Abstract: A metal halide discharge lamp with which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: A metal halide discharge lamp with which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: A metal halide discharge lamp which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of a metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: Disclosed is a metal halide discharge lamp which essentially permits disusing mercury. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide and a rare gas, the first halide being a halide of a metal which achieves a desired light emission, the second halide having a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide, and acting as a buffer gas.

Abstract: Disclosed is a metal halide discharge lamp which essentially permits disusing mercury. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide and a rare gas, the first halide being a halide of a metal which achieves a desired light emission, the second halide having a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide, and acting as a buffer gas.

Abstract: Disclosed is a metal halide discharge lamp which essentially permits disusing mercury. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide and a rare gas, the first halide being a halide of a metal which achieves a desired light emission, the second halide having a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide, and acting as a buffer gas.

Abstract: A metal halide discharge lamp which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of a metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: A high-pressure discharge lamp which includes a light-transmitting air-tight discharge container, an electrode formed of tungsten as a main component and fixedly sealed in the discharge container, and a discharge medium containing a halide of a light emitting metal and sealed in the discharge container. The surface of the electrode is defined as follows. That is, the average value of center line average roughness Ra of the surface, is set to 0.3 &mgr;m or less, or the average value of the center line average roughness Rz of the surface of the electrode, is set to 1.0 &mgr;m or less, or the average value of the surface area increasing rate of the surface of the electrode is set to 1.0% or less.

Abstract: Disclosed is a metal halide discharge lamp which essentially permits disusing mercury. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide and a rare gas, the first halide being a halide of a metal which achieves a desired light emission, the second halide having a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide, and acting as a buffer gas.

Abstract: A metal halide discharge lamp which essentially permits disusing mercury is provided. The metal halide discharge lamp comprises a refractory and transparent hermetic vessel, a pair of electrodes fixed to the hermetic vessel, and a discharge medium sealed in the hermetic vessel and containing a first halide, a second halide, and a rare gas. The first halide is a halide of a metal which achieves a desired light emission. The second halide has a relatively high vapor pressure, being at least one halide of a metal which is unlikely to emit a visible light compared with the metal of the first halide and acts as a buffer gas.

Abstract: A high-pressure discharge lamp which includes a light-transmitting air-tight discharge container, an electrode formed of tungsten as a main component and fixedly sealed in the discharge container, and a discharge medium containing a halide of a light emitting metal and sealed in the discharge container. The surface of the electrode is defined as follows. That is, the average value of center line average roughness Ra of the surface, is set to 0.3 &mgr;m or less, or the average value of the center line average roughness Rz of the surface of the electrode, is set to 1.0 &mgr;m or less, or the average value of the surface area increasing rate of the surface of the electrode is set to 1.0% or less.

Abstract: A high-pressure discharge lamp which includes a light-transmitting air-tight discharge container, an electrode formed of tungsten as a main component and fixedly sealed in the discharge container, and a discharge medium containing a halide of a light emitting metal and sealed in the discharge container. The surface of the electrode is defined as follows. That is, the average value of center line average roughness Ra of the surface, is set to 0.3 &mgr;m or less, or the average value of the center line average roughness Rz of the surface of the electrode, is set to 1.0 &mgr;m or less, or the average value of the surface area increasing rate of the surface of the electrode is set to 1.0% or less.

Abstract: The present invention provides a high-voltage discharge lamp having an internal volume of 0.05 cc or less that is small yet maintains a desirable lifetime and a high luminous efficiency, a high-voltage discharge lamp device using the lamp, and a lighting apparatus using the lamp. The high-voltage discharge lamp comprises a ceramic discharge vessel that has a spherical, bulging section and a pair of small diameter cylindrical sections. The spherical, bulging section surrounds a discharge space. The small diameter cylindrical sections are connected to the ends of the spherical, bulging section. Electrode-integrated power-supplying conductors are used. Each conductor comprises a seal part and a halide-resistant part. The halide-resistant part having a proximal end connected to the distal end of the seal part. The distal end of the halide-resistant part projects into the spherical, bulging section of the translucent ceramic discharge vessel forming an electrode.

Abstract: A high pressure metal vapor discharge lamp including an outer bulb having a seal portion, an arc tube enclosed within the outer bulb, the arc tube having at least a pair of electrodes and containing at least a light emitting material and a rare gas, a pair of first lead wires of which one ends connect to the electrodes respectively and another ends mounted at the seal portion of outer bulb, a pre-heater disposed within the outer bulb, the pre-heater comprises a heat element and an insulating material covers the heat element and facing the arc tube to give the heat to the arc tube, and a second lead wires connected to the heat element of pre-heater, the portion of the second lead wires which are exposed in the outer bulb are surrounded by a heat-resisting insulator and the base portion of the second lead wires are mounted at the seal portion of outer bulb.