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

• US 7,667,818 B2
• Filed: 09/26/2006
• Issued: 02/23/2010
• Est. Priority Date: 06/05/2003
• Status: Active Grant

• Current Assignee: Point Financial, Inc.
• Original Assignee: Universite Laval
• Inventors: Galstian, Tigran, Tork, Amir, Asatryan, Karen, Presniakov, Vladimir
• Primary Examiner(s): Caley; Michael H
• Assistant Examiner(s): CHANG, CHARLES S
• Application Number:
  US11/535,089
• Publication Number:
  US 20070052915A1
• Time in Patent Office: 1,246 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 variable focus liquid crystal lens comprising:

a cell containing a liquid crystal/monomer mixture having a spatially non-homogenous polymer network structure distributed within the liquid crystal/monomer mixture, the polymer network having a predetermined spatial density variance that creates a corresponding spatial variance in the electro-optical response of the liquid crystal; and

at least one electrode for applying a substantially uniform voltage to the liquid crystal/monomer mixture in the cell.

2. The variable focus liquid crystal lens of claim 1, wherein the spatially non-homogenous polymer network structure is circularly symmetrical.

3. The variable focus liquid crystal lens of claim 1, wherein the liquid crystal/monomer contains less than 3% polymer chains.

4. The variable focus liquid crystal lens of claim 1, wherein the liquid crystal/monomer mixture contains approximately 97% liquid crystal.

5. The variable focus liquid crystal lens of claim 1, wherein the non-homogeneous polymer network is formed by photopolymerization.

6. The variable focus liquid crystal lens of claim 5, wherein photopolymerization comprises irradiating the liquid crystal/monomer mixture using a light beam having a shaped intensity distribution.

7. The variable focus liquid crystal lens of claim 1, wherein the monomer contained in the liquid crystal/monomer mixture is a glycidyl methacrylate.

8. A variable focus liquid crystal lens comprising:

a cell filled with a liquid crystal containing a polymer network structure distributed within the liquid crystal/monomer mixture, the polymer network having a predetermined spatial density variance that creates a corresponding spatial variance in the electro-optical response of the liquid crystal; and

a variable alternating field source coupled to said cell for applying an alternating electric field of spatially uniform magnitude to the liquid crystal mixture in the cell.

9. The variable focus liquid crystal lens of claim 8, wherein the polymer network structure is circularly symmetrical.

10. The variable focus liquid crystal lens of claim 8, wherein the cell is filled with a liquid crystal/monomer mixture containing less than 3% polymer chains.

11. The variable focus liquid crystal lens of claim 8, wherein the cell is filled with a liquid crystal/monomer mixture containing approximately 97% liquid crystal.

12. The variable focus liquid crystal lens of claim 8, wherein the polymer network is formed by photopolymerization.

13. The variable focus liquid crystal lens of claim 12, wherein the cell is filled with a liquid crystal/monomer mixture, and photopolymerization comprises irradiating the liquid crystal/monomer mixture using a light beam having a shaped intensity distribution.

14. The variable focus liquid crystal lens of claim 8, wherein the cell is filled with a liquid crystal/monomer mixture, the monomer contained in the liquid crystal/monomer mixture is a glycidyl methacrylate.