US4625142A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of manufacturing a dispenser cathode and dispenser cathode manufactured according to the method
Assignee: US Philips Corp
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Filing: 1983-03-21
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Granted: 1986-11-25
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Expires: 2003-03-21
Abstract
Abstract A dispenser cathode body is manufactured from a sintered metallic powder. A large scandium oxide concentration is provided beneath an emissive surface of the body, resulting in increased life, increased current density, and decreased sensitivity to ion bombardment.
Inventors
- 👤 Johannes van Esdonk
- 👤 Jacobus Stoffels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:55
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20; H01J1/28; H01J9/00; H01J9/02; H01J9/04
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
42 words
In a dispenser cathode comprising a body having an emissive surface for emitting electrons from a barium containing emissive material included in the cathode; the improvement comprising a 20-100 micrometer thick scandium-oxide-containing region of the body disposed immediately beneath said emissive surface.
Claim 2
Dependent Claim
42 words
In a dispenser cathode comprising a body having an emissive surface for emitting electrons from a barium containing emissive material included in the cathode; the improvement comprising a 20-100 micrometer thick scandium-oxide-containing region of the body disposed immediately beneath said emissive surface.
Claim 3
Dependent Claim
26 words
A dispenser cathode as in claim 1 where the barium containing emissive material is disposed adjacent a surface of said body opposite from said emissive surface.
Claim 4
Dependent Claim
18 words
A dispenser cathode as in claim 1 where said barium containing emissive material is impregnated in said body.
Claim 5
Independent Claim
44 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder to form the body; (b) sintering the body;
Claim 6
Independent Claim
44 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder to form the body; (b) sintering the body;
Claim 7
Dependent Claim
26 words
(c) adding a layer of scandium oxide powder to the body; (d) sintering the body; and thereafter (e) providing the cathode with a barium-containing emissive material.
Claim 8
Dependent Claim
26 words
(c) adding a layer of scandium oxide powder to the body; (d) sintering the body; and thereafter (e) providing the cathode with a barium-containing emissive material.
Claim 9
Dependent Claim
28 words
A method as in claim 4 where the layer of scandium oxide powder is added by providing a scandium oxide suspension on the body of pressed metallic powder.
Claim 10
Independent Claim
66 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder to form the body; (b) adding a layer of scandium oxide powder to the body; (c) sintering the body; and thereafter (b) providing the cathode with a barium-containing emissive material.
Claim 11
Independent Claim
66 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder to form the body; (b) adding a layer of scandium oxide powder to the body; (c) sintering the body; and thereafter (b) providing the cathode with a barium-containing emissive material.
Claim 12
Independent Claim
67 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder, which is mixed at least near said emissive surface with scandium oxide, to form the body; (b) sintering the body; and (c) providing the cathode with a barium containing emissive material.
Claim 13
Independent Claim
67 words
A method of manufacturing a dispenser cathode comprising a body having an emissive surface and including scandium oxide material disposed immediately beneath said emissive surface, said method comprising the steps of: (a) pressing a metallic powder, which is mixed at least near said emissive surface with scandium oxide, to form the body; (b) sintering the body; and (c) providing the cathode with a barium containing emissive material.
Claim 14
Dependent Claim
47 words
A method of manufacturing a dispenser cathode as in claim 7 where the body is pressed from a metallic powder which is mixed with scandium oxide only near said emissive surface, the pressed mixture forming a concentration of scandium oxide beneath the emissive surface of the body.
Claim 15
Dependent Claim
28 words
A method as in claim 7 or 8 where the amount of scandium oxide mixed with the metallic powder is approximately 2-15% by weight of the resulting mixture.
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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) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |