# US 11,908,376 B1 · Compensation schemes for 1x1 sub-pixel uniformity compensation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,376 B1 - Document ID: US11908376B1 - Status: Granted - Kind: B1 - Application number: 17/710,133 - Filed: 2022-03-31 - Granted: 2024-02-20 - Earliest claimed: 2021-04-06 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Lingtao Wang; Giovanni Carbone; Chaohao Wang; Enkhamgalan Dorjgotov; Sheng Zhang; Jim C Chou; Shereef Shehata; Yung-Chin Chen - Web page: https://patentgrep.com/patent/US11908376B1 ## CPC - G09G 3/2092: {Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto (suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165)} - G09G 5/06: using colour palettes, e.g. look-up tables - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - G09G 3/2074: {using sub-pixels} - G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0276: for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction - G09G 2320/0673: for control of gamma adjustment, e.g. selecting another gamma curve - G09G 2340/02: Handling of images in compressed format, e.g. JPEG, MPEG - G09G 2360/08: Power processing, i.e. workload management for processors involved in display operations, such as CPUs or GPUs - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) ## Abstract A compensation system includes a processor configured to determine compensated data for display on a sub-pixel of the display device. The processor may receive image data configured to be displayed on the sub-pixel, convert the gray level data to first voltage data; fetch, from a memory, compressed 1×1 sub-pixel uniformity compensation data for the sub-pixel, and decompress the compressed 1×1 sub-pixel uniformity compensation data via a decompressor. The decompressed data comprises the 1×1 sub-pixel uniformity compensation data for the sub-pixel. The processor may also determine a voltage compensation offset value associated with the sub-pixel based on the second voltage data, generate compensated voltage data based in part on the voltage compensation offset value and the first voltage data, convert the compensated voltage data to compensated gray level data; and transmit the compensated gray level data to pixel driving circuitry associated with the sub-pixel. ## Claims ### Claim 1 A display device comprising: a display panel comprising: a group of pixels, wherein each of the group of pixels comprise one or more pixels that each control a luminance of a color component of a corresponding pixel; and display driving circuitry configured to program, onto the group of pixels, image data to be displayed via the group of pixels; a processor; and a memory accessible by the processor; wherein the processor is configured to: receive image data configured to be displayed via the group of pixels, wherein the image data comprises gray level data for a first pixel of the group of pixels; convert the gray level data to first voltage data; fetch second voltage data from encoding data of a compensation map, the second voltage data comprising 1×1 pixel uniformity compensation data for at least a portion of the group of pixels including the first pixel, wherein the 1×1 pixel uniformity compensation data comprises compensation data to mitigate non-uniformity between at least a portion of the group of pixels when supplied with a same electrical input signal and wherein the second voltage data is configured to be inputted to a look-up table configured to decode the second voltage data into voltage compensation data for the first pixel, and wherein the look-up table stores at least one voltage compensation offset value corresponding to the 1×1 pixel uniformity compensation data for the one or more pixels of the group of pixels; determine a voltage compensation offset value associated with the first pixel based on the second voltage data; generate compensated voltage data based in part on the voltage compensation offset value and the first voltage data; convert the compensated voltage data to compensated gray level data; and transmit the compensated gray level data to the display driving circuitry associated with the first pixel. ### Claim 2 (depends on 1) The display device of claim 1, wherein the processor is configured to: fetch third voltage data from a global compensation map; determine a global voltage compensation offset value associated with the first pixel based on the third voltage data; and wherein the processor is configured to generate the compensated gray level data at least in part on the global voltage compensation offset value and the voltage compensation offset value. ### Claim 3 (depends on 1) The display device of claim 1, wherein spatial interpolation is applied to the compensated gray level data. ### Claim 4 (depends on 1) The display device of claim 1, wherein the compensation map comprises a 2-bit encoded pixel uniformity compensation map. ### Claim 5 (depends on 4) The display device of claim 4, wherein the fetched second voltage data comprises 2-bit code. ### Claim 6 (depends on 1) The display device of claim 1, wherein the compensation map comprises a 4-bit encoded compensation map, and wherein the second voltage data includes 2×2 voltage compensation data for some the group of pixels of the display panel not including the first pixel. ### Claim 7 (depends on 1) The display device of claim 1, wherein the display panel is an 8-bit display panel, wherein the look-up table is configured to output 8-bit compensation data, and wherein the voltage compensation offset value comprises a portion of the 8-bit compensation data. ### Claim 8 (depends on 1) The display device of claim 1, wherein the look-up table is configurable on a per color basis. ### Claim 9 (depends on 1) The display device of claim 1, wherein the image data comprises gray level data for a 2×2 binning including the first pixel of the group of pixels and wherein the look-up table is configured to output a local offset compensation factor for each pixel of the 2×2 binning including the first pixel of the group of pixels. ### Claim 10 A method for encoding a compensation map for compensating one or more pixels of a group of pixels in a display device, the method comprising: receiving 1×1 pixel uniformity compensation calculation data comprising compensation data to mitigate non-uniformity between at least a portion of the group of pixels when supplied with a same electrical input signal; binning, into a binning greater than 1×1, at least a portion of the 1×1 pixel uniformity compensation calculation data; and encoding the 1×1 pixel uniformity compensation calculation data to generate a foveated compensation map, wherein the foveated compensation map includes an encoded 1×1 pixel uniformity compensation map and encoded compensation map for the binning greater than 1×1 binning. ### Claim 11 (depends on 10) The method of claim 10, comprising: loading, into the display device, the foveated compensation map and a look-up table to decode the foveated compensation map. ### Claim 12 (depends on 10) The method of claim 10, wherein the encoded 1×1 pixel uniformity compensation map of the foveated compensation map is mapped to a portion of the display device and wherein the encoded compensation map for a binning higher than 1×1 binning is mapped to another portion of the display device. ### Claim 13 (depends on 10) The method claim 10, comprising: configuring a look-up table to decode the foveated compensation map. ### Claim 14 (depends on 13) The method of claim 13, wherein the foveated compensation map is encoded using 4-bit code and wherein the look-up table is configured to receive data from the foveated compensation map and output compensation data. ### Claim 15 A compensation system of a display device, the compensation system comprising: a processor configured to provide compensated data to display driving circuitry configured to program image data onto a pixel of a group of pixels of the display device by: receiving image data configured to be displayed on the pixel, wherein the image data comprises gray level data for the pixel; converting the gray level data to first voltage data; fetching, from a memory of the display device, compressed 1×1 pixel uniformity compensation data for the pixel, wherein the compressed 1×1 pixel uniformity compensation data comprises compensation data to mitigate non-uniformity between the pixel and one or more other pixels when supplied with a same electrical input signal; decompressing the compressed 1×1 pixel uniformity compensation data via a decompressor, wherein the decompressed data comprises the 1×1 pixel uniformity compensation data for the pixel; determining a voltage compensation offset value associated with the pixel based on the 1×1 pixel uniformity compensation data for the pixel; generating compensated voltage data based in part on the voltage compensation offset value and the first voltage data; converting the compensated voltage data to compensated gray level data; and transmitting the compensated gray level data to the display driving circuitry to program the pixel based upon the compensated data. ### Claim 16 (depends on 15) The compensation system of claim 15, wherein the compressed 1×1 pixel uniformity compensation data is part of a compressed 1×1 pixel uniformity compensation map. ### Claim 17 (depends on 16) The compensation system of claim 16, wherein the compressed 1×1 pixel uniformity compensation data for the pixel was compressed via a lossy or lossless algorithm. ### Claim 18 (depends on 15) The compensation system of claim 15, wherein the compressed 1×1 pixel uniformity compensation data is part of an encoded per pixel uniformity compensation map. ### Claim 19 (depends on 15) The compensation system of claim 15, wherein the compressed 1×1 pixel uniformity compensation data is part of a foveated compensation map. ### Claim 20 (depends on 15) The compensation system of claim 15, wherein the processor is configured to transmit the compensated gray level data to a plurality of pixels including the pixel, and wherein the processor is configured to apply spatial interpolation to the compensated gray level data.