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:
Jun. 30, 1987
Filed:
Jul. 10, 1986
Junichi Akiyama, Yokohama, JP;
Shu Chiba, Yokohama, JP;
Norikazu Sawazaki, Yokohama, JP;
Shigeru Yatabe, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An apparatus for reproducing a signal recorded, in the form of a perpendicular signal magnetization, on a perpendicular magnetic recording layer backed with a high permeability layer of a magnetic recording medium. A thin-film magnetic material is disposed to face the recording layer so that an enlarged magnetized region is formed in the high permeability layer, which includes the position at which the magnetic material faces the recording layer. In this region, magnetic variation occurs in response to the signal magnetization of the recording layer at the position the magnetic material faces the recording layer. A detecting member such as a coil is disposed in the proximity of the magnetic material so as to be magnetically coupled to the enlarged magnetized region of the high permeability layer. The detecting member is used as a tuning element of a tuning circuit supplied with high frequency energy. A resonance output voltage of the high frequency circuit varies in response to the detection of magnetic variation in the high permeability layer. A reproducing circuit detects the variation in the resonance output voltage of the high frequency circuit to reproduce the signal recorded on the recording layer.