# US 10,504,453 B1 · Displays with adjustable direct-lit backlight units > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,504,453 B1 - Document ID: US10504453B1 - Status: Granted - Kind: B1 - Application number: 16/388,427 - Filed: 2019-04-18 - Granted: 2019-12-10 - Earliest claimed: 2019-04-18 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Tobias Jung; Marc Albrecht; Duane M. Petrovich; Sean C. Chang; David S. Zalatimo; Pierre-Yves Emelie; Manev Luthra; Chengrui Le; Lingyu Hong; Wei H. Yao - Web page: https://patentgrep.com/patent/US10504453B1 ## CPC - G09G 3/3406: {Control of illumination source (illumination devices structurally associated with liquid crystal cells G02F1/1336)} - G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - G09G 3/36: using liquid crystals - G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)} - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0247: Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes - G09G 2320/041: Temperature compensation - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - G09G 2320/0653: Controlling or limiting the speed of brightness adjustment of the illumination source - G09G 2360/144: the light being ambient light - 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 display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements. ## Claims ### Claim 1 An electronic device comprising: a plurality of pixels; a backlight having a plurality of light-emitting diodes that are configured to produce backlight illumination for the plurality of pixels; and control circuitry configured to: during a first frame, determine brightness values for the plurality of light-emitting diodes based on a first set of image data; during a second frame that is subsequent to the first frame, display images using a second set of image data while the plurality of light-emitting diodes produces backlight illumination using the brightness values determined during the first frame; and during the second frame, generate a simulated backlight reconstruction based on the brightness values determined during the first frame. ### Claim 2 (depends on 1) The electronic device defined in claim 1, wherein generating the simulated backlight reconstruction comprises using one or more point spread functions to simulate an actual backlight brightness value associated with each pixel of the plurality of pixels. ### Claim 3 (depends on 2) The electronic device defined in claim 2, wherein the control circuitry is configured to: compensate the second set of image data based on the simulated backlight reconstruction. ### Claim 4 (depends on 3) The electronic device defined in claim 3, wherein the control circuitry is configured to: during the second frame, generate a plurality of tone maps based on the compensated second set of image data. ### Claim 5 (depends on 4) The electronic device defined in claim 4, wherein the control circuitry is configured to: during a third frame that is subsequent to the second frame, adjust a third set of image data using the tone maps generated during the second frame; and during the third frame, display images using the adjusted third set of image data. ### Claim 6 An electronic device comprising: a plurality of pixels; a backlight having a plurality of light-emitting diodes that are configured to produce backlight illumination for the plurality of pixels; and control circuitry configured to: during a first frame, determine brightness values for the plurality of light-emitting diodes based on a first set of image data; and during a second frame that is subsequent to the first frame, display images using a second set of image data while the plurality of light-emitting diodes produces backlight illumination using the brightness values determined during the first frame, wherein determining the brightness values for the plurality of light-emitting diodes based on the first set of image data comprises determining initial target brightness values based on content of the first set of image data. ### Claim 7 (depends on 6) The electronic device defined in claim 6, wherein determining the brightness values for the plurality of light-emitting diodes based on the first set of image data comprises modifying the initial target brightness values based at least on additional brightness values used in an additional frame prior to the first frame. ### Claim 8 (depends on 7) The electronic device defined in claim 7, wherein modifying the initial target brightness values based at least on the additional brightness values used in the additional frame comprises modifying the initial target brightness values in response to a comparison between the additional brightness values used in the additional frame and the initial target brightness values indicating a scene change. ### Claim 9 (depends on 7) The electronic device defined in claim 7, wherein modifying the initial target brightness values based at least on the additional brightness values used in the additional frame comprises applying a temporal filter to the initial target brightness values and the additional brightness values. ### Claim 10 An electronic device comprising: a plurality of pixels; a backlight having a plurality of light-emitting diodes, wherein each one of the plurality of light-emitting diodes is configured to produce backlight illumination for a respective subset of the plurality of pixels; and control circuitry configured to generate a brightness value for each one of the plurality of light-emitting diodes based on image data for the respective subset of the plurality of pixels associated with that light-emitting diode, wherein the control circuitry is configured to use a temporal filter and backlight brightness values from a previous frame to generate the brightness values for the plurality of light-emitting diodes.