Abstract: The invention relates to a mercury short-arched-high pressure discharge lamp (1) which operates with direct-current, comprising a discharge vessel (2) having two necks (4) arranged in a diametrical manner opposite each other, wherein an anode (26) and a cathode (7), made respectively from tungsten, are melted in a gas-tight manner and said vessel is filled with mercury and at least one inert gas. According to the invention, the material of the cathode tip (11) contains, in addition to the tungsten, lanthanum oxide La2O3 and the mercury content of the filling in the discharging vessel volume is at least 1 mg/cm3 and at the most 6 mg/cm3.

Abstract: A gas discharge lamp is described with a discharge gas comprising a light-emitting substance enclosed in a discharge vessel, which is characterized in particular in that the light-emitting substance is formed by a compound of at least one element from the group IV-A (Si, Ge, Sn, Pb) and at least one element from the group VI-A (O, S, Se, and Te) of the periodic system, with the exception of the compound GeSe. It was surprisingly found that the emission maximum lies approximately in the center of the visible spectral range of the light with such a substance, in particular GeTe, at a comparatively low vapor pressure already, and that in addition a very high radiant efficacy is obtained. Furthermore, the emitted light has a color temperature substantially corresponding to that of natural daylight also without additives, in contrast to many other gas discharge lamps, thus opening the way to a use of the lamp for general lighting purposes.

Abstract: In a discharge tube of the present invention, a filler gas is composed of a mixture of inert gas and hydrogen gas and an airtight cylinder 10 in which the filler gas is enclosed in an airtight manner is provided. A pair of first and second discharge electrodes 22 and 24 are opposed to each other within an internal space of the airtight cylinder, so that an electric discharge is generated between discharging surfaces of the first and second discharge electrodes. In the discharge tube, a concentration of the hydrogen gas in the filler gas is set in a range from 20 percent by volume to 80 percent by volume.

Abstract: An arc tube for a discharge bulb is provided for use in a vehicular lighting system. The arc tube includes a closed glass bulb that is pinch-sealed at opposite ends. Inner ends of a first electrode and a second electrode extend into the closed glass bulbs from the ends of the closed glass bulb. The atmosphere inside the closed glass bulb includes a starting rare gas, a primary light-emitting metal halide, and optionally, a buffer metal halide. The distance between the inner ends of the electrodes is between about 0.3 and 1.8, and the inner diameter of the closed glass bulb at a middle portion is between about 1.5 mm and 2.7 mm. Accordingly, a stable discharge is produced using between 15 W and 30 W of power.

Abstract: A high-pressure mercury discharge lamp comprises a light-transmitting discharge vessel having a region surrounding a discharge space and seal portion, a spaced apart electrodes disposed in the discharge vessel and defining a discharge path, and a filling contained in the discharge vessel including mercury, halogen and lithium (Li). Components of the filling are selected such that a ratio of relative spectral energies B/A is within a range 0.15 to 0.45; wherein A represents the relative spectral energy of mercury (Hg) within a wavelenth range of 402.5 nm to 407.5 nm, and B represents the rlative spectral energy of lithium (Li) within a wavelength range of 667.5 nm to 672.5 nm.

Abstract: A high pressure discharge lamp includes a quartz glass bulb, a conductive element which is sealed at a sealing portion of the bulb, and a pair of electrodes. Each electrode is disposed in the quartz glass bulb so as to be opposite the other and connected to the conductive element. A part of each electrode is sealed with the quartz glass bulb at the sealing portion so as to generate a contacting portion formed by the part of each electrode and the bulb. The maximum length, Lmax, of the contacting portion is defined as: Lmax (mm)≦200/(P×D); and the minimum length, Lmin, of the contacting portion is defined as: Lmin (mm)≧0.8/(D2×&pgr;) or Lmin (mm)≧0.7 whichever is longer, where D is the diameter (mm) of the electrode and P is the power (W) supplied to the electrode.

Abstract: A metal halide lamp has an arc tube including an envelope as an arc tube container made of an oxide-based translucent ceramic material, and the arc tube is filled with luminescent materials comprising at least a cerium halide, a sodium halide, a thallium halide and an indium halide. An amount of the cerium halide is in a range from 20 wt % to 69.0 wt %, an amount of the sodium halide is in a range from 30 wt % to 79.0 wt %, and a total amount of the thallium halide and the indium halide is in a range from 1.0 wt % to 20 wt % with respect to the entire metal halides. Accordingly, the arc discharge is spread, bending of the arc discharge toward the arc tube wall is suppressed, and thus, the metal halide lamp has improved luminescent efficiency, where lowering of the flux maintenance factor is suppressed even after a long-time use, and hues of the luminescent colors are corrected.

Abstract: A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI3). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).

Abstract: An improved microwave-excited electrodeless discharge bulb and a lamp system using the bulb are designed to produce a nearly white light at an increased luminous efficacy. The bulb encloses a filling containing a mixture of a rare earth halide, a sodium halide, mercury, and a rare gas. The rare earth halide is at least one selected from a group consisting of a cerium halide and praseodymium halide. With the inclusion of cerium halide and/or praseodymium halide in combination with the mercury, the bulb can produce nearly white light at superior luminous efficacy, when energized by the microwave.

Abstract: A discharge light-emitting device includes a gas-filled discharge spaces (30) to use electric discharge in the gas. The gas contains at least 0.01-1% water vapor by volume. The specified amount of water vapor decreases discharge voltage markedly. Water vapor is introduced between a sealing step and an evacuation step so that the gas-filled discharge spaces can finally contain a desired amount of water vapor.

Abstract: The invention relates to a metal halide lamp having a nominal power of more than 100 W, comprising a discharge vessel with a ceramic wall. The discharge vessel encloses a discharge space having an ionizable filling which, in addition to Hg, contains a quantity of iodide of Na, Tl, Ho and Ca. Two electrodes each having an electrode tip at a mutual distance EA are arranged inside the discharge vessel. The discharge vessel has a cylindrical part with an internal diameter ID and extends through at least the distance EA. According to the invention, the relation EA/ID<1 is satisfied.

Abstract: A low-pressure gas discharge lamp comprising a gas discharge vessel with a gas filling containing mercury, and comprising electrodes, means for igniting and maintaining a gas discharge, and a phosphor coating containing at least one phosphor layer and a UV-C phosphor and a phosphor that can be excited by UV-C radiation.

Abstract: A short arc mercury discharge lamp including an arc tube filled with at least mercury and a rare gas, a cathode and an anode positioned opposite to each other within the arc tube, the cathode having an tapered area which tapers in a direction towards the anode and a projection which protrudes from the tapered area in a direction towards the anode. The amount of mercury to be added in the arc tube is in a range of 0.2≦n≦52, where n is the weight (mg/cm3) of the mercury per unit of volume, and a pressure of the rare gas to be added in the arc tube is in a range of 0.1≦p≦800, where p is the pressure (kPa) of the rare gas at an ambient temperature of 25° C.

Abstract: A light source with a sealed, light-transmissive tube filled with high pressure gases or high pressure gas mixtures and a microhollow cathode (MHC) discharge capable of excimer production are provided.

Abstract: An electric discharge lamp includes a light transmissive inner jacket that defines a sealed inner chamber, a first material in the inner chamber that emits light when activated, and a light transmissive outer jacket around the inner jacket. The outer jacket defines a sealed outer chamber between the inner and outer jackets that contains a second fill material. The second fill material, when activated by heat from the inner chamber when the lamp is operating, converts ultraviolet (UV) and deep blue light emitted from the inner chamber to visible light, thereby increasing an amount of visible light transmitted through the outer jacket compared to an amount of visible light transmitted through the inner jacket.

Abstract: The high-pressure discharge lamp of the present invention includes: a discharge chamber that is formed in a silica glass tube, a pair of electrodes that are arranged with ends confronting each other in the discharge chamber; metal foil parts that are superposed and bonded to the other ends of the electrodes, and sealing sections for hermetically sealing the discharge chamber and which are parts for embedding the other ends of the electrodes and the metal foil parts in the glass at the two ends of the silica glass tube. The electrodes and the metal foil parts are embedded in the glass in a state in which metal coils are wrapped around the vicinities of the junctions of the electrodes and metal foil parts. The ends of the metal foil parts on the electrode side are further formed as tapered portions.

Abstract: In a gas discharge tube 1 of the present invention, a focusing electrode portion 14 and a discharge limiting portion 30 are electrically insulated, and the discharge limiting portion 30 comprises a discharge limiting opening 31 which opposes an arc ball shaping concave portion 16. Thus the formation of a discharge path from a cathode portion 20 to the concave portion 16 is ensured and a starting discharge can be reliably generated. Further, by means of the discharge limiting opening 31 which opposes the concave portion 16, an arc ball S can be continuously maintained in an appropriate shape even when a lamp is illuminated, and thus the arc ball S can be shaped with stability, thereby stabilizing the luminance and light quantity.

Abstract: To provide an optical device in which fragments of a concave reflection mirror surrounding a discharge lamp and fragments of an optically permeable glass plate covering the aperture at the front of the concave reflection mirror do not fall and scatter, even if a short-arc high pressure discharge lamp that lights at extremely high mercury vapor pressure should rupture, the outer surface of the glass concave reflection mirror (20) surrounding the high pressure mercury discharge lamp (10) in which 0.16 mg/mm3 or more of mercury is sealed in a discharge envelope is covered by a scatter prevention film (40) made of a polymer material, for example, a fluorine-based resin. Furthermore, a scatter prevention film is applied to the outer surface of the concave reflection mirror in a region of incidence of light over a range within ±40° of the direction orthogonal to the axis of the high pressure mercury discharge lamp.

Abstract: To provide, in a special situation of a mercury-free lamp in which a luminance flicker tends to occur unlike a mercury-containing lamp, a metal halide lamp having an electrode structure modified so as to suppress the luminous flicker that is suitably used as an automotive headlamp, and an automotive headlamp apparatus incorporating the same. A metal halide lamp includes: a hermetic vessel 1 which is fire resistant and translucent; a pair of electrodes 3, 3 sealed in the hermetic vessel 1 with facing each other at a distant of 5 mm or less, the electrodes each having a shaft part 3a having a diameter of 0.25 mm or more and a tip 3b, which originates an arc, having a curved surface having a radius of one-half or less of the diameter of the shaft part; and a discharge medium essentially containing no mercury, sealed in the hermetic vessel 1, and containing halides of metals including a light-emitting metal in an amount of 0.

Abstract: An electrodeless discharge lamp includes an envelope filled with a luminescent material to be excited to emit light and a filling material that substantially does not discharge to emit light. The filling material stabilizes a discharge of the luminescent material.

Abstract: A solid halogen-containing lamp fill material and a method of introducing small amounts of halogen into a HID lamp are disclosed. The solid material may include an admixture of a metal and a metal halide in the form of spheres of high purity, uniform size and uniform composition. Solid lamp fill material and methods of introducing small quantities of one or more metals into a HID lamp are also disclosed.

Abstract: To realize high irradiation efficiency and intensity stability for extending lifetime of the short-arc discharge lamp to be used for IC exposure apparatus or the like. For this end, mercury and rare gases are sealed in the inner space 21 of the discharge tube 1. The rare gases are a mixture of a relatively high molecular weight rare gas such as xenon, krypton, argon, etc. and 5%-40% by volume of a relatively low molecular weight rare gas such as helium, neon, etc. And pressure of the mixed rare gases is set to 2 atmospheric pressure or higher. The anode 3 comprises the columnar body portion 14, the tapered portion 13 and the flat portion 12.

Abstract: A pair of electrodes (3) are provided in an arc tube (1) I/S is 20 (A/mm2) or less on a condition that an area of a cross section at a tip of the electrodes (3) is S (mm2) and an operating current between the electrodes (3) is I (A). According to this constitution, a long lamp life can be obtained without causing a rise in the lamp voltage and the blackening of the arc tube (1) by the evaporation of the electrodes while operation time becomes longer.

Abstract: A high pressure mercury lamp for a projector device in which a discharge vessel made of quartz glass is filled with at least 0.15 mg/mm3 mercury in which both devitrification of as well as damage to the discharge vessel can be eliminated is obtained by the quartz glass of the discharge vessel being given a fictive temperature of 1000° C. to 1250° C., a total content of alkali metals of 0.1 ppm by weight to 3 ppm by weight and an aluminum content of from 1 ppm by weight to 30 ppm by weight.

Abstract: An apparatus and method for obtaining short-term color stability in an HID lamp, the apparatus comprising in a first embodiment a high intensity discharge lamp with a discharge vessel and electrodes; with a filling within the discharge vessel containing a metal halide dose of at least 20 mg/cc, where volume is defined as the volume of the main cylindrical section of the discharge vessel. In a preferred embodiment, the filling within the discharge vessel contains Hg of at least 20 mg/cc, where volume is defined as the volume of the main cylindrical section of the discharge vessel. In a yet further aspect, the resulting color temperature is stabilized independent of the shape and frequency of the current and voltage waveforms that drive the HID lamp.

Abstract: A mercury-free metal halide lamp includes an arc tube including a pair of electrodes inside the tube. In the arc tube, a rare gas and a metal halide are contained, and no mercury is contained. The mercury-free metal halide lamp is horizontally operated such that the pair of electrodes is substantially horizontal. The mercury-free metal halide lamp further includes magnetic field applying means for applying a magnetic field including a component substantially perpendicular to a straight line connecting heads of the pair of electrodes in a substantially vertical direction. The density of halogen atoms evaporated during steady-state operation with respect to unit inner volume of the arc tube is 20 &mgr;mol/cc or more.

Abstract: An electrodeless lamp is disclosed. The electrodeless lamp according to the present invention is characterized in that SnI2 is used as a major component filled into a bulb as a filler, and the filler is excited by applying a microwave or high frequency to the bulb for thereby generating a visual ray for thereby obtaining a certain color temperature proper as a light source and implementing a faster light emission start-up at a lower cost without an additive.

Abstract: A compact fused silica, electroded HID lamp for automotive forward lighting, which contains no mercury. The lamps voltage, approximately 40 volts, is developed in this lamp by vaporizing zinc iodide instead of mercury. A compromise between voltage and luminous flux is achieved through the choice of the sodium scandium (Na:Sc) molar ratio, between 4.5:1 and 6:1 and a zinc iodide (ZnI2) dose of 2 to 6 micrograms per cubic millimeter that permits the lamp to operate within the North America, European and Japanese automotive color specifications for white light. The voltage in the lamp can be controlled according to the zinc iodide doping level without seriously impacting the visible spectrum otherwise provided by the other known dopants in the lamp.

Abstract: The invention relates to a high-pressure gas discharge lamp, particularly a motorcar lamp, comprising a bulb including at least two neck portions and a vacuum-tight discharge vessel of quartz glass, at least two electrodes projecting into the discharge vessel, and a filling in the discharge vessel which, in the operating state, is in a discharge state. Such lamps are used, in particular, in headlights of motorcars. In order to ensure that the arc of the high-pressure gas discharge lamp generates a higher luminescence in a small area, and the lamp can be used as a light source in motorcar headlights, the discharge vessel of the high-pressure gas discharge lamp in accordance with the invention encloses a discharge space having a width B below 4 mm and a length C below 8 mm, and the filling comprises NaJ, ScJ3, Xe, ZnJ2, and is free of Hg. Surprisingly it has been found that the use of ZnJ2 in the filling causes the arc to generate a higher luminescence in the area of the arc axis per dimension of the arc.

Abstract: A UV radiation source is tunable to optimize the process of densifying a carbon-doped silicon oxide film. The composition and relative concentration of stimulated gases stimulated within an airtight bulb is controlled to produce radiation optimized for absorption by undesirable chemical bonds of the carbon-doped silicon oxide film, leading to disruption of these bonds and their replacement by more desirable stable chemical bonds. The energy of radiation emitted by the source is determined by the identity of excited chemical species, and the intensity of the radiation emitted by the source is determined by the concentration of the excited chemical species. By exciting a specific mixture of gases, radiation is emitted at a combination of energies and intensities calculated to disrupt populations of unstable bonds in the carbon-doped silicon oxide film while leaving desirable bonds in the film unaffected.

Abstract: A pelletized lamp fill material suitable for delivering a precise quantity of rhenium and a halogen into the light emitting chamber of a tungsten halogen lamp. The pellet is formed by pressure aggregating a mixture of a metal powder and a rhenium-halogen compound. In a pellet suitable for delivering bromine into the lamp, the metal powder may be mixed with rhenium tribromide powder to form the pellet. The release of the bromine and rhenium is desirably controlled over time as a function of temperature.

Abstract: The present invention provides a tungsten-halogen light bulb having an arc tube with a seal portion at one end. A filament is provided in the interior of the arc tube, and a basic gas mainly comprising at least either gaseous xenon or gaseous krypton is filled in the arc tube. When V (V) denotes a rated voltage of the tungsten-halogen light bulb, P(MPa) denotes a filling pressure of the basic gas at a room temperature, and Xe vol. % and Kr vol. % respectively denote composition ratios of the gaseous xenon and of the gaseous krypton, the following formulas (1) and (2) are satisfied simultaneously, in which ‘%’ means ‘volume %’. V≧100 (Volt)  (1) P≧0.7+{0.1×(Kr%/(Kr%+Xe%))}  (2) In these formulas, Kr %+Xe %=100(%), 0≦Kr %≦100, and 0≦Xe %≦100. Accordingly, a crack at the seal portion of the arc tube is prevented and the lifetime is improved.

Abstract: A low-pressure gas discharge lamp having a gas discharge vessel containing a gas filling including a copper compound. The copper compound is selected from the oxides, chalcogenides, hydroxides, hydrides and the metalorganic compounds of copper. In addition to the copper compound, the gas filling includes a buffer gas such as argon, and may also include a thallium compound and/or a copper halogenide.

Abstract: A discharge light-emitting device includes a gas-filled discharge spaces (30) to use electric discharge in the gas. The gas contains at least 0.01-1% water vapor by volume. The specified amount of water vapor decreases discharge voltage markedly. Water vapor is introduced between a sealing step and an evacuation step so that the gas-filled discharge spaces can finally contain a desired amount of water vapor.

Abstract: A low-wattage mercury vapor discharge lamp is provided for use with existing 110V high frequency electronic ballasts. The lamp has a discharge sustaining fill of mercury and an inert gas mixture of krypton and argon that does not require a starting aid. The phosphor layer has a coating weight of 2.0-3.9 mg/cm2.

Abstract: A high pressure discharge lamp includes a quartz glass bulb having a sealing portion; and a pair of electrodes. Each electrode of the pair of electrodes is disposed so as to be opposite the other in the quartz glass bulb. The quartz glass bulb of the high pressure discharge lamp contains at least mercury and a halogen gas. The partial pressure of oxygen (O) in the quartz glass bulb is about 2.5×10−3 Pa or less and the partial pressure of the halogen gas in the quartz glass bulb is in the range between about 1×10−8 &mgr;mol/mm3 and 1×10−7 &mgr;mol/mm3.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Xenon gas and at least one selected from argon gas and krypton gas are sealed in the discharge tube, in which the xenon gas accounts for 60 vol % to 80 vol %. Thus, it is possible to provide a light source device and a liquid crystal display device that provide light emission with high brightness and excellent brightness distribution and that can be manufactured readily.

Abstract: The invention relates to a high-pressure discharge lamp provided with a discharge vessel made of glass which encloses a discharge space having an ionizable filling and an electrode. The discharge vessel is provided with a seal which encloses an Mo foil having knife edges and forms a feedthrough for an electric conductor to the electrode. At the location of the foil, the seal has a gastight sealed cavity and a first antenna on the outer side of the cavity. Preferably, a second antenna is placed at the neck where the seal is connected to the discharge vessel. This reduces both hot restrike voltage and hot restrike delay.

Abstract: The invention relates to a tubular discharge lamp (1) with a wall (4) which is transparent to UV-radiation. The tube (2) encloses a discharge space (5) having an internal diameter D. The discharge space (5) comprises a filling of mercury metal vapor in a concentration range of 0.4-2.5 mg/cm3. A reduction of both the diameter D from about 22 mm down to about 13.5 mm and the average mercury concentration from about 1.7 mg/cm3 down to about 0.8 mg/cm3 leads to an increase in the effective germicidal UV-output of the lamp (1) of about 35%.

Abstract: A high-pressure mercury lamp includes an arc tube, and a pair of electrodes is provided in a discharge space of the arc tube. In the discharge space, mercury and xenon gas are sealed. The amount of mercury per unit volume that is to be sealed in the discharge space is within a range of 0.12 mg/mm3 to 0.35 mg/mm3. A pressure of the xenon gas in the discharge space is within a range of 2.0×105 Pa to 2.0×106 Pa.

Abstract: A light source device includes at least one discharge tube, a discharge medium sealed inside the discharge tube, and first and second electrodes for exciting the discharge medium. The first electrode is arranged inside or outside the discharge tube, and the second electrode has a plurality of contact portions at which the second electrode is in contact with an outer surface of the discharge tube. The contact portions are located at different distances from the first electrode and are provided discontinuously. Thus, it is possible to provide a light source device with an improved light emission efficiency, and a liquid crystal display device in which the light source device is employed.

Abstract: A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI3). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).

Abstract: A metal halide discharge lamp which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of a metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: Fluorescent lamp (1) comprising a glass discharge vessel (2) in which a gas is present, which discharge vessel (2) is on two sides provided with a tubular end portion (3) having a longitudinal axis, which end portion (3) includes a glass stem (5), wherein an exhaust tube (6) extends axially outwardly from said stem (5) for supplying and/or discharging gases during the production of the lamp (1), wherein an electrode (8) extends axially inwardly through the stem (5) for generating and maintaining a discharge in the discharge vessel (2).

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor series having power ranges of about 150 W to about 1000 W. Such lamps are provided with outer bulb (10) enclosing a cylindrical ceramic discharge vessel (20) enclosing a discharge space, said cylindrical ceramic discharge vessel including within said discharge space an ionizable material comprising a metal halide; a first and second discharge electrode feedthrough means (30, 40); and a first and second current conductor (12, 13) connected to said first and second discharge electrode feedthrough means (30, 40), respectively.

Abstract: A metal halide lamp has an arc tube including an arc tube container as an envelope made of an oxide-based translucent ceramic material such as alumina, and the arc tube is filled with cerium halide as a luminescent material and a halide of a rare earth element that is more reactive with the ceramic material than is the cerium halide. Accordingly, a reaction between the oxide-based translucent ceramic material and the halide of a rare earth element is accelerated while a reaction between the oxide-based translucent ceramic material and the cerium halide is suppressed. This suppresses a decrease of the cerium halide that serves for light emission, and also reduces changes in the lamp color temperature. Thereby, lowering of flux maintenance factor and color temperature in aging of the lamp are suppressed, and the thus provided metal halide lamp with an alumina ceramic tube for indoor and outdoor use has a white light source color and it has a high-wattage, high luminous efficiency, and a long service life.

Abstract: A metal halide lamp has an arc tube including an envelope as an arc tube container made of an oxide-based translucent ceramic material, and the arc tube is filled with luminescent materials comprising at least a cerium halide, a sodium halide, a thallium halide and an indium halide. An amount of the cerium halide is in a range from 20 wt % to 69.0 wt %, an amount of the sodium halide is in a range from 30 wt % to 79.0 wt %, and a total amount of the thallium halide and the indium halide is in a range from 1.0 wt % to 20 wt % with respect to the entire metal halides. Accordingly, the arc discharge is spread, bending of the arc discharge toward the arc tube wall is suppressed, and thus, the metal halide lamp has improved luminescent efficiency, where lowering of the flux maintenance factor is suppressed even after a long-time use, and hues of the luminescent colors are corrected.

Abstract: A discharge lamp includes means for containing a light emitting fill, the fill being capable of absorbing light at one wavelength and re-emitting the light at a different wavelength, the light emitted from the fill having a first spectral power distribution in the absence of reflection of light back into the fill; means for exciting the fill to cause the fill to emit light; and means for reflecting some of the light emitted by the fill back into the fill while allowing some light to exit, the exiting light having a second spectral power distribution with proportionately more light in the visible region as compared to the first spectral power distribution, wherein the light re-emitted by the fill is shifted in wavelength with respect to the absorbed light and the magnitude of the shift is in relation to an effective optical path length.

Abstract: A low-pressure gas discharge lamp comprising a gas discharge vessel containing a gas filling with a chalcogenide of the elements of the 4th main group of the periodic systems of elements and a buffer gas, and comprising inner or outer electrodes and means for generating and maintaining a low-pressure gas discharge.

Abstract: A thallium-free high pressure ceramic metal halide lamp having superior dimming characteristics with a fill composition comprising MgI2 and CeI3. In addition, the fill chemistry comprises NaI and the halides of rare earth metals such as Dy, Ho and Tm.