US4786922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron beam recording and reproducing apparatus
Assignee: Hitachi Ltd
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Filing: 1987-02-12
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Granted: 1988-11-22
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Expires: 2007-02-12
Abstract
Abstract An electron beam recording and reproducing apparatus which radiates the electron beam emitted from a needle cathode to a disc for recording and reproduction is disclosed. The needle cathode moves on the disc. A magnetic field is applied in the axial direction of the needle cathode in order to converge and radiate the electron beam emitted from the needle cathode to the disc.
Inventors
- 👤 Shigeyuki Hosoki
- 👤 Keiji Takata
- 👤 Toshiyuki Aida
- 👤 Sumio Hosaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:25
CPC Classifications
G; G11; G11B; G11B9/00; G11B9/10; G11B11/00; G11B11/03; G11B11/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
An electron beam recording and reproducing apparatus comprising: a needle cathode; a disc disposed in such a manner as to face said needle cathode with a fine gap therebetween; means for moving said needle cathode with respect to a surface of said disc; means for rotating said disc; and means for applying a magnetic field in the axial direction of said needle cathode in order to converge an electron beam emitted from said needle cathode onto said disc; wherein the electron emitted from said needle cathode to said disc is used as means for recording and reproduction.
Claim 2
Dependent Claim
97 words
An electron beam recording and reproducing apparatus comprising: a needle cathode; a disc disposed in such a manner as to face said needle cathode with a fine gap therebetween; means for moving said needle cathode with respect to a surface of said disc; means for rotating said disc; and means for applying a magnetic field in the axial direction of said needle cathode in order to converge an electron beam emitted from said needle cathode onto said disc; wherein the electron emitted from said needle cathode to said disc is used as means for recording and reproduction.
Claim 3
Dependent Claim
26 words
An electron beam recording and reproducing apparatus according to claim 1, wherein said means for applying a magnetic field is constituted integrally with said needle cathode.
Claim 4
Dependent Claim
25 words
An electron beam recording and reproducing apparatus according to claim 1, which further comprises means for deflecting the electron beam emitted from said needle cathode.
Claim 5
Dependent Claim
22 words
An electron beam recording and reproducing apparatus according to claim 3, wherein said deflection means is constituted integrally with said needle cathode.
Claim 6
Dependent Claim
43 words
An electron beam recording and reproducing apparatus according to claim 1, wherein level control means is disposed between said needle cathode and said moving means for moving said needle cathode in order to control the gap between said needle cathode and said disc.
Claim 7
Dependent Claim
30 words
An electron beam recording and reproducing apparatus according to claim 1, wherein said moving means for said needle cathode includes a support and a moving mechanism mounted to said support.
Claim 8
Dependent Claim
23 words
An electron beam recording and reproducing apparatus according to claim 1, wherein corrugations corresponding to recording signals are formed on the disc surface.
Claim 9
Dependent Claim
32 words
An electron beam recording and reproducing apparatus according to claim 1, wherein different work functions are provided on the disc surface in such a manner as to correspond to the recording signals.
References Cited (Backward Citations)
US2726289A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |