Abstract: In a simple and slim double-faced vacuum fluorescent display device having no grid with low power consumption and low fabrication cost, in order to turn on fluorescent layers P111 to P141 of segments D11 to D14 in an anode electrode set D1 on a back plate S2, 12V, 0V, 0V and −12V are applied to the segments D11 to D14 in the anode electrode set D1 on the back plate S2, the other segments on the back plate S1, segments C11 to C15 in an anode electrode set C1 on a front plate S2 and the other segments on the front plate S1, respectively. In order to turn on segments C12 and C16 in the anode electrode set C1 on the front plate S1, 12V, 0V, 0V and −12V are applied to the segments C12 and C16 in the anode electrode set C1 on the front plate S1, the other segments on the front plate S1, the segments D1 to D14 on the back S2 and the other segments on the back plate S2, respectively.

Abstract: A direct current discharge lamp includes: a bulb portion 1a containing therein an anode 2b and a cathode 2a; a first seal portion 5 outwardly extending from the bulb portion 1a on the anode side; a second seal portion 4 outwardly extending from the bulb portion 1a on the cathode side; a pair of feeder elements 3 respectively inserted through the first and second seal portions 5 and 4 for feeding electricity to the anode 2b and cathode 2a; and an extended tube portion 6 interconnecting the bulb portion 1a and the first seal portion 5.

Abstract: A high pressure discharge lamp comprises a portion composed of a luminescence tube having a swelled portion at the middle thereof, and an anode and a cathode placed opposite to each other, the cathode is composed of a metal with a high melting temperature doped with a electron-emitting substance and having a tapered portion toward the discharge side, the slope portion of said tapered portion being subjected to carburization at said tapered portion, and a non-treated portion being formed at the edge of the tapered portion continuous to the carburized portion.

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 noble gas discharge lamp of the present invention comprises an outer enclosure comprising a light emitting layer comprising at least one fluorescent substance, the light emitting layer formed therein and a pair of outer electrodes having tape shapes comprise a metal, which are adhered to the entire length of the outside of the outer enclosure so as to separate one outer electrode and the other outer electrode at a certain distance, and to form a first opening portion and a second opening portion; wherein the coated amount of fluorescent substance is in a range of 5 to 30 mg/cm.sup.2.

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 fluorescent lamp includes a bulb, a fluorescent material coated on an internal surface of the bulb, a stem, a discharge chamber filled with gas and mercury, a thermal cathode filament coated with electron emitting material, an anode, a pair of lead wires passing air-tightly through the stem and supporting the thermal cathode filament, and a lead wire supporting the anode. The anode is a substantially rectangular plate, and is substantially parallel to the thermal cathode filament in a cross sectional view taken along a bulb axis Z. The thermal cathode filament and the rectangular anode plate can be configured of an angle range of 30-60 degrees in a cross sectional view perpendicular to the lamp axis Z. The rectangular anode plate and the lead wire supporting the anode can be attached to each other in a substantially flag-shaped configuration. The invention produces a smaller discharge spot to improve thermal electron emission efficiency such that efficiency of the fluorescent lamp is improved.

Abstract: A discharge lamp of the short arc type with good light intensity stability in which arc fluctuation is suppressed is achieved, according to the invention by providing a discharge lamp of the short arc type which has an arc tube which surrounds the discharge space, hermetically sealed portions on the two ends of the arc tube, a cathode and an anode which are arranged opposite one another in the arc tube and which is operated such that the cathode is pointed upward, in by the cathode being supported by an inner lead which is held securely by the hermetically sealed portion, the outside diameter of the cathode being greater than the outside diameter of the inner lead, and by the relationship L.gtoreq.2.5D being satisfied, where D is the outside diameter of the cathode (mm) and L is the axial length of the cathode (mm).

Abstract: A fluorescent lamp comprising a bulb, a fluorescent material coated on an internal surface of the bulb, a stem, a discharge chamber filled with gas and mercury, a thermal cathode filament coated with electron emitting material, lead wires passing air-tight through the stem and supporting the thermal cathode filament and an anode, where the anode is substantially rectangular with a thickness 1/16.about.3/16 of the longitudinal length of the thermal cathode filament and is substantially parallel to cathode filament in a cross-sectional view along an axis Z. The thermal cathode filament and the rectangular anode are arranged such that either the thermal cathode filament or the rectangular anode is in a rotated position relative to the other on a parallel flat surface within an angle range of 30-60 degrees. In this composition, the smaller discharge spot is obtained to improve thermal electron emission efficiency and efficiency of the fluorescent lamp.

Abstract: A composite glow discharge lamp having an elongated glass tube, in which an electrode assembly is located in said elongated glass tube at each of opposite ends thereof, the electrode assembly comprising a center electrode for emitting electrons and a glow electrode surrounding the center electrode, and the glow electrode being formed of an enclosure having an opening and a closed bottom and laid so that the opening faces the opposite end of the glass tube which is near thereto, and the closed bottom faces the longitudinally middle part of the glass tube, thereby it is possible to prevent blackening of the glass tube, and to prolong the use life of the composite discharge lamp.

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: Novel emitter materials, electrode assemblies amd lamps comprising the same are provided in which, in accordance with the invention, novel electrodes are provided having a lamp electrode structure, preferably including a hollow ferrule for sealing in a lamp to permit evacuation; an emitter material of the invention on at least one surface thereof, preferably on a protrusion attached to the hollow ferrule; a thermal isolator, preferably in the form of a low thermal conductivity wire or an incised or cut-out portion of the hollow ferrule body, for thermally isolating the protrusion from the ferrule to maintain a sufficiently high temperature for thermionic emission, and further comprising an emitter material requiring no in-lamp processing. The emitter materials are a mixed oxide of Ba, Sr and mixtures thereof with one or more of the metals from the series comprising Ta, Ti, Zr, Sc, Y, and La, are preferably selected from the group consisting of Ba.sub.4 Ta.sub.2 O.sub.9, Ba.sub.5 Ta.sub.4 O.sub.15, BaY.sub.

Abstract: A plasma display panel has a front plate (10) and a back plate (3) disposed in parallel and opposite to each other, and spaced a predetermined distance apart from each other by partition walls (1a, 1b, 1c). The partition walls (1a, 1b, 1c) define discharge spaces (2) each having a plurality of discharge cells. Phosphor layers (9) are formed on surfaces of the discharge spaces (2). The partition walls (1a, 1b, 1c) is formed of a material containing at least one of red, green and blue pigments. Since the partition walls (1a, 1b, 1c) are capable of luminance adjustment and white balance adjustment, the plasma display panel does not need any additional manufacturing processes and can be fabricated at a relatively low cost.

Abstract: A field emission cathode has particular use in a light source. The light source includes an evacuated container having walls, at least a portion of which consists of an outer glass layer which on at least a major part thereof is coated on the inside with a layer of phosphor forming a luminescent layer and a conductive layer forming an anode. The layer of phosphor is excited to luminescence by electron bombardment from a field emission cathode located in the interior of the container. A modulator electrode is arranged between the cathode and the anode for creating an electrical field necessary for the emission of electrons. The field emission cathode, includes a base body, and field emitting bodies extending from the base body. The base body includes a longitudinally extending core having a central axis. The field emitting bodies are elongate and are distributed along at least a part of the length of the core, extend radially outwards from the core, and have free ends provided with field emitting surfaces.

Abstract: A high intensity lamp is provided based on an open discharge between a cathode grid anode and a collector. A phosphor layer on the collector is excited by an electron beam to produce light or ultraviolet radiation to produce light.

Abstract: Novel emitter materials, electrode assemblies amd lamps comprisinfg the same are provided in which, in accordance with the invention, novel electrodes are provided having a lamp electrode structure, preferably including a hollow ferrule for sealing in a lamp to permit evacuation; an emitter material of the invention on at least one surface thereof, preferably on a protrusion attached to the hollow ferrule; a thermal isolator, preferably in the form of a low thermal conductivity wire or an incised or cut-out portion of the hollow ferrule body, for thermally isolating the protrusion from the ferrule to maintain a sufficiently high temperature for thermionic emission, and further comprising an emitter material requiring no in-lamp processing. The emitter materials are a mixed oxide of Ba, Sr and mixtures thereof with one or more of the metals from the series comprising Ta, Ti, Zr, Sc, Y, and La, are preferably selected from the group consisting of Ba.sub.4 Ta.sub.2 O.sub.9, Ba.sub.5 Ta.sub.4 O.sub.15, BaY.sub.

Abstract: A ceramic cathode fluorescent discharge lamp is provided including a pair of electrodes, a bulb plated with a fluorescent body on an inner surface of same, at least one of said pair of electrodes being a ceramic cathode having a bottomed cylindrical housing including an electron emission material of an aggregate type porous structure of conductive oxide having a first component consisting of at least one of Ba, Sr, and Ca, a second component consisting of at least one of Zr and Ti, and a third component consisting of at least one of Ta and Nb, said aggregate type porous structure having a surface plated with a conductive or semiconductive layer of at least one of carbide, nitride and oxide of Ta or Nb, rare gas being sealed in said bulb, and sealing pressure of said rare gas being in the range between 10 Torr and 170 Torr.

Abstract: A tubular glow discharge electrode is formed therein with a slot in which front end parts of support leads are inserted. The slot has a widened center part which defines an opening. The tube-like glow discharge tube is welded at its one end part to one of the support lead so as to be electrical conductive to the same, and is caulked at it's the other end part to the other one of the support leads through the intermediary of an insulator. A filament electrode (ark discharge electrode) carrying an electron-emissive substance is supported to the free end parts of the support leads within the tube-like glow discharge electrode which therefore surrounds the arc discharge electrode with a small gap defined between the glow discharge electrode and the filament electrode.

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 of the short arc type including an arc tube and an anode and cathode within the arc tube positioned opposite one another. The present invention includes an anode arrangement in which the temperature increase of the anode in luminous operation is suppressed as much as possible, in which blackening of the inside wall of the arc tube as a result of premature vaporization of the anode material is suppressed, and in which the durability of the above described lamp is prolonged. Specifically, the outer surface of the anode includes sintered layers of fine-particle tungsten adjacent the tip of the anode. In this way, the effective surface area of the anode is increased, the heat radiation from the anode is accelerated, and the premature vaporization of the anode material is suppressed.

Abstract: A mercury lamp of the short arc type with high radiant efficiency which satisfies the demand for an increase of the radiation amount of the light source, by suppressing the motion of the bright spot in the vicinity of the cathode tip suppresses the flickering of the irradiance and thus increases the arc stability, is achieved in a mercury lamp of the short arc type in which within an arc tube mercury and at least one rare gas are encapsulated, by either at least Ar being filled as the rare gas at an filling pressure of from 1 to 8 atm, and by the current density in the tip area of the cathode being 10 to 250 A/mm.sup.2 or alternatively, at least Kr being filled as the rare gas at an filling pressure of from 1 to 8 atm, and the current density in the tip area of the cathode being 10 to 310 A/mm.sup.2 during operation of the lamp.

Abstract: The present invention is a system and method for reducing the voltage necessary to produce a glow discharge in a gas. This is done by fabricating the cathode in a gas discharge device out of a conductive material that is permeable to the subject gas rather than out of a solid material, as in the prior art. Fabricating the cathode with a permeable material rather than a solid material increases the surface area of the cathode and provides the gas with greater access to the cathode's surface. Increasing the surface area of the cathode increases the total discharge current which can be extracted from the cathode without increasing the extraction voltage. This allows the gas discharge device to be operated at a lower voltage than is possible using a cathode fabricated of a solid material.

Abstract: An electric gas discharge lamp includes an electrode having a tip portion comprised by a mesh body carrying an emitter material. The mesh body in a favorable embodiment is circular cylindrical and is attached via an electrically conductive thermal isolator to a conductive feed-through, such as a hollow ferrule, extending through a seal of the lamp vessel. As compared to a continuous walled tip portion of similar shape and material, the mesh body has a lower mass and heat capacity, and can therefore be operated at higher temperatures without increasing the temperature of the seal area. The higher operating temperature of the tip portion promotes greater electron emission from the emitter material, and therefore a lower cathode fall. A lower cathode fall enables the lamp to be operated at higher lamp currents for greater light output.

Abstract: The cathode for a gas discharged lamp includes gettering materials which are placed within the interior of the cathode shell. Other components may also be placed inside the cathode for continuous activation. For example, in mercury vapor lamps, a mercury amalgam is placed within the cathode. In another embodiment, a mass of electron emission assisting compound is placed within the cathode to replenish the emission assisting compound which deteriorates from the cathode.

Abstract: A cold cathode electrode for a discharge lamp has a metal substrate supporting a layer of diamond, so as to increase the electron yield of the electrode. The substrate may be a helical nickel wire with a layer of diamond forming it into a continuous tube.

Abstract: The invention relates to an electrode for discharge lamps, with an electron mitter which contains a barium compound from the group barium zirconate (BaZrO.sub.3), barium hafnate (BaHfO.sub.3), barium titanate (BaTiO.sub.3) and barium cerate (BaCeO.sub.3) as well as one or more metallic components.

Abstract: A field emission cathode (40) includes field emitting bodies (42) in the form of fibers, and a base body having a longitudinally extending core (41) formed by at least two wires (43) between which the fibers are secured. The fibers are distributed along at least a part of the length of the core (41) and extend radially outwards from the core. A light source (10) includes an evacuated container having walls at least a portion of which consists of an outer glass layer (23) on which at least a major part thereof is coated on the inside with a layer of phosphor (24) forming a luminescent layer, and a conductive layer forming an anode (25). The layer of phosphor (24) is excited to luminescence by electron bombardment from a field emission cathode (40) located in the interior of the container, and a modulator electrode or grid (30) is arranged between the cathode (40) and the anode (25) for creating an electric field for the emission of electrons.

Abstract: An electrode structure for use in a sealed arc lamp is described. The electrode structure includes a tungsten containing rod surrounded by a block of sintered tungsten containing powder. The block may be impregnated with a thermally conductive material such as copper, silver or braze, and may have a high thermal emissivity surface.

Abstract: The present invention relates to a short arc discharge lamp having a quartz envelope with a bulb and a support for supporting at least one electrode rod within the quartz envelope for specific alignment. The support includes a collar surrounding the at least one electrode rod and being made from a material having a melting point above an operating temperature of the short arc lamp. The collar also has at least one coil spring and at least one placement means for placing at least one coil spring around an outer surface of said collar. Connected to the support is a securing piece for securing the collar to the at least one electrode rod.

Abstract: A light transmitting discharge vessel encloses a discharge space, sealed in a gas-tight manner, in which electrodes connected to current conductors which extend to the exterior are disposed. A filling in the discharge vessel comprises a rare gas, a buffer gas and at least one transition metal halide chosen from the halides of hafnium, zirconium and tantalum. Each of the electrodes comprises an electrode part containing a carbide chosen from the carbides of hafnium, zirconium and tantalum. As a result diffusion of transition metal from the plasma into the electrode is strongly suppressed so that the lamp keeps very good color rendering properties throughout its operation.

Abstract: A collector for an electron beam tube includes a ceramic cylinder within which are located rings of a first material, such as copper, and rings of a second material, such as molybdenum, arranged alternately along the longitudinal axis of the cylinder. The ratio of the axial lengths of the rings at the inner surface of the ceramic cylinder is selected so as to provide temperature compensation. The rings of one material surround part of adjacent rings of the other material to confine thermal expansion in a radial direction.

Abstract: An AC plasma display panel includes a plurality of opaque scanning electrodes (3b, 3c) and maintaining electrodes (4b, 4c) which are parallel to each other, formed on a first glass substrate (1) at the display side of the display, a plurality of ribs (9) formed on a second glass substrate (7) and arranged orthogonally to the scanning and maintaining electrodes, a data electrode (8) formed on the second glass substrate (7), positioned between the ribs and arranged parallel to the ribs (9), wherein a discharge cell (2) is defined by dividing the space between two ribs (9) and includes at least two of the scanning electrodes (3b, 3c) and at least two of the maintaining electrodes (4b, 4c). The maintaining discharge is generated between the two scanning electrodes (3b, 3c) and the two maintaining electrodes (4b, 4c). Consequently, a discharge region can be widened without decreasing the opening ratio, and an AC plasma display panel with high brightness and high efficiency can be obtained.

Abstract: A lamp in which a stable, long-term luminous operation can be accomplished is achieved by the fact that, in a mercury lamp of the short arc type in which a cathode and an anode located next to one another within an arc tube and in which both ends of the arc tube are provided with hermetically sealed portions, the cathode is installed on the tip of a rod-shaped component which extends from a respective one of the hermetically sealed portions, the cathode having a greater outer diameter than the rod-shaped component on which it is installed, and the rear end of the cathode tapering toward the respective hermetically sealed portion.

Abstract: A discharge lamp includes a first and a second substrate (12, 14), a cavity disposed in the first substrate (12) or in a portion of the first and a second substrate (12, 14), a first and a second aligned electrode (270, 272) disposed between the first and a second substrate (12, 14) having respective ends extending into the cavity, wherein the first and the second aligned electrode (270, 272) are "T-shaped" when viewed in cross-section. The T-shaped electrodes provide mechanical support that minimizes bending and distortion in the horizontal and vertical directions. The discharge lamp may include a charge of mercury or an inert gas, and may further include a phosphor layer (80).

Abstract: The invention relates to electrode coils for discharge lamps having a coiled wire (1) which is wound around by a braiding wire (2). The coiled wire (1) has both turns (II) with an essentially circular cross-section and turns (I, III) with an oval cross-section. In order to produce the bar-shaped coil according to the invention, the unit comprising the coiled wire (1), the first core wire (3) and the braiding wire (2) is wound around a second core wire (4) which is flattened in places. Unrolling of the braiding wire (2) is prevented thereby. Production of the coil is cost-effective, since only two core wires are required and the coil ends are not fused.

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: To improve the arc stability of high-pressure discharge lamps, particularly f power ratings of up to about only 250 W, the cathode (4) is formed as an elongated, essentially cylindrical base body (8) having a tapering, conical region (9) terminating in a tip (10). The base body (8), only, is covered with a carbide coating along its length, except for an end portion for electrical connection; the carbide coating starts at the junction or transition between the cylindrical base body portion and the conical end portion. This cathode construction is easier and cheaper to make than prior art cathodes, by coating an essentially cylindrical cathode and then etching or grinding and polishing the tapering end region (9). The electrode is preferably made essentially of tungsten, doped with thorium oxide present up to about 0.6%, optionally also potassium, aluminum and silicon in tiny amounts. The electrode spacing is between 0.4 to 0.

Abstract: A discharge lamp in which vaporization and melting of a cathode tip are prevented and which has stable luminous operation over a long is achieved according to the invention by the fact that the discharge lamp has a cathode in which a sintered body made of a powdered metal with a high melting point and a powdered emitter material is inserted in the tip, and the relationship:(-0.002d+0.01).ltoreq.D/W.ltoreq.(-0.002d+0.04)is fulfilled, where D is an outside diameter of the sintered body in millimeters (mm), W is a lamp input power in watts (w) and d is a distance between the anode and cathode in millimeters (mm). Furthermore, these benefits are achieved according to the invention by encapsulating mercury in an amount of 10 mg to 80 mg/cc of fluorescent tube internal volume and inert gas with at least 2 atm air pressure (at a reference temperature of 25.degree. C.).

Abstract: A xenon electronic flash tube has a transparent glass tube body. Xe gas is enclosed in the tube body. An anode is projected inside the tube body. A cathode, inside the tube body, is projected toward the anode, and includes base metal material and a Cs compound having a characteristic of emitting electrons, such as Cs.sub.2 Ta.sub.2 O.sub.6.

Abstract: There is presented a cold cathode subminiature fluorescent lamp comprising a glass envelope, a pair of lead wires sealed to the envelope and extending through the envelope at an entry location to the interior thereof, an electrode mounted on the lead wires in the envelope, and a ceramic-glass bead formed on and around the lead wires in the envelope between the electrode and the entry location. The electrode includes a plurality of metal wire tabs. The envelope contains a fill gas comprising neon and argon.

Abstract: A cold-cathode fluorescent lamp includes an opposing pair of electrodes in spaced relationship in a tubular glass bulb of which the inner wall surface is coated with fluorescent material, and each of the electrodes is divided into four plate-like electrode members each having mercury and getter preliminarily coated thereon while maintaining a necessary area for each electrode without any contact with the inner wall surface of the tubular glass bulb. The opposite ends of the tubular glass bulb are airtightly sealed with beads through which electricity feeding wires extend for feeding electricity to the electrodes while holding the electrodes in the tubular glass bulb. Two of the four plate-like electrode members are located on one side of each electricity feeding wire, while another two of the same are located on the opposite side of the same. The respective plate-like electrode members are spot-welded to each electricity feeding wire.

Abstract: An arc lamp comprises an electrode assembly with O-ring seals that seal in xenon gas within a glass tube envelope and shaped electrode that, together with a contoured tube geometry inside the glass tube envelope near the electrode, will aerodynamically redirect the supersonic forces of gas ignition to reduce the mechanical impact pulses that would otherwise ultimately work the electrode assembly out of the end of the glass the envelope.

Abstract: The present invention provides a method of lighting a hot-cathode type low-pressure rare gas discharge lamp without flicker. The method has the steps of operating, as a hot cathode, at least one of electrodes provided at both ends of a glass valve in a stable discharge state, and emitting light from a fluorescent material with the ultraviolet rays generated by the discharge of low-pressure rare gas sealed in the glass valve, or directly with visible light. The hot cathode is heated at least during lighting. In the method, the temperature of the hot cathode relative to the lamp current flowing between the electrodes is set within a region to prevent flicker in the discharge lamp.

Abstract: Plasma-cathode electron gun structures capable of operation in low-pressure, e.g., <5.times.10.sup.-3 Torr, ionizable gas environments are disclosed. They utilize a thermionic emitter within an enclosure with a partially transparent electrode defining a plasma face. Spaced anodes are disposed adjacent the electrode to extract an electron beam from the plasma face. A magnetic system forms an inward directed field, and a portion of the plasma electrons are directed through this field to enhance ionization efficiency.

Abstract: The discharge or arc tube chamber of a low-power high-pressure discharge lamp is, in one single step, sealed and shaped by mold or form-blowing by using pinch or press jaws (30, 31) which have concave hollows (34) formed therein to clearly define the shape of the discharge vessel, and hence of the discharge or arc tube chamber, to permit reproducible results with little variation between individual lamps to be made in a single manufacturing step. Additionally, an inclined ramp-like surface can be formed at the narrow sides (14) of the pinch seal extending towards the walls (11) of the discharge chamber (3) to thereby eliminate pockets beneath the electrodes. Preferably, the electrode shafts diverge with respect to the optical axis (A) of the lamp to increase the electrode spacing, and thus permit operation at a lower operating pressure, with respect to prior art lamps.

Abstract: To reduce flicker in low-power, high-pressure discharge lamps, the electrs, in the region in which they face each other, have wrap windings, of about 2 to 4 turns wrapped thereabout and the terminal end of the electrode has an essentially spherical end head element (19, 19', 39) melted thereon, which essentially spherical head element may be a segment of a sphere, ellipsoid-shaped or similarly formed. The electrode shaft, the wrap winding and the sphere preferably are all made of undoped tungsten, although the electrode shaft may be of a lower melting metal, such as rhenium.

Abstract: An apparatus to generate corona discharges that consists of (a) a ground electrode tube, (b) a single-opening insulating tube inserted into the ground electrode tube, (c) a high-voltage electrode tube inserted into the insulating tube, and (d) two insulating caps. An air gap is formed between the ground electrode tube and the insulating tube. The high-voltage tube is inserted in the center of the assembly, which is held in position by the insulating caps.

Abstract: A hollow cathode discharge tube is used for atomic absorption analysis. The tube has a cathode which includes a first hollow portion and a second hollow portion connected to each other. The second hollow portion has a diameter greater than the first hollow portion and a close end. Inserted through the closed end is a rod-like anode which has a part within the hollow space of the cathode. There is a auxiliary electrode which can be an auxiliary anode that surrounds the rod-like anode and is insulated therefrom. There is an additional electrode which can be an auxiliary cathode at the front end portion of the cathode. The cathode is formed of a material that is a material or includes a material that is to be analyzed.

Abstract: A high pressure discharge lamp having a discharge vessel with opposing end chambers includes discharge electrodes each consisting of an open elongate filament of refractory metal wire having a plurality of succesive coil turns extending transverse to the longitudinal axis of the discharge vessel. The filament electrodes are dimensioned so that the discharge arc which terminates thereon is sufficiently retracted into the end chamber of the discharge vessel so that the fill constituents condense on a region of the discharge vessel which is primarily axially between the filament electrodes. In a favorable embodiment, the lamp is a metal halide lamp in which the electrode and the discharge sustaining fill is free of thoria and its compounds.

Abstract: A cathode for a discharge lamp includes a longitudinally extending central core of a high temperature, electrically conductive metal; and a coil of high temperature, electrically conductive metal wound thereabout, said coil being fastened to said core at least in part by mechanical interference. The mechanical interference can be achieved by keyways formed in the core surface. During winding, at least some of the turns of the coil enter the keyways providing a good, mechanical engagement of the coil with the core. The keyways can be formed by heating the core and compressing or forging areas with tools or the keyways can be formed by grinding or by any other suitable means.