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:
Jul. 05, 1994
Filed:
Mar. 28, 1991
Kazuo Muramatsu, Kobe, JP;
Nobuhiro Ohta, Kobe, JP;
Shunsuke Takada, Kobe, JP;
Motoharu Sato, Kobe, JP;
Masami Takao, Kobe, JP;
Hiroko Nagata, Kobe, JP;
Satoru Takada, Kobe, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
The surface of a blank for a textured amorphous carbon substrate is polished in a surface with a predetermined surface roughness, and then the blank with a polished surface is heated at a predetermined temperature in an oxidizing atmosphere to form minute irregularities in the polished surface through a reaction expressed by C+O.sub.2 =CO.sub.2 so that the surface is textured in an appropriate surface roughness. A randomly textured amorphous carbon substrate has a randomly textured surface with a surface roughness Ra in the range of 20 to 100 .ANG. and the ratio Ra.sub.2 /Ra.sub.1, where Ra.sub.1 is the surface roughness with respect to a circumferential direction, and Ra.sub.2 is the surface roughness with respect to a radial direction, in the range of 0.75 to 1.25 .ANG.. A concentrically textured amorphous carbon substrate has a concentrically textured surface with a surface roughness Ra in the range of 30 to 100 .ANG. or in the range of 40 to 200 .ANG., and the ratio Ra.sub.2 /Ra.sub.1 of 1.75 or greater.