Abstract: A high-voltage type photoflash lamp having an ignition structure including an improved primer material for the reliable ignition of filamentary combustible material distributed within the oxygen-filled envelope of the lamp. The primer material comprises a particulate fuel such as zirconium powder, a binding agent such as nitrocellulose, and an additive of finely divided inert material which is insoluble and nonconductive and has a particle size of less than about five microns diameter.

Abstract: A multilamp photoflash unit including an elongated plastic housing having a longitudinal channel therein. Within the channel is positioned a thin, flat circuit board to which are connected several (e.g. six) flashlamps arranged in a linear array. The lamps are divided into two opposing pluralities such that those in the plurality being fired are inverted during firing.

Abstract: A photoflash unit comprising a linear array of flashlamps mounted on a printed circuit strip disposed within the longitudinal channel of an elongated housing member. A light-transmitting cover panel is attached to the housing member for enclosing the flashlamps. To prevent sympathetic ignition of adjacent lamps, the one-piece cover is molded to have integrally projecting transverse webs which function as light-attenuating partitions between respective pairs of lamps. In addition, the webs bridge the housing channel to provide structural rigidity.

Abstract: A photoflash lamp array comprising a plurality of high-voltage type flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive high-voltage firing pulses applied thereto. Each of the flashlamps has a pair of lead-in wires connected to the circuit board by eyelets which project through to the opposite side of the board, one lead of each lamp being connected via its respective eyelet to a common circuit conductor. Electrostatic protection is provided by a conductive shield of planar configuration disposed parallel to the circuit board and spaced therefrom on the side opposite that on which the lamps are disposed. Selected ones of the common circuit connected eyelets project from the back of the circuit board in a manner which maintains the spacing between the shield and circuit board, to prevent short circuiting of leads, and facilitates electrical connection of the planar shield to the common circuit conductor.

Abstract: A high-voltage type photoflash lamp having an ignition structure including an improved primer material with enhanced breakdown voltage characteristics for the reliable ignition of filamentary combustible material distributed within the oxygen-filled envelope of the lamp. The primer material comprises a particulate fuel such as zirconium powder, a binding agent such as nitrocellulose, and an additive of relatively coarse inert material which is nonconductive and insoluble in the vehicle used in the applied slurry. A preferred additive consists of glass microbeads having a particle size substantially larger than the zirconium powder used.

Abstract: A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having an ignition structure comprising a pair of spaced apart lead-in wires bridged at their inner ends by a mass of primer material. An insulating sleeve encloses one of the wires, with the inner end of that wire and the top of the sleeve having a melted down configuration with a smooth and rounded surface. The other lead-in wire lies outside the sleeve and is formed to terminate and make contact with the exterior of the sleeve at or near its top end. The primer material is disposed to cover the top end of the sleeve and bridge the ends of the lead-in wires. Also disclosed is a method of making the lamp including the step of applying a flame to melt down a protruding end of the sleeve lead-in wire prior to sealing the ignition mount into the glass tubing to be formed into the lamp envelope.