Granted Patent B2

US 12,380,828 · App. 18/722,975 · Granted Aug 5, 2025

Inventors: Chien-Hui Wen (Cupertino, CA); Hsin-Yu Chen (Taoyuan, TW)

Assignee: Google LLC

G09G3/2003G09G2320/0233G09G2320/0242G09G2320/0247G09G2320/0673G09G2340/0435G09G2360/144G09G2360/16

Abstract

Claims (62)

1. A method comprising:

measuring, from a device having a display panel and for an input gray level at a given refresh rate, a plurality of luminance values of the display panel for a plurality of pixels located along a cross-section of the display panel;

selecting, based on the measured plurality of luminance values, a target luminance value for the display panel;

determining a luminance compensation profile for the input gray level at the given refresh rate, wherein the luminance compensation profile comprises ratios of the measured plurality of luminance values to the target luminance value; and

storing, at the device, the luminance compensation profile for the input gray level at the given refresh rate, wherein subsequent to the storing, the device is configured to adjust input display data using the luminance compensation profile for the input gray level when the display panel is providing a display, and wherein the luminance compensation profile maintains a color uniformity of the display.

2. The method of claim 1 , further comprising:

determining, based on the luminance compensation profile and for the input gray level at the given refresh rate, modified luminance values for use by the device, wherein the modified luminance values maintain the color uniformity of the display.

3. The method of claim 1 , wherein the storing comprises storing, on a system on a chip (SoC) and for a plurality of input gray levels and a plurality of refresh rates, a plurality of respective luminance compensation profiles.

4. The method of claim 1 , wherein the cross-section is a longitudinal cross-section, and wherein the target luminance value corresponds to a luminance value from a central portion of the longitudinal cross-section.

5. The method of claim 1 , wherein the display panel is configured to operate at multiple refresh rates, and the method further comprising:

measuring, from the device and for the input gray level at a second refresh rate different from the given refresh rate, a second plurality of luminance values of the display panel for a second plurality of pixels located along the cross-section of the display panel;

determining a second luminance compensation profile for the input gray level at the second refresh rate, wherein the second luminance compensation profile comprises products of the measured second plurality of luminance values with the ratios of the measured plurality of luminance values to the target luminance value; and

storing, at the device, the second luminance compensation profile for the input gray level at the second refresh rate, wherein subsequent to the storing, the device is configured to adjust input display data using the second luminance compensation profile for the input gray level when the display panel is transitioning from the given refresh rate to the second refresh rate.

6. The method of claim 5 , wherein the given refresh rate is 60 Hertz (Hz) and the second refresh rate is 90 Hz.

7. The method of claim 1 , wherein the display panel has a plurality of color channels, and wherein the display panel comprises a partitioning into a plurality of sections, and the method further comprising:

determining a perceived difference in a color intensity between the plurality of sections;

determining, based on the perceived difference in the color intensity, a color compensation profile for the plurality of sections, wherein the color compensation profile modifies a default register value for at least one color channel of the plurality of color channels to offset the perceived difference in the color intensity; and

storing, at the device, the color compensation profile for the input gray level at the given refresh rate, wherein subsequent to the storing, the device is configured to adjust the input display data using the color compensation profile for the input gray level when the display panel is providing a display.

8. The method of claim 7 , wherein the plurality of color channels comprise red, green and blue (RGB) color channels.

9. The method of claim 1 , wherein the measuring is performed by an image capturing device configured to measure the plurality of luminance values.

10. The method of claim 1 , wherein the measuring of the plurality of luminance values, the selecting of the target luminance value, and the determining of the luminance compensation profile, is performed for a given display brightness value (DBV) for the display panel.

11. The method of claim 1 , wherein the input gray level is below a threshold gray level, and the display panel is operating at a brightness level below a threshold brightness level.

12. A computer-implemented method comprising:

identifying an input gray level for a display panel operating at a given refresh rate;

determining that the input gray level is below a threshold gray level, and that the display panel is operating at a brightness level below a threshold brightness level;

retrieving, from a storage at the device and for the input gray level at the given refresh rate, one or more of a luminance compensation profile or a color compensation profile, and wherein:

(a) the luminance compensation profile has been determined to maintain a color uniformity of a display provided by the display panel based on:

measured plurality of luminance values of the display panel for a plurality of pixels located along a cross-section of the display panel, and

determined ratios of the measured plurality of luminance values to a target luminance value, and

(b) the color compensation profile has been determined based on:

a perceived difference in a color intensity between a plurality of sections of the display panel, and

a modified default register value for at least one color channel of a plurality of color channels to offset the perceived difference; and

adjusting input display data for the input gray level at the given refresh rate using the luminance compensation profile, the color compensation profile, or both.

13. The method of claim 12 , further comprising:

determining a histogram data for the display, wherein the histogram data comprises a pixel-wise distribution of color intensity of the display while the display panel is operating at a given refresh rate, and

wherein the retrieving and the adjusting is based on the histogram data.

14. The method of claim 12 , wherein the display panel comprises a plurality of zones, and wherein the histogram data is based on the plurality of zones, and wherein the retrieving and the adjusting is based on the plurality of zones.

15. The method of claim 14 , wherein the plurality of zones comprises a top, middle, and bottom portion of the display panel.

16. The method of claim 14 , wherein the plurality of zones are in alignment with the plurality of sections.

17. The method of claim 12 , wherein the retrieving comprises retrieving from a system on a chip (SoC).

18. The method of claim 12 , wherein the display panel is configured to operate at multiple refresh rates, and the method further comprising:

retrieving, from the storage at the device and based on the histogram data and for the input gray level at a second refresh rate different from the given refresh rate, a second luminance compensation profile, wherein the second luminance compensation profile has been determined based on:

measured second plurality of luminance values of the display panel for the plurality of pixels located along the cross-section of the display panel, and

determined ratios of the measured second plurality of luminance values to the target luminance value;

adjusting the input display data for the input gray level at the second refresh rate using the second luminance compensation profile; and

transitioning, based on the adjusted input display data at the second refresh rate, the display panel from the given refresh rate to the second refresh rate.

19. The method of claim 18 , further comprising:

identifying a rate change triggering event while the display panel is operating at the given refresh rate, and

wherein the transitioning of the display panel from the given refresh rate to the second refresh rate is performed in response to the identifying of the rate change triggering event.

20. A system comprising:

one or more processors; and

data storage, wherein the data storage has stored thereon computer-executable instructions that, when executed by the one or more processors, cause the system to carry out operations comprising:

identifying an input gray level for a display panel operating at a given refresh rate;

determining that the input gray level is below a threshold gray level, and that the display panel is operating at a brightness level below a threshold brightness level;

retrieving, from a storage at the device and for the input gray level at the given refresh rate, one or more of a luminance compensation profile or a color compensation profile, and wherein:

(a) the luminance compensation profile has been determined to maintain a color uniformity of a display provided by the display panel based on:

measured plurality of luminance values of the display panel for a plurality of pixels located along a cross-section of the display panel, and

determined ratios of the measured plurality of luminance values to a target luminance value, and

(b) the color compensation profile has been determined based on:

a perceived difference in a color intensity between a plurality of sections of the display panel, and

a modified default register value for at least one color channel of a plurality of color channels to offset the perceived difference; and

adjusting input display data for the input gray level at the given refresh rate using the luminance compensation profile, the color compensation profile, or both.

Assignments (1)

Continuity (1)

References Cited (96)