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. 13, 2001
Filed:
Apr. 22, 1998
Applicant:
Inventors:
Koichi Terunuma, Tokyo, JP;
Yasufumi Uno, Nagano, JP;
Tetsuya Mino, Chiba, JP;
Koji Matsukuma, Hyogo, JP;
Assignee:
TDK Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/31 ;
U.S. Cl.
CPC ...
G11B 5/31 ;
Abstract
A thin film magnetic head includes a recording gap layer, and lower and upper magnetic pole layers made of polycrystalline magnetic substances, deposited to sandwich the recording gap layer. An average particle size D of crystal substances at least in a region of the upper magnetic pole layer, near the recording gap layer with respect to a recording track width W is set to D≦W/20.