Complementary color liquid crystal display

• US 4,834,508 A
• Filed: 12/16/1986
• Issued: 05/30/1989
• Est. Priority Date: 03/01/1985
• Status: Expired due to Term

• Current Assignee: Manchester R & D Partnership
• Original Assignee: Manchester R & D Partnership
• Inventors: Fergason, James L.
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US06/942,517
• Time in Patent Office: 896 Days
• Field of Search: 350/339 F, 350/349, 350/334, 350/335
• US Class Current: 349/79
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: C09K 19/60 Pleochroic dyes
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G02F 1/13475 in which at least one liquid crystal cell or layer is doped with a pleochroic dye, e.g. GH-LC cell G02F1/13476 takes precedence
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence

Abstract

A liquid crystal color device (10) includes at least one pel (14) for affecting light (36) incident thereon to produce output light (38), the pel includes three complementary color subsets (30, 32, 34), each having controllable color filtering capability in the respective complementary colors thereof. The color subsets are arranged in optical additive relation, and the color subsets include complementary color parts (30a, 30b, 32a, 32b, 34a, 34b) which are arranged, respectively, in optical serial subtractive relation. The color filtering function is carried out using liquid crystal materials with respective pleochroic dyes. A method of parametric color control of a liquid crystal device, formed of plural picture elements, each picture element including plural pairs of complementary color filters, includes directing light to or through an array of such electrically controllable pairs of complementary color filters, and controlling the filtering characteristics of at least one of such filters.

Claims

1. A liquid crystal color device, comprising

at least one picture element (pel) means for controllably affecting light incident thereon to produce output light,

said at least one picture element (pel) means including at least two color subsets,

one subset including first and second color parts, respectively of a first color and the complement thereof, and the other subset including first and second color parts, respectively of a second color and the complement thereof,

said subsets being arranged in optical additive relation, and

means for selectively controlling each of the colors of said subsets to determine the color of such output light.

2. The device of claim 1, said picture element means comprising a plurality of picture element means arranged in optical additive relation.

3. The device of claim 2, said picture element means being arranged in a substantially flat display.

4. The device of claim 3, further comprising light source means for providing incident light for impingement on one side of said display, and said means for selectively controlling comprising driving means for selectively applying electrical input to said picture element means to determine the effect each of said picture element means has on such incident light thereby to determine characteristics of such output light.

5. A color television display comprising the device of claim 4.

6. The device of claim 3, further comprising light source means for providing incident light for impingement on one side of said display, and said means for selectively controlling comprising driving means for selectively applying electrical input to said picture element means to determine the effect each of said picture element means has on such incident light thereby to determine characterisitics of such output light.

7. A color television display comprising the device of claim 6.

8. The device of claim 1, each of said subsets comprising one plurality of volumes of liquid crystal containing pleochroic dye of one of said first and second colors and a second plurality of volumes of liquid crystal containing pleochroic dye of the respective complement of said one of said first and second colors.

9. The device of claim 8, each of said volumes of liquid crystal material and pleochroic dye comprising operationally nematic or operationally smectic liquid crystal in a containment medium means for distorting the natural structure of the liquid crystal therein to cause coloring or color filtering of incident light, and said liquid crystal and pleochroic dye reducing the extent of such coloring or color filtering in response to such prescribed input.

10. The device of claim 1, said picture element means further comprising at least a third color subset, said third color subset including a third color and the complement thereof.

11. The device of claim 10, said first, second and third colors comprising a red, green and blue triad.

12. The device of claim 11, said picture element means comprising a plurality of picture element means arranged in generally two dimensional relation to form a multicolor display.

13. The device of claim 1, wherein said color subsets of a plurality of said picture element means are operative in response to a prescribed input to transmit substantially all incident light thereon with substantially no coloring of such light thereby to produce a bright appearance that is a function of the color of the incident light.

14. A method for displaying a multicolor output using a liquid crystal device, comprising

directing incident light to at least one picture element means for affecting light such incident thereon to produce a specified output light,

such picture element means having at least two color subsets, one color subset including a first color and the complement thereof, and the other including a second color and the complement thereof, the two colors of such respective subsets being in optical serial relation, and such color subsets being in optical additive relation,

said directing including directing incident light to all of such subsets of such picture element means, and

selectively controlling each of the colors of such subsets thereby to determine the color of output light of the liquid crystal device.

15. The method of claim 14, further comprising controlling said picture element means to transmit substantially all light incident thereon without coloring such light thereby to produce a bright output of a color that is substantially the same as that of the incident light.

16. The combination of subtractive and additive elements in an optical display cooperative to provide independent control of color and brightness.

17. The combination of claim 16, said elements being independently operative to control saturation and hue.

18. The combination of claim 17, wherein each element comprises a complementary color pair.

19. The combination of claim 18, wherein said elements comprise three complementary color pairs, each pair having a different respective primary color and the complement thereof.

20. The combination of claim 19, wherein each pair is capable of providing a two color system.

21. The combination of claim 16, wherein light is controlled by plural volumes of liquid crystal in a containment medium, and pleochroic dye in respective volumes of liquid crystal.

22. The combination of claim 21, wherein respective groups of volumes of liquid crystal are discriminating with respect to a prescribed input to alter the output color of light produced in response to incident light on such volumes of liquid crystal and pleochroic dye.

23. The combination of claim 16, said elements being operative to color light or to transmit substantially all light incident thereon without coloring the light thereby to produce a relatively bright output which is a color that is substantially the same as the color of the incident light.

28. The display of claim 23, further comprising a light source to provide input light to said complementary color pairs.

24. A color display using a multiplicity of elements made up of complementary color pair parts, each part being controllable to affect light.

25. The display of claim 24, each of said elements comprising a picture element.

26. The display of claim 24, further comprising reflector means for reflecting light through the respective complementary color pairs to achieve a prescribed color output.

27. The display of claim 24, wherein said complementary color pairs are arranged to transmit light to color the same.

29. The display of claim 24, wherein each of said elements comprises a set of primary colors and their complements.

30. The display of claim 29, said primary colors comprising three primary colors.

31. The display of claim 30, said three primary colors comprising, respectively, red, green and blue.

32. The display of claim 30, wherein said primary colors are a set of unique hues.

33. The display of claim 24, wherein each element comprises plural complementary color pairs.

34. The display of claim 33, wherein each element comprises three complementary color pairs.

35. The display of claim 24, further comprising reflector means for reflecting light transmitted through the complementary color pairs, whereby the display is operative to provide color output in response to ambient lighting.

36. The display of claim 24, wherein said complementary color pairs are operative to provide substantially full gray scale.

37. The display of claim 24, said complementary color pairs comprising plural groups of volumes of liquid crystal and respective pleochroic dyes.

38. The display of claim 37, wherein said liquid crystal comprises operationally nematic liquid crystal, said volumes comprise volumes of liquid crystal material in a containment medium, and said containment medium including means for distorting the natural structure of the liquid crystal in the absence of a prescribed input to effect coloring of light by the dye;

and such liquid crystal being responsive to such prescribed input to reduce the amount of coloring.

39. The invention of claim 24, wherein light is controlled by plural volumes of liquid crystal in a containment medium, and pleochroic dye in respective volumes of liquid crystal.

40. The display of claim 24, wherein said complementary color pair parts are controllable to color light or to transmit substantially all incident light thereon without substantially coloring such light to produce a bright output that has a color which is substantially the same as that of the incident light.

41. A method of producing a controllable optical output, comprising directing light at or through an array of elements made up of electrically controllable complementary color filtering devices, and controlling such devices.

42. The method of claim 41, said controlling including controlling the amount of filtering by respective devices.

43. The method of claim 42, said controlling further comprising controlling the alignment properties of liquid crystal and pleochroic dye.

44. The method of claim 41, said complementary color filtering devices comprising plural complementary color pairs, and said controlling comprising controlling the filtering by such complementary color pairs to achieve color and brightness control.

45. The method of claim 44, wherein a display includes a plurality of such complementary color pairs to form a picture element, each picture element including a triad of complementary color pairs, and said controlling comprising controlling respective picture elements to produce a variety of color and brightness output responses.

46. The method of claim 45, further comprising controlling a plurality of such picture elements to form a dynamic image.

47. The method of claim 41, wherein the color filters include liquid crystal material that is responsive to a prescribed input to change at least one characteristic of the liquid crystal.

48. The method of claim 47, wherein at least one of such liquid crystal materials has a response that is frequency dependent, and said controlling comprising applying a prescribed input of a predetermined voltage and/or frequency.

49. The invention of claim 41, wherein light is controlled by plural volumes of liquid crystal in a containment medium, and pleochroic dye in respective volumes of liquid crystal.

50. The method of claim 41, further comprising controlling said elements to transmit substantially all light incident thereon without coloring such light thereby to produce a bright output of a color that is substantially the same as that of the incident light.

66. The method of claim 50, further comprising controlling said pairs of complementary color filters to transmit substantially all light incident thereon without coloring such light thereby to produce a bright output of a color that is substantially the same as that of the incident light.

51. A method of controlling a picture element, comprising directing light to or through an array of electrically controllable pairs of complementary color filters, and controlling the filtering characteristics of at least one of such filters.

52. The method of claim 51, further comprising placing respective pairs of complementary color filters in optical series alignment.

53. The method of claim 52, wherein such pairs of complementary color filters comprises plural such pairs.

54. The method of claim 53, said pairs comprising three pair, and each pair including a respective primary color.

55. The method of claim 51, wherein the color filters include liquid crystal material that is responsive to a prescribed input to change at least one characteristic of the liquid crystal.

56. The method of claim 55, wherein at least one of such liquid crystal materials has a response that is frequency dependent, and said controlling comprising applying a prescribed input of a predetermined voltage and/or frequency.

57. The method of claim 51, further comprising controlling said pairs of complementary color filters to transmit substantially all light incident thereon without coloring such light thereby to produce a bright output of a color that is substantially the same as that of the incident light.

58. A method of controlling an optical display formed of plural picture elements, each picture element including plural pairs of complementary color filters, comprising directing light to or through an array of such electrically controllable pairs of complementary color filters, and controlling the filtering characteristics of at least one of such filters.

59. The invention of claim 58, wherein light is controlled by plural volumes of liquid crystal in a containment medium, and pleochroic dye in respective volumes of liquid crystal.

60. A method of parametric color control of a liquid crystal device, formed of plural picture elements, each picture element including plural pairs of complementary color filters, comprising directing light to or through an array of such electrically controllable pairs of complementary color filters, and controlling the filtering characteristics of at least one of such filters.

61. The method of claim 60, wherein the color filters include liquid crystal material that is responsive to a prescribed input to change at least one characteristic of the liquid crystal.

62. The method of claim 61, wherein at least one of such liquid crystal materials has a response that is frequency dependent, and said controlling comprising applying a prescribed input of a predetermined voltage and/or frequency.

63. The method of claim 60, wherein such prescribed input is electric field, and the color output of the device is a function of the application of such electric field.

64. The method of claim 63, wherein such color filters are responsive to at least one of magnitude of electric field or frequency of electric field, and further comprising altering at least one of the magnitude or frequency of electric field to effect parametric control of color response of such color filters.

65. The method of claim 64, wherein the color filters include liquid crystal materials and pleochroic dye, such liquid crystal materials being responsive to such prescribed input to change the alignment characteristics of such liquid crystal material and pleochroic dye contained therein to alter the color filtering effected by such pleochroic dye.