Abstract: The invention relates to a method for producing an electric lamp, in particular the application of an optical shield (5) to a cylindrical part of the lamp vessel (2). According to the invention, the optical shield (5) is applied to the lamp vessel (2) with the aid of at least two prefabricated opaque wax films (5a, 5b) which are provided with a colored layer and are joined in such a way that the width of the transparent window can be set independently of tolerances of the diameter of the lamp vessel (2). The wax of the films (5a, 5b) is vaporized by a heat treatment such that only the heat resistant colored layer remains on the lamp vessel (2).

Abstract: A discharge vessel with an excimer fill comprises a cap, electrodes and a fill having at least one noble gas and a halogen, which, when the lamp is operating, together form an excimer, the discharge vessel being manufactured from quartz glass. The inner wall of the discharge vessel is completely covered with a passivation layer of a metal oxide of the metals Al, Hf, Y or Sc or the mixed oxides thereof, the layer having an amorphous structure and its layer thickness being 20 to 200 nm.

Abstract: A low-pressure gas discharge lamp comprising a gas discharge vessel with a gas filling containing mercury, and comprising electrodes, means for igniting and maintaining a gas discharge, and a phosphor coating containing at least one phosphor layer and a UV-C phosphor and a phosphor that can be excited by UV-C radiation.

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. Each of the pair of metal foils has an external lead on a side opposite to a side electrically connected to a corresponding electrode of the pair of electrodes. At least one of the pair of sealing portions is provided with a reflective film on a surface of the sealing portion in a portion where a connection portion of the external lead and the metal foil is sealed. The reflective film contains a material having a reflectance larger than that of a material constituting the sealing portion.

Abstract: An electric lamp (10) which emits a blue color when energized and which comprises a light transmissive envelope (12) enclosing an electric light source (16) within, said envelope (12) having a surface (11) on which is a coating comprising sulfate precipitated silica, aluminum silicate pigment, and cobalt blue aluminate spinel. The lamp is useful in appliances such as refrigerators.

Abstract: The invention relates to a high-pressure discharge lamp with a substantially elongate bulb which has two neck regions and a vacuumtight discharge chamber in a central position. The invention further relates to a reflector lamp and a projection system comprising such a high-pressure discharge lamp. A disadvantage of known lamps is formed by the too high temperatures of critical components. According to the invention, therefore, it is suggested that the high-pressure discharge lamp is provided at least partly with a reflection layer at least in a neck region. The reflection layer reflects radiation in the entire spectrum (ultraviolet, visible, infrared) and is used in particular as a heat shield layer which reflects the radiation incident on the neck region at the lamp end and acting as heat radiation, so that an additional heating is prevented or at least reduced.

Abstract: A heat resistant scattering-preventing composite material is produced by applying, to a substrate, a material comprising a fluorine-containing ethylenic polymer having functional group which is prepared by copolymerizing (a) 0.05 to 30% by mole of at least one of fluorine-containing ethylenic monomers having at least one functional group selected from the group consisting of hydroxyl, carboxyl, a carboxylic salt group, a carboxylic ester group and epoxy, and (b) 70 to 99.95% by mole of at least one of fluorine-containing ethylenic monomers which do not have said functional group. The heat resistant scattering-preventing composite material is produced by applying, to the substrate, the material comprising the fluorine-containing polymer having an excellent adhesive property to the substrate without necessitating complicated steps.

Abstract: An optical interference coating for reflecting infra-red radiation and transmitting visible light. The coating comprises alternating layers of high index of refraction material and low index of refraction material. As the total number of layers increases, the ratio of high index of refraction material to low index of refraction material must also increase.

Abstract: In a discharge bulb having an arc tube formed with pinch seal portions on both ends of a sealed glass bulb that is a light-emitting discharge section, infrared transmitting films for blocking visible light and transmitting infrared light are applied to at least the pinch seal portions of the arc tube to prevent visible light from exiting the pinch seal portions and to suppress generation of glare. Infrared light from the pinch seal portions can pass through the infrared transmitting films, which prevents accumulation of heat in the arc tube (pinch seal portions and sealed glass bulb), thereby preventing the temperature of the arc tube from increasing excessively.

Abstract: A method for applying a coating (23) to a part of a surface of a lamp (20). The aim is to provide a simple manner of applying exact coatings to parts of surfaces with complicated designs. To this end, the lamp is vacuum-coated. The parts of the surface of the lamp (20) that are not to be coated are covered by a mask (3) and at least one coat is applied to the non-covered parts of the surface. The mask (3) is located at a predetermined distance (d) from the part of the surface of the lamp (20) and the mask (3) is oriented in relation to an illumination element (2) or a base (21) of the lamp (20). The invention also relates to a coated lamp that is produced according to a method of this type.

Abstract: A high pressure mercury lamp includes a luminous bulb in which at least mercury is enclosed inside the bulb, and a pair of sealing portions that retain airtightness of the luminous bulb. The amount of the enclosed mercury is 230 mg/cm3 or more based on the volume of the luminous bulb, and heat-retaining means for retaining beat in the luminous bulb is provided. Thus, the present invention can suppress blackening of high pressure mercury lamps having a very high operating pressure.

Abstract: An electric lamp (10) which emits a blue color when energized and which comprises a light transmissive envelope (12) enclosing an electric light source (16) within, said envelope (12) having a surface (11) on which is a coating comprising precipitated silica, aluminum silicate pigment, manganese ammonium pyro phosphate and cobalt aluminate spinel. The lamp is useful for general household illumination and provides pleasing skin tones.

Abstract: A discharge lamp of the short arc type in which a lead pin, located within a hermetically sealed tube, is prevented from being irradiated with light. Such a construction prevents the lead pin from undergoing a temperature rise thereby preventing the destruction of the hermetically sealed tube. The discharge lamp of the short arc type includes an arc tube adjoined laterally by hermetically sealed tubes through which a lead pin, which supports an electrode, is routed. The hermetically sealed tubes are sealed by graded glass on the lead pins, and the lead pin is prevented from being irradiated with light by providing the outside surface of the hermetically sealed tube, at least in part, with a high emissivity material and then providing a reflectivity material on the exterior surface of the emissivity material.

Abstract: The invention relates to an incandescent lamp whose lamp vessel (20) has an interference filter (30) with locally differing layer thickness for producing red light. The interference filter (30) has a second absorber layer and additional layers of low optical refraction and high optical refraction for reducing its transmission in the violet, blue and green spectral regions.

Abstract: A low-wattage fluorescent lamp is provided. The lamp has at least one mercury cold spot region effective to maintain the mercury in the lamp at less than 30° C., preferably 25° C., in an enclosed lamp fixture. The lamp also features a reduced distance between electrodes resulting in less power being required to sustain an electric arc discharge during operation of the lamp. The lower power electric arc generates less heat to raise the temperature of mercury vapor within the lamp.

Abstract: A red automotive incandescent lamp having a sealed lamp envelope formed from an amber glass, a pair of filaments located within the lamp envelope, and a red pigmented coating applied to an external surface of the envelope. The amber glass provides initial filtering of the shorter wavelengths of visible light, so that the red pigment has to filter out less light and therefore can be made less opaque. As a result, the lamp produces the desired red colored light at a total light output that meets applicable SAE and ECE requirements for automotive lamps.

Abstract: A metal halide discharge lamp which is capable of reducing a color change when subjected to a variation in the lamp power and/or the voltage supplied to the lamp. The metal halide lamp has an arc tube filled with at least sodium halide and scandium halide. The arc tube is formed at its opposite ends with electrodes which gives an arc discharge therebetween. The lamp has regulator means for keeping a coldest spot temperature of the arc tube at 550° C. or more when operating the lamp at a lamp power which is 50% or rated lamp power. It is found that when the lamp is configured to have a coldest spot temperature at 550° C. or more when operating the lamp at a lamp power which is 50% of the rated lamp power, the lamp shows much less color variation even subjected to the lamp voltage variation, thereby maintaining a desired color.

Abstract: A low-pressure discharge lamp with a double spiral shaped discharge tube including two spiral shaped tube portions. The tube portions define a central axis of the discharge tube. A cold chamber portion connects the ends of the spiral shaped tube portions. The cold chamber portion has a first transversal dimension substantially perpendicular to the central axis which is larger than the diameter of the tube portions. The cold chamber portion further has a second transversal dimension substantially parallel to the central axis. The second transversal dimension of the cold chamber portion substantially corresponds to the diameter of the tube portions.

Abstract: The high-pressure discharge lamp comprises a discharge vessel provided with a first and a second lamp electrode, an outer envelope which surrounds the discharge vessel with space and which is provided with a lamp cap. A tube-like UV enhancer having a longitudinal axis is provided in the space having a ceramic wall and provided with an internal enhancer electrode connected to the first lamp electrode and by way of a capacitive coupling connected to the second lamp electrode, and which enhancer electrode has an end inside the enhancer. The capacitive coupling is formed by a metal curl positioned around the UV enhancer in a plane perpendicular to the longitudinal axis of the UV enhancer and close to the end of the enhancer electrode. The lamp shows on ignition with a relative small ignition voltage only a very small ignition delay.

Abstract: A line light source according to the present invention is provided with a plurality of external electrode rare gas fluorescent lamps, and a fixing member fixing the plurality of external electrode rare gas fluorescent lamps such that the center lines thereof are aligned. A contact image sensor of the present invention is provided with the above mentioned line light source.

Abstract: An electric light bulb that minimizes peeling of the coating, suppresses reduction of the number of light fluxes, and is easy to manufacture is described. The electric light bulb 1 has a glass bulb 2 having a straight tube 2a and a leading edge portion 2b that is continuous with the straight tube. A blue coating 5 is applied onto the straight tube, and a white or silver shield coating 6 is applied onto the leading end portion 2b.

Abstract: The invention relates to a discharge lamp with a discharge vessel of silica glass which has a higher operating pressure than atmospheric pressure, where the high temperature viscosity (VA) in the outer surface area of the arc tube portion of the discharge vessel is lower than the high temperature viscosity (VB) at a depth of 100 microns from the outer surface of the arc tube portion. Since the high temperature viscosity (VA) in the outer surface area of the arc tube portion of the discharge vessel is lower than the high temperature viscosity (VB) at a depth of 100 microns from the outer surface of the arc tube portion, formation of thermal distortion in the vicinity of the outer surface of the arc tube portion can be suppressed. This prevents the discharge vessel from being damaged or from breaking by thermal distortion even after operation for a long time.

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: The lighting system comprises a body (1) to emit visible light and an envelope (5) which is transparent to light. The invention is characterized in that the lighting system comprises at least one opto-electronic element (2, 2′) to emit light in a first wavelength range, in that the body (1) is provided with conversion means (3) for absorbing light emitted by the opto-electronic element (2, 2′) and re-emitting light in a second wavelength range, and in that the envelope (5) is provided with a coating (6) reflecting light of the first wavelength range. In a preferred embodiment, the opto-electronic elements (2, 2′) are light-emitting diodes, which preferably emit blue light. Preferably, the conversion means (3) consist of a luminescent material and can be excited, preferably, by light originating from the wavelength range of 400 to 500 nm. Preferably, the coating (6) comprises a multilayer optical filter and is, preferably, provided on an inside surface of the envelope (5).

Abstract: The present invention relates to an improved maintenance, low-pressure mercury vapor discharge lamp having a discharge vessel enclosing a discharge space provided with a filling of mercury and a rare gas in a gastight manner. The discharge vessel is made from a glass of essentially 60-80% by weight SiO2 and 10-20% by weight Na2O. Preferably, the composition of this so-called sodium-rich glass is made of 70-75% by weight SiO2, 15-18% by weight Na2O and 0.25-2% by weight K2O. At least a part of the inner surface of the discharge vessel is provided with a transparent layer having a borate or a phosphate of an alkaline-earth metal and/or of scandium, yttrium or another rare earth metal. Preferably, the alkaline-earth metal is calcium, strontium and/or barium. In a particularly preferred embodiment, the transparent layer is made of yttrium borate and strontium borate. Additionally, the transparent layer preferably has a thickness between 5 and 200 nm and has provided on it a luminescent layer.

Abstract: A low-wattage mercury vapor discharge lamp is provided for use with existing 110V high frequency electronic ballasts. The lamp has a discharge sustaining fill of mercury and an inert gas mixture of krypton and argon that does not require a starting aid. The phosphor layer has a coating weight of 2.0-3.9 mg/cm2.

Abstract: A discharge lamp which enables glare reduction, so that a lighting fixture can be simplified and reduced in weight. The discharge lamp includes an arc tube having a discharge space, a pair of electrodes having tips facing with each other within the discharge space, an outer tube enclosing the arc tube, a base that fixes one side of the outer tube, and two band-shaped light-intercepting films extending on a surface of the outer tube in the direction of the axis of the arc tube and in parallel with each other, wherein in at least one of the light-intercepting films, an extending portion is formed that extends on the side of the top of the outer tube with respect to the tip of the electrode within the discharge space and in the circumferential direction of the outer tube. Accordingly, unevenness in the intensity distribution of the light distribution pattern can be reduced, and generation of glare can be prevented.

Abstract: The invention relates to a luminaire (1) comprising a reflector body (9) having a reflecting part (2) provided with a light reflective coating (5), and comprising contact means (6) for electrically connecting a light source. The coating (5) comprises at least two, light reflective particle groups, the groups exhibiting a mutually different color because of an interference layer (12a-d) provided on the particles (10a-d) which is different for the respective groups. A white color impression of the coating (5) is obtainable when the groups are jointly used in relative proportions in the coating (5). The coating (5) does not suffer from intrinsic absorption, or from color shift.

Abstract: An umber paint, which is excellent in transparency and heat resistance, and which does not bring about environmental pollution, bulbs coated with the umber paint, and turn signal lams equipped with the bulbs. The umber paint, for turn signal lamps, contains at least a red pigment 10a and a yellow pigment 10b, wherein the yellow pigment comprises acetylacetone metal chelateumber.

Abstract: The electric lamp comprises a lamp vessel (11) which transmits visible light and which accommodates a light source (12). The electric lamp comprises a light-absorbing medium (16). The lamp vessel (11) is covered with an optical interference film (15) which comprises layers composed of a first layer of silica and a second layer of a material having a relatively high refractive index which alternate with each other. According to the invention, light from the light source (12) travels through the light-absorbing medium (16) before reaching the interference film (15). Preferably, the light-absorbing layer (16) is disposed between the lamp vessel (11) and the interference film (15). Alternatively, the light-absorbing layer is contained in a wall of the lamp vessel. Preferably, the interference film (15) reflects substantially in the same wavelength range as that wherein the light-absorbing medium (16) absorbs, preferably in the range from 570 to 620 nm.

Abstract: A short arc type mercury lamp in which a cathode and an anode are disposed opposite one another inside an arc tube, at least a noble gas and mercury are filled into the arc tube, cathode contains thorium oxide, a cone-shaped part that continues on from a cathode body is formed on the cathode, and a protruding part that continues on from the cone-shaped part is formed, wherein the number of grain boundaries on a straight line that passes through the approximate center of an arbitrary section in the radial direction of the protruding part is at least 0.5 per mm but not more than 100 per mm.

Abstract: A high intensity discharge (HID) lamp includes a starting gas, a vaporizable fill, and only one electrode sealed within a light transmissive envelope. The one electrode produces a high intensity discharge during operation of the lamp and is connected to an inlead that extends outside the sealed envelope. A ground for electric field lines emanating from the electrode during operation of the lamp is outside the envelope. The ground may be a reflector for the lamp that has an electrically conductive surface. The high intensity discharge is initiated by applying high frequency power to the inlead.

Abstract: An emission mix slurry for coating fluorescent lamp electrodes is provided having a suspension medium of polyethylene glycol 200, and a mixture of calcium-, strontium-, and barium carbonate powder as suspended solids. In another embodiment, the suspension medium is primarily water. The slurry is formulated such that upon activation, the carbonates are oxidized to their corresponding oxides to form the emission mix oxide coating while the polyethylene glycol suspension medium is cleanly oxidized evolving substantially only CO2 and H2O vapor. A method for preparing the emission mix slurry is also provided.

Abstract: A light diffusing coating for use on the exterior surfaces of the glass envelopes of electric lamps. The light diffusing coating containing a bimodal distribution of fine and ultrafine silica scattering centers which are adhered to each other and the glass surface by a sol gel derived silica.

Abstract: In a low-pressure mercury vapor discharge lamp which has an effective light emission length not shorter than 40 cm and a lamp input density not lower than 0.9 W/cm and which contains at least mercury as a light-emitting metal and an activating rare gas, the mercury is provided in an amalgam with another metal, and a thin coating functioning to trap a very minute amount of the mercury is formed on a glass inner surface of the discharge lamp. The thin coating contains, as its main ingredient, an oxide of at least one metal selected from a group of aluminum, silicon, calcium, magnesium, yttrium, zirconium and hafnium. The amalgam is secured to one or more locations of the glass inner surface facing a discharge space of the discharge lamp. Thus, it is possible to lower a necessary discharge-starting voltage and accelerate a rise time of a light amount of ultraviolet rays.

Abstract: A high-pressure mercury lamp includes an arc tube, and a pair of electrodes is provided in a discharge space of the arc tube. In the discharge space, mercury and xenon gas are sealed. The amount of mercury per unit volume that is to be sealed in the discharge space is within a range of 0.12 mg/mm3 to 0.35 mg/mm3. A pressure of the xenon gas in the discharge space is within a range of 2.0×105 Pa to 2.0×106 Pa.

Abstract: An interference coating (22) for reflecting both visible light and a portion of the region of the infrared spectrum is disclosed. The coating includes a dichroic structure of a plurality of layers of a material having a low index of refraction and a plurality of layers of a material having a high index of refraction. The coating has an average spectral high reflectance of at least 80% for wavelengths in the visible light section of the electromagnetic spectrum and of at least 50% for wavelengths in a portion of the infrared section of the electromagnetic spectrum at least 150 nm wide.

Abstract: A mercury vapor discharge fluorescent lamp is provided having a single composite phosphor-containing layer. The composite layer contains both a heterogeneous mixture of halophosphors, rare earth triphosphors and colloidal alumina particles. The coating weight and relative proportion of halophosphors to triphosphors are both tunable to obtain a lamp having specific performance characteristics suitable to a particular application. The colloidal alumina particles contained in the composite layer eliminate the need for a separately applied alumina layer as is conventional in the prior art.

Abstract: To enable the easy and adequately reliable cleaning of the inner surface of the chamber material, and as a result, to provide a dielectric barrier discharge lamp with good lighting characteristics and simplicity of manufacture, a dielectric barrier discharge lamp having a discharge chamber with a cylindrical, double-tube construction with an outer tube and an inner tube, in which the cylindrical discharge space formed between the outer tube and the inner tube is filled with a discharge gas in which excimer molecules are formed by a dielectric barrier discharge, two or more fluid distribution tube remnants connecting to each discharge chamber. It is preferable that the dielectric barrier discharge lamp described above have two or more fluid distribution tube remnants formed on opposite ends of the discharge chamber.

Abstract: A vehicular bulb with its front end coated with a glare-protection paint that contains silicon carbide (SiC) as its pigment substance. With this silicon carbide contained paint, the front end externally assumes a color that is substantially the same color as reflectors and is thus prevented from being easily recognized from the outside of a lighting fixture that is installed with such a bulb.

Abstract: A colored luminaire, in particular a colored signaling light for automobiles, fitted with a lamp and a luminaire cover in which the lamp has a bulb with a coating of a first layer comprising a pigment, which pigment is chosen from the group of perylene pigments, perinone pigments, isoindoline pigments, and thioindigo pigments, is remarkable for a long useful life. It is not attacked by UV radiation, moisture, and spraying salt and is resistant to temperatures of between 250 and 350° C. Colored luminaires with bulb coatings comprising these pigments alone or in combination with further pigments for color correction comply with the color standards for automobile luminaires.

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 are provided with outer bulb (10) enclosing a cylindrical ceramic discharge vessel (20) enclosing a discharge space, said cylindrical ceramic discharge vessel including within said discharge space an ionizable material comprising a metal halide; a first and second discharge electrode feedthrough means (30, 40); and a first and second current conductor (12, 13) connected to said first and second discharge electrode feedthrough means (30, 40), respectively.

Abstract: A method and apparatus for preventing the formation of leachable mercury in mercury arc vapor discharge lamps which comprises coating at least one of the metallic components of the mercury arc vapor discharge lamps with at least one noble metal coating.

Abstract: A photo catalyzer includes a light-transmitting substrate and a catalytic layer provided on the substrate. The catalytic layer substantially includes anatase form of titanium oxide and has a thickness of 0.01 to 0.3 microns. The photocatalyzer can be part of a lamp or lighting fixture arrangement.

Abstract: An environmentally favorable method is described for treating an incandescent lamp with a heat curable substantially organic solvent free silicone composition to improve the shatter resistance of the lamp.

Abstract: An arc discharge lamp, particularly an ultra high pressure lamp, a glass faceplate for such lamp and a method of controlling transmission during lamp operation, the glass containing cuprous halide microcrystals dispersed therein and being capable of absorbing radiation below a wavelength of about 420 nm, the glass faceplate having a film that reflects ultra-violet radiation, and the method comprising maintaining the faceplate at a low temperature during lamp operation to prevent a phase change in the duprous halide.

Abstract: An arc discharge lamp, such as a metal halide arc discharge lamp, has an extended life by reducing loss of the metallic portion of the fill. At least one component of the fill reacts with fused silica in the arc tube or diffuses through the arc tube walls. The fill will generally comprise a sodium halide, at least one additional metal halide, and an inert starting gas. A borosilicate glaze which is vitreous and light-transmissive is provided on the wall of the arc tube. The borosilicate glaze is comprised of a borosilicate glass containing at least one metal oxide selected from aluminum, scandium, yttrium, and the rare earth elements. The borosilicate glaze may further contain additional rare earth elements or transition metals to alter the light or energy emission of the lamp by absorbing select wave lengths. For instance, titanium, ceria, cobalt, chromium, iron or neodymium, or combinations of the foregoing, may be added.

Abstract: Improved lamp of the type comprising the crystal bulb of an incandescent lamp or the crystal tube of a fluorescent lamp or preferably of the type comprised of a tube-shaped fluorescent lamp, characterized in that the structure of the tube itself forms a support for a luminescent product arranged as a coating which captures the light proceeding from a source and generated by the lamp itself thereby enabling it to emit its own light after the excitation has stopped thereby providing a self-contained lighting element.

Abstract: Optical interference coatings applied to electric lamps for transmitting, on average, 90% of the visible light radiation in the wavelength range from 400 to 760 nm and for reflecting infrared radiation, comprise three spectrally adjacent multilayer stacks of alternately a first layer (L) of a material having a low refractive index and a second layer (H) of a material having a high refractive index. According to the invention, the reflectance of the interference film amounts, on average, to at least 75% in the wavelength range from 800 to 2200 nm, whereas the transmittance amounts, on average, to at least 90% in the wavelength range from 400 to 760 nm. Preferably, the reflectance of the interference coating amounts, on average, to at least 85% in the wavelength range from 800 to 2500 nm. The first stack S1 (design wavelength &lgr;(S1) 2100 nm) of the interference film as shown in FIG. 2 is based on a design comprising eleven layers of alternately a high and a low refractive index material.

Abstract: The present invention relates to a lamp device using a high-pressure vapor discharge lamp, particularly to an improvement for controlling the influence of the generation of heat, which accompanies an increase in lamp power and a reduction in the size of a reflector. A lamp device of the present invention comprises a discharge lamp having an arc tube enclosing luminescent materials and having a pair of opposing electrodes disposed therein and a pair of sealed portions extending from the arc tube; a reflector which reflects light radiated by the discharge lamp; a transparent member covering an open end of the reflector and accommodating the discharge lamp in a space between the transparent member and the reflector; and means for preventing an excessive temperature rise wherein the temperature rise of welded parts of wiring members electrically connected to the electrodes of the discharge lamp is restricted.