Illuminating device and liquid-crystal display apparatus

• US 20010017674A1
• Filed: 02/02/2001
• Published: 08/30/2001
• Est. Priority Date: 02/02/2000
• Status: Active Grant

• Current Assignee: Eagle New Media Investments, LLC (Nexstar Media Group, Inc.)
• Original Assignee: Eagle New Media Investments, LLC (Nexstar Media Group, Inc.)
• Inventors: Yamaguchi, Akira
• Granted Patent: US 6,527,410 B2
• Time in Patent Office: Days
• US Class Current: 349/61
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133524 Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133562 on the viewer side
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses

Abstract

The illuminating device includes light sources, a housing of the light sources that has its inner surfaces covered with a diffuse reflecting layer, an optical collimator for collimating the light issued from the light sources and the light reflected by the diffuse reflecting layer, and a directivity regulating member for regulating the directivity of the collimated light emerging from the optical collimator. The liquid-crystal display apparatus has a liquid-crystal display panel and the illuminating device. The illuminating device can emit collimated light of very high directivity and may be utilized in the liquid-crystal display apparatus to display images of high quality and contrast over a wide range of viewing angles.

Claims

1. An illuminating device comprising light sources, a housing of said light sources that has its inner surfaces covered with a diffuse reflecting layer, an optical collimator for collimating light issued from said light. sources and the light reflected by the diffuse reflecting layer, and a directivity regulating member for regulating directivity of the collimated light emerging from said optical collimator.

2. The illuminating device according to

claim 1

, wherein said directivity regulating member has a plurality of optical paths through which the light passes and anti-reflection layers that absorb the light incident on wall surfaces of said optical paths.

3. The illuminating device according to

claim 1

, wherein the following relation is satisfied:

p/tan θ

≦

La

where p is a pitch of emergence of the collimated light from said optical collimator, θ

is a divergence angle of th e collimated light emerging from said optical collimator, and La is a distance from said optical collimator to the directivity regulating member.

4. A liquid-crystal display apparatus comprising:

a liquid-crystal display panel; and

an illuminating device including light sources, a housing of said light sources that has its inner surfaces covered with a diffuse reflecting layer, an optical collimator for collimating light issued from said light sources and the light reflected by the diffuse reflecting layer, and a directivity regulating member for regulating directivity of the collimated light emerging from said optical collimator.

5. The liquid-crystal display apparatus according to

claim 4

, wherein said directivity regulating member has a plurality of optical paths through which the light passes and anti-reflection layers that absorb the light incident on wall surfaces of said optical paths.

6. The liquid-crystal display apparatus according to

claim 4

, wherein the following relation is satisfied:

p/tan θ

≦

La

where p is a pitch of emergence of the collimated light;

from said optical collimator, θ

is a divergence angle of the collimated light emerging from said optical collimator, and La is a distance from said optical collimator to the directivity regulating member.

7. The liquid-crystal display apparatus according to

claim 4

, further comprising:

a light diffusing plate for diffusing image-bearing light that has passed through said liquid-crystal display panel.

8. The liquid-crystal display apparatus according to

claim 4

, wherein the following relation is satisfied:

p/tan φ

≦

Lb

where q is a pitch of emergence of the collimated light from said illuminating device, φ

is a divergence angle of the collimated light emerging from said illuminating device, and Lb is a distance from said illuminating device to a liquid-crystal layer of the liquid-crystal display panel.