Abstract: A high pressure discharge lamp includes a vessel made mainly of quartz including a luminous portion and side tube portions extending from both sides of the luminous portion; mercury enclosed in the luminous portion; a metal foil buried in each of the side tube portion; and an electrode rod, one end of which is connected to the metal foil and the other of which is extending to the luminous portion. The electrode rod has a surface area increase structure for increasing a surface area in at least a part of a portion buried in the side tube portion. A sealing portion glass containing at least one metal material selected from the group consisting of metals and metal oxides thereof is provided in a portion of the side tube portion including at least a part of the metal foil, a connection portion between the metal foil and the electrode rod and a part of the surface area increase structure.

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: The high-pressure discharge lamp comprises a lamp vessel (1) in which an anode (4) and a cathode (5) are disposed spaced apart by an electrode distance D of 1-2 mm, the anode (4) having a tip (9) with a blunt end surface S. The area of the end surface S in mm2 and the lamp current I in amperes satisfy a relationship according to which 0.09≦S/I≦0.16, with 3.5≦I≦8.0 amperes. The ionizable filling containing metal halide comprises an amount of mercury between 65-125 mg/cm3. The power range of the lamp is between 200 and 400 watts. The calculated power gap ratio, PGR=P/D, is over 120 W/mm. The lamp is suitable for comparatively high brightness applications and at the same time is comparatively stable and has a comparatively long life.

Abstract: The invention relates to a plasma cell able to be fixed in a vacuum chamber by means of a first flange, having an outer envelope in which a gas under pressure (P′) is added and provided in its upper part with a discharge opening, and electrodes, at least one anode and one cathode, arranged in said envelope and mounted on a second flange, to whose terminals a voltage may be applied, such as to cause ionization of the gas producing the monoatomic species which are to be discharged through the opening. Electrodes can be dismounted and are assembled on a second removable flange. Electrically insulated separation means are provided between cathode and anode(s). A gas inlet opening is provided in the lower part of the envelope.

Abstract: A method and apparatus for preventing the formation of leachable mercury in mercury arc vapor discharge lamps is provided which comprises providing in the lamp structure an effective amount of a silver salt, gold salt, or combination thereof.

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 150W to about 1000W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gas-tight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gas-tight connection.

Abstract: A discharge lamp includes a light transmissive envelope, a fill disposed within the light transmissive envelope, the fill producing a light discharge when excited, and an excitation structure for exciting the fill to produce the light discharge, wherein the fill includes a primary fill constituent of indium halide and a fill additive of a small amount of erbium. A two panel projection system utilizes the indium and erbium discharge lamp, with one panel dedicated to blue light and the other panel sequenced between red and green light.

Abstract: A compact energy lamp having high luminous flux, long life and a very similar color temperature of between 2300° K and 6500° K which includes a vacuum-type discharge vessel filled with mercury and a noble gas. The inside of the discharge vessel is provided with a luminescent layer and is provided with means for maintaining discharge. The luminescent layer includes two phosphors. The first phosphor is a green-emitting gadolinium magnesium borate silicate, activated with cerium and terbium, and the second phosphor is yttrium oxide: Eu3+, which emits in the red spectral region.

Abstract: To provide a lamp device that is a point light source, that withstands high pressure, and that produces high-intensity light, a high-frequency excitation point light source lamp device has been devised having a discharge vessel made of a transparent, non-conductive material and having an expanded part forming a discharge space and with tubules joined to the expanded part; at least one discharge concentrator, that concentrates the electrical field within the discharge space of the expanded part, which is supported in a tubule with an end within the discharge space; and a high-frequency supply external to the lamp for providing excitation energy that excites a discharge of the concentrator.

Abstract: A high pressure mercury lamp comprises a quartz envelope that contains an atmosphere and a pair of arc-discharge electrodes. These are coil-wound tungsten that has been doped to grain-stabilize the tungsten crystalline structure, e.g., with potassium or potassium and alumina. Preferred potassium doping levels of the tungsten material are in the range of 35-75 ppm. A suitable commercial product of alumina and potassium doped tungsten material is Type BSD-Sylvania. The atmosphere generally comprises a rare gas like xenon, to which is added no more than 0.2 mg/mm3 of mercury so as to keep operating pressure under 200 bar (197 atm). But the electrical power applied is sufficient to maintain arc power loadings of at least 150 watts/mm. The resultant wall loading is more than 0.8 watts/mm2, and lamp operating-power levels can be greater than 150 watts.

Abstract: An image projector has a lamp unit 23 having a high-pressure mercury vapor discharge lamp 21 and a parabolic mirror 22. To the high-pressure mercury vapor discharge lamp 21, a driving system 24 applies an alternating voltage such that wandering of a cathode luminescent spot generated in the vicinity of a tip of each of the discharge electrodes of the high-pressure mercury vapor discharge lamp 21 is suppressed, the frequency being within the range of 20-42 kHz. This construction allows to prevent flicker in a projected image of a liquid crystal projector and the like, and therefore achieves high quality in the projected image.

Abstract: A metal halide lamp with high color rendering index, greater then 80, with substantially constant color temperature through life. The lamp arc discharge vessel has a small volume, i.e., less than 1 cc, and contains iodides of sodium, scandium, lithium, dysprosium, and thallium along with mercury, a buffer gas and scandium metal. The addition of the scandium metal does not raise the arc discharge vessel temperature and significantly reduces the color temperature decline during life.

Abstract: A high pressure discharge lamp formed of a polycrystalline alumina ceramic arc tube which includes a discharge zone and end tubes on each side to seal the tube, the discharge zone containing light emitting metal halides and mercury and a starting gas of argon or xenon. The end tubes have longitudinally extending openings therein. The end tubes have proximal ends adjacent the arc tube and distal ends furthermost removed from the arc tube. An electrical feed through is disposed in each of the end tubes which includes a thin metal foil section disposed between two electrically conductive lead in wire wires. One of the lead in wire wires has an electrode disposed thereon. A sealing compound seals the electrical feed through to the alumina of the end tubes at the outer ends thereof.

Abstract: A super-high pressure mercury lamp with an internal pressure during operation of one hundred and some dozen atm, which has a new arrangement in which in the hermetically sealed portions neither damage the lamp nor shortening its operating service life is achieved, in a high pressure mercury lamp in which a silica glass discharge vessel contains a pair of spaced apart, opposed electrodes and which is filled with a rare gas and with mercury in an amount of greater than or equal to 0.16 mg/mm3, and in which the wall load is greater than or equal to 0.

Abstract: The amount of a metal halide to be enclosed in a generally ellipsoidal discharge space 24 within a discharge vessel 20a is set in the range 0.006-0.01 mg per unit volume (&mgr;l) of the discharge space 24. If the amount is less than 0.01 mg/&mgr;l, the deposit of metal halide 32 on the inner surface of the discharge space 20a in its lowest position midway between the narrow end portions thereof will not cause “shunting” of the arc between the electrodes 26A, 26B. As a result, the arc is effectively prevented from fizzling out after the metal halide lamp is switched on. To ensure that the metal halide lamp produces the intended luminous flux and color of light, the amount of the metal halide to be enclosed in the discharge space 24 should not be lower than 0.006 mg/&mgr;l.

Abstract: An apparatus and method for improving the performance of a lamp includes an envelope (10) enclosing an amalgam or dose (24) of mercury housed in a container (20). The container maintains mercury vapor equilibrium during lamp operation and prevents mercury diffusion during lamp off periods. The container has an opening (24) therein selectively adjustable between an open position and a closed position. A bimetal member (30) is associated with the opening of the container and provides the actuating means by which the container opens and closes. A stopping member (32), such as a valve or ball bearing, is attached to the bimetal member and extends into the container. When the lamp is in operation, the bimetal member is heated causing it to deflect. The deflection moves the stopping member from the container opening and enables the amalgam to maintain mercury vapor pressure equilibrium.

Abstract: A high pressure mercury lamp comprises a quartz envelope that contains an atmosphere and a pair of arc-discharge electrodes. These are coil-wound tungsten that has been doped to grain-stabilize the tungsten crystalline structure, e.g., with potassium or potassium and alumina. Preferred potassium doping levels of the tungsten material are in the range of 35-75 ppm. A suitable commercial product of alumina and potassium doped tungsten material is Type BSD-Sylvania. The atmosphere generally comprises a rare gas like xenon, to which is added no more than 0.2 mg/mm3 of mercury so as to keep operating pressure under 200 bar (197 atm). But the electrical power applied is sufficient to maintain arc power loadings of at least 150 watts/mm. The resultant wall loading is more than 0.8 watts/mm2, and lamp operating-power levels can be greater than 150 watts.

Abstract: An electric lamp has an envelope with an inner surface and two electrodes located at each end of the envelope. The electrodes transfer electric power to generate ultraviolet radiation in the envelope which is filled with mercury and a charge sustaining gas. The inner surface of the envelope is pre-coated with an aluminum oxide layer to reflect ultraviolet radiation back into the envelope. A phosphor layer is formed over the aluminum oxide to convert the ultraviolet radiation to visible light. The phosphor layer is a mixture of three phosphors, namely, blue luminescing Blue Halophosphor (BH), red-luminescing Cerium Gadolinium Magnesium Borate (CBTM), and 3000K-luminescing Calcium Halophosphor, also referred to as Warm White (WW).

Abstract: High-pressure discharge lamp having two electrodes inside a discharge vessel which is filled with mercury and/or noble gas, the electrode comprising a shank and a head which is fitted thereto, at least the head of an electrode being at least partially covered with a rhenium-containing layer

Abstract: In the luminescent screen of a flourescent lamp an organic europium compound is incorporated for converting mercury radiation between 350 nm and 450 nm into red light. The organic europium compound is diluted in an organic polymer. When the fluorescent lamp is dimmed its colour point shifts into the red similar to incandescent lamps and not into the blue.

Abstract: A metal-halide lamp including a discharge vessel with a ceramic wall, the discharge vessel enclosing a discharge space which contains an ionizable filling which filling contains halides of Na and Tl in addition to Hg. The ionizable filling also contains Ca and is free from rare-earth halides.

Abstract: A high-pressure metal halide discharge lamp having a power rating of at most 100 W is provided with a discharge vessel having a translucent ceramic wall with a thickness d of at least 1.2 mm. In the discharge space enclosed thereby, two electrodes are arranged with their electrode tips at a mutual interspacing EA. The discharge vessel contains an ionizable filling comprising at least Na and a halide.

Abstract: A discharge tube is provided inside an outer tube. At least a pair of electrodes is arranged inside the discharge tube, and at least mercury is sealed into the discharge tube. The electrode includes an electrode pin and a metal pipe that surrounds the electrode pin. Because a contact area of the electrode pin and the inner surface of the metal pipe is sufficiently maintained in a stable manner, a tip temperature of the electrode pin can be lowered sufficiently without a variation. As a result, it is possible to obtain a high pressure discharge lamp that has excellent lifetime characteristics and can considerably reduce the variation of the lifetime characteristics between lamps.

Abstract: A direct-current-lighting, ultra-high-pressure mercury lamp that is resistant to loss of transparency even after being lit for a long period, and has little wastage of electrodes and particularly the cathode tip, and also exhibits a long service life. The direct-current ultra-high-pressure mercury lamp includes a cathode and anode of tungsten facing each other within a quartz glass tube, and a cathode coil which is wrapped around the cathode. The cathode is composed of tungsten doped with potassium, and the anode is composed of tungsten having a purity of at least 99.99%. The cathode coil can also be advantageously formed of tungsten having a purity of at least 99.99%.

Abstract: The invention relates to a low-pressure gas discharge lamp which includes at least one discharge vessel and at least two capacitive coupling-in structures and operates at an operating frequency f. In order to achieve a better efficiency in combination with a small structural volume, a high luminous flux, a low operating voltage, a low electromagnetic emission, a high resistance against switching transients and a long service life for the low-pressure gas discharge lamp, it is proposed to form each capacitive coupling-in structure from at least one dielectric having a thickness d and a dielectric constant &egr;, each dielectric being subject to the condition d/(f.&egr;)<10−8 cm.s. A substantially larger amount of light can thus be generated per lamp length (lumen/cm).

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 metal halide lamp includes a pair of electrodes with a spacing of 0.5 to 1.5 mm therebetween, an envelope enclosing the pair of electrodes, and at least one metal halide, other than a mercury halide, that is encapsulated in the envelope in an amount of from 0.04 to 0.3 mg/cc, wherein the metal halide lamp operates in a power range from 75 to 270 watts per millimeter across the spacing between the pair of electrodes.

Abstract: The invention relates to a high pressure mercury lamp which is operated with an internal pressure at least equal to one hundred and some dozen atm and in which the thermal load and gas convection are considered. A fused silica glass discharge vessel is filled with mercury in an amount at least equal to 0.15 mg/mm3 and rare gas. The length of the electrode which projects into the discharge vessel and which is positioned at the top is greater than the length of the electrode which projects into the discharge vessel and which is positioned at the bottom. Where the lamp wattage is W (W) and the maximum value of the inside diameter in the direction perpendicular to the axis which extends between the pair of electrodes within the discharge vessel is D (mm), the following conditions are met: 0.35×(W)½≦L1≦0.69×(W)½ L2≦0.76×(W){fraction (1/2.64)} and at the same time (2.50)e0.0022W≦D≦(5.0)e0.0034W.

Abstract: A high pressure mercury lamp in which formation and spreading of milky opacification in the fused silica glass forming the discharge vessel can be advantageously prevented, and thus a rapid decrease of screen illuminance prevented, when it is used as the light source of a liquid crystal projector and the like by, in a high pressure mercury lamp in which a discharge vessel of fused silica glass contains a pair of opposed tungsten electrodes, mercury in an amount that is at least equal to 0.16 mg/mm3, rare gas, and at least one halogen, and in which the wall load is at least equal to 0.8 W/mm2, the amount of mercury added being fixed in a range from 2×10−4 to 7×10−3 &mgr;mole/mm3, and/or the at least one halogen being in the form of a carbonless halogen compound, and/or the average OH radical concentration in an area of a wall of the discharge vessel at a depth of 0.2 mm from an inner surface of the wall of the discharge vessel being at most 20 ppm.

Abstract: In a microwave-excited discharge lamp of the present invention, a rare gas 2, a mercury halide 3 as a buffer material, and a metal halide 4 as a luminous material are sealed within an discharge tube 1. This achieves a microwave-excited discharge lamp having excellent stability and a variety of light colors.

Abstract: The formation of leachable mercury upon disposal or during TCLP testing of mercury vapor discharge lamps is substantially prevented by adding soluble copper salts which are capable of being reduced to elemental copper which deposits on aluminum and other metal surfaces thereby inhibiting formation of oxidized forms of mercury by chemical reaction or amalgamation.

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 &mgr;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.

Abstract: An improvement in a mercury vapor discharge lamp having an envelope of light-transmitting vitreous material containing an inert starting gas and a quantity of elemental mercury at least in part convertible to soluble mercury, and first and second electrodes located within the envelope for an arc discharge therebetween. The improvement comprises an effective amount of a soluble copper-containing compound in combination with an effective amount of a selected one of a group of materials consisting of a soluble chloride, a soluble bromide, a soluble nonmetallic iron-containing compound, and a soluble nonmetallic manganese-containing compound. The copper-containing compound and the material in combination, when the lamp is pulverized into granules and subjected to a suitable aqueous acid solution, produce a concentration of extracted mercury of less than 0.2 mg/l of the aqueous solution.

Abstract: A metal halide lamp comprises a pair of electrodes and a discharge vessel filled with at least one metal halide comprising at least one rare earth metal halide, halogen in excess of the stoichiometry of the metal halide(s), mercury, and a rare gas. The amount of the mercury is between 7.7 mg/cc and 9.9 mg/cc, the excess halogen is 25-100% (in terms of atoms) of the halogen included in the metal halide(s), and the rated tube power for 200V rated tube voltage is 2000 W-3000 W.

Abstract: A high pressure mercury lamp with an extremely high mercury vapor pressure and extremely high tube wall load in which the arc during operation is advantageously stabilized is achieved in a high pressure mercury lamp having a discharge vessel of fused silica glass which contains a pair of opposed tungsten electrodes, mercury in an amount at least equal to 0.16 mg/mm.sup.3 and a rare gas, and in which the discharge tube has a tube wall load at least equal to 0.8 W/mm.sup.2, by at least one metal halide with a metal having an ionization potential that is at most 0.87 times as high as the mercury ionization potential being added to the discharge tube in a range of from 2.times.10.sup.-4 to 7.times.10.sup.-2 .mu.mole/mm.sup.3.

Abstract: The high-pressure sodium discharge lamp of low power described here is chcterized by a very high xenon cold filling pressure of at least 1 bar. The pressure ratio to the sodium operating pressures lies between 10 and 30. Luminous efficacies of approximately 100 lm/W and more can be obtained with a lamp power of 50 to 100 W.

Abstract: The metal-halide direct-current arc discharge lamp has a fill system which as cadmium and/or zinc as components of the central fill in addition to an ignition gas, mercury, and a halogen. Preferably, the fill is retained in a bulb (10) which is asymmetrical with respect to a central plane (1) perpendicular to a longitudinal axis (2) of the lamp. The lamp is particularly suitable for use in combination with an optical projection system (R), especially when operating in horizontal position.

Abstract: Metal halide lamp radiates light with a color temperature T.sub.c of between 3900 K and 4200 K and with a general color rendering index R.sub.a .gtoreq.90. The ionizable metal halide filling comprises between 30 and 50 mole % CaI.sub.2. The lamp has a limited crest factor, and accordingly a long useful life.

Abstract: In a mercury vapor discharge lamp having an envelope of light-transmitting vitreous material and containing an inert gas and a quantity of elemental mercury at least partially convertible to soluble mercury, and first and second electrodes disposed within the envelope for establishing an arc discharge therebetween, an improvement comprising an effective amount of a nonmetallic copper-containing compound disposed in the lamp which, when the lamp is pulverized to granules and subjected to a suitable aqueous acid solution, dissolves in the aqueous acid solution, resulting in a concentration of extracted mercury less than 0.2 mg per liter of solution; and a method for reducing the amount of mercury extracted from a mercury vapor discharge lamp when the lamp is pulverized to granules and subjected to a suitable aqueous acid solution, such that the resulting concentration of extracted mercury is less than 0.

Abstract: A metal halide lamp in which the radiant efficiency is not adversely affected, in which outstanding color reproducibility is obtained, and which is suitable for a light source of an OHP or a direct projector is achieved, according to the invention, by the fact that, within an arc tube provided with a pair of electrodes, together with mercury and a starting rare gas, halides of dysprosium (Dy), yttrium (Y) and cesium (Cs) are encapsulated with the molar ratio of the encapsulated metals Dy to Y is being fixed in the range of 0.3.ltoreq.Dy/Y.ltoreq.1.0. In this way the green portion to which there is a sensitive visual reaction is reduced, the blue portion increased, and thus the color reproducibility is increased.

Abstract: A high performance miniature projection lamp which includes a glass envelope having a pair of opposite neck portions each with a coaxial central opening having a reduced section and an hermetically sealed central chamber having a volume of about 130 mm.sup.3 which contains a fill. The fill includes an argon pressure at room temperature at a range of about 0.5 atmospheres to about 2.0 atmospheres and mercury in an amount in the range of about 5 mg to about 15 mg, and a mixture of metal halide material in an amount from about 50 up to 1000 micrograms. A pair of axially aligned electrodes are positioned at opposite neck portions and separated form each other by a predetermined distance. The electrodes each have a shank portion which each having a coil wrapped around its end.

Abstract: A metal-halide high-pressure discharge lamp (1) with a discharge vessel (2) nd two electrodes (4, 5) has inside discharge vessel (2) an ionizable filling, which contains yttrium (Y) in addition to inert gas, mercury, halogen, thallium (Tl), hafnium (Hf), whereby hafnium can be replaced wholly or partially by zirconium (Zr), dysprosium (Dy) and/or gadolinium (Gd) as well as, optionally, cesium (Cs). Preferably, the previously conventional quantity of the rare-earth metal is partially replaced by a molar equivalent quantity of yttrium. With this filling system, a relatively small tendency toward devitrification is obtained even with high specific arc powers of more than 120 W per mm of arc length or with high wall loads. Thus, the filling quantity of cesium can be clearly reduced relative to a comparable filling without yttrium, whereby an increase in the light flux and particularly in the brightness can be achieved.

Abstract: A novel type of glass having a low sodium content (<0.1 wt. % Na.sub.2 O), which can be used as a bulb glass (10) for "TL" lamps and for compact fluorescent lamps. Said glass is free of the toxic and/or corrosive components PbO, F, As.sub.2 0.sub.3 and Sb.sub.2 0.sub.3. Apart from favorable properties as regards phosphor poisoning and mercury absorption, resulting in a favorable maintenance of the lamp, said glass is characterized by a wide working range W.R. (=T.sub.work -T.sub.soft), so that glass tubing can be readily made of said glass. By virtue of the low liquidus temperature (T.sub.liq), the glass can be drawn into glass tubing which is free of crystals.

Abstract: A lamp for providing visible radiation includes tellurium or a tellurium compound in the fill. This substance is present in an amount such that when the fill is excited with sufficient power, substantially all of the radiation resulting from tellurium is emitted at wavelengths exceeding 400 nm. When tellurium is added to a sulfur or selenium based lamp for emitting visible radition, the spectrum is shifted towards the red region.

Abstract: A high pressure mercury ultraviolet lamp with high dimensional accuracy in which the emitter material during lamp operation is prevented from spraying and being deposited on the wall of the discharge vessel and the UV radiation transmission factor is prevented from being reduced is achieved by the fact that at least one of a group of halides which consists of halides of yttrium, lanthanum, cerium, dysprosium, gadolinium and thorium and at least one of a group of halides which consists of halides of alkali metal elements are filled at a filling ratio in the range from 1:4 to 1:20 to one another as a molar fraction. This also yields the same action as the application of emitter material to the upholding parts of the electrodes. Furthermore, high dimensional accuracy can be ensured by the measure by which the discharge vessel is made of a translucent ceramic, such as YAG.

Abstract: A low pressure mercury vapor fluorescent lamp includes a lamp vessel having a mercury protective coating on the inner surface of the lamp envelope and a halophosphate phosphor layer. The lamp has a discharge sustaining filling including mercury and a rare gas. The level of mercury is selected such that the lamp has a standard average lamp life of about 20,000 hours while passing the Environmental Protection Agency's Toxicity Characteristic Leachate Procedure (TCLP) test and the State of California's Waste Extraction Test (WET).

Abstract: High-pressure sodium vapor lamp with high color rendering including, in an arc tube of a light transmitting material formed in a substantially cylindrical shape sealed hermetically at both axial ends, a pair of electrodes disposed internally at both axial ends of the tube and xenon gas of at least 2.5.times.10.sup.4 (Pa) sealed in the tube together with sodium vapor, is so constituted that a lamp voltage upon lighting of the lamp and represented by V (V as a unit), lamp power represented by W (watt), internal diameter of the arc tube represented by .phi. (mm) and distance between the pair of electrodes represented by d (mm) will satisfy the following formulas:2.0.ltoreq.V/d.ltoreq.2.7 (1)and20.ltoreq.W/.phi..ltoreq.

Abstract: A metal-halide discharge lamp for photo-optical purposes contains an ionisable fill, comprising mercury, at least one noble gas, at least one halogen, aluminum (Al) and indium (In) as well as gallium (Ga) in addition. By the addition of Ga, typically in the range between 0.02 mg/cm.sup.3 and 1 mg/cm.sup.3, a reduction in the starting voltage is attained, while maintaining an Ra>85 at color temperatures typically between 5000 K and 11000 K.

Abstract: A metal halide lamp in which no color shadowing occurs on the light acceptance surface and which at the same time emits with sufficient brightness is achieved according to the invention by encapsulating lutetium halide and one or more of the metal halides from groups A, B and C in an arc tube of a metal halide lamp together with a mercury halide:Group A: dysprosium halide, holmium halide, erbium halide, thulium halideGroup B: cerium halide, praseodymium halide, neodymium halideGroup C: cesium halide.

Abstract: A compact fluorescent lamp having improved warm-up characteristics is provided. The lamp includes a sealed glass envelope formed from U-shaped tubes each having a pair of substantially parallel leg sections closed at one end and a transversely extending bridging section joining the other end of the leg sections. Adjacent leg sections of adjacent tubes are joined by connecting conduits which complete a convoluted and elongate discharge path between a pair of electrodes. A main amalgam located within in a sealed stem at a closed end of an interior leg section for controlling mercury vapor pressure during a discharge period except for a starting period thereof. Auxiliary amalgams are attached to electrode support structures extending from the closed ends of the exterior leg sections for emitting mercury vapor during the starting period.