Patent US4987342A successfully refreshed from Google Patents.
US4987342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-ballasted glow discharge lamp having indirectly-heated cathode
Assignee: Osram Sylvania Inc
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Filing: 1989-03-27
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Granted: 1991-01-22
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Expires: 2009-03-27
Abstract
Abstract A negative glow discharge lamp including an anode and an indirectly-heated cathode disposed within a phosphor-coated envelope. The cathode includes a heater filament surrounded by a metallic cylinder which is coated with an emissive material. The differential resistance of the heater filament is sufficient to internally ballast the flow discharge lamp.
Inventors
- 👤 Valery Godyak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:48
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/64; H01J61/02; H01J61/56
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
107 words
A self-ballasted negative glow discharge lamp comprising: a light-transmitting envelope containing a gas fill material; a phosphor coating disposed on the inner surface of said envelope; an anode located within said envelope; an indirectly-heated cathode located within said envelope for emitting electrons, said indirectly-heated cathode including a heater filament surrounded by a metallic cylinder coated with an emissive material, said heater filament connected in series with the discharge so that discharge current flows therethrough, said heater filament having a resistance sufficient by itself to ballast said negative glow discharge lamp; and lead-in wires coupled to said cathode and anode extending through and hermetically sealed in said envelope.
Claim 2
Dependent Claim
107 words
A self-ballasted negative glow discharge lamp comprising: a light-transmitting envelope containing a gas fill material; a phosphor coating disposed on the inner surface of said envelope; an anode located within said envelope; an indirectly-heated cathode located within said envelope for emitting electrons, said indirectly-heated cathode including a heater filament surrounded by a metallic cylinder coated with an emissive material, said heater filament connected in series with the discharge so that discharge current flows therethrough, said heater filament having a resistance sufficient by itself to ballast said negative glow discharge lamp; and lead-in wires coupled to said cathode and anode extending through and hermetically sealed in said envelope.
Claim 3
Dependent Claim
27 words
The negative glow discharge lamp as set forth in claim 1 wherein said anode is in the form of a cylindrical wire cage surrounding said indirectly-heated cathode.
Claim 4
Dependent Claim
23 words
The negative glow discharge lamp as set forth in claim 1 wherein said fill material includes neon at a pressure of 2 torr.
Claim 5
Dependent Claim
148 words
A negative glow discharge lamp system comprising: a glow discharge lap including a light-transmitting envelope containing a gas fill material, a phosphor coating disposed on the inner surface of said envelope, an anode located within said envelope, an indirectly-heated cathode located within said envelope for emitting electrons, said indirectly-heated cathode including a heater filament surrounded by a metallic cylinder coated with an emissive material, said heater filament connected in series with the discharge so that discharge current flows therethrough, said heater filament having a resistance sufficient by itself to ballast said negative glow discharge lamp, and lead-in wires coupled to said cathode and anode extending through and hermetically sealed in said envelope; a dc power source having a positive and negative terminal, said positive terminal connected to said anode and said negative terminal connected to one end of said heater filament; and a starter means shunting said lamp.
Claim 6
Dependent Claim
148 words
A negative glow discharge lamp system comprising: a glow discharge lap including a light-transmitting envelope containing a gas fill material, a phosphor coating disposed on the inner surface of said envelope, an anode located within said envelope, an indirectly-heated cathode located within said envelope for emitting electrons, said indirectly-heated cathode including a heater filament surrounded by a metallic cylinder coated with an emissive material, said heater filament connected in series with the discharge so that discharge current flows therethrough, said heater filament having a resistance sufficient by itself to ballast said negative glow discharge lamp, and lead-in wires coupled to said cathode and anode extending through and hermetically sealed in said envelope; a dc power source having a positive and negative terminal, said positive terminal connected to said anode and said negative terminal connected to one end of said heater filament; and a starter means shunting said lamp.
Claim 7
Dependent Claim
19 words
The glow discharge lamp system as set forth claim 4 wherein said starter means is a glow discharge starter.
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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) | 1994-01-21 | 1994-07-23 | 1995-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-21 | 1998-07-23 | 1999-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-21 | 2002-07-23 | 2003-01-22 | $7700.00 | Window Closed / Lapsed |