Liquid crystal display with optically anisotropic member having a twisted structure and phase plate

• US 5,400,158 A
• Filed: 07/23/1993
• Issued: 03/21/1995
• Est. Priority Date: 07/24/1992
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ohnishi, Hiroshi, Kishimoto, Keiko
• Primary Examiner(s): GROSS, ANITA P
• Application Number:
  US08/097,263
• Time in Patent Office: 606 Days
• Field of Search: 359/73, 359/53
• US Class Current: 349/119
• CPC Class Codes: G02F 1/133636 with twisted orientation, e.g. comprising helically oriented LC-molecules or a plurality of twisted birefringent sublayers
• CPC Class Codes: G02F 1/1397 the twist being substantially higher than 90°, e.g. STN-, SBE-, OMI-LC cells

Abstract

A liquid crystal display is disclosed. The liquid crystal display includes: a liquid crystal panel including a pair of substrates and super twisted nematic liquid crystal having a twisted structure with a twist angle of 180° or more, the super twisted nematic liquid crystal being contained between the pair of substrates; a pair of polarizing plates which sandwich the liquid crystal panel; an optically anisotropic plate having a twisted structure with a twist angle of 90° or less, the optically anisotropic plate being disposed between one of the pair of polarizing plates and the liquid crystal panel, or between the other one of the pair of polarizing plates and the liquid crystal panel; and a phase plate of a polymeric film which is uniaxially extended, the phase plate being disposed between one of the pair of polarizing plates and the liquid crystal panel, or between the other one of the pair of polarizing plates and the liquid crystal panel.

Claims

1. A liquid crystal display comprising:

a liquid crystal panel including a pair of substrates and super twisted nematic liquid crystal having a twisted structure with a twist angle of 180°

or more, said super twisted nematic liquid crystal being contained between said pair of substrates;

a pair of polarizing plates which sandwich said liquid crystal panel;

a member of an optically anisotropic substance having a twisted structure with a twist angle of 90°

or less, said member being disposed between one of said pair of polarizing plates and said liquid crystal panel, or between the other one of said pair of polarizing plates and said liquid crystal panel; and

a phase plate of a polymeric film which is uniaxially extended, said phase plate being disposed between one of said pair of polarizing plates and said liquid crystal panel, or between the other one of said pair of polarizing plates and said liquid crystal panel.

2. A liquid crystal display according to claim 1, wherein a twist direction of said super twisted nematic liquid crystal is in reverse to a twist direction of said member.

3. A liquid crystal display according to claim 2, wherein a product d·

Δ

n is in the range from 180 nm to 700 nm, where d is a thickness of said member and Δ

n is the anisotropy of refractive index.

4. A liquid crystal display according to claim 1, wherein a twist direction of said super twisted nematic liquid crystal is the same as a twist direction of said member.

5. A liquid crystal display according to claim 4, wherein a product of d·

Δ

n is in the range from 500 nm to 1100 nm, where d is a thickness of said optically anisotropic substance and Δ

n is the anisotropy of refractive index.

6. A liquid crystal display according to claim 1, wherein said phase plate is a film of polycarbonate.

7. A liquid crystal display according to claim 1, wherein said phase plate is a film of polyvinylalcohol.

8. A liquid crystal display according to claim 1, wherein said phase plate is a quarter-wave plate of polycarbonate.

9. A liquid crystal display according to claim 1, wherein said phase plate is a quarter-wave plate of polyvinylalcohol.

10. A liquid crystal display according to claim 1, wherein the member of an optically anisotropic substance and the phase plate of a polymeric film are provided on one side of the liquid crystal panel.

11. A liquid crystal display according to claim 1, wherein the member of an optically anisotropic substance is a liquid crystal polymeric film.

12. A liquid crystal display comprising:

a liquid crystal panel including a pair of substrates and super twisted nematic liquid crystal having a twisted structure with a twist angle of 180°

or more, said super twisted nematic liquid crystal being contained between said pair of substrates;

a pair of polarizing plates which sandwich said liquid crystal panel;

a member of an optically anisotropic substance having a twisted structure with a twist angle from 60°

to 130°

, said member being disposed between one of said pair of polarizing plates and said liquid crystal panel; and

a phase plate of a polymeric film which is uniaxially extended, said phase plate being disposed between the other one of said pair of polarizing plates and said liquid crystal panel.

13. A liquid crystal display according to claim 12, wherein a twist direction of said super twisted nematic liquid crystal is in reverse to a twist direction of said member.

14. A liquid crystal display according to claim 13, wherein a product d·

Δ

n is in the range from 180 nm to 700 nm, where d is a thickness of said member and Δ

n is the anisotropy of refractive index.

15. A liquid crystal display according to claim 12, wherein a twist direction of said super twisted nematic liquid crystal is the same as a twist direction of said member.

16. A liquid crystal display according to claim 15, wherein a product of d·

Δ

n is in the range from 500 nm to 1100 nm, where d is a thickness of said member and Δ

n is the anisotropy of refractive index.

17. A liquid crystal display according to claim 12, wherein said phase plate is a film of polycarbonate.

18. A liquid crystal display according to claim 12, wherein said phase plate is a film of polyvinylalcohol.

19. A liquid crystal display according to claim 12, wherein said phase plate is a quarter-wave plate of polycarbonate.

20. A liquid crystal display according to claim 12, wherein said phase plate is a quarter-wave plate of polyvinylalcohol.