Granted Patent B2

US 12,361,900 · App. 18/503,424 · Granted Jul 15, 2025

Inventors: Masao Orio (Tokyo, JP); Takashi Nose (Kanagawa, JP); Hirobumi Furihata (Tokyo, JP); Tomoo Minaki (Tokyo, JP); Kazutoshi Aogaki (Kanagawa, JP)

Assignee: Synaptics Incorporated

G09G3/3426G09G3/3607G09G2320/0247G09G2320/0646G09G2320/066G09G2330/021G09G2360/16

Abstract

Claims (72)

1. A display device, comprising:

a backlight device comprising a plurality of light sources configured to illuminate a plurality of zones of a display panel, respectively, the plurality of zones being aligned in a first direction, each of the plurality of zones comprising a plurality of subzones aligned in a second direction perpendicular to the first direction; and

a backlight control circuit configured to:

receive an input image; and

determine a backlight value for a target light source of the plurality of light sources, the target light source corresponding to a target zone of the plurality of zones;

wherein determining the backlight value for the target light source comprises:

determining local brightness values of respective subzones of the target zone based on the input image; and

determining the backlight value for the target light source based on the local brightness values of the subzones of the target zone;

wherein determining the local brightness values of the respective subzones comprises:

selecting target parts of the input image for the respective subzones of the target zone:

filtering the target parts to generate filtered image parts for the respective subzones; and

determining the local brightness values of the respective subzones based on the filtered image parts.

2. The display device of claim 1 , wherein the plurality of zones have a substantially rectangular shape that extends in the second direction; and

wherein the subzones have a substantially square shape.

3. The display device of claim 1 , wherein determining the local brightness values of the respective subzones comprises:

calculating average picture levels (APL) of the respective filtered image parts; and

determining the local brightness values of the respective subzones based on the APLs.

4. The display device of claim 1 , wherein filtering the target parts comprises applying filter coefficients to pixel luminance levels of pixels of the target parts of the input image:

wherein the filter coefficients applied to the pixel luminance levels of the pixels of a respective one of the target parts selected for a respective one of the subzones are defined depending on respective distances between the pixels of the respective one of the target parts and a center of the respective one of the subzones.

5. The display device of claim 1 , wherein determining the backlight value for the target light source further comprises:

averaging the local brightness values determined for respective combinations of two or more adjacent ones of the subzones to determine averaged local brightness values; and

determining the backlight value for the target light source based on the averaged local brightness values.

6. The display device of claim 5 , wherein determining the backlight value for the target light source is based on a maximum value of the averaged local brightness values.

7. The display device of claim 1 , further comprising:

a light guide plate having a major surface attached to a rear surface of the display panel;

wherein the plurality of light sources is attached to a side face of the light guide plate.

8. A display driver, comprising:

a driver circuit configured to drive a display panel based on an input image, wherein the display panel is illuminated by a backlight device comprising a plurality of light sources aligned in a first direction and configured to illuminate a plurality of zones of the display panel, respectively, each of the plurality of zones comprising a plurality of subzones aligned in a second direction perpendicular to the first direction; and

a backlight control circuit configured to determine a backlight value for a target light source of the plurality of light sources, the target light source corresponding to a target zone of the plurality of zones:

wherein determining the backlight value for the target light source comprises:

determining local brightness values of respective subzones of the target zone based on the input image; and

determining the backlight value for the target light source based on the local brightness values of the subzones of the target zone;

wherein determining the local brightness values of the respective subzones comprises:

selecting target parts of the input image for the respective subzones of the target zone;

filtering the target parts to generate filtered image parts for the respective subzones; and

determining the local brightness values of the respective subzones based on the filtered image parts.

9. The display driver of claim 8 , wherein the plurality of zones have a substantially rectangular shape that extends in the second direction; and

wherein the subzones have a substantially square shape.

10. The display driver of claim 8 , wherein filtering the target parts comprises applying filter coefficients to pixel luminance levels of pixels of the target parts of the input image;

wherein the filter coefficients applied to the pixel luminance levels of the pixels of a respective one of the target parts selected for a respective one of the subzones are defined depending on respective distances between the pixels of the respective one of the target parts and a center of the respective one of the subzones.

11. The display driver of claim 8 , wherein determining the backlight value for the target light source further comprises:

averaging the local brightness values determined for respective combinations of two or more adjacent ones of the subzones to determine averaged local brightness values; and

determining the backlight value for the target light source based on the averaged local brightness values.

12. The display driver of claim 11 , wherein determining the backlight value for the target light source is based on a maximum value of the averaged local brightness values.

13. The display driver of claim 8 , wherein the backlight control circuit comprises a memory configured to store the local brightness values of the respective subzones of the target zone.

14. The display driver of claim 13 , wherein the driver circuit is further configured to drive a second display panel based on a second input image, the second display panel comprising a plurality of second zones arrayed in rows and columns, the plurality of second zones being illuminated by a plurality of second light sources, respectively; and

wherein the backlight control circuit is further configured to:

determine second local brightness values of the plurality of second zones, respectively, based on the second input image;

store the second local brightness values in the memory; and

determine second backlight values for the plurality of second light sources based on the second local brightness values.

15. A method, comprising:

illuminating, by a display device comprising a plurality of light sources, a plurality of zones of a display panel, wherein the plurality of light sources respectively illuminate the plurality of zones, wherein the plurality of zones are aligned in a first direction, and wherein each of the plurality of zones comprises a plurality of subzones aligned in a second direction perpendicular to the first direction;

receiving, by the display device, an input image; and

determining, by the display device, a backlight value for a target light source of the plurality of light sources, the target light source corresponding to a target zone of the plurality of zones:

wherein determining the backlight value for the target light source comprises:

determining local brightness values of respective subzones of the target zone based on the input image; and

determining the backlight value for the target light source based on the local brightness values of the subzones of the target zone;

wherein determining the local brightness values of the respective subzones comprises:

selecting target parts of the input image for the respective subzones of the target zone;

filtering the target parts to generate filtered image parts for the respective subzones; and

determining the local brightness values of the respective subzones based on the filtered image parts.

16. The method of claim 15 , wherein the plurality of zones have a substantially rectangular shape that extends in the second direction; and

wherein the subzones have a substantially square shape.

17. The method of claim 15 , wherein determining the backlight value for the target light source further comprises:

averaging the local brightness values determined for respective combinations of two or more adjacent ones of the subzones to determine averaged local brightness values; and

determining the backlight value for the target light source based on the averaged local brightness values.

18. The method of claim 17 , wherein determining the backlight value for the target light source is based on a maximum value of the averaged local brightness values.

19. The method of claim 15 , wherein determining the local brightness values of the respective subzones comprises:

calculating average picture levels (APL) of the respective filtered image parts; and

determining the local brightness values of the respective subzones based on the APLs.

20. The method of claim 15 , wherein filtering the target parts comprises applying filter coefficients to pixel luminance levels of pixels of the target parts of the input image;

wherein the filter coefficients applied to the pixel luminance levels of the pixels of a respective one of the target parts selected for a respective one of the subzones are defined depending on respective distances between the pixels of the respective one of the target parts and a center of the respective one of the subzones.

Assignments (1)

Continuity (1)

References Cited (31)