US3567989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron tube with mesh-type cathode having emissive portions between cross strips
Assignee: Japan Radio Co Ltd
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Filing: 1968-10-25
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Granted: 1971-03-02
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Expires: 1988-10-25
Abstract
Abstract A cathode structure of substantially uniform thickness exhibiting reduced heating time in an electron tube having a mesh grid, the cathode comprising a mesh portion consisting of substantially flat cross-strips and a number of depressed portions formed between the cross-strips, the depressed portions being coated with an electronic emissive material.
Inventors
- 👤 Michio Koshizuka
- 👤 Hideo Uno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:40
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
57 words
In an electron tube having a mesh grid structure (2), a cathode comprising: a base metal plate (1) of substantially uniform thickness including a mesh type portion consisting of a plurality of cross-strips (3) and a plurality of depressed portions (4) formed between said cathode cross-strips (3); and electronic emissive material coating only said depressed portions (4).
Claim 2
Dependent Claim
57 words
In an electron tube having a mesh grid structure (2), a cathode comprising: a base metal plate (1) of substantially uniform thickness including a mesh type portion consisting of a plurality of cross-strips (3) and a plurality of depressed portions (4) formed between said cathode cross-strips (3); and electronic emissive material coating only said depressed portions (4).
Claim 3
Dependent Claim
31 words
The tube defined in claim 1 wherein the width of said cathode cross-strips (3) is at least as great as the width of the cross-strips which comprise said mesh grid (2).
Claim 4
Dependent Claim
42 words
The tube defined in any one of claims 1 and 2 wherein said grid mesh (2) is spaced from said cathode structure, the cross-strips of said grid projecting over the cross-strips of said grid projecting over the cross-strips (3) of said cathode.
Claim 5
Dependent Claim
20 words
The tube defined in any one of claims 1, 2 and 3 wherein said grid and cathode structures are cylindrical.
Claim 6
Dependent Claim
21 words
The tube defined in claim 4 wherein said cylindrical cathode structure is mounted within and coaxial with said cylindrical grid structure.
Claim 7
Dependent Claim
14 words
The tube defined in claim 1 wherein said cathode cross-strips (3) are substantially flat.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |