Abstract: A photoflash lamp having an ignition filament composed of a combustible metal, such as zirconium, hafnium, or titanium, to assure reliable lamp operation from low current power sources. In miniature high pressure lamps, the combustible filament may be employed as the sole ignition source, without the need for primer beads.

Abstract: A circuit arrangement for triggering an arc discharge flash lamp that is directly coupled through series circuitry across an alternating current (AC) source. The lamp is ignited by a high voltage pulse generated from a pulse transformer in response to discharge of a voltage doubler charging capacitor by a controlled switch trigger from an RC timing circuit at a predetermined phase of the alternating current power source. Circuit operation is initiated by a switching arrangement which is coupled to the timing circuit through a zero crossing detector and shunt switch for assuring that the timing circuit starts at a predetermined point on the alternating current waveform. In this manner, the lamp reliably flashes with the same intensity each time a flash is requested.

Abstract: A photoflash unit having a plurality of high voltage type flashlamps mounted in a planar array on a printed circuit board containing circuitry for sequentially igniting the flash lamps in response to successive high voltage firing pulses applied thereto. The circuitry includes a plurality of solid state switches capable of being easily activated by radiant energy generated during flashing of the lamps. Initially, the switches have a high resistance, and after being activated by radiation, they undergo chemical conversion to a conductive state. The switches are prepared from compositions particularly resistant to high relative humidity and above normal ambient temperatures. The switch material composition comprises silver carbonate, a binder such as polystyrene resin, and an oxidizer such as barium chromate.

Abstract: A photoflash lamp array comprising a plurality of low voltage filament-type flashlamps mounted on a printed circuit board containing circuitry for sequentially igniting the flashlamps in response to successive low voltage firing pulses applied thereto. A plurality of reflectors respectively associated with the flashlamps are disposed between the lamps and the circuit board, with each reflector having an aperture in alignment with a corresponding aperture in the circuit board. The lamps are divided into upper and lower groups, with the circuit board having an upper connector coupled to the lower group of lamps and a lower connector coupled to the upper group of lamps, whereby one group of lamps functions as an extender for the other group to reduce the "red-eye" photographic effect.

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: For a device comprising a plurality of percussively-ignitable flashlamps mounted on a support member and arranged in an array, a selective mechanism for sequentially firing respective flashlamps in response to successive indexing. The selective firing mechanism comprises a spring-loaded ratchet bar retained in a longitudinal channel in the support member in combination with a slidable member which is also retained in the channel in engageable contact with the ratchet bar. The lamps have respective depending primer tubes and are mounted in a row parallel to the channel with the primer tubes overlying the channel. The slidable member may comprise a helical torsion spring having a first leg for engaging the ratchet bar and a second leg projecting as a striker in alignment with the overlying primer tubes and adapted for resiliently engaging them.

Abstract: For a signal device comprising a plurality of percussively ignitable flashlamps mounted on a support member and arranged in an array with respectively associated preenergized striker springs, a selective actuating mechanism for sequentially releasing the striker springs to fire respective flashlamps in response to successive hand actuated indexing. The selective actuating mechanism comprises a spring-loaded ratchet bar retained in a longitudinal channel in the support member in combination with a slidable member which is also retained in the channel in engageable contact with the ratchet bar. The lamps and striker springs are mounted in a row parallel to the channel with the strikers projecting beyond the periphery of the channel. The slidable member, which may comprise a folded flat spring having a first tang for engaging the ratchet bar and a second tang for engaging a surface of the channel, has a trip wire projection which is aligned with the projecting portions of the strikers.

Abstract: A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having a beadless ignition structure comprising a pair of spaced apart lead-in wires with spherically shaped terminations, a glass frit coating over the lead-in wires with scraped-off portions exposing the bare metal of the wire adjacent each termination, and a coating of primer material over the frit-coated terminations and bared portions of the wires. The primer may bridge the wire terminations or comprise separate spaced apart coatings on the respective terminations, with the filamentary combustible being in contact with both terminations to provide a conducting path therebetween. The frit coating is thick enough to prevent preignition short circuits.

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 signal device comprising a partially transparent package containing a plurality of percussively-ignitable flashlamps arranged in an array with respectively associated preenergized striker springs, and a movable member for sequentially releasing the striker springs to fire respective flashlamps in response to successive indexing. The device is adapted to be hand held and the movable member is adapted to be actuated and indexed directly by hand.

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 protective shield for an ultraviolet-emitting fluorescent lamp comprising a tubular sleeve coaxially surrounding the lamp envelope and formed of a plastic material, such as a fluorocarbon resin of a fluorinated ethylene-propylene, which has a spectral transmittance of at least about 80 percent of the ultraviolet radiation emitted from the lamp over the wavelength range from about 320 to 400 nanometers and substantially maintains such transmittance, along with mechanical integrity, after at least about 1000 hours of lamp operation.

Abstract: A photoflash lamp having an envelope composed of a crystallized glass which exhibits high refractoriness and mechanical strength and minimizes the propagation of flaws. The thermal expansion coefficient of the glass permits a match seal to commonly employed dumet wire leads.

Abstract: A photoflash lamp having a borosilicate glass envelope with a relatively high coefficient of thermal expansion and a depending metal primer tube, or set of lead-in wires, sealed to the glass envelope. The envelope maintains or enhances strong containment characteristics while at the same time economically providing an improved glass-to-metal seal wherein the glass is in radial compression.

Abstract: A multilamp photoflash array with lamp-reflector units in linear rows facing in opposite directions and nested back-to-back. The rows of reflectors for both sides of the array are vacuum-formed from a single sheet web between the reflector rows for providing a spring-hinged center support. Each reflector has a parabolic surface with an elongated cylindrical recess behind its associated tubular lamp whereby an air space is provided between the reflector and lamp which functions as a thermal insulator for minimizing heat distortion of adjacent reflectors upon flashing of the lamp.

Abstract: An electric lamp having a light-transmitting envelope, such as a glass bulb, secured to a plastic base having a symmetrical wedge-lock portion. Lead-in wires from the glass bulb are threaded through channels in the plastic base and extend alongside the wedge-lock portion to form contacts without soldering.

Abstract: A photoflash lamp having a filament type ignition structure coated with a primer comprising a mixture of combustible metal powder and a binding agent but free of oxidizers.

Abstract: A retrofit assembly for replacing a lens-containing lamp in an overhead projector. The assembly comprises a quartz-halogen lamp, having an internal reflector and an enlarged base removably mounted in the projector, and a lens holding bracket removably mounted in the projector in alignment with the lamp. The bracket is resiliently pivoted toward the lamp and has a tab for striking the lamp base to retain the lens at a predetermined distance from the lamp.

Abstract: A high power tungsten-halogen lamp having a filament arrangement suspended between a pair of alumina bridge members which are supported by a pair of vertically disposed tungsten rods. To provide a ruggedized mount, the free ends of the vertical rods are retained in respective externally protruding cavities provided in the dome of the lamp envelope.

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.