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. 16, 2002
Filed:
May. 11, 1999
Yoshibumi Matsuda, Hiratsuka, JP;
Yotsuo Yahisa, Odawara, JP;
Hiroyuki Suzuki, Fujisawa, JP;
Koji Sakamoto, Odawara, JP;
Yoko Ogawa, Odawara, JP;
Hiroshi Tani, Kanagawa-ken, JP;
Susumu Funamoto, Odawara, JP;
Akira Kato, Odawara, JP;
Yuzuru Hosoe, Hino, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A magnetic recording medium having a high reliability of durability against frictional motion can be ensured even in a severe rubbing test, while a low noise characteristic important for achievement of high-density recording is kept. A first underlayer made of an alloy containing Co or Ni as a main component and containing Cr and Zr simultaneously is formed over a base, a second underlayer having a rough surface is formed on the first underlayer, a third underlayer made of an alloy containing Ni as a main component and containing Cr and Zr simultaneously is formed over the second underlayer, a fourth underlayer as a film for controlling crystalline orientation is formed on the third underlayer, a magnetic layer made of an alloy containing cobalt a main component is formed over the fourth underlayer, and a protective film containing carbon as a main component is formed on the magnetic layer.