Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube.

Abstract: A high-pressure discharge lamp employs an outer bulb that is provided with a lamp cap and surrounds a discharge vessel having a ceramic wall with a clearance. In the clear space, a conductor extends over a length L between the lamp cap and an electrode of the discharge vessel, which conductor is at least formed of a heat-resistant metal. A section Ld of the length L of the conductor is provided with an Ni coating.

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

Abstract: An arc lamp comprises a single edge-to-edge cathode support strut on which the cathode is mounted with an end slot. Such makes heat and thermal stress loading on the assembly symmetrical over operational time, and arc tip wander from the anode center is practically eliminated. Nine component parts that are brought together in only three brazes and one TIG-weld to result in a finished product. An anode assembly is brazed with the rest of a body sub-assembly in one step instead of two. A single-bar cathode-support strut is brazed together as one step. A window flange and a sapphire output window are brazed together with the product of the strut braze step in a mounted-cathode-braze step. A copper-tube fill tubulation, a kovar sleeve, a ceramic reflector body, an anode flange, and a tungsten anode are all brazed together in a “body-braze” step. The products of the mounted-cathode-braze step and body-braze step are tungsten-inert-gas (TIG) welded together in a final welding step.

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

Abstract: A plasma-addressed liquid crystal display device capable of high-speed drive and improved viewing characteristic is composed of a liquid crystal cell structure and plasma cell structure stacked with each other. The liquid crystal cell structure is formed by sandwiching a liquid crystal having a spontaneous polarization between a first transparent substrate having therein transparent electrode stripes and an alignment film covering the electrode stripes, and a dielectric sheet having thereon an alignment film. The plasma cell structure is formed of a second transparent substrate having thereon cathode stripes and anode stripes disposed alternately with a spacing therebetween, stacked via stripe-shaped partitions disposed along the anode stripes onto the dielectric sheet so as to form plasma channels between the partitions filled with an ionizable gas sealed up therein.

Abstract: An arc discharge lamp comprising an arc tube including a starting aid is provided. The starting aid comprises at least one prealloyed powder bound to the surface of the arc tube.

Abstract: The present invention is a microwave excited electrodeless bulb and a process of generating ultraviolet light with a microwave excited electrodeless bulb. A process of generating ultraviolet light with a microwave excited electrodeless bulb in accordance with the invention includes providing an electrodeless bulb (19) with an envelope (32) containing an ultraviolet emissive material which emits ultraviolet light in response to microwave excitation. The envelope is filled with an ultraviolet emissive material. The envelope has a major internal dimension (30) between ⅓ and ½&lgr; to which a strong field of the microwave excitation is coupled during emission of ultraviolet light with &lgr; being the free space wavelength of the microwave excitation which varies between 2.4 and 2.5 GHz. The strong field is produced by a microwave source having a steady state rated output power of no greater than 0.85 kW. The bulb is rotated at a rotational velocity of at least 20 revolutions per minute.

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

Abstract: An arc discharge lamp comprising an arc tube including a starting aid is described. The starting aid comprises at least one metal cermet coating applied to the surface of the arc tube, or a metal layer including refractory glass disposed over said cermet coating or said metal layer.

Abstract: A light source device includes a substrate, a plurality of discharge tubes arranged on one principal surface of the substrate, a driving circuit mounted on the other principal surface of the substrate that is opposite to the foregoing principal surface, a discharge medium sealed in the discharge tubes, and first and second electrodes for exciting the discharge medium. The foregoing discharge medium does not contain mercury. Thus, the light source device can be formed smaller in size and thinner in thickness, and a liquid crystal display device employing the same can be provided.

Abstract: A transparent airtight vessel 1a, a discharge medium enclosed in a transparent airtight vessel 1a and composed mainly of rare gas, a fluorescent lamp 1 provided with at least a pair of electrodes 1b, 1e which generate discharge inside the transparent airtight vessel 1a, a reflection means 2 arranged in the vicinity of the fluorescent lamp 1, and a transparent resin 3 which exists between the fluorescent lamp 1 and the reflection means 2 and contacting with both of them. The transparent resin 3 conducts heat generated by the fluorescent lamp 1 to the reflection means 2 and promotes the heat radiation. The heat radiation of the rare gas discharge lamp is then promoted and the decrease of the light emitting efficiency is suppressed.

Abstract: To extend the life of electric discharge and enhance the characteristic of electric discharge in the life test in a gas filled switching electric discharge tube. A gas filled switching electric discharge tube comprises: a cylindrical body (1) made of insulating material; two electrodes (2, 3) for airtightly closing both ends of the cylindrical body; an electric discharge gap, an airtightly closed space formed in the cylindrical body including the electric discharge gap being filled with gas; metallized faces formed on both end faces of the electrodes of the cylindrical body; first trigger wires (10a, 10b) formed on an inner wall face of the cylindrical body, connected with the metallized faces; and second trigger wires (10c) formed on the inner wall face of the cylindrical body, not connected with the metallized faces, wherein the first electrode face and second electrode face are plated with copper or silver.

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

Abstract: 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: A high pressure sodium vapour lamp having a fill consisting of sodium, mercury and xenon in an arc tube with a sodium weight portion within the sodium-mercury-amalgam of approx. 12% to approx. 20%, having a xenon filling pressure in the cold state between approx. 180 Torr and approx. 350 Torr, having a D-line reversal width (distance of the tops of both wings of the sodium-D-line of the radiation spectrum) of approx. 110 Å to approx. 200 Å, and having approx. 14% to approx. 18% radiation portion in the red wave length range 635 nm to 750 nm and having approx. 7% to approx. 10% radiation portion in the blue wave length range 380 nm to 500 nm, in each case of the radiation power in the wave length range 380 nm to 780 nm for promotion of plant growth is provided.

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

Abstract: A gas discharge lamp fitted with a gas discharge vessel filled with a gas filling is suitable for a gas discharge which emits VUV radiation, with a luminophore coating containing a down conversion luminophore and with means for igniting and maintaining a gas discharge in which the down conversion luminophore has in a host lattice a pair of activators of the a first lanthanoid ion and a second lanthanoid ion and a sensitizer selected from the group of the cerium (III) ion, praseodymium (III) ion, neodymium (III) ion, samarium (III) ion, europium (III) ion, gadolinium (III) ion, terbium (III) ion, dysprosium (III) ion, holmium (III) ion, erbium (III) ion, thulium (III) ion, ytterbium (III) ion and lutetium (III) ion, is environmentally friendly and has a high lamp efficiency &eegr;lamp.

Abstract: The present invention relates to a discharge lamp containing a radioactive gas for starting said lamp. The radioactive gas is enclosed in a capsule, a wall of which is transparent to the radioactive radiation. Thus, the capsule promotes the starting of the discharge lamp, whilst preventing consumption of the radioactive gas which it contains, since the latter is isolated from the filling gas by the sealed walls of the capsule. The service life of the discharge lamp is thus increased.

Abstract: An electrodeless lamp includes a stationary bulb (10) containing a fill for producing a discharge, the fill has a primary radiating material which ordinarily produces an unstable discharge in the absence of bulb rotation. The fill further includes an alkali metal in an amount sufficient to stabilize the discharge without bulb rotation. The alkali metal may be, for example, cesium bromide. Preferably, the fill is excited by a non-stationary electric field (E, E1) such as, for example, a circular polarized electric field.

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: A gas discharge lamp has at least one capacitive electrode of a dielectric material having a dielectric saturation polarization P and an effective surface A wherein the product of P·A>10−5 C. This lamp can be operated without drive electronics or a ballast, using power available at private households.

Abstract: Fluorescent lamp (1) comprising a glass discharge vessel (2) in which a gas is present, which discharge vessel (2) is on two sides provided with a tubular end portion (3) having a longitudinal axis, which end portion (3) includes a glass stem (5), wherein an exhaust tube (6) extends axially outwardly from said stem (5) for supplying and/or discharging gases during the production of the lamp (1), wherein an electrode (8) extends axially inwardly through the stem (5) for generating and maintaining a discharge in the discharge vessel (2). The fluorescent lamp (1) is characterised in that it meets at least one of the following equations: 1 ξ = R 1 R 2 + 1 R 3 R 4 + 1 < 0.4 ⁢   ⁢ or α = R 1 R 2 < 0.

Abstract: An arc discharge lamp comprising an arc tube comprising a starting aid is provided. The starting aid comprises a coating on the surface of the arc tube. The coating is comprised of metal oxide, nitride, carbide, silicide, and mixtures thereof.

Abstract: Visible light emission is obtained from a plasma containing elemental barium including neutral barium atoms and barium ion species. Neutral barium provides a strong green light emission in the center of the visible spectrum with a highly efficient conversion of electrical energy into visible light. By the selective excitation of barium ionic species, emission of visible light at longer and shorter wavelengths can be obtained simultaneously with the green emission from neutral barium, effectively providing light that is visually perceived as white. A discharge vessel contains the elemental barium and a buffer gas fill therein, and a discharge inducer is utilized to induce a desired discharge temperature and barium vapor pressure therein to produce from the barium vapor a visible light emission. The discharge can be induced utilizing a glow discharge between electrodes in the discharge vessel as well as by inductively or capacitively coupling RF energy into the plasma within the discharge vessel.

Abstract: In a glow discharge starter, a layer of lanthanum is present on one of the conductors and the gas filling is a Penning mixture. The glow discharge starter does not contain radioactive material. The delay time between the application of a voltage between the conductors and establishing a glow discharge remains short during the whole life of the glow discharge starter, even when the starter was kept in a room with a low light level for a prolonged time.

Abstract: A metal halide lamp for general illumination purposes contains as the essential component of the metal halide fill manganese in an amount of from 0.01 to 50 &mgr;mol per cm3. It serves as a replacement for sodium at warm white or neutral white luminous colors.

Abstract: A flat panel lamp has internal walls forming a serpentine discharge path between two internal electrodes. Two glow mode electrodes in the form of interdigitated combs are laid on the outside of the front panel of the lamp, on top of the walls. The internal electrodes are connected to a first drive circuit; the glow mode electrodes are connected to a second drive circuit, which drives them at a frequency of about 10 MHz. At high brightness, only the internal electrodes are operative; at low brightness, only the glow mode electrodes are operative; and at intermediate brightness the two sets of electrodes are alternately energized.

Abstract: A mercury-containing material, a method for producing the same and a fluorescent lamp using the same that can enclose a minimal amount of mercury in a glass bulb precisely, prevent flaws in a fluorescent coating while suppressing a noise during a lamp transportation, and prevent deterioration in appearance are provided. A surface of liquid mercury is coated with a continuous film made of metal oxide or metal complex oxide by dipping the mercury in a metal alkoxide solution and then heating the mercury on which the metal alkoxide solution adheres. Accordingly, the minimal amount of the mercury can be enclosed in the fluorescent lamp precisely, thus achieving friendliness to the environment. It also is possible to prevent flaws in the fluorescent coating while suppressing a noise during the lamp transportation and further to prevent deterioration in appearance.

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 display member, particularly a plasma display member, can be produced by a process comprising applying a paste which comprises a urethane compound and inorganic fine particles onto a substrate and then firing the paste. The display member has a post-firing pattern without any defect.

Abstract: In a flash lamp, a mirror structure (20, 30, 40) is fixed at an inner end portion of an exhaust pipe (21, 34, 44) secured to a center of a stem (6) disposed at a bottom portion of an envelope (H). An arc emission part (S) is located at a focal position of a rounded mirror surface 24.

Abstract: In gas-filled discharge gaps having a vitreous electrode activation compound formed of several components. In order to prevent excessive fluctuations of the d.c. sparkover voltage Uag under load, potassium silicate and cesium tungstate are provided as base components of the electrode activation compound to sodium silicate, cesium silicate and titanium.

Abstract: A bulb comprises an airtight envelope having a filling gas therein. A conductive wire extends outwardly from the airtight envelope. A conductive pipe pin has the conductive wire passed therethrough, a predetermined welding portion, and a welded portion including a smooth surface. An outer diameter of the welded portion is no greater than the outer diameter of the pin. The welded portion may be formed in the pipe pin by the fluid of the melted conductive wire and predetermined welding portion flowing into the pipe pin and hardening.

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 low-pressure mercury-vapor discharge lamp is provided with a discharge vessel and a first and a second end portion (12a). The discharge vessel encloses a discharge space provided with a filling of mercury and an inert gas in a gastight manner. Each end portion (12a) supports an electrode (20a) arranged in the discharge space. An electrode shield (22a) encompasses the electrodes (20a) and, according to the invention, carries an electric current during operation, and is at a temperature ≧250° C., preferably ≧450° C., during nominal operation of the discharge lamp. Preferably, a first current supply conductor (30a) electrically contacts a first current divider (23a), which is electrically connected to a second current divider (23a′) via a shell-shaped body (24a). Said second current divider (23a′) electrically contacts the electrode (20a), which is connected to the second current supply conductor (30a′).

Abstract: A neon lamp including a sealed glass bulb, electrodes and leads connected to the electrodes has a flat head whose center region descends into the interior of the sealed glass bulb. A method of producing the neon lamp includes steps of charging neon gas into a glass tube through a fine glass tube at the head of the glass tube, sealing the fine glass tube to obtain a sealed glass bulb having a projecting tip portion, removing excess glass of the projecting tip portion, and shaping the projecting tip portion into a substantially flat or lenticular head portion. A system for producing the neon lamp includes a shaping head for accommodating the sealed glass bulb with its projecting tip portion exposed outside the shaping head, heating means for melting the projecting tip portion, a projecting tip cutter for removing excess glass of the projecting tip portion, and a head presser for shaping the projecting tip portion into a substantially flat or lenticular shape.

Abstract: At least at one end of a discharge lamp, for example a metal-halide discharge lamp or a sodium high-pressure discharge lamp, which has a ceramic discharge vessel (4), a feed-through (9, 10; 30) is provided which includes a cermet. The cermet may be in pin or capillary tube form, and has a metal content which is so high that it can be welded like a metal. The cermet can be directly sintered into an end plug (26) or into an end portion (34a, 34b) of the vessel itself. The seal thus is effected by a sealing arrangement (11, 21, 34a, 34b, 31) devoid of glass melt, which would be degraded by attack of corrosive fills within the lamp, while additionally having the capability of withstanding higher operating temperatures.

Abstract: A high pressure discharge lamp used as a light source for an automobile headlight and a method of forming the high pressure discharge lamp are disclosed. The high pressure discharge lamp includes a discharge chamber portion defining a discharge chamber filled with metal halide and rare gas, a pair of opposing electrodes, a portion of each electrode respectively projecting a predetermined distance into the discharge chamber, molybdenum foils, lead wires, and a bulb. The bulb includes a tapered portion, a sealed portion, and a sealed end having portions of a molybdenum foil, an electrode, and a lead wire disposed therein.

Abstract: A plasma display having a transparent front panel spaced from a back panel which is a metal core having layers of a dielectric material extending over and bonded to the core. Conductive electrodes are on the surface of or imbedded in the dielectric layer of the back panel. The materials of which the back panel is made are chosen to form a back panel having a thermal coefficient of expansion compatible with that of the front panel. The dielectric material is made from a green ceramic tape which is bonded to the core and cofired with the core to form the back panel. Barrier ribs are formed on the back panel by embossing or scribing the green tape before cofiring the bonded assembly. Slight differences in the TCEs of the front and back panels may be compensated for by heating the panel having the lower TCE to a temperature hotter than the panel having the lower TCE during the frit seal process.

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: The present invention is directed to a metal hydrides lamp and a fill for such a lamp. The lamp chamber includes a fill of at least one metal, a buffer gas, and hydrogen and/or deuterium. When energy is provided to the fill, metal combines with the hydrogen and/or deuterium to form a molecule at an excited energy level which emits visible light when the molecule moves to a ground state energy level. The lamp may be an electrode lamp, an electrodeless lamp, a microwave lamp, or any other power source capable of imparting energy into a fill contained within a lamp chamber.

Abstract: An optical emitter is provided, in particular for ultraviolet or infrared radiation, with a lamp bulb (1) from which extend at least two connecting wires (4, 5) for electrical connection, in each case through a stem press (2, 3) at the upper end and the lower end of the lamp bulb (1). The first connecting wire (4) is electrically connected with a first contact pin (15) via a flexurally rigid holding bracket (6), and the second connecting wire (5) is electrically connected with a second contact pin (16) via a metallic contact element (7). The contact pins (15, 16) each extend out from a bore of a ceramic base (10). To provide an improved optical emitter which can be manufactured with lower expenditures of time and cost, the holding bracket (6) and the first connecting pin (15) are designed in one piece and the first contact pin (15) is provided with an anti-slip safety on both sides of the first bore in the base (10).

Abstract: A lamp for a halogen lamp a single-tube, high-intensity discharge lamp, a double-tube high-intensity discharge lamp having an outer housing formed of quartz, and the like, being characterized in that a film having desirable heat conductivity and emissivity is formed on the surface of each sealing portion thereof, whereby the temperature at the distal end of the molybdenum foil in the sealing portion away from the center of the bulb can be kept at about 350.degree. C. or less while the lamp is burning.

Abstract: An electrodeless lamp includes a light transmissive envelope and a fill disposed in the envelope where the fill has the characteristic of emitting light when ignited and is excited by high frequency electrical energy provided by an R.F. or microwave source. The lamp includes a fill material enabling more reliable and effective ignition and shorter restrike intervals after an operating lamp has been extinguished. The fill includes a first component (preferably sulfur, selenium or a mixture of sulfur and selenium) and a second component (preferably xenon gas) included at a partial pressure in the range of 50 to 200 torr. A third component (preferably argon gas) is included at a partial pressure in the range of 5 to 20 torr. Preferably, approximately 5 torr of argon is added to a selected fill pressure of xenon (e.g., a partial pressure of 100 torr or more).

Abstract: The high-pressure metal halide discharge lamp has opposite tungsten electrodes (5) carried by electrode rods (7). These rods (7) have a first portion (71) of tungsten adjacent the electrodes (5) and a second portion (72) having a core of tungsten and a skin of at least 90% by weight of rhenium. Their common boundaries are at a location having during operation a temperature in the range of 1900-2100 K. The gas filling contains metal oxyhalide and is devoid of rare earth metal compounds. The lamp has a long life and a high luminous maintenance.

Abstract: A noble gas discharge lamp of the present invention comprises an outer enclosure comprising a light emitting layer formed therein, and a pair of outer electrodes having tape shapes comprising a metal, which are adhered to the entire length of the outside of the outer enclosure so as to separate one outer electrode and the other outer electrode at a certain distance. The electrodes form a first opening portion and a second opening portion; wherein the outer enclosure is filled with at least one kind of noble gas under the confining pressure is in a range of 83 to 200 Torr. There is at least one nonlinear portion formed at at least one side portion of the outer electrodes.

Abstract: A plasma display device comprising: a rear substrate; a plurality of first electrodes formed on the rear substrate in a predetermined pattern; a dielectric layer formed on the rear substrate where the first electrodes are to be embedded; a plurality of second electrodes formed on the dielectric layer to be orthogonal with respect to the first electrodes; and at least one auxiliary electrode formed between the second electrodes.

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 power-saving discharge lamp 1 wherein gap control material 6 is provided in a clearance between an internal bulb 2 and an external bulb 5, having a smaller thickness than the dimension of the clearance. Nonuniformity of the clearance between the both bulbs caused by difficulties in supporting the internal bulb 2 while welding the external bulb 5 is eliminated and a suitable clearance is automatically provided by the gap control material 6 to prevent degradation of the heat insulation effect.