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. 23, 1990
Filed:
Jun. 02, 1988
Sony Corporation, Tokyo, JP;
Abstract
A signal reproducing system for use in an optical disc player comprises a photodetector including at least first and second photodetecting elements which are so disposed that a beam spot is formed on the first and second photodetecting elements by a light beam caused to impinge upon and reflected at an optical record disc and are aligned along a direction of movement of a diffraction pattern appearing in the beam spot in accordance with a record track on the optical record disc, a phase shifter for varying at least a phase of one of first and second output signals obtained respectively based on detection outputs of the first and second photodetecting elements, a switch for causing the first and second output signals selectively to pass through the phase shifter in response to a direction of movement of the record track in relation to the light beam incident upon the optical record disc, and a mixer operative to add one of the first and second output signals derived from the phase shifter to the other of the first and second output signals so as to produce a reproduced information signal.