# US 11,908,370 B2 · Method of driving display panel and display apparatus for performing the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,908,370 B2 - Document ID: US11908370B2 - Status: Granted - Kind: B2 - Application number: 18/109,106 - Filed: 2023-02-13 - Published: 2023-10-05 - Granted: 2024-02-20 - Earliest claimed: 2022-03-25 - Assignees: Samsung Display Co., Ltd. - Applicants: Samsung Display Co., Ltd. - Inventors: Geonhwi Park; Hyunjoo Seo; Kihyun Pyun - Web page: https://patentgrep.com/patent/US11908370B2 ## CPC - G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} - G09G 3/2007: {Display of intermediate tones} - G09G 3/2096: {Details of the interface to the display terminal specific for a flat panel (suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167)} - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0242: Compensation of deficiencies in the appearance of colours - G09G 2320/0276: for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction - G09G 2320/0626: for control of overall brightness - G09G 2320/0666: for control of colour parameters, e.g. colour temperature - G09G 2340/06: Colour space transformation - G09G 2360/16: Calculation or use of calculated indices related to luminance levels in display data - 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 method of operating a display apparatus includes the following steps: calculating a first color reference luminance ratio, a second color reference luminance ratio, and a third color reference luminance ratio for a reference grayscale value; calculating first color target luminance ratios, second color target luminance ratios, and third color target luminance ratios for adjustment target grayscale values; generating first adjustment values, second adjustment values, and third adjustment values based on the first, second, and third color reference luminance ratios and the first, second, and third color target luminance ratios; performing gamma conversions of first, second and third colors using the first, second, and third adjustment values for the adjustment target grayscale values; using results of the gamma conversions to generate data voltages; and using the data voltage and a display panel of the display apparatus to emit or transmit light for displaying an image. ## Claims ### Claim 1 A method of operating a display apparatus, the display apparatus comprising a display panel and driver set electrically connected to each other, the method comprising: calculating a first color reference luminance ratio, which is a ratio of a first color luminance value to a total color luminance value for a reference grayscale value; calculating a second color reference luminance ratio, which is a ratio of a second color luminance value to the total color luminance value for the reference grayscale value; calculating a third color reference luminance ratio, which is a ratio of a third color luminance value to the total color luminance value for the reference grayscale value; calculating first color target luminance ratios, which are ratios of first color luminance values to total color luminance values for adjustment target grayscale values; calculating second color target luminance ratios, which are ratios of second color luminance values to the total color luminance values for the adjustment target grayscale values; calculating third color target luminance ratios, which are ratios of third color luminance values to the total color luminance values for the adjustment target grayscale values; generating first color adjustment values based on the first color reference luminance ratio and the first color target luminance ratios; generating second color adjustment values based on the second color reference luminance ratio and the second color target luminance ratios; generating third color adjustment values based on the third color reference luminance ratio and the third color target luminance ratios; performing a gamma conversion of a first color using the first color adjustment values for the adjustment target grayscale values; performing a gamma conversion of a second color using the second color adjustment values for the adjustment target grayscale values; performing a gamma conversion of a third color using the third color adjustment values for the adjustment target grayscale values; generating first data voltages using results of the gamma conversion of the first color, the gamma conversion of the second color, and the gamma conversion of the third color; and emitting or transmitting first light using the display panel and the first data voltages to display a first image. ### Claim 2 (depends on 1) The method of claim 1, wherein the adjustment target grayscale values are equal to or greater than 1 and equal to or less than an adjustment limit grayscale value. ### Claim 3 (depends on 2) The method of claim 2, wherein the adjustment limit grayscale value is less than a half of a maximum grayscale value associated with the display panel. ### Claim 4 (depends on 1) The method of claim 1, wherein the reference grayscale value is a maximum grayscale value associated with the display panel. ### Claim 5 (depends on 1) The method of claim 1, wherein the first color adjustment values are calculated by dividing the first color reference luminance ratio by the first color target luminance ratios for the adjustment target grayscale values, wherein the second color adjustment values are calculated by dividing the second color reference luminance ratio by the second color target luminance ratios for the adjustment target grayscale values, and wherein the third color adjustment values are calculated by dividing the third color reference luminance ratio by the third color target luminance ratios for the adjustment target grayscale values. ### Claim 6 (depends on 5) The method of claim 5, wherein the first color is red, wherein the second color is green, and wherein the third color is blue. ### Claim 7 (depends on 6) The method of claim 6, wherein each of the second color adjustment values is greater than 1, wherein each of the third color adjustment values is less than 1, wherein a first one of the first color adjustment values is greater than 1 for a first one of the adjustment target grayscale values, and wherein a second one of the first color adjustment values is less than 1 for a second one of the adjustment target grayscale values. ### Claim 8 (depends on 7) The method of claim 7 wherein the first one of the adjustment target grayscale values is 1, and wherein the second one of the adjustment target grayscale values is 16. ### Claim 9 (depends on 1) The method of claim 1, further comprising: performing a gamma conversion of the first color without applying the first color adjustments value for a normal grayscale value that is not one of the adjustment target grayscale values; performing a gamma conversion of the second color without applying the second color adjustment values for the normal grayscale value; and performing a gamma conversion of the third color without applying the third color adjustment values for the normal grayscale value. ### Claim 10 (depends on 1) The method of claim 1, wherein the total color luminance value for the reference grayscale value is a sum of the first color luminance value, the second color luminance value, and the third color luminance value for the reference grayscale value. ### Claim 11 (depends on 10) The method of claim 10, wherein each of the total color luminance values for the adjustment target grayscale values is a sum of a corresponding one of the first color luminance values, a corresponding one of the second color luminance values, and a corresponding one of the third color luminance values for a corresponding one of the adjustment target grayscale values. ### Claim 12 (depends on 1) The method of claim 1, wherein the total color luminance value for the reference grayscale value is a white luminance for the reference grayscale value. ### Claim 13 (depends on 12) The method of claim 12, wherein each of the total color luminance values for the adjustment target grayscale values is a white luminance for a corresponding one of the adjustment target grayscale values. ### Claim 14 (depends on 1) The method of claim 1, further comprising generating a lookup table including first color voltage codes, second color voltage codes, and third color voltage codes corresponding to input grayscale values based on at least the first color adjustment values, the second color adjustment values, and the third color adjustment values. ### Claim 15 (depends on 1) The method of claim 1, further comprising: generating a first lookup table including first color voltage codes, second color voltage codes, and third color voltage codes corresponding to input grayscale values based on a target gamma value and target color coordinates; and generating a second lookup table by applying the first color adjustment values, the second color adjustment values, and the third color adjustment values to the first lookup table. ### Claim 16 (depends on 15) The method of claim 15, further comprising: performing a first gamma conversion using the first lookup table in a first mode; performing a second gamma conversion using the second lookup table in a second mode; generating second data voltages using results of at least the second gamma conversion; and emitting or transmitting second light using the display panel and the second data voltages to display a second image. ### Claim 17 A display apparatus comprising: a display panel; a driving controller configured to generate data signals based on input image data; and a data driver electrically connected to each of the display panela and the driving controller, configured to use the data signals to generate data voltages, and configured to output the data voltages to the display panel, wherein the display panel is configured to emit or transmit light using the data voltage to display an image, and wherein the driving controller is configured to perform a gamma conversion of a first color, a gamma conversion of a second color, and a gamma conversion of a third color for generating the data signals using first color adjustment values, second color adjustment values, and third color adjustment values that are generated based on a first color reference luminance ratio, a second color reference luminance ratio, a third color reference luminance ratio, first color target luminance ratios, second color target luminance ratios, and third color target luminance ratios, which are respectively a ratio of a first color luminance value to a total color luminance value for a reference grayscale value, a ratio of a second color luminance value to the total color luminance value for the reference grayscale value, a ratio of a third color luminance value to the total color luminance value for a reference grayscale value, ratios of first color luminance values to total color luminance values for adjustment target grayscale values, ratios of second color luminance values to the total color luminance values for the adjustment target grayscale values, and ratios of third color luminance values to the total color luminance values for the adjustment target grayscale values. ### Claim 18 (depends on 17) The display apparatus of claim 17, wherein the first color adjustment values are calculated by dividing the first color reference luminance ratio by the first color target luminance ratios for the adjustment target grayscale values, wherein the second color adjustment values are calculated by dividing the second color reference luminance ratio by the second color target luminance ratios for the adjustment target grayscale values, and wherein the third color adjustment values are calculated by dividing the third color reference luminance ratio by the third color target luminance ratios for the adjustment target grayscale values. ### Claim 19 (depends on 17) The display apparatus of claim 17, wherein the driving controller is configured to perform the gamma conversion of the first color, the gamma conversion of the second color, and the gamma conversion of the third color using a lookup table generated based on at least the first color adjustment values, the second color adjustment values, and the third color adjustment values, the lookup table including first color voltage codes, second color voltage codes, and third color voltage codes corresponding to input grayscale values. ### Claim 20 (depends on 17) The display apparatus of claim 17, wherein the driving controller is configured to perform the gamma conversion of the first color, the gamma conversion of the second color, and the gamma conversion of the third color based on at least one of a first lookup table and a second lookup table according to a mode signal that selects the first lookup table or the second lookup table, wherein the first lookup table is generated based on a target gamma value and target color coordinates, the first lookup table including first color voltage codes, second color voltage codes, and third color voltage codes corresponding to input grayscale values, and wherein the second lookup table is generated by applying the first color adjustment values, the second color adjustment values, and the third color adjustment values to the first lookup table.