Real-time dynamic design of liquid crystal display (LCD) panel power management through brightness control

• US 20040160435A1
• Filed: 02/14/2003
• Published: 08/19/2004
• Est. Priority Date: 02/14/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Wyatt, David, Cui, Ying, Witter, Todd M., Sadhasivan, Sathyamurthi, Kuchibhotla, Venu M., Jensen, Richard W.
• Granted Patent: US 7,348,957 B2
• Time in Patent Office: Days
• US Class Current: 345/211
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/28 using luminous gas-discharge panels, e.g. plasma panels
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

According to one embodiment of the present invention, a method of power management for a flat panel display is disclosed. The method includes: receiving image data; determining a segment mode for the received image data; selecting a portion of the received image data corresponding to the determined segment mode; accumulating a value of the selected portion of the received image data; comparing the accumulated value to a threshold value; and generating an interrupt signal if the accumulated value exceeds the threshold value.

Claims

1. A power management method comprising:

receiving image data;

determining a segment mode for the received image data;

selecting a portion of the received image data corresponding to the determined segment mode;

accumulating a value of the selected portion of the received image data;

comparing the accumulated value to a threshold value; and

generating an interrupt signal if the accumulated value exceeds the threshold value.

2. The method of claim 1 further including providing the interrupt signal to a software module to control a brightness of a display.

3. The method of claim 2 wherein the software module controls the brightness of the display based on ambient light sensor information.

4. The method of claim 2 wherein the display is selected from a group comprising an LCD, a flat panel display, and a plasma screen.

5. The method of claim 1 wherein the image data is in a format selected from a group comprising RGB and YUV.

6. The method of claim 1 further including calculating a Y function of the received image data prior to the selecting act.

7. The method of claim 6 wherein the Y function for an RGB formatted image data is calculated by:

0.299*R+0.587*G+0.114*B.

8. The method of claim 6 wherein the Y function for an RGB formatted image data is calculated by:

(¼

+{fraction (1/32)}+{fraction (1/64)})*R+(½

+{fraction (1/16)}+{fraction (1/64)}+{fraction (1/128)})*G+(⅛

)*B.

9. The method of claim 1 further including updating a status register at an end of each frame of the received image data.

10. The method of claim 1 wherein the accumulating act is performed by a bank of counters.

11. The method of claim 1 wherein the portion of the received image data encompasses the entire received image data.

13. The computer system of claim 11 wherein the backlight brightness is reduced to achieve a power consumption reduction of about 30% to about 70%.

12. A computer system comprising:

a central processing unit (CPU);

a chipset coupled to the CPU;

a flat panel display to display an image;

a backlight modulation circuit coupled to the flat panel display and the chipset to increase image brightness and reducing backlight brightness to reduce power consumption of the flat panel display.

14. The computer system of claim 12 wherein the backlight modulation circuit includes:

a bank of comparators;

a threshold register and a bank of accumulators coupled to the bank of comparators, the bank of comparators generating an interrupt signal if a value provided by the bank of accumulators exceeds a threshold value provided by the threshold register.

15. The computer system of claim 14 further including a segment mode register to select a portion of received image data to be displayed on the flat panel display.

16. The computer system of claim 12 further including an enable register to enable a generation of an interrupt signal.

17. The computer system of claim 12 further including a mask register to enable a generation of an interrupt signal.

18. The computer system of claim 12 further including a status register to indicate an end of a frame of image data being processed by the backlight modulation circuit.

19. An article of manufacture comprising:

a machine readable medium that provides instructions that, if executed by a machine, will cause the machine to perform operations including;

receiving image data;

determining a segment mode for the received image data;

selecting a portion of the received image data corresponding to the determined segment mode;

accumulating a value of the selected portion of the received image data;

comparing the accumulated value to a threshold value; and

generating an interrupt signal if the accumulated value exceeds the threshold value.

20. The article of claim 19 wherein the operations further include providing the interrupt signal to a software module to control a brightness of a display.

21. The article of claim 20 wherein the software module controls the brightness of the display based on ambient light sensor information.

22. The article of claim 20 wherein the display is selected from a group comprising an LCD, a flat panel display, and a plasma screen.

23. The article of claim 19 wherein the image data is in a format selected from a group comprising RGB and YUV.

24. The article of claim 19 wherein the operations further include calculating a Y function of the received image data prior to the selecting operation.

25. The article of claim 24 wherein the Y function for an RGB formatted image data is calculated by:

0.299*R+0.587*G+0.114*B.

26. The article of claim 24 wherein the Y function for an RGB formatted image data is calculated by:

(¼

+{fraction (1/32)}+{fraction (1/64)})*R+(½

+{fraction (1/16)}+{fraction (1/64)}+{fraction (1/128)})*G+(⅛

)*B.

27. The article of claim 19 wherein the operations further include updating a status register at an end of each frame of the received image data.

28. The article of claim 19 wherein the accumulating operation is performed by a bank of counters.

29. The article of claim 19 wherein the portion of the received image data encompasses the entire received image data.