Claims
- 1. A fluorescent lamp of the type having a sealed envelope with a phosphor coating on an internal wall thereof and having an electrode at each end adapted to receive current from an external current source and an ionizable medium for supporting an electron arc stream therein between said electrode, wherein at least one of said electrodes comprises:
- first cathode means having first and second ends adapted to be electrically connected to two active leads of said external current source for emitting electrons resonsive to an electric current received from said external source;
- second cathode means having first and second ends for emitting electrons responsive to an electric current, said second cathode means first end being electrically connected to said first cathode means first end and thereby adapting it to be connected to one active lead of said external current source and its second end left unconnected; and
- electron collecting means electrically connected to said second cathode means second end and extending outwardly from said second cathode means toward the electrode at the other end of the envelope and into the electron arc stream for capturing electrons from said arc stream and supplying the electric current resulting therefrom to said second cathode means, said electron collecting means collecting electrons in an amount of sufficient current to induce thermionic heating of said second cathode means to cause it to emit electrons such that at least a part of the production of said electron arc stream transfers from said first to said second cathode means.
- 2. The fluorescent lamp according to claim 1 wherein said envelope is elongated and has a longitudinal axis parallel to the direction of elongation and said electrodes are mounted opposing each other along said axis at the respective end of said envelope.
- 3. The fluorescent lamp according to claim 2 wherein said first and second cathode means of said at least one of said elecrodes, comprises first and second filaments, respectively.
- 4. The fluorescent lamp according to claim 3 wherein each of said first and second filament is substantially linear, and each is mounted substantially transverse to said longitudinal axis.
- 5. The fluorescent lamp according to claim 4 wherein said first and second cathode means are mounted in said envelope and have an included angle of less than 90.degree. therebetween.
- 6. The fluorescent according to claim 5 wherein each of first and second cathode means has an electron emissive coating thereon.
- 7. The fluorescent lamp according to claim 6 wherein said coating is comprised of an alkaline earth oxide.
- 8. The fluorescent lamp according to claim 5 wherein said electron collecting means comprises a flag extending into said arc stream and having a portion substantially transverse to said longitudinal axis of said envelope.
- 9. The fluorescent lamp according to claim 8 wherein said flag is of an electrically conductive metal.
- 10. The fluorescent lamp according to claim 5 wherein said electron collecting means comprises a probe extending into said arc stream and having a portion substantially transverse to said longitudinal axis of said envelope.
- 11. The fluorescent lamp according to claim 10 wherein said probe is an electrically conductive wire.
- 12. A fluorescent lamp as in claim 1 wherein said at least one of said electrodes having said first and second cathode means is located at each end of said envelope.
- 13. A fluorescent lamp as in claim 1 wherein said at least one of said electrodes having said first and second cathode means is located at each of said envelope.
Parent Case Info
This is a continuation of application Ser. No. 599,456, filed Apr. 12, 1984, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3504218 |
Emidy et al. |
Mar 1970 |
|
3898503 |
Shurgan |
Aug 1975 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
599456 |
Apr 1984 |
|