An electrode (1) of a discharge device (e.g. the cathode of a discharge lamp) having a side area (4) and a tip area (5) implanted with an emissive material dopant induced by ion implantation is disclosed. The side area (4) of the electrode (1) may be masked (3) during ion implantation or a diffusion barrier layer (7) may be added on the side area (4) after ion implantation.

A high-pressure discharge lamp with a burner unit which has a discharge vessel which encloses a discharge space and in which two electrodes are arranged opposite one another, wherein the electrodes each have an electrode support and an electrode tip, wherein the electrode tips are located opposite one another to form an electric arc during operation of the high-pressure discharge lamp, wherein at least a first one of the electrodes is configured as a coil electrode which has an electrode support and an electrode coil formed by a wire wound around the electrode support, wherein an exposed end of the electrode support forms the electrode tip, and wherein the electrode coil is arranged in a tip region of the electrode support adjacent to the electrode tip in the discharge space, and wherein an antenna to which voltage can be applied is routed along an outer surface of the discharge vessel. The electrode coil of the first electrode has a protrusion that protrudes beyond the outer circumference of the electrode coil toward the antenna.

A high-pressure discharge lamp with a burner unit which has a discharge vessel which encloses a discharge space and in which two electrodes are arranged opposite one another, wherein the electrodes each have an electrode support and an electrode tip, wherein the electrode tips are located opposite one another to form an electric arc during operation of the high-pressure discharge lamp, wherein at least a first one of the electrodes is configured as a coil electrode which has an electrode support and an electrode coil formed by a wire wound around the electrode support, wherein an exposed end of the electrode support forms the electrode tip, and wherein the electrode coil is arranged in a tip region of the electrode support adjacent to the electrode tip in the discharge space, and wherein an antenna to which voltage can be applied is routed along an outer surface of the discharge vessel. The electrode coil of the first electrode has a protrusion that protrudes beyond the outer circumference of the electrode coil toward the antenna.

The disclosure relates to a discharge lamp including a light emitting tube having a discharge space therein, and a pair of electrodes disposed in the discharge space so as to be opposed to each other, wherein a changing rate of a cross-sectional area is equal to or lower than 200%. The changing rate is a rate of change of the cross-sectional area in every 0.25 mm in a direction along an optical axis of the light emitting tube. The cross-sectional area is an area of a plane perpendicular to the optical axis in a space between an outside shape of at least one of the pair of electrodes and an inside wall of the light emitting tube.

The present invention relates to an electrical gas-discharge lamp comprising an inner bulb (1) arranged within an outer bulb (2), said inner bulb (1) being filled with a discharge gas and comprising a first electrode (3) and an opposing second electrode (4) having a distance from the first electrode (3) which allows ignition of a gas-discharge by applying an ignition voltage between the electrodes (3, 4). At least one through hole (11) is formed in the feedthrough to the electrically conductive lead (5) to the first electrode (3). An electrically conductive member (10) extents within a space formed between the inner (1) and the outer bulb (2) from a position close to the through hole (11) to a distance from the second electrode (4) which is smaller than the distance between the two electrodes (3,4). When applying the ignition voltage between the electrodes (3,4) an electrically conducting path (12) forms through the through hole (11) between the electrically conductive member (10) and the electrically conductive lead (5) by ionization of the gas in the outer bulb (2). With this transient conductive path the coating (10) forms an active antenna effectively lowering the ignition voltage. The fabrication of the proposed lamp with reduced ignition voltage requires only few additional fabrication steps compared to a lamp without such an ignition aid.

A discharge lamp includes a luminous tube and a pair of electrodes. At least one of the pair of electrodes includes a core material, a coil section in which a metal wire is wound on the core material in three or more layers, a distal end portion made of a conductor and provided, with respect to the coil section, at an end portion of the core material on a side where the other electrode is disposed, and a rear end portion made of a conductor and provided on the opposite side of the distal end portion with respect to the coil section. The rear end portion includes a first diameter section having a first diameter and a second diameter section having a second diameter smaller than the first diameter and present in a position farther from the coil section than the first diameter section.

A discharge lamp includes a cathode in a luminous tube, and an emitter, other than thorium, is added to the cathode. The emitter is prevented from being excessively vaporized from the cathode and depleted soon. Smooth lighting is enabled even at start-up. A main body part (31) of the cathode (3) is made from a metallic material having a high melting point and containing no thorium. A front end (32) is made from a metallic material having a high melting point and containing an emitter (excepting thorium). Inside a sealed space (33) formed in the main body part (31) and/or the front end part (32) is received a sintered compact (34) containing an emitter (excepting thorium) that is higher in concentration than the emitter contained in the front end part (32).

Sulfur arc lamp includes an arc chamber that has a cathode and an anode both made of refractory metals that include pure tungsten, pure molybdenum, tungsten alloy, molybdenum alloy or a composite in which tungsten is at least 90%, or a composite in which molybdenum is at least 90%; a plasma initiation gas filling the plasma chamber; power supply configured to switch on and off electric arc discharge between the cathode and anode; second chamber connected to the arc chamber for releasing sulfur vapor into the plasma arc chamber, thereby creating a sulfur-containing plasma gas when the discharge occurs, and configured to selectively remove the sulfur vapor from the sulfur-containing plasma gas when the discharge occurs, wherein the second chamber is configured to reduce a concentration of the sulfur vapor in the arc chamber below 10.sup.13 molecules per cm.sup.3 before the electric arc discharge is off.

A tungsten-containing material that has an oxygen generation quantity of more than 1 ppm and 20 ppm or less at 2100 C. to 2300 C. as detected by oxygen analysis based on an oxygen separation method, and contains 5 ppm or more and 30 ppm or less of potassium.

A discharge lamp includes: a pair of electrodes disposed so as to face each other in a single axis direction; a bulb that includes an arc tube and two side tubes connected to both respective ends in the single axis direction of the arc tube, the arc tube having the pair of the electrodes inside; two lead rods supporting the pair of the electrodes respectively; a support member that has no conductivity and that is inside at least one of the two side tubes to support the corresponding lead rod; a conductive member being inside the side tube that has the support member inside, the conductive member being in contact with the corresponding lead rod; and a trigger member being outside the bulb and being disposed around an outer periphery of the conductive member.