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:
Oct. 17, 1989
Filed:
Oct. 18, 1988
Hermann Grobecker, Garbsen, DE;
Werner Heher, Lehrte, DE;
Adelbert Zielasek, Burgwedel, DE;
Frederik B Nusselder, Bussum, NL;
Polygram GmbH, New York, NY (US);
Abstract
High storage density information carriers, particularly optically readable video discs and digital records, can only be read error-free by a playback device when the high requirements made of freedom from warping also remain guaranteed over long storage times. A cassette is provided to support and fix an information carrier only within its central portion which is free of information tracks and, by a sufficient spacing of the information carrier in the support-free area between a bottom portion and a cover portion contact with the information carrier in this area is avoided, even given consideration of maximally-admissible warping tolerances of the storage cassette and of the information carrier.