Toshiba Lighting & Technology Corporation

Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Yasuki Mori

Masakazu Shibuya

Yoichiro Mitsuyuki

Kazuo Honda

Akihiro Kamiya

Yoshiyuki Tokuda

Hiroki Sasaki

Toshihiko Ishigami

Hiromichi Kawashima

Kazuyoshi Okamura

Hisanori Sano

Kazuiki Uchida

Atsushi Matsuura

Akihiro Yonezawa

Katsusuke Uchino

Akira Itoh

Mamoru Furuya

Yasuhiro Iwafuji

Tadatoshi Higashi

Youichiro Mitsuyuki

Kimihito Sato

Hirochika Shiohama

Mitsuho Kotabe

The invention provides a high-pressure discharge lamp incorporating an outer envelope storing a pair of electric terminals a plurality of arc tubes which are respectively stored in this outer envelope and electrically connected in parallel, and a plurality of ignition aids available for assisting operating of these arc tubes, where these ignition aids are provided for each of these arc tubes and contain potentials different from each other. In addition, the invention also provides a lighting system for operating the high-pressure discharge lamp. The lighting system comprises the first and second power supply lines which respectively provides mutual connection between a pair of terminals of the high-pressure discharge lamp, a ballast which is at least provided for either of the first and second power supply lines, a power switch which is provided for either the first or the second power supply line, a pulse generating means which generates either the positive or the negative ignition pulses to be superimposed on AC power voltage output from an AC power supply source, and a control circuit which alters polarity of the ignition pulses output from the pulse generator.

High-pressure discharge lamp and lighting method

A metal vapor discharge lamp has a small arc tube of a single end type. The maximum and minimum thicknesses of the wall of the arc tube and the ratio of the minimum thickness to the maximum thickness are set to the values in predetermined ranges. The set thicknesses prevents breakage of the arc tube and deterioration of the lamp characteristics.

Metal vapor discharge lamp having single end arc tube of predetermined

A prescribed amount of tin halide is sealed in the arc tube of a metal halide lamp wherein a given amount of metal halide including a target amount of halogen and at least a predetermined amount of rare earth metal is sealed in the arc tube thereof to maintain a high lumen maintenance factor for an extended operation period. The prescribed amount of tin halide is preferably within 4.6.about.234 mol % of the predetermined amount of rare earth metal.

Metal halide lamp maintaining a high lumen maintenance factor over an

Arc discharged by a short arc discharge lamp can be made so small in diameter as to appear like a spot. Therefore, the illuminance efficiency of the short arc discharge lamp can be made high and its brightness can also be enhanced.

Short arc discharge lamp

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 pressure discharge lamp includes a glass enclosure defining a hermetically sealed discharge space filled with an ionizable gas. A pair of electrodes extend into the discharge space, each electrode having a connection end and a discharge end, between which electrodes, in the operating condition of the lamp, a discharge takes place. A pair of holding portions on opposite sides of the glass enclosure and hold the respective connection ends of the electrodes. Metal lead foils connected to the connection ends are sealed in the holding portions. One or both of the connection ends is shaped, e.g., as a conical frustrum or as a wedge, such that the thickness of its inner end is reduced with respect to the thickness of its outward end. The joining portion of the glass enclosure is internally necked at a position adjacent the reduced thickness portion of the connection end.

High pressure discharge lamp

A pulse generating apparatus includes a base current supply section for generating a constant DC current having a first prescribed current level for turning on a xenon lamp, and a pulse current section for adding a pulse current having a second current level greater than the first current level and a prescribed pulse duration within a prescribed repetition period to the constant DC current. The base current supply section and pulse current section should satisfy the following equations:

Pulse generating apparatus for xenon lamp and lighting method thereof

This invention provides a small metal halide lamp which has a power input of 100 W or less, provided with: an arc tube having a pair of electrodes spaced apart from each other and containing a rare gas, mercury, sodium halide and scandium halide therein; and an envelope for housing the arc tube. The mixing ratio of sodium halide to scandium halide based on weight is 3:1 to 10:1, and the total content of the sodium halide and the scandium halide is 10 to 40 mg per unit volume (cc) of the arc tube. At least one phospor selected from the group consisting of a manganese-activated magnesium fluorogermanate phosphor and a cerium-activated yttrium aluminate phosphor is applied to the inner surface of the envelope. In addition, a green-emitting phosphor is preferably coated on the inner surface of the envelope.

Small metal halide lamp

Growing community of inventors

Yokohama, Japan

Yasuki Mori