Abstract: An ion source for forming a plasma has a cathode with a cavity and a cathode surface defining a cathode step. A filament is disposed within the cavity, and a cathode shield has a cathode shield surface at least partially encircling the cathode surface. A cathode gap is defined between the cathode surface and the cathode shield surface, where the cathode gap defines a tortured path for limiting travel of the plasma through the gap. The cathode surface can have a stepped cylindrical surface defined by a first cathode diameter and a second cathode diameter, where the first cathode diameter and second cathode diameter differ from one another to define the cathode step. The stepped cylindrical surface can be an exterior surface or an interior surface. The first and second cathode diameters can be concentric or axially offset.

Abstract: A method is provided for manufacturing a plurality of arresters as a composite structure. A ceramic carrier having a plurality of holes and two electrode bodies are provided. The ceramic carrier and the two electrode bodies are assembled into a base under gas atmosphere. The ceramic carrier is located between the electrode bodies. The electrode bodies are soldered to the ceramic carrier. The base body is separated into a plurality of gas-filled arresters is carried out. In addition, a gas-filled arrester is provided which has a height of maximal 2 mm and electrode surfaces of maximal 1.2×1.2 mm2.

Abstract: A high-pressure discharge lamp having a starting aid and having a discharge vessel is disclosed, wherein the discharge vessel has two ends with seals, in which electrodes and possibly power supply lines are fastened, wherein the starting aid includes a wire system consisting of a core wire and a wrapping wire applied thereto, wherein the wrapping wire is a flat-pressed or flattened wire.

Abstract: The present invention aims to prevent breakage of a sealing part and an electrode of a high pressure discharge lamp, and provides an electrode 100 used for a discharge lamp and having a rod-shaped part 101, one end of the rod-shaped part 101 to be sealed by a sealing part of an arc tube of the discharge lamp, the other end of the rod-shaped part 101 to be in a discharge space in the arc tube, wherein the rod-shaped part 101 has a rough surface that is composed of a plurality of types of crystal grains each having a different surface condition due to differences in crystal orientation.

Abstract: A lamp including a first and second lamp substrate with a first and second external electrode, respectively, and a first and second internal phosphor coating, respectively, wherein the first phosphor coating is a phosphor monolayer. A method of manufacturing a lamp, including screen-printing a phosphor monolayer on a first lamp substrate; screen-printing a phosphor layer on a second lamp substrate; joining the phosphor-coated faces of the first and second lamp substrates together with a seal; and joining a first and second electrode to the uncoupled exterior faces of the first and second lamp substrates, respectively.

Abstract: An electrode for a high-pressure discharge lamp may include a shaft and a head mounted thereon, wherein at least a section of the head includes ceramic material, wherein the ceramic material is a boride or carbide.

Abstract: A lamp device includes a lamp, a socket, two magnetic electrodes, and two electrode boxes. The lamp comprises a bulb portion, a stem portion, and two magnetic contacts. The socket has a receptacle portion configured to accept the lamp. The two magnetic electrodes are disposed in the receptacle portion. Each of the two electrode boxes encloses each of the two magnetic electrodes. The magnetic electrode is free to move in the electrode box, and the magnetic electrode makes an electrical contact all the time. The lamp device may further comprise a guiding groove and an insulating wall. The guiding groove may be provided on a bottom surface of the lamp between the two magnetic contacts.

Abstract: A short arc type discharge lamp wherein a cathode and an anode are arranged opposite to each other in an interior of a light emitting tube and said cathode consists of a main body part with tungsten as the main constituent and an emitter part comprised of thoriated tungsten, wherein an oxygen content of the main body part of said cathode is lower than that of the emitter part, and band-shaped tungsten carbide is formed at the tip end face of the emitter part of said cathode.

Abstract: A fluorescent lamp includes a discharge tube having an inner wall forming a discharge chamber. One or more coiled electrodes are disposed within the discharge tube. A mercury containing composition is disposed on at least one coiled electrode.

Abstract: An electron emission device including a first substrate, a second substrate, a gas, a sealant, and a phosphor layer is provided. The first substrate has a cathode thereon, and the cathode has a patterned profile. The second substrate is opposite to the first substrate and has an anode thereon. The sealant is disposed at edges of the first substrate and the second substrate to assemble the first and second substrates. The gas is disposed between the cathode and the anode and configured to induce a plurality of electrons from the cathode, wherein the pressure of the gas is between 10 torr and 10?3 torr. The phosphor layer is disposed on the moving path of the electrons to react with the electrons so as to emit light.

Abstract: The invention relates to a high-pressure discharge lamp having a discharge vessel (10) sealed at both ends, a filling which can be ionized and is enclosed in the discharge area (106) of the discharge vessel (10), and electrodes (11, 12) which extend into the discharge area (106), in order to produce a gas discharge, with the discharge vessel (10) having an electrically conductive coating (107) which is designed as a starting aid and is arranged at least in the boundary area (109) between the discharge area (106) and a first sealed end (102) of the discharge vessel (10).

Abstract: A high-pressure discharge lamp with an axial symmetry axis and metal halogenide filling has electrodes with shafts designed as pins with a diameter of 0.5 to 1.15 mm. The halogen for the halogenide is composed of iodine and possibly bromine components, iodine being used alone or in combination with bromine, and the bromine/iodine atomic ratio amounting to maximum 2.

Abstract: An arc tube includes: a tube spherical portion containing a pair of electrodes each of which has a shaft portion and a coil winding portion formed by winding coil around the shaft portion; and a pair of seal portions extending from both sides of the tube spherical portion. The coil winding portion of at least one of the electrodes has a coil portion formed by winding the coil at least once around the shaft portion in the longitudinal direction of the shaft portion, a tip disposed on the tip side of the coil portion, and a base disposed on the base side of the coil portion. The coil of the base positioned on the surface side of the electrode is melt-treated. The coil forming the base is not melted to be combined with the shaft portion.

Abstract: An all-metal electron emissive structure for low-pressure lamps is disclosed. The all-metal electron emissive structure consisting of one or more metal is operable to emit electrons in response to a thermal excitation, wherein an active region of the electron emissive structure under steady state operating conditions has a temperature greater than about 1500 degree K, and wherein the cathode fall voltage in the discharge medium under steady state operating conditions is less than about 100 volts. A lamp including an envelope, an electrode including the all-metal electron emissive structure, and a medium, is also disclosed.

Abstract: An electrode includes thorium as a minor component for a high-pressure discharge lamp, where the electrode rod is free of thorium/thorium oxide, or comprises thorium/thorium oxide, as a minor constituent. A covering member made of refractory metal, free of thorium/thorium oxide, is circumference coated on the electrode rod in the vicinity of the discharge side tip. The entire surface of the electrode rod is completely coated over the range where the covering member extends. The electrode rod tip of the electrode rod is not, or at least partly, coated with the covering member. The part of the electrode tip, which is not coated by the covering member, is free of thorium/thorium oxide.

Abstract: Alpha particles are directed and focused onto a delta-ray cathode target, where an alpha fusion reaction is generated. Delta radiation or high-energy secondary electrons are generated from the said alpha reaction. The cathode also becomes thermally active generating thermionic electrons. The electrons flow in the direction of an anode that absorbs their energy, generating electrical current in one direction, known in the electrical field as direct current.

Abstract: The disclosed subject matter includes a fluorescent lamp and particularly a cold cathode fluorescent lamp that can be employed as a light source for a LCD backlight unit for a television, a computer, a display, and the like. The fluorescent lamp can include a couple of electrode units located opposite to each other at each end of a tube, a couple of welding beads sealing both the tube and the couple of electrode units, and a filler gas located in the tube. Each of the electrode units can include an emitter electrode that is configured with a crystalline silicon carbide material having an electrical conductivity and including a concave portion formed thereon. The electrode units can prevent blackening on an inner surface of the tube by avoiding the occurrence of spattering. Thus, the fluorescent lamp using the electrode units can enjoy a long life, high reliability, easy manufacture, and the like.

Abstract: This cold cathode tube lamp comprises: a discharge tube composed of a glass tube (11) having at least a rare gas sealed therein and a pair of electrodes (21, 22) arranged opposite each other inside the glass tube (11) at opposite ends thereof. The electrodes (21, 22) have cylindrical portions (21a, 22a) having a cylindrical shape with an opening at one end and bottom portions (21b, 22b) closing the other end of the cylindrical portions (21a, 22a). Projecting portions (41, 42) are formed on interior surfaces of the cylindrical portions (21a, 22a).

Abstract: A discharge lamp in which fluctuation of the arc when the lamp starts and in which devitrification and damage of the arc tube are prevented, so that light intensity can be kept uniform over a long time is achieved by the cathode having a tapering part with a diameter which decreases in the direction to the tip that is formed with an area with different diameters extending around the tapering part in the peripheral direction which has concave-convex parts with groups of convex parts which are located next to one another in the axial direction of the cathode, the concave-convex parts in longitudinal cross section being arranged such that corner points of each convex part are located inside of an edge line of the tapering part, and an envelope curve which connects the corner points is convex with respect to the center line of the cathode.

Abstract: A ceramic discharge vessel is described that is provided a feedthrough comprised of a molybdenum alloy containing at least 75 weight percent molybdenum and greater than 5 weight percent of nickel and at least one other alloying metal selected from copper and iron, wherein the weight ratio of the amount of nickel to the combined amount of copper and iron, Ni:(Fe,Cu), in the alloy is in the range of 1:1 to 9:1. The thermal expansion coefficient of the alloy is sufficiently matched to that of the ceramic so that the feedthrough may be sealed to the discharge vessel without causing cracking. Preferably, the feedthrough is directly sealed to the ceramic discharge vessel without the use of an intermediate frit material.

Abstract: A lamp including a hermetic tube and a filament configured to radiate thermal energy within the tube. Further, the filament extends along a length direction of the tube and is spaced apart from an inner wall of the tube.

Abstract: To increase radiation intensity of deuterium lamp with continuous spectrum in UV region including vacuum UV in order to enable the lamp to illuminate wide area in high intensity. A pair of electrodes 7 and 8 is covered with dielectrics, placed outside of a UV transparent tubular discharge vessel 1 and plunged into the discharge vessel 1. There is a shield box 2 with a separator 3 between the electrodes 7 and 8 in the discharge vessel 1. Deuterium gas, hydrogen gas, mixture gas with deuterium, or mixture gas with hydrogen is enclosed in the discharge vessel 1 as discharge gas. A slit 4 is formed on the separator 3 along the axis of the discharge vessel 1 in order to squeeze the discharge path arising between the electrodes 7 and 8. The slit 4 makes radiant points continuous and then the lamp length would not be limited. When sine wave in high voltage is applied between the electrodes 7 and 8, dielectric-barrier discharge is caused.

Abstract: A bulb for a discharge lamp, includes an inner burner chamber, the outer contour of the bulb and the burner chamber each having a central region and adjacent edge regions, each central region being toroidal, and each edge region of the burner chamber adapted to be in the form of a truncated cone away from the central region and rotationally symmetrically with respect to the bulb axis, at a specific angle of taper. The midpoints of the circle segments, which form the central region of the outer contour and of the burner chamber, have a distance in the direction of the bulb axis; and/or the angles of taper of the two edge regions of the burner chamber are not the same; and/or the bulb axis lies between the circle segment, which forms the central region of the outer contour and/or of the burner chamber, and its midpoint.

Abstract: The invention relates to a method and a device for the generation of a plasma through electric discharge in a discharge space which contains at least two electrodes, at least one of which is constructed from a matrix material or carrier material, such that an erosion-susceptible region with an evaporation spot is formed at least by the current flow. To present a method or a device for the generation of a plasma by electric discharge, it is suggested that a sacrificial substrate (38) is provided at least at the evaporation spot, the boiling point of said sacrificial suvstrate (38) during discharge operation lying below the melting point of the carrier material (30), such that charge carriers arising in the current flow are mainly generated from the sacrificial substrate (38).

Abstract: A high-pressure discharge lamp has a pressure chamber with two opposite end regions and delimited by a cylindrical envelope made of glass. An electrode is provided at each of the two end regions, the electrodes projecting into the pressure chamber and being arranged in the pressure chamber as anode and cathode. A discharge chamber is formed between the electrodes. The two end regions of the pressure chamber are designed differently at least outside of the discharge chamber.

Abstract: Disclosed are a lamp, a method of fabricating the same and an LCD having the same. Electrode is disposed on an outer surface of a lamp tube, and an adhesive member is interposed between the electrode and the lamp tube. The adhesive member is hardened and expanded by means of heating, and adheres the electrode to the lamp tube. Thus, voids generated during forming the electrode on the outer surface is removed, and images having a high quality are obtained.

Abstract: In an arc tube for discharge lamp, an electrode assembly is formed by integrally joining an electrode rod, a molybdenum foil, and a molybdenum lead wire. The electrode assembly is sealed into pinch seal portions located at both ends of a glass tube. The electrode assembly, before being pinch-sealed into the pinch seal portions, receives vacuum heat treatment at 200 to 800° C. Hereby, the water content of the assembly is adjusted to 10 ppm or less, and desirably to 3 ppm less and an oxide film attached to the surface of the electrode assembly is removed. Therefore, the quantity of impurity (water or gas) enclosed in the closed glass bulb is very small, so that it is possible to provide an arc tube in which the flicker is not produced, luminous flux of 3000 lm or more is obtained, and starting voltage can be lowered to about 15 kV.

Abstract: A ceramic discharge vessel for a high-intensity discharge lamp includes a hollow body and two capillaries attached to the body. The capillaries have respective electrodes therein, where portions of the electrodes inside the body are spaced from each other and have longitudinal axes that are not coplanar. That is, in contrast to the prior art where the longitudinal axes are coplanar, the capillaries herein are moved (in effect, rotated) to positions in which a first plane defined by a longitudinal axis of one capillary and a first point where a second capillary is attached to the body is intersected by a longitudinal axis of the second capillary only at the first point.

Abstract: The invention relates to a gas discharge lamp for EUV radiation with an anode (1) and a hollow cathode (2), wherein the hollow cathode (2) has at least two openings (3, 3?) and the anode (1) has a through hole (4), which is characterized in that the longitudinal axes (5, 5?) of the hollow cathode openings (3) have a common point of intersection S lying on the axis of symmetry (6) of the anode opening (4).

Abstract: Cathode unit for installation in a fluorescent tube body (3) belonging to a fluorescent tube (1), which cathode unit (5) comprises a cathode screen (15a, 15, 15?-15??) which partially surrounds an electrode (9) which is electrically insulated from the said cathode screen (15), a power supply device (11) arranged to make an electrical connection between the said electrode (9) and a contact (13), the said cathode screen (15a, 15 , 15?-15??) comprising a first end (19) facing towards the discharge, which first end (19) comprises a central opening (21), and a second end (39) facing towards the said contact (13). The first end (19) of the cathode screen (15a, 15, 15?-15??) is designed with a rounded-off part (25) in order to facilitate the insertion of the cathode unit (5) in the said fluorescent tube body (3).

Abstract: The invention relates to a low-pressure discharge lamp comprising a glass discharge vessel (1) which is substantially tubular in form and which is closed in a gas-tight manner on the ends thereof, a filling consisting of an inert gas mixture and quicksilver, in addition to an optional luminous coating on the inner wall of the discharge vessel (1). Two current supply inlets are respectively melted into the two ends of the discharge vessel (1), with a helical electrode secured thereto (5). The invention is characterized in that in order to increase the switching resistance of the lamp in a cold start operation, at least one other electrode (7,8) made of a conductive material is arranged in the region between the helical electrode (5) and the connecting end of the discharge vessel (1) and one end of said other electrode (7, 8) is electrically connected to one of the two current supply inlets (3,4).

Abstract: A device for operating a discharge lamp of the short arc type having a feed device which supplies a direct current to the discharge lamp when operation starts and an alternating current afterwards, in which the feed device supplies a direct current which is smaller than the rated current to the discharge lamp at the start of operation, and a direct current which is at least as large as the rated current, afterwards. A control which ascertains whether the discharge lamp at the start of operation is in a hot or cold start operating state, and which establishes one of the following parameters based on whether the hot or cold operating state ascertained to exist: the value of the direct current which is at least as great as the rated current; the feed duration of the direct current which is at least as great as the rated current.

Abstract: A light source device has a bulb, a discharge medium containing rare gas sealed inside the bulb, an internal electrode disposed inside the bulb, and an external electrode disposed outside the bulb. A holder member holds the external electrode so that the external electrode is opposed to the bulb with a predetermined distance of a space therebetween.

Abstract: A discharge tube is driven by a multiple-phase drive circuit, and includes a discharge container having an internal discharge space and multiple electrodes that are secured to the discharge container and correspond to each phase of the multiple-phase drive circuit. The tips of the multiple electrodes protrude into the discharge space, and are oriented toward a predetermined single point of union. All of the electrodes located on one side of a virtual plane that includes the predetermined point of union. Furthermore, a discharge lamp having the discharge tube includes three electrodes, and electric discharge can take place between each pair of electrodes. When the discharge lamp is driven at maximum output, voltage is impressed to the three electrode terminals such that at least one of the voltages VeAB, VeBC, VeCA between the three electrode terminals will be in a discharge period.

Abstract: High pressure vapor discharge lamp provided with a discharge vessel. The discharge vessel encloses a discharge space provided with a filling of mercury and a rare gas, for example, in a gastight manner. An electrode is arranged in the discharge space for generating and maintaining a discharge therein, while the electrode comprises a rod electrode having an enlarged head at its end which projects into the discharge space. According to the invention, the enlarged head comprises a preformed electrode projection having an at least substantially conical shape.

Abstract: An arc lamp with a filter mounted internally has been disclosed. The arc lamp includes an anode, a cathode, a body defining a cavity, wherein the anode and the cathode are inside the cavity, and a filter mounted within the cavity. Other embodiments are claimed and described.

Abstract: A short arc type super high pressure discharge lamp has a pair of electrodes, a light emitting portion in which greater than 0.15 mg/mm3 of mercury is enclosed, and sealing portions provided on both sides of the light emitting portion, wherein at least one of the pair of electrodes has a thick portion which extends into one of the sealing portions and a coil is wound around the thick portion in the one of the sealing portion via a gap.

Abstract: The present invention discloses a dual spiral fluorescent lamp that is smaller in volume than a conventional one. To provide for a reduced size compact fluorescent lamp, the end portions of the spiral glass tube are anchored into the holes within the cover of a bi-pin case. Inside of each end portion is a glass stem through which a pair of cathode support wires are passed. The cathode itself is welded to the extreme ends of each cathode support wire. To achieve the short-legged lamp, the cathode support wires lying between the cathode and the stem are bent downward at approximately 60 degrees from the vertically positioned stem. Therefore, by successfully avoiding the cathode coming in contact with the phosphor coating lining the interior of the tube, which may affect the natural lighting emitted by the fluorescent lamp, the two end portions of the fluorescent lamp of the present invention can be much shortened, resulting in a smaller volume than a conventional compact fluorescent lamp.

Abstract: A short arc discharge lamp has improved starting properties in which there is no danger of damaging the arc tube that surrounds a discharge space and in which the radiant light from the arc tube is not adversely shielded. This is achieved by providing the short arc discharge lamp with a first electrode having an electrical potential and to which a high voltage is applied, and a second electrode opposite the first at a in spaced relationship. Additionally, in the discharge space, there is positioned at least one conductive component with a tip projecting into the discharge space. The conductive component has an electrical potential which is identical to the electrical potential of the first electrode and has a tip spaced a distance from the second electrode which is greater than the distance between the first and the second electrode.

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: There is provided an improved high-pressure discharge lamp which includes an arc tube encapsulating a halogen, and a pair of tungsten electrodes disposed in the arc tube. The oxygen content in the tungsten electrodes is not more than 15 ppm, while the amount of the encapsulated halogen lies in the range of 1×10?7 to 1×10?2 ?mol/mm3.

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×?) 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: The electrode system for a metal halide lamp with ceramic discharge vessel (4) comprises an electrically conductive leadthrough (9, 10) and an electrode connected thereto, the leadthrough having a fusible region with respect to the electrode, in which that end of the electrode which faces the leadthrough is embedded, at least the fusible region containing one of the high-melting metals Mo or W, and the electrode having a shank made from tungsten. In the regions surrounded by the material of the leadthrough, the electrode has a positively locking means which at least comprises a recess in the shank of 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: An improved electrode capable of smaller variances and mean breakdown voltage, increased breakdown reliability, smaller electron emission turn-on requirements, and stable electron emissions capable of high current densities include a first electrode material, an adhesion-promoting layer disposed on at least one surface of the first electrode material, and a nanostructure-containing material disposed on at least a portion of the adhesion promoting layer. An improved gas discharge device is provided incorporating an electrode formed as described above. An improved circuit incorporating an improved gas discharge tube device as set forth above is also provided. Further, an improved telecommunications network, incorporating an improved gas discharge tube device as set forth above can also be provided. An improved lighting device is also provided incorporating an electrode constructed as described above.

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1?0.4 [mm]?D2<D1.

Abstract: A high pressure discharge lamp includes a luminous bulb in which a pair of electrodes are opposed to each other in the bulb. At least mercury and halogen are contained in the luminous bulb, and at least one metal selected from the group consisting of Pt, Ir, Rh, Ru and Re is present in the luminous bulb.

Abstract: A short-arc ultra-high pressure mercury lamp in which the change in the shape of the electrodes can be suppressed and a stable arc discharge can always be produced is achieved in an arrangement in which, in the silica glass arc tube, there is a pair of opposed electrodes with a distance between them of at most 2 mm and the tube is filled with at least 0.15 mg/mm3 of mercury, a rare gas, and a halogen in the range from 1×10−6 &mgr;mole/mm3 to 1×10−2 &mgr;mole/mm3, by at least one of the electrodes having a melt part formed toward the electrode tip by winding the electrode rod with a coil and by melting the part of the coil oriented towards the electrode tip at least in the area of its surface. A part of the coil located away from the electrode tip is unmelted and the base point side area of the coil facing away from the electrode tip is rounded and does not have sharp edges.

Abstract: There is provided an improved high-pressure discharge lamp which includes an arc tube encapsulating a halogen, and a pair of tungsten electrodes disposed in the arc tube. The oxygen content in the tungsten electrodes is not more than 15 ppm, while the amount of the encapsulated halogen lies in the range of 1×10−7 to 1×10−2 &mgr;mol/mm3.

Abstract: The present invention has an object to provide a cold-cathode fluorescent lamp which can suppress sputtering caused by electric discharge and reduce consumption of mercury so as to achieve a longer lifetime even if a lamp current is large and a lighting tube has a small diameter. The cold-cathode fluorescent lamp according to the present invention is characterized in that a distance between the inner surface of the lighting tube and the outer surface of a cylindrical electrode is set such that electric discharge develops mainly on the inner surface of the cylindrical electrode. When the lighting tube has an inside diameter D1 of 1 to 6 mm and the maximum lamp current is 5 mA or more, an outside diameter D2 of the cylinder electrode is preferably set at D1−0.4 [mm]≦D2<D1.