JP2007011101A - Electrooptical device and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust luminance of an electrooptical device while keeping color tone balance. <P>SOLUTION: A reference voltage generating circuit has a reference voltage R generation section which sets a reference voltage R to be supplied to a data line of a pixel circuit of R, a reference voltage G generation section which sets a reference voltage G to be supplied to a data line of a pixel circuit of G, and a reference voltage B generation section which sets a reference voltage B to be supplied to a data line of a pixel circuit of B. A storage circuit is stored with a first voltage to be applied to data lines for minimum gray-scale display and voltages R, G, and B to be supplied to the data lines of R, G, and B set so that an optimum white balance is obtained during display of a maximum gray scale and maximum luminance. A control circuit sets the reference voltages R, G, and B so that when display luminance is varied, the ratio of "the difference between the first voltage and reference voltage R", "the difference between the first voltage and reference voltage G", and "the difference between the first voltage and reference voltage B" is equal to the ratio of "the difference between the first voltage and voltage R", "the difference between the first voltage and voltage G", and "the difference between the first voltage and voltage B". <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electro-optical device and an electronic apparatus including an electro-optical element such as an OLED (Organic Light Emitting Diode) element, and more particularly to a technique for adjusting the luminance of the electro-optical device.

  An electro-optical device that displays an image using an electro-optical element is widely used as a display device for various electronic devices. In this type of electro-optical device, it is an important problem that the luminance can be adjusted while ensuring the color balance.

  In order to solve this problem, for example, Patent Document 1 discloses a color display device having a half-life, a light emission time measurement unit that measures the light emission time of the display device, and a light emission time measured by the light emission time measurement unit. Brightness adjustment means for adjusting the brightness of the display device when the total of the predetermined time reaches a predetermined time, and the brightness adjustment means has the light emission brightness of each light emitting element that emits the three primary colors of light constituting the display device. Can be adjusted to a predetermined ratio. With this configuration, when the accumulated light emission time reaches a predetermined time, in order to adjust the light emission luminance of each light emitting element that emits the three primary colors of light constituting the display device to a predetermined ratio, Although the brightness as a whole is lowered, the lifetime is extended, and the color tone is restored to the original, so that a sufficient natural hue can be obtained.

JP 2003-195817 A (paragraph 0010)

  However, in Patent Document 1, luminance adjustment is performed so that the ratio becomes a predetermined ratio when the usage time of the display device reaches a certain time, and the luminance is not configured to be adjusted in real time.

  SUMMARY An advantage of some aspects of the invention is that it provides an electro-optical device and an electronic apparatus capable of controlling light emission luminance while ensuring a color tone balance of the electro-optical device.

  In order to solve the above-described problems, the electro-optical device according to the present invention includes an electro-optical element at each of a plurality of scanning lines, a plurality of data lines, and the plurality of scanning lines and the plurality of data lines. A plurality of pixel circuits; a scanning line driving circuit for selecting a predetermined scanning line by outputting a scanning signal to the scanning line; and the electro-optic via the data line based on image data supplied from the outside. A data line driving circuit for outputting a gradation signal to the element; a driving signal generating circuit for outputting a driving signal to the scanning line driving circuit and the data line driving circuit; and a data line of the pixel circuit at the maximum gradation. An electro-optical device comprising at least a reference voltage generation circuit that supplies a reference voltage to be applied, a storage circuit that stores various setting values at the time of shipment, and a control circuit that controls a change in display luminance. The generation circuit generates reference voltages VR, VG, and VB respectively supplied to the data lines corresponding to the pixel circuits for displaying each color of red (R), green (G), and blue (B). A VR generation unit, a reference voltage VG generation unit, and a reference voltage VB generation unit; and the storage circuit includes a first voltage that is a voltage applied to the data line when the electro-optical device is displayed with the minimum gradation. The white balance is set so as to obtain an optimum white balance when the electro-optical device is displayed with the maximum gradation and the maximum brightness, and is applied to the data lines corresponding to the pixel circuits for displaying R, G, and B colors. The control circuit stores optimum voltages VR0, VG0, and VB0 that are voltages, and the control circuit changes the ratio between the three differences between the first voltage and the reference voltages VR, VG, and VB when changing the display brightness. 1 The reference voltages VR, VG, and VB are set to be equal to a ratio between three differences between the voltage and the optimum voltages VR0, VG0, and VB0, and the reference voltage VR generator, the reference voltage VG generator, The gist of the present invention is to output each to the reference voltage VB generator.

  According to this configuration, the voltage value to be applied to the pixel circuit of each RGB color is set so that the optimum white balance is achieved in a state where the electro-optical device is displayed with the maximum gradation and the maximum luminance at the time of shipment of the electro-optical device. When the voltage value is stored and the luminance is changed, the control circuit sets the reference voltage values of RGB so as to maintain this voltage balance, so that the optimum white balance can be maintained even if the luminance is changed. .

  In the electro-optical device according to the aspect of the invention, the reference voltage VR generation unit, the reference voltage VG generation unit, and the reference voltage VB generation unit may use the reference voltages VR, VG, and VB set by the control circuit. Each register has a register and a D / A conversion circuit that converts the voltage value stored in the register into an analog signal.

  According to this configuration, the current reference voltage R, reference voltage G, and reference voltage B voltage values are stored in the respective registers of the reference voltage R generation unit, the reference voltage G generation unit, and the reference voltage B generation unit. The control circuit can calculate the reference voltage value after changing the luminance from the voltage value of each RGB color stored in the storage circuit and the current reference voltage value stored in each register, and the luminance is changed. Can maintain the optimal white balance.

  In the electro-optical device according to the aspect of the invention, the electro-optical device includes an image correction table (LUT), and corrects the image data using the image correction table (LUT).

  In the electro-optical device according to the aspect of the invention, each of the reference voltage VR generation unit, the reference voltage VG generation unit, and the reference voltage VB generation unit includes a multiplier, and the reference voltage VR generation unit is based on an instruction from the control circuit. Recalculate the voltage values of the voltages VR, VG and VB.

  In the electro-optical device according to the aspect of the invention, the optimum voltages VR0, VG0, and VB0 are set within a range that is allowed to maintain white balance when the electro-optical device is displayed with the maximum gradation and the maximum luminance. .

  In the electro-optical device according to the aspect of the invention, the electro-optical element is an organic light emitting diode element.

  Next, an electronic apparatus according to the present invention includes the above-described electro-optical device, and corresponds to, for example, a personal computer, a mobile phone, and a portable information terminal.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
(First embodiment)

<Configuration of electro-optical device>
FIG. 1 is a block diagram showing the configuration of the electro-optical device according to the first embodiment of the invention. As shown in the figure, the electro-optical device 1 includes an electro-optical panel 10, a drive signal generation circuit 200, a scanning line drive circuit 300, a data line drive circuit 400, a reference voltage generation circuit 500, and a controller 600 that is a control circuit. And an EEPROM 610 which is a memory circuit.

  A pixel region 100 is formed in the electro-optical panel 10. In the pixel region 100, m scanning lines 120 extending in the X direction (row direction) are formed (m is a natural number). In addition, n data lines 121 extending in the Y direction (column direction) orthogonal to the X direction are formed in the pixel region 100 (n is a natural number). A pixel circuit 110 is arranged corresponding to each intersection of the scanning line 120 and the data line 121. Therefore, these pixel circuits 110 are arranged in a matrix over the X direction and the Y direction in the pixel region 100. Each pixel circuit 110 is assigned one of red (R), green (G), and blue (B) electro-optic elements.

  The scanning line driving circuit 300 sequentially selects each of the m scanning lines 120, and sequentially outputs the scanning signals Y1, Y2,..., Ym to each scanning line 120 for each horizontal scanning period. As will be described later, the scanning line 120 includes a Vth compensation line 122, a data write line 123, a precharge line 124, and a light emission control line 125.

  On the other hand, the data line driving circuit 400 supplies data signals X1, X2,..., Xn to the pixel circuits 110 connected to the scanning line 120 selected by the scanning line driving circuit 300. The data signal Xj (j is an integer satisfying 1 ≦ j ≦ n) specifies the luminance (gradation) of the pixel circuit 110 in the j-th column by the voltage amplitude.

  The drive signal generation circuit 200 receives the clock signal CLK, the vertical synchronization signal VSYNC, the horizontal synchronization signal HSYNC, and the video data signal DATA from an external device (not shown), and controls the operation of the electro-optical device 1. Upon receiving these signals, the drive signal generation circuit 200 extracts the red signal RDATA obtained by extracting only the red (R) video data from the video data signal DATA and the green (G) from the video data signal DATA. ), The green signal GDATA from which only the video data is extracted, the blue signal BDATA from which only the blue (B) video data is extracted from the video data signal DATA, the data line driving circuit (hereinafter referred to as X) clock signal XCK, and X A start pulse signal XSP is output. Further, the drive signal generation circuit 200 sends a light emission control signal GEL, a data write signal GWRT, a Vth compensation signal GINIT, a scan line drive circuit (hereinafter referred to as Y) clock signal YCK to the scan line drive circuit 300. Y start pulse signal YSP is output. Note that the scanning line driving circuit 300, the data line driving circuit 400, and the driving signal generation circuit 200 may be mounted on the electro-optical panel 10 by, for example, COG (Chip On Glass) technology, or outside the electro-optical panel 10. For example, it may be mounted on a wiring board mounted on the electro-optical panel 10.

  The reference voltage generation circuit 500 includes a reference voltage R generation unit 510 that is a reference voltage VR generation unit that generates the reference voltage VR of the pixel circuit 110 for red (R) display, and a pixel circuit 110 for green (G) display. A reference voltage G generator 520 that is a reference voltage VG generator that generates the reference voltage VG, and a reference voltage B generator that is a reference voltage VB generator that generates the reference voltage VB of the pixel circuit 110 for blue (B) display. 530.

  Next, a more detailed configuration of the reference voltage generation circuit 500 will be described with reference to FIG. As shown in FIG. 2, the reference voltage R generation unit 510 includes a register 511 that stores the reference voltage value Rd of the pixel circuit 110 for red (R) display, and a D / D that generates the reference voltage VR from the reference voltage value Rd. A conversion circuit 512 is included. The reference voltage G generation unit 520 includes a register 521 that stores the reference voltage value Gd of the pixel circuit 110 for green (G) display, and a D / A conversion circuit 522 that generates the reference voltage VG from the reference voltage value Gd. Have. Further, the reference voltage B generation unit 530 includes a register 531 that stores the reference voltage value Bd of the pixel circuit 110 for blue (B) display, and a D / A conversion circuit 532 that generates the reference voltage VB from the reference voltage value Bd. Have.

  The reference voltage VR is supplied to the data line driving circuit 400 via the voltage supply line 514 and is used as a reference voltage for the pixel circuit 110 for red (R) display. The reference voltage VG is supplied to the data line driving circuit 400 via the voltage supply line 524 and used as a reference voltage for the pixel circuit 110 for green (G) display. Further, the reference voltage VB is supplied to the data line driving circuit 400 through the voltage supply line 534 and used as a reference voltage for the pixel circuit 110 for blue (B) display.

  In the EEPROM 610, after the electro-optical device 1 is manufactured, the electro-optical panel 10 is displayed with the maximum gradation and the maximum luminance, and red (R), green (G), and blue are adjusted so as to obtain an optimal white balance. The voltage value (voltage R0, voltage G0, voltage B0) applied to the data line 121 of each pixel circuit 110 in (B) and the data line 121 when the electro-optic panel 10 is displayed with the minimum gradation are applied. The voltage value (first voltage M0) to be stored is stored at the time of shipment.

  The controller 600 receives a brightness adjustment signal CTRL for adjusting the brightness from an interface of an external device (not shown), the voltage values R0, G0, B0, and the first voltage M0 stored in the EEPROM 610, and the register 511. Based on the current reference voltage value Rd, reference voltage value Gd, and reference voltage value Bd stored in each of 521, 531, the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd after brightness adjustment are calculated. Then, the values of the registers 511, 521, and 531 are updated.

<Configuration of pixel circuit>
Next, the configuration and operation of the pixel circuit 110 will be described with reference to FIGS. FIG. 3 is a circuit diagram showing the configuration of the pixel circuit 110, and FIG. 4 is a timing chart for explaining the operation of the pixel circuit 110. As shown in FIG. In FIG. 3, only one pixel circuit 110 in the j-th column (j is an integer from 1 to n) belonging to the i-th row (i is an integer from 1 to m) is illustrated, and the other pixel circuits are illustrated. The configuration of 110 is the same. The pixel circuit 110 in this embodiment is a voltage-driven (so-called voltage programming method) circuit capable of threshold compensation that controls the luminance (gradation) of the OLED element 117 according to the voltage amplitude of the data signal Xj. The scanning line 120 includes a Vth compensation line 122, a data write line 123, a precharge line 124, and a light emission control line 125. In the i-th row, a Vth compensation signal GINITi, a data write signal GWRTi, The charge signal PRCGi and the light emission control signal GELi are input.

  As illustrated in FIG. 3, the pixel circuit 110 includes five TFTs 111 to 115 (for example, thin film transistors), a capacitor 116, and an OLED element 117. The conductivity type of the TFT 111 is a p-channel type, and the conductivity types of the TFTs 112 to 115 are n-channel types.

  Among these, the source terminal of the TFT 111 is connected to a power supply line to which a higher potential (hereinafter referred to as “power supply potential”) VEL of the power source for driving the pixel is supplied, and its drain terminal is connected to the drain of the TFT 115 via the node 118. The node 118 is further connected to the drain terminal of the TFT 112 and the drain terminal of the TFT 114. The gate terminal is connected to the source terminal of the TFT 112 and one end of the capacitor 116. The other end of the capacitor 116 is connected to the drain terminal of the TFT 113.

  The source terminal of the TFT 114 is connected to the data line 121, the gate terminal is connected to the precharge line 124, and the potential of the node 118 is precharged to the potential of the data line 121 when the precharge signal PRCGi is at the H level. As shown in FIG. 4, the precharge signal PRCGi rises at the rising edge of the Y clock signal YCK (for example, time t1) in the selected row (for example, the first row), and falls at the falling edge of the Y clock signal YCK (for example, for example). Fall at time t2).

  The gate terminal of the TFT 112 is connected to the Vth compensation line 122. When the Vth compensation signal GINITi is at the H level, the gate terminal and the drain terminal of the TFT 111 are made conductive, and the potential charged to the capacitor 116 is set to the potential of the node 118. To do. As shown in FIG. 4, the Vth compensation signal GINITi rises at the rising edge of the Y clock signal YCK (eg, time t1) in the selected row (eg, the first row) and falls (eg, falls) of the Y clock signal YCK (eg, the first row). Fall at time t2).

  The source terminal of the TFT 113 is connected to the data line 121, the gate terminal is connected to the data write line 123, and the potential of the data line 121 is charged to the capacitor 116 when the data write signal GWRTi is at H level. When the capacitor 116 is charged with the potential of the data line 121, the potential of the data line 121 is applied to the gate terminal of the p-channel TFT 111, and the potential of the data line 121 is subtracted from the sum of the power supply potential VEL and the threshold voltage of the TFT 111. A potential is applied to node 118. As shown in FIG. 4, the data write signal GWRTi rises at the time when the Y clock signal YCK falls (for example, time t2) in the selected row (for example, the first row) and rises when the Y clock signal YCK rises (for example, for example). Fall at time t3).

  The gate terminal of the TFT 115 is connected to the light emission control line 125, and the source terminal is connected to the anode of the OLED element 117. The cathode of the OLED element 117 is connected to a ground line to which a lower potential (hereinafter referred to as “ground potential”) VCT of the power source is supplied. When the light emission control signal GELi is at the H level, the potential of the node 118 is applied to the anode of the OLED element 117, and the OLED element 117 emits light. As shown in FIG. 4, the light emission control signal GELi becomes L level in one horizontal scanning period 1H (for example, time t1 to t3) in one vertical scanning period 1F (for example, time t1 to t4), and other period (for example, time) From t3 to t4) becomes H level. While the light emission control signal GELi is at the H level, the light emission of the OLED element 117 is continued by the potential charged in the capacitor 116.

  Although the voltage program method capable of threshold compensation as shown in FIG. 3 has been described as the pixel circuit 110, the pixel circuit 110 including two TFTs 111 and 113, a capacitor 116, and an OLED element 117 as shown in FIG. It can also be applied to.

<Operation of reference voltage generation circuit>
Next, operations of the controller 600 and the reference voltage generation circuit 500 will be described with reference to FIGS.

  FIG. 6 is a graph showing an example of setting reference voltages for each color of RGB at the maximum gradation and the maximum luminance. In the graph of FIG. 6, the horizontal axis represents the gradation value (00h to FFh) of the video data signal DATA, and the vertical axis represents the voltage value applied to the data line 121.

Since the conductivity type of the TFT 111 is a p-channel type, the potential Voled of the node 118 that generates a voltage for causing the OLED element 117 to emit light is changed from the sum of the power supply potential VEL applied to the source terminal of the TFT 111 and the threshold voltage Vth of the TFT 111 to the gate terminal. This is a potential obtained by subtracting the potential Vdata of the applied data line 121. That is, the following expression (1) is obtained.
Voled = (VEL + Vth) −Vdata (1)

  For example, when the power supply potential VEL = 11.5V and the threshold voltage Vth of the TFT 111 = −1.5V, the first voltage M0 = 10V which is a voltage applied to the data line 121 at the minimum gradation (00h) is obtained. Further, when the electro-optical panel 10 is displayed with the maximum gradation (FFh) and the maximum luminance, red (R), green (G), and blue (B) adjusted to obtain an optimal white balance. Assume that the voltage values (voltage R0, voltage G0, voltage B0) applied to the data line 121 of each pixel circuit 110 are, for example, voltage R0 = 2V, voltage G0 = 5V, and voltage B0 = 4V, respectively.

These values, the first voltage M0 = 10V, the voltage R0 = 2V, the voltage G0 = 5V, and the voltage B0 = 4V are stored in the EEPROM 610 at the time of shipment. In this case, the ratio of “the difference between the first voltage M0 and the voltage R0”, “the difference between the first voltage M0 and the voltage G0”, and “the difference between the first voltage M0 and the voltage B0” is expressed by the following equation (2). .
(M0-R0) :( M0-G0) :( M0-B0) = 8: 5: 6 (2)

  Next, with reference to FIG. 7, a method for setting the reference voltages for the respective RGB colors when the luminance is changed will be described. FIG. 7 is a graph showing the setting of reference voltages for each color of RGB when the luminance is lowered.

FIG. 7 shows set values of the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd at the maximum gradation (FFh) when the brightness is halved with respect to the maximum brightness. The ratio of “difference between the first voltage M0 and the reference voltage value Rd”, “difference between the first voltage M0 and the reference voltage value Gd”, and “difference between the first voltage M0 and the reference voltage value Bd” is expressed by the equation (2). Set to be equal to the ratio. That is, it sets so that it may become the following (3) Formula.
(M0-Rd) :( M0-Gd) :( M0-Bd) = 8: 5: 6 (3)

  At this time, the voltage Vdata of the data line 121 of the pixel circuit 110 for red (R) has the maximum luminance with reference to the voltage R0 which is the minimum voltage among the voltage R0 = 2V, the voltage G0 = 5V, and the voltage B0 = 4V. Since Vdata = M0−R0 = 8V at the time, when the luminance is halved, Vdata = M0−Rd = 4V, so the reference voltage value Rd = 6V. From this value and equation (3), the reference voltage value Gd = 7.5V and the reference voltage value Bd = 7V can be calculated.

  Next, operations of the controller 600 and the reference voltage generation circuit 500 will be described with reference to FIG. FIG. 8 is a flowchart for explaining the operation of the controller 600 and the reference voltage generation circuit 500.

  First, in step S100, the controller 600 acquires voltage values of the first voltage M0, the voltage R0, the voltage G0, and the voltage B0 from the EEPROM 610.

  Next, in step S110, the maximum value among M0-R0, M0-G0, and M0-B0 is stored as Mmax.

  Next, in step S120, the controller 600 determines whether or not there is an instruction to change the luminance by the luminance adjustment signal CTRL from the external device. If there is an instruction, the controller 600 proceeds to step S130, and if there is no instruction, The brightness adjustment signal CTRL is continuously monitored.

  Next, in step S130, the controller 600 acquires the reference voltage value Rd from the register 511, the reference voltage value Gd from the register 521, and the reference voltage value Bd from the register 531.

  Next, in step S140, the maximum value among M0-Rd, M0-Gd, and M0-Bd is stored as Mnow.

  Next, in step S150, it is determined whether or not the instruction of the brightness adjustment signal CTRL is 1 brightness Up (1 brightness Down). If it is 1 brightness Up, the process proceeds to step S160; The brightness Down) proceeds to step S170.

Next, in step S160, the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd are calculated by the following equations (4) to (6), and the process proceeds to step S180. However, if the current brightness is the maximum brightness, skip.
Rd = M0− (Mnow + 1) × (M0−R0) / Mmax (4)
Gd = M0− (Mnow + 1) × (M0−G0) / Mmax (5)
Bd = M0− (Mnow + 1) × (M0−B0) / Mmax (6)

On the other hand, in step S170, the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd are calculated by the following equations (7) to (9), and the process proceeds to step S180. However, if the current luminance is the minimum luminance, skip.
Rd = M0− (Mnow−1) × (M0−R0) / Mmax (7)
Gd = M0− (Mnow−1) × (M0−G0) / Mmax (8)
Bd = M0− (Mnow−1) × (M0−B0) / Mmax (9)

  Next, in step S180, the calculated reference voltage value Rd, reference voltage value Gd, and reference voltage value Bd are stored (updated) in the register 511, the register 521, and the register 531, respectively, and each D / A conversion circuit 512 is stored. 522 and 532 convert the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd into the reference voltage VR, the reference voltage VG, and the reference voltage VB, and supply them to the data line driving circuit 400, and the process proceeds to step S120. To do.

  According to the embodiment described above, the following effects can be obtained.

  In the present embodiment, the voltage value to be applied to the data lines 121 of the pixel circuits 110 for each of the RGB colors is set so that the optimum white balance is obtained when the electro-optical device 1 is displayed with the maximum gradation and the maximum luminance at the time of shipment. When the luminance is changed, the controller 600 sets the reference voltage value for each of the RGB so as to maintain this voltage balance. Therefore, even if the luminance is changed, the optimum white balance is stored. Can keep.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, In the range which does not deviate from the meaning of this invention, it can be implemented with various forms. Hereinafter, a modification will be described.

  (Modification 1) A first modification of the electro-optical device 1 according to the present invention will be described. In the first embodiment, it has been described that the controller 600 calculates the reference voltage value. However, the reference voltage R generation unit 510, the reference voltage G generation unit 520, and the reference voltage B generation unit 530 are each provided with a multiplier. The controller 600 sends the luminance change instruction information of the luminance adjustment signal CTRL to these multipliers, and recalculates the reference voltage value Rd, the reference voltage value Gd, and the reference voltage value Bd of each of the registers 511, 521, and 531. It may be.

<Electronic equipment>
Next, electronic devices to which the electro-optical device 1 according to the above-described embodiments and modifications are applied will be described. FIG. 9 shows a configuration of a mobile personal computer to which the electro-optical device 1 is applied. The personal computer 2000 includes the electro-optical device 1 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 1 uses the OLED element 117, it is possible to display an easy-to-see screen with a wide viewing angle.

  FIG. 10 shows a configuration of a mobile phone to which the electro-optical device 1 is applied. A cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the electro-optical device 1 as a display unit. By operating the scroll button 3002, the screen displayed on the electro-optical device 1 is scrolled.

  FIG. 11 shows the configuration of a portable information terminal (PDA: Personal Digital Assistants) to which the electro-optical device 1 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the electro-optical device 1 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 1.

  The electronic apparatus to which the electro-optical device 1 is applied includes, in addition to those shown in FIGS. 9 to 11, 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 1 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 showing a schematic configuration of an electro-optical device 1 according to a first embodiment of the invention. FIG. 3 is a block diagram showing a configuration of a reference voltage generation circuit 500. 4 is a circuit diagram of a pixel circuit 110. FIG. 4 is a timing chart illustrating the operation of the pixel circuit 110. 4 is another circuit diagram of the pixel circuit 110. FIG. The graph which shows the setting of the reference voltage of each RGB color at the time of the maximum gradation and the maximum brightness. The graph which shows the setting of the reference voltage of each color of RGB when a brightness | luminance is made low. 6 is a flowchart for explaining operations of a controller 600 and a reference voltage generation circuit 500. 2 is a perspective view showing a personal computer using the electro-optical device 1. FIG. FIG. 2 is a perspective view showing a mobile phone using the electro-optical device 1. 2 is a perspective view showing a portable information terminal using the electro-optical device 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electro-optical apparatus, 10 ... Electro-optical panel, 100 ... Pixel region, 110 ... Pixel circuit, 111 ... P channel type TFT, 112-115 ... N channel type TFT, 116 ... Capacitance element, 117 ... OLED element, 120 ... Scan line 121... Data line 122 122 Vth compensation line 123 Data write line 124 Precharge line 125 Light emission control line 200 Drive signal generation circuit 300 Scan line drive circuit 400 Data line Drive circuit, 500 ... reference voltage generation circuit, 510 ... reference voltage R generation unit, 520 ... reference voltage G generation unit, 530 ... reference voltage B generation unit, 600 ... controller, 610 ... EEPROM, 2000 ... personal computer, 2001 ... power supply Switch 2002 2002 Keyboard 2010 Main body 3000 Mobile phone 3001 Operation button , 3002 ... scroll button, 4000 ... portable information terminal, 4001 ... operation button, 4002 ... power switch.

Claims (7)

A plurality of scanning lines, a plurality of data lines, a plurality of pixel circuits each having an electro-optic element at each intersection of the plurality of scanning lines and the plurality of data lines, and outputting a scanning signal to the scanning lines. A scanning line driving circuit that selects a predetermined scanning line, a data line driving circuit that outputs a gradation signal to the electro-optic element via the data line based on image data supplied from the outside, and the scanning A line drive circuit, a drive signal generation circuit that outputs a drive signal to the data line drive circuit, a reference voltage generation circuit that supplies a reference voltage to be applied to the data line of the pixel circuit at the maximum gradation, and various types at the time of shipment An electro-optical device comprising at least a storage circuit that stores a setting value and a control circuit that controls a change in display luminance,
The reference voltage generation circuit generates reference voltages VR, VG, and VB respectively supplied to the data lines corresponding to the pixel circuits for displaying each color of red (R), green (G), and blue (B). A reference voltage VR generator, a reference voltage VG generator, and a reference voltage VB generator.
The storage circuit is optimal for a first voltage that is a voltage applied to the data line when the electro-optical device is displayed with a minimum gradation, and when the electro-optical device is displayed with a maximum gradation and maximum luminance. Storing optimum voltages VR0, VG0 and VB0 which are set to be white balance and which are applied to the data lines corresponding to the pixel circuits for displaying R, G and B colors;
When the display brightness is changed, the control circuit determines that the ratio between the three differences between the first voltage and the reference voltages VR, VG, and VB is the three of the first voltage and the optimum voltages VR0, VG0, and VB0. The reference voltages VR, VG, and VB are set so as to be equal to the ratio between the two differences, and output to the reference voltage VR generation unit, the reference voltage VG generation unit, and the reference voltage VB generation unit, respectively.
An electro-optical device. 2. The electro-optical device according to claim 1, wherein the reference voltage VR generation unit, the reference voltage VG generation unit, and the reference voltage VB generation unit are voltage values of the reference voltages VR, VG, and VB set by the control circuit. And a D / A conversion circuit for converting the voltage value stored in the register into an analog signal, respectively.
An electro-optical device. The electro-optical device according to claim 1, wherein the electro-optical device includes an image correction table (LUT), and corrects the image data using the image correction table (LUT).
An electro-optical device. 4. The electro-optical device according to claim 1, wherein each of the reference voltage VR generation unit, the reference voltage VG generation unit, and the reference voltage VB generation unit includes a multiplier, and the control circuit Recalculate the voltage values of the reference voltages VR, VG and VB based on the instructions from
An electro-optical device. 5. The electro-optical device according to claim 1, wherein the optimum voltages VR <b> 0, VG <b> 0, and VB <b> 0 are used to maintain white balance when the electro-optical device is displayed with maximum gradation and maximum luminance. Set within the allowable range,
An electro-optical device. The electro-optical device according to claim 1, wherein the electro-optical element is an organic light-emitting diode element.
An electro-optical device. An electronic apparatus comprising the electro-optical device according to claim 1.

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