Matsushita Electric Industrial Co., Ltd.

Hiroshi Enami

Yoshiharu Nishiura

Shunsuke Kakisaka

Masanori Higashi

Shigefumi Oda

Tatsuya Kawamura

Takaharu Yanata

Toshizo Kobayashi

Hiroshi Nohara

Takashi Maniwa

Shiki Nakayama

Mikio Miura

Masato Wada

Tatsuo Nishimoto

A metal halide lamp has an arc tube including an arc tube container made of an oxide-based translucent ceramic material. The arc tube is filled with cerium halide as a luminescent material and a halide of a rare earth element that is more reactive with the ceramic material than is the cerium halide. Accordingly, a reaction between the oxide-based translucent ceramic material and the halide of a rare earth element is accelerated while a reaction between the oxide-based translucent ceramic material and the cerium halide is suppressed. This suppresses a decrease of the cerium halide that serves for light emission, and also reduces changes in the lamp color temperature. Thereby, during aging of the lamp, the flux maintenance factor and color temperature are improved. Therefore, the indoor-outdoor metal halide lamp provides a white light source color that has high-wattage, high luminous efficiency, and a long service life.

Metal halide lamp

A first electrode part in a rod shape is placed on an upper side, and a second electrode part in a rod shape having a higher melting point than that of the first electrode part is placed on a lower side, so that ends of the first and second electrode parts are brought into contact. Contact ends or vicinities thereof are irradiated with a laser beam, so that the electrode parts are welded. Here, a region irradiated with the laser beam is in a long narrow shape having a minor axis directed in a vertical direction and a major axis directed in a horizontal direction. This makes it possible to manufacture an electrode with a consistent high quality with a high yield.

Electrode, manufacturing method thereof, and metal vapor discharge lamp

A metal vapor discharge lamp including an arc tubethat includes a containerand power transmission membersand. The container, made of translucent ceramic, is divided into a main tube portionand narrow tube portionsandextending out from both ends of the main tube portion. The power transmission membersandrespectively include electrode pinsandmade of tungsten. Coilsandmade of tungsten are respectively wound around ends of electrode pinsand, which are respectively joined with electrode supporting membersandmade of conductive cermet. Electrode length Lis set to (0.041P+0.5) mm to (0.041P+8.0) mm, 'P' representing a lamp power in watts. Alternatively, a narrow tube portion length Lis set to (0.032P+3.5) mm to (0.032P+8.0) mm inclusive.

Metal vapor discharge lamp and lighting apparatus capable of stable maintenance of characteristics

To provide a high-efficiency and long-life high intensity discharge lamp that is obtained by a configuration in which a neon gas or a neon-based gaseous mixture is filled as a starting-assistance rare gas for an alumina ceramic arc tube, and a filling pressure is set to 13 kPa or more. The high intensity discharge lamp is provided with the alumina ceramic arc tube having a discharge arc tube, alumina ceramic narrow tubes formed at both end portions of the discharge arc tube, electrodes and power feeders, the electrodes and the power feeders being arranged to form spaces in the narrow tubes. The discharge arc tube is filled with the neon gas or the neon-based gaseous mixture as the starting-assistance rare gas at a filling pressure of 13 kPa or more.

High intensity discharge lamp and high intensity discharge lamp system using the same

A metal halide lamp has an arc tube including an envelope as an arc tube container made of an oxide-based translucent ceramic material, and the arc tube is filled with luminescent materials comprising at least a cerium halide, a sodium halide, a thallium halide and an indium halide. An amount of the cerium halide is in a range from 20 wt % to 69.0 wt %, an amount of the sodium halide is in a range from 30 wt % to 79.0 wt %, and a total amount of the thallium halide and the indium halide is in a range from 1.0 wt % to 20 wt % with respect to the entire metal halides. Accordingly, the arc discharge is spread, bending of the arc discharge toward the arc tube wall is suppressed, and thus, the metal halide lamp has improved luminescent efficiency, where lowering of the flux maintenance factor is suppressed even after a long-time use, and hues of the luminescent colors are corrected.

A high-pressure discharge lamp includes: an arc tube that is made from a translucent ceramic material and composed of a main-tube part in which a discharge space is formed and thin-tube parts extending from both ends of the main-tube part; and a pair of electrodes having rods respectively extending from the two thin-tube parts into the discharge space so that the tops face each other with a distance in-between. The rod of at least one of the electrodes is held by a tubular electrode holder made of a halide-resistant metal embedded in and bonded to the thin-tube part via an adhesive agent including a sintered halide-resistant metal impregnated with mixture glass. The electrode holder is at such a position that satisfies &ldquo;L&gE;0.012P&plus;2.5 &lsqb;mm&rsqb;&rdquo;, where &ldquo;L&rdquo; is distance &lsqb;mm&rsqb; between the electrode top and one end of the electrode holder closer to the discharge space, and &ldquo;P&rdquo; is lamp wattage &lsqb;W&rsqb;.

High-pressure discharge lamp

A safety metal halide lamp with a high luminous efficiency and a long lamp life is provided. The metal halide lamp includes an arc tube made of light-transmissive ceramic, in which a pair of electrodes is provided and cerium iodide (CeI ) and sodium iodide (NaI) are enclosed as a light-emitting substance, wherein a molar composition rate NaI/CeI of the light-emitting substance is specified within a range of 3.8 to 10, inclusive, and a wall load on the arc tube ranges from 13 to 23 W/cm , inclusive, and on a series of X, Y coordinates, where X denotes a value of a lamp watt (W) and Y denotes a value of Le/&phgr;i, where Le and &phgr;i denote a distance between the pair of electrodes and an internal diameter of the arc tube, respectively, values of the Le/&phgr;i and the lamp watt are specified to be within a range surrounded by lines passing through the points (200, 0.75), (300,0.80), (400, 0.85), (700, 1.00), (1,000, 1.15), (1,000, 2.10), (700, 2.00), (400, 1.90), (300, 1.80), and (200, 1.70) in this stated order.

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Nishinomiya, Japan

Hiroshi Enami