LCD plateau power conservation

• US 9,135,884 B2
• Filed: 02/15/2010
• Issued: 09/15/2015
• Est. Priority Date: 07/16/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Plut, William J.
• Primary Examiner(s): Elahi, Towfiq
• Application Number:
  US12/705,929
• Publication Number:
  US 20100141635A1
• Time in Patent Office: 2,038 Days
• Field of Search: 345/102, 345/690
• US Class Current: 1/1
• 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:

identifying whether an inactive time reaches a predetermined threshold inactivity time to determine when alteration to video information begins;

altering the video information at preset alteration intervals 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;

changing the backlight to a second backlight luminance level;

increasing transmissivity of the altered video information when the backlight changes to the second backlight luminance level; and

determining a rate of the alteration of the video information by dividing a total alteration of the video information over a period of time by a number of intervals over the period of time,

wherein an aggregate output luminance formed by combining the first backlight luminance level and the altered video information is equal to or less than a new aggregate output luminance formed by the second backlight luminance level and the video information that was altered to produce a new maximum luminance.

2. The method of claim 1 wherein the alteration includes a progression of multiple alterations and a final alteration in the progression produces the altered video information.

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

4. 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.

5. The method of claim 1 further comprising:

subsequently altering the video information to produce secondly altered video information while the backlight is at the second backlight luminance level;

changing the backlight to a third backlight luminance level; and

increasing transmissivity of the secondly altered video information when the backlight changes to the third backlight luminance level.

6. The method of claim 5 wherein a third aggregate output luminance formed by combining the second backlight luminance level and the secondly altered video information is equal to or less than a fourth aggregate output luminance formed by the third backlight luminance level and the video information that was altered to produce the secondly altered video information.

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

a monitoring apparatus designed or configured to monitor user activity in a display area for the liquid crystal display device; and

a power conservation apparatus designed or configured to a) determine whether user activity information is received through the monitoring apparatus, b) identify whether an inactive time reaches a predetermined threshold inactivity time to determine when alteration to video information begins, c) alter the video information at preset alteration intervals 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, d) increase transmissivity of the altered video information when the backlight changes to a second backlight luminance level, and e) determine a rate of the alteration of the video information by dividing a total alteration of the video information over a period of time by a number of intervals over the period of time,

wherein an aggregate output luminance formed by combining the first backlight luminance level and the altered video information is equal to or less than a new aggregate output luminance formed by the second backlight luminance level and the video information that was altered to produce a new maximum luminance.

8. The system of claim 7 wherein the power conservation apparatus comprises a power conservation control designed or configured to determine the alteration to the video information according to stored power conservation instructions, and to output a signal indicative of the alteration.

9. The system of claim 7 wherein the power conservation apparatus further comprises a video adaptor designed or configured to receive the signal produced by the power conservation control and to alter the video information based on the signal.

10. The system of claim 7 wherein the power conservation apparatus is further designed or configured to:

d) subsequently alter the video information to produce secondly altered video information while the backlight is at the second backlight luminance level;

e) change the backlight to a third backlight luminance level; and

f) increase transmissivity of secondly altered video information when the backlight changes to the third backlight luminance level.

11. The system of claim 10 wherein a third aggregate output luminance formed by combining the second backlight luminance level and the secondly altered video information is equal to or less than a fourth aggregate output luminance formed by the third backlight luminance level and the video information that was altered to produce the secondly altered video information.

12. An electronics device comprising:

a liquid crystal display device that includes a backlight offering multiple backlight luminance levels, wherein the liquid crystal display device changes power consumption with each backlight luminance level; and

a power conservation apparatus designed or configured to a) identify whether an inactive time reaches a predetermined threshold inactivity time to determine when alteration to video information begins, b) alter video information at preset alteration intervals 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, c) increase transmissivity of the altered video information when the backlight changes to a second backlight luminance level, and d) determine a rate of the alteration of the video information by dividing a total alteration of the video information over a period of time by a number of intervals over the period of time,

wherein an aggregate output luminance formed by combining the first backlight luminance level and the altered video information is equal to or less than a new aggregate output luminance formed by the second backlight luminance level and the video information that was altered to produce a new maximum luminance.

13. The electronics device of claim 12 wherein the electronics device is one of a desktop computer, laptop computer, a handheld computer, a portable phone or a portable music player.

14. The electronics device of claim 12 the difference between the aggregate output luminance and the new aggregate output luminance is not readily noticeable to a viewer.

15. The electronics device of claim 12 wherein the liquid crystal display device offers five or more backlight luminance levels.

16. The electronics device of claim 12 wherein the power conservation apparatus increases transmissivity of the altered video information to return to the video information that was present before alteration.

17. The electronics device of claim 12 wherein the power conservation apparatus is further designed or configured to:

c) subsequently alter the video information to produce secondly altered video information while the backlight is at the second backlight luminance level;

d) change the backlight to a third backlight luminance level; and

e) increase transmissivity of altered video information when the backlight changes to the third backlight luminance level.

18. The electronics device of claim 17, wherein a third aggregate output luminance formed by combining the second backlight luminance level and the secondly altered video information is equal to or less than a fourth aggregate output luminance formed by the third backlight luminance level and the video information that was altered to produce the secondly altered video information.