Liquid-crystal display device

• US 6,144,429 A
• Filed: 01/23/1997
• Issued: 11/07/2000
• Est. Priority Date: 01/25/1996
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakai, Yutaka, Akiyama, Masahiko
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Duong, Tai V.
• Application Number:
  US08/787,602
• Time in Patent Office: 1,384 Days
• Field of Search: 349/113, 349/64, 349/112, 349/165, 349/122, 349/138
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence

Abstract

A liquid crystal display device comprises a reflector made of a high-reflectance material, a light scattering layer formed on the reflector, the light scattering layer containing light scattering particles introduced into a transparent resin, a first transparent electrode formed on the light scattering layer, a transparent substrate opposed to the light scattering layer with a prescribed gap interposed therebetween, a second transparent electrode formed on the transparent substrate and having a portion that is opposed to the first transparent electrode, and a layer of a guest-host type liquid crystal introduced into the gap between the light scattering layer and the transparent substrate and having a portion that is sandwiched between the first and the second transparent electrode.

Claims

1. A liquid crystal display device comprising:

a reflector;

a light scattering layer formed on the reflector, and formed of light scattering particles introduced into a transparent resin;

a first transparent electrode formed on the light scattering layer;

a transparent substrate opposed to the light scattering layer with a prescribed gap interposed therebetween;

a second transparent electrode formed on the transparent substrate and having a portion that is opposed to the first transparent electrode; and

a liquid crystal layer introduced into the gap between the light scattering layer and the transparent substrate and having a portion that is inserted between the first and the second transparent electrode,

wherein a ratio of total scattering energy to incident energy per unit cross-sectional area of a single particle is in a range between 0.8 to 3.0.

2. The liquid crystal display device according to claim 1, wherein a volume concentration PVC of the light scattering particles in the light scattering layer, an average size D of the light scattering particles, and an effective thickness d of the light scattering layer are related by the following expression

3. The liquid crystal display device according to claim 2, wherein the effective thickness d of the light scattering layer is 10 micrometers or less.

4. The liquid crystal display device according to claim 1, wherein the reflector is made of an electrically conducting material, the light scattering layer has at least one opening to expose the reflector, and the first transparent electrode is electrically connected to the reflector through the at least one opening.

5. The liquid crystal display device according to claim 1, wherein the transparent resin comprises an acrylic resin.

6. The liquid crystal display device according to claim 1, wherein the particles are made of one selected from a group of titanium oxide, zinc oxide, antimony oxide, zirconium oxide, calcium carbonate, calcium sulfate, barium sulfate and alminum oxide.

7. The liquid crystal display device according to claim 1, wherein the liquid crystal layer includes guest-host type liquid crystal.

8. A liquid crystal display device comprising:

a reflector;

a light scattering layer formed on the reflector, and formed of light scattering particles introduced into a transparent resin;

a first transparent electrode formed on the light scattering layer;

a transparent substrate opposed to the light scattering layer with a prescribed gap interposed therebetween;

a second transparent electrode formed on the transparent substrate and having a portion that is opposed to the first transparent electrode; and

a layer of a guest-host type liquid crystal introduced into the gap between the light scattering layer and the transparent substrate and having a portion that is inserted between the first and the second transparent electrode,

wherein a ratio of total scattering energy to incident energy per unit cross-sectional area of a single particle is in a range between 0.8 to 3.0.

9. The liquid crystal display device according to claim 8, wherein a volume concentration PVC of the particles in the light scattering layer, an average size D of the particles and an effective thickness d of the light scattering layer are related by

10. The liquid crystal display device according to claim 9, wherein the effective thickness d of the light scattering layer is 10 micrometers or less.

11. The liquid crystal display device according to claim 8, wherein the reflector is made of an electrically conducting material, the light scattering layer has at least one opening to expose the reflector, and the first transparent electrode is electrically connected to the reflector through the at least one opening.

12. The liquid crystal display device according to claim 8, wherein the transparent resin comprises an acrylic resin.

13. The liquid crystal display device according to claim 8, wherein the particles are made of one selected from a group of titanium oxide, zinc oxide, antimony oxide, and zirconium oxide.

14. A liquid crystal display device, comprising:

a reflector;

a light scattering layer formed on the reflector, and formed of light scattering particles introduced into a transparent resin;

a first transparent electrode formed on the light scattering layer;

a transparent substrate opposed to the light scattering layer with a prescribed gap interposed therebetween;

a second transparent electrode formed on the transparent substrate and having a portion that is opposed to the first transparent electrode; and

a liquid crystal layer introduced into the gap between the light scattering layer and the transparent substrate and having a portion that is inserted between the first and the second transparent electrode,

wherein the reflector is made of an electrically conducting material, the light scattering layer has at least one opening to expose the reflector, and the first transparent electrode is electrically connected to the reflector through the at least one opening.

15. The liquid crystal display device according to claim 14, wherein an effective thickness of the light scattering layer is 10 micrometers or less.

16. The liquid crystal display device according to claim 14, wherein the liquid crystal layer includes guest-host type liquid crystal.