Patent US3814975A successfully refreshed from Google Patents.
US3814975A
Expired / Lapsed
US
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Electron emission system
Assignee: General Electric Co
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Filing: 1971-07-01
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Granted: 1974-06-04
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Expires: 1991-07-01
Abstract
Abstract A storage system for the mass recording and readout of digital data with ultra high resolution. An electron beam structure is provided for forming a beam of extremely small focused spot diameter, on the order of 0.1 microns, and high current density capability, on the order of 1,000 amperes per sq. cm., which records data by scanning over defined areas of the storage medium surface and micromachining elemental portions of said medium as a function of beam modulation. Readout may be subsequently accomplished by similarly scanning the beam at reduced power density and detecting electrons that have been transmitted by or reflected from the storage medium.
Inventors
- 👤 J Wolfe
- 👤 G Ledges
- 👤 H Glascock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:32
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/06; G; G11; G11C; G11C13/00; G11C13/04; G11C13/048; H01J1/00; H01J1/02; H01J1/13; H01J1/15; H01J1/16; H01J31/00; H01J31/08; H01J31/58; H01J31/60; H01J37/063; H01J37/073; H01J37/30; H01J37/302; H01J2237/00; H01J2237/06; H01J2237/063; H01J2237/06308; H01J2237/06316
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
An electron emission system, comprising: a. a hairpin filamentary heater, b. a cathode needle of single-crystal tungsten having an emissive tip joined to the vertex of said filament, said needle provided with a singly oriented 100 crystal face at said tip, c. a bead of zirconium coating material for reducing the work function at said supply oriented crystal face applied to the foregoing filamentary needle cathode in the vicinity of the junction between said needle and filament, said material migrating over the needle surface and coating the tip as a very thin layer in response to heating of said filament and cathode needle, and d. means for operating said filamentary cathode in an atmosphere containing oxygen at a medium vacuum, said oxygen continuously combining with said migrating zirconium to facilitate continuous replenishment of said work function reducing coating.
Claim 2
Dependent Claim
138 words
An electron emission system, comprising: a. a hairpin filamentary heater, b. a cathode needle of single-crystal tungsten having an emissive tip joined to the vertex of said filament, said needle provided with a singly oriented 100 crystal face at said tip, c. a bead of zirconium coating material for reducing the work function at said supply oriented crystal face applied to the foregoing filamentary needle cathode in the vicinity of the junction between said needle and filament, said material migrating over the needle surface and coating the tip as a very thin layer in response to heating of said filament and cathode needle, and d. means for operating said filamentary cathode in an atmosphere containing oxygen at a medium vacuum, said oxygen continuously combining with said migrating zirconium to facilitate continuous replenishment of said work function reducing coating.
Claim 3
Dependent Claim
22 words
An electron emission system as in claim 1 wherein said medium vacuum is on the order of 10 7 millimeters of mercury.
Claim 4
Dependent Claim
28 words
An electron emission system as in claim 2 in which said filament and cathode needle are heated to a temperature within the range of approximately 1,750*K to 1,850*K.
Claim 5
Dependent Claim
21 words
An electron emission system as in claim 3 in which said emissive has a radius on the order of one micron.
Claim 6
Dependent Claim
45 words
An electron emission system as in claim 1 wherein the cross sectional dimension of said hairpin filament in the region of said vertex is reduced so as to intensify heating of this region and assist in migration of the coating material over the needle surface.
Claim 7
Dependent Claim
46 words
An electron emissive system as in claim 1 which further includes field means for providing an electric field of generally hemispherical configuration about said emissive tip with a sufficiently high electric field gradient in the vicinity of said emissive tip to produce a high density emission.
References Cited (Backward Citations)
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US2786955A
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US3259782A
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US3374386A
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US3356887A
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US3678325A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-03 | 1977-12-03 | 1978-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-03 | 1981-12-03 | 1982-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-03 | 1985-12-03 | 1986-06-04 | $7700.00 | Window Closed / Lapsed |