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:
Nov. 20, 1990
Filed:
Jan. 17, 1989
Marino G Carasso, Eindhoven, NL;
Johannes J Verboom, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
An optically readable record carrier for storing digitally coded information having a power spectrum with a substantially zero level at a predetermined frequency. The information is recorded on and/or reproduced from substantially parallel elongated tracks on the record carrier which have a periodic undulation at the aforesaid predetermined frequency. Such undulation generates a clock signal for synchronizing the recording and/or reproduction of the digitally encoded information on the tracks, and does not interfere with the recording or reproduction of such information. Apparatus is disclosed for forming such tracks on the record carrier.