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:
Jan. 16, 1979
Filed:
Apr. 14, 1977
Antonius A Van Alem, Eindhoven, NL;
Lieuwe Boonstra, Eindhoven, NL;
Francois D Dekker, Amsterdam, NL;
Johannes T Van de Veerdonk, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
An optical scanning device scans recording tracks on a record carrier with the aid of a beam of radiation, while an objective, which concentrates the beam of radiation to a scanning spot, performs automatic electrically controlled movements in a direction perpendicular to the plane of the record carrier with the aid of a focussing bearing arrangement, so as to ensure a continuous focussing of the scanning spot on the recording tracks. Moreover, in order to follow the oscillations of the recording track, the objective also performs electrically controlled movements which are such that the scanning spot moves at least substantially parallel to the plane of the record carrier.