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:
Jun. 12, 1990
Filed:
Jun. 15, 1988
Aartje W Veenis, Eindhoven, NL;
Winslow M Mimnagh, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
An optical record carrier having an information recording track which is inscribed with control data indicative of the change in average level of read-out signals from recorded and unrecorded portions of the track. Read apparatus for such record carrier scans the track with a radiation beam and derives a read-out electrical signal therefrom. The apparatus includes a signal-processing circuit which is adjusted for operation at the average level of signals derived from recorded portions of the track, such average level being determined by a programmable control unit from the recorded control data and the measured average level of signals from unrecorded portions of the track. Tracking of the scanning beam is also controlled in conformity with the difference in average signal strength from recorded and unrecorded portions of the track.