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:
Apr. 14, 1987
Filed:
Apr. 26, 1985
Horst-Christian Langowski, Hanover, DE;
Klaus Schmitz, Hanover, DE;
Polygram GmbH, Hamburg, DE;
Abstract
An optically readable, high storage density information carrier usually in the form of a disk, for example, a digitally recorded audio disk (CD) or a video disk (VLP) including a base, and a microstructure on the base which contains the recorded information, and consists of spiral or annular tracks or channels on one or both sides thereof. A reflective layer of a suitable metal or alloy is applied to the side of the information disk carrying the microstructure in at least that portion in which the microstructure exists. The present invention provides an improved reflective layer which, in turn, is covered by a protective layer. The improved reflective layer is a metal alloy selected from one of the following groups of alloys: (1) a Cu-Cr alloy containing from 0.3 to 1.5% chromium, (2) an Al-Mg-Si alloy containing 0.5 to 1.5% each of magnesium and silicon, and (3) an Mg-Mn-Si alloy containing 1.2 to 2% manganese and 0.05 to 0.1% silicon.