Tunable electronic lens and prisms using inhomogeneous nano scale liquid crystal droplets

• US 7,327,434 B1
• Filed: 05/04/2006
• Issued: 02/05/2008
• Est. Priority Date: 05/08/2002
• Status: Expired due to Term

• Current Assignee: University of Central Florida Research Foundation Inc. (State University System of Florida)
• Original Assignee: University of Central Florida Research Foundation Inc. (State University System of Florida)
• Inventors: Wu, Shin-Tson, Ren, Hongwen
• Primary Examiner(s): Schechter; Andrew
• Assistant Examiner(s): NGUYEN, HOAN C
• Application Number:
  US11/418,510
• Time in Patent Office: 642 Days
• Field of Search: 349/200, 349183-186, 349171-172, 349/175, 349177-180, 349 86- 93
• US Class Current: 349/200
• CPC Class Codes: G02B 3/0087 with index gradient
• CPC Class Codes: G02B 3/14 of variable focal length
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• 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 1/292 by controlled diffraction or phased-array beam steering controlled diffraction for optical switching G02F1/31
• CPC Class Codes: G02F 1/294 Variable focal length devices

Abstract

Using inhomogeneous sized liquid crystal (LC) droplets for lens and prisms. For forming a positive lens, the LC droplet size can gradually increase from the center to the side edges. For forming a negative lens, the LC droplet size can gradually decrease from the center to the side edges. The lens can be created by Ultra Violet light exposure to patterns. The lens can be tuned by applying voltage to the droplets. The inhomogeneous droplets can also be used in Fresnel lens and prisms. Applications of the invention can be used for eyeglasses, arrays, camera type zoom lenses and beam steering applications.

Claims

1. A variable focus liquid crystal lens comprising:

a nematic liquid crystal/monomer mixture having a circularly symmetrical spatially inhomogeneous liquid crystal nano-size droplets in polymer mixture gradually changing in size in a circular pattern from the center of the lens to side edges of the lens; and

at least one electrode for applying a substantially uniform voltage to the nematic liquid crystal/monomer mixture, wherein the spatially inhomogeneous liquid crystal droplets creates a lens effect when said substantially uniform voltage is applied to the nematic liquid crystal/monomer mixture.

2. A method for making a variable focus liquid crystal lens, the method comprising the steps of:

applying a substantially uniform elastic field to a nematic liquid crystal/monomer mixture having nano-size liquid crystal droplets within a cell; and

simultaneously irradiating the nematic liquid crystal/monomer mixture using a light source having a circularly symmetrical shaped intensity distribution so as to induce formation of a spatially inhomogeneous liquid crystal droplets in polymer matrix with a droplet size gradually changing from a center of the cell to side edges of the cell, wherein the spatially inhomogeneous liquid crystal droplets modulates light as phase modulating and beam steering.

3. The method of claim 2, wherein the uniform electric field has a substantially zero field.

4. The method of claim 3, further comprising the step of reorienting the nematic liquid crystal.

5. The method of claim 2, wherein the uniform electric field has a field strength of greater than zero.