IP Library Granted Patent US 7,253,845
Granted Patent B2
US 7,253,845 · App. 10/142,573 · Granted Aug 7, 2007

Color non-uniformity correction for LCOS

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Quick Facts
Patent No.
US 7,253,845
App. No.
10/142,573
Granted
Aug 7, 2007
Kind
B2
Abstract

A method ( 400 ) and a system ( 100 ) for providing video signals to video displays includes the steps of receiving at least one input video signal ( 150 ), dithering the non-uniformity color correction ( 445 ), applying the non-uniformity color correction to the input video signal to generate a color corrected video signal ( 450 ), and increasing a frame rate of the color corrected video signal ( 120 ). Gamma correction ( 125 ) can be applied to the color correction. Generating a dithered non-uniformity color correction can include selecting from a data storage ( 115 ) a plurality of RGB correction matrices ( 300 ), measuring at least one brightness level of the input video signal, selecting for the picture level correction a first RGB correction matrix if the brightness is within a first range of values ( 425 ), a second RGB correction matrix if the brightness is within a second range of values ( 435 ), and interpolating ( 440 ) the plurality of RGB correction matrices if the brightness is within a third range of values.

Claims (60)

1. A method for color correcting video signals in video displays, comprising the steps of:

receiving at least one input video signal;

generating a dithered non-uniformity color correction;

applying said dithered non-uniformity color correction to said input video signal to generate a color corrected video signal; and

increasing a frame rate of said color corrected video signal.

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

following the frame rate increase step, applying a gamma correction to said color corrected video signal to generate an output video signal; and

providing said output video signal to a light engine of a liquid crystal on silicon video display.

3. The method of claim 1 , wherein said step of generating the dithered non-uniformity color correction comprises:

selecting from a data storage a plurality of RGB correction matrices;

deriving a picture level correction from said plurality of RGB correction matrices; and

dithering said picture level correction.

4. The method of claim 3 , wherein said deriving the picture level correction step comprises:

measuring at least one brightness level of said input video signal; and

interpolating said picture level from said plurality of RGB correction matrices based at least upon said at least one brightness level.

5. The method of claim 3 , wherein said deriving the picture level correction step comprises:

measuring at least one brightness level of said input video signal; and

selecting for said picture level correction at least one of said plurality of RGB correction matrices based at least upon said at least one brightness level.

6. The method of claim 3 , wherein said deriving the picture level correction step comprises:

measuring at least one brightness level of said input video signal;

selecting for said picture level correction a first RGB correction matrix if said brightness level is within a first range of values; and

selecting for said picture level correction a second RGB correction matrix if said brightness level is within a second range of values.

7. The method of claim 6 , wherein said deriving the picture level correction step further comprises interpolating said picture level from said plurality of RGB correction matrices if said brightness level is within a third range of values.

8. The method of claim 3 , further comprising the step of applying horizontal and vertical pixel interpolation on said RGB correction matrices after said selecting the plurality of RGB correction matrices step.

9. The method of claim 1 , wherein said applying said dithered non-uniformity color correction to said input video signal step comprises adding said dithered non-uniformity color correction to said input video signal.

10. The method of claim 1 , wherein said applying said dithered non-uniformity color correction to said input video signal step comprises multiplying said input video signal by said dithered non-uniformity color correction.

11. The method of claim 1 , wherein said step of generating a dithered non-uniformity color correction comprises:

selecting from a data storage at least one RGB correction matrix;

applying horizontal and vertical pixel interpolation on said RGB correction matrix to generate a pixel interpolated RGB correction matrix;

deriving a picture level correction from said pixel interpolated RGB correction matrix; and

dithering said picture level correction.

12. A method for color correcting video signals in video displays, comprising the steps of:

receiving at least one input video signal;

generating a non-uniformity color correction;

applying said non-uniformity color correction to said input video signal to generate a color corrected video signal; and

increasing a frame rate of said color corrected video signal by generating frames of opposite polarities for each color corrected frame of video.

13. A system for color correcting video signals for video displays, comprising:

a video input for receiving at least one input video signal;

a color non-uniformity corrector for generating a color corrected video signal; and

a frame rate increaser for increasing the frame rate of said color corrected video signal by generating frames of opposite polarities for each color corrected frame of video.

14. The system of claim 13 , further comprising a gamma corrector for applying gamma correction to said color corrected video signal.

15. The system of claim 13 , wherein said color non-uniformity corrector comprises:

a correction generator for generating a non-uniformity color correction signal;

a ditherer for dithering said non-uniformity color correction signal; and

a processor for incorporating said non-uniformity color correction into said at least one input video signal to generate a color corrected video signal.

16. The system of claim 15 wherein said processor is an adder.

17. The system of claim 15 wherein said processor is a multiplier.

18. The system of claim 15 further comprising at least one data storage for storing a plurality of RGB correction matrices.

19. The system of claim 18 wherein said at least one data storage comprises at least one EEPROM.

20. The system of claim 15 further comprising at least one horizontal and vertical interpolator for performing pixel interpolation on said RGB correction matrices.

21. The system of claim 15 wherein said correction generator comprises:

a brightness detector for detecting the brightness of said input video signal and outputting a brightness level measurement; and

a soft switch for receiving said brightness level measurement and generating a color correction based on said brightness level measurement.

22. The system of claim 21 further comprising:

at least one of a data storage and a horizontal and vertical interpolator;

wherein said soft switch receives at least one RGB correction matrix from at least one of said data storage and said horizontal and vertical interpolator and generates said color correction from said at least one RGB correction matrix.

23. The system of claim 22 wherein:

said soft switch selects a first RGB correction matrix if said brightness measurement level is within a first range of values:

said soft switch selects a second RGB correction matrix if said brightness measurement level is within a second range of value; and

said soft switch interpolates a plurality of RGB correction matrices if said brightness measurement level is within a third range of values.

Assignments (2)
CORRECTIVE ASSIGNMENT TO CORRECT THE RECEIVING PARTY NAME FROM INTERDIGITAL CE PATENT HOLDINGS TO INTERDIGITAL CE PATENT HOLDINGS, SAS. PREVIOUSLY RECORDED AT REEL: 47332 FRAME: 511. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Feb 28, 2024
From: THOMSON LICENSING
To: INTERDIGITAL CE PATENT HOLDINGS, SAS
Reel/Frame 066703/0509 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 26, 2018
From: THOMSON LICENSING
To: INTERDIGITAL CE PATENT HOLDINGS
Reel/Frame 047332/0511 →