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:
Apr. 28, 1992
Filed:
May. 06, 1991
Masanobu Hanazono, Mito, JP;
Shinji Narishige, Mito, JP;
Yutaka Sugita, Tokorozawa, JP;
Hiroshi Fukui, Hitachi, JP;
Hirotsugu Fukuoka, Sendai, JP;
Hajime Aoi, Tachikawa, JP;
Masayuki Katsumoto, Kodaira, JP;
Takuji Ogawa, Odawara, JP;
Jun Naruse, Odawara, JP;
Yokuo Saitoh, Kanagawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formula