Ushio Denki Kabushiki Kaisha

Kyosuke Fujina

Yasuro Kikuchi

Takeo Matsushima

Katsuoki Miyasu

Norihiro Inaoka

Takumi Yamane

Yoichiro Higashimoto

Shoichi Mayama

Kazuhiro Inaoka

Takeo Matushima

Katuoki Miyasu

A xenon lamp having a lamp tube made of silica glass containing titanium oxide and having a discharge chamber with a light emitting part containing xenon and in which a cathode and an anode are arranged in opposition to each other, the cathode and anode being mounted on an end of a respective lead rod, the lamp tube also having side tube parts extending from each of opposite sides of the light emitting part, each lead rod being sealed by a gradient binding part which is arranged in a respective side tube part, and the side tube parts having a narrowed shrink part in a region facing the light emitting part, wherein a conductive film is provided on an outer surface area of the shrink part and an adjoining area of an outer surface of the light emitting part at the cathode side of the lamp tube; and wherein the conductive film is electrically connected to the cathode.

Xenon lamp

A discharge lamp includes a cathode and an anode which face each other in an arc tube, wherein the cathode is made of tungsten in which thorium oxide is doped. The cathode has a cylindrical body portion, a tip portion having a cone shape, and a middle portion formed between the body portion and the tip portion, wherein an angle &#x3b8;of the tip portion is set to a range of 55 degrees&#x2266;&#x3b8;&#x2266;65 degrees, and an angle &#x3b8;formed by side faces of the middle portion is smaller than that of the tip portion.

Discharge lamp cathode having tip, middle, and body portions

A high pressure discharge lamp in which the cathode has a cylindrical body part and a conical part which is doped with thorium dioxide (ThO), and with a diameter which decreases in a direction from the body part toward the tip area of the conical part by at least one light receiving surface area being formed between the body part and the tip area of the cone in a base part of the conical part. The light receiving area lies at an angle with respect to the center axis of the conical part and the body part, said angle which is measured from the side of the body part being greater than the angle of inclination which is formed between the outer periphery of the conical part in the tip area of the cone and the center axis.

High pressure discharge lamp having a conical part and a cylindrical body part

A xenon lamp in which fluctuation of the arc can be suppressed and the time until formation of the flicker phenomenon delayed by having an anode with a flattened or rounded anode tip, a rounded or flattened back end; a portion with a diameter that gradually increases from the anode tip toward the back end of the anode; a portion with a decreasing diameter located behind the portion with the increasing diameter of an axial length which is greater than the length in the axial direction of the portion with an increasing diameter; and a portion with a maximum outside diameter formed in a transition area between the portion with the increasing diameter and the portion with a decreasing diameter, and that the transition area between the portion with the increasing diameter and the portion with the decreasing diameter is formed to be continuous.

It is an object to provide a xenon discharge lamp lighting device with few or no lamp startup lighting failures, even when a xenon discharge lamp is near the end of its useful life. In the xenon discharge lamp, when a lamp voltage increases, from the ending point of the rush current supply time period, occurring upon starting a xenon discharge lamp lighting igniter, for a preset specified time T, the input power is increased in accordance with the lamp voltage increase amount, whereby constant power control is provided thereafter.

Xenon discharge lamp lighting device

To provide a long-lived short-arc type discharge lamp and light-source device in which high temperature oxidation of external lead rods is inhibited, a short-arc type discharge lamp of the type in which external lead rods ( ) are electrically connected to electrodes ( ) that extend from sealing tubes ( ) that are located at each of opposite ends of an emission envelope ( ), and in external lead rods are electrically connected via lead lines ( ) to bases ( ) that are attached to a respective sealing tube, by a first ventilation aperture ( ) being formed in a peripheral wall of each base and second ventilation aperture ( ) being formed in the tail end of at least one base. Ventilation-concentration hoods ( ) that conduct cooling air can be mounted at the first aperture. The lamp is held by fixing the periphery of each base in a lamp support plate ( ).

Short-arc type discharge lamp having ventillation apertures at the bottom of the bases

Discharge lamp of the short arc type

A discharge lamp provided with an anode of the water cooled type achieves advantageous cooling directly connected a tungsten tip piece to a tip of a body element of the anode that is formed of copper has a water cooling arrangement therein, by having a maximum outer diameter of the tungsten tip piece about equal to an outer diameter D (mm) of the body element, and by maintaining the relationship between the outer diameter D and the thickness of the tungsten tip piece L of: 0.2.ltoreq.L/D.ltoreq.0.5. In accordance with a preferred embodiment, the tungsten tip piece is directly connected to a tip of a cylindrical body element inside of which a cooling water feed tube is arranged extending coaxially to the body element, and in which cooling water is fed from a base of this cooling water feed tube, along the cooling water feed tube, strikes an inner side of the tip end of the body element and finally is conveyed through a gap between an inner side of the body element and an outer side of the cooling water feed tube which serves as a cooling water drainage duct. Preferably, the tungsten tip piece has the shape of a truncated cone whose maximum outer diameter is about equal to the outer diameter D (mm) of the body element and a thickness in a lengthwise direction of the body element.

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Shiso-gun, Japan

Kyosuke Fujina