Abstract: An ultraviolet ray lamp includes a discharge vessel made of quartz glass, filled with a filling. A pair of electrodes is able to generate a discharge in the discharge vessel. An optical filter made of metal oxide, which is partly formed on the outer surface of the discharge vessel, transmits ultraviolet rays of long wavelength and cuts off ultraviolet rays of short wavelength. Furthermore, A device for generating ultraviolet rays includes an ultraviolet ray lamp generating ultraviolet rays including short and long wavelength, having a discharge vessel made of quartz glass. An enclosure accommodates the discharge vessel, transmitting at least ultraviolet ray of short wavelength. An optical filter made of metal oxide, which is partly formed on at least one side of the surface of the enclosure, transmits ultraviolet rays of long wavelength and cuts off ultraviolet rays of short wavelength.

Abstract: A plasma display device which improves the adhesion rate of a thermal conductive medium. A chassis base is disposed substantially parallel to a plasma display panel. A thermally conductive medium is disposed between the plasma display panel and the chassis base and is closely adhered to both the plasma display panel and the chassis base. An adhesive pad is interposed between the plasma display panel and the chassis base along the edge of the thermally conductive medium and is adhered to both the plasma display panel and the chassis base. The thermally conductive medium includes a plurality of thermally conductive particles of high thermal conductivity.

Abstract: A joined body is provided, including a joining portion interposed between a first member wade of a metal and a second member, made of a ceramic or a cermet that joins the first and second members. The joining portion includes a main phase contacting the first member and an intermediate glass layer between the second member and the main phase. The main phase is composed of a porous bone structure having open pores and is made of a sintered product of metal powder. A glass phase is impregnated into the open pores in the porous bone structure. Preferably, the glasses of the intermediate glass layer and the impregnated glass phase have substantially the same composition.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures comprising a discharge chamber having light permeable walls of a selected shape including therein a pair of end region wall portions through each of which a corresponding one of a pair of electrodes are supported separated from one another by a separation length. The ratio of the separation length to the effective operation inner diameter of the chamber is greater than two. The lengths of the wall sides between the end wall portions is greater than the effective operation inner diameter. The end wall portions have inner surfaces of constant or smaller varying radii of curvature and they are separated from the interior ends of the electrodes by more than one millimeter. The discharge chamber can be constructed of polycrystalline alumina and contain metal halides.

Abstract: A ceramic discharge chamber for a lamp, according to an exemplary embodiment of the invention, comprises a first member which includes a leg portion and a transition portion, wherein the leg portion and the transition portion are integrally formed as one piece from a ceramic material, and a second member which includes a body portion, wherein the body portion is bonded to the transition portion of the first member. The ceramic discharge chamber can be formed by injection molding a ceramic material to form the first member, the first member forming a first portion of the ceramic discharge chamber; and bonding the first member to a second member which forms a second portion of the ceramic discharge chamber. The members which form the ceramic discharge chamber can greatly facilitate assembly of the discharge chamber, because the discharge chamber can be constructed with only one or two bonds between the members.

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 is enclosed, and sealing portions provided on both side 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 gap.

Abstract: A photocatalyst sterilizing lamp is constructed to include an UV lamp body and a photocatalyst coating coated on the surface of the lamp body, the lamp body having non-coating zones surrounded by the photocatalyst coating for the passing of ultraviolet light from the UV lamp body to activate the photocatalyst of the photocatalyst coating.

Abstract: A halogen lamp of a 12V type including: a glass part, a portion of which is a light emitting portion having a space therein and the rest of which is a sealing portion, both portions being made of quartz glass; an infrared reflective coating formed to cover an outer surface of the glass part; a filament which, supported by the sealing portion, is provided in the inner space of the light emitting portion; a molybdenum foil which is embedded in the sealing portion and is electrically connected to the filament; and a power supply line, one end of which is connected to the molybdenum foil, the other end exposed to outside. The halogen lamp satisfies 450 mm2≦Sb<650 mm2 and Se≧−0.35Sb+520, where Sb and Se designate outer surface areas of the light emitting portion and the sealing portion, respectively.

Abstract: A high-pressure gas discharge lamp (HID [high intensity discharge] lamp) is described which is designed in particular so as to be free from mercury and suitable for use in automobile technology. To achieve improved lamp properties, in particular a substantially equal luminous efficacy compared with lamps of the same power and having a gas filling with mercury, as well as a burning voltage which is as high as possible, a geometry is proposed for the discharge space (2) which raises the temperature of the coldest spot in the lamp to such a degree that the light-generating substances can enter the gas phase to a sufficient extent also without mercury, and in particular in combination with the use of a metal halide as a voltage gradient generator.

Abstract: A cold cathode fluorescent lamp (CCFL) comprises an inner fluorescent tube and an outer glass tube which is sheathed on the outside of said inner tube, characterized in that said inner fluorescent tube and said outer glass tube is separately disposed, and there is a space therebetween. Said CCFL further comprises electrodes sealed at the ends of said inner fluorescent tube and said outer glass tube. The CCFL of the present invention has a double-tube construction, as a result, the inner fluorescent tube is not so much affected by a change in the environmental temperature. Further, the inner fluorescent tube and the outer glass tube are separately disposed so that the end of the inner fluorescent tube and the end of the outer glass tube are not integrally joined, so that a rate of the breakage caused by the temperature difference between two ends is dramatically reduced.

Abstract: Arc tube (10) has a bulbous body (12) with a hollow center portion (14) and opposite ends (16, 18). Each of these ends has a cylindrical terminal-receiving section (20, 22) extending therefrom. The hollow center portion (14) has an internal length A and an internal diameter B that provides an aspect ratio of less than 5 and an outer surface area to inner surface area ratio, measured in square units, of less than 1.5. Electrodes (24) and (26) are hermetically sealed in the terminal-receiving sections (20, 22). The lamp uses less than 7 mgs of mercury. The low pressure operation allows the use of the arc tube in lamps without a shroud and the low mercury allow the lamp to pass TCLP requirement and be conventionally landfilled.

Abstract: In a circular fluorescent lamp unit comprising: a glass bulb 1 which is bent into a ring shape with both ends abutting on each other, has phosphor powder coated on an inner wall thereof, has electrodes provided at the respective ends in an inner space thereof and has mercury and inert gas sealed therein; and a cap which has connection pins used for electrically connecting the electrodes in the glass bulb with the outside and is attached so as to cut across the both ends of the glass bulb, a tube outer diameter of the glass bulb 1 is 13 mm to 20 mm, a ring outer diameter of the ring is 145 mm to 170 mm, lamp wattage is not more than 20 W, and lighting is carried out with a high frequency which is not less than 10 kHz.

Abstract: A high pressure discharge lamp 1A has a light emitting vessel 2A made of a semitransparent ceramic material and having a pair of end portions 2a each with an opening formed in the end portion and a light emitting portion 2a, a pair of discharge electrodes 5, and electrode supporting members 4 each supporting the electrode 5 and fixed to the end portion 2a. The vessel 2A defines an inner space 6 with an ionizable light emitting substance and starter gas filled in the inner space 6. The electrodes 5 are contained in the inner space 6. The light emitting portion 2b has a thicker portion 2g and a thinner portion 2c. The thinner portion 2c has a cross sectional area of not smaller than 35 percent and not larger than 80 percent of that of the thicker portion 2g so that the light emitting portion 2b has a brightness center 9 in the thinner portion 2c.

Abstract: The present invention is directed to horizontally burning formed-body arc tubes and arc tube blanks for high intensity discharge lamps. The bottom portion of the light emitting chamber of the arc tubes is flattened in an area between the electrodes to reduce the distance between the bottom wall of the arc tube and the arc, and to increase the surface area of the pool of condensed halides during operation of a metal halide lamp. The flattened bottom of the arc tubes may be generally planar, slightly arcuate longitudinally and/or transversely, or slightly v-shaped longitudinally and/or transversely. The top portion of the arc tube conforms generally to the shape of the arc during operation of the lamp.

Abstract: A metal vapor discharge lamp including an outer tube having a closed portion at a first end and a base at a second end; a discharge tube inside of which an electrode is provided, located in the outer tube; and a sleeve enveloping the discharge tube and located in the outer tube, wherein the sleeve includes an open portion on the closed portion side of the outer tube; the closed portion side of the outer tube is provided with a support for supporting an end of the closed portion side of the sleeve; the support comprises a column portion having a narrow plate shape or a narrow stick shape separated from the open portion of the closed portion side of the sleeve, and a sleeve holding portion provided at an end of the column portion and is in contact with the sleeve; and the support is connected to a feeding body connected to the electrode and led from the discharge tube toward the side of the closed portion, and the support also is connected to an electric power supply wire extending toward the side of the base.

Abstract: Arc tube (10) has a bulbous body (12) with a hollow center portion (14) and opposite ends (16, 18). Each of these ends has a cylindrical terminal-receiving section (20, 22) extending therefrom. The hollow center portion (14) has an internal length A and an internal diameter B that provides an aspect ratio of less than 5 and an outer surface area to inner surface area ratio, measured in square units, of less than 1.5. Electrodes (24) and (26) are hermetically sealed in the terminal-receiving sections (20, 22). The lamp uses less than 7 mgs of mercury. The low pressure operation allows the use of the arc tube in lamps without a shroud and the low mercury allow the lamp to pass TCLP requirement and be conventionally landfilled.

Abstract: Disclosed is a compact self-ballasted fluorescent lamp that includes a phosphor coating provided inside a glass tube bent to have a double-spiral configuration. The arc tube has two spiral parts that are wound around an axis “A”, and a turning part joining the two spiral parts. At any cross section of the glass tube, the applied phosphor coating is thicker in the inner surface of the glass tube near the ends of the glass tube in the axis “A” direction, than in the inner surface near the turning part.

Abstract: A circular filament lamp comprises a filament supported within an envelope which comprises a tube formed as the major part of a circle. The ends of the tube terminate in pinch seals through which extend current carrying assemblies connected to the filament. The pinch seals overlap one another circumferentially of the lamp, and are offset from one another on either side of a plane containing the axis of the filament.

Abstract: A mercury-free arc tube includes a closed glass bulb held between pinch seal portions located at opposite ends of the close glass bulb; and a pair of electrodes provided in the closed glass bulb so as to be opposite to each other. The closed glass bulb does not contain mercury but contains main light emitting metal halide (NaI and ScI3). A rare gas is enclosed in the closed glass bulb with a charged pressure set to be in a range of from 8 to 20 atmospheres. If necessary, a predetermined buffer metal halide acting as a buffer substance is enclosed in the closed glass bulb. The charged pressure of the rare gas is higher than the conventional charged pressure (6 atmospheres).

Abstract: A plasma display apparatus includes a plasma display panel, a circuit board mounting a drive circuit for driving the plasma display panel, a chassis structure provided on the backside of the plasma display panel for supporting the plasma display panel and for mounting the circuit board. In particular, the chassis structure comprises a first chassis member mounting the circuit board, and a second chassis member fixed on the backside of the plasma display panel, a plurality of support portions provided between the first and second chassis members for supporting the two chassis members and for forming a predetermined interval between the two chassis members.

Abstract: Disclosed is a discharge lamp with enhanced vertical illuminance and accordingly improved light distribution characteristics that is easy to manufacture and suitable for mass production. For a discharge lamp in which a discharge path with a double helix configuration is formed or a discharge lamp in which a plurality of U-shaped tubes are placed on an arc tube holder to form a single tortuous discharge path, a width of a turning part 106 is specified so as to narrow spaces formed in an arc tube top part, or swelling parts are provided in a vicinity of the arc tube top part so as to narrow the spaces.

Abstract: A low-pressure gas discharge lamp comprising a gas discharge vessel with a gas filling containing mercury, and comprising electrodes, means for igniting and maintaining a gas discharge, and a phosphor coating containing at least one phosphor layer and a UV-C phosphor and a phosphor that can be excited by UV-C radiation.

Abstract: An arc tube that effectively prevents a metal halide from being deposited in a light emitting tube portion, causing the change of a light emitting color or the generation of lighting failures in an arc tube. An axial distance L1 from a neck portion 20C of an arc tube body formed between a light emitting tube portion 20A and a pinch seal portion 24B of the arc tube body to a step-down plane portion 20Ba2 of each pinch seal surface 20Ba in a pinch seal portion 20B is set to 1 mm or less. During pinch seal, consequently, a sufficient pinching pressure is applied to a electrode 26, such as a tungsten electrode up to a portion close to a tip portion thereof. Thus, it is possible to reduce the volume of an almost wedge-shaped slit 24a formed around the tungsten electrode 26 on an end in the axial direction of a discharge space 24, thereby decreasing the amount of a metal halide deposited on the slit 24a.

Abstract: A high pressure sodium lamp (100) having an evacuated glass envelope (6) with a plurality of electrically conductive support members therein and extending therethrough. An elongated arc tube (14) having a pair of electrodes (26) extending therethrough is affixed to the electrically conductive support members within the glass envelope. A gas fill includes a quantity of mercury and sodium within the elongated tube. The arc tube is selected from a translucent material that, when the lamp is operating, will have a wall temperature of about 1250 degrees Celsius, a wall loading of from about 18.9 to about 22.2 w/cm sqr., and a power consumption of from 150 to 400 watts. Further, the amount of mercury is reduced from 14.4 mgs/arc tube to 10.8 mgs/arc tube, allowing lamps having power consumption from 150 to 400 watts to pass the Toxicity Characteristics Leaching Procedure (TCLP).

Abstract: A quartz arc tube for a metal halide lamps and its method of making are described. The quartz arc tube has a cylindrical design which promotes a nearly symmetric longitudinal surface temperature profile during operation. The profile has a maximum temperature of about 900° C. which allows for longer operating life at high average wall loadings.

Abstract: A miniature or subminiature incandescent lamp designed to operate with an energy source of 20 volts or less includes a filament enclosed in a first glass envelope and supported by a pair of metal contact pins. A first glass bead seals the envelope and has a pair of openings through which the metal contact pins penetrate and wherein they are hermetically sealed. A second glass bead of low melting solder glass is larger than the first bead and is sealed below the first bead and extends circumferentially beyond the perimeter of the first bead. A third bead of high melting glass is disposed below the second bead also in sealing relationship with the second bead. The outside perimeter of the third bead is substantially co-extensive with that of the second bead. A second glass envelope is sealed to the outside perimeter of the second bead and is also in abutting relationship with the third bead. The interior of the first envelope is evacuated or contains an inert gas of the type normally used in incandescent lamps.

Abstract: A low pressure arc discharge lamp with an end-of-life structure is described. The lamp has a discharge tube with sealed ends, and the sealed ends contain a filament for forming a discharge arc. The filament is supported by lead-in wires. The discharge lamp further comprises a connecting element made of an insulating material which transversely connects the lead-in wires within the discharge tube. The transverse dimension of the connecting element is chosen so as not to allow the discharge arc beyond the connecting element upon end-of-life of the discharge lamp.

Abstract: Tungsten electrodes are arranged on two rhenium rods in an electrode chamber in a high-pressure gas discharge lamp, such that the rhenium rods project to inside the electrode chamber.

Abstract: In a fluorescent lamp having a plurality of glass tubes that are connected with each other to form a discharge path, spacers that do not drop off even with insufficient accuracy of a gap between the glass tube are provided in a gap between the connected glass tubes, so as to improve the gap compression resistance and the torsion resistance. Each spacer is composed of a plurality of tonguelets and a bridge. The tonguelets are in contact with surfaces of the glass tubes and are connected by the bridge that is directed in an axial direction of the glass tubes.

Abstract: A low pressure mercury vapor discharge lamp includes an arc tube in which one discharge path is formed by connecting a plurality of U-shaped glass tubes that are provided with a fluorescent layer at the internal surface. The arc tube is held by a holder and is enclosed into a globe. A lighting circuit is connected to the arc tube. The light circuit and the holder are enclosed into a case having a lamp cap. The globe and the case integrally form a housing. The outline of the sectional face of a U-shaped glass tube at the bent part includes a circular arc and a gentle curve.

Abstract: An object of the present invention is to provide an electrodeless discharge lamp whose discharge vessel will not fall off for long until the last stage of the lifespan of the lamp, and is capable of obtaining a uniform luminous performance throughout its luminous area by assuring a positioning accuracy of the discharge vessel and the induction coil thereof.

Abstract: The electric lamp has a ceramic lamp vessel (1) having a filling of rare gas and metal halide. Current conductors (2, 3) which support electrodes (4, 5) inside the discharge vessel (1) enter the discharge vessel (1) in a gastight manner through a ceramic sealing compound (6). At least one of the current conductors (2, 3) has inside the lamp vessel (1) a first, halogen-resistant part (21, 31) which is selected from tungsten silicide, molybdenum aluminide, molybdenum boride, pentamolybdenum trisilicide and combinations of at least two of these intermetallic compounds. These compounds have a coefficient of thermal expansion which corresponds to that of the discharge vessel (1). It is thereby prevented that the discharge vessel starts leaking if the ceramic sealing compound (6) extends beyond the first part (21, 31).

Abstract: A vessel according to the present invention is made of a transparent or translucent material and includes a main portion and end portions which are integrated into the main portion, respectively. At least a center area of the main portion has a thickness smaller than at the respective end portions and at the boundary areas of the respective end portions and the main portion. The inner diameter of the respective end portions is not more than about 2 mm.

Abstract: A lamp unit (3) for use with digital micromirror devices has a direct current short arc discharge lamp (1) in which at least 0.15 mg/mm3 of mercury is sealed.

Abstract: The present invention is a microwave excited electrodeless bulb and a process of generating ultraviolet light with a microwave excited electrodeless bulb. A process of generating ultraviolet light with a microwave excited electrodeless bulb in accordance with the invention includes providing an electrodeless bulb (19) with an envelope (32) containing an ultraviolet emissive material which emits ultraviolet light in response to microwave excitation. The envelope is filled with an ultraviolet emissive material. The envelope has a major internal dimension (30) between ⅓ and ½&lgr; to which a strong field of the microwave excitation is coupled during emission of ultraviolet light with &lgr; being the free space wavelength of the microwave excitation which varies between 2.4 and 2.5 GHz. The strong field is produced by a microwave source having a steady state rated output power of no greater than 0.85 kW. The bulb is rotated at a rotational velocity of at least 20 revolutions per minute.

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: The present invention provides a metal halide lamp having a ceramic arc tube vessel that includes a discharge arc tube member and thin tube members, the discharge arc tube member including taper parts and a main tube part in the middle in a longitudinal direction, the taper parts and the main tube part having a larger outside diameter than an outside diameter of ends of the discharge arc tube in a longitudinal direction, and the thin tube members each being fit to the respective ends of the discharge arc tube, where a minimum curvature radius R is set to be 0.3 mm or more at each transitional area of an external surface between each taper part and a corresponding end of the discharge arc tube.

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

Abstract: A discharge lamp comprises an arc tube 6 made of a translucent ceramic dosed with a metallic halide. The discharge is conducted between electrodes 20 disposed in the arc tube 6. The arc tube 6 comprises a main tube body 11 having a large diameter portion 11A and a small diameter portion 11C, and a narrow tube 12 airtightly fixed to the small diameter portion 11C while penetrating the small diameter portion 11C. In the discharge lamp, supposing that L (mm) is the length of a protrusion from the main tube body of the narrow tube portion 12 and P (W) is the rated power of the discharge lamp, L and P satisfy the relationship (P+268.75)/31.25≦L≦(P+456.25)/31.25 and 200≦P≦450.

Abstract: A lighting system for generating pre-determined beam-pattern comprises a reflector body for reflecting the light forwardly thereof, an optical means for receiving and transmitting said reflected light, a discharge lamp and a lamp base. The discharge lamp is positioned between the reflector body and the optical means. The discharge lamp comprises a sealed discharge vessel made of ceramic light-transmitting material and contains an ionizable fill. The discharge lamp has at least one leg, a pair of spaced-apart electrodes within the discharge vessel between which an electric discharge is developed when the lamp is operated. The lamp base provides for supporting and positioning the discharge lamp, and includes contact elements for connecting the discharge lamp to an operating circuit.

Abstract: The invention relates to a tubular discharge lamp (1) with a wall (4) which is transparent to UV-radiation. The tube (2) encloses a discharge space (5) having an internal diameter D. The discharge space (5) comprises a filling of mercury metal vapor in a concentration range of 0.4-2.5 mg/cm3. A reduction of both the diameter D from about 22 mm down to about 13.5 mm and the average mercury concentration from about 1.7 mg/cm3 down to about 0.8 mg/cm3 leads to an increase in the effective germicidal UV-output of the lamp (1) of about 35%.

Abstract: A low pressure arc discharge lamp with an end-of-life structure is disclosed. The lamp has a discharge tube with sealed ends, and the sealed ends contain a filament for forming a discharge arc. The filament is supported by lead-in wires. The discharge lamp further comprises a connecting element made of an insulating material which transversally connects the lead-in wires within the discharge tube. The transversal dimension of the connecting element is chosen so as not to allow the discharge arc beyond the connecting element upon end-of-life of the discharge lamp.

Abstract: A bulb comprises an airtight envelope having a filling gas therein. A conductive wire extends outwardly from the airtight envelope. A conductive pipe pin has the conductive wire passed therethrough, a predetermined welding portion, and a welded portion including a smooth surface. An outer diameter of the welded portion is no greater than the outer diameter of the pin. The welded portion may be formed in the pipe pin by the fluid of the melted conductive wire and predetermined welding portion flowing into the pipe pin and hardening.

Abstract: A low-pressure discharge lamp with a double spiral shaped discharge tube including two spiral shaped tube portions. The tube portions define a central axis of the discharge tube. A cold chamber portion connects the ends of the spiral shaped tube portions. The cold chamber portion has a first transversal dimension substantially perpendicular to the central axis which is larger than the diameter of the tube portions. The cold chamber portion further has a second transversal dimension substantially parallel to the central axis. The second transversal dimension of the cold chamber portion substantially corresponds to the diameter of the tube portions.

Abstract: Fluorescent lamp (1) comprising a glass discharge vessel (2) in which a gas is present, which discharge vessel (2) is on two sides provided with a tubular end portion (3) having a longitudinal axis, which end portion (3) includes a glass stem (5), wherein an exhaust tube (6) extends axially outwardly from said stem (5) for supplying and/or discharging gases during the production of the lamp (1), wherein an electrode (8) extends axially inwardly through the stem (5) for generating and maintaining a discharge in the discharge vessel (2). The fluorescent lamp (1) is characterised in that it meets at least one of the following equations: 1 ξ = R 1 R 2 + 1 R 3 R 4 + 1 < 0.4 ⁢   ⁢ or α = R 1 R 2 < 0.

Abstract: A ceramic arc tube for high intensity discharge (HID) lighting applications is provided wherein the arc tube contains a high buffer gas pressure. A method and apparatus for making the arc tube are also provided wherein RF induction heating is used to melt a frit material to form a hermetic seal.

Abstract: This invention relates to a kind of illuminator particularly to a cold-end device of a low-pressure mercury vapor (LPMV) discharge lamp. The external glass tube of the invention is connected onto the lamp tube wall, which is opened up to the inner room of the lamp tube, and isolated from the outside. Since the cold-end device can be adjusted by the length of the external glass tube fore-mentioned and the sealing end position of the glass tube, the optimal cold-end temperature can be achieved and thus a larger light flux can be output from the energy conservation lamp in working.

Abstract: This invention provides a TIR (total internal reflecting) lens to capture and redirect light from multiple light sources, such as neon or fluorescent lamps, to generate a light of uniform brightness across the lens face.

Abstract: A discharge lamp comprising an arc tube containing a pair of electrodes in a light-emitting portion and an outer tube that envelops the light-emitting portion and is at least partly fused to the arc tube, wherein the outer tube comprises silicon dioxide in the range from 90 to 99.88 wt. % and boron in the range from 0.12 wt. % or more. The discharge lamp can inhibit the arc tube from deforming when the outer tube and arc tube are fused to each other by adjusting a softening temperature of the outer tube to an appropriate temperature and can realize a high accuracy of luminous intensity distribution.

Abstract: The invention relates to a high-pressure discharge lamp with a substantially elongate bulb which has two neck regions and a vacuumtight discharge chamber in a central position. The invention further relates to a reflector lamp and a projection system comprising such a high-pressure discharge lamp. A disadvantage of known lamps is formed by the too high temperatures of critical components. According to the invention, therefore, it is suggested that the high-pressure discharge lamp is provided at least partly with a reflection layer at least in a neck region. The reflection layer reflects radiation in the entire spectrum (ultraviolet, visible, infrared) and is used in particular as a heat shield layer which reflects the radiation incident on the neck region at the lamp end and acting as heat radiation, so that an additional heating is prevented or at least reduced.