Display system

• US 8,767,306 B1
• Filed: 09/22/2011
• Issued: 07/01/2014
• Est. Priority Date: 09/22/2011
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Miao, Xiaoyu, Wong, Adrian, Amirparviz, Babak, Spitzer, Mark
• Primary Examiner(s): Sugarman, Scott J
• Assistant Examiner(s): Manikeu, Daniele
• Application Number:
  US13/240,994
• Time in Patent Office: 1,013 Days
• Field of Search: 359629-633, 345/8
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• 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 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0983 being curved
• CPC Class Codes: G02B 27/1006 for splitting or combining different wavelengths G02B27/1086, G02B27/141 take precedence

Abstract

An optical system has an aperture through which virtual and real-world images are viewable along a viewing axis. The optical system may be incorporated into a head-mounted display (HMD). By illuminating a viewing location with an infrared light source, an eye pupil may be illuminated. Infrared light is reflected from the viewing location and is collected with a proximal beam splitter. An image former is configured to reflect at least a portion of the visible light pattern generated by the display panel to form the virtual image and transmit at least a portion of the collected infrared light. The transmitted infrared light may be imaged by a camera. The HMD may use images from the camera to provide, for example, context-sensitive virtual images to a wearer.

Claims

1. An optical system comprising:

a display panel configured to generate a visible light pattern;

an infrared light source configured to illuminate a viewing location with infrared light such that infrared light is reflected from the viewing location as reflected infrared light;

a camera, wherein the camera is configured to image the viewing location based on the reflected infrared light;

an image former optically coupled to the camera and the display panel, wherein the image former is configured to transmit the reflected infrared light through the image former to the camera, and wherein the image former is configured to reflect at least a portion of the visible light pattern to form a virtual image; and

a proximal beam splitter, wherein the proximal beam splitter is configured to transmit light from a real-world environment through the proximal beam splitter to the viewing location, transmit the visible light pattern from the display panel to the image former, reflect the virtual image from the image former to the viewing location, and reflect the reflected infrared light from the viewing location to the image former.

2. The optical system of claim 1, wherein the infrared light source comprises an infrared light-emitting diode (LED).

3. The optical system of claim 2, wherein the infrared LED is configured to illuminate the viewing location through the proximal beam splitter.

4. The optical system of claim 1, further comprising a visible light source.

5. The optical system of claim 4, wherein the display panel is configured to generate the visible light pattern by spatially modulating visible light from the visible light source.

6. The optical system of claim 5, further comprising:

a distal beam splitter optically coupled to the visible light source, display panel, and proximal beam splitter, wherein the distal beam splitter is configured to reflect visible light from the visible light source onto the display panel.

7. The optical system of claim 1, wherein the image former comprises a concave mirror.

8. The optical system of claim 7, wherein the concave mirror comprises a coating of dichroic material that reflects visible light and transmits infrared light.

9. The optical system of claim 1, wherein the image former comprises a concave mirror with a central pinhole.

10. The optical system of claim 9, wherein the camera includes a filter that blocks visible light and transmits infrared light.

11. The optical system of claim 1, wherein the camera is configured to image an eye pupil located at the viewing location.

12. A system comprising:

a head-mountable support;

an optical system attached to the head-mountable support, wherein the optical system comprises;

a display panel configured to generate a visible light pattern;

an infrared light source configured to illuminate a viewing location with infrared light such that infrared light is reflected from the viewing location as reflected infrared light;

a camera, wherein the camera is configured to image the viewing location based on the reflected infrared light;

an image former optically coupled to the camera and the display panel, wherein the image former is configured to transmit the reflected infrared light through the image former to the camera, and wherein the image former is configured to reflect at least a portion of the visible light pattern to form a virtual image; and

a proximal beam splitter, wherein the proximal beam splitter is configured to transmit light from a real-world environment through the proximal beam splitter to the viewing location, transmit the visible light pattern from the display panel to the image former, reflect the virtual image from the image former to the viewing location, and reflect the reflected infrared light from the viewing location to the image former;

a computer, wherein the computer is configured to control the display panel and receive images of the viewing location obtained by the camera.

13. The system of claim 12, wherein the viewing location corresponds to an eye of a wearer of the head-mounted display.

14. The system of claim 13, wherein the computer is configured to determine locations of the pupil of the wearer'"'"'s eye from the received images.

15. The system of claim 14, wherein the computer is configured to control the display based on the determined pupil locations.

16. A method comprising:

generating a visible light pattern using a display panel;

forming, by reflection from a concave mirror, a virtual image from the visible light pattern, wherein the virtual image and a field of view of a real-world environment are viewable from a viewing location, wherein the concave mirror is configured to transmit infrared light and reflect visible light;

illuminating the viewing location with infrared light;

collecting infrared light reflected from the viewing location;

transmitting, through the concave mirror, at least a portion of the infrared light collected from the viewing location; and

imaging the viewing location using the collected infrared light transmitted through the concave mirror.

17. The method of claim 16, wherein imaging the viewing location comprises capturing at least one image of an eye pupil.

18. The method of claim 17, further comprising:

determining a location of the eye pupil from the at least one image.

19. The method of claim 18, further comprising controlling the display panel based on the determined location of the eye pupil.

20. The method of claim 17, further comprising:

determining a direction of motion of the eye pupil from the at least one image.

21. The method of claim 20, further comprising:

identifying a user instruction based on the determined direction of motion of the eye pupil.

22. The method of claim 17, further comprising:

determining a size of the eye pupil from the at least one image.

23. The method of claim 22, further comprising:

adjusting a brightness of the virtual image based on the determined size of the eye pupil.