Polarizing optical system

• US 10,598,937 B2
• Filed: 06/21/2018
• Issued: 03/24/2020
• Est. Priority Date: 11/08/2005
• Status: Active Grant

• Current Assignee: Lumus Ltd.
• Original Assignee: Lumus Ltd.
• Inventors: Amitai, Yaakov
• Primary Examiner(s): Shafer, Ricky D
• Application Number:
  US16/013,983
• Publication Number:
  US 20180373039A1
• Time in Patent Office: 642 Days
• Field of Search: 35948501, 35948505, 35948507, 35948907, 35948908, 35948909, 35948915, 35948916
• CPC Class Codes: G02B 2027/0125 Field-of-view increase by wavefront division
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/285 comprising arrays of elements, e.g. microprisms
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02B 6/003 Lens or lenticular sheet or layer
• 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: G02B 6/34 utilising prism or grating G02B6/293 takes precedence

Abstract

There is provided an optical system, including a light-transmitting substrate having at least two major surfaces parallel to each other edges, and an optical device for coupling light into the substrate by total internal reflection. The device includes a polarization sensitive reflecting surface.

Claims

1. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major surfaces parallel to each other;

an optical device for coupling light waves emanating from a display source into the light-transmitting substrate by total internal reflection, the optical device including a polarizing beamsplitter deployed non-parallel to the major surfaces of the light-transmitting substrate;

a retardation plate located next to one of the major surfaces; and

a lens located next to the retardation plate,

wherein the light waves to the optical device are p-polarized or s-polarized and transmitted through the polarizing beamsplitter so as to impinge on the retardation plate which converts the light waves into circular polarized light, and wherein the transmitted light waves are subsequently reflected back through the retardation plate by a reflecting surface of the lens so as to change a polarization state of the light waves such that the light waves are s-polarized or p-polarized, and wherein the s-polarized or p-polarized light waves are reflected from the polarizing beamsplitter and trapped inside the light-transmitting substrate by total internal reflection.

2. The optical system of claim 1, wherein the polarizing beamsplitter is embedded inside the light-transmitting substrate.

3. The optical system of claim 1, wherein the polarizing beamsplitter includes a wire grid polarizer.

4. The optical system of claim 1, wherein the polarizing beamsplitter includes a polarization sensitive dielectric coating.

5. The optical system of claim 1, wherein the polarizing beamsplitter transmits the p-polarized light and reflects the s-polarized light.

6. The optical system of claim 1, wherein the polarizing beamsplitter transmits the s-polarized light and reflects the p-polarized light.

7. The optical system of claim 1, further comprising at least one partially reflecting surface located in the light-transmitting substrate for coupling light waves out of the light-transmitting substrate.

8. The optical system of claim 7, wherein the polarizing beamsplitter is parallel to the at least one partially reflecting surface.

9. The optical system of claim 1, further comprising at least one display source for producing input light waves.

10. The optical system of claim 9, wherein the input light waves are linearly polarized.

11. The optical system of claim 9, wherein the input light waves are unpolarized.

12. The optical system of claim 9, further comprising an optical module for collimating the input light waves.

13. The optical system of claim 12, wherein the optical module includes at least one folding prism.

14. The optical system of claim 13, wherein the optical module further includes at least one polarizing beamsplitter embedded inside the folding prism.

15. The optical system of claim 1, wherein the reflection of the light waves by the reflecting surface of the lens acts to collimate the light waves.

16. The optical system of claim 1, wherein the lens is a converging lens.

17. The optical system of claim 1, wherein the lens is a plano-convex lens.

18. The optical system of claim 1, wherein the retardation plate is a quarter-wavelength retardation plate.

19. The optical system of claim 1, wherein the lens is optically attached to the retardation plate.

20. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major external surfaces parallel to each other;

at least one partially reflecting surface located in the light-transmitting substrate for coupling light waves out of the light-transmitting substrate; and

an optical device for coupling light waves emanating from a display source into the light-transmitting substrate to effect total internal reflection between the two major external surfaces, the optical device including a polarizing beamsplitter and a retardation plate, wherein the light waves emanating from the display source pass at least once through the retardation plate prior to being coupled into the light-transmitting substrate, and wherein the polarizing beamsplitter is oriented so that the light waves coupled into the light-transmitting substrate are reflected from the beamsplitter at oblique angles with respect to the major external surfaces, such that the reflected light waves are trapped inside the light-transmitting substrate by total internal reflection and are reflected at least once by one of the major external surfaces before being coupled out of the light-transmitting substrate by the at least one partially reflecting surface.

21. The optical system of claim 20, wherein the polarizing beamsplitter is embedded inside the light-transmitting substrate.

22. The optical system of claim 20, wherein the polarizing beamsplitter includes a wire grid polarizer.

23. The optical system of claim 20, wherein the polarizing beamsplitter includes a polarization sensitive dielectric coating.

24. The optical system of claim 20, wherein the polarizing beamsplitter transmits p-polarized light and reflects s-polarized light.

25. The optical system of claim 20, wherein the polarizing beamsplitter transmits s-polarized light and reflects p-polarized light.

26. The optical system of claim 20, wherein the at least one partially reflecting surface is non-parallel to the major external surfaces of the light-transmitting substrate.

27. The optical system of claim 20, wherein the polarizing beamsplitter is parallel to the at least one partially reflecting surface.

28. The optical system of claim 20, further comprising at least one display source for producing input light waves.

29. The optical system of claim 28, wherein the input light waves are linearly polarized.

30. The optical system of claim 28, wherein the input light waves are unpolarized.

31. The optical system of claim 28, further comprising an optical module for collimating the input light waves.

32. The optical system of claim 31, wherein the optical module includes at least one folding prism.

33. The optical system of claim 32, wherein the optical module further includes at least one polarizing beamsplitter embedded inside the folding prism.

34. The optical system of claim 20, wherein the optical device further includes a reflecting lens.

35. The optical system of claim 34, wherein the reflecting lens is a converging lens.

36. The optical system of claim 34, wherein the reflecting lens is a plano-convex lens.

37. The optical system of claim 20, wherein the retardation plate is a quarter-wavelength retardation plate.

38. An optical system, comprising:

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

an optical device for coupling light waves emanating from a display source into the light-transmitting substrate to effect total internal reflection between the two major surfaces, the optical device including;

a polarizing beamsplitter deployed non-parallel to the major surfaces of the light-transmitting substrate,

a retardation plate located next to one of the major surfaces,

a first reflecting surface located in the light-transmitting substrate, and

a second reflecting surface located next to the retardation plate,

wherein the light waves emanating from the display source include a first component of the light waves in a first polarization state and a second component of the light waves in a second polarization state, and wherein the first component of the light waves are reflected from the polarizing beamsplitter, reflected a first time by the first reflecting surface so as to impinge on the retardation plate, reflected back through the retardation plate by the second reflecting surface to change the polarization state of the first component of the light waves from the first polarization state to the second polarization state, reflected a second time by the first reflecting surface, and transmitted through the polarizing beamsplitter and trapped inside the light-transmitting substrate by total internal reflection.

39. The optical system of claim 38, wherein the polarizing beamsplitter is embedded inside the light-transmitting substrate.

40. The optical system of claim 38, wherein the polarizing beamsplitter includes a wire grid polarizer.

41. The optical system of claim 38, wherein the polarizing beamsplitter includes a polarization sensitive dielectric coating.

42. The optical system of claim 38, wherein the polarizing beamsplitter transmits p-polarized light and reflects s-polarized light.

43. The optical system of claim 38, wherein the polarizing beamsplitter and the first reflecting surface are parallel to each other.

44. The optical system of claim 38, wherein the polarizing beamsplitter transmits s-polarized light and reflects p-polarized light.

45. The optical system of claim 38, wherein the first component of the light waves is p-polarized and the second component of the light waves is s-polarized.

46. The optical system of claim 38, wherein the first component of the light waves is s-polarized and the second component of the light waves is p-polarized.

47. The optical system of claim 38, wherein the polarizing beamsplitter is arranged such that the second component of the light waves are coupled into the light-transmitting substrate, and wherein the first component of the light waves coupled into the light-transmitting substrate merge with the second component of the light waves coupled into the light-transmitting substrate.

48. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major surfaces parallel to each other;

an optical module for collimating light waves emanating from a display source, the optical module including a folding prism including a first polarizing beamsplitter and having a plurality of surfaces including at least two major surfaces parallel to each other, a first retardation plate located next to one of the major surfaces of the folding prism, and a lens located next to the first retardation plate; and

an optical device for coupling the collimated light waves from the optical module into the light-transmitting substrate to effect total internal reflection between the two major surfaces of the light-transmitting substrate, the optical device including a second polarizing beamsplitter, a second retardation plate located next to one of the major surfaces of the light-transmitting substrate, and a reflecting surface located next to the second retardation plate,

wherein the light waves emanating from the display source are reflected at least once from a reflecting surface of the folding prism, reflected at least once from a first of the major surfaces of the folding prism, reflected at least once from the first polarizing beamsplitter, reflected at least once from a reflecting surface of the lens, pass at least twice through the first retardation plate, pass at least once through the first polarizing beamsplitter, pass at least twice through a second of the major surfaces of the folding prism, pass at least once through the second polarizing beamsplitter, reflected at least once from the reflecting surface located next to the second retardation plate, pass at least twice through the second retardation plate, and reflected at least once from the second polarizing beamsplitter prior to being coupled in to the light-transmitting substrate.

49. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major surfaces parallel to each other;

an optical module for collimating light waves emanating from a display source, the optical module including a folding prism including a first polarizing beamsplitter and having a plurality of surfaces including at least two major surfaces parallel to each other, a first retardation plate located next to one of the major surfaces of the folding prism, and a lens located next to the first retardation plate; and

an optical device for coupling the collimated light waves from the optical module into the light-transmitting substrate to effect total internal reflection between the two major surfaces of the light-transmitting substrate, the optical device including a second polarizing beamsplitter, a second retardation plate located next to one of the major surfaces of the light-transmitting substrate, and a reflecting surface located next to the second retardation plate,

wherein the light waves emanating from the display source are s-polarized or p-polarized and are reflected from a reflecting surface of the folding prism so as to couple the light waves into the folding prism, and wherein the light waves coupled into the folding prism are reflected from a first of the major surfaces of the folding prism, reflected from the first polarizing beamsplitter and coupled out of the folding prism through the first of the major surfaces of the folding prism so as to impinge on the first retardation plate which converts the light waves into circular polarized light, and wherein the circular polarized light waves are reflected back through the first retardation plate by a reflecting surface of the lens so as to change a polarization state of the light waves such that the light waves are p-polarized or s-polarized, and wherein the p-polarized or s-polarized light waves are transmitted through the first polarizing beamsplitter and coupled out of the folding prism through a second of the major surfaces of the folding prism, transmitted through the second polarizing beamsplitter so as to impinge on the second retardation plate which converts the light waves into circular polarized light waves, reflected back through the second retardation plate by the reflecting surface located next to the second retardation plate so as to change the polarization state of the light waves such that the light waves are s-polarized or p-polarized, and wherein the s-polarized or p-polarized light waves are reflected from the second polarizing beamsplitter and trapped inside the light-transmitting substrate by total internal reflection.

50. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major surfaces parallel to each other;

an optical module for collimating light waves emanating from a display source, the optical module including;

a folding prism including a first polarizing beamsplitter and a second polarizing beamsplitter, and having a plurality of surfaces including at least two major surfaces parallel to each other,

a first retardation plate located next to one of the major surfaces of the folding prism, and

a first lens and a second lens, each located next to the first retardation plate; and

an optical device for coupling the collimated light waves from the optical module into the light-transmitting substrate to effect total internal reflection between the two major surfaces of the light-transmitting substrate, the optical device including;

a third polarizing beamsplitter,

a second retardation plate located next to one of the major surfaces of the light-transmitting substrate, and

a reflecting surface located next to the second retardation plate,

wherein the light waves emanating from the display source pass at least once through the first polarizing beamsplitter, are reflected at least once from a reflecting surface of the first lens, reflected at least once from the first polarizing beamsplitter, reflected at least once from a first of the major surfaces of the folding prism, reflected at least once by the second polarizing beamsplitter, reflected at least once from a reflecting surface of the second lens, pass at least four times through the first retardation plate, pass at least once through the second polarizing beamsplitter, pass at least twice through a second of the major surfaces of the folding prism, pass at least once through the second polarizing beamsplitter, reflected at least once from the reflecting surface located next to the second retardation plate, pass at least twice through the second retardation plate, and reflected at least once from the second polarizing beamsplitter prior to being coupled in to the light-transmitting substrate.

51. An optical system, comprising:

a light-transmitting substrate having a plurality of surfaces including at least two major surfaces parallel to each other;

an optical module for collimating light waves emanating from a display source, the optical module including;

a folding prism including a first polarizing beamsplitter and a second polarizing beamsplitter, and having a plurality of surfaces including at least two major surfaces parallel to each other,

a first retardation plate located next to one of the major surfaces of the folding prism, and

a first lens and a second lens, each located next to the first retardation plate; and

an optical device for coupling the collimated light waves from the optical module into the light-transmitting substrate to effect total internal reflection between the two major surfaces of the light-transmitting substrate, the optical device including;

a third polarizing beamsplitter,

a second retardation plate located next to one of the major surfaces of the light-transmitting substrate, and

a reflecting surface located next to the second retardation plate,

wherein the light waves emanating from the display source are p-polarized or s-polarized and are transmitted through the first polarizing beamsplitter so as to impinge on the first retardation plate which converts the light waves into circular polarized light waves, and wherein the circular polarized light waves are reflected back through the first retardation plate by a reflecting surface of the first lens so as to change a polarization state of the light waves such that the light waves are s-polarized or p-polarized, and wherein the s-polarized or p-polarized light waves are reflected from the first polarizing beamsplitter so as to couple the light waves into the folding prism, and wherein the light waves coupled into the folding prism are reflected from a first of the major surfaces of the folding prism, reflected from the second polarizing beamsplitter and coupled out of the folding prism through the first of the major surfaces of the folding prism so as to impinge on the first retardation plate which converts the light waves into circular polarized light, and wherein the circular polarized light waves are reflected back through the first retardation plate by a reflecting surface of the second lens so as to change the polarization state of the light waves such that the light waves are p-polarized or s-polarized, and wherein the p-polarized or s-polarized light waves are transmitted through the second polarizing beamsplitter and coupled out of the folding prism through a second of the major surfaces of the folding prism, transmitted through the third polarizing beamsplitter so as to impinge on the second retardation plate which converts the light waves into circular polarized light waves, reflected back through the second retardation plate by the reflecting surface located next to the second retardation plate so as to change the polarization state of the light waves such that the light waves are s-polarized or p-polarized, and wherein the s-polarized or p-polarized light waves are reflected from the third polarizing beamsplitter and trapped inside the light-transmitting substrate by total internal reflection.