System and method for variable area-based compensation of burn-in in display panels

Abstract

To provide a burn-in compensation system and a method which perform compensation in a mode different from a pixel in another area of a display for a pixel arranged on an image pick-up device.SOLUTION: A display driver includes image processing circuitry and a source driver. The image processing circuitry is configured to perform burn-in compensation to determine a first compensated luminance value for a first pixel in a first area of a display panel on the basis of at least in part, a first accumulated luminance value for the first pixel. The first area has a first pixel layout. The image processing circuitry is further configured to scale a second accumulated luminance value for a second pixel in a second area of the display panel to determine a scaled accumulated luminance value. The second area has a second pixel layout different from the first pixel layout. The image processing circuitry is further configured to perform the burn-in compensation to determine a second compensated luminance value for the second pixel on the basis of, at least in part the scaled accumulated luminance value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This application is a non-provisional application of U.S. Patent Application No. 63 / 248,394, filed on September 24, 2021, and thus claims the benefit under 35 U.S.C. § 119(e) to U.S. Patent Application No. 63 / 248,394. U.S. Patent Application No. 63 / 248,394 is hereby incorporated by reference in its entirety.

[0002] The present disclosure relates generally to the field of display panels, and more particularly to compensating for the effects of burn-in.

Background Art

[0003] Display devices such as organic light-emitting diode (OLED) displays, micro light-emitting diode (LED) displays, and liquid crystal displays (LCDs) may be susceptible to burn-in artifacts due to excessive use of pixel elements. These burn-in artifacts depend on the lifetime usage of individual pixels of the panel. Frequently used pixels may degrade faster than pixels with limited usage. Proprietary pixel compensation may be added to compensate for burn-in. Memory attached to the substrate may store long-term usage data for each pixel. Compensation may apply a large gain factor to frequently used pixels and a small gain factor to less used pixels.

[0004] Recent display systems may include image sensors such as cameras disposed under the display. Pixels disposed above these image sensors may be arranged in a different pixel layout than pixels in other areas so that sufficient light can pass through the pixels and reach the image sensors. In this case, the pixels above the image sensor may be driven with a brighter signal to keep the display uniform. As a result, pixels disposed for the information of the image sensor may degrade faster than pixels in other areas of the display.

[0005] There is a need for burn-in compensation systems and methods that compensate for pixels located above the image sensor in a different manner than pixels in other areas of the display. [Overview of the project]

[0006] This abstract is provided in a concise form to introduce the selection of concepts that will be further described below in the detailed description of the invention. This abstract is not intended to identify any major or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0007] In general, in one embodiment, one or more embodiments relate to a display driver comprising an image processing circuit and a source driver. The image processing circuit is configured to determine a first compensated luminance value of a first pixel in a first region of a display panel by performing burn-in compensation based at least partially on a first cumulative luminance value of the first pixel. The first region has a first pixel layout. The image processing circuit is further configured to determine a scaled cumulative luminance value by scaling a second cumulative luminance value of a second pixel in a second region of the display panel. The second region has a second pixel layout different from the first pixel layout. The image processing circuit is further configured to determine a second compensated luminance value of the second pixel by performing burn-in compensation based at least partially on the scaled cumulative luminance value. The source driver is configured to update the first pixel based at least partially on the first compensated luminance value and update the second pixel based at least partially on the second compensated luminance value.

[0008] In one or more embodiments, the long-term cumulative luminance of the display pixels may be recorded in a memory device. The output gradation level to the display panel may be compensated based on the cumulative luminance value and the burn-in profile of the individual display panel. In one or more embodiments, different compensation values ​​may be used for multiple regions of the display panel using pixels of different densities or configurations.

[0009] In general, in one embodiment, one or more embodiments relate to a display device comprising a display panel and a display driver. The display panel comprises a first region having a first pixel layout and a second region having a second pixel layout different from the first pixel layout. The display driver is configured to determine a first compensated luminance value of a first pixel in the first region of the display panel by performing burn-in compensation on at least a portion of the first cumulative luminance value of the first pixel. The display driver is further configured to determine a scaled cumulative luminance value by scaling the second cumulative luminance value of a second pixel in the second region of the display panel. The display driver is further configured to determine a second compensated luminance value of the second pixel by performing burn-in compensation on at least a portion of the scaled cumulative luminance value. The display driver is configured to update the first pixel on at least a portion of the first compensated luminance value and update the second pixel on at least a portion of the second compensated luminance value.

[0010] In general, one embodiment relates to a method for driving a display panel comprising a first region and a second region. The first region has a first pixel layout, and the second region has a second pixel layout different from the first pixel layout. The method includes determining a first compensated luminance value of a first pixel in the first region of the display panel by performing burn-in compensation on at least a portion of a first cumulative luminance value of the first pixel. The method further includes determining a scaled cumulative luminance value by scaling a second cumulative luminance value of a second pixel in the second region of the display panel. The method further includes determining a second compensated luminance value of the second pixel by performing burn-in compensation on at least a portion of the scaled cumulative luminance value. The method further includes updating the first pixel on at least a portion of the first compensated luminance value and updating the second pixel on at least a portion of the second compensated luminance value.

[0011] Other aspects of the embodiments will be apparent from the following description and the attached claims. [Brief explanation of the drawing]

[0012] To enable a detailed understanding of the features of this disclosure, a more specific description of this disclosure, which is briefly summarized above, may be given with reference to embodiments. Some of these embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only exemplary embodiments, and this disclosure recognizes other equally valid embodiments, and should not be considered to limit the scope of the invention.

[0013] [Figure 1A] Figure 1A illustrates an exemplary configuration of a display device comprising a display panel including multiple regions having different pixel layouts, according to one or more embodiments.

[0014] [Figure 1B] Figure 1B illustrates an exemplary configuration of a display panel according to one or more embodiments.

[0015] [Figure 1C] Figure 1C illustrates an exemplary pixel layout of a first region of a display panel according to one or more embodiments.

[0016] [Figure 1D] Figure 1D illustrates an exemplary pixel layout of a second region of a display panel according to one or more embodiments.

[0017] [Figure 1E] Figure 1E illustrates an exemplary pixel layout of a first and second region of a display panel according to one or more embodiments.

[0018] [Figure 1F] Figure 1F illustrates a graph of the compensation value along the y-axis relative to the cumulative luminance value along the x-axis, according to one or more embodiments.

[0019] [Figure 2] Figure 2 illustrates a block diagram of one embodiment of the disclosed system.

[0020] [Figure 3] Figure 3 illustrates an embodiment of the details inside the devern controller.

[0021] [Figure 4A] Figure 4A illustrates an exemplary configuration of a tone adjustment block according to one or more embodiments.

[0022] [Figure 4B] Figure 4B illustrates an exemplary relationship between the original tone value and the adjusted tone value according to one or more embodiments.

[0023] [Figure 5] Figure 5 illustrates an embodiment of the compensation block.

[0024] [Figure 6] Figure 6 illustrates an exemplary method of driving a display panel according to one or more embodiments.

[0025] For ease of understanding, if possible, the same reference numerals are used to indicate the same elements common to the drawings. It is expected that elements disclosed in one embodiment can be beneficially used in other embodiments without specific description. To distinguish the same elements from each other, subscripts may be attached to the reference numerals. The drawings referred to in this specification should not be understood as being drawn to scale unless otherwise noted. Also, for clarity of presentation and explanation, the drawings are often simplified by omitting details or components. The drawings and discussions are useful for explaining the principles discussed below, and like reference numerals indicate like elements.

Embodiments for Implementing the Invention

[0026] The detailed description below is essentially illustrative and is not intended to limit this disclosure or its uses and applications. Furthermore, it is not intended to be bound by the aforementioned technical fields, background, or any explicit or implicit theories presented in the detailed description below.

[0027] The detailed description of the embodiments below includes many specific details to provide a deeper understanding of the disclosed technology. However, it will be obvious to those skilled in the art that the disclosed technology can be implemented even without these specific details. For example, well-known configurations are not described in detail to avoid unnecessarily complicating the description.

[0028] Throughout the application, ordinal numbers (e.g., 1st, 2nd, 3rd, etc.) may be used as adjectives for elements (i.e., any noun in the application). The use of ordinal numbers is not intended to suggest or generate any particular ordering of elements, nor to limit any element to being only a single element, unless explicitly disclosed by the use of terms such as “before,” “after,” “single,” and other similar terminology. Rather, the use of ordinal numbers is for distinguishing elements. For example, the 1st element is distinct from the 2nd element, the 1st element may encompass more than one element, and may follow (or precede) the 2nd element in the ordering of elements.

[0029] Display devices such as OLED displays, microLED displays, and LCDs can be susceptible to burn-in artifacts from excessive pixel use. These burn-in artifacts depend on how much each pixel is used on the panel during its lifetime. Overused pixels may degrade faster than less used pixels. The cumulative luminance value of individual pixels may be used to compensate for burn-in.

[0030] Areas of a display may contain pixels with different pixel layouts, which can result in differing long-term burn-in profiles. Differences in pixel layout may include differences in one or more of the following: pixel density (sometimes measured in pixels per inch (PPI)), configuration, size, and arrangement. For example, pixels in low-pixel-density areas may be used more frequently to compensate for their low density. As a result, they are at a higher risk of burn-in artifacts compared to pixels in high-density areas. A given display panel may be characterized for the degradation of pixel elements and the compensation applied to the display to correct long-term degradation in different areas of the display.

[0031] Figure 1A illustrates an exemplary configuration of a display device 100 comprising a display panel 102 including multiple regions having different pixel layouts, according to one or more embodiments. Examples of the display panel 102 include an OLED display panel, a microLED display panel, and an LCD panel. In the illustrated embodiment, the display panel 102 comprises a first region 105 having a first pixel layout and a second region 106 having a second pixel layout different from the first pixel layout. Although only two regions are illustrated, more than two regions may exist without departing from the scope of one or more embodiments. The display panel 102 may be connected to a display driver 104 configured to update the display panel 102.

[0032] The shape and / or arrangement of the first region 105 and the second region 106 of the display panel 102 can be varied. Figure 1B illustrates another exemplary configuration of the display panel 102 according to one or more embodiments. In the illustrated embodiment, the second region 106 is a rectangular region defined in the display panel 102, and the first region 105 is defined as the remaining region. The second region 106 may be used as an under-display camera (UDC) region. The UDC 150 is positioned behind the UDC region and is configured to capture images through the UDC region. In such an embodiment, the second region 106 has a lower pixel density than the first region 105.

[0033] Figure 1C illustrates an exemplary pixel layout of a first region 105 according to one or more embodiments. In the illustrated embodiments, the first region 105 comprises a pixel set 107, each having a red (R) pixel, two green (G) pixels, and a blue (B) pixel. In Figure 1C (and Figure 1D), “R”, “G”, and “B” refer to the red, green, and blue pixels, respectively. The R, G, and B pixels of the pixel set 107 are configured to be updated by data signals received from a display driver 104 and to emit light with a brightness corresponding to the data signals.

[0034] Figure 1D illustrates an exemplary pixel layout in a second region 106 according to one or more embodiments. In the illustrated embodiments, the second region 106 may comprise a plurality of pixel sets 108, each having one R pixel, one G pixel, and one B pixel. The pixels are arranged such that the pixel density of the second region 106 is lower than that of the first region 105. In one implementation, the spacing between two adjacent pixels in the second region 106 is greater than that in the first region 105. The R, G, and B pixels of the pixel set 108 are each configured to be updated by data signals received from a display driver 104 and to emit light with a brightness corresponding to the data signals.

[0035] Figure 1E illustrates another example of the pixel layout of the first region 105 and the second region 106 of the display panel 102 according to one or more embodiments. In the illustrated embodiment, the first region 105 comprises pixel sets 107A and 107B, each having one red (R) pixel, two green (G) pixels, and one blue (B) pixel. Pixel sets 107A and 107B differ in the relative positions of the red and blue pixels with respect to two green subpixels. The second region 106 comprises a pixel set 108A configured identically to pixel set 107A. In the illustrated embodiment, pixel sets 107A and 107B are adjacent to each other in the first region 105, while pixel set 108A is spaced apart in the second region 106. Consequently, the pixel density of the second region 106 is lower than that of the first region 105. In the illustrated embodiment, the pixel density of the second region 106 is one-quarter of the pixel density of the first region 105.

[0036] To display a continuous image spanning a first region 105 and a second region 106 having different pixel layouts, the signal level (e.g., voltage level) of the data signal used to update the pixels differs between the first region 105 and the second region 106, even for the same grayscale. Differences in the signal levels of the data signal can result in different long-term burn-in profiles. In one or more embodiments, burn-in compensation is performed depending on the area, i.e., the pixel layout.

[0037] Figure 1F illustrates a graph of compensation values ​​along the y-axis 110 against cumulative luminance values ​​along the x-axis 120. In one implementation, the cumulative luminance value of a pixel may be the sum of the luminance values ​​of that pixel. The luminance values ​​of the pixel may be calculated individually based on the corresponding grayscale values ​​specified for that pixel in order to update the pixel. For a given grayscale value, the calculated luminance value of a pixel may correspond to the luminance of that pixel. In one embodiment, as the cumulative luminance value of a pixel increases in direction 120, the required compensation value increases in direction 110. The trend line 130 drawn in this example is for illustrative purposes only. In other embodiments, the trend line 130 may have a negative slope, may have a linear relationship, or may have a nonlinear relationship different from the relationship illustrated in Figure 1F.

[0038] In one embodiment, the system may be configured to compensate for the cumulative luminance value by applying a compensation value. In the example shown at position 140, the cumulative luminance value may be recorded as value A, and the corresponding compensation value may be value B. In one or more embodiments, the system may receive the cumulative luminance value by accessing a memory element and calculate the corresponding compensation value based on a lookup table. In other embodiments, the system may receive the cumulative luminance value from a register and calculate the corresponding compensation value by applying a calculation based on the shape of the trend line 130.

[0039] A pair represented by a cumulative luminance value A and a corresponding compensation value B may represent compensation applied to pixels in a first region of the display panel (e.g., the first region 105 illustrated in Figures 1A-1E). A second region of the display panel (e.g., the second region 106 illustrated in Figures 1A-1E) may contain pixels that respond to cumulative luminance in a different manner than the first region. In one embodiment, the pixels in the second region have a different density and / or configuration to accommodate an image sensor (e.g., a camera) including but not limited to a camera, beneath the display panel. The pixels in the second region may be subjected to stronger luminance driving to produce the same luminance as a standard pixel in the first region and may degrade faster than the pixels in the first region. A scaling factor (or correction factor) x may be applied to the pixels in the second region such that the cumulative luminance value at position A is scaled or adjusted by the scaling factor x to obtain a scaled cumulative luminance value at position C. This adjusted cumulative luminance value C results in a compensation value D. The scaling factor x may depend on the pixel layout of the first and second regions. In one or more embodiments, the scaling factor x is based on the pixel densities of the first and second regions. In embodiments where the first region has a first pixel density and the second region has a second pixel density, the scaling factor may be based on the ratio of the first pixel density to the second pixel density.

[0040] Figure 2 is a block diagram of one embodiment of the disclosed system. The display driver 200 may be communicatively coupled to a host device 210. The host device 210 may transmit image information to the display driver 200, and the display driver 200 may be configured to update the display panel 270 based on the image information. In one implementation, the display driver 200 may be a display driver integrated circuit (DDIC).

[0041] In the illustrated embodiment, the display panel 270 comprises a first region 271 and a second region 272. In the illustrated embodiment, the first region 271 is the region outside the second region 272. The first region 271 and the second region 272 have different pixel layouts. The first region 271 may be one embodiment of the first region 105 illustrated in Figures 1A to 1E, and the second region 272 may be one embodiment of the second region 106 illustrated in Figures 1A to 1E. The second region 272 may contain pixels having different optical responses than the pixels in the first region 271. For example, the gamma characteristics of the pixels in the second region 272 may differ from the gamma characteristics of the pixels in the first region 271. Here, gamma characteristics refer to the dependence of pixel brightness on the grayscale level. To accommodate an under-display camera (UDC), the pixels in the second region 272 may have a different density and / or configuration than the pixels in the first region 271. Pixels in the second region 272 may be more spaced apart than pixels in the first region 271, resulting in a lower pixel density in the second region 272 than in the first region 271. Pixels in the second region 272 may have a different long-term burn-in profile than pixels in the first region 271. Pixels in the second region 272 may require larger or smaller compensation values ​​than pixels in the first region 271.

[0042] In the illustrated embodiment, the display driver 200 comprises an image data receiver 220, a brightness control block 221, an image processing circuit unit 230, a deburn random access memory (RAM) 250, and a source driver 260. The image data receiver 220 is configured to receive image information from the host device 210 and decode the received image information into image data 225. The image data 225 includes the original grayscale value 226 and the corresponding unique pixel position 227.

[0043] The brightness control block 221 is configured to receive brightness information from the host device 210 and generate a brightness setting 222 based at least partially on the brightness information. The brightness setting 222 may include a display brightness value (DBV) that specifies a desired display brightness level for the display panel 270. The desired display brightness level may also be a desired brightness level for the entire image displayed on the display panel 270.

[0044] The Devarn RAM 250 is configured to store cumulative brightness values ​​for each pixel of the display panel 270. The cumulative brightness value of a pixel may be the sum of brightness values ​​determined or calculated for that pixel. The brightness value of a pixel may be calculated based on a grayscale value specified for that pixel in order to update that pixel. The cumulative brightness values ​​may be stored in the Devarn RAM 250 for each individual pixel, or this may be done over a larger rectangular area of ​​M × N pixels in order to save memory bandwidth and size in the Devarn RAM 250, where M and N are integers greater than or equal to 2. The size of the rectangular area may differ between the first area 271 and the second area 272.

[0045] The image processing circuit unit 230 receives image data 225 and brightness setting 222, and is configured to process the image data 225 based on the brightness setting 222. In the illustrated embodiment, the image processing circuit unit 230 is configured to perform burn-in compensation on the image data 225 based at least partially on the cumulative brightness value 251 received from the deburn RAM 250 to generate a compensated brightness value for each pixel of the display panel 270.

[0046] The source driver 260 is configured to update a pixel of the display panel 270 based at least partially on a corresponding compensated luminance value generated for that pixel. The source driver 260 may be configured to generate a data signal for each pixel such that the data signal has a signal level (e.g., voltage level) corresponding to the compensated luminance value generated for each pixel of the display panel 270. The source driver 260 may further be configured to supply the generated data signal to the corresponding pixel, thereby updating each pixel.

[0047] In the illustrated embodiment, the image processing circuit 230 includes a gamma correction block 235, a deburn controller 240, and an adder 280. The gamma correction block 235 receives image data 225 and a brightness setting 222, performs gamma correction on the image data 225 based on the brightness setting 222, and outputs a gamma-corrected brightness value for each pixel of the display panel 270. In embodiments where the brightness setting 222 includes DBV, the input / output characteristics of the gamma correction block 235 (i.e., the correspondence between the original grayscale value 226 described in the image data 225 and the gamma-corrected brightness value output from the gamma correction block 235) are adjusted based on DBV so that the display panel 270 achieves the display brightness level specified by DBV.

[0048] The deburn controller 240 is configured to read a cumulative luminance value 251 for each pixel of the display panel 270 from the deburn RAM 250 and to calculate a compensation value 245 for each pixel based at least partially on the cumulative luminance value 251. In one implementation, the compensation value 245 increases as the corresponding cumulative luminance value 251 increases. The compensation value 245 may be calculated based on a lookup table containing values, or it may be calculated based on a stored formula for converting the cumulative luminance value 251 to a compensation value 245. The compensation value 245 for each pixel may further depend on the original tone value 226 in the image data 225 corresponding to each pixel. The compensation values ​​245 thus calculated are supplied to the adder 280.

[0049] The adder 280 is used to generate a compensated luminance value for each pixel of the display panel 270 by applying burn-in compensation to the gamma-corrected luminance value. The adder 280 may be configured to generate the compensated luminance value by applying a compensation value 245, determined based on the cumulative luminance value 251, to the gamma-corrected luminance value. The compensated luminance value is intended to address long-term burn-in of individual pixel positions. In one implementation, the adder 280 may be configured to generate a corresponding compensated luminance value for each pixel by adding the compensation value 245 to the corresponding gamma-corrected luminance value. The compensated luminance value is supplied to the source driver 260 and used to generate a data signal used to update each pixel.

[0050] In one or more embodiments, the deburn controller 240 may be further configured to receive image data 225 and update the cumulative luminance value 251 in the deburn RAM 250 using the original grayscale value 226 and the luminance setting 222. As pixels are driven at higher luminance values, the cumulative luminance value 251 of those pixels increases, is updated in the deburn RAM 250, and stored. Periodically, the contents of the deburn RAM 250 may be written to the non-volatile memory 255. The contents of the deburn RAM 250 may be written to the non-volatile memory 255 as part of a power-down sequence of the display driver 200, or as part of a timer-induced or user-initiated operation to update the contents of the non-volatile memory 255.

[0051] During operation, the display system may read a cumulative brightness value 251 from the deburn RAM 250. The reading of the cumulative brightness value 251 may be based on individual pixel positions 227 in the image data 225. The deburn controller 240 may be configured to generate a compensation value 245 based on the read cumulative brightness value 251. To compensate for pixels in the second region 272, which are more susceptible to burn-in, the pixel positions in the second region 272 may generate a larger compensation value 245 than the pixel positions in the first region 271.

[0052] During operation, when the power to the display driver 200 is turned on, the contents of the non-volatile memory 255 may be written to the deburn RAM 250. In this way, the most recently stored value for the cumulative brightness value 251 may be used when calculating the compensation value 245.

[0053] Figure 3 shows one embodiment of the internal details of the deburn controller 240. The deburn controller 240 may be configured to receive or acquire the original tone value 226 and the brightness setting 222 in the image data 225 as input. The deburn controller 240 may further be configured to read the cumulative brightness value 251 from the deburn RAM 250 and generate a compensation value 245 based on the cumulative brightness value 251 and the original tone value 226. The deburn controller 240 may further be configured to update the cumulative brightness value 251 in the deburn RAM 250 based on the original tone value 226 and the brightness setting 222. In the illustrated embodiment, the deburn controller 240 includes a tone adjustment block 320, a compensation block 350, and a data capture block 370. In addition, the deburn controller 240 may receive or acquire region information 330 as input. The region information 330 may indicate that individual primary grayscale values ​​226 correspond to pixels located in the second region 272 of the display panel 270, and the second region 272 exhibits a different long-term burn-in profile than the first region 271.

[0054] The tone adjustment block 320 may be configured to calculate an adjusted tone value 340 for each pixel using the input original tone value 226 and the brightness setting 222. The adjusted tone value 340 may be calculated by multiplying the original tone value 226 by an adjustment coefficient determined based on the brightness setting 222, or by using other numerical calculations that utilize the original tone value 226 and the brightness setting 222. The calculation of the adjusted tone value 340 may include certain parameters not shown in Figure 3. The calculation of the adjusted tone value 340 may be via a lookup table based on at least one of the original tone value 226 and the brightness setting 222.

[0055] In embodiments where the luminance setting 222 includes DBV, DBV may be used to calculate the adjusted tone value 340. Figure 4A illustrates an exemplary configuration of a tone adjustment block 320 according to such an embodiment. In the illustrated embodiment, the tone adjustment block 320 comprises a DBV lookup table (LUT) 322 and a multiplier 324. The DBV LUT 322 is configured to receive or acquire DBV as input and determine the adjustment coefficient 326 corresponding to DBV by a DBV-based table lookup. The multiplier 324 is configured to calculate the adjusted tone value 340 by multiplying the original tone value 226 by the adjustment coefficient 326.

[0056] Figure 4B illustrates an exemplary relationship between the original tone value 226 and the adjusted tone value 340, related via a corresponding adjustment coefficient 326, according to one or more embodiments. The adjustment coefficient 326 is determined such that the pixel brightness produced by the original tone value 226 for a DBV specified by the brightness setting 222 is the same as the pixel brightness produced by the adjusted tone value 340 for a maximum DBV. Note that in the illustrated embodiments, DBV is measured as a percentage, with maximum DBV being 100%. In one embodiment, if the original tone value 226 is 255 and the DBV is 50%, the adjustment coefficient 326 is determined as 0.73 (≒186 / 255) such that the adjusted tone value 340 is 186. In another embodiment, when the original tone value 226 is 255 and the DBV is 20%, the adjustment coefficient 326 is determined to be 0.50 (≒128 / 255) such that the adjusted tone value 340 becomes 128.

[0057] Returning to Figure 3, the data capture block 370 is configured to receive or acquire the adjusted tone value 340 and region information 330 as input. The data capture block 370 is configured to capture the adjusted tone value 340 applied to each pixel and to update the cumulative luminance value 251 stored in the deburn RAM 250 for each pixel. In one or more embodiments, the data capture block 370 may be configured to calculate an updated value for the cumulative luminance value 251 applied to each pixel throughout the lifetime of the display panel 270 based on the adjusted tone value 340, and to update the cumulative luminance value 251 stored in the deburn RAM 250 with the calculated updated value. The updated cumulative luminance value may be written to the deburn RAM 250 at each scan of the display panel 270, or the updated value may be written at a predetermined subsample rate to reduce the computational load and bandwidth requirements.

[0058] Figure 5 illustrates one embodiment of the compensation block 350. The compensation block 350 may receive or acquire the adjusted gradation value 340 as input. In addition, the cumulative luminance value 251 from the deburn RAM 250 may be input to the compensation block 350. In addition, region information 330 may be input to the compensation block 350. In the illustrated embodiment, the compensation block 350 comprises a logic circuit 420, a multiplier 435, and a compensation value generation block 450.

[0059] In operation, the logic circuit 420 may be configured to receive region information 330 as input and select a scaling factor 430. The logic circuit 420 may also be a multiplexer, but this should not be interpreted as an exclusive example. The logic circuit 420 may also include other logic gates, synchronous circuits, or memory elements.

[0060] In operation, region information 330 may be set to a first polarity that indicates that adjustments should be made to the cumulative brightness value 251 for pixels in the second region 272. In one or more embodiments, the positive polarity may select a degradation correction coefficient 470 as the scaling coefficient 430 for pixels in the second region 272. The scaling coefficient 430 may be used to compensate for accelerated burn-in of pixels in the second region 272 of the display panel 270. The degradation correction coefficient 470 may be stored in a register or memory element and input to the logic circuit 420. The degradation correction coefficient 470 may represent long-term degradation information based on a characterization of the long-term behavior of the display panel 270. The value of the degradation correction coefficient 470 may be based on a characterization of the display panel 270, or it may be based on a modeling of the long-term degradation behavior. The degradation correction coefficient 470 (i.e., the scaling coefficient 430 for pixels in the second region 272) is determined based on the pixel density of the first region 271 and the second region 272. In one implementation, the degradation correction coefficient 470 is based on the ratio of the pixel density of the first region 271 to the pixel density of the second region 272.

[0061] The region information 330 may take on an opposite polarity, indicating that no adjustment is made to the cumulative brightness value 251 for pixels in the first region 271. This opposite polarity selects 1 or the value of the identity element as the scaling factor 430 for pixels in the first region 271. In other embodiments, the opposite polarity of the region information 330 may result in a constant value greater than or less than 1 being selected as the scaling factor 430.

[0062] The scaling factor 430 is supplied to the multiplier 435. The multiplier 435 is configured to generate an adjusted cumulative luminance value 440 for each pixel by multiplying the cumulative luminance value 251 by the scaling factor 430. The adjusted cumulative luminance value 440 for pixels in the first region 271 is the same as the cumulative luminance value 251, while the adjusted cumulative luminance value 440 for pixels in the second region 272 is a scaled cumulative luminance value obtained by scaling the cumulative luminance value 251 with a degradation correction factor 470 (selected as the scaling factor 430).

[0063] The compensation value generation block 450 is configured to receive or acquire an adjusted tone value 340 and an adjusted cumulative luminance value 440 as input for each pixel. The compensation value generation block 450 is further configured to output a compensation value 245 for each pixel based at least partially on the adjusted tone value 340 and the adjusted cumulative luminance value 440. The compensation value generation block 450 may also be configured to output a compensation value 245 based on the relationship between the compensation value and the cumulative luminance value as illustrated in Figure 1F. For each pixel of the first region 271 where the scaling coefficient 430 is 1 or the identity element, the compensation value generation block 450 receives a cumulative luminance value 251 as input and outputs a compensation value 245 corresponding to the cumulative luminance value 251. For each pixel in the second region 272, the compensation value generation block 450 receives a scaled cumulative luminance value obtained by scaling the cumulative luminance value 251 using a degradation correction coefficient 470, through the functions of the logic circuit 420 and the multiplier 435, and outputs a compensation value 245 corresponding to the scaled cumulative luminance value. In one implementation, the compensation value generation block 450 includes a LUT 452 that describes the input / output characteristics of the compensation value generation block 450. These input / output characteristics may represent the relationship between the adjusted cumulative luminance value 440 and the compensation value 245 (for example, as illustrated in Figure 1F). The compensation value generation block 450 may be configured to generate the compensation value 245 by a table lookup of the LUT 452 using the adjusted cumulative luminance value 440 as an index.

[0064] Figure 6 illustrates a flowchart representing an exemplary method 600 according to one or more embodiments. While various steps in the flowchart are presented and described in order, those skilled in the art will understand that some or all of the steps may be performed in a different order, combined or omitted, and some or all of the steps may be performed in parallel. Additional steps may be performed further. Therefore, the scope of the disclosure should not be considered to be limited to the specific sequence of steps illustrated in Figure 6.

[0065] In one or more embodiments, Method 600 is a method for driving a display panel (e.g., a display panel 102 as shown in Figures 1A-1E and Figure 2) comprising a first region (e.g., first regions 105 and 271 in Figures 1A-1C, 1E and Figure 2) and a second region (e.g., second regions 106 and 272 in Figures 1A, 1B, 1D, 1E and Figure 2). The first region has a first pixel layout, and the second region has a second pixel layout different from the first pixel layout. The first and second regions may have different pixel densities. In some embodiments, the pixel density of the second region may be lower than that of the first region, and the second region may be used as an under-display camera (UDC) region with a camera mounted behind it. A lower pixel density in the second region may facilitate image capture through the second region.

[0066] Method 600 includes, in step 602, determining a first compensated luminance value for a first pixel by performing burn-in compensation on at least a portion of the first cumulative luminance value of the first pixel in a first area of ​​the display panel. The first cumulative luminance value of the first pixel may be the sum of the luminance values ​​of the first pixel. The luminance values ​​of the first pixel may be calculated individually based on the corresponding grayscale values ​​specified for the first pixel to update the first pixel. In one embodiment, burn-in compensation for the first pixel includes determining a first compensation value corresponding to the first cumulative luminance value based on the relationship between the compensation value and the cumulative luminance value illustrated in Figure 1F, and determining a first compensated luminance value for the first pixel using the first compensation value.

[0067] Method 600 further includes, in step 604, scaling the second cumulative luminance value of a second pixel in a second region of the display panel to determine a scaled cumulative luminance value. The second cumulative luminance value of a second pixel may be the sum of the luminance values ​​of the second pixel. The luminance values ​​of the second pixels may be calculated individually based on corresponding grayscale values ​​specified for the second pixel to update the second pixel. The scaling of the second cumulative luminance value may be based on the pixel densities of the first and second regions. In one or more embodiments, the first region has a first pixel density and the second region has a second pixel density. In such embodiments, the second cumulative luminance value may be scaled by a scaling factor determined based on the ratio of the first pixel density to the second pixel density.

[0068] Method 600 further includes, in step 606, determining a second compensated luminance value for the second pixel by performing burn-in compensation on at least a portion of the scaled cumulative luminance value. In one embodiment, burn-in compensation for the second pixel includes determining a second compensation value corresponding to the scaled cumulative luminance value based on the relationship between the compensation value and the cumulative luminance value illustrated in Figure 1F, and determining a second compensated luminance value for the second pixel using the second compensation value.

[0069] Method 600 further includes updating a first pixel in step 608 based at least partially on a first compensated luminance value, and updating a second pixel in step 610 based at least partially on a second compensated luminance value.

[0070] Although many embodiments have been described, those skilled in the art who are interested in this disclosure will likely find that other embodiments within the scope are possible. Therefore, the technical scope of the present invention should be limited only by the appended claims.

Claims

1. performing burn-in compensation based at least in part on a first accumulated luminance value of a first pixel in a first region of the display panel having a first pixel layout to determine a first compensated luminance value of the first pixel; determining a scaled accumulated luminance value by scaling second accumulated luminance values ​​of second pixels in a second region of the display panel having a second pixel layout different from the first pixel layout; image processing circuitry configured to perform burn-in compensation based at least in part on the scaled accumulated luminance value to determine a second compensated luminance value for the second pixel; a source driver configured to update the first pixel based at least in part on the first compensated luminance value and to update the second pixel based at least in part on the second compensated luminance value; A display driver comprising:

2. the first region having a first pixel density; the second region having a second pixel density; Scaling the second accumulated luminance values ​​includes scaling the second accumulated luminance values ​​by a scaling factor determined based on a ratio of the first pixel density to the second pixel density.

2. The display driver according to claim 1.

3. the image processing circuit unit includes a compensation value generation block configured to receive the first cumulative luminance value as an input and output a first compensation value corresponding to the first cumulative luminance value, and to receive the scaled cumulative luminance value as an input and output a second compensation value corresponding to the scaled cumulative luminance value, determining the first compensated luminance value based at least in part on the first compensation value; Determining the second compensated luminance value is based at least in part on the second compensation value.

2. The display driver according to claim 1.

4. the image processing circuitry includes a gamma correction block configured to output a first gamma-corrected luminance value based at least in part on a first gradation value of the first pixel and to output a second gamma-corrected luminance value based at least in part on a second gradation value of the second pixel; determining the first compensated luminance value of the first pixel includes performing burn-in compensation on the first gamma-corrected luminance value based at least in part on the first accumulated luminance value; determining the second compensated luminance value of the second pixel includes performing burn-in compensation on the second gamma-corrected luminance value based at least in part on the second accumulated luminance value; 2. The display driver according to claim 1.

5. a display panel including a first region having a first pixel layout and a second region having a second pixel layout different from the first pixel layout; performing burn-in compensation based at least in part on a first accumulated luminance value of a first pixel in the first region of the display panel to determine a first compensated luminance value of the first pixel; scaling second accumulated luminance values ​​of second pixels in the second region of the display panel to determine scaled accumulated luminance values; performing burn-in compensation based at least in part on the scaled accumulated luminance value to determine a second compensated luminance value for the second pixel; updating the first pixel based at least in part on the first compensated luminance value; a display driver configured to update the second pixel based at least in part on the second compensated luminance value; A display device comprising:

6. the first region having a first pixel density; the second region having a second pixel density; Scaling the second accumulated luminance values ​​includes scaling the second accumulated luminance values ​​by a scaling factor determined based on a ratio of the first pixel density to the second pixel density. The display device according to claim 5 .

7. the display driver comprises a compensation value generation block configured to receive the first accumulated luminance value as an input and output a first compensation value corresponding to the first accumulated luminance value, and to receive the scaled accumulated luminance value as an input and output a second compensation value corresponding to the scaled accumulated luminance value; determining the first compensated luminance value based at least in part on the first compensation value; Determining the second compensated luminance value is based at least in part on the second compensation value. The display device according to claim 5 .

8. performing burn-in compensation based at least in part on first accumulated luminance values ​​of first pixels in a first region having a first pixel layout of the display panel to determine first compensated luminance values ​​of the first pixels; scaling second accumulated luminance values ​​of second pixels in a second region of the display panel having a second pixel layout different from the first pixel layout to determine scaled accumulated luminance values; performing burn-in compensation based at least in part on the scaled accumulated luminance value to determine a second compensated luminance value for the second pixel; updating the first pixel based at least in part on the first compensated luminance value; updating the second pixel based at least in part on the second compensated luminance value; Contains method.

9. the first region having a first pixel density; the second region having a second pixel density; Scaling the second accumulated luminance values ​​includes scaling the second accumulated luminance values ​​by a scaling factor determined based on a ratio of the first pixel density to the second pixel density. The method of claim 8.

10. Furthermore, a compensation value generating block receiving the first accumulated luminance value as an input and outputting a first compensation value corresponding to the first accumulated luminance value; The compensation value generating block receives the scaled cumulative luminance value as an input and outputs a second compensation value corresponding to the scaled cumulative luminance value; Including, determining the first compensated luminance value based at least in part on the first compensation value; Determining the second compensated luminance value is based at least in part on the second compensation value. The method of claim 8.

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