LCD plateau power conservation

• US 20050270265A1
• Filed: 05/04/2005
• Published: 12/08/2005
• Est. Priority Date: 07/16/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Honeywood Technologies LLC
• Inventors: Plut, William J.
• Granted Patent: US 7,663,597 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G06F 1/3218 of display devices
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0686 with two or more screen areas displaying information with different brightness or colours
• CPC Class Codes: G09G 2330/022 in absence of operation, e.g. no data being entered during a predetermined time
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• 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: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Described herein are power conservation systems and methods that reduce power consumption for an electronics device including a liquid crystal display (LCD). The LCD includes a backlight that offers multiple luminance levels, where each level consumes a different amount of power. The systems and methods alter video information while the backlight remains at a backlight luminance level. The alteration reduces luminance for the video information to produce new video information that can be presented at a lower backlight luminance level. Change to the lower backlight luminance level may then occur without significantly affecting aggregate luminance of the new video information, as perceived by a user. The LCD and electronics device consume less power at the lower luminance level.

Claims

1. A method for reducing power consumed by an electronics device that includes a liquid crystal display device, the method comprising:

altering video information for output on the liquid crystal display device to produce altered video information while a backlight included in the liquid crystal display device provides light at a first backlight luminance level, wherein the altered video information includes a high luminance limit that is less than or about equal to a second backlight luminance level offered by the backlight; and

changing the backlight to the second backlight luminance level.

2. The method of claim 1 wherein the alteration includes a progression of multiple alterations and a final alteration in the progression includes the high luminance limit.

3. The method of claim 2 wherein each alteration in the progression produces a difference between the altered video information and the video information that is not readily noticeable to a viewer.

4. The method of claim 1 wherein the alteration includes manipulating information included in a histogram for the video information.

5. The method of claim 4 wherein the histogram manipulation includes a histogram shift or a histogram compression.

6. The method of claim 1 further comprising subsequently altering the altered video information to produce secondly altered video information while the backlight is at the second backlight luminance level, wherein the secondly altered video information includes a second high luminance limit that is less than or about equal to a third backlight luminance level offered by the backlight.

7. The method of claim 1 further comprising increasing transmissivity of altered video information when the backlight changes to the second backlight luminance level.

8. The method of claim 7 wherein an aggregate luminance formed by combining the first backlight luminance level and the new high luminance limit is about equal to or less than a new aggregate luminance formed by the second backlight luminance level and an original luminance of the video information that was altered to produce the new high luminance limit.

9. The method of claim 1 wherein the liquid crystal display device offers five or more backlight luminance levels.

10. The method of claim 1 wherein the video information and the altered video information are represented according to an HSL scheme and further comprising converting the altered video information to RGB values.

11. The method of claim 1 wherein the electronics device is one of a desktop computer, laptop computer, a handheld computer, a portable phone or a portable music player.

12. A method for reducing power consumed by an electronics device that includes a liquid crystal display device, the method comprising:

reducing transmissivity of video information for output on the liquid crystal display device to produce altered video information while a backlight included in the liquid crystal display device provides light at a first backlight luminance level, wherein the altered video information includes a new maximum luminance that is less than or about equal to a second backlight luminance level offered by the backlight;

changing the backlight to the second backlight luminance level, which consumes less power than the first backlight luminance level; and

increasing transmissivity of altered video information.

13. The method of claim 12 wherein the alteration includes a progression of multiple alterations and a final alteration in the progression includes the new maximum luminance.

14. The method of claim 13 wherein each alteration in the progression produces a difference between the altered video information and the video information that is not readily noticeable to a viewer.

15. The method of claim 12 wherein the alteration includes manipulating information included in a histogram for the video information.

16. The method of claim 12 wherein increasing transmissivity of altered video information occurs about when the backlight changes to the second backlight luminance level.

17. The method of claim 16 wherein an aggregate luminance formed by combining the first backlight luminance level and the new maximum luminance is about equal to or less than a new aggregate luminance formed by the second backlight luminance level and an original luminance of the video information that was altered to produce the new maximum luminance.

18. The method of claim 12 further comprising subsequently altering the altered video information to produce secondly altered video information while the backlight is at the second backlight luminance level, wherein the secondly altered video information includes a second new maximum luminance that is less than or about equal to a third backlight luminance level offered by the backlight.

19-25. -25. (canceled)

26. A computer readable medium including instructions for reducing power consumed by an electronics device that includes a liquid crystal display device, the computer-readable medium comprising:

instructions for altering video information for output on the liquid crystal display device to produce altered video information while a backlight included in the liquid crystal display device provides light at a first backlight luminance level, wherein the altered video information includes a high luminance limit that is less than or about equal to a second backlight luminance level offered by the backlight; and

instructions for changing the backlight to the second backlight luminance level.

28. The computer readable medium of claim 26 wherein the alteration includes manipulating information included in a histogram for the video information.

27. (canceled)

29. (canceled)

30-38. -38. (canceled)