Light-modulating element, display element, and exposure element

• US 7,050,219 B2
• Filed: 06/17/2002
• Issued: 05/23/2006
• Est. Priority Date: 07/19/2001
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Kimura, Koichi
• Primary Examiner(s): MARTINEZ, JOSEPH P
• Assistant Examiner(s): Hanig, Richard
• Application Number:
  US10/484,151
• Publication Number:
  US 20050018272A1
• Time in Patent Office: 1,436 Days
• Field of Search: 359/295, 359/290, 359/291, 359/298, 359/320, 385/901, 385/147, 385/32, 385/31, 385/30, 385/120
• US Class Current: 359/298
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02F 1/1326 Liquid crystal optical waveguides or liquid crystal cells specially adapted for gating or modulating between optical waveguides
• CPC Class Codes: G02F 1/315 based on the use of controlled internal reflection

Abstract

Subjects for the invention are to provide a light-modulating element having an elevated energy efficiency while preventing a decrease in contrast at low cost without using a display technique employing a waveguide or lightguide plate, and to provide a display element capable of producing high-quality display images and an exposure element capable of exposure treatment.

In the invention, the light-modulating element comprises: a total-reflection optical member 2 having such a property that at least part of planar incident light introduced into the light-modulating element is totally reflected at an interface (total reflection plane) 22 of a layer constituted by the light-modulating element and the incident light does not substantially go out through the side opposite to the incident-light introduction side; and light-coupling elements 6 which are disposed on the total reflection plane 22 side of the total-reflection optical member 2 and serve to selectively couple with the incident light and take out the same from the total reflection plane 22.

Claims

1. A light-modulating element having a flat shape, which comprises:

a total-reflection optical member having such a property that at least part of incident light introduced into the light-modulating element is totally reflected at an total reflection plane provided at a side opposite to the incident-light introduction side and the incident light does not substantially go out through a side opposite to the incident-light introduction side; and

a light-coupling element which is disposed on the total reflection plane side of the total-reflection optical member and serves to selectively couple with the incident light and take out the same from the total reflection plane;

wherein the total-reflection optical member has, disposed therein, an optical element which selects a light path, and that at least part of the planar incident light introduced into the total-reflection optical member is introduced into the optical element selecting a light path and substantially all the incident light thus introduced is reflected by total reflection at an interface of a layer constituted by the total-reflection optical member.

2. The light-modulating element of claim 1, wherein the light-modulating element has a transparent medium constituting part of the total-reflection optical member and the optical element selecting a light path has been disposed on the light-path front side of the transparent medium.

3. The light-modulating element of claim 1, wherein the optical element selecting a light path has such a property that substantially all the transmitted light emitted by the optical element has components having an angle larger than the critical total reflection angle at an interface of a layer disposed on the incident light light-path front side of the optical element selecting a light path or at the interface of the incident light light-path front side of the optical element selecting a light path and the incident light components having any other angle are selectively reflected and are not transmitted therethrough.

4. The light-modulating element of claim 1, wherein the optical element selecting a light path transmits substantially all light having an angle θ

s satisfying the requirement

sinθ

s>

nw/ns

wherein ns is the average refractive index of the optical element selecting a light path, nw is the refractive index of the medium disposed on the light-path front side of the total reflection plane, and θ

s is the angle of the light passing through the medium of the optical element selecting a light path.

5. The light-modulating element of claim 1, wherein the optical element selecting a light path functions to reflect incident light selectively with respect to wavelength region, and that as the incidence angle of the light striking on the optical element selecting a light path with the plane of the optical element becomes smaller, the wavelength of the incident light selectively reflected shifts to the shorter-wavelength side.

6. The light-modulating element of claim 1, wherein when the incidence angel of the light striking on the optical element selecting a light path is regulated so that the angle of incidence on the total reflection plane on the incident light light-path front side is not larger than the critical total reflection angle, then the optical element selecting a light path selectively reflects substantially all the incident light.

7. The light-modulating element of claim 1, wherein the optical element selecting a light path is an optical interference filter comprising a dielectric multilayer film.

8. The light-modulating element of claim 1, wherein the optical element selecting a light path is a Bragg reflection filter comprising either a cholesteric liquid crystal or a volume hologram.

9. A light-modulating element having a flat shape, which comprises:

a total-reflection optical member having such a property that at least part of incident light introduced into the light-modulating element is totally reflected at an total reflection plane provided at a side opposite to the incident-light introduction side and the incident light does not substantially go out through a side opposite to the incident-light introduction side; and

a light-coupling element which is disposed on the total reflection plane side of the total-reflection optical member and serves to selectively couple with the incident light and take out the same from the total reflection plane;

wherein the total-reflection optical member has an optical element changing a light path and an optical element selecting a light path which are disposed in this order from the incident-light introduction side in the direction of the thickness of the total-reflection optical member, and that when planar incident light is introduced into the optical element changing a light path, then at least part of the incident light introduced is introduced into the optical element selecting a light path and substantially all the incident light thus introduced is reflected by total reflection at an interface of a layer constituted by the light-modulating element.

10. The light-modulating element of claim 9, wherein the optical element changing a light path and the optical element selecting a light path are in optical contact with each other.

11. The light-modulating element of claim 9, wherein the optical element changing a light path and the optical element selecting a light path are in optical contact with each other through a medium having a refractive index higher than 1.

12. The light-modulating element of claim 9, wherein the light-modulating element has a transparent medium constituting part of the total-reflection optical member, and the optical element changing a light path and the optical element selecting a light path have been disposed in this order on the light-path front side of the transparent medium.