Granted Patent B2

US 12,614,491 · App. 18/328,661 · Granted Apr 28, 2026

Inventors: Vincent Z Young (San Francisco, CA); Mahesh B Chappalli (San Jose, CA); Maofeng Yang (Santa Clara, CA); Weijun Yao (Saratoga, CA)

Assignee: Apple Inc.

G09G3/2003G09G3/3607G09G2300/0452G09G2320/0233G09G2320/0242G09G2320/0285G09G2330/028G09G2360/16

Abstract

Claims (73)

1 . An electronic device comprising:

a display panel comprising display pixels; and

image processing circuitry coupled to the display panel, the image processing circuity configured to:

convert gray level data corresponding to a first display pixel of the display pixels to first voltage data;

receive a brightness level of the display panel;

compare the brightness level to a plurality of threshold brightness levels;

retrieve a number of compensation maps based on the comparison;

determine a voltage offset value based on the first voltage data and the number of compensation maps;

generate compensated voltage data using the voltage offset value and the first voltage data; and

convert the compensated voltage data into compensated gray level data for the first display pixel.

2 . The electronic device of claim 1 , wherein the image processing circuitry is configured to:

retrieve one compensation map based on the brightness level being above a first threshold brightness level of the plurality of threshold brightness levels;

retrieve two compensation maps based on the brightness level being below the first threshold brightness level and above a second brightness level of the plurality of threshold brightness levels; and

retrieve at least three compensation maps based on the brightness level being below a second threshold brightness level of the plurality of threshold brightness levels.

3 . The electronic device of claim 2 , wherein the image processing circuitry is configured to convert the gray level data to the first voltage data by:

determining a first voltage value of the first voltage data based on the gray level data and a first lookup table of a first set of lookup tables; and

determining a second voltage value of the first voltage data based on the gray level data and a second lookup table of the first set of lookup tables.

4 . The electronic device of claim 3 , wherein the image processing circuitry is configured to determine the voltage offset value by:

determining a first voltage offset value of the voltage offset value by interpolating between the at least three compensation maps and the first voltage value; and

determining a second voltage offset value of the voltage offset value by interpolating between the at least three compensation maps and the second voltage value.

5 . The electronic device of claim 4 , wherein converting the compensated voltage data into the compensated gray level data comprises:

determining a first gray level based on a first lookup table of a second set of lookup tables and a first compensated voltage value comprising the first voltage offset value and the first voltage value;

determining a second gray level based on a second lookup table of the second set of lookup tables and a second compensated voltage value comprising the second voltage offset value and the second voltage value; and

interpolating between the first gray level and the second gray level.

6 . The electronic device of claim 2 , wherein determining the voltage offset value comprises extrapolating from a nearest compensation map of the at least three compensation maps based on the first voltage data.

7 . The electronic device of claim 2 , wherein determining the voltage offset value comprises clipping to a nearest compensation map of the three compensation maps based on the first voltage data.

8 . The electronic device of claim 1 , wherein converting the gray level data to the first voltage data comprises:

configuring a first set of lookup tables based on the brightness level of the display panel, wherein each of the first set of lookup tables comprises a gray level and a voltage value; and

determining a high voltage value and a low voltage value based on the first set of lookup tables and the gray level data.

9 . The electronic device of claim 1 , wherein determining the voltage offset value comprises:

determining a bounding set based on at least two compensation maps, wherein the bounding set comprises a low input voltage value and a high input voltage value; and

determining the voltage offset value based on the first voltage data and the bounding set by interpolation, extrapolation, or clipping.

10 . The electronic device of claim 1 , wherein the image processing circuitry is configured to:

retrieve a plurality of compressed compensation maps from a memory, wherein each of the plurality of compressed compensation maps is stored as a compressed frame buffer; and

spatially interpolate each of the plurality of compressed compensation maps.

11 . Processing circuitry, comprising:

first conversion circuitry configured to convert image data corresponding to a display pixel of a plurality of display pixels of an electronic display from gray level data of the image data to first voltage data;

non-uniformity correction circuitry configured to generate first compensated voltage data corresponding to the display pixel by:

comparing a brightness level of the electronic display to a plurality of threshold brightness levels;

retrieving one compensation map based on the brightness level being above a first threshold brightness level of the plurality of threshold brightness levels;

retrieving at least two compensation maps based on the brightness level being below the first threshold brightness level; and

applying a voltage offset to the first voltage data based on the first voltage data and a number of compensation maps; and

second conversion circuitry configured to convert the first compensated voltage data to compensated gray level data corresponding to the display pixel.

12 . The processing circuitry of claim 11 , wherein the non-uniformity correction circuitry is configured to:

retrieve at least three compensation maps based on the brightness level of the electronic display being below the first threshold brightness level and a second threshold brightness level of the plurality of threshold brightness levels, wherein the first threshold brightness level is greater than the second threshold brightness level; and

determine a bounding set based on a low voltage value of the at least three compensation maps, a high voltage value of the at least three compensation maps, or both.

13 . The processing circuitry of claim 12 , wherein the non-uniformity correction circuitry is configured to:

determine first values of the first voltage data within the bounding set; and

generate the voltage offset by interpolating between the at least three compensation maps based on the first values.

14 . The processing circuitry of claim 13 , wherein the non-uniformity correction circuitry is configured to:

determine second values of the first voltage data outside of the bounding set; and

generate the voltage offset by extrapolating to a nearest compensation map of the at least three compensation maps, clipping to the nearest compensation map of the at least three compensation maps, or both based on the second values.

15 . A method comprising:

obtaining, via processing circuitry, image data, wherein the image data comprises input voltage values for a first display pixel of a plurality of display pixels of an electronic display;

receiving, via the processing circuitry, a brightness level of the electronic display;

comparing, via the processing circuitry, the brightness level to a plurality of threshold brightness levels;

retrieving, via the processing circuitry, a number of compensation maps based on the comparison; and

generating, via the processing circuitry, compensated image data by applying a compensation to the image data based on at least one compensation map of the number of compensation maps.

16 . The method of claim 15 , wherein retrieving, via the processing circuitry, the number of compensation maps comprises:

retrieving one compensation map based on the brightness level being above a first threshold brightness level of the plurality of threshold brightness levels;

retrieving two compensation maps based on the brightness level being below the first threshold brightness level and above a second threshold brightness level of the plurality of threshold brightness levels; and

retrieving three compensation maps based on the brightness level being below the second threshold brightness level.

17 . The method of claim 15 , wherein generating, via the processing circuitry, the compensated image data comprises:

determining a bounding set based on the at least one compensation map, wherein the bounding set comprises a low voltage, a high voltage, or both;

determining the compensation by interpolating between the at least one compensation map using the image data based on the image data being within the bounding set; and

applying the compensation to the image data.

18 . The method of claim 15 , wherein generating, via the processing circuitry, the compensated image data comprises:

determining a bounding set based on the at least one compensation map, wherein the bounding set comprises a low voltage, a high voltage, or both; and

determining the compensation by extrapolating or clipping to a nearest compensation map of the at least one compensation map using the image data based on the image data being outside the bounding set.

19 . The method of claim 15 , wherein retrieving, via the processing circuitry, the number of compensation maps comprises:

retrieving a compressed frame buffer of the at least one compensation map; and

up-sampling the compressed frame buffer using spatial interpolation, bilinear interpolation, nearest neighbor, or a combination thereof.

20 . The electronic device of claim 2 , wherein the first threshold brightness level is greater than the second threshold brightness level.

Assignments (1)

Continuity (1)

References Cited (19)