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:
May. 10, 1988
Filed:
Feb. 24, 1986
Applicant:
Inventor:
Richard E Fayling, White Bear Lake, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
428212 ; 427131 ; 428323 ; 428694 ; 428900 ;
Abstract
Some prior magnetic recording tapes have a backside layer of electrically conductive particles and friction-imparting nonmagnetic particles in a nonmagnetic binder. The novel tape differs in that the nonmagnetic particles are replaced by high-H.sub.c ferromagnetic particles, onto which may be recorded a distinctive magnetic pattern. This provides a 'magnetic watermark' that should protect recordings from being counterfeited, because if one were to copy a recording onto ordinary magnetic recording tape, the copy would lack the 'watermark'. This should inhibit unauthorized copying of video recordings such as motion pictures.