Display device and method of compensating degradation of display panel

Abstract

The invention relates to a display device and a method of compensating for degradation of a display panel. The display device includes a display panel, a driving controller, and a data driver. The display panel includes a low degradation area and a high degradation area. The drive controller generates a data signal based on input image data. The data driver converts the data signal into a data voltage, and the data driver outputs the data voltage to the display panel. The drive controller includes a degradation compensator that generates the data signal based on a degradation ratio. The degradation ratio may be a ratio between a sense current of the low-degradation region and a sense current of the high-degradation region.

Description

Technical Field

[0001] One or more embodiments of the inventive concept relate to a display device and a method of compensating for degradation of a display panel included in the display device. Background Art

[0002] The display device includes a display panel and a display panel driver. The display panel may include a plurality of gate lines, a plurality of data lines, a plurality of sensing lines, and a plurality of pixels. The display panel driver may include a gate driver that provides a gate signal to the gate line and a data driver that provides a data voltage to the data line. In some cases, the display panel driver may include a sensing driver that performs a sensing operation of a driving characteristic of a pixel. The display panel driver may include a drive controller that controls the gate driver, the data driver, and the sensing driver.

[0003] Over time, the display panel may degrade. For example, the sensing current corresponding to black (or grayscale value) may change according to the degradation time. However, when performing a non-emission sensing operation, such a change in the sensing current corresponding to black may not be considered. As a result, the accuracy of the degradation compensation operation may be reduced due to the degradation compensation error. Summary of the invention

[0004] One or more embodiments of the inventive concept provide a display device that compensates for degradation of a display panel.

[0005] One or more embodiments may perform compensation by reflecting a change in a sensing current corresponding to black when performing non-emission sensing of a display panel. This may improve the display quality of the display panel by improving the accuracy of degradation compensation.

[0006] Embodiments of the inventive concept also provide a method of compensating for degradation of a display panel using a display device.

[0007] In an embodiment of a display device according to the concept of the present invention, a display device includes a display panel, a drive controller and a data driver. The display panel includes a low-degradation region and a high-degradation region. The drive controller generates a data signal based on input image data. The data driver converts the data signal into a data voltage and is configured to output the data voltage to the display panel. The drive controller includes a degradation compensator. The degradation compensator generates a data signal based on a degradation ratio, which is a ratio between a sensing current of one or more pixels in a low-degradation region and a sensing current of one or more pixels in a high-degradation region.

[0008] In an embodiment of the inventive concept, the drive controller may further include a stress converter that outputs a brightness reduction rate of the pixel according to the degradation time to the degradation compensator. The low degradation region may be a region where the brightness reduction rate is at a first level (e.g., minimum). The high degradation region may be a region where the brightness reduction rate is at a second level (e.g., maximum) greater than the first level.

[0009] In an embodiment of the inventive concept, the degradation compensator may output a data signal based on a luminance reduction rate corresponding to the degradation ratio.

[0010] In an embodiment of the inventive concept, the driving controller may further include a nonvolatile memory configured to store a brightness reduction rate according to a degradation time.

[0011] In an embodiment of the inventive concept, the driving controller may store the degradation ratio and the luminance reduction rate corresponding to the degradation ratio.

[0012] In an embodiment of the inventive concept, the degradation compensator may generate a prediction function based on a stored degradation ratio and a stored luminance reduction rate corresponding to the degradation ratio.

[0013] In an embodiment of the inventive concept, the prediction function may be a linear function.

[0014] In an embodiment of the present inventive concept, the low-degradation region and the high-degradation region may be changed according to degradation time.

[0015] In an embodiment of the present invention, the degradation ratio may be a ratio between a value obtained by dividing a sensing current of one or more pixels in a high degradation region after a degradation time by a sensing current of one or more pixels in a low degradation region after a degradation time and a value obtained by dividing a sensing current of one or more pixels in a high degradation region at an initial time by a sensing current of one or more pixels in a low degradation region at an initial time.

[0016] In an embodiment of the present invention, the display device may further include a sensing driver. The high-degradation region may include one or more high-degradation red pixels, one or more high-degradation green pixels, and one or more high-degradation blue pixels. The low-degradation region may include one or more low-degradation red pixels, one or more low-degradation green pixels, and one or more low-degradation blue pixels. The sensing driver may perform a sensing operation of receiving a sensing current of one or more pixels in the low-degradation region and a sensing current of one or more pixels in the high-degradation region. The sensing operation may be performed on one or more high-degradation red pixels, one or more high-degradation green pixels, one or more high-degradation blue pixels, one or more low-degradation red pixels, one or more low-degradation green pixels, and one or more low-degradation blue pixels.

[0017] In an embodiment of the present invention, the degradation ratios may include: a red degradation ratio, which is the ratio between the sensing current of one or more highly degraded red pixels and the sensing current of one or more less degraded red pixels; a green degradation ratio, which is the ratio between the sensing current of one or more highly degraded green pixels and the sensing current of one or more less degraded green pixels; and a blue degradation ratio, which is the ratio between the sensing current of one or more highly degraded blue pixels and the sensing current of one or more less degraded blue pixels.

[0018] In an embodiment of the present invention, the drive controller may further include a stress converter that outputs a brightness reduction rate of a pixel according to a degradation time to the degradation compensator. The drive controller may store a red degradation ratio and a brightness reduction rate corresponding to the red degradation ratio, and the drive controller may generate a red prediction function based on the red degradation ratio and the brightness reduction rate corresponding to the red degradation ratio. The drive controller may store a green degradation ratio and a brightness reduction rate corresponding to the green degradation ratio, and the drive controller may generate a green prediction function based on the green degradation ratio and the brightness reduction rate corresponding to the green degradation ratio. The drive controller may store a blue degradation ratio and a brightness reduction rate corresponding to the blue degradation ratio, and the drive controller may generate a blue prediction function based on the blue degradation ratio and the brightness reduction rate corresponding to the blue degradation ratio. The drive controller may generate a data signal based on the red prediction function, the green prediction function, and the blue prediction function.

[0019] In an embodiment of the inventive concept, a sensing operation may be performed in response to a power-on signal.

[0020] In an embodiment of the present invention, the display device may further include a sensing driver. The sensing driver may perform a sensing operation of receiving a sensing current of one or more pixels in a low-degradation area and a sensing current of one or more pixels in a high-degradation area. The data driver may apply a data voltage corresponding to white to the high-degradation area and the low-degradation area. The drive controller may calculate a red degradation ratio, a green degradation ratio, and a blue degradation ratio based on the sensing current corresponding to the white in the high-degradation area and the sensing current corresponding to the white in the low-degradation area, the red degradation ratio being the ratio between the sensing current of one or more high-degradation red pixels and the sensing current of one or more low-degradation red pixels, the green degradation ratio being the ratio between the sensing current of one or more high-degradation green pixels and the sensing current of one or more low-degradation green pixels, and the blue degradation ratio being the ratio between the sensing current of one or more high-degradation blue pixels and the sensing current of one or more low-degradation blue pixels.

[0021] In an embodiment of the present invention, the drive controller may further include a stress converter configured to output the brightness reduction rate of the pixel according to the degradation time to the degradation compensator. The drive controller may store a red degradation ratio and a brightness reduction rate corresponding to the red degradation ratio, and the drive controller may generate a red prediction function based on the red degradation ratio and the brightness reduction rate corresponding to the red degradation ratio. The drive controller may store a green degradation ratio and a brightness reduction rate corresponding to the green degradation ratio, and the drive controller may generate a green prediction function based on the green degradation ratio and the brightness reduction rate corresponding to the green degradation ratio. The drive controller may store a blue degradation ratio and a brightness reduction rate corresponding to the blue degradation ratio, and the drive controller may generate a blue prediction function based on the blue degradation ratio and the brightness reduction rate corresponding to the blue degradation ratio. The drive controller may generate a data signal based on the red prediction function, the green prediction function, and the blue prediction function.

[0022] In an embodiment of the present inventive concept, the low-degradation region and the high-degradation region may include a pixel. The pixel may include: a driving transistor configured to output a driving current; a light-emitting element configured to emit light based on the driving current; an initialization transistor configured to apply an initialization voltage to a second electrode of the driving transistor; a scanning transistor configured to apply a data voltage to a control electrode of the driving transistor; a compensation transistor configured to apply a reference voltage to the control electrode of the driving transistor; an emission control transistor configured to control the generation of the driving current; a first capacitor including a first electrode connected to the control electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor; and a second capacitor including a first electrode receiving a first power supply voltage and a second electrode connected to the second electrode of the driving transistor.

[0023] In an embodiment of compensating for degradation of a display panel according to the concept of the present invention, the method includes: storing a brightness reduction rate of a pixel according to a degradation time; calculating a degradation ratio, which is a ratio between a sensing current of one or more pixels in a high degradation area where the brightness reduction rate is at a first level (e.g., maximum) and a sensing current of one or more pixels in a low degradation area where the brightness reduction rate is at a second level (e.g., minimum) lower than the first level; storing the degradation ratio and the brightness reduction rate corresponding to the degradation ratio; and generating a data signal based on the brightness reduction rate.

[0024] In an embodiment of the inventive concept, the method may further include: after storing the luminance reduction rate corresponding to the degradation ratio, generating a prediction function based on the stored degradation ratio and the stored luminance reduction rate corresponding to the degradation ratio. The data signal may be generated based on the prediction function.

[0025] In an embodiment of the present inventive concept, the low-degradation region and the high-degradation region may be changed according to degradation time.

[0026] In an embodiment of the present invention, the degradation ratio may be a ratio between a value obtained by dividing a sensing current of one or more pixels in a high degradation region after a degradation time by a sensing current of one or more pixels in a low degradation region after a degradation time and a value obtained by dividing a sensing current of one or more pixels in a high degradation region at an initial time by a sensing current of one or more pixels in a low degradation region at an initial time.

[0027] According to one or more embodiments, a method for compensating a display device includes: receiving a first sensing current of a pixel in a high-degradation area of ​​a display panel; receiving a second sensing current of a pixel in a low-degradation area of ​​the display panel; calculating a degradation ratio based on the first sensing current and the second sensing current; determining a brightness reduction rate corresponding to the degradation ratio; generating a prediction function based on the degradation ratio and the brightness reduction rate; and generating a data signal based on the prediction function.

[0028] The pixels in the high-degradation region may be configured to emit a first level of light, and the pixels in the low-degradation region may be configured to emit a second level of light lower than the first level. The low-degradation region and the high-degradation region change over time.

[0029] According to the above-mentioned display device and the method for compensating the degradation of the display panel using the display device, the degradation of the display panel is compensated by using the degradation ratio between the high-degraded area and the low-degraded area of ​​the display panel, so that the degradation compensation error can be reduced. In addition, the prediction function is generated based on the degradation ratio and the brightness reduction rate corresponding to the degradation ratio.

[0030] Therefore, the accuracy of degradation compensation can be improved, and the display quality of the display device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other features and advantages of the present invention will become more apparent by describing detailed embodiments of the present invention with reference to the accompanying drawings, in which:

[0032] Figure 1 is a block diagram illustrating a display device according to an embodiment of the inventive concept;

[0033] Figure 2 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A circuit diagram of a pixel and a portion of a sensing driver;

[0034] Figure 3 is a diagram showing a method according to an embodiment of the present invention. Figure 1 The block diagram of the drive controller;

[0035] Figure 4 is a diagram showing storage in accordance with an embodiment of the present invention Figure 1A graph showing an example of a brightness reduction rate according to a degradation time in a driving controller of FIG.

[0036] Figure 5 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A graph of an example of a prediction function generated by a drive controller;

[0037] Figure 6 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A diagram showing an example of a highly degraded area and a lowly degraded area in a display panel at a first time;

[0038] Figure 7 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A diagram showing an example of a highly degraded area and a lowly degraded area of ​​a display panel in a second time;

[0039] Figure 8 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A flowchart of the operation of the drive controller and the sensing driver;

[0040] Fig. 9 is a diagram showing a method according to an embodiment of the present invention. Figure 1 A flowchart of the operation of the drive controller and the sensing driver;

[0041] Fig.10 is a block diagram illustrating an electronic device according to an embodiment of the inventive concept; and

[0042] Fig.11 It is shown Fig.10 A diagram of an example in which the electronic device is implemented as a smart phone. DETAILED DESCRIPTION

[0043] Hereinafter, the inventive concept will be described in more detail with reference to the accompanying drawings.

[0044] Figure 1 is a block diagram illustrating a display device according to an embodiment of the inventive concept.

[0045] Reference Figure 1, a display device according to an embodiment of the present invention may include a display panel 100 including a plurality of pixels PX and a panel driver for driving the display panel 100. In an embodiment, the panel driver may include a gate driver 300, a data driver 500, a sensing driver 600, and an emission driver 700. The gate driver 300 provides one or more gate signals to the corresponding gate lines. In one embodiment, the gate driver 300 provides a first gate signal GW, a second gate signal GR, and a third gate signal GI to the pixel PX. The data driver 500 is connected to the pixel PX through a data line DL. The sensing driver 600 is connected to the pixel PX through a sensing line SL to help perform a degradation compensation operation. The emission driver 700 is connected to the pixel PX through an emission line EL. The display device may also include a drive controller 200 that controls the gate driver 300, the data driver 500, the sensing driver 600, and the emission driver 700.

[0046] The display panel 100 may include data lines DL and pixels PX connected to the data lines DL. In addition, the display panel 100 may include a plurality of gate lines (e.g., gate lines GWL, GRL, and GIL) for respectively providing a first gate signal GW, a second gate signal GR, and a third gate signal GI to the pixels PX. For example, the display panel 100 may be, for example, an organic light emitting diode (OLED) display panel or a quantum dot (QD) display panel, but the inventive concept is not limited thereto.

[0047] In the present embodiment, the display panel 100 may include at least one high degradation region HDR and at least one low degradation region LDR. Each of the at least one high degradation region HDR and the at least one low degradation region LDR may include one or more pixels PX. In the present embodiment, the high degradation region HDR may refer to a region where the brightness reduction rate is at a first level, for example, the first level may be a high or maximum ratio. In addition, in the present embodiment, the low degradation region LDR may refer to a region where the brightness reduction rate is at a second level less than the first level. The second level may be a low or minimum ratio. For example, the high degradation region HDR may be a region where one or more pixels PX emit light having a maximum cumulative grayscale value. For example, the low degradation region LDR may be a region where one or more pixels PX emit light having a minimum cumulative grayscale value.

[0048] The display device may include a display panel 100, a driving controller 200, a gate driver 300, a data driver 500, a sensing driver 600, and an emission driver 700. In an embodiment, the driving controller 200 and the data driver 500 may be integrally formed with each other, for example, in the same chip.

[0049] The display panel 100 includes a display area configured to display an image and a peripheral area adjacent to the display area. In an embodiment, the gate driver 300 may be disposed in the peripheral area. In an embodiment, the gate driver 300 may be integrated in the peripheral area.

[0050] The display panel 100 may include gate lines GWL, GRL, and GIL, data lines DL, emission lines EL, and pixels PX electrically connected to the gate lines GWL, GRL, and GIL, the data lines DL, and the emission lines EL. The gate lines GWL, GRL, and GIL may extend in a first direction D1 that intersects a second direction D2 in which the data lines DL extend.

[0051] The drive controller 200 receives input image data IMG, input control signal CONT and power-on signal POS from a main processor (e.g., an application processor) and / or a graphics processing unit (GPU). For example, the input image data IMG may include red image data, green image data and blue image data corresponding to the image to be displayed. In one embodiment, the input image data IMG may include white image data. In one embodiment, the input image data IMG may include magenta image data, yellow image data and cyan image data. The input control signal CONT may include a plurality of signals. For example, the input control signal CONT may include a master clock signal and a data enable signal. In one embodiment, the input control signal CONT may also include a vertical synchronization signal and a horizontal synchronization signal.

[0052] The driving controller 200 may generate a plurality of control signals. For example, the driving controller 200 may generate a first control signal CONT1, a second control signal CONT2, a third control signal CONT3, a fourth control signal CONT4, and a fifth control signal CONT5. The driving controller 200 may also generate a data signal DATA based on the input image data IMG and the input control signal CONT.

[0053] The driving controller 200 may generate a first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and may output the generated first control signal CONT1 to the gate driver 300. The first control signal CONT1 may include, for example, a vertical start signal and a gate clock signal.

[0054] The driving controller 200 may generate a third control signal CONT3 for controlling the operation of the gamma reference voltage generator 400 based on the input control signal CONT, and may output the generated third control signal CONT3 to the gamma reference voltage generator 400 .

[0055] The driving controller 200 may generate a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and may output the generated second control signal CONT2 to the data driver 500. The second control signal CONT2 may include, for example, a horizontal start signal and a load signal.

[0056] The driving controller 200 may generate a data signal DATA based on the input image data IMG. The driving controller 200 may output the data signal DATA to the data driver 500.

[0057] The driving controller 200 may generate a fourth control signal CONT4 based on the power-on signal POS and the input control signal CONT. The driving controller 200 may output the fourth control signal CONT4 to the sensing driver 600.

[0058] The driving controller 200 may generate a fifth control signal CONT5 for controlling the operation of the emission driver 700 based on the input control signal CONT, and may output the generated fifth control signal CONT5 to the emission driver 700 .

[0059] The gate driver 300 may generate gate signals GW, GR, and GI for driving the gate lines GWL, GRL, and GIL in response to the first control signal CONT1 received from the driving controller 200. The gate driver 300 may output the gate signals GW, GR, and GI to the gate lines GWL, GRL, and GIL.

[0060] The gamma reference voltage generator 400 generates a gamma reference voltage VGREF in response to a third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF has a value corresponding to each data signal DATA. For example, the gamma reference voltage generator 400 may be provided in the driving controller 200 or the data driver 500.

[0061] The data driver 500 receives the second control signal CONT2 and the data signal DATA from the driving controller 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 converts the data signal DATA into a data voltage VDATA in an analog form using the gamma reference voltage VGREF. The data driver 500 outputs the data voltage VDATA to the pixel PX through a corresponding one of the data lines DL.

[0062] In an embodiment, the data driver 500 may be implemented with one or more integrated circuits. In another embodiment, the data driver 500 and the driving controller 200 may be implemented as a single integrated circuit, and for example, the single integrated circuit may be referred to as a timing controller embedded data driver (TED).

[0063] The sensing driver 600 may be used to help perform degradation compensation operations. The sensing driver 600 may receive a fourth control signal CONT4 from the driving controller 200, and may generate sensing data SD by sensing characteristic data of the pixel PX through the sensing line SL. For example, the sensing driver 600 may sense the driving characteristics (e.g., mobility and / or threshold voltage) of the driving transistor by measuring the sensing current (or sensing voltage) of the driving transistor of the pixel PX through the sensing line SL. For example, the operation of sensing the driving characteristics (e.g., mobility and / or threshold voltage) of the driving transistor may be referred to as a sensing operation.

[0064] In the present embodiment, the sensing driver 600 may output the sensing data SD of the high degradation region HDR and the sensing data SD of the low degradation region LDR to the driving controller 200. In an embodiment, the sensing driver 600 may be implemented with an integrated circuit separate from the integrated circuit of the data driver 500. In other embodiments, the sensing driver 600 may be included in the data driver 500, or may be included in the driving controller 200.

[0065] The emission driver 700 may generate an emission signal EM for driving the emission line EL in response to the fifth control signal CONT5 received from the driving controller 200. The emission driver 700 may output the emission signal EM to the emission line EL. In an embodiment of the inventive concept, the emission driver 700 may be integrated in a peripheral area of ​​the display panel 100. In an embodiment of the inventive concept, the emission driver 700 may be mounted on the peripheral area of ​​the display panel 100.

[0066] Although for ease of explanation, Figure 1 The gate driver 300 is disposed on a first side of the display panel 100, and the emission driver 700 is disposed on a second side of the display panel 100, but the inventive concept is not limited thereto. The gate driver 300 and the emission driver 700 may be disposed on the same (e.g., first) side of the display panel 100. For example, the gate driver 300 and the emission driver 700 may be disposed in a peripheral region of the display panel 100 on the same side of a display region of the display panel 100. For example, the gate driver 300 and the emission driver 700 may be formed integrally with each other.

[0067] Figure 2 is a diagram showing a method according to an embodiment of the present invention. Figure 11 is a circuit diagram of a pixel PX and a portion of a sensing driver 600.

[0068] Reference Figure 1 and Figure 2 , each of the pixels PX may include a driving transistor T1, a scanning transistor T2, a compensation transistor T3, an initialization transistor T4, an emission control transistor T5, a first capacitor Cst, a second capacitor Chold, and a light emitting element EE. In an embodiment, the pixel PX may further include a parasitic capacitor Cee. In another embodiment, the pixel PX may have a different number of transistors and capacitors.

[0069] The driving transistor T1 may include a first electrode connected to the first node N1, a control electrode connected to the second node N2, and a second electrode connected to the third node N3. The driving transistor T1 may output a driving current based on a voltage of the second node N2. The characteristic data of the driving transistor T1 may be output from the sensing driver 600 to the driving controller 200 as sensing data SD so as to perform degradation compensation of the display panel 100.

[0070] The scanning transistor T2 may include a first electrode connected to the data line DL, a control electrode receiving the first gate signal GW, and a second electrode connected to the second node N2. When the scanning transistor T2 is turned on in response to the first gate signal GW, the data voltage VDATA may be applied to the gate electrode (e.g., the second node N2) of the driving transistor T1.

[0071] The compensation transistor T3 may include a first electrode receiving a reference voltage VREF, a control electrode receiving a second gate signal GR, and a second electrode connected to a control electrode (e.g., a second node N2) of the driving transistor T1. When the compensation transistor T3 is turned on in response to the second gate signal GR, the reference voltage VREF may be applied to the control electrode (e.g., the second node N2) of the driving transistor T1.

[0072] The initialization transistor T4 may include a first electrode connected to the second electrode (e.g., the third node N3) of the driving transistor T1, a control electrode receiving the third gate signal GI, and a second electrode connected to the sensing line SL and receiving the initialization voltage VINT. When the initialization transistor T4 is turned on in response to the third gate signal GI, the initialization voltage VINT may be applied to the second electrode (e.g., the third node N3) of the driving transistor T1.

[0073] The initialization transistor T4 may be connected to the sensing driver 600 through the sensing line SL. The initialization transistor T4 may apply an initialization voltage VINT to the second electrode (e.g., the third node N3) of the driving transistor T1. Similarly, the driving current of the driving transistor T1 may flow to the sensing driver 600 through the initialization transistor T4 and the sensing line SL. In the present embodiment, the driving current may flow to the sensing line SL and may be referred to as a sensing current representing the driving characteristics of the driving transistor T1. In the present embodiment, the sensing driver 600 may generate sensing data SD.

[0074] In one embodiment, the sensing driver 600 may include an integrator and an analog-to-digital converter ADC. The integrator (e.g., an operational amplifier) ​​may be connected to one or more pixels PX via a sensing line SL, may receive a sensing current of a driving transistor T1 of the pixel PX via the sensing line SL, and may generate an output voltage. The first (inverting) input of the integrator may receive an initialization voltage VINT. The integrator may include an integration capacitor Cf connected to a second (non-inverting) input of the integrator. The sensing driver 600 may also include a first switch SW1 that selectively connects the integrator to the sensing line SL. The sensing driver 600 may also include a second switch SW2 that selectively applies an initialization voltage VINT to the sensing line SL.

[0075] The emission control transistor T5 may include a first electrode receiving the first power supply voltage ELVDD, a control electrode receiving the emission signal EM, and a second electrode connected to the first electrode (e.g., the first node N1) of the driving transistor T1. When the emission control transistor T5 is turned on in response to the emission signal EM, the light emitting element EE may emit light based on the driving current.

[0076] The light emitting element EE may include an anode connected to the third node N3 and a cathode receiving the second power voltage ELVSS. In one embodiment, the first power voltage ELVDD may be greater than the second power voltage ELVSS.

[0077] The light emitting element EE may emit light based on the driving current. In an embodiment, the light emitting element EE may be an organic light emitting diode (OLED), but is not limited thereto. In an embodiment, the light emitting element EE may be any suitable light emitting element. For example, the light emitting element EE may be a nano light emitting diode (NED), a quantum dot (QD) light emitting diode, a micro light emitting diode, an inorganic light emitting diode, or any other suitable light emitting element.

[0078] The first capacitor Cst (eg, storage capacitor) may include a first electrode connected to the control electrode (eg, second node N2) of the driving transistor T1 and a second electrode connected to the second electrode (eg, third node N3) of the driving transistor T1. The first capacitor Cst may store the data voltage VDATA.

[0079] The second capacitor Chold may include a first electrode coupled to receive the first power supply voltage ELVDD and a second electrode connected to the second electrode (e.g., the third node N3) of the driving transistor T1. The second capacitor Chold may be referred to as a holding capacitor for holding the voltage of the second electrode (e.g., the third node N3) of the driving transistor T1.

[0080] When the sensing operation according to the present embodiment is performed, the voltage of the third node N3 may be set to the initialization voltage VINT. Therefore, when the sensing operation is performed, the light emitting element EE may not emit light. Therefore, the display device according to the inventive concept may perform a non-emission sensing operation used in the degradation compensation of the display panel 100.

[0081] Figure 3 is a diagram showing a method according to an embodiment of the present invention. Figure 1 1 is a block diagram of a driving controller 200 . Figure 4 is a diagram showing storage in accordance with an embodiment of the present invention Figure 1 FIG. 2 is a graph showing an example of a luminance reduction rate according to a degradation time in the driving controller 200 . Figure 5 is a diagram showing a method according to an embodiment of the present invention. Figure 1 Graph of an example of a prediction function PRF generated by the drive controller 200. Figure 6 is a diagram showing a method according to an embodiment of the present invention. Figure 1 FIG. 1 is a diagram of an example of a high-degradation region HDR1 and a low-degradation region LDR1 of the display panel 100 in a first time TP1. Figure 7 is a diagram showing a method according to an embodiment of the present invention. Figure 1 FIG. 1 is a diagram of an example of a high-degradation region HDR2 and a low-degradation region LDR2 of the display panel 100 in the second time TP2.

[0082] Reference Figures 1 to 7 , the driving controller 200 includes a degradation compensator 220, a nonvolatile memory 240, and a stress converter 260. The degradation compensator 220 may generate a data signal DATA that compensates for degradation of the display panel 100. For example, when a specific area of ​​the display panel 100 displays an image brighter than a desired image due to degradation, the degradation compensator 220 may adjust the data signal DATA to be dark (e.g., to a predetermined grayscale value) so that the specific area can display the desired image. For example, the predetermined grayscale value may be black.

[0083] The degradation compensator 220 may receive sensing data SD of the high degradation region HDR and sensing data SD of the low degradation region LDR. The sensing data SD may include data of sensing current output from the driving transistor T1 of the pixel PX in the high degradation region HDR and the low degradation region LDR.

[0084] The nonvolatile memory 240 may store the degradation time and the brightness reduction rate according to the degradation time of each pixel PX in the high degradation area HDR and the low degradation area LDR. The nonvolatile memory 240 may accumulate and store the degradation time and the brightness reduction rate according to the degradation time of the pixel PX. Therefore, the nonvolatile memory 240 may store a function representing the brightness reduction rate according to the degradation time.

[0085] In addition, the non-volatile memory 240 may store data of a high degradation region HDR (which is a region where the brightness reduction rate is increased or the largest) and data of a low degradation region LDR (which is a region where the brightness reduction rate is reduced or the smallest). For example, the non-volatile memory 240 may be a flash memory. In an embodiment, the non-volatile memory 240 may not be included in the drive controller 200 and may be integrated in the display panel driver.

[0086] The stress converter 260 may output a luminance reduction rate of the pixel PX according to degradation time.

[0087] In the present embodiment, the degradation compensator 220 may calculate a degradation ratio HLR, which is a ratio between a sensing current of a pixel PX in a high degradation region HDR and a sensing current of a pixel PX in a low degradation region LDR. The degradation compensator 220 may store the degradation ratio HLR. For example, when the display panel 100 degrades during a first time TP1, a high degradation region HDR corresponding to the first time TP1 and a low degradation region LDR corresponding to the first time TP1 may be calculated. The stress converter 260 may output a brightness reduction rate corresponding to the first time TP1 to the nonvolatile memory 240. The nonvolatile memory 240 may output a brightness reduction rate corresponding to the first time TP1 to the degradation compensator 220.

[0088] The sensing driver 600 may perform a sensing operation for the pixels PX in the first high degradation region HDR1 corresponding to the first time TP1 and the pixels PX in the first low degradation region LDR1 corresponding to the first time TP1. The sensing driver 600 may output sensing data SD of the first high degradation region HDR1 and sensing data SD of the first low degradation region LDR1 to the degradation compensator 220.

[0089] The degradation compensator 220 may receive the sensing data SD of at least one pixel PX in the first high degradation region HDR1 and the sensing data SD of at least one pixel PX in the first low degradation region LDR1, and may calculate the degradation ratio HLR corresponding to the first time TP1. For example, the degradation ratio HLR corresponding to the first time TP1 may be the first degradation ratio HLR1. The degradation compensator 220 may store the first degradation ratio HLR1 and the brightness reduction rate of the first high degradation region HDR1 corresponding to the first time TP1. In the present embodiment, the brightness reduction rate corresponding to the first time TP1 may correspond to the first degradation ratio HLR1. The driving controller 200 may store the brightness reduction rate of the first high degradation region HDR1 corresponding to the first degradation ratio HLR1.

[0090] For example, when the display panel 100 degrades during a second time TP2 different from (e.g., later than) the first time TP1, the high degradation region HDR and the low degradation region LDR may change. For example, the high degradation region HDR corresponding to the second time TP2 may be a second high degradation region HDR2 different from the first high degradation region HDR1 corresponding to the first time TP1. The low degradation region LDR corresponding to the second time TP2 may be a second low degradation region LDR2 different from the first low degradation region LDR1 corresponding to the first time TP1. The high degradation region HDR and the low degradation region LDR may change so that the degradation ratio HLR may change. The degradation ratio HLR corresponding to the second time TP2 may be a second degradation ratio HLR2. The stress converter 260 may output a brightness reduction rate corresponding to the second time TP2 to the nonvolatile memory 240. The nonvolatile memory 240 may output a brightness reduction rate corresponding to the second time TP2 to the degradation compensator 220. In the present embodiment, the brightness reduction rate corresponding to the second time TP2 may correspond to the second degradation ratio HLR2. The driving controller 200 may store the luminance reduction rate corresponding to the second degradation ratio HLR2 of the second high degradation region HDR2.

[0091] In this embodiment, the degradation compensator 220 may accumulate and store the degradation ratio HLR and the brightness reduction rate corresponding to the degradation ratio HLR. Figure 5 As shown in , the degradation compensator 220 can generate a prediction function PRF based on the (accumulated and stored) degradation ratio HLR and the accumulated and stored brightness reduction rate corresponding to the degradation ratio HLR. The degradation compensator 220 can output a data signal DATA based on the prediction function PRF. In an embodiment, the prediction function PRF can be based on, for example, a linear function model, or the prediction function PRF can correspond to a curve.

[0092] In a display device without a degradation compensator, when a non-emission sensing operation is performed, the display quality of the display panel may be reduced because a change in a sensing current corresponding to a predetermined (e.g., black) color is not considered. On the other hand, a display device according to the present invention can output a data signal DATA by considering the degradation ratio HLR. Therefore, the display quality of the display device according to the present invention can be improved.

[0093] In an embodiment, the degradation ratio HLR may be a ratio between a value obtained by dividing a sensed current of at least one pixel PX in a high degradation region HDR after a degradation time by a sensed current of at least one pixel PX in a low degradation region LDR after a degradation time and a value obtained by dividing a sensed current of at least one pixel PX in a high degradation region HDR in an initial time by a sensed current of at least one pixel PX in a low degradation region LDR in an initial time. For example, the initial time may refer to a time after a production stage of a display device and before a sensed current of a pixel PX changes due to degradation.

[0094] Therefore, in the display device according to the inventive concept, the degradation ratio HLR can be calculated by reflecting the initial distribution of the sensing current. Therefore, the display quality of the display device according to the inventive concept can be further improved.

[0095] Figure 8 is a diagram showing a method according to an embodiment of the present invention. Figure 1 Flowchart of operations of the driving controller 200 and the sensing driver 600.

[0096] Reference Figure 1 , Figure 3 , Figure 5 and Figure 8 In this embodiment, the high degradation region HDR may include one or more high degradation red pixels, one or more high degradation green pixels, and one or more high degradation blue pixels. The low degradation region LDR may include one or more low degradation red pixels, one or more low degradation green pixels, and one or more low degradation blue pixels. The driving controller 200 may determine the high degradation region HDR and the low degradation region LDR (S110). The sensing driver 600 may perform a sensing operation on one or more high degradation red pixels and one or more low degradation red pixels (S120-1). The sensing driver 600 may perform a sensing operation on one or more high degradation green pixels and one or more low degradation green pixels (S120-2). The sensing driver 600 may perform a sensing operation on one or more high degradation blue pixels and one or more low degradation blue pixels (S120-3). In an embodiment, the sensing operation may be performed in response to a power-on signal POS received by the driving controller 200. In an embodiment, when the sensing operation is performed, the stress converter 260 may be turned off.

[0097] In this embodiment, the degradation ratio HLR may include: a red degradation ratio, which is a ratio between the sensing current of one or more highly degraded red pixels and the sensing current of one or more poorly degraded red pixels; a green degradation ratio, which is a ratio between the sensing current of one or more highly degraded green pixels and the sensing current of one or more poorly degraded green pixels; and a blue degradation ratio, which is a ratio between the sensing current of one or more highly degraded blue pixels and the sensing current of one or more poorly degraded blue pixels. The driving controller 200 may calculate the red degradation ratio, the green degradation ratio, and the blue degradation ratio (S130).

[0098] In addition, the drive controller 200 can accumulate and store the red degradation ratio and the brightness reduction rate corresponding to the red degradation ratio. The drive controller 200 can generate a red prediction function (S140-1) based on the red degradation ratio and the brightness reduction rate corresponding to the red degradation ratio. The drive controller 200 can accumulate and store the green degradation ratio and the brightness reduction rate corresponding to the green degradation ratio. The drive controller 200 can generate a green prediction function (S140-2) based on the green degradation ratio and the brightness reduction rate corresponding to the green degradation ratio. The drive controller 200 can accumulate and store the blue degradation ratio and the brightness reduction rate corresponding to the blue degradation ratio. The drive controller 200 can generate a blue prediction function (S140-3) based on the blue degradation ratio and the brightness reduction rate corresponding to the blue degradation ratio.

[0099] In the present embodiment, the driving controller 200 may generate the data signal DATA based on the red prediction function, the green prediction function, and the blue prediction function ( S150 ).

[0100] Fig. 9 is a diagram showing a method according to an embodiment of the present invention. Figure 1 Flowchart of operations of the driving controller 200 and the sensing driver 600.

[0101] Reference Figure 1 , Figure 3 , Figure 5 and Fig. 9 In this embodiment, the driving controller 200 may determine the high degradation region HDR and the low degradation region LDR (S210). The high degradation region HDR and the low degradation region LDR may correspond to different pixels PX in the display panel 100. The data driver 500 may apply a data voltage VDATA corresponding to a predetermined color (e.g., white) to the high degradation region HDR and the low degradation region LDR (S220). The sensing driver 600 may receive a sensing current corresponding to white of the high degradation region HDR and a sensing current corresponding to white of the low degradation region LDR.

[0102] The driving controller 200 may receive a sensing current corresponding to white of the high-degradation region HDR and a sensing current corresponding to white of the low-degradation region LDR (S230). The driving controller 200 may calculate a sensing current of one or more low-degradation red pixels and a sensing current of one or more high-degradation red pixels based on a current ratio between red and white (S240-1). The driving controller 200 may calculate a sensing current of one or more low-degradation green pixels and a sensing current of one or more high-degradation green pixels based on a current ratio between green and white (S240-2). The driving controller 200 may calculate a sensing current of one or more low-degradation blue pixels and a sensing current of one or more high-degradation blue pixels based on a current ratio between blue and white (S240-3).

[0103] The driving controller 200 may calculate a red degradation ratio, which is a ratio between a sensing current of one or more highly degraded red pixels and a sensing current of one or more less degraded red pixels. The driving controller 200 may calculate a green degradation ratio, which is a ratio between a sensing current of one or more highly degraded green pixels and a sensing current of one or more less degraded green pixels. The driving controller 200 may calculate a blue degradation ratio, which is a ratio between a sensing current of one or more highly degraded blue pixels and a sensing current of one or more less degraded blue pixels.

[0104] In the present embodiment, the drive controller 200 may calculate the red degradation ratio, the green degradation ratio, and the blue degradation ratio (S250). The drive controller 200 may generate a red prediction function (S260-1) based on the red degradation ratio and the brightness reduction rate corresponding to the red degradation ratio. The drive controller 200 may generate a green prediction function (S260-2) based on the green degradation ratio and the brightness reduction rate corresponding to the green degradation ratio. The drive controller 200 may generate a blue prediction function (S260-3) based on the blue degradation ratio and the brightness reduction rate corresponding to the blue degradation ratio. The drive controller 200 may generate a data signal DATA (S270) based on the red prediction function, the green prediction function, and the blue prediction function.

[0105] Therefore, in the present embodiment, the data voltage VDATA corresponding to white is generated so that the time to perform the sensing operation can be reduced.

[0106] Fig.10 is a block diagram illustrating an electronic device 1000 according to an embodiment of the inventive concept. Fig.11 It is shown Fig.10 FIG. 1 is a diagram of an example in which the electronic device 1000 is implemented as a smart phone.

[0107] Reference Fig.10 and Fig.11, the electronic device 1000 may include a processor 1010, a memory device 1020, a storage device 1030, an input / output (I / O) device 1040, a power supply 1050, and a display device 1060. Here, the display device 1060 may be Figure 1 In addition, the electronic device 1000 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, and / or other electronic devices.

[0108] According to the embodiment, Fig.11 As shown in , the electronic device 1000 can be implemented as a smart phone. However, the electronic device 1000 is not limited thereto. For example, the electronic device 1000 can be implemented as a cellular phone, a video phone, a smart tablet, a smart watch, a tablet personal computer (PC), a car navigation system, a computer monitor, a laptop computer, and a head mounted display (HMD) device, etc.

[0109] The processor 1010 may perform various computing functions or various tasks. The processor 1010 may be a microprocessor, a central processing unit (CPU), an application processor (AP), etc. The processor 1010 may be coupled to other components via an address bus, a control bus, a data bus, etc. In addition, the processor 1010 may be coupled to an expansion bus such as a peripheral component interconnect (PCI) bus. The processor 1010 may send Figure 1 The driving controller 200 outputs input image data IMG and an input control signal CONT.

[0110] The memory device 1020 may store data used for the operation of the electronic device 1000. For example, the memory device 1020 may include at least one nonvolatile 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, and a ferroelectric random access memory (FRAM) device, etc.) and / or at least one volatile memory device (such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, and a mobile DRAM device, etc.).

[0111] The storage device 1030 may include a solid state drive (SSD) device, a hard disk drive (HDD) device, a compact disk read-only memory (CD-ROM) device, etc. The I / O device 1040 may include input devices such as a keyboard, a keypad, a mouse device, a touch pad, and a touch screen, and output devices such as a printer and a speaker. In some embodiments, a display device 1060 may be included in the I / O device 1040. The power supply 1050 may provide power for performing operations of the electronic device 1000. The display device 1060 may be coupled to other components via a bus or other communication link.

[0112] According to the display device and the method of compensating for degradation of a display panel described above, the display quality of the display panel can be improved by improving the accuracy of degradation compensation.

[0113] Method described herein, process and / or operation can be performed by the code or instruction executed by computer, processor, controller or other signal processing device.Computer, processor, controller or other signal processing device can be those described herein, or the element except the element described herein.Because the algorithm of the basis of formation method (or the operation of computer, processor, controller or other signal processing device) is described in detail, the code or instruction for realizing the operation of method embodiment can convert computer, processor, controller or other signal processing device into the special processor for performing the method herein.

[0114] In addition, another embodiment may include a computer-readable medium, such as a non-transitory computer-readable medium, for storing the above code or instructions. The computer-readable medium may be a volatile or non-volatile memory or other storage device that can be removably or fixedly coupled to a computer, processor, controller, or other signal processing device that executes code or instructions for performing the operations of the method embodiments or apparatus embodiments herein.

[0115] In one embodiment, a non-transitory computer-readable medium may store instructions that cause one or more processors to perform the following operations: calculate a degradation ratio between a sensing current of at least one pixel in a high degradation area where the brightness reduction rate is at a first level and a sensing current of at least one pixel in a low degradation area where the brightness reduction rate is at a second level lower than the first level; obtain a brightness reduction rate corresponding to the degradation ratio; generate a prediction function based on the degradation ratio and the brightness reduction rate; and generate a data signal based on the brightness reduction rate.

[0116] The controllers, processors, compensators, drivers, converters, generators, and other signal generation and signal processing features of the embodiments disclosed herein may be implemented, for example, in non-transitory logic that may include hardware, software, or both. When implemented at least partially in hardware, the controllers, processors, compensators, drivers, converters, generators, and other signal generation and signal processing features may be, for example, any of a variety of integrated circuits (including, but not limited to, application specific integrated circuits, field programmable gate arrays, combinations of logic gates, systems on chips, microprocessors, or other types of processing or control circuits). In some embodiments, these features may be implemented by neural networks, machine learning logic, or other forms of artificial intelligence.

[0117] When implemented at least in part in software, controllers, processors, compensators, drivers, converters, generators, and other signal generation and signal processing features may include, for example, a memory or other storage device for storing codes or instructions executed, for example, by a computer, processor, microprocessor, controller, or other signal processing device. The computer, processor, microprocessor, controller, or other signal processing device may be those described herein, or an element other than the elements described herein. Because the algorithm forming the basis of the method (or the operation of a computer, processor, microprocessor, controller, or other signal processing device) is described in detail, the code or instructions for implementing the operation of the method embodiment may convert the computer, processor, controller, or other signal processing device into a dedicated processor for performing the method described herein.

[0118] The foregoing is an illustration of the inventive concept and will not be construed as limiting the inventive concept. Although some embodiments of the inventive concept have been described, it will be readily understood by those skilled in the art that many modifications are possible in the embodiments without substantially departing from the novel teachings and advantages of the inventive concept. Therefore, all such modifications are intended to be included within the scope defined in the claims of the inventive concept. In the claims, the device-plus-function clause is intended to cover the structures described herein as performing the functions listed, and not only structural equivalents, but also equivalent structures. Therefore, it will be understood that the foregoing is an illustration of the inventive concept and will not be construed as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The inventive concept is defined by the appended claims, and the equivalents of the claims are included in the appended claims. The embodiments may be combined to form additional embodiments.

Claims

1. A display device, wherein: The display device comprises: A display panel including a low-degradation region and a high-degradation region; a driving controller configured to generate a data signal based on input image data; and a data driver configured to convert the data signal into a data voltage, and the data driver is configured to output the data voltage to the display panel; Wherein, the drive controller includes a degradation compensator, and The degradation compensator is configured to generate the data signal based on a degradation ratio between a sensing current of one or more pixels in the low-degradation region and a sensing current of one or more pixels in the high-degradation region.

2. The display device according to claim 1, wherein: The driving controller further includes a stress converter configured to output a brightness reduction rate according to a degradation time to the degradation compensator, The low-degradation region is a region where the luminance reduction rate is at a first level, and The high degradation region is a region where the luminance reduction rate is at a second level greater than the first level.

3. The display device according to claim 2, wherein: The degradation compensator is configured to output the data signal based on the luminance reduction rate corresponding to the degradation ratio.

4. The display device according to claim 2, wherein: The driving controller further includes a nonvolatile memory configured to store the brightness reduction rate according to the degradation time.

5. The display device according to claim 2, wherein: The driving controller is configured to store the degradation ratio and the luminance reduction rate corresponding to the degradation ratio.

6. The display device according to claim 5, wherein: The degradation compensator is configured to generate a prediction function based on the stored degradation ratio and the stored luminance reduction rate corresponding to the degradation ratio, and The degradation compensator is configured to output the data signal based on the prediction function.

7. The display device according to claim 6, wherein: The prediction function is a linear function.

8. The display device according to claim 2, wherein: The low-degradation region and the high-degradation region are changed according to the degradation time.

9. The display device according to claim 1, wherein: The degradation ratio is the ratio between a value obtained by dividing the sensing current of the one or more pixels in the high degradation area after the degradation time by the sensing current of the one or more pixels in the low degradation area after the degradation time, and a value obtained by dividing the sensing current of the one or more pixels in the high degradation area at the initial time by the sensing current of the one or more pixels in the low degradation area at the initial time.

10. The display device according to claim 1, wherein: The display device further includes: Sense driver, The highly degraded region includes one or more highly degraded red pixels, one or more highly degraded green pixels, and one or more highly degraded blue pixels. The degraded area includes one or more degraded red pixels, one or more degraded green pixels and one or more degraded blue pixels. wherein the sensing driver is configured to perform a sensing operation of receiving the sensing current of the one or more pixels in the low-degradation area and the sensing current of the one or more pixels in the high-degradation area, and Wherein, the sensing operation is performed on the one or more highly degraded red pixels, the one or more highly degraded green pixels, the one or more highly degraded blue pixels, the one or more poorly degraded red pixels, the one or more poorly degraded green pixels and the one or more poorly degraded blue pixels.

11. The display device according to claim 10, wherein: The degradation ratio includes: a red degradation ratio, which is a ratio between a sense current of the one or more highly degraded red pixels and a sense current of the one or more less degraded red pixels; a green degradation ratio, which is a ratio between a sense current of the one or more highly degraded green pixels and a sense current of the one or more less degraded green pixels; and The blue degradation ratio is a ratio between the sensing current of the one or more highly degraded blue pixels and the sensing current of the one or more less degraded blue pixels.

12. The display device according to claim 11, wherein: The driving controller further includes a stress converter configured to output a brightness reduction rate according to a degradation time to the degradation compensator, The driving controller is configured to store the red degradation ratio and the luminance reduction rate corresponding to the red degradation ratio, and the driving controller generates a red prediction function based on the red degradation ratio and the luminance reduction rate corresponding to the red degradation ratio, The driving controller is configured to store the green degradation ratio and the luminance reduction rate corresponding to the green degradation ratio, and the driving controller generates a green prediction function based on the green degradation ratio and the luminance reduction rate corresponding to the green degradation ratio, The driving controller is configured to store the blue degradation ratio and the luminance reduction rate corresponding to the blue degradation ratio, and the driving controller generates a blue prediction function based on the blue degradation ratio and the luminance reduction rate corresponding to the blue degradation ratio, and The driving controller is configured to generate the data signal based on the red prediction function, the green prediction function, and the blue prediction function.

13. A method for compensating for degradation of a display panel, wherein: The method comprises: storing a brightness reduction rate of a pixel according to degradation time; calculating a degradation ratio, the degradation ratio being a ratio between a sensed current of one or more pixels in a high degradation region where the luminance reduction rate is at a first level and a sensed current of one or more pixels in a low degradation region where the luminance reduction rate is at a second level lower than the first level; storing the degradation ratio and the luminance reduction rate corresponding to the degradation ratio; and A data signal is generated based on the brightness reduction rate.

14. The method according to claim 13, wherein: The method further comprises: After storing the luminance reduction rate corresponding to the degradation ratio, a prediction function is generated based on the stored degradation ratio and the stored luminance reduction rate corresponding to the degradation ratio, wherein the data signal is generated based on the prediction function.

15. The method according to claim 13, wherein: The degradation ratio is the ratio between a value obtained by dividing the sensing current of the one or more pixels in the high degradation area after the degradation time by the sensing current of the one or more pixels in the low degradation area after the degradation time, and a value obtained by dividing the sensing current of the one or more pixels in the high degradation area at the initial time by the sensing current of the one or more pixels in the low degradation area at the initial time.

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