Device for reversible optical data storage using polymeric liquid crystals
AssigneeRohm GmbH Chemische Fabrik
InventorsManfred Eich, Joachim Wendorff
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Abstract
A device for reversible optical information storage with a polymeric liquid crystalline storage medium, with the storage medium consisting of a macroscopically oriented film of a liquid crystalline polymer that contains photochromic groups, and with the information being stored by local disorientation of the molecules induced by photoisomerization by means of a selectively acting light source.
Claims16
A method of reversible optical information storage using a device comprising (i) a substrate, and (ii) a film in an oriented or disoriented state in contact with said substrate, said film comprising a liquid crystalline polymer and photopolymerizable azo, azoxy or carbon-carbon double bond-containing photochromic groups capable of reversible light-induced isomerization, wherein said photochromic groups are contained in the monomers in said liquid crystalline polymer or are present in low molecular weight compounds added to said polymer, comprising the steps of:
- (a) writing information in said device by locally reorienting said film by photoisomerizing said photochromic groups in said film, film is in the shape-stable state below the glass temperature of said polymer when the information is;
- and
- (b) reading said stored information by illuminating said film with coherent monochromic light, wherein said film is in the shape-stable state below the glass transition temperature of said polymer during said writing and reading steps.
Dependencies are inferred from the claim text.