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:
Feb. 12, 2002
Filed:
Oct. 10, 2000
Toshinori Watanabe, Niigata-ken, JP;
Akira Takahashi, Niigata-ken, JP;
Fumihito Koike, Niigata-ken, JP;
Nobuhiro Hayashi, Niigata-ken, JP;
Yoshihiro Kanada, Niigata-ken, JP;
Kiyoshi Kobayashi, Niigata-ken, JP;
Kiyoshi Sato, Niigata-ken, JP;
Eiji Umetsu, Niigata-ken, JP;
Takashi Hatanai, Niigata-ken, JP;
Akihiro Makino, Niigata-ken, JP;
Alps Electric Co., Ltd., Tokyo, JP;
Abstract
A thin film magnetic head includes an upper core layer and a lower core layer which are made of an Fe—M—O alloy, an Fe—M—T—O alloy or an NI—Fe—X alloy so that the upper core layer has a high saturation magnetic flux density, low coercive force and high resistivity, and the lower core layer has a lower saturation magnetic flux density than the upper core layer, low coercive force, high resistivity, and a low magnetostriction constant. Also the lower core layer is formed so that the thickness gradually decreases toward both side ends, and a gap layer can be formed on the lower core layer to have a uniform thickness. Since the lower core layer is formed by sputtering, a material having excellent soft magnetic material can be used, thereby enabling recording at high frequency.