Abstract: A high-voltage type photoflash lamp having a nonconducting, noncombustible, fibrous material, such as zirconia wool, positioned around the lead-in wires at the base of the lamp to prevent shorting across the wires.

Abstract: A high-voltage type photoflash lamp having an ignition structure comprising a mass of primer material bridging a pair of lead-in wires, one of which is enclosed in an insulating sleeve. The lamp contains a quantity of shredded metallic combustible and an amount of oxygen in excess of that needed to completely burn the combustible so as to burn back the unsleeved lead-in wire during flashing. The primer material comprises a mixture of combustible metal powder, one or more metal oxides and a binding agent and is free of oxidizer salts.

Abstract: A high-voltage type photoflash lamp having an ignition structure comprising a mass of primer material bridging a pair of lead-in wires. An insulating sleeve encloses one of the lead-in wires and a fine conductor wire is attached to and projects from the unsleeved lead-in wire to assure contact with filamentary combustible material within the envelope so as to provide electrostatic protection. When mounted in a multilamp unit, each lamp is oriented with the unsleeved lead-in wire connected to a common circuit conductor.

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. A plurality of reflectors respectively associated with the flashlamps are disposed between the lamps and circuit board, with each reflector having an aperture in alignment with a corresponding aperture in the circuit board. Connected in series with each but the last lamp of the array is a radiant-energy-activated quick-disconnect switch comprising a strip of electrically conductive heat shrinkable, polymeric material which is attached at both ends to the circuit board so as to bridge a respective one of the apertures therein.

Abstract: A high-voltage type photoflash lamp having an ignition structure comprising a mass of primer material bridging a pair of lead-in wires which comprise the two legs of a generally hairpin-shaped wire. The bight of the hairpin-shaped wire is disposed outside the lamp envelope and provides electrostatic protection by short circuiting the lamp prior to use. Also disclosed is a method of making a photoflash unit containing such a lamp wherein the bight is cut (to enable the lamp) prior to assembling it into the unit.

Abstract: A photoflash lamp having a polycarbonate coating over its glass envelope with an alkali-barrier coating disposed between the glass envelope and polycarbonate coating for extending the shelf-life of the polycarbonate coating by preventing alkali released by the glass from reacting with the polycarbonate. The alkali-barrier coating may be applied to the glass envelope before vacuum-forming a preformed polycarbonate sleeve thereon, or the alkali-barrier may be applied as a thin film on the interior surface of a preformed polycarbonate sleeve before vacuum-forming the sleeve onto the glass envelope.

Abstract: A photoflash lamp containing a readily ignitable, hydrogen-containing substance, such as shredded paper or a spot of sucrose, to controllably induce bursting of the lamp upon ignition for purposes of testing the relative strength and reliability of lamp containment systems, including the envelope, envelope coatings and flash unit enclosures.

Abstract: A polycarbonate resin having an acidic additive for providing improved resistance to stress cracking under humid conditions while retaining tensile and impact strength at elevated temperatures.

Abstract: A photoflash lamp having a protective coating over its glass envelope which is composed of an acidified polycarbonate resin for providing a strong containment vessel with improved aging charcteristics under conditions of stress and humidity. A preferred coating comprises a vacuum-formed sleeve composed of a polycarbonate resin with a phthalic anhydride additive.

Abstract: A multilamp photographic flashlamp unit, the lamps of which are of the percussive primer type, having self-contained means in the form of a self-latching folded torsional spring for firing each of said lamps and featuring a short latch and a spring formation designed to give thereto a net downward force which holds the striker in contact with the flashcube base member.