Curved retarder-based optical filters

Patent metadata

Field	Value
Publication number	US-9457523-B2
Application number	US-201414216561-A
Country	US
Kind code	B2
Filing date	Mar 17, 2014
Priority date	Oct 11, 2007
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Curved polarization filters and methods of manufacturing such filters are described in the present disclosure. An exemplary method includes laminating a planar polarization layer to a planar retarder layer at a predetermined orientation and bending the laminate to create a curved filter. The strain on the retarder layer results in stress-induced birefringence, and the predetermined orientation of the retarder substantially compensates for the stress-induced birefringence. In some embodiments, the predetermination is based on mathematical models. In some other embodiment, the predetermination is based on experimental data.

First claim

What is claimed is:

1. A method for manufacturing a curved optical filter, the method comprising:
providing a drum having a curved surface;
feeding a first optical film onto the drum at a first rate;
feeding a second optical film onto an outer surface of the first optical film at a second rate;
coating the outer surface of the first optical film or an inner surface of the second optical film with an adhesive;
rotating the drum as the first and second optical films are being fed; and
laminating the first and second optical films together using a press roller, whereby the laminated first and second optical films have a curvature.

2. The method of claim 1 , wherein the first optical film is fed onto the curved surface of the drum.

3. The method of claim 1 , wherein the first and second optical films are fed into the drum at different angles with respect to a tangent of the curved surface of the drum.

4. The method of claim 1 , wherein the drum and an inner surface of the curved filter have the same curvature.

5. The method of claim 1 , wherein the first optical film is a polarizer.

6. The method of claim 1 , wherein the first optical film is a retarder.

7. The method of claim 5 , wherein the second optical film is a retarder.

8. The method of claim 1 , wherein the adhesive is a pressure-sensitive adhesive.

9. The method of claim 1 , wherein the second rate is faster than the first rate.

Assignees

• Reald Inc

Inventors

• Coleman David A
• Sharp Gary D

Classifications

• B29D11/00634 Primary

  Production of filters · CPC title

• B29K2995/0034

  Polarising · CPC title

• B32B2307/40

  having particular optical properties · CPC title

• B32B38/18

  Handling of layers or the laminate · CPC title

• Y10T156/10

  Methods of surface bonding and/or assembly therefor · CPC title