IP Library Granted Patent US 12,651,580
Granted Patent B2
US 12,651,580 · App. 18/478,588 · Granted Jun 9, 2026

Backlight reconstruction and compensation

Inventor: Mahesh B. Chappalli (San Jose, CA)
Assignee: Apple Inc.
G09G5/10G09G3/2003G09G2310/0237G09G2320/0233
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 12,651,580
App. No.
18/478,588
Granted
Jun 9, 2026
Kind
B2
Abstract

A processor or other circuitry may obtain emissive element strength information for an array of emissive elements of an electronic display. The processor or other circuitry may reconstruct backlight information at multiple locations within the electronic display. The processor or other circuitry also compensates display of image data based at least in part on the reconstructed backlight information.

Claims (45)

1 . A system, comprising:

a plurality of emissive elements;

brightness estimation circuitry configured to estimate brightnesses of addressable backlight zones of the plurality of emissive elements based at least in part on pixel values of image data;

a backlight reconstruction and compensation system, comprising:

backlight reconstruction circuitry configured to:

receive emissive element strength information for the plurality of emissive elements;

receive the estimated brightnesses of the addressable backlight zones of the plurality of emissive elements from the brightness estimation circuitry;

generate brightnesses at a plurality of grid points based at least in part on the emissive element strength information and the estimated brightnesses of the addressable backlight zones; and

calculate pixel gains based at least in part on the brightnesses at the plurality of grid points; and

backlight compensation circuitry configured to:

receive the pixel gains from the backlight reconstruction circuitry;

receive the image data; and

adjust pixels of the image data using the pixel gains to compensate for backlight variance of the brightnesses at the plurality of grid points.

2 . The system of claim 1 , wherein the brightness estimation circuitry comprises statistics circuitry configured to generate statistics relating to display of the image data.

3 . The system of claim 1 , wherein the emissive element strength information comprises singular value decomposition sets for the plurality of grid points.

4 . The system of claim 3 , wherein the singular value decomposition sets each comprise decomposed horizontal and vertical weights.

5 . The system of claim 3 , comprising memory, wherein the backlight reconstruction circuitry is configured to receive the singular value decomposition sets from the memory.

6 . The system of claim 5 , wherein receiving the singular value decomposition sets from the memory comprises using a direct memory access (DMA) to access the singular value decomposition sets.

7 . The system of claim 1 , comprising a display comprising the plurality of emissive elements, wherein the addressable backlight zones comprise overlapping zones of the display.

8 . The system of claim 7 , wherein the brightness estimation circuitry is configured to compensate for brightness differences and color shifts of the plurality of emissive elements.

9 . The system of claim 8 , wherein the brightness estimation circuitry is configured to enhance contrast while reducing or minimizing halo and flicker artifacts.

10 . The system of claim 9 , wherein the brightness estimation circuitry comprises an emissive element processor configured to perform compute brightnesses for individual addressable backlight zones based at least in part on pixel values in the image data.

11 . The system of claim 10 , wherein the plurality of emissive elements are configured to perform local dimming based on the computed brightnesses for the individual addressable backlight zones.

12 . The system of claim 1 , wherein the brightness estimation circuitry is configured to compute brightness maximums, brightness minimums, brightness averages, en-gamma/de-gamma information, or uniformity statistics for the image data, wherein the brightness estimation is based at least in part on the brightness maximums, brightness minimums, brightness averages, en-gamma/de-gamma information, or uniformity statistics for the image data.

13 . The system of claim 1 , wherein the backlight reconstruction circuitry is configured to receive pixel coordinates, and the pixel gains are based at least in part on the pixel coordinates.

14 . A method for operating a backlight comprising:

estimate, in brightness estimation circuitry, brightnesses of addressable backlight zones of a plurality of emissive elements in the backlight based at least in part on pixel values of image data;

receive, in backlight reconstruction circuitry, emissive element strength information for the plurality of emissive elements;

receive, in the backlight reconstruction circuitry, the estimated brightnesses of the addressable backlight zones of the plurality of emissive elements from the brightness estimation circuitry;

generate, in the backlight reconstruction circuitry, brightnesses at a plurality of grid points based at least in part on the emissive element strength information and the estimated brightnesses of the addressable backlight zones;

calculate, in the backlight reconstruction circuitry, pixel gains based at least in part on the brightnesses at the plurality of grid points;

receive, in backlight compensation circuitry, the pixel gains from the backlight reconstruction circuitry;

receive, in the backlight compensation circuitry, the image data; and

adjust, in the backlight compensation circuitry, pixels of the image data using the pixel gains to compensate for backlight variance of the brightnesses at the plurality of grid points.

15 . The method of claim 14 , wherein the emissive element strength information comprises singular value decomposition sets for the plurality of grid points, wherein the singular value decomposition sets each comprise decomposed horizontal and vertical weights.

16 . The method of claim 15 , comprising receiving the singular value decomposition sets at the backlight reconstruction circuitry from memory using a direct memory access (DMA) to access the singular value decomposition sets.

17 . The method of claim 15 , wherein the brightnesses at the plurality of grid points indicate brightnesses from one or more respective emissive elements of the plurality of emissive elements.

18 . A tangible, non-transitory, and computer-readable medium having stored thereon instructions, that when executed are configured to cause a processor to:

obtain emissive element strength information for a plurality of emissive elements of an electronic display, wherein the emissive element strength information comprises singular value decomposition sets for the electronic display, and the singular value decomposition sets each comprise decomposed horizontal and vertical weights;

receive an estimated brightnesses of addressable backlight zones of the plurality of emissive elements from brightness estimation circuitry;

generate brightnesses at a plurality of grid points based at least in part on the emissive element strength information and the estimated brightnesses of the addressable backlight zones;

calculate pixel gains based at least in part on the brightnesses at the plurality of grid points; and

adjust pixels of image data using the pixel gains to compensate for backlight variance of the brightnesses at the plurality of grid points.

19 . The tangible, non-transitory, and computer-readable medium of claim 18 , wherein adjusting the pixels of the image data comprises determining a brightness at a pixel by interpolating two or more grid points of the plurality of grid points.

20 . The tangible, non-transitory, and computer-readable medium of claim 18 , wherein the emissive element strength information comprises color drift information for the plurality of emissive elements, and adjusting the image data comprises compensating for the color drift information.

Continuity (4)
Continuation 17940835 · Sep 8, 2022
Continuation 17149415 · Jan 14, 2021
Provisional Application 63072091 · Aug 28, 2020
Related Publication 20240029687A1 · Jan 25, 2024
References Cited (33)
US 8982036B2 · Kim · 2015 [cited by examiner]
US 10504453B1 · Jung et al. · 2019 [cited by applicant]
US 10571744B1 · Chang · 2020 [cited by examiner]
US 10643549B1 · Jung · 2020 [cited by examiner]
US 11100830B2 · Aksit · 2021 [cited by applicant]
US 20070232241A1 · Carley et al. · 2007 [cited by applicant]
US 20090115718A1 · Qiao et al. · 2009 [cited by applicant]
US 20100053132A1 · Miyamoto · 2010 [cited by applicant]
US 20100156927A1 · Takase · 2010 [cited by applicant]
US 20100182346A1 · Sano · 2010 [cited by examiner]
US 20120287146A1 · Elliot et al. · 2012 [cited by applicant]
US 20120287167A1 · Higgins et al. · 2012 [cited by applicant]
US 20130215360A1 · Pollack et al. · 2013 [cited by applicant]
US 20130265346A1 · Yu et al. · 2013 [cited by applicant]
US 20170244376A1 · Morris et al. · 2017 [cited by applicant]
US 20210350732A1 · Aksit · 2021 [cited by applicant]
US 20210358427A1 · Wang et al. · 2021 [cited by applicant]
US 20220084474A1 · Rajamani et al. · 2022 [cited by applicant]
CN 101329459A · 2008 [cited by applicant]
CN 108389552A · 2018 [cited by applicant]
EP 2099019A1 · 2009 [cited by applicant]
EP 2477176A1 · 2012 [cited by applicant]
EP 3147893A1 · 2017 [cited by applicant]
JP 2008116850A · 2008 [cited by applicant]
JP 2009069468A · 2009 [cited by applicant]
JP 2010145773A · 2010 [cited by applicant]
JP 2019095559A · 2019 [cited by applicant]
KR 1020120128091A · 2012 [cited by applicant]
KR 1020140120819A · 2014 [cited by applicant]
WO 2013038560A · 2013 [cited by applicant]
Notice of Preliminary Rejection for Korean Patent Application No. 10-2022-0106806, dated Nov. 24, 2023; 4 pgs. [cited by applicant]
International Search Report and Written Opinion for PCT Patent Application No. PCT/US2021/047016 dated Nov. 19, 2021; 20 pgs. [cited by applicant]
Korean Search Report for Korean Patent Application No. 10-2023-7009972 dated Apr. 6, 2023; 16 pgs. [cited by applicant]