Electrically variable focus polymer-stabilized liquid crystal lens having non-homogenous polymerization of a nematic liquid crystal/monomer mixture

• US 8,031,323 B2
• Filed: 07/14/2009
• Issued: 10/04/2011
• Est. Priority Date: 06/05/2003
• Status: Active Grant

• Current Assignee: Point Financial, Inc.
• Original Assignee: Universite Laval
• Inventors: Presniakov, Vladimir, Galstian, Tigran, Asatryan, Karen, Tork, Amir
• Primary Examiner(s): Robinson; Mark
• Assistant Examiner(s): CHANG, CHARLES S
• Application Number:
  US12/502,737
• Publication Number:
  US 20100007844A1
• Time in Patent Office: 812 Days
• Field of Search: 349/200, 349/86, 349/88, 349/183
• US Class Current: 349/200
• CPC Class Codes: G02F 1/13775 Polymer-stabilized liquid crystal layers
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: G02F 1/294 Variable focal length devices
• CPC Class Codes: G02F 2203/28 focussing or defocussing

Abstract

A variable focus liquid crystal lens includes a nematic liquid crystal/monomer mixture having a spatially inhomogenous polymer network structure, and an electrode for applying a substantially uniform voltage to the nematic liquid crystal/monomer mixture. The lens is created within a cell by applying a substantially uniform electric field to the nematic liquid crystal/monomer mixture within the cell, while simultaneously irradiating the nematic liquid crystal/monomer mixture using a laser beam having a shaped intensity distribution, so as to induce formation of a spatially inhomogenous polymer network structure within the cell.

Claims

1. A method of making a variable focus liquid crystal lens, the method comprising inducing formation of a spatially non-homogenous density polymer network structure distributed within a volume of liquid crystal of a liquid crystal cell of said lens, the polymer network structure having a predetermined spatial density variance that creates a corresponding spatial variance in the electro-optical response of the liquid crystal.

2. A method as claimed in claim 1, wherein said liquid crystal cell is filled with a mixture of a liquid crystal material and a photopolymerizable monomer, and wherein said inducing comprises irradiating the liquid crystal/monomer mixture with light having a non-homogenous intensity distribution so as to induce formation of the spatially non-homogenous polymer network structure within the cell.

3. A method as claimed in claim 2, wherein said polymer network structure is less than 3% by weight of a combined weight of said polymer network structure and said liquid crystal material.

4. A method as claimed in claim 3, wherein said monomer is about 3% of said mixture by weight.

5. A method as claimed in claim 2, wherein said irradiating comprises irradiating using a laser light source.

6. A method as claimed in claim 5, wherein the intensity distribution is circularly symmetrical.

7. A method as claimed in claim 6, wherein the intensity distribution is a Gaussian distribution.

8. A method as claimed in claim 6, wherein said inducing is carried out while subjecting the liquid crystal/monomer mixture within said cell to a uniform electric field.

9. A method as claimed in claim 2, wherein said inducing is carried out while subjecting the liquid crystal/monomer mixture within said cell to a uniform electric field.

10. A method as claimed in claim 9, further comprising a step of providing a surfactant for orientating the liquid crystal/monomer mixture.

11. A method as claimed in claim 2, wherein the intensity distribution is circularly symmetrical.

12. A method as claimed in claim 11, wherein the intensity distribution is a Gaussian distribution.

13. A method as claimed in claim 2, wherein the liquid crystal material is nematic.

14. A method as claimed in claim 1, wherein the liquid crystal is nematic.

15. A method as claimed in claim 1, wherein said inducing is carried out while subjecting a liquid crystal within said cell to a uniform electric field.

16. A method as claimed in claim 15, further comprising a step of providing a surfactant for orientating the liquid crystal/monomer mixture.

17. A method as claimed in claim 1, wherein said liquid crystal cell contains a photopolymerizable monomer, and wherein said inducing comprises irradiating the cell using light to induce formation of a spatially non-homogenous density polymer network structure within the cell.

18. A method of making a variable focus liquid crystal lens, the method comprising irradiating a liquid crystal/monomer mixture within a cell with light having a non-homogenous intensity distribution so as to induce formation of a spatially non-homogenous polymer network structure within the cell, the polymer network structure having a predetermined spatial density variance that creates a corresponding spatial variance in the electro-optical response of the liquid crystal.

19. A method as claimed in claim 18, further comprising applying a substantially uniform electric field to the liquid crystal/monomer mixture within the cell simultaneously with the irradiating.

20. A method as claimed in claim 18, further comprising providing a surfactant for orientating the liquid crystal/monomer mixture.

21. A method as claimed in claim 18, wherein said irradiating comprises using a laser light source to generate the light.