The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 1992
Filed:
Feb. 10, 1988
Gerhard Wagenblast, Frankenthal, DE;
Karl-Heinz Etzbach, Frankenthal, DE;
Bernd Hisgen, Limburgerhof, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
A laser-optical write and read process whereby a thermally alterable recording layer which contains liquid-crystalline compounds in homogeneous planar orientation and forms part of a multilayer, sheet-like recording material is written by means of a write laser beam with analogue or digital data in the form of thermally altered areas, whereafter the written data are read by means of a read laser beam, including: analyzing the light transmitted or reflected by the recording material, and reading the data by determining the polarization-optical contrast between the thermally altered and the unaltered areas and/or utilizing for this purpose the interference of the light rays which form from the laser lightwaves in a Gaussian intensity distribution owing to the different phase velocities of the light in the center of thermally altered areas on the one hand and their thermally unaltered surroundings on the other.