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 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: 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: 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: 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.

Abstract: A discharge lamp arc tube comprises: a glass tube having a linear extension portion, a closed glass bulb, and pinch seal portions at both sides of the closed glass bulb; and electrode assemblies, each having an electrode rod, a molybdenum foil and a lead wire integrally series-connected, the molybdenum foil having oxide films thereon, wherein the electrode assemblies are inserted into the glass tube and pinch-sealed such that the molybdenum foils are positioned at the respective pinch seal portions.

Abstract: A metallic halide lamp has an envelope of silica glass defining a discharge chamber with a pair of pinch seals extending in opposite directions therefrom. A pair of tungsten electrode stems are partly buried in the respective seals and electrically connected to a pair of molybdenum lead wires via a pair of molybdenum foils which are wholly embedded in the pinch seals. The molybdenum foils have a recrystallization grain size of not more than about 50 .mu.m.

Abstract: The invention is directed to preventing occurrence of molybdenum foil breakage during a pinch sealing operation in a method of fabricating an arc tube having a pair of molybdenum foils pinch-sealed on both sides of a spherical portion of a glass tube by sequentially pinch-sealing the respective molybdenum foils. A first molybdenum foil is not pinch-sealed (first pinch seal) with an inert gas introduced into a glass tube as in a conventional embodiment, but is pinch-sealed with the internal pressure of the glass tube maintained at a vacuum of 0.5 torr or less. As a result, oxidation of the molybdenum foils causing breakage of the molybdenum foils during a pinch sealing operation is minimized. Hence, an arc tube having each of a pair of molybdenum foils made of molybdenum whose purity is 99.95% or more and with a thickness of 20 .mu.m or less can be fabricated.

Abstract: A discharge lamp arc tube comprises: a glass tube having a linear extension portion, a closed glass bulb, and pinch seal portions at both sides of the closed glass bulb; and electrode assemblies, each having an electrode rod, a molybdenum foil and a lead wire integrally series-connected, the molybdenum foil having oxide films thereon, wherein the electrode assemblies are inserted into the glass tube and pinch-sealed such that the molybdenum foils are positioned at the respective pinch seal portions.

Abstract: An electric discharge lamp assembly including a lamp bulb having two lead wires, and a lamp base supporting two lead support members with respective tip ends thereof being connected respectively to the lead wires of the lamp bulb. One of the lead support members is formed to have an elongated length and is covered by an insulating tubular member substantially. The rear end portion of the insulating tubular member is fitted on and secured to a tubular portion of the lamp base which portion is integrally formed with the lamp base. Whereby the electric discharge between the two support members is prevented effectively, and the insulating tubular member is secured to the lamp base reliably.