POLARIZING BEAM SPLITTER

• US 20070030456A1
• Filed: 06/28/2006
• Published: 02/08/2007
• Est. Priority Date: 07/29/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: O'Keefe, Michael, Ma, Jiaying, Duncan, John, Phillips, William, Destain, Patrick
• Granted Patent: US 7,529,029 B2
• Time in Patent Office: Days
• US Class Current: 353/20
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28

Abstract

A polarizing beam splitter that includes at least one prism, and a reflective polarizing film. The prism comprises a first polymeric material, and has at least one curved outer surface and an incident surface, where the reflective polarizing film is disposed adjacent the incident surface.

Claims

1. A polarizing beam splitter comprising:

a first prism comprising a polymeric material, the first prism having a first curved outer surface, a second curved outer surface, and a first incident surface, wherein the first prism is configured to transmit light through at least the first curved outer surface and the second curved outer surface; and

a reflective polarizing film disposed adjacent the first incident surface of the first prism.

2. The polarizing beam splitter of claim 1, wherein at least one of the first curved outer surface and the second curved outer surface has a geometry selected from the group consisting of a convex surface, a concave surface, an aspherical surface, an anamorphic surface, a cylindrical surface, a sub-lens array surface, and combinations thereof.

3. The polarizing beam splitter of claim 1, further comprising a second prism comprising a second polymeric material, the second prism having a third curved outer surface and a second incident surface, wherein the reflective polarizing film disposed between the first incident surface of the first prism and the second incident surface of the second prism.

4. The polarizing beam splitter of claim 3, wherein the first prism comprises at least one male member disposed on a surface adjacent to the reflective polarizing film and projecting therefrom, and wherein the second prism comprises at least one female portion capable of receiving the at least one male member therein.

5. The polarizing beam splitter of claim 1, wherein the polymeric material is selected from the group consisting of acrylic polymers, cyclic-olefin copolymers, polycarbonates, and combinations thereof.

6. The polarizing beam splitter of claim 1, wherein the first curved outer surface is orientated at a tilted angle from an optical axis of the second curved outer surface.

7. The polarizing beam splitter of claim 1, wherein at least one of the first curved outer surface and the second curved outer surface is curved along two axial directions.

8. The polarizing beam splitter of claim 1, wherein the first prism exhibits a colored tint.

9. An image display system comprising:

an illumination source;

a polarizing beam splitter comprising;

a first prism comprising a polymeric material, the first prism having a first curved outer surface, a second curved outer surface, and a first incident surface, wherein the first prism is disposed such that the first curved outer surface receives light from the illumination source; and

a reflective polarizing film disposed adjacent the first incident surface of the prism; and

an image-forming device disposed to receive light from the polarizing beam splitter.

10. The image display system of claim 9, wherein at least one of the first curved outer surface and the second curved outer surface of the first prism has a geometry selected from the group consisting of a convex surface, a concave surface, an aspherical surface, an anamorphic surface, a cylindrical surface, a sub-lens array surface, and combinations thereof.

11. The image display system of claim 9, wherein the image-forming device is selected from the group consisting of a reflective polarization-rotating imager, a transmissive imager, and a digital-mirror device.

12. The image display system of claim 11, wherein the reflective polarization-rotating imager comprises a liquid crystal on silicon device.

13. The image display system of claim 9, wherein the polarizing beam splitter further comprises a second prism comprising a second polymeric material, the second prism having a third curved outer surface and a second incident surface, wherein the reflective polarizing film disposed between the first incident surface of the first prism and the second incident surface of the second prism.

14. The image display system of claim 13, wherein the first prism comprises at least one male member disposed on a surface adjacent to the reflective polarizing film and projecting therefrom, and wherein the second prism comprises at least one female portion capable of receiving the at least one male member therein.

15. The image display system of claim 9, wherein the polymeric material is selected from the group consisting of acrylic polymers, cyclic-olefin copolymers, polycarbonates, and combinations thereof.

16. The image display system of claim 9, wherein the first curved outer surface is orientated at a tilted angle from an optical axis of the second curved outer surface.

17. The image display system of claim 9, wherein the image display system exhibits volumetric dimensions of about 16 cubic centimeters or less.

18. An image display system comprising:

an illumination source;

a polarizing beam splitter comprising;

an first prism comprising a first polymeric material, the first prism having a first curved outer surface, wherein the polarizing beam splitter is disposed such that the first curved outer surface receives light from the illumination source;

a second prism comprising a second polymeric material, the second prism having a second curved outer surface; and

a reflective polarizing film disposed between the first prism and the second prism; and

an image-forming device disposed to receive light from the polarizing beam splitter.

19. The image display system of claim 18, wherein at least one of the first prism and the second prism comprises an additional curved outer surface.

20. The image display system of claim 18, wherein at least one of the first curved outer surface and the second curved outer surface has a geometry selected from the group consisting of a convex surface, a concave surface, an aspherical surface, an anamorphic surface, a cylindrical surface, a sub-lens array surface, and combinations thereof.

21. The image display system of claim 18, wherein the image-forming device is selected from the group consisting of a reflective polarization-rotating imager, a transmissive imager, and a digital-mirror device.

22. The image display system of claim 21, wherein the reflective polarization-rotating imager comprises a liquid crystal on silicon device.

23. The image display system of claim 18, further comprising a projection lens disposed to receive light from the polarizing beam splitter.

24. The image display system of claim 18, wherein the image display system exhibits volumetric dimensions of about 16 cubic centimeters or less.

25. The image display system of claim 18, wherein the image display system is characterized by a footprint having an area of about 9 square centimeters or less.