Display device

Abstract

A display device is provided. The display device includes: a display panel including a plurality of pixels; a data driver configured to generate a data voltage provided to the pixels; a light stress compensator configured to determine whether a pixel among a plurality of pixels satisfies a light stress condition based on input image data, and configured to output a data voltage control signal that changes a voltage level of the data voltage provided to the pixel that satisfies the light stress condition; a scan driver configured to generate a scan signal provided to the pixels; and a timing controller configured to generate a control signal for controlling the data driver and the scan driver.

Description

Technical Field

[0001] Aspects of the present invention generally relate to a display device and an electronic device having the display device. Background Art

[0002] Since flat panel display (FPD) devices are relatively light and thin compared to cathode ray tube (CRT) display devices, FPD devices are widely used as display devices of electronic devices. Examples of FPD devices are liquid crystal display (LCD) devices, field emission display (FED) devices, plasma display panel (PDP) devices, and organic light emitting display (OLED) devices. Since OLED devices have various advantages such as wide viewing angle, fast response speed, small thickness, low power consumption, etc., OLED devices have attracted much attention as next generation display devices.

[0003] The characteristics of a thin film transistor (TFT) included in a pixel of an OLED device may change due to continuous light. When the gate-source voltage of the TFT is less than the threshold voltage, the TFT may have a greater characteristic change due to light output from an adjacent pixel. There is a problem that the brightness of the pixel is changed or a static image is generated due to the change in the characteristics of the TFT.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute the prior art. Summary of the invention

[0005] Aspects of embodiments of the present invention are directed to a display device capable of improving display quality.

[0006] Aspects of embodiments of the present invention are directed to an electronic device having a display device capable of improving display quality.

[0007] According to some example embodiments, a display device is provided, the display device including: a display panel including a plurality of pixels; a data driver configured to generate a data voltage provided to the plurality of pixels; a light stress compensator configured to determine whether a pixel among the plurality of pixels satisfies a light stress condition based on input image data, and configured to output a data voltage control signal that changes a voltage level of a data voltage provided to the pixel satisfying the light stress condition; a scan driver configured to generate a scan signal provided to the plurality of pixels; and a timing controller configured to generate a control signal for controlling the data driver and the scan driver.

[0008] In some embodiments, the light stress compensator includes: a light stress determiner, configured to determine that a pixel satisfies a light stress condition when at least one sub-pixel of the pixel emits light and at least one other sub-pixel of the pixel does not emit light; and a data voltage controller, configured to generate a data voltage control signal that changes a voltage level of a data voltage provided to a sub-pixel that does not emit light, the sub-pixel belonging to the pixel satisfying the light stress condition.

[0009] In some embodiments, the light stress determiner is configured to determine that the subpixel emits light when the subpixel displays light having a grayscale value greater than a first grayscale value, and is configured to determine that the subpixel does not emit light when the subpixel displays light having a grayscale value of 0.

[0010] In some embodiments, the light stress determiner is configured to determine that the subpixel emits light when the subpixel displays light having a grayscale value greater than a first grayscale value, and is configured to determine that the subpixel does not emit light when the subpixel displays light having a grayscale value less than a second grayscale value.

[0011] In some embodiments, the data voltage controller includes a lookup table storing data voltage control signals corresponding to grayscale values ​​of sub-pixels that do not emit light.

[0012] In some embodiments, the light stress compensator further comprises: a duration determiner configured to measure a duration for which the pixel meets the light stress condition.

[0013] In some embodiments, the data voltage controller is configured to generate a data voltage control signal that changes a voltage level of the data voltage according to a duration.

[0014] In some embodiments, the data voltage controller is configured to periodically output the data voltage control signal.

[0015] In some embodiments, the data voltage controller is configured to output the data voltage control signal non-periodically.

[0016] In some embodiments, the data voltage controller is configured to continuously output the data voltage control signal.

[0017] In some embodiments, the data voltage controller is configured to output the data voltage control signal discontinuously.

[0018] In some embodiments, the light stress compensator includes: an identification detector configured to detect an identification area of ​​a display identification based on input image data; and a data voltage controller configured to generate a data voltage control signal that changes a voltage level of a data voltage provided to a non-luminous sub-pixel, the sub-pixel belonging to a pixel among multiple pixels in the identification area.

[0019] In some embodiments, the identification detector is configured to detect a peripheral area surrounding the identification area, and the data voltage controller is configured to generate a data voltage control signal that changes a voltage level of a data voltage supplied to a non-luminous sub-pixel, the sub-pixel belonging to a pixel among multiple pixels in the identification area or the peripheral area.

[0020] According to some example embodiments, there is provided an electronic device including a display device and a processor for controlling the display device, the display device including: a display panel including a plurality of pixels; a data driver configured to generate a data voltage provided to the plurality of pixels; a light stress compensator configured to determine whether a pixel among a plurality of pixels satisfies a light stress condition based on input image data, and configured to output a data voltage control signal that changes a voltage level of a data voltage provided to the pixel that satisfies the light stress condition; a scan driver configured to generate a scan signal provided to the plurality of pixels; and a timing controller configured to generate a control signal for controlling the data driver and the scan driver.

[0021] In some embodiments, the light stress compensator includes: a light stress determiner configured to determine that a pixel satisfies a light stress condition when at least one sub-pixel of the pixel emits light and at least one other sub-pixel of the pixel does not emit light; and a data voltage controller configured to generate a data voltage control signal that changes a voltage level of a data voltage provided to at least one other sub-pixel.

[0022] In some embodiments, the light stress determiner is configured to determine that the subpixel emits light when the subpixel displays light having a grayscale value greater than a first grayscale value, and is configured to determine that the subpixel does not emit light when the subpixel displays light having a grayscale value of 0.

[0023] In some embodiments, the light stress determiner is configured to determine that the subpixel emits light when the subpixel displays light having a grayscale value greater than a first grayscale value, and is configured to determine that the subpixel does not emit light when the subpixel displays light having a grayscale value less than a second grayscale value.

[0024] In some embodiments, the light stress compensator further includes a duration determiner configured to measure a duration for which the pixel meets the light stress condition, and the data voltage controller is configured to generate a data voltage control signal that changes a voltage level of the data voltage according to the duration.

[0025] In some embodiments, the light stress compensator includes: an identification detector configured to detect an identification area of ​​a display identification based on input image data; and a data voltage controller configured to generate a data voltage control signal that changes a voltage level of a data voltage provided to a non-luminous sub-pixel, the sub-pixel belonging to a pixel among multiple pixels in the identification area.

[0026] In some embodiments, the identification detector is configured to detect a peripheral area surrounding the identification area, and the data voltage controller is configured to generate a data voltage control signal that changes a voltage level of a data voltage provided to a non-luminous sub-pixel, which is a pixel among multiple pixels in the identification area or the peripheral area.

[0027] Therefore, the display device can determine whether the pixel satisfies the light stress condition, and the data voltage controller is configured to generate a data voltage control signal that changes the voltage level of the data voltage provided to the non-luminous sub-pixel included in the pixel that satisfies the light stress condition, so that the degradation of the driving transistor included in the non-luminous sub-pixel due to the light stress can be prevented or substantially reduced. Therefore, the display quality can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Illustrative, non-limiting example embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0029] Figure 1 is a block diagram illustrating a display device according to some example embodiments of the present invention.

[0030] Figure 2 It is shown that the Figure 1 FIG. 1 is a diagram of an example of pixels of a display panel in a display device.

[0031] Figure 3 It is shown that the Figure 1 A block diagram of an example of a light stress compensator in a display device.

[0032] FIG. 4A to FIG. 4B It is shown that the Figure 1 FIG. 1 is a diagram of an example of pixels of a display panel in a display device.

[0033] Figure 5 It is shown that the Figure 3 FIG. 1 is a table showing an example of a lookup table in a data voltage controller of a light stress compensator.

[0034] Figure 6 It is shown that the Figure 1 Block diagram of other examples of light stress compensators in display devices.

[0035] Figure 7 It is shown that the Figure 6 FIG. 1 is a diagram of the operation of a data voltage controller in a light stress compensator.

[0036] FIG. 8A to FIG. 8E It is shown that the Figure 6 FIG. 1 is a diagram of the operation of a data voltage controller in a light stress compensator.

[0037] Fig. 9 It is shown that the Figure 1 A block diagram of another example of a light stress compensator in a display device.

[0038] Fig.10 is shown in the included Figure 1 FIG. 1 is a diagram showing an example of an image displayed on a display panel in a display device.

[0039] FIG. 11A to FIG. 11B It is shown Fig. 9 FIG. 1 is a diagram of an example of the operation of a light stress compensator.

[0040] Fig.12 is a block diagram illustrating an electronic device according to some example embodiments.

[0041] Fig.13 It shows that Fig.12 FIG. 1 is a diagram of an example embodiment in which the electronic device is implemented as a smart phone. DETAILED DESCRIPTION

[0042] Hereinafter, the inventive concept will be explained in detail with reference to the accompanying drawings.

[0043] Figure 1 is a block diagram illustrating a display device according to some example embodiments of the present invention. Figure 2 It is shown that the Figure 1 FIG. 1 is a diagram of an example of pixels of a display panel in a display device.

[0044] Reference Figure 1 , the display device 100 may include a display panel 110 , a timing controller 120 , a scan driver 130 , a light stress compensator 140 , and a data driver 150 .

[0045] The display panel 110 may include a plurality of pixels PX. The display panel 110 may include data lines DL and scan lines SL. Each pixel PX may be coupled to the scan lines SL and the data lines DL, respectively. The scan lines SL may extend in a first direction D1 and be arranged in a second direction D2 perpendicular to the first direction D1. The data lines DL may extend in a second direction D2 and be arranged in the first direction D1. The first direction D1 may be parallel to a long side of the display panel 110, and the second direction D2 may be parallel to a short side of the display panel 110. Each pixel PX may be formed in a cross region of the data lines DL and the scan lines SL.

[0046] Reference Figure 2, each pixel PX may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3. For example, the first sub-pixel SP1 may display red light, the second sub-pixel SP2 may display green light, and the third sub-pixel SP3 may display blue light. Figure 2 , a pixel PX including a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3 is described, but the pixel PX is not limited thereto. For example, the pixel PX may further include a fourth sub-pixel that displays white light. Each sub-pixel may include a driving transistor. The driving transistor may be a thin film transistor (TFT). The driving transistor may be driven by a data voltage Vdata supplied to a gate electrode. When the gate-source voltage of the driving transistor is greater than a threshold voltage, the sub-pixel including the driving transistor may emit light. When the gate-source voltage of the driving transistor is less than the threshold voltage, the sub-pixel including the driving transistor may not emit light. When the gate-source voltage of the driving transistor is less than the threshold voltage, the characteristics of the driving transistor may be changed by light emitted from surrounding sub-pixels. The display device 100 according to an example embodiment may determine whether the pixel PX satisfies the light stress condition based on the input image data, and change the voltage level of the data voltage Vdata supplied to the non-emitting sub-pixel included in the pixel PX that satisfies the light stress condition. Therefore, the degradation of the driving transistor may be prevented or substantially reduced. Hereinafter, the display device 100 will be described in detail.

[0047] The timing controller 120 may convert the first image data IMG1 provided from the external device into the second image data IMG2, and generate a data control signal CTL_D and a scan control signal CTL_S to control driving of the second image data IMG2. The timing controller 120 may convert the first image data IMG1 into the second image data IMG2 by executing an image enhancement algorithm (e.g., dynamic capacitance compensation (DCC)). When the timing controller 120 does not include the image enhancement algorithm, the first image data IMG1 may be output as the second image data IMG2. The timing controller 120 may provide the second image data IMG2 to the light stress compensator 140 and the data driver 150. The timing controller 120 may receive a control signal CON from the external device, and generate a data control signal CTL_D provided to the data driver 150 and a scan control signal CTL_S provided to the scan driver 130. For example, the data control signal CTL_D may include a horizontal start signal and at least one clock signal. For example, the scan control signal CTL_S may include a vertical start signal and at least one clock signal.

[0048] The scan driver 130 may provide the scan signal SCAN to the pixel PX through the scan line SL. The scan driver 130 may generate the scan signal SCAN based on the scan control signal CTL_S provided from the timing controller 120. The scan driver 130 may provide the scan signal SCAN to the pixel PX in the display panel 110 through the scan line SL.

[0049] In some example embodiments, the light stress compensator 140 may determine whether the pixel PX satisfies the light stress condition based on the second image data IMG2, and generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage Vdata provided to the pixel PX that satisfies the light stress condition. The light stress compensator 140 may determine whether the pixel PX satisfies the light stress condition based on the second image data IMG2 provided from the timing controller 120. When at least one subpixel included in the pixel PX emits light and at least one other subpixel included in the pixel PX does not emit light, the light stress compensator 140 may determine that the pixel PX satisfies the light stress condition. For example, when the third subpixel SP3 displaying blue light emits light, and the first subpixel SP1 displaying red light and the second subpixel SP2 displaying green light do not emit light, the light stress compensator 140 may determine that the pixel PX satisfies the light stress condition. In some example embodiments, the light stress compensator 140 may determine that the sub-pixel emits light when the sub-pixel displays light having a gray value greater than a first gray value (e.g., a set or predetermined first gray value), and determine that the sub-pixel does not emit light when the sub-pixel displays light having a gray value of 0. For example, when the display device 100 is driven in an 8-bit mode, the first gray value may have a gray value of 100. The light having a gray value of 0 may be black light. That is, when the pixel PX includes at least one sub-pixel that displays light having a gray value greater than 100 and at least one sub-pixel that displays light having a gray value of 0, the light stress compensator 140 may determine that the pixel PX satisfies the light stress condition. In other example embodiments, the light stress compensator 140 may determine that the sub-pixel emits light when the sub-pixel displays light having a gray value greater than a first gray value (e.g., a set or predetermined first gray value), and determine that the sub-pixel does not emit light when the sub-pixel displays light having a gray value less than a second gray value (e.g., a set or predetermined second gray value). For example, when the display device 100 is driven in the 8-bit mode, the first gray value may have a gray value of 100, and the second gray value may have a gray value of 10. That is, when the pixel PX includes at least one sub-pixel that displays light having a gray value greater than 100 and at least one sub-pixel that displays light having a gray value less than 10, the light stress compensator 140 may determine that the pixel PX satisfies the light stress condition.

[0050] The light stress compensator 140 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel (i.e., the non-emitting sub-pixel) included in the pixel PX satisfying the light stress condition. For example, the data voltage control signal CTL_VD may be a signal that increases the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel. For example, when the third sub-pixel SP3 emits light and the first sub-pixel SP1 and the second sub-pixel SP2 do not emit light, the light stress compensator 140 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the first sub-pixel SP1 and the second sub-pixel SP2. Here, because the characteristic change rate of the driving transistor of the first sub-pixel SP1 and the characteristic change rate of the driving transistor of the second sub-pixel SP2 are different from each other, the data voltage control signal CTL_VD provided to the first sub-pixel SP1 and the data voltage control signal CTL_VD provided to the second sub-pixel SP2 may be different from each other. The data voltage control signal CTL_VD may be provided to the data driver 150 .

[0051] In other example embodiments, the light stress compensator 140 may detect the identification area of ​​the display identification based on the second image data IMG2, and generate a data voltage control signal CTL_VD, which changes the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel (i.e., the non-emitting sub-pixel) included in the identification area. Because the pixel PX in the identification area continuously emits light, the driving transistor in the pixel PX included in the identification area may be rapidly degraded. The light stress compensator 140 may detect the identification area when the display device 100 is driven. That is, the light stress compensator 140 may determine that the pixel PX included in the identification area satisfies the light stress condition. The light stress compensator 140 may generate the data voltage control signal CTL_VD, which changes the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel in the pixel PX included in the identification area.

[0052] In addition, the light stress compensator 140 may detect the logo area and the peripheral area surrounding the logo area based on the second image data IMG2. The light stress compensator 140 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage Vdata provided to the non-emitting sub-pixels of the pixels PX included in the logo area and the peripheral area. Here, the light stress compensator 140 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage Vdata provided to the non-emitting sub-pixels of the pixels PX included in the peripheral area to be different from the voltage level of the data voltage Vdata provided to the non-emitting sub-pixels of the pixels PX included in the logo area. For example, the light stress compensator 140 may generate a first data voltage control signal that changes the voltage level of the data voltage Vdata supplied to the non-emitting sub-pixel of the pixel PX in the identification area to a first voltage level, and the light stress compensator 140 may generate a second data voltage control signal that changes the voltage level of the data voltage Vdata supplied to the non-emitting sub-pixel of the pixel PX in the peripheral area to a second voltage level that is lower than the first voltage level. Therefore, the boundary of the identification area may not be recognized (e.g., may not be recognized by the user).

[0053] The data driver 150 may generate a data voltage Vdata based on the second image data IMG2 and the data voltage control signal CTL_VD. The data driver 150 may generate a grayscale voltage corresponding to the second image data IMG2 as the data voltage Vdata. The data driver 150 may change the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel included in the pixel PX satisfying the light stress condition based on the data voltage control signal CTL_VD. For example, the data driver 150 may increase the voltage level of the data voltage Vdata provided to the non-emitting sub-pixel displaying a grayscale value of 0 based on the data voltage control signal CTL_VD. When the voltage level of the data voltage Vdata increases, the brightness of the sub-pixel increases and affects the display quality, and the increase amount of the data voltage Vdata may be obtained and pre-set through experiments. The data driver 150 may provide the data voltage Vdata to the pixel PX in the display panel 110 through the data line DL. Therefore, a gate-source voltage greater than the threshold voltage of the driving transistor of the non-emitting sub-pixel included in the pixel PX satisfying the light stress condition may be applied so that the change in the characteristics of the driving transistor may not affect the light emission of the pixel.

[0054] Despite Figure 1, the light stress compensator 140 connected to the timing controller 120 and the data driver 150 is described, but the light stress compensator 140 may not be limited thereto. For example, the light stress compensator 140 may be located in the timing controller 120 or in the data driver 150.

[0055] As mentioned above, Figure 1 The display device 100 can determine whether the pixel PX satisfies the light stress condition, and change the voltage level of the data voltage Vdata provided to the non-luminous sub-pixel included in the pixel PX that satisfies the light stress condition, so that the degradation of the driving transistor caused by the light stress can be prevented or substantially reduced.

[0056] Figure 3 It is shown that the Figure 1 A block diagram of an example of a light stress compensator in a display device. Figure 4A and Figure 4B It is shown that the Figure 1 FIG. 1 is a diagram of an example of pixels of a display panel in a display device. Figure 5 It is shown that the Figure 3 FIG. 1 is a table showing an example of a lookup table in a data voltage controller of a light stress compensator.

[0057] Reference Figure 3 , the light stress compensator 200 may include a light stress determiner 220 and a data voltage controller 240 . Figure 3 The light stress compensator 200 may correspond to Figure 1 The light stress compensator 140 is provided.

[0058] When at least one sub-pixel included in the pixel emits light and at least one other sub-pixel included in the pixel does not emit light, the light stress determiner 220 may determine that the pixel satisfies the light stress condition based on the second image data IMG2. In some example embodiments, the light stress determiner 220 may determine that the sub-pixel emits light when the sub-pixel displays light having a gray value greater than a first gray value, and determine that the sub-pixel does not emit light when the sub-pixel displays light having a gray value of 0. In other example embodiments, the light stress determiner 220 may determine that the sub-pixel emits light when the sub-pixel displays light having a gray value greater than the first gray value, and determine that the sub-pixel does not emit light when the sub-pixel displays light having a gray value less than a second gray value.

[0059] Reference Figure 4A, the pixel of the display panel may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3. For example, the first sub-pixel SP1 may display red light by including a red organic light-emitting layer EL1, the second sub-pixel SP2 may display green light by including a green organic light-emitting layer EL2, and the third sub-pixel SP3 may display blue light by including a blue organic light-emitting layer EL3. When at least one of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 emits light and at least one other sub-pixel of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 does not emit light, the light stress determiner 220 may determine that the pixel satisfies the light stress condition. For example, when the third sub-pixel SP3 emits light and the first sub-pixel SP1 and the second sub-pixel SP2 do not emit light, the light stress determiner 220 may determine that the pixel satisfies the light stress condition.

[0060] Reference Figure 4B , the pixel of the display panel may include a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3. For example, the first sub-pixel SP1 may display red light by including a white organic light-emitting layer EL and a red filter C1, the second sub-pixel SP2 may display green light by including a white organic light-emitting layer EL and a green filter C2, and the third sub-pixel SP3 may display blue light by including a white organic light-emitting layer EL and a blue filter C3. When at least one of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 emits light and at least one other sub-pixel of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 does not emit light, the light stress determiner 220 may determine that the pixel satisfies the light stress condition. For example, when the first sub-pixel SP1 and the third sub-pixel SP3 emit light and the second sub-pixel SP2 does not emit light, the light stress determiner 220 may determine that the pixel satisfies the light stress condition.

[0061] The data voltage controller 240 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the non-emitting sub-pixel included in the pixel satisfying the light stress condition. For example, the data voltage control signal CTL_VD may be a signal that increases the voltage level of the data voltage provided to the non-emitting sub-pixel. For example, when the third sub-pixel SP3 emits light and the first and second sub-pixels SP1 and SP2 do not emit light, the data voltage controller 240 may generate a data voltage control signal CTL_VD that increases the voltage level of the data voltage provided to the first sub-pixel SP1 and a data voltage control signal CTL_VD that increases the voltage level of the data voltage provided to the second sub-pixel SP2. Here, the data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the first sub-pixel SP1 and the data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the second sub-pixel SP2 may be different from each other. For example, the data voltage controller 240 may generate a data voltage control signal CTL_VD increasing the voltage level of the data voltage supplied to the first subpixel SP1 to about 0.3V, and generate a data voltage control signal CTL_VD increasing the voltage level of the data voltage supplied to the second subpixel SP2 to about 0.2V.

[0062] In some example embodiments, when the light stress determiner 220 determines that the sub-pixel displaying light having a gray value of 0 is a non-emitting sub-pixel, the data voltage controller 240 may generate a data voltage control signal CTL_VD that increases a voltage level of a data voltage supplied to the sub-pixel displaying light having a gray value of 0. The data voltage controller 240 may generate the data voltage control signal CTL_VD corresponding to each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3.

[0063] In other example embodiments, when the light stress determiner 220 determines that the sub-pixel displaying light having a light value less than or equal to the second gray value is a non-emitting sub-pixel, the data voltage controller 240 may include a lookup table storing the data voltage control signal CTL_VD corresponding to the gray value less than the second gray value. In example embodiments, the lookup table stores the data voltage control signal CTL_VD corresponding to the gray value of the non-emitting sub-pixel. For example, referring to Figure 5, when the second gray value has a gray value of 10, the data voltage controller 240 may store the 0th data voltage control signal CTL_VD0 to the 10th data voltage control signal CTL_VD10 corresponding to the gray value of 0 to the gray value of 10, respectively. The data voltage controller 240 may output the data voltage control signal CTL_VD corresponding to the gray value of the non-emitting sub-pixel based on the lookup table. For example, when the non-emitting sub-pixel displays light with a gray value of 0, the data voltage controller 240 may output the 0th data voltage control signal CTL_VD0. When the non-emitting sub-pixel displays light with a gray value of 10, the data voltage controller 240 may output the 10th data voltage control signal CTL_VD10. The data voltage controller 240 may include a lookup table storing the data voltage control signal CTL_VD corresponding to each of the gray values ​​of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3. The data driver 150 may change the voltage of the data voltage based on the data voltage control signal CTL_VD.

[0064] Figure 6 It is shown that the Figure 1 A block diagram of another example of a light stress compensator in a display device. Figure 7 It is shown that the Figure 6 FIG. 1 is a diagram of the operation of a data voltage controller in a light stress compensator.

[0065] Reference Figure 6 , the light stress compensator 300 may include a light stress determiner 320 , a duration determiner 340 , and a data voltage controller 360 . Figure 6 The light stress compensator 300 may correspond to Figure 1 The light stress compensator 140 is provided.

[0066] When at least one subpixel included in a pixel emits light and at least one other subpixel included in the pixel does not emit light, the light stress determiner 320 may determine that the pixel satisfies the light stress condition based on the second image data IMG2. Figure 6 The light stress determiner 320 may be connected with Figure 3 The light stress compensator 200 is substantially the same or similar.

[0067] The duration determiner 340 may measure the duration that the pixel satisfies the light stress condition. For example, the duration determiner 340 may measure the duration by counting a clock signal provided at regular time intervals (e.g., counting pulses of the clock signal). The characteristic change of the driving transistor included in the non-luminous sub-pixel may decrease as the duration that the pixel satisfies the light stress condition increases. That is, as the duration increases, the threshold voltage of the driving transistor may decrease and the brightness of the non-luminous sub-pixel may increase.

[0068] The data voltage controller 360 may generate a data voltage control signal CTL_VD that changes a voltage level of a data voltage according to a duration. The data driver 150 may generate a data voltage based on the data voltage control signal CTL_VD. For example, the data driver 150 may change a voltage level of a data voltage by adding the data voltage control signal CTL_VD to the data voltage. Figure 7 , the data voltage controller 360 may generate the data voltage control signal CTL_VD such that the voltage level of the data voltage increases as the duration T increases. Since the threshold voltage of the driving transistor decreases and the characteristics of the driving transistor included in the non-emitting sub-pixel change as the duration T increases, the increase in brightness due to the degradation of the driving transistor may be prevented or substantially reduced by increasing the voltage level of the data voltage.

[0069] FIG. 8A to FIG. 8E It is shown that the Figure 6 FIG. 1 is a diagram of the operation of a data voltage controller in a light stress compensator.

[0070] The data voltage controller 360 may generate a data voltage control signal CTL_VD that changes a voltage level of the data voltage. For example, the data driver 150 may change the voltage level of the data voltage by adding the data voltage control signal CTL_VD to the data voltage.

[0071] Reference Fig. 8A and Figure 8B , the data voltage controller 360 can continuously output the data voltage control signal CTL_VD. Fig. 8A , the data voltage controller 360 may continuously output the data voltage control signal CTL_VD having a constant level. Figure 8B , the data voltage controller 360 may output the data voltage control signal CTL_VD which increases as time T elapses.

[0072] See also Figure 8C and Fig.8D , the data voltage controller 360 may output the data voltage control signal CTL_VD discontinuously. Figure 8C , the data voltage controller 360 may periodically output the data voltage control signal CTL_VD. Fig.8D , the data voltage controller 360 may non-periodically output the data voltage control signal CTL_VD.

[0073] Reference Fig. 8E , the data voltage controller 360 may periodically change and output the data voltage control signal CTL_VD.

[0074] Fig. 9 It is shown that the Figure 1 A block diagram of another example of a light stress compensator in a display device. Fig.10 is shown in the included Figure 1 FIG. 1 is a diagram showing an example of an image displayed on a display panel in a display device. Fig.11A and Fig. 11B It is shown Fig. 9 FIG. 1 is a diagram of an example of the operation of a light stress compensator.

[0075] Reference Fig. 9 , the light stress compensator 400 may include a flag detector 420 and a data voltage controller 440 . Fig. 9 The light stress compensator 400 may correspond to Figure 1 The light stress compensator 140. Fig.10 , when a broadcast image is displayed on the display panel, a logo of a broadcast company may be continuously displayed on the upper right or upper left of the display panel. When the logo is being displayed, some sub-pixels in the logo area may continuously emit light, and some other sub-pixels in the logo area may continuously not emit light. In this case, the characteristics of the driving transistor included in the non-emitting sub-pixel may be changed by the light emitted from the emitting sub-pixel. That is, the pixels in the logo area may satisfy the light stress condition.

[0076] Reference Fig.11A The logo detector 420 may detect a logo area LA on which a logo is displayed based on the second image data IMG2. The logo area LA may include pixels including sub-pixels that emit light and sub-pixels that do not emit light.

[0077] The data voltage controller 440 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage supplied to the non-emitting sub-pixels (i.e., the sub-pixels that do not emit light) of the pixels in the identification area LA. For example, the data voltage control signal CTL_VD may be a signal that increases the voltage level of the data voltage supplied to the non-emitting sub-pixels.

[0078] Reference Fig. 11B The logo detector 420 may detect a logo area LA on which a logo is displayed and a peripheral area PA surrounding the logo area LA based on the second image data IMG2. Pixels in the logo area LA and the peripheral area PA may include sub-pixels that emit light and sub-pixels that do not emit light.

[0079] The data voltage controller 440 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the non-emitting sub-pixels of the pixels included in the identification area LA and the peripheral area PA. For example, the data voltage control signal CTL_VD may be a signal that increases the voltage level of the data voltage provided to the non-emitting sub-pixels. The data voltage controller 440 may generate a data voltage control signal CTL_VD provided to each non-emitting sub-pixel in the identification area LA and a data voltage control signal CTL_VD provided to each non-emitting sub-pixel in the peripheral area PA, respectively. For example, the light stress compensator 400 may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the non-emitting sub-pixels of the pixels in the identification area LA to a first voltage level, and may generate a data voltage control signal CTL_VD that changes the voltage level of the data voltage provided to the non-emitting sub-pixels of the pixels in the peripheral area PA to a second voltage level. Therefore, the boundary LA of the identification area may not be recognized (e.g., may not be recognized by the user).

[0080] Fig.12 is a block diagram illustrating an electronic device according to an example embodiment. Fig.13 It shows that Fig.12 FIG. 1 is a diagram of an example embodiment in which the electronic device is implemented as a smart phone.

[0081] Reference Fig.12 and Fig.13 , the electronic device 500 may include: a processor 510, a memory device 520, a storage device 530, an input / output (I / O) device 540, a power supply device 550, and a display device 560. Here, the display device 560 may correspond to Figure 1 In addition, the electronic device 500 may further include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus (USB) device, other electronic devices, etc. Although Fig.13 6 shows that the electronic device 500 is implemented as a smart phone 600, but the type / category of the electronic device 500 is not limited thereto.

[0082] The processor 510 may perform various computing functions. The processor 510 may be a microprocessor, a central processing unit (CPU), etc. The processor 510 may be coupled to other components via an address bus, a control bus, a data bus, etc. In addition, the processor 510 may be coupled to an expansion bus, such as a peripheral component interconnect (PCI) bus. The memory device 520 may store data for the operation of the electronic device 500. For example, the memory device 520 may include at least one non-volatile memory device (such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc.) and / or at least one volatile memory device (such as a dynamic random access memory (DRAM), a static random access memory (SRAM) device, a mobile DRAM device, etc.). The storage device 530 may be a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc.).

[0083] The I / O device 540 may include an input device such as a keyboard, a keypad, a touch pad, a touch screen, a mouse, etc., and an output device such as a printer, a speaker, etc. In some example embodiments, a display device 560 may be included in the I / O device 540. The power supply device 550 may provide power for the operation of the electronic device 500. The display device 560 may communicate with other components via a bus and / or other communication links. As described above, the display device 560 may include a display panel, a timing controller, a scan driver, a light stress compensator, and a data driver.

[0084] The display panel may include a plurality of pixels, and each pixel may include a sub-pixel. The timing controller may convert the first image data provided from the external device into the second image data, and generate a data control signal and a scan control signal for controlling the driving of the second image data. The scan driver may provide the scan signal to the pixel through the scan line. The light stress compensator may determine whether the pixel satisfies the light stress condition based on the second image data, and generate a data voltage control signal, which changes the voltage level of the data voltage provided to the pixel that satisfies the light stress condition. In some example embodiments, when at least one sub-pixel included in the pixel emits light and at least one other sub-pixel in the pixel does not emit light, the light stress compensator may determine that the pixel satisfies the light stress condition. In other example embodiments, the light stress compensator may determine that the pixel included in the identification area satisfies the light stress condition. The light stress compensator may generate a data voltage control signal, which changes the voltage level of the data voltage provided to the non-emitting sub-pixel (i.e., the non-emitting sub-pixel) of the pixel that satisfies the light stress condition. For example, the data voltage control signal may be a signal that increases the voltage level of the data voltage provided to the non-emitting sub-pixel. The data driver may generate a data voltage based on the second image data and the data voltage control signal. The data driver may generate a grayscale voltage corresponding to the second image data as the data voltage. The data driver may change the voltage level of the data voltage provided to the non-luminous sub-pixel included in the pixel satisfying the light stress condition. The data driver may provide the data voltage to the pixel in the display panel. Therefore, a gate-source voltage greater than a threshold voltage of the driving transistor may be provided to the non-luminous sub-pixel included in the pixel satisfying the light stress condition, so that the change in the characteristics of the driving transistor may not affect the light emission of the pixel.

[0085] As mentioned above, Fig.12 The electronic device 500 may include a display device 560, which determines whether a pixel satisfies a light stress condition, and changes the voltage level of a data voltage provided to a non-luminous sub-pixel included in the pixel that satisfies the light stress condition, so that degradation of the driving transistor due to light stress can be prevented or substantially reduced.

[0086] The inventive concept can be applied to a display device and an electronic device having a display device. For example, the inventive concept can be applied to a computer display, a laptop computer, a digital camera, a cellular phone, a smart phone, a smart tablet, a television, a personal digital assistant (PDA), a portable multimedia player (PMP), an MP3 player, a navigation system, a game console, a videophone, etc.

[0087] The terms used herein are for the purpose of describing specific embodiments and are not intended to limit the inventive concept. As used herein, unless the context clearly indicates otherwise, the singular forms "one" and "one (kind / person)" are also intended to include plural forms. It will also be understood that when the terms "include", "comprise" and / or variations thereof are used in this specification, the description indicates the presence of the described features, integral bodies, steps, operations, elements, components and / or components, but does not exclude the presence or addition of one or more other features, integral bodies, steps, operations, elements and / or their components. As used herein, the term "and / or" includes any combination and all combinations of one or more of the related listed items.

[0088] For the purpose of the present disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be interpreted as any combination of only X, only Y, only Z, or two or more of X, Y, and Z, such as, for example, XYZ, XYY, YZ, and ZZ.

[0089] Furthermore, when describing embodiments of the inventive concepts, the use of “may” indicates “one or more embodiments of the inventive concepts.” Furthermore, the term “exemplary” is intended to indicate an example or illustration.

[0090] It should be understood that when an element or layer is referred to as being "on," "connected to," "bound to," or "adjacent to" another element or layer, the element or layer may be directly on, directly connected to, directly bound to, or directly adjacent to the other element or layer, and intervening elements or layers may be present. When an element or layer is referred to as being "directly on," "directly connected to," "directly bound to," or "immediately adjacent to" another element or layer, there are no intervening elements or layers.

[0091] As used herein, the terms "substantially," "approximately," and other similar terms are used as terms of approximation rather than terms of degree, and are intended to account for the inherent variations in measurements or calculations that would be recognized by those of ordinary skill in the art.

[0092] As used herein, the term "use" and variations thereof may be considered synonymous with the term "utilize" and variations thereof, respectively.

[0093] The display device and / or any other related device or component according to the embodiment of the present invention described herein can be implemented using any suitable hardware, firmware (e.g., application specific integrated circuit), software, or a suitable combination of software, firmware, and hardware. For example, the various components of the display device can be formed on an integrated circuit (IC) chip or a separate IC chip. In addition, the various components of the display device can be implemented on a flexible printed circuit board film, a carrier package (TCP), a printed circuit board (PCB), or formed on the same substrate. In addition, the various components of the display device can be processes or threads, which run on one or more processors in one or more computing devices, execute computer program instructions and interact with other system components to perform the various functions described herein. Computer program instructions are stored in a memory, and the memory can be implemented in a computing device using a standard memory device (such as, for example, a random access memory (RAM)). Computer program instructions can also be stored in other non-temporary computer-readable media (such as, for example, a CD-ROM, a flash drive, etc.). In addition, those skilled in the art should recognize that, without departing from the scope of the exemplary embodiments of the present invention, the functions of various computing devices can be combined or integrated into a single computing device, or the functions of a specific computing device can be distributed on one or more other computing devices.

[0094] The foregoing is an illustration of example embodiments of the present invention and should not be construed as limiting thereof. Although some example embodiments have been described, it will be readily appreciated by those skilled in the art that many modifications in the example embodiments are possible without substantially departing from the novel teachings and advantages of the present invention. Therefore, all such modifications are intended to be included within the scope of the present invention as defined in the claims. Therefore, it should be understood that the foregoing is an illustration of various example embodiments and should not be construed as being limited to the specific example embodiments disclosed, and modifications to the disclosed example embodiments as well as other example embodiments are intended to be included within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. A display device, comprising: A display panel including a plurality of pixels; a data driver configured to generate data voltages provided to the plurality of pixels; a light stress compensator configured to determine whether a pixel among the plurality of pixels satisfies a light stress condition based on input image data, and configured to output a data voltage control signal that changes a voltage level of the data voltage supplied to the pixel satisfying the light stress condition, wherein the pixel is determined to satisfy the light stress condition when it includes a sub-pixel that emits light and a sub-pixel that does not emit light; a scan driver configured to generate a scan signal provided to the plurality of pixels; and a timing controller configured to generate control signals for controlling the data driver and the scan driver, Wherein, the light stress compensator includes a light stress determiner, which is configured to: determine that the pixel satisfies the light stress condition when at least one of the multiple sub-pixels of the pixel emits light and at least one other sub-pixel of the multiple sub-pixels of the pixel does not emit light; determine that the sub-pixel emits light when the sub-pixel displays light with a grayscale value greater than a first grayscale value; and determine that the sub-pixel does not emit light when the sub-pixel displays light with a grayscale value less than a second grayscale value.

2. The display device according to claim 1, wherein: The light stress compensator further comprises: A data voltage controller is configured to generate the data voltage control signal for changing the voltage level of the data voltage supplied to the sub-pixel that does not emit light, the sub-pixel belonging to the pixel that satisfies the light stress condition.

3. The display device according to claim 2, wherein: The light stress determiner is configured to determine that the sub-pixel emits light when the sub-pixel displays light having a grayscale value greater than a first grayscale value, and is configured to determine that the sub-pixel does not emit light when the sub-pixel displays light having a grayscale value of 0.

4. The display device according to claim 2, wherein: The data voltage controller comprises: A lookup table stores the data voltage control signal corresponding to the grayscale value of the sub-pixel that does not emit light.

5. The display device according to claim 2, wherein: The light stress compensator further comprises: A duration determiner is configured to measure a duration for which the pixel meets the light stress condition.

6. The display device according to claim 5, wherein: The data voltage controller is configured to generate the data voltage control signal that changes the voltage level of the data voltage according to the duration.

7. The display device according to claim 2, wherein: The data voltage controller is configured to periodically output the data voltage control signal.

8. The display device according to claim 2, wherein: The data voltage controller is configured to output the data voltage control signal non-periodically.

9. The display device according to claim 2, wherein: The data voltage controller is configured to continuously output the data voltage control signal.

10. The display device according to claim 2, wherein: The data voltage controller is configured to discontinuously output the data voltage control signal.

11. The display device according to claim 1, wherein: The light stress compensator further includes: a logo detector configured to detect a logo area showing a logo based on the input image data, and A data voltage controller is configured to generate the data voltage control signal for changing the voltage level of the data voltage supplied to a first sub-pixel that does not emit light, the first sub-pixel belonging to the pixel among the plurality of pixels in the identification area.

12. The display device according to claim 11, wherein: The identification detector is also configured to detect a peripheral area surrounding the identification area, and the data voltage controller is further configured to generate the data voltage control signal that changes the voltage level of the data voltage provided to a second non-luminous sub-pixel, the second sub-pixel belonging to the pixel among the multiple pixels in the peripheral area.

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