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. 04, 1989
Filed:
Sep. 09, 1987
Hilde M Overath, Eindhoven, NL;
Cornelius A Hezemans, Eindhoven, NL;
Johannes L Bakx, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A read apparatus for reading a record carrier (1) having a concentric track pattern comprises a scanning device (2, 3) for reading the information, and a separator circuit (4) for extracting a periodic synchronizing signal (Ps) from the information read. By means of a servo system, which inter alia includes a drive motor (9) for driving the disc 1 and a control circuit (5), the rotational speed of the disc is controlled so as to maintain the periodic synchronizing signal (Ps) in synchronism with a reference signal (Pr). The circuit (9a) rejects those signal components in the control signal (U) for the motor (9) which are caused by an eccentric position of the center of rotation of the disc relative to the track pattern. This prevents these signal components from causing an unnecessary dissipation of electric power in the motor, yielding a substantial improvement in motor efficiency.