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:
Dec. 17, 1985
Filed:
Sep. 09, 1982
Applicant:
Inventors:
Robert L Hazel, Thousand Oaks, CA (US);
Gilbert Y Chan, Agoura, CA (US);
Assignee:
Burroughs Corporation, Detroit, MI (US);
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
369 45 ; 369 46 ;
Abstract
An optical storage system is disclosed having improved focus detecting and controlling apparatus which is responsive to a reading laser beam reflected from an optical medium so as to provide a focus error signal having a high gain in the immediate vicinity of the in-focus position along with a wide capture range. Focus detection is achieved based on determining the difference between the diameters of the beams applied to a pair of photosensitive elements located so that the diameters of the beams applied thereto are indicative of the quality of focusing of the reading beam on the optical medium.