Method and system for compensating for defects in a multi-light valve display system

• US 6,359,662 B1
• Filed: 11/05/1999
• Issued: 03/19/2002
• Est. Priority Date: 11/05/1999
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Walker, Richard C.
• Primary Examiner(s): Lee, Michael
• Assistant Examiner(s): Yenke, Brian P.
• Application Number:
  US09/435,094
• Time in Patent Office: 865 Days
• Field of Search: H04/N.574, H04/N.902, 348/750, 348/758, 348/742, 348/743, 348/754, 348/615, 348/616, 348/617
• US Class Current: 348/743
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 2330/10 Dealing with defective pixels
• CPC Class Codes: G09G 3/34 by control of light from an independent source
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources

Abstract

A method and system for compensating for defects in a multi-light valve display allows for the compensation of defective pixels in a display. By sequentially illuminating all light valves in a multi-light valve system with all colors, or wavelengths, available in the display, each light valve modulates the full gamut of colors available in the system. In this manner, the remaining light valves can compensate for a defective pixel in one of the light valves. The invention also includes an active compensation feature, whereby defective pixels in the display are identified and are compensated for by an associated display driver.

Claims

1. A method for operating a display including light valves, each light valve including pixels, the method comprising the steps of:

controlling, during a time period, light of a first color by a first light valve and light of a second color by a second light valve in said display;

shifting, in a subsequent time period, said light of said first color and said light of said second color such that said light of said second color is controlled by said first light valve and said light of said first color is controlled by said second light valve; and

modifying an output of a first pixel associated with said first light valve to compensate for a defective second pixel associated with said second light valve, said first pixel corresponding to said defective second pixel in said display.

2. The method of claim 1, further comprising the step of:

controlling a light of a third color in said time period, such that said light of said first color, said light of said second color and said light of said third color are shifted such that said light of said first color is controlled by said second light valve, said light of said second color is controlled by a third light valve and said light of a third color is controlled by said first light valve.

3. The method of claim 1, wherein over a plurality of said time periods said light of said first color and said light of said second color are each controlled by each of said first light valve and said second light valve.

4. The method of claim 1, further comprising the step of identifying a defective pixel in said display.

5. The method of claim 4, wherein said defective pixel is associated with one of said plurality of light valves.

6. The method of claim 5, further comprising the step of compensating for said defective pixel using a remaining light valve.

7. The method of claim 4, wherein said defective pixel is failed in the off state.

8. The method of claim 4, wherein said defective pixel is failed in the on state.

9. A system for operating a display, the display including light valves, each light valve including pixels, the system comprising:

a first light source for supplying a light of a first color and a second light source for supplying a light of a second color;

a first light valve and a second light valve;

means for illuminating, during a time period, said first light valve with said light of said first color and said second light valve with said light of said second color, wherein in a subsequent time period, said light of said first color and said light of said second color are shifted such that said light of said second color illuminates said first light valve and said light of said first color illuminates said second light valve; and

means for modifying an output of a first pixel associated with said first light valve to compensate for a defective second pixel associated with said second light valve, said first pixel corresponding to said defective second pixel in said display.

10. The system of claim 9, further comprising:

means for controlling a light of a third color in said time period, such that said light of said first color, said light of said second color and said light of said third color are shifted such that said light of said first color illuminates said second light valve, said light of said second color illuminates a third light valve and said light of said third color illuminates said first light valve.

11. The system of claim 9, wherein over a plurality of said time periods said light of said first color and said light of said second color each illuminate each of said first light valve and said second light valve.

12. The system of claim 9, further comprising:

a computer in communication with said illuminating means; and

a device configured to identify and communicate to said computer the location of a defective pixel in said display.

13. The system of claim 12, wherein said defective pixel is associated with one of said light valves.

14. The system of claim 13, further comprising means for compensating for said defective pixel using a remaining light valve.

15. The system of claim 12, wherein said defective pixel is failed in the off state.

16. The system of claim 12, wherein said defective pixel is failed in the on state.