IMAGE DISPLAY APPARATUS

• US 20080180596A1
• Filed: 09/13/2007
• Published: 07/31/2008
• Est. Priority Date: 09/14/2006
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fujimoto, Makoto
• Granted Patent: US 7,688,399 B2
• Time in Patent Office: Days
• US Class Current: 349/62
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00

Abstract

An image display apparatus including a light source unit, a liquid crystal display panel, an illumination optical system leading light from the light source unit to the liquid crystal display panel, and a display optical system leading light from the liquid crystal display panel to an observer. The illumination optical system and the display optical system share an optical surface having dielectric multilayer films and being concave toward the liquid crystal display panel on a plane including a center ray corresponding to an angle of view. The optical surface reflects light from the light source unit for leading the light to the liquid crystal display panel while transmitting light reflected from the liquid crystal display panel. On the plane including the center ray, the brightness of the light-emitting surface of the light source unit is reduced toward the optical surface smaller than that in the remote from the optical surface.

Claims

1. An image display apparatus comprising:

a light source unit;

a liquid crystal display panel;

an illumination optical system configured to lead the light from the light source unit to the liquid crystal display panel; and

a display optical system configured to lead the light from the liquid crystal display panel to an observer,

wherein the illumination optical system and the display optical system share an optical surface having dielectric multilayer films laminated thereon and being concave toward the liquid crystal display panel on a plane including a center ray corresponding to an angle of view, the optical surface reflecting the light from the light source unit so as to lead the reflected light to the liquid crystal display panel while transmitting the light reflected from the liquid crystal display panel, and

wherein on the plane including the center ray corresponding to an angle of view, the brightness of the light-emitting surface of the light source unit is reduced toward the optical surface smaller than that in the remote from the optical surface.

2. The apparatus according to claim 1, wherein the optical surface is arranged such that the portion of the optical surface close to the light-emitting surface of the light source unit is remote from the liquid crystal display panel in comparison with the portion of the optical surface remote from the light-emitting surface.

3. The apparatus according to claim 1, wherein the light source unit includes a light-emitting element and a diffusing plate configured as the light-emitting surface of the light source unit by the incident light from the light-emitting element.

4. The apparatus according to claim 3, wherein the light-emitting element is displaced from a correct position opposing the diffusing plate.

5. The apparatus according to claim 1, wherein the dielectric multilayer films laminated on the optical surface satisfy the following condition:

30%<

Rs×

Tp,

where the reflectance of the films when S-polarized light with a wavelength 550 nm is incident in the films at an incidence angle of 40°

is Rs, and the transmittance of the films when P-polarized light is incident in the films at an incidence angle of 40°

is Tp.