VIRTUAL IMAGE DEVICE

• US 20130201094A1
• Filed: 02/07/2012
• Published: 08/08/2013
• Est. Priority Date: 02/07/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Travis, Adrian, Kollin, Joel S., Lanier, Jaron Z.
• Granted Patent: US 9,052,414 B2
• Time in Patent Office: Days
• US Class Current: 345/156
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 2027/0187 slaved to motion of at least a part of the body of the user, e.g. head, eye
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/4205 having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant
• CPC Class Codes: G02B 27/44 Grating systems; Zone plate systems G02B27/46 takes precedence
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3197 using light modulating optical valves

Abstract

This document describes various apparatuses embodying, and techniques for implementing, a virtual image device. The virtual image device includes a projector and a lens configured to generate a virtual image as well as two diffraction gratings, substantially orthogonally-oriented to each other, that act to increase a field-of-view of the virtual image. The virtual image device can be implemented as a pair of eyeglasses and controlled to generate the virtual image in front of lenses of the eyeglasses so that a wearer of the eyeglasses, looking through the lenses of the eyeglasses, sees the virtual image.

Claims

1. A virtual image device comprising:

a projector configured to output light rays;

a lens configured to receive the light rays from the projector and to generate a virtual image; and

two diffraction gratings, positioned proximate the lens, to increase a field-of-view of the virtual image, the two diffraction gratings substantially orthogonally-oriented to each other.

2. A virtual image device as described in claim 1, wherein the two diffraction gratings comprise passive liquid crystal diffraction gratings.

3. A virtual image device as described in claim 2, wherein the virtual image device comprises a pair of eyeglasses, and wherein the projector, the lens, and the two passive liquid crystal diffraction grating are coupled to the pair of eyeglasses to generate the virtual image for a wearer of the pair of eyeglasses.

4. A virtual image device as described in claim 1, wherein the two diffraction gratings comprise:

a horizontal diffraction grating configured to increase a vertical field-of-view of the virtual image; and

a vertical diffraction grating configured to increase a horizontal field-of-view of the virtual image.

5. A virtual image device as described in claim 4, wherein the lenses of the pair of eyeglasses are rectangular, and tilted relative to a face of the wearer, to maximize a vertical and a horizontal field-of-view of the virtual image.

6. A virtual image device as described in claim 1, wherein the virtual image device comprises a three-dimensional display device or a multi-view display device.

7. A virtual image device as described in claim 1, further comprising a pupil tracker configured to locate positions of pupils of a viewer, wherein the virtual image device is controlled to generate the virtual image based on the positions of the pupils.

8. A virtual image device as described in claim 7, further comprising a light re-director to deflect the virtual image based on the positions of the pupils of the viewer.

9. A virtual image device as described in claim 1, wherein the lens comprises a wedge light guide, the wedge light guide configured to receive the light rays from the projector and to generate the virtual image by projecting the virtual image from a surface of the wedge light guide.

10. A virtual image device as described in claim 1, wherein the lens is further configured to generate the virtual image for a first eye of a viewer and the virtual image device further comprises:

an additional projector configured to output additional light rays; and

an additional lens configured to receive the additional light rays from the additional projector and to generate an additional virtual image for a second eye of the viewer.

11. A virtual image device as described in claim 1, wherein the projector is at least partially transparent.

12. A virtual image device as described in claim 1, wherein the projector comprises a holographic projector.

13. A method comprising:

receiving data corresponding to a virtual image;

receiving positions of pupils of a viewer; and

controlling a projector to inject light rays into a lens positioned proximate two liquid crystal diffraction gratings, substantially orthogonally-oriented to each other, effective to generate the virtual image with a wide field-of-view based on the positions of the pupils of the viewer.

14. A method as described in claim 13, wherein the lens comprises a wedge light guide.

15. A method as described in claim 13, wherein the two liquid crystal diffraction gratings comprise:

a horizontal liquid crystal diffraction grating configured to increase a vertical field-of-view of the virtual image; and

a vertical liquid crystal diffraction grating configured to increase a horizontal field-of-view of the virtual image.

16. A method as described in claim 13, further comprising:

receiving a change in the positions of the pupils of the viewer; and

controlling the projector to inject light rays into the lens effective to generate the virtual image with a wide field-of-view based on the change in the positions of the pupils of the viewer.

17. A head-mounted display device comprising:

a pupil tracker configured to locate a position of a first pupil and a position of a second pupil of a wearer of the head-mounted display device;

a first projector configured to inject light rays into a first wedge light guide effective to generate a first virtual image based on the position of the first pupil;

a second projector configured to inject light rays corresponding to the virtual image into a second wedge light guide effective to generate a second virtual image based on the position of the second pupil;

two liquid crystal diffraction gratings, substantially orthogonally-oriented to each other, comprising;

a horizontal liquid crystal diffraction grating configured to increase a vertical field-of-view of the first virtual image and the second virtual image; and

a vertical liquid crystal diffraction grating configured to increase a horizontal field-of-view of the first virtual image and the second virtual image.

18. A head-mounted display device as described in claim 17, wherein the head-mounted display device is a pair of eyeglasses.

19. A head-mounted display device as described in claim 17, wherein the head-mounted display device comprises a pair of eyeglasses, with rectangular lenses that are tilted relative to a face of the wearer, to further increase the vertical field-of-view and the horizontal field-of-view of the virtual image.

20. A head-mounted display device as described in claim 17, further comprising a turning film configured to direct the first virtual image to the first pupil and to direct the second virtual image to the second pupil.