Abstract: An electric lamp is provided having an outer envelope or jacket with a lamp base attached thereto, the lamp base having an aperture extending therethrough. A sealed inner capsule is supported within the outer envelope and electrically connected to the lamp base and to an electrically conductive elongated member one end of which engages an inner wall of the outer envelope and an opposite end of which extends through the aperture in the lamp base. A spring is provided which urges the one end of the elongated member against the inner wall and which will urge the opposite end of the elongated member out of the aperture if the envelope is broken thereby disconnecting voltage to a lead of the inner capsule.

Abstract: A metal halide discharge lamp includes an arc tube having a chemical fill, and a pair of electrodes sealed in the arc tube. The electrodes are tungsten and have differing thoria contents. The electrodes with differing thoria contents provide faster starting times than electrodes with equal low thoria contents and eliminate the electrode meltback, voltage increase and lumen loss that is characteristic of electrodes with equal but higher thoria contents. Preferably, one electrode has a thoria content of about 1.5 to 2 weight percent, and the other electrode has a thoria content of about one weight percent or less.

Abstract: A high pressure sodium arc tube assembly includes a light-transmitting arc tube containing a fill material including sodium and mercury, a pair of electrodes sealed in opposite ends of the arc tube, and a filament or other resisitive member located within the arc tube and extending between opposite ends thereof. The filament is electrically connected to the electrodes. The filament provides a sufficient electric field and an abundance of electrons dispersed throughout the discharge region to initiate an arc discharge when the electrodes are energized. The filament is selected to produce an electric field in the discharge region prior to initiation of arc discharge of at least 20 volts per centimeter. After an arc discharge is initiated, the voltage between the electrodes drops, and the filament is partially short-circuited by the arc discharge. The filament provides fast initial starting and fast hot restarting, while eliminating the requirement for high voltage starting pulses.

Abstract: An electric lamp having a coiled filament and at least one intermediate filament support which effectively restrains the filament from excessive swaying or sagging whereby premature lamp failure because of electrical shorting of the filament or thermal shocking of the glass envelope is substantially reduced. The intermediate filament support includes at least one flat segment interposed between two adjacent turns of the outermost coil of the filament. The maximum thickness of the flat segment is less than the winding separation of adjacent turns of the outermost coil. In preferred embodiments of the invention, the intermediate support encloses but does not grasp the filament so that no coil of the filament, inner or outer, is distended in the process of closing the support about the filament. A support in accordance with the invention effectively restrains filament movement in directions along and normal to the filamentary axis.

Abstract: A thin-film optical interference filter designed and manufactured to have high transmission of blue light and high reflectance of infrared light. The novel feature of this filter rests in the thin-film layer design at the top and bottom of a quarterwave stack and the manufacturing technique by which this thin-film design is deposited. The thin-film layer design suppresses the so called halfwave holes which occur at wide angles of incidence of the incoming light. This desirable effect is achieved by the proper layer thickness and refractive index control in the manufacturing process.

Abstract: This invention provides an improved compact fine wire incandescent lamp coiled-coil filament and method for making the same. The filament has a secondary mandrel ratio in the range of about 3.0 and a primary mandrel ratio which is less than or equal to the secondary mandrel ratio. The length between supports is kept less than or equal to 20 times the secondary diameter. The improved filament design exhibits an increase in compactness and retains or increases structural rigidity while exhibiting minimal sag when the filament is incorporated into an incandescent lamp of the tungsten halogen type variety. The compact coiling method is particulalry useful in designing compact filaments for high voltage applications where it is desirable to eliminate the use of rectifying means to lower the effective voltage across the filament.

Abstract: An arc tube for horizontal operation and arc discharge lamp employing same wherein the arc tube has devices in each end for suppressing crystalline deposit penetration into the arc tube press seals along the shanks of the main electrodes. Experimental evidence shows that crystalline penetration into a press seal weakens the press seal and is the likely cause of an occasional arc tube burst during lamp operation, a problem well known in the art. In a preferred embodiment, a starting electrode is mounted above the main electrode in each end of the operationally positioned arc tube. So placed, each starting electrode is upstream in the convective flow of the gaseous fill within the arc tube. Each starting electrode may be electrically coupled with the lamp's circuit or electrically isolated therefrom without substantially affecting the starting electrode's ability to suppress crystalline penetration of the press seal about the base of the adjacent main electrode.

Abstract: A method of prolonging the life of thin film dichroic coated lamp components and of employing inexpensive components has been discovered. This method is the use of a hydrogen getter located in the outer jacket of the lamp, adjacent to the dichroic coating. The getter is preferably located and aligned so as to reach an optimum operating temperature.

Abstract: A double-enveloped lamp having a shield surrounding a light-source capsule within a thick-walled outer envelope so that the lamp may be safely operated without necessity of a protective fixture. In the rare event of a burst of the light-source capsule, the shield absorbs and dissipates a portion of the burst energy sufficient to permit the thick-walled outer envelope to remain intact and contain shards and other internal parts within the lamp. In alternate embodiments, the shield may be reinforced, such as with a wire mesh, or the outer envelope may be reinforced, such as with a polymer coating, or both. A thin-walled capsule may be employed in combination with a shield and thick outer envelope. A lamp in accordance with the invention provides the unexpected benefits of improved luminous efficacy and better color rendering characteristics, since the presence of an optimally positioned shield causes the operation of the light-source capsule to be more nearly isothermal.

Abstract: The present invention is directed to a novel system for producing selectable color bands from a single emission source. More particularly, this invention is directed to a small emission source consisting of a gas discharge means. The emission source in the present invention is preferably a single-ended fused silica capsule which encloses one or more predetermined metal halide salts and an inert gas, preferably argon gas.

Abstract: Electrodes for lamps comprising elongated structures comprised of layers containing varying amounts of metal and refractory oxide. In a preferred embodiment the electrode has a first end comprising 9.6 volume percent tungsten or molybdenum and the remainder alumina. The second end comprises substantially 100% tungsten. The intermediate body contains layers of, e.g., 12, 20, 35, 50 and 75% tungsten.

Abstract: A pulsed metal halide arc discharge light source comprising a hermetically sealed light transmissive envelope with an anode and cathode protruding therein and an emissive material including at least one recrystallized metal halide salt covering the cathode. There is no mercury in the emissive material. During an application of a short-duration electrical pulse across the anode and cathode in a preferred embodiment of the invention, bright colored light is emitted from the lamp, the color of such emission being determined in large part by the choice of the metal halide salt or combination of metal halide salts employed in the emissive material and the duration of the electrical pulse, and the temperature of the emissive material remains less than one hundred degrees Centigrade. A lamp in accordance with the invention is particularly well suited for use as a signal lamp, such as a navigational beacon.

Abstract: A metal-halide arc tube and lamp having improved uniformity of azimuthal luminous intensity and being particularly suited for navigational signal applications. The arc tube when operationally positioned about a vertical axis has a body which is substantially egg-shaped with the lower half of the body being more oblate than the upper half. During operation, the surface of the upper half of the arc tube body remains entirely free of metal-halide condensate so that no emitted light is blocked by condensate in any direction and nearly uniform azimuthal intensity is achieved. A heat-reflecting coating about the lower electrode prevents the formation of a condensate puddle about the lower electrode and relocates the condensate during operation to an area of the lower half above the coating and below the center of the arc tube.

Abstract: An improved metal-halide arc discharge lamp includes an arc tube having a substantially cylindrical body surrounded laterally by a substantially cylindrical heat-conserving sleeve within an evacuated outer envelope. The ratio of the outer radius of the arc tube divided by the inner radius of the sleeve falls within an optimum range of approximately 0.54 to approximately 0.68, and preferably within a range of approximately 0.60 to approximately 0.63. A lamp constructed in accordance with the invention exhibits improved luminous efficacy and color rendering in comparison to prior art counterparts. The improved performance is believed to be attributable to the more nearly isothermal operation of the arc tube for a given wall loading.

Abstract: A thin-film optical interference filter designed and manufactured to have high transmission of blue light and high reflectance of infrared light. The novel feature of this filter rests in the thin-film layer design at the top and bottom of a quarterwave stack and the manufacturing technique by which this thin-film design is deposited. The thin-film layer design suppresses the so called halfwave holes which occur at wide angles of incidence of the incoming light. This desirable effect is achieved by the proper layer thickness and refractive index control in the manufacturing process.

Abstract: The present invention is directed to a method for the elimination of end pockets in metal halide arc tube envelopes (or other irregularities) in order to improve the color stability thereof.The present invention is also directed to the improved lamps having reduced or substantially eliminated end pockets.The magnitude of this improvement will increase with decreasing arc tube size, since in smaller arc tubes, the tube ends represent a larger fraction of the overall inner surface of the device.

Abstract: The present invention is directed to a method for the elimination of end pockets in metal halide arc tube envelopes (or other irregularities) in order to improve the color stability thereof.The present invention is also directed to the improved lamps having reduced or substantially eliminated end pockets.The magnitude of this improvement will increase with decreasing arc tube size, since in smaller arc tubes, the tube ends represent a larger fraction of the overall inner surface of the device.