Ushio Denki Kabushiki Kaisha

Yasuro Kikuchi

Kyosuke Fujina

Takeo Matsushima

Norihiro Inaoka

Takumi Yamane

Shunichi Morimoto

Yoichiro Higashimoto

A short-arc discharge lamp includes a pair of electrodes disposed facing each other inside a light-emitting tube, a scale-like structure being formed on an outer surface of at least one electrode of the pair of electrodes, and a coating film covering the outer surface on which the scale-like structure is formed. The scale-like structure includes a plurality of flaky protrusions protruding from the outer surface in a direction inclined with respect to a normal direction of the outer surface, each flaky protrusion having a front surface whose angle formed with the outer surface is an obtuse angle and a back surface whose angle formed with the outer surface is an acute angle. The coating film contains at least one of metal oxides, metal carbides, metal borides, metal silicides, and metal nitrides. A part of the coating film enters a space sandwiched between the back surface and the outer surface.

Short-arc discharge lamp

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 an anode and a cathode are disposed opposite each other in a bulb, achieves a long service life due to thorium (Th) being stably supplied to the cathode tip for a long time after lamp operation has been commence since the formation of the flicker phenomenon is suppressed over a long time due to the cathode being made of tungsten which contains thorium oxide on a surface space from the cathode tip, a carbide layer of tungsten carbide is formed and the cathode being bordered by an emitter containing body of tungsten which contains thorium dioxide, and a carbide layer of tungsten carbide being formed at least in a region bordering the cathode.

Discharge lamp having a cathode and emitter assembly composed of tungsten and thorium oxide and joined through a carbide interface region

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 short arc discharge lamp has improved starting properties in which there is no danger of damaging the arc tube that surrounds a discharge space and in which the radiant light from the arc tube is not adversely shielded. This is achieved by providing the short arc discharge lamp with a first electrode having an electrical potential and to which a high voltage is applied, and a second electrode opposite the first at a in spaced relationship. Additionally, in the discharge space, there is positioned at least one conductive component with a tip projecting into the discharge space. The conductive component has an electrical potential which is identical to the electrical potential of the first electrode and has a tip spaced a distance from the second electrode which is greater than the distance between the first and the second electrode.

Growing community of inventors

Himeji, Japan

Yasuro Kikuchi