Liquid crystal display with compensation means of multiaxially elongated high polymer films

• US 5,166,817 A
• Filed: 10/06/1988
• Issued: 11/24/1992
• Est. Priority Date: 10/07/1987
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Ota, Isao, Fujita, Shingo, Tatsumichi, Toshio, Yoshida, Shigeru, Kumagawa, Katsuhiko, Yamazoe, Hiroshi
• Primary Examiner(s): Miller, Stanley D.
• Assistant Examiner(s): GROSS, ANITA P
• Application Number:
  US07/254,085
• Time in Patent Office: 1,510 Days
• Field of Search: 350/347 R, 350/337, 350/339 R, 359/73
• 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 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 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 1/1397 the twist being substantially higher than 90°, e.g. STN-, SBE-, OMI-LC cells
• CPC Class Codes: G02F 1/141 using ferroelectric liquid crystals

Abstract

A liquid crystal display comprises as liquid crystal panel having a liquid crystal layer disposed between electrode layers, polarizers disposed at both sides of the panel, and a solid birefringent film having the maximum refractive index direction varying with its depth and disposed at at least one side of the liquid crystal panel between the polarizers. The solid birefringent film conpensates the dependence of the polarization characteristic on wave length, thus being capable of obtaining either a monochrome display or a display having an extremely low coloration.

Claims

1. A liquid crystal display comprising:

a liquid crystal panel having a liquid crystal layer of a twisted structure disposed between electrode layers;

two polarizers between which said liquid crystal panel is disposed; and

optical compensation means disposed at at least one side of said liquid crystal panel between said two polarizers to compensate for the dependence of the state of polarization on the wave length so that a black and white image is obtained, said optical compensation means being made of laminated solid multiaxially elongated high polymer films whose maximum refractive index direction is twisted in one direction with depth.

2. A liquid crystal display comprising:

a liquid crystal panel having a liquid crystal layer of a twisted structure disposed between electrode layers;

two polarizers between which said liquid crystal panel is disposed; and

optical compensation means disposed at at least one side of said liquid crystal panel between said two polarizers to compensate for the dependence of the state of polarization on the wave length so that a black and white image is obtained,

wherein said optical compensation means is made of laminated solid films which are multiaxially elongated high polymer films at least one of which is arranged in a direction such that the direction of the refractive index thereof differs from those of the remainder of the films.

3. A liquid crystal display comprising:

a liquid crystal panel having a liquid crystal layer of a twisted structure disposed between electrode layers;

two polarizers disposed at both sides of said liquid crystal panel; and

optical compensation means disposed at each side of said liquid crystal panel between said two polarizers for compensating a dependence of the state of polarization on the wave length so that a black and white image is obtained,

wherein said optical compensation means is made of multiaxially elongated high polymer films.