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:
Dec. 25, 1984
Filed:
Jan. 18, 1982
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A thin-film magnetic head having a magnetic substrate made from ferrite, iron-aluminum-silicon alloy or like material, and an upper magnetic layer formed on the magnetic substrate with a lower magnetic layer and a conductive layer interposed therebetween. A portion of the upper magnetic layer is jointed to the magnetic substrate while another portion of the upper magnetic layer is jointed to the lower magnetic layer through a non-magnetic layer of SiO.sub.2 or like material constituting a magnetic gap. The lower magnetic layer, magnetic substrate, upper magnetic layer and the non-magnetic layer in combination form a closed magnetic circuit. A groove is defined between the lower magnetic layer and the magnetic substrate, and formed in the side surface of the magnetic substrate adapted to face a magnetic recording medium. The recess is filled with a non-magnetic material such as glass. Accordingly, it is possible to realize a definite pole piece length to permit an improvement in short-wavelength reproduction characteristics.