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:
Dec. 25, 2001
Filed:
Jul. 28, 2000
Hiroyuki Hirata, Ohtsu, JP;
Tatsuo Araki, Ohtsu, JP;
Osamu Ishizaki, Suita, JP;
Hideo Daimon, Ibaraki, JP;
Yasuhiko Kokufuda, Kyoto, JP;
Tsuyoshi Maro, Kyoto, JP;
Makoto Aihara, Fujisawa, JP;
Hitachi Maxwell, Ltd., Osaka, JP;
Abstract
A cavity surface-forming plate of a mold for injection-molding a plastic substrate is coarsely polished, and then a surface for defining a cavity is applied with electroless Ni—P plating. The surface of the plating is polished with abrasive grains to obtain surface roughness of Ra≦2.0 nm and Rmax≦22 nm. The plastic substrate molded with the mold has smoothness equivalent to the polished plating surface. A concave-convex pattern for forming pits may be formed on the cavity surface. A magnetic disk or an optical disk provided with the substrate makes it possible to realize the near contact system for a magnetic or magneto-optical head. Thus, it is possible to realize high density recording.