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 ?mole/mm3 to 1×10?2 ?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: An electrodeless discharge lamp has a magnetic core 3, an induction coil 5, and a fixation member 7. The fixation member 7 has an elongation portion 7b extending in a direction along an axial line of the magnetic core 3, a holding portion 7c for holding the magnetic core 3 positioned closer to the magnetic core 3 than the elongation portion 7b, and hook portions 7d and 7e to which a winding wire 7 is hooked so as to be inflected. The hook portions 7d and 7e positioned away from a boundary between the holding portion 7c and magnetic core 3 toward the elongation portion 7b by a distance between once and twice of a diameter of the winding wire.

Abstract: The flat noble-gas discharge lamp of the present invention includes an outer enclosure that has a rear-surface substrate and a light-extraction-side substrate that is positioned to confront the rear-surface substrate. A first fluorescent film and a second fluorescent film that emit visible light of different colors are formed on respective inner surfaces of the rear-surface substrate and the light-extraction-side substrate; a first electrode and a second electrode are formed at a distance from each other on the rear-surface substrate; and a third electrode that confronts both of the first electrode and second electrode is formed on the light-extraction-side substrate.

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 mercury-free arc tube for a discharge lamp has a closed chamber filled with rare gas and a metal halide containing at least Na halide or Sc halide and electrodes disposed on both end portions of the closed chamber so as to be opposed to each other, wherein the electrode rod is stepped shape which satisfies relationship of 1.1<A1/A2<7.3, whereas A1 is a cross sectional area of the electrode in a top-end side area protruded into the closed chamber and A2 is a cross sectional area of the electrode in a base-end side area fixed to the end portion of the closed chamber.

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: An electron emission thin-film with improved secondary electron emission characteristics compared with conventional ones, a plasma display panel including the electron emission thin-film, and their manufacturing methods. Using a vacuum deposition system, a protective layer that is an MgO thin-film is formed on a dielectric layer formed on a front glass substrate. At the time of deposition, angles that lines linking the central point of a target material for the protective layer respectively with the central point and both ends points of the front glass substrate form with the front glass substrate are exclusively in a range of 30 to 80 °. This enables at least some of MgO columnar crystals constituting the protective layer to have flat planes that are inclined with respect to the surface of the thinfilm.

Abstract: In order to ensure hermeticity of a hermetic container and to suppress occurrence of electrical leakage, a display device is provided with a faceplate including an anode to be supplied with an externally-supplied electric potential, a rear plate arranged facing the faceplate at a predetermined spacing therefrom, a metal pin for supplying the electric potential to the anode from outside of the rear plate through a penetration hole in the rear plate, wherein the penetration hole includes the metal pin by insertion. The metal pin includes an axis portion disposed in the penetration hole and a flange portion which is integral with this axis portion and which is located adjacent an opening end of the penetration hole. The flange portion is joined to the rear plate for hermetically sealing the penetration hole.

Abstract: The present invention relates to novel discharge structures for dielectric barrier discharge lamps, in which discharge electrode sections, which are associated with the individual discharges, of the respective electrode strips overhang adjacent sections of the electrode strips.

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 high-pressure discharge lamp includes a discharge vessel having a wall of a ceramic material. The lamp also includes at least a feedthrough of an electrode having a cermet rod. The cermet rod is connected at a first end to a first end of a predominantly tungsten electrode pin by a welded joint. The electrode pin is in line with the cermet rod and has, at its first end, a solidified tungsten melt that is located near the interface between electrode pin and cermet rod.

Abstract: An assembly for lamp construction, including a solid tungsten W component (10) and at least one film (9) having two contact faces, comprising a metallic molybdenum base body and a coating, which is applied at least in part to said base body and which includes ruthenium or rhenium alone or as an alloy in the region of the first contact face, which produces the contact with the W component, whereas the second contact face is not coated and is intended to be in contact with glass.

Abstract: An arc tube for a discharge bulb is provided for use in a vehicular lighting system. The arc tube includes a closed glass bulb that is pinch-sealed at opposite ends. Inner ends of a first electrode and a second electrode extend into the closed glass bulbs from the ends of the closed glass bulb. The atmosphere inside the closed glass bulb includes a starting rare gas, a primary light-emitting metal halide, and optionally, a buffer metal halide. The distance between the inner ends of the electrodes is between about 0.3 and 1.8, and the inner diameter of the closed glass bulb at a middle portion is between about 1.5 mm and 2.7 mm. Accordingly, a stable discharge is produced using between 15 W and 30 W of power.

Abstract: A xenon lamp in which fluctuation of the arc can be suppressed and the time until formation of the flicker phenomenon delayed by having an anode with a flattened or rounded anode tip, a rounded or flattened back end; a portion with a diameter that gradually increases from the anode tip toward the back end of the anode; a portion with a decreasing diameter located behind the portion with the increasing diameter of an axial length which is greater than the length in the axial direction of the portion with an increasing diameter; and a portion with a maximum outside diameter formed in a transition area between the portion with the increasing diameter and the portion with a decreasing diameter, and that the transition area between the portion with the increasing diameter and the portion with the decreasing diameter is formed to be continuous.

Abstract: A display device for displaying images having a plurality of rib walls, a plurality of cells formed by the rib walls, a plurality of column electrodes extending in the column direction, and a plurality of row electrodes extending in the row direction and traverse the column electrodes. The display device further includes at least two of the column electrodes that are electrically shorted.

Abstract: A metal vapor discharge lamp, comprises: a translucent ceramic envelope, the envelope comprising a center bulb for defining a discharge space and side tubes, the center bulb and the side tubes being integrally molded; a pair of current suppliers extending through hollows of the side tubes respectively, each of the current suppliers comprising an electrode and a lead-in wire, a first end of the electrode being disposed in the discharge space, a second end of the electrode being connected with the lead-in wire; a sealant for hermetically sealing open ends of the side tubes; and a light-emitting metal contained in the discharge space. An inner wall and an external wall of a seamless boundary portion between the center bulb and each of the side tubes have the smallest curvature radius of Ri mm and Ro mm, respectively. The center bulb has an inner diameter of D mm. The lamp has an electric power of P watts. The radius Ri, radius Ro, diameter D and electric power P satisfy, ?0.00076P+0.304?Ri/D??0.00076P+0.

Abstract: A discharge panel capable of high-quality display by preventing erroneous discharge between adjacent lines in a sustaining electrode or the like. A sectional shape in a direction orthogonal to the longitudinal directions of both a first display electrode (101a) and a second display electrode (101b) has a stepped shape, a film thickness of a discharge gap (Gap1) side portion is greater than that on a non-discharge gap side, the film thickness of the respective steps being specified as L1, L2, L3 (L1>L2>L3). Accordingly, a discharge start voltage on the discharge gap side is lower than that on the non-discharge gap side even when the discharge gap and the non-discharge gap have the same width geometrically, thereby reducing erroneous discharge between adjacent cells positioned on an adjacent lines.

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: An ultra-high pressure mercury lamp is provided in which the disadvantage caused by projections formed on the electrode tips during operation can be eliminated. This is achieved by an arrangement in which a silica glass arc tube, filled with at least 0.15 mg/mm3 of mercury, rare gas and halogen in the range from 10?6 ?mole/mm3 to 10?2 ?mole/mm3, includes a pair of opposed electrodes spaced a distance of at most 2 mm. Additionally, at least one of the electrodes includes a part with a greater diameter which is formed on the electrode shaft using a melting process, a projection which is formed by the tip of the electrode shaft, and a part with a decreasing diameter which extends from the part with the greater diameter in the direction toward the projection.

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: The present invention decreases invalid light emitting regions, which are generated at both ends of an outer tube and enlarges a valid light emitting region of a phosphor layer, which enlarges the light emitting region of a lighting device. In a cold cathode fluorescent tube, cup-shaped electrodes are provided on the inside of both ends of a glass tube, which has a phosphor layer on the inner surface thereof, wherein each cup-shaped electrode connects to an inner lead, which supplies an electric power. A sputter source is formed on an inner wall surface of the cup-shaped electrode by sintering white metal oxide, whereby the white metal oxide which constitutes a sputter source is sputtered by evaporation, which forms a sputter film on a portion of the opening end of the cup-shaped electrode and inner wall surface of the glass tube.

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: A high-pressure discharge lamp includes a bulb that is made from glass in which a discharge space has been formed and a pair of electrode assemblies that are sealed in the end portions of this bulb. The electrode assemblies are each provided with an electrode rod for electrical discharge, and the electrode assemblies are sealed in the bulb with one part of each electrode rod extending into the discharge space. The part of each electrode assembly that is sealed in the bulb is in turn enclosed in an intermediate part. This intermediate part has a thermal expansion coefficient that is between the thermal expansion coefficient of the electrode rod and the thermal expansion coefficient of the bulb, is interposed between the electrode assembly and the bulb, and adheres to both the electrode assembly and the bulb.

Abstract: A mercury-free arc tube for a discharge lamp unit including a closed glass bulb and a pair of electrode rods provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury as in the related art arc tubes, but contains main light emitting metal halide and starting rare gas enclosed in the closed glass bulb. In accordance with necessity, predetermined buffer metal halide in place of mercury may be enclosed to suppress the lowering of the tube voltage to some extent. In addition, the tube current I is increased to make the tube voltage high. The tube current I (unit: A) and the outer diameter d (unit: mm) of each electrode rod are set to have a relationship of 1.0?I/d?5.0. As a result, though such an increased tube current is used, the electrode temperature is kept in optimum temperature.

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: Method and apparatus for mitigating the transport of debris generated and dispersed from electric discharge sources by thermophoretic and electrostatic deposition. A member is positioned adjacent the front electrode of an electric discharge source and used to establish a temperature difference between it and the front electrode. By flowing a gas between the member and the front electrode a temperature gradient is established that can be used for thermophoretic deposition of particulate debris on either the member or front electrode depending upon the direction of the thermal gradient. Establishing an electric field between the member and front electrode can aid in particle deposition by electrostatic deposition.

Abstract: A coiled filament has a light emitter with a reduced volume as best possible to serve in downsizing a light bulb and elevate an illumination with high efficiency in an illuminated field. A flat coiled filament wound into flatness is arranged in the form of a helix or ring, locating the longer axis of the flatness in parallel with the central axis of the coiled filament or to cross the central axis at an appropriate angle. Alternatively, it is arranged in coincident with the radial axis of the coiled filament or at an appropriate angle. Alternatively, the flat coiled filament is U-shaped and a pair of such U-shaped flat coiled filaments are mated with each other through their open ends, while the inner surfaces of their closed ends are kept in non-contact with each other. Alternatively, the flat coiled filament is formed circular.

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 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: The present invention discloses a plasma display panel which can improve screen quality, by dividing a rear substrate into a plurality of regions and by varying a structure of cells in each region, thereby preventing luminance from being reduced according to a process property and an electric property of a panel.

Abstract: A method of producing an arc tube including inserting an electrode assembly in which a bent portion is formed in a lead wire into a glass tube to self-hold the electrode assembly to a predetermined position of the glass tube. After the electrode has been inserted to the predetermined position, pinch-sealing is conducted on a portion of the glass tube where the assembly is inserted. In the method, the electrode assembly is inserted into a metal guide pipe which is coaxially disposed with respect to the glass tube, to be once held into the pipe. Thereafter, the assembly may be pushed by a thin rod-like pushing member to be inserted to the predetermined position in the glass tube. One or more vertical grooves which are to be axially engaged with the bent portion of the assembly to circumferentially lock the bent portion may be formed in the inner side of the guide pipe. Using the one or more grooves, the assembly may be guided to the glass tube W without being in sliding contact with the guide pipe.

Abstract: In order to ensure hermeticity of a hermetic container and to suppress occurrence of electrical leakage, a display device is provided with a faceplate including an anode to be supplied with an externally-supplied electric potential, a rear plate arranged facing the faceplate at a predetermined spacing therefrom, a metal pin for supplying the electric potential to the anode from outside of the rear plate through a penetration hole in the rear plate, wherein the penetration hole includes the metal pin by insertion. The metal pin includes an axis portion disposed in the penetration hole and a flange portion which is integral with this axis portion and which is located adjacent an opening end of the penetration hole. The flange portion is joined to the rear plate for hermetically sealing the penetration hole.

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: To devise an arrangement with relatively high pressure tightness, in a short-arc super-high pressure mercury lamp which is operated with an extremely high mercury vapor pressure, a light emitting part has a pair of opposed electrodes and is filled with at least 0.15 mg/mm3 of mercury; and side tube parts extend from opposite sides of the light emitting part, and in which the electrodes are partially hermetically sealed and are each welded to a respective metal foil, in the areas in which the electrodes are welded to the metal foils, the electrodes are deformed in the direction perpendicular to the metal foils to a degree of deformation that is at most 10%.

Abstract: A high-pressure discharge lamp comprises a lamp tube made of quartz glass and having a central portion formed in a spherical shape, and a pair of opposing tungsten electrodes inserted into the lamp tube. At least one of the tungsten electrodes is made of a tungsten material which contains more than 10 ppm of one of Co and Ni, or 10 ppm of Co and Ni in total, or a tungsten material which contains 20 ppm or more of at least two of Fe, Co and Ni in total, or a tungsten material which contains 20 ppm or more of Fe. Fe, Co and Ni belong to iron-group metals. The inter-electrode distance, i.e., distance between the leading ends of both tungsten electrodes is set to approximately 1-2 mm or less.

Abstract: A plasma display panel includes a first substrate, a second substrate, and discharge gas filled in a space defined between the first and second substrates, the first substrate including at least one first electrode extending in a first direction, and at least one second electrode extending in parallel with the first electrode, the second substrate including at least one third electrode extending in a second direction perpendicular to the first direction, and a plurality of partition walls extending in the second direction for partitioning a display area, wherein at least one of the first and second electrodes is comprised of a first portion being in the form of a line extending in the first direction, and defining a discharge gap between itself and an adjacent electrode, and a second portion radially extending from the first portion in a direction away from the discharge gap.

Abstract: A discharge lamp with a high output power in which an increase of the current to be supplied to the discharge lamp can be enabled without the need to enlarge the discharge lamp and the surrounding system. The discharge lamp includes an arc tube having a pair of opposed electrodes, at least one of the electrodes having an electrode body in which a hermetically sealed interior space is formed, and a heat conductor partially filling the hermetically sealed interior space. This heat conductor consists of metal that has a higher thermal conductivity or a lower melting point than the metal comprising the electrode body.

Abstract: A lamp assembly for a liquid crystal display device includes a lamp tube for generating light, and electrodes each having a suitable shape for receiving end portions of the lamp tube. The lamp tube and the electrodes are combined to generate the light by applying electric power to the electrodes. The lamp assembly may include multiple lamp tubes having different brightness from each other, in which the brightness difference between the lamp tubes is compensated by uniformly diffusing the light generated from the lamp tubes.

Abstract: A light source device includes a discharge tube, a discharge medium sealed inside the discharge tube, and inner and outer electrodes for exciting the discharge medium. The inner electrode is arranged inside the discharge tube. The outer electrode includes a first outer electrode and a second outer electrode that are connected electrically with each other. The first outer electrode is in contact with an outer surface of the discharge tube at a plurality of first contact portions that are located at different distances from the inner electrode and are provided discontinuously. The second outer electrode is in contact with the outer surface of the discharge tube at second contact portions. The second contact portions are arranged closer to the inner electrode than the first contact portions at a surface density greater than that of the first contact portions.

Abstract: A light source, in particular incandescent lamp, with a bulb (1), a filament (2) arranged in the bulb (1), and a heating device (3) for the filament (2), the filament (2) emitting both visible light and heat radiation, is designed and constructed with respect to a high conversion efficiency between an electrical power input and emitted light output such that the filament (2) includes a flat section (4). A light source of this type may be produced by a method, wherein initially a filament (2) of a sintered metal powder is provided. Subsequently, the filament (2) is exposed to an atmosphere of carbon dioxide or of carbon dioxide and inert gas for forming a metal carbide. Finally, the filament (2) is sealed into the bulb (1).

Abstract: An arrangement with a relatively high pressure tightness in a super-high pressure mercury lamp which is operated with an extremely high mercury vapor pressure is achieved in accordance with the invention in a super-high pressure discharge lamp of the short arc type having a light emitting part in which a pair of electrodes are disposed opposite each other and which is filled with at least 0.15 mg/mm3 mercury; and side tube parts which extend from each side of the light emitting part and in each of which a respective one of the electrodes is partially hermetically sealed and is connected to a metal foil, by the area of the respective metal foil which is connected to the respective electrode has a smaller width than the width in the remaining area of the metal foil, the area with the smaller width wrapping at least partially around the outside surface of the electrode.

Abstract: A progressive display is realized that has an electrode structure in which two neighboring rows share a display electrode. A PDP has display electrodes arranged so that two neighboring rows share one electrode for display, and the display electrodes crosses an address electrode in each column. A row selection is performed by temporarily biasing one display electrode Yj of the electrode pair corresponding to the selected row to the selecting potential Vy, while an addressing is performed by controlling the potential of the address electrode Ak in accordance with the display data. At that time, the cell-selecting voltage Vay that is applied to the interelectrode AY between the display electrode Yj and the address electrode Ak made lower than the discharge starting voltage VAY of the interelectrode AY.

Abstract: A driving electrode structure of a plasma display panel for improving operation margin is described. A plurality openings is formed in a transparent electrode according to the driving characteristics of fluorescent layer of each luminous cell to adjust the effective area of the transparent electrode in each luminous cell, thereby increasing the operation margin of the sustaining voltage.

Abstract: A discharge lamp of the present invention, which has an starting property, an arc stability and a service life which are improved even if the lamp produces a short arc. The discharge lamp includes a light emitting bulb, sealing members disposed on both sides of the light emitting bulb, metal foils sealed in the sealing members, a pair of electrodes which are connected to the metal foils and have large-diameter portions formed on tips, coils disposed at the rear of the large-diameter portions of the electrodes, external conductors, and a discharge medium enclosed in the light emitting bulb.

Abstract: A lighting system that includes a lamp and a control circuit configured to apply signals to the lamp in pulsed mode operation. The lamp may employ ferroelectric ceramic cathodes to enhance life of the lamp when used with the pulsed mode drive circuitry. The drive circuitry applies signals within a desired frequency range to lower input power while providing enhance output within a desired wavelength band, such as 365 nm to make use of an afterglow regime from an emissive medium within the lamp.

Abstract: A light source device includes a substrate, a plurality of discharge tubes arranged on one principal surface of the substrate, a driving circuit mounted on the other principal surface of the substrate that is opposite to the foregoing principal surface, a discharge medium sealed in the discharge tubes, and first and second electrodes for exciting the discharge medium. The foregoing discharge medium does not contain mercury. Thus, the light source device can be formed smaller in size and thinner in thickness, and a liquid crystal display device employing the same can be provided.

Abstract: An arc tube, which is capable of prolonging the life thereof by preventing occurrence of a leak caused from a crack of an arc-tube body, has the average surface roughness of each of outer surfaces 26Aa and 26Ba of tungsten electrodes 26A and 26B pinch-sealed to pinch seal portions 20b1 and 20b2 on the two sides of a light-emission tube 20a of an arc-tube body 20 is set to be 3 ?m or smaller. Thus, the state of pinch-sealing of the tungsten electrodes 26A and 26B to the pinch seal portions 20b1 and 20b2 is brought to a state in which the two elements are engaged with small pits and projections. Therefore, great compressive stress is not left in the region adjacent to the joint surface between the pinch seal portions 20b1 and 20b2 and the tungsten electrodes 26A and 26B as distinct from the conventional structure. In a case where a crack of the arc-tube body 20 is formed owing to the residual compressive stress, the crack is limited to a local portion which is the region adjacent to the joint surface.

Abstract: An ultrahigh pressure mercury lamp which is small and has high light radiation intensity and moreover good color reproduction with high efficiency in which, even with a large amount of mercury added, a failure of the mercury to vaporize in the bulb part does not occur, and in which blackening of the bulb part due to wearing of the electrodes even under a large electrode load as a result of shortening of the distance between the electrodes is low is obtained by an ultrahigh pressure mercury lamp in which a bulb part of the discharge vessel made of translucent material has an essentially ovoid shape, is filled with at least 0.2 mg/mm3 of mercury and which is operated at an input wattage of at most 400 W using direct current, has the length D of the tip area of the anode and the length L of the bulb part in the direction of the tube axis of the lamp set in accordance with the relationship D?L/2.

Abstract: The present invention provides a high pressure discharge lamp which is provided with a discharge tube containing a pair of electrodes therein and being filled with mercury, an inert gas and a halogen gas, the amount of the mercury filled being 0.12 to 0.35 mg/mm3, the halogen gas being at least one gas selected from the group consisting of Cl, Br and I and being present in an amount of 10?7 to 10?2 ?mol/mm3, and the electrodes being mainly composed of tungsten, and the tungsten as a material of the electrodes contains not more than 12 ppm of potassium oxide (K2O). In such a high pressure discharge lamp, blackening of the discharge tube due to the potassium oxide (K2O) contained in the tungsten, and decrease in illumination maintenance can be prevented, thus providing a high pressure discharge lamp with a long lifetime, a lighting optical apparatus using the high pressure discharge lamp as a light source, and an image display system using the lighting optical apparatus.