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:
Nov. 02, 1999
Filed:
Aug. 29, 1997
Applicant:
Inventors:
Kazunobu Chiba, Miyagi, JP;
Jota Ito, Miyagi, JP;
Tsutomu Takeda, Miyagi, JP;
Shinichi Matsumura, Miyagi, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428141 ; 428212 ; 428457 ; 4286 / ; 4286 / ; 428900 ;
Abstract
A base film for a magnetic recording medium including one surface, on which a magnetic layer can be formed, having a surface roughness of center line average roughness Ra of 10 nm or less, a ten-point average roughness Rz of 80 nm or less and a maximum height Rmax of 150 nm or less. The base film includes the other surface having a surface roughness of center line average roughness Ra of 4.5 to 20 nm, a ten-point average roughness Rz of 35 to 350 nm and a maximum height Rmax of 40 to 400 nm.