US4751100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium and method for making the same
Assignee: Panasonic Holdings Corp
•
Filing: 1987-03-02
•
Granted: 1988-06-14
•
Expires: 2007-03-02
Abstract
Abstract A method for making a magnetic recording medium which comprises: energizing ferromagnetic ultra-fine particles with a predetermined energy level, and implanting the energized ultra-fine particles into a non-magnetic substrate, at a predetermined range of depth from a principle surface of the substrate, to form a magnetic recording layer.
Inventors
- 👤 Kazufumi Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:37
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
107 words
A method for making a magnetic recording medium, comprising: energizing a plurality of ferromagnetic ultra-fine particles with a predetermined energy level by ionizing a ferromagnetic metal into an ion plasma; implanting said energized ferromagnetic ultra-fine particles into a non-magnetic substrate made of an organic polymer resin, with a predetermined range of depth from a principal surface of said substrate, to form a magnetic recording layer, by accelerating said ions by use of an electric field of a predetermined intensity and thereby implanting said ions into said non-magnetic substrate; and treating said principal surface of said substrate with a reactive plasma in an atmosphere including a fluorine-containing gas.
Claim 2
Independent Claim
107 words
A method for making a magnetic recording medium, comprising: energizing a plurality of ferromagnetic ultra-fine particles with a predetermined energy level by ionizing a ferromagnetic metal into an ion plasma; implanting said energized ferromagnetic ultra-fine particles into a non-magnetic substrate made of an organic polymer resin, with a predetermined range of depth from a principal surface of said substrate, to form a magnetic recording layer, by accelerating said ions by use of an electric field of a predetermined intensity and thereby implanting said ions into said non-magnetic substrate; and treating said principal surface of said substrate with a reactive plasma in an atmosphere including a fluorine-containing gas.
Claim 3
Dependent Claim
57 words
The method for making a magnetic recording medium in accordance with claim 1, which is further characterized in that said implanting is carried out in a dominant magnetic field applied from an opposite surface to said principal surface, thereby to orientate axes of easy-magnetization of said ferromagnetic ultra-fine particles in a vertical direction to said principal surface.
Claim 4
Dependent Claim
21 words
The method for making a magnetic recording medium in accordance with claim 1, wherein said substrate is of a light-transparent material.
Claim 5
Independent Claim
87 words
A method for making a magnetic recording medium, comprising: depositing a film of ferromagnetic material onto a principal surface of a non-magnetic substrate made of an organic polymer resin; implanting ions into said film of ferromagnetic material by accelerating an ionized substance by use of an electric field of a predetermined intensity, thereby to alter said ferromagnetic material into an amorphous ferromagnetic material provided on said substrate; and treating said principal surface of said substrate with a reactive plasma in an atmosphere including a gas containing fluorine.
Claim 6
Independent Claim
87 words
A method for making a magnetic recording medium, comprising: depositing a film of ferromagnetic material onto a principal surface of a non-magnetic substrate made of an organic polymer resin; implanting ions into said film of ferromagnetic material by accelerating an ionized substance by use of an electric field of a predetermined intensity, thereby to alter said ferromagnetic material into an amorphous ferromagnetic material provided on said substrate; and treating said principal surface of said substrate with a reactive plasma in an atmosphere including a gas containing fluorine.
Claim 7
Dependent Claim
89 words
The method for making a magnetic recording medium according to claim 4, wherein: said ionized substance has an atomic number or a molecular number which is larger than that of said ferromagnetic material, and an effect of accelerating said ionized substance into said film of ferromagnetic material is to knock some atoms of said ferromagnetic material through said principal surface and into said substrate to a predetermined range of depth; and thereafter removing a remainder of said ferromagnetic film from said substrate so as to expose said principal surface.
Claim 8
Dependent Claim
39 words
The method of claim 5, wherein: the step of treating said principal surface of said substrate with a reactive plasma in an atmosphere including a fluorine-containing gas is conducted after said remainder of said ferromagnetic film has been removed.
References Cited (Backward Citations)
US3792452A
Cited
US3915757A
Cited
US4177297A
Cited
US4188426A
Cited
US4372985A
Cited
US4495242A
Cited
US4451500A
Cited
US4491653A
Cited
US4565734A
Cited
US4520040A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |