Harison Toshiba Lighting Corporation

Toshiba Lighting & Technology Corporation

Hiroyuki Kato

Hiromichi Kawashima

Kozo Uemura

Makoto Deguchi

Seiko Kawashima

Toshihiko Ishigami

Mikio Matsuda

Toshio Hiruta

Nobuhiro Tamura

Takuya Honma

Sakae Katayama

Yoshiyuki Watanuki

The present invention provides a high-pressure discharge lamp that uses substantially no mercury and reduces discharge flicker. The high-pressure discharge lamp is kept on with a lamp power of 50 W or lower in a stable state, and the temperature T (&#xb0; C.) of the electrode at a point at a distance of 0.3 mm from the tip end to the base end in the stable state and the amount A (mol/cc) of free iodine produced when the lamp is turned off after 100 hours of on-time satisfy the formula (1):T/A&#x3e;10.

High-pressure discharge lamp, high-pressure discharge lamp lighting device and automotive headlamp apparatus

A metal halide lamp includes a fire-resistant and translucent hermetic vessel containing amounts of scandium halide and sodium halide sealed in the hermetic vessel satisfying the formula of 0.25&#x3c;a/(a+b)&#x3c;0.5, where reference character 'a' denotes the mass of scandium halide and reference character 'b' denotes the mass of sodium halide.

Metal halide lamp and automotive headlamp apparatus

A metal halide lamp comprises a discharge container including a discharge space and a pair of sealing sections. A discharge medium containing a metal halide and a rare gas and essentially free from mercury is sealed in the discharge container. A pair of electrodes are arranged to face each other within the discharge space, and the side edge portions on the side of the proximal end portion of these electrodes are held by the sealing sections. The amount of water contained in the metal halide, i.e., the light-emitting material, included in the metal halide lamp essentially free from mercury, i.e., Hg-less metal halide lamp, is controlled to 50 ppm or less.

Metal halide lamp, headlight apparatus for vehicle using the same, and method of manufacturing metal halide lamp

To provide, in a special situation of a mercury-free lamp in which a luminance flicker tends to occur unlike a mercury-containing lamp, a metal halide lamp having an electrode structure modified so as to suppress the luminous flicker that is suitably used as an automotive headlamp, and an automotive headlamp apparatus incorporating the same. A metal halide lamp includes: a hermetic vesselwhich is fire resistant and translucent; a pair of electrodessealed in the hermetic vesselwith facing each other at a distant of 5 mm or less, the electrodes each having a shaft parthaving a diameter of 0.25 mm or more and a tip, which originates an arc, having a curved surface having a radius of one-half or less of the diameter of the shaft part; and a discharge medium essentially containing no mercury, sealed in the hermetic vessel, and containing halides of metals including a light-emitting metal in an amount of 0.005 mg/mmof an inner volume of the hermetic vessel or more and a xenon gas at 5 atmospheres or higher at a temperature of 25&#xb0; C., in which the metal halide lamp is turned on with a lamp power of 60 W or lower in a stable state.

Metal halide lamp with electrodes having a curved surface part and automotive headlamp apparatus

Growing community of inventors

Ehime-ken, Japan

Hiroyuki Kato