Reflector, liquid crystal display device, and indenter used for manufacturing reflector

• US 20060077668A1
• Filed: 09/29/2005
• Published: 04/13/2006
• Est. Priority Date: 10/12/2004
• Status: Active Grant

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Chikira, Chie, Yoshii, Katsuma
• Granted Patent: US 7,542,113 B2
• Time in Patent Office: Days
• US Class Current: 362/341
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 2201/14 asymmetric

Abstract

A reflector is provided in a reflective or transmissive liquid crystal display device. In the reflector, when light is incident on the reflector in a first direction, a reflection characteristic profile of light reflected therefrom shows a reflectance distribution which is asymmetric with respect to a specular reflection angle of the incident light and shows a non-Gaussian distribution in which a maximum value of reflectance is within a reflection angle range smaller than the specular reflection angle of the incident light. In addition, when light is incident on the reflector in a second direction perpendicular to the first direction, a reflection characteristic profile of light reflected therefrom shows the non-Gaussian distribution, similar to the case in which the light is incident on the reflector in the first direction.

Claims

1. A reflector used for a reflective or transflective liquid crystal display device,

wherein, when light is incident on the reflector in a first direction, a reflection characteristic profile of light reflected therefrom shows a reflectance distribution which is asymmetric with respect to a specular reflection angle of the incident light and shows a non-Gaussian distribution in which a maximum value of reflectance is within a reflection angle range smaller than the specular reflection angle of the incident light, and

when light is incident on the reflector in a second direction perpendicular to the first direction, a reflection characteristic profile of light reflected therefrom shows the non-Gaussian distribution, similar to the case in which the light is incident on the reflector in the first direction.

2. The reflector according to claim 1,

wherein a plurality of concave portions is provided in a reflective surface of a substrate, and

an inner surface of each concave portion includes:

a concave curved surface that extends from an opening portion of the concave portion to a lowest point of the concave portion;

a first flat surface that is provided adjacent to the concave curved surface so as to be perpendicular to the first direction; and

a second flat surface that is provided adjacent to the concave curved surface so as to be perpendicular to the second direction.

3. The reflector according to claim 2, wherein the first flat surface and the second flat surface are adjacent to each other.

4. The reflector according to claim 2, wherein the first flat surface and the second flat surface are separated from each other.

5. The reflector according to claim 1,

wherein a plurality of concave portions is provided in a reflective surface of a substrate,

an opening portion of each concave portion is formed in a circular or elliptical shape,

an inner surface of the concave portion is composed of a concave curved surface, and

a ring-shaped flat portion is provided around a lowest point of the concave curved surface.

6. The reflector according to claim 1,

wherein a plurality of concave portions is provided in a reflective surface of a substrate, and

the concave portions include:

first concave portions which show the reflection characteristic profile of the non-Gaussian distribution type with respect to the light incident in the first direction; and

second concave portions which show the reflection characteristic profile of the non-Gaussian distribution type with respect to the light incident in the second direction.

7. The reflector according to claim 6,

wherein an inner surface of each of the first concave portions includes:

a concave curved surface that extends from an opening portion of the first concave portion to a lowest point of the first concave portion; and

a first flat portion that is adjacent to the concave curved surface so as to be perpendicular to the first direction, and

an inner surface of each of the second concave portions includes;

a concave curved surface that extends from an opening portion of the second concave portion to a lowest point of the second concave portion; and

a second flat portion that is adjacent to the concave curved surface so as to be perpendicular to the second direction.

8. The reflector according to claim 2, wherein an outline of the opening portion formed by the concave curved surface is an arc-shaped curved line.

9. The reflector according to claim 2, wherein an outline of the opening portion formed by the concave curved surface is an elliptical curved line.

10. The reflector according to claim 2,

wherein the first flat surface extends to the opening portion, and

an outline of the opening portion formed by the first flat surface is a straight line.

11. The reflector according to claim 2,

wherein the second flat surface extends to the opening portion, and

an outline of the opening portion formed by the second flat surface is a straight line.

12. The reflector according to claim 2, wherein the concave curved surface is a spherical surface.

13. The reflector according to claim 2, wherein the concave curved surface has an asymmetric shape with respect to the lowest point.

14. A liquid crystal display device comprising the reflector according to claim 1.

15. The liquid crystal display device according to claim 14,

wherein the liquid crystal display device has a rectangular display surface, and

the reflector is arranged such that the first direction coincides with a lengthwise direction of the display surface and the second direction coincides with a widthwise direction of the display surface.

23. The reflector according to claim 6, wherein an outline of the opening portion formed by the concave curved surface of at least one of the first or second concave portions is an arc-shaped curved line.

24. The reflector according to claim 6, wherein an outline of the opening portion formed by the concave curved surface of at least one of the first or second concave portions is an elliptical curved line.

25. The reflector according to claim 7,

wherein the first flat portion extends to the opening portion of the first concave portion, and

an outline of the opening portion formed by the first flat portion is a straight line.

26. The reflector according to claim 7,

wherein the second flat portion extends to the opening portion of the second concave portion, and

an outline of the opening portion formed by the second flat portion is a straight line.

27. The reflector according to claim 7, wherein the concave curved surface of at least one of the first or second concave portions is a spherical surface.

28. The reflector according to claim 6, wherein a concave curved surface of at least one of the first or second concave portions has an asymmetric shape with respect to the lowest point.

16. An indenter used for forming an original mold surface in a manufacturing method of a reflector,

the method including:

forming the original mold surface on a base plate to manufacture an original mold;

transferring the original mold surface onto a transfer substrate to manufacture a transfer mold having a transfer surface corresponding to the original mold surface; and

transferring the transfer surface onto a substrate to form a reflective surface having the same shape as that of the original mold surface on the substrate,

the indenter including;

an indenter body; and

a concave portion forming part that is provided at a leading end of the indenter body,

wherein the concave portion forming part includes;

a convex curved surface including the tip of the indenter body;

a first flat surface which is adjacent to the convex curved surface; and

a second flat surface which is adjacent to the convex curved surface so as to be perpendicular to the first flat surface.

17. The indenter used for manufacturing a reflector according to claim 16, wherein the first flat surface and the second flat surface are adjacent to each other.

18. The indenter used for manufacturing a reflector according to claim 16, wherein the first flat surface and the second flat surface are separated from each other.

21. The indenter used for manufacturing a reflector according to claim 16, wherein the convex curved surface is a spherical surface.

22. The indenter used for manufacturing a reflector according to claim 16, wherein the convex curved surface has an asymmetric shape with respect to the tip.

19. An indenter used for forming an original mold surface in a manufacturing method of a reflector,

the method including:

forming the original mold surface on a base plate to manufacture an original mold;

transferring the original mold surface onto a transfer substrate to manufacture a transfer mold having a transfer surface corresponding to the original mold surface; and

transferring the transfer surface onto a substrate to form a reflective surface having the same shape as that of the original mold surface on the substrate,

the indenter including;

an indenter body; and

a concave portion forming part that is provided at a leading end of the indenter body,

wherein the concave portion forming part includes;

a convex curved surface including the tip of the indenter body; and

a flat surface which is adjacent to the convex curved surface.

29. The indenter used for manufacturing a reflector according to claim 19, wherein the convex curved surface is a spherical surface.

30. The indenter used for manufacturing a reflector according to claim 19, wherein the convex curved surface has an asymmetric shape with respect to the tip.

20. An indenter used for forming an original mold surface in a manufacturing method of a reflector,

the method including:

forming the original mold surface on a base plate to manufacture an original mold;

transferring the original mold surface onto a transfer substrate to manufacture a transfer mold having a transfer surface corresponding to the original mold surface; and

transferring the transfer surface onto a substrate to form a reflective surface having the same shape as that of the original mold surface on the substrate,

the indenter including;

an indenter body; and

a concave portion forming part that is provided at a leading end of the indenter body,

wherein the concave portion forming part includes;

a convex curved surface including the tip of the indenter body; and

a ring-shaped flat portion which is positioned around the tip.

31. The indenter used for manufacturing a reflector according to claim 20, wherein the convex curved surface is a spherical surface.

32. The indenter used for manufacturing a reflector according to claim 20, wherein the convex curved surface has an asymmetric shape with respect to the tip.