JP5078363B2 - Display device - Google Patents

Description

The present invention relates to a display device. In particular, the present invention relates to a circuit configuration that includes a light emitting element and drives a scanning line or a data line of a pixel in an active matrix display device.

In recent years, the demand for thin displays has rapidly expanded mainly for televisions, computer monitors, mobile terminals, and the like, and further development has been underway. Thin displays include liquid crystal display devices (LCDs) and display devices equipped with light emitting elements. In particular, active matrix displays using light emitting elements are combined with the advantages of existing LCDs such as thinness, light weight, and high image quality. Therefore, it is expected as a next-generation display because it has features such as a high response speed and a wide visual field characteristic.

In an active matrix display using a light-emitting element, the most basic pixel structure is shown in FIG. 11A (see, for example, Patent Document 1). In FIG. 11A, a pixel includes a driving transistor 2402 that controls supply of current to the light-emitting element 2404. When the pixel is selected by a scan line 2405, the potential of the data line 2406 is applied to the gate node G of the driving transistor 2402. A switch transistor 2401 to be taken in and a storage capacitor 2403 for holding the potential of the node G are provided. One electrode of the storage capacitor 2403 and the source electrode or the drain electrode of the driving transistor 2402 are connected to the current supply line 2407. The other of the source electrode and the drain electrode of the driving transistor 2402 is connected to the counter electrode 2408 through the light emitting element 2404. FIG. 11B illustrates an example of signal timing in the scan line 2405, the data line 2406, and the node G.

In addition, there are analog driving and digital driving as methods for expressing gradation. In analog driving, an analog voltage is supplied to the gate of the driving transistor, and the current value supplied to the light emitting element is changed in an analog manner. Digital driving, on the other hand, supplies a binary signal indicating whether or not the light emitting element emits light to the gate of the driving transistor. When the light emitting element emits light, it emits light with a constant luminance and temporally controls the light emitting time. By doing so, gradation is expressed.
Japanese Patent No. 3620538

In many cases, the scanning lines and the data lines are driven by a scanning line driving circuit and a signal line driving circuit arranged on one side of the periphery of the pixel portion. However, depending on the number of pixels, the screen size, and the driving method, the scanning line driving circuit and the signal line driving circuit arranged along one side of the pixel portion are normally used due to the wiring resistance and parasitic capacitance of the scanning lines and data lines. It may not be possible to drive.

Therefore, there is a method in which each of the scanning line driver circuit and the signal line driver circuit is arranged to face each other with the pixel portion interposed therebetween and driven from both sides. However, disposing the drive circuits on both sides leads to an increase in layout area and power consumption.

The gist of the present invention is that a display device is provided with a scanning line driving circuit and a scanning line auxiliary circuit whose circuit scale and power consumption are smaller than those of the scanning line driving circuit. In the present invention, the scanning line auxiliary circuit has at least a switching element, and controls the switching element by using a scanning line selection pulse or a signal of a scanning line driving circuit, thereby passing the scanning line through the switching element. A circuit that operates to connect to a power supply line having a fixed potential. A transistor or the like is used as the switching element. When the scanning line potential is switched by the scanning line driving circuit, the scanning line auxiliary circuit operates so that the scanning line is connected to the power supply line, and drives the scanning line from both sides. The configuration of the scan line auxiliary circuit is not limited to one, and a configuration having a function of driving the scan line from both sides, such as a configuration using an inversion potential of the scan line potential, can be applied.

One aspect of the present invention is a scanning line driving circuit, a scanning line having one end connected to the scanning line driving circuit, and a scanning line auxiliary circuit having at least one switching element connected to the other end of the scanning line. And a display device. The scanning line auxiliary circuit conducts the scanning line with a power supply line having a fixed potential through the switching element by controlling a switching element when a signal potential of the scanning line is changed by the scanning line driving circuit. Let

In another embodiment of the present invention, a first scanning line driving circuit, a second scanning line driving circuit, a first scanning line having one end connected to the first scanning line driving circuit, and one end Is a display device having a second scanning line connected to the second scanning line driving circuit and a scanning line auxiliary circuit connected to the other end of the first scanning line and having at least one switching element. is there. When the signal potential of the first scanning line is changed by the first scanning line driving circuit, the scanning line auxiliary circuit detects the inverted potential of the signal potential of the first scanning line and the second scanning line. The switching element is controlled by the signal potential of the second scanning line supplied by the driving circuit, and the first scanning line is brought into conduction with a power supply line having a fixed potential through the switching element.

By providing the scanning line auxiliary circuit, the scanning line can be driven with the same ability as driving from both sides. The circuit scale can be reduced and the layout area and power consumption can be reduced compared with the case where the same scanning line driving circuit is arranged on both sides of the pixel portion.

An example of a structure to which the scanning line auxiliary circuit of the present invention is added is shown in FIG. The pixel circuit in the pixel portion is a type including four transistors and one capacitor, and one frame has a reset period, a selection period, and a light emission period as shown in FIG. In addition, a first scanning line 107, a second scanning line 108, a data line 109, and a current supply line 110 are connected to the pixel circuit. Although only one pixel is shown here, the pixel portion of the display device actually has a plurality of pixels arranged in a matrix in the row and column directions.

The pixel 100 includes a selection transistor 101, a reset transistor 102, a switch transistor 103, a driving transistor 104, a storage capacitor 105, a light emitting element 106, and a counter electrode 111, and includes a data line 109, a current supply line 110, a first scanning line 107, and , Connected to the second scanning line 108. The first scan line 107 is connected to the first scan line driver circuit 116, and the second scan line 108 is connected to the second scan line driver circuit 117.

The scanning line auxiliary circuit 119 is disposed on the opposite side of the first scanning line driving circuit 116 that drives the first scanning line 107 through the pixel portion 118.

One end of the first scanning line 107 is connected to the first scanning line driving circuit 116, and the other end is connected to the input portion of the inverter 112 of the scanning line auxiliary circuit 119. A first n-channel transistor 113 and a second n-channel transistor 114 are connected in series as switching elements between the input portion of the inverter 112 and the GND 115, and the gate of the first n-channel transistor 113 is connected to the inverter 112. Connected to the output section, the gate of the second n-channel transistor 114 is connected to the output section of the second scan line driver circuit 117 from which the second scan line 108 is output.

FIG. 1A includes a pixel 100 that includes a first scan line 107, a second scan line 108, a data line 109, and a current supply line 110, and includes a light-emitting element 106 and an element that controls light emission. The display device is shown. The pixel unit 118 is configured by arranging a plurality of the pixels 100. The first scanning line 107 has one end connected to the first scanning line driving circuit 116 and the other end connected to the scanning line auxiliary circuit 119, and the potential is controlled by these circuits. One end of the second scanning line 108 is connected to the second scanning line driving circuit 117 and supplies a signal potential to the scanning line auxiliary circuit 119. The pixel portion 118 includes a driving transistor 104 connected in series between the current supply line 110 and the light emitting element 106, a storage capacitor 105 connected between the gate electrode of the driving transistor 104 and the current supply line 110, The first scanning line 107 and the gate electrode are connected, the reset transistor 102 connected to supply the potential of the current supply line 110 to the storage capacitor 105, the second scanning line 108 and the gate electrode are connected, and the reset is performed. A switch transistor 103 connected between the transistor 102 and the storage capacitor 105, a data line 109 and a gate electrode are connected, and a selection transistor 101 inserted in series between the switch transistor 103 and the first scanning line 107. And have. The scanning line auxiliary circuit 119 is connected to the other end of the first scanning line 107, and when the signal potential of the first scanning line 107 is changed by the first scanning line driving circuit 116, The first scanning line 107 is electrically connected to the GND 115 and the gate electrode of the driving transistor 104 is electrically connected to the GND 115 by the signal potential supplied to the second scanning line 108 by the second scanning line driver circuit 117. Operate. Note that in FIG. 1A, the GND 115 can be replaced with a power supply line having a desired fixed potential.

FIG. 1B shows a timing chart. Hereinafter, examples of potentials are shown in parentheses. In the reset period, the first scan line 107 and the second scan line 108 are set to a high potential (10 V) (hereinafter also referred to as “H” level), and the reset transistor 102 and the switch transistor 103 are turned on. The gate electrode of the drive transistor 104 becomes the potential (8 V) of the current supply line 110, and the drive transistor 104 is turned off.

Here, the potentials of the data lines in all the columns are determined in accordance with the video signal during the reset period. However, if all the signals are in the light emission state, all the data lines in all the columns are at the “H” level (3 V). In the selection period, the first scanning line 107 becomes a low potential (0 V) (hereinafter also referred to as “L” level), and the “H” level (8 V) of the storage capacitors 105 of all the pixels in the X row. Is lowered to "L" level (0V).

At this time, the output of the inverter 112 becomes “H” level (10 V) and the first n-channel transistor 113 is turned on, and the second scanning line 108 also becomes “H” level (10 V) and the second n-channel. Since the type transistor 114 is also on, the first scanning line 107 can draw a current to the GND 115 from both sides of the first scanning line driving circuit 116 and the scanning line auxiliary circuit 119. By driving the first scanning line 107 from both sides, it can be surely set to a predetermined potential as compared with driving on only one side.

Assuming that there are 720 (240 × RGB) pixels in the X direction and the storage capacity per pixel is 100 fF, the total storage capacity per row in the X direction is 72 pF. When this capacitance is driven only on one side of the first scanning line, the burden on the wiring resistance of the first scanning line 107, the buffer of the first scanning line driving circuit 116, the resistance of the current supply line 110, etc. is large, and the predetermined time is exceeded. It becomes difficult to obtain a fixed potential. The scanning line auxiliary circuit 119 is disposed on the opposite side of the first scanning line driving circuit 116 for driving the first scanning line 107 through the pixel portion 118, and the first scanning line 107 is arranged from both sides. By driving, the driving ability can be greatly improved. The scanning line auxiliary circuit 119 can be controlled by using selection pulses of the first scanning line 107 and the second scanning line 108, and a large effect can be obtained with a small circuit.

Further, the structure of the scanning line auxiliary circuit 119 is not limited to the structure of FIG. The gate connection destination of the first n-channel transistor 113 and the second n-channel transistor 114 may be interchanged, or a circuit having the same function may be modified.

The pixel circuit connected to the scan line auxiliary circuit 119 is not limited to the structure in FIG. 1A, and a pixel circuit having another structure may be provided.

In the present specification, the connection means an electrical connection unless otherwise specified.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention can be implemented in many different aspects. That is, it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the following examples.

A cross-sectional structure of the display device according to the present embodiment will be described with reference to FIG. Here, a cross-sectional structure of the display device including the selection transistor 212, the driving transistor 213, and the light-emitting element 214 described with reference to FIG.

As the substrate 201 having an insulating surface, a glass substrate, a quartz substrate, a stainless steel substrate, or the like can be used. In addition, a substrate made of a plastic such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) or a flexible synthetic resin such as acrylic can be used as long as it can withstand the processing temperature in the manufacturing process.

First, a base film is formed on the substrate 201. As the base film, an insulating film such as silicon oxide, silicon nitride, or silicon nitride oxide can be used. Next, an amorphous semiconductor film is formed over the base film. The thickness of the amorphous semiconductor film is 25 to 100 nm. As the amorphous semiconductor, not only silicon but also silicon germanium can be used. Subsequently, the amorphous semiconductor film is crystallized as necessary to form a crystalline semiconductor film 202. As a method for crystallization, heat treatment using a heating furnace, laser irradiation, irradiation of light emitted from a lamp, or a combination thereof can be used. For example, a crystalline semiconductor film is formed by adding a metal element to an amorphous semiconductor film and performing heat treatment using a heating furnace. Thus, the addition of a metal element is preferable because crystallization can be performed at a low temperature.

Note that a thin film transistor (TFT) formed using a crystalline semiconductor has higher field-effect mobility and higher on-state current than a TFT formed using an amorphous semiconductor, and thus is more suitable as a transistor used in a display device.

Next, the crystalline semiconductor film 202 is patterned into a predetermined shape. Next, an insulating film functioning as a gate insulating film is formed. The insulating film is formed with a thickness of 10 nm to 150 nm so as to cover the semiconductor film. For example, a silicon oxynitride film, a silicon oxide film, or the like can be used, and a single layer structure or a stacked structure may be used.

Next, a conductive film functioning as a gate electrode is formed through the gate insulating film. The gate electrode may be a single layer or a stack, but here, the gate electrode is formed by stacking conductive films (203A and 203B). The conductive films 203A and 203B are formed of an element selected from Ta, W, Ti, Mo, Al, and Cu, or an alloy material or a compound material containing these elements as main components. For example, a tantalum nitride film with a thickness of 10 nm to 50 nm is formed as the conductive film 203A, and a tungsten film with a thickness of 200 nm to 400 nm is formed as the conductive film 203B.

Next, an impurity element is added to the crystalline semiconductor film 202 using the gate electrode as a mask to form an impurity region. At this time, a low concentration impurity region may be formed in addition to the high concentration impurity region. The low concentration impurity region is called an LDD (Lightly Doped Drain) region.

Next, a first insulating film 204 and a second insulating film 205 that function as the interlayer insulating film 206 are formed. The first insulating film 204 is preferably an insulating film containing nitrogen. Here, the first insulating film 204 is formed using a silicon nitride film with a thickness of 50 nm to 100 nm by a plasma CVD method. The second insulating film 205 is preferably formed using an organic material or an inorganic material. As the organic material, polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, or siloxane can be used. Siloxane has a skeletal structure with a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Examples of the inorganic material include oxygen such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x> y), silicon nitride oxide (SiNxOy) (x> y) (x and y are natural numbers), and the like. Alternatively, an insulating film containing nitrogen can be used. Note that a film made of an organic material has good flatness, but moisture and oxygen are absorbed by the organic material. In order to prevent this, an insulating film containing an inorganic material is preferably formed over the insulating film made of an organic material.

Next, after a contact hole is formed in the interlayer insulating film 206, a conductive film 207 functioning as a source wiring and a drain wiring of the transistor is formed. As the conductive film 207, a film formed of an element of aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), or silicon (Si) or an alloy film using these elements can be used. For example, a titanium film, a titanium nitride film, an alloy film of titanium and aluminum, or a stacked film of titanium films is formed.

Next, a third insulating film 208 is formed so as to cover the conductive film 207. The material shown for the interlayer insulating film 206 can be used for the third insulating film 208. Next, a pixel electrode 209 (also referred to as a first electrode) is formed in the opening provided in the third insulating film 208. In order to improve the step coverage of the pixel electrode 209 in the opening, the end surface of the opening may be rounded so as to have a plurality of radii of curvature.

As a material for the pixel electrode 209, a conductive material such as a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (work function of 4.0 eV or more) is preferably used. Specific examples of the conductive material include indium oxide containing tungsten oxide (IWO), indium zinc oxide containing tungsten oxide (IWZO), indium oxide containing titanium oxide (ITO), and indium tin oxide containing titanium oxide. A thing (ITTiO) etc. can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

The composition proportion of the conductive material is as follows. The composition ratio of indium oxide containing tungsten oxide may be 1 wt% tungsten oxide and 99 wt% indium oxide. The composition ratio of indium zinc oxide containing tungsten oxide may be 1 wt% tungsten oxide, 0.5 wt% zinc oxide, and 98.5 wt% indium oxide. The indium oxide containing titanium oxide may be titanium oxide 1 wt% to 5 wt% and indium oxide 99 wt% to 95 wt%. The composition ratio of indium tin oxide (ITO) may be 10 wt% tin oxide and 90 wt% indium oxide. The composition ratio of indium zinc oxide (IZO) may be 11 wt% zinc oxide and 89 wt% indium oxide. The composition ratio of indium tin oxide containing titanium oxide may be 5 wt% titanium oxide, 10 wt% tin oxide, and 85 wt% indium oxide. The above composition ratio is an example, and the ratio of the composition ratio may be set as appropriate.

Next, the light emitting layer 210 is formed by an evaporation method or an inkjet method. The light emitting layer 210 includes an organic material or an inorganic material, and includes an electron injection layer (EIL), an electron transport layer (ETL), a light emission layer (EML), a hole transport layer (HTL), and a hole injection layer (HIL). Etc. are appropriately combined. Note that the boundaries between the layers are not necessarily clear, and there are cases where the materials constituting the layers are partially mixed and the interface is unclear.

Note that the light-emitting layer is preferably formed using a plurality of layers having different functions such as a hole injecting and transporting layer, a light emitting layer, and an electron injecting and transporting layer.

Note that the hole injecting and transporting layer is preferably formed using a composite material including a hole transporting organic compound material and an inorganic compound material that exhibits an electron accepting property with respect to the organic compound material. By adopting such a configuration, many hole carriers are generated in an organic compound that has essentially no intrinsic carrier, and extremely excellent hole injection and transport properties can be obtained. Due to this effect, the drive voltage can be made lower than in the prior art. In addition, since the hole injecting and transporting layer can be thickened without causing an increase in driving voltage, a short circuit of the light emitting element due to dust or the like can be suppressed.

Examples of hole transporting organic compound materials include copper phthalocyanine (abbreviation: CuPc), vanadyl phthalocyanine (abbreviation: VOPc), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) triphenyl. Amine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 1,3,5-tris [N , N-di (m-tolyl) amino] benzene (abbreviation: m-MTDAB), N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4 '-Diamine (abbreviation: TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4,4'-bis {N- [4-di ( m-tri ) Amino] phenyl-N-phenylamino} biphenyl (abbreviation: DNTPD), 4,4 ′, 4 ″ -tris (N-carbazolyl) triphenylamine (abbreviation: TCTA), and the like. Never happen.

Note that examples of the inorganic compound material exhibiting electron acceptability include titanium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, and zinc oxide. Vanadium oxide, molybdenum oxide, tungsten oxide, and rhenium oxide are particularly preferable because they can be vacuum-deposited and are easy to handle.

Note that the electron injecting and transporting layer is formed using an electron transporting organic compound material. Specifically, tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [h] -quinolinato) beryllium (Abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq), bis [2- (2′-hydroxyphenyl) benzoxazolate] zinc (abbreviation) : Zn (BOX) ₂ ), bis [2- (2′-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), 2- ( 4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole Abbreviation: PBD), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 2,2 ′, 2 ″-(1,3,5-benzenetriyl) -tris (1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 3- (4-biphenylyl) -4-phenyl-5- (4- tert-butylphenyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-biphenylyl) -4- (4-ethylphenyl) -5- (4-tert-butylphenyl) -1,2 , 4-triazole (abbreviation: p-EtTAZ) and the like, but is not limited thereto.

Note that the light-emitting layer includes 9,10-di (2-naphthyl) anthracene (abbreviation: DNA), 9,10-di (2-naphthyl) -2-tert-butylanthracene (abbreviation: t-BuDNA), 4 , 4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), coumarin 30, coumarin 6, coumarin 545, coumarin 545T, perylene, rubrene, periflanthene, 2,5,8,11-tetra (tert-) Butyl) perylene (abbreviation: TBP), 9,10-diphenylanthracene (abbreviation: DPA), 5,12-diphenyltetracene, 4- (dicyanomethylene) -2-methyl- [p- (dimethylamino) styryl] -4H -Pyran (abbreviation: DCM1), 4- (dicyanomethylene) -2-methyl-6- [2- (julolidin-9-yl) e And tenenyl] -4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) styryl] -4H-pyran (abbreviation: BisDCM), and the like. In addition, bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (picolinate) (abbreviation: FIrpic), bis {2- [3 ′, 5′-bis (trifluoromethyl) ) Phenyl] pyridinato-N, C ^{2 ′} } iridium (picolinate) (abbreviation: Ir (CF ₃ ppy) ₂ (pic)), tris (2-phenylpyridinato-N, C ^{2 ′} ) iridium (abbreviation: Ir (Ppy) ₃ ), bis (2-phenylpyridinato-N, C ^{2 ′} ) iridium (acetylacetonate) (abbreviation: Ir (ppy) ₂ (acac)), bis [2- (2′-thienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) _{(abbreviation: Ir (thp) 2 (acac} )), bis (2-phenylquinolinato--N, C ^2') iridium (Asechirua Tonato) _{(abbreviation: Ir (pq) 2 (acac} )), bis [2- (2'-benzothienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) (abbreviation: Ir _(btp) 2 (acac A compound capable of emitting phosphorescence such as)) can also be used.

In addition to the singlet excited light emitting material, a triplet excited light emitting material containing a metal complex or the like may be used for the light emitting layer. For example, among red light emitting pixels, green light emitting pixels, and blue light emitting pixels, a red light emitting pixel having a relatively short luminance half time is formed of a triplet excitation light emitting material, and the other A singlet excited luminescent material is used. The triplet excited luminescent material has a feature that the light emission efficiency is good, so that less power is required to obtain the same luminance. That is, when applied to a red pixel, the amount of current flowing through the light emitting element can be reduced, so that reliability can be improved. As a reduction in power consumption, a red light-emitting pixel and a green light-emitting pixel may be formed using a triplet excitation light-emitting material, and a blue light-emitting pixel may be formed using a singlet excitation light-emitting material. By forming a green light-emitting element having high human visibility with a triplet excited light-emitting material, power consumption can be further reduced.

The light emitting layer may be configured to perform color display by forming light emitting layers having different emission wavelength bands for each pixel. Typically, a light emitting layer corresponding to each color of R (red), G (green), and B (blue) is formed. In this case as well, it is possible to improve the color purity and prevent mirror reflection (reflection) of the pixel portion by providing a filter that transmits light in the emission wavelength band on the light emission side of the pixel. Can do. By providing the filter, it is possible to omit a circularly polarizing plate that has been conventionally required, and the loss of light emitted from the light emitting layer can be eliminated. Furthermore, a change in color tone that occurs when the pixel portion (display screen) is viewed obliquely can be reduced.

In addition, examples of the polymer electroluminescent material that can be used for forming the light emitting layer include polyparaphenylene vinylene, polyparaphenylene, polythiophene, and polyfluorene.

In addition, an inorganic material may be used for the light emitting layer. As the inorganic material, a compound semiconductor such as zinc sulfide (ZnS) added with manganese (Mn) or rare earth (Eu, Ce, etc.) as impurities can be applied. These impurities are called luminescent center ions, and light emission is obtained by electronic transition in the ions. In addition, a compound semiconductor such as zinc sulfide (ZnS) is added with Cu, Ag, Au, or the like as an acceptor element and F, Cl, Br, or the like as a donor element, and emits light by transition between the acceptor and the donor. Can be applied. Further, GaAs may be added in order to further improve the light emission efficiency. The light emitting layer may be provided with a thickness of 100 to 1000 nm (preferably 300 to 600 nm). A dielectric layer is provided between such a light emitting layer and the electrodes (anode and cathode) in order to increase the light emission efficiency. As the dielectric layer, barium titanate (BaTiO ₃ ) or the like can be used. The dielectric layer is provided with a thickness of 50 nm to 500 nm (preferably 100 nm to 200 nm).

In any case, the layer structure of the light-emitting layer can be changed, and instead of having a specific hole or electron injecting and transporting layer or light-emitting layer, the light-emitting layer has an electrode layer exclusively for this purpose, or has a light-emitting property. Such a modification that the material is dispersed and provided can be tolerated as long as the object as the light emitting element can be achieved.

Further, a color filter (colored layer) may be formed on the sealing substrate. The color filter (colored layer) can be formed by an evaporation method or a droplet discharge method. When the color filter (colored layer) is used, high-definition display can be performed. This is because the color filter (colored layer) can correct a broad peak to be sharp in the emission spectrum of each RGB.

Further, full color display can be performed by forming a material exhibiting monochromatic light emission and combining a color filter and a color conversion layer. The color filter (colored layer) and the color conversion layer may be formed, for example, on the second substrate (sealing substrate) and attached to the substrate.

Then, a counter electrode (also referred to as a second electrode) 211 is formed by a sputtering method or an evaporation method. One of the pixel electrode 209 and the counter electrode 211 serves as an anode, and the other serves as a cathode.

As the cathode material, it is preferable to use a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function (work function of 3.8 eV or less). Specific examples of the cathode material include elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr, and alloys containing these (Mg : Ag, Al: Li) and compounds (LiF, CsF, CaF ₂ ), as well as transition metals including rare earth metals. However, since the cathode needs to have a light-transmitting property, these metals or an alloy containing these metals are formed very thin, and are formed by lamination with a metal (including an alloy) such as ITO.

Thereafter, a protective film made of a silicon nitride film or a DLC (Diamond Like Carbon) film may be provided so as to cover the counter electrode 211. Through the above steps, the display device of the present invention is completed.

In this embodiment, an example of an active matrix display using the pixel configuration of the present invention will be described with reference to FIG.

The active matrix display includes a substrate 201 on which transistors and wirings are formed, a flexible wiring substrate 217 for connecting a wiring portion to an external circuit, a light emitting element, and a counter substrate 215 for sealing the light emitting element.

The substrate 201 includes a pixel portion 118 including a plurality of pixels arranged in a matrix, a signal line driver circuit 120, a first scan line driver circuit 116, a second scan line driver circuit 117, and a scan line auxiliary circuit (not shown). ), And a flexible wiring board connecting portion 216 connected to a flexible wiring board 217 for inputting various power sources and signals.

The signal line driver circuit 120 includes circuits such as a shift register, a latch, a level shifter, and a buffer, and outputs data to the data lines in each column. The first scan line driver circuit 116 and the second scan line driver circuit 117 include circuits such as a shift register, a level shifter, and a buffer.

Light emission of the light emitting element is controlled in accordance with a data signal written to each pixel at the timing when the selection pulse is output by the scanning line driving circuit.

In addition to the above driving circuit, a circuit such as a microprocessor or a controller may be integrally formed on the substrate 201. Then, the number of external circuits (IC) to be connected is reduced, and the weight and thickness can be further increased.

Note that in this specification, as shown in FIG. 3, a panel in which even a flexible wiring board is attached and an EL element is used as a light emitting element is referred to as a display module in this specification.

This embodiment can be freely combined with Embodiment 1.

In this embodiment, a configuration is described in which the potential of the current supply line can be controlled to suppress the influence of variations in luminance due to changes in the current value of the light-emitting element due to changes in environmental temperature and deterioration over time.

The light-emitting element has a property that its resistance value (internal resistance value) changes with changes in ambient temperature. Specifically, when the room temperature is a normal temperature, the resistance value decreases when the ambient temperature becomes higher than normal, and the resistance value increases when the ambient temperature becomes lower than normal. For this reason, when the ambient temperature increases, the current value increases and becomes higher than the desired luminance. When the same voltage is applied when the temperature decreases, the current value decreases and the luminance becomes lower than the desired luminance. Further, the light emitting element has a property that its current value decreases with time. Specifically, when the light emission time and the non-light emission time are accumulated, the resistance value increases with the deterioration of the light emitting element. For this reason, when the same voltage is applied when the light emission time and the non-light emission time are accumulated, the current value decreases and the luminance becomes lower than desired luminance.

Due to the properties of the light-emitting element described above, when the environmental temperature changes or the deterioration with time occurs, the luminance varies. In the display device of this embodiment, by controlling the potential of the current supply line, a change in the current value of the light-emitting element due to a change in environmental temperature and deterioration with time can be suppressed.

FIG. 4 shows a circuit configuration of such a display device. The pixel circuit shown in FIG. 1A is arranged in the pixel, and the description similar to that in FIG. 1A is omitted. In FIG. 4, elements that are the same as those in FIG.

This display device includes a monitor circuit in addition to the first scanning line driving circuit 116, the second scanning line driving circuit 117, and the signal line driving circuit 120 for supplying a video signal. The pixel is provided with a reset transistor 102 whose gate is connected to the first scanning line 107 and a switch transistor 103 whose gate is connected to the second scanning line 108. In the case of such a pixel configuration, if the potentials of the current supply line 110 and the counter electrode 111 are fixed, the characteristics deteriorate if current continues to flow through the light emitting element 106. Further, the characteristics of the light emitting element 106 change depending on the ambient temperature change.

Specifically, when a current continues to flow through the light emitting element 106, the voltage-current characteristics shift. That is, the resistance value of the light emitting element 106 is increased, and the flowing current value is decreased even when the same voltage is applied. Moreover, even if the same magnitude | size electric current flows, luminous efficiency will fall and a brightness | luminance will fall. As temperature characteristics, when the ambient temperature decreases, the voltage-current characteristics of the light-emitting element 106 shift, and the resistance value of the light-emitting element 106 increases.

Therefore, the influence of deterioration and fluctuation as described above is suppressed by using a monitor circuit. In this embodiment, the potential of the current supply line 110 is controlled to suppress the fluctuation of the current value due to the deterioration of the light emitting element 106 over time and the ambient temperature change.

A monitor current source 122 and a monitor light emitting element 124 are connected between the first monitor power line 121 and the second monitor power line 125. An input terminal of a sampling circuit 123 for outputting a voltage of the monitor light emitting element is connected to a contact point between the monitor current source 122 and the monitor light emitting element 124. A current supply line 110 is connected to the output terminal of the sampling circuit 123. Therefore, the potential of the current supply line 110 is controlled by the output of the sampling circuit 123.

Next, the operation of the monitor circuit will be described. First, the monitoring current source 122 supplies a current necessary for causing the light emitting element 106 to emit light with the highest luminance (high gradation number). The current value at this time is Imax.

Then, a voltage having a magnitude necessary for flowing Imax is applied to both ends of the monitor light emitting element 124. Even if the voltage-current characteristic of the monitor light emitting element 124 changes due to deterioration with time or a change in ambient temperature, the voltage at both ends of the monitor light emitting element 124 changes accordingly, and becomes an optimum magnitude. Therefore, the influence of fluctuation (deterioration, temperature change, etc.) of the monitor light emitting element 124 can be suppressed.

A voltage applied to the monitor light emitting element 124 is input to the input terminal of the sampling circuit 123. Therefore, the potential of the output terminal of the sampling circuit 123, that is, the potential of the current supply line 110 is corrected by the monitor circuit. As a result, the current value fluctuates due to deterioration of the light emitting element 106 over time and ambient temperature change. It is suppressed.

The sampling circuit 123 may be a circuit that outputs a voltage corresponding to the input current. For example, an amplifier circuit can be applied to the voltage follower circuit. In addition, an operational amplifier may be used. These may be configured by combining any one or a plurality of bipolar transistors and MOS transistors.

Note that the monitor light emitting element 124 is preferably formed on the same substrate by the same manufacturing method as the pixel light emitting element 106. By manufacturing the light-emitting element for monitoring and the light-emitting element arranged in the pixel in the same process, electrical characteristics can be made uniform.

Note that a period in which no current flows is frequently generated in the light-emitting element 106 arranged in the pixel, so that the deterioration of the light-emitting element 106 does not progress, but if a current is continuously supplied to the monitor light-emitting element 124. The light emitting element for monitoring 124 is greatly deteriorated and the resistance is increased. Therefore, the sampling circuit 123 is strongly corrected and outputs a large voltage. As a result, the potential of the current supply line 110 becomes high, causing the light emitting element 106 to emit light with a luminance higher than necessary. Therefore, it may be adapted to the degree of deterioration in actual pixels. For example, if the lighting rate of the entire screen is 30% on average, a current may be passed through the monitor light emitting element 124 only during a period corresponding to 30% luminance. At that time, a period in which no current flows in the monitor light emitting element 124 occurs, but it is necessary to keep the voltage supplied from the output terminal of the sampling circuit 123 unchanged. In order to realize such supply of voltage, a storage capacitor may be provided at the input terminal of the sampling circuit 123 so as to hold the potential when a current is supplied to the monitor light emitting element 124.

Note that if the monitor circuit is operated in accordance with the one having the highest number of gradations, the sampling circuit 123 is strongly corrected, and a large voltage is output, which causes image burn-in (degree of deterioration for each pixel). Therefore, it is desirable to operate the monitoring circuit in accordance with the brightest number of gradations.

In the present embodiment, it is more preferable that the driving transistor 104 is operated in a linear region. By operating in the linear region, the driving transistor 104 generally operates as a switch. For this reason, it is possible to make it difficult for the driving transistor 104 to be affected by fluctuations in characteristics due to deterioration over time or changes in ambient temperature. When operating only in the linear region, it is often digitally controlled whether or not a current flows through the light emitting element 106. In that case, in order to increase the number of gradations, it is preferable to combine a time gradation method, an area gradation method, or the like.

In addition, since the on / off potential applied to the gate electrode of the driving transistor and the data line potential can be set separately in the pixel portion, the maximum amplitude of the data line potential can be set low. Become. Accordingly, a display device with significantly reduced power consumption can be provided, and an electronic device with significantly reduced power consumption can be provided.

This embodiment can be freely combined with Embodiments 1 and 2.

In this embodiment, the electronic device according to the present invention is shown in FIGS. 5, 6, 7 A to 7 B, 8 A to 8 B, 9, and 10 ( A) to FIG. 10 (E).

FIG. 5 shows a display module in which the display panel 200 and the circuit board 300 are combined. A control circuit 304, a signal dividing circuit 305, and the like are formed on the circuit board 300, and are electrically connected to the display panel 200 by a flexible wiring board 217.

In the display panel 200, a video signal is supplied to the pixel portion 118 provided with a plurality of pixels, the first scan line driver circuit 116, the second scan line driver circuit 117, the scan line auxiliary circuit 119, and the pixels. A signal line driver circuit 120 is provided. As the configuration of the display panel 200, one equivalent to that of the first to third embodiments can be applied.

FIG. 6 is a block diagram illustrating a main configuration of the television device. The transmission / reception circuit 301 receives a video signal and an audio signal. The video signal includes a video signal amplifying circuit 302, a video signal processing circuit 303 that converts a signal output from the video signal into a color signal corresponding to each color of red, green, and blue, and an input of the converted signal to the driver IC. Processing is performed by a control circuit 304 for conversion into specifications. The control circuit 304 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 305 may be provided on the signal line side and an input digital signal may be divided into m pieces and supplied.

Of the signals received by the transmission / reception circuit 301, the audio signal is sent to the audio signal amplification circuit 306, and the signal output therefrom is supplied to the speaker 310 via the audio signal processing circuit 307. The control circuit 308 receives control information on the receiving station (reception frequency) and volume from the input unit 309 and sends a signal to the transmission / reception circuit 301 and the audio signal processing circuit 307.

As shown in FIG. 7A, a television set can be completed by incorporating a display module into a housing 401. A display panel 200 is formed by the display module. Further, a speaker 310, an input unit 309, and the like are provided as appropriate.

FIG. 7B illustrates a television device in which only a display can be carried wirelessly. The housing 402 incorporates a battery and a signal receiver, and the display panel 200 and the speaker 310 are driven by the battery. The battery can be repeatedly charged by the charger 403. The charger 403 can transmit and receive a video signal, and can transmit the video signal to a signal receiver of the display. The housing 402 is controlled by the input unit 309. The device illustrated in FIG. 7B can also be referred to as a video / audio two-way communication device because a signal can be sent from the housing 402 to the charger 403 by operating the input portion 309. Further, by operating the input unit 309, a signal is transmitted from the housing 402 to the charger 403, and further, a signal that can be transmitted by the charger 403 is received by another electronic device, thereby controlling communication of the other electronic device. It can be said to be a general-purpose remote control device. The present invention can be applied to the display panel 200.

The television device shown in FIGS. 5, 6, and 7A to 7B has the structure according to the present invention, so that on and off potentials applied to the gate electrode of the driving transistor in the pixel portion. And the potential of the data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low. As a result, it is possible to provide a display device with significantly reduced power consumption, and it is possible to provide customers with products with significantly reduced power consumption.

Of course, the present invention is not limited to a television device, but can be applied to various uses such as a monitor for a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

FIG. 8A shows a display module in which the display panel 200 and the circuit board 500 are combined. The display panel 200 includes a pixel portion 118 provided with a plurality of pixels, a first scanning line driving circuit 116, a second scanning line driving circuit 117, and a signal line driving circuit that supplies a video signal to a selected pixel. 120.

The circuit board 500 includes a controller 504, a microprocessor 503 (MPU), a memory 506, a power supply circuit 507, an audio signal processing circuit 505, a transmission / reception circuit 502, and the like. The circuit board 500 and the display panel 200 are connected by a flexible wiring board 217 (FPC). The flexible wiring board 217 may be provided with a storage capacitor, a buffer circuit, and the like to prevent noise from being applied to the power supply voltage and the signal and the rise of the signal from being slowed down. In addition, the controller 504, the audio signal processing circuit 505, the memory 506, the microprocessor 503, the power supply circuit 507, and the like can be mounted on the display panel 200 using a COG (Chip On Glass) method. The scale of the circuit board 500 can be reduced by the COG method.

Various control signals are input / output via an interface 508 provided in the circuit board 500. In addition, an antenna port 501 for transmitting and receiving signals to and from the antenna is provided on the circuit board 500.

FIG. 8B is a block diagram of the display module illustrated in FIG. This display module includes a VRAM 513, a DRAM 514, a flash memory 515, and the like as the memory 506. The VRAM 513 stores image data to be displayed on the panel, the DRAM 514 stores image data or audio data, and the flash memory 515 stores various programs.

The power supply circuit 507 supplies power for operating the display panel 200, the controller 504, the microprocessor 503, the audio signal processing circuit 505, the memory 506, and the transmission / reception circuit 502. Depending on the panel specifications, the power supply circuit 507 may be provided with a current source.

The microprocessor 503 includes a control signal generation circuit 516, a decoder 517, a register 518, an arithmetic circuit 519, a RAM 520, an interface 521 for the microprocessor 503, and the like. Various signals input to the microprocessor 503 via the interface 521 are once held in the register 518 and then input to the arithmetic circuit 519, the decoder 517, and the like. The arithmetic circuit 519 performs an operation based on the input signal and designates a place to send various commands. On the other hand, the signal input to the decoder 517 is decoded and input to the control signal generation circuit 516. The control signal generation circuit 516 generates a signal including various instructions based on the input signal, and a location designated by the arithmetic circuit 519, specifically, the memory 506, the transmission / reception circuit 502, the audio signal processing circuit 505, and the controller 504. Send to etc.

The memory 506, the transmission / reception circuit 502, the audio signal processing circuit 505, and the controller 504 operate according to the received commands. The operation will be briefly described below.

A signal input from the input unit 512 is sent to the microprocessor 503 mounted on the circuit board 500 via the interface 508. The control signal generation circuit 516 converts the image data stored in the VRAM 513 into a predetermined format in accordance with a signal sent from the input unit 512 such as a pointing device or a keyboard, and sends the image data to the controller 504.

The controller 504 performs data processing on a signal including image data sent from the microprocessor 503 in accordance with the panel specifications, and supplies the processed signal to the display panel 200. The controller 504 also uses the Hsync signal, the Vsync signal, the clock signal CLK, the AC voltage (AC Cont), the switching signal L / based on the power supply voltage input from the power supply circuit 507 and various signals input from the microprocessor 503. R is generated and supplied to the display panel 200.

In the transmission / reception circuit 502, a signal transmitted / received as a radio wave is processed by the antenna 511. Specifically, a high frequency such as an isolator, a band pass filter, a VCO (Voltage Controlled Oscillator), an LPF (Low Pass Filter), a coupler, and a balun. Includes circuitry. A signal including audio information among signals transmitted and received in the transmission / reception circuit 502 is sent to the audio signal processing circuit 505 in accordance with a command from the microprocessor 503.

A signal including audio information sent in accordance with a command from the microprocessor 503 is demodulated into an audio signal in the audio signal processing circuit 505 and sent to the speaker 510. The audio signal transmitted from the microphone 509 is modulated by the audio signal processing circuit 505 and is transmitted to the transmission / reception circuit 502 in accordance with a command from the microprocessor 503.

The controller 504, the microprocessor 503, the power supply circuit 507, the audio signal processing circuit 505, and the memory 506 can be mounted as a package of this embodiment. This embodiment can be applied to any circuit other than a high-frequency circuit such as an isolator, a band pass filter, a VCO (Voltage Controlled Oscillator), an LPF (Low Pass Filter), a coupler, and a balun.

FIG. 9 illustrates one mode of a mobile phone including the display module illustrated in FIGS. 8A to 8B. The display panel 200 is incorporated in the housing 604 so as to be detachable. The shape and dimensions of the housing 604 can be changed as appropriate in accordance with the size of the display panel 200. A housing 604 to which the display panel 200 is fixed is fitted to the circuit board 500 and assembled as a display module.

The display panel 200 is connected to the circuit board 500 via the flexible wiring board 217. In addition to a signal processing circuit including a transmission / reception circuit, a microprocessor, a controller, and the like, a speaker 510, a microphone 509, and the like are mounted on the circuit board 500. Such a display module, the input means 512, the battery 603, and the antenna 511 are combined and housed in the housings 601 and 602. The pixel portion of the display panel 200 is disposed so as to be visible from an opening window formed in the housing 601.

The mobile phone according to the present embodiment can be transformed into various modes according to the function and application. For example, a configuration in which a plurality of display panels are provided, or a configuration in which a housing is divided into a plurality of portions and can be opened and closed by a hinge may be employed.

In the mobile phone of FIG. 9, the display panel 200 is configured by arranging pixels similar to those described in the first embodiment in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, the power supply circuit can be significantly reduced or reduced in the cellular phone, so that the housing 601 can be reduced in size and weight. Since the mobile phone according to the present invention has low power consumption and reduced size and weight, a product with improved portability can be provided to customers.

FIG. 10A illustrates a television device, which includes a housing 701, a support base 702, a display panel 200, and the like. In this television apparatus, the display panel 200 is configured by arranging pixels similar to those described in the first embodiment in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, the power supply circuit can be significantly reduced or reduced in the television device. Therefore, the housing 701 can be reduced in size and weight. In the television device according to the present invention, low power consumption and reduction in size and weight are achieved, so that a product suitable for a living environment can be provided to a customer.

FIG. 10B illustrates a computer, which includes a main body 703, a housing 704, a display panel 200, a keyboard 705, an external connection port 706, a pointing mouse 708, and the like. In this computer, the display panel 200 is configured by arranging pixels similar to those described in the first embodiment in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, the power supply circuit can be significantly reduced or reduced in the computer, so that the main body 703 and the housing 704 can be reduced in size and weight. In the computer according to the present invention, low power consumption and reduction in size and weight are achieved, so that a highly convenient product can be provided to customers.

FIG. 10C illustrates a portable computer, which includes a main body 709, a display panel 200, a switch 710, operation keys 712, an infrared port 711, and the like. In this portable computer, the display panel 200 is configured by arranging pixels similar to those described in Embodiment 1 in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, in a portable computer, the power supply circuit can be significantly reduced or reduced, so that the main body 709 can be reduced in size and weight. In the portable computer according to the present invention, low power consumption and reduction in size and weight are achieved, so that a highly convenient product can be provided to customers.

FIG. 10D illustrates a portable game machine including a housing 713, a display panel 200, a speaker portion 714, operation keys 715, a recording medium insertion portion 716, and the like. In this portable game machine, the display panel 200 is configured by arranging pixels similar to those described in the first embodiment in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, in a portable game machine, the power supply circuit can be significantly reduced or reduced, so that the housing 713 can be reduced in size and weight. In the portable game machine according to the present invention, low power consumption and reduction in size and weight are achieved, so that a highly convenient product can be provided to customers.

FIG. 10E shows a portable image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 717, a housing 718, a display panel 200a, a display panel 200b, and a recording medium (DVD or the like). A reading unit 719, an operation key 720, a speaker unit 721, and the like are included. The display panel 200a mainly displays image information, and the display panel 200b mainly displays character information. In this image reproducing apparatus, the display panel 200a and the display panel 200b are configured by arranging pixels similar to those described in the first embodiment in a matrix. In the display panel, an on / off potential applied to a gate electrode of a driving transistor in a pixel and a potential of a data line can be set separately. Therefore, the maximum amplitude of the potential of the data line can be set low, and the power consumption can be greatly suppressed. With such a feature, the power supply circuit can be significantly reduced or reduced in the image reproducing device, so that the main body 717 and the housing 718 can be reduced in size and weight. Since the image reproducing apparatus according to the present invention achieves low power consumption and reduction in size and weight, a highly convenient product can be provided to customers.

Display panels used in these electronic devices can use not only a glass substrate but also a heat-resistant plastic substrate depending on the size, strength, or purpose of use. As a result, the weight can be further reduced.

It should be noted that the examples shown in the present embodiment are only examples and are not limited to these applications.

In addition, this embodiment can be implemented by freely combining with the configurations of the first to third embodiments.

FIG. 5A is a circuit diagram of a display device referred to in an embodiment. FIG. 5B is a timing chart. 2 is a cross-sectional view of a display device referred to in Embodiment 1. FIG. FIG. 10 is a perspective view of a display device referred to in Example 2. FIG. 10 is a circuit diagram of a display device referred to in Example 3. FIG. 10 is a diagram of an electronic device referred to in Example 4. FIG. 10 is a diagram of an electronic device referred to in Example 4. FIG. 10 is a diagram of an electronic device referred to in Example 4. FIG. 10 is a diagram of an electronic device referred to in Example 4. FIG. 10 is a diagram of an electronic device referred to in Example 4. FIG. 10 is a diagram of an electronic device referred to in Example 4. The figure which shows a prior art example.

Explanation of symbols

100 pixel 101 selection transistor 102 reset transistor 103 switch transistor 104 drive transistor 105 holding capacitor 106 light emitting element 107 first scanning line 108 second scanning line 109 data line 110 current supply line 111 counter electrode 112 inverter 113 first n channel Transistor 114 Second n-channel transistor 115 GND
116 First scanning line driving circuit 117 Second scanning line driving circuit 118 Pixel portion 119 Scanning line auxiliary circuit 120 Signal line driving circuit 121 First monitoring power supply line 122 Monitoring current source 123 Sampling circuit 124 Monitoring light emitting element 125 Second monitor power line 200 Display panel 200a Display panel 200b Display panel 201 Substrate 202 Crystalline semiconductor film 203A Conductive film 203B Conductive film 204 First insulating film 205 Second insulating film 206 Interlayer insulating film 207 Conductive film 208 Third Insulating film 209 Pixel electrode 210 Light emitting layer 211 Counter electrode 212 Select transistor 213 Drive transistor 214 Light emitting element 215 Counter substrate 216 Flexible wiring board connection portion 217 Flexible wiring board 300 Circuit board 301 Transmission / reception circuit 302 Video signal amplification circuit 303 Video signal Logic circuit 304 Control circuit 305 Signal division circuit 306 Audio signal amplification circuit 307 Audio signal processing circuit 308 Control circuit 309 Input unit 310 Speaker 401 Case 402 Case 403 Charger 500 Circuit board 501 Port for antenna 502 Transmission / reception circuit 503 Microprocessor 504 Controller 505 Audio signal processing circuit 506 Memory 507 Power supply circuit 508 Interface 509 Microphone 510 Speaker 511 Antenna 512 Input means 513 VRAM
514 DRAM
515 Flash memory 516 Control signal generation circuit 517 Decoder 518 Register 519 Arithmetic circuit 520 RAM
521 Interface 601 Case 602 Case 603 Battery 604 Housing 701 Case 702 Support base 703 Main body 704 Case 705 Keyboard 706 External connection port 708 Pointing mouse 709 Main body 710 Switch 711 Infrared port 712 Operation key 713 Case 714 Speaker portion 715 Operation Key 716 Recording medium insertion portion 717 Main body 718 Case 719 Recording medium reading portion 720 Operation key 721 Speaker portion 2401 Switch transistor 2402 Drive transistor 2403 Retention capacitance 2404 Light emitting element 2405 Scan line 2406 Data line 2407 Current supply line 2408 Counter electrode

Claims (6)

A power line;
A first scanning line having one end connected to the first scanning line driving circuit;
A second scanning line having one end connected to the second scanning line driving circuit;
A scanning line auxiliary circuit connected to the other end of the first scanning line and having at least one switching element;
The switching element is controlled by the signal potential of the first scanning line and the signal potential of the second scanning line supplied by the second scanning line driving circuit, and the switching element is interposed through the switching element. A display device, wherein a power supply line and the first scanning line are made conductive. A power line;
A first scanning line having one end connected to the first scanning line driving circuit;
A second scanning line having one end connected to the second scanning line driving circuit;
A scanning line auxiliary circuit connected to the other end of the first scanning line and having at least one switching element;
A drive transistor connected in series between the current supply line and the light emitting element;
A storage capacitor in which one electrode is connected to the gate electrode of the driving transistor and the other electrode is connected to the current supply line;
A reset transistor in which the first scanning line and a gate electrode are connected, and the current supply line and one of a source electrode and a drain electrode are connected;
A switch transistor connected between the second scanning line and a gate electrode, and connected between the other electrode of the reset transistor and one electrode of the storage capacitor;
A data line and a gate electrode, and a selection transistor inserted in series between the switch transistor and the first scan line, and
The switching element is controlled by the signal potential of the first scanning line and the signal potential of the second scanning line supplied by the second scanning line driving circuit, and the switching element is interposed through the switching element. A display device, wherein a power supply line and the first scanning line are made conductive and a gate potential of the driving transistor is made equal to a potential of the power supply line. A power line;
A first scanning line driving circuit;
A second scanning line driving circuit;
A first scan line;
A second scan line;
A first transistor;
A second transistor;
An inverter,
One end of the first scanning line is connected to the first scanning line driving circuit,
The other end of the first scanning line is connected to an input terminal of the inverter,
One end of the second scanning line is connected to the second scanning line driving circuit,
A gate electrode of the first transistor is connected to an output terminal of the inverter;
One of the source electrode and the drain electrode of the first transistor is connected to the other end of the first scanning line,
A gate electrode of the second transistor is connected to one end of the second scanning line or the second scanning line driving circuit;
One of a source electrode and a drain electrode of the second transistor is connected to the other of the source electrode and the drain electrode of the first transistor;
The other of the source electrode and the drain electrode of the second transistor is connected to the power supply line. A power line;
A first scanning line driving circuit;
A second scanning line driving circuit;
A first scan line;
A second scan line;
A first transistor;
A second transistor;
An inverter,
One end of the first scanning line is connected to the first scanning line driving circuit,
The other end of the first scanning line is connected to an input terminal of the inverter,
One end of the second scanning line is connected to the second scanning line driving circuit,
A gate electrode of the first transistor is connected to one end of the second scanning line or the second scanning line driving circuit;
One of the source electrode and the drain electrode of the first transistor is connected to the other end of the first scanning line,
A gate electrode of the second transistor is connected to an output terminal of the inverter;
One of a source electrode and a drain electrode of the second transistor is connected to the other of the source electrode and the drain electrode of the first transistor;
The other of the source electrode and the drain electrode of the second transistor is connected to the power supply line. A power line;
A first scanning line having one end connected to the first scanning line driving circuit;
A second scanning line having one end connected to the second scanning line driving circuit;
A scanning line auxiliary circuit connected to the other end of the first scanning line and having at least one switching element;
A drive transistor connected in series between the current supply line and the light emitting element;
A selection transistor in which a data line and a gate electrode are connected, and the first scanning line and one of a source electrode and a drain electrode are connected;
A switch transistor connected between the second scanning line and the gate electrode, and connected between the other of the source or drain of the selection transistor and the gate of the driving transistor;
The switching element is controlled by the signal potential of the first scanning line and the signal potential of the second scanning line supplied by the second scanning line driving circuit, and the switching element is interposed through the switching element. A display device, wherein a power supply line and the first scanning line are made conductive and a gate potential of the driving transistor is made equal to a potential of the power supply line. In any one of Claims 1 thru | or 5 ,
A display device, wherein a signal potential supplied from the first scan line driver circuit is equal to a potential of the power supply line.

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