Controlled liquid crystal optical polarizer method and apparatus

• US 5,523,863 A
• Filed: 01/30/1995
• Issued: 06/04/1996
• Est. Priority Date: 10/19/1988
• Status: Expired due to Fees

• Current Assignee: James L. Fergason
• Original Assignee: James L. Fergason
• Inventors: Fergason, James L.
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): PAPALAS, MICHAEL
• Application Number:
  US08/381,012
• Time in Patent Office: 491 Days
• Field of Search: 350/349, 350/350 R, 252/299.1, 252/299.7, 156/244.12, 156/494, 156/495, 359/37, 359/51, 359/52, 351/49
• US Class Current: 349/89
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: G02C 7/101 having an electro-optical light valve electro-optical elements per se G02F
• CPC Class Codes: G02C 7/12 Polarisers
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/13725 based on guest-host interaction G02F1/13762, G02F1/13737, take precedence

Abstract

A controllable liquid crystal polarizer has nematic liquid crystal and pleochroic dye in plural, parallel, elongate volumes in a sheet-like containment medium. Polarization effectiveness is variable as a function of electric field. A method of making the polarizer includes continuously forming a sheet-like film of a containment medium having a plurality of volumes of liquid crystal and pleochroic dye therein, and during curing of the film, stretching it to elongate the volumes.

Claims

1. A method of making a liquid crystal material polarizer comprising continuously casting an emulsion of liquid crystal material in a containment medium, and stretching such cast material to form elongate volumes of liquid crystal in such containment medium.

2. The method of claim 1 wherein said stretching comprises substantially unidirectional stretching.

3. The method of claim 1 further comprising selecting such liquid crystal as operationally nematic liquid crystal.

4. The method of claim 1 further comprising the step of forming an emulsion of liquid crystal and pleochroic dye with such containment medium to obtain volumes of liquid crystal and pleochroic dye in such containment medium.

5. The method of claim 1, further comprising curing said cast material to retain a generally elongate shape of volumes therein.

6. The method of claim 1, further comprising allowing such cast material to cure to retain a generally elongate shape of volumes therein.

7. The method of claim 1, further comprising selecting such liquid crystal material as low birefringence liquid crystal material.

8. The method of claim 7, wherein pleochroic dye is included with the liquid crystal, and said casting comprises casting an emulsion of liquid crystal, pleochroic dye and containment medium.

9. The method of claim 1, said casting comprising casting such emulsion of liquid crystal, and containment medium.

10. The method of claim 9, wherein pleochroic dye is included with the liquid crystal, and said casting comprises casting an emulsion of liquid crystal, pleochroic dye and containment medium.

11. The method of claim 1, further comprising final curing such cast material subsequent to said stretching step.

12. The method of claim 1, comprising selecting the liquid crystal material to respond to a prescribed input to change structural alignment for affecting polarization of light as a function of such alignment.

13. A liquid crystal polarizer made by the process of continuously casting an emulsion of liquid crystal material in a containment medium, and stretching such cast material to form elongate volumes of liquid crystal material in such containment medium.

14. The polarizer of claim 13, said casting comprising casting the emulsion using a reverse coating roller process.

15. The polarizer of claim 14, said stretching comprising substantially unidirectional stretching to form a three-dimensional matrix of such elongate volumes.

16. The polarizer of claim 14, further comprising selecting such liquid crystal material as operationally nematic liquid crystal.

17. The polarizer of claim 14, further comprising forming an emulsion of such liquid crystal material and pleochroic dye in a containment medium thereby to form plural volumes of liquid crystal material with pleochroic dye in such containment medium.

18. The polarizer of claim 13, the process by which said polarizer is made further comprising curing such cast material to retain a generally elongate shape of volumes therein.

19. The polarizer of claim 13, the process by which said polarizer is made further comprising allowing such cast material to cure to retain a generally elongate shape of volumes therein.

20. The polarizer of claim 13, wherein said liquid crystal material has low birefringence characteristics.

21. The polarizer of claim 20, wherein pleochroic dye is included with the liquid crystal, and said casting comprises casting an emulsion of liquid crystal, pleochroic dye and containment medium.

22. The polarizer of claim 13, said casting comprising casting such emulsion of liquid crystal, and containment medium.

23. The polarizer of claim 22, wherein pleochroic dye is included with the liquid crystal, and said casting comprises casting an emulsion of liquid crystal, pleochroic dye and containment medium.

24. The polarizer of claim 13, further comprising final curing such cast material subsequent to said stretching step.

25. A liquid crystal polarizer as set forth in claim 13, comprising selecting the liquid crystal material to respond to a prescribed input to change structural alignment for affecting polarization of light as a function of such alignment.