US4415835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electron emissive coatings for electric discharge devices
Assignee: General Electric Co
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Filing: 1981-06-22
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Granted: 1983-11-15
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Expires: 2001-06-22
Abstract
Abstract An electric discharge type device is described having electrode means which include a refractory metal substrate having sintered thereon an open porous coating of refractory metal particles at a thickness up to about 1 millimeter thickness with electron emissive material being disposed in the pores of said sintered refractory metal coating. Representative electric discharge devices having said improved electrode means include discharge type electric lamps and photographic flash tubes wherein the electrode members have an elongated shaped body which is terminated at one end to provide more surface area for the coatings sintered thereon. Various electron emissive materials can be employed for impregnation of the open porous coating of refractory metal particles by such conventional techniques as dipping or spraying.
Inventors
- 👤 Amarendra Mishra
- 👤 Dimitri M. Speros
- 👤 Roger M. Eastin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:07
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/02; H01J61/04; H01J61/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
49 words
A cathode member for an electric discharge device which comprises a refractory metal substrate having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating.
Claim 2
Dependent Claim
49 words
A cathode member for an electric discharge device which comprises a refractory metal substrate having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating.
Claim 3
Dependent Claim
19 words
A cathode member as in claim 1 wherein said open porous coating comprises a mixture of different refractory metals.
Claim 4
Dependent Claim
18 words
A cathode member as in claim 1 wherein the substrate and open porous coating are both tungsten metal.
Claim 5
Dependent Claim
24 words
A cathode member as in claim 2 wherein the major constituent in said mixture is tungsten metal and the minor constituent is tantalum metal.
Claim 6
Dependent Claim
14 words
A cathode member as in claim 1 wherein the substrate is a tungsten wire.
Claim 7
Dependent Claim
15 words
A cathode member as in claim 5 wherein the tungsten wire has a bent shape.
Claim 8
Dependent Claim
19 words
A cathode member as in claim 1 wherein the electron emissive material is an interoxide containing a refractory metal.
Claim 9
Dependent Claim
18 words
A cathode member as in claim 1 wherein the electron emissive material is Cs 2 MoO 4 .
Claim 10
Dependent Claim
29 words
A cathode member as in claim 1 wherein the electronic emissive material includes both Cs 2 MoO 4 and an interoxide coating of a refractory metal other than molybdenum.
Claim 11
Dependent Claim
26 words
A cathode member as in claim 1 wherein the electron emissive material includes oxides of scandium and dysprosium and the borides of thorium, scandium, and lanthanum.
Claim 12
Dependent Claim
28 words
A cathode member as in claim 1 having an elongated shaped body which is terminated at one end to provide more surface areas for the coating sintered thereon.
Claim 13
Dependent Claim
74 words
An electric discharge device comprising a transparent envelope containing a pair of spaced apart discharge electrodes hermetically sealed within said envelope and an ionizable atmosphere within said envelope, at least one of said electrodes comprising a refractory metal substrate having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating.
Claim 14
Dependent Claim
74 words
An electric discharge device comprising a transparent envelope containing a pair of spaced apart discharge electrodes hermetically sealed within said envelope and an ionizable atmosphere within said envelope, at least one of said electrodes comprising a refractory metal substrate having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating.
Claim 15
Dependent Claim
80 words
A photographic flash tube which comprises: (a) an elongated closed tube of glass having molybdenum electrodes sealed at each end of said closed tube by direct hermetic seal to the glass material, (b) one of said electrodes having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating, and (c) a xenon filling within said tube.
Claim 16
Dependent Claim
80 words
A photographic flash tube which comprises: (a) an elongated closed tube of glass having molybdenum electrodes sealed at each end of said closed tube by direct hermetic seal to the glass material, (b) one of said electrodes having sintered thereto an open porous coating of refractory metal particles at a thickness up to about 1 millimeter and with electron emissive material being disposed in the pores of the sintered refractory metal coating, and (c) a xenon filling within said tube.
Claim 17
Dependent Claim
37 words
An electric discharge device as in claim 12 wherein said at least one of said electrodes has an elongated shaped body which is terminated at one end to provide more surface area for the coating sintered thereon.
Claim 18
Dependent Claim
27 words
An electric discharge device as in claim 14 wherein the electron emissive material includes oxides of scandium and dysprosium and the borides of thorium, scandium, and lanthanum.
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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) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |