DISPLAY DEVICE CONTROL

• US 20140168288A1
• Filed: 02/21/2014
• Published: 06/19/2014
• Est. Priority Date: 08/22/2011
• Status: Active Grant

• Current Assignee: Arm Ltd. (United Kingdom) (SoftBank Group Corp.)
• Original Assignee: Apical Limited (SoftBank Group Corp.)
• Inventors: TUSCH, Michael
• Granted Patent: US 9,489,920 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: G09G 5/10 Intensity circuits

Abstract

A method of controlling in a display device screen brightness and strength of dynamic range compression of display data in dependence on ambient light level. Ambient light level values are required from one or more ambient light sensors. The ambient light level values are averaged using a first method to obtain a first average value and using a second, different method to obtain a second average value. The first average value is used for controlling the screen brightness and the second average value is used for controlling the strength of the dynamic range compression.

Claims

1. A method of controlling in a display device screen brightness and strength of dynamic range compression of display data in dependence on ambient light level, the method comprising:

acquiring ambient light level values from one or more ambient light sensors;

averaging the ambient light level values using a first method to obtain a first average value;

averaging the ambient light level values using a second, different method to obtain a second average value;

using the first average value to control the screen brightness; and

using the second average value to control the strength of the dynamic range compression.

2. The method of claim 1, wherein the first method uses a first temporal averaging, and wherein the second method uses a second, different temporal averaging.

3. The method of claim 2, wherein the first temporal average is over a longer period than the second temporal average.

4. The method of claim 2, wherein the first and/or second temporal averaging uses moving window averaging.

5. The method of claim 2, wherein an averaging window is reset when at least one of one or more latest acquired ambient light levels deviates from a current first or second average value by more than a predetermined threshold value.

6. The method of claim 3, wherein an averaging window is reset when at least one of one or more latest acquired ambient light levels deviates from a current first or second average value by more than a predetermined threshold value.

7. The method of claim 4, wherein an averaging window is reset when at least one of one or more latest acquired ambient light levels deviates from a current first or second average value by more than a predetermined threshold value.

8. The method of claim 2, wherein the second temporal averaging uses recursive averaging.

9. The method of claim 1, wherein acquiring ambient light level values from one or more ambient light sensors comprises acquiring ambient light level values from a plurality of ambient light sensors, and wherein the first method forms a first weighted average over the plurality of ambient light sensors and the second method forms a second, different weighted average over the plurality of ambient light sensors.

10. The method of claim 9, wherein the first weighted average weights equally over the plurality of ambient light sensors.

11. The method of claim 9, wherein the second weighted average weights more heavily towards those of the plurality of ambient light sensors that face in the same direction as a front of the display device.

12. The method of claim 1, wherein the dynamic range compression is locally adaptive.

13. The method of claim 5, wherein the dynamic range compression is locally adaptive.

14. The method of claim 6, wherein the dynamic range compression is locally adaptive.

15. The method of claim 7, wherein the dynamic range compression is locally adaptive.

16. The method of claim 9, wherein the dynamic range compression is locally adaptive.

17. A display control system for controlling screen brightness and strength of dynamic range compression of display data in a display device based on ambient light level, the display control system comprising:

a processing component configured to;

acquire ambient light level values from one or more ambient light sensors;

average the ambient light level values using a first method to obtain a first average value;

average the ambient light level values using a second, different method to obtain a second average value;

use the first average value for controlling the screen brightness; and

use the second average value for controlling the strength of the dynamic range compression.

18. A computer-readable medium comprising computer-executable instructions, which, when executed by a processor, cause a computing device to perform a method of controlling in a display device screen brightness and strength of dynamic range compression of display data in dependence on ambient light level, the method comprising:

acquiring ambient light level values from one or more ambient light sensors;

averaging the ambient light level values using a first method to obtain a first average value;

averaging the ambient light level values using a second, different method to obtain a second average value;

using the first average value for controlling the screen brightness; and

using the second average value for controlling the strength of the dynamic range compression.

19. A system for controlling screen brightness and strength of dynamic range compression of display data based on ambient light level, the system comprising:

a display device; and

a processing component configured to;

acquire ambient light level values from one or more ambient light sensors;

average the ambient light level values using a first method to obtain a first average value;

average the ambient light level values using a second, different method to obtain a second average value;

use the first average value for controlling the screen brightness on the display device; and

use the second average value for controlling the strength of the dynamic range compression on the display device.