Color display device

• US 4,908,609 A
• Filed: 04/06/1987
• Issued: 03/13/1990
• Est. Priority Date: 04/25/1986
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Stroomer, Martinus V. C.
• Primary Examiner(s): OBERLEY, ALVIN E
• Application Number:
  US07/034,194
• Time in Patent Office: 1,072 Days
• Field of Search: 340/701, 340/702, 340/703, 340/784, 340/811, 350/333, 350/332, 350/339 F, 358/56
• US Class Current: 345/88
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 2201/52 RGB geometrical arrangements
• CPC Class Codes: H04N 9/12 Picture reproducers H04N9/11 takes precedence

Abstract

In a color display device color elements (17, 18, 19, 21, 22, 23) are built up with the aid of picture cells (2) from juxtaposed rows of picture cells which are driven by line electrodes (3). The resolving power in the horizontal sense is increased by building up the color elements from picture cells of different rows of picture cells. The period t₁ which is required for driving a color element is split up into sub-periods 1/2t₁ during which period samples of the signal to be displayed (length t_o) are presented to the column electrodes (4). Since notably for LCD-TV there applies that t₁ >t_o, these samples can be presented during a period which is longer than 1/2t_o.

Claims

1. A display device for color display comprising

an electro-optical medium,

a pattern of line electrodes crossing a pattern of column electrodes to provide display elements in a matrix of picture cells of said electro-optical medium,

wherein at least two adjacent rows of said picture cells constitute a row of N color elements,

first means for driving said line electrodes,

conversion circuit means for sampling incoming signals having a length of t₀, said incoming signals being displayed at a frequency of f₀ =N/t₀, and said conversion circuit means converting each of said incoming signals into at least two sampling signals applied to said column electrodes during a display period of t₁, where t₁ >

t₀,

wherein only one of said two sampling signals is applied to said column electrodes during driving of a line electrode associated with at least one row of said picture cells, said line electrode being energized during a period of at most 1/2t₁.

2. A display device according to claim 1 for displaying a television picture, wherein two juxtaposed rows of said picture cells are provided each time for displaying only one picture line.

3. A display device according to claim 1 for displaying a television picture, wherein a row of said picture cells is provided for displaying different picture lines.

4. A display device according to claim 3, wherein said incoming signals are divided into a first raster of odd picture lines and a second raster of even picture lines, wherein beginning with a first of said line electrodes said signals of said first raster of odd picture lines are presented to said column electrodes during driving of successive ones of said line electrodes, and wherein beginning with a second of said line electrodes said sampling signals of said second raster of even picture lines are presented to said column electrodes during driving of successive ones of said line electrodes.

5. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein color elements in said row of N color elements are contiguous but non-overlapping, and wherein said sampling signals from two successive rasters are provided to said line electrodes to shift said color elements originating from said two rasters with respect to one another, said shift being one half a period of a pattern of said color elements.

6. A display device according to claim 1, claim 2, claim 3 or claim 4, wherein said sampling signals are provided from two successive rasters, said sampling signals being passed to said line electrodes to at least partly overlap color elements from said row of N color elements, said successive rasters being sampled for said sampling signals according to a mutual position of said color elements within said row of N color elements.

7. A display device according to claim 5, wherein said picture cells have a shape of a regular polygon.

8. A display device according to claim 6, wherein said picture cells have a shape of a regular polygon.

9. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein said picture cells have a shape of a regular polygon.

10. A display device according to claim 5, wherein said electro-optical medium is a liquid crystal.

11. A display device according to claim 6, wherein said electro-optical medium is a liquid crystal.

12. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein said electro-optical medium is a liquid crystal.

13. A display device according to claim 5, wherein said electro-optical medium is an electrophoretic suspension.

14. A display device according to claim 6, wherein said electro-optical medium is an electrophoretic suspension.

15. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein said electro-optical medium is an electrophoretic suspension.

16. A display device according to claim 5, wherein said electro-optical medium is an electrochromic material.

17. A display device according to claim 6, wherein said electro-optical medium is an electrochromic material.

18. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein said electro-optical medium is an electrochromic material.

19. A display device according to claim 1, claim 2, claim 3, or claim 4, wherein said first means include a plurality of active circuit elements.

20. A display device according to claim 19, wherein said active circuit elements include thin film IGFET transistors having source zones electrically connected to said line electrodes, having gate electrodes electrically connected to said column electrodes, and having drain zones electrically connected to said display elements.