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:
Jul. 04, 1989
Filed:
Aug. 12, 1987
Junichi Nakata, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
In an apparatus for optically reproducing the recorded information, a circuit to reproduce an RF signal is provided. At least a pair of photo sensors are arranged adjacently in a direction parallel with a tangential line of a recording track of an information recording disc. A light beam is irradiated onto the recording surface of the disc and the reflected light from the recording surface is received by these photo sensor. The phases of both output signals of the photo sensors are made coincident by the phase shift means. The resultant output signals having the same phase are added thereby to form the RF signal. For this purpose, the phase difference between both output signals of the photo sensors is detected and either one of phases of the output signals is shifted in accordance with the phase difference detecting output.