IP Library Granted Patent US 7,250,997
Granted Patent B2
US 7,250,997 · App. 10/975,478 · Granted Jul 31, 2007

Liquid crystal display device

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Quick Facts
Patent No.
US 7,250,997
App. No.
10/975,478
Granted
Jul 31, 2007
Kind
B2
Abstract

A liquid crystal display device includes first and second electrode substrates, a liquid crystal layer which is held between the substrates and in which nematic liquid crystal molecules are arranged in substantially parallel to each of the substrates without distortion, first and second optical anisotropic elements respectively disposed on the substrates on the sides opposite to the liquid crystal layer, first and second half-wavelength plates respectively disposed on the optical anisotropic elements, and first and second polarizing plates respectively disposed on the half-wavelength plates. Particularly, the substrate includes a light transmitting section which permits backlight light from the polarizing plate side to transmit therethrough and a light reflecting section which reflects ambient light from the polarizing plate side and at least one of the optical anisotropic elements is formed of two retardation plates having a retardation in a plane.

Claims (33)

1. A liquid crystal display device comprising:

first and second electrode substrates;

a liquid crystal layer which is held between the first and second electrode substrates and in which nematic liquid crystal molecules are arranged in substantially parallel to each of the substrates without distortion;

first and second optical anisotropic elements respectively disposed on the first and second electrode substrates on the sides opposite to the liquid crystal layer;

first and second half-wavelength plates respectively disposed on the first and second optical anisotropic elements; and

first and second polarizing plates respectively disposed on the first and second half-wavelength plates;

wherein the first electrode substrate includes a light transmitting section which permits backlight light incident from the first polarizing plate side to transmit therethrough and a light reflecting section which reflects ambient light incident from the second polarizing plate side, and at least one of the first and second optical anisotropic elements is formed of two retardation plates having a retardation in a plane;

wherein at least one of the two retardation plates is a liquid crystal film; and

wherein the liquid crystal film is one of a nematic liquid crystal and smectic liquid crystal which are aligned and solidified.

2. A liquid crystal display device comprising:

first and second electrode substrates;

a liquid crystal layer which is held between the first and second electrode substrates and in which nematic liquid crystal molecules are arranged in substantially parallel to each of the substrates without distortion;

first and second optical anisotropic elements respectively disposed on the first and second electrode substrates on the sides opposite to the liquid crystal layer;

first and second half-wavelength plates respectively disposed on the first and second optical anisotropic elements; and

first and second polarizing plates respectively disposed on the first and second half-wavelength plates;

wherein the first electrode substrate includes a light transmitting section which permits backlight light incident from the first polarizing plate side to transmit therethrough and a light reflecting section which reflects ambient light incident from the second polarizing plate side, and at least one of the first and second optical anisotropic elements is formed of two retardation plates having a retardation in a plane; and

wherein one of the two retardation plates is a liquid crystal film of a structure having liquid crystal molecules whose optical axes continuously or gradually tilt depending on the position in a thickness direction and the other one of the two retardation plates is a uniaxial retardation plate disposed between the liquid crystal film and the liquid crystal layer.

3. The liquid crystal display device according to claim 2 , wherein the uniaxial retardation plate is a liquid crystal film.

4. A liquid crystal display device comprising:

first and second electrode substrates;

a liquid crystal layer which is held between the first and second electrode substrates and in which nematic liquid crystal molecules are arranged in substantially parallel to each of the substrates without distortion;

first and second optical anisotropic elements respectively disposed on the first and second electrode substrates on the sides opposite to the liquid crystal layer;

first and second half-wavelength plates respectively disposed on the first and second optical anisotropic elements; and

first and second polarizing plates respectively disposed on the first and second half-wavelength plates;

wherein the first electrode substrate includes a light transmitting section which permits backlight light incident from the first polarizing plate side to transmit therethrough and a light reflecting section which reflects ambient light incident from the second polarizing plate side, at least one of the first and second optical anisotropic elements is formed of three retardation plates having a retardation in a plane, and at least one of the three retardation plates is a nematic liquid crystal film of a structure having liquid crystal molecules whose optical axes continuously or gradually tilt depending on the position in a thickness direction.

5. A liquid crystal display device comprising:

first and second electrode substrates;

a liquid crystal layer which is held between the first and second electrode substrates and in which nematic liquid crystal molecules are arranged in substantially vertical to each of the substrates;

first and second optical anisotropic elements respectively disposed on the first and second electrode substrates on the sides opposite to the liquid crystal layer;

first and second half-wavelength plates respectively disposed on the first and second optical anisotropic elements; and

first and second polarizing plates respectively disposed on the first and second half-wavelength plates;

wherein the first electrode substrate includes a light transmitting section which permits backlight light incident from the first polarizing plate side to transmit therethrough and a light reflecting section which reflects ambient light incident from the second polarizing plate side, at least one of the first and second optical anisotropic elements is formed of a plurality of retardation films, and the plurality of retardation films include liquid crystal films of a structure having discotic liquid crystal molecules whose optical axes are aligned with each other in a thickness direction.

6. The liquid crystal display device according to claim 2 , wherein the liquid crystal film is one of a nematic liquid crystal and smectic liquid crystal which are aligned and solidified.

Assignments (3)
CHANGE OF NAME Recorded Jun 8, 2012
From: TOSHIBA MOBILE DISPLAY CO., LTD.
To: JAPAN DISPLAY CENTRAL INC.
Reel/Frame 028339/0316 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 6, 2011
From: KABUSHIKI KAISHA TOSHIBA
To: TOSHIBA MOBILE DISPLAY CO., LTD.
Reel/Frame 026859/0288 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 29, 2004
From: OOTAKE, TOSHIYA; KIZU, YUKO; NAKAI, YUTAKA; YAMADA, YOSHITAKA
To: KABUSHIKI KAISHA TOSHIBA
Reel/Frame 015944/0170 →