Display Uniformity Correction Method and System

• US 20080068293A1
• Filed: 09/19/2006
• Published: 03/20/2008
• Est. Priority Date: 09/19/2006
• Status: Abandoned Application

• Current Assignee: Tvia, Inc.
• Original Assignee: Tvia, Inc.
• Inventors: Ishii, Takatoshi
• Application Number:
  US11/533,277
• Publication Number:
  US 20080068293A1
• Time in Patent Office: Days
• US Class Current: 345/3.1
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers

Abstract

A method and system are provided for correcting non-uniformity of a display device having a display screen comprising a pixel matrix. Aspects the exemplary embodiment include in response to receiving display data for display, reading from a memory of the display device compensation data stored for a subset of pixel locations on the display screen, the compensation data configured to correct non-uniformity characteristics of the display screen; interpolating the compensation data to generate uniformity correction data; overlaying the display data with the uniformity correction data to produce uniformity corrected display data; and outputting the uniformity corrected display data for subsequent display.

Claims

1. A method of correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

in response to receiving display data for display, reading from a memory of the display device compensation data stored for a subset of pixel locations of the display screen, the compensation data configured to correct non-uniformity characteristics of the display screen;

interpolating the compensation data to generate uniformity correction data;

overlaying the display data with the uniformity correction data to produce uniformity corrected display data; and

outputting the uniformity corrected display data for subsequent display.

2. The method of claim 1 wherein storing of the compensation data is performed during a configuration stage comprising:

measuring non-uniformity characteristics of the display screen;

determining compensation data for correcting the non-uniformity characteristics;

dividing the pixel matrix into a pixel grid of rows and columns, wherein points at row and column intersections of the pixel grid are used to define shapes that encompass multiple pixels;

compressing the compensation data by storing in a memory of the display the compensation data for the points of the pixel grid defining the shapes.

3. The method of claim 2 wherein the compensation data for the points of the pixel grid are stored as differential values, wherein the differential values are differences between the compensation data values between adjacent points.

4. The method of claim 1 wherein the subset of pixel locations define a matrix of shapes across the display screen, wherein at least a portion of the shapes encompass multiple rows and columns of pixel locations on the display.

5. The method of claim 2 wherein in response to receiving a current pixel location from the display data, reading from the memory the compensation data corresponding to the shape encompassing the current pixel location, and interpolating the compensation data to generate uniformity correction data for the current pixel location.

6. The method of claim 4 wherein the matrix of shapes comprises a pixel grid of blocks defined by row and column intersections of the display screen.

7. The method of claim 1 further comprising generating at least one of gain uniformity correction data for correcting premeasured gain error of a display screen, bias uniformity correction data for correcting premeasured bias error of the display screen, and black level uniformity correction data for correcting premeasured backlight leakage of the display screen.

8. The method of claim 7 further comprising summing display data with the gain uniformity correction data, the bias uniformity correction data, and the black level uniformity correction data to produce the uniformity corrected display data.

9. The method of claim 1 wherein a data width of the uniformity corrected display data is wider than a data width of the display data.

10. The method of claim 9 further comprising inputting the display data to a gamma lookup table that outputs gamma corrected data display data that is wider than the data width of the display data, and inputs the gamma corrected data display data to the display uniformity controller.

11. The method of claim 10 further comprising inputting the uniformity corrected display data to a frame rate controller that reduces the data width of the uniformity corrected display data to match the data width of the display data prior to display.

12. A controller for correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

a memory for storing compensation data, the compensation data stored for a subset of pixel locations of the display screen and configured to correct non-uniformity characteristics of the display screen;

means responsive to receiving display data for reading the compensation data from the memory;

means for interpolating the compensation data to generate uniformity correction data; and

means for overlaying the display data with the uniformity correction data to produce uniformity corrected display data, and for outputting the uniformity corrected display data for subsequent display.

13. A display uniformity controller, comprising:

a gain uniformity correction generator for generating gain uniformity correction data for correcting premeasured gain error of a display screen;

a bias uniformity correction generator for generating bias uniformity correction data for correcting premeasured bias error of the display screen;

a black level correction generator for generating black level uniformity correction data for correcting premeasured backlight leakage of the display screen; and

an adder coupled to the gain uniformity correction generator, the bias uniformity correction generator, and the black level correction generator for summing display data to be displayed on the display screen with the gain uniformity correction data, the bias uniformity correction data, and the black level uniformity correction data to produce uniformity corrected display data.

14. The display uniformity controller of claim 13 wherein a data width of the uniformity corrected display data is wider than a data width of the display data.

15. The display uniformity controller of claim 13 wherein the display data is input to a gamma lookup table, which outputs gamma corrected data display data that is wider than the data width of the display data, and inputs the gamma corrected data display data to the display uniformity controller.

16. The display uniformity controller of claim 15 wherein a frame rate controller is used to reduce the data width of the uniformity corrected display data to match the data width of the display data prior to display.

17. The display uniformity controller of claim 13 wherein the gain uniformity correction generator generates the gain uniformity correction data through a multiplication operation.

18. The display uniformity controller of claim 13 wherein the bias uniformity correction generator generates the bias uniformity correction data through an addition/subtraction operation.

19. The display uniformity controller of claim 13 wherein the black level correction generator generates the black level uniformity correction data through a multiplication operation.

20. The display uniformity controller of claim 13 wherein the uniformity corrected display data is generated through a combination of multiplication and addition/subtraction operations.

21. The display uniformity controller of claim 13 further comprising at least one memory for storing compensation data for a subset of pixel locations on the display screen, the compensation data configured to correct non-uniformity characteristics of the display screen, wherein the gain uniformity correction generator, the bias uniformity correction generator, and the black level correction generator perform interpolation on the compensation data to generate the gain uniformity correction data, the bias uniformity correction data, and the black level uniformity correction data, respectively.

22. The display uniformity controller of claim 21 wherein the compensation data is complementary data to non-uniformities of the display screen.

23. The display uniformity controller of claim 21 wherein the compensation data comprises gray data common to separate red, green, and blue data in the display data.

24. The display uniformity controller of claim 21 wherein the compensation data comprises red, green, and blue data corresponding to red, green, and blue data in the display data, respectively.

25. The display uniformity controller of claim 21 wherein the subset of pixel locations define a matrix of shapes across the display screen, wherein at least a portion of the shapes encompass multiple rows and columns of pixel locations on the display screen.

26. The display uniformity controller of claim 25 wherein the matrix of shapes comprises a pixel grid of blocks defined by row and column intersections of the display screen.

27. The display uniformity controller of claim 25 wherein in response to receiving a current pixel location from the display data, the compensation data corresponding to the shape encompassing the current pixel location is read from the memory and used for the interpolation.

28. The display uniformity controller of claim 21 wherein the memory comprises separate memories including a first memory accessed by the gain uniformity correction generator for storing gain compensation data, a second memory accessed by the bias uniformity correction generator for storing bias compensation data, and a third memory accessed by the black level correction generator for storing black level compensation data.

29. A method of correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

in response to receiving display data for display, reading from a memory of the display device compensation data stored for a subset of pixel locations of the display screen, the compensation data configured to correct non-uniformity characteristics of the display screen;

overlaying the display data with the compensation data to produce uniformity corrected display data;

performing dithering on the uniformity corrected display data to produce spatial and temporal energy across frames; and

outputting the dithered uniformity corrected display data for subsequent display.

30. The method of claim 29 further comprising interpolating the compensation data to generate uniformity correction data and overlaying the display data with the uniformity correction data to produce the produce uniformity corrected display data.

31. A system for correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

a memory for storing compensation data, the compensation data stored for a subset of pixel locations of the display screen and configured to correct non-uniformity characteristics of the display screen;

means responsive to receiving display data for reading the compensation data from the memory;

means for overlaying the display data with the uniformity correction data to produce uniformity corrected display data;

means for performing dithering on the uniformity corrected display data to produce spatial and temporal energy across frames; and

means for outputting the dithered uniformity corrected display data for subsequent display.

32. The system of claim 31 further comprising means for interpolating the compensation data to generate the uniformity correction data, and for overlaying the display data with the uniformity correction data to produce the produce uniformity corrected display data.

33. A method of correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

in response to receiving display data for display, reading from a memory of the display device compensation data stored for a subset of pixel locations of the display screen, the compensation data configured to correct non-uniformity characteristics of the display screen;

generating black level uniformity correction data from the compensation data for correcting premeasured backlight leakage of the display screen;

overlaying the display data with the black level uniformity correction data to produce uniformity corrected display data; and

outputting the uniformity corrected display data for subsequent display.

34. The method of claim 33 further comprising generating black level uniformity correction data by interpolating the compensation data.

35. The method of claim 33 further comprising performing dithering on the uniformity corrected display data to produce spatial and temporal energy across frames;

and outputting the dithered uniformity corrected display data for display.

36. A system for correcting non-uniformity of a display device having a display screen comprising a pixel matrix, comprising:

a memory for storing compensation data, the compensation data stored for a subset of pixel locations of the display screen and configured to correct non-uniformity characteristics of the display screen;

means responsive to receiving display data for reading the compensation data from the memory;

means for generating black level uniformity correction data from the compensation data for correcting premeasured backlight leakage of the display screen;

means for overlaying the display data with the black level uniformity correction data to produce uniformity corrected display data;

means for performing dithering on the uniformity corrected display data to produce spatial and temporal energy across frames; and

means for outputting the dithered uniformity corrected display data for subsequent display.

37. A method of correcting non-uniformity of a display device having a display screen, comprising:

measuring non-uniformity characteristics of the display screen, the display screen comprising a pixel matrix;

determining compensation data for correcting the non-uniformity characteristics;

dividing the pixel matrix into a pixel grid of rows and columns, wherein points at row and column intersections of the pixel grid are used to define blocks, each having four grid points, and at least a portion of the blocks encompass multiple pixels;

compressing the compensation data by storing in a memory of the display the compensation data for the points of the pixel grid defining the blocks;

in response to receiving display data for display, reading from the memory the compensation data for the grid points of the block encompassing a current pixel location;

decompressing the compensation data by interpolating the compensation data read from the memory to generate uniformity correction data for the current pixel position;

overlaying the display data with the uniformity correction data to produce uniformity corrected display data; and

outputting the uniformity corrected display data for subsequent display.