Abstract: Disclosed is a flat type fluorescent lamp having a discharge space divided into a plurality of discharge areas. The flat type fluorescent lamp includes a first substrate, a second substrate separated from the first substrate in a predetermined distance to provide a discharge space containing a discharge material, first and second electrodes for applying a voltage to the discharge space and being disposed on the second substrate, and a sealing member for sealing side portions of the first and second substrates to isolate the discharge space from a peripheral space thereof. A plurality of barrier ribs having a slender shape are disposed in the discharge space and perpendicular to the first and second electrodes to divide the discharge space into a plurality of discharge areas. Accordingly, plasma converted from the discharge material has a uniform density through out the discharge space, thereby increasing brightness and uniformity of a light to be supplied to a display panel.

Abstract: A luminous element (10) for a lamp is double helix-shaped, with two connection parts (18, 20) situated at one end of said double helix. The diameter (D1, D2) of the double helix increases consistently in the direction of the two connection parts (18, 20) of the luminous element (10). The invention also relates to a lamp with a luminous element of this type, to a method for producing a luminous element of this type and to a device for carrying out the production method.

Abstract: A fluted feed-through for a discharge lamp includes a fluted ceramic core with plural channels and plural individual molybdenum or tungsten wires running in different ones of the plural channels. The wires are twisted together at the ends of the feed-through. The feed-through is insertable into a capillary tube of a ceramic discharge lamp. The wires of the feed-through have a different thermal coefficient of expansion than the ceramic discharge lamp. The wires are thin enough so that the absolute magnitude of the thermal coefficients of expansion is sufficiently small to prevent seal cracks and leaking.

Abstract: A support device is provided for use with an electric lamp having a sealed outer envelope that encloses an environment, and a lamp capsule and end-of-life device positioned within such environment. The support device serves to support the lamp capsule and the end-of-life device within the outer envelope. The end-of-life device is electrically connected in series with the lamp circuit through the support device.

Abstract: The electrode comprises a pin-like shank (7) and a head part (8), the electrode, in the region of its discharge-side end, forming a vessel (9) for an emitter, in which there is a bore (16) which is filled with emitter material (10). The vessel, at its discharge-side end face, forms a collar, having an inner collar part (13) which is curved convexly toward the bore and an outer collar part (14) which is curved convexly toward the side wall of the vessel.

Abstract: A high pressure discharge lamp includes a quartz glass bulb, a conductive element which is sealed at a sealing portion of the bulb, and a pair of electrodes. Each electrode is disposed in the quartz glass bulb so as to be opposite the other and connected to the conductive element. A part of each electrode is sealed with the quartz glass bulb at the sealing portion so as to generate a contacting portion formed by the part of each electrode and the bulb. The maximum length, Lmax, of the contacting portion is defined as: Lmax (mm)≦200/(P×D); and the minimum length, Lmin, of the contacting portion is defined as: Lmin (mm)≧0.8/(D2×&pgr;) or Lmin (mm)≧0.7 whichever is longer, where D is the diameter (mm) of the electrode and P is the power (W) supplied to the electrode.

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 super-high pressure discharge lamp of the short arc type which has an arc tube portion in which there is a pair of opposed electrodes and which is filled with at least 0.15 mg/mm3 mercury, and side tube portions which extend from opposite sides of the arc tube portion and in which there are metal foils. The electrodes are each electrically connected to a respective one of the metal foils by a metallic component with cross-sectional area that is smaller than the cross sectional area of the electrodes in the area in which the electrodes are located in the side tube portions.

Abstract: The present invention is a short arc type ultra-high pressure discharge lamp in which a pair of electrodes 3 are disposed inside an arc tube 1 that comprises quartz glass, seal portions 2 are formed that comprise quartz glass and extend to both sides of the arc tube 1, and at least 0.15 mg/mm3 of mercury is filled into the arc tube 1, wherein a metal foil 4 is embedded in each of the seal portions 2, and metal granular lumps 6 are protrusively provided on surfaces of each metal foil 4.

Abstract: A light source with a sealed, light-transmissive tube filled with high pressure gases or high pressure gas mixtures and a microhollow cathode (MHC) discharge capable of excimer production are provided.

Abstract: The object of the invention is to improve the thermal radiation characteristic of the electrodes in a high pressure discharge lamp of the short arc type in which the input power has been increased in order to increase the amount of radiant light, and to reduce the electrode temperature with high efficiency. The object is achieved as claimed in the invention in a high pressure discharge lamp of the short arc type in the emission tube of which there is a pair of electrodes, in that at least part of the sides of the above described electrodes is provided with a groove area, that the depth D of this groove area is within 12% of the electrode diameter and that the relation D/P is between the depth D of the groove area and the pitch P between the grooves is greater than or equal to 2.

Abstract: An incandescent lamp comprising a glass bulb (3) of tubular shape in which a filament (4) is axially arranged. The end is hermetically sealed by means of a pinch (5) applied around a metal foil (1) to which an outer current lead (7) and an inner current lead (6) electrically connected to the filament are fixed. A second, intermediate flat foil (2) is connected directly to the end (9) of the filament, between the latter and the inner current lead (6), and the bulb is elbowed at the level of said second flat foil (2).

Abstract: A method for producing a discharge lamp of the present invention includes the steps of: preparing a glass pipe for a discharge lamp having a luminous bulb portion and a side tube portion, and a single electrode assembly including an electrode structure portion that will be formed into a pair of electrodes of the discharge lamp; inserting the single electrode assembly into the glass pipe for a discharge lamp such that the electrode structure portion of the single electrode assembly is positioned in the luminous bulb portion of the glass pipe for a discharge lamp; forming a luminous bulb in which the electrode structure portion is arranged inside by attaching the side tube portion of the glass pipe for a discharge lamp to a part of the single electrode assembly; and forming a pair of electrodes in the luminous bulb by melting and cutting a part of the electrode structure portion selectively.

Abstract: A mercury-free metal halide lamp includes an arc tube including a pair of electrodes inside the tube. In the arc tube, a rare gas and a metal halide are contained, and no mercury is contained. The mercury-free metal halide lamp is horizontally operated such that the pair of electrodes is substantially horizontal. The mercury-free metal halide lamp further includes magnetic field applying means for applying a magnetic field including a component substantially perpendicular to a straight line connecting heads of the pair of electrodes in a substantially vertical direction. The density of halogen atoms evaporated during steady-state operation with respect to unit inner volume of the arc tube is 20 &mgr;mol/cc or more.

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: A low-pressure mercury-vapor discharge lamp is provided with a discharge vessel and a first and a second end portion (12a). The discharge vessel encloses a discharge space provided with a filling of mercury and an inert gas in a gastight manner. Each end portion (12a) supports an electrode (20a) arranged in the discharge space. An electrode shield (22a) encompasses the electrodes (20a) and, according to the invention, carries an electric current during operation, and is at a temperature ≧250° C., preferably ≧450° C., during nominal operation of the discharge lamp. Preferably, a first current supply conductor (30a) electrically contacts a first current divider (23a), which is electrically connected to a second current divider (23a′) via a shell-shaped body (24a).

Abstract: In a high-power dual-filament incandescent lamp for use in a reflector having an optical axis, which incandescent lamp comprises two incandescent coils which are substantially parallel to one another, which in their correct operational positions are arranged substantially parallel to the optical axis of the reflector in a lamp bulb, and which can be operated alternately, the glass bulb is arranged such that it shows a horizontal and vertical displacement relative to the optical axis of the reflector when in the correct operational position.

Abstract: A short-arc lamp (1) with a discharge vessel (2) which contains an anode (3) and cathode (4) which are opposite one another. The filling medium contains inert gases and/or metal vapors, and the anode comprises a body having a front section (11), a substantially cylindrical body (12) and a rear face (13). Provided in the region of the front half of the cylindrical body is a projection (20) whose radial length (X) projects at least 0.5 mm beyond the cylindrical body (12).

Abstract: A high-pressure discharge lamp employs an outer bulb that is provided with a lamp cap and surrounds a discharge vessel having a ceramic wall with a clearance. In the clear space, a conductor extends over a length L between the lamp cap and an electrode of the discharge vessel, which conductor is at least formed of a heat-resistant metal. A section Ld of the length L of the conductor is provided with an Ni coating.

Abstract: A light source device for a video monitor including a concave reflector with a middle opening and an optical axis, said optical axis being positioned tilted obliquely and a discharge lamp including an emission part with a cathode and an anode located opposite to one another and being supported by hermetically sealed portions, one of the hermetically sealed portions being mounted in the middle opening of the concave reflector in a manner that a lengthwise axis of the discharge lamp substantially aligns with the optical axis of the concave reflector, where the anode of the discharge lamp is positioned closer to the rear reflector than the cathode of the discharge lamp, and a tip of the anode is positioned underneath an obliquely tilted plane that includes the lengthwise axis of the discharge lamp.

Abstract: The present invention is a short arc type ultra-high pressure discharge lamp in which a pair of electrodes 3 are disposed inside an arc tube 1 that comprises quartz glass, seal portions 2 are formed that comprise quartz glass and extend to both sides of the arc tube 1, and at least 0.15 mg/mm3 of mercury is filled into the arc tube 1, wherein a metal foil 4 is embedded in each of the seal portions 2, and metal granular lumps 6 are protrusively provided on surfaces of each metal foil 4.

Abstract: A high-pressure discharge lamp is configured to regulate the relationship between the radius r (mm) of the tungsten rods forming the electrodes and the lamp current I (amperes) using the formula 1.5 ≤ I π · r 2 ≤ 9 when the ratio of the circumference of the circle to its diameter is expressed as &pgr;. The high-pressure discharge lamp suppresses early blackening, and achieves a long-life light source.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: (Object)

Abstract: A short-arc discharge lamp (10) including a light-emitting tube (1) having at least 15 mg/cc of mercury sealed therein, an anode (2) and cathode (3) facing each other and disposed within the light-emitting tube (1), and a heat-release layer (6) covering a substantial portion of an outer surface of the cathode (3) so that when the short-arc discharge lamp (10) is provided with electricity having a current value of at least 50 A, an inter-electrode power value defined by a ratio Y/X is at least 500 W/mm, X being defined as a distance in millimeters between the anode (2) and the cathode (3), and Y being defined as an input power in Watts provided to the short-arc discharge lamp (10).

Abstract: The compact low-pressure discharge lamp (1) has a wound tubular discharge vessel (2) with at least four straight tubes (6, 7) which are in a polygonal arrangement and, close to or at the ends of the straight tubes (6, 7), are connected by transverse connections (8, 10, 11) to form a single continuous discharge path which is closed off in a gastight manner. A coil spring (14) made from metal, which runs parallel to the tubes (6, 7) is arranged in the center of the cylindrical cavity (13) formed by the straight tubes (6, 7) of the discharge vessel (2). The coil spring (14) reduces the firing voltage required.

Abstract: A discharge lamp comprises a discharge tube having discharge electrodes (10) at both ends thereof. Two lead wires (8) are connected to each of said electrodes (10) that lead to the outside atmosphere from the inside of the discharge tube. The discharge tube contains a fill as an arc discharge generating and sustaining medium. A tungsten coil (14) is connected to at least one lead wire (8) of at least one electrode (10) and placed adjacent to said electrode (10). At least one material selected from the group consisting of calcium carbonate, barium carbonate and strontium carbonate is applied to the inside and the surface of the tungsten coil (14).

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A discharge lamp having a discharge space is bounded by an external tube formed of dielectric material and by an internal tube formed of dielectric material. An external electrode is arranged proximate the external tube, and an internal electrode rests against the internal tube. The internal electrode is formed from an elastic spiral band having an external diameter that is greater than the internal diameter of the internal tube when the elastic spiral band is not compressed.

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 low-cost ceramic arc lamp comprises an optical coating on a sapphire window, a window shell flange, and a body sleeve. A gas-fill tubulation attaches to the side of the body sleeve and permits a charge of xenon gas to be injected during manufacture. This contrasts with the prior art where the xenon gas is introduced through the anode base. A single-piece strut assembly is used that is compatible with mass-production techniques. The single-piece strut assembly supports and suspends a cathode inside an elliptical reflector. An anode flange replaces a more conventional shell, copper anode base, and base support ring. A tungsten anode completes the lamp. All of these parts are brazed together in an assembly process that is far less complex than the prior art.

Abstract: An arc discharge lamp includes a light transmissive envelope (3), two electrodes (1, 2) disposed at least partially inside the light transmissive envelope, and a plasma forming fill which includes selenium when excited disposed inside the light transmissive envelope (3). The exterior surfaces of the part of the electrodes (1, 2) disposed inside the light transmissive envelope (3) comprise an electrode material selected from the group of molybdenum and molybdenum compounds.

Abstract: A high pressure discharge lamp having a pair of electrodes with a space of 0.5 mm to 2.0 mm inclusive between them and disposed in an arc tube. An electrical discharge takes place between the electrodes. Each of the electrodes has an electrode rod and a head that is provided at the discharge side end of the electrode rod and having a larger diameter than the electrode rod. A surface of the head being opposite to the other electrode is convexly curved and a protruding part is formed in the vicinity of the center portion of the end of the head.

Abstract: A short-arc lamp (1) with a discharge vessel (2) which contains an anode (3) and cathode (4) which are opposite one another. The filling medium contains inert gases and/or metal vapors, and the anode comprises a body having a front section (11), a substantially cylindrical body (12) and a rear face (13). Provided in the region of the front half of the cylindrical body is a projection (20) whose radial length (X) projects at least 0.5 mm beyond the cylindrical body (12).

Abstract: A low-pressure mercury-vapor discharge lamp is provided with a discharge vessel and a first and a second end portion (12a). The discharge vessel encloses a discharge space provided with a filling of mercury and an inert gas in a gastight manner. Each end portion (12a) supports an electrode (20a) arranged in the discharge space. An electrode shield (22a) encompasses the electrodes (20a) and, according to the invention, carries an electric current during operation, and is at a temperature ≧250° C., preferably ≧450° C., during nominal operation of the discharge lamp. Preferably, a first current supply conductor (30a) electrically contacts a first current divider (23a), which is electrically connected to a second current divider (23a′) via a shell-shaped body (24a). Said second current divider (23a′) electrically contacts the electrode (20a), which is connected to the second current supply conductor (30a′).

Abstract: An yttrium film is formed on the surface of a substrate made of an Ni—Cr-based material by deposition or sputtering using resistance heating or an electron beam. The yttrium film is heated in an inert gas atmosphere containing a very small amount of hydrogen to hydrogenate yttrium. The resultant yttrium hydride is excellent as a cold emission material for a cold emission electrode and can be used for a cold emission discharge fluorescent tube.

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 flat radiator having dielectrically impeded, strip-like cathodes (12;15) and anodes (8;9a) which are arranged alternately next to one another on the wall of the discharge vessel (14) has in each case an additional anode (9b) between neighbouring cathodes (12;12,15), that is to say an anode pair (9) is arranged in each case between the cathodes (12;12,15). The cathodes (15) have nose-like extensions (28) which face the respectively neighbouring anodes (8) and are arranged more densely in a spatially increasing fashion in the direction of the edges (26,27) of the flat radiator (13). As an alternative or in addition thereto, the two anode strips (9a,9b) of each anode pair (9) are widened in the direction of the edges (26,27) of the flat radiator (13) at one end in the direction of the respective partner strip (9b or 9b). Owing to these measures, the surface luminous density of the flat radiator (13) is largely constant towards the edges (26,27,29,30) in pulsed operation.

Abstract: An arc discharge lamp body made from a material selected from glass and ceramic materials and defining a discharge space; an arc generating and sustaining medium contained within said discharge space; and an electrically conducting member in at least one end of said body and extending both interiorly and exteriorly thereof, said electrically conducting member being formed of an electrically conductive ceramic material having a thermal coefficient of expansion substantially matching that of said body.

Abstract: A starting aid for a metal halide discharge lamp. An arc discharge tube is positioned in a hermetically sealed jacket. The jacket contains a partial pressure (e.g., 400 torr nitrogen) of a gas that will aid in starting the discharge and one of the arc tube lead-ins has an electrical conductor affixed thereto and exposed to the partial pressure of the gas. An outer conductor extends on the outside of the jacket and is electrically connected to the other lead-in. When voltage is applied to the electrodes a capacitive coupling takes place between the inner conductor and the outer conductor which generates a discharge that causes a breakdown in the arc generating and sustaining medium within the arc tube and causes the lamp to start.

Abstract: An electrode for electrical lamps comprises a core pin with a pushed-on helical member. A boss (9) projecting beyond the diameter of the core pin (7) is laterally constructed on the core pin at a spacing from the tip, the helical member (8) being arranged with at least one turn behind the boss.

Abstract: A method for manufacturing a metal halide lamp in which tungsten coils are made to have diameters wider than the outer diameters of electrodes, and to have a coil pitch sufficient to prevent molten quartz glass from entering therebetween; and after the tungsten coils have been fixed around the electrodes, the pitch of the tungsten coils on the sides of the electrodes which are nearest molybdenum foils is extended by dragging a part of the tungsten coils toward the discharge ends of the electrodes to fix it tightly around the electrodes. As a result, when sealing is performed with quartz glass bulb, gaps between the electrodes and the glass bulb are provided on the discharge sides of the electrodes, whereby it can be prevented to occur cracks in the quartz glass bulb due to the thermal expansion of the electrodes; and on the molybdenum foil sides of the electrodes, the quartz glass bulb contacts the electrodes, thereby preventing peeling-off and accumulation of sealed material.

Abstract: A tipless discharge lamp of the short arc type in which on the outside surface of the arc tube there is no residual filling tube tip, and in which an exact distance between the electrodes is obtained is achieved in a metal halide lamp of the short arc type by a pair of electrodes being located in an arc tube, by the electrodes are parts of a one-piece electrode component that has been fracture-split so that, at least to some extent, fracture traces are present on the faces of these electrodes which have not undergone mechanical processing such as cutting, polishing, or the like, and elimination of the use of a filling tube, so that no residual filling tube tip projections remain on the outside surface of the arc tube. Furthermore, precise positioning of the pair of electrodes in the arc tube results from the hermetically sealed portion being drawn outwardly in the base area of at least one of the electrodes creating an area with a smaller diameter than the remainder of that hermetically sealed portion.

Abstract: An arc lamp suitable for use as a high intensity light source in a projection system is described. A reflector is arranged to reflect the light produced by the arc into a directional light beam, secondary reflection means being arranged to direct part of the reflected beam so as to compensate for regions which are obscured by the electrodes. Means are provided within the light source to dissipate heat generated by the electrodes.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: The electric incandescent lamp has a lamp vessel (1) in which a filament (3) is disposed substantially concentric with the longitudinal axis (2) of the lamp vessel (1). Current conductors (4) extend from the lamp vessel (1), an internal conductor (10) part of which is substantially concentrically with the axis (2) and has an end portion (11) having unround cross-sections (12). An end portion (6) of the filament (3) is wound onto the unround cross-sections (12) of a respective internal conductor (10) to constitute clamping windings (5). The lamp is of a simple construction to obtain reliably a concentrically mounted filament.

Abstract: A high performance miniature projection lamp which includes a glass envelope having a pair of opposite neck portions each with a coaxial central opening having a reduced section and an hermetically sealed central chamber having a volume of about 130 mm.sup.3 which contains a fill. The fill includes an argon pressure at room temperature at a range of about 0.5 atmospheres to about 2.0 atmospheres and mercury in an amount in the range of about 5 mg to about 15 mg, and a mixture of metal halide material in an amount from about 50 up to 1000 micrograms. A pair of axially aligned electrodes are positioned at opposite neck portions and separated form each other by a predetermined distance. The electrodes each have a shank portion which each having a coil wrapped around its end.

Abstract: A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.

Abstract: A metal halide headlamp comprising an electrode and a coil wrapping around said electrode to prevent the occurrence of cracks in a sealing portion, in which the diameter d.sub.0 of said electrode, the cross-section S of said electrode including said coil, the inner diameter ID of said coil, the pitch P of said coil, the distance L between an end of said coil and a metal foil, and the amount of metal halides with a NaI-to-ScI.sub.3 ratio are specifically limited. Thereby, the prior art problems, i.e., changes in the lamp characteristics, the degradation of durability, and so on, can be solved.

Abstract: A fluorescent lamp having an attachment mounted therein for reduction of soluble mercury contained in the lamp, and to act as a fail-safe at the end of lamp life, comprises a collar of iron mesh providing an iron surface area sufficiently large to reduce a portion of the soluble mercury to elemental mercury when the lamp is pulverized to granules and subjected to a suitable aqueous acid solution, such that a remaining portion of soluble mercury leachable is less than 0.2 milligram per liter of the aqueous acid solution, whereby to provide a substantially non-soluble mercury leachable lamp. The attachment is adapted for disposition around an electrode mount in the lamp and is electrically isolated from lead-in contacts in the mount, such that upon exhaustion of a cathode coating in the lamp, an electrical arc stream impinges on the attachment, causing the mount within the attachment to crack, whereby to provide for safe termination of operation of the lamp.