JP4893207B2 - Electronic circuit, electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to a technique for controlling the behavior of various electro-optical elements such as a light-emitting element made of an organic EL (Electro Luminescence) material.

  2. Description of the Related Art Conventionally, an electro-optical device that displays an image by controlling the luminance of light emitting elements arranged in a planar shape has been proposed. Of this type of electro-optical device, a type of electro-optical device in which light emission of each light-emitting element is maintained over substantially the entire length of one frame period is called a hold type.

  As disclosed in Non-Patent Document 1, in a hold-type display device, due to a shift between a movement of a subject included in an image and a movement of an observer's viewpoint that follows the movement, A phenomenon (hereinafter referred to as “moving image blur”) in which the outline of the perceived subject becomes unclear occurs. As a measure for solving this motion blur, each light emitting element does not maintain the gradation of each light emitting element over the entire length of the frame period, but instead emits each light like an impulse type display device represented by CRT (Cathode Ray Tube). There is a method in which the element emits light intermittently. An organic light-emitting diode element (hereinafter referred to as OLED (Organic Light Emitting Diode)) element is referred to. In order to reduce moving image blur even in a display device using the above), it is necessary to perform impulse type driving.

FIG. 12 shows an example of a pixel circuit using an OLED element. In this pixel circuit, the transistor Q1 is turned on during the selection period, and the data potential corresponding to the gradation to be displayed is taken in and held in the capacitor C. A drive current corresponding to the data potential is output from the transistor Q2. The transistor Q3 is provided between the OLED element EL and the transistor Q2, and controls the light emission period of the OLED element EL.
Shingaku Techniques, EID2001-84 (2002-01) p13-p18 “Time Response of Display and High Quality of Video”, Yashiro Kurita / The Institute of Electronics, Information and Communication Engineers (especially Figure 3)

By the way, when the impulse type drive is performed, the light emission period is reduced as compared with the hold type drive, so that the luminance is lowered. In order to compensate for this luminance, it is necessary to increase the luminance for the light emission period as shown in FIG.
However, in order to cause the OLED element EL to emit light with instantaneously high luminance, a large drive current is required, and there is a problem that the circuit load increases due to problems such as withstand voltage.
The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress moving image blur with a simple configuration.

In order to solve the above problems, an electronic circuit according to the present invention includes a drive transistor that generates a drive current according to a gate potential, a gate potential control unit that changes the gate potential within a drive period, and the drive current. In each of a plurality of unit periods that divide the driving period, an electro-optical element that emits light when supplied, a first switching element that switches conduction or interruption of a path for supplying the driving current to the electro-optical element, and A light emission period control unit that controls an on state or an off state of one switching element according to a gradation to be displayed , wherein the gate potential control unit includes a first electrode connected to a gate of the driving transistor; A second electrode connected to a source of the driving transistor, and a voltage between the first electrode and the second electrode is continuously reduced with a predetermined time constant. The first capacitor for changing the gate potential within the driving period, the potential line to which the reference potential for setting the initial value of the driving current by being applied to the gate of the driving transistor is supplied, and the first capacitor A second switching element provided between the first electrode of one capacity and turned on in an initialization period immediately before the driving period and turned off in the driving period.

According to the present invention, since it is possible to control whether or not the electro-optic element emits light for each unit period using the first switching element and the light emission period control unit , the drive method can be brought close to impulse type drive. Compared with hold-type driving, it is possible to suppress moving image blur. If the magnitude of the drive current in each unit period is constant, the number of gradations that can be engraved in the drive period is limited by the number of unit periods included therein. On the other hand, according to the present invention, since the gate potential control unit changes the gate potential of the drive transistor during the drive period , the magnitude of the drive current changes accordingly. In addition, since it is controlled in which unit period constituting the drive period the drive current is supplied to the electro-optic element, it is possible to engrave multiple gradations.

The voltage held in the first capacitor changes with a predetermined time constant. This time constant is determined by the capacitance component of the first capacitor and the resistance component in parallel therewith. Thus, by setting the potential of the first electrode of the first capacitor to the reference potential immediately before the driving period, the gate potential of the driving transistor can be changed from the reference potential with a predetermined time constant within the driving period . The time constant may be determined such that the voltage held by the first capacitor in the driving period changes from 100% to 20% or less. By doing so, the capacitance component can be designed to be smaller than the conventional value. That is, the area occupied by the first capacitor can be reduced.

In the electronic circuit described above, the first switching element is turned on when the logic level of the control terminal is the first level and is conducted through the path, and is turned off when the logic level of the control terminal is the second level. The light emission period control unit shuts off the path, the light emission period control unit includes a second capacitor that holds the potential of the control terminal, a third switching element provided between a data line to which a data signal is supplied and the control terminal, And the third switching element is turned on for a predetermined time from the start of the unit period, and the data signal has the predetermined period according to the gradation to be displayed by the electro-optical element in the predetermined period. In each of the plurality of divided unit periods, it is preferable to be one of the first level and the second level.

According to the present invention, since the binary data signal is held by the second capacitor element, the data signal can be taken in by turning on the third switching element in a very short predetermined time from the start of the unit period .

Next, an electro-optical device according to the present invention includes a plurality of scanning lines, a plurality of data lines, a plurality of light emission control lines, and a plurality of scanning lines provided corresponding to the intersections of the scanning lines and the data lines. An electro-optical device that drives each of the plurality of electronic circuits by dividing into an initialization period and a drive period composed of a plurality of unit periods, the scanning signal being effective in the initialization period Scanning line driving means for sequentially supplying the plurality of scanning lines to each of the plurality of scanning lines, and in each of the plurality of unit periods, a light emission control signal that is valid for a predetermined time from the start of the unit period is sequentially supplied to the plurality of light emission control lines. Light emission control means and data line driving means for supplying binary data signals to each of the plurality of data lines, and each of the plurality of electronic circuits generates a drive current according to a gate potential. Driving transition And a gate potential controller configured to set the gate potential of the drive transistor to a reference potential in the initialization period based on the scanning signal, and to change the gate potential from the reference potential in the drive period; and An electro-optical element that emits light when supplied; a first switching element that switches between conduction and interruption of a path for supplying the driving current to the electro-optical element; and each of the plurality of unit periods based on the light emission control signal. A light emission period control unit that controls an on state or an off state of the first switching element according to a gradation to be displayed by sample-holding a data signal, and the gate potential control unit includes the drive A first electrode connected to the gate of the transistor and a second electrode connected to the source of the driving transistor; The voltage between the first electrode and the second electrode is continuously applied with a predetermined time constant so that the gate potential is changed within the driving period, and applied to the gate of the driving transistor. Thus, it is provided between the potential line to which the reference potential for setting the initial value of the drive current is supplied and the first electrode of the first capacitor, and in the initialization period immediately before the drive period. A second switching element that is turned on and turned off during the driving period.

According to the present invention, since it is possible to control whether or not the electro-optic element emits light for each unit period, the driving method can be brought close to the impulse type driving, and the moving image blur is suppressed as compared with the hold type driving. It becomes possible to do. If the magnitude of the drive current in each unit period is constant, the number of gradations that can be engraved in the drive period is limited by the number of unit periods included therein. On the other hand, according to the present invention, since the gate potential of the driving transistor is changed over the driving period, the magnitude of the driving current changes accordingly. Since it is controlled in which unit period the drive current is supplied to the electro-optical element, it becomes possible to engrave multiple gradations.

Next, an electronic apparatus according to the invention includes the above-described electro-optical device. A typical example of this electronic apparatus is an apparatus using an electro-optical device as a display device. Examples of this type of electronic device include a personal computer and a mobile phone. However, the use of the electro-optical device according to the present invention is not limited to image display. For example, an exposure device (exposure head) for forming a latent image on an image carrier such as a photosensitive drum by irradiation of light, a device (backlight) that is arranged on the back side of the liquid crystal device and illuminates it, or The electro-optical device of the present invention can be applied to various applications such as various illumination devices such as a device that illuminates a document by being mounted on an image reading device such as a scanner.
The electro-optical element according to the present invention means an element whose optical characteristics change depending on electric energy. For example, a light-emitting diode such as an organic light-emitting diode or an inorganic light-emitting diode, or a transmittance changes depending on an applied voltage. Various light emitting elements such as a liquid crystal element, a field emission element, a surface conduction electron emission element, and a ballistic electron emission element are applicable.

<A: Embodiment>
FIG. 1 is a block diagram showing a specific form of an electro-optical device used in various electronic devices as means for displaying an image. As shown in the figure, the electro-optical device D generates a display panel 10 that displays an image, a control circuit 40 that controls each part of the electro-optical device D, a power supply potential VEL, and a ground voltage Gnd. And a power supply circuit 50 to be supplied to

  The display panel 10 includes an element array unit 11 in which a plurality of unit circuits (pixel circuits) U are arranged, a scanning line driving circuit 22 that controls each unit circuit U under the control of the control circuit 40, and a light emission control circuit 23. And a data line driving circuit 25. Each unit circuit U includes a light emitting element E that emits light by supplying electric energy. Each light emitting element E emits light in any of a plurality of light emission colors (red, green, and blue). The three light-emitting elements E that emit red, green, and blue constitute a pixel that is the minimum unit of an image. The light emitting element E of the present embodiment is an OLED element in which a light emitting layer made of an organic EL (ElectroLuminescent) material is interposed between an anode and a cathode. The light quantity of the light emitting element E is determined according to the magnitude of the drive current IEL.

  The element array unit 11 includes m scanning lines 12 extending in the X direction, m light emission control lines 13 extending in the X direction in pairs with the scanning lines 12, and orthogonal to the X direction. N data lines 15 extending in the Y direction are formed (each of m and n is a natural number of 2 or more). Each unit circuit U (electronic circuit) is arranged at a position corresponding to each intersection of the pair of scanning lines 12 and light emission control lines 13 and the data lines 15. Accordingly, these unit circuits U are arranged in a matrix of m rows × n columns. In the element array section 11, a power supply line 17 and a potential line 18 extending from the power supply circuit 50 to each unit circuit U are formed. The power supply potential VEL output from the power supply circuit 50 is supplied to each unit circuit U via the feeder line 17, and the reference potential Vref output from the power supply circuit 50 is supplied to each unit circuit U via the potential line 18. Is done.

  The control circuit 40 defines the operation timing of each part of the electro-optical device D by supplying various control signals such as a clock signal and a synchronization signal. The control circuit 40 of this embodiment includes a conversion circuit 42 that converts the input gradation data G1 according to a predetermined rule to generate output image data G2. The input gradation data G1 is data that designates the gradation (luminance) of each light emitting element E, and is supplied to the conversion circuit 42 from various host devices such as a CPU of an electronic device in which the electro-optical device D is mounted.

  FIG. 2 shows an outline of the operation of the unit circuit U. One field period 1F in which the unit circuit U operates is divided into an initialization period Tini and a driving period Td (predetermined period). The initialization period Tini is a period for setting an initial value of the drive current IEL. In this embodiment, the magnitude of the drive current IEL set in the initialization period Tini is changed in the drive period Td. The driving period Td is divided into a plurality of subfield periods FS (unit period). In this example, the driving period Td is composed of 16 subfield periods FS. Then, it is controlled whether or not the drive current IEL is supplied to the light emitting element E every subfield period FS. The gradation of the light emitting element E is determined by the average light amount of the light emitting element E in each sub-fard period FS. The output image data G2 designates whether or not the drive current IEL is supplied to the light emitting element E in each subfield period FS. The conversion circuit 42 described above includes a table in which the values of the input gradation data G1 and the values of the output image data G2 are stored in association with each other, and the output image data G2 is generated with reference to this table.

  Returning to FIG. The scanning line driving circuit 22 generates scanning signals Gwrt [1] to Gwrt [m] for selecting each of the m scanning lines 12 and outputs the scanning signals Gwrt [1] to Gwrt [m] to each scanning line 12. In the driving period, each of the scanning signals Gwrt [1] to Gwrt [m] sequentially changes to a high level. That is, the scanning signal Yi output to the scanning line 12 in the i-th row (i is an integer satisfying 1 ≦ i ≦ m) is at a high level in the i-th horizontal scanning period in the frame period (that is, the first line). The i-th scanning line 12 is selected), and the low level is maintained in other periods.

Further, the scanning line driving circuit 22 generates the light emission control signals GEL [1] to GEL [m] that become high level for a predetermined time from the start of each subfield period FS, and outputs the light emission control signals GEL [1] to GEL [m] to each light emission control line 13.
The data line driving circuit 25 outputs data signals X1 to Xn to each data line 15. The data signals X1 to Xn are signals that are generated based on the output image data G2, and specify whether or not to supply the drive current IEL to the light emitting element E in each subfield period FS. The data signal X (X1 to Xn) has a binary logic level. At the logic level “0”, the ground potential Gnd is set, and the first transistor Tr1 is set to the OFF state. On the other hand, at the logic level “1”, the potential becomes equal to or higher than the power supply potential VEL, and the first transistor Tr1 is turned on. Note that the data signal X (X1 to Xn) is set to “0” for a predetermined time from the start of the initialization period Tini, and the light emission control signals GEL [1] to GEL [m] are at a high level in synchronization with this. It becomes. As a result, the first transistor Tr1 is turned off in the initialization period Tini.

  Next, the configuration of each unit circuit U will be described with reference to FIG. In the figure, only one unit circuit U in the j-th column belonging to the i-th row is shown, but all unit circuits U of the element array unit 11 have the same configuration. As shown in FIG. 3, the unit circuit U includes a light emitting element E disposed on a path from the power supply line 17 to the ground line (ground voltage Gnd). The light emitting element E of the present embodiment emits light with luminance (luminous intensity) corresponding to the current value of the drive current IEL. The cathode of the light emitting element E is grounded (ground potential Gnd).

  A p-channel transistor (hereinafter referred to as “driving transistor”) Tdr is disposed on the path of the current IEL (between the feeder line 17 and the light emitting element E). The drive transistor Tdr is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) that controls the current value of the current IEL according to the gate potential, and the source is connected to the power supply line 17. Between the drain of the drive transistor Tdr and the anode of the light emitting element E, an n-channel first transistor Tr1 for controlling electrical connection (conduction / non-conduction) between the two is interposed. The gate potential control unit Ua functions as means for changing the gate potential of the drive transistor Tdr over the drive period Td. Further, the light emission period control unit Ub functions as means for controlling whether the first transistor Tr1 is turned on or off for each subfield period FS.

  FIG. 4 shows a detailed configuration of the unit circuit U. The gate potential control unit Ua includes a first capacitive element C1 and an n-channel second transistor Tr2. The first electrode C1a of the first capacitive element C1 is connected to the gate of the driving transistor Tdr, and the second electrode C1b is connected to the source of the driving transistor Tdr. Since the power supply potential VEL is supplied to the source of the driving transistor Tdr, the potential of the second electrode C1b is fixed. The second transistor Tr2 is provided between the first electrode C1a of the first capacitor C1 and the potential line 18, and the gate thereof is electrically connected to the scanning line 12. The second transistor Tr2 functions as a switching element that sets the reference potential Vref supplied via the potential line 18 as the initial potential of the drive transistor Tdr.

  When the second transistor Tr2 is turned off, the first capacitor element C1 ideally holds the reference potential Vref, but there is a leakage current in the first capacitor element C1 in this example. An equivalent circuit of the first capacitive element C1 is shown in FIG. As shown in this figure, the first capacitive element C1 is equivalently an element in which a resistor Rx and a capacitor Cx are connected in parallel, and its time constant is Rx · Cx. When the second transistor Tr2 is turned on, the reference potential Vref is applied to the first electrode C1a, while the power supply potential VEL is applied to the second electrode C1b. Therefore, the voltage ΔV held by the first capacitive element C1 is ΔV = VEL−Vref. This voltage ΔV decreases according to the time constant described above. For this reason, the gate potential of the drive transistor Tdr gradually increases. Therefore, the gate potential control unit Ua functions as means for monotonically increasing the gate potential of the drive transistor Tdr from the reference potential Vref in the drive period Td. The gate potential control unit Ua may be configured to monotonously decrease the gate potential of the drive transistor Tdr from the reference potential Vref in the drive period Td.

  Returning to FIG. The light emission period control unit Ub includes a second capacitive element C2 and an n-channel third transistor Tr3. The first electrode C2a of the second capacitive element C2 is connected to the gate of the first transistor Tr1, and the second electrode C2b is grounded. The third transistor Tr3 is provided between the first electrode C2a of the second capacitive element C2 and the data line 15, and its gate is electrically connected to the light emission control line 13. The light emission control signal GEL [i] supplied via the light emission control line 13 becomes high level for a predetermined time from the start of each subfield period FS. During this predetermined time, the data signal Xj is captured and held in the second capacitor element C2.

FIG. 6 is a timing chart for explaining the operation of the electro-optical device D. As shown in this figure, the scanning signals Gwrt [1] to Gwrt [m] are sequentially set to the high level every horizontal scanning period 1H. Thereby, the reference potential Vref is sequentially taken into each unit circuit U.
As shown in FIG. 7, in the unit circuit U of i row and j column, in the initialization period Tini in which the scanning signal Gwrt [i] is at the high level, the second transistor Tr2 is turned on and the reference potential Vref is set to the first capacitance. Applied to element C1. As a result, the voltage VEL−Vref is held in the first capacitor element C1. On the other hand, the light emission control signal GEL [i] remains at a high level until a predetermined time has elapsed from the initialization period Tini. At this time, the data signal Xj is “0”. Therefore, in the initialization period Tini, the second capacitor element C2 holds the ground potential Gnd, and the first transistor Tr1 is turned off. Note that the initialization period Tini is extremely short compared to the driving period Td, and if the light emitting element E emits light during this period and the influence on the gradation to be displayed is small enough to be allowed, the initialization period Tini The light emission control signal GEL [i] may be set to a low level.

  Here, when the voltage held in the first capacitive element C1 is ΔV with the potential of the first electrode C1a as a reference, the holding voltage ΔV gradually decreases in the driving period Td as shown in FIG. The light emission control signal GEL [i] becomes high level for a predetermined time from the start of each subfield period FS constituting the driving period Td. At this time, the data signal Xj specifying the gradation of the unit circuit U in the i-th row and j-th column is supplied to the j-th data line 15 in synchronization with the light emission control signal GEL [i]. In this example, “0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0” is obtained, and the gate potential of the first transistor Tr1 is third. It becomes the high level in the sixth, seventh, twelfth and twelfth subfield periods FS. For example, in the period in which the light emission control signal GEL [i] is at a high level from the start of the third subfield period FS, the unit circuit U in the i row and j column operates as shown in FIG. When the light emission control signal GEL [i] transits from the high level to the low level in the third subfield period FS, the third transistor Tr3 is turned off. At this time, since the high-level potential is held in the second capacitor element C2, the first transistor Tr1 is kept on in the third subfield period FS.

  Thus, the first transistor Tr1 is turned on in the third, sixth, seventh, and twelfth subfield periods FS. Therefore, the drive current IEL is as shown in FIG. Since the holding voltage ΔV of the first capacitive element C1 changes in the driving period Td, the driving current IEL flowing through the light emitting element E also changes in the third, sixth, seventh, and twelfth subfield periods FS. To do.

  If the magnitude of the drive current IEL in each subfield period FS is constant, only the gradations 0 to 16 can be carved in the 16 subfield periods FS. On the other hand, in this embodiment, since the gate potential of the drive transistor Tdr is controlled using the gate potential control unit Ua so as to change the magnitude of the drive current IEL in the drive period Td, each subfield period FS The light emission luminance of the light emitting element E is different. Therefore, multiple gradations can be engraved by a combination of subfield periods FS in which the light emitting element E emits light. Further, in the present embodiment, since it is controlled whether or not the driving current IEL is supplied to the light emitting element E every subfield period FS, the driving method can be made to be an impulse type, and motion blur can be reduced. it can. As a result, it is possible to realize multi-gradation while improving blurring of moving images, and to greatly improve display quality.

  In the above-described embodiment, an organic light-emitting diode element is exemplified as the light-emitting element E. However, the present invention is also applied to an electro-optical device using other light-emitting elements. For example, a light-emitting element or light-emitting diode element including a light-emitting layer made of an inorganic EL material, a field emission (FE) element, a surface-conduction electron-emitter (SE) element, a ballistic electron emission (BS) : Various ballistic electron surface emitting elements can be used in the electro-optical device of the present invention.

<B: Application example>
Next, electronic equipment using the electro-optical device according to the invention will be described. 9 to 11 show a form of an electronic apparatus that employs the electro-optical device D according to any one of the above forms as a display device.
FIG. 9 is a perspective view showing the configuration of a mobile personal computer employing the electro-optical device D. The personal computer 2000 includes an electro-optical device D that displays various images, and a main body 2010 on which a power switch 2001 and a keyboard 2002 are installed. Since the electro-optical device D uses an organic light-emitting diode element as the light-emitting element E, it is possible to display an easy-to-see screen with a wide viewing angle.

  FIG. 10 is a perspective view illustrating a configuration of a mobile phone to which the electro-optical device D is applied. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and an electro-optical device D that displays various images. By operating the scroll button 3002, the screen displayed on the electro-optical device D is scrolled.

  FIG. 11 is a perspective view illustrating a configuration of a personal digital assistant (PDA) to which the electro-optical device D is applied. The portable information terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and an electro-optical device D that displays various images. When the power switch 4002 is operated, various information such as an address book and a schedule book are displayed on the electro-optical device D.

  The electronic apparatus to which the electro-optical device according to the present invention is applied includes the digital still camera, the television, the video camera, the car navigation device, the pager, the electronic notebook, and the electronic paper in addition to the apparatuses shown in FIGS. Calculators, word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices with touch panels, and the like. The use of the electro-optical device according to the invention is not limited to image display. For example, in an image forming apparatus such as an optical writing type printer or an electronic copying machine, an optical head (writing head) that exposes a photosensitive member according to an image to be formed on a recording material such as paper is used. The electro-optical device of the present invention is also used as this type of optical head.

1 is a block diagram illustrating a configuration of an electro-optical device according to an embodiment of the invention. FIG. It is a timing chart which shows the outline of operation | movement of a unit circuit. It is a block diagram which shows the structure of a unit circuit. It is a circuit diagram which shows the detailed structure of a unit circuit. It is a circuit diagram which shows the equivalent circuit of a 1st capacitive element. 6 is a timing chart showing the operation of the electro-optical device. It is explanatory drawing which shows operation | movement of the unit circuit in an initialization period. It is explanatory drawing which shows operation | movement of the unit circuit in a unit period. It is a perspective view which shows the form (personal computer) of the electronic device which concerns on this invention. It is a perspective view which shows the form (cellular phone) of the electronic device which concerns on this invention. It is a perspective view which shows the form (mobile information terminal) of the electronic device which concerns on this invention. It is a circuit diagram which shows an example of the pixel circuit using the conventional OLED element. It is a graph which compares an impulse type drive and a hold type drive.

Explanation of symbols

D: Electro-optical device, 10: Display panel, 11: Element array section, U: Unit circuit, E: Light emitting element, 12: Scan line, 13: Light emission control line, 15: Data line , 17... Power supply line, 18... Potential line, 22... Scanning line drive circuit, 25... Data line drive circuit, 40... Control circuit, Tdr ... drive transistor, Tr1 ... first transistor, Tr2. ... second transistor, Tr3 ... third transistor, C1 ... first capacitor element, C2 ... second capacitor element, Ua ... data potential control unit, Ub ... light emission period control unit.

Claims (4)

A drive transistor that generates a drive current according to the gate potential;
A gate potential controller that changes the gate potential within a driving period;
An electro-optical element that emits light by supplying the driving current;
A first switching element that switches between conduction and interruption of a path for supplying the driving current to the electro-optic element;
A light emission period control unit configured to control an on state or an off state of the first switching element according to a gradation to be displayed in each of a plurality of unit periods into which the driving period is divided;
The gate potential controller is
A first electrode connected to a gate of the driving transistor; and a second electrode connected to a source of the driving transistor, wherein a voltage between the first electrode and the second electrode is a predetermined time constant. A first capacitor that continuously decreases to change the gate potential within the driving period;
Immediately before the driving period, provided between a potential line to which a reference potential for setting an initial value of the driving current is applied by being applied to the gate of the driving transistor and the first electrode of the first capacitor. And a second switching element that is turned on in the initialization period and turned off in the driving period. The first switching element is turned on when the logic level of the control terminal is at the first level to conduct the path, and the logic level of the control terminal is turned off at the second level to block the path.
The light emission period controller is
A second capacitor for holding the potential of the control terminal;
A third switching element provided between a data line to which a data signal is supplied and the control terminal;
The third switching element is turned on for a predetermined time from the start of the unit period,
The data signal is one of the first level and the second level in each of a plurality of unit periods in which the predetermined period is divided according to the gradation that the electro-optic element should display in a predetermined period. ,
The electronic circuit according to claim 1. A plurality of scanning lines, a plurality of data lines, a plurality of light emission control lines, and a plurality of electronic circuits provided corresponding to intersections of the scanning lines and the data lines. An electro-optical device that drives each of the plurality of electronic circuits divided into a driving period consisting of a unit period,
A scanning line driving means for sequentially supplying a scanning signal effective in the initialization period to the plurality of scanning lines;
In each of the plurality of unit periods, a light emission control unit that sequentially supplies a light emission control signal that is valid for a predetermined time from the start of the unit period to the plurality of light emission control lines;
Data line driving means for supplying a binary data signal to each of the plurality of data lines,
Each of the plurality of electronic circuits is
A drive transistor that generates a drive current according to the gate potential;
A gate potential controller configured to set a gate potential of the driving transistor to a reference potential in the initialization period based on the scanning signal, and to change the gate potential from the reference potential in the driving period;
An electro-optical element that emits light by supplying the driving current;
A first switching element that switches between conduction and interruption of a path for supplying the driving current to the electro-optic element;
In each of the plurality of unit periods, the data signal is sampled and held based on the light emission control signal, so that the on state or the off state of the first switching element is controlled according to the gradation to be displayed. A period control unit,
The gate potential controller is
A first electrode connected to a gate of the driving transistor; and a second electrode connected to a source of the driving transistor, wherein a voltage between the first electrode and the second electrode is a predetermined time constant. A first capacitor that continuously decreases to change the gate potential within the driving period;
The drive transistor is provided between a potential line to which the reference potential for setting an initial value of the drive current is applied by being applied to the gate of the drive transistor and the first electrode of the first capacitor, An electro-optical device including: a second switching element that is turned on in the immediately preceding initialization period and turned off in the driving period. An electronic apparatus comprising the electro-optical device according to claim 3.

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