Abstract: A light fixture for an LED lamp having a glass bulb and at least one light-emitting diode. The glass bulb is filled with a heat-conducting gas and the at least one light-emitting diode is arranged inside the glass bulb. The heat-conducting gas in the glass bulb has a pressure of at least 2.2 bar at room temperature.

Abstract: The present high-pressure discharge lamp is composed of an arc tube part having an internal space, a pair of tungsten electrodes disposed in opposition to each other within the internal space, and mercury and halogen encapsulated in the internal space. The halogen is excessively encapsulated into the internal space relatively to the capacity of the internal space so as to establish an appropriate halogen cycle when the mercury partially deposits without evaporating.

Abstract: A mercury vapor short arc lamp for DC operation may include a cathode and an anode arranged in an interior of a discharge vessel, wherein the atmosphere in the interior contains at least one halogen or one halogen compound, and the mercury density in the interior is between 1 and 60 mg/cm3.

Abstract: The present invention is to provide a novel ultraviolet irradiation metal halide lamp which can produce more intense light of ultraviolet region with a wavelength near 365 [nm]. This lamp is a metal halide lamp to produce mainly light of ultraviolet region. In order to produce light with a high spectrum in ultraviolet region, particularly, light of a wavelength of 350 to 380 [nm], at least mercury (Hg) and an iron are sealed into this lamp together with a rare gas. The sealed iron into the lamp is supplied by iron iodide (FeI2) and iron bromide (FeBr2) as iron halide (FeX2) and metal iron (Fe). When a quantity of materials sealed into the lamp is expressed such that A represents a quantity of metal iron sealed into the lamp, B represents a quantity of iron iodide sealed into the lamp and C represents a quantity of iron bromide sealed into the lamp, respectively, the quantity A of the metal iron falls within the range of 0.5(B+C)?A?10.

Abstract: An operating device for operating at least one Hg low-pressure discharge lamp which has a first and a second electrode coil may include a unit for providing a variable that is correlated with the Hg vapor pressure in the at least one Hg low-pressure discharge lamp comprises at least one unit for capturing emission spectra of at least specifiable spectral ranges, wherein the unit for capturing emission spectra may include at least one light receiving unit which is arranged in the beam path of the at least one Hg low-pressure discharge lamp.

Abstract: In various embodiments, a high pressure discharge lamp is provided having a bulb, which surrounds a discharge volume, wherein a filler, which contains indium halide, quicksilver and inert gas from the group neon, argon, krypton, xenon, is accommodated in the discharge volume, wherein the filler simultaneously contains the halide of iodine and bromine, wherein the portion of InI amounts at most to 90 mol %, in respect of the total of all halides of In.

Abstract: Disclosed herein are mercury free ceramic metal halide high intensity discharge lamps of specified arc tube geometry and composition of ionizable fill. Embodiments herein generally employ a discharge vessel formed of a ceramic material having an aspect ratio satisfied by 1<ITL/ID<4.5 where ITL is the inner total length of the discharge vessel and ID is the inner diameter of the discharge vessel. The ionizable fill typically comprises xenon at a cold fill pressure of from about 3 to about 15 bar, and a halide component comprising sodium halide, thallium halide and/or indium halide, and at least one rare earth halide. Disclosed advantages may include betterment in both lumen run-up and color shift upon dimming, as compared to mercury-containing CMH HID lamps.

Abstract: A metal halide lamp is comprised of an airtight tube having a discharge section in which a discharge space is formed; a discharge medium which is enclosed in the discharge space, contains metal halide exhibiting a molar ratio of sodium halide to scandium halide of 1.5 or below and 8 atm or higher of xenon but does not substantially contain mercury; and a pair of electrodes with their tip ends arranged to oppose to each other in the discharge space, wherein halogen atoms bonded to metal in the metal halide mostly consist of iodine and bromine atoms, and a ratio of the bromine atoms is in a range of 10 to 50% and the total amount of the metal halide enclosed is 0.02 mg/?l or less.

Abstract: A mercury-free arc tube for a discharge lamp unit including a closed glass bulb in which main light emitting substances of NaI, ScI3, and ScBr3 and buffer substances of InI and ZnI2 are enclosed together with Xe gas, and wherein an amount of enclosed ScBr3 is in a range of about 5 wt % to about 24 wt % relative to a total weight of the substances enclosed in the closed glass bulb. The mercury-free arc tube may also include a shroud glass tube, which is surrounds the closed glass bulb and a pair of electrodes, which are disposed to be opposed to each other in the closed glass bulb.

Abstract: In various embodiments, a high pressure discharge lamp may include a ceramic discharge vessel which contains two electrodes and a metal halide filling in a discharge volume V, wherein the filling contains a starting gas that is selected individually or in mixture from the group of the noble gases, wherein the filling moreover contains metal halides that are selected individually or in mixture from the group MXn, M being a representative from the group In, Zn, Mg, Mn, Al, Tl, Sn, Sc, Hg and X being a representative from the group I, Br, Cl, wherein moreover the filling contains a stoichiometric excess of the metallic portion M in relation to MXn, wherein the concentration of the metallic portion is in the range from 0.1 to 20 mg/cm3.

Abstract: An electric lamp is described, which has a quartz glass lamp vessel (10) accommodating an electric element (3, 4). The lamp vessel locally has a light-absorbing, non-reflective coating (11, 12). The coating mainly consists of iron, iron oxide, silicon, and silicon dioxide, the ratio of the weight percentages of iron (compounds) and silicon (compounds) being in the range of 0.17<=iron (compounds)/silicon (compounds)<-12, and the ratio of the weight percentages of silicon and silicon dioxide being in the range of 0.5<=silicon/silicon dioxide<=50.

Abstract: An entire length of a fluorescent lamp is made short to allow the fluorescent lamp to be downsized and the part other than the fluorescent lamp to be shortened so as to advantageously improve the design potentials and enhance the lighting effect. A fluorescent lamp to be fitted to a feeding side member, or a hook ceiling, having a pair of retaining holes and a pair of feeding side terminals arranged at corresponding positions, comprises a fluorescent lamp main body, an inverter-containing case arranged at a proximal end side of the fluorescent lamp main body and a pair of terminals arranged at the side of the case opposite to the fluorescent lamp main body. The pair of terminals have the tip ends bent so as to be retained by the feeding side member and establish electric connection to the feeding side terminals as they are respectively inserted into the pair of retaining holes of the feeding side member and displaced in the rotating direction around the center of the fluorescent lamp.

Abstract: A low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel enclosing, in a gastight manner, a discharge space provided with a filling of mercury and a rare gas. The discharge vessel includes electrode(s) for maintaining a discharge in the discharge space. The discharge vessel further includes a dispenser for controllably dispensing hydrogen into the discharge space during lamp operation. The hydrogen gas pressure during lamp operation is in the range between 10?3 Pa and 10 Pa.

Abstract: With regard to a metal vapor discharge lamp with a triple tube structure including a discharge tube, an inner tube, and an outer tube, misalignment of axes of the inner tube and the outer tube is prevented. The metal vapor discharge lamp (14) is composed of a discharge tube (30) having a pair of electrodes therein, an inner tube (32) having a pinch-sealed part (86) at an end thereof and hermitically housing the discharge tube therein, and an outer tube (34) housing the inner tube therein, and a base (36). In a clearance between the inner tube and the outer tube, there disposed a restrain member (37) for restraining movement of the inner tube relative to the outer tube in a direction orthogonal to an axis of the metal vapor discharge lamp.

Abstract: The invention relates to novel gas fillings of low-pressure gas discharge lamps for reducing the starting and arc drop voltages at low Hg vapor pressures. In favor of a mixture consisting of Ne and Kr, the Ar portion of the gas filling is considerably reduced.

Abstract: The present invention provides a discharge tube for infrared communication interference suppression, a lighting device for liquid crystal display devices, and a liquid crystal display device, each capable of suppressing infrared communication interference. The present invention is a discharge tube for infrared communication interference suppression, including a pair of electrodes, wherein the discharge tube contains mercury, argon gas, and rare gas thereinside, the rare gas having an excitation energy lower than that of argon gas. Krypton gas is mentioned as the rare gas. The discharge tube may further contain neon gas thereinside.

Abstract: To devise a UV light source which has an increased UV irradiance in the short wavelength range, prevents blackening of the light emission tube and a decrease of the irradiance and has a long durability, a high pressure mercury lamp of the direct current type is provided, comprising a light emission tube, a cathode and an anode arranged at a distance oppositely to each other inside said light emission tube, said cathode having a shape of a truncated cone with a flat part at a tip end thereof, mercury filled inside said light emission tube in an amount of 0.05 to 0.10 mg/mm3, wherein the distance between the cathode and the anode is 1.4 to 1.8 mm, and a tip diameter of the flat part at the tip end of the cathode is 0.1 to 0.3 mm.

Abstract: In various embodiments, a high-pressure discharge lamp has a metal halide fill, iodine and bromine being used as the halogen. In addition, noble gas and Hg are used. Thallium is used as the metal, with the proportion of TlI being in the range from 25 to 75 wt. % of the mixture of TlI and TlBr.

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: A metal halide discharge lamp comprises a lamp body and a chamber formed within the body. A pair of electrodes extends into the chamber and have electrode tips spaced apart from one another. A discharge medium composition is sealed within the chamber that generates a plasma, which generates visible light. The composition comprises a rare gas, a first metal halide that produces a luminous flux and a second metal halide that generates a desired lamp operating voltage. The composition may also comprise a metal, sealed in the chamber, in elemental form and is not derived from the first metal halide or the second metal halide. The second metal halide serves as a substitute for mercury for purposes of generating desired lamp operating voltage.

Abstract: The invention relates to novel gas fillings of low-pressure gas discharge lamps for reducing the starting and arc drop voltages at low Hg vapor pressures. In favor of a mixture consisting of Ne and Kr, the Ar portion of the gas filling is considerably reduced.

Abstract: The low-pressure mercury vapor discharge lamp has a light-transmitting discharge vessel (2) enclosing, in a gastight manner, a discharge space (1) provided with a filling of mercury and a rare gas. The discharge vessel comprises discharge means (8) for maintaining a discharge in the discharge space (1). The discharge vessel comprises dispenser means (20) for controllably dispensing hydrogen into the discharge space. The hydrogen gas pressure is in the range between 10?3 Pa and 10 Pa. Preferably, the hydrogen gas pressure is in the range between 10?2 Pa and 1 Pa. A low-pressure mercury vapor discharge lamp with a good maintenance is obtained.

Abstract: A metal halide lamp having a high pressure quartz arc tube in which the electrodes are non-thoriated.

Abstract: The invention relates to aluminoborosilicate glasses as a glass casing body of a lighting means, especially for background illumination, which glass composition is equally suitable for use in lighting means with external contacting as well as for lighting means with internal contacting.

Abstract: A process for producing an electrode for high-pressure discharge lamps, at least the discharge-side section of the electrode being produced from a prefabricated tungsten wire, which is shortened to the required length during the production process of the electrode and subjected to an annealing process as well as being mounted on other components of the electrode that may be present. The annealing process is carried out exclusively at temperatures below 1500 degrees Celsius. The invention also relates to an electrode for high-pressure discharge lamps, at least the discharge-side section of the electrode being constructed as a tungsten rod that has a long crystalline structure or an isotropic crystalline structure with grain diameters in the radial direction of the tungsten rod of less than or equal to 50 micrometers with the centroid of the grain size distribution in the range from 10 micrometers to 20 micrometers.

Abstract: A discharge lamp includes a glass tube having electrodes with an electron emissive material coated thereon, the electrodes being provided on respective ends of the glass tube, wherein the glass tube has a gas containing a luminescent material sealed therein and has a fluorescent material coated on its inner surface, the glass tube has a diameter less than 6.5 mm and the gas sealed into the glass tube is gases of more than one kind selected from an Ar (argon) gas , a Kr (krypton) gas and a Xe (xenon) gas or a mixed gas mainly made of gases of more than one kind selected from the Ar gas, the Kr gas and the Xe gas. Thus, the discharge lamp can reduce a diameter of its tube and it is able to provide high luminous efficiency.

Abstract: A metal halide lamp of the present invention has an arc tube formed of ceramic and a pair of opposing electrodes. This lamp includes a Pr (praseodymium) halide, a Na (sodium) halide, and a Ca (calcium) halide enclosed within the arc tube. The Pr halide content Hp [mol], the Na halide content Hn [mol], and the Ca halide content Hc [mol] satisfy the relationships of 0.4?Hc/Hp?15.0 and 3.0?Hn/Hp?25.0.

Abstract: Process for producing a discharge lamp having a silica discharge vessel with an emission space in which there is a pair of electrodes at least 0.15 mg/mm3 of mercury, argon (Ar), and halogen by measuring the relation b/a1 between the emission intensity a1 of argon (Ar) at a wavelength of 668 nm and the emission intensity b of OH radicals at a wavelength of 309 nm in a state of glow discharge of the discharge lamp; supplying hydrogen into the discharge vessel of the discharge lamp; measuring the relation c/a2 between the emission intensity a2 of argon (Ar) at a wavelength of 668 nm and the emission intensity c of OH radicals at a wavelength of 309 nm in the state of glow discharge of the discharge lamp; and fixing the difference c/a2?b/a1 at a value in the range of 0.001 to 15.

Abstract: The invention relates to a low-pressure mercury vapor discharge lamp (10) comprising a light-transmitting discharge vessel (12) having a first layer (20) and a second layer (22), the first layer (20) facing the discharge space (14) and the second layer (22) being arranged between the first layer (20) and an inner wall (18) of the discharge vessel (12). The first layer (20) comprising a first luminescent material for converting ultraviolet light (24) into output light (26). The second layer (22) comprising a second luminescent material for converting at least part of the ultraviolet light (26) transmitted through the first layer (20) into recycled ultraviolet light (28).

Abstract: The disclosed subject matter includes a fluorescent lamp and particularly a cold cathode fluorescent lamp that can be employed as a light source for a LCD backlight unit for a television, a computer, a display, and the like. The fluorescent lamp can include a couple of electrode units located opposite to each other at each end of a tube, a couple of welding beads sealing both the tube and the couple of electrode units, and a filler gas located in the tube. Each of the electrode units can include an emitter electrode that is configured with a crystalline silicon semiconductor material having an electrical conductivity or configured with other semiconductor materials, and can include a concave portion formed thereon. The electrode units can prevent blackening on an inner surface of the tube by avoiding the occurrence of spattering. Thus, the fluorescent lamp using the electrode units can enjoy a long life, high reliability, easy manufacture, and the like.

Abstract: The present invention relates to a fluorescent lamp, and in particular to a fluorescent lamp with an improved in-dark starting characteristic. A fluorescent lamp includes: a glass bulb (101) having a discharge space therein; two external electrodes (102 and 103) provided at both ends of the glass bulb; and a phosphor layer (106) provided on an inner surface of the glass bulb. The glass bulb is made of glass that contains 3% to 20% inclusive of sodium oxide. The phosphor layer includes phosphor particles (106R and 106G) containing no alumina and phosphor particles (106B) containing alumina. A metal oxide (107) is attached to surfaces of the phosphor particles containing alumina. Sodium oxide precipitated on the inner surface of the glass bulb improves the in-dark starting characteristic. The phosphor particles containing alumina are protected by the metal oxide for being susceptible to deterioration due to reaction thereof with sodium oxide.

Abstract: A low mercury consumption electric lamp is provided having a layer of a luminescent material comprising a phosphor derived from a mixture of a mixture of a cool-white calcium halophosphate, a red-emitting yttrium oxide (YOX), a green-emitting cerium, terbium lanthanum phosphate (LAP), and a blue-emitting europium-activated barium magnesium hexa-aluminate (BAM).

Abstract: A low-pressure discharge lamp (1) is provided that includes a glass tube (2) having an inner diameter in a range of 1 to 5 mm and a pair of electrodes (3) disposed at end portions in the glass tube (2). The pair of electrodes (3) contain at least one transition metal selected from transition metals of Groups IV to VI. Mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube (2). A relationship between a cathode glow discharge density J and a composition index ? of the sealed rare gas of the low-pressure discharge lamp (1) satisfies the following expression ??J=I/(S·P2)?1.5? (where S represents an effective discharge surface area (mm2) of an electrode, I represents a RMS lamp current (mA), P represents a pressure (kPa) of a sealed rare gas, and ? represents a composition index of a sealed rare gas that is a constant expressed by ?=(90.5A+3.4N)×10?3 when a total of a composition ratio A of argon and a composition ratio N of neon is expressed by A+N=1).

Abstract: Low-pressure mercury vapor discharge lamp has a discharge vessel (10) enclosing, in a gastight manner, a discharge space (13) provided with a filling of mercury and an inert gas in a gastight manner. The discharge vessel comprising electrodes (20a; 20b) arranged in the discharge space for maintaining a discharge in the discharge space. According to the invention, the probability of failure of the low-pressure mercury vapor discharge lamp being substantially determined by one of the electrodes. As upon igniting the low-pressure mercury vapor discharge lamp the ignition-related events influence the electrodes, preferably, the ignition-related events substantially are prevented affecting the one electrode.

Abstract: The metal halide lamp has a ceramic discharge vessel and contains two groups of metal halides: a first group made up of the emitters and a second group made up of the wetters. The second group comprises at least one of the metal halides of Mg or Yb.

Abstract: The invention relates to a high-pressure discharge lamp with a discharge vessel having a filling comprising—a rare gas, for example argon, —mercury, and —chlorine, wherein the filling quantities of mercury [Hg] and chlorine [Cl] comply with the following conditions: —[Hg](E[Cl]3 200 (?mole/cm3)2, —[Cl] £ 10 ?mole/cm3. The condition [Hg](E[Cl]3 200 (?mole/cm3)2 achieves HgCl vapor pressures in the discharge sufficient for generating significant radiation components of the B2S+-X2S+ band system of this molecule. The condition [Cl] £ 10 ?mole/cm3 serves to limit the chemical aggressiveness of the chlorine filling, in particular to limit the attacks on the wall and electrodes and thus to achieve longer lamp lives. The addition of chlorine-binding metals, in particular of germanium, leads to a further improvement in the radiation and life properties of the lamp.

Abstract: An arc tube for a discharge lamp has a closed chamber filled with rare gas and a metal halide containing at least Na halide or Sc halide, and electrodes, wherein sealing pressure of the rare gas is 0.6 MPa or more, and a sealing density of the Sc halide in the closed chamber is ranging from 1.25 to 4.70 mg/ml. In the arc tube, since the Xe gas sealing pressure slightly higher than 0.6 MPa, the pressure in the closed chamber is increased during its lightening state. Thus, reactions leading to a flicker occurrence may be accelerated. However, the flicker occurrence can be suppressed by setting the Sc halide sealing density to 4.70 mg/ml or less. Further, a luminous efficiency required for the lamp can be assured by setting the Sc halide sealing density to 1.25 mg/ml or more.

Abstract: It is an object of the present invention to provide a high pressure discharge lamp lighting apparatus, has a structure to control decrease of illuminance on a screen which is thought to be a cause of wear of an anode in an early stage of the life span. The high pressure discharge lamp lighting apparatus has a high pressure discharge lamp in which a pair of electrodes is arranged so as to face each other at an interval of 2 mm or less in an arc tube which is made of quartz glass, and mercury of 0.16 mg/mm3 or more, rare gas, and halogen of 1×10?6 to 1×10?2 ?mol/mm3 is enclosed, and a power supply apparatus supplying direct current to the discharge lamp, wherein the power supply apparatus superimposes an alternating component on the direct current and impress the superimposed current to the discharge lamp.

Abstract: A metal halide lamp comprising a substantially cylindrical discharge vessel having an internal diameter Di<2.0 mm and filled with an ionizable filling, wherein two electrodes are present at a mutual distance EA for maintaining a discharge in the discharge vessel, wherein the filling comprises an inert gas, such as Xe, having a pressure at room temperature between 5 and 25 bar, and an ionizable salt, characterized in that said ionizable salt is selected from the group comprising PrI3, NdI3 and LuI3.

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: A short arc ultra-high pressure mercury lamp, at least one of the electrodes of which has a melted part towards the electrode head and a coil part which extends from the melted part continuously and integrally with it in a direction away from the electrode head, avoids blackening of the tube wall and achieves a long service life by the provision of a power supply which supplies the discharge lamp with direct current when operation is starting and afterwards supplies it with an alternating current, the direct current supplied by the power supply to the discharge lamp being initially 0.3 to 0.6 times as great as the rated current and afterwards increasing to 1.0 to 2.0 times are great as the rated current.

Abstract: A metal halide fill for forming an ionizable fill comprising at least one inert gas, mercury, and at least one halogen, the fill additionally comprising the following constituents: Mn halide and V halide. This fill may in particular be present in the discharge vessel of a metal halide lamp.

Abstract: A phosphor layer is composed of tri-band phosphor particles bound together by a binder. A material as the main component of the binder is a mixture of (1) a compound formed by calcium oxide, barium oxide, and boron oxide, and (2) calcium pyrophosphate. Dissolved in the main component material of the binder is a luminescent component that converts ultraviolet radiation of 254 nm to ultraviolet radiation of longer wavelengths or to visible light. Examples of such a luminescent component include an oxide of gadolinium (Gd), terbium (Tb), europium (Eu), neodymium (Nd), or dysprosium (Dy), each of which belongs to lanthanum series, and an oxide of thallium (Tl), tin (Sn), lead (Pb), or bismuth (Bi).

Abstract: A long-life high-pressure discharge lamp suffers reduced blackening and luminance drop even after it has been turned on over a long period of time, and is arranged to prevent the internal gases from leaking out and also to prevent the lamp bulb from being ruptured. The high-pressure discharge lamp has a pair of confronting electrodes inserted in a lamp bulb which confines therein at least mercury and a halogen gas. The lamp bulb contains oxygen at a partial pressure lower than a partial pressure which can maintain a luminance of 80% after 100 hours of operation and equal to or higher than 1.0×10?5 Pa.

Abstract: An ultrahigh pressure mercury lamp which is small and has high light radiation intensity and moreover good color reproduction with high efficiency in which, even with a large amount of mercury added, a failure of the mercury to vaporize in the bulb part does not occur, and in which blackening of the bulb part due to wearing of the electrodes even under a large electrode load as a result of shortening of the distance between the electrodes is low is obtained by an ultrahigh pressure mercury lamp in which a bulb part of the discharge vessel made of translucent material has an essentially ovoid shape, is filled with at least 0.2 mg/mm3 of mercury and which is operated at an input wattage of at most 400 W using direct current, has the length D of the tip area of the anode and the length L of the bulb part in the direction of the tube axis of the lamp set in accordance with the relationship D?L/2.

Abstract: A metal vapor discharge lamp has an arc tube in which mercury, a rare gas, and at least one luminous metal are enclosed, and an outer tube in which a nitrogen gas is enclosed and which covers the arc tube. The metal members which are provided in the outer tube and which include wiring for supplying power to the arc tube will not react with one of nitrogen and a nitrogen compound in the nitrogen gas atmosphere in the outer tube when the temperature exceeds 350° C. in a steady-state illumination. The use of a metal member such as stainless steel will increase the life of the discharge lamp.

Abstract: The present invention provides a high-pressure discharge lamp 100 including a luminous bulb 10 enclosing at least a rare gas and halogen in the bulb and made substantially of quartz glass; and an electrode 12 made substantially of tungsten and disposed in the luminous bulb. The mole number of the halogen is larger than the sum of the total mole number of metal elements (except the tungsten element and the mercury element) that have the property of bonding to the halogen and are present in the luminous bulb 10 and the mole number of the tungsten present in the luminous bulb by evaporation from the electrode 12 during lamp operation.

Abstract: A mercury vapor discharge fluorescent lamp is provided that has a mercury barrier. The mercury barrier is effective to inhibit mercury atoms from absorbing into the glass envelope and amalgamating with sodium atoms in the envelope. The mercury barrier is substantially non-mercury absorptive, both when the lamp is on and when it is off.

Abstract: Metal halide lamps have a discharge vessel operable at a high coldest spot temperature. The discharge vessel encloses a discharge space comprising an ionizable gas filling and, in addition to Hg, also an alkali iodide of Na of Li or a combination of both. According to the invention, the filling also comprises TbI3 or GdI3 or a combination thereof.

Abstract: The present invention provides a high pressure discharge lamp which is provided with a discharge tube containing a pair of electrodes therein and being filled with mercury, an inert gas and a halogen gas, the amount of the mercury filled being 0.12 to 0.35 mg/mm3, the halogen gas being at least one gas selected from the group consisting of Cl, Br and I and being present in an amount of 10?7 to 10?2 ?mol/mm3, and the electrodes being mainly composed of tungsten, and the tungsten as a material of the electrodes contains not more than 12 ppm of potassium oxide (K2O). In such a high pressure discharge lamp, blackening of the discharge tube due to the potassium oxide (K2O) contained in the tungsten, and decrease in illumination maintenance can be prevented, thus providing a high pressure discharge lamp with a long lifetime, a lighting optical apparatus using the high pressure discharge lamp as a light source, and an image display system using the lighting optical apparatus.