Abstract: A carbon heating element and a method for manufacturing a carbon heating element are provided. The carbon heating element may efficiently dissipate heat and prevent disconnection or destruction of a heating element to prolong a lifespan thereof without generating a spark and plasma under a high voltage. The carbon heating element may include carbon (C) and silicon carbide (SiC), and the carbon heating element may have a thermal conductivity of 1.6 W/m·K or more.

Abstract: Disclosed are a light emitting diode package and a backlight unit having the same. The light emitting diode package includes a light emitting diode including generating a light in response to a driving voltage applied from the outside, first and second main leads connected to first and second electrodes, respectively, and a body section provided therein with the light emitting diode and fixes the first and second main leads thereto. The light emitting diode package includes a first sub-lead having one end portion connected to the first main lead, and a second sub-lead having one end portion connected to the second main lead and an opposite end portion spaced apart from an opposite end portion of the first sub-lead at a predetermined distance while facing the opposite end portion of the first sub-lead. The backlight unit includes a plurality of the light emitting diode packages.

Abstract: An overmolded light-emitting diode (LED) lamp for a decorative light string. The lamp includes a light-emitting diode, a first lead electrically connected to the light-emitting diode at a top portion of the first lead, a second lead electrically connected to the first lead through the LED, a lens encapsulating the light-emitting diode, a top portion of the first lead, and a top portion of the second lead, and a housing having a solid uniform body encapsulating a bottom portion of the lens, a portion of the first lead, and a portion of the second lead, such that bottom portions of the first lead and the second lead extend outward and away from a bottom portion of the housing.

Abstract: In a light emitting apparatus including a plane-shape light emitting area, a power supply area extending along the light emitting area, and a power supply voltage feeding part configured to feed a power supply voltage to the power supply area. The power supply area supplies a current to the light emitting area across an edge of the power supply area facing the light emitting area. The power supply voltage feeding part is connected to a power supply port provided on another edge of the power supply area opposite to the light emitting area. The power supply area includes a first non-conductive area surrounded by a conductive area located on a shortest path from the power supply port to the edge of the power supply area facing the light emitting area.

Abstract: A high pressure discharge lamp comprises a pair of electrodes that face each other in an electric discharge container, wherein an electrode axis of each electrode is buried in a sealing portion, each electrode axis is joined to a metallic foil, two or more grooves are formed in an axis direction on a portion of the electrode axis, which corresponds to the sealing portion, an upper shoulder portion of each groove is formed in a shape of a curved surface, a diameter of the electrode axis is 0.3 mm to 1 mm, and a curvature radius of the curved surface upper shoulder portion is 5 ?m-50 ?m.

Abstract: An ultraminiature light source using a double-spiral shaped tungsten filament includes end contact portions which are separated to allow for radial and length-wise unwinding of the spiral. The double-spiral filament is spaced relatively far apart at the end portions thereof so that contact between portions of the filament upon expansion is avoided. The light source is made by fabricating a double-spiral ultraminiature tungsten filament from tungsten foil and housing the filament in a ceramic package having a reflective bottom and a well wherein the filament is suspended. A vacuum furnace brazing process attaches the filament to contacts of the ceramic package. Finally, a cover with a transparent window is attached onto the top of the ceramic package by solder reflow in a second vacuum furnace process to form a complete hermetically sealed package.

Abstract: A discharge lamp may include a substantially ellipsoidal discharge vessel that surrounds an anode and a cathode that are respectively fixed by current-carrying electrode holders, the latter being guided through bulb shafts arranged diametrically on the discharge vessel, there being provided around the electrode holders at the transition from the discharge vessel to the bulb shafts constrictions that form a connecting channel between the discharge space, surrounded by the discharge vessel, and in each case the bulb shaft spaces surrounded by the bulb shafts, wherein at least one of the discharge vessel, the constrictions and the anode coating is designed in such a way as to reduce or avoid blackening of the discharge vessel in the light-emitting region.

Abstract: A lamp includes a lamp holder module and light-emitting module disposed in the lamp holder module. The lamp holder module includes a body, a pressing mechanism disposed on the body, and an upper cover engaging removably the body. The light-emitting module is placed on the body and is pressed into position through the pressing mechanism. The pressing mechanism is operable to release the light-emitting module, thereby facilitating removal and installation of the light-emitting module. The upper cover serves as a lens of the light-emitting module and covers the light-emitting module.

Abstract: The present invention is directed to a method for manufacturing a high-pressure discharge lamp including: a spherical portion forming a light-emitting portion (1a); sealing portions that are connected with both ends of the spherical portion; an electrode (2a) that is sealed to each of the sealing portions; and a metal foil (3a) that is connected with a rear end of each electrode. A vessel provided with a cylindrical glass tube (8) on both ends of the spherical portion is used, a connection structure of the metal foil and the electrode are disposed in the glass tube such that a front end of the electrode is positioned in the spherical portion, and the glass tube is melted by heat and shrunk for sealing the metal foil and the electrode so as to form the sealing portion. An inner diameter ? of the glass tube before the heat-melt processing and a distance L from an edge of the metal foil to the internal space of the spherical portion are set to satisfy a relationship of L/??1.

Abstract: Disclosed is a lamp, particularly for a vehicle headlight, comprising two spiral-wound filaments which are retained by three feeders within a bulb that is inserted into a base. The feeders are arranged on top of one another when the lamp is adequately oriented. A tail of the first spiral-wound filament is connected to a dimming cap, said tail being located at a distance from the base, while a tail of the second spiral-wound filament is connected to the central feeder, said tail being close to the base. The second filament tail that faces away and is located at a distance from the base is connected to the upper feeder. According to the invention, the lower feeder is connected to the dimming cap by means of an end, some sections of which are angled away from a longitudinal axis of the lamp.

Abstract: A field emission device includes: a first substrate on which a gate electrode line, a cathode line, and an electron emission source are formed; a second substrate disposed to face the first substrate, and on which an anode and a phosphor layer are formed; and a side frame surrounding an area between the first substrate and the second substrate, and forming a sealed internal space, wherein the first substrate and the second substrate respectively comprise a first protrusion part and a second protrusion part that protrude outside the side frame in the same direction, wherein a rear terminal part for applying a voltage to the gate electrode line and the cathode line is formed on the first protrusion part, wherein an anode terminal for applying a voltage to the anode is formed on the second protrusion part.

Abstract: In a discharge tube, a conductive ferrule is provided on an end portion of a glass tube. The ferrule includes a body that is to be mounted to the outer circumference of the glass tube and has a contact portion to be electrically conductively fixed to a relay connector (or a bearing device). Further included is a conductive portion that extends from the body so as to have elastic contact with an outer lead. The outer lead will not be under load due to the weight of the discharge tube, but the conductive portion solely has elastic contact therewith. Thus, stress concentration on the outer lead can be prevented.

Abstract: An extra high pressure mercury lamp that includes an arc tube, which includes a light emission section enclosing 0.2 mg/mm3 or more of mercury, sealing sections that respectively extend from both ends of the light emission section, a pair of electrodes that face each other in the light emission section, wherein an electrode axis portion of each electrode is held by the sealing portion, and a metallic foil that is buried in the sealing section and that is electrically connected with the electrode axis portion, wherein the metallic foil has a covering portion fixed to the electrode axis portion so as to roll up the electrode axis portion; an extended portion that extends towards the outside of a tube axis without being connected with the electrode axis portion; and a main body portion that extends from the extended portion.

Abstract: A fluorescent display device includes an aluminum wiring layer formed on an insulating substrate; an insulating layer formed on the aluminum wiring layer, the insulating layer being provided with a through-hole disposed on the aluminum wiring layer; a conductive layer filled in the through-hole. The fluorescent display device further includes an anode conductor formed on the insulating layer to cover the conductive layer and a phosphor layer formed on the anode conductor. The conductive layer is formed of solid mixture containing aluminum and graphite.

Abstract: In a light emitting apparatus including a plane-shape light emitting area, a power supply area extending along the light emitting area, and a power supply voltage feeding part configured to feed a power supply voltage to the power supply area. The power supply area supplies a current to the light emitting area across an edge of the power supply area facing the light emitting area. The power supply voltage feeding part is connected to a power supply port provided on another edge of the power supply area opposite to the light emitting area. The power supply area includes a first non-conductive area surrounded by a conductive area located on a shortest path from the power supply port to the edge of the power supply area facing the light emitting area.

Abstract: An interconnection arrangement for interconnecting a high-current carrying cable with a metal thin-film (3, 4) on a transparent and insulating substrate (1). According to the invention the high-current carrying cable is designed as a flat cable (5) and the inter-connection between the flat cable and the metal thin-film (3, 4) is an ultrasonic weld joint (6a, 7a).

Abstract: A method for making a field emission lamp generally includes the steps of: (a) providing a cathode emitter; (b) providing a transparent glass tube having a carbon nanotube transparent conductive film and a fluorescent layer, wherein the carbon nanotube transparent conductive film and the fluorescent layer are both disposed on an inner surface of the transparent glass tube; (c) providing a first glass feedthrough, a second glass feedthrough, and a nickel pipe, wherein the first glass feedthrough has an anode down-lead pad and an anode down-lead pole connected to the anode down-lead pad, and the second glass feedthrough has a cathode down-lead pole; (d) securing the nickel pipe to one end of the cathode emitter and securing the other end of the cathode emitter to one end of the cathode down-lead pole of the second glass feedthrough; and (e) melting and assembling the first and second glass feedthroughs to ends of the transparent glass tube respectively.

Abstract: An organic light emitting display device includes a display panel provided with a pad region having a plurality of pads. A flexible circuit board having lead terminals is coupled into the pad region. The pad region includes a plurality of first pads electrically coupled to the flexible circuit board through the lead terminals and a plurality of second pads electrically isolated from the flexible circuit board.

Abstract: A xenon short arc lamp which has a middle section with a length to diameter ratio greater than 1.6 and which is directly interchangeable with a xenon short arc lamp of the same wattage in a lamphouse without modifying the lamphouse.

Abstract: A lamp type light emitting device for safety fuse, including a substrate, an electrode layer, a chip set, a wire set, two leads and an encapsulator. The electrode layer is arranged on the substrate and includes a first T-shaped electrode, a second T-shaped electrode, a first stripe electrode and a second stripe electrode. The chip set includes a first resistor chip and a first light emitting chip arranged on the first T-shaped electrode and a second resistor chip and a second light emitting chip arranged on the second T-shaped electrode. The wire set has fuse wires electrically connected the first resistor chip, the first light emitting chip, the first stripe electrode, the second resistor chip, second light emitting chip, and the second stripe electrode. The leads are electrically connected to the first and the second T-shaped electrodes. The encapsulator encapsulates the electrode layer, the chip set and the wire set.

Abstract: It is possible to enhance the luminance of a cold-cathode type discharge lamp and to contribute to a prolongation of service life thereof. A discharge lamp 1 is provided with an electrode 3 having a cup 4 with such a shape that a bottom is provided at each of both opposed ends of the glass tube 2. The cup 4 is connected to a lead-in wire 8 which is inserted through the end of the glass tube 2 and held thereby. The collision-preventing ring 5 covering an end surface of the cup 4 is provided to the open end 4a of the cup 4. The porous tungsten disk 6 impregnated with a ternary metal oxide composed of barium (Ba), aluminum (Al), and calcium (Ca) as an electron emission material is provided at a bottom in an inside of the cup 4.

Abstract: The invention relates to a discharge lamp, in particular a high-pressure discharge lamp, having a discharge vessel (1) which has two diametrically opposite necks (2, 3) into each of which a holding rod (5, 10) is fused at least in places, with an electrode (4, 9) which extends into the discharge vessel (1) being arranged on each holding rod (5, 10), and with in each case at least one annular plate (7, 12) at least partially clasping a holding rod (5, 10), with at least one of the annular plates (7, 12) being arranged in the discharge vessel (1).

Abstract: An ion cyclotron spectrometer may include a vacuum chamber that extends at least along a z-axis and means for producing a magnetic field within the vacuum chamber so that a magnetic field vector is generally parallel to the z-axis. The ion cyclotron spectrometer may also include means for producing a trapping electric field within the vacuum chamber. The trapping electric field may comprise a field potential that, when taken in cross-section along the z-axis, includes at least one section that is concave down and at least one section that is concave up so that ions traversing the field potential experience a net magnetron effect on a cyclotron frequency of the ions that is substantially equal to zero. Other apparatuses and a method for performing ion cyclotron spectrometry are also disclosed herein.

Abstract: A connector, which is fixed to an outer surface of an airtight container and connects a cable and an electrode terminal to each other, comprises a base member fixed to the outer surface of the airtight container and wherein a pointed end of the electrode terminal extends up to the inside of the base member, a cap member having a cable insertion portion wherein one end of the cable has been inserted and fixed to the base member, and a conductive member held between the base member and the cap member. The conductive member has a first portion being in contact with the inserted cable and a second portion being in contact with the pointed end of the electrode terminal, and the first portion and the second portion are located at positions mutually different on the same plane which is in parallel with the contact surface of the base member.

Abstract: The invention is directed to a process for the creation of a photonic lattice on the surface of an emissive substrate comprising first depositing a thin film metal layer on at least one surface of the substrate, the thin film metal comprising a metal having a melting point lower than the melting point of the substrate, then annealing the thin film metal layer and the substrate to create nano-particles on the substrate surface, and anodizing or plasma etching the annealed thin film metal and substrate to create pores in the nano-particles and the substrate such that upon exposure to high temperature the emissivity of the substrate is refocused to generate emissions in the visible and lower infrared region and to substantially eliminate higher infrared emission, and to the substrate thus created.

Abstract: The present invention provides an electrode assembly for a cold cathode fluorescent lamp, including: a body connector made of glass; a connecting wire sealingly embedded in the body connector in a manner of penetrating the body connector; an electrode defining an electron emission space therein, the electrode being connected to one end of the connecting wire and being disposed in a glass tube; and an external wire which is connected to the other end of the connecting wire and is disposed outside the glass tube, wherein the connecting wire includes a central part made of a material having high electric conductivity and thermal conductivity, and a circumferential part made of a material having lower electric conductivity and thermal conductivity than those of the material used to make the central part.

Abstract: It is possible to enhance the luminance of a cold-cathode type discharge lamp and to contribute to a prolongation of service life thereof. A discharge lamp 1 is provided with an electrode 3 having a cup 4 with such a shape that a bottom is provided at each of both opposed ends of the glass tube 2. The cup 4 is connected to a lead-in wire 8 which is inserted through the end of the glass tube 2 and held thereby. The collision-preventing ring 5 covering an end surface of the cup 4 is provided to the open end 4a of the cup 4. The porous tungsten disk 6 impregnated with a ternary metal oxide composed of barium (Ba), aluminum (Al), and calcium (Ca) as an electron emission material is provided at a bottom in an inside of the cup 4.

Abstract: A discharge lamp includes a cathode and an anode which face each other in an arc tube, wherein the cathode is made of tungsten in which thorium oxide is doped. The cathode has a cylindrical body portion, a tip portion having a cone shape, and a middle portion formed between the body portion and the tip portion, wherein an angle ?1 of the tip portion is set to a range of 55 degrees??1?65 degrees, and an angle ?2 formed by side faces of the middle portion is smaller than that of the tip portion.

Abstract: A foil connector (28, 30) suited for use in a lamp (10) is provided. The foil connector includes a substrate layer (40) formed from an electrically conductive material. A coating (42) is provided for reducing oxidation of the substrate during lamp operation. The coating includes a first coating layer (44) on the substrate comprising a noble metal, a second coating layer (46) spaced from the substrate by the first coating layer, the second coating layer comprising a noble metal, and optionally, a third coating layer (48) spaced from the substrate by the first and second coating layers, the third coating layer comprising a noble metal.

Abstract: Metal halide lamp with ceramic discharge vessel (4), the discharge vessel having two ends (6) which are closed off by stoppers, and an electrically conductive leadthrough (9) being passed through this stopper (12), an electrode (15) having a shank (16), which projects into the interior of the discharge vessel, being secured to the leadthrough. The leadthrough is composed of two portions of different diameters, with the outer portion resting on the end face of the stopper.

Abstract: An ultra high pressure mercury lamp having a light emitting part, a pair of electrodes; hermetically sealed portions; part of the electrodes and metal foils installed in the hermetically sealed portions and connected to the base parts of the electrodes; and outer leads connected to the base parts of the metal foils. The metal foils have a region with a small width which is groove-shaped and with which the electrodes are connected, and a wide region which borders the region with a small width, and which has an ?-shaped end region which borders the groove of the region with a small width, in which an end groove is formed, and which extends in the lengthwise direction, a base-side ?-region which is connected to the outer lead, in which a base-side groove is formed, and a middle, flat region which extends between the end ?-region and the base-side ?-region.

Abstract: A method of producing a cathode for use in an x-ray tube assembly is provided including machining an emission aperture into a cup emission surface portion of a cup structure. The cup structure is comprised of a cup base portion opposite the cup emissions surface portion. Electro-discharge machining is used to form an electro-discharge machining slot into the cup structure to provide access to the interior of the cup structure. Electro-discharge machining is used to form a transverse coil chamber within the interior by way of the electro-discharge machining slot such that the transverse coil chamber is formed between the cup base portion and the cup emissions surface portion while retaining an essentially contiguous emissions surface perimeter surrounding the emission aperture.

Abstract: A xenon short arc lamp which has a middle section with a length to diameter ratio greater than 1.6 and which is directly interchangeable with a xenon short arc lamp of the same wattage in a lamphouse without modifying the lamphouse.

Abstract: To implement an electrode structure which brings about extinction of arc quickly in a reliable manner without maintaining discharge current, and provide an electron source and image display apparatus equipped with the electrode structure. Device electrodes 2 and 3 are partially narrowed in areas where they are connected to scan wiring 6 and signal wiring 4, and an insulating layer 5 which insulates the scan wiring 6 and signal wiring 4 are extended to cover the narrow portions of the device electrodes 2 and 3.

Abstract: An electric lamp has a lamp vessel accommodating an electric element. The element is connected to current conductors including molybdenum portions which have a coating of material chosen from the group of chromium-manganese, chromium-cobalt, chromium-iron and chromium-boron alloys as a protection against oxidation.

Abstract: The subject matter of the disclosure is a power supply system for a lamp, having foils, which are embedded in a gas-tight manner in a pinch seal of the lamp and on which are arranged, in each case on two opposing narrow sides, an inner power supply line and an outer power supply line for the purpose of supplying power to a luminous element of the lamp, the outer power supply lines having lamp-side end sections, which are connected to the foils. According to the invention, the end sections of the outer power supply lines extend at least in sections approximately at right angles to a longitudinal axis of the foils.

Abstract: A method of making a unitized tungsten electrode which exhibits superior mechanical and electrical properties which includes providing a length of cylindrical cut stock having a predetermined diameter and length. The stock is ground to form a rough unfinished electrode having an enlarged tip or nose portion at one end integrally connected to an elongated shank section. The unfinished electrode is treated by exposure to a chemical etchant for a time sufficient to form a finished electrode characterized by a smooth nose and shank surface and rounded undercut and ends. The invention includes the electrode formed by the described process.

Abstract: A mercury-free 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 disposed on both end portions of the closed chamber so as to be opposed to each other, wherein the electrode rod is stepped shape which satisfies relationship of 1.1<A1/A2<7.3, whereas A1 is a cross sectional area of the electrode in a top-end side area protruded into the closed chamber and A2 is a cross sectional area of the electrode in a base-end side area fixed to the end portion of the closed chamber.

Abstract: An apparatus and a method for stabilizing the threshold voltage in an active matrix field emission device are disclosed. The method includes the formation of radiation-blocking elements between a cathodoluminescent display screen of the FED and semiconductor junctions formed on a baseplate of the FED.

Abstract: A first electrode part in a rod shape is placed on an upper side, and a second electrode part in a rod shape having a higher melting point than that of the first electrode part is placed on a lower side, so that ends of the first and second electrode parts are brought into contact. Contact ends or vicinities thereof are irradiated with a laser beam, so that the electrode parts are welded. Here, a region irradiated with the laser beam is in a long narrow shape having a minor axis directed in a vertical direction and a major axis directed in a horizontal direction. This makes it possible to manufacture an electrode with a consistent high quality with a high yield.

Abstract: The electrode system for a metal halide lamp with ceramic discharge vessel (4) comprises an electrically conductive leadthrough (9, 10) and an electrode connected thereto, the leadthrough having a fusible region with respect to the electrode, in which that end of the electrode which faces the leadthrough is embedded, at least the fusible region containing one of the high-melting metals Mo or W, and the electrode having a shank made from tungsten. In the regions surrounded by the material of the leadthrough, the electrode has a positively locking means which at least comprises a recess in the shank of the electrode.

Abstract: An electric discharge lamp comprising: a light-transmissive ceramic lamp vessel (1); a first and a second current conductor (2,3) entering the lamp vessel (1), and each supporting an electrode (4,5) in the lamp vessel (1); an ionizable filling comprising a rare gas and a metal halide in the lamp vessel (1); at least the first current conductor (2) within the lamp vessel (1) being halide-resistant, characterized in that the first current conductor (2) at least substantially comprises a material with an at least substantially isotropic coefficient of thermal expansion, said material preferably being chosen from the group of pentamolybdenum boride disilicide, pentamolybdenum diboride silicide, or a combination of these two materials.

Abstract: A display device includes a plurality of emitting tubes constituted by elongated tubes each having a phosphor layer disposed and a discharge gas enclosed inside, a supporter for supporting the plurality of emitting tubes while making contact therewith, and a plurality of electrodes disposed on a surface of the supporter facing the emitting tubes for generation of electric discharges within the emitting tubes. The supporter has a connecting portion at an edge. The connecting portion of the supporter is detachably connected to a connector for applying a voltage to the plurality of electrodes.

Abstract: An arc tube, which is capable of prolonging the life thereof by preventing occurrence of a leak caused from a crack of an arc-tube body, has the average surface roughness of each of outer surfaces 26Aa and 26Ba of tungsten electrodes 26A and 26B pinch-sealed to pinch seal portions 20b1 and 20b2 on the two sides of a light-emission tube 20a of an arc-tube body 20 is set to be 3 ?m or smaller. Thus, the state of pinch-sealing of the tungsten electrodes 26A and 26B to the pinch seal portions 20b1 and 20b2 is brought to a state in which the two elements are engaged with small pits and projections. Therefore, great compressive stress is not left in the region adjacent to the joint surface between the pinch seal portions 20b1 and 20b2 and the tungsten electrodes 26A and 26B as distinct from the conventional structure. In a case where a crack of the arc-tube body 20 is formed owing to the residual compressive stress, the crack is limited to a local portion which is the region adjacent to the joint surface.

Abstract: A discharge chamber for an arc discharge metal halide lamp having light permeable walls bounding a discharge region in which ionizable materials are provided with at least one electrode accommodation opening therein extending along a selected path between that discharge region and a region outside those walls. An electrode arrangement extends through the electrode accommodation opening having therein a thin electrical conductor positioned at least in part therein with a major surface that has surface curvature in at least some of those portions thereof positioned in said electrode accommodation opening to be in one of many alternative configurations. A sealing frit of mixed metal oxides is positioned about at least a portion of the thin electrical conductor within the electrode accommodation opening both at the major surface thereof and on an opposite side thereof.

Abstract: A double-layer electrode coil for a high intensity discharge (HID) lamp and a method of making the electrode coil are provided. A more stable layer of coils is made by front winding, instead of back winding, the layers of wire. The second layer of wire is entirely within a helical groove on the exterior surface of the first layer of wire. This arrangement is particularly stable and permits more rapid insertion of the electrode shank after removal of the mandrel.

Abstract: The present invention relates to a method for marking quartz glass lamps having at least one fusible metal foil 10, 12, which is surrounded by quartz glass, for supplying electric voltage to luminous means 15 arranged in the interior chamber of a lamp vessel, in which method the fusible metal foil 10, 12 is marked through the quartz glass by means of a laser. The invention also relates to a quartz glass lamp having at least one fusible metal foil 10, 12 which is surrounded by quartz glass, for supplying electric voltage to luminous means 15 arranged in the interior chamber of a lamp vessel, in which lamp the fusible metal foil 10, 12 forms a marking area 16, the marking of the marking area 16 taking place through the quartz glass by means of a laser.

Abstract: A discharge tube is comprised of a glass bulb, a cathode, and an anode. Impregnating porous tungsten with barium makes the cathode tip portion. A clearance between the end face of a lead rod and the end face of the cathode tip portion is filled with a molybdenum-ruthenium brazing filler metal.

Abstract: A metal halide lamp using a ceramic arc tube in which less lamp flickering occurs, the flux maintenance factor during the lifetime is high and the possibility of lamp break-off is low. The metal halide lamp includes an arc tube 1 in which iodide pellet of metal halide is filled, and a pair of electrodes are arranged in the ceramic arc tube so that the electrode coils are facing each other. The following relation is satisfied: 0.00056×W+0.061≦&agr;≦0.0056×W+1.61 where &agr; (in mm) denotes a length of the portion of the electrode bar protruding from the end face of the electrode coil and W (in Watt) denotes the lamp power.

Abstract: A discharge lamp having a pair of electrodes (2) within a light-emitting tube (30) with air-tight seals (31) formed covering a metallic foil (1) is bonded to each electrode (2). To stiffen the metallic foil, it is provided with a length-wise crease (M).