EP2626889A1 - Tube céramique et son procédé de production - Google Patents

Tube céramique et son procédé de production Download PDF

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Publication number
EP2626889A1
EP2626889A1 EP11830531.7A EP11830531A EP2626889A1 EP 2626889 A1 EP2626889 A1 EP 2626889A1 EP 11830531 A EP11830531 A EP 11830531A EP 2626889 A1 EP2626889 A1 EP 2626889A1
Authority
EP
European Patent Office
Prior art keywords
capillary
light
ceramic
hole
axis line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11830531.7A
Other languages
German (de)
English (en)
Other versions
EP2626889A4 (fr
Inventor
Sugio Miyazawa
Keiichiro Watanabe
Tsuneaki Ohashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NGK Insulators Ltd
Original Assignee
NGK Insulators Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NGK Insulators Ltd filed Critical NGK Insulators Ltd
Publication of EP2626889A1 publication Critical patent/EP2626889A1/fr
Publication of EP2626889A4 publication Critical patent/EP2626889A4/fr
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/002—Producing shaped prefabricated articles from the material assembled from preformed elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/24—Producing shaped prefabricated articles from the material by injection moulding
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/302—Vessels; Containers characterised by the material of the vessel
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
    • H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
    • H01J7/22—Tubulations therefor, e.g. for exhausting; Closures therefor
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/24—Manufacture or joining of vessels, leading-in conductors or bases
    • H01J9/245—Manufacture or joining of vessels, leading-in conductors or bases specially adapted for gas discharge tubes or lamps
    • H01J9/247—Manufacture or joining of vessels, leading-in conductors or bases specially adapted for gas discharge tubes or lamps specially adapted for gas-discharge lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/24—Manufacture or joining of vessels, leading-in conductors or bases
    • H01J9/26—Sealing together parts of vessels
    • H01J9/265—Sealing together parts of vessels specially adapted for gas-discharge tubes or lamps
    • H01J9/266—Sealing together parts of vessels specially adapted for gas-discharge tubes or lamps specially adapted for gas-discharge lamps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/38—Exhausting, degassing, filling, or cleaning vessels
    • H01J9/395—Filling vessels

Definitions

  • the present invention relates to a method for producing a ceramic tube usable in a high-intensity discharge lamp such as a high-pressure sodium vapor lamp or a metal halide lamp, and further relates to the ceramic tube.
  • a pair of electrodes are inserted into a ceramic tube for a high-intensity discharge lamp, and a metal halide is ionized by the electrodes to show discharge emission.
  • Such a ceramic tube has a pair of capillaries, and the axis lines of the capillaries extend toward a light-emitting portion.
  • Each capillary has an electrode insertion hole, into which the electrode is inserted.
  • Various types of the ceramic tubes are disclosed in e.g. Japanese Laid-Open Patent Publication Nos. 63-143738 , 5-334962 , 7-021990 , 8-055606 , 2010-514125 (PCT), and 2010-514127 (PCT), US Patent Application Publication No. 2006/0001346 , and Japanese Laid-Open Patent Publication Nos. 2009-530127 (PCT) and 2008-044344 .
  • one electrode is inserted into the electrode insertion hole in one of the two capillaries
  • the electrode insertion hole is sealed with a fritted glass or the like, a light-emitting material is introduced from the other electrode insertion hole into a light-emitting container, the other electrode is inserted into the other electrode insertion hole, and then the other electrode insertion hole is sealed by the fritted glass or the like, to obtain an arc tube.
  • the ceramic tube has a third capillary or small hole in addition to the above two capillaries for electrode insertion, and the light-emitting material is introduced through the third capillary or small hole into the light-emitting container after the electrodes are sealed.
  • Japanese Laid-Open Patent Publication No. 63-143738 discloses a ceramic discharge lamp containing an arc tube bulb composed of a translucent ceramic and closure members composed of a conductive cermet.
  • the arc tube bulb has openings at either end, and the openings are sealed by solid-phase-bonding the closure members having electrodes.
  • the arc tube bulb further has a small hole for discharging an exhaust gas from the tube and for supplying an inclusion, and the small hole is closed by welding a ceramic cover.
  • Japanese Laid-Open Patent Publication No. 5-334962 discloses a translucent bulb composed of a polycrystalline alumina.
  • the translucent bulb has cylindrical openings at either end, and closure members are attached to the cylindrical openings.
  • Each closure member has a hole at the center, and an electrode is inserted into the hole.
  • the translucent bulb further has an opening, and a light-emitting material is introduced from the opening into the translucent bulb.
  • the opening is formed in a position eccentrically with respect to the center of one of the closure members.
  • Japanese Laid-Open Patent Publication No. 7-021990 discloses a discharge tube, wherein pin-like current conductors having a diameter of 300 ⁇ m are inserted into the ends of the discharge tube, and plugs are directly bonded to the ends by sintering. Especially, as shown in FIGS. 3 and 4 of this patent document, a filling hole having a diameter of 1 mm or more may be formed, for introducing a light-emitting material into the discharge tube, in a wall of the discharge tube around the second end or in the second plug.
  • Japanese Laid-Open Patent Publication No. 8-055606 discloses an arc tube having an infundibular portion, which is formed integrally with a small-diameter tube having a closed lower end.
  • the small-diameter tube extends downward from the center of the infundibular portion, and a liquid metal halide is stored in a lower portion (coldest portion, which is coldest during lighting) of the small-diameter tube.
  • the liquid metal halide is not vaporized and remains in the arc tube.
  • this patent document describes that one opening formed on a flange-like intermediate portion may be used as an inlet for the metal halide and mercury, and the small-diameter tube may be used as an inlet tube.
  • Japanese Laid-Open Patent Publication No. 2010-514125 discloses a ceramic burner containing a discharge vessel.
  • One end of the discharge vessel is formed integrally with a wall of the tube, and the other end of the discharge vessel is sealed with a ceramic plug.
  • a tube extends outward from a ceramic wall of the discharge vessel, and is used for introducing an ionizing filler into the discharge vessel in the manufacture of the ceramic burner.
  • the tube is air-tightly sealed.
  • Japanese Laid-Open Patent Publication 2010-514127 discloses a discharge vessel having a substantially spherical or oval shape containing two independent portions (separated by a dashed line in FIG. 2A of this patent document).
  • a tube is formed only on the first portion of the discharge vessel, extends outward from a ceramic wall of the discharge vessel, and is used for introducing an ionizing filler into the discharge vessel in the manufacture of a ceramic burner. Incidentally, the tube is air-tightly sealed.
  • US Patent Application Publication No. 2006/0001346 discloses a structure containing a tube portion and end members bonded to either end of the tube portion.
  • An electrode is disposed at the center of each end member, and extends toward the inside of the tube portion.
  • Particularly one end member has an inlet hole, which extends from the outer surface of the member to the inner surface (the surface facing the tube portion).
  • a metal halide or the like is introduced from the inlet hole into the tube portion, and then the inlet hole is sealed with a plug member.
  • a production method containing preparing a plurality of inorganic powder compacts, applying a slurry to the joining surfaces of the compacts, and integrating and sintering the compacts to obtain a strongly-bonded sintered body is known from e.g. Japanese Laid-Open Patent Publication No. 2009-530127 (PCT), and a bonded assembly of inorganic powder compacts that can be produced while preventing or avoiding the deformation of the joining portion and the increase of surface roughness is known from e.g. Japanese Laid-Open Patent Publication No. 2008-044344 .
  • Japanese Laid-Open Patent Publication No. 2009-530127 discloses a method for producing a sintered body suitable for use in an arc tube of a discharge lamp.
  • the method uses an inorganic powder, an organic dispersion medium having a reactive functional group, and a gelling agent, and contains the steps of performing a chemical solidification reaction between the organic dispersion medium and the gelling agent to obtain first and second inorganic powder compacts, applying a slurry containing a powder and an organic dispersion medium to the joining surface of the first inorganic powder compact, bringing the inorganic powder compacts into contact with each other with the slurry applied therebetween to obtain an integrated bonded assembly, and sintering the bonded assembly to produce the sintered body.
  • Japanese Laid-Open Patent Publication No. 2008-044344 discloses a sintered body suitable for use in an arc tube of a discharge lamp.
  • the sintered body is derived from a bonded assembly of two or more inorganic powder compacts, and has a first portion corresponding to the two or more inorganic powder compacts in the bonded assembly and a second portion corresponding to a joining portion in the bonded assembly.
  • the sintered body has one or both of the flowing properties (a) and (b).
  • the first and second capillaries are formed to introduce and seal the electrodes into the light-emitting portion and seal the electrodes
  • the third capillary (or the third small hole) is formed to introduce the light-emitting material into the light-emitting portion.
  • the first, second, and third capillaries have first, second, and third through-holes extending in the axis directions respectively. Specifically, the axis directions of the first and second capillaries are different from that of the third capillary (or the third small hole).
  • the drawing directions of pins for forming the first and second through-holes are different from that of a pin for forming the third through-hole (or the third small hole).
  • this process requires a molding apparatus having a mechanism suitable for the drawing directions and a production equipment having an expensive complicated structure, thereby resulting in high production cost.
  • a portion having the third capillary or small hole exhibits a light transmittance lower than those of the other portions. Therefore, in a case where the third capillary or small hole is located in a position corresponding to the discharge area around the electrode end, the lamp efficiency and the light distribution are deteriorated due to the lowered light transmittance. Meanwhile, in a case where the third capillary or small hole is located in the vicinity of the first or second electrode-sealing capillary, the third capillary or small hole is likely to act as the coldest portion during lighting. In this case, when the light-emitting material is stored in the third capillary or small hole, the ceramic may be corroded to reduce the lifetime of the tube.
  • the disc-shaped portion (plug) having the third small hole is formed in advance separately from the first and second electrode-sealing capillaries and attached to the tube body, the axis direction of the third small hole being parallel to the axis directions of the first and second electrode-sealing capillaries, the third small hole is located in a thick portion in the vicinity of the electrode in the assembled lamp, and is disadvantageously corroded by the coldest portion.
  • an edge having a sharp cross-sectional angle is formed at the boundary between the through-hole of the third capillary and the inner surface of the light-emitting portion.
  • the edge is easily chipped off in the production, transport, or the like. Consequently, waste may be generated, and the chipped portion may be cracked.
  • the third capillary when the third capillary is excessively long, the third capillary is not sufficiently heated and acts as the coldest portion during the lighting, whereby the ceramic may be corroded undesirably as described above.
  • an object of the present invention is to provide a ceramic tube for a high-intensity discharge lamp, which has a third small hole or capillary for introducing a light-emitting material into a light-emitting portion and can be highly reliably produced at low production cost and high productivity while preventing light transmittance deterioration without using a production equipment having a complicated structure.
  • Another object of the present invention is to provide a method capable of easily producing a ceramic tube for a high-intensity discharge lamp, which has a third small hole or capillary for introducing a light-emitting material into a light-emitting portion, at low production cost, high productivity, and high yield by using a simple production equipment.
  • a numeric range of "A to B" includes both the numeric values A and B as the lower limit and upper limit values.
  • the ceramic tube is preferably used as an arc tube in a discharge lamp.
  • a high-pressure discharge lamp containing the ceramic tube can be used in various illumination devices such as road illuminations, store illuminations, car headlamps, and liquid-crystal projectors.
  • the arc tube may be used in a metal halide lamp or a high-pressure sodium vapor lamp.
  • a ceramic tube according to a first embodiment contains a light-emitting portion 12, a first capillary 14a, and a second capillary 14b that are formed integrally.
  • the light-emitting portion 12 is adapted to emit a light inside the first ceramic tube 10A.
  • the first capillary 14a and the second capillary 14b are disposed on either side of the light-emitting portion 12, and electrodes are sealed therein.
  • the light-emitting portion 12 has a through-hole 16 formed in a position close to the first capillary 14a, and the through-hole 16 extends from the inside to the outside of the light-emitting portion 12 in a direction parallel to the extending direction of the first capillary 14a.
  • the through-hole 16 is used as an inlet hole for introducing a light-emitting material or the like into the light-emitting portion 12. Therefore, the through-hole 16 is sealed after the introduction of the light-emitting material or the like.
  • an inert start gas such as an argon gas
  • mercury and metal halide additives are contained in the light-emitting portion 12. Incidentally, the mercury additive is not an essential component.
  • the first ceramic tube 10A is produced by bonding and firing a first ceramic compact 22A containing a first curved portion 18a and a first cylindrical portion 20a formed integrally and a second ceramic compact 22B containing a second curved portion 18b and a second cylindrical portion 20b formed integrally.
  • the first ceramic tube 10A has an expanded portion obtained by bonding and firing the first curved portion 18a and the second curved portion 18b (the light-emitting portion 12) at the center, and further has the first capillary 14a and the second capillary 14b that are formed integrally with either end of the light-emitting portion 12.
  • a hollow portion 24 is formed in the first ceramic tube 10A, and extends from the first capillary 14a to the second capillary 14b.
  • a first electrode 26A and a second electrode 26B are inserted into and sealed in the first capillary 14a and the second capillary 14b respectively.
  • the first electrode 26A has a first electrode shaft 28a, a first coil 30a wound around the inner end of the first electrode shaft 28a, and a first lead 32a connected to the outer end of the first electrode shaft 28a by welding or the like.
  • the first lead 32a is sealed in the inner wall of the first capillary 14a, whereby the entire first electrode 26A is sealed in the first capillary 14a.
  • the second electrode 26B has a second electrode shaft 28b, a second coil 30b wound around the inner end of the second electrode shaft 28b, and a second lead 32b connected to the outer end of the second electrode shaft 28b by welding or the like.
  • the second lead 32b is sealed in the inner wall of the second capillary 14b, whereby the entire second electrode 26B is sealed in the second capillary 14b.
  • a region between the first coil 30a and the second coil 30b in the light-emitting portion 12 acts as a discharge area 34 for emitting a light.
  • a first curved surface 36a is formed between a portion corresponding to the discharge area 34 and the first capillary 14a, and the diameter thereof decreases continuously from the portion corresponding to the discharge area 34 to the first capillary 14a.
  • a second curved surface 36b is formed between the portion corresponding to the discharge area 34 and the second capillary 14b, and the diameter thereof decreases continuously from the portion to the second capillary 14b.
  • the through-hole 16 is formed on the first curved surface 36a closer to the first capillary 14a than a position corresponding to the inner end of the first electrode 26A (the first coil 30a). Specifically, as shown in FIG.
  • the axis line n1 has a position Pa on a perpendicular line Ln (perpendicular to the axis line n1) extending from the point 35, the axis line n1 has a position Pb on the inner end of the first electrode 26A, the direction from the position Pb toward the first capillary 14a is considered as the positive direction, and the direction from the position Pb toward the second capillary 14b is considered as the negative direction, it is preferred that the position Pa is equal to the position Pb or is shifted from the position Pb in the positive direction.
  • the axis line m1 of the through-hole 16 is preferably parallel to the axis line n1 of the first capillary 14a.
  • the axis line m1 of the through-hole 16 may be perpendicular to the axis line n1 of the first capillary 14a.
  • such a structure has the following disadvantage.
  • the first ceramic tube 10A is produced by bonding and firing the first and second ceramic compacts 22A and 22B.
  • this process requires a casting mold shown in FIG. 5A , which has a stationary mold 38 and a movable mold 40 for forming the first curved portion 18a and the first cylindrical portion 20a, and further has a pin 42 for forming the through-hole 16.
  • a hole 44, into which the pin 42 is inserted, has to be formed in the stationary mold 38
  • a clearance hole 46 into which the end of the pin 42 is inserted, has to be formed in the movable mold 40.
  • a simple first casting mold can be used for forming the first ceramic compact 22A without significant design change.
  • a pin 48 for forming the through-hole 16 is formed on a surface of the movable mold 40 facing the stationary mold 38, and a clearance hole 50, into which the pin 48 is inserted, is formed on the stationary mold 38.
  • the first casting mold can be removed only by drawing out the movable mold 40 as shown in FIG. 6B . Therefore, the specific mechanism and control system for controlling the pin are not required. Thus, only the mechanism and control system for controlling the reciprocating movement of the movable mold 40 is required, and the large complicated structure of the production equipment is not required.
  • the through-hole 16 is preferably closer to the first capillary 14a than the position corresponding to the inner end of the first electrode 26A (the first coil 30a) in the light-emitting portion 12, and is further preferably closer by 0.5 mm or more to the first capillary 14a than the inner end of the first electrode 26A. Consequently, the light transmittance of the first ceramic tube 10A is not affected by the through-hole 16, and the light-emitting efficiency and the light distribution are not deteriorated by the through-hole 16.
  • the distance La between the axis line m1 of the through-hole 16 and the axis line n1 of the first capillary 14a is preferably 0.55 or more times as large as the outer diameter Da of the first capillary 14a.
  • the sealing portion of the through-hole 16 can be prevented from acting as the coldest portion and from being corroded, during the lighting.
  • a portion around the first capillary 14a may have a high heat capacity, and thereby may act as the coldest portion during the lighting. Even when the portion does not act as the coldest portion, the portion is likely to have a low temperature.
  • the through-hole 16 is preferably formed in a portion, which has a low heat capacity and exhibits a relatively high temperature during the lighting, e.g. on the first curved surface 36a.
  • the distance La is preferably 1.6 or less times as large as the outer diameter Da of the first capillary 14a. When the distance La is more than 1.6 times as large as the outer diameter Da, the light-emitting portion 12 is readily cracked due to solidification shrinkage of a gelling agent in the molding process.
  • a method for producing the first ceramic tube 10A will be described below with reference to FIG. 7 .
  • step S1 of FIG. 7 the first and second ceramic compacts 22A and 22B are prepared as shown in FIG. 2 .
  • the first ceramic compact 22A has a through-hole 52, which acts as the through-hole 16 when in the sintered body (the first ceramic tube 10A).
  • the second ceramic compact 22B does not have through-holes.
  • step 51a a ceramic powder, a dispersion medium, a gelling agent, and the like are mixed to prepare a gel casting slurry (hereinafter referred to as a molding slurry).
  • step S1b the molding slurry is cast into and then solidified in a first casting mold for forming the first ceramic compact 22A and a second casting mold for forming the second ceramic compact 22B.
  • the movable mold 40 has the pin 48 for forming the through-hole 16
  • the stationary mold 38 has the clearance hole 50, which the pin 48 is inserted into.
  • the pin 48 and the clearance hole 50 are not formed.
  • step S1c the first and second casting molds are separated to obtain the first and second ceramic compacts 22A and 22B shown in FIG. 2 .
  • the first and second ceramic compacts 22A and 22B each have a cylindrical shape with a hollow portion 54. More specifically, the shapes of the first and second ceramic compacts 22A and 22B are similar to shapes obtained by dividing the first ceramic tube 10A as a final product (see FIG. 1 ) into two parts at the length-direction center of the axis line p1. As shown in FIGS. 2 and 8 , the first ceramic compact 22A has a shape containing the first curved (bowl-shaped) portion 18a and the first cylindrical portion 20a integrally formed. The through-hole 52 is formed on the first curved portion 18a, and the axis line m2 of the through-hole 52 is parallel to the axis line n2 of the first cylindrical portion 20a. The second ceramic compact 22B has a shape containing the second curved (bowl-shaped) portion 18b and the second cylindrical portion 20b integrally formed.
  • Joining surfaces 56a and 56b of the first and second ceramic compacts 22A and 22B are positioned at the ends of the first and second curved portions 18a and 18b, and are parallel to a plane perpendicular to the axis direction of the first and second ceramic compacts 22A and 22B. Though not shown in the drawings, the outer and inner peripheries of the joining surfaces 56a and 56b of the first and second ceramic compacts 22A and 22B may be chamfered to form e.g. an R- or C-surface.
  • step S2 of FIG. 7 the first and second ceramic compacts 22A and 22B are bonded to each other to prepare a first bonded assembly 58A.
  • step S2a a ceramic powder, a solvent, a binder, and the like are mixed to prepare a bonding slurry (hereinafter referred to as a bonding slurry 60, see FIG. 8 ).
  • step S2b the bonding slurry 60 is applied (supplied) e.g. to the joining surface 56a of the first ceramic compact 22A.
  • step S2c the joining surface 56a of the first ceramic compact 22A is pressed toward the joining surface 56b of the second ceramic compact 22B to obtain the first bonded assembly 58A shown in FIG. 8 .
  • the shape of the first bonded assembly 58A see FIG.
  • first ceramic tube 10A which is obtained by bonding the first and second ceramic compacts 22A and 22B, is geometrically similar to the shape of the first ceramic tube 10A, which is obtained by firing the first bonded assembly 58A.
  • the first bonded assembly 58A is shrunk to produce the first ceramic tube 10A.
  • step S3 of FIG. 7 the first bonded assembly 58A is fired to produce the sintered body (the first ceramic tube 10A).
  • the through-hole 52 formed on the first curved portion 18a of the first ceramic compact 22A, extends along the axis direction of the first cylindrical portion 20a. Therefore, in the first ceramic tube 10A produced by bonding and firing the first and second ceramic compacts 22A and 22B, the through-hole 16 can be easily formed in the position closer to the first capillary 14a in the light-emitting portion 12. The through-hole 16 extends from the inside to the outside of the light-emitting portion 12 in the direction parallel to the extending direction of the first capillary 14a. Furthermore, the through-hole 52 can be formed on the first curved portion 18a in the first ceramic compact 22A by using the simple first casting mold without the significant design change and the additional mechanism.
  • the first ceramic tube 10A can be produced without using the large complicated structure of the production equipment.
  • the first ceramic tube 10A which has the through-hole 16 for introducing the light-emitting material or the like into the light-emitting portion 12, can be easily produced by using a simple production equipment at low production cost, high productivity, and high yield.
  • a ceramic tube according to a second embodiment (hereinafter referred to as a second ceramic tube 10B) will be described below with reference to FIGS. 9 to 16 .
  • the second ceramic tube 10B is approximately equal to the first ceramic tube 10A, and is different from the first ceramic tube 10A in that, as shown in FIG. 9 , the light-emitting portion 12 has a third capillary 70 formed in a position close to the first capillary 14a, the third capillary 70 protrudes in a direction parallel to the extending direction of the first capillary 14a, and a through-hole 72 extends from the end of the third capillary 70 to the inside of the light-emitting portion 12.
  • the third capillary 70 is used as the inlet hole for introducing the light-emitting material or the like into the light-emitting portion 12. Therefore, the through-hole 72 in the third capillary 70 is sealed after the introduction of the light-emitting material or the like.
  • the third capillary 70 is formed on the first curved surface 36a closer to the first capillary 14a than the position corresponding to the inner end of the first electrode 26A (the first coil 30a).
  • the axis line n1 when the inner opening of the through-hole 72 has the point 35 farthest from the axis line n1 of the first capillary 14a, the axis line n1 has the position Pa on the perpendicular line Ln (perpendicular to the axis line n1) extending from the point 35, the axis line n1 has the position Pb on the inner end of the first electrode 26A, the direction from the position Pb toward the first capillary 14a is considered as the positive direction, and the direction from the position Pb toward the second capillary 14b is considered as the negative direction, it is preferred that the position Pa is equal to the position Pb or is shifted from the position Pb in the positive direction.
  • the axis line m3 of the third capillary 70 is parallel to the axis line n1 of the first capillary 14a.
  • a simple first casting mold can be used for forming the first ceramic compact 22A without significant design change.
  • a pin 74 for forming the through-hole 72 is formed on a surface of the movable mold 40 facing the stationary mold 38, and a cavity 76 for forming the third capillary 70 and a clearance hole 78, into which the pin 74 is inserted, are formed on the stationary mold 38.
  • the specific mechanism and control system for controlling the pin 74 are not required. Thus, only the mechanism and control system for controlling the reciprocating movement of the movable mold 40 is required, and the large complicated structure of the production equipment is not required.
  • the third capillary 70 is preferably positioned closer to the first capillary 14a than the position corresponding to the inner end of the first electrode 26A (the first coil 30a) in the light-emitting portion 12, and is further preferably positioned closer by 0.5 mm or more to the first capillary 14a than the inner end of the first electrode 26A. Consequently, the light transmittance of the second ceramic tube 10B is not affected by the third capillary 70, and the light-emitting efficiency and the light distribution are not deteriorated by the third capillary 70.
  • the distance Lb between the axis line m3 of the third capillary 70 and the axis line n1 of the first capillary 14a is 0.55 or more times as large as the outer diameter Da of the first capillary 14a.
  • the sealing portion of the through-hole 72 in the third capillary 70 can be prevented from acting as the coldest portion and from being corroded, during the lighting.
  • a portion around the first capillary 14a may have a high heat capacity, and thereby may act as the coldest portion during the lighting.
  • the portion does not act as the coldest portion, the portion is likely to have a low temperature. If the third capillary 70 is formed in this portion, the heat capacity is often further increased, and the temperature is often further lowered, so that a large amount of the light-emitting material is not vaporized and is stored in the vicinity of the third capillary 70 even during the lighting, whereby the corrosion is rapidly caused. Therefore, the third capillary 70 is preferably formed in a portion, which has a low heat capacity and exhibits a relatively high temperature during the lighting, e.g. on the first curved surface 36a.
  • the distance Lb is preferably 1.6 or less times as large as the outer diameter Da of the first capillary 14a. When the distance Lb is more than 1.6 times as large as the outer diameter Da of the first capillary 14a, the light-emitting portion 12 is readily cracked due to solidification shrinkage of a gelling agent in the molding process.
  • the inner surface of the light-emitting portion 12 has a cross-sectional outline 80 in a plane containing the axis line m3 of the third capillary 70, it is preferred that the axis line m3 and a tangent line 84 at an intersection 82 between the outline 80 and the axis line m3 form an angle ⁇ of 30° or more.
  • the angle ⁇ is excessively lowered, an edge having a sharp cross-sectional angle is formed at the boundary between the through-hole 72 in the third capillary 70 and the inner surface of the light-emitting portion 12. The edge is easily chipped off in the production, transport, or the like, so that waste may be generated, and the chipped portion may be cracked.
  • the angle ⁇ is 30° or more, this problem is not caused.
  • the third capillary 70 has a base point 88, which is a reference point of the maximum length Lc of the third capillary 70 along the axis line m3, it is preferred that the maximum length Lc of the third capillary 70 is 1/10 to 5/10 of the length Ld between the base point 88 and the end of the first capillary 14a along the axis line n1.
  • the maximum length Lc of the third capillary 70 is excessively reduced, it is difficult to seal the through-hole 72 in the third capillary 70.
  • the maximum length Lc of the third capillary 70 is excessively increased, the third capillary 70 is easily deformed in the firing step, and the third capillary 70 is likely to act as the coldest portion and thereby readily corroded during the lighting.
  • a method for producing the second ceramic tube 10B will be described below with reference to FIG. 14 .
  • step S101 of FIG. 14 the first and second ceramic compacts 22A and 22B are prepared as shown in FIG. 15 .
  • the first ceramic compact 22A has a third cylindrical portion 90 and a through-hole 92, which acts as the third capillary 70 and the through-hole 72 in the sintered body (the second ceramic tube 10B).
  • the second ceramic compact 22B does not have the third cylindrical portion 90 and the through-hole 92.
  • the ceramic powder, the dispersion medium, the gelling agent, and the like are mixed to prepare the molding slurry (step S101a of FIG. 14 ), the molding slurry is cast into and then solidified in the first casting mold (see FIG. 11A ) and the second casting mold (not shown) (step S101b), and then the first and second casting molds are separated (step S101c), to obtain the first and second ceramic compacts 22A and 22B shown in FIG. 15 .
  • the first ceramic compact 22A has a shape containing the first curved (bowl-shaped) portion 18a and the first cylindrical portion 20a integrally formed.
  • the first curved portion 18a has the third cylindrical portion 90 protruding in the direction parallel to the extending direction of the first cylindrical portion 20a, and the through-hole 92 extends from the end of the third cylindrical portion 90 to the inside of the first curved portion 18a.
  • the axis line m4 of the third cylindrical portion 90 is parallel to the axis line n2 of the first cylindrical portion 20a.
  • the second ceramic compact 22B has a shape containing the second curved (bowl-shaped) portion 18b and the second cylindrical portion 20b integrally formed.
  • step S102 of FIG. 14 the first and second ceramic compacts 22A and 22B are bonded to each other to prepare a second bonded assembly 58B shown in FIG. 16 .
  • the ceramic powder, the solvent, the binder, and the like are mixed to prepare the bonding slurry 60 (step S102a), the bonding slurry 60 is applied (supplied) e.g. to the joining surface 56a of the first ceramic compact 22A (step S102b), and then the joining surface 56a of the first ceramic compact 22A is pressed toward the joining surface 56b of the second ceramic compact 22B, to obtain the second bonded assembly 58B shown in FIG. 16 .
  • step S103 of FIG. 14 the second bonded assembly 58B is fired to produce the sintered body (the second ceramic tube 10B).
  • the third cylindrical portion 90 formed on the first curved portion 18a of the first ceramic compact 22A, extends along the axis direction of the first cylindrical portion 20a. Therefore, in the second ceramic tube 10B produced by bonding and firing the first and second ceramic compacts 22A and 22B, the third capillary 70 can be easily formed in the position closer to the first capillary 14a in the light-emitting portion 12.
  • the third capillary 70 extends from the inside to the outside of the light-emitting portion 12 in the direction parallel to the extending direction of the first capillary 14a.
  • the third cylindrical portion 90 and the through-hole 92 can be formed on the first curved portion 18a in the first ceramic compact 22A by using the simple first casting mold without the significant design change and the additional mechanism. Therefore, the second ceramic tube 10B can be produced without using the large complicated structure of the production equipment.
  • the second ceramic tube 10B which has the third capillary 70 and the through-hole 72 for introducing the light-emitting material or the like into the light-emitting portion 12, can be easily produced by using a simple production equipment at low production cost, high productivity, and high yield.
  • first and second ceramic compacts 22A and 22B When it is not necessary to distinguish the above first and second ceramic compacts 22A and 22B, they may be referred to simply as the ceramic compacts 22.
  • joining surfaces 56a and 56b When it is not necessary to distinguish the joining surfaces 56.
  • the ceramic compact 22 is prepared.
  • the ceramic compact 22 can be easily produced by various known method.
  • the ceramic compact 22 may be produced by a gel casting method.
  • the gel casting method the molding slurry containing an inorganic powder and an organic compound is cast into the casting mold, a chemical reaction of the organic compound (such as a reaction between the dispersion medium and the gelling agent or a reaction of the gelling agent) is carried out to solidify the slurry, and the casting mold is separated.
  • the molding slurry contains the dispersion medium and the gelling agent in addition to the raw material powder, and may further contain a dispersing agent or catalyst for controlling the viscosity or the solidification.
  • the components will be described below.
  • the ceramic powder used for the ceramic compact 22 may contain alumina, aluminum nitride, zirconia, YAG, or a mixture of two or more thereof.
  • a sintering aid such as magnesium oxide may be used to improve the sintering or the property.
  • Preferred examples of the sintering aids include ZrO 2 , Y 2 O 3 , La 2 O 3 , and SC 2 O 3 .
  • the dispersion medium is preferably a reactive medium such as an organic dispersion medium having a reactive functional group. It is preferred that the organic dispersion medium having the reactive functional group is a liquid substance that can be chemically bonded to the gelling agent to solidify the molding slurry and can be used for preparing the molding slurry with a high fluidity suitable for the casting.
  • the organic dispersion medium, which can be chemically bonded to the gelling agent to solidify the molding slurry preferably has a functional group capable of forming a chemical bond with the gelling agent (such as a hydroxyl, carboxyl, or amino group) in the molecule.
  • the organic dispersion medium preferably has a lower viscosity, and particularly preferably has a viscosity of 20 cps or less at 20°C.
  • a small amount of a polyol or a polybasic acid can be effectively used for improving the strength as long as it does not act to greatly increase the viscosity of the molding slurry.
  • the gelling agent can be reacted with the reactive functional group of the dispersion medium to solidify the slurry.
  • the gelling agent may be as follows.
  • the gelling agent preferably has a viscosity of 3000 cps or less at 20°C.
  • Examples of the gelling agents having an isocyanate group and/or an isothiocyanate group include MDI (4,4'-diphenylmethane diisocyanate) based agents (resins), HDI (hexamethylene diisocyanate) based agents (resins), TDI (tolylene diisocyanate) based agents (resins), IPDI (isophorone diisocyanate) based agents (resins), and isothiocyanates (resins).
  • MDI 4,4'-diphenylmethane diisocyanate
  • HDI hexamethylene diisocyanate
  • TDI tolylene diisocyanate
  • IPDI isophorone diisocyanate
  • isothiocyanates resins
  • the slurry exhibits a high shrinkage ratio in the solidification
  • a force acts on a portion between the first capillary 14a and the third capillary 70 due to the shrinkage, and the portion is often cracked.
  • the slurry exhibits a lower shrinkage ratio (of 3% or less) in the solidification.
  • the MDI based agent can be preferably used to achieve a low dry shrinkage ratio (of 3% or less).
  • the molding slurry for preparing the ceramic compact 22 may be selected from examples described in Japanese Laid-Open Patent Publication No. 2008-044344 , International Publication No. WO 2002/085590 , etc.
  • the molding slurry may be prepared in the following manner.
  • the raw material powder may be dispersed first in the dispersion medium, and then the gelling agent may be added thereto to prepare the molding slurry.
  • the raw material powder and the gelling agent may be simultaneously added to and dispersed in the dispersion medium to prepare the molding slurry.
  • the viscosity of the molding slurry is preferably 30000 cps or less, more preferably 20000 cps or less, at 20°C.
  • the viscosity of the molding slurry can be controlled by changing the viscosities of the above reactive dispersion medium and the gelling agent, and also by changing the type of the powder, the amount of the dispersing agent, and the concentration of the slurry (the volume ratio % of the powder to the entire slurry).
  • the concentration of the molding slurry is preferably 25% to 75% by volume. In view of reducing the cracking due to the dry shrinkage, the concentration is more preferably 35% to 75% by volume.
  • the bonding slurry 60 is used to bond the ceramic compacts 22 to each other.
  • the bonding slurry 60 is preferably a non-self-curable slurry, which is not solidified by a chemical reaction.
  • the non-self-curable bonding slurry 60 can be easily maintained under a surface tension to obtain a joining portion with a small surface roughness (after drying and after sintering).
  • the non-self-curable bonding slurry 60 can form a layer under the surface tension. Therefore, the shape of the layer of the bonding slurry 60 can be easily controlled, and thus the cross-sectional shape of the joining portion can be controlled (after sintering).
  • the bonding slurry 60 may contain the raw material powder used in the molding slurry and the unreactive dispersion medium, and may further contain a binder such as a polyvinyl acetal or ethyl cellulose resin, or the like.
  • the bonding slurry 60 may contain a dispersing agent such as DOP (bis(2-ethylhexyl) phthalate) and an organic solvent such as acetone or isopropanol, or the like for controlling the viscosity in the mixing step.
  • the bonding slurry 60 can be prepared by mixing the raw material powder, the solvent, and the binder in a common ceramic paste or slurry production method using a triroll mill, a pot mill, etc.
  • the dispersing agent or the organic solvent may be appropriately added to the bonding slurry 60.
  • butyl carbitol, butyl carbitol acetate, terpineol, or the like may be used in the bonding slurry 60.
  • Two or more ceramic compacts 22 are bonded to each other by the bonding slurry 60 to prepare the bonded assembly.
  • the layer of the bonding slurry 60 is formed, while maintaining the surface tension, between the joining surfaces 56 of the two or more ceramic compacts 22 to be bonded.
  • the bonding slurry 60 may be applied between the joining surfaces of the ceramic compacts 22 by a known method such as a dispenser, screen printing, or metal mask printing method.
  • the joining surfaces 56 may be maintained at a predetermined distance.
  • the bonding slurry 60 is the non-self-curable slurry
  • the shape of the bonding slurry 60 is maintained due to the surface tension for a certain time.
  • the shape of the layer of the bonding slurry 60 can be controlled while maintaining the surface tension by controlling or changing the distance between the joining surfaces 56 of the ceramic compacts 22, by vibrating the bonding slurry 60, by rotating the bonding slurry 60, or by relatively displacing the ceramic compact 22 in the direction parallel to the joining surface 56.
  • the shape of the layer of the bonding slurry 60 can be easily controlled by changing the load acting in the direction perpendicular to the joining surfaces 56 and/or the distance between the joining surfaces 56, to obtain the sintered body (the ceramic tube) without defects such as air bubbles.
  • the layer of the bonding slurry 60, formed between the joining surfaces 56 of the ceramic compacts 22 facing each other, is dried.
  • the drying step may be appropriately controlled depending on the composition and the application amount of the bonding slurry 60. In general, the drying is carried out at a temperature of 40°C to 200°C for about 5 to 120 minutes.
  • bonded assembly at least two ceramic compacts 22 are bonded by a joining portion (dried layer) formed by drying the layer of the bonding slurry 60.
  • the two ceramic compacts 22 are bonded in the preparation of the bonded assembly, the preparation is not limited thereto.
  • Three or more ceramic compacts 22 may be bonded by the layers of the bonding slurry 60 simultaneously or successively, to obtain the bonded assembly.
  • the bonded assembly is fired, whereby sinterable components in the ceramic compacts 22 and the joining portion (the dried layer) are sintered to obtain the sintered body.
  • the bonded assembly may be degreased or calcined.
  • Sintered bodies (ceramic tubes) were produced by production methods according to Examples 1 and 2 and Comparative Examples 1 to 3 respectively. The cracking of each sintered body and the leakage of the light-emitting portion were measured.
  • Ten first ceramic tubes 10A shown in FIG. 1 were produced by the production method of FIG. 7 .
  • the molding slurry for forming the first and second ceramic compacts 22A and 22B was prepared in the following manner.
  • a raw material powder containing 100 parts by weight of an alumina powder and 0.025 parts by weight of a magnesia, 30 parts by weight of a dispersion medium of a polybasic acid ester, 4 parts by weight of a gelling agent of an MDI resin, 2 parts by weight of a dispersing agent, and 0.2 parts by weight of a triethylamine catalyst were mixed to obtain the molding slurry.
  • the molding slurry was cast at the room temperature into the first casting mold (see FIG. 6A ) and the second casting mold (not shown), composed of an aluminum alloy, and solidified at the room temperature for 1 hour. Then, the molds were separated from the solidified slurries, and the resultant solids were left at the room temperature for 2 hours and at 90°C for 2 hours.
  • Ten first ceramic compacts 22A and ten second ceramic compacts 22B were prepared in this manner.
  • the outer and inner peripheries of the joining surfaces 56a and 56b of the first and second ceramic compacts 22A and 22B were chamfered (to form e.g. an R-surface) within a radius range of 0.05 to 0.15 mm.
  • the bonding slurry 60 was prepared in the following manner. 100 parts by weight of a raw material powder of an alumina powder, 0.025 parts by weight of a magnesia, 100 parts by weight of terpineol, 30 parts by weight of butyl carbitol, and 8 parts by weight of a polyvinyl acetal resin were mixed to obtain the bonding slurry 60.
  • a screen plate having an emulsion thickness of 100 ⁇ m and a mesh of #290 was prepared.
  • the screen plate had a ring-shaped pattern (having an inner diameter of 12.8 mm and an outer diameter of 13.7 mm) corresponding to the joining surface 56a of the first ceramic compact 22A.
  • the first ceramic compact 22A was positioned, for example, on a stage of a screen printer such that the joining surface 56a
  • the bonding slurry 60 was applied to the joining surface 56a of the first ceramic compact 22A by the screen printer using the screen plate. Then, the joining surface 56a of the first ceramic compact 22A was pressed toward the joining surface 56b of the second ceramic compact 22B, and dried by a dryer at 95°C for 15 minutes. Ten first bonded assemblies 58A having the through-holes 52 on the first curved portions 18a (see FIG. 8 ) were prepared in this manner.
  • each of the prepared first bonded assemblies 58A was calcined in the air at 1200°C, and fired at 1800°C in a hydrogen/nitrogen (3/1) atmosphere, to increase the density and translucency. Consequently, the sintered body (the first ceramic tube 10B) shown in FIG. 1 was obtained.
  • the light-emitting portion 12 had the through-hole 16 formed in a position close to the first capillary 14a, the through-hole 16 extended from the inside to the outside of the light-emitting portion 12 in a direction parallel to the extending direction of the first capillary 14a, the light-emitting portion 12 had an outer diameter of 11 mm, and the first and second capillaries had a length of 17 mm.
  • the through-hole 16 was formed such that the position Pa was shifted by 0.5 mm from the position Pb in the positive direction as shown in FIG. 3 .
  • Example 1 produced ten sintered bodies (the first ceramic tubes 10A) of Example 1 did not have a cracked or deformed portion.
  • the thermal shock resistances of the sintered bodies were evaluated by an in-water rapid cooling method. As a result, in all the sintered bodies, any cracking was not caused even at 150°C. Thus, the sintered bodies had resistances equal to that of a ceramic tube having the same shape except for the through-hole 16. Furthermore, after the thermal shock resistance evaluation, the through-holes 16 on the light-emitting portions 12 of the sintered bodies were closed, and the leakages of the light-emitting portions 12 were measured by an He (helium) leakage measuring apparatus.
  • He helium
  • the sintered bodies each exhibited a leakage of 1 ⁇ 10 -8 atm ⁇ cc/sec or less.
  • the sintered bodies were each used as an arc tube, and it was confirmed that the light transmittances of the sintered bodies were not affected by the through-holes 16.
  • the practical luminance of each sintered body was measured, to evaluate whether the measured value was at least 98% of the designed luminance (the design value) or not.
  • the measured values of the sintered bodies were 99.5% of the design value.
  • Example 2 (second ceramic tubes 10B) shown in FIG. 9 were produced by the production method of FIG. 14 .
  • the molding slurry was prepared in the same manner as Example 1.
  • the molding slurry was cast at the room temperature into the first casting mold (see FIG. 11A ) and the second casting mold (not shown), composed of an aluminum alloy, and solidified at the room temperature for 1 hour. Then, the molds were separated from the solidified slurries, and the resultant solids were left at the room temperature for 2 hours and at 90°C for 2 hours.
  • Ten first ceramic compacts 22A and ten second ceramic compacts 22B were prepared in this manner.
  • the outer and inner peripheries of the joining surfaces 56a and 56b of the first and second ceramic compacts 22A and 22B were chamfered (to form e.g. an R-surface) within a radius range of 0.05 to 0.15 mm.
  • the bonding slurry 60 was prepared in the same manner as Example 1, and was applied to the joining surface 56a of the first ceramic compact 22A by a screen printer using a screen plate.
  • the screen plate had the same structure as that of Example 1.
  • each of the prepared second bonded assemblies 58B was calcined and fired in the same manner as Example 1, to increase the density and translucency. Consequently, the second ceramic tube 10B shown in FIG. 9 was obtained.
  • the light-emitting portion 12 had an outer diameter of 11 mm
  • the first and second capillaries 14a and 14b had a length of 17 mm
  • the light-emitting portion 12 had the third capillary 70 formed in a position close to the first capillary 14a
  • the third capillary 70 protruded in a direction parallel to the extending direction of the first capillary 14a
  • the through-hole 72 extended from the end of the third capillary 70 to the inside of the light-emitting portion 12.
  • the through-hole 72 was such that the position Pa was shifted by 0.5 mm from the position Pb in the positive direction as shown in FIG. 10 .
  • Example 2 Thus produced ten sintered bodies of Example 2 did not have a cracked or deformed portion.
  • the thermal shock resistances of the sintered bodies were evaluated by an in-water rapid cooling method. As a result, in all the sintered bodies, the cracking was not caused even at 150°C. Thus, the sintered bodies had resistances equal to that of an arc tube having the same shape except for the third capillary 70. Furthermore, after the thermal shock resistance evaluation, the leakages of the sintered bodies were measured by an He leakage measuring apparatus. As a result, the sintered bodies each exhibited a leakage of 1 ⁇ 10 -8 atm ⁇ cc/sec or less.
  • the sintered bodies were each used as an arc tube, and it was confirmed that the light transmittances of the sintered bodies were not affected by the third capillaries 70 and the through-holes 72.
  • the practical luminance of each sintered body was measured, to evaluate whether the measured value was at least 98% of the designed luminance (the design value) or not.
  • the measured values of the sintered bodies were 99.5% of the design value.
  • Example 1 Ten sintered bodies of Comparative Example 1 were produced as follows. First, the molding slurry was prepared in the same manner as Example 1. The molding slurry was cast at the room temperature into the second casting mold composed of an aluminum alloy, and solidified at the room temperature for 1 hour. Then, the mold was separated from the solidified slurry, and the resultant solid was left at the room temperature for 2 hours and at 90°C for 2 hours. Twenty second ceramic compacts 22B were prepared in this manner. One of each pair of the second ceramic compacts 22B was subjected to a hole forming processing using a drill or the like, whereby a through-hole having a diameter of 0.3 mm was formed on the second curved portion 18b.
  • the bonding slurry 60 was prepared in the same manner as Example 1, and was applied to the joining surface 56b of the one second ceramic compact 22B by a screen printer using a screen plate. Then, the joining surfaces 56b of each pair of the second ceramic compacts 22B were pressed toward each other, and dried by a dryer at 95°C for 15 minutes. Ten bonded assemblies were prepared in this manner. Each of the prepared bonded assemblies was calcined and fired in the same manner as Example 1. Consequently, ten sintered bodies of Comparative Example 1 were obtained.
  • Example 2 Ten sintered bodies of Comparative Example 2 were produced as follows. First, twenty second ceramic compacts 22B were prepared in the same manner as Comparative Example 1. One of each pair of the second ceramic compacts 22B was subjected to a hole forming processing using a drill or the like, whereby a through-hole having a diameter of 0.9 mm was formed on the second curved portion 18b.
  • each pair of the second ceramic compacts 22B were bonded to each other, and a ceramic pipe was connected to the through-hole portion.
  • Ten bonded assemblies were prepared in this manner.
  • Each of the prepared bonded assemblies was calcined and fired in the same manner as Example 1. Consequently, ten sintered bodies of Comparative Example 2 were obtained.
  • Example 3 Ten sintered bodies shown in FIG. 17 of Comparative Example 3 were produced in the same manner as Example 1.
  • the third capillary 70 was formed on the light-emitting portion 12 such that the axis line m3 of the third capillary 70 was perpendicular to the axis line n1 of the first capillary 14a.
  • the third capillary 70 had a maximum length of 9 mm.
  • Example 11 Ten sintered bodies of Example 11 were produced in the same manner as Example 1 except that the distance La between the axis line m1 of the through-hole 16 and the axis line n1 of the first capillary 14a was 0.55 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • Example 12 Ten sintered bodies of Example 12 were produced in the same manner as Example 1 except that the distance La was 0.7 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • Example 13 Ten sintered bodies of Example 13 were produced in the same manner as Example 1 except that the distance La was 0.85 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • Example 14 Ten sintered bodies of Example 14 were produced in the same manner as Example 2 except that the distance Lb between the axis line m3 of the third capillary 70 and the axis line n1 of the first capillary 14a was 0.55 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • Example 15 Ten sintered bodies of Example 15 were produced in the same manner as Example 2 except that the distance Lb was 0.7 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • Example 16 Ten sintered bodies of Example 16 were produced in the same manner as Example 2 except that the distance Lb was 0.85 times as large as the outer diameter Da of the first capillary on the light-emitting portion 12.
  • the produced sintered bodies were evaluated as follows. An arc tube was produced using each sintered body, and subjected to a continuous lighting test. The lamp effective time of each arc tube (the time from the start of lighting until the luminance is reduced to 80%) was measured.
  • Example 11 The effective time of Example 11 was considered as h (hour), and the effective times of Examples 12 to 16 and Reference Examples 1 to 4 were represented as ratios to h.
  • Example 1 Da ⁇ 0.4 - 0.7h Reference Example 2 Example 1 Da ⁇ 0.5 - 0.8h Reference Example 3
  • Example 2 - Da ⁇ 0.4 0.7h Reference Example 4 Example 2 - Da ⁇ 0.5 0.8h
  • Example 11 Example 1 Da ⁇ 0.55 - h
  • Example 12 Example 1 Da ⁇ 0.7 - 1.2h
  • Example 13 Example 1 Da ⁇ 0.8 - 1.3h
  • Example 14 Example 2 - Da ⁇ 0.55 h
  • Example 15 Example 2 - Da ⁇ 0.7 1.2h
  • Example 16 Example 2 - Da ⁇ 0.8 1.3h
  • the distance La between the axis line m1 of the through-hole 16 and the axis line n1 of the first capillary 14a or the distance Lb between the axis line m3 of the third capillary 70 and the axis line n1 of the first capillary 14a is 0.55 or more times as large as the outer diameter Da of the first capillary.
  • Example 21 Ten sintered bodies of Example 21 were produced in the same manner as Example 2 except that the shape of the curved surface was changed, whereby the angle ⁇ between the axis line m3 and the tangent line 84 (at the intersection 82 between the outline 80 and the axis line m3) was 30°.
  • Example 22 Ten sintered bodies of Example 22 were produced in the same manner as Example 2 except that the angle ⁇ was 35°.
  • Example 22 Ten sintered bodies of Example 22 were produced in the same manner as Example 2 except that the angle ⁇ was 45°.
  • Table 2 Angle ⁇ Cracking Reference Example 11 20° 5/10 Reference Example 12 25° 4/10 Example 21 30° Not observed Example 22 35° Not observed Example 23 40° Not observed
  • Example 31 to 35 and Reference Examples 21 and 22 (similar to Example 2), a property was evaluated under various maximum lengths Lc. As shown in FIG. 13 , the maximum length Lc is a length along the axis line m3 of the third capillary 70.
  • Example 31 Ten sintered bodies of Example 31 were produced in the same manner as Example 2 except that the maximum length Lc of the third capillary 70 was 1/10 of the length Ld between the base point 88 and the end of the first capillary 14a along the axis line n1.
  • Example 32 Ten sintered bodies of Example 32 were produced in the same manner as Example 2 except that the maximum length Lc of the third capillary 70 was 2/10 of the length Ld.
  • Example 33 Ten sintered bodies of Example 33 were produced in the same manner as Example 2 except that the maximum length Lc of the third capillary 70 was 3/10 of the length Ld.
  • Example 34 Ten sintered bodies of Example 34 were produced in the same manner as Example 2 except that the maximum length Lc of the third capillary 70 was 4/10 of the length Ld.
  • Example 35 Ten sintered bodies of Example 35 were produced in the same manner as Example 2 except that the maximum length Lc of the third capillary 70 was 5/10 of the length Ld.
  • the produced sintered bodies were evaluated as follows. In the same manner as Second Example, an arc tube was produced using each sintered body, and subjected to a continuous lighting test. The lamp effective time of each arc tube (the time from the start of lighting until the luminance is reduced to 98%) was measured.
  • Example 35 The effective time of Example 35 was considered as h (hour), and the effective times of Examples 31 to 34 and Reference Examples 21 and 22 were represented as ratios to h.
  • the maximum length Lc of the third capillary 70 is 1/10 to 5/10 of the length Ld between the base point 88 and the end of the first capillary 14a along the axis line n1.
  • Example 41 Ten sintered bodies of Example 41 were produced in the same manner as Example 1 except that the through-hole 16 was formed such that the position Pa was equal to the position Pb.
  • the inner opening of the through-hole 16 had the point 35 farthest from the axis line n1 of the first capillary 14a
  • the axis line n1 had the position Pa on the perpendicular line Ln extending from the point 35
  • the axis line n1 had the position Pb on the inner end of the first electrode 26A
  • the direction from the position Pb toward the first capillary 14a was considered as the positive direction
  • the direction from the position Pb toward the second capillary 14b was considered as the negative direction.
  • Example 42 Ten sintered bodies of Example 42 were produced in the same manner as Example 1.
  • the through-hole 16 was formed such that the position Pa was shifted by 0.5 mm from the position Pb in the positive direction in the same manner as Example 1.
  • Example 43 Ten sintered bodies of Example 43 were produced in the same manner as Example 1 except that the through-hole 16 was formed such that the position Pa was shifted by 2 mm from the position Pb in the positive direction.
  • Example 44 Ten sintered bodies of Example 44 were produced in the same manner as Example 2 except that the third capillary 70 and the through-hole 72 were formed such that the position Pa was equal to the position Pb as shown in FIG. 10 .
  • Example 45 Ten sintered bodies of Example 45 were produced in the same manner as Example 2.
  • the third capillary 70 and the through-hole 72 were formed such that the position Pa was shifted by 0.5 mm from the position Pb in the positive direction in the same manner as Example 2.
  • Example 46 Ten sintered bodies of Example 46 were produced in the same manner as Example 2 except that the third capillary 70 and the through-hole 72 were formed such that the position Pa was shifted by 2 mm from the position Pb in the positive direction.
  • the produced sintered bodies were evaluated as follows. An arc tube was produced using each sintered body, the practical luminance of the arc tube was measured, and the reduction of the measured value from the designed luminance (the design value) was evaluated. The arc tube was evaluated as "A” when the measured value was 99% or more of the design value, as "B” when the measured value was 98% or more but less than 99% of the design value, as "C” when the measured value was 97% or more but less than 98% of the design value, and as "D” when the measured value was less than 97% of the design value.
  • Example 4 Basic structure Relation of position Pa to position Pb Evaluation Example 41
  • Example 1 0 B Example 42
  • Example 43 Example 1 +2 mm A Reference Example 21
  • Example 1 -0.5 mm C Reference Example 22 Example 1 -2 mm D
  • Example 44 Example 2 0 B
  • Example 45 Example 2 +0.5 mm A
  • Example 46 Example 2 +2 mm A Reference Example 23
  • the light transmittance was hardly affected by the through-hole 16 (or the third capillary 70 and the through-hole 72) on the light-emitting portion 12.
  • the through-hole 16 or the third capillary 70 and the through-hole 72

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Publication number Priority date Publication date Assignee Title
JPS63143738A (ja) 1986-12-05 1988-06-16 Toshiba Corp セラミツク放電灯
JPH04163828A (ja) * 1990-10-26 1992-06-09 Nec Kagoshima Ltd 蛍光表示管用カバーガラスの製造方法
JPH05334962A (ja) 1992-05-29 1993-12-17 Toto Ltd 金属蒸気放電灯の製造方法
JP3225963B2 (ja) * 1992-07-09 2001-11-05 東陶機器株式会社 発光管の封止部構造
DE69324790T2 (de) 1993-02-05 1999-10-21 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Keramisches Entladungsgefäss für Hochdruckentladungslampe und Herstellungsverfahren derselben und damit verbundene Dichtungsmaterialien
JP3336342B2 (ja) * 1993-07-22 2002-10-21 岩崎電気株式会社 メタルハライドランプの製造方法
JPH0855606A (ja) 1994-08-15 1996-02-27 Toto Ltd 金属蒸気発光管
JPH10340705A (ja) * 1997-06-06 1998-12-22 Matsushita Electron Corp 放電ランプ、この放電ランプの製造方法、この放電ランプを用いたランプユニット、およびこのランプユニットを用いた光学システム
DE19727429A1 (de) * 1997-06-27 1999-01-07 Patent Treuhand Ges Fuer Elektrische Gluehlampen Mbh Metallhalogenidlampe mit keramischem Entladungsgefäß
JP2002334653A (ja) * 2001-02-09 2002-11-22 Matsushita Electric Ind Co Ltd 発光管の製造方法及びそれに用いられる中子
CN1250382C (zh) 2001-04-17 2006-04-12 日本碍子株式会社 成形体的制造方法
JP2003346723A (ja) * 2002-05-30 2003-12-05 Toshiba Lighting & Technology Corp 放電ランプおよびその製造方法
US20060001346A1 (en) 2004-06-30 2006-01-05 Vartuli James S System and method for design of projector lamp
JP4311319B2 (ja) * 2004-09-22 2009-08-12 ウシオ電機株式会社 ショートアーク型放電ランプ
JP5197975B2 (ja) 2006-03-24 2013-05-15 日本碍子株式会社 焼結体、発光管及びその製造方法
CN101410348B (zh) * 2006-03-24 2013-01-09 日本碍子株式会社 烧结体、发光管及其制造方法
KR101388838B1 (ko) 2006-03-24 2014-04-23 엔지케이 인슐레이터 엘티디 소결체 제조 방법 및 소결체
WO2008078228A1 (fr) 2006-12-20 2008-07-03 Koninklijke Philips Electronics N.V. Brûleur en céramique pour lampe d'halogénure de métal en céramique
EP2122653B1 (fr) * 2006-12-20 2010-08-18 Koninklijke Philips Electronics N.V. Lampe d'halogénure de métal et brûleur en céramique pour une telle lampe

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No further relevant documents disclosed *
See also references of WO2012046598A1 *

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