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:
May. 23, 1989
Filed:
Jan. 28, 1988
Yoshihiro Shiroishi, Hachiouji, JP;
Sadao Hishiyama, Sayama, JP;
Hiroyuki Suzuki, Kawasaki, JP;
Tomoyuki Ohno, Kokubunji, JP;
Yoshibumi Matsuda, Kokubunji, JP;
Kazumasa Takagi, Tokyo, JP;
Yoshio Gobara, Hadano, JP;
Norikazu Tsumita, Kanagawa, JP;
Masaki Ohura, Odawara, JP;
Masaaki Hayashi, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a magnetic recording medium including an underlayer and a magnetic layer formed sequentially on a substrate, the underlayer is composed of a composite underlayer having an at least two-layered structure, the underlayer on the side of the substrate is made of a material providing low modulation to the magnetic recording medium while the underlayer on the side of the magnetic layer is made of a material providing a high S/N ratio to the medium. This makes it possible to obtain a magnetic recording medium having low modulation and high S/N ratio.