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. 04, 1986
Filed:
Sep. 09, 1982
Robert L Hazel, Thousand Oaks, CA (US);
Gilbert Y Chan, Agoura, CA (US);
Burroughs Corporation, Detroit, MI (US);
Abstract
An optical storage system is disclosed having improved spatial combining and separating apparatus along with improved focus detection and control apparatus. The spatial combining and separating apparatus functions to precisely combine a writing laser beam with a reading beam prior to focusing on an optical medium, and also functions to separate the reading and writing beams after reflection from the medium in a manner so as to prevent interference therebetween. The improved focus detecting and control apparatus employs a portion of the reflected reading beam to derive 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.