 Sampling circuit (data holding circuit, signal latch circuit)
881, 882 Multiplier 883 Adder 884 Summation circuit (SUM circuit, data processing circuit, total current calculation circuit)
1191 DCDC converter (voltage value conversion circuit, DC power supply circuit)
1193 Regulator 1261 Antenna 1262 Key 1263 Case 1264 Display panel 1271 Voltage gradation circuit (Program voltage generation circuit)
1311 Decoder 1431 Adder circuit 1541 Eyepiece ring 1542 Magnifying lens (positive lens)
1543 Convex lens (positive lens)
1551 fulcrum (rotating part)
1552 Photographic lens (photographing means)
1553 Storage unit 1554 Switch 1561 Main unit 1562 Shooting unit 1563 Shutter switch 1571 Mounting frame 1572 Leg 1573 Mounting base 1574 Fixing unit 1581 Control electrode 1582 Video signal circuit 1583 Electron emission projection 1584 Holding circuit 1585 On-off control circuit 1621 Trimming device (trimming means, adjustment) means)
1622 Laser light 1623 Resistance (Adjustment unit)
1681 Correction (Adjustment) Transistor 1691 Source Terminal 1692 Gate Terminal 1693 Drain Terminal 1694 Transistor 1731 Selection Switch (Selection Unit)
1732 Common line 1733 Ammeter (Current measuring means)
1734 Terminal electrode 1801 Connector terminal (connection terminal)
1802 Flexible substrate 1811 Cathode wiring 1812 Cathode connection position 1813 Gate driver signal 1814 Source driver signal 1815 Anode wiring 1881 Current holding circuit 1882 Gradation current wiring 1883 Output control terminal 1901 Differential signal 1902 Signal wiring 1912 Power supply module 1913 Coil (transformer circuit, Booster circuit)
1914 Connection terminal 2031 Anode terminal wiring 2032 Short chip (short circuit)
2033 Chip terminal 2034 Source signal line terminal 2041 Short liquid (short gel, short resin)
2081 Cascade wiring 2191 Switch (on / off means)
2231 ON / OFF control means 2232 inspection switch 2251 protective diode 2252 voltage wiring 2261 voltage source (inspection signal generation means, inspection signal generation section)
2280 output circuit (output stage, current output circuit, current holding circuit)
2281 Transistor 2282 Gate signal line 2283 Current signal line 2284 Gate signal line 2289 Capacitor 2301 Reset circuit 2311 Switch transistor 2285 Gate signal line 2301 IV conversion circuit 2501 Trimming adjustment unit 2511 Sealing resin 2512 Speaker 2513 Sealing film 2611 Regulator 2612 Charge Pump 2621 Switching circuit (AC circuit)
2622 Transformer 2623 Smoothing circuit 2741 Dummy pixel row 2831 Inverted output generation circuit 2841 FF (flip-flop circuit, delay circuit)
2851 Timing generation circuit 2852 Wiring 2871 Correction data calculation circuit 2872 Current measurement circuit 2873 Probe 2874 Correction circuit (data conversion circuit)
2881 Gate wiring pad 2882 Gate wiring pad 2883 Input signal line pad 2884 Output signal line pad 2885 Wiring 2901 Input signal line 2902 Terminal electrode 2903 Anode wiring 2904 Gold bump 2911 Flexible substrate 2921 Differential-parallel signal conversion circuit 2941 Voltage selector circuit 2951 selector circuit 3031 flash memory 3051 luminance meter 3052 arithmetic unit 3053 control circuit 3141 light shielding film 3271 battery (battery, power supply means)
3272 Power supply module (voltage generating means)
3451 Adder circuit 3611 PLL circuit 3681 Differential signal-parallel signal conversion circuit

Claims (1)

A display area in which pixels are arranged in a matrix, and
A source driver circuit for applying a current as a video signal to the pixels;
An electronic volume circuit for generating a precharge voltage configured in the source driver circuit;
A gate driver circuit for controlling the writing timing of the pixel,
An output voltage range of the electronic volume is an EL display device defined by a resistor connected to the outside of the source driver circuit.

Images