Substrate-guided optical device utilizing thin transparent layer

• US 7,724,443 B2
• Filed: 02/08/2006
• Issued: 05/25/2010
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: Lumus Ltd.
• Original Assignee: Lumus Ltd.
• Inventors: Amitai, Yaakov
• Primary Examiner(s): Dinh; Jack
• Application Number:
  US11/815,547
• Publication Number:
  US 20090122414A1
• Time in Patent Office: 1,567 Days
• Field of Search: 359/633, 359/629, 359/630, 359/486, 385129-133, 385/146
• US Class Current: 359/633
• CPC Class Codes: G02B 2027/0116 comprising devices for correcting chromatic aberration
• CPC Class Codes: G02B 2027/0123 comprising devices increasing the field of view
• CPC Class Codes: G02B 2027/0174 holographic
• 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 5/28 Interference filters
• CPC Class Codes: G02B 5/30 Polarising elements light-modulating devices with active elements G02F1/00
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it

Abstract

There is provided an optical device, including a light-transmitting substrate having two major surfaces and edges, an optical element (16) for coupling light waves into the substrate by total internal reflexion, and a plurality of partially reflecting surfaces (22a, 22b, 22c) carried by the substrate. The partially reflecting surfaces are parallel to each other and are not parallel to any of the edges of the substrate. At least one of the partially reflecting surfaces (22a, 22b, 22c) does not intersect with at least one of the two major surfaces, and the optical element (16) intersects with at least one of the two major surfaces.

Claims

1. An optical device, comprising:

a light-transmitting substrate having at least two major surfaces and edges, a plurality of partially reflecting surface carried by the substrate, the partially reflecting surfaces being parallel to each other and not parallel to any of the edges of the substrate with at least one of the partially reflecting surfaces not intersecting at least one of the two major surfaces; and

optical means with an active input aperture for coupling light waves from a display source into the substrate by total internal reflection, the optical means intersecting with at least one of the two major surfaces of the substrate, the active input aperture being sufficiently large and illuminated by light waves from the display source so that a single point on the boundary line between the edge of the optical means and one of the major surfaces of the substrate is illuminated by two different rays from one of the light waves from the display source entering the substrate at two different locations.

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

3. The optical device according to claim 1, further comprising means for producing image light waves coupled by said optical means into said substrate by total internal reflection.

4. The optical device according to claim 3, wherein said means for producing image light waves is located next to one of said two major, surfaces acting as the input surface of the substrate.

5. The optical device according to claim 3, wherein said means for producing image light waves comprises a display source and an imaging lens.

6. The optical device according to claim 5, wherein said imaging lens is a collimating lens.

7. 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 through one of said major surfaces acting as the output surface of the substrate.

8. The optical device according to claim 1, wherein said one major surface which does not intersect with at least one of said partially reflecting surfaces, is the input surface.

9. The optical device according to claim 1, wherein said one major surface which intersects with said optical means is located opposite to the input surface.

10. The optical device according to claim 1, wherein at least one of said partially reflecting surfaces is coated with thin-film angular-sensitive material.

11. The optical device according to claim 1, wherein at least one of said partially reflecting surfaces is an anisotropic surface.

12. The optical device according to claim 11, 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 wave in relation to the major axis of the surface.

13. The optical device according to claim 12, wherein said anisotropic surface reflects the incident light waves with its electrical field vector parallel to said major axis and transmits incident light waves with its electrical field vector perpendicular to said major axis.

14. The optical device according to claim 11, wherein said anisotropic partially reflecting surface is a wire grid polarizing beamsplitter.

15. The optical device according to claim 14, 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 the wire grid polarizing beamsplitter is parallel to the array of conductors.

16. The optical device according to claim 1, wherein said major surface which does not intersect with at least one of said partially reflecting surfaces located opposite said one major surface which intersects with said optical means.

17. The optical device according to claim 1, wherein the distance between said major surface which does not intersect with at least one of said partially reflecting surfaces and said partially reflecting surfaces, is constant.

18. The optical device according to claim 1, wherein the distance between said major surface which does not intersect with at least one of said partially reflecting surfaces and said partially reflecting surfaces is changed gradually.

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

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

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

22. The optical device according to claim 1, wherein one of the two rays directly illuminates the boundary line and the second of the rays is reflected by the other of the major surfaces of the substrate prior to illuminating the boundary line.

23. An optical device, comprising:

a light-transmitting substrate having at least a first and a second major surface and edges, a plurality of partially reflecting surfaces carried by the substrate, the partially reflecting surfaces being parallel to each other and not parallel to any edge of the substrate with all of the partially reflecting surfaces intersecting the first and second major surfaces;

optical means with an active input aperture for coupling light from a display source into said substrate by total internal reflection, the optical means intersecting with at least one of the first and second major surfaces, the active input aperture of the optical means being sufficiently large and illuminated by the light waves from the display source so that a single point on the boundary line between the edge of the optical means and one of the two major surfaces of the substrate is illuminated by the different rays from one of the light waves for the display source that enters the substrate in two different locations; and

a light transmitting plate having at least two major surfaces, one of the major surfaces being attached to one of the first or second major surfaces of the substrate.

24. The optical device according to claim 23, wherein one of the first or second major surfaces, of the first substrate is non-parallel to the other major surface of the substrate.

25. The optical device according to claim 24, wherein one of the major surfaces of the substrate is attached to one of the major surfaces of the light transmitting plate and wherein the other surface of the substrate is parallel to the other surface of the plate.

26. The optical device according to claim 23, wherein the plate is optically cemented to said substrate.