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:
Sep. 05, 1989
Filed:
May. 20, 1987
Chikuni Kawakami, Tokyo, JP;
Koji Shimanuki, Tokyo, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A magnetic record erase circuit which is capable of substantially erasing frequency signals such as video signals recorded in a rotary magnetic recording medium such as a magnetic disc or a magnetic drum. In the magnetic record erase circuit, when a plurality of frequency-multiplexed signals recorded in one or all of tracks provided on the rotary magnetic recording medium are to be erased, the frequency of an erase signal to be supplied to a magnetic head forming a part of recording means can be varied increasingly stepwise in a given range and at least in the lower frequency region of the given range the current value of the erase signal can be set higher than the optimum recording current value of the magnetic head.