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:
Aug. 21, 1990
Filed:
Feb. 15, 1989
Toshifumi Yoshida, Suita, JP;
Mitsuo Nabae, Nagaokakyo, JP;
Yasuo Nishinaka, Hirakata, JP;
Mitsuro Moriya, Neyagawa, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
The present invention discloses a control circuit. An AGC circuit has an input of an x input signal and a gain control amplifier has an input of a z input signal. A division operation of z/x is made by controlling the gain of the gain control amplifier by a gain control voltage issued from the AGC circuit. A division output signal is obtained from an output terminal of the gain control amplifier, and is usable for compensating focus error, tracking error or the like in an optical recording and reproducing apparatus which makes recording and reproducing by a light of laser light or the like. Also included is a switching circuit that allows offset voltages to be reduced.