Non-orthogonal plate in a virtual reality or heads up display

• US 5,991,087 A
• Filed: 06/06/1995
• Issued: 11/23/1999
• Est. Priority Date: 11/12/1993
• Status: Expired due to Fees

• Current Assignee: i-O Display Systems LLC (Ilixco, Inc.)
• Original Assignee: i-O Display Systems LLC (Ilixco, Inc.)
• Inventors: Rallison, Richard Dennis
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): LETENDRE, SUZANNE M
• Application Number:
  US08/469,542
• Time in Patent Office: 1,631 Days
• Field of Search: 359/630, 359/631
• US Class Current: 359/631
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 6/08 with fibre bundle in form of plate

Abstract

The present invention eliminates the relay lens systems found in conventional helmet mounted displays (HMDs) by removing field distortions and aberrations with a contoured fiber optic faceplate placed in close proximity to a liquid crystal display (LCD) or cathode ray tube. The optical system typically consists of a spherical dielectric or holographically made collimator-combiner, a dielectric or holographically made fold mirror, and a contoured fiber optic faceplate. The fold mirror is flat, and the collimator-combiner is made by coating a spherical eye glass blank. The system is configured as a folded and tilted catadioptric projector with the novel feature being the contoured faceplate. There are no dispersive elements in the imaging assembly which means it can be completely polychromatic (full color) without the need for additional color correction optics as found in all refractive color systems. When designed for full color, highest brightness, and see through capability it must be made with two or three narrow spectral and angular sensitive coatings on the fold mirror and on the collimator-combiner. These coatings allow the use of a tilt of the collimator-combiner with respect to the fold mirror which induces a small amount of astigmatism and keystone distortion but at the same time allows image light to pass through the folded optics to the eye with a minimum of loss.

Claims

1. A method for providing a head-mounted display comprising:

generating image light using a first image generator;

positioning a plate adjacent said image generator to receive said image light, said plate having fibers traversing in a first direction, an end of said fibers defining an output surface, said output surface substantially defining an output plane wherein in operative alignment with a user'"'"'s eye, said output plane is inclined at an angle toward the user'"'"'s eye and such that, with respect to the first direction, said output plane is other than 90 degrees for redirecting an energy window output from said plate;

first providing a fold mirror which receives said image light from said output surface of said fibers and reflects said image light in a second direction substantially away form the user'"'"'s eye; and

second providing a reflector for receiving said light for transmission to the user'"'"'s eye.

2. A method as claimed in claim 1, wherein said first providing step includes orienting said fold mirror so when said head-mounted display is in operative alignment with the user'"'"'s eye, at least a portion of said fold mirror is adjacent a brow of the user'"'"'s eye.

3. Head-mounted display apparatus comprising:

an image generator;

a fold mirror positioned to receive light output by said image generator;

a plate positioned between said image generator and said fold mirror, said plate having a plurality of fibers substantially aligned in a first linear direction and having an output surface substantially defining a plane lying at an angle with respect to said first linear direction at other than 90 degrees, wherein when said head-mounted apparatus is operatively mounted on a user'"'"'s head, one or more of;

(a) said plane is inclined toward an eye of a user; and

(b) said fold mirror is inclined so that it is closer to the head of the user above the eye than below the eye;

a reflector for receiving light from said fold mirror and redirecting said light for transmission to the eye of the user.

4. Head mounted display apparatus comprising:

an image generator;

a fold mirror positioned to receive light output by said image generator;

means for redirecting an energy window, said means including a plurality of fibers and having an output surface substantially defining a plane lying at an angle other than 90 degrees to said plurality of fibers so that said means for redirecting is operatively positioned for transmitting light between said image generator and said fold mirror;

a reflector receiving light from the fold mirror and redirecting said light for transmission to an eye of a user operatively using said head mounted display.

5. A method of redirecting, in one plane, an energy window from a fiber optic faceplate, comprising:

orienting a contoured output surface of said fiber optic faceplate at an angle other than ninety degrees with respect to a direction of a plurality of optical fibers in said fiber optic faceplate;

positioning a fold mirror to receive a transmission of the energy window from said contoured output surface.

6. A method for providing a head-mounted display comprising:

generating image light using a first image generator;

positioning a plate adjacent said image generator to receive said image light, said plate having fibers traversing in a first direction, an end of said fibers defining an output surface, said output surface substantially defining an output plane, wherein, in operative alignment with a user'"'"'s eye, said output plane is inclined at an angle other than 90 degrees, with respect to the first direction, for redirecting an energy window output from said plate;

positioning a fold mirror which receives said image light from said output surface and reflects said image light in a second direction substantially away from the user'"'"'s eye, wherein said fold mirror is inclined so that it is closer to the head of the user above the user'"'"'s eye than below the user'"'"'s eye; and

positioning a reflector for receiving said light for transmission to the user'"'"'s eye.