Substrate-Guide Optical Device Utilizing Polarization Beam Splitters

• US 20080151379A1
• Filed: 02/08/2006
• Published: 06/26/2008
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: Lumus Ltd.
• Original Assignee: Lumus Ltd.
• Inventors: Amitai, Yaakov
• Granted Patent: US 8,432,614 B2
• Time in Patent Office: Days
• US Class Current: 359/630
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: G02B 2027/0118 comprising devices for improving the contrast of the display / brillance control visibility
• 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 2027/0134 of stereoscopic type
• CPC Class Codes: G02B 2027/0136 with a single image source for both eyes
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 2027/015 involving arrangement aiming to get less bulky devices
• 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 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/0176 characterised by mechanical features
• CPC Class Codes: G02B 27/1066 for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/14 operating by reflection only
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• 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 6/003 : Lens or lenticular sheet or layer
• CPC Class Codes: G02B 6/0031 : Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0055 : Reflecting element, sheet or layer
• 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: G02B 6/105 : having optical polarisation effects
• CPC Class Codes: G02C 11/10 : Electronic devices other than hearing aids

Abstract

There is provided an optical device, including a light waves-transmitting substrate having two major surfaces and edges, optical means for coupling light into the substrate by total internal reflection, and a plurality of partially reflecting surfaces (22a, 22b) carried by the substrate wherein the partially reflecting surfaces (22a, 22b) are parallel to each other and are not parallel to any of the edges of the substrate, and wherein one or more of the partially reflecting surfaces (22a, 22b) is an anisotropic surface.

Claims

1. An optical device, comprising:

a light waves-transmitting substrate having at least two major surfaces and edges;

optical means for coupling light into said substrate by total internal reflection, and

a plurality of partially reflecting surfaces carried by said substrate wherein said partially reflecting surfaces are parallel to each other and are not parallel to any of the edges of said substrate;

characterized in that at least one of said partially reflecting surfaces is an anisotropic surface.

2. The optical device according to claim 1, wherein said at least one anisotropic surface has a major axis parallel to the surface plane characterized in that the reflection and transmission properties of the surface substantially depend on the orientation of the polarization of the incident light in relation to the major axis of the surface.

3. The optical device according to claim 2, wherein said anisotropic surface reflects the incident light with its electrical field vector parallel to said major axis and transmits incident light with its electrical field vector perpendicular to said major axis.

4. The optical device according to claim 1, wherein said anisotropic partially reflecting surface is a wire grid polarizing beamsplitter.

5. The optical device according to claim 4, wherein said wire grid polarizing beamsplitter comprising an array of thin parallel conductors supported by a transparent substrate, characterized in that the major axis of a wire grid polarizing beamsplitter is parallel to the array of conductors.

6. The optical device according to claim 1, wherein at least one of said anisotropic surfaces is oriented to reflect s-polarized incident light waves.

7. The optical device according to claim 1, wherein at least one of said anisotropic surfaces is oriented to reflect p-polarized incident light waves.

8. The optical device according to claim 1, wherein said two major surfaces are parallel.

9. The optical device according to claim 1, wherein said optical means is a light waves-reflecting surface carried by said substrate.

10. The optical device according to claim 1, wherein at least one of said edges is oriented at an oblique angle with respect to said major surfaces and wherein said means for coupling light is located next to said slanted edge.

11. The optical device according to claim 1, wherein said optical means for coupling light is a prism.

12. The optical device according to claim 1, further comprising a retardation plate attached to one of the major surfaces of said substrate.

13. The optical device according to claim 12, wherein said retardation plate is a half-wavelength plate.

14. The optical device according to claim 1, further comprising a retardation plate attached to one of said plurality of partially reflecting surfaces.

15. The optical device according to claim 14, wherein said retardation plate is a half-wavelength plate.

16. The optical device according to claim 1, wherein said plurality of partially reflecting surfaces couples the light waves trapped by total internal reflection out of said substrate.

17. The optical device according to claim 16, further comprising means for producing image light waves from readout light waves, wherein said readout light waves and image light waves are located on the same side of said substrate.

18. The optical device according to claim 16, further comprising means for producing image light waves from readout light waves, wherein said readout light waves are located on one side of said substrate and said image light waves are located on another side of said substrate.

19. The optical device according to claim 16, further comprising means for producing image light waves from readout light waves, wherein said readout light waves are coupled into said substrate through one of its peripheral edges.

20. The optical device according to claim 16, wherein each of said plurality of anisotropic surfaces is oriented in a different orientation.

21. The optical device according to claim 16, wherein the orientation of each of said plurality of anisotropic reflecting surfaces is determined to achieve a field-of-view having uniform brightness.

22. The optical device according to claim 16, wherein the orientation of each of said plurality of anisotropic reflecting surfaces is determined to achieve a field-of-view having predefined brightness.

23. The optical device according to claim 1, wherein the distances between said partially reflecting surfaces are determined to achieve a contiguous image.

24. The optical device according to claim 1, wherein said substrate is partially transparent, for allowing see-through operations.

25. The optical device according to claim 1, further comprising an opaque layer attached to the surface of said substrate, for blocking the entrance of light waves from the external scene.

26. The optical device according to claim 1, further comprising a variable transmittance layer attached to the surface of said substrate, for controlling the brightness of light waves passing through said device from the external scene.

27. The optical device according to claim 26, wherein the transmittance of said variable transmittance layer is automatically determined according to the brightness of the external scene.

28. The optical device according to claim 1, further comprising a blank plate having at least two major surfaces, wherein one of said major surfaces is attached to one of the major surfaces of said substrate.

29. The optical device according to claim 28, wherein one of the major surfaces of said substrate is unparallel to the other major surface of said substrate.

30. The optical device according to claim 29, wherein one of the major surfaces of said substrate is attached to one of the major surfaces of said blank plate and wherein the other surface of said substrate is parallel to the other surface of said blank plate.

31. The optical device according to claim 28, wherein said blank plate is optically cemented to said substrate.

32. The optical device according to claim 16, wherein said plurality of partially reflecting surfaces reflects trapped light waves into a direction calculated to reach one eye of an observer.

33. The optical device according to claim 16, wherein said plurality of partially reflecting surfaces reflects trapped light waves into a direction calculated to reach both eyes of an observer.

34. The optical device according to claim 1, wherein said substrate is composed of a plurality of prisms.

35. The optical device according to claim 1, wherein said substrate is composed of a plurality of transparent forms created by injection molding techniques.

36. The optical device according to claim 1, wherein said substrate is composed of a plurality of parallel transparent plates.

37. The optical device according to claim 1, wherein said anisotropic partially reflecting surfaces are composed of thin transparent plates.

38. The optical device according to claim 1, wherein said anisotropic partially reflecting surfaces are composed of flexible transparent sheet portions coated with optical coating.

39. The optical device according to claim 1, wherein said device is embedded inside a spectacle frame.

40. The optical device according to claim 39, further comprising a camera attached to said spectacle frame.

41. The optical device according to claim 39, further comprising an image processing unit attached to said spectacle frame.

42. The optical device according to claim 41, wherein said device functions as a night vision goggle.

43. The optical device according to claim 41, wherein said device functions as a low-vision aid.

44. The optical device according to claim 1, wherein said device is embedded inside a cellular phone.

45. The optical device according to claim 1, wherein said device is embedded inside an entertainment device.