Matsushita Electric Industrial Co., Ltd.

Hideaki Kiryu

Kiyoshi Takahashi

Mamoru Takeda

Yuriko Kaneko

Masato Yoshida

Takayuki Murase

Makoto Horiuchi

Ryo Minamihata

Takeshi Saito

Takeshi Saitoh

Makoto Kai

Kenji Mukai

Kazuhisa Tanaka

Tetsuji Takeuchi

A metal halide lamp for an automobile headlight is provided, which includes an arc tube in which a pair of tungsten electrodes are provided at both ends and a metal halide as a main component of a luminescent material and xenon gas as a buffer gas are sealed, wherein the tungsten electrodes contain not more than 0.4 wt % of thorium oxide, the metal halide contains scandium iodide, and a pressure of the xenon sealed in the arc tube is at least 0.4 MPa. This makes it possible to provide a long-life metal halide lamp for an automobile headlight that can achieve a further improved lumen maintenance factor and other life characteristics during 2000 hours or more of lighting.

Metal halide lamp for automobile headlight

A pair of electrodes ( ) are provided in an arc tube ( ) I/S is 20 (A/mm ) or less on a condition that an area of a cross section at a tip of the electrodes ( ) is S (mm ) and an operating current between the electrodes ( ) is I (A). According to this constitution, a long lamp life can be obtained without causing a rise in the lamp voltage and the blackening of the arc tube ( ) by the evaporation of the electrodes while operation time becomes longer.

Mercury-free metal-halide lamp

A mercury-free metal halide lamp includes an arc tube including a pair of electrodes inside the tube. In the arc tube, a rare gas and a metal halide are contained, and no mercury is contained. The mercury-free metal halide lamp is horizontally operated such that the pair of electrodes is substantially horizontal. The mercury-free metal halide lamp further includes magnetic field applying means for applying a magnetic field including a component substantially perpendicular to a straight line connecting heads of the pair of electrodes in a substantially vertical direction. The density of halogen atoms evaporated during steady-state operation with respect to unit inner volume of the arc tube is 20 &mgr;mol/cc or more.

Mercury-free metal halide lamp

Mercury-free high-intensity discharge lamp operating apparatus and mercury-free metal halide lamp

A high-intensity discharge lamp includes an arc tube including a pair of electrodes opposed to each other therein; and a trigger wire made of a conductive material provided in an outer circumference of the arc tube. The trigger wire is turned to be in a conductive state with one electrode of the pair of electrodes when a start-up voltage is applied across the pair of electrodes, and discharge is started between the pair of electrodes in a state where an electrical field is formed between the trigger wire that is in the conductive state and the other electrode of the pair of electrodes.

High-intensity discharge lamp and high-intensity discharge lamp operating apparatus

A discharge lamp which enables glare reduction, so that a lighting fixture can be simplified and reduced in weight. The discharge lamp includes an arc tube having a discharge space, a pair of electrodes having tips facing with each other within the discharge space, an outer tube enclosing the arc tube, a base that fixes one side of the outer tube, and two band-shaped light-intercepting films extending on a surface of the outer tube in the direction of the axis of the arc tube and in parallel with each other, wherein in at least one of the light-intercepting films, an extending portion is formed that extends on the side of the top of the outer tube with respect to the tip of the electrode within the discharge space and in the circumferential direction of the outer tube. Accordingly, unevenness in the intensity distribution of the light distribution pattern can be reduced, and generation of glare can be prevented. Furthermore, because it is not necessary to add a further mechanism for reducing glare such as a light-intercepting plate, a lighting fixture can be simplified and reduced in weight.

Discharge lamp with light-intercepting film bands

A high-pressure discharge lamp includes an arc tube portion enclosing a luminous material in the tube; a side tube portion substantially made of quartz glass that extends from the arc tube portion; and an electrode rod whose first end is arranged in the arc tube portion and a part of which is provided in the side tube portion. The electrode rod is substantially made of tungsten. A region containing at least one of copper oxide and copper is present in at least a part of the portion of the side tube portion in which the part of the electrode rod is positioned.

High-pressure discharge lamp and method for producing the same

In a high intensity discharge lamp, at least one of an arc bend amount and an apparent width of arc is controlled by a simple configuration at low cost. A high intensity discharge lamp system has a high intensity discharge lamp and an operating circuit for driving the high intensity discharge lamp . In the high intensity discharge lamp , a rare gas and a filling material containing a metal halide as a light generating substance are enclosed in the arc tube provided with a pair of electrodes a and b. The lamp system is disposed such that the line connecting the electrodes a and b is horizontal, and by applying a magnetic field having a vertical magnetic flux thereto and by varying the frequency of alternating current for driving the high intensity discharge lamp , at least one of an arc bend amount and an apparent width of arc can be easily controlled.

High intensity discharge lamp, driving apparatus for high intensity discharge lamp, and high intensity discharge lamp system

A discharge lamp comprising an arc tube containing a pair of electrodes in a light-emitting portion and an outer tube that envelops the light-emitting portion and is at least partly fused to the arc tube, wherein the outer tube comprises silicon dioxide in the range from 90 to 99.88 wt. % and boron in the range from 0.12 wt. % or more. The discharge lamp can inhibit the arc tube from deforming when the outer tube and arc tube are fused to each other by adjusting a softening temperature of the outer tube to an appropriate temperature and can realize a high accuracy of luminous intensity distribution.

Discharge lamp with outer tube comprising silicon dioxide and boron

A discharge lamp for an automobile headlight has a light color that lies in a region common to the following three regions: a region bounded by an ellipse with a color point (u, v)&equals;(0.224, 0.331) as a center thereof, a major axis of 0.080, a minor axis of 0.024, and an angle from a u axis of 35 degrees in the CIE 1960 UCS diagram; a region bounded by an ellipse with a color point (u, v)&equals;(0.220, 0.332) as a center thereof, a major axis of 0.060, a minor axis of 0.022, and an angle from a u axis of 15 degrees in the CIE 1960 UCS diagram; and a region bounded by an ellipse with a color point (u, v)&equals;(0.235, 0.335) as a center thereof, a major axis of 0.060, a minor axis of 0.030, and an angle from a u axis of 30 degrees in the CIE 1960 UCS diagram. The light color lies in a range on a side of color temperature lower than an isotemperature line of a correlated color temperature of 3800K and higher than an isotemperature line of a correlated color temperature of 3400K in the CIE 1960 UCS diagram.

Discharge lamp for automobile headlight and the automobile headlight

The present invention provides a mercury-free metal halide lamp with an increased lamp operating voltage and prolonged lamp life without enclosing mercury or excessively increasing an inner pressure of an arc tube. A lamp in accordance with the present invention contains, as a content of a fill material,, 0.04 mg of ScI,, 0.21 mg of NaI, 7 atm of Xe at room temperature, and 0.1 mg of YI,, which is an iodide of Y, Y having an ionization potential as a simple substance being 5 to 10 eV and a vapor pressure at a temperature of lamp operation being 10,or higher.

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Takatsuki, Japan

Hideaki Kiryu