Abstract: An ionization chamber with spatial distribution electrode for monitor hadron beam currents used for therapeutic treatment. Ionization chamber comprises humidity control, environmental sensing and real-time correction thereof. A flexible hermetic seal provide for ambient pressure equalization. X-Y electrode planes measure Gaussian distribution of incident particle beam. Methods described herein are suitable to fabricate highly accurate, low scattering electrodes with high spatial resolutions.

Abstract: An atmospheric plasma apparatus and a method for manufacturing the same are disclosed. The atmospheric plasma apparatus includes an anode, a cathode, and an insulation medium disposed between the anode and the cathode. An ionizable gas is filled between the anode and the cathode. The cathode includes a plurality of plasma generating and removing units, each of which includes a plasma generating region and a plasma removing region. The plasma generating regions and the plasma removing regions are distributed uniformly and equal to each other in area. Any two plasma removing regions among every three plasma removing regions which are adjacent to each other have a same center-to-center distance. In this way, erosion caused by the plasma to the cathode and the insulation medium may be reduced to prolong the service life of the atmospheric plasma apparatus, and uniformity of cleaning of a substrate surface may be improved.

Abstract: A high-pressure discharge lamp having a single socket, comprising: a discharge vessel (100) having two opposite sealed ends (120, 130) and a discharge chamber (110) arranged between the sealed ends (120, 130), a first sealed end (120) extending into a lamp base (400) and the second sealed end (130) protruding out of the lamp base (400), a first electrode (20) which is fixed in the first sealed end (120) of the discharge vessel (100) and has an end on the discharge side extending into the discharge chamber (110), a second electrode (30) which is fixed in the second sealed end (130) of the discharge vessel (100) and has an end on the discharge side extending into the discharge chamber; and (110), a base flange (420) arranged on the lamp base (400) and defining a plane (421) which is usable for adjusting the high-pressure discharge lamp in an optical system wherein for the distance A from the end of the first electrode (20) on the discharge side to the plane (421) of the base flange (420) and for the distance B

Abstract: The invention relates to a gas discharge lamp with a gas discharge tube having a cylindrical discharge region and having two electrodes which are arranged at an outer side of the gas discharge tube. To achieve an improved gas discharge tube having external electrodes with an increased lifetime it is proposed that each electrode has a planar disc shaped holding section which each have a respective opening and in that the cylindrical discharge region is received in the openings in a shape matched manner, wherein the cylinder axis of the cylindrical discharge region lies perpendicular to the planar holding sections.

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: An exemplary backlight module includes a light guiding plate, a light source, and a light guiding bar. The light guiding plate includes a light incident surface and a light emitting surface. The light guiding bar includes a light incident surface and a light emitting surface. The light incident surface of the light guiding bar faces the light source. The light source is configured for emitting light along a lengthwise direction of the light guiding bar. The light emitting surface of the light guiding bar is opposite to the light incident surface of the light guiding plate. The light emitting surface of the light guiding bar has a larger length than that of the light incident surface of the light guiding plate. Thus two opposite end portions of the light emitting surface of the light guiding bar is offset across from the light incident surface of the light guiding plate.

Abstract: The present invention relates to a metal halogen lamp comprising, inside an outer casing (7), first (3) and second (5) arc tube members, which are electrically parallel-connected and are connected via conductive members (9) to a base part (11), each arc tube member having a first end (15), facing toward the top part (17) of the outer casing (7) opposite the base part (11), and a second end (19), facing toward the base part (11). The first arc tube member (3) is arranged closer to the top part (17) than the second arc tube member (5), and the second end (19) of the first arc tube member (3) and the first end (15) of the second arc tube member (5) adjoin an imaginary plane (P) defined substantially transversely to the center line (CL) of the outer casing (7), which center line extends from the top part (17) to the base part (11).

Abstract: A method of forming a discharge lamp and the resultant discharge lamp include providing an arc tube having first and second ends offset from a central arcuate or curvilinear portion of the discharge chamber formed between the arc tube ends. Electrodes extend from the first and second ends and at least partially into the discharge chamber which is locally substantially rotationally symmetric, i.e., substantially circular cross-section over a length thereof. Preferably, the arc tube and discharge chamber have a curvilinear conformation where the first and second ends are located below the central portion of the arc tube and associated discharge chamber in horizontal orientation during operation. Terminal ends of the electrodes preferably follow a local axis of the curvilinear conformation. The wall thickness of the discharge chamber may be alternatively constant or non-constant along a longitudinal extent thereof.

Abstract: The invention relates to a discharge lamp with a discharge vessel (2) and at least one bulb neck (I, II) connected thereto with an inner quartz bar (6) and a first foil arrangement (9), which is arranged on the outer side (63) of the quartz bar (6) and is connected to power supply lines (7a, 7b) for an electrode (4, 5) which are arranged on both sides of the quartz bar (6), wherein the bulb neck (I, II) comprises at least one second foil arrangement (13), which is connected to the power supply lines (7a, 7b) and has a greater distance with respect to the longitudinal axis (A) of the quartz bar (6) than the first foil arrangement (9). The invention also relates to a method for producing a bulb neck of a discharge lamp.

Abstract: A spark gap includes two terminal electrodes enveloping a cavity. The cavity includes an electrical discharge space between the two terminal electrodes. The spark gap also includes an electrical insulator between the two terminal electrodes.

Abstract: High-pressure discharge lamp having a ceramic discharge vessel, in which two electrodes and a light-emitting filling are contained, wherein capillaries are positioned at the ends of the discharge vessel, in which capillaries leadthroughs are sealed off, which leadthroughs are each connected to an electrode (15) consisting of tungsten. The electrode (15) is in the form of a pin and integrally comprises two parts (25, 26) having different diameters, wherein the first part (25) having a given diameter D1 forms the electrode tip, the second part (26) having a diameter D2 is positioned in the capillary, and the diameter D2 of the second part makes up at least 108% of the diameter D1 of the first part.

Abstract: The invention relates to a gas discharge lamp with a gas discharge tube having a cylindrical discharge region and having two electrodes which are arranged at an outer side of the gas discharge tube. To achieve an improved gas discharge tube having external electrodes with an increased lifetime it is proposed that each electrode has a planar disc shaped holding section which each have a respective opening and in that the cylindrical discharge region is received in the openings in a shape matched manner, wherein the cylinder axis of the cylindrical discharge region lies perpendicular to the planar holding sections.

Abstract: A filament lamp comprising a bulb which has a hermetically sealed portion on at least one end and multiple filament assemblies, each filament assembly comprising a coiled filament and connected leads to supply power to that filament, the filament assemblies being sequentially arranged in the axial direction of the bulb, the leads of each filament assembly being electrically connected to respective multiple conductive parts set in the sealed portions, and power being independently suppliable to each of the filaments. A respective one of the coiled filaments is located in a respective first quadrant formed by intersecting planes that are perpendicular to each other and that are tangent to an outer coil diameter of the respective coiled filament. The leads are positioned in quadrants other than the quadrant in which the coiled filament is located. A light irradiation type heat treatment apparatus uses a plurality of such filament lamps.

Abstract: In a metal halide lamp having a rated lamp wattage of greater than or equal to 450 W, which includes: a translucent ceramic arc tube enclosure including: a main tube inside which a discharge space is formed; and two narrow tubes having smaller diameter than the main tube, each connected to either end of the main tube; two electrodes; and a metal halide provided inside the arc tube enclosure, in which one of the two electrodes is disposed so that it protrudes inside the main tube from inside of one of the two narrow tubes, and the other one of the two electrodes is disposed so that it protrudes inside the main tube from the other one of the two narrow tubes, and when the rated lamp wattage is denoted by W (watt), an inside diameter of the main tube by D (mm), an electrode protruding length which is the distance from boundary between the main tube and the narrow tubes to an end of the electrode by L (mm), and the distance between ends of the two electrodes by E (mm), a bulb wall loading G (watt/cm2) represented

Abstract: A fluorescent tube in which no luminance gradient in the longitudinal direction occurs even when a one-side high-voltage driving method is used, a method of driving the fluorescent tube, an illuminating device for display device, and a display device having the illuminating device are provided. The fluorescent tube for one-side high-voltage driving is arranged behind a display panel via optical sheets. An internal diameter of the fluorescent tube is arranged to become larger gradually toward an electrode part at a high-voltage driving side, which prevents the occurrence of the luminance gradient in the longitudinal direction when a one-side high-voltage driving method is used.

Abstract: A patterned beam of radiation is projected onto a substrate. A reflective optical element is used to help form the radiation beam from radiation emitted from a plasma region of a plasma source. In the plasma source, a plasma current is generated in the plasma region. To reduce damage to the reflective optical element, a magnetic field is applied in the plasma region with at least a component directed along a direction of the plasma current. This axial magnetic field helps limit the collapse of the Z-pinch region of the plasma. By limiting the collapse, the number of fast ions emitted may be reduced.

Abstract: An HID lamp with a canted arc tube including a high intensity discharge (HID) lamp with an outer envelope (1) having a neck portion (34) and a lamp axis (32); a frame (9) having first frame section (9a), second frame section (9b), third frame section (9c), the first frame section (9a) being pivotably connected to the second frame section (9b) in a first connection, and the second frame section (9b) being pivotably connected to the third frame section (9c) in a second connection; and an arc tube (4) having an arc tube axis (33) attached to the second frame section (9b). At least one of the first connection and the second connection is a deformable connector (130, 132) paired with a rotary joint (21, 23); and the arc tube axis (33) forms a predetermined angle with the lamp axis (32) when the frame (9) is in a final configuration.

Abstract: A sulfur lamp including a power supply that supplies electrical power includes a transparent bulb having a space inside that contains sulfur. Additionally, a plurality of electrodes may be provided on an outside surface of the transparent bulb. Further, one end of each electrode may be connected to the power supply so that the sulfur is excited by an electric discharge to emit light. Therefore, the changing of sulfur contained in the space of the bulb into a plasma phase using the electrodes (not microwaves) avoids a need to use a magnetron, which has a low energy transfer rate, thereby increasing a system efficacy and saving a cost of replacing the magnetron with a new one.

Abstract: A metal halide lamp according to the present invention includes: a main tube (6) made of a light-transmitting ceramic and forming a part of an arc tube; a first thin tube (7a) coupled to a first end of the main tube (6); a second thin tube (7b) coupled to a second end of the main tube (6); a pair of electrodes (5a, 5b), which are inserted into the first and second thin tubes (7a, 7b), respectively, such that the far ends thereof face each other inside the main tube (1); and a first metal halide enclosed in the arc tube. A second metal halide, which has a lower vapor pressure than that of the first metal halide, is further enclosed in the arc tube. And the main tube (6) has portions, of which the inside diameter decreases monotonically toward the ends.

Abstract: A flat discharge lamp (19) for an illumination device includes a transparent electrode (15) formed on a glass plate (12) located on an illumination surface side. A shield plate (34) is arranged between at attachment surface (31) and an electrode (14). The attachment surface has ground potential, and the transparent electrode and shield plate are electrically connected to a ground terminal (28E) of the drive circuit (28). The shield plate and transparent electrode, which have ground potential, electromagnetically shields the discharge lamp.

Abstract: A discharge lamp includes a glass bulb and a pair of electrodes provided at both ends of the glass bulb. At least one of the electrodes is an external electrode formed on an outer surface of the glass bulb as a thin layer whose maximum thickness is 70 ?m or less, and an end portion of the external electrode becomes smaller in thickness towards an end of the external electrode.

Abstract: A metal halide lamp comprising a discharge vessel enclosing a discharge space of volume V(cm) and containing an ionizable gas filling comprising Hg in a quantity of mass m(g) and at least a metal halide, wherein in said discharge space two electrodes are arranged whose tips have a mutual interspacing EA so as to define a discharge path between them, the discharge space having a length L(mm) measured along the discharge path and a largest diameter D(mm) square thereto, wherein the ratio X=L/D satisfies the relation 0.7<X<6, and, wherein 0.28 3.

Abstract: To provide a ceramic metal halide lamp having a rated lamp wattage of not less than 450 W, which will not cause flicker due to instable arc during operating of the lamp and early blacking of an arc tube.

Abstract: A Plasma Display Panel (PDP) has a high aperture ratio of a discharge cell, a high light transmittance, and a high luminous efficiency and a stable and efficient discharge occurs uniformly at a low driving voltage on inner sidewalls of the discharge cell and concentrates in the center of the discharge cell.

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: A high intensity discharge lamp, the lamp including a light emitting vessel having a wall made of ceramic material that defines an inner space with a first end portion having a respective first opening formed therein and a second end portion having a respective second opening formed therein, two discharge electrodes, with a first electrode extending therethrough the first opening of the first end portion of the vessel and a second electrode extending therethrough the second opening of the second end portion of the vessel, together forming a gap between ends of the discharge electrodes positioned within the vessel, wherein the light emitting vessel defines an inner space characterized by an inner diameter ranging from and including 1 millimeters to 3 millimeters and an inner length between and including 5 millimeters to 10 millimeters, wherein the wall of the vessel has a thickness ranging between and including 0.3 millimeters to 0.

Abstract: A short arc lamp incorporates a cylindrical reflector body having a reflector cavity opening to a first end and an anode aperture through a base surface at a second end. The body has a step at the second end. A front sleeve with a step for positional engagement of a land is received over the first end of the reflector body. A cathode support is received within the second end of the front sleeve and includes a ring to engage a second oppositely oriented positioning step. A window mount received within the second end of the front sleeve abuts a front surface of the ring. A highly conductive base concentrically supporting an anode received through the anode aperture has a flange in flush abutment with the base surface for braze attachment.

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 ultra-high pressure high pressure discharge lamp device in which the lamp voltage and the distance between the lamp electrodes can be kept stable is achieved by an operating device supplying an alternating current with rectangular waves to the discharge lamp and control is exercised such that a lower boundary value is set and the operating voltage is increased by reducing the operating frequency of the discharge lamp by a given amount, when the operating voltage of the discharge lamp is below the set lower boundary value. Furthermore, control can also be exercised in such a way that an upper boundary value is set and the operating voltage is reduced by increasing the operating frequency of the discharge lamp by a given amount when the operating voltage of the discharge lamp exceeds the set upper boundary value.

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 discharge volume has an internal length L and a maximum diameter D at its center, with the discharge vessel being equipped with a light-emitting filling and with two electrodes at the ends of the discharge vessel, with the lamp being operated by means of high frequency such that an acoustic longitudinal mode is formed, with the wall thickness varying along the length L of the discharge volume, with the wall thickness S being thinnest at the center of the discharge vessel, while it is at least 1.2 S at an optimum point Popt, with the optimum point in each case being at a distance of {fraction (7/24)} L from the end of the discharge vessel.

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 ceramic body (14) for a discharge vessel (12) includes a central barrel portion (60) and two end plus (64, 66), which close opposite ends of the barrel. Main electrode (32, 34) and an initiator electrode 50 are supplied with power via conductors in leg members (70, 76, 72). In one embodiment, a first electrode 32 and the initiator electrode are supplied with current through two separate leg members. In another embodiment, a dual electrode leg member is provided with two bores (124, 126).

Abstract: A safety metal halide lamp with a high luminous efficiency and a long lamp life is provided. The metal halide lamp includes an arc tube made of light-transmissive ceramic, in which a pair of electrodes is provided and cerium iodide (CeI3) and sodium iodide (NaI) are enclosed as a light-emitting substance, wherein a molar composition rate NaI/CeI3 of the light-emitting substance is specified within a range of 3.8 to 10, inclusive, and a wall load on the arc tube ranges from 13 to 23 W/cm2, inclusive, and on a series of X, Y coordinates, where X denotes a value of a lamp watt (W) and Y denotes a value of Le/&phgr;i, where Le and &phgr;i denote a distance between the pair of electrodes and an internal diameter of the arc tube, respectively, values of the Le/&phgr;i and the lamp watt are specified to be within a range surrounded by lines passing through the points (200, 0.75), (300,0.80), (400, 0.85), (700, 1.00), (1,000, 1.15), (1,000, 2.10), (700, 2.00), (400, 1.90), (300, 1.80), and (200, 1.

Abstract: Discharge lamp includes a synthetic quartz glass tube having an inside diameter of 8 mm or over and a pair of filaments provided within and at opposite ends of the glass tube with an L (cm) filament-to-filament distance, and rare gas and metal including at least mercury are sealed in the interior of the glass tube. Lamp voltage V (V) and lamp current I (A) during illumination of the discharge lamp, filament-to-filament distance L (cm) and inside diameter D (cm) of the glass tube have relationship represented by the following mathematical expression. Namely, (V−Vf)/L=X/({square root over ( )}D·{square root over ( )}I) and 2.6≦X≦4.2, where Vf is a constant factor depending solely on a illuminating power source and where that if the discharge lamp is illuminated by a high-frequency power source of 1 kHz or over, Vf is 10, but if the discharge lamp is illuminated by a power source of 1 kHz or below, Vf is 50.

Abstract: A high pressure electric discharge lamp adapted to utilize dielectric barrier discharges can include an arc tube having a discharge space that contains at least a rare gas and an outer tube airtightly surrounding the arc tube. At least one material selected from Ne, Ar, Kr, Xe, F2, Cl2, Br2, I2 and N2 or a mixture thereof that are apt to produce a dielectric barrier discharge can be filled in the space between the arc tube and the outer tube at pressure preferably between 1.3 and 100 [kPa] and more preferably between 40 and 80 [kPa]. The type and the pressure of the rare gas contained in the space is selected as to make the dielectric barrier discharge starting voltage in the space lower than the discharge starting voltage in the discharge space.

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

Abstract: An overvoltage protection device (1) with a first electrode (2) which has a first arcing horn (3), with a second electrode (4) which has a second arcing horn (5), with an air-breakdown spark gap (6) which is active between the arcing horns (3, 5), and with a housing (7) which accommodates the electrodes (2, 4), has the two arcing horns (3, 5) shaped and arranged relative to one another such that they diverge from a lower ignition area (8) to their outer ends (9, 10), so that the air-breakdown spark gap (6) widens outwardly, proceeding from the ignition area (8). The overvoltage protection device (1) has a current carrying capacity which is as high as possible and a high network follow current extinction capacity with an overall height which is as small as possible by the first arcing horn (3) being made in the shape of a truncated cone and the second arcing horn (5) being located concentrically around the first arcing horn (3).

Abstract: A safety metal halide lamp with a high luminous efficiency and a long lamp life is provided. The metal halide lamp includes an arc tube made of light-transmissive ceramic, in which a pair of electrodes is provided and cerium iodide (CeI3) and sodium iodide (NaI) are enclosed as a light-emitting substance, wherein a molar composition rate NaI/CeI3 of the light-emitting substance is specified within a range of 3.8 to 10, inclusive, and a wall load on the arc tube ranges from 13 to 23 W/cm2, inclusive, and on a series of X, Y coordinates, where X denotes a value of a lamp watt (W) and Y denotes a value of Le/&phgr;i, where Le and &phgr;i denote a distance between the pair of electrodes and an internal diameter of the arc tube, respectively, values of the Le/&phgr;i and the lamp watt are specified to be within a range surrounded by lines passing through the points (200, 0.75), (300,0.80), (400, 0.85), (700, 1.00), (1,000, 1.15), (1,000, 2.10), (700, 2.00), (400, 1.90), (300, 1.80), and (200, 1.

Abstract: The high-pressure discharge lamp comprises a lamp vessel (1) in which an anode (4) and a cathode (5) are disposed spaced apart by an electrode distance D of 1-2 mm, the anode (4) having a tip (9) with a blunt end surface S. The area of the end surface S in mm2 and the lamp current I in amperes satisfy a relationship according to which 0.09≦S/I≦0.16, with 3.5≦I≦8.0 amperes. The ionizable filling containing metal halide comprises an amount of mercury between 65-125 mg/cm3. The power range of the lamp is between 200 and 400 watts. The calculated power gap ratio, PGR=P/D, is over 120 W/mm. The lamp is suitable for comparatively high brightness applications and at the same time is comparatively stable and has a comparatively long life.

Abstract: The system contains a quartz arc tube surrounding a gas tight envelope containing mercury, a metal halide, a rare earth gas and a pair of end to end spaced apart tungsten electrodes attached at a distal end to a molybdenum foil seal. A circuit is provided to generate an initial ignition voltage of 30,000 volts and thereafter, a circuit of 100-2,000 watts with a timer to automatically break and reconnect the circuit to provide a strobe light. A single driver actuates multiple lamps.

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

Abstract: A three-electrode-discharge surge arrester has two opposing discharging parts of a pair of line electrodes, defining a gap therebetween, and a ground electrode disposed between the two discharging parts and provided with a penetration hole in the center. Each of the two discharging parts has a substantially conical shape. In accordance with this substantially conical shape, each of inner surfaces of upper and lower parts of the penetration hole of the ground electrode is substantially funnel-shaped. Hence, oblique parallel gaps for a primary discharge are formed between the substantially funnel-shaped inner surfaces of the upper and lower parts of the penetration hole and the two substantially conical discharging parts. Also, parallel gaps for a secondary discharge are formed between peripheral parts of the ground electrode around the penetration hole and peripheral parts of the line electrodes. Each of the oblique parallel gaps is formed narrower than each of the parallel gaps.

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 metal halide lamp with a distance of less than 3.0 mm between the electrodes, in which in the hermetically sealed portion no cracks occur, which can be produced without difficulty, and which enables advantageous operation is achieved with a halide lamp in which an arc tube made of quartz glass contains a cathode and an anode spaced from each other at a distance of less than or equal to 2.9 mm together with mercury and metal halides, and which is operated with a nominal wattage range of from 100 to 400 W using direct current, by causing the ratio D/H to be greater than or equal to 1.9 when D is the maximum inside diameter in millimeters in a direction which orthogonally intersects the axial direction of the electrodes in the discharge space and H is the length of the cathode projecting within the discharge space, also in millimeters.

Abstract: To minimize "color hue" and "flickering" on an irradiated surface such as a screen or the like, is achieved by the fact that, in a metal halide lamp of the short arc type which has a cathode and an anode in which at least rare earth halides and mercury are encapsulated and which is operated with an essentially horizontal discharge direction using direct current power, the cathode has a tungsten electrode shaft about which a tungsten coil is wound, and the relationship 0.029<S/I<0.076 is satisfied where S is the cross section of the electrode shaft (mm.sup.2) and I the current in steady-state luminous operation (A). In accordance with another aspect of the invention, the lamp is operable with a current I (amperes) in steady-state luminous operation in a range from 1.6<I<5.0 and the anode has a tip formed of a roughly cylindrical rod with a bevelled edge between a blunt end of the rod and a peripheral surface of the rod, and with the relationship of the current I and the area S of the blunt end (mm.

Abstract: A mercury lamp of the short arc type in which tantalum can absorb impurity gases to a sufficient degree even if the inside of the arc tube reaches a high temperature is achieved by providing an arc tube, within which mercury and an inert gas are encapsulated, with a pair of electrodes disposed opposite each other within the arc tube, each of the electrodes being supported by a respective terminal post, tantalum being provided on the terminal post of one of the electrodes, and by ensuring that both of the relationships (D2/D1)>1.3 and the relationship 0.2.ltoreq.(D2/D1).sup.2 /L.ltoreq.0.5 are satisfied at the same time, where D1 is an outer diameter of the terminal post in millimeters, D2 is an outer diameter of the electrode supported by the respective terminal post in millimeters, and L is a distance between a tip of the electrode on which the tantalum is provided and the tantalum on the terminal post of that electrode.

Abstract: An overvoltage protection element for discharging transient overvoltages, with two electrodes (2), a disruptive discharge-spark air between the electrodes (2) and a housing (4) containing the electrodes (2). Each electrode (2) has a connecting leg (5) and an arcing horn (6) which runs at an acute angle relative to the connecting leg (5). The disruptive discharge-spark air gap is formed by facing surfaces of the arcing horns (6) of the electrodes (2), which are spaced from one another. In preferred embodiments, the arcing horns (6) of the electrodes (2), in their areas near the connecting leg (5), are provided with at least one hole (7) running therethrough which, preferably, has a diameter that is less than 2 mm.

Abstract: An emission device which operates a cadmium lamp with a light intensity sufficient for used in industrial applications is achieved by an emission device having a cadmium lamp with a fluorescent tube within which a cathode and an anode are space a small distance apart and a buffer gas for easier initiation of luminous operation and metallic cadmium in an amount per unit volume of the fluorescent tube of 1.times.10.sup.-4 g/cm.sup.3 to 3.times.10.sup.-3 g/cm.sup.3 are encapsulated, and a power source device for supplying an electrical input between the cathode and the anode in an electrical input range from 0.5 kW to 5.0 kW with the condition:6.03+2.79 W.ltoreq.r.ltoreq.40being satisfied, where the electrical input of the power source device into the cadmium lamp in steady-state luminous operation is W (kW) and the maximum inside radius of the fluorescent tube is r (mm).

Abstract: An improved arc tube for a horizontal burning metal halide arc discharge lamp is disclosed to avoid light output fluctuations which otherwise occur during lamp operation. The improved arc tube construction employs opposing planar pinch seal regions which are angularly displaced with respect to each other while further positioning the opposing discharge electrodes below the longitudinal central axis of the arc tube member.