Abstract: 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.

Abstract: A metal halide lamp includes a ceramic arc tube that is composed of a main body and two narrow tube parts provided at respective ends of the main body; a pair of electrodes provided inside the main body; two feeders, each being connected at one end thereof to a different one of the electrodes inside the main body, and extending through a different one of the narrow tube parts, so as to be external to the arc tube at another end; a starting wire that is connected to one of the feeders, and that is in a vicinity of or contacts an outer surface of the arc tube; and a current suppressing unit that is on a current path of the starting wire, and suppresses or cuts off current on the path.

Abstract: A metal vapor discharge lamp including an arc tube 1 that includes a container 10 and power transmission members 20a and 20b. The container 10, made of translucent ceramic, is divided into a main tube portion 11 and narrow tube portions 12a and 12b extending out from both ends of the main tube portion 11. The power transmission members 20a and 20b respectively include electrode pins 21a and 21b made of tungsten. Coils 22a and 22b made of tungsten are respectively wound around ends of electrode pins 21a and 21b, which are respectively joined with electrode supporting members 23a and 23b made of conductive cermet. Electrode length L1 is 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 L2 is set to (0.032P+3.5) mm to (0.032P+8.0) mm inclusive.

Abstract: A metal halide lamp includes: an arc tube having a light-emitting unit forming a discharge space therein, and two thin-tube units fitted into openings in both ends of the light-emitting unit; two electrode holding members provided through the thin-tube units so that one ends hold the electrodes and the other ends extend from one ends of the thin-tube units not facing the discharge space, and sealed to the thin-tube units via sealing members; and a metal tubular member through which the electrode and/or electrode holding member is inserted within the thin-tube units. Expressions “X≧0.0056P+0.194” and “0≦L≦0.44X” are satisfied, where “P” is lamp wattage [W], “X” distance [mm] from one end of the thin-tube unit facing the discharge space to one end of the coil facing the thin-tube unit, and “L” length [mm] of a part of the tubular member protruding into the discharge space.

Abstract: 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 “L≧0.012P+2.5 [mm]”, where “L” is distance [mm] between the electrode top and one end of the electrode holder closer to the discharge space, and “P” is lamp wattage [W].

Abstract: 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 (CeI3) and sodium iodide (NaI) are enclosed as a light-emitting substance, wherein a molar composition rate NaI/CeI3 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/cm2, 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.

Abstract: A high-pressure discharge lamp having an arc tube that includes a main tube part and a pair of capillary tube parts is provided. The main tube part includes a pair of electrodes and a metal halide enclosed, and the pair of capillary tube parts is arranged at the of the main tube part. The pair of capillary tube parts is sealed by means of a seal member to a different one of the feeders, and supplies electricity to each of the electrodes. At least one of the feeders includes a first conductive member that is resistant to halides and sealed to the capillary tube part, and a second conductive member that is connected to the first conductive member outside the capillary tube part and fixed at an outer end of the capillary tube part by means of the seal member.

Abstract: A metal vapor discharge lamp having a highly reliable sealed portion. The lamp has an arc tube including a discharge portion of translucent ceramic in which a discharge metal is filled and a pair of electrodes is disposed; small tubular portions coupled to both ends of the discharge portion; feeder bodies inserted into the small tubular portions; and a sealing material sealing the gap between the feeder body and the small tubular portion at the end portion opposite to the discharge portion. The end of the small tubular portions and the inner surface of the discharge portion define a discharge space. The feeder bodies are composed of a conductive cermet and connected to the electrodes. The ends of the feeder bodies extend at least to the ends of the small tubular portions. The temperature of the end of the sealing material on the discharge space side during the lamp operation is not more than 800° C.

Abstract: A metal halide lamp using a ceramic arc tube in which less lamp flickering occurs, the flux maintenance factor during the lifetime is high and the possibility of lamp break-off is low. The metal halide lamp includes an arc tube 1 in which iodide pellet of metal halide is filled, and a pair of electrodes are arranged in the ceramic arc tube so that the electrode coils are facing each other. The following relation is satisfied: 0.00056×W+0.061≦&agr;≦0.0056×W+1.61 where &agr; (in mm) denotes a length of the portion of the electrode bar protruding from the end face of the electrode coil and W (in Watt) denotes the lamp power.

Abstract: The present invention provides a metal halide lamp in which the change of the color temperature is suppressed regardless of the orientation of the light emitting bulb in use. The metal halide lamp includes a light emitting bulb of translucent ceramics that includes a light emitting portion and tubular portions that are connected to the light emitting portion. The light emitting portion includes a liquid holding portion on the inner surface of the light emitting portion so as to hold a liquefied substance that moves on the inner surface toward one of the tubular portions. The internal diameter d of the light emitting bulb at the liquid holding portion satisfies 0.4 D<d<0.7 D, where D is an internal diameter of the light emitting bulb at the maximum internal diameter portion of the light emitting portion.

Abstract: 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 “L≧0.012P+2.5 [mm]”, where “L” is distance [mm] between the electrode top and one end of the electrode holder closer to the discharge space, and “P” is lamp wattage [W].

Abstract: The present invention provides a metal halide lamp having a ceramic arc tube vessel that includes a discharge arc tube member and thin tube members, the discharge arc tube member including taper parts and a main tube part in the middle in a longitudinal direction, the taper parts and the main tube part having a larger outside diameter than an outside diameter of ends of the discharge arc tube in a longitudinal direction, and the thin tube members each being fit to the respective ends of the discharge arc tube, where a minimum curvature radius R is set to be 0.3 mm or more at each transitional area of an external surface between each taper part and a corresponding end of the discharge arc tube.

Abstract: 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. This prevents a discharge arc from jumping from tip portions of the electrodes to the spaces at starting of the lamp, and avoids occurrence of cracks and breakages in the narrow tubes.

Abstract: 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.

Abstract: 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 (CeI3) and sodium iodide (NaI) are enclosed as a light-emitting substance, wherein a molar composition rate NaI/CeI3 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/cm2, 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.

Abstract: A metal halide lamp has an arc tube including an arc tube container as an envelope made of an oxide-based translucent ceramic material such as alumina, and 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, lowering of flux maintenance factor and color temperature in aging of the lamp are suppressed, and the thus provided metal halide lamp with an alumina ceramic tube for indoor and outdoor use has a white light source color and it has a high-wattage, high luminous efficiency, and a long service life.

Abstract: 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.

Abstract: A metal halide lamp using a ceramic arc tube in which less lamp flickering occurs, the flux maintenance factor during the lifetime is high and the possibility of lamp break-off is low. The metal halide lamp includes an arc tube 1 in which iodide pellet of metal halide is filled, and a pair of electrodes are arranged in the ceramic arc tube so that the electrode coils are facing each other.

Abstract: A metal halide lamp including a discharge tube of a transparent ceramic in which a discharge metal and a buffer gas are sealed, the discharge tube having electrodes at both ends thereof, including a discharge portion, slender tube portions provided at both ends of the discharge portion, into which feedthroughs including the electrodes and lead-in wires are inserted, and slender tube sealing portions in which gaps between the slender tube portions and the feedthroughs are sealed with a sealing material, an outer tube containing the discharge tube, and a transparent protecting cylinder provided inside the outer tube so as to surround the discharge tube is provided. At least one of the slender tube sealing portions is exposed beyond the protecting cylinder. This provides a metal halide lamp that suppresses leaks in a discharge tube sealing portion while maintaining high efficiency and high color rendition by using a ceramic discharge tube, and that is tolerant of an external shock.

Abstract: A discharge tube (1) made of transparent ceramics includes a main tube (17) and slender tubes provided on both sides thereof. In one of the slender tubes, a main electrode lead-in member that is connected to a main electrode (6b) is inserted and sealed. In the other two-hole slender tube, a main electrode lead-in member that is connected to a main electrode (6a) and an auxiliary electrode lead-in member that is connected to an auxiliary electrode (9) are inserted and sealed so as to be isolated electrically from each other. With such a structure, it is possible to achieve highly efficient and stable lifetime characteristics and suppress changes in characteristics during lifetime caused by leaks during an operation and reaction between a sealing material and an enclosed material inside the discharge tube. In addition, it is possible to obtain a high-pressure metal vapor discharge lamp that has stable lamp starting characteristics and allows a free design of the discharge tube.