Abstract: Improved performance of rare earth oxyhalide phosphors and X-ray image intensifying screens may be realized by admixing a small but effective amount of particular trivalent antimony compounds with the phosphor prior to screen preparation. If the phosphor powder is washed with an aqueous solution of said additive still further improvements are derived.

Abstract: An x-ray image converter for converting x-rays to visible light after passage through a photographed object in order to produce improved colored radiographs on an associated color photographic film attributable to localized color shift in the photographic film medium. The desired color shift produced by the x-ray image converter is achieved with use of a phosphor material which exhibits differential absorption of the x-radiation in the 35-50 KeV region due to K.sub..alpha. edge effects. In the conversion of x-rays to visible light in the desired manner, the new phosphor combination is useful in x-ray image intensifier tubes, in fluoroscopic screens, in radiographic intensifier screens, and other x-ray image converter devices.

Abstract: A photoflash lamp unit is described having a plurality of flash lamps fired individually and in sequence to include a plurality of solid state switching devices each capable of being converted from a high electrical resistance to a low electrical resistance upon activation by either radiant energy or a high voltage pulse. The switch material composition comprises an admixture of a metallic silver source with a sufficient amount of a metal containing material to convert the switch to said low electrical resistance state by the high voltage pulse customarily employed to flash the individual lamps. In this manner, the switch device can be more reliably converted to the conductive state if not already completely converted by radiant energy supplied from an adjacent flash lamp and so provide a conductive path in the electrical circuit.

Abstract: A photoflash lamp unit is described having a plurality of flash lamps fired individually and in sequence to include a plurality of switching devices each connected in the electrical circuit so as to interrupt the circuit path to a lamp that is flashed in response to the radiation emitted therefrom but still provide a circuit path to other unflashed lamps in the electrical circuit. In this manner, the desired firing sequence can be carried out although a particular flash lamp in the electrical circuit fails to fire because of defects other than a before-flash shorted condition and a more reliable switching arrangement is thereby provided.

Abstract: Increased optical transmission is provided for a body of light transmissive polycrystalline alumina having relatively uniform size equiaxed grains of alumina and which is essentially free of porosity and secondary phase material. A tube of the improved optical material can be used as the light transmissive envelope for high intensity discharge lamps especially sodium and other metal vapor lamps exhibiting increased light output as a result of said improved optical transmission. A method of producing the improved optical material is also disclosed.

Abstract: A method and apparatus is described for melting of a glass batch with electrical energy supplied by electrodes disposed in a vertically oriented melting chamber and which ameliorates the problems encountered when the raw batch blanket cannot be continuously and uniformly melted in said chamber. Specifically, improved electrode heating means are provided to generate localized hot spots in the molten glass adjacent the underside of the batch blanket and cause a flow of gas bubbles upwardly through the glass at the hot spot locations for escape through the batch blanket. The electrical energy rate supplied to said electrode means is also controlled so that a crust of only partially melted foam-type glass material is not formed within the batch blanket to impede escape of the gas bubbles. The improved system can further include cooperative means to refine the molten glass being continuously withdrawn from the bottom of the melting chamber in a separate refining chamber connected thereto.

Abstract: Increased optical transmission is provided for a body of light transmissive polycrystalline alumina having relatively uniform size equiaxed grains of alumina and which is essentially free of porosity and secondary phase material. A tube of the improved optical material can be used as the light transmissive envelope for high intensity discharge lamps especially sodium and other metal vapor lamps exhibiting increased light output as a result of said improved optical transmission. A method of producing the improved optical material is also disclosed.

Abstract: A power control system to distribute the electrical energy being supplied to a glass melting furnace of the vertically oriented type wherein raw glass batch is fed at the top level of the melting chamber and molten glass withdrawn at the bottom level of said chamber. Specifically, the present control system supplies electrical power to three sets of electrodes located at different elevation levels in the melting chamber so that when power is increased to the intermediate level electrodes, there is a decrease in power applied to the top level electrodes while a constant power ratio is maintained between the intermediate and bottom level electrodes. Said control system can further include cooperative electrode heating means to refine the molten glass being continuously withdrawn from the bottom of the melting chamber in a separate refining chamber connected thereto.

Abstract: A marking ink for glass and ceramic substrates is disclosed which can be deposited from a liquid dispersion and heat-cured rapidly to provide an insoluble adherent film. The adhesive binder for the marking ink is an inorganic cement produced by heat-reaction between phosphoric acid and an aluminum salt of a weak organic acid to form an insoluble vitreous matrix in the final product. Various liquid dispersions for said marking ink are disclosed which are particularly suitable for application as indicia means upon the glass envelope of an electric lamp and can be applied during conventional lamp manufacture.

Abstract: Reflecting coating means are provided to replace the conventional reflector cavities surrounding each photoflash lamp of a multilamp photoflash array. A reflective adhesive coating for this purpose can be applied to each photoflash lamp around a portion of the lamp circumference to reflect the light outwardly in a desired direction. A reflective adhesive coating can also be applied to the circuit board member used with a photoflash lamp array to provide sequential firing of flash lamps as an alternate means to provide the desired light reflection and without need for individual lamp processing in achieving this result. The coating material comprises light reflective particulate solids bonded to the substrate with an adhesive binder.

Abstract: A voltage sensitive switch is provided characterized by an irreversible change in resistance from a high resistance state greater than one megohm to a low resistance state less than one thousand ohms and comprising a mixture of substantially pure grade copper powder with copper oxide powder which further contains a binder. Said switch interconnects a pair of spaced electrodes for use in sequentially firing a plurality of flash lamps.

Abstract: An electrically insulative adhesive coating for a circuit board used with a photoflash lamp array to provide sequential firing of the flash lamps. The circuit board includes the lamp firing circuitry along with switching elements connected in said circuitry and the insulative coating prevents electrical shorting of the circuitry. In a preferred embodiment, the coating material may be an organic polymer and may be provided with openings to permit radiation transfer from the flashing lamps to the underlying switches which are radiation-responsive.

Abstract: Fuse elements are used with a circuit board to provide more reliable sequential firing in a flash lamp array. The circuit board includes the lamp firing circuitry along with radiation switches connected in said circuitry and the fuse elements cooperate with said radiation switches in the circuit operation. Fuse elements are deposited on the circuit pattern adjacent to the flash lamps for actuation by radiation being emitted therefrom and the activated fuse elements interrupt the circuit path by thermal action. In a preferred embodiment, the circuit board is constructed from an organic polymer and the fuse elements are deposited at circuit locations wherein the underlying substrate has a thickness less than the substrate thickness elsewhere to produce holes in the circuit board by melting or thermal decomposition.

Abstract: An improved pressed glass lens member for a sealed beam lamp unit is provided to include an outer sealing rim of varying thickness to compensate for thermal contraction of the lens member when molded in a predetermined manner. Specifically, the ordinary warped condition encountered with thermal contraction of the pressed glass article when initially formed is compensated for so as to permit subsequent heat sealing with a pressed glass reflector member by thermally fusing the glass material of both members in the sealing regions and without encountering the manufacturing defects now being experienced. The preferred embodiments illustrate such controlled thickness variation of the body section in the outer sealing rim region of a pressed glass lens member for both circular-shaped and rectangular-shaped lens configurations.

Abstract: A multiple photoflash system is provided which employs a high voltage type flashlamp construction, including a shorting primer material. The primer material is converted to a conductive residue upon ignition of flashlamp to provide a short circuit path between spaced apart inleads of the lamp. Further series connection of the individual lamps in the flashlamp system which are operatively associated with switching devices to provide an open circuit condition upon flashing of the associated lamps permits sequential flashing. The particular primer material which enables the flashlamp system to be operated in this manner comprises a solid mixture of a combustible metal fuel and an oxidizer for the fuel such as alkaline metal chlorates and perchlorates, and which further contains particular proportions of various combustion supporting oxides.

Abstract: Radiation sensitive switches which undergo thermal decomposition to physically interrupt the circuit path when activated are operatively associated with a plurality of high voltage flash lamps utilizing a shorting primer material to provide an electrical path across said lamps after flashing as the means of enabling the flash lamps to be sequentially flashed in a high-voltage activated multiple flash lamp array. The thermal decomposition of the radiation sensitive switching elements produces self-destruction of the switch elements per se and which can be accompanied by further destruction of the underlying substrate on which the switch elements have been deposited. The switching elements are deposited on a circuit board member and electrically connected in the sequential lamp firing circuitry at circuit board locations adjacent to the associated flash lamps.

Abstract: Thermoluminescent materials have been found suitable for measuring long term exposures to low level ionizing radiation. Oxyhalides of lanthanum, gadolinium and yttrium, including the oxychlorides and oxybromides are activated with terbium and have been found to be most efficient oxygen dominated phosphors having thermoradiant efficiencies with excitation by low level ionizing radiation. Thermoluminescence response increases when the previous materials have elemental hafnium and zirconium additives. The thermoluminescent oxyhalide of the invention is prepared by forming mixed oxalates of the metal constituents, firing the mixed oxalates in air to form an oxide mixture, blending the oxide mixture with an ammonium halide and firing the resultant mixture to form the oxyhalide.

Abstract: A multiple photoflash system is provided which employs a high voltage type flashlamp construction, including a shorting primer material. Said primer material is converted to a conductive residue upon ignition of flashlamp to provide a short circuit path between spaced apart inleads of the lamp. Further series connection of the individual lamps in the flashlamp system which are operatively associated with switching devices to provide an open circuit condition upon flashing of the associated lamps permits sequential flashing. The particular primer material which enables the flashlamp system to be operated in this manner comprises a solid mixture of a combustible metal fuel and an oxidizer for the fuel such as alkaline metal chlorates and perchlorates, and which further contains particular proportions of various combustion supporting oxides.

Abstract: Aluminosilicate glasses containing BaO and CaO are provided having combined high softening points along with exceptionally low liquidus temperatures. These glasses are within the following compositional limits in percent by weight:______________________________________ Percentage Oxides Range ______________________________________ SiO.sub.2 55-68 Al.sub.2 O.sub.3 15-18 CaO 7-13 BaO 6-16 ______________________________________except for incidental impurities, residual fluxes and refining agents. The weight ratio of Al.sub.2 O.sub.3 to combined weight ratio of CaO and BaO in the present glass composition is maintained in the range 0.6:1 to 1:1. Such glasses provide an improved hermetic seal for high temperature lamp envelopes.

Abstract: A circuit board having a photoflash array is provided based on the screen printing of a radiation curable ink onto the surface of a substrate followed by the radiation cure of the ink.