# US 2020/0286431 A1 · Device and method for driving a self-luminous display panel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0286431 A1 - Document ID: US20200286431A1 - Status: Published application - Kind: A1 - Application number: 16/810,497 - Filed: 2020-03-05 - Published: 2020-09-10 - Earliest claimed: 2019-03-07 - Assignees: Synaptics Incorporated - Applicants: Synaptics Incorporated - Inventors: Akio SUGIYAMA; Takashi NOSE; Hirobumi FURIHATA; Masao ORIO; Susumu SAITO - Web page: https://patentgrep.com/patent/US20200286431A1 ## CPC - G09G 3/3258: with pixel circuitry controlling the voltage across the light-emitting element - G09G 3/2003: {Display of colours (specific for liquid crystal displays G09G3/3607)} - 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 5/026: {Control of mixing and/or overlay of colours in general (G09G5/022 and G09G5/024 take precedence)} - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2310/0286: Details of a shift registers arranged for use in a driving circuit - G09G 2320/0626: for control of overall brightness - G09G 2320/064: by time modulation of the brightness of the illumination source - G09G 2320/0673: for control of gamma adjustment, e.g. selecting another gamma curve - G09G 2320/0686: with two or more screen areas displaying information with different brightness or colours - 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 display driver comprises gamma processing circuitry, compensation circuitry, and driver circuitry. The gamma processing circuitry is configured to process the image data to generate gamma processed image data. The compensation circuitry is configured to process the gamma-processed image data, based on a ratio of a number of display elements that emit light to a total number of display elements of a display panel, to generate compensated image data. The driver circuitry is configured to drive the display panel based on the compensated image data. ## Claims ### Claim 1 A display driver comprising: gamma processing circuitry configured to process image data to generate gamma-processed image data; compensation circuitry configured to process the gamma-processed image data, based on a ratio of a number of display elements that emit light to a total number of display elements of a display panel, to generate compensated image data; and driver circuitry configured to drive the display panel based on the compensated image data. ### Claim 2 (depends on 1) The display driver of claim 1, further comprising: emission pulse generator circuitry configured to supply an emission pulse that controls the ratio, wherein the compensation circuitry is configured to perform the compensation processing based on an emission pulse width of the emission pulse. ### Claim 3 (depends on 2) The display driver of claim 2, wherein the compensation circuitry comprises: compensation coefficient generator circuitry configured to generate a compensation coefficient based on the emission pulse width; and compensation processing circuitry configured to generate the compensated image data by processing the gamma-processed image data based on the compensation coefficient. ### Claim 4 (depends on 3) The display driver of claim 3, wherein the compensation coefficient generator circuitry is configured to generate the compensation coefficient based on correlation data that indicates a correlation between the emission pulse width and the compensation coefficient. ### Claim 5 (depends on 3) The display driver of claim 3, wherein the compensation circuitry is configured to perform the compensation processing so that a display brightness level of the display panel changes linearly with the emission pulse width. ### Claim 6 (depends on 3) The display driver of claim 3, wherein the gamma processing circuitry is configured to perform the gamma processing based on a gamma parameter determined based on desired gamma characteristics; and wherein the compensation circuitry is configured to perform compensation processing so as to compensate for a change of the gamma characteristics from the desired gamma characteristics caused by a change of the emission pulse width. ### Claim 7 (depends on 3) The display driver of claim 3, wherein the compensation circuitry is further configured to compensate for a change in chromaticity characteristics of the display panel caused by a change of the emission pulse width. ### Claim 8 (depends on 3) The display driver of claim 3, wherein the compensation circuitry is further configured to perform compensation processing for respective colors of the display elements of the display panel. ### Claim 9 (depends on 3) The display driver of claim 3, further comprising emission pulse width control circuitry configured to control the emission pulse width based on a brightness command value that specifies a display brightness level of the display panel. ### Claim 10 (depends on 9) The display driver of claim 9, wherein the emission pulse width control circuitry is configured to control the emission pulse width so that the emission pulse width monotonically and non-linearly increases with an increase in the brightness command value. ### Claim 11 (depends on 10) The display driver of claim 10, wherein the emission pulse width control circuitry is further configured to control an emission pulse width change rate based at least in part on the brightness command value. ### Claim 12 (depends on 11) The display driver of claim 11, wherein the emission pulse width change rate increases with an increase in the brightness command value. ### Claim 13 (depends on 10) The display driver of claim 10, wherein the emission pulse width control circuitry is further configured to control a duty ratio of the emission pulse based on: a number of emission pulses per frame period and the brightness command value. ### Claim 14 A display driver comprising: emission pulse generator circuitry configured to supply, to a display panel, an emission pulse that controls a ratio of a number of display elements that emit light to a total number of display elements of the display panel; and emission pulse width control circuitry configured to control a pulse width of the emission pulse, based on a brightness command value specifying a display brightness level of the display panel, such that the pulse width of the emission pulse monotonically and non-linearly increases with an increase in the brightness command value. ### Claim 15 (depends on 14) The display driver of claim 14, wherein the emission pulse width control circuitry is further configured to control the pulse width change rate based at least in part on the brightness command value. ### Claim 16 A method comprising: processing image data to generate gamma-processed image data; processing the gamma-processed image data based on a ratio of a number of display elements that emit light to a total number of display elements of a display panel; to generate compensated image data; and driving the display panel based on the compensated image data. ### Claim 17 (depends on 16) The method of claim 16, further comprising supplying an emission pulse that controls the ratio, and wherein generating the compensated image data comprises performing compensation processing based on a width of the emission pulse. ### Claim 18 (depends on 17) The method of claim 17, wherein performing the compensation processing based on the emission pulse width further comprises performing the compensation processing so that a display brightness level of the display panel changes linearly with the width of the emission pulse. ### Claim 19 (depends on 17) The method of claim 17, wherein generating the gamma-processed image data comprises performing gamma processing based on a gamma parameter that is determined based on desired gamma characteristics, and wherein generating the compensated image data comprises compensating for a change in gamma characteristics from the desired gamma characteristics caused by a change in the width of the emission pulse. ### Claim 20 (depends on 17) The method of claim 17, wherein generating the compensated image data comprises compensating for a change in chromaticity characteristics of the display panel caused by a change in the width of the emission pulse. ### Claim 21 (depends on 17) The method of claim 17, further comprising: controlling the width of the emission pulse based on a brightness command value that specifies a display brightness level of the display panel, wherein the width of the emission pulse monotonically and non-linearly increases with an increase in the brightness command value.