Abstract: A lighting unit having a filament serving as a supplementary light source, an improved gas discharge tube serving as a main light source having improved electrodes and an improved ballast circuit operating in cooperation with the improved electrodes is disclosed. Various embodiments of the improved electrodes and various embodiments of the improved ballast circuits are disclosed. The improved ballast circuit operating in cooperation with the improved electrodes provides for thermionic arc conditions in the operation of the gas discharge tube substantially immediately after the application of voltage applied to the unit.

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.

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.

Abstract: A discharge type electric lamp construction is described having electrode means which include a porous sintered body of refractory metal having an electron emissive material containing cesium ion dispersed in the pores of said porous sintered body as Cs.sub.2 MO.sub.4 wherein M is a refractory metal. Said electron emissive material is preferably employed in combination with another electron emissive material containing barium ions to provide a lower breakdown voltage as well as operating voltage characteristics for said discharge lamps. Representative electron emissive materials containing barium ions include barium aluminate and barium tungstate materials.