Patent ID: 6114405
Filing Date: 2000-09-05
Classification: G02F

Abstract:
A method for preparing a film suitable for use as the light-modulating unit of an SPD light valve, comprising a cross-linked polymer matrix having droplets of a liquid light valve suspension distributed in the cross-linked polymer matrix, said light valve suspension comprising particles suspended in a liquid suspending medium; which comprises admixing a UV-cross-linkable liquid oligomer or polymer and said liquid light valve suspension, emulsifying the resulting admixture to form an emulsion of said liquid light valve suspension in said UV-cross-linkable liquid oligomer or polymer, and cross-linking said UV-cross-linkable liquid oligomer or polymer while said mixture is in the form of a thin layer of said emulsion by exposing said thin layer of said emulsion to UV-radiation or to an electron beam such that said film is not damaged due to said exposing, said oligomer or polymer and said particles being free of deleterious effects on one another wherein the index of refraction of the polymer matrix and the liquid light valve suspension are the same or as near to equal as possible.