Substrate-guided optical devices

• US 20070091445A1
• Filed: 09/09/2004
• Published: 04/26/2007
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Lumus Ltd.
• Original Assignee: Lumus Ltd.
• Inventors: Amitai, Yaakov
• Granted Patent: US 7,724,442 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: G02B 2027/0114 comprising dichroic elements
• CPC Class Codes: G02B 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• CPC Class Codes: G02B 2027/012 comprising devices for attenuating parasitic image effects
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/0132 comprising binocular systems
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0081 with means for altering, e.g. enlarging, the entrance or exit pupil
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/02 Viewing or reading apparatus stereoscopic systems G02B30/00
• CPC Class Codes: G02B 27/28 for polarising used in stereoscopes G02B30/25
• 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: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02C 7/086 Auxiliary lenses located directly on a main spectacle lens or in the immediate vicinity of main spectacles

Abstract

There is provided an optical device, having a light-transmitting substrate (20) having at least two major surfaces parallel to each other and edges; a display light source; optical means for coupling light from the light source into the substrate (20) by internal reflection, and at least one partially reflecting surface (22) located in the substrate (20) which is non-parallel to the major surfaces of the substrate wherein the source emits light waves located in a given field-of-view, that the light waves are collimated, that an angular resolution is defined for the optical device, and wherein the angular deviation between any two different rays located in one of the collimated light waves, is smaller than the angular resolution.

Claims

1. An optical device, comprising:

a light-transmitting substrate having at least two major surfaces parallel to each other and edges;

a display light source;

optical means for coupling light from the light source into said substrate by internal reflection, and

at least one partially reflecting surface located in the substrate which is non-parallel to said major surfaces of the substrate

characterized in that said source emits light waves located in a given field-of-view, that said light waves are collimated, that an angular resolution is defined for said optical device, wherein the angular deviation between any two different rays located in one of said collimated light waves, is smaller than said angular resolution.

2. The optical device according to claim 1, wherein said optical means is a plane wave-reflecting surface located in said substrate and wherein a single point on the boundary line between the edge of said plane wave-reflecting surface and one of said major surfaces of said substrate, is illuminated by two different rays from one of said collimated light waves that enter the substrate in two different locations.

3. The optical device according to claim 2, wherein said plane wave-reflecting surface is disposed at an angle to said major surfaces to cause one of the rays to illuminate directly said boundary line, and a second of the rays to be reflected first by said plane wave-reflecting surface and then by the other of the major surfaces of the substrate before illuminating said boundary line.

4. The optical device according to claim 1, wherein said at least one partially reflecting surface couples the collimated light waves trapped by internal reflection out of said substrate.

5. The optical device according to claim 1, wherein collimated light waves located in said field-of view reach an eye of an observer.

6. The optical device according to claim 1, wherein the reflectance of said at least one partially reflecting surface, is a non-uniform coating.

12. The optical device according to claim 1, wherein said display light source is a liquid crystal display.

13. The optical device according to claim 1, wherein said display light source is an organic light emitting diode display.

14. The optical device according to claim 1, wherein said display light source is a virtual retinal display.

15. The optical device according to claim 1, wherein said display light source is a liquid crystal display light source operating in such a way that the Fourier transform of the desired image is formed on the plane of said liquid crystal display.

16. The optical device according to claim 1, wherein said substrate is partially transparent, to enable see-through operation.

17. The optical device according to claim 1, further comprising an opaque surface located on or in said substrate, so as to block the entrance of light traversing the substrate from an external scene.

18. The optical device according to claim 1, further comprising a variable transmittance surface located so as to attenuate the entrance of light traversing the substrate, for controlling the brightness of light passing through said device from an external scene.

19. The optical device according to claim 18, wherein the transmittance of said variable transmittance surface is determined according to the brightness of light directed to traverse the substrate.

20. The optical device according to claim 1, wherein said at least one partially reflecting surface reflects trapped waves into a direction calculated to reach both eyes of an observer.

21. The optical device according to claim 1, wherein said device is mounted in an eyeglasses frame.

22. The optical device according to claim 1, wherein said device is located in a head-up-display.

23. The optical device according to claim 1, further comprising a lens located next to one of the major surfaces of the substrate.

24. The optical device according to claim 23, wherein said lens is an ophthalmic lens designed to correct aberrations of a viewer'"'"'s eye.

25. The optical device according to claim 1, further comprising a collimating lens located next to the second of said major surfaces of the substrate.

26. The optical device according to claim 25, wherein said lens is a focusing lens designed to focus a collimating image to a predefined distance.

27. The optical device according to claim 25, wherein said lens is a Fresnel lens.

28. The optical device according to claim 25, wherein said lens is a dynamic lens.

29. The optical device according to claim 28, wherein said dynamic lens is an electronically controlled lens.

30. The optical device according to claim 26, wherein said collimating lens is a Fresnel lens.

31. The optical device according to claim 26, wherein said collimating lens is a dynamic lens.

32. The optical device according to claim 31, wherein said dynamic lens is an electronically controlled lens.

7. The optical device according to claim 7, wherein the reflectance of said at least one partially reflecting surface, changes monotonically.

8. The optical device according to claim 7, wherein the reflectance of said at least one partially reflecting surface, changes gradually.

9. The optical device according to claim 7, wherein the reflectance of said at least one partially reflecting surface, changes continuously.

10. The optical device according to claim 7, wherein the reflectance of said at least one partially reflecting surface produces a field of view having uniform brightness.

11. The optical device according to claim 7, wherein the reflectance of said at least one partially reflecting surface produces a field of view having a predefined brightness.