Abstract: A UV source comprising an arc lamp containing deuterium gas at an initial fill pressure in excess of that at which peak UV light intensity occurs, thereby extending the useful life of the lamp.

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 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.

Abstract: A flash tube having an elongated tubular envelope containing a pair of anode electrodes disposed at opposite ends and a centrally located cathode electrode which is common to both anodes for simultaneously defining two separate arc discharge paths during operation. The three-electrode configuration is particularly useful in photograhic and photocopying applications for minimizing dark spots and providing a shorter flash duration.

Abstract: A xenon flashtube having an envelope formed of soft glass tubing with a pair of electrodes disposed at each end of the envelope for providing a wall-stabilized discharge. The use of soft glass permits a match seal to dumet lead-in wires and results in a lower cost 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: 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 are bent around the wedge-lock portion to form contacts without soldering.

Abstract: The resistance of a conductive film coating on the interior bulb wall of a fluorescent lamp is measured by capacitive coupling from the exterior bulb wall. A pair of metal bands engage the exterior bulb wall, with one band being connected to ground through a sensing resistor and the other band being connected through a series inductance to a variable frequency signal generator. The sinusoidal voltage output of the generator is set to a fixed frequency equal to or less than 15 KHz, and the series inductance is selected to provide a resonant circuit during lamp testing. The voltage across the sensing resistor is measured and compared with a predetermined reference voltage or a measurement of the generator output voltage to provide an indication of the internal film resistance of the tested lamp.

Abstract: A method of coating the glass envelope of a photoflash lamp with a thermoplastic material, the method comprising: preheating the glass envelope at a predetermined temperature for approximately one minute; immersing the heated envelope into a fluidized bed of powdered thermoplastic material from 1 to 5 seconds; removing the coated lamp from the fluidized bed; and postheating the coated envelope at a predetermined temperature for about 1 minute. To assist in preventing inadvertent flashing during these steps, the lamp can be held by a heat sink structure gripping the ignition leads or primer tube.

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.

Abstract: A photoflash lamp having a glass envelope with an inner layer or coating of a material selected to have a low thermal conductivity and diffusivity for minimizing heat losses during the collision of molten droplets of combustible metal with the inner wall of the envelope during flashing. In this manner, radiative energy losses resulting from the droplet-wall collisions are minimized and light output is improved.

Abstract: A photoflash lamp having an envelope comprised of a lead-containing glass having a low coefficient of thermal expansion and a pair of filament-supporting lead-in wires secured to the glass envelope by means of a graded seal having a lead-free intermediate expansion glass disposed between the envelope and lead-in wires. The lead-in wires are composed of an iron-nickel-cobalt alloy. The intermediate expansion glass may be in the form of a bead having its midportion between the lead-in wires stretched to protrude toward the filament to prevent post-ignition short circuits.

Abstract: A photoflash lamp having an hermetically sealed envelope containing a pair of lead-in wires spaced apart by a glass bead and having a glass insulator sleeve located about one of the lead-in wires between the bead and the inner end of the wire. A moisture indicating material is coated on portions of the lead-in wires and the glass sleeve for indicating by a change in coloration the presence of air contamination within the envelope and for insulating the lead-in wires to prevent pre-ignition short circuits through filamentary combustible material located within the envelope. The indicating material comprises a mixture of cobaltous cobalticyanide and colloidal magnesium silicate, which composition tends to minimize pressure build up during flashing.

Abstract: A thin foil of hafnium or a hafnium alloy is disposed within a high pressure metal halide discharge lamp for selectively gettering any hydrogen contaminant within the lamp. In one embodiment a long strip of hafnium foil is welded along the current return wire which extends from the remote end of the arc tube to the base of the lamp, while in another embodiment, bowed-out strips are welded to support straps on each of the arc tube press seals. In this manner, a significant portion of the hafnium getter is disposed in a location where it is subjected to operating temperatures lower than about 330.degree.C.

Abstract: An on-off switch having a time delayed "off" position provided by a series-connected PTC thermistor.