Reflector and liquid-crystal display device

• US 6,219,119 B1
• Filed: 03/16/1999
• Issued: 04/17/2001
• Est. Priority Date: 03/16/1998
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakai, Yutaka
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): VU, QUYNH-NHU HOANG
• Application Number:
  US09/270,674
• Time in Patent Office: 763 Days
• Field of Search: 349/95, 349/113, 349/143, 349/586, 349/587
• US Class Current: 349/113
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133565 inside the LC elements, i.e. between the cell substrates

Abstract

A reflector including a reflecting surface having hills and valleys, and light-condensing regions disposed above the hills. The light-condensing regions have a larger refractive index than other regions around it. The reflecting surface may include a substrate of, for example, resin or the like having hills and valleys thereon, and a layer of a high-reflectance metal of, for example, aluminium, silver or the like disposed on the substrate. The light-condensing regions are selectively disposed on each hill of the reflecting surface so that the incident rays entering the greatly inclined region between the hill and an adjacent valley on the reflecting surface are condensed in the hill.

Claims

1. A reflector comprising:

a plane reflecting surface having continuous hills and valleys;

a corresponding one of pillar-shaped light-condensing regions respectively disposed above each of said hills, said light-condensing regions having a first refractive index; and

a layer disposed above said reflecting surface and on said light-condensing regions, and having a second refractive index smaller than said first refractive index.

2. A reflector according to claim 1, wherein said layer is disposed directly on the valleys.

3. A reflector according to claim 2, further comprising:

a light-condensing film disposed on said valleys having said first refractive index.

4. A reflector according to claim 1, wherein said light-condensing regions are disposed directly on said hills.

5. A reflector according to claim 3, wherein said light-condensing film is disposed along said valleys.

6. A reflector according to claim 3, wherein said light-condensing film has a substantially plane surface on said valleys.

7. A reflector according to claim 4, wherein at least one light-condensing region of said light-condensing regions is disposed on a top of said hill.

8. A reflector according to claim 4, wherein at least one light-condensing region of said light-condensing regions is shifted from a top of said hill.

9. A reflector according to claim 8, wherein said light-condensing regions are uniformly shifted on said plane reflecting surface.

10. A reflector according to claim 8, wherein said light-condensing regions are shifted to concentrate reflected light to a center of said plane reflecting surface.

11. A reflector according to claim 1, wherein said light-condensing regions are disposed within said layer.

12. A reflector according to claim 1, wherein a side surface of said at least one light-condensing region inclines between 60 degrees and 90 degrees against the plane surface.

13. A reflector according to claim 1, wherein said at least one light-condensing region comprises a polygonal cross-section.

14. A reflector according to claim 13, wherein normal directions of side surfaces of said light-condensing regions are randomly disposed.

15. A reflector according to claim 13, wherein normal directions of side surfaces of said light-condensing regions are the same.

16. A reflector according to claim 1, wherein a side surface of said at least one light-condensing region is curved and broadened at a skirt portion.

17. A reflector according to claim 1, wherein at least one of a top surface and a bottom surface of at least one light-condensing region of the light-condensing regions comprises a curved shape.

18. A reflector according to claim 1, wherein said hills and valleys are randomly disposed.

19. A reflector according to claim 1, wherein a top surface of said light-condensing regions and said layer have substantially a same level.

20. A reflector according to claim 1, wherein a ratio of said second refractive index to said first refractive index is between 0.82 and 1.00.

21. A reflector comprising:

a plane reflecting surface having continuous hills and valleys;

portions disposed on said valleys, and having a first refractive index; and

a corresponding one of light-condensing regions respectively disposed on each of said hills, said light-condensing regions covering said portions and having a second refractive index larger than said first refractive index.

22. A reflective type liquid crystal display comprising:

a substrate;

a plane reflecting surface having continuous hills and valleys on said substrate;

a corresponding one of pillar-shaped light-condensing regions respectively disposed on each of said hills, said light-condensing regions having a first refractive index;

a layer on said plane reflecting surface, and having a second refractive index smaller than said first refractive index;

a first electrode on said layer, and electrically insulated for a pixel;

a liquid crystal layer on said first electrode;

a second electrode on said liquid crystal layer; and

means for supplying image signals to said first electrode.

23. A reflective type liquid crystal display comprising:

a substrate;

a plane reflecting surface having continuous hills and valleys on said substrate, and electrically insulated for a pixel;

a corresponding one of pillar-shaped light-condensing regions respectively disposed on each of said hills, said light-condensing regions having a first refractive index;

a layer on said plane reflecting surface, having a second refractive index smaller than said first refractive index;

a liquid crystal layer on said layer;

an electrode on said liquid crystal layer; and

means for supplying image signals to said plane reflecting surface.

24. A reflective type liquid crystal display comprising:

a substrate;

a plane reflecting surface having continuous hills and valleys on said substrate;

a corresponding one of pillar-shaped light-condensing regions respectively disposed on each of said hills, said light-condensing regions having a first refractive index;

a layer on said plane reflecting surface, having a second refractive index smaller than said first refractive index, and electrically insulated for a pixel;

a liquid crystal layer on said layer;

an electrode on said liquid crystal layer; and

means for supplying image signals to said layer.