IP Library Granted Patent US 6,858,328
Granted Patent B1
US 6,858,328 · App. 09/646,139 · Granted Feb 22, 2005

Master information support

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Quick Facts
Patent No.
US 6,858,328
App. No.
09/646,139
Granted
Feb 22, 2005
Kind
B1
Abstract

A master information carrier with excellent durability is provided, for the use of static and a real lump-sum recording of digital information signals on magnetic recording medium. The master information carrier comprises a non-magnetic substrate on which a ferromagnetic film is disposed with an embossed pattern. Protrusions of the embossed pattern correspond to a disposition of the digital information signals. Recessed portions of the embossed pattern of the ferromagnetic film are filled with non-magnetic solid material. Alternately, A non-magnetic substrate has an embossed pattern and recessed portions of the embossed pattern correspond to a disposition of the digital information signals. A ferromagnetic film is filled in the recessed portions of the embossed pattern.

Claims (17)

1. A master information carrier used for recording information signals on a magnetic recording medium, comprising a non-magnetic substrate; a pattern of a ferromagnetic film which is disposed on the surface of the non-magnetic substrate, the pattern being disposed in the track length direction so as to correspond to uniform and non-uniform arrangements of the information signals; and a non-magnetic solid material filled in portions between respective neighboring ferromagnetic film areas composing the pattern, top surfaces of the ferromagnetic films and the non-magnetic solid material forming a substantially flat surface,

wherein the ferromagnetic film comprises a material selected from the group consisting of Co, Fe, and an alloy comprising Co or Fe as the main component, and the non-magnetic solid material is selected from the group consisting of SiO 2 , Al 2 O 3 , Cu, Ag and an alloy comprising Cu or Ag as the main component.

2. A master information carrier used for recording information signals on a magnetic recording medium, comprising a non-magnetic substrate having an embossed surface that forms a pattern of recessed portions, the pattern being disposed in the track length direction so as to correspond to uniform and non-uniform arrangements of the information signals; and a ferromagnetic film filled in the recessed portions of the pattern, top surfaces of the non-magnetic substrate and the ferromagnetic films forming a substantially flat surface,

wherein the ferromagnetic film comprises a material selected from the group consisting of Co, Fe, and an alloy comprising Co or Fe as the main component and the non-magnetic substrate comprises a material selected from the group consisting of SiO 2 , Al 2 O 3 , Si, and C.

3. A method of manufacturing a magnetic recording medium comprising: bringing the master information carrier according to claim 1 into contact with the magnetic recording medium; and applying a magnetic field, whereby the magnetic recording medium is recorded a magnetized pattern corresponding the pattern formed on the master information carrier.

4. A method of manufacturing a magnetic recording medium comprising: bringing the master information carrier according to claim 2 into contact with the magnetic recording medium; and applying a magnetic field, whereby the magnetic recording medium is recorded a magnetized pattern corresponding the pattern formed on the master information carrier.

5. A master information carrier used for recording information signals on a magnetic recording medium, comprising a non-magnetic substrate; a pattern of ferromagnetic film which is disposed on the surface of the non-magnetic substrate, the pattern being disposed in the track length direction so as to correspond to uniform and non-uniform arrangements of the information signals; and a non-magnetic solid materials filled in portions between the respective neighboring ferromagnetic films areas composing the pattern, top surfaces of the ferromagnetic films and the non-magnetic solid material forming a substantially flat surface

wherein the ferromagnetic film comprises a material selected from the group consisting of Co, Fe, and an alloy comprising Co or Fe as the main component, and the non-magnetic solid material comprises a polymer material.

6. A master information carrier according to claim 5 , wherein the polymer material is formed by diluting polyimide in a solvent to prepare a polyimide solution, spin-coating the polyimide solution, and curing it with heat.

7. A master information carrier according to claim 1 , wherein a protective film is formed on the surface of said ferromagnetic film and said non-magnetic solid material.

8. A master information carrier according to claim 7 , wherein the protective film comprises carbon as the main component formed by sputtering.

9. A master information carrier according to claim 2 , wherein the cross section of said ferromagnetic film in a bit length direction of the information signals has a substantially trapezoidal shape with an upper side at the surface that is longer than a lower side on the substrate.

10. A master information carrier according to claim 2 , wherein a protective film is formed on the surface of said substrate and said ferromagnetic film filled in the recessed portions.

11. A master information carrier according to claim 10 , wherein said protective film comprises carbon as the main component formed by sputtering.

12. A master information carrier according to claim 7 , wherein the protective film has a thickness of 20 nm or less.

13. A master information carrier according to claim 7 , wherein the protective film is electrically conductive.

14. A master information carrier according to claim 10 , wherein the protective film has a thickness of 20 nm or less.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 16, 2014
From: PANASONIC CORPORATION
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 034650/0885 →
CHANGE OF NAME Recorded Aug 18, 2014
From: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
To: PANASONIC CORPORATION
Reel/Frame 033551/0062 →