KR20050112921A - Organic electro luminescence display and driving method for protecting reddish aging thereof - Google Patents

Abstract

The present invention relates to an organic light emitting diode display and a driving method thereof. An organic light emitting display device according to the present invention includes a plurality of pixels each consisting of a red subpixel, a green subpixel, and a blue subpixel, and includes an image display unit displaying an image according to a plurality of data signals and selection signals applied thereto; And a controller for transmitting a data signal and a selection signal to the driver, and a controller for transmitting an image signal including a red subpicture signal, a green subpicture signal, and a blue subpicture signal corresponding to the plurality of data signals to the driver. Receives a gray level image signal including a black level sub picture signal for turning off the longest life of the green and blue sub pixels, and the black level sub picture signal is changed into a gray level data signal And operate to be delivered to the longest subpixel.

Description

Organic electroluminescent display and its reddening prevention driving method {Organic electro luminescence display and driving method for protecting reddish aging

The present invention relates to an organic light emitting display device and a method for preventing reddening thereof.

In general, a flat panel display device is an image display device that is thinner and lighter than a television or computer monitor having a cathode ray tube structure. The flat panel display includes, for example, a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and an organic electro luminescence display. Etc. The organic light emitting display device is a display device using a phenomenon in which electrons and holes injected through a cathode and an anode are recombined in an organic thin film to form excitons, and light of a specific wavelength is generated from the formed excitons.

1A is a schematic block diagram of a conventional organic light emitting display. FIG. 1B is a circuit diagram of a pixel of the organic light emitting diode display of FIG. 1A.

1A and 1B, a conventional organic light emitting diode display 100 includes an image display unit 110 including a plurality of pixels 104 for displaying an image according to an applied data voltage, and an image display unit 110. A scan driver 106 for applying a selection signal to the scan lines S1 to Sn, a data driver 108 for supplying a data voltage to the image display unit 110 through data lines D1 to Dm, and a scan driver And a control unit (not shown) for supplying control signals, data signals, and power, such as clock signals and synchronization signals, to the 106 and the data driver 108. In the organic light emitting diode display 100, as shown in FIG. 1B, an active driving method for controlling each pixel by disposing an active element such as a switching element in the pixel 104 may be adopted. In this case, a thin film transistor (TFT) is mainly used as an active element.

For example, the pixel 104 includes two transistors and one capacitor, respectively, and includes a plurality of subpixels displaying any one color of red (R), green (G), and blue (B). The subpixel stores data voltages applied to the organic light emitting diodes OLED and the data lines Dm-1, Dm, and Dm + 1 in response to a selection signal of the scan line Sn. Switching elements M2, M4 and M6 respectively transferred to Cs2 and Cs3, and driving transistors M1, M3 and M5 connected to a power supply voltage VDD to supply driving voltages to the organic light emitting elements, respectively.

The organic light emitting diode is formed in a laminated thin film structure including an emission layer (EML) and a hole transport layer (HTL) between the cathode electrode and the anode electrode. In addition, the organic light emitting device has an electron injecting layer (EIL), a hole injecting layer (HIL), and a hole blocking layer (hole blocking layer) in order to improve emission efficiency by improving the injection and transport characteristics of electrons and holes. layer, HBL) may be additionally included.

Since the organic light emitting diode display is a self-luminous element, it does not require a separate light source unlike the liquid crystal display. In addition, the organic light emitting diode display has a wide viewing angle, a high contrast ratio, an ultra-thin display of about 2 mm, a moving image with a response time of several seconds, and a low voltage of 5-15V. It has the advantage of being able to drive. In addition, the luminance of the OLED display is controlled by the amount of current flowing through the OLED.

However, when the conventional organic light emitting diode display is driven for a long time, the screen becomes reddish overall. This occurs because the lifetime of the blue and green organic light emitting materials is shorter than the lifetime of the red organic light emitting material among the lifetimes of the red, green, and blue organic light emitting materials used in the organic light emitting display. Accordingly, in the related art organic light emitting diode display, the screen of the display apparatus becomes red before the end of the display device's life, thereby preventing the display of the desired color.

SUMMARY OF THE INVENTION The present invention was derived to solve the above-described problems, and an object of the present invention is to drive a subpixel having an organic light emitting material having the longest lifetime in a pixel more than the rest of the subpixels, thereby reducing the The present invention provides an organic light emitting display device and a method of driving the same, by controlling the lifespan to be similar, thereby preventing the monochrome tendency of the color organic light emitting display device.

Another object of the present invention is to provide an organic light emitting display device and a method of driving the same, which substantially extend the service life of the display device by preventing reddening caused by different lifetimes of the organic light emitting material.

In order to achieve the above object, according to an aspect of the present invention, it comprises a plurality of pixels each consisting of a red sub-pixel, a green sub-pixel, a blue sub-pixel, the image according to a plurality of data signals and selection signals to be applied And an image signal including an image display unit for displaying, a driving unit for transmitting the data signal and the selection signal to the pixel, and an image signal including a red subpicture signal, a green subpicture signal, and a blue subpicture signal corresponding to the plurality of data signals. And a control unit for transmitting to a driving unit, wherein the control unit receives a gray level image signal including a black level sub-picture signal for turning off the longest subpixel among the red, green, and blue sub-pixels. The black level sub-picture signal is converted into the gray level data signal so that the lifetime is transmitted to the longest sub-pixel. An organic light emitting display device is provided.

In one preferred embodiment, the longest subpixel is a red subpixel.

The subpixel further includes a white subpixel, and the subpixel signal further includes a white subpixel signal.

The gray level data signal has a level reduced by 0.5% or more and 3% or less when the black level data signal is 100.

In addition, the data signal is any one of a voltage signal and a current signal.

The control unit may transmit a gray level sub-picture signal to the driver when the black level sub-picture signal is received, and the driving unit transmits the gray level data signal corresponding to the gray level sub-picture signal to the lifetime. Pass in this longest subpixel.

The controller may transmit the black level sub-picture signal and the control signal to the driver when the black level sub-picture signal is received, and the driver receives the black level sub-picture signal and the control signal. The black level sub-picture signal is converted into the gray level data signal and output.

The driver may include a data driver for providing the data signal to the image display unit and a scan driver for providing the selection signal to the image display unit. The data driver may include the black level sub-picture signal for the black level data. And a digital-to-analog converter for converting the signal, and an output amplifier for converting the data signal of the black level into the data signal of the gray level.

According to another aspect of the present invention, an image display unit including a plurality of pixels each consisting of a red subpixel, a green subpixel, and a blue subpixel, and displays an image according to a plurality of data signals and selection signals applied thereto; And a controller configured to transmit the data signal and the selection signal to the driver, and a controller configured to transmit an image signal including a red subpicture signal, a green subpicture signal, and a blue subpicture signal corresponding to the plurality of data signals to the driver. A method of driving an organic light emitting display device, the method comprising: receiving a gray level image signal including a black level sub-picture signal for turning off a subpixel having the longest lifetime among the red, green, and blue subpixels; Converting the sub-picture signal of to a gray level data signal, and the gray level data signal The driving method of the OLED display device including the step of passing the service life of the longest sub-pixels is provided.

The converting of the black level sub-picture signal into a gray level data signal may include converting the black level sub-picture signal received by the controller into a gray level sub-picture signal. And transmitting, by the driver, the sub-level signal of the gray level into a data signal of the gray level.

The converting of the black level sub-picture signal into a gray level data signal may include: transmitting, by the controller, the sub-picture signal and the control signal of the black level to the driving unit, and the driving unit to the control signal. And converting the black level sub-picture signal into the gray level data signal.

The converting of the black level sub-picture signal into the gray level data signal according to the control signal may include converting the black level sub-picture signal into a black level data signal through a digital-to-analog converter. And converting the black level data signal into the gray level data signal through an output amplifier connected to an output terminal of the digital-analog converter.

In addition, the gray level data signal includes a level reduced from 0.5% or more to 3% or less when the level of the black level data signal is 100.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention. However, the present invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein.

2 is a schematic block diagram of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

Referring to FIG. 2, the organic light emitting diode display 200 includes a controller 300, a data driver 400, a scan driver 500, an image display unit 600 including a plurality of pixels 700, and reddening prevention. A portion 800 is included.

The controller 300 receives an image signal from an external device (not shown) such as a video card. The controller 300 supplies the synchronization signal and the clock signal to the data driver 400 and the scan driver 500, respectively. In addition, the controller 300 stores the image signals in frame units, for example, and supplies the image signals to the data driver 400 in accordance with the timing of the synchronization signal or the clock signal.

The data driver 400 receives an image signal from the controller 300. The received image signal is converted into a data signal suitable for the driving method of the image display unit 600. The data driver 400 supplies the data signal converted through the data lines D1 to Dm to the image display unit 600. In this case, the data signal may be a data voltage or a data current.

The scan driver 500 applies the selection signal to the image display unit 600 through the scan lines S1 to Sn. The selection signal turns on a switching element (not shown) connected to the organic light emitting element in the pixel 700, whereby a data signal is supplied into the pixel 700 from a data line connected to one end of the switching element.

The image display unit 600 includes a plurality of pixels 700 which respectively display an image according to an applied data signal. Each pixel 700 includes an organic light emitting device that emits red, green, or blue colors and a pixel circuit connected to each of the organic light emitting devices, as shown in FIG. 1B. Each organic light emitting element includes a red, green or blue organic light emitting layer made of any one of organic light emitting materials of red, green and blue organic light emitting materials. Red, green and blue organic light emitting materials have their own inherent lifetimes due to the properties of the material itself. For example, the lifetime of the organic light emitting material that emits red has approximately twice the lifespan of the organic light emitting material that emits green and blue.

In addition, the controller 300 according to the present exemplary embodiment includes the reddening prevention part 800. As an example, the control unit 300 according to the present invention may include a greening prevention unit or a bluening prevention unit instead of the redization prevention unit 800. The reddening prevention unit 800 includes a series of control routines for preventing reddening of the image display unit 600. Here, redization means that the lifespan of the green and blue organic light emitting layers is shorter than the lifespan of the red organic light emitting layer according to the life difference of each organic light emitting material, so that the color image of the image display unit 600 is displayed as a red series image. The series of control routines of the anti-reddening unit 800 refers to controlling the data driver 400 such that the red organic light emitting layer is driven for more time than the green and blue organic light emitting layers.

To this end, when the gray level image signal including the black level sub-picture signal for turning off the sub-pixel including the red organic light emitting layer having the longest lifetime is input, the controller 300 performs the first processing of the reddening prevention unit 800. The image signal is directly controlled in order to transfer the gray level image signal including the predetermined gray level subpicture signal to the data driver 400 instead of the black level subpicture signal. Here, the gray level is a black level for turning off the organic light emitting element in the pixel and a white level at which the organic light emitting element displays the maximum luminance when the brightness of the pixel is divided into, for example, 64 gray scales for digital image display. Indicates the gradation level or the luminance level belonging to between. The sub-picture signal represents a signal transmitted to each of the red, green, and blue sub-pixels included in one pixel.

On the other hand, if the gray level image signal including the black level sub-picture signal for turning off the sub-pixel including the red organic light-emitting layer having the longest lifetime is input, the control unit 300 receives the second of the reddening prevention unit 800. The control signal for preventing reddening is transmitted to the data driver 400 along with the image signal according to the processing order, so that the black level sub-picture signal is converted into the gray level data signal in the data driver 400 to have the longest lifespan. It is supplied to the red organic light emitting layer. A method of preventing redening of the organic light emitting diode display will be described in more detail below.

3 and 4 are flowcharts illustrating a method for preventing reddening of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

Referring to FIG. 3, first, the controller receives an RGB image signal (302). Then, it is determined whether the RGB image signal is gray level (304). Here, the RGB image signal includes a red subpicture signal for red (R) display, a green subpicture signal for green (G) display, and a blue subpicture signal for blue (B) display. Next, if the RGB image signal is a gray level, it is determined whether the RGB image signal includes the first sub-picture signal of the black level (306). Here, the black level represents an off level voltage signal or a current signal for turning off the organic light emitting element, and the first sub-picture signal includes an organic light emitting element including an organic light emitting material having the longest lifetime among the plurality of organic light emitting elements in one pixel. Represents a sub-picture signal of any one of the red, green and blue sub-picture signals transmitted to.

After that, if the RGB image signal contains the first sub-picture signal of the black level, the control unit processes the first sub-picture signal of the black level to be replaced with the first sub-picture signal of the gray level (308a).

Next, the controller supplies the modified RGB image signal including the gray level first sub-picture signal to the driver instead of the RGB image signal including the black level first sub-picture signal (310a).

On the other hand, if the RGB image signal is not a gray level or a black level or a white level in step 304, or if the RGB image signal does not include the first sub-picture signal of a black level in step 306, the control unit controls the existing RGB image signal. Process in the manner (312). Here, the RGB image signal of the black level indicates that all of the red, green, and blue sub-picture signals are the black level for turning off the organic light emitting element, and the white level indicates the gradation level at which the red, green, and blue sub-picture signals all have the maximum luminance. Or white level. The conventional method indicates that the RGB image signal is stored in the frame memory or the like and then transferred to the data driver according to a predetermined command. Thereafter, the control unit transmits the RGB image signal to the driving unit (314).

Next, referring to FIG. 4, the driver receives an RGB image signal or a modified RGB image signal from the controller (322). The driver converts the RGB image signal input in the conventional manner into an RGB data signal according to the gamma curve (324). The RGB data signal is output to the image display unit (326). The image display unit displays an image corresponding to the applied RGB data signal on the screen (328).

According to the present embodiment, when the organic light emitting device including the organic light emitting material having the longest lifetime is a red organic light emitting device, the organic light emitting material of the red organic light emitting device having a longer life than the organic light emitting material of the green and blue organic light emitting devices is green. And the driving time for more time than the material of the blue subpixel is shortened. Therefore, the lifespan of the organic light emitting material in the red, green and blue subpixels included in the organic light emitting element can be adjusted substantially the same or almost similarly. As described above, the present invention not only prevents redness of the organic light emitting display device but also substantially extends the life of the organic light emitting display device.

5 and 6 are flowcharts illustrating a method for preventing reddening of an organic light emitting diode display according to a second exemplary embodiment of the present invention.

Referring to FIG. 5, a control unit first receives an RGB image signal (302). Then, it is determined whether the RGB image signal is gray level (304). Next, if the RGB image signal is a gray level, it is determined whether the RGB image signal includes the first sub-picture signal of the black level (306). Here, the first sub-picture signal is one of red, green, and blue sub-picture signals transmitted to the organic light-emitting device including the organic light emitting material having the longest lifetime among the plurality of organic light-emitting devices in one pixel, similar to the first embodiment described above. Represents either sub-picture signal.

After that, if the RGB image signal contains the first sub-picture signal of the black level, the control unit controls to convert the first sub-picture signal of the black level into the first sub-picture signal of the gray level when processing the image signal. Generate a control signal for the device (308b). Next, the controller supplies a control signal to the driver along with the RGB image signal including the first sub-picture signal of the black level (310b).

On the other hand, if in step 304 the RGB image signal is not a gray level but is a black level or a white level, or if in step 306 the RGB image signal does not contain the first sub-picture signal of the black level, then the control unit is the same as the first embodiment described above. As in the case, the RGB image signal is processed in the conventional manner (312). Thereafter, the control unit transmits the RGB image signal to the driving unit (314).

Next, referring to FIG. 6, the driver receives an RGB image signal and a control signal from the controller (332). The driving unit converts the RGB image signal input in the conventional manner into an RGB data signal according to the gamma curve (334). When the switching means connected to the output terminal of the data driver is operated by the control signal (336), the data driver converts the first data signal of the black level among the RGB data signals into the first data signal of the gray level (338). Thereafter, the data driver supplies an RGB data signal including the gray level first data signal to the image display unit (340).

On the other hand, if the leveling means by the control signal does not operate in step 336, the data driver supplies the RGB data signal to the image display unit in the conventional manner (342). The image display unit displays an image corresponding to the RGB data signal received from the driver on the screen (344).

As described above, according to the second exemplary embodiment of the present invention, the data level of the black level applied to the organic light emitting element having the organic light emitting material having the longest lifetime is switched by using a switching means connected to the output terminal of the driving unit. By changing to the data voltage, the organic light emitting element having the longest lifetime organic light emitting material in the pixel is driven without being turned off even at some black levels, so that the organic light emitting element having the longest lifetime organic light emitting material has different organic They are driven for a longer time than the light emitting device, and thus their lifespan is similar to prevent redness of the organic light emitting display, and the organic light emitting display can display a desired color for a longer time than the conventional organic light emitting display. do.

Next, the data driver and the switching means connected to the output terminal of the organic light emitting diode display according to the second exemplary embodiment will be described. The data driver is included in the driver according to the present invention described above.

7 is a block diagram of a data driver of an organic light emitting diode display according to a second exemplary embodiment of the present invention.

Referring to FIG. 7, the data driver 400 may include a shift register 420, a sampling latch 430, a holding latch 440, and a digital to analog converter (DAC); 450).

The shift register 420 supplies the first latch enable signal to the sampling latch 430 to sequentially store the RGB image signal in the sampling latch 430 according to the horizontal clock signal and the horizontal synchronization signals HCLK and HSYNK. .

The sampling latch 430 sequentially stores the RGB image signal input from the controller in response to the first latch enable signal. The sampling latch 430 transfers a series of RGB image signals to the holding latch 440. Holding latch 440 receives a series of RGB image signals from sampling latch 430 and delivers them to DAC 450.

The DAC 450 converts the RGB image signal received from the holding latch 440 into an RGB data signal and outputs the RGB image signal to each data line of the image display unit. In this case, the DAC 450 includes an output buffer or an output amplifier (not shown) connected to the output terminal. The DAC 450 converts an input analog signal into a digital signal, amplifies the output appropriately, and outputs the output signal on each data line. The DAC 450 may be driven by any one of a voltage driving method and a current driving method.

Further, the DAC 450 is turned off when the sub-pixel having the longest life organic light emitting element is a red sub-pixel, for example, and when a gray level RGB image signal for turning off the red sub-pixel is input. And turn on the sub-pixel for a longer time than other sub-pixels by turning it on by a minute amount. This configuration will be described in detail below.

8 is a schematic block diagram of a digital-to-analog converter of the data driver of FIG. 7. In the following description with reference to FIG. 8, the DAC is described as a voltage DAC.

Referring to FIG. 8, the DAC 450 may include a first output amplifier 462 and a green DAC 454 connected to outputs of a red DAC 452, a green DAC 454, a blue DAC 456, and a red DAC 452. A second output amplifier 464 connected to an output terminal of the N-axis, a third output amplifier 466 connected to an output terminal of the blue DAC 456, and a switching means 470.

The red, green, and blue DACs 452, 454, and 456 represent DACs respectively connected to red, green, and blue organic light emitting devices (not shown) including organic light emitting layers emitting red, green, or blue colors, respectively. In addition, the DACs 452, 454, and 456 include respective input terminals input1, input2, and input3, and output terminals connected to the red, green, and blue organic light emitting diodes, respectively.

The first to third output amplifiers 462, 464, 466 are connected to the output terminals of the red, green, and blue DACs 452, 454, 456, respectively. The first to third output amplifiers 462, 464, and 466 amplify the outputs of the DACs 452, 454, and 456 to predetermined sizes, respectively, and output them on the data lines of the image display unit. The first to third output amplifiers 462, 464, and 466 are connected to the first and second reference voltages Vref1 and Vref2. In addition, the first amplifier 462 is selectively connected to the third reference voltage Vref3 through a switching means 470 that is turned on or off in response to a control signal of the controller.

The switching means 470 is connected to an input terminal of two reference voltages out of three reference voltages of the red DAC 452. The switching means 470 changes the size of the black level data signal transmitted to the red organic light emitting element as the longest lifetime element by a predetermined size in response to the control signal CTL of the controller. To this end, the switching means 470 converts the first reference voltage of the first output amplifier 462 connected to the output terminal of the red DAC 452 into the third reference voltage according to the control signal CTL of the controller. Here, the first and third reference voltages are set such that an output with respect to the input of the output promoter varies in a range of 0.5% or more to 3% or less. For example, when the voltage of the black level output from the red DAC 452 and input to one input terminal of the first output amplifier 462 is 5V, the output voltage of the first output amplifier 462 is 4.85V to 4.97V. It is in the range of.

This range is determined by the minimum level range for aging the red subpixel, which has the longest lifetime, without turning it off from off level, and the maximum level range in which the color of the displayed image is different from color or the luminance does not seem strange. do.

For example, the switching means 470 may comprise two switching elements which are turned on and off at substantially the same time by the control signal CTL. In this case, the switching means 470 includes a PMOS transistor having a gate terminal to which the control signal CTL is applied, a source terminal connected to the first reference voltage Vref1, and a drain terminal connected to the output terminal, and the control signal CTL. The switching circuit may include a NMOS transistor having a gate terminal to which a is applied, a drain terminal connected to the third reference voltage Vref3, and a source terminal commonly connected to the output terminal.

As described above, when the subpixel including the organic light emitting element having the longest lifetime is the red subpixel and the DAC is the voltage DAC, the black level data signal transmitted to the red organic light emitting element is changed by a predetermined magnitude. By means of changing, the black level, which is the off level of the red organic light emitting element, is changed from the gray level which is the on level of the red organic light emitting element (see FIG. 9). Therefore, the organic light emitting element having the longest lifetime is kept on even at some off levels and is driven for a longer time, thereby preventing redness of the organic light emitting diode display caused by the difference in lifespan of the organic light emitting material.

9 is a diagram for an RGB data signal according to a preferred embodiment of the present invention.

Referring to FIG. 9, from time t0 to t5, the red data signal is a gray level among the RGB data signals, and the green data signal and the blue data signal are any one of gray level, white level, and black level. At this time, the red, green, and blue data signals are transmitted to the image display unit as they are.

Next, from time t5 to t8, the red data signal of the RGB data signals is the black level, and the green data signal and the blue data signal are the white level, the gray level, and the black level. However, the green data signal and the blue data signal are not simultaneously black levels. At this time, according to the reddening prevention method according to the present invention, the red data signal of the black level is changed to the red data signal of the gray level by a predetermined magnitude. Then, the RGB data signal including the red data signal of the changed gray level is transmitted to the image display unit.

Next, from time t8 to t9, all of the red, green and blue data signals among the RGB data signals are black level. At this time, the red, green, and blue data signals are transmitted to the image display unit as they are as black level data signals.

As described above, the present invention prevents redness of the organic light emitting display by driving the organic light emitting element having the longest life for more time. Accordingly, the present invention provides an organic light emitting display device which prevents redness and substantially extends its service life.

In the present embodiment, the data signal transmitted to the organic light emitting diode has been described as an example of the data voltage. However, the present invention can be made so that the data current is transferred to the organic light emitting device using the current DAC of the current driving method.

In the above-described embodiment, the red light emitting material has the longest lifetime among the RGB light emitting materials of the organic light emitting display. However, the present invention is not limited to such a configuration, and the same can be applied to the case where the green or blue light emitting material has the longest lifetime. Further, the present invention can be applied not only to the case where one light emitting material has a longer life than other light emitting materials, but also to a case where two light emitting materials have a long life with respect to the other light emitting material.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, the present invention is not limited to the above-described embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. Modifications are possible.

As described above, according to the present invention, the red light emitting device of the organic light emitting diode display may be adjusted to be substantially the same as that of the green and blue light emitting diodes, thereby preventing reddening of the organic light emitting diode display.

In addition, when the lifetime of the RGB light emitting material for displaying the color of RGB used in the organic light emitting display is different, the organic light emitting display may be substantially organic by preventing a specific colorization tendency of the organic light emitting display that may occur after long time driving of the display. The service life of the light emitting display device can be extended.

1A is a schematic block diagram of a conventional organic light emitting display.

1B is a circuit diagram of a pixel of a conventional organic light emitting display.

2 is a block diagram of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

3 and 4 are flowcharts illustrating a method for preventing reddening of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

5 and 6 are flowcharts illustrating a method for preventing reddening of an organic light emitting diode display according to a second exemplary embodiment of the present invention.

7 is a block diagram of a data driver of an organic light emitting diode display according to a second exemplary embodiment of the present invention.

8 is a schematic block diagram of a digital-to-analog converter of the data driver of FIG. 7.

9 is a diagram for an RGB data signal according to a preferred embodiment of the present invention.

<Description of the symbols in the main part of the drawing>

200: organic light emitting display 300: controller

400: data driver 450: digital-to-analog converter

470: switching means 500: scan driver

600: image display unit 700: pixels

800: reddening prevention unit

Claims (15)

An image display unit including a plurality of pixels each consisting of a red subpixel, a green subpixel, and a blue subpixel, and displaying an image according to a plurality of data signals and a selection signal to be applied; A driver transferring the data signal and the selection signal to the pixel; And And a controller configured to transmit an image signal including a red sub-picture signal, a green sub-picture signal, and a blue sub-picture signal corresponding to the plurality of data signals to the driving unit. The control unit receives a gray level image signal including a black level sub picture signal for turning off the longest subpixel among the red, green, and blue sub pixels, and the black level sub picture signal is a gray level. The organic light emitting diode display of claim 1, wherein the organic light emitting diode display is configured to be changed to the data signal of and to be transmitted to the longest pixel. The method of claim 1, The subpixel having the longest lifetime is a red subpixel. The method of claim 1, The subpixel further includes a white subpixel, and the subpixel signal further includes a white subpixel signal. The method of claim 1, The gray level data signal has a level reduced by 0.5% or more and 3% or less when the level of the black level data signal is 100. The method of claim 1, The data signal is one of a voltage signal and a current signal. The method of claim 1, When the control unit receives the black level sub-picture signal, the controller transfers the gray level sub-picture signal to the driving unit. And the driver transfers the gray level data signal corresponding to the gray level sub-picture signal to the longest subpixel. The method of claim 1, When the controller receives the black level sub-picture signal, the controller transmits the black level sub-picture signal and the control signal to the driving unit. And the driver converts the black level sub-picture signal and the control signal into the gray level data signal and outputs the gray level data signal. The method of claim 7, wherein The driver includes a data driver for providing the data signal to the image display unit and a scan driver for providing the selection signal to the image display unit. The data driver includes a digital-analog converter for converting the black level sub-picture signal to a black level data signal, and an output amplifier for converting the black level data signal to the gray level data signal and outputting the gray level data signal. Light emitting display. An image display unit including a plurality of pixels each consisting of a red subpixel, a green subpixel, and a blue subpixel, and displaying an image according to a plurality of data signals and selection signals applied thereto; And a control unit configured to transmit an image signal including a red sub-picture signal, a green sub-picture signal, and a blue sub-picture signal corresponding to the plurality of data signals, to the driver. In Receiving a gray level image signal including a black level subpicture signal for turning off the longest subpixel among the red, green, and blue subpixels; Converting the black level sub-picture signal into a gray level data signal; And And transmitting the gray level data signal to the longest subpixel. The method of claim 9, Converting the black level sub-picture signal to a gray level data signal, Converting the black level sub-picture signal received by the controller into a gray level sub-picture signal and transferring the gray level sub-picture signal to the driving unit; And And the driving unit converts the gray level sub-picture signal into the gray level data signal. The method of claim 9, Converting the black level sub-picture signal to a gray level data signal, Transmitting, by the controller, the sub-picture signal and the control signal of the black level to the driver; And And the driving unit converts the black level sub-picture signal into the gray level data signal according to the control signal. The method of claim 11, The driving unit converts the black level sub-picture signal into the gray level data signal according to the control signal. Converting the black level sub-picture signal into a black level data signal through a digital-to-analog converter; And And converting the black level data signal into the gray level data signal through an output amplifier connected to an output terminal of the digital-analog converter. The method of claim 9, The gray level data signal includes a level reduced from 0.5% or more to 3% or less when the black level data signal is 100. The method of claim 9, The subpixel having the longest lifetime is a red subpixel. The method of claim 9, And the data signal is any one of a voltage signal and a current signal.