Lens With Embedded Multilayer Optical Film for Near-Eye Display Systems

• US 20150185480A1
• Filed: 12/31/2013
• Published: 07/02/2015
• Est. Priority Date: 12/31/2013
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Ouderkirk, Andrew J., Binder, Erin A.
• Granted Patent: US 9,841,598 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 1/041 Lenses
• 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 27/142 Coating structures, e.g. thin films multilayers
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/28 Interference filters
• CPC Class Codes: G02B 5/287 comprising at least one layer of organic material
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers

Abstract

A lens is formed from at least two sections or bodies that are shaped to mate with each other, and a multilayer optical film is sandwiched between these two sections. Smooth surfaces of each section combine to provide a first optical surface of the lens, e.g., a concave, convex, or flat optical surface. The multilayer optical film includes a stack of polymer layers configured to selectively reflect light by constructive or destructive interference, at least some of the polymer layers being birefringent. The multilayer optical film may thus be or comprise e.g. a reflective polarizer and/or a narrow band or otherwise notched reflector. The multilayer optical film has an extended terminus that separates the smooth surfaces of the two sections. Any edge defects such as cracks or delaminations that may exist along the extended terminus are characterized by an average defect distance of no more than 100 or 50 microns.

Claims

1. A lens having first and second opposed optical surfaces connected by a circumferential surface, the lens comprising:

a first lens section having a first smooth surface and a side surface;

a second lens section having a first smooth surface, a second smooth surface, and a side surface; and

a multilayer optical film embedded in the lens between the first and second lens sections, the multilayer optical film comprising a plurality of polymer layers configured to selectively reflect light by constructive or destructive interference, at least some of the polymer layers being birefringent;

wherein the first optical surface comprises the first smooth surface of the first lens section and the first smooth surface of the second lens section;

wherein the second optical surface comprises the second smooth surface of the second lens section; and

wherein the multilayer optical film comprises a first extended terminus that separates the first smooth surface of the first lens section from the first smooth surface of the second lens section.

2. The lens of claim 1, wherein the circumferential surface comprises the side surface of the first lens section and the side surface of the second lens section.

3. The lens of claim 1, wherein the first optical surface also comprises the first extended terminus.

4. The lens of claim 1, wherein the first extended terminus is disposed in a first extended notch that separates the first smooth surface of the first lens section from the first smooth surface of the second lens section.

5. The lens of claim 4, wherein the first extended notch is no more than 250 microns deep.

6. The lens of claim 1, wherein to the extent the multilayer optical film has any edge defects along the first extended terminus, such edge defects are characterized by a first average defect distance of no more than 100 microns.

7. The lens of claim 6, wherein the first average defect distance is no more than 50 microns.

8. The lens of claim 1, wherein the first optical surface is curved, and the first extended terminus is arc-shaped.

9. The lens of claim 1, wherein the first optical surface is flat, and the first extended terminus is straight.

10. The lens of claim 1, wherein the first lens section also has a second smooth surface, wherein the second optical surface comprises the second smooth surface of the first lens section and the second smooth surface of the second lens section, and wherein the multilayer optical film comprises a second extended terminus that separates the second smooth surface of the first lens section from the second smooth surface of the second lens section.

11. The lens of claim 10, wherein the second optical surface also comprises the second extended terminus.

12. The lens of claim 10, wherein the second extended terminus is disposed in a second extended notch that separates the second smooth surface of the first lens section from the second smooth surface of the second lens section.

13. The lens of claim 10, wherein to the extent the multilayer optical film has any edge defects along the second extended terminus, such edge defects are characterized by a second average defect distance of no more than 100 microns.

14. The lens of claim 13, wherein the second average defect distance is no more than 50 microns.

15. The lens of claim 1, wherein, for at least one visible wavelength of normally incident light, the multilayer optical film is configured as a reflective polarizer.

16. The lens of claim 1, wherein, for at least one polarization state of normally incident light, the multilayer optical film is configured as a notch filter.

17. The lens of claim 16, wherein, for at least one visible wavelength of normally incident light, the multilayer optical film is configured as a reflective polarizer.

18. The lens of claim 1, further comprising a protective coating that covers the first smooth surface of the first lens section, the first smooth surface of the second lens section, and the first extended terminus.

19. The lens of claim 1, further comprising an absorptive layer that covers the first optical surface or the second optical surface.

20. The lens of claim 19, wherein the absorptive layer comprises an absorptive polarizer.

21. A compound lens, comprising:

the lens of claim 1; and

a second lens bonded to the lens of claim 1.

22. A system, comprising:

the lens of claim 1; and

an imaging device disposed to direct imaging light towards the multilayer optical film.

23. The system of claim 22, wherein the multilayer optical film is configured to selectively reflect visible light of a first characteristic and selectively transmit visible light of a second characteristic, and wherein the imaging light comprises the first characteristic.

24. The system of claim 23, wherein the first and second characteristics are orthogonal first and second polarization states, respectively, and wherein the lens further comprises an absorptive polarizer configured to absorb light of the second polarization state.

25. The system of claim 22, wherein the system comprises eyewear.

26. An optical component having first and second opposed optical surfaces connected by a circumferential surface, the optical component comprising:

a first section having a first smooth surface and a side surface;

a second section having a first smooth surface, a second smooth surface, and a side surface, the second section shaped to mate with the first section; and

a multilayer optical film embedded in the optical component between the first and second sections, the multilayer optical film comprising a plurality of polymer layers arranged to selectively reflect light by constructive or destructive interference, at least some of the polymer layers being birefringent;

wherein the first optical surface comprises the first smooth surface of the first section and the first smooth surface of the second section;

wherein the second optical surface comprises the second smooth surface of the second section; and

wherein the multilayer optical film comprises a first extended terminus that separates the first smooth surface of the first section from the first smooth surface of the second section.

27. The optical component of claim 26, wherein both the first and second optical surfaces are flat.

28. A method of making a lens, comprising:

providing a first optical body and a second optical body, the second optical body shaped to mate with the first optical body;

providing a multilayer optical film, the multilayer optical film comprising a plurality of polymer layers configured to selectively reflect light by constructive or destructive interference, at least some of the polymer layers being birefringent;

bonding the first and second optical bodies together with the multilayer optical film sandwiched therebetween to form a compound optical body;

forming a first optical surface in the compound optical body, the forming being carried out to give a first smooth surface to the first optical body and a second smooth surface to the second optical body, the first and second smooth surfaces being portions of the first optical surface, the optical body also having, or made to have, a second optical surface opposite the first optical surface, and a circumferential surface that connects the first and second optical surfaces; and

terminating the multilayer optical film along an extended terminus that separates the first smooth surface from the second smooth surface.

29. The method of claim 28, wherein the terminating is carried out to avoid edge defects in the multilayer optical film along the extended terminus, with any such edge defects being characterized by a first average defect distance of no more than 100 microns.

30. The method of claim 29, wherein the terminating comprises polishing an end of the multilayer optical film, and wherein the forming comprises polishing the first and second optical bodies.