JP4797336B2 - Electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an electro-optical device that drives a current-driven element such as an organic light-emitting diode element, a driving method thereof, and an electronic apparatus.

In recent years, organic light emitting diodes (Organic Light Emitting), called organic electroluminescent elements and light emitting polymer elements, are the next generation of light emitting devices that can replace liquid crystal elements.
Diodes (hereinafter referred to as “OLED elements” where appropriate) are drawing attention. Since this OLED element is a self-luminous type, it has less viewing angle dependence, and since it does not require a backlight or reflected light, it is suitable for low power consumption and thinning. It has characteristics.
Here, the OLED element is a current-type driven element that does not have voltage holdability like a liquid crystal element and cannot maintain a light emitting state when current is interrupted. Therefore, when an OLED element is driven by an active matrix method, a voltage corresponding to the gradation of the pixel is written to the gate of the driving transistor in the writing period (selection period), and the voltage is held by a gate capacitance or the like. In general, the drive transistor keeps a current corresponding to the gate voltage flowing through the OLED element.

In this configuration, it has been pointed out that the threshold voltage characteristics of the driving transistor vary, and therefore the brightness of the OLED element is different for each pixel and the display quality is lowered. Therefore, in recent years, during the writing period, the drive transistor is diode-connected, and a constant current is passed from the drive transistor to the data line, so that the current corresponding to the current to be passed to the OLED element is passed to the gate of the drive transistor. There has been proposed a technique that compensates for variations in threshold voltage characteristics of drive transistors by programming to write a voltage (see, for example, Patent Documents 1 and 2).
US Pat. No. 6,229,506 (see FIG. 2) Japanese Patent Laying-Open No. 2003-177709 (see FIG. 3)

  By the way, when the display area of the electro-optical device is divided into a plurality of sub-areas, and there are variations in the characteristics of the OLED elements and transistors for each sub-area, when each sub-area is driven by an individual drive module, In some cases, different types of elements are used as the OLED elements in each region. In such an electro-optical device, the conventional technique has a problem that the display brightness cannot be made uniform among a plurality of sub-regions, and the brightness in the screen is different.

  SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device, a driving method thereof, and an electronic apparatus that can make the luminance of a plurality of regions uniform. is there.

  In order to solve the above problems, an electro-optical device according to the present invention supports a plurality of scanning lines, a plurality of data lines, and an intersection of the scanning lines and the data lines in a display region having a plurality of sub-regions. And each of the plurality of pixel circuits is based on an electro-optic element, a reference voltage, and a data voltage supplied via the data line. Current supply means for generating a drive current and supplying the drive current to the electro-optic element, and individually supplying the reference voltage corresponding to each of the plurality of sub-regions so that the luminance of the plurality of sub-regions approaches a target value. And a power supply means for generating.

  According to the present invention, since the drive current of the electro-optical element is determined based on the reference voltage and the data voltage, the luminance of the electro-optical element is adjusted by adjusting the reference voltage. Since the reference voltage is set for each sub-region, the luminance between the plurality of sub-regions can be adjusted. The electro-optical element means an element whose optical characteristics can be controlled by an electric action, and includes, for example, an organic light emitting diode. Note that the current supply means preferably generates a drive current according to a differential voltage between the data voltage and the reference voltage.

  In the electro-optical device, the current supply unit is turned on in a first period between a driving transistor that controls a driving current flowing in the electro-optical element, and a gate and a drain of the driving transistor, and the first A first switching element that is turned off by the start timing of the second period after the period, a capacitive element having one end connected to the gate of the driving transistor, and turned on in the first period, and the reference voltage Is applied to the other end of the capacitor, while the second switching element is turned off in the second period and in a third period after the second period, and the other of the data line and the capacitor And a third switching element that is turned on in the second period between the first end and the second end.

  According to this electro-optical device, the voltage corresponding to the threshold value of the driving transistor is held at one end of the capacitor and the gate (node A) of the driving transistor by turning on and off the first switching element. The other end of the capacitive element is changed from the reference voltage by applying a data voltage corresponding to the current to be passed through the electro-optical element, and the voltage at the node A is also changed and held by the amount corresponding to the voltage change. A drive current corresponding to the voltage of the node A after the change flows through the electro-optical element, but the threshold current characteristic of the drive transistor is canceled for the current flowing at this time. In addition, since the capacitor element is held by forcing a current to flow through the electro-optic element, it does not require time. Furthermore, since a voltage corresponding to the current to be passed through the electro-optic element is applied to the other end of the capacitive element and not directly applied to the gate of the driving transistor, the time required for writing the voltage can be shortened. .

  In the electro-optical device described above, the sub-region is configured by a display panel, and the power supply unit has the same target value as the voltage generation unit that individually generates the reference voltage for each of the sub-regions. Preferably, voltage adjusting means for adjusting the reference voltage so that the luminances of the sub-regions approach each other is provided. According to the present invention, when the display area is composed of a plurality of display panels, the luminance between the panels can be made uniform. As a result, the boundary between the panels can be made inconspicuous, and a plurality of display panels can be used as if they were one large display panel.

  The electro-optical device described above includes a plurality of drive modules that drive the plurality of data lines, and the plurality of sub-regions correspond to the data lines that are driven by the plurality of drive modules, Voltage generating means for individually generating the reference voltage for each of the sub-regions, voltage adjusting means for adjusting the reference voltage so that the target values are the same and the luminance of the plurality of sub-regions approaches each other; It is preferable to provide. According to the present invention, when driving using a plurality of drive modules, the luminance of the plurality of sub-regions can be made uniform by adjusting the reference voltage even if there are variations in characteristics between the drive modules. Thereby, the boundary of a sub-region can be made inconspicuous. When one display area is constituted by a plurality of display panels and each display panel is driven by a plurality of drive modules, the range of data lines corresponding to each drive module corresponds to each sub-area. Of course.

  In the electro-optical device described above, each of the plurality of sub-regions is provided with a plurality of types of electro-optical elements having different emission colors, and the power supply unit generates the reference voltage for each sub-region. It is preferable to include a voltage generating unit that generates individually and a voltage adjusting unit that individually sets the target value and adjusts the reference voltage so as to achieve white balance. In electro-optical elements having different emission colors, different materials are selected depending on the emission color, and therefore the emission efficiency is usually different. According to the present invention, the electro-optic elements having different emission colors are arranged for each sub-region, and the reference voltage is individually supplied for each sub-region. Therefore, white balance can be adjusted by individually setting the reference voltages.

  In addition, it is preferable that the voltage adjustment unit measures a current consumed by the pixel circuits in the plurality of sub-regions for each of the sub-regions, and adjusts the reference voltage based on a measurement result. According to the present invention, since the reference voltage is adjusted according to the current consumption for each sub-region, not only the reference voltage is set at the factory but also the reference voltage is constantly adjusted to maintain the optimum state. Is possible.

  Next, an electronic apparatus according to the present invention includes the above-described electro-optical device, and corresponds to, for example, a large display in which a plurality of panels are connected, a personal computer, a mobile phone, and a portable information terminal.

  Next, the driving method of the electro-optical device according to the present invention corresponds to the intersection of the plurality of scanning lines, the plurality of data lines, and the scanning lines and the data lines in the display region having the plurality of sub-regions. And each of the plurality of pixel circuits drives a current generated based on an electro-optic element, a reference voltage, and a data voltage supplied via the data line. Assuming an electro-optical device having a current supply means for supplying current to the electro-optical element as a current, a first step of measuring the luminance of each of the plurality of sub-regions, and the measured luminance is determined for each sub-region. A second step of individually generating the reference voltage corresponding to each of the plurality of sub-regions and supplying the reference voltage to the plurality of sub-regions so as to approach the target value. According to this invention, since the reference voltage supplied to each sub-region is adjusted based on the measurement result of the luminance of each sub-region, the actually measured luminance can be reflected on the luminance to be displayed. As a result, the luminance of the sub area can be adjusted accurately.

  Next, the driving method of the electro-optical device according to the present invention corresponds to the intersection of the plurality of scanning lines, the plurality of data lines, and the scanning lines and the data lines in the display region having the plurality of sub-regions. And each of the plurality of pixel circuits drives a current generated based on an electro-optic element, a reference voltage, and a data voltage supplied via the data line. Assuming an electro-optical device having a current supply means for supplying current to the electro-optical element as a current, a first step of measuring current consumed by the pixel circuits in the plurality of sub-regions for each sub-region is measured. A second reference voltage corresponding to each of the plurality of sub-regions is generated and supplied to the plurality of sub-regions so that the luminance of the plurality of sub-regions approaches a target value based on the measured current; Steps, Provided. According to the present invention, since the reference voltage is set by measuring the current consumption for each sub-region, it is possible to always maintain the optimum state by adjusting the reference voltage.

Here, it is preferable that the target value described above is set so that the luminance values of the plurality of sub-regions are equal. In this case, the luminance between the sub-regions can be made uniform.
In addition, when a plurality of types of electro-optical elements having different emission colors are provided in each of the plurality of sub-regions, it is preferable that the target value is set so as to achieve white balance.

<First Embodiment>
FIG. 1 is a block diagram illustrating a configuration of an electro-optical device according to a first embodiment of the present invention, and FIG. 2 is a circuit diagram of a pixel circuit. As shown in FIG. 1, the electro-optical device 10 is configured by connecting four display panels Z1, Z2, Z3, and Z4. In each of the plurality of display panels Z1 to Z4, a plurality of scanning lines 102 are extended in the horizontal direction (X direction), while a plurality of data lines (signal lines) 112 are arranged in the vertical direction (Y direction in the figure). ). A pixel circuit (electronic circuit) 200 is provided so as to correspond to each intersection of the scanning line 102 and the data line 112.
Here, for convenience of explanation, in the present embodiment, the number of scanning lines 102 (number of rows) of each display panel Z1 to Z4 is “360”, the number of data lines (number of columns) is “480”, and the pixel circuit 200 However, a configuration is assumed in which the pixels are arranged in a matrix of 360 rows × 480 columns. A display area Z of 720 rows × 960 columns is formed by the four display panels Z1 to Z4. In other words, the display area Z is divided into a plurality of sub areas (corresponding to the display panels Z1 to Z4). However, the present invention is not intended to be limited to this arrangement.

Reference voltages V _INI1 , V _INI2 , V _INI3 , and V _INI4 are respectively supplied from the power supply circuit 18 to the display panels _Z1 to _Z4 , and the high voltage VEL and the low voltage Gnd are supplied to the display panels Z1 to Z4. Commonly supplied to Z4. The technical significance of the reference voltages V _{INI1 to} V _INI4 and the higher voltage VEL will be described later. Note that the pixel circuit 200 includes an OLED element 230 described later, and a predetermined image is displayed in gradation by controlling the current to the OLED element 230 for each pixel circuit 200.
In FIG. 1, only the scanning line 102 is extended in the X direction. However, in the present embodiment, in addition to the scanning line 102, as shown in FIG. And 108 extend in the X direction for each row. For this reason, the scanning line 102 and the control lines 104, 106, and 108 are combined into one set and used as the pixel circuit 200 for one row.

The Y driver 14 selects the scanning line 102 row by row for each horizontal scanning period, supplies an H level scanning signal to the selected scanning line 102, and outputs various control signals synchronized with this selection. , Are supplied to the control lines 104, 106 and 108, respectively. That is, the Y driver 14 supplies scanning signals and control signals to the scanning lines 102 and the control lines 104, 106, and 108 for each row.
Here, for convenience of explanation, the scanning signal supplied to the scanning line 102 of the i-th row (i is an integer satisfying 1 ≦ i ≦ 360 and used for generalizing the row) is represented by GWRT-i. Is written. Similarly, control signals supplied to the i-th control lines 104, 106, and 108 are denoted as GSET-i, GINI-i, and GEL-i, respectively.

On the other hand, the X driver 16 applies the pixel circuit for one row corresponding to the scanning line 102 selected by the Y driver 14, that is, to each of the pixel circuits 200 of 1 to 480 columns located in the selected row. A data signal having a voltage corresponding to a current (that is, pixel gradation) to be passed through the OLED element of the circuit 200 is supplied via the data lines 112 in the 1st to 480th columns. Here, the data signal (data voltage) is specified such that the higher the voltage is, the brighter the pixel is. On the contrary, the lower the voltage is, the darker the pixel is specified.
For convenience of explanation, a data signal supplied to the data line 112 in the j-th column (j is an integer satisfying 1 ≦ j ≦ 480 and generalizing the column) is represented by X−j. write.

All the pixel circuits 200 are supplied with a high voltage VEL serving as a power source for the OLED element via the power line 114. In addition, all the pixel circuits 200 are commonly grounded to the voltage reference potential Gnd via the power supply line 118 in this embodiment.
The voltage of the data signal X-j that specifies the black is the lowest gradation of the pixel higher than Gnd, the voltage of the data signal X-j that specifies the white is the highest gray level of the pixel is lower than V _EL Is set. In other words, the voltage range of the data signal Xj is set to be within the power supply voltage.
On the other hand, in the present embodiment, the pixel circuit 200 is supplied with the reference voltage V _INI via the feeder line 116. Here, in this embodiment, the reference voltage V _INI substantially coincides with the lowest value of the voltage range that the data signal X-j can take, that is, the data signal voltage that specifies the lowest gradation of the pixel.
The control circuit 12 supplies the Y driver 14 and the X driver 16 with clock signals (not shown), respectively, to control both drivers, and supplies the X driver 16 with image data that defines the gradation for each pixel. To do.

In the present embodiment, the pixel circuits 200 arranged in a matrix form all have a common configuration. Therefore, the configuration of the pixel circuit 200 will be described as a representative example of the pixel circuit located in i rows and j columns. The reference voltage V _INI1 , V _INI2 , V _INI3 , and V _INI4 to be supplied _differ depending on which display panel _{Z1 to Z4} the pixel circuit 200 belongs to. Described as V _INI .
As illustrated in FIG. 2, the pixel circuit 200 includes an n-channel driving transistor 210, n-channel transistors 211, 212, 213, and 214 that function as first to fourth switching elements, and capacitive elements. It has a functioning capacitor 220 and an OLED element 230 which is an electro-optic element.
Among these, one end (drain) of the transistor 214 is connected to the power supply line 114, and the other end (source) of the transistor 214 is connected to the drain of the driving transistor 210 and one end (drain) of the transistor 211, respectively. Has been. Here, the gate of the transistor 214 is connected to the control line 108 in the i-th row. For this reason, the transistor 214 is turned on when the control signal G _EL-i is at the H level, and is turned off when the control signal G _EL-i is at the L level.

The source of the driving transistor 210 is connected to the anode of the OLED element 230, while the cathode of the OLED element 230 is grounded to the lower voltage Gnd of the power source. For this reason, the OLED element 230 is configured to be electrically inserted together with the drive transistor 210 and the transistor 214 in a path between the high voltage VEL and the low voltage Gnd of the power supply.
The gate of the driving transistor 210 is connected to one end of the capacitor 220 and the source of the transistor 211. For convenience of explanation, one end of the capacitor 220 (the gate of the driving transistor 210) is a node A. As shown by a broken line in FIG. 2, a capacitance is parasitic on this node A. This capacitance is a parasitic capacitance between the node A and the cathode of the OLED element 230, and the capacitance caused by the gate capacitance of the driving transistor, the capacitance of the OLED element 230, the parasitic capacitance of the wiring between the node A and the cathode, and the like. Contains.

The transistor 211 is electrically inserted between the drain and gate of the driving transistor 210, and the gate of the transistor 211 is connected to the control line 104 in the i-th row. Therefore, the transistor 211 is turned on when the control signal G _SET-i becomes the H level, and causes the driving transistor 210 to function as a diode.
On the other hand, one end (drain) of the transistor 212 is connected to the power supply line 116, while the other end (source) is connected to one end (drain) of the transistor 213 and the other end of the capacitor 220. The gate of the transistor 212 is connected to the i-th control line 106. Therefore, the transistor 212 is turned on when the control signal G _INI-i becomes H level.
Further, the other end (source) of the transistor 213 is connected to the data line 112 in the j-th column, and the gate thereof is connected to the scanning line 102 in the i-th row. Therefore, the transistor 213 is turned on when the scanning signal _GWRT-i becomes the H level, and the data signal Xj (voltage) supplied to the data line 112 in the j-th column is supplied to the capacitor 220. It will be applied to the edge.
Here, for convenience of explanation, the other end of the capacitor (the source of the transistor 212 and the drain of the transistor 213) is referred to as a node B.

  Note that the pixel circuits 200 arranged in a matrix type are formed together with the scanning lines 102 and the data lines 112 on a transparent substrate such as glass. For this reason, the driving transistor 210 and the transistors 211, 212, 213, and 214 are configured by TFTs (thin film transistors) using a polysilicon process. The OLED element 230 has a transparent electrode film such as ITO (indium tin oxide) as an anode (individual electrode) and a single metal film such as aluminum or lithium or a laminated film thereof as a cathode (common electrode) on the substrate. The light emitting layer is sandwiched.

Next, the operation of the electro-optical device 10 will be described. FIG. 3 is a timing chart for explaining the operation of the electro-optical device 10.
First, as shown in FIG. 3, the Y driver 14 scans the scanning lines 102 in the first row, the second row, the third row,..., The 360th row from the start of one vertical scanning period (1F). One by one is selected for each horizontal scanning period (1H), and only the scanning signal of the selected scanning line 102 is set to H level, and the scanning signal to the other scanning lines is set to L level.
Here, focusing on one horizontal scanning period (1H) in which the _i-th scanning line 102 is selected and the scanning signal _GWRT-i is at the H level, the horizontal scanning period and operations before and after the horizontal scanning period are shown in FIG. 3 and FIG. 4 will be described with reference to FIGS.

As shown in FIG. 3, the preparation for the writing operation of the pixel circuit 200 in the i-th row and the j-th column starts from the timing t1 that precedes the timing at which the scanning signal GWRT-i changes to the H level by the period Ti. On the other hand, when the scanning signal GWRT-i changes from the H level to the L level again, light emission based on the written voltage starts.
For this reason, the operation of the pixel circuit 200 in the i row and j column is roughly divided into the first period (1) from the timing t1 until the scanning signal GWRT-i changes to the H level, and the scanning signal GWRT-i is The second period can be divided into three, that is, the second period when the level is H level and the third period after the scanning signal GWRT-i is changed to the L level.
These first to third periods are referred to as an initialization period (1), a writing period (2), and a light emission period (3), respectively, paying attention to the operation contents. Of these, the initialization period (1) can be further divided into three periods (1a), (1b), and (1c) in the present embodiment.
Hereinafter, the operation during these periods will be described in order.

First, before the timing t1, the scanning signal G _WRT-i , the control signals G _SET-i , GINI-i, and G _{EL-i are} all at the L level. When the timing t1 is reached, the first period (1a) of the initialization period (1) is reached, and the Y driver 14 sets the control signals GSET-i, GINI-i, and GEL-i to the H level. . Therefore, in the pixel circuit 200, as shown in FIG. 4, the transistor 211 is turned on by the control signal G _SET-i at the H level, so that the driving transistor 210 functions as a diode. Further, the transistor 214 is also turned on by the control signal G _EL-i at the H level.
Therefore, in the period (1a), in the pixel circuit 200, the current flows through the path of the power supply line 114 → the transistor 214 → the driving transistor 210 → the OLED element 230 → the ground Gnd, so that the node A has a voltage corresponding to the current, Specifically, this is the gate voltage of the driving transistor 210 through which the current flows.
On the other hand, the control signal GINI-i is at the H level over the entire initialization period (1) to turn on the transistor 212. For this reason, since the node B is fixed to the reference voltage V _INI throughout the initialization period (1), the voltage state is maintained in the node A located on the opposite side of the node B with respect to the capacitor 220. . Therefore, the node A is held at a voltage corresponding to the current flowing through the OLED element 230 in the period (1a).

  In this period (1a), since a current flows through the OLED element 230, the OLED element 230 emits light. However, since this period (1a) is set to be negligibly short as compared with one vertical scanning period (1F) which is a unit period of display, light emission in the period (1a) is a light emission period described later. The light emission in (3), that is, the light emission due to the flow of the target current to the OLED element 230 is not affected.

Next, when the start timing of the period (1b) of the initialization period (1) is reached, the Y driver 14 returns the control signal GEL-i to the L level, while the control signals GSET-i and GINI-i are both set to H. Keep on level. For this reason, in the pixel circuit 200, as shown in FIG. 5, since the transistor 214 is turned off, the current path of the OLED element 230 is cut off. However, since the transistor 211 is kept on, the driving transistor 210 continues to function as a diode. Therefore, the node A gradually shifts in a self-compensating manner toward the threshold voltage V _thn of the driving transistor 210.
Then, at the end timing of the period (1b), the node A substantially coincides with the threshold voltage V _thn .

Subsequently, at the start timing of the period (1c) of the initialization period (1), the Y driver 14 returns the control signal GSET-i to the L level. For this reason, in the pixel circuit 200, as shown in FIG. 6, the diode connection of the driving transistor 210 is released, so that the voltage of the node A is determined to be V _thn .

Next, in the writing period (2), the Y driver 14 returns the control signal GINI-i to the L level and sets the scanning signal GWRT-i to the H level. Therefore, as shown in FIG. 7, the transistor 212 is turned off and the transistor 213 is turned on.
In the writing period (2), the X driver 16 supplies the data signal Xj having a voltage corresponding to the gradation of the pixel in the i row and the j column to the data line 112 in the j column. As described above, the voltage of the data signal Xj that designates the lowest gradation of the pixel is V _INI , and the voltage of the data signal Xj increases as the pixel designates brighter. Assuming that the data voltage of the data signal Xj corresponding to Vdata is Vdata, Vdata is given by the following equation (a).
Vdata = (V _INI + ΔV) (a)
Note that ΔV is a voltage change (rise) from the reference voltage V _INI and is zero when the pixel is designated as the lowest gradation black, and gradually increases as the bright gradation is designated. Therefore, the node B varies by ΔV from the initialization period (1) to the writing period (2).

On the other hand, in the writing period (2), since the transistor 211 is off in the pixel circuit 200, the node A is held only by the gate capacitance of the driving transistor 210. For this reason, the node A rises from the voltage Vthn in the initialization period (1) by the amount of voltage change ΔV at the node B distributed by the capacitance ratio between the capacitor 220 and the gate capacitance of the driving transistor 210.
Specifically, when the size of the capacitor 220 is Ca and the gate capacitance of the driving transistor 210 is Cb, the node A rises from the voltage Vthn by {ΔV · Ca / (Ca + Cb)}. The voltage Vg of the node A can be expressed as the following equation.
Vg = Vthn + ΔV · Ca
/ (Ca + Cb) (b)

When the light emission period (3) is reached, the Y driver 14 sets the scanning signal GWRT-i to the L level and sets the control signal G _EL-i to the H level.
For this reason, in the pixel circuit 200, as shown in FIG. 8, the transistor 213 is turned off, but the voltage holding state in the capacitor 220 does not change, so the node A is maintained at the voltage Vg. On the other hand, since the transistor 214 is turned on, the current I _EL corresponding to the voltage Vg flows through the OLED element 230 through the current path. As a result, the OLED element 230 continues to emit light with brightness according to the current I _EL .

In the light emission period (3), the current I _EL flowing through the OLED element 230 is determined by the conduction state between the source and drain of the driving transistor 210, and the conduction state is set by the voltage of the node A. Here, since the voltage of the gate viewed from the source of the driving transistor 210 is the voltage Vg of the node A itself, the current I _EL is expressed as follows.
I _EL = (β / 2) (Vg−V _thn ) ² (c)
In this equation, β is a gain coefficient of the driving transistor 210.

Here, when formula (c) is substituted by formula (a) and formula (b), formula (d) is obtained.
I _EL = (β / 2) {k · (Vdata−V _INI )} ² (d)
However, k is a constant and becomes k = Ca / (Ca + Cb). As shown in the equation (d), a current _{I EL} flowing to the OLED element 230, without depending on the threshold _{V thn} of the driving transistor 210, the data voltage Vdata and the reference voltage _{V INI} and the difference [Delta] V (= Vdata−V _INI ) only.

When the light emission period (3) continues for a period specified in advance, the Y driver 14 sets the control signal GEL-i to the L level. As a result, the transistor 214 is turned off. As a result, the current path is interrupted, so that the OLED element 230 is turned off.
Here, the Y driver 14 performs control such that the H level periods of the control signals G _{EL-1 to} G _EL-720 corresponding to the first to 720th rows are the same. In other words, control is performed so that the proportion of the light emission period (3) is constant in one vertical scanning period for all the OLED elements 230. For this reason, when the light emission period (3) is lengthened, the entire screen is brightened, while when it is shortened, the whole screen can be darkened.
The longest light emission period (3) is the entire period excluding the initialization period (1) and the writing period (2) in one vertical scanning period (1F). For this reason, in the i-th row, the control signal GEL-i returns to the i-th row again after one vertical scanning period (1F) has elapsed from the timing when the scanning signal GWRT-i changes from the H level to the L level. The H level can be taken in a period up to timing t1 preceding the timing at which the scanning line 102 is selected by a period Ti.

Here, the operation of the pixel circuit 200 in the i row and j column has been described. However, the operations of the initialization period (1), the writing period (2), and the light emission period (3) are simultaneously performed for all the other pixels in the i row. Run in parallel.
In addition, the i-th row has been described, but for the first to 720th rows, the scanning line 102 is selected in order for each horizontal scanning period (1H), and the writing period in the selected period. The operation (2) is executed. The initialization period (1) is executed before the writing period (2), and the light emission period (3) is executed after the writing period (2). For example, for the (i + 1) -th row following the i-th row, as shown in FIG. 3, the initialization period starts from the timing t2 preceding the timing when the scanning signal G _{WRT- (i + 1)} becomes the H level by the period Ti. After that, the writing period (2) is reached in a period in which the scanning signal G _{WRT- (i + 1)} is at the H level. In the writing period of the (i + 1) th row, the data signal X-j having a voltage corresponding to the gradation of the pixel in the (i + 1) th row j column is supplied to the data line 112 in the jth column, and the voltage change thereof Minutes are written in the node A, and thereafter, the light emission period (3) is entered.
Therefore, the initialization period (1) may be executed in parallel over two or more adjacent rows. Similarly, the light emission period (3) is also executed in parallel over two or more adjacent rows.

According to this embodiment, in the period (1a) of the initialization period (1), the drive transistor 210 is diode-connected, and a current is forced to flow through the OLED element 230, thereby causing the node A to respond to the current. On the other hand, the node B is fixed to the reference voltage V _INI . Therefore, the node A immediately reaches some voltage and is held. After that, the transistor 214 is turned off while the diode connection is maintained, so that the voltage of the node A is shifted to V _thn by the end timing of the period (1b). Then, in the period (1c), the voltage of the node A is fixed to V _thn . This initialization period (1) is a period unrelated to the writing period (2) in which a row is selected, and is executed in a period before this time. Therefore, in one vertical scanning period (1F), A sufficiently long period can be secured.
Next, in the writing period (2), the data signal X-j is applied to the node B to change the voltage of the other end of the capacitor 220, and the charge is redistributed due to this voltage change. A voltage corresponding to the current to be passed through the OLED element 230 is written. For this reason, coupled with the securing of the initialization period (1), the time required for voltage writing is shortened as compared with the method of directly writing the voltage corresponding to the current to be passed through the OLED element 230 to the gate of the driving transistor 210. Can be realized.
Further, in the light emission period (3), the current flowing through the OLED element 230 does not depend on the threshold voltage V _thn of the drive transistor 210. For this reason, even if the threshold voltage V _thn of the drive transistor 210 varies for each pixel circuit 200, the current flowing through the OLED element 230 can be made uniform.
Therefore, according to the electro-optical device according to the first embodiment, even when the number of pixels increases as the resolution increases, the writing time of the data signal can be shortened, and the uniformity of the current flowing through the OLED element 230 can be reduced. It can be secured.

Further, the current I _EL flowing in the OLED element 230 is determined only by the difference ΔV (= Vdata−V _INI ) between the data voltage Vdata and the reference voltage V _INI as shown in the above-described equation (d). Therefore, the light emission luminance of the OLED element 230 can be adjusted by adjusting the value of the reference voltage V _INI . When the electro-optical device 10 is configured by a plurality of display panels Z1 to Z4 as in the present embodiment, the display panels Z1 to Z4 are individually manufactured, and thus the characteristics of the OLED element 230 are the characteristics of the plurality of display panels Z1 to Z4. Usually, they are not the same and vary.
The power supply circuit 18 of this embodiment includes a voltage source 18A and an adjustment unit 18B. The voltage source 18A _generates reference voltages V _INI1 , V _INI2 , V _INI3 , and V _INI4 , and the adjusting unit 18B controls the voltage source 18A so that the luminance of the display panels _{Z1 to Z4} is uniform. , V _INI2 , V _INI3 , and V _INI4 are adjusted. Specifically, the processing of the adjustment unit 18B has the following modes.
In the first aspect, each of the display panels Z1 to Z4 is driven with gradation data indicating the same gradation, and the current consumed by the plurality of display panels Z1 to Z4 is measured in the power supply circuit 18, respectively. The reference voltages V _INI1 , V _INI2 , V _INI3 , and V _INI4 are adjusted so that. According to this adjustment method, for example, by performing the above-described adjustment process immediately after the electro-optical device 10 is turned on, even if the characteristics of the OLED element 230 and the like change with time, each display panel Z1 to Z1. The brightness of Z4 can be made uniform. In addition, each display panel _{Z1 to Z4} is provided with a dummy pixel circuit that does not contribute to display, the current flowing through the dummy pixel circuit is measured, and the reference voltages V _INI1 , V _INI2 , V _INI3 , and so on are equalized. V _INI4 may be adjusted. In this case, it is possible to always correct the brightness by measuring the current consumption.

In the second mode, the reference voltages V _{INI1 to} V _INI4 are set when the electro-optical device 10 is shipped. In this embodiment, first, the display panels Z1 to Z4 are driven with gradation data indicating the same gradation. Secondly, the luminance of each of the display panels Z1 to Z4 is measured using a measuring device (for example, a CCD camera). Third, the reference voltages V _INI1 , V _INI2 , V _INI3 , and V _INI4 are set so that the measured luminances are close to each other. A volume may be provided so that the user can subsequently change the reference voltages V _{INI1 to} V _INI4 set at the time of shipment.
As described above, in the present embodiment, the reference voltages V _{INI1 to} V _INI4 are individually set for the display panels _Z1 to _Z4 as the plurality of sub-regions constituting the display region Z, so that the brightness of the entire screen is made uniform. can do. A plurality of panels can be used as a single panel.

Second Embodiment
In the electro-optical device 10 according to the first embodiment described above, one display region Z is configured by combining a plurality of display panels Z1 to Z4. On the other hand, in the electro-optical device 10 according to the second embodiment, the display area Z is configured by a single display panel.
FIG. 9 is a block diagram illustrating a configuration of the electro-optical device 10 according to the second embodiment. As shown in the figure, the X driver 16 includes a plurality of drive modules M1, M2, and M3. Each of the drive modules M1 to M3 drives the sub areas S1, S2, and S3 obtained by dividing the display area. Here, the reference voltage V _INI is independent in each of the sub-regions S1, S2, and S3, and is given as the reference voltages V _INI1 , V _INI2 , and V _INI3 .

  The characteristics of the transistors constituting the drive modules M1 to M3 are not necessarily the same and have certain variations. Due to the variation in the characteristics of the transistors, the voltage value of the data signal X varies between the drive modules M1 to M3 even if the same gradation data is supplied to the drive modules M1 to M3. As a result, the luminance may be non-uniform between the sub-regions S1, S2, and S3.

Similar to the electro-optical device 10 according to the first embodiment, the electro-optical device 10 according to the second embodiment includes the reference voltages V _INI1 , V _INI2 , and the like so that the luminance of the sub-regions S1 to S3 is uniform in the power supply circuit 18. V _INI3 is generated. Specifically, there are the following modes.
In the first mode, the sub-regions S1 to S3 are driven with gradation data indicating the same gradation, and the current consumed in the plurality of sub-regions S1 to S3 is measured in the power supply circuit 18, respectively. The reference voltages V _INI1 , V _INI2 , and V _INI3 are adjusted to be equal. According to this adjustment method, even if the transistor characteristics of the drive modules M1 to M are changed with time by performing the above-described adjustment process immediately after the electro-optical device 10 is turned on, each subregion The brightness of S1 to S3 can be made uniform. In addition, dummy pixel circuits that do not contribute to display are provided in each of the sub-regions S1 to S3, currents flowing through the dummy pixel circuits are measured, and reference voltages V _INI1 , V _INI2 , and V _INI3 are set so that current consumption becomes equal. You may adjust. In this case, it is possible to always correct the brightness by measuring the current consumption.

In the second mode, the reference voltages V _{INI1 to} V _INI3 are set when the electro-optical device 10 is shipped. In this embodiment, first, each of the sub-regions S1 to S3 is driven with gradation data indicating the same gradation. Second, the luminance of each of the sub-regions S1 to S3 is measured using a measuring device (for example, a CCD camera). Third, the reference voltages V _INI1 , V _INI2 , and V _INI3 are set so that the measured luminances are close to each other. It should be noted that a volume may be provided so that the user can subsequently change the reference voltages V _{INI1 to} V _INI3 set at the time of shipment.
As described above, in the present embodiment, the reference voltages V _{INI1 to} V _INI3 are individually set for the plurality of sub-regions S1 to S3 constituting the display region Z, so that the characteristics of the drive modules M1 to M3 are different. The brightness of the entire screen can be made uniform. As a result, the boundary of the sub-region can be made inconspicuous.

<Third Embodiment>
The electro-optical device 10 according to the first and second embodiments described above is configured to perform gradation display for single-color pixels, but the electro-optical device 10 according to the third embodiment corresponds to color display. Is.
FIG. 10 is a block diagram illustrating a configuration of the electro-optical device 10 according to the third embodiment. The display area Z of the electro-optical device 10 is configured by a single display panel. The display area Z is constituted by sub-areas Zr, Zg, and Zb corresponding to R (red), G (green), and B (blue). An R pixel circuit 200R is disposed in the sub-region Zr, a G pixel circuit 200G is disposed in the sub-region Zg, and a B pixel circuit 200B is disposed in the sub-region Zb.
FIG. 11 shows the arrangement of the pixel circuits 200R, 200G, and 200B. In these configurations, the light emitting layers are selected so that the OLED elements 230R, 230G, and 230B emit light in red, green, and blue, respectively. That is, different types of light emitting materials are used corresponding to each color. For this reason, the luminous efficiencies of the OLED elements 230R, 230G, and 230B are often different. In this case, it is necessary to vary the power supply voltage V _EL and the reference voltage V _INI for each color.
Therefore, in the present embodiment, the power supply circuit 18 sets the reference voltage V _{INI (R)} and the power supply voltage V _{EL (R)} to the sub-region Zr, and the reference voltage V _{INI (G)} and the power supply voltage V to the sub-region Zg. A set of reference voltage V _{INI (B)} and a set of power supply voltage V _{EL (B)} are respectively supplied to the set of _{EL (G)} and sub-region Zb.
That is, independent reference voltages V _{INI (R)} , V _{INI (G)} , and V _{EL (G)} are set for each of the plurality of sub-regions Zr, Zg, and Zb obtained by dividing the display region Z. Since these determine the gradation of each color of RGB, they are adjusted at the factory so as to achieve white balance. A volume may be provided so that the user can subsequently change the reference voltages V _{INI (R)} , V _{INI (G)} , and V _{EL (G)} set at the time of shipment.

<Configuration example of pixel circuit>
(1) Configuration Example 1 In the pixel circuits 200, 200R, 200G, and 200B according to the above-described embodiments, the transistor 211 has a function of diode-connecting the drive transistor 210 by being turned on, whereas the transistor 214 is , Which has a function of cutting off the current paths of the drive transistor 210 and the OLED element 230 by turning them off, and the functions of both are completely different. Therefore, in the first embodiment, as shown in FIG. 2, the transistor 211 is controlled to be turned on and off independently by the control line 104 and the transistor 214 by the control line 108.
However, as shown in FIG. 12, for example, by changing the conductivity type of the transistor 214 to the p-channel type, the channel types of the transistors 211 and 214 are made different from each other, and the on / off control is performed by the common control line 108. It is also good. When such a configuration is adopted, the control line 104 is not necessary as compared with the configuration of FIG. 2, and as a result, one control line is reduced per row, resulting in an improvement in yield and an opening in the case of the bottom emission type. Bright display with an increased rate is possible. Since the transistors 211 and 212 are both of the same channel type, the transistors 211 and 212 have the same threshold voltage, and therefore operate in accordance with the same control signal GINI-i as compared with the case of being configured with different channel types. Can be reliably controlled. For example, malfunctions such as one transistor turning on and the other transistor turning off with respect to the same control signal GINI-i can be prevented. Further, by using the same channel type, it is not necessary to provide a margin when impurities are implanted into the transistor, and the transistor 211 and the transistor 212 can be arranged closer to each other. Therefore, the transistor occupation region in the pixel region can be minimized, and the transistor characteristics of the transistor 211 and the transistor 212 can be manufactured without variation. Further, if the driving transistor 210 is the same channel type as the transistors 211 and 212, the same effect can be obtained. Further, by using only the same channel type, the voltage range of the power supply with respect to the signal supplied to the pixel circuit can be minimized, so that a highly reliable electronic circuit can be realized.

(2) Configuration Example 2 The pixel circuits 200, 200R, 200G, and 200B according to the above-described embodiments may be replaced with the pixel circuit 200 illustrated in FIG. The pixel circuit 200 shown in FIG. 2 has a configuration in which the on / off of the transistors 211 and 212 is independently controlled by separate control signals G _SET-i and G _INI-i , but the pixel circuit shown in FIG. Is configured to be commonly controlled by a control signal G _INI-i supplied to the control line 106.

FIG. 14 is a timing chart for explaining the operation of the electro-optical device according to the second embodiment. As shown in this figure, in the second embodiment, since the transistors 211 and 212 are commonly controlled to be turned on and off according to the control signal G _INI-i , the initialization period (1) includes the period (1c). Not included. However, in the pixel circuit 200 shown in FIG. 13, the transistors 211 and 212 are simultaneously turned off at the end of the period (1b), so that the voltage at the node A is determined simultaneously with the end of the initialization period (1b). Become.
Since other operations are the same as those in the first embodiment, description thereof is omitted. According to the electro-optical device according to this application example, as in the pixel circuit shown in FIG. 12, the control line 104 is not necessary and one control line is reduced per row, so that the yield and the aperture ratio are improved. be able to.

(3) Configuration Example 3 The pixel circuits 200, 200R, 200G, and 200B according to the above-described embodiments may be replaced with the pixel circuit 200 illustrated in FIG. A pixel circuit 200 shown in FIG. 15 has a configuration in which the transistor 214 is removed from the pixel circuit shown in FIG. Therefore, the control line 108 is not necessary in the pixel circuit 200 shown in FIG.
FIG. 16 is a timing chart for explaining the operation of the electro-optical device using the configuration example 3.
As shown in this figure, in the configuration example 3, in the i-th row, the control signal G _INI-i only during the period Ti before the writing period (2) in which the scanning signal GWRT-i is at the H level. Is provided with an initialization period (1) in which becomes H level.
In this initialization period (1), the transistors 211 and 212 are simultaneously turned on, so that a current flows through the drive transistor 210 and the OLED element 230 (diode-connected). Then, at the end timing of the initialization period (1), the control signal G _INI-i becomes L level and the transistors 211 and 212 are turned off at the same time. Thus, as in the first and second embodiments, the diode of the drive transistor 210 Self-compensating node A voltage shift due to continued connection does not occur.
Therefore, at the end of the initialization period (1), the voltage at the node A is a voltage corresponding to the current flowing through the OLED element 230, which reflects the threshold voltage V _thn of the driving transistor 210, and Compared to the first and second embodiments. Therefore, in the configuration example 3, the reference voltage V _INI supplied via the feeder line 116 is also set high in response to the increase in the voltage at the node A.
Specifically, the reference voltage V _INI is a reference voltage when the voltage of the node B changes from the initialization period (1) to the writing period (2), and the voltage corresponding to this voltage change is the writing period (2 ) Is the same as in the first and second embodiments. However, in the third embodiment, since the voltage point of the node A in the initialization period (1) is high, if the initialization voltage V _INI is set low as in the first and second embodiments, the writing period (2 ), The node A only rises from a high voltage point, and a low voltage is written to the node B, so that a current corresponding to a low gradation (dark gradation) cannot flow through the OLED element 230. Therefore, in the configuration example 3, if the reference voltage V _INI is set higher than that in the first embodiment and the configuration examples 1 and 2, and only the voltage of the node B rises from the initialization period (1) to the writing period (2). In other words, the structure may be lowered.
In this configuration, when a current corresponding to a low gradation (dark gradation) is supplied to the OLED element 230, the node B is lowered (discharged) from the initialization period (1) to the writing period (2). Since the voltage corresponding to the decrease is written into the node A, the voltage at the node B can be lowered and a current corresponding to a low gradation (dark gradation) can be supplied to the OLED element 230. is there.
Note that the reference voltage V _INI in the configuration example 3 corresponds to the voltage of the data signal designating the intermediate gradation (gray) between the lowest gradation (black) and the highest gradation (white) of the pixel. .

According to the electro-optical device using the configuration example 3, the control line 104 is not necessary as compared with the pixel circuit shown in FIGS. 12 and 13, and therefore, one control line per line (FIG. 2). Compared to the pixel circuit, the number of transistors is reduced by two), and the number of transistors per pixel circuit is also reduced by one, so that the yield and the aperture ratio can be further increased.
However, in the configuration example 3, since the transistor 214 does not exist, the luminance of the entire screen cannot be adjusted by adjusting the light emission period (3). Also in the writing period (2), a current corresponding to the voltage at the node A flows through the OLED element 230.

(4) Configuration Example 4 The pixel circuits 200, 200R, 200G, and 200B according to the above-described embodiments may be replaced with the pixel circuit 200 illustrated in FIG. The pixel circuit 200 shown in FIG. 17 has a configuration in which, in the pixel circuit shown in FIG. 15, the power supply line 114 is extended in the X direction for each row, and the voltage is changed with time. is there. In other words, the power supply line 114 in the fourth embodiment is combined with the scanning line 102 and the control line 106 to be used as a set for the pixel circuit 200 for one row.
Such a power supply line 114 is driven by, for example, a Y driver 14. In the fourth embodiment, the reference voltage V _INI applied to the power supply line 116 is a voltage that matches the data signal that specifies the lowest gradation of the pixel, as in the first embodiment.

FIG. 18 is a timing chart for explaining the operation of the electro-optical device according to Configuration Example 4. As shown in this figure, in the configuration example 4, as in the configuration example 3, in the i-th row, the initialization period before the writing period (2) in which the scanning signal GWRT-i is at the H level. In (1), the control signal G _INI-i is at the H level for the period Ti.
However, in the configuration example 4, in the initialization period, the Y driver 14 sets the voltage V _EL-i of the _i-th power line 114 to the reference voltage V _ini . The reference voltage V _ini is a voltage that is slightly higher than the sum of the threshold voltage V _thn of the driving transistor 210 and the threshold voltage of the OLED element 230. Specifically, when the reference voltage _Vini is applied to the drain of the drive transistor 210 that is diode-connected when the transistor 211 is turned on, a voltage that causes a very small current to flow through the drive transistor 210 and the OLED element 230. It is.

On the other hand, in the configuration example 4 as well, in the initialization period (1), the node B is fixed to the reference voltage V _INI when the transistor 212 is turned on, so that the voltage corresponding to the current is held in the node A. It will be.
Here, unlike the third embodiment, the current flowing through the OLED element 230 in the initialization period (1) is very small, so that the voltage held at the node A is approximately equal to the threshold V _{thn of the} driving transistor. It can be made.

Next, when the writing period (2) is reached, the Y driver 14 drops the voltage V _EL-i to Gnd and sets the control signal GWRT-i to the H level. As a result, the transistor 213 is turned on, so that the voltage at the node B changes by ΔV, and the voltage at the node A rises by the amount corresponding to the change by the capacitance ratio. The gate voltage can be written to the node A in order to pass a current through the OLED element 230.
Subsequently, when the light emission period (3) is reached, the Y driver 14 sets the voltage V _EL-i to the power supply voltage V _EL while setting the control signal GWRT-i to the L level. As a result, as in the first embodiment and the like, a current corresponding to the voltage of the node A flows through the OLED element 230, and light emission continues at a brightness corresponding to the current.
When the light emission period (3) ends, the Y driver 14 drops the voltage V _EL-i to Gnd. Thereby, the OLED element 230 is turned off, and the light emission period (3) is adjusted.

According to the electro-optical device according to the configuration example 4, as in the configuration example 3, the control lines 108 are not necessary as compared with the pixel circuit illustrated in FIGS. One (two compared with the pixel circuit in FIG. 2) is reduced and the number of transistors per pixel circuit is also reduced by one, so that the yield and the aperture ratio can be further increased. Furthermore, according to the configuration example 4, unlike the configuration example 3, the brightness of the entire display screen can be changed by adjusting the light emission period (3).
In the configuration example 4, the power supply line 114 is extended in the X direction for each row of the scanning lines 102. However, one power supply line 114 is extended for each adjacent row and used across the pixel circuits 200 in the plurality of rows. It is good also as a structure. Such a configuration is advantageous in terms of the aperture ratio because the number of wirings can be reduced.

(5) Configuration Example 5 The pixel circuits 200, 200R, 200G, and 200B according to the above-described embodiments may be replaced with the pixel circuit 200 illustrated in FIG. As illustrated in FIG. 19, in the pixel circuit 200 in the configuration example 5, in the pixel circuit illustrated in FIG. 14, the connection destination of one end (drain) of the transistor 212 is connected from the power supply line 116 to the power supply line 114 for each row. And changed.
The operation of the electro-optical device according to Configuration Example 5 is the same as that of Configuration Example 4 except that the node B is fixed at the reference voltage _Vini of the power supply line 114 in the initialization period (1). The description is omitted.
According to the fifth configuration example, the feeder line 116 is not necessary, which is advantageous in terms of yield and aperture ratio compared to the fourth configuration example.

(6) In each embodiment, the driving transistor 210 is an n-channel type, but may be a p-channel type. The same applies to the channel types of the transistors 211, 212, 213, and 214. However, in the case of the configuration shown in FIG. 12, as described above, one of the transistors 211 and 214 needs to be a p-channel type and the other an n-channel type. In the case of the configuration shown in FIG. 13, FIG. 15, FIG. 17 or FIG. 19, the transistors 211 and 212 are simultaneously controlled to be turned on or off by the common control line 106. It is necessary to unify the channel type.
Further, each of these transistors may be constituted by a transmission gate in which a p-channel type and an n-channel type are combined in a complementary manner, and the voltage drop may be suppressed to a level that can be almost ignored. In addition, the OLED element 230 may be connected to the drain side of the transistor 214 instead of connecting the OLED element 230 to the source side of the transistor 214.

  The OLED element 230 uses a light emitting organic material such as a low molecule, a polymer, or a dendrimer. The OLED element 230 is an example of a current-driven element. Instead, an inorganic EL element, a field emission (FE) element, a surface conduction emission (SE) element, a ballistic electron emission (BS) element, an LED Other self-luminous elements such as electrophoretic elements and electrochromic elements may also be used. The present invention can also be applied to electro-optical devices such as write heads used in optical writing type printers and electronic copying machines, as in the above embodiments.

<5. Electronic equipment>
Next, an electronic apparatus to which the electro-optical device 10 according to the above-described first to third embodiments and application examples is applied will be described. FIG. 20 shows a configuration of a mobile personal computer to which the electro-optical device 10 is applied. The personal computer 2000 includes an electro-optical device 10 as a display unit and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. Since the electro-optical device 10 uses the OLED element 230, it is possible to display an easy-to-see screen with a wide viewing angle.
FIG. 21 shows a configuration of a mobile phone to which the electro-optical device 10 is applied. A cellular phone 3000, a plurality of operation buttons 3001, scroll buttons 3002, and the electro-optical device 10 as a display unit are provided. By operating the scroll button 3002, the screen displayed on the electro-optical device 10 is scrolled.
FIG. 22 shows a configuration of a portable information terminal (PDA: Personal Digital Assistants) to which the electro-optical device 10 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the electro-optical device 10 as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the electro-optical device 10.
In addition, as an electronic device to which the electro-optical device 10 is applied, in addition to those shown in FIGS. 20 to 22, a digital still camera, a liquid crystal television, a viewfinder type, a monitor direct-view type video tape recorder, a car navigation device, a pager, Examples include electronic notebooks, calculators, word processors, workstations, videophones, POS terminals, and devices equipped with touch panels. The electro-optical device 10 described above can be applied as a display unit of these various electronic devices. In addition, it is not limited to a display unit of an electronic device that directly displays an image or a character, but is applied as a light source of a printing device that is used to indirectly form an image or a character by irradiating light to the photosensitive member. Also good.

1 is a block diagram illustrating a configuration of an electro-optical device according to a first embodiment of the invention. FIG. It is a figure which shows the pixel circuit of the same electro-optical apparatus. 6 is a timing chart showing the operation of the electro-optical device. It is operation | movement explanatory drawing of the pixel circuit. It is operation | movement explanatory drawing of the pixel circuit. It is operation | movement explanatory drawing of the pixel circuit. It is operation | movement explanatory drawing of the pixel circuit. It is operation | movement explanatory drawing of the pixel circuit. FIG. 6 is a block diagram illustrating a configuration of an electro-optical device according to a second embodiment of the invention. FIG. 10 is a block diagram illustrating a configuration of an electro-optical device according to a third embodiment of the invention. It is a figure which shows the pixel circuit of the apparatus. It is a circuit diagram which shows the structural example 1 of a pixel circuit. It is a circuit diagram which shows the structural example 2 of a pixel circuit. 10 is a timing chart showing the operation of Configuration Example 2; It is a circuit diagram which shows the structural example 3 of a pixel circuit. 14 is a timing chart illustrating an operation of the configuration example 3; It is a circuit diagram which shows the structural example 4 of a pixel circuit. 10 is a timing chart showing an operation of the same configuration example 4; It is a circuit diagram which shows the structural example 5 of a pixel circuit. It is a figure which shows the personal computer using the same electro-optical apparatus. It is a figure which shows the mobile telephone using the same electro-optical apparatus. It is a figure which shows the portable information terminal using the same electro-optical apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Electro-optical apparatus, 12 ... Control circuit, 14 ... Y driver, 16 ... X driver, 18 ... Power supply circuit, 18A ... Voltage source, 18B ... Adjustment part, 102 ... Scanning line, 104, 106, 108 ... Control line, DESCRIPTION OF SYMBOLS 112 ... Data line, 114, 118 ... Power supply line, 116 ... Feeding line, 200 ... Pixel circuit, 210 ... Drive transistor, 211, 212, 213, 214 ... Transistor (1st, 2nd, 3rd, 4th respectively Switching element), 220... Capacity (capacitance element), 230... OLED element.

Claims (3)

A plurality of scanning lines, a plurality of data lines, and a plurality of pixel circuits respectively provided corresponding to intersections of the scanning lines and the data lines in a display area having a plurality of sub-areas configured by a display panel ; An electro-optical device comprising:
Each of the plurality of pixel circuits includes an electro-optic element, a current supply unit that generates a drive current based on a reference voltage and a data voltage supplied via the data line, and supplies the drive current to the electro-optic element; With
Power supply means for individually generating the reference voltage corresponding to each of the plurality of sub-regions is provided so that the luminance of the plurality of sub-regions approaches a target value,
The current supply means includes
A drive transistor for controlling a drive current flowing in the electro-optic element;
A first switching element that is turned on in a first period between the gate and drain of the driving transistor and turned off by a start timing of a second period after the first period;
A capacitive element having one end connected to the gate of the driving transistor;
The second voltage is turned on in the first period, and the reference voltage is applied to the other end of the capacitive element, while the second period is turned off in the second period and a third period after the second period. A switching element;
A third that is turned on in the second period between the data line and the other end of the capacitor;
Switching elements and
The power source means
Voltage generating means for individually generating the reference voltage for each of the sub-regions;
An electro-optical device comprising: a voltage adjusting unit that adjusts the reference voltage so that the target values are the same and the luminance of a plurality of sub-regions approaches each other. Said voltage adjustment means, according to claim 1, characterized in that the current consumed by the pixel circuits of the plurality of sub-regions is measured for each of the sub-region, to adjust the reference voltage based on the measurement results Electro-optic device. An electronic apparatus comprising the electro-optical device according to claim 1 .

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