Abstract: An alloy for a lead member is used for an electric lamp having a metal/vitreous material interface. Molybdenum or tungsten serving as an electric lamp current conductor is used as a base for the lead member, wherein the molybdenum or tungsten contains titanium oxide or other oxides. Automotive bulbs use this alloy for a lead member.

Abstract: A mercury-free arc tube having a closed glass bulb held between pinch seal portions located at opposite ends of the closed glass bulb and a pair of electrodes provided in the closed glass bulb. The closed glass bulb does not contain mercury (Hg), but contains a main light emitting, a buffer metal halide, and a starting rare gas enclosed in the closed glass bulb. The buffer metal halide includes a halide selected from halides of Ta, Th, Cu, Rb, Nb and Pd. Preferably, at least one of the halides is Ta, Cu, Rb or Nb. The halides serve as a buffer substance and a light emitting substance in substitution for the mercury, and have an ionization potential of about 5 to 8.5 eV and excitation potential of about 4.5 eV or less having emission spectrum in a visible range, and are sealed with the rare gas.

Abstract: A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI3). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).

Abstract: A discharge bulb including an arc tube 16 having a light-emitting tube portion 20a and shroud glass 18 surrounding the arc tube 16 in a tubular form. An inert gas and metal halides are sealed in a discharge space 24 inside the light-emitting tube portion 20a, which is mercury-free. Xenon gas is filled in an annular space 34 between the arc tube 16 and the shroud glass 18. Heat is restrained from being transmitted from the light-emitting tube portion 20a to the shroud glass 18 through the annular space 34. An increase in the heat loss and the temperature rise of the shroud glass 18 are restrained.

Abstract: An arc tube that effectively prevents a metal halide from being deposited in a light emitting tube portion, causing the change of a light emitting color or the generation of lighting failures in an arc tube. An axial distance L1 from a neck portion 20C of an arc tube body formed between a light emitting tube portion 20A and a pinch seal portion 24B of the arc tube body to a step-down plane portion 20Ba2 of each pinch seal surface 20Ba in a pinch seal portion 20B is set to 1 mm or less. During pinch seal, consequently, a sufficient pinching pressure is applied to a electrode 26, such as a tungsten electrode up to a portion close to a tip portion thereof. Thus, it is possible to reduce the volume of an almost wedge-shaped slit 24a formed around the tungsten electrode 26 on an end in the axial direction of a discharge space 24, thereby decreasing the amount of a metal halide deposited on the slit 24a.

Abstract: A lamp unit for emitting near-infrared light by electric discharge, has: a hollow discharge tube; a cesium halide enclosed in the hollow of the discharge tube; a near-infrared penetration filter covering around the discharge tube. The cesium halide may include at least one of cesium iodide and cesium bromide. Also, an indium halide and thallium halide may further be enclosed in the hollow discharge tube.

Abstract: A method of producing an arc tube including inserting an electrode assembly in which a bent portion is formed in a lead wire into a glass tube to self-hold the electrode assembly to a predetermined position of the glass tube. After the electrode has been inserted to the predetermined position, pinch-sealing is conducted on a portion of the glass tube where the assembly is inserted. In the method, the electrode assembly is inserted into a metal guide pipe which is coaxially disposed with respect to the glass tube, to be once held into the pipe. Thereafter, the assembly may be pushed by a thin rod-like pushing member to be inserted to the predetermined position in the glass tube. One or more vertical grooves which are to be axially engaged with the bent portion of the assembly to circumferentially lock the bent portion may be formed in the inner side of the guide pipe. Using the one or more grooves, the assembly may be guided to the glass tube W without being in sliding contact with the guide pipe.

Abstract: A method of manufacturing an arc tube having a light emitting tube portion, a first pinch seal portion, and a second pinch seal portion, all formed on a quartz glass tube. The first and second pinch seal portions are disposed on both sides of the light emitting tube portion. The quartz glass is provided almost vertically with the first pinch seal portion down. A thermal insulating plate is provided in a boundary position between the light emitting tube portion and a portion to be pinch-sealed in an outer peripheral space of the quartz glass tube. Liquid nitrogen is jetted from a cooling nozzle provided obliquely below the light emitting tube portion toward the same, thereby cooling the light emitting tube portion. The portion to be pinch-sealed is heated with a burner, and pinch-sealed with a pincher immediately thereafter.

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

Abstract: A method of manufacturing an arc tube for a discharge lamp unit, incorporating a primary pinch-sealing step for mounting an electrode assembly in an open end of a glass tube W with a chamber portion 12. The electrode assembly comprises an electrode rod 6, a connecting foil 7 and a lead wire 8 integrally connected in series. The electrode assembly is inserted into an open end of the glass tube W such that a leading end of the electrode rod projects into the chamber portion 12. A temporary pinch seal region L1 of the glass tube W is pinch-sealed such that a portion of the connecting foil that is connected to the lead wire is contacted by the glass tube W. A vacuum is maintained inside the glass tube and a main pinch seal region L2 of the glass tube is pinch-sealed such that a portion of the connecting foil connected to the electrode rod is contacted by the glass tube.

Abstract: A mercury-free arc tube having a closed glass bulb held between pinch seal portions located at opposite ends of the closed glass bulb and a pair of electrodes provided in the closed glass bulb. The closed glass bulb does not contain mercury (Hg), but contains a main light emitting, a buffer metal halide, and a starting rare gas enclosed in the closed glass bulb. The buffer metal halide includes a halide selected from halides of Ta, Th, Cu, Rb, Nb and Pd. Preferably, at least one of the halides is Ta, Cu, Rb or Nb. The halides serve as a buffer substance and a light emitting substance in substitution for the mercury, and have an ionization potential of about 5 to 8.5 eV and excitation potential of about 4.5 eV or less having emission spectrum in a visible range, and are sealed with the rare gas.

Abstract: A mercury-free arc tube for a discharge lamp unit including a closed glass bulb and a pair of electrode rods provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury as in the related art arc tubes, but contains main light emitting metal halide and starting rare gas enclosed in the closed glass bulb. In accordance with necessity, predetermined buffer metal halide in place of mercury may be enclosed to suppress the lowering of the tube voltage to some extent. In addition, the tube current I is increased to make the tube voltage high. The tube current I (unit: A) and the outer diameter d (unit: mm) of each electrode rod are set to have a relationship of 1.0≦I/d≦5.0. As a result, though such an increased tube current is used, the electrode temperature is kept in optimum temperature.

Abstract: A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI3). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).

Abstract: A discharge lamp arc tube in which a pair of electrode assemblies each having an electrode rod, a sheet of molybdenum foil and a lead wire integrally series-connected to one another have respective molybdenum foil containing regions pinch-sealed with glass, and electrodes are disposed opposite to each other in a closed glass bulb containing a light emitting substance or the like enclosed therein. The surface of the sheet of molybdenum foil sealed at each of the pinch seal portions has a micro-asperity surface roughened by an etching treatment including oxidation and reduction, so that silica glass is closely packed in the micro-asperity of the surface of the sheet of molybdenum foil. As a result, the adhesion (mechanical bonding strength) in the interface between silica glass and molybdenum foil is improved so that foil rising is suppressed and, accordingly, the lifetime of the arc tube is extended.

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

Abstract: An arc tube provided with a central sealed chamber 12, in which light-emitting substances are enclosed, having a pair of electrode assemblies disposed opposite to each other. The electrode assemblies are sealed in pinch seal portions 13. The arc tube incorporates a residual-compressive-stress layer 16 formed on a surface of the glass layer 15 in each of the pinch seal portions 13 that contacts the electrode rod 6 included in each electrode assembly. The residual-compressive-stress layer has a length greater than or equal to 30% of the axial length of a glass layer region that only contacts the electrode rod 6 and/or an angular range greater than or equal to 180° in a circumferential direction of the electrode rod. Thermal stress (tensile stress) produced in the boundary between the glass layer 15 and the electrode rods 6 after the arc tube 10 has been turned on is absorbed and dispersed by the residual-compressive-stress layer 16 surrounding the electrode rods 6.

Abstract: An arc tube body 20 and a foil such as molybdenum foil 30 are joined with each other such that a compressive stress of 105 N/m2 or more remains at an ordinary temperature in the arc tube body 20 along a junction surface. The compressive stress is always generated on the arc tube body 20 even if a fluctuation in the stress is caused on the junction surface by the repetition of the ON/OFF of the arc tube (or a tensile stress is caused to have a very small value even if the compressive stress and the tensile stress are alternately generated). Thus, the junction strength of both members may be increased. In one embodiment, a plurality of cracks (intercrystalline cracks) may be generated on the molybdenum foil 30 by a high pressure acting during pinch seal, and quartz glass is caused to enter the cracks so that the junction strength of both members can be increased.

Abstract: A method of manufacturing an arc tube for a discharge lamp device. The method comprises: inserting a first electrode assembly having an electrode, a molybdenum foil and a molybdenum lead wire connected integrally in series from a first open end of a glass pipe for the arc tube having a swollen chamber portion formed in a middle part in a longitudinal direction such that a tip of the electrode of the first electrode assembly is protruded into the chamber portion; introducing an antioxidant gas from a second open end of the glass pipe into the glass pipe; inserting the first open end of the glass pipe into a gas chamber to which the antioxidant gas is to be supplied; and pinch-sealing a first region including the molybdenum foil of the first electrode assembly in the glass pipe for a primary pinch seal with holding the first open end of the glass pipe in an antioxidant gas atmosphere.

Abstract: An arc tube that effectively prevents a metal halide from being deposited in a light emitting tube portion, causing the change of a light emitting color or the generation of lighting failures in an arc tube.

Abstract: The pinch-sealing for the first one of a pair of molybdenum foils is not performed by flowing inactive gas within a quartz glass tube like the prior art but performed in a manner that the lower end portion of the quartz glass tube 4 is sealed, and then and a pinch seal estimation portion 4b is squeezed by a pincher while air within the quartz glass tube is exhausted from the upper end portion thereof so that pressure within the quartz glass tube becomes in a negative pressure state of 100 torr or less and while heating the pinch seal estimation portion 4b. Accordingly, at the time of the squeezing, the inner wall surface 4c of the pinch seal estimation portion 4b thus heated is attracted to the molybdenum foil 12 side thereby to form fine concave and convex portions on the interfaces between the molybdenum foil 12 and the quartz glass tube 4, so that the molybdenum foil and the quartz glass tube are placed in an engaged state and the contact area therebetween is increased.