US3735186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Field emission cathode
Assignee: US Philips Corp
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Filing: 1971-03-10
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Granted: 1973-05-22
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Expires: 1991-03-10
Abstract
Abstract A field emission cathode comprises a glass substrate in combination with an insulating layer sandwiched between two conducting layers functioning as electrodes. Cavities extending through one of the electrodes and the insulating layer to the surface of the other electrode contain highly compacted and porous electron emissive layers which provide high electrical resistance between said electrodes and are diffused with metallic gold to form needle-shaped metal deposits on the surface as well as within the emissive layers. Such cathodes are used in image converters and image display tubes.
Inventors
- 👤 A Klopfer
- 👤 G Dittmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:04
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/30; H01J1/304; H01J1/3042; H01J2201/00; H01J2201/30; H01J2201/304; H01J2201/30403
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
20 words
A cathode assembly as claimed in claim 1 wherein said electrodes comprise aluminum layers having thicknesses of about 1000 A.
Claim 2
Dependent Claim
21 words
A cathode assembly as claimed in claim 1 wherein said insulating layer comprises SiO2 having a thickness of 1 Mu .
Claim 3
Dependent Claim
20 words
A cathode assembly as claimed in claim 1 wherein said cavities are spaced apart approximately 50 Mu from each other.
Claim 4
Dependent Claim
22 words
A cathode assembly as claimed in claim 1 wherein said highly compacted electron emissive layer Al2O3 have a thickness about 50 A.
Claim 5
Dependent Claim
36 words
A cathode assembly as claimed in claim 1 wherein said high resistance electron emissive layer comprises a layer of Al2O3 having a compactness of about 40 to 50 percent of the maximum compactness of this material.
Claim 6
Dependent Claim
19 words
A cathode assembly as claimed in claim 1 wherein said gold layer has a thickness of about 50 A.
References Cited (Backward Citations)
US3500102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |