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:
Nov. 11, 1986
Filed:
Sep. 09, 1982
Robert L Hazel, Thousand Oaks, CA (US);
Gilbert Y Chan, Agoura, CA (US);
Burroughs Corporation, Detroit, MI (US);
Abstract
Focus detecting apparatus is disclosed which is useful, for example, in an optical storage system for detecting the quality of focusing of a laser beam on the surface of an optical medium. For focus detection purposes, the reflected beam is collected and separated into two beams which are applied to first and second photosensitive elements, respectively. Focus detection is achieved based on determining the difference between the diameters of the beams incident on the photosensitive elements which are located so that the diameters of the beams applied thereto are indicative of the quality of focusing of the beam on the surface.