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 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 metal vapor discharge lamp including an outer tube having a closed portion at a first end and a base at a second end; a discharge tube inside of which an electrode is provided, located in the outer tube; and a sleeve enveloping the discharge tube and located in the outer tube, wherein the sleeve includes an open portion on the closed portion side of the outer tube; the closed portion side of the outer tube is provided with a support for supporting an end of the closed portion side of the sleeve; the support comprises a column portion having a narrow plate shape or a narrow stick shape separated from the open portion of the closed portion side of the sleeve, and a sleeve holding portion provided at an end of the column portion and is in contact with the sleeve; and the support is connected to a feeding body connected to the electrode and led from the discharge tube toward the side of the closed portion, and the support also is connected to an electric power supply wire extending toward the side of the base.

Abstract: A discharge tube is provided inside an outer tube. At least a pair of electrodes is arranged inside the discharge tube, and at least mercury is sealed into the discharge tube. The electrode includes an electrode pin and a metal pipe that surrounds the electrode pin. Because a contact area of the electrode pin and the inner surface of the metal pipe is sufficiently maintained in a stable manner, a tip temperature of the electrode pin can be lowered sufficiently without a variation. As a result, it is possible to obtain a high pressure discharge lamp that has excellent lifetime characteristics and can considerably reduce the variation of the lifetime characteristics between lamps.

Abstract: A metal vapor discharge lamp comprises a discharge tube having a ceramic container into which a pair of electrodes and a discharge metal compound are sealed. The container comprises a first cylindrical portion, tapered portions, second cylindrical portions and third cylindrical portions. The third cylindrical portions are shrinkage-fitted to the second cylindrical portions. The electrodes are attached to the third cylindrical portion with a sealing member. An inner wall of the third cylindrical portions and the electrodes define a gap. The inner surface of the tapered portions and a central axis of the electrodes define an angle of 40°-80°. Thus, a metal vapor discharge lamp is provided whose discharge tube does not include disks among its parts, and which can maintain, over a long period of operation, good operating characteristics that depend only little on the lamp orientation.

Abstract: A metal halide lamp comprises a discharge tube of transparent ceramic in which a discharge metal is sealed, the discharge tube having a main cylindrical portion, ring portions provided at both ends of the main cylindrical portion, and tubular cylindrical portions provided at the ring portions; and a pair of electrodes inside the discharge tube; wherein a wall thickness .alpha. (in mm) of the main cylindrical portion satisfies the relation0.0023.times.W+0.22.ltoreq..alpha..ltoreq.0.0023.times.W+0.62,and a wall thickness .beta. (in mm) of the ring portion satisfies the relation0.0094.times.W+0.5.ltoreq..beta..ltoreq.0.0094.times.W+1.5,wherein W is the lamp power expressed in Watt. Alternatively, the discharge tube is air-tightly enclosed in the outer tube; the outer tube is filled with a gas comprising nitrogen gas; and the wall thickness .alpha. (in mm) of the main cylindrical portion satisfies the relation0.0023.times.W+0.12.ltoreq..alpha..ltoreq.0.0023.times.W+0.62,and the wall thickness .beta.

Abstract: A metal halide lamp of the present invention has a ceramic discharge tube and a proximity conductor disposed adjacent to the ceramic discharge tube.

Abstract: A high-pressure metal vapor discharge lamp of the present invention has a discharge tube made of a ceramic material having a transparent or translucent property, and the discharge tube has a main tube, and a first and a second disks for sealing the main tube. The first disk is disposed at one opening of said main tube, and the second disk disposed at the other opening of said main tube. Further, the first and the second disks have a cylindrical narrow tube. A lead-through-part for disposing either of a first and a second main electrodes and an auxiliary electrode in the main tube and a sealing member integrated with the lead-through-wire are inserted in the cylindrical narrow tube, and the sealing member is fixed to the cylindrical narrow tube so that the cylindrical narrow tube is sealed airtightly.