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:
Feb. 25, 1992
Filed:
Mar. 22, 1989
Yutaka Maeda, Tokyo, JP;
Kiyotaka Kaneko, Tokyo, JP;
Izumi Miyake, Tokyo, JP;
Yoshio Nakane, Tokyo, JP;
Hiroshi Shimaya, Tokyo, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
The gain of an envelope detector circuit for detecting the envelope of a signal read from a magnetic head is capable of being changed over between two, namely high and low, stages. The gain of the envelope detector circuit is raised when track search processing is performed. When peak position detection processing is executed for detecting the peak position of the envelope of a recorded signal with regard to a designated track, first the gain of the envelope detector circuit is raised. The gain is lowered when the envelope saturates. This makes it comparatively easy to perform envelope detection, shortens the time required and makes it possible to use even a relatively low-precision A/D converter in the envelope detector circuit.