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:
Feb. 16, 1988
Filed:
Jan. 14, 1987
Applicant:
Inventors:
Assignee:
Toray Industries, Inc., Otsu, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428141 ; 428143 ; 428147 ; 428156 ; 428480 ; 428694 ; 428900 ; 428910 ;
Abstract
A biaxially oriented polyester film is provided, which has a plurality of depressions and a plurality of protrusions on at least one surface thereof, in a configuration such that at least one protrusion exists within each depression or at least protrusion exists in the area where two or more depressions are contiguous to each other depressions having an area fraction of from 1.times.10.sup.-3 to 6.times.10.sup.-1. The polyester film is useful as a substrate for magnetic recording tapes such as audio and video tapes, and the resultant magnetic recording tapes are excellent in both electromagnetic transducing characteristics and runnability.