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. 26, 1977
Filed:
Mar. 06, 1975
Kenkichi Umeda, Tokyo, JA;
Hiroyuki Yamauchi, Urawa, JA;
Sony Corporation, Tokyo, JA;
Abstract
A device for sensing the type of magnetic coating on a magnetic tape while the latter is at rest, for example, in a magnetic tape recording and/or reproducing apparatus, has a DC magnetic recording head energizable by a predetermined DC voltage for applying a DC magnetic flux to the tape with which such head is engaged, a magnetic sensing element preferably coupled with the DC magnetic recording head for sensing the remanence or residual magnetism in the tape while the latter remains at rest following the application of the DC magnetic flux to the tape, and a level detector for detecting the level of the sensed remanence of the tape as an indication of the type of magnetic coating thereon. Such level detector may be advantageously employed for controlling a frequency equalizing circuit and/or a bias oscillator included in the signal recording circuit of the recording and/or reproducing apparatus so as to automatically adapt the latter for recording operations on the particular type of tape installed therein.