Light ray shift devices and projection display apparatus using the same

• US 5,626,411 A
• Filed: 03/05/1996
• Issued: 05/06/1997
• Est. Priority Date: 07/14/1992
• Status: Expired due to Fees

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Takahashi, Yukio, Okimura, Takayuki, Nomura, Tomoyoshi
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US08/611,023
• Time in Patent Office: 427 Days
• Field of Search: 353/31, 353/22, 353/33, 353/34, 353/37, 353/38, 353/69, 353/70, 353/81, 353/94, 359/40, 359/49, 348/745, 348/806, 348/832
• US Class Current: 353/94
• CPC Class Codes: G02B 1/06 made of fluids in transparent cells
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35
• CPC Class Codes: G02B 26/0875 by means of one or more refracting elements
• CPC Class Codes: H04N 17/04 for receivers
• CPC Class Codes: H04N 9/3185 Geometric adjustment, e.g. keystone or convergence optical or mechanical adjustment of convergence H04N9/317; using scanning means H04N3/22; optical or mechanical adjustments of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/14
• CPC Class Codes: H04N 9/3194 including sensor feedback

Abstract

The present invention relates to a light ray shift element which provides controlled refraction of the incident ray and an optical axis displacement device using the above light ray shift element. An application of these optical devices to an interleave projection display system is demonstrated. The optical element is constructed from transparent flat plate materials containing a first optical medium and are disposed at a predetermined spacing along the optical axis. The orientation angle of the transparent flat plates with respect to the optical axis can be varied independently. A bulkhead consisting of the transparent flat plates and a second optical medium having an index of refraction different from the first optical medium, which is enclosed in a hermetic extendable seal, is utilized to provide light ray shift and optical axis displacement. By selecting the first and second optical media suitably, the angle of refraction of the incident ray can be controlled to optimize the quality of the image generated by the interleave projection system.

Claims

1. An interleave projection display apparatus comprising a plurality of projectors, in which each of said plurality of projectors includes a separate projector lens system and projects an image component provided on a light valve to synthesize a composite image on a screen, wherein each of a plurality of light ray shift elements provides a shift of a light ray path to a parallel path and is associated with a respective one of said plurality of projectors, and said each of said plurality of light ray shift elements is disposed on a side of a corresponding to one of each said projector lens system selected from a ray entry side and a ray exit side of said projector lens system.

2. A projection display apparatus as claimed in claim 1, said apparatus further comprising an optical evaluation means for evaluating the optical quality of a test pattern image provided on said light valve of each projector, wherein said evaluating means computes positional displacement of said test pattern image projected by a projector from a predetermined position of said test pattern image, and optically adjusts said test pattern image with said light ray shift element.

3. A projection display apparatus as claimed in one of claims 1 or 2, wherein said light ray shift element is chosen from a group consisting of a plurality of transparent flat plates and a plurality of transparent wedge materials.

4. A projection display apparatus as claimed in claim 3, wherein said light ray shift element comprises two transparent wedge materials, each wedge having a flat surface and an inclined surface, disposed so that a flat surface of one wedge material faces a flat surface of the other wedge material.

5. A projection display apparatus as claimed in claim 3, wherein said light ray shift element comprises three transparent wedge materials, in which flat surfaces of two wedge materials are disposed so that the flat surfaces face each other.

6. A projection display apparatus as claimed in one of claims 1 or 2, wherein said light ray shift element is an optical axis displacement device comprising:

a plurality of optical elements, each including;

(a) a plurality of transparent flat plates disposed at a predetermined spacing along an optical axis of an incident ray passing through a first optical medium, wherein the orientation with respect to said optical axis of an incident ray surface of each of said transparent flat plates is freely adjustable;

(b) a freely extendable bulkhead enclosing said plurality of transparent flat plates so as to provide a hermetic space between said transparent flat plates; and

(c) a second optical medium filling said hermetic space of a different index of refraction from said fist optical medium;

said optical axis displacement device further comprising;

(a) a ray entry plate comprising an incident ray surface and an exit ray surface, and

(b) a ray exit plate opposite to said ray entry plate having an incident ray surface and an exit ray surface;

wherein the direction of propagation of an incident ray is altered by disposing a plurality of said optical axis displacement devices on an optical axis so that a ray exit surface of one optical element is adjacent to a ray entry surface of said another optical element.

7. An interleave projection display module system comprising:

an independent projection lens system;

a plurality of projection modules without a projection lens system;

a plurality of reflection mirrors;

wherein a light ray shift element is disposed between said plurality of projection modules and said plurality of reflection mirrors so that incident rays from a plurality of said projection modules are refracted so as to synthesize a composite image from each image component present on each projection module on a screen.

8. An interleave projection display module system claimed in claim 7, wherein the system further comprises means for projecting a test pattern image on a light valve;

means for evaluating the quality of said test pattern image; and

means for optically adjusting the quality of said test pattern image with an optical element.

9. An interleave projection display module system as claimed in one of claims 7 or 8, wherein said light ray shift element is chosen from a group consisting of transparent flat plates and transparent wedge materials.

10. An interleave projection display module system as claimed in claim 9, wherein said light ray shift element comprises two transparent wedge materials, each wedge having a flat surface and an inclined surface, disposed so that a flat surface of one wedge material faces a flat surface of the other wedge material.

11. A projection display system as claimed in claim 9, wherein said light ray shift element comprises three wedge materials, in which flat surfaces of two wedge materials are disposed so that the flat surfaces face each other.

12. A projection display system as claimed in one of claims 7 or 8, wherein said light ray shift element is an optical axis displacement device comprising:

a plurality of optical elements, each including;

(a) a plurality of transparent flat plates disposed at a predetermined spacing along an optical axis of an incident ray passing through a first optical medium, wherein the orientation with respect to said optical axis of an incident ray surface of each of said transparent flat plates is freely adjustable;

(b) a freely extendable bulkhead enclosing said plurality of transparent flat plates so as to provide a hermetic space between said transparent flat plates; and

(c) a second optical medium filling said hermetic space of a different index of refraction from said fist optical medium;

said optical axis displacement device further comprising;

(a) a ray entry plate comprising an incident ray surface and an exit ray surface, and

(b) a ray exit plate opposite to said ray entry plate having an incident ray surface and an exit ray surface;

wherein the direction of propagation of an incident ray is altered by disposing a plurality of said optical axis displacement devices on an optical axis so that a ray exit surface of one optical element is adjacent to a ray entry surface of said another optical element.