Hamamatsu-Photonics K.k.

Shigeki Ishihara

Kouji Kawai

Naoki Masuda

Koji Kawai

Osamu Yogi

Hirohisa Ota

A metal halide lamp comprises a sealed tube containing mercury vapor and halide, and electrodes extending to a center of the sealed tube, supported by sealed portions at both ends of the sealed tube. A notch extending in a direction perpendicular to an axis of the electrode is formed in each electrode. A transverse cross sectional area of a portion where the notch is formed is smaller than the transverse cross sectional area of another portions and functions as a heat dam portion for damming heat. Accordingly, temperature of a proximal portion from the heat dam portion to the support portion is lower than that of the same portion of the conventional electrode, and temperature of a distal end portion is higher than that of the same portion of the conventional electrode. Thus, formation of low-melting alloy due to reaction of the proximal portion of the electrode and the metal halide can be suppressed.

Metal halide lamp having heat dam portion

A light irradiation device emits a visible light and an ultraviolet ray by using one light source to reduce an energy cost and simplify a mechanism. A light source 7, a first reflection mirror 8 and a second reflection mirror 9 are provided in a case 6. A radiation light ranging from an ultraviolet area to a visible light area is emitted from the light source 7. The first reflection mirror 8 is a visible light reflection mirror and the second reflection mirror 9 is an ultraviolet ray reflection mirror. Of the light emitted from the light source 7, the visible light is reflected by the first reflection mirror 8 and the ultraviolet ray passes through the first reflection mirror 8 and is reflected by the second reflection mirror 9.

Light irradiation device

A discharge tube for emitting light of the present invention includes an inner bulb including a hollow portion for defining therein an arc discharge chamber which encloses therein gas for emitting light, the inner bulb further including a pair of electrodes and a pair of metal members each of which is connected to a corresponding one of the pair of electrodes, the pair of electrodes being projected in the arc discharge chamber from the inner bulb and the pair of metal members being projected outwardly of the inner bulb, the hollow portion having an outer diameter of a first value and an outer tube for sealingly enclosing therein the inner bulb, the outer tube including a small-diameter portion having an outer diameter of a second value which is equal to or smaller than the first value, wherein the inner bulb is held in the interior of the outer tube, with a gap being formed between an outer surface of the inner bulb and an inner surface of the outer tube, in such a manner that the outer tube supports the metal members projected outwardly of the inner bulb.

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Hamamatsu, Japan

Shigeki Ishihara