Color flat panel display sub-pixel arrangements and layouts for sub-pixel rendering with increased modulation transfer function response

• US 7,492,379 B2
• Filed: 10/22/2002
• Issued: 02/17/2009
• Est. Priority Date: 01/07/2002
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Higgins, Michael Francis, Credelle, Thomas Lloyd, Brown Elliott, Candice Hellen
• Primary Examiner(s): Lefkowitz; Sumati
• Assistant Examiner(s): Beck; Alexander S.
• Application Number:
  US10/278,353
• Publication Number:
  US 20030128225A1
• Time in Patent Office: 2,310 Days
• Field of Search: 345/72, 345/83, 345/88, 345/92, 345204-205, 345/209, 345/96, 345/690, 345694-696, 349106-109
• US Class Current: 345/695
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2340/0457 Improvement of perceived resolution by subpixel rendering
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• 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 3/3614 Control of polarity reversal in general

Abstract

Various embodiments of a sub-pixel octal grouping are disclosed. The octal grouping may comprise three-color sub-pixels with one colored sub-pixel comprising twice the number of positions within the octal sub-pixel grouping as the other two colored sub-pixels. Various embodiments for performing sub-pixel rendering on the sub-pixel groupings are disclosed.

Claims

1. A method of converting incoming three-color pixel data of a first format for rendering onto a display panel;

said display panel comprising a plurality of a sub-pixel group;

said sub-pixel group further comprising eight sub-pixels;

wherein each said sub-pixel is one of a first color sub-pixel, a second color sub-pixel and a third color sub-pixel;

wherein said sub-pixel group further comprises four sub-pixels of said first color, two sub-pixels of said second color and two sub-pixels of said third color;

wherein further said sub-pixels of said second color and said sub-pixels of said third color form substantially a checkerboard pattern;

the method comprising;

determining implied sample areas for each data point of said incoming three-color pixel data;

determining a resample area for each color sub-pixel on said display panel;

forming a set of coefficients for each resample area, said coefficients comprising fractions whose denominators are a function of the resample area and whose numerators are a function of an area of each implied sample area that may partially overlap said resample area;

multiplying the incoming pixel data for each implied sample area by a coefficient resulting in a product; and

adding each product to obtain a luminance value for said color sub-pixel on said display panel represented by each resample area.

2. The method as recited in claim 1 wherein a plurality of resample areas for each color sub-pixel in the display forms a resample area array, and wherein the method further comprises:

determining a phase relationship among the resample area arrays for each color sub-pixel.

3. The methods as recited in claim 2 wherein determining a phase relationship further comprises:

positioning resample points for each said color resample areas such that the resample points for said second color and said third color substantially overlay the resample points for said first color.

4. The method as recited in claim 1 wherein said first color is green, and said second and third colors are red and blue respectively;

wherein said set of coefficients for said resample areas for the green color comprises a unity filter; and

wherein said set of coefficents for said resample areas for the red and blue colors are each a 3×

3 filter coefficient matrix.

5. The method as recited in claim 1 wherein said unity filter is centered to substantially match an input pixel by adjusting said unity filter with respect to a sub-pixel grid.

6. The method as recited in claim 1 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein two sub-pixels of said first color, one sub-pixel of said second color and one sub-pixel of said third color are disposed in each of said two rows.

7. The method as recited in claim 1 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein said checkerboard pattern is formed by one of said sub-pixel of said second color following one of said sub-pixel of said third color in a first row, and one of said sub-pixel of said third color following one of said sub-pixel of said second color in a second row.

8. The method as recited in claim 1 wherein a combined area of said two sub-pixels of said first color is substantially equal to the area of one of said sub-pixel of said second color and said sub-pixel of said third color.

9. The method as recited in claim 1 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein said sub-pixels of said first color are disposed in columns in said sub-pixel group.

10. The method as recited in claim 9 wherein a first one of said columns of said sub-pixels of said first color is offset from a second one of said columns of said sub-pixels of said first color in said sub-pixel group.

11. The method of claim 1 wherein said display panel is an element of a display system utilizing one of a group of display technologies, said group of technologies comprising passively addressed Liquid Crystal Display (LCD), ElectroLuminescent (EL) Display, Plasma Display, passively addressed Inorganic Light Emitting Diode, Organic Light Emitting Diode Display, Active Matrix Liquid Crystal Display (AMLCD), and Active Matrix Organic Light Emitting Diode Display (AMOLED).

12. A system comprising:

a display panel, said display panel comprising a plurality of a sub-pixel group;

said sub-pixel group comprising eight sub-pixels specifying an output data format;

said sub-pixel group further comprising four sub-pixels of a first color, two sub-pixels of a second color and two sub-pixels of a third color;

said sub-pixels of said second color and said sub-pixels of said third color substantially forming a checkerboard pattern;

means for receiving input image data specified in an input data format different from said output data format; and

means for subpixel rendering said input image data specified in said input data format to said output data format of said plurality of sub-pixel groups on said display panel.

13. The system as recited in claim 12 wherein said means for subpixel rendering input image data further comprises:

means for determining implied sample areas for each data point of said input image data;

means for determining a resample area for each color sub-pixel in the display;

means for forming a set of coefficients for each resample area, said coefficients comprising fractions whose denominators are a function of the resample area and whose numerators are a function of an area of each implied sample area that may partially overlap said resample area;

means for multiplying the input image data for each implied sample area by a coefficient resulting in a product; and

means for adding each product to obtain a luminance value for each resample area.

14. The system as recited in claim 13 wherein a plurality of resample areas for each color sub-pixel in the display forms a resample area array, and wherein the system further comprises:

means for determining a phase relationship among the resample area arrays for each color sub-pixel.

15. The system as recited in claim 14 wherein means for determining a phase relationship further comprises:

means for positioning resample points for each said color resample areas such that the resample points for said second color and said third color substantially overlay the resample points for said first color.

16. The system as recited in claim 13 wherein said first color is green, and said second and third colors are red and blue respectively;

wherein said set of coefficients for said resample areas for the green color comprises a unity filter; and

wherein said set of coefficents for said resample areas for the red and blue colors are each a 3×

3 filter coefficient matrix.

17. The system as recited in claim 16 wherein said unity filter is centered to substantially match an input pixel by adjusting said filter with respect to a sub-pixel grid.

18. The system as recited in claim 12 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein two sub-pixels of said first color, one sub-pixel of said second color and one sub-pixel of said third color are disposed in each of said two rows.

19. The system as recited in claim 12 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein said checkerboard pattern is formed by one of said sub-pixel of said second color following one of said sub-pixel of said third color in a first row, and one of said sub-pixel of said third color following one of said sub-pixel of said second color in a second row.

20. The system as recited in claim 12 wherein a combined area of said two sub-pixels of said first color is substantially equal to the area of one of said sub-pixel of said second color and said sub-pixel of said third color.

21. The system as recited in claim 12 wherein said eight sub-pixels of said sub-pixel group are disposed in two rows of four sub-pixels, and wherein said sub-pixels of said first color are disposed in columns in said sub-pixel group.

22. The system as recited in claim 21 wherein a first one of said columns of said sub-pixels of said first color is offset from a second one of said columns of said sub-pixels of said first color in said sub-pixel group.

23. The system as recited in claim 12 wherein said system utilizes one of a group of display technologies, said group of technologies comprising passively addressed Liquid Crystal Display (LCD), ElectroLuminescent (EL) Display, Plasma Display, passively addressed Inorganic Light Emitting Diode, Organic Light Emitting Diode Display, Active Matrix Liquid Crystal Display (AMLCD), and Active Matrix Organic Light Emitting Diode Display (AMOLED).

24. A method of rendering input image data specified in a first format comprising first, second and third color data values onto a display panel substantially comprising a sub-pixel repeating group comprising eight sub-pixels of first, second and third colors disposed in two rows;

said sub-pixel repeating group further comprising two sub-pixels of said first color, one sub-pixel of said second color and one sub-pixel of said third color disposed in each of said two rows;

the method comprising;

determining a plurality of input sample areas for said input image data;

each said input sample area representing one input image pixel indicating first, second and third color data values in said input image data;

determining a first color resample area array for said first color sub-pixels on the display panel;

said first color resample area array comprising a plurality of first color resample areas each comprising a first color resample point such that one first color resample point represents one first color sub-pixel on the display panel;

for each first color resample point in said first color resample area array, assigning said first color data value of said one input image pixel represented by a corresponding implied sample area to a first luminance value for said first color sub-pixel represented by said first color resample point;

determining a second color resample area array and a third color resample area array for said respective second color and third color sub-pixels on the display panel;

each of said second color and third color resample area arrays comprising a plurality of respective second color and third color resample areas each comprising respective second color and third color resample points such that one second color resample point represents one second color sub-pixel on the display panel and one third color resample point represents one third color sub-pixel on the display panel;

computing a set of coefficients for each of said second color resample areas and said third color resample areas, said coefficients comprising fractions whose denominators are a function of the respective resample area and whose numerators are a function of any partial area of each input sample area that may overlap said respective resample area when said respective resample area array overlays said input sample areas; and

producing a second luminance value and a third luminance value for each respective second color sub-pixel and third color sub-pixel on the display panel by multiplying respective ones of said coefficients of a corresponding resample area by respective second color and third color data values of the input image data for each input sample area overlaid by said resample area, and adding the resulting products.

25. The method as recited in claim 24 wherein said first color is green, said second color is red and said third color is blue;

said sub-pixel repeating group comprising two green sub-pixels, one blue sub-pixel and one red sub-pixel disposed in each of said two rows.

26. The method as recited in claim 25 wherein a combined area of said two green sub-pixels disposed in each row is substantially equal to the area of one of said blue sub-pixel and said red sub-pixel.

27. The method as recited in claim 24 wherein said first color is green, and wherein said sub-pixel repeating group comprises four green sub-pixels disposed in columns in said sub-pixel repeating group.

28. The method as recited in claim 24 wherein said sub-pixels of said second color and said sub-pixels of said third color form substantially a checkerboard pattern in said two rows such that a sub-pixel of said second color is followed by a sub-pixel of said third color in said first row, and a sub-pixel of said third color is followed by a sub-pixel of said second color in said second row.

29. The method as recited in claim 24 wherein each of said respective second color and third color resample areas overlaps at least two partial rows of input sample areas representing input image pixels in said input image data.

30. The method as recited in claim 24 wherein each of said respective second color and third color resample areas overlaps at most one partial row of input sample areas representing input image pixels in said input image data.

31. The method as recited in claim 24 wherein a plurality of said respective second color and third color resample areas has a diamond shape.

32. The method as recited in claim 24 further comprising determining a phase relationship among said first, second and third resample area arrays.

33. The method as recited in claim 32 wherein determining a phase relationship among said first, second and third resample area arrays comprises positioning said first, second and third color resample points for each respective first, second and third color resample area such that said first, second and third color resample points are substantially coincident.

34. The method as recited in claim 32 wherein determining a phase relationship among said first, second and third resample area arrays comprises positioning said first, second and third color resample points for each respective first, second and third color resample area such that none of said first, second and third color resample points are substantially coincident.

35. The method as recited in claim 24 wherein the step of computing a set of coefficients for each of said second color resample areas and said third color resample areas comprises computing a 3×

3 filter coefficient matrix having the values

36. The method as recited in claim 24 wherein the step of computing a set of coefficients for each of said second color resample areas and said third color resample areas comprises computing a 3×

2 filter coefficient matrix having the values

37. The method of claim 24 wherein said display panel is an element of a display system utilizing one of a group of display technologies, said group of technologies comprising passively addressed Liquid Crystal Display (LCD), ElectroLuminescent (EL) Display, Plasma Display, passively addressed Inorganic Light Emitting Diode, Organic Light Emitting Diode Display, Active Matrix Liquid Crystal Display (AMLCD), and Active Matrix Organic Light Emitting Diode Display (AMOLED).