EDGE CONFIGURATIONS FOR REDUCING ARTIFACTS IN EYEPIECES

• US 20140320971A1
• Filed: 04/25/2013
• Published: 10/30/2014
• Est. Priority Date: 04/25/2013
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Gupta, Anurag, James, Steven Vincent, Luttmann, Amber Marie
• Granted Patent: US 9,069,115 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0121 Parasitic image effect attenuation by suitable positioning of the parasitic images
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 5/22 Absorbing filters G02B5/201 - G02B5/208 take precedence

Abstract

An eyepiece for a head mounted display (“HMD”) includes a first end for receiving computer generated image (“CGI”) light and a second end disposed opposite the first end. The eyepiece also includes an image directing element to direct the CGI light out of the eyepiece in an eye-ward direction. The image directing element is disposed between the first end and the second end. At least one edge running between the first end and the second end is configured to reduce reflection of the CGI light back into the eyepiece.

Claims

1. An eyepiece for a head mounted display (“

HMD”

) comprising;

a light receiving end for receiving computer generated image (“

CGI”

) light propagating along a forward optical path;

an end reflector disposed at an opposite end of the eyepiece from the light receiving end to reflect the CGI light along a reverse optical path within the eyepiece;

a beam splitter positioned to direct the CGI light propagating along the reverse optical path in an eye-ward direction, wherein the beam splitter is disposed between the light receiving end and the end reflector; and

at least one edge of the eyepiece running between the light receiving end and the end reflector, wherein the at least one edge is beveled to reduce reflection of the CGI light back into the eyepiece.

2. The eyepiece of claim 1, wherein the at least one edge is a chamfered edge to reduce said reflection of the CGI light.

3. The eyepiece of claim 1, wherein the at least one edge is a filleted edge to reduce said reflection of the CGI light.

4. The eyepiece of claim 1, wherein a beveled portion of the at least one edge is textured to form a diffuse surface.

5. The eyepiece of claim 1, wherein a beveled portion of the at least one edge is darkened to absorb the CGI light.

6. The eyepiece of claim 1, wherein the at least one edge includes a first edge that joins a bottom surface of the eyepiece with an eye-ward surface of the eyepiece.

7. The eyepiece of claim 6, wherein the bottom surface and the eye-ward surface are approximately orthogonal.

8. The eyepiece of claim 1, wherein the at least one edge includes:

a first edge that joins a bottom surface of the eyepiece with an eye-ward surface of the eyepiece;

a second edge that joins the bottom surface with a scene surface of the eyepiece that is disposed opposite the eye-ward surface;

a third edge that joins a top surface with the scene surface, the top surface opposite the bottom surface; and

a fourth edge that joins the top surface and the eye-ward surface.

9. A head mounted display (“

HMD”

) comprising;

a display module for launching computer generated image (“

CGI”

) light along a forward propagating path; and

an eyepiece including;

a first end optically coupled to receive the CGI light from the display module;

a second end disposed opposite the display module and the first end;

an image directing element to direct the CGI light in an eye-ward direction, wherein the image directing element is disposed between the first end and the second end; and

at least one edge running between the first end and the second end, wherein the at least one edge is beveled to reduce reflection of the CGI light back into the eyepiece.

10. The HMD of claim 9, wherein the at least one edge is a chamfered edge to reduce said reflection of the CGI light.

11. The HMD of claim 9, wherein the at least one edge is a filleted edge to reduce said reflection of the CGI light.

12. The HMD of claim 9, wherein a beveled portion of the at least one edge is textured to form a diffuse surface.

13. The HMD of claim 9, wherein a beveled portion of the at least one edge is darkened to absorb the CGI light.

14. The HMD of claim 9, wherein the at least one edge includes a first edge that joins a bottom surface of the eyepiece with an eye-ward surface of the eyepiece.

15. The HMD of claim 14, wherein the bottom surface and the eye-ward surface are approximately orthogonal.

16. An optical apparatus comprising:

a first end for receiving computer generated image (“

CGI”

) light;

a second end disposed opposite the first end;

an image directing element to direct the CGI light out of the optical apparatus in an eye-ward direction, wherein the image directing element is disposed between the first end and the second end; and

at least one edge running between the first end and the second end, wherein the at least one edge is configured to reduce reflection of the CGI light back into the optical apparatus.

17. The optical apparatus of claim 16, wherein the at least one edge is a chamfered edge to reduce said reflection of the CGI light.

18. The optical apparatus of claim 16, wherein the at least one edge is a filleted edge to reduce said reflection of the CGI light.

19. The optical apparatus of claim 16, wherein intersecting surfaces that form the at least one edge include textured portions to create a diffuse surface along the at least one edge.

20. The optical apparatus of claim 16, wherein the at least one edge has darkening elements disposed along the edge on intersecting surfaces that form the edge, the darkening elements to absorb the CGI light.