Color subtractive display with at least three layers having different pixel resolution

• US 8,638,274 B2
• Filed: 11/27/2007
• Issued: 01/28/2014
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Roosendaal, Sander Jurgen, Van Delden, Martinusj Hermanus Wilhelmus Maria
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): CRAWLEY, KEITH L
• Application Number:
  US12/516,035
• Publication Number:
  US 20100045860A1
• Time in Patent Office: 2,254 Days
• Field of Search: 345/1.1, 345 33- 36, 345/49, 345105-107, 345600-604, 345694-695, 345698-699, 359/259, 359265-267, 359272-274, 359/296, 348/448, 348/450, 382298-299
• US Class Current: 345/4
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 2001/1678 characterised by the composition or particle type
• CPC Class Codes: G02F 2201/52 RGB geometrical arrangements
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2300/0434 Flat panel display in which a field is applied parallel to the display plane
• 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 2340/0407 Resolution change, inclusive of the use of different resolutions for different screen areas
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167
• CPC Class Codes: G09G 3/348 based on the deformation of a fluid drop, e.g. electrowetting
• CPC Class Codes: G09G 3/38 using electrochromic devices
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/227 Resolution modifying circuits, e.g. variable screen formats, resolution change between memory contents and display screen

Abstract

The present invention relates to a display (10) comprising a vertical stack of at least two different color absorbing layers (14) of pixels (18). The display is characterized in that the pixel resolution of at least two of the layers is different. The present invention also relates to a display system (50) comprising such a display and a method for controlling such a display.

Claims

1. A display comprising:

a vertical stack of at least three different color absorbing layers (14) of pixels,

wherein the pixel resolution of at least three of the layers is different,

wherein a layer having the lowest resolution is a top layer of the vertical stack placed at a viewing side of the display,

wherein layers having increasingly higher resolution are placed further down in the vertical stack,

wherein a layer having the highest resolution is a bottom layer of the vertical stack,

wherein each layer is comprised of pixels of a single color,

the display further comprising an element provided behind the stack adjacent the bottom layer.

2. A display according to claim 1, wherein a layer comprising color(s) determining the chrominance has lower resolution than a layer comprising color(s) determining the luminance.

3. A display according to claim 1, wherein a layer comprising cyan has lower resolution than a layer comprising magenta.

4. A display according to claim 3, wherein the area ratio of a cyan pixel to a magenta pixel is 4:

1 or lower.

5. A display according to claim 1, wherein a layer comprising yellow has lower resolution than a layer comprising magenta.

6. A display according to claim 5, wherein the area ratio of a yellow pixel to a magenta pixel is 16:

1 or lower.

7. A display according to claim 1, wherein a top layer placed at the viewing side of the display comprises yellow, an intermediate layer comprises cyan and a bottom layer laced at the opposite side of the stack comprises magenta, the bottom layer having higher resolution than the intermediate layer and the intermediate layer having higher resolution than the top layer.

8. A display according to claim 1, wherein a top layer comprises yellow and cyan and a bottom layer placed at the viewing side of the display comprises magenta, the bottom layer having higher resolution than the top layer.

9. A display according to claim 7, wherein the bottom layer additionally comprises black.

10. A display according to claim 7, further comprising an additional layer comprising sing black.

11. A display according to claim 1, wherein at least one layer is provided with light shields for covering collector areas in the pixels of said at least one layer.

12. A display according to claim 11, wherein one layer comprises magenta and the light shields are provided in the magenta layer only.

13. A display according to claim 1, wherein the shape of the pixels is one of square and hexagonal.

14. A display according to claim 1, wherein the display is a reflective or transmissive display.

15. A display according to claim 1, wherein the display is an electrophoretic, electrowetting or electrochromism display.

16. A display system, comprising a display according to claim 1, and a control unit adapted to receive a video signal, scale the video signal signals in accordance with the resolutions of the display layers, and control the display in accordance with the scaled input video signal.

17. A display system according to claim 16, wherein the control unit is adapted to scale the video signal by averaging, over a group of higher resolution pixels, a scaling property of one or more corresponding lower resolution pixel(s).

18. A display system according to claim 17, wherein the scaling property is one of optical density, luminance, and bit level.

22. The display according to claim 1, wherein the display is a color subtractive electrophoretic display.

23. The display according to claim 1, wherein the element is a reflector.

24. The display according to claim 1, wherein the element is a light source.

25. The display according to claim 24, wherein the light source is a backlight.

19. A method for controlling a display, the method comprising:

receiving a video signal,

scaling the video signal in accordance with the resolutions of the display layers of the display, and,

controlling the display in accordance with the scaled video signal,

wherein the display comprises a vertical stack of at least three different color absorbing layers of pixels,

wherein the pixel resolution of at least three of the layers of the vertical stack is different,

wherein a layer of the vertical stack having the lowest resolution is a top layer of the vertical stack placed at a viewing side of the display,

wherein layers having increasingly higher resolution are placed further down in the vertical stack,

wherein a layer having the highest resolution is a bottom layer of the vertical stack,

wherein each layer is comprised of pixels of a single color,

wherein the display further comprises an element provided behind the stack adjacent the bottom layer.

20. A method according to claim 19, wherein the scaling comprises averaging, over a group of higher resolution pixels, a scaling property of one or more corresponding lower resolution pixel(s).

21. A method according to claim 20, wherein the scaling property is one of optical density, luminance, and bit level.