US4254357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-arrayed micro-patch emitter with integral control grid
Assignee: United States Department of the Navy
•
Filing: 1979-09-14
•
Granted: 1981-03-03
•
Expires: 1999-09-14
Abstract
Abstract A multi-arrayed electron emitter for microwave tubes in which the emittingurface is an array of continually replenished low-work-function regions, (micro-patches), whose boundaries include a control grid which is integral with the cathode surface and which controls emission from the low-work-function micro-patches. The continually replenished low-work-function regions are uniformly positioned relative to a matrix of uniformly spaced openings through which the low-work-function material is released.
Inventors
- 👤 George A. Haas
- 👤 Richard E. Thomas
- 👤 Richard F. Greene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:43
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/02; H01J23/04; H01J19/00; H01J19/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
An electron-emitter cathode assembly with an integral control grid which comprises: a container for low-work-function material having a porous metal top serving as a cathode, the low-work-function material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitting areas centered at the pores; and an insulated grid disposed on the porous metal top of the container and having a plurality of openings, each opening being aligned with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures.
Claim 2
Dependent Claim
121 words
An electron-emitter cathode assembly with an integral control grid which comprises: a container for low-work-function material having a porous metal top serving as a cathode, the low-work-function material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitting areas centered at the pores; and an insulated grid disposed on the porous metal top of the container and having a plurality of openings, each opening being aligned with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures.
Claim 3
Dependent Claim
29 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 including: an insulator disposed between the insulated grid and the porous metal top of the container.
Claim 4
Dependent Claim
23 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the top of the container is made of iridium.
Claim 5
Dependent Claim
20 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid is formed of zirconium.
Claim 6
Dependent Claim
20 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid is formed of tantalum.
Claim 7
Dependent Claim
22 words
The electron-emitter cathode assembly with an integral control grid recited in claim 1 wherein: the grid insulator is formed of boron nitride.
Claim 8
Dependent Claim
27 words
The electron-emitter cathode assembly with an integral control grid recited in claim 2 wherein: the isulator is made of the same material as that of the grid.
Claim 9
Independent Claim
127 words
A method of forming an electron-emitter cathode assembly with an integral control grid comprising the steps of: forming a container for low-work-function material; providing a porous metal top for the container to serve as a cathode, the low-work-function-material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitters areas centered at the pores; disposing on the porous top of the container an insulated grid having a plurality of openings, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures; aligning each opening with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material.
Claim 10
Independent Claim
127 words
A method of forming an electron-emitter cathode assembly with an integral control grid comprising the steps of: forming a container for low-work-function material; providing a porous metal top for the container to serve as a cathode, the low-work-function-material being dispensed from the pores to the cathode when the container is heated to provide an array of low-work-function electron-emitters areas centered at the pores; disposing on the porous top of the container an insulated grid having a plurality of openings, the grid being made of a material to which the low-work-function material will not adhere at operating temperatures; aligning each opening with a single respective pore to control electron emission from the respective low-work-function electron-emitting area centered at the pore and to contain the spread of low-work-function material.
Claim 11
Dependent Claim
25 words
The method recited in claim 8 including the step of: disposing an isolator between the insulated grid and the porous metal top of the container.
References Cited (Backward Citations)
US3154711A
Cited
US3373307A
Cited
US3694260A
Cited
US3638062A
Cited
US3967150A
Cited
US4096406A
Cited
US4165473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |