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: An electric discharge lamp apparatus which incorporates an arc tube 10 structured such that an enclosed glass bulb 12 of an arc tube body 11 is enclosed in an ultraviolet-ray shielding globe 20 and having a front end which is supported by a metal lead support 36 forwards extending from an insulating plug 30 provided with a focusing ring 34 and made of synthetic resin and which has a structure that a rear end of the globe 20 of the arc tube 10 is supported by a metal support member 50 secured to the insulating plug 30, wherein the metal support member 50 is constituted by a metal base plate 51 secured to the insulating plug 30 and forming a reference plane f2 running parallel to the focusing ring 34 on the front surface of the insulating plug and a metal vertically-holding member 60 (a slide plate 61 and an arc-tube holding band 71) integrally joined to the metal base plate 51 and arranged to vertically hold an electrically-discharge axis L of the held arc tube 10 with respect to reference plane f2 of the meta

Abstract: An electric discharge lamp apparatus incorporates: a metal lead support 36 which projects over the front surface of an insulating plug 30 made of synthetic resin, which supports the leading end of an arc tube 10 and which serves as a passage for electric power arranged to be supplied to the arc tube 10; and an insulating sleeve 38 which is made of ceramics formed into a pipe shape and through which the lead support 36 is inserted, wherein a predetermined gap S2 is provided between the insulating sleeve 38 and the lead support 36. Thus, insertion of the lead support 36 into the insulating sleeve 38 can easily be performed, and a dimension error of the insulating sleeve 38 can be absorbed. Since a bent portions 36a is provided for a portion of the lead support 36 into which the insulating sleeve is inserted, the insulating sleeve 38 and the lead support 36 can hermetically integrated with each other. Thus, rattle of the insulating sleeve 38 with respect to the lead support 36 can be prevented.

Abstract: An insulating plug for an electric discharge lamp apparatus, includes: a front portion includes an outer cylindrical portion and an inner cylindrical portion, the inner cylindrical portion having a substantially unique thickness and an opening to receive an arc tube of an electric discharge lamp; a focusing ring extending from the outer cylindrical portion of the front portion; and a rear portion having a rear-end cylindrical portion and a center portion. The front portion, the focusing ring and the rear portion are integrally molded by injecting a synthetic resin into a mold from a gate of the mold, the gate facing the rear-end cylindrical portion of the rear porition of the insulating plug. Furthermore, the electric discharge lamp apparatus in which an arc tube is inserted into the opening of the insulating plug described above.

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: An arc tube for a discharge lamp device comprises: a cylindrical glass tube made of glass, having linear extension portions, each having an opening portion at an end, and a spherically swollen portion formed between the linear extension portions; and electrode assemblies inserted in the respective linear extension portions, wherein neck portions are formed in boundaries between the spherically swollen portion and the linear extension portions so that the glass in each of the linear extension portions side is prevented from flowing into the inside of the spherically swollen portion when the linear extension portions are pinch-sealed.

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 method for manufacturing an arc tube which obtains a high luminous flux retention rate by completely removing impurities, such as oxides, from the surfaces of the electrodes within the arc tube. An exhaust tube is connected to a glass tube of an arc tube in which a pair of electrodes are oppositely disposed. After gas is exhausted through the exhaust tube from the glass tube, inert gas is introduced. An arc discharge generating circuit is connected to the oppositely disposed electrodes, and an ion bombardment process is carried out in which an arc discharge is caused between the electrodes in the inert gas atmosphere at a current density of 30 to 100 A/mm.sup.2. Due to the arc discharge process, impurities (oxides), which lead to a reduction of the luminous flux retention rate, are completely removed from the electrode surfaces.

Abstract: In the manufacture of arc tubes for use as light sources of vehicle headlamps, there is first prepared a semifinished arc tube by inserting one electrode assembly into a tubular glass envelope through one end thereof and by sealing this end. The semifinished arc tube is then placed in communication with a hermetically enclosed space filled with argon under pressure, with the consequent introduction of the inert gas into the glass envelope through a second end thereof. Another electrode assembly and chemicals such as a metal halide and mercury are then introduced from the enclosed space into the semifinished arc tube through the second end, totally without contact with the atmospheric air. Then, with the glass envelope placed out of communication with the enclosed space, the argon is exhausted from within the envelope, and xenon is charged instead into the envelope through the second end, which is closed subsequently.

Abstract: An arc tube for a discharge lamp unit which emits light which is suitable in luminous flux, color temperature, and chromaticity. The arc tube is composed of a closed glass ball in which electrodes confront one another and which is sealingly charged with light emitting materials, namely, mercury and a metal iodide of NaI and ScI.sub.3 groups together with Xe inert gas. In accordance with the invention, the closed glass ball has a volume of 20 to 50 .mu.l, the density of the mercury in the closed glass ball is in a range of 2.times.10.sup.-2 to 4.times.10.sup.-2 mg/.mu.l, the density of the metal iodide is in a range of 6.times.10.sup.-3 to 12.times.10.sup.-3 mg/.mu.l, and the charged Xe gas pressure is 3 to 6 atm. These ranges make it possible to readily manufacture on a large scale arc tubes which are substantially equal in performance, being substantially uniform in tube voltage, luminous flux, color temperature and chromaticity.

Abstract: An arc tube having a closed glass bulb having no broken-off portion, and a method of manufacturing the arc tube. A glass bulb is formed on a glass tube substantially at the middle. An electrode assembly is inserted into one end portion of the glass tube, and the one end portion is closed by pinch-sealing. A light emitting material is supplied into the glass bulb through the other end portion of the glass tube, another electrode assembly is inserted into the other end portion, and the latter is closed by pinch-sealing. Since the closed glass bulb has no broken-off portion, the arc tube is free from the difficulty that the distribution of light is adversely affected. Moreover, in manufacturing the arc tube of the invention, it is unnecessary to connect an exhaust tube to the glass tube. Therefore, the number of manufacturing steps is small, and the arc tube can be manufactured with ease.

Abstract: A discharge lamp device having an insulator base made of a synthetic resin integrally bonded to a globe holding member made of ceramic wherein a discharge lamp is attached. Also provided is a pair of lead supports for supporting the discharge lamp at its opposite ends. The discharge lamp and lead supports are completely surrounded by an ultraviolet ray shielding globe which is fixed to globe holding member. The globe effectively absorbs harmful ultraviolet rays having a wavelength in a predetermined wavelength range.

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.

Abstract: A discharge lamp has a lamp assembly including a discharge lamp unit with a pair of lamp leads extending therefrom, and a base assembly including a pair of base leads electrically connected to the pair of lamp leads and mechanically supporting the lamp unit in position with respect to the base assembly. The base assembly comprises a hollow base structure of electrically insulating material molded in one piece with a partition dividing the interior thereof into a pair of completely isolated spaces. Electrically connected to the base leads, a pair of sheet metal conductors are received with clearances in the respective isolated spaces in order to preclude the possibility of an electric discharge taking place between the pair of conductors within the base structure.