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. 25, 1997
Filed:
Jan. 22, 1993
Akira Ishikawa, Kodaira, JP;
Sadao Hishiyama, Sayama, JP;
Tomoo Yamamoto, Hachioji, JP;
Yoshihiro Shiroishi, Hachioji, JP;
Tomoyuki Ohno, Odawara, JP;
Yotsuo Yahisa, Kokubunji, JP;
Yukio Kato, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A thin-film magnetic recording medium improves the magnetostatic and dynamic magnetic characteristics of the conventional magnetic recording media. In one embodiment, the substrate surface is textured in both the circumferential and radial directions. In further embodiments, a variety of underlayers (13) and crystal orientation control layers (17) are provided in accordance with specific parameters to control the crystal structure of the magnetic layer (14). Finally, an embodiment includes multiple magnetic layers (14, 19) having respectively different residual magnetic flux densities and thicknesses, but similar dot products of residual magnetic flux density and thickness.