Controllable bandwidth polarizer
AssigneeReveo, Inc.
InventorsBunsen Fan, Jian-feng Li, Le Li, Sadeg Faris
Life of this patent
Estimating the term…
Abstract
A light controlling film is described comprising a polymerized polymer network of a crosslinked high molecular weight polymeric material and a low molecular weight cholesteric liquid crystal (CLC) material, wherein the high molecular weight and the low molecular weight form a material having cholesteric liquid crystal (CLC) order such that the film is a reflective circular polarizer whose bandwidth is controllable by an electric field impressed in the film.
Claims27
A light controlling film, the film having a first surface and a second surface, comprising:
- a polymerized polymer network, comprising:
- a crosslinked high molecular weight polymeric material;
- and
- a low molecular weight cholesteric liquid crystal (CLC) material,
- wherein the high molecular weight and the low molecular weight form a material having cholesteric liquid crystal (CLC) order, the CLC order oriented with respect to the first and the second surfaces, and
- wherein light having a first polarization and a first bandwidth incident on the first surface is substantially reflected from the film, and wherein light having a second polarization and the first bandwidth incident on the first surface is not substantially reflected from the film, and wherein an electric field impressed in the film substantially changes the first bandwidth of reflection of light having the first polarization.
A method of making a light controlling film, the film having a first surface and a second surface, comprising:
- applying a mixture of high molecular weight polymeric material and low molecular weight polymeric material on a surface which produces a CLC order in the mixture;
- and
- crosslinking the high molecular weight polymeric material so that the low molecular weight material does not significantly diffuse and remains uniformly distributed in the film;
- wherein light having a first polarization and a first bandwidth incident on the first surface is substantially reflected from the film, and wherein light having a second polarization and the first bandwidth incident on the first surface is not substantially reflected from the film, and wherein an electric field impressed in the film substantially increases the first bandwidth of reflection of light having the first polarization.
A system for controlling unpolarized electromagnetic (EM) radiation comprising:
- a substrate;
- a single layer of material on the substrate, the material reflecting the electromagnetic (EM) radiation, the reflected EM radiation being polarized, the reflected EM radiation having a bandwidth;
- an electric field generator for generating a variable electric field in the layer of material;
- and
- a controller for controlling the electric field generator;
- whereby the controller controls the electric field generator to generate a field in the layer of material and whereby the bandwidth of the reflected EM radiation changes in response to the change of the electric field.
A switchable reflective polarizer for reflecting light of a first polarization, wherein the bandwidth of polarized light reflected from the reflective polarizer may be changed from a broad bandwidth to a narrower bandwidth by the application of an voltage to the reflective polarizer.
Dependencies are inferred from the claim text.