Abstract: A light source and optical delivery arrangement for use with a projection lighting system as may be used in the stage and studio fields, includes a high brightness light source which achieves a light output in excess of 4000 lumens at a power rating of approximately 60 watts and wherein such efficiency is achieved in conjunction with a rated life of greater than about 4000 hours for such light source. The light source is disposed at the first optical focal point of an ellipsoidally shaped reflector with an input end of an optical coupler disposed at the second optical focal point of the reflector in order to receive the light output from the light source. The optical coupler member has a cross-sectional surface area which is polygonal in shaped and is effective so as to provide a light output therefrom which is essentially uniform in terms of color and intensity. A prismatic member is disposed on the optical coupler member for re-directing the light output into a lens member.

Abstract: Circuit arrangements generate start, glow, and/or run signals to be applied to and for operating a DC arc discharge lamp. A first circuit arrangement provides start, glow, and run signals. The first circuit arrangement includes a tapped transformer flyback converter circuit for combining the start and glow functions; a buck/boost converter for providing the run function; and blocking diodes for providing a blocking function for the glow circuit during the start and run modes, and further for providing a blocking function for the run circuit during the start and glow modes. A second circuit arrangement provides start and glow functions, and includes a tapped transformer flyback converter circuit for combining the start and glow functions; and a blocking diode for providing a blocking function for the glow circuit during the start mode. A third circuit arrangement includes a buck/boost converter for providing glow and run functions, and further includes an inductive storage element, such as an inductor.

Abstract: A glass composition, particularly well suited for use in constructing sodium containing lamp envelopes. The glass composition is comprised of silica doped with yttrium and/or cesium, preferably in combination aluminum.

Abstract: A lamp cathode-to-ballast interconnect is provided in combination with a lamp having elongated cathodes and ballast circuitry for supplying power to the cathodes. The lamp cathode-to-ballast interconnect comprises a plurality of conductive clips connected to the ballast circuitry. Each clip has a generally flat portion connected at a first end to ballast circuitry and has a pinching groove formed through the flat portion and extending to a cathode-receiving opening at a second end. The interconnect further comprises a loom for holding the lamp cathodes. The loom comprises, for each cathode, a pair of cathode-receiving support grooves separated by a space in which a second end of an associated conductive clip is to be received. Walls of each of the pair of cathode-receiving support grooves grip therein-received portions of the cathode with sufficient force to enable a gas-tight contact to be made with its associated conductive clip when the cathode is received within the pinching groove of the clip.

Abstract: A single-ended low pressure mercury vapor discharge lamp including a lamp envelope having at least two tube portions being connected with each other and dosed with additive and gas, and a housing member made in a manner suitable for electrical and mechanical connection to a lamp holder on one end, and mechanically fixing and making electrical contact with the lamp envelope on the other end. The end portion of the tube portions of the lamp envelope which are set at the housing member side are externally coated with a light-reflecting layer.

Abstract: Incandescent lamps or arc lamps having an infrared red reflecting multilayer optical interference filter on the outer surface of the vitreous or fused quartz lamp envelope enclosing the filament have a light-scattering coating applied over the filter to scatter light emitted by the lamp and thereby diffuse the filament image. The light-scattering coating consists of light-scattering particles, such as alumina, dispersed in a silica matrix. This coating is formed by applying to the filter a silicone solution in which is dispersed colloidal silica and light-scattering particles and pyrolyzing at high temperature to drive off the organic components and form the silica matrix.

Abstract: This invention relates to a single-ended discharge lamp having an electric circuitry placed in its base member, which discharge lamp comprises a discharge tube filled with additive and gas, is sealed in a gas-tight manner and is provided with electrodes. A base member is provided for the mounting of the discharge tube and for incorporating the electric circuitry mounted on a printed circuit board therein. The base member has a screw base mounted thereon both for mechanical and electrical connection to a socket. Furthermore, the terminals of the circuitry are fixed and are electrically connected with the electrode lead wires by means of mechanical connector arrangement where the mechanical connector component is one contiguous metal part.

Abstract: A ballast circuit for a gas discharge lamp comprises a resonant load circuit incorporating a gas discharge lamp and including first and second resonant impedances whose values determine the operating frequency of the resonant load circuit. A d.c.-to-a.c. converter circuit is coupled to the resonant load circuit so as to induce an a.c. current in the resonant load circuit, and comprises first and second switches serially connected in the mentioned order between a bus conductor at a d.c. bus voltage and ground, and having a common switch node through which the a.c. current flows. A bridge capacitor has one end connected to ground. First and second feedback circuits regeneratively control the first and second switches, respectively, in response to a.c. current in the resonant load circuit.

Abstract: An electric lamp includes a sealed outer envelope, an arctube located within the envelope, a shroud separate from the arctube having an ellipsoidally-shaped reflecting portion positioned around the arctube, and a coating disposed on the reflecting section of the shroud for reflecting light having predetermined wavelengths emitted by the arctube. The ellipsoidal shape of the shroud is effective for reflecting the light substantially back toward the arctube. Particularly when the coating is a color correcting coating, the shape of the reflecting section is tailored to maximize reflection of radiation at selected wavelengths back toward the arc of the arctube.

Abstract: A fluorescent lamp with an ultraviolet reflecting barrier layer between the glass envelope and the phosphor layer(s). The barrier layer is a blend of gamma alumina and alpha alumina, preferably 5-80 weight percent gamma alumina and 20-95 weight percent alpha alumina. The barrier layer is effective to reflect UV light back into the phosphor layer(s), leading to improved phosphor utilization and more efficient production of visible light.

Abstract: This lamp comprises an envelope of vitreous light-transmitting material enclosing an internal space, light-generating means within said space, and conductive lead structure projecting into said space and comprising inner and outer lead members and a foil member connected between said lead members. A first portion of the envelope surrounds the foil member and is sealed thereto, and a second portion of the envelope is located inwardly of the first portion. A tubular bead of vitreous material is provided about the inner lead member. This bead fits within the second envelope portion, is joined thereto, and supports the inner lead member in a precise predetermined portion within the envelope. The inner lead member projects inwardly beyond the bead and provides support for the light-generating means.

Abstract: A lamp assembly having an improved mounting arrangement for a light source and shroud configuration provides for such improved mounting arrangement in a manner such that manufacturing of the lamp assembly is simplified and the light source is protected against vibration and shock forces during manufacture and operation. The light source includes an arc tube which is under pressure and which is disposed within a shroud member that is then mounted within an outer lamp envelope. Top and bottom support members made of an insulative material are disposed on opposite ends of the shroud member. One of the lead wires used to couple energy to the light source, extends through the shroud member and has an insulative sleeve disposed in surrounding relation to a portion thereof. As the one lead wire extends through a hole formed in the bottom support member, a resilient clip member is slid over the bottom portion of such lead wire.

Abstract: Disclosed is a power-level selection circuit in combination with a lamp circuit including a fluorescent lamp having first and second cathodes with resistive-heating filaments each spaced at a respective end of a lamp tube; first and second power leads for respectively connecting the cathodes to an a.c. power source whose power can be selectively enabled and interrupted by a main power switch; and a ballast inductor in serial circuit with one of the power leads and including a plurality of filament-heating windings for supplying power to the cathodes. The power-level selection circuit is interposed between a first cathode and a filament-heating winding, and includes a power-receiving circuit coupled to the filament-heating winding to receive power therefrom. Further included is a filament-supply circuit for continuously supplying available power to the first cathode.

Abstract: An interference filter or coating is provided in a predetermined pattern on a lamp envelope. The coating is comprised of alternating layers of high and low index of refraction materials applied to a vitreous outer surface of a lamp envelope. The coating may be geometrically symmetric or asymmetric, continuous or discontinuous with respect to the coating itself or the envelope to which it has been applied. The envelope can be masked prior to deposition of the coating so that removal of the mask leaves the filter in the desired pattern. The preferred process for forming the coating includes forming a boric oxide mask on a portion of the envelope, applying the coating over the mask and removing the coating from masked areas of the envelope by dissolving the mask in an aqueous solution.

Abstract: A reflector lamp assembly having an integral photo-sensor and sensing circuit arrangement associated therewith provides for sensing the ambient light conditions at a point adjacent the top surface of the lamp envelope. The photo-sensor element is disposed within a sensor housing member mounted along an edge portion of the top surface of the lamp. A channel pathway is integrally formed with the sensor housing member and extends along the side lamp envelope to protect the sensor lead wires extending from the photo-sensor device to the sensing circuitry contained in the threaded screw base. The sensing circuitry is disposed vertically within a cavity formed in the bottom of the screw base so as to achieve optimum thermal dissipation properties for the sensing circuit. A collimator tube can be inserted into an opening formed at the top of the sensor housing member so as to control the field of view for sensing the ambient light conditions occurring near the top surface of the lamp assembly.

Abstract: A sports lighting fixture having improved light delivery characteristics includes an elongated bare arc tube, high intensity discharge lamp disposed near the apex of a parabolically shaped reflector member. The reflector is constructed of a non-metallic material and by the orientation and positioning of the lamp within the reflector, an essentially oval shaped light pattern is generated. A light transmissive cover is disposed over the open end of the reflector. When projected onto the playing surface of a sports field, the oval shaped light pattern translates to an essentially circular shaped pattern which allows for a more uniform and efficient overlapping of the multiple light outputs at the playing field level. Louvers can be disposed within the reflector to further redirect any high angle light output into a lower angle which is more useful at the playing surface level.

Abstract: An electric lamp is provided having a quartz envelope and a light source capable of generating light within the envelope. Disposed on a surface of the envelope is a filter which absorbs a portion of the light emitted by the light source to produce light output poorly seen by insects. The filter includes a blue absorbing pigment in a vitreous glassy silica binder derived from a coating precursor comprising a liquid dispersion of colloidal silica in a silicone. The blue absorbing pigment is preferably a praseodymium doped zircon or an antimony doped nickel titanate. Preferably, the filter also includes a precoat of ultra-fine titania to improve the reduction of ultraviolet radiation.

Abstract: Included in a ballast circuit arrangement for a gas discharge lamp is a ballast transformer arrangement receptive of an input power signal and providing an output, ballast voltage. Further included is a pulse transformer having a secondary winding in serial circuit with the lamp for impressing a high voltage, hot restrike starting pulse across the lamp. A bypass capacitor is coupled to the ballast transformer for being charged by the ballast voltage. A hot restrike starting circuit for pulsing a primary winding of the pulse transformer comprises a serially connected starting capacitor and resistor coupled across the bypass capacitor; and a circuit for discharging the starting capacitor including, in serial circuit, the primary winding of the pulse transformer and a current switch having a control electrode responsive to a control signal.

Abstract: An optical interference filter produced on a vitreous, light transmissive substrate, such as an electric lamp envelope, includes a plurality of alternating layers of tantala and silica in which each tantala layer includes titania in an amount of less than about 10 mole % whereby the microstructure of the tantala layers is controlled during subsequent crystallization and extrinsic stress in the tantala layers is reduced. Rather than or in addition to including titania in each tantala layer, the present invention additionally contemplates placing at least some of the tantala layers in contact with a titania layer (pre-layer and/or post-layer) whereby the microstructure of the tantala layers is controlled during subsequent crystallization and extrinsic stress in the tantala layers is reduced.

Abstract: Fused quartz containing europium oxide, titanium dioxide and cerium oxide has been found to be effective for absorbing UV radiation while transmitting visible light radiation. Uses for this material include lamp envelopes and shrouds for halogen-incandescent lamps and metal halide arc discharge lamps which emit both UV and visible light radiation.