Abstract: A low-pressure mercury vapor discharge lamp having a lamp envelope (1) which encloses a folded tubular discharge vessel (2), the discharge vessel being provided with an appendix (6) which is kept at a relatively low temperature by a heat shield (7) located within the lamp envelope. The heat shield shields the outer wall surface of the appendix from the outer wall of the discharge vessel. The cooler appendix serves to maintain the mercury vapor pressure at an optimum value during operation of the lamp.

Abstract: A discharge lamp provided with a U-shaped discharge tube and an outer envelope surrounding this tube. The bend of the discharge tube is supported with respect to the outer envelope by means of a metal member of sheet material. A few strips of this member engage the bend of the discharge tube. The metal member is composed of two parts twisted together which provide together a substantially light-tight transverse separation between the outer envelope and the discharge tube. The metal member maintains the bend of the operating lamp being kept at a relatively high temperature to improve luminous efficacy.

Abstract: A long-life cesium lamp is disposed within an evacuable outer envelope surrounding a cesium lamp arc tube with their respective surfaces spaced a fixed distance apart so that a heat-transferring gas, such as helium, is disposed between the arc tube and the wall of the outer envelope. Furthermore, means are provided for cooling the outer envelope, such as by surrounding it with a water jacket. The resulting lamp system is capable of operating at higher levels of average lamp power and arc tube wall loading (watts/cm.sup.2) without causing too low a cesium pressure, as would happen if one directly water-cooled the alumina arc tube, and without causing too high an alumina arc tube temperature, as would happen if one merely evacuated the outer envelope.

Abstract: A metal halide arc discharge lamp having a gaseous fill within the outer envelope and means for suppressing convection currents within such fill; and methods of operating and constructing such lamps. A light-transmissive sleeve or enclosure surrounding the arc tube laterally and about at least one end thereof is so shaped and mounted with respect to the arc tube as to insure that the Rayleigh Number, a quantitative measure of convection flow, in the atmosphere laterally surrounding the arc tube will be less than 5.times.10.sup.4 during operation of the lamp whereby excessive convective heat loss in such lamp will be effectively suppressed.

Abstract: To improve the color rendition index R.sub.a, and to lower the color tempture without decreasing the light yield and efficiency of the lamp, the discharge vessel (1, 12, 22) is surrounded by an envelope which comprises a first, or inner envelope element (4, 13, 21) and a second, or outer envelope element (5, 14, 20). The space between the first and second envelope elements, preferably, is evacuated, and the space between the first, inner envelope element and the discharge vessel may include an inert gas, such as nitrogen and/or a noble gas; if the inner envelope element and the discharge vessel are both made of sodium resistant materials, such as Al.sub.2 O.sub.3, the space between the inner envelope element and the discharge vessel may also include sodium of such quantity as to balance the vapor pressure within the discharge vessel and said space outside of the discharge vessel. The lamp can be made double-ended (FIGS. 1, 2) or single-ended (FIG. 3).

Abstract: In a metal vapor discharge lamp for operating it by high voltage generated in the actuation of a heat sensitive switch means in an outer bulb, a relatively low pressure of a sealed gas or mercury is sealed in the outer bulb to operate the heat sensitive switch means in the gas atmosphere to control the surge voltage to a desired degree whereby the discharge lamp is operated without failure and the insulation breakdown of a ballast and an operation circuit is prevented.

Abstract: The invention relates to a high-pressure metal halide lamp in which the filling of the discharge vessel also comprises an alkali metal. The discharge vessel is surrounded by an outer envelope. One electrode of the discharge vessel is connected to a current supply conductor extending between the discharge vessel and the outer envelope. A plate-shaped element is mounted between the discharge vessel and the outer envelope in such manner that, viewed from the discharge vessel, the current supply conductor is present substantially entirely behind the plate-shaped element.According to the invention, the plate-shaped element comprises boron nitride.Increase of the arc voltage of the lamp and increase of the color temperature of the radiation emitted by the lamp is prevented in this manner.

Abstract: A fluorescent lamp comprises a source of near ultraviolet radiation together with an outer shell at least partially surrounding the ultraviolet source and comprising an ultraviolet transmissive material, the shell having embedded or dissolved therein a phosphor material having an indexed refraction approximately, but not quite equal, to the index of refraction of the shell.

Abstract: The efficacy of a high-pressure sodium lamp is increased significantly by enlarging the arc tube diameter and deploying a composite infrared-reflective film on the interior of the outer lamp envelope. The infrared-reflective film acts to maintain the wall temperature of the enlarged arc tube at the same optimum temperature as the arc tube wall in a conventional high-pressure sodium lamp. In one embodiment, the IR reflective film is a multi-layer composite film of In.sub.2 O.sub.3 :Sn or SnO.sub.2 :F overcoated with a TiO.sub.2 or SiO.sub.2 dielectric film. In another embodiment, a three-layer composite film is made up of TiO.sub.2, In.sub.2 O.sub.3 :Sn, or SnO.sub.2 :F, and SiO.sub.2 films sequentially overlaid on the outer envelope. The dielectric films improve lamp efficacy and enhance the high temperature chemical stability of In.sub.2 O.sub.3 :Sn and SnO.sub.2 :F.

Abstract: A compact halogen-cycle type incandescent lamp is provided with an envelope that is composed of a selected hard glass (a borosilicate or an aluminosilicate type glass for example) and then dosed with an amount of bromine which is correlated with the glass composition in such a manner that it counteracts the deleterious release of water-vapor forming constituents by the glass envelope when the lamp is energized and the glass is hot. The halogen-cycle lamp is especially adapted for use as the concentrated light source in a general service type lamp or a sealed-beam headlamp and, when so employed, has a fill gas pressure that is so correlated with the gas pressure of the non-oxidizing atmosphere in the outer envelope that the total gas pressure does not exceed 1,000 Torr and the envelope of the halogen-cycle lamp operates at a temperature which is sufficient to reliably sustain the halogen cycle but is below the softening temperature of the particular hard glass from which the halogen lamp envelope is made.

Abstract: A high intensity discharge lamp is provided with means for reflecting infrared radiation from the hot central portion of the arc tube onto the cooler end portions of the tube. The infrared reflective means may be provided by one or more infrared reflecting shields surrounding a portion of the arc tube or by an indentation in the outer glass envelope of the lamp.

Abstract: Low-pressure sodium vapor discharge lamp. The lamp comprises a cylindrical discharge tube and an outer bulb enveloping this tube. The outer bulb has a transparent layer which reflects infrared radiation.According to the invention the resistance per square of the infrared reflecting layer is approximately 5 ohm. A luminous efficacy of 100 lumen per watt can be obtained at a lamp power of 8 watts. The lamp is particularly suitable for security lighting.

Abstract: Transverse mounting of an arc tube with a pivoting attachment to a support rod extending through a lamp jacket is effected by a hinge plate comprising a metal ribbon folded back on itself and encircling a hinge pin. The hinge plate is welded to the support rod, and the hinge pin together with a wrap-around metal band clamps the pinched upper end of the arc tube. A two-piece connector having a bendable joint serves in lieu of a latch and assures accurate orientation of the arc tube after it has been transversely erected within the jacket.

Abstract: Transverse mounting of the arc tube within the lamp jacket is effected through a mount featuring a hinged selflatching attachment of the arc tube to a support rod extending the length of the jacket and serving also as electrical connector to one electrode. A flexible connector makes connection to the other electrode. During manufacture the hinges permit the arc tube to be folded in line with the support rod for passage through the neck and then to be transversely erected in the jacket, and the latch thereupon locks the arc tube in the transverse attitude.

Abstract: A high pressure sodium vapor discharge lamp having an arc tube coaxially mounted within an outer glass envelope by means including a coiled spring engaging one end of the arc tube and coaxially disposed in the partially compressed state between that end of the arc tube and a dome portion of the outer envelope. In one embodiment the dome of the outer envelope is disk-shaped and a large diameter end of the coiled spring bearing against the dome is constrained in a coaxially centered position by the sidewalls of the outer envelope. In another embodiment, the dome of the outer envelope is provided with an inwardly projecting dimple about which the coiled spring is coaxially fitted to provide self-centering of the arc tube. The partially compressed spring compensates for arc tube length variations and thermal expansion.

Abstract: A high pressure metal (sodium) vapor lamp comprises an outer vitreous envelope and an inner ceramic arc tube supported within it. The arc tube contains vaporizable metal in excess of the quantity vaporized in operation and the heat balance determines a cold spot whereat excess metal collects. The temperature of the cold spot determines the metal vapor pressure and the voltage drop across the lamp which must lie between specified limits. A thermal link is provided to a metal member such as the exhaust tube the heat loss from which influences significantly the temperature of the cold spot. In completed lamps measuring too low in voltage, such thermal link may be partly severed without breaking open the outer envelope in order to raise the voltage. One convenient way utilizes an auxiliary wire which is cut by aiming a laser beam at it.

Abstract: A jacketed discharge lamp which would release ultraviolet radiation in the event of fracture of the outer envelope is provided with a disabling fuse link which oxidizes in the event of breakage. The link consists of an alkaline earth metal film, suitably a barium film which may be deposited on a ceramic substrate for connection into the circuit. The outer envelope is evacuated or may contain an inert gas.

Abstract: A reflector lamp comprises an arc discharge tube disposed at about the focus of a parabolic reflector. The arc tube is supported by two lead-in support wires which extend through the back of the reflector. The external ends of the lead-in support wires are secured in a stabilizer support which is adhesively bonded to the back of the reflector.

Abstract: Transverse mounting of the arc tube within the lamp jacket is effected through a mount featuring a hinged attachment of the arc tube between divergent support rods which serve also as electrical connectors to the electrodes. During manufacture the hinges permit the arc tube to be folded in line with one support rod attached at the stem leading and the other trailing for passage through the neck, and then allow the arc tube to be transversely erected in the jacket after which the other rod is attached at the stem. Erection of the arc tube simultaneously causes leaf springs to engage the sides of the bulb and centralize the arc tube in its transverse attitude.

Abstract: A sealed beam lamp assembly, suitable for use as a motor vehicle headlight, has an incandescent lamp mounted within an inert-gas-filled, molded-glass housing integrally comprising a reflector and a control-lens cover. For supporting the lamp in position within the housing, a metal-made support rod extends forwardly from one of ferrules on the reflector and has its front end preformed into the shape of a U to provide a rearwardly directed fold. Welded to this fold of the support rod is a metal band rigidly encircling the base of the lamp. The lamp position relative to the reflector is therefore adjustable as required by manually turning the fold of the support rod about its main straight portion. The support rod serves also to provide electrical connection between the ferrule and one of the lamp leads.

Abstract: In high intensity discharge lamps, particularly those that are configured to operate in a particular orientation, end coatings are provided which increase the efficacy of the lamp. In one embodiment of the present invention, reflective end coatings are provided exteriorly and at the ends of the discharge tube except for an approximately semicircularly shaped portion through which the optical output of the lamp radiates. The particular coating pattern provided in the present invention reduces the number of internal reflections occurring within the discharge tube and accordingly increases the efficacy of the lamp.

Abstract: A high pressure arc discharge lamp comprises an elongated arc tube disposed substantially axially within a concave shaped outer jacket.

Abstract: A electric gas discharge lamp having a tubular ceramic discharge vessel which is provided at one end with a ceramic end plug which extends axially outside the end of the discharge vessel. The outside diameter of the projecting portion of the end plug being not more than 90% of the outside diameter of the discharge vessel.

Abstract: An electric lamp including a reflector and a lens secured together to define an enclosure therebetween. A bulb is supported in the enclosure by support wires. Each support wire has a substantially U-shaped portion, and the base portion of the bulb is engaged in the substantially U-shaped portions of the support wires.

Abstract: An improved mounting of the ceramic arc tube on a support rod attached to one lead-in within an outer vitreous envelope allows for thermal expansion. The inlead at one end of the arc tube is fastened to the support rod which serves also as conductor, while that at the other end extends through an insulating bushing supported from the rod and is connected by a curved flexible conductor to the other lead-in of the outer envelope. Differential thermal expansion is accommodated by sliding of the inlead through the bushing and flexing of the curved conductor.

Abstract: The invention relates to a high-pressure sodium-vapor discharge lamp having substantially the same color temperature as an incandescent lamp. The invention provides a high-pressure sodium-vapor discharge lamp having a low re-ignition voltage.This is achieved by including xenon and mercury in the discharge tube such that (i) the weight of mercury is between 50% and 90% of the combined weight of the mercury and sodium, (ii) the pressure of the xenon at room temperature is between 100 and 1000 torr, and (iii) the sodium vapor pressure is between 300 and 800 torr in the operating condition of the lamp. The power consumed by such a lamp is typically one-fifth of that consumed by an incandescent lamp having the same light output.

Abstract: Miniature metal vapor arc lamps containing mercury and one or more metal halides are subject to severe blackening of the arc tube and poor lumen maintenance unless a high pressure of starting gas is used. A Penning mixture of neon admixed with 0.01 to 10% argon, krypton or xenon at a fill pressure from about 100 to 200 torr provides lower starting voltage together with better lumen maintenance than can be achieved with the conventional argon starting gas.

Abstract: A reflector-type high-intensity-discharge vapor lamp unit having a generally parabolic rear reflector member is provided with a dichroic reflector carried as a coating on the inner surface thereof. The dichroic reflector selectively reflects visible light having a wave-length from about 400 to 750 nanometers and selectively transmits infrared radiation having a wavelength from about 750 to 1600 nanometers.

Abstract: A lamp changing module for totally enclosing a lamp when the module is withdrawn from a support such as an illuminator cabinet, and permitting exposure of the lamp when properly installed and connected to the support. A potentially explosive lamp is thereby contained within the module when it is removed so that even if it explodes it will not harm nearby personnel. It also protects personnel from burn hazards associated with lamp changing.

Abstract: Novel geometries for high intensity discharge solenoidal electric field lamps are disclosed providing good coupling between the magnetic fields within the ferrite and the plasma discharge. In addition, the geometries provide for good heat sinking and cooling capabilities as well as escape of most of the generated light. In accordance with one embodiment of the present invention, a plurality of toroidal shaped ferrite cores are arranged about the high intensity discharge tube, the tube being threaded through the holes in the toroidal ferrite cores. In accordance with another embodiment of the present invention, a bundle of ferrite rods is disposed through the hole of a toroidal shaped discharge tube, the packing density of the ferrite rods in the bundle being less than one hundred percent efficient whereby channels for cooling air are formed.

Abstract: The invention relates to high pressure sodium vapor discharge lamp comprising a discharge tube and an outer bulb enveloping this tube, a glow starter being disposed in the space between that discharge tube and the outer bulb.In accordance with the invention the glow starter is resiliently clamped between the two rigid electric conductors which supply the discharge tube with current.

Abstract: Safety devices for high intensity discharge lamps, having an outer envelope and an inner arc tube in which the arc discharge is produced, for extinguishing the arc in a relatively short period of time. A switching element is placed in series with the current supply to the arc tube and the element opens when the outer envelope is broken. In one embodiment, the switching element is a normally closed thermostatic switch in series with a second filament which is connected in parallel with a first filament. During starting the switching element is closed and both of the filaments are in series with the arc tube and both receive a part of the high starting lamp current. The thermostatic switch opens when the lamp reaches operating temperature so that all of the current passes through the first filament if the envelope breaks causing the first filament to burn out. The switch then closes so that all of the current passes through the second filament causing it to burn out.

Abstract: A metal halide arc discharge lamp has an elongated outer envelope within which is disposed an arched arc tube, the position of the arc tube being transverse to the axis of the envelope.

Abstract: The invention relates to a low-pressure sodium vapor discharge lamp provided with a U-shaped discharge tube which is enveloped by an outer bulb. The bend of that discharge tube is supported by means of a metal element relative to the outer bulb.In accordance with the invention the bend of the discharge tube is partly passed through a hole in the metal element and bears against two fingers which are part of the metal element.

Abstract: A high frequency discharge lamp for a spectral-line source includes a discharge envelope in which a substance contributive to the emission of desired spectral lines is contained and in which one electrode is included, the discharge envelope being made of a material, such as quartz, which is electrically insulating and capable of transmitting the spectral lines. A cylindrical metallic container surrounds the discharge envelope and has at a part thereof an opening for taking out the spectral lines. There is further provided means for applying a high-frequency voltage between the electrode and the metallic container.

Abstract: A high intensity discharge lamp in which the arc tube is located within an outer envelope. A multi-filament assembly is located within the outer envelope in series with the current supply to the arc tube. When the lamp outer envelope is broken, the filaments will burn out in the presence of air, open the current supply to the arc tube and extinguish the arc. The use of multi-filaments permits better control of the filament burn out time.

Abstract: A sun lamp comprising an arc tube integrally mounted in an envelope transmissive to UV-radiation. The arc tube is of the halogen metal vapor discharge lamp type and contains mercury, together with (i) at least one rare earth metal halide or (ii) iron halide. The light transmissive envelope comprises a glass which transmits large amounts of the UV-A component of ultraviolet radiation, and transmits substantially no UV-C component of the radiation. The ratio of transmitted UV-A to UV-B is similar to that in natural radiation.

Abstract: The light output of a high-presure discharge lamp that employs a mercury arc tube is selectively modified by two luminescent coatings on the inner surface of the outer protective envelope to provide color rendering and a source-color that are similar to those of an incandescent-type lamp. The coating in contact with the envelope surface comprises a blend of two selected phosphors -- one which absorbs and is excited by blue-violet radiations produced by the arc discharge and emits in the green portion of the spectrum, and another which also absorbs and is excited by the blue-violet radiations and by yellow radiations produced by the discharge and emits in the red portion of the spectrum. The second luminescent coating facing the arc tube comprises a phosphor that absorbs ultraviolet radiations produced by the mercury discharge and converts them into red radiations.

Abstract: Jacketed high pressure sodium vapor lamps of conventional construction operated on sonic frequency pulses with short duty cycles in order to raise the color temperature produce excessive acoustic noise. The noise level is reduced by using non-magnetostrictive material for the inleads extending from the base into the outer envelope and including the portions embedded in the press of the stem, and for the frame parts that support the arc tube within the outer envelope.

Abstract: The light output of a high-pressure metal-halide lamp that employs a sodium-scandium discharge and has an efficacy of approximately 90 lumens per watt is selectively modified by a luminescent coating on the inner surface of the outer envelope to provide color rendering and a source-color that are similar to those of an incandescent type lamp. The luminescent coating comprises a blend of two selected phosphor materials, one of which absorbs and is excited by blue-violet radiations produced by the arc discharge and emits in the green portion of the spectrum, and the other of which absorbs and is excited by the violet to yellow band of radiations produced by the arc discharge and emits in the red portion of the spectrum.

Abstract: A long life tungsten halogen lamp comprising a fused silica envelope containing a coiled tungsten filament connected across inleads sealed therein which include inner portions of molybdenum wire. The molybdenum wire has been treated to increase its ductility and reduce the concentration of impurities at the surface. The fill gas at a room temperature total pressure of at least 2,000 torr comprises nitrogen, an inert gas and a bromine-bearing component which provides from 1.6 .times. 10.sup.-.sup.8 to 8.0 .times. 10.sup.-.sup.8 gram atoms of bromine per cubic centimeter of envelope volume.

Abstract: A long life tungsten halogen lamp comprising a fused silica envelope containing a coiled tungsten filament connected across inleads sealed therein which include inner portions of molybdenum wire. The molybdenum wire has been treated to increase its ductility and reduce the concentration of impurities at the surface. The fill gas at a room temperature total pressure of at least 2,000 torr comprises nitrogen, an inert gas and an iodine-bearing component which provides from 3.1 .times. 10.sup..sup.-7 to 9.6 .times. 10.sup..sup.-7 gram atoms of iodine per cubic centimeter of envelope volume.

Abstract: A high pressure metal halide lamp comprises an outer envelope and an inner fused silica arc tube whose fill includes sodium iodide. Notwithstanding the use of a divided mount side-rod-less construction, the arc tube is subject to loss of sodium by electrolysis through the walls. The sodium loss is reduced by means of a collector wire within the outer envelope having a control potential thereon which shadows the current carrying lead wire in order to collect electrons that otherwise drift to the arc tube and promote electrolysis.

Abstract: An arc discharge lamp of the ceramic arc tube type wherein the mounting hardware for the arc tube at the end remote from the lamp base is significantly reduced in mass to eliminate an excessive heat sink characteristic and an expansion accommodating mounting is provided for the arc tube adjacent the base end of the lamp at the juncture of the base lead-in conductor and the arc tube lead.

Abstract: A method and means for suppressing ozone generated by high pressure xenon arc lamps and similar luminous discharge arc lamps of a type normally generating ozone. The ozone-generating lamp is enclosed in a gas-tight housing having a quartz or sapphire light emission window able to transmit light including ultraviolet. The housing has metal cover plates on its various sides acting as heat sinks, each of which has a large number of external heat-radiating fins. Clearance is provided inside the housing sufficient to cause the ozone formed by short wavelengths to be broken down by thermal contact with the lamp and to be thus converted into stable O.sub.2. The heat generated by the lamp in the housing is transferred to the walls of the housing and is dissipated by the external heat-radiating fins. The inner surfaces of the cover plates are blackened to absorb waste light.

Abstract: An elongated discharge lamp which is particularly intended for use in photo-chemical reaction processes. The discharge tube of the lamp is supported at its ends by two end mountings, one of which carries the input terminals for the lamp. A conductor extending along the length of the discharge tube joins one of the terminals to the electrode at the remote end of the tube, and the tube and conductor are separately enclosed in respective transparent tubular envelopes sealed to the end mountings at their ends.A liquid-cooling jacket is provided, cooling liquid being circulated therethrough by means of a tube of transparent material supported in the end mountings.

Abstract: A method and means for suppressing ozone generated by high pressure xenon arc lamps and similar luminous discharge arc lamps of a type normally generating ozone. The ozone-generating lamp is enclosed in a gas-tight housing having a quartz or sapphire light emission window able to transmit light including ultraviolet. The housing has metal cover plates on its various sides acting as heat sinks, each of which has a large number of external heat-radiating fins. Clearance is provided inside the housing sufficient to cause the ozone formed by short wavelengths to be broken down by thermal contact with the lamp and to be thus converted into stable O.sub.2. The heat generated by the lamp in the housing is transferred to the walls of the housing and is dissipated by the external heat-radiating fins. The inner surfaces of the cover plates are blackened to absorb waste light.