Double-layer liquid crystal device having a three dimensional network structure

• US 5,296,952 A
• Filed: 08/02/1993
• Issued: 03/22/1994
• Est. Priority Date: 05/27/1991
• Status: Expired due to Term

• Current Assignee: Dainippon Ink & Chemicals Incorporated
• Original Assignee: Dainippon Ink & Chemicals Incorporated
• Inventors: Takeuchi, Kiyofumi, Takatsu, Haruyoshi, Umezu, Yasuo
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MAI, HUY KIM
• Application Number:
  US08/100,207
• Time in Patent Office: 232 Days
• Field of Search: 359/53, 359/51, 359/52, 359/63, 359/64, 359/70, 359/96, 359/73, 359/68
• US Class Current: 349/77
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133533 Colour selective polarisers G02F1/1347 takes precedence
• CPC Class Codes: G02F 1/13476 in which at least one liquid crystal cell or layer assumes a scattering state
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence
• CPC Class Codes: G02F 1/1396 the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell G02F1/141 takes precedence
• CPC Class Codes: G02F 2203/01 transmissive
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: G02F 2203/03 scattering

Abstract

A light scattering liquid crystal device having a double structure composed of (1) a first display panel of light scattering type which comprises a pair of transparent substrates each having a transparent electrode layer and a light controlling layer formed therebetween, said light controlling layer containing a liquid crystal material and a transparent solid substance and (2) a second display panel comprising a pair of transparent substrates each having an electrode layer and a liquid crystal material filled therebetween, selected from a guest-host type liquid crystal display panel containing a dichroic dye and a twisted or super-twisted nematic liquid crystal display panel having a pair of polarizers. The device achieves brightness and high contrast.

Claims

1. A light scattering liquid crystal device having a double structure composed of (1) a first display panel of light scattering type which comprises a pair of transparent substrates each having a transparent electrode layer and a light controlling layer formed therebetween, said light controlling layer containing a liquid crystal material and a transparent solid substance and (2) a second display panel comprising a pair of transparent substrates each having an electrode layer and a liquid crystal material filled therebetween.

2. A light scattering liquid crystal device as claimed in claim 1, wherein said second display panel is a guest-host type liquid crystal display panel containing a dichroic dye.

3. A light scattering liquid crystal device as claimed in claim 2, wherein said dichroic dye is present in an amount of from 0.01 to 10% by weight based on the liquid crystal material.

4. A light scattering liquid crystal device as claimed in claim 1, wherein said second display panel is a twisted nematic liquid crystal display panel having a pair of polarizers.

5. A light scattering liquid crystal device as claimed in claim 4, wherein at least one of said polarizers is a color polarizer.

6. A light scattering liquid crystal device as claimed in claim 4, wherein said polarizers are perpendicular to each other.

7. A light scattering liquid crystal device as claimed in claim 4, wherein said polarizers are parallel to each other.

8. A light scattering liquid crystal device as claimed in claim 1, wherein said second display panel has a color filter.

9. A light scattering liquid crystal device as claimed in claim 2, wherein said second display panel has a color filter.

10. A light scattering liquid crystal device as claimed in claim 4, wherein said second display panel has a color filter.

11. A light scattering liquid crystal device as claimed in claim 1, wherein said second display panel has a reflective plate on the side opposite to said first display panel.

12. A light scattering liquid crystal device as claimed in claim 2, wherein said second display panel has a reflective plate on the side opposite to said first display panel.

13. A light scattering liquid crystal device as claimed in claim 4, wherein said second display panel has a reflective plate on the side opposite to said first display panel.

14. A light scattering liquid crystal device as claimed in claim 1, wherein said light controlling layer of the first panel comprises a continuous phase of the liquid crystal material in which a transparent solid substance forms a three-dimensional network structure.

15. A light scattering liquid crystal device as claimed in claim 2, wherein said light controlling layer of the first panel comprises a continuous phase of the liquid crystal material in which a transparent solid substance forms a three-dimensional network structure.

16. A light scattering liquid crystal device as claimed in claim 4, wherein said light controlling layer of the first panel comprises a continuous phase of the liquid crystal material in which a transparent solid substance forms a three-dimensional network structure.

17. A light scattering liquid crystal device as claimed in claim 1, wherein said light controlling layer of the first panel contains at least 60% by weight of the liquid crystal material.

18. A light scattering liquid crystal device as claimed in claim 2, wherein said light controlling layer of the first panel contains at least 60% by weight of the liquid crystal material.

19. A light scattering liquid crystal device as claimed in claim 4, wherein said light controlling layer of the first panel contains at least 60% by weight of the liquid crystal material.

20. A light scattering liquid crystal device as claimed in claim 19, wherein said light controlling layer has a thickness of from 2 to 30 μ

m.