Patent US1145305A successfully refreshed from Google Patents.
US4354908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of magnetic recording members
Assignee: Fujifilm Holdings Corp
•
Filing: 1978-07-11
•
Granted: 1982-10-19
•
Expires: 1998-07-11
Abstract
Abstract A process for the production of a magnetic recording member which comprises effecting electric field vapor deposition under conditions such that the angle of incidence at which the vapor beam of a ferromagnetic metal strikes a support is at least about 50° and the electric field between the support and a vaporization source is at least about 5 kv/m.
Inventors
- 👤 Ryuji Shirahata
- 👤 Tatsuji Kitamoto
- 👤 Yasuo Tamai
- 👤 Masaaki Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:24
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
109 words
A process for producing a magnetic recording member, comprising the steps of: generating ferromagnetic metal vapor particles from a vaporization source in a reduced pressure of about 10 -4 Torr to about 10 -7 Torr; ionizing said ferromagnetic vapor particles by means of an electron beam; and accelerating said ionized ferromagnetic metal vapor particles, by means of an electric field between said vaporization source and a support having a field strength of at least about 5 kv/m, toward said support to form a vapor beam which has an angle of incidence of at least about 50° with respect to said support, thereby producing a magnetic film on said support.
Claim 2
Dependent Claim
109 words
A process for producing a magnetic recording member, comprising the steps of: generating ferromagnetic metal vapor particles from a vaporization source in a reduced pressure of about 10 -4 Torr to about 10 -7 Torr; ionizing said ferromagnetic vapor particles by means of an electron beam; and accelerating said ionized ferromagnetic metal vapor particles, by means of an electric field between said vaporization source and a support having a field strength of at least about 5 kv/m, toward said support to form a vapor beam which has an angle of incidence of at least about 50° with respect to said support, thereby producing a magnetic film on said support.
Claim 3
Dependent Claim
24 words
The process according to claim 1, wherein the angle of incidence of the vapor beam of a ferromagnetic metal is from 60° to 80°.
Claim 4
Dependent Claim
24 words
The process according to claim 2, wherein the electric field strength between the support and the vaporization source is 8 kv/m to 30 kv/m.
Claim 5
Dependent Claim
26 words
The process according to claim 1, wherein the ferromagnetic metal is selected from the group consisting of iron, nickel, cobalt, other ferromagnetic metals and magnetic alloys.
Claim 6
Dependent Claim
22 words
The process according to claim 1, wherein the thickness of the magnetic film produced is about 0.05 μm to about 2.0 μm.
Claim 7
Dependent Claim
19 words
The process according to claim 1, wherein said generating and ionizing steps are performed by the same electron beam.
Claim 8
Dependent Claim
20 words
The improvement of claim 1 wherein said support is maintained at a temperature from room temperature to about 150° C.
Claim 9
Dependent Claim
21 words
The improvement of claim 1 wherein the vapor deposition occurs at a rate of from about 5 to about 500 A/sec.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |