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.

Date of Patent:
Sep. 02, 2003

Filed:

Jul. 17, 2000
Applicant:
Inventors:

Akira Saito, Kanagawa, JP;

Kazuo Nimura, Nagano, JP;

Akihiro Otsuki, Nagano, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B 3/220 ; B32B 1/504 ; G11B 5/855 ; G11B 5/012 ; G11B 5/62 ;
U.S. Cl.
CPC ...
B32B 3/220 ; B32B 1/504 ; G11B 5/855 ; G11B 5/012 ; G11B 5/62 ;
Abstract

A master magnetic information carrier has embedded magnetic films that are free from protrusion and recess. The master disk is fabricated by the steps of laminating Co-based soft magnetic film on a resin base plate, forming isolated magnetic films in predetermined region by patterning the magnetic film, pressing a die from above the isolated magnetic films while heating the base plate with the magnetic films thereon, and releasing the die. Since the master disk is a mold product fabricated by pressing the die, the embedded magnetic films and the resin surface portion surrounding the magnetic films are intimately adjoined and protrusions and recesses at the boundary between them are suppressed to a minimum. The surface of the master disk is so smooth and flat that generation of flaws and gouges on the magnetic recording medium and transfer of particles and chemical contaminants to the recording medium in the contact duplication process are reduced.


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