JPH0213420B2 - - Google Patents
Info
- Publication number
- JPH0213420B2 JPH0213420B2 JP59074474A JP7447484A JPH0213420B2 JP H0213420 B2 JPH0213420 B2 JP H0213420B2 JP 59074474 A JP59074474 A JP 59074474A JP 7447484 A JP7447484 A JP 7447484A JP H0213420 B2 JPH0213420 B2 JP H0213420B2
- Authority
- JP
- Japan
- Prior art keywords
- light source
- cathode
- discharge tube
- melting point
- discharge
- 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.)
- Expired - Lifetime
Links
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 239000002184 metal Substances 0.000 claims description 16
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 12
- 229910052721 tungsten Inorganic materials 0.000 claims description 12
- 239000010937 tungsten Substances 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 10
- 238000002844 melting Methods 0.000 claims description 10
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 9
- 229910052753 mercury Inorganic materials 0.000 claims description 8
- 230000008018 melting Effects 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 6
- 238000010891 electric arc Methods 0.000 claims description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 239000000758 substrate Substances 0.000 claims description 4
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 3
- 150000004645 aluminates Chemical class 0.000 claims description 3
- 239000011733 molybdenum Substances 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 2
- QKYBEKAEVQPNIN-UHFFFAOYSA-N barium(2+);oxido(oxo)alumane Chemical compound [Ba+2].[O-][Al]=O.[O-][Al]=O QKYBEKAEVQPNIN-UHFFFAOYSA-N 0.000 claims description 2
- 239000001257 hydrogen Substances 0.000 claims description 2
- 229910052739 hydrogen Inorganic materials 0.000 claims description 2
- 229910052702 rhenium Inorganic materials 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- 229910052724 xenon Inorganic materials 0.000 claims description 2
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 claims description 2
- 238000010304 firing Methods 0.000 claims 1
- 238000000465 moulding Methods 0.000 claims 1
- 239000000843 powder Substances 0.000 claims 1
- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 claims 1
- 238000007789 sealing Methods 0.000 claims 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims 1
- 230000004907 flux Effects 0.000 description 7
- 239000013078 crystal Substances 0.000 description 6
- 238000012423 maintenance Methods 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 3
- 239000010453 quartz Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- ZCUFMDLYAMJYST-UHFFFAOYSA-N thorium dioxide Chemical compound O=[Th]=O ZCUFMDLYAMJYST-UHFFFAOYSA-N 0.000 description 2
- 229910003452 thorium oxide Inorganic materials 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/04—Electrodes; Screens; Shields
- H01J61/06—Main electrodes
- H01J61/073—Main electrodes for high-pressure discharge lamps
- H01J61/0732—Main electrodes for high-pressure discharge lamps characterised by the construction of the electrode
Description
【発明の詳細な説明】
（技術分野）
本発明は光源用放電管、特に水銀と稀ガスとが
放電発光に寄与する放電管であつて、特に改良さ
れた陰極をもつ光源用放電管に関する。
この放電管は、例えば超LSI製造時の遠紫外露
光源に好適に利用できる。
（従来技術）
まず従来の水銀稀ガス放電管の問題を図面を参
照して簡単に説明する。
第１図は光源用放電管の一般的な構成を示す図
である。
回転楕円体状の石英製の発光管１１の長径方向
の両端に、電極導入管１２ａ，１２ｂが設けられ
ている。この枝管１２ａ，１２ｂ内に、モリブデ
ン箔１３ａ，１３ｂを介して外部に外部リード１
４ａ，１４ｂおよび内部に陽極１５、陰極１６が
封入されている。
石英製の発光管１１に排気用の管が接続されて
おり、排気管は排気後適量の水銀と稀ガスを封入
して１７の示すように封じ切られる。
陰極側には水銀蒸気圧を高めるための白金保温
用反射膜１８が表面に塗布されている。
光源用放電管用の陰極１６として、通常２重量
％以下の酸化トリウムを含有したトリエテツドタ
ングステン材料が用いられている。
陽極１５と陰極１６との間に20〜30KVの電圧
を印加すればランプは放電を開始する。
続いて放電電流を一定に制御すると陽極１５と
陰極１６の間には安定な放電が発生し発光する。
このとき陰極１６は放電によつて生じる正イオ
ンの衝突によつて加熱され動作中の陰極先端部
は、規定のアーク放電を維持するに必要な電流密
度が得られる温度まで上昇する。
従来から、水銀稀ガス放電管の欠点として点灯
時間の経過とともにアークの「ゆらぎ」が大きく
なり、超LSI露光用光源等精密な点光源として用
いる場合不都合であると言う問題が指摘されてい
る。
これは、通常アーク不安定と呼ばれており、以
下のような原因によると考えられている。
第２図は陰極の端部を拡大して示した図であつ
て、同図Ａは使用開始時の陰極の形状、同図Ｂは
使用後相当時間経過後の形状を示している。陰極
１６の先端１６ａは第２図Ａのように当初は尖つ
ている。
光源用放電管でアーク放電を長時間、継続させ
ると、使用前または初期においては、尖つていた
陰極１６の先端１６ａは長い間、高温にさらされ
るために第２図Ｂに示すように、溶融蒸発し球面
状に変形させられる。
また、頂部の結晶組織も変化し、斜線を付して
示すようにタングステンの単結晶が成長して１６
ｂ，１６ｃに示すように粗大化する。
このような状態が形成されると、先端部への電
子放射物質の拡散が阻害され、電子の供給が不十
分となる。その結果、アーク発生点が単結晶１６
ｂ，１６ｃ領域の後部、例えば点ｐもしくはｑの
示す位置に後退すると共にｐ、ｑの示す単結晶領
域の後部に沿つて不安定に動きまわる。
このようなアーク発生点が移動するのは好まし
くないから、酸化トリウムの含有量を増やすなど
の対策が検討されているが十分な成果が得られて
いない。
（発明の目的）
本発明の目的はアーク発生点の移動が発生しに
くい改良された光源用放電管を提供することにあ
る。
（発明の構成および作用）
前記目的を達成するために、本発明による光源
用放電管は、陰極と陽極を水銀と稀ガスの雰囲気
中に封入してアーク放電を行わせる光源用放電管
において、尖頭をもつ多孔質の高融点金属基体に
易電子放射物質を含浸させた陰極先端部を導電路
を形成する金属棒の一端に固定して陰極を形成し
て構成されている。
前記構成によれば、易電子放射物質が基体の孔
を通つて陰極の先端に容易に達するので、前述し
た陰極輝点の位置の変動は少なくなる。
易電子放射物質が蒸発して、管球の内壁に付着
し不透明にする可能性があるが、実験の結果問題
にならないことが確認できた。
（実施例の説明）
以下、図面等を参照して本発明をさらに詳しく
説明する。
本発明による光源用放電管の実施例の外形は第
１図に示したものと変わらない。
前記発光管１１の最大外径を20mmとして、陽極
１５として直径3.0mmのタングステン棒を用いる。
第３図にこの実施例の陰極を取り出して示して
ある。
直径2.4mmの導電路を形成するタングステン棒
２０の先端に、直径2.0mm、長さ2.0mmで易電子放
射物質であるアルミン酸アルカリ土類を含浸した
多孔質タングステン陰極先端部２１を取り付け
る。
この多孔質の高融点金属基体は平均粒径が2μ
〜8μのタングステン粉末をプレス成形加工し、
真空中または水素雰囲気中で焼成したものであ
り、空孔率は10〜35％の範囲を用いた理由は10％
以下では、含浸剤の充填量が少なく、また、存在
する空孔の連結が完全でなくなり、このため含浸
剤の供給が十分行われないので、電子放射特性が
不十分でアークが不安定になる可能性があるから
である。
35％以上では逆に含浸剤は十分充填されるが、
空孔が多いために含浸剤の蒸発が極端に大きくな
り、寿命を短くする可能性があることによる。
この多孔質タングステン基体に、電子放射物質
として、少なくともアルミン酸バリウムを含むア
ルミン酸アルカリ土類からなる易電子放射物質を
含浸させることにより陰極先端部２１が形成され
る。この実施例では、
BaO：CaO：Al2O3が４：１：１のものを含浸
させた。
陰極先端部２１と金属棒２０は高融点蝋付けま
たは圧入等により固定する。
陰極先端部２１を前記のように構成したのは次
の理由による。
陰極先端部２１を多孔質状にすると、従来の
電極で発生した前記好ましくない結晶の成長を
妨げることができる。
この陰極の仕事函数は約1.5〜1.8eVで、トリ
エテツドタングステンの約2.6eVと比較すると
十分低い。
このため陰極動作温度をトリエテツドタング
ステンの場合の約1900℃から約1000℃と十分下
げることができる。
このため陰極先端の単結晶の粗大化が起こり
にくい。
基体が多孔質状となつているために、電子放
射物質の供給が円滑に行われ、陰極輝点の移動
を抑制できる。
次に本発明による第１図に示す放電管の実施例
と従来の放電管の特性を比較する。
実施例放電管は、バルブ内容積１c.c.当たりの封
入水銀量を８mg／c.c.（25℃）とした。
またキセノンガス圧は５気圧（25℃）とした。
陽極１５と陰極１６の先端面の距離は2.5mmであ
る。
前記構造の放電管を動作電圧20V、動作電流
12.5A、放電管消費電力250Wで動作させる。比
較の対象である従来例の放電管は外形寸法、電極
の形状、間隔、封入ガス圧等の条件は全く同じに
し、陰極だけを従来の材質（２重量％ThO2を含
むタングステン電極）とし、同じ動作条件で動作
させ、光束維持率と安定度についての比較をし
た。
第４図に光束維持率の経時的変化を対比して示
してある。
光束維持率とは使用開始時の光束を100として
経時的な光束の変化を示すものである。
第４図は実施例の方が従来管よりも、光束維持
率がわずかではあるが小さいことを示している。
しかしながら、この種の光源用放電管として
は、後述するアーク安定度Ｓの方が重要であり、
この程度の差は問題にならない。
本発明は、光束維持率は許容できる範囲に維持
して良好なアーク安定度Ｓを得ようとするもので
ある。
発明の詳細な説明の末尾に別表１として前記実
施例と従来管のアーク安定度Ｓを比較して示して
ある。
アーク安定度Ｓは以下のとおり定義される。
アーク安定度Ｓはアークを投影し、細いスリツ
トをアーク投影像の中心部に入れ、スリツトを通
過する光強度のゆらぎを測定する。
Ｓ（％）＝〔（Imax−Imin）／Imax〕
×100（％）
ここでImaxは最大光強度、Iminは最小光強度
である。
別表１から明らかなように、実施例では1000時
間点灯後においても、アーク安定性は初期値とほ
とんど変化が見られない。
（実施例）
以上多孔質物質の高融点金属の基体にタングス
テンを用いた例について詳細に説明した。
同様な範囲の粒径の素材を用い空孔率を同様に
すれば、Mo、Re、Taを素材にしても略同様な
結果が得られることを確認することができた。
（発明の効果）
以上説明したように、本発明によれば、多孔質
の高融点金属の基体に易電子放射物質を含浸させ
た陰極先端部を導電路を形成する金属棒の一端に
固定して陰極を形成してあるから、陰極先端部の
変形変質を防止できる。
その結果、輝点の移動の少ない光源用放電管を
提供することができた。
金属棒の直径と基体の形状を適当に選択するこ
とによりゆらぎが少なく充分な寿命を持つ光源用
放電管を提供することができる。
【表】DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a discharge tube for a light source, particularly a discharge tube in which mercury and a rare gas contribute to discharge light emission, and particularly to a discharge tube for a light source having an improved cathode. This discharge tube can be suitably used, for example, as a far-ultraviolet exposure source during VLSI manufacturing. (Prior Art) First, problems with conventional mercury rare gas discharge tubes will be briefly explained with reference to drawings. FIG. 1 is a diagram showing a general configuration of a discharge tube for a light source. Electrode introduction tubes 12a and 12b are provided at both ends of the spheroidal quartz arc tube 11 in the major axis direction. External leads 1 are connected to the outside through molybdenum foils 13a and 13b within these branch pipes 12a and 12b.
4a, 14b and an anode 15 and a cathode 16 are sealed inside. An exhaust pipe is connected to the quartz arc tube 11, and after exhausting, the exhaust pipe is filled with an appropriate amount of mercury and rare gas and sealed off as shown at 17. On the cathode side, a platinum heat-retaining reflective film 18 is coated on the surface to increase the mercury vapor pressure. As the cathode 16 for a discharge tube for a light source, a triated tungsten material containing 2% by weight or less of thorium oxide is usually used. When a voltage of 20 to 30 KV is applied between the anode 15 and the cathode 16, the lamp starts discharging. Subsequently, when the discharge current is controlled to be constant, a stable discharge occurs between the anode 15 and the cathode 16, and light is emitted. At this time, the cathode 16 is heated by the collision of positive ions generated by the discharge, and the tip of the cathode during operation rises to a temperature at which a current density necessary to maintain a specified arc discharge is obtained. Conventionally, it has been pointed out that a drawback of mercury rare gas discharge tubes is that the "fluctuation" of the arc increases as the lighting time passes, making it inconvenient when used as a precision point light source such as a light source for VLSI exposure. This is usually called arc instability and is thought to be caused by the following causes. FIG. 2 is an enlarged view of the end of the cathode, in which FIG. 2A shows the shape of the cathode at the beginning of use, and FIG. 2B shows the shape after a considerable period of time has passed after use. The tip 16a of the cathode 16 is initially sharp as shown in FIG. 2A. When arc discharge is continued for a long time in a light source discharge tube, the tip 16a of the cathode 16, which was sharp before or in the initial stage of use, is exposed to high temperature for a long period of time, as shown in FIG. 2B. It melts and evaporates and is transformed into a spherical shape. The crystal structure at the top also changes, and as shown with diagonal lines, a single crystal of tungsten grows to 16
It becomes coarse as shown in b and 16c. When such a state is formed, the diffusion of the electron emitting substance to the tip is inhibited, and the supply of electrons becomes insufficient. As a result, the point of arc generation is the single crystal 16
It retreats to the rear part of regions b and 16c, for example, to the position indicated by point p or q, and moves unstably along the rear part of the single crystal region indicated by p and q. Since it is undesirable for such an arc generation point to move, countermeasures such as increasing the content of thorium oxide have been considered, but sufficient results have not been obtained. (Object of the Invention) An object of the present invention is to provide an improved discharge tube for a light source in which movement of the arc generation point is less likely to occur. (Structure and operation of the invention) In order to achieve the above object, a light source discharge tube according to the present invention is a light source discharge tube in which a cathode and an anode are sealed in an atmosphere of mercury and a rare gas to cause arc discharge. The cathode is formed by fixing the tip of a cathode, which is a porous high-melting point metal base with a sharp point impregnated with an electron-emitting substance, to one end of a metal rod that forms a conductive path. According to the above configuration, the electron-emissive substance easily reaches the tip of the cathode through the hole in the base, so that the above-mentioned fluctuation in the position of the cathode bright spot is reduced. There is a possibility that the electron-emissive material may evaporate and adhere to the inner wall of the tube, making it opaque, but experiments have confirmed that this is not a problem. (Description of Examples) Hereinafter, the present invention will be described in more detail with reference to the drawings and the like. The external shape of the embodiment of the discharge tube for light source according to the invention is the same as that shown in FIG. The maximum outer diameter of the arc tube 11 is 20 mm, and a tungsten rod with a diameter of 3.0 mm is used as the anode 15. FIG. 3 shows the cathode of this embodiment. A porous tungsten cathode tip 21 impregnated with alkaline earth aluminate, which is an electron-emitting substance, is attached to the tip of a tungsten rod 20 having a diameter of 2.0 mm and a length of 2.0 mm. This porous high melting point metal substrate has an average particle size of 2μ
~8μ tungsten powder is press-molded,
It is fired in a vacuum or in a hydrogen atmosphere, and the reason for using a porosity range of 10 to 35% is 10%.
Below, the filling amount of the impregnating agent is small, and the existing pores are not completely connected, so the impregnating agent is not sufficiently supplied, resulting in insufficient electron emission characteristics and unstable arc. This is because there is a possibility. On the other hand, if it is over 35%, the impregnating agent will be sufficiently filled.
This is because the large number of pores causes extremely high evaporation of the impregnating agent, potentially shortening the service life. The cathode tip 21 is formed by impregnating this porous tungsten base with an electron emissive material made of alkaline earth aluminate containing at least barium aluminate as an electron emitting material. In this example, a BaO:CaO:Al 2 O 3 ratio of 4:1:1 was impregnated. The cathode tip 21 and the metal rod 20 are fixed by high melting point brazing or press fitting. The reason why the cathode tip 21 is configured as described above is as follows. Making the cathode tip 21 porous can prevent the undesirable crystal growth that occurs with conventional electrodes. The work function of this cathode is approximately 1.5 to 1.8 eV, which is sufficiently low compared to the approximately 2.6 eV of trietated tungsten. Therefore, the operating temperature of the cathode can be sufficiently lowered from about 1900°C in the case of triated tungsten to about 1000°C. Therefore, coarsening of the single crystal at the tip of the cathode is less likely to occur. Since the base is porous, the electron emitting material can be supplied smoothly and the movement of the cathode bright spot can be suppressed. Next, the characteristics of the embodiment of the discharge tube according to the present invention shown in FIG. 1 and the conventional discharge tube will be compared. In the discharge tube of the example, the amount of mercury sealed per 1 c.c. of bulb internal volume was 8 mg/cc (25° C.). Moreover, the xenon gas pressure was 5 atm (25°C).
The distance between the tip surfaces of the anode 15 and cathode 16 is 2.5 mm. The discharge tube with the above structure has an operating voltage of 20V and an operating current of
Operates at 12.5A, discharge tube power consumption 250W. The conventional discharge tubes for comparison had exactly the same external dimensions, electrode shape, spacing, and filled gas pressure, and only the cathode was made of a conventional material (a tungsten electrode containing 2% ThO 2 by weight). They were operated under the same operating conditions and compared in terms of lumen maintenance and stability. FIG. 4 shows a comparison of changes in luminous flux maintenance factor over time. The luminous flux maintenance rate indicates the change in luminous flux over time, with the luminous flux at the start of use being 100. FIG. 4 shows that the luminous flux maintenance factor of the embodiment is slightly smaller than that of the conventional tube. However, for this type of light source discharge tube, arc stability S, which will be described later, is more important.
This degree of difference is not a problem. The present invention aims to maintain the luminous flux maintenance factor within an allowable range and obtain good arc stability S. At the end of the detailed description of the invention, Attached Table 1 shows a comparison of the arc stability S of the above embodiment and the conventional tube. Arc stability S is defined as follows. Arc stability S is determined by projecting an arc, inserting a thin slit into the center of the arc projection image, and measuring the fluctuation of the light intensity passing through the slit. S(%)=[(Imax-Imin)/Imax]×100(%) Here, Imax is the maximum light intensity and Imin is the minimum light intensity. As is clear from Attached Table 1, in the examples, the arc stability shows almost no change from the initial value even after 1000 hours of lighting. (Example) An example in which tungsten is used as a high melting point metal base of a porous material has been described in detail above. We were able to confirm that almost the same results could be obtained using Mo, Re, and Ta as materials by using materials with particle sizes in the same range and with the same porosity. (Effects of the Invention) As explained above, according to the present invention, the tip of the cathode, which has a porous high-melting point metal base impregnated with an electron-emitting substance, is fixed to one end of a metal rod forming a conductive path. Since the cathode is formed using the same structure, deformation and deterioration of the cathode tip can be prevented. As a result, it was possible to provide a discharge tube for a light source in which the bright spot moves less. By appropriately selecting the diameter of the metal rod and the shape of the base, it is possible to provide a light source discharge tube with little fluctuation and a sufficient lifespan. 【table】
第１図は従来の光源用放電管の典型的な構成例
を示す図であつて中央部を破断して示してある。
第２図は従来の光源用放電管の陰極に原因するゆ
らぎの原因を説明するための陰極先端部の拡大図
であつて、同図Ａは当初の状態、同図Ｂは相当時
間経過後の状態を示している。第３図は本発明に
より光源用放電管の陰極の実施例を示す拡大図で
ある。第４図は従来管と実施例の光束維持率を比
較して示したグラフである。
１１……石英製発光管、１２ａ，１２ｂ……電
極導入枝管、１３ａ，１３ｂ……モリブデン箔、
１４ａ，１４ｂ……引出し線、１５……陽極、１
６……陰極、１７……排気管跡、１８……反射
膜、２０……導電路を兼ねる金属棒、２１……陰
極先端部。
FIG. 1 is a diagram showing a typical configuration example of a conventional discharge tube for a light source, with the central portion cut away.
Figure 2 is an enlarged view of the tip of the cathode to explain the cause of fluctuations caused by the cathode of a conventional light source discharge tube. It shows the condition. FIG. 3 is an enlarged view showing an embodiment of the cathode of the discharge tube for light source according to the present invention. FIG. 4 is a graph showing a comparison of the luminous flux maintenance factors of the conventional tube and the example. 11... Quartz arc tube, 12a, 12b... Electrode introduction branch tube, 13a, 13b... Molybdenum foil,
14a, 14b...Leader line, 15...Anode, 1
6... Cathode, 17... Exhaust pipe trace, 18... Reflective film, 20... Metal rod that also serves as a conductive path, 21... Cathode tip.
Claims (1)
してアーク放電を行わせる光源用放電管におい
て、尖頭をもつ多孔質の高融点金属基体に易電子
放射物質を含浸させた陰極先端部を導電路を形成
する金属棒の一端に固定して陰極を形成して構成
したことを特徴とする光源用放電管。 ２ 前記多孔質の高融点金属基体は平均粒径が
2μ〜8μの高い融点金属粉末をプレス成形後、真
空中または水素雰囲気中で焼成した10〜35％の空
孔率を有する多孔質タングステン基体である特許
請求の範囲第１項記載の光源用放電管。 ３ 前記易電子放射物質は、少なくともアルミン
酸バリウムを含むアルミン酸アルカリ土類からな
る電子放射物質である特許請求の範囲第１項記載
の光源用放電管。 ４ 前記ガス雰囲気に含まれる稀ガスは、水銀と
キセノンガスとの混合稀ガスである特許請求の範
囲第１項記載の光源用放電管。 ５ 前記多孔質の高融点金属の基体を支持する金
属棒は、タングステン、モリブデン、タンタル、
レニウムの高融点金属である特許請求の範囲第１
項記載の光源用放電管。[Claims] 1. In a discharge tube for a light source in which an arc discharge is performed by sealing a cathode and an anode in an atmosphere of mercury and a rare gas, an electron-emissive substance is coated on a porous high-melting point metal base having a pointed tip. 1. A discharge tube for a light source, characterized in that the cathode is formed by fixing an impregnated cathode tip to one end of a metal rod forming a conductive path. 2 The porous high melting point metal substrate has an average particle size of
The discharge for a light source according to claim 1, which is a porous tungsten substrate having a porosity of 10 to 35%, which is obtained by press-molding a high melting point metal powder of 2 μ to 8 μ and then firing in a vacuum or a hydrogen atmosphere. tube. 3. The discharge tube for a light source according to claim 1, wherein the electron emissive material is an electron emissive material made of alkaline earth aluminate containing at least barium aluminate. 4. The discharge tube for a light source according to claim 1, wherein the rare gas contained in the gas atmosphere is a mixed rare gas of mercury and xenon gas. 5. The metal rod supporting the porous high melting point metal substrate is made of tungsten, molybdenum, tantalum,
Claim 1, which is a high melting point metal of rhenium
A discharge tube for a light source as described in .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7447484A JPS60218755A (en) | 1984-04-13 | 1984-04-13 | Discharge tube for light source |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7447484A JPS60218755A (en) | 1984-04-13 | 1984-04-13 | Discharge tube for light source |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60218755A JPS60218755A (en) | 1985-11-01 |
| JPH0213420B2 true JPH0213420B2 (en) | 1990-04-04 |
Family
ID=13548289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7447484A Granted JPS60218755A (en) | 1984-04-13 | 1984-04-13 | Discharge tube for light source |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60218755A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0517799Y2 (en) * | 1986-03-14 | 1993-05-12 | ||
| JP2919156B2 (en) * | 1992-03-13 | 1999-07-12 | 松下電工株式会社 | Cathode for discharge lamp |
| DE19527348A1 (en) * | 1995-07-26 | 1997-01-30 | Wolfram Ind Mbh Ges | Electrode with heat sink |
| DE102005022376B4 (en) * | 2005-05-13 | 2009-11-19 | Perkinelmer Optoelectronics Gmbh & Co.Kg | Lamp and method of making the same |
| JP5024466B1 (en) * | 2011-03-10 | 2012-09-12 | ウシオ電機株式会社 | Short arc type discharge lamp |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49119481A (en) * | 1973-03-16 | 1974-11-14 | ||
| JPS5230787A (en) * | 1975-09-04 | 1977-03-08 | Ebara Infilco Co Ltd | Method for preventing back wash of counter current desalting equipment |
| JPS55121260A (en) * | 1979-03-08 | 1980-09-18 | Gen Electric | Cathode |
-
1984
- 1984-04-13 JP JP7447484A patent/JPS60218755A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49119481A (en) * | 1973-03-16 | 1974-11-14 | ||
| JPS5230787A (en) * | 1975-09-04 | 1977-03-08 | Ebara Infilco Co Ltd | Method for preventing back wash of counter current desalting equipment |
| JPS55121260A (en) * | 1979-03-08 | 1980-09-18 | Gen Electric | Cathode |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60218755A (en) | 1985-11-01 |
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