Koito Manufacturing Company, Ltd.

Kunimasa Mochiduki

Shinichi Irisawa

Yasuyoshi Numajiri

Takeshi Fukuyo

Yoshitaka Ohshima

Masato Harazaki

An electric discharge lamp apparatus which incorporates an arc tube,structured such that an enclosed glass bulb,of an arc tube body,is enclosed in an ultraviolet-ray shielding globe,and having a front end which is supported by a metal lead support,forwards extending from an insulating plug,provided with a focusing ring,and made of synthetic resin and which has a structure that a rear end of the globe,of the arc tube,is supported by a metal support member,secured to the insulating plug,wherein the metal support member,is constituted by a metal base plate,secured to the insulating plug,and forming a reference plane f,running parallel to the focusing ring,on the front surface of the insulating plug and a metal vertically-holding member,(a slide plate,and an arc-tube holding band,) integrally joined to the metal base plate,and arranged to vertically hold an electrically-discharge axis L of the held arc tube,with respect to reference plane f,of the metal base plate,so that the electrically-discharge axis L of the arc tube,is accurately brought to a predetermined required position with respect to the focusing ring

Electric discharge lamp apparatus

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

Electric discharge lamp apparatus with insulating plug

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.

Electric discharge lamp apparatus and insulating plug therefor having a particular front portion

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.

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Shizuoka, Japan

Kunimasa Mochiduki