Complementary color liquid display

• US 4,953,953 A
• Filed: 12/21/1989
• Issued: 09/04/1990
• 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:
  US07/456,060
• Time in Patent Office: 257 Days
• Field of Search: 350/334, 350/335, 350/349, 350/339 F, 350/408
• 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, 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.

Claims

1. A method for producing a light output, comprising directing light to a plurality of color aligned in optical series, wherein a first one of such filters has one color characteristic and a second one of such filters has the complementary color characteristic, and controlling the amount of filtering by at least one of such filters, whereby such light output has characteristics that are a function of the filtering of both such first and second filters.

2. The method of claim 1, said controlling comprising controlling the filtering of such second filter to determine the brightness of such output light without substantially affecting the hue of such output light.

3. The method of claim 1, said controlling comprising controlling the filtering of such first filter to determine the hue of such output light without substantially affecting the brightness of such output light.

4. The method of claim 1, said controlling comprising controlling the filtering of both filters to determine both the hue and brightness of such output light.

5. The method of claim 4, wherein such plurality of filters comprises two filters in optical series forming a first color subset and wherein there is positioned in proximity to such first color subset a second color subset including a second plurality of color filters aligned in optical series, wherein a first one of such second plurality of filters has one color characteristic different from the color characteristic of such first filter of such first plurality of filters and a second one of such second plurality of filters has the complementary color characteristic, said directing comprising directing light to both of such color subsets to provide additive color function.

6. The method of claim 5, wherein a third color subset having one color filter and a complementary color filter is positioned in proximity of such first and second color subsets, and said directing comprising directing light to all three color subsets.

7. The method of claim 6, further comprising selecting the first color filter of each of such color subsets to be, respectively, red, green and blue.

8. The method of claim 1, wherein such plurality of filters comprises two filters in optical series forming a first color subset and wherein there is positioned in proximity to such first color subset a second color subset including a second plurality of color filters aligned in optical series, wherein a first one of such second plurality of filters has one color characteristic different from the color characteristic of such first filter of such first plurality of filters and a second one of such second plurality of filters has the complementary color characteristic, said directing comprising directing light to both of such color subsets to provide additive color function.

9. Apparatus for producing a light output, comprising means for directing light to a plurality of color filters aligned in optical series, said plurality of color filters including a first filter having one color characteristic and a second filter having the complementary color characteristic, and means for controlling the amount of filtering by at least one of said filters, whereby such light output has characteristics that are a function of the filtering of both said first and second filters.

10. The apparatus of claim 9, said means for controlling comprising means for controlling the filtering of said second filter to determine the brightness of such output light without substantially affecting the hue of such output light.

11. The apparatus of claim 9, said means for controlling comprising means for controlling the filtering of said first filter to determine the hue of such output light without substantially affecting the brightness of such output light.

12. The apparatus of claim 9, said means for controlling comprising means for controlling the filtering of both filters to determine both the hue and brightness of such output light.

13. The apparatus of claim 12, wherein said plurality of filters comprises two filters in optical series forming a first color subset, the apparatus further comprising positioned in proximity to said first color subset a second color subset including s second plurality of color filters aligned in optical series, wherein a first one of said second plurality of filters has one color characteristic different from the color characteristic of said first filter of said first plurality of filters and a second one of said second plurality of filters has the complementary color characteristic, said means for directing comprising means for directing light to both of said color subsets to provide additive color function.

14. The apparatus of claim 13, further comprising a third color subset having one color filter and a complementary color filter positioned in proximity of said first and second color subsets, and said directing means comprises means for directing light to all three color subsets.

15. The apparatus of claim 14, further comprising means for selecting the first color filter of each of such color subsets to be, respectively, red, green and blue.

16. The apparatus of claim 9, wherein said plurality of filters comprises two filters in optical series forming a first color subset and the apparatus further comprising positioned in proximity to said first color subset a second color subset including a second plurality of color filters aligned in optical series, and wherein a first one of said second plurality of filters has one color characteristic different from the color characteristic of said filter of said first plurality of filters and a second one of said second plurality of filters has the complementary color characteristic, and wherein said directing means comprises means for directing light to both of said color subsets to provide additive color function.