Anti-reflective structure, illuminating device, liquid crystal display device, and mold for forming anti-reflective film

• US 20040105646A1
• Filed: 11/25/2003
• Published: 06/03/2004
• Est. Priority Date: 11/28/2002
• Status: Abandoned Application

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Aoki, Daigo, Naito, Koichi, Honda, Kenji, Fukuda, Tetsuya, Ishibashi, Naohiro, Ishitaka, Yoshihiko
• Application Number:
  US10/721,664
• Publication Number:
  US 20040105646A1
• Time in Patent Office: Days
• US Class Current: 385/129
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/118 having sub-optical wavelength surface structures designed to provide an enhanced transmittance, e.g. moth-eye structures
• CPC Class Codes: G02B 5/1809 with pitch less than or comparable to the wavelength

Abstract

An anti-reflective film has an anti-reflective structure having many micro holes extending from a reference surface (first surface) in the thickness direction of the film. Each of the holes has an opening exposed at the reference surface, and a bottom facing the second surface on the attachment side. Light incident on the anti-reflective film is mostly introduced into the holes through the openings and diffused by the bottoms, thereby avoiding reflection at a predetermined angle. The ratio of a connecting surface which reflects light is suppressed to increase the ratio of the openings, thereby maximizing the anti-reflective ability of the anti-reflective structure.

Claims

1. An anti-reflective structure comprising many micro holes each having an opening at a first surface and a bottom facing a second surface opposite to the first surface, each hole extending from the opening to the bottom.

2. The anti-reflective structure according to claim 1, wherein the ratio of the openings to the first surface is set to 70% to 85% per unit area.

3. The anti-reflective structure according to claim 1, wherein the reflectance is set to 1% or less.

4. The anti-reflective structure according to claim 1, wherein the bottom of each hole has a quadratic surface.

5. The anti-reflective structure according to claim 1, wherein the opening of each hole has a polygonal shape.

6. The anti-reflective structure according to claim 1, wherein the openings are disposed in a staggered arrangement in the first surface.

7. An anti-reflective film comprising an anti-reflective structure according to claim 1 which is formed on at least one of the front face and the rear face of the film.

8. A light guide comprising:

an anti-reflective structure having many micro holes each having an opening at a first surface and a bottom facing a second surface opposite to the first surface, each hole extending from the opening to the bottom; and

a reflective structure having many micro grooves formed in the second surface.

9. An illuminating device comprising a light guide according to claim 8, and a light source for irradiating the light guide.

10. A liquid crystal display device comprising an illuminating device according to claim 9, and a liquid crystal display unit.

11. A mold for forming an anti-reflective film comprising an anti-reflective structure having many micro holes each having an opening at a first surface and a bottom facing a second surface opposite to the first surface, each hole extending from the opening to the bottom, the mold comprising a first inner surface for forming the first surface, a second inner surface for forming the second surface, and many micro protrusions protruding from the first inner surface to the second inner surface for patterning the outlines of the holes.

12. The mold for forming an anti-reflective film according to claim 11, wherein the protrusions are disposed in a staggered arrangement.