Kabushiki Kaisha Toshiba

Toshiba Lighting & Technology Corporation

Tokyo Shibaura Denki Kabushiki Kaisha

Akihiro Yonezawa

Hiroki Sasaki

Toshihiko Ishigami

Takashi Oosawa

Akihiro Kamiya

Shinji Inukai

Kazuyoshi Okamura

Yasuki Mori

Kazuiki Uchida

Akira Itoh

Takahiro Sugimoto

Yoichiro Mitsuyuki

Kenji Araki

Yoshio Hirose

Kazuo Takita

Takayuki Aoki

Makoto Nishizawa

Youichiro Mitsuyuki

Kazuhiko Yoshikawa

Youichirou Mitsuyuki

Zenzou Mitamura

Shinichi Ooshima

Yujiro Ike

In a discharge lamp having a discharge medium sealed in a discharge tube assembly including electrodes for producing a discharge, a nitride layer is formed on a surface of an envelope tube of the discharge tube assembly. The nitride layer is formed by substituting an oxygen component of an oxide constituting the tube wall of the envelope tube with nitrogen, and exhibits a continuous and smooth reduction in nitride content in the direction of depth. This chemically stable nitride layer prevents a reaction between the discharge medium and the tube wall material, and removal or injection of the discharge medium. In addition, since the nitride layer also exhibits a continuous change in thermal expansion coefficient in the direction of depth, the thermal stress is reduced, and cracking, peeling, removal, and the like do not occur.

Nitride layer for discharge lamps

A low pressure discharge lamp apparatus has a low pressure discharge lamp with an arc tube. The arc tube has a first end and a second end, each with electrodes which define a discharge space therebetween. A mercury/rare gas is sealed in the arc tube. The low pressure discharge lamp apparatus further has a lighting circuit apparatus for lighting the lamp by supplying a current with a polarity reversed for each half cycle to electrodes in the first and second ends of the arc tube. The lighting circuit apparatus supplies, to the lamp, a current whose waveform has a flat peak for each half cycle and a maximum current value of the current is restricted to less than a level in which the excitation of mercury atoms is saturated.

Low pressure discharge lamp apparatus

In order to maintain an ultraviolet-ray intensity of a metal halide lamp for a long period, the present invention provides a high intensity discharge lamp comprising an arc tube having electrodes at its both ends, and a rare gas, mercury, iron, a halogen and silver enclosed in the tube, wherein a gram atom ratio of silver to iron is 0.05 to 0.2. The present invention also provides a high intensity discharge lamp comprising an arc tube having electrodes at its both ends, and a rare gas, mecury, iron, a halogen, tin and silver enclosed in the tube, wherein ([Fe]+[Sn])/[J]&lt;0.5 and (2[Fe]+2[Sn]+[Ag])/[J]&gt;1, where [Fe], [Sn], ]Ag] and [J] are, respectively, gram atoms of iron, tin, silver and the halogen.

High intensity discharge lamp containing iron and silver in the arc tube

A high-efficacy, high power ultraviolet radiation lamp is disclosed. Electrodes are respectively provided at two ends of a discharge tube, and at least a rare gas is sealed in the discharge tube. The discharge tube is curved in a U shape. A reservoir for reserving a radiant material for radiating ultraviolet rays projects from the discharge tube. An isolating section is provided to surround at least the reservoir. The isolating section adjusts the temperature of the reservoir and supplies an appropriate amount of radiant material into the discharge tube.

Lamp for generating ultraviolet radiation

A high pressure sodium lamp includes an arc tube having an inner diameter greater than 12 mm. An amalgam including a prescribed quantity of sodium and mercury is sealed in the arc tube. To achieve the maximum lamp efficiency in different values of the inner diameter of the arc tube, the lamp should satisfy the following relationships:

High pressure sodium lamp

The molybdenum foil coupling member is disclosed in which potassium (K) and silicon dioxide (SiO.sub.2) are respectively dispersed in the range from 200 to 800 ppm and from 200 to 2000 ppm so as to resist to fracturing upon exposed to high temperature. This coupling member is particularly well suited for used in electric lamps having quartz glass envelopes which are pinch sealed at either end.

Electric lamp

Growing community of inventors

Yokosuka, Japan

Akihiro Yonezawa