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:
Oct. 12, 1982
Filed:
Nov. 17, 1980
Applicant:
Inventors:
Kornelis A Immink, Eindhoven, NL;
Martinus P Bierhoff, Eindhoven, NL;
Jacobus P Heemskerk, Eindhoven, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
250201 ; 369 45 ;
Abstract
A focusing system for focusing a radiation beam onto an object, in particular an optical disc. The focusing system comprises focusing-error detection means and two control elements for correcting the focusing depending on the detected focusing error. The detection means are constructed so that via one of the two control elements a feedback servo system is obtained while via the other control element a servo system without feedback, i.e. a feed-forward system, is obtained.