Personal visual display

• US 6,097,543 A
• Filed: 04/21/1995
• Issued: 08/01/2000
• Est. Priority Date: 02/07/1992
• Status: Expired due to Fees

• Current Assignee: i-O Display Systems LLC (Ilixco, Inc.)
• Original Assignee: i-O Display Systems LLC (Ilixco, Inc.)
• Inventors: Conner, Arlie R., Amadon, C. Gregory, Rallison, Richard Dennis, Mack, Wolfgang Adam Jr.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): SCHWARTZ, JORDAN MARC
• Application Number:
  US08/416,840
• Time in Patent Office: 1,929 Days
• Field of Search: 359/630, 359/631, 359/632, 359/633, 359/583, 359/589, 359/629, 349/11
• US Class Current: 359/633
• 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 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• 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

A visual display device is provided for delivering a generated image, preferably combinable with environment light, to the eye of a user. Light from an image generator such as a CRT, LED or LCD is reflected from a fold mirror away from a user'"'"'s eye towards a combiner. The image is reflected from the combiner and magnified, optionally combined with light from the environment and passes back through the fold mirror towards the eye of the user. In one embodiment, an optical element such as a meniscus lens or PCX lens is used to present the user with a substantially flat focal field and/or a Fresnel lens or diffractive optical element is used to aim rays from the image to the field curvature corrective lens in order to maintain maximum contrast.

Claims

1. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes, wherein wavelengths of said image light are from approximately 480 nanometers to approximately 630 nanometers;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

wherein said visual display apparatus is provided in the absence of any optically active components between said image generator and said fold mirror.

2. An apparatus, as claimed in claim 1, wherein said image light includes red, green and blue light.

3. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

an optical element, distinct from said combiner and said fold mirror, positioned between said fold mirror and said combiner.

4. Apparatus, as claimed in claim 3, wherein said optical element positioned between said fold mirror and said combiner comprises a phase retarder.

5. An apparatus, as claimed in claim 3, wherein said optical element is positioned for receiving said image light from said image generator prior to said image light contacting said fold mirror.

6. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

a refractive optical element located between said image generator and the fold mirror

wherein said refractive optical element avoids a reduction in contrast in the image.

7. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eve position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

wherein one of a phase retarder and a polarization rotating device is positioned along the optical path.

8. Apparatus, as claimed in claim 7, wherein said phase retarder is a quarter-wave plate.

9. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a second mirror situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, wherein at least some of said image light is transmitted through said fold mirror in a second direction to the eve position of the user, providing an optical path from said image generator to said fold mirror to said second mirror to said eve position of the user;

said image generator and said second mirror being mounted on the head of said user at a level below the top of the head of said user;

wherein said second mirror is substantially non-transmissive.

10. Visual display apparatus for a user, comprising:

an image generator having a first output surface, which outputs image light;

a fold mirror positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first reflected direction;

a magnifier situated to receive said first portion of said image light from said fold mirror, reflect and magnify at least a second portion of said image light combined with environmental light transmitted through the magnifier to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second reflected direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said magnifier to said eye position of the user; and

means which redirect light received at normal incidence, for preventing loss of contrast of said image.

11. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

an optical element positioned between said fold mirror and said combiner, wherein said optical element comprises a phase retarder.

12. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

wherein at least one of said fold mirror and reflective combiner provides an on-axis configuration for said visual display apparatus.

13. An apparatus, as claimed in claim 12, wherein said on-axis configuration includes one of:

(a) said fold mirror being at an angle of approximately 45°

to said planar output surface, and (b) said reflective combiner being at an angle of approximately 90°

to said planar output surface.

14. Head-mounted visual display apparatus for a user, comprising:

an image generator which outputs image light, said image generator having a substantially planar output surface to output said image light in an image plane, said planar output surface being non-orthogonal to the plane of the user'"'"'s eyes;

a fold mirror configured to reflect light evenly across the visible spectrum, positioned to receive the image light from the image generator and to reflect at least a first portion of said image light in a first direction;

a reflective combiner situated to receive said first portion of said image light from said fold mirror, reflect at least a second portion of said image light, combined with environmental light transmitted through the reflective combiner to produce combined light, wherein at least some of said combined light is transmitted through said fold mirror in a second direction to the eye position of the user, providing an optical path from said image generator to said fold mirror to said combiner, back through said fold mirror and to said eye position of the user;

said image generator and said reflective combiner being mounted on the head of said user at a level below the top of the head of said user;

said fold mirror and said reflective combiner are used for combining a wavelength of light from said image light with said wavelength of light transmitted through said reflective combiner.