US 5,751,452 AGranted

Optical devices with high polymer material and method of forming the same

AssigneeNippon Telegraph and Telephone Corporation

InventorsKeiji Tanaka, Kinya Kato, Shinji Tsuru, Shigenobu Sakai

Life of this patent

Estimating the term…

Loading patent…

Abstract

A polymer dispersed liquid crystal optical device is presented which has optical elements which control reflection, transmission and diffraction of incident light entering the device by adjusting the magnitude of the electrical field applied to the device between a maximum and a minimum limits. An optical element consists of a polymer material having an electrical field-independent refractive index, and a liquid crystal material having an electrical field-dependent refractive index. The optical elements are distributed through the device at specific inter-element spacings, thus enabling to generate reflection of incident light in accordance with Bragg's law of reflection. The inter-element spacings can also be varied by the application of the field, thus enabling to generate reflection of light of a desired wavelength. Such optical elements are ideal for use in full color optical display apparatus of a matrix driven type. Methods for producing the optical device and optical display apparatus are also presented.

Claims19

Dependent claims

An optical device comprising a pair of transparent electrodes, a plurality of optical elements formed as an interference pattern, having a periodicity in inter-element spacings, disposed between said transparent electrodes, wherein:

each optical element comprises a high polymer material having an electrical field-independent refractive index and a liquid crystal material having an electrical field-dependent refractive index, and wherein each optical element is orientated at a specific angle to an incident surface of said optical device, and reflection, transmission and diffraction of incident light entering said optical device are regulated by the application of an electrical field between said transparent electrodes;
and
said high polymer material is an optically isotropic material and said liquid crystal material is an optically anisotropic material, and said high polymer material comprises a multifunctional carbon/unsaturated carbon compound that can be additionally polymerized, and a light hardenable resin containing at least multifunctional thiol, and wherein the refractive index of the liquid crystal material is controlled by the application of an electric field on said pair of transparent electrodes.

Dependencies are inferred from the claim text.