Display pixel balancing for a multi color discrete level display

• US 5,751,272 A
• Filed: 03/13/1995
• Issued: 05/12/1998
• Est. Priority Date: 03/11/1994
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.), Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Silverbrook, Kia, Naylor, William Clark Jr.
• Primary Examiner(s): LEE, MICHAEL
• Application Number:
  US08/402,507
• Time in Patent Office: 1,156 Days
• Field of Search: 345/149, 345/147, 345/152, 345/43, 345/103, 345/89, 349/144, 349/146, 349/85
• US Class Current: 345/694
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2320/041 Temperature compensation
• CPC Class Codes: G09G 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 2370/045 using multiple communication channels, e.g. parallel and serial
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/364 with use of subpixels
• CPC Class Codes: G09G 3/3681 suitable for passive matrices only
• CPC Class Codes: G09G 3/3692 suitable for passive matrices only
• CPC Class Codes: G09G 5/42 characterised by the display of patterns using a display memory without fixed position correspondence between the display memory contents and the display position on the screen

Abstract

A pixel display includes a pixel pattern containing multiple pixels each of which having multiple primary color sub-regions of illumination. These sub-regions are arranged such that they extend in a first direction substantially from one side of the pixel to the other, and in a second direction, substantially normal to the first direction, they have only a limited extent in the pixel. These sub-regions include a multiple number of illumination areas and are arranged such that the center of illumination is substantially stable with respect to movement in the first direction and is substantially constrained to movement in the second direction.

Claims

1. A display having a pixel pattern comprising a multiplicity of pixels with each pixel having a multiplicity of primary colour sub-regions of illumination each of which further comprises a multiplicity of illumination areas, the illumination areas being able to be set to an illuminating state or a non-illuminating state wherein:

(a) the primary colour sub-regions extend in a first direction substantially from one side of the pixel to the other, but in a second direction substantially normal to the first direction have only a limited extent in the pixel; and

(b) the colour sub-regions are arranged to be able to be illuminated with changing intensity with a centre of illumination which is substantially stable with respect to movement in the first direction and is substantially constrained to movement in the second direction.

2. A display as claimed in claim 1 wherein the multiplicity of primary colours comprises red, blue and green.

3. A display having a pixel pattern comprising a multiplicity of pixels with each pixel having a multiplicity of primary colour sub-regions of illumination each of which further comprises a multiplicity of illumination areas, the illumination areas being able to be set to an illuminating state or a non-illuminating state wherein:

(a) the primary colour sub-regions extend in a first direction substantially from one side of the pixel to the other, but in a second direction substantially normal to the first direction have only a limited extent in the pixel;

(b) the colour sub-regions are arranged to be able to be illuminated with changing intensity with a centre of illumination which is substantially stable with respect to movement in the first direction and is substantially constrained to movement in the second direction and wherein the distance between the centre of illumination of any primary colour sub-region and the centre of illumination of the next adjacent pixel in the first direction is substantially equal to the distance between the centre of illumination of the primary colour sub-region and the centre of illumination of the corresponding primary colour sub-region of the next adjacent pixel in the second direction.

4. A display as claimed in claim 3 wherein the multiplicity of primary colours comprises red, blue and green.

5. A display having a pixel pattern comprising a multiplicity of pixels with each pixel having a multiplicity of primary colour sub-regions of illumination each of which further comprises a multiplicity of illumination areas, the illumination areas being able to be set to an illuminating state or a non-illuminating state wherein:

(a) the primary colour sub-regions extend in a first direction substantially from one side of the pixel to the other but in a second direction substantially normal to the first direction have only a limited extent in the pixel;

(b) the colour sub-regions are arranged to be able to be illuminated with changing intensity with a centre of illumination which is substantially stable with respect to movement in the first direction and is substantially constrained to movement in the second direction and wherein at least one distance between the centre of illumination of any primary colour sub-region and the corresponding primary colour sub-region of any next adjacent pixel is maximized.

6. A display as claimed in claim 5 wherein the multiplicity of primary colours comprises red, blue and green.

7. A method of determining a pixel layout pattern for a discrete level display, the display comprising a multiplicity of pixels, with each pixel including a multiplicity of primary colour sub-regions of illumination and each primary colour sub-region of illumination further comprising a multiplicity of illumination areas with each illumination area setable to an illuminating or a non illuminating state, said method comprising the steps of:

(a) determining a distance measure from the centre of the primary colour sub-region to the centre of each corresponding primary colour sub-region of adjacent next pixels;

(b) determining a minimum of the distance measures;

(c) determining a series of patterns of the illumination areas, each pattern of the series having an optical centre of illumination whose distance remains substantially constant with respect to the corresponding optical centre of illumination of a closest adjacent next primary colour sub-region but whose optical centre is able to move in a normal direction thereto.

8. A pixel layout pattern for a multi colour discrete level display, the display including a multiplicity of pixels, with each pixel including a multiplicity of primary colour sub-regions of illumination and each primary colour sub-region of illumination further comprising a multiplicity of illumination areas, with each illumination being area setable to an illuminating or a non illuminating state, wherein the illumination areas are divided into a series of illumination levels, each illumination level having an optical centre of illumination and wherein a first pixel direction is defined to be the shortest distance from the optical centre of illumination of the primary colour sub-region to the centre of a neighbouring corresponding primary colour sub-region and wherein the optical centre of illumination remains substantially constant for each level with respect to the first direction while the optical centre is able to be moved in a direction substantially normal to the first direction.

9. A pixel layout pattern as claimed in claim 8, wherein the multiplicity of primary colours comprises red, green and blue.

10. A display having a pixel pattern comprising a multiplicity of sub-regions, wherein:

(a) the sub-regions consist of a first sub-region, a second sub-region arranged at one side of a first direction of the first sub-region, a third and a fourth region arranged at both sides of a second direction of either one of the first and the second sub-regions and a fifth and a sixth sub-region arranged at both sides of the second direction of the other of the first and the second sub-regions; and

(b) the ratio of the area of the first sub-region, the second sub-region, the third and the fourth sub-regions together and the fifth and the sixth sub-regions together is 1;

2;

4;

8.

11. A display according to claim 10, wherein the third and the fourth sub-regions are set to an illuminating state or non-illuminating state in response to an image signal.

12. A display according to claim 10, wherein the first and the second sub-regions are on a same first common line.

13. A display according to claim 10, wherein the third and the fourth sub-regions are on a same first segment line, and the fifth and the sixth sub-regions are on a same second segment line.

14. A display according to claim 12 or 13, wherein the third and the fifth sub-regions are on a same second common line, and the fourth and the sixth sub-regions are on a same third common line.

15. A display according to claim 13, wherein the first sub-region is on the first segment line, and the second sub-region is on the second segment line.

16. A display according to claim 10, wherein the display is a liquid crystal display.

17. A colour display where at least two pixel patterns of pixel patterns provided for each colour comprise a multiplicity of sub-regions, respectively, wherein:

(a) the sub-regions consist of a first sub-region, a second sub-region arranged at one side of a first direction of the first sub-region, a third and a fourth region arranged at both sides of a second direction of either one of the first and the second sub-regions and a fifth and a sixth sub-region arranged at both sides of the second direction of the other of the first and the second sub-regions; and

(b) the ratio of the area of the first sub-region, the second sub-region, the third and the fourth sub-regions together and the fifth and the sixth sub-regions together is 1;

2;

4;

8.

18. A display according to claim 17, wherein the third and the fourth sub-regions are set to an illuminating state or non-illuminating state in response to an image signal.

19. A display according to claim 17, wherein the first and the second sub-regions are on a same first common line.

20. A display according to claim 17, wherein the third and the fourth sub-regions are on a same first segment line, and the fifth and the sixth sub-regions are on a same second segment line.

21. A display according to claim 19 or 20, wherein the third and the fifth sub-regions are on a same second common line, and the fourth and the sixth sub-regions are on a same third common line.

22. A display according to claim 20, wherein the first sub-region is on the first segment line, and the second sub-region is on the second segment line.

23. A display according to claim 17, wherein said display is a liquid crystal display.