# US 12,223,920 B2 · Backlight control circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,223,920 B2 - Document ID: US12223920B2 - Status: Granted - Kind: B2 - Application number: 18/402,645 - Filed: 2024-01-02 - Published: 2024-05-02 - Granted: 2025-02-11 - Earliest claimed: 2021-08-31 - Assignees: Radiant Opto-Electronics Corporation - Applicants: Radiant Opto-Electronics Corporation - Inventors: Li-Fei Wang; Yu-Lin Hsieh; Sheng-Kai Fang; Pei-Ling Kao - Web page: https://patentgrep.com/patent/US12223920B2 ## CPC - G09G 3/3426: {the different display panel areas being distributed in two dimensions, e.g. matrix} - G09G 2310/0264: Details of driving circuits - G09G 2320/0233: Improving the luminance or brightness uniformity across the screen - G09G 2320/0626: for control of overall brightness - 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 backlight control circuit for a surface light emitting device is provided. The backlight control circuit includes a driving circuit. The driving circuit is configured to generate a plurality of driving currents to drive the surface light emitting device such that a plurality of backlight blocks of the surface light emitting device generate a plurality of brightness values. The surface light emitting device is divided into a first backlight area and a second backlight area. The second backlight area is closer to an edge of the surface light emitting device than the first backlight area. A first driving current of the plurality of driving currents is utilized for driving the light source of the first backlight area. A second driving current of the plurality of driving currents is utilized for driving the light source of the second backlight area. The second driving current is greater than the first driving current. ## Claims ### Claim 1 A backlight control circuit for driving a surface light-emitting device, comprising: a driving circuit configured to generate a plurality of driving currents to drive the surface light-emitting device such that a plurality of backlight zones generates a plurality of brightness values according to a plurality of target uniformities for the plurality of backlight zones, and each backlight zone comprising at least one light source for emitting light; and a light source module, wherein the light source module comprises a substrate and a plurality of light-emitting diodes disposed on the substrate, the light source module defines a plurality of light-emitting zones arranged below the plurality of backlight zones, and each light-emitting zone comprises at least one of the light-emitting diode; wherein the number of the plurality of light-emitting zones is greater than or equal to the number of the plurality of backlight zones; wherein the surface light emitting device is divided into at least a first backlight area and a second backlight area, the second backlight area is closer to an edge of the surface light emitting device than the first backlight area, a first driving current of the plurality of driving currents is utilized for driving the light source of the backlight zone of the first backlight area, a second driving current of the plurality of driving currents is utilized for driving the light source of the backlight zone of the second backlight area, and the second driving current is greater than the first driving current; wherein the surface light-emitting device further comprises an outer frame surrounding the plurality of backlight zones, and among the light-emitting zones arranged below the backlight zones on the same edge, the driving current utilized for driving at least one of the light-emitting diodes farther from the outer frame at one light-emitting zone is greater than the driving current utilized for driving at least one of the light-emitting diodes closer to the outer frame at another light-emitting zone. ### Claim 2 (depends on 1) The backlight control circuit of claim 1, wherein the first backlight area comprises a central backlight zone located at or near a center of the surface light-emitting device. ### Claim 3 (depends on 1) The backlight control circuit of claim 1, wherein the second backlight area comprises at least one backlight zone located at an outermost edge of the surface light-emitting device. ### Claim 4 (depends on 3) The backlight control circuit of claim 3, wherein the surface light-emitting device further comprises a third backlight area, the third backlight area comprises at least one corner backlight zone, and the second backlight area comprises at least one backlight zone located at the outermost edge of the surface light-emitting device except for the at least one corner backlight zone of the third backlight area, wherein a third driving current of the plurality of driving currents is utilized for driving the light source of the backlight zone of the third backlight area, and the third driving current is greater than the first driving current and the second driving current. ### Claim 5 (depends on 4) The backlight control circuit of claim 4, wherein the surface light-emitting device is quadrangular, the third backlight area comprises corner backlight zones located at four corners of the surface light-emitting device, and the second backlight area comprises backlight zones located at four outermost edges of the surface light-emitting device except for the corner backlight zones. ### Claim 6 (depends on 1) The backlight control circuit of claim 1, wherein the surface light-emitting device further comprises a third backlight area, the third backlight area at least partially surrounds the second backlight area, wherein a third driving current of the plurality of driving currents is utilized for driving the light source of the backlight zone of the third backlight area, and the third driving current is greater than the first driving current and the second driving current. ### Claim 7 (depends on 6) The backlight control circuit of claim 6, wherein the third backlight area comprises backlight zones located at all outermost edges of the surface light-emitting device. ### Claim 8 (depends on 1) The backlight control circuit of claim 1, wherein the surface light-emitting device further comprises a third backlight area, the third backlight area at least partially surrounds the second backlight area, wherein a third driving current of the plurality of driving currents is utilized for driving the light source of the backlight zone of the third backlight area, and the third driving current is greater than the first driving current and the second driving current.