Virtual image display with curved light path

• US 10,459,233 B2
• Filed: 07/14/2017
• Issued: 10/29/2019
• Est. Priority Date: 01/05/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Travis, Adrian, Kollin, Joel S., Georgiou, Andreas
• Primary Examiner(s): Haley, Joseph R
• Assistant Examiner(s): Frank, Emily J
• Application Number:
  US15/650,697
• Publication Number:
  US 20170315362A1
• Time in Patent Office: 837 Days
• Field of Search: None
• CPC Class Codes: G02B 2027/0105 Holograms with particular structures
• CPC Class Codes: G02B 2027/011 comprising device for correcting geometrical aberrations, distortion
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/013 comprising a combiner of particular shape, e.g. curvature
• 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 2027/0194 with combiner of laminated type, for optical or mechanical aspects
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/0103 comprising holographic elements
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/1828 having means for producing variable diffraction controlling the direction of light by means of one or more diffracting elements G02B26/0808; acousto-optical elements G02F1/11, G02F1/33; electro- or magneto-optical diffraction G02F1/292, G02F1/2955
• CPC Class Codes: G02C 9/00 Attaching auxiliary optical parts auxiliary optical parts per se G02C7/08 - G02C7/16
• CPC Class Codes: G03B 21/10 Projectors with built-in or built-on screen
• CPC Class Codes: G03H 1/0248 Volume holograms
• CPC Class Codes: G03H 1/2205 using downstream optical component
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator
• CPC Class Codes: G03H 1/265 Angle multiplexing; Multichannel holograms G03H1/268 takes precedence
• CPC Class Codes: G03H 2223/16 Optical waveguide, e.g. optical fibre, rod
• CPC Class Codes: G03H 2223/23 : Diffractive element
• CPC Class Codes: G03H 2225/32 : Phase only
• CPC Class Codes: G06F 1/163 : Wearable computers, e.g. on a belt
• CPC Class Codes: G06F 3/013 : Eye tracking input arrangements G06F3/015 takes precedence
• CPC Class Codes: H04N 7/183 : for receiving images from a single remote source

Abstract

A display includes a projector configured to provide light of a virtual image, a waveguide into which the light of the virtual image is injected at an injection angle by the projector, and a combiner disposed along the waveguide and configured to redirect the light of the virtual image. The waveguide is configured to emit the light at a point established by the injection angle. The combiner is further configured to allow ambient light from beyond the waveguide to pass through the combiner. The waveguide constrains the light of the virtual image through total internal reflection along a curved path for the light between the projector and the combiner.

Claims

1. A display comprising:

a projector configured to provide light of a virtual image;

a waveguide into which the light of the virtual image is injected at an injection angle by the projector, wherein the waveguide is configured to emit the light at a point established by the injection angle; and

a volume grating disposed along a planar extraction section of the waveguide and configured to redirect the light of the virtual image;

wherein the waveguide constrains the light of the virtual image through total internal reflection along a curved path for the light between the projector and the volume grating.

2. The display of claim 1, wherein the volume grating is configured to redirect the light of the virtual image toward a viewer of the display.

3. The display of claim 1, wherein the pitch of the volume grating varies as a function of position.

4. The display of claim 1, wherein the volume grating has wavelength-dependent reflectivity.

5. The display of claim 1, wherein the volume grating is configured to allow ambient light from beyond the waveguide to pass through the volume grating.

6. The display of claim 1, wherein the waveguide is tapered for extraction of the light from the waveguide.

7. The display of claim 1, wherein the waveguide comprises a wedge waveguide section, the wedge waveguide section being tapered to emit the light after a number of reflections within the wedge waveguide section in accordance with the injection angle.

8. The display of claim 1, wherein the volume grating comprises a set of volume holograms embedded in the waveguide in a section of the waveguide, each volume hologram of the set of volume holograms being configured to extract the light from the waveguide in accordance with the injection angle and redirect the extracted light in a predetermined direction established via recording of the volume hologram.

9. The display of claim 1, wherein the waveguide comprises a first section disposed along an eyeglass temple, a second section disposed along the volume grating, and a third section disposed between the first and second sections and defining the curved path.

10. The display of claim 1, further comprising:

a camera to capture data indicative of an image of a pupil of a viewer viewing the display; and

a processor configured to determine a position of the pupil based on the captured data, and further configured to generate a control signal to establish the injection angle of the projector; and

wherein the projector is configured to adjust the injection angle in accordance with the control signal.

11. The display of claim 10, further comprising a scanner configured to concentrate the light redirected by the volume grating at a plurality of possible positions of the pupil.

12. The display of claim 11, wherein:

the scanner comprises a stack of switchable gratings disposed between the volume grating and the pupil; and

the processor is further configured to generate further control signals to selectively activate one or more respective switchable gratings of the set of switchable gratings to steer the light redirected by the volume grating toward a respective one of the plurality of possible positions of the pupil.

13. The display of claim 12, wherein the stack of switchable gratings comprises:

a first subset of switchable gratings to steer the light horizontally to one of a plurality of horizontal position offsets; and

a second subset of switchable gratings to steer the light vertically to one of a plurality of vertical position offsets.

14. The display of claim 12, wherein each switchable grating of the set of switchable gratings is pixelated to modulate an amount of steering provided by the respective switchable grating as a function of position.

15. The display of claim 10, further comprising a peripheral vision system, the peripheral vision system comprising:

a backlight unit configured to generate converging rays of light; and

a liquid crystal display (LCD) panel illuminated by the converging rays,

wherein the processor is configured to control the backlight unit in accordance with the position of the pupil to converge the rays of light at the pupil, and to control the LCD panel to provide peripheral vision imagery and to establish a deactivated region of the LCD panel through which the light emitted from the waveguide passes to reach a fovea of the viewer.

16. The display of claim 15, wherein the backlight unit comprises an array of volume holograms, each volume hologram being configured to direct the rays to a respective pupil position upon excitation.

17. The display of claim 1, wherein the projector is a holographic projector configured to correct for aberration arising from the curved path.

18. A display comprising:

a foveal vision system comprising;

a projector configured to provide light of a virtual image;

a waveguide into which the light of the virtual image is injected at an injection angle by the projector, wherein the waveguide is configured to emit the light at a point established by the injection angle; and

a peripheral vision system comprising;

a backlight unit configured to generate converging rays of light;

a liquid crystal display (LCD) panel illuminated by the converging rays; and

a processor configured to control the backlight unit in accordance with pupil position to converge the rays of light at the pupil position, and to control the LCD panel to provide peripheral vision imagery and to establish a deactivated region of the LCD panel through which the light emitted from the waveguide passes.

19. The display of claim 18, wherein the foveal vision system further comprises a volume grating disposed along the waveguide and configured to redirect the light of the virtual image toward a viewer of the display.

20. The display of claim 18, wherein the backlight unit comprises an array of volume holograms, each volume hologram being configured to direct the rays to a respective pupil position upon excitation.