US4081713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directly heated oxide cathode
Assignee: Hitachi Ltd
•
Filing: 1976-07-30
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Granted: 1978-03-28
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Expires: 1996-07-30
Abstract
Abstract A directly heated oxide cathode comprises a base metal of alloy containing Ni as a host material, an electron emissionable oxide of alkaline earth metal deposited on the base metal, and powders of metal selected from Ni sample substance, Co simple substance, Ni-Co alloy, alloy containing Ni, Ni-Co, or Co as a host material, and alloy containing Ni as a host material and a reducing agent such as Zr, deposited on both sides of the base metal onto which the oxide is deposited. Provision of the powders of metal on both sides can minimize deformation of the base metal and prevent peeling of the oxide from the cathode effectively. Provision of a reducing agent in the powders of metal further assures a sufficient supply of the reducing agent to the oxide, thereby effectively maintaining the electron emissionability and life of the oxide for a longer period of time.
Inventors
- 👤 Akira Misumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:31
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
116 words
In a directly heated oxide cathode comprising a base metal substrate of alloy containing Ni as a host material and a layer of an electron emissionable oxide of alkaline earth metal deposited on a face side of the base metal substrate, an improvement which comprises powders of metal selected from the group consisting of Ni simple substance, Co simple substance, Ni-Co alloy, and alloy containing Ni, Ni-Co, or Co as a host material, deposited on both the face and back sides of the base metal substrate onto which the oxide is deposited whereby strains developed during diffusion of Ni are balanced on the face and back sides of the base material substrate thereby minimizing deformation thereof.
Claim 2
Dependent Claim
116 words
In a directly heated oxide cathode comprising a base metal substrate of alloy containing Ni as a host material and a layer of an electron emissionable oxide of alkaline earth metal deposited on a face side of the base metal substrate, an improvement which comprises powders of metal selected from the group consisting of Ni simple substance, Co simple substance, Ni-Co alloy, and alloy containing Ni, Ni-Co, or Co as a host material, deposited on both the face and back sides of the base metal substrate onto which the oxide is deposited whereby strains developed during diffusion of Ni are balanced on the face and back sides of the base material substrate thereby minimizing deformation thereof.
Claim 3
Dependent Claim
21 words
A directly heated oxide cathode according to claim 1, wherein the base metal contains at least W and a reducing agent.
Claim 4
Dependent Claim
19 words
A directly heated oxide cathode according to claim 2, wherein the reducing agent is Mg, Al, Si, or Zr.
Claim 5
Dependent Claim
27 words
A directly heated oxide cathode according to claim 1, wherein the powder of metal is deposited in a deposition ratio of 0.3 to 4.0 mg/cm 2 .
Claim 6
Dependent Claim
28 words
A directly heated oxide cathode according to claim 1, wherein the powders of metal selected from the alloy containing Ni as a host material contains a reducing agent.
Claim 7
Dependent Claim
20 words
A directly heated oxide cathode according to claim 5, wherein the reducing agent is Zr, C, Mg, Si, or Al.
Claim 8
Dependent Claim
15 words
A directly heated oxide cathode according to claim 5, wherein the reducing agent is Zr.
Claim 9
Dependent Claim
19 words
A directly heated oxide cathode according to claim 7, wherein 0.1 to 10% by weight of Zr is contained.
Claim 10
Dependent Claim
110 words
In a directly heated oxide cathode comprising a base metal substrate of alloy containing Ni as a host material and a layer of an electron emissionable oxide of alkaline earth metal deposited on one side of the base metal substrate, an improvement which comprises powders of metal containing Ni as a host material and a reducing agent, and powders of Ni-based alloy free from a reducing agent, deposited on both sides of the base metal substrate onto which the oxide is deposited whereby strains developed during diffusion of Ni are balanced on both sides of the base material substrate thereby preventing distortion thereof and improving electron emissionability of the oxide.
Claim 11
Dependent Claim
110 words
In a directly heated oxide cathode comprising a base metal substrate of alloy containing Ni as a host material and a layer of an electron emissionable oxide of alkaline earth metal deposited on one side of the base metal substrate, an improvement which comprises powders of metal containing Ni as a host material and a reducing agent, and powders of Ni-based alloy free from a reducing agent, deposited on both sides of the base metal substrate onto which the oxide is deposited whereby strains developed during diffusion of Ni are balanced on both sides of the base material substrate thereby preventing distortion thereof and improving electron emissionability of the oxide.
Claim 12
Dependent Claim
25 words
A directly heated oxide cathode according to claim 9, wherein the powders are deposited in a deposition ratio of 0.3 to 4.0 mg/cm 2 .
Claim 13
Dependent Claim
15 words
A directly heated oxide cathode according to claim 10, wherein the reducing agent is Zr.
Claim 14
Dependent Claim
28 words
A directly heated oxide cathode according to claim 4, wherein the powders of metal deposited on each side of the base metal substrate are of the same kind.
Claim 15
Dependent Claim
30 words
A directly heated oxide cathode according to claim 12, wherein the powders of metal are deposited at the same ratio of deposition on each side of the base metal substrate.
Claim 16
Dependent Claim
28 words
A directly heated oxide cathode according to claim 11, wherein the powders of metal deposited on each side of the base metal substrate are of the same kind.
Claim 17
Dependent Claim
30 words
A directly heated oxide cathode according to claim 14, wherein the powders of metal are deposited at the same ratio of deposition on each side of the base metal substrate.
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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) | 1981-03-27 | 1981-09-26 | 1982-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-27 | 1985-09-26 | 1986-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-27 | 1989-09-26 | 1990-03-28 | $7700.00 | Window Closed / Lapsed |