Abstract: An apparatus and method for achieving desired spectral emission characteristics in plasma lamps is disclosed. The apparatus and method use multi-layer thin film optical interference coatings to selectively reflect a portion of the light such that it can be absorbed in the plasma. The multi-layer thin film coating is applied to any surface of the lamp, which substantially surrounds the plasma. The number and thickness of the layers in the coating are selected to ensure that a significant portion of the selected light emitted from the plasma is reflected by the coating and absorbed by the plasma. The properties of the coating, reflectance, transmittance and absorption are determined as a function of plasma and lamp characteristics.

Abstract: A discharge lamp includes a luminous bulb in which a luminous material is enclosed and a pair of electrodes are opposed to each other in the luminous bulb; and a pair of sealing portions for sealing a pair of metal foils electrically connected to the pair of electrodes, respectively. The pair of metal foils have a pair of external leads on the side opposite to the side electrically connected to the pair of electrodes, respectively. At least one of the pair of external leads is joined to a lead wire for external connection that is to be electrically connected to an external circuit by the plastic flow of a caulking member.

Abstract: A short arc discharge lamp in which the wear on the cathode tip area is suppressed, in which moreover in the arc discharge only little polarization occurs and flickering in the arc discharge occurs only rarely, and thus, a reduction of illuminance or flickering on the light irradiation surface of a device or the like in which the short arc discharge lamp has been installed is prevented. Furthermore, a short arc discharge lamp is devised in which the radiance is hardly impaired and stable light emission is enabled, even when it is operated over a long time. To obtain these advantages, a short arc discharge lamp which has an essentially spherical arc tube in which there are a cathode and an anode opposite one another, is provided with a cathode in which the cathode tip area has a crystal structure formed of several crystals which, as compared to the crystal size in the back end area of the cathode, are coarsened, and in which the emissive material contained in the cathode tip area is less than or equal to 0.

Abstract: The discharge volume has an internal length L and a maximum diameter D at its center, with the discharge vessel being equipped with a light-emitting filling and with two electrodes at the ends of the discharge vessel, with the lamp being operated by means of high frequency such that an acoustic longitudinal mode is formed, with the wall thickness varying along the length L of the discharge volume, with the wall thickness S being thinnest at the center of the discharge vessel, while it is at least 1.2 S at an optimum point Popt, with the optimum point in each case being at a distance of {fraction (7/24)} L from the end of the discharge vessel.

Abstract: A high-pressure discharge lamp which includes a translucent ceramic discharge vessel having a swollen portion defining a discharge space and a pair of cylindrical portions formed in and communicating with the swollen portion and extending from the swollen portion in the opposite directions with each other. The high-pressure discharge lamp also includes metal tubes each having a outer diameter D and fit with its one end on the cylindrical portion, a pair of fusible metal plugs each plugged in the outer end of the metal tube, the fusible metal plug sealing the discharge vessel by being fused to the inner surface of the metal tube for a specified height T from the outer end of the metal plug, a pair of electrode systems each supported its one end to the fusible metal plug and facing the interior of swollen portion with its other end, and ionizing filling filled in the discharge vessel The ratio T/D of the height T concerning the fusible metal plug and the diameter D satisfies the following equation 0.

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: The present invention is a short arc type ultra-high pressure discharge lamp in which a pair of electrodes 3 are disposed inside an arc tube 1 that comprises quartz glass, seal portions 2 are formed that comprise quartz glass and extend to both sides of the arc tube 1, and at least 0.15 mg/mm3 of mercury is filled into the arc tube 1, wherein a metal foil 4 is embedded in each of the seal portions 2, and metal granular lumps 6 are protrusively provided on surfaces of each metal foil 4.

Abstract: A short arc lamp is optimized for improved thermal performance characteristics. The short arc lamp includes a ceramic body having a concave reflective surface formed in an upper end thereof, a base adapted to receive the base end of the ceramic body in abutting relation, and a window frame assembly positioned in abutting concentric relation with the upper end of the ceramic body. In particular, the ceramic body is formed from beryllia (beryllium oxide) which has superior thermal transfer characteristics. The lamp is further provided with a specialized coating which help keep infra-red (IR) light energy from escaping from the lamp. In one instance, the coating is an IR reflective coating placed on the window of the lamp to reflect IR light energy back into the lamp where it can be conducted outwardly through the beryllium oxide body and base.

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 high pressure discharge lamp includes a quartz glass bulb having an expanded portion and sealing portions, conductive elements, and a pair of electrodes. The conductive elements are sealed at the sealing portions of the quartz glass bulb. Each electrode is disposed so as to be opposite the other and connected to one conductive element. The lamp is characterized in that Dp (the distance between an end of each electrode) is in the range between 1.0 and 1.6 mm, S (the longest length of the expanded portion in the direction of a discharge path)=e×Di (wherein 0.8<e<1.0), Di (the largest inside diameter of the expanded portion transverse to the discharge path)=g×Dp (wherein 4<g<8 ), and Do (the largest outside diameter of the expanded portion transverse to the discharge path)<Di+4 mm.

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 short-arc high pressure discharge lamp with a shorter distance between electrodes than a conventional lamp that realizes a long life of at least 3000 hours and suppresses the arc jump phenomenon is disclosed. In the high pressure discharge lamp, an electrode tip 124 is transformed into a semi-sphere by fusing and processing an electrode rod 122 and a coil 123 wound around an end of the electrode rod 122. A thickness “de” and a diameter “&phgr;e” of the semi-sphere are each set in a range predetermined in correspondence with a power input (W) of the short-arc high pressure discharge lamp.

Abstract: A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers.

Abstract: A high pressure discharge lamp includes: a quartz glass bulb having an expanded portion and sealing portions; conductive elements, and a pair of electrodes. The conductive elements are airtightly sealed at the sealing portions of the quartz glass bulb. Each electrode of the pair of electrodes is disposed so as to be opposite the other and each electrode is connected to one of the conductive elements. An angle &thgr;1 between a tangent along the inner surface of the expanded portion at a position 0.5 mm away from an origin of one of the sealing portions along the length direction of each electrode and the direction of the length of each electrode is at least about 40°.

Abstract: A discharge bulb including: an arc tube having a light emitting portion constructed in a manner that a light emitting substance is enclosed therein by pinch-sealing the arc tube, and discharge electrodes are oppositely arranged therein; and a shroud glass tube hermetically sealing and covering the arc tube, so as to form a space between the shroud glass tube and the arc tube. And a water content or pressure of gas enclosed in the sealed space is specified.

Abstract: A high-intensity arc lamp comprises a glass envelope with a pressurized gas atmosphere. A cathode and an anode structure are disposed within. A pointed tip of the cathode is juxtaposed by a central hole in a face of the anode and a small gap between them. Such central hole is vented away from the arc down inside the anode structure. During operation, heat from the arc at the entrance to the central hole drives a wind of xenon gas down through such vents in the anode structure.

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 mercury-free high pressure sodium vapor lamp is dosed with sodium, xenon and zinc as an elemental metal additive. The addition of the metal additive prevents an undesirable low-voltage operating mode of the sodium-xenon discharge associated with a mercury-free HPS lamp, which otherwise occurs when sodium is no longer available to participate in the arc discharge.

Abstract: A discharge lamp of the short arc type having a trigger wire which can be installed in a state which is suitable for a directional capacity of the electrode regardless of what type of base the lamp has is achieved by the trigger wire on the outside surface of an arc tube having the following characteristic:

Abstract: A high intensity discharge lamp constructed with a tubular envelope composed of single crystal sapphire in which a continuous non-flash arc is created across multiple electrodes to generate a radiation emitting plasma. The lamp may operate at higher temperatures and pressures than conventional high intensity discharge lamps to produce greater luminance at any given power input. The lamp fill may be chosen from a wide range of gases and additives to produce the desired light spectra in the range from ultraviolet through near infra-red. The effective life of the lamp may be significantly extended. The lamp may be utilized particular benefits in image projection where a small powerful light source is required to optically match increasingly smaller image generation devices. In particular, the lamp may maintain a pre-selected correlated color temperature from 4,000 to 9,000° K over the life of the lamp.

Abstract: A high pressure, lamp may be made in a pressure vessel by using an induction coil to melt an edge portion of a sealing wafer pressed against the circumference of an opening in the body of the lamp envelope. The pressure vessel and the lamp envelope are filled with desired fill materials. Induction heating is carried out by the induction coil and induction receiver that presses against the wafer, the lamp envelope or both to hold the melting piece or pieces in contact. The induction receiver may be fused to the lamp body forming a functional part of the overall lamp structure. The preferred resulting lamp includes a bonded metal piece that can be conveniently used for electrical or mechanical coupling or positioning of the lamp with respect to a base.

Abstract: Mercury-free metal halide lamp with a warm white luminous color, the fill of which comprises the following components: an inert gas which acts as a buffer gas; a first group of metal halides (MH), the boiling point of which is above 1000° C. (preferably above 1150° C.), the first group comprising at least Dy and Ca used simultaneously as metals, and the molar ratio of the two metal halides Ca-MH:Dy-MH being between 0.1 and 10; these are components with a low volatility which are present in saturated form; a second group of metal halides, the boiling point of which is below 1000° C. (preferably below 900° C.

Abstract: A method for replacing non-HID landing and taxi lights in an aircraft wing housing that originally was designed to contain the non-HID landing and taxi lights in side-by-side relationship, is accomplished by installing an HID landing light, an HID taxi light and a power control device in the space originally designed to accommodate the non-HID landing and taxi lights. A single ballast provides power to both lamps which each comprise a housing, an HID bulb supported within the housing, a lens for passage of light from the HID bulb out of the housing, a primary reflector surface disposed behind the HID bulb, and a secondary reflector surface disposed in front of the bulb for reflecting light from the bulb back through the bulb for further forward reflection from the primary reflector surface through the lens. The lens may have a lenticular array including a plurality of cylindrical surface elements for spreading the light beam emitted by the lamp.

Abstract: In the case of a sodium high-pressure lamp having a ceramic, tubular discharge vessel (1), an electrically conducting starting aid is fitted outside on the discharge vessel. Said aid comprises an axially parallel longitudinal strip (4) of prescribed width B to which a partial circle (6) surrounding the discharge vessel is attached approximately at the level of each electrode (2).

Abstract: The invention relates to a metal halide lamp having an outer bulb containing besides a discharge vessel a UV enhancer (UVE). The UVE has a ceramic wall and, according to the invention, is provided with a pair of internal electrodes. Preferably, at least one of the electrodes has an electrode winding with emitter.

Abstract: An electrode is fixed hermetically to one end of a conductive tube with a titanium solder and the other end of the conductive tube is closed. Thus, the conductive tube has an airtight structure and an argon gas is sealed therein. This conductive tube is fixed hermetically to a transparent alumina tube using a sealer. Further, sodium amalgam is provided at an inner end of the transparent alumina tube. The conductive tube is prevented from being deformed and sodium of a luminescent material is positioned inside the discharge tube, thus providing a high-pressure sodium lamp in which a lighting color and lamp voltage are prevented from varying during the lamp lifetime, the time required for reaching a stable lighting state after turning on the lamp is short, and the variation in lamp voltage is suppressed.

Abstract: An electrodeless discharge lamp and an electrodeless discharge lamp apparatus which prevent the devitrification are provided, where the devitrification occurs due to the use of, as a luminescent substance, a metal halide, particularly a compound made up of a group IIIB metal and a halogen. The inventors recognize the cause of the devitrification as follows: atoms of the metal are dissociated from the luminescent substance and precipitate on the surface of the arc tube wall to melt it as the luminescent substance is excited and emits light. Based on this recognition, a substance is added to the interior of the arc tube to prevent the melting of the arc tube wall and extend the life of the lamp. More specifically, the added substance is another metal halide which contains a halogen, but the valence of the metal of the added metal halide is larger than that of the luminescent-substance metal halide.

Abstract: A method applicable in the field of electric light source technology for thoroughly eliminating “Electrophoresis effects” of a DC fluorescent lamp tube is used for the DC fluorescent lamp. It is characterized by that this method involves changing the relative positions and structures of the cathode and anode of the lamp tube solely and/or simultaneously, coating a euphotic infrared film on either inside or outside wall at the cathode end of the lamp tube, placing mercury-absorbed material into the vent-pipe at the anode end, assembling a heat-preservation sealed encloser with high transparency under the lampshade and charging krypton gas and xenon gas accounting for 20-60% of the total volume of inert gases with volumeter. The method can thoroughly eliminate “Electrophoresis effects” of DC fluorescent lamp tube and has solved the extremely difficult problem in the world, and prolonged the working life of the lamp tube, with the advantages of simple structure and low cost.

Abstract: Plasma display panels of the prior art are prone to cross talk leading to unstable image. The present invention provides a gas discharge panel comprising a first panel substrate 104 having first electrodes 24, a second panel substrate 108 having second electrodes 23 opposing the first panel substrate 104, a sealing portion provided between peripheries of the two substrates for forming a gas discharge space 112 between the first and second panel substrates 104, 108 and division walls 30 provided on the second panel substrate 108 for dividing the gas discharge space 112, wherein ridges of the division walls 30 are bonded onto the inner surface of the first panel substrate 104 by a frit glass 31.

Abstract: A low-cost ceramic arc lamp comprises an optical coating on a sapphire window, a window shell flange, and a body sleeve. A gas-fill tubulation attaches to the side of the body sleeve and permits a charge of xenon gas to be injected during manufacture. This contrasts with the prior art where the xenon gas is introduced through the anode base. A single-piece strut assembly is used that is compatible with mass-production techniques. The single-piece strut assembly supports and suspends a cathode inside an elliptical reflector. An anode flange replaces a more conventional shell, copper anode base, and base support ring. A tungsten anode completes the lamp. All of these parts are brazed together in an assembly process that is far less complex than the prior art.

Abstract: An arc discharge lamp includes a light transmissive envelope (3), two electrodes (1, 2) disposed at least partially inside the light transmissive envelope, and a plasma forming fill which includes selenium when excited disposed inside the light transmissive envelope (3). The exterior surfaces of the part of the electrodes (1, 2) disposed inside the light transmissive envelope (3) comprise an electrode material selected from the group of molybdenum and molybdenum compounds.

Abstract: A high pressure discharge lamp having a pair of electrodes with a space of 0.5 mm to 2.0 mm inclusive between them and disposed in an arc tube. An electrical discharge takes place between the electrodes. Each of the electrodes has an electrode rod and a head that is provided at the discharge side end of the electrode rod and having a larger diameter than the electrode rod. A surface of the head being opposite to the other electrode is convexly curved and a protruding part is formed in the vicinity of the center portion of the end of the head.

Abstract: A ceramic lamp in which the hermetically sealing bodies of electrically conductive cermet are sealed to hermetically sealed tube portions of the lamp vessel with a sealing material is arranged and provided with material components designed to give the hermetically sealing portions a high reliability.

Abstract: The high-pressure discharge lamp of the present invention comprises a light-transmitting ceramic discharge vessel (1), power-supplying conductors (2), a pair of electrodes (3, 3), seals (4) made of ceramic-sealing compound, and a discharge medium. The discharge vessel has an inner volume of 0.1 cc or less. The distal ends of the electrodes are arranged so as to maintain a distance d1 of 1.0 mm or more from the inner surface of the light-transmitting vessel on a plane which is perpendicular to the axis of the light-transmitting vessel and includes the distal ends of the electrodes.

Abstract: A xenon arc lamp is provided with an improved cathode support. The improvements reduce the number of assembly procedures and parts needed to produce an arc lamp. Such reduces the overall cost of manufacturing. The cathode suspension system is made by starting with a single piece of sheet Kovar material that is formed into a cup. Pieces are cut from the bottom of the cup such that three webs connect the outside ring to the center. The three webs each have a flap that is then folded back 90° to form a rigid strut arm. A tungsten cathode electrode is brazed at the center and apex of the three struts with a sleeve that helps bridge the fillet area.

Abstract: A long-life, environmentally disposable high pressure sodium lamp comprising: an arc tube capable of withstanding internal wall temperatures of 1250 to 1300° C. and having electrodes sealed therein and being designed for operation at a given wattage; a discharge space within the arc tube and an arc generating and sustaining medium within the discharge space, the medium being mercury-free and containing sodium in an amount of about 0.02 mg to 0.06 mg/watt of designed operation, and xenon at a pressure of 100 to 200 Torr; mounting means supporting the arc tube within a glass outer envelope, the glass outer envelope being lead-free and arsenic-free; and an electrically conductive base closing the outer envelope and containing lead-in wires affixed to the electrodes, the lead-in wires being attached to the base by welding.

Abstract: The present invention provides a mercury-free metal halide lamp with an increased lamp operating voltage and prolonged lamp life without enclosing mercury or excessively increasing an inner pressure of an arc tube. A lamp in accordance with the present invention contains, as a content of a fill material 202, 0.04 mg of ScI3, 0.21 mg of NaI, 7 atm of Xe at room temperature, and 0.1 mg of YI3, which is an iodide of Y, Y having an ionization potential as a simple substance being 5 to 10 eV and a vapor pressure at a temperature of lamp operation being 10−5 or higher.

Abstract: A light source apparatus includes a spherical optical member formed with a transparent material and having an outer wall and an inner wall, and a light emitting part having a light emission center located within a space surrounded with the inner wall of the optical member, wherein the light emission center deviates from at least one of a center of the outer wall and a center of the inner wall, and the optical member is arranged to deflect in a predetermined direction a light flux emitted from the light emission center to be led to a reflector, so that the efficiency of use of light can be enhanced.

Abstract: Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

Abstract: An improved arc lamp with a ceramic body, an anode supported by a base, and a cathode suspended by a strut system opposite to the anode, and having an inside volume filled with xenon gas. The improvements include a groove in the ceramic body such that an angled area is presented to a head area of the anode that reduces heat coupling by radiation. A neck in the anode provides for a thermal choking such that a head portion of the anode will elevate in temperature during operation. A cavity is relieved in the base and all around the anode to provide a fixed means for managing the temperature of a head portion of the anode during operation. A stem portion of the cathode has a reduced diameter for attachment to the strut system and this provides reduced optical blockage. A base for the anode has a longer length than its diameter for improved heat transfer to an anode heatsink.

Abstract: A high pressure discharge lamp in which, in the silica glass which comprises the hermetically sealed portion on the cathode side, fractures originating from the contact area with the cathode are prevented from propagating as in a high pressure discharge lamp of the direct current operating type which has: a discharge vessel of silica glass in which opposite sides an arc tube portion are each joined to a respective hermetically sealed portion; a metal foil is located in each of the hermetically sealed portions; a supply lead is attached in each the hermetically sealed portion with an inner end of the supply lead being connected to a respective one of the metal foils and an outer end projecting outwardly from the discharge vessel; an anode and a cathode are each attached in one of the hermetically sealed portions and have a base which is connected to one of the metal foils and a tip which projects into the arc tube portion; by the outer surface of the cathode-side hermetically sealed portion being surrounded by

Abstract: A lamp bulb for a high pressure discharge lamp that includes a pair of opposing electrodes that projects a predetermined distance into a discharge chamber, molybdenum foils, lead wires, and a bulb, the lamp bulb includes a discharge chamber filled with a metal halide and a rare gas, the discharge chamber including at least a concave surface curving inwardly with respect to a Z-axis of the automotive high pressure discharge lamp, a discharge chamber portion surrounding the discharge chamber, including at least a convex surface curving outwardly along the Z-axis of the discharge lamp, tapered portions tapering towards the discharge chamber, sealed ends in which are located the molybdenum foils, the electrodes, and the lead wires, and sealed portions substantially free from substantial curvature change, the sealed portions being located between the discharge chamber and the sealed ends.

Abstract: A high pressure lamp bulb adapted to simultaneously emit distinct emission spectra of a desired wavelength, the lamp bulb comprising an envelope for containing a fill material under pressure and a fill material, the fill material including a material capable of forming at least two dissimilar excimer species in an amount to provide a total fill pressure no less than about 750 Torr at room temperature.

Abstract: An arc lamp suitable for use as a high intensity light source in a projection system is described. A reflector is arranged to reflect the light produced by the arc into a directional light beam, secondary reflection means being arranged to direct part of the reflected beam so as to compensate for regions which are obscured by the electrodes. Means are provided within the light source to dissipate heat generated by the electrodes.

Abstract: In a metal halide lamp which includes a discharge tube (2) retaining a fill of mercury and at least one metal halide added as a luminous material, an energy density of the arc discharge portion (3) represented by a product E.times.j is in the range of 70.0.ltoreq.E.times.j.ltoreq.150.0 (VA/mm.sup.3) where E=V/d, j=I/S, assuming that I is a lamp current in amperes with a lamp voltage of V volts applied between the paired discharge electrodes in a stable lighting condition of the lamp and that each of the electrodes has a tip face (1a, 1a') of which a cut area in section is S mm.sup.2 and the gap distance is d in millimeters, and thus a high luminous flux retention rate and high luminance of an arc discharge portion can be accomplished with a longer life of the lamp, suppressing a lamp voltage varying rate, and avoiding a change in color temperature, which remarkably improves additional merits when in utilization as a light source in various display apparatuses such as optical projection systems.

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 high-pressure metal halide discharge lamp comprises a quartz-glass lamp vessel (1) with an ionizable filling and two electrodes (2) which are connected to current conductors (3). The electrodes are provided with an emitter (6) which contains tungsten as a main component and at least three oxides, a first oxide which is chosen from hafnium oxide and zirconium oxide, a second oxide being lanthanum oxide, and a third oxide which is chosen from yttrium oxide.

Abstract: A single-tube high-watt metal halide lamp being characterized in that its fixture socket installation portions are formed at caps secured to a pair of sealing portions formed at both sides of a discharge tube, and the distance between the fixture socket installation portion and the sealing portion is set at 8.5 mm or less so as to dispose the molybdenum foil of the sealing portion close to a socket of a lighting fixture, whereby the lamp can reduce the temperatures at the ends of the sealing portions and can have a long service life.

Abstract: A light source device for a liquid crystal projector in which it is possible to prevent distinct appearance of a shadow of the conducting wiring of a lamp on a screen, even if an integrator lens is used, is achieved according to the invention by the fact that, in a light source device which has a metal halide lamp with bilateral sealed terminations in which seal areas are joined in one piece to two ends of an arc tube, and a concave reflector, in which one of the seal areas of the lamp is installed and held in a base opening of the concave reflector, and in which the other seal area extends in toward the front opening of the concave reflector, by conducting wiring connected to the outer lead pin which projects from the seal area toward the front opening of the concave reflector being positioned running toward the arc tube in a manner resting directly on this seal area, and then being drawn out in the vicinity of the arc tube with to behind the concave reflector.

Abstract: A high-pressure metal vapor discharge lamp of the present invention has a discharge tube made of a ceramic material having a transparent or translucent property, and the discharge tube has a main tube, and a first and a second disks for sealing the main tube. The first disk is disposed at one opening of said main tube, and the second disk disposed at the other opening of said main tube. Further, the first and the second disks have a cylindrical narrow tube. A lead-through-part for disposing either of a first and a second main electrodes and an auxiliary electrode in the main tube and a sealing member integrated with the lead-through-wire are inserted in the cylindrical narrow tube, and the sealing member is fixed to the cylindrical narrow tube so that the cylindrical narrow tube is sealed airtightly.