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US4004189A Expired / Lapsed US ⏱️ 0.0 years remaining

Three-electrode short duration flash tube

Assignee: GTE Sylvania Inc
•
Filing: 1976-06-07
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Granted: 1977-01-18
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Expires: 1996-06-07
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Abstract

Abstract A flash tube having an elongated tubular envelope containing a pair of anode electrodes disposed at opposite ends and a centrally located cathode electrode which is common to both anodes for simultaneously defining two separate arc discharge paths during operation. The three-electrode configuration is particularly useful in photograhic and photocopying applications for minimizing dark spots and providing a shorter flash duration.

Inventors

  • 👤 Robert J. Cosco
  • 👤 John A. Pappas
  • 👤 Thomas A. Brewin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 15:52
CPC Classifications
H; H01; H01J; H01J61/00; H01J61/92; H01J61/02; H01J61/30; H01J61/32; H01J61/84; H01J61/90

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 114 words
A flash tube comprising: an elongated, light-transmitting tubular envelope which is hermetically sealed; a rare gas in said envelope; a pair of anode electrodes in said envelope, one disposed at each end thereof; a cathode electrode disposed in said envelope between said anode electrodes, said cathode being common to both of said anodes to thereby provide two discharge paths; and means for providing external triggering of both of said discharge paths whereby two separate arc discharge paths are simultaneously defined through respective portions of said envelope between the common cathode and respective anodes during operation of said flash tube, whereby a shorter flash duration is provided for a flash tube envelope of given length.
Claim 2
Dependent Claim 114 words
A flash tube comprising: an elongated, light-transmitting tubular envelope which is hermetically sealed; a rare gas in said envelope; a pair of anode electrodes in said envelope, one disposed at each end thereof; a cathode electrode disposed in said envelope between said anode electrodes, said cathode being common to both of said anodes to thereby provide two discharge paths; and means for providing external triggering of both of said discharge paths whereby two separate arc discharge paths are simultaneously defined through respective portions of said envelope between the common cathode and respective anodes during operation of said flash tube, whereby a shorter flash duration is provided for a flash tube envelope of given length.
Claim 3
Dependent Claim 16 words
A flash tube according to claim 1 wherein said two discharge paths have substantially equal impedances.
Claim 4
Dependent Claim 28 words
A flash tube according to claim 1 wherein said envelope further includes a chamber offset from the elongated tubular portion, with said cathode being disposed in said chamber.
Claim 5
Dependent Claim 19 words
A flash tube according to claim 1 wherein said elongated tubular envelope is formed in an unclosed circular configuration.
Claim 6
Dependent Claim 26 words
A flash tube according to claim 4 wherein said external trigger means is wrapped about the exterior of said envelope over both of said discharge paths.
Claim 7
Dependent Claim 29 words
A flash tube according to claim 5 wherein said elongated tubular envelope has a substantially uniform internal diameter throughout, and said two discharge paths are of substantially equal length.
Claim 8
Dependent Claim 13 words
A flash tube according to claim 1 wherein said rare gas is xenon.
Claim 9
Dependent Claim 18 words
A flash tube according to claim 1 wherein said elongated tubular envelope is formed in a semi-rectangular configuration.
Claim 10
Dependent Claim 28 words
A flash tube according to claim 8 wherein said envelope further includes a chamber offset from the elongated tubular portion, with said cathode being disposed in said chamber.
Claim 11
Dependent Claim 16 words
A flash tube according to claim 9 wherein said two discharge paths have substantially equal impedances.
Claim 12
Dependent Claim 18 words
A flash tube according to claim 10 wherein said offset chamber is centrally located on said semi-rectangular envelope.
Claim 13
Dependent Claim 13 words
A flash tube according to claim 11 wherein said rare gas is xenon.
Claim 14
Dependent Claim 26 words
A flash tube according to claim 8 wherein said external trigger means is wrapped about the exterior of said envelope over both of said discharge paths.
Claim 15
Dependent Claim 52 words
A flash tube according to claim 4 wherein said envelope further includes a centrally located chamber offset from the elongated tubular portion and containing said cathode, and a pair of end chambers offset from the elongated tubular portion at opposite ends thereof and each containing a respective one of said anode electrodes.
Claim 16
Dependent Claim 136 words
Apparatus comprising, in combination: a flash tube having an elongated, light-transmitting tubular envelope which is hermetically sealed; a rare gas in said envelope; a pair of anode electrodes in said envelope, one disposed at each end thereof; and a cathode electrode disposed in said envelope between said anode electrodes, said cathode being common to both of said anodes; a supply voltage means connected for simultaneously energizing both of said anodes and said common cathode; and means coupled to said flash tube for applying a high voltage trigger pulse to ignite said flash tube, whereby two separate arc discharge paths are simultaneously defined through respective portions of said envelope between the common cathode and respective anodes during operation of said flash tube, whereby a shorter flash duration is provided for a flash tube envelope of given length.
Claim 17
Dependent Claim 136 words
Apparatus comprising, in combination: a flash tube having an elongated, light-transmitting tubular envelope which is hermetically sealed; a rare gas in said envelope; a pair of anode electrodes in said envelope, one disposed at each end thereof; and a cathode electrode disposed in said envelope between said anode electrodes, said cathode being common to both of said anodes; a supply voltage means connected for simultaneously energizing both of said anodes and said common cathode; and means coupled to said flash tube for applying a high voltage trigger pulse to ignite said flash tube, whereby two separate arc discharge paths are simultaneously defined through respective portions of said envelope between the common cathode and respective anodes during operation of said flash tube, whereby a shorter flash duration is provided for a flash tube envelope of given length.
Claim 18
Dependent Claim 14 words
Apparatus according to claim 15 wherein said two discharge paths have substantially equal impedance.
Claim 19
Dependent Claim 27 words
Apparatus according to claim 16 wherein said elongated tubular envelope has a substantially uniform internal diameter throughout, and said two discharge paths are of substantially equal length.

References Cited (Backward Citations)

US2018874A Cited
US2102190A Cited
US2102189A Cited
US2121333A Cited
US3047763A Cited
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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) 1980-01-18 1980-07-19 1981-01-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-01-18 1984-07-19 1985-01-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-01-18 1988-07-19 1989-01-18 $7700.00 Window Closed / Lapsed

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