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.

Date of Patent:
Mar. 17, 1998

Filed:

Sep. 09, 1996
Applicant:
Inventors:

Seiichi Sakai, Tokyo, JP;

Teruyuki Yoshida, Kanagawa, JP;

Assignee:

Sony Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G01R / ; G01N / ;
U.S. Cl.
CPC ...
324237 ; 324210 ; 360137 ;
Abstract

A magnetic sensor is disposed in an opposing relationship to a rotating magnetic head device with a magnetic head mounted thereon and placed in noncontact therewith so as to fall outside a lap angle .alpha. of a magnetic tape. The magnetic sensor is used as a part of oscillating elements of an oscillator circuit. By noting that a magnetic resistance of a magnetic circuit at a rotational position where the magnetic head faces the magnetic sensor changes according to the degree of extension of the magnetic head from the surface of a drum, and taking the change in magnetic resistance as a variation in oscillating frequency, the rate of wear of the magnetic head is measured. Since the change in magnetic resistance is taken as the variation in oscillating frequency, the degree of extension of the magnetic head, i.e., the rate of wear of the magnetic head can be measured with high accuracy. Since an apparatus for measuring the rate of wear of the magnetic head is a noncontact type, there is no risk that the magnetic head to be measured will be damaged. Owing to the above construction, the rate of wear of the magnetic head can be measured in the noncontact state and with high accuracy.


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