Method and apparatus for head worn display with multiple exit pupils

Patent metadata

Field	Value
Publication number	US-10254547-B2
Application number	US-201715498354-A
Country	US
Kind code	B2
Filing date	Apr 26, 2017
Priority date	Mar 25, 2013
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A method for displaying an image viewable by an eye, the image being projected from a portable head worn display, comprises steps of: emitting a plurality of light beams of wavelengths that differ amongst the light beams; directing the plurality of light beams to a scanning mirror; modulating in intensity each one of the plurality of light beams in accordance with intensity information provided from the image, whereby the intensity is representative of a pixel value within the image; scanning the plurality of light beams in two distinct axes with the scanning mirror to form the image; and redirecting the plurality of light beams to the eye using a holographic optical element acting as a reflector of the light beams, whereby the redirecting is dependent on the wavelength of the light beam, to create for each light beam an exit pupil at the eye that is spatially separated from the exit pupils of the other light beams.

First claim

What is claimed is:

1. A method for displaying an image via a head-worn display, the method comprising:
emitting a plurality of light beams, a wavelength of at least one of the plurality of light beams to differ from a wavelength of at least one other of the plurality of light beams;
modulating an intensity of at least one of the plurality of light beams based at least in part on intensity information corresponding to an image to be projected;
scanning the plurality of light beams in two distinct axes towards a holographic optical element of the head-worn display to form the image; and
redirecting the plurality of light beams via the holographic optical element to a plurality of spatially separated exit pupils to project the image at the plurality of exit pupils.

2. The method of claim 1 , wherein the intensity of the light beams is representative of pixel values within the image.

3. The method of claim 1 , comprising applying, for each of the light beams of the plurality of light beams, one or more of image registration or image distortion correction to the image to align the projected image based on the spatial location of the plurality of exit pupils relative to each other.

4. The method of claim 1 , comprising spatially arranging the plurality of exit pupils to form an enlarged eyebox for viewing the image.

5. The method of claim 1 , comprising combining the plurality of light beams coaxially to correct angular differences between the plurality of light beams corresponding to each of the plurality of exit pupils.

6. The method of claim 1 , further comprising determining a gaze direction of a user.

7. The method of claim 1 , wherein scanning the plurality of light beams comprises scanning the plurality of light beams with at least one s33canning mirror comprising a microelectromechanical system (MEMS)-based scanning mirror.

8. A head-worn display comprising:
a light source, the light source to emit a plurality of light beams, a wavelength of at least one of the plurality of light beams to differ from a wavelength of at least one other of the plurality of light beams;
at least one scanning mirror to scan the plurality of light beams in two distinct axes to form an image;
a holographic optical element to receive the scanned plurality of light beams from the at least one scanning mirror and to redirect the plurality of light beams to a plurality of spatially separated exit pupils to project the image at the plurality of exit pupils; and
a frame to hold the light source, at least one scanning mirror, and holographic optical element in fixed relation to one another, the frame adapted to be worn on the head of a user.

9. The head-worn display of claim 8 , the light source to modulate an intensity of at least one of the plurality of light beams based at least in part on intensity information corresponding to an image to be projected.

10. The head-worn display of claim 9 , wherein the intensity of the light beams is representative of pixel values within the image.

11. The head-worn display of claim 8 , comprising an image processor to apply, for each of the light beams of the plurality of light beams, one or more of image registration or image distortion correction to the image to align the projected image based on the spatial location of the plurality of exit pupils relative to each other.

12. The head-worn display of claim 8 , wherein the spatial arrangement of the plurality of exit pupils form an enlarged eyebox for viewing the image.

13. The head-worn display of claim 8 , comprising a combiner lens to combine the plurality of light beams coaxially to correct angular differences between the plurality of light beams corresponding to each of the plurality of exit pupils.

14. The head-worn display of claim 8 , wherein the plurality of spatially separated exit pupils to expand an eyebox of the user.

15. The head-worn display of claim 8 , further comprising an eye tracker to determine a gaze direction of the user.

16. The head-worn display of claim 8 , wherein the frame comprises an eyewear frame.

17. The head-worn display of claim 8 , wherein the light source comprises a laser light source.

18. The head-worn display of claim 8 , wherein the at least one scanning mirror comprises a microelectromechanical system (MEMS)-based scanning mirror.

19. The head-worn display of claim 8 , further comprising:
an eyeglass lens held by the frame, wherein the holographic optical element is integrated with the eyeglass lens;
a scanning projector held by the frame, the scanning projector positioned adjacent to the eyeglass lens, the scanning projector including the light source and the at least one scanning mirror; and
a scanning projection lens coupled to the scanning projector.

20. A method for displaying an image viewable by an eye, the image being projected from a portable head-worn display, comprising steps of:
emitting a plurality of light beams;
directing each of the plurality of light beams to at least one scanning mirror;
modulating an intensity each one of the plurality of light beams in accordance with intensity information provided from the image, whereby the intensity is representative of a pixel value within an image;
scanning each one of the plurality of light beams in two distinct axes with the at least one scanning mirror to form the image; and
redirecting the plurality of light beams to the eye using an optical element acting as a reflector of the light beams, whereby the redirecting is dependent on an incidence angle of the light beam on the optical element, to create for each light beam an exit pupil at the eye that is spatially separated from the exit pupils of the other light beams.

21. The method of claim 20 , further comprising applying an image registration and a distortion correction to the image for each of the light beams, to align the image produced by the plurality of light beams in accordance to a location of the exit pupil for each light beam.

22. The method of claim 20 , further comprising spatially arranging the exit pupils formed by the plurality of light beams to form an enlarged area in which the eye is aligned to the portable head-worn display for viewing of the image.

23. The method of claim 20 , wherein the plurality of light beams are three light beams of separate visible wavelengths, thereby creating for each of the exit pupils, three light beams for a full color image.

24. The method of claim 23 , wherein the optical element is a holographic optical element.

25. The method of claim 24 , wherein the holographic optical element is recorded with a plurality of hologram writing lasers closely matched to the wavelengths of the plurality of light beams, and whereby the beams of each of the hologram writing lasers are arranged spatially in a hologram recording setup to match the spatial and angular orientation of the exit pupils and projection source points created by the portable head-worn display.

26. The method of claim 25 , wherein the beams of each of the hologram writing lasers are arranged spatially by means of optical fibers.

27. The method of claim 20 , further comprising steps of:
tracking an eye position of a user of the head-worn display; and
deactivating at least one of the plurality of light beams associated to each of the exit pupils, in correspondence to the eye's position at a given moment, to deactivate misaligned exit pupils and re

Assignees

• North Inc

Inventors

• Tremblay Eric
• Guillaumee Mickael
• Moser Christophe

Classifications

• G03H2222/13

  Multi-wavelengths wave with discontinuous wavelength ranges (G03H2222/18 takes precedence) · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B5/189

  Structurally combined with optical elements not having diffractive power · CPC title

• G02B2027/014

  comprising information/image processing systems · CPC title

• G03H2001/266

  Wavelength multiplexing · CPC title