Liquid crystal color display device having plural color filters per segment electrode

• US 4,709,993 A
• Filed: 12/17/1986
• Issued: 12/01/1987
• Est. Priority Date: 12/18/1985
• Status: Expired due to Fees

• Current Assignee: Hitachi Device Engineering Co., Ltd., Hitachi, Ltd.
• Original Assignee: Hitachi Device Engineering Co., Ltd., Hitachi, Ltd.
• Inventors: Ishii, Akira, Matsuyama, Shigeru, Kanazaki, Mikio, Aoki, Norio
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): Gallivan, Richard F.
• Application Number:
  US06/942,634
• Time in Patent Office: 349 Days
• Field of Search: 350/333, 350/339 F, 350/336
• US Class Current: 349/108
• CPC Class Codes: G02F 1/133514 Colour filters

Abstract

A liquid crystal color display device comprising at least two kinds of plural color filter members provided for patterned electrodes serving to apply an electric field across a liquid crystal layer sandwiched therebetween, each of the above-mentioned at least two kinds of color filter members transmitting light having wavelengths representative of a particular color, in which at least one of the color filter members is constituted by a combination of at least two kinds of filter members segmented to a degree unresolvable by the eyes specifically arranged.

Claims

1. A liquid crystal color display device comprising:

at least one first patterned electrodes and at least one second electrodes formed on a pair of opposed transparent substrates, respectively, for applying an electric field across a liquid crystal layer sandwiched between said first and second electrodes, each of said first electrodes defining, together with a one mating second electrode, a display element operable for display in a particular color; and

a filter layer formed for each of said first electrodes on one of said substrates, said filter layer being supported by said one substrate and placed in an optical path of light having entered the display device, in which the filter layer formed for at least one of said first electrodes includes at least two kinds of plural filtering segments, a first kind of filtering segments among said at least two kinds being made of a material having optical characteristics to pass therethrough light having wavelengths representative of a first color, and a second kind of filtering segments among said at least two kinds being made of a material having optical characteristics to pass therethrough light having wavelengths representative of a second color, said at least two kinds of plural filtering segments being arranged so that the display element including said at least two kinds of plural filtering segments gives, when activated, a display in a color of a hue visually perceived different, as viewed at a distance, from those of said filtering segments.

2. A liquid crystal color display device according to claim 1, in which the filter layer for at least one of said first electrodes other than that associated with said at least two kinds of filtering segments is a solid layer of the same material as that of said first kind of filtering segments and the filter layer for at least one of said first electrodes other than any of the above-mentioned at least one first electrode is a solid layer of the same material as that of said second kind of filtering segments.

3. A liquid crystal color display device according to claim 1, in which the ratio between the total areas of said at least two kinds of said plural filtering segments of said filter layer formed for said at least one first electrode is defined so as to determine the hue of a particular color for said first electrode.

4. A liquid crystal color display device according to claim 3, in which the area of each of said filtering segments is defined so as to provide said total area ratio.

5. A liquid crystal color display device according to claim 3, in which the numbers of said at least two kinds of plural filtering segments are defined so as to provide said total area ratio.

6. A liquid crystal color display device according to claim 1, in which each of said filtering segments is in the form of a stripe.

7. A liquid crystal color display device according to claim 6, in which said stripe has a width substantially not larger than 150 μ

m.

8. A liquid crystal color display device according to claim 1, in which said filtering segments are substantially in the form of a rectangle and are arranged in mosaic.

9. A liquid crystal color display device according to claim 8, in which each of said rectangular filtering segments has dimensions substantially not larger than 200 μ

m×

200 μ

m.

10. A liquid crystal color display device according to claim 1, in which each of said filter layers is made of a dyed gelatin.

11. A liquid crystal color display device according to claim 1, in which those parts of said filter layer which do not contribute to a display in cooperation with any electrode are opaque.

12. A liquid crystal color display device according to claim 11, in which said opaque parts comprise at least two kinds of filtering segments overlapped.

13. A liquid crystal color display device according to claim 1, in which said first and second colors are red and green, respectively.

14. A liquid crystal color display device according to claim 1, in which said filter layer for each of said first patterned electrodes on said one substrate is formed between said liquid crystal layer and said each first patterned electrode on said one substrate.

15. A liquid crystal color display device according to claim 14, further comprising a protective film formed between said liquid crystal layer and said filter layer.

16. A liquid crystal color display device according to claim 15, in which said protective film is made of an acrylic resin or epoxy resin.

17. A liquid crystal color display device according to claim 1, in which ,the filter layer formed for at least one first electrode includes a plurality of filtering films laminated with a protective film interposed between the adjacent ones of said filtering films.