JP3562112B2

JP3562112B2 - Rare gas discharge lamp

Info

Publication number: JP3562112B2
Application number: JP06131296A
Authority: JP
Inventors: 真一堀田
Original assignee: Ushio Denki KK
Current assignee: Ushio Denki KK
Priority date: 1996-03-18
Filing date: 1996-03-18
Publication date: 2004-09-08
Anticipated expiration: 2016-03-18
Also published as: JPH09259829A

Description

【０００１】
【発明の属する技術分野】
この発明は希ガス放電灯に関し、特にガラスバルブの外周面に一対の帯状の外部電極を有する希ガス放電灯において、外部電極の端部からの端子の導出構造の改良に関する。
【０００２】
【従来の技術】
従来のこの種希ガス放電灯は、例えば図１２〜図１４に示すように構成されている。即ち、Ａは例えばガラスバルブよりなる直管状の外囲器であって、その内面には希土類蛍光体，ハロリン酸塩蛍光体などの蛍光体よりなる発光層Ｂが形成されている。尚、外囲器Ａの内部空間には例えば水銀などの金属蒸気を含まないキセノンガスなどを主成分とする希ガスが所定量封入されている。一方、外囲器Ａの外周面には、例えばアルミニウムなどの不透光性の金属部材よりなる帯状の一対の外部電極Ｃ，Ｄが互いに対向するように貼着されており、その外周面は熱収縮性樹脂よりなる保護チュ−ブＥにて被覆・保護されている。又、外部電極Ｃ，Ｄの端部には例えば銅などの端子Ｆ，Ｆが鉛−錫−銀−アンチモンの四元合金よりなるアルミニウム接続用の半田（以下、アルミ半田という）Ｇ，Ｇにて半田付けされている。
【０００３】
この希ガス放電灯は、外部電極Ｃ，Ｄに高周波高電圧（例えば２９ＫＨｚで２５００Ｖｏ−ｐ）を印加することによりキセノンガスの放電が生じ、キセノンガスの励起線によって発光層Ｂが励起されて発光するものであり、光は外部電極Ｃ，Ｄの端部Ｃａ，Ｄａ間の開口部Ｐから放出される。特に、この希ガス放電灯には水銀が用いられていないために、点灯後における光量の立ち上がりが急峻であり、点灯と同時に光量がほぼ１００％近くにまで達するという特徴を有している。このために、近時、ファクシミリ，イメ−ジスキャナ，複写機などのＯＡ機器の原稿読取用の光源として脚光を浴びている。
【０００４】
【発明が解決しようとする課題】
しかしながら、この希ガス放電灯は、次のように製造されるために、最終製品の形態の一定化が難しい上、量産性の改善も難しいという問題がある。
【０００５】
即ち、まず、図１３に示すように、外囲器Ａの外周面に一方の面に接着層を有する外部電極Ｃ，Ｄを、互いに所定の間隔だけ離隔するように、手作業によって貼付ける。そして、外部電極Ｃ，Ｄの端部に端子Ｆ，Ｆをアルミ半田Ｇ，Ｇにて半田付けすると共に、端子Ｆ，Ｆに図示しない外部導出用のハ−ネスを半田付けする。尚、外部電極Ｃ，Ｄの外囲器Ａへの貼着は、外部電極Ｃ，Ｄに端子Ｆ，Ｆを半田付けした後に行なうこともできる。次に、外囲器Ａをシリコ−ンワニス液に浸漬し引き上げた後、例えば１時間程度乾燥させることにより、外囲器Ａ及び外部電極Ｃ，Ｄの表面にはシリコ−ンワニスの被膜が形成される。然る後、図１２及び図１４に示すように、外囲器Ａに熱収縮性樹脂よりなる保護チュ−ブＥを被せると共に、この保護チュ−ブＥを１５０〜２００°Ｃ程度に加熱して熱収縮させ、外囲器Ａの外周面に保護チュ−ブＥを密着させることによって希ガス放電灯が製造される。
【０００６】
このように希ガス放電灯の製造工程には、外部電極Ｃ，Ｄの端部に端子Ｆ，Ｆをアルミ半田Ｇ，Ｇにて半田付けする工程があるが、外部電極Ｃ，Ｄに対する端子Ｆ，Ｆの幅が大きく半田付け面積が広い上に、手作業によって行なわれるために、作業者間のバラツキが大きく、アルミ半田Ｇ，Ｇの盛り上がり形態が一定化しない傾向にある。例えばアルミ半田Ｇ，Ｇが大きく盛り上がってしまうと、端子Ｆ，Ｆの面積が広いために、図１４に示すように、保護チュ−ブＥを装着した状態において、端子Ｆ，Ｆの外部電極Ｃ，Ｄへの半田付け部分の外径が外囲器Ａの中央部分の外径に比べて局部的に大きくなる。
【０００７】
ところで、近時、ファクシミリ，イメ−ジスキャナ，複写機などのＯＡ機器は、ユ−ザ−などの要請に基づいて小形化が進められており、これに組み込まれる原稿読取用光源としての希ガス放電灯に対しても同様に小形化が求められている。従って、組み込み部所における希ガス放電灯とＯＡ機器との間のクリアランスは極めて小さいものである。
【０００８】
このために、希ガス放電灯の外径のバラツキが全長に亘って小さい場合には何ら問題はないものの、上述のように希ガス放電灯の外径が局部的に大きくなると、ＯＡ機器の所定位置に組み込めなくなるという問題が生ずる。
【０００９】
しかも、この希ガス放電灯では、外部電極Ｃ，Ｄの外囲器Ａへの密着性，貼着性及び端子Ｆ，Ｆの外部電極Ｃ，Ｄへの接続強度などの観点から、外部電極Ｃ，Ｄには肉厚の小さいアルミニウムが、端子Ｆ，Ｆには外部電極Ｃ，Ｄの幅の５０％を超える幅の短冊状の銅がそれぞれ使用されている。これらの金属部材は腐食電位列が大きく離れているために、長期間の使用によって双方の接触部分が異種金属接触腐食を起こす。特に、この希ガス放電灯は、使用状態において、それの外部電極Ｃ，Ｄに端子Ｆ，Ｆを介して高周波高電圧が印加されるために、異種金属接触腐食が加速され、ついには、端子Ｆ，Ｆと外部電極Ｃ，Ｄとの電気的な接続関係が断たれてしまい、希ガス放電灯の点灯維持ができなくなるという問題がある。
【００１０】
一方、この希ガス放電灯の製造には、例えば手作業による外部電極Ｃ，Ｄの貼着工程，シリコ−ンワニスの被着−乾燥工程，保護チュ−ブＥの装着−熱収縮工程などのように数多くの製造工程を経なければならないこともあって、量産性を改善し難いという問題もある。
【００１１】
それ故に、本発明の目的は、比較的に簡単な構成によって最終製品の形態のバラツキを小さくでき、生産性を改善できる上、異種金属接触腐食も抑制可能な希ガス放電灯を提供することにある。
【００１２】
【課題を解決するための手段】
従って、本発明は、上述の目的を達成するために、内面に発光層を有する直管状の外囲器と、外囲器の外周面に、それのほぼ全長に亘って離隔して配置した金属部材よりなる帯状の一対の外部電極と、外部電極と電気的な接続関係を有し、かつ外部電極の端部から導出した外部電極とは異なる金属より構成された端子と、外囲器の外周面に、外部電極が被覆されるように装着した透光性の絶縁部材とを具備し、前記外部電極の幅Ｗと端子の幅ｄとを０．１Ｗ≦ｄ≦０．５Ｗの関係に設定し、外部電極と端子とを導電性接着剤にて電気的に接続したものであり、本発明の第２の発明は、前記透光性の絶縁部材を、透光性シ−ト又は熱収縮性樹脂よりなる保護チュ−ブにて構成したことを特徴とする。
【００１３】
又、本発明の第３の発明は、内面に発光層を有する直管状の外囲器と、外囲器の全長とほぼ同程度の長さを有する透光性シートの一方の面に金属部材よりなる帯状の一対の外部電極を互いに離隔して配置し、かつ外部電極の端部に外部電極とは異なる金属より構成された端子を導電性接着剤にて電気的接続してなるシート構体とを具備し、前記外部電極の幅Ｗと端子の幅ｄとを０．１Ｗ≦ｄ≦０．５Ｗの関係に設定すると共に、前記外囲器の外周面にシート構体を、外囲器と透光性シートとの間に外部電極が位置するように巻回・密着したことを特徴とする。
【００１４】
さらに、本発明の第４の発明は、前記外部電極及び端子をほぼ同一平面に配置し、それぞれを導電性接着剤にて電気的に接続したことを特徴とし、第５の発明は、前記外部電極及び端子を重ね合わせると共に、それぞれの重なり部分に導電性接着剤を介在させることにより、外部電極及び端子を電気的に接続したことを特徴とする。
【００１５】
【発明の実施の形態】
次に、本発明の第１の実施例について図１〜図５を参照して説明する。同図において、１は例えばガラスバルブにて密閉状に構成された直管状の外囲器であって、その内面には希土類蛍光体，ハロリン酸塩蛍光体などの蛍光体よりなる発光層２が形成されている。特に、外囲器１の封着構造はガラスバルブの端部にディスク状の封着ガラス板１ａ，１ｂを封着して構成されているが、例えば単にガラスバルブを加熱しながら縮径加工し溶断して構成することもできる。尚、この外囲器１の密閉空間には水銀などの金属蒸気を含まない例えばキセノン（Ｘｅ），クリプトン（Ｋｒ），ネオン（Ｎｅ），ヘリウム（Ｈｅ）などの希ガスが単一又は混合して所定量封入されているが、キセノンを主成分とする希ガスを例えば２０〜１１０Ｔｏｒｒの圧力で封入することが望ましい。
【００１６】
この外囲器１の外周面にはシ−ト構体３が密着するように巻回されている。このシ−ト構体３は、例えば外囲器１の全長とほぼ同程度の長さを有し、かつ厚さが２０〜１００μｍの範囲に設定された透光性シ−ト４と、この透光性シ−ト４の一方の面に互いに所定の間隔だけ離隔配置して接着され、かつ端部にほぼコ字状の切欠き５Ａ，６Ａを有する不透光性の金属部材よりなる帯状の一対の外部電極５，６と、この外部電極５，６の端部から、一方の端部が外部電極５，６の切欠き５Ａ，６Ａに位置し、他方の端部が透光性シ−ト４の端縁部分より突出するように導出された端子５１，６１と、外部電極５，６と端子５１，６１とを電気的に接続する導電性接着剤５２と、透光性シ−ト４の一方の面に付与された粘着ないし接着機能を有する接着層９とから構成されている。
【００１７】
特に、このシ−ト構体３において、導電性接着剤５２は樹脂系接着剤に導電性粉末を所定量分散させて構成されており、例えばアクリル系接着剤にニッケル粉末を分散させたものが好適するが、樹脂系接着剤としてはアクリル系の他、シリコ−ン系，エポキシ系，ビニル系などが、導電性粉末としてはニッケルの他、カ−ボン，銅，銀などの部材をそれぞれ適宜に組み合わせて使用することもできる。又、接着層９としてはシリコ−ン系接着剤が好適するが、アクリル系接着剤なども使用できる。特に、この接着層９は外部電極５，６の露出面にも形成されているが、予め透光性シ−ト４の一方の面にのみ形成して外部電極５，６の露出面には形成しないように構成することもできる。さらに、透光性シ−ト４としては、例えばポリエチレンテレフタレ−ト（ＰＥＴ）樹脂が好適するが、ポリエステル樹脂なども利用できる。
【００１８】
又、外部電極５，６及び端子５１，６１は、腐食電位列が離れた位置にある金属部材にて構成されており、例えば外部電極５，６としては帯状のアルミニウム箔が、端子５１，６１としては短冊状の銅が好適する。しかしながら、外部電極５，６としては導電性に優れ、かつ不透光性の金属部材であればアルミニウムの他に、ニッケルなどの金属部材も利用できるし、端子５１，６１としては銅の他に、銀，ステンレス，Ｃｕ−Ｎｉ合金などの金属部材も利用できる。特に、外部電極５，６の幅Ｗと端子５１，６１の幅ｄとは、０．１Ｗ≦ｄ≦０．５Ｗなる関係に設定されている。特に、端子５１，６１の肉厚は０．１〜０．５ｍｍの範囲が望ましい。
【００１９】
上述のシ−ト構体３は外囲器１の外周面に、外部電極５，６が外囲器１と透光性シ−ト４との間に位置するように装着されており、後述の第２の開口部（８）において、透光性シ−ト４の一方の端部４ａに他方の端部４ｂを重ね合わせた上で接着されている。特に、シ−ト構体３の外囲器１への装着状態において、外部電極５，６の一端５ａ，６ａの間には第１の開口部７が、外部電極５，６の他端５ｂ，６ｂの間には第２の開口部８がそれぞれ形成されており、発光層２からの光は主として第１の開口部７から放出される。尚、第１，第２の開口部７，８の開口角θ_１，θ_２はθ_１＞θ_２の関係に設定することが望ましいが、同一に設定することもできる。
【００２０】
この希ガス放電灯は、例えば次のように製造される。まず、図６（ａ）に示すように、透光性シ−ト４に外部電極５，６を、ほぼコ字状の切欠き５Ａ，６Ａの形成された端部が同一側になるように所定の位置に配置し、接着する。次に、同図（ｂ）に示すように、端子５１，６１の一方の端部が切欠き５Ａ，６Ａに位置し、他方の端部が透光性シ−ト４の端縁部分より突出するように配置し、接着する。次に、同図（ｃ）に示すように、端子５１，６１の一方の端部を含む外部電極５，６の切欠き部分５Ａ，６Ａに導電性接着剤５２を被着し固化させることにより、外部電極５，６と端子５１，６１とが電気的機械的に接続され、シ−ト構体３が完成する。
【００２１】
次に、図７に示すように、シ−ト構体３を展開した状態で所定の部位例えば組み立てステ−ジに載置する。次に、外囲器１をシ−ト構体３の透光性シ−ト４の一端４ａに、外囲器１の長手方向が外部電極５，６の長手方向に沿うように（平行となるように）位置させる。この状態で、外囲器１を透光性シ−ト４に若干押しつけるようにして図示矢印方向（透光性シ−ト４の他端４ｂの方向）に転動させる。これによって、シ−ト構体３は、図１に示すように、外囲器１の外周面に巻回される上、透光性シ−ト４の一端４ａに他端４ｂが重ね合わされ、接着層９によって接着される。尚、接着層９に熱硬化性接着剤を使用する場合には、熱処理することが望ましい。
【００２２】
この希ガス放電灯によれば、端子５１，６１の一方の端部は外部電極５，６の切欠き５Ａ，６Ａに、外部電極５，６とほぼ同一平面となるように配置した上で導電性接着剤５２にて電気的に接続されているために、その厚みを十分に小さくできる。このために、シ−ト構体３を外囲器１の外周面に巻回・密着させた状態において、放電灯の外径は全長に亘ってほぼ均斉化され、外囲器端部で局部的に外径が大きくなるということはなくなる。従って、ＯＡ機器において、希ガス放電灯の組み込み空間部がかなり制約された状態であっても、確実に組み込むことができる。
【００２３】
特に、外部電極５，６の幅Ｗと端子５１，６１の幅ｄとの関係が、０．１Ｗ≦ｄ≦０．５Ｗに設定されているために、外部電極５，６と端子５１，６１とを導電性接着剤５２を利用して接続しても、異種金属接触腐食の発生を効果的に抑制できる。従って、長期間に亘って安定した動作状態を維持できる。しかしながら、端子５１，６１の幅ｄが０．１Ｗ未満になると、透光性シ−ト４に対する接続強度が低下する。逆に、それの幅ｄが０．５Ｗを超えると、シ−ト構体３を外囲器１に巻回する際に、端子５１，６１を外囲器１の外周面に倣い易くするために、予め、外囲器１の外周面に倣う曲面に加工しなければならず、その加工が極めて面倒になるという問題が生ずる。従って、両者は上述の関係に設定することが望ましい。
【００２４】
一方、上述の方法によれば、外囲器１をシ−ト構体３の上で単に転動させるだけで、外部電極５，６を外囲器１の外周面に貼着できるし、外部電極５，６は透光性シ−ト４に予め所定の間隔で配列されているために、貼り付けの際に外部電極５，６の間隔を所定の間隔となるように調整する必要が全くなく、仮に手作業であっても作業能率を著しく向上できる。具体的には、従来方法では製造に６０分間を要していたものが、本発明方法によれば１分程度に短縮できる。
【００２５】
又、シ−ト構体３における透光性シ−ト４の一方の面には、接着層９が形成されているために、外囲器１をシ−ト構体３の上で転動させるだけの単純動作によって、シ−ト構体３を外囲器１の外周面に巻回し密着させることができる。従って、作業能率を飛躍的に改善できるのみならず、機械化が可能となり、一層の量産効果が期待できる。
【００２６】
しかも、シ−ト構体３の外囲器１の外周面への巻回・密着状態において、透光性シ−ト４の端部４ａ，４ｂは互いに重ね合わせて接着されているために、外部電極５，６の被覆信頼性を高めることができる。特に、透光性シ−ト４の厚さを２０〜１００μｍの範囲に設定すれば、端部４ａ，４ｂの安定した重合・接着性が得られる。しかしながら、その厚さが２０μｍ未満になると、十分の絶縁性を確保できなくなるし、逆に１００μｍを超えると、シ−トの腰が強くなって端部４ａ，４ｂの重ね合わせ部分が剥がれ易くなり、巻回作業も面倒になる。従って、シ−ト厚さは上記範囲に設定することが望ましい。
【００２７】
又、外部電極５，６は、シ−ト構体３を外囲器１に装着する際に、透光性シ−ト４と外囲器１の外周面との間に位置するように配慮されているために、ファクシミリなどのＯＡ機器に適用されて使用時に高電圧が印加されても、外部電極間は勿論のこと、対地間絶縁をも十分に確保することができる。
【００２８】
図８〜図９は本発明の第２の実施例を示すものであって、基本的な構成は図１〜図４に示す希ガス放電灯と同じである。異なる点は、第１の開口部７に対応する外囲器１の内面部分に発光層２を形成しないアパ−チャ部（光放出部）２ａを形成したこと、外部電極５，６の端部における切欠き５Ａ，６Ａを省略すると共に、端子５１，６１を外部電極５，６に、両者の間に導電性接着剤５２を層状に介在させて電気的機械的に接続したことである。この導電性接着剤５２としては、例えばアクリル系接着剤にニッケル粉末を分散・混入したものが好適するが、他の導電性接着剤を適用することもできる。又、アパ−チャ部２ａの開口角は例えば７０〜１１０度の範囲に設定されているが、用途，目的などに応じて適宜に変更できる。
【００２９】
この実施例によれば、外部電極５，６と端子５１，６１とは、その間に導電性接着剤５２を層状に介在させることによって接続されているために、端子部分の最終外径は端子のない部分の外径とほぼ同程度に抑えることができる。このために、ＯＡ機器が小形化され、組み込み空間が狭くなっても、確実に組み込むことができる。
【００３０】
その上、外部電極５，６と端子５１，６１との間には導電性接着剤５２が介在されているために、異種金属接触腐食の進行を抑制できる。特に、ニッケル粉末を含む導電性接着剤を適用すれば、一層の抑制効果が期待できる。
【００３１】
又、発光層２から放射された光は外囲器内において高密度化されてアパ−チャ部２ａから第１の開口部７を経て外部に放出されるために、原稿照射装置に適用した場合、原稿面の照度を高めることができ、原稿の読み取り精度を高めることができる。
【００３２】
特に、外部電極５，６の外囲器側の面に光反射性を付与すれば、アパ−チャ部２ａの照度をさらに高めることができ、原稿の読み取り精度も一層改善できる。これの材料としては、例えばアルミニウム箔のように光反射性を有する金属部材が好適する。
【００３３】
図１０は本発明の第３の実施例を示すものであって、基本的な構成は図８〜図９に示す希ガス放電灯と同じである。異なる点は、シ−ト構体３の外囲器１への巻回・密着状態において、透光性シ−ト４のそれぞれの端部４ａ，４ｂの主たる重ね合わせ部分を外部電極５の外面側に設定したことである。尚、この重ね合わせ部分は外部電極４の外面側とすることもできる。
【００３４】
図１１は本発明の第４の実施例を示すものであって、基本的な構成は図１〜図４に示す希ガス放電灯と同じである。異なる点は、シ−ト構体３の外周面に熱収縮性樹脂よりなる保護チュ−ブ１０を被せたことである。尚、この保護チュ−ブ１０は外囲器１に装着した後、例えば１５０〜２００°Ｃ程度に加熱し、収縮させることによりシ−ト構体３に密着される。
【００３５】
この実施例によれば、希ガス放電灯の適用部所における環境条件が厳しい，安全基準が高いなどの場合には、例えば耐熱性などに優れ、かつ透光性を有する保護チュ−ブ１０にてシ−ト構体３を被覆することによって、より高品位の製品を提供できる。
【００３６】
特に、この実施例の構造は、図８，図１０に示す第２，第３の実施例にも適用することができる。
【００３７】
図８，図１０に示す第２，第３の実施例を利用して本発明の第５の実施例について説明する。この実施例は、外囲器１の外周面に一対の外部電極５，６を貼着した後、透光性シ−ト４を外囲器１の外周面に、外部電極５，６が被覆されるように巻回・密着させると共に、透光性シ−ト４のそれぞれの端部４ａ，４ｂを重ね合わせて接着するものである。
【００３８】
この実施例によれば、上述の各実施例に比較すると、機械化，作業能率の点で劣るものの、従来例よりは改善できる。特に、透光性シ−ト４の巻回に先立って、予め、外囲器１の外周面にシリコ−ンワニスなどの絶縁被膜を形成しておけば、絶縁性の一層の改善が可能となる。
【００３９】
尚、本発明は、何ら上記実施例にのみ制約されることなく、例えば外部電極と端子との接続は両者を重ね合わせた上で、端子及び外部電極の表面に跨がって導電性接着剤を被着することによって行なうこともできる。外囲器の外周面へのシ−ト構体の貼着は、外囲器をシ−ト構体の上で転動させる他、シ−ト構体を回転させて貼着することもできるし、それぞれの動作を併用させることもできる。又、シ−ト構体のそれぞれの端部は重ね合わせる他、突き合わせたり，若干隙間が形成されるように処理することもできる。さらに、外部電極と端子との幅は、異種金属接触腐食を問題にしない場合には、上述の関係以外に設定することもできる。
【００４０】
【実施例】
次に、第１の実験例について説明する。外径が８ｍｍ，長さが３００ｍｍの鉛ガラスよりなる外囲器に図４に示すシ−ト構体を巻回・密着させる。このシ−ト構体における外部電極には端部に幅が３ｍｍ，長さが４ｍｍの切欠きを有し、かつ肉厚が７０μｍ，幅Ｗが８ｍｍの帯状のアルミニウムを用い、端子には肉厚が０．１５ｍｍ，幅ｄが２ｍｍの短冊状の銅を用い、両者は（株）スリ−ボンド製の二液性常温硬化型接着剤３３８１（ニッケル粉末を含むアクリル系導電性接着剤）で電気的に接続されている。この希ガス放電灯を周囲温度が６０°Ｃ，相対湿度が９０％の雰囲気に配置し、外部電極に２５ＫＨｚ，２０００Ｖｏ−ｐの高周波高電圧を端子を介して印加する加速試験を行なったところ、１５００時間を経過するも、外部電極と端子との接続部分に腐食は全く認められなかった。しかしながら、端子の幅ｄを４．５ｍｍに設定し、外部電極と端子とを鉛（５９％）−錫（４０％）−銀（０．５％）−アンチモン（０．５％）よりなるアルミ半田で接続した以外は本発明品と同一構成の従来品では、７００時間を経過した段階で腐食が進行し始めていることが認められた。
【００４１】
これは、本発明品において、腐食電位の高い銅の端子の幅ｄが腐食電位の低いアルミニウムの外部電極の幅Ｗに対してほぼ０．２５と十分に狭くなっているために、腐食の進行が抑制されたものと推測される。しかしながら、従来品では、０．５６であり、この状態で腐食の進行が認められたことから、端子の幅ｄと外部電極の幅Ｗとの関係はｄ＝０．１Ｗ〜０．５Ｗに設定することが望ましい。
【００４２】
又、本発明品では、外径のバラツキ（最大値−最小値）が０．２５ｍｍであったのに対し、従来品ではバラツキが２．６ｍｍであった。このために、本発明品では、小形化されたＯＡ機器への組み込みに何の支障も生じなかったが、従来品では組み込みに支障の生ずるものが発生した。これは、本発明品における端子が外部電極の切欠き内に配置されているためと推測される。
【００４３】
次に、第２の実験例について説明する。外径が６ｍｍ，長さが２８０ｍｍの鉛ガラスよりなる外囲器に図４に示すシ−ト構体を巻回・密着させる。このシ−ト構体における外部電極には肉厚が７０μｍ，幅Ｗが５ｍｍの帯状のアルミニウムを用い、端子には肉厚が０．２ｍｍ，幅ｄが１．５ｍｍの短冊状の銅を用い、両者はそれぞれの間に介在させた（株）スリ−ボンド製の二液性常温硬化型接着剤３３８１にて電気的機械的に接続されている。この希ガス放電灯を第１の実験例と同一の雰囲気に配置し、外部電極に２５ＫＨｚ，１５００Ｖｏ−ｐの高周波高電圧を端子を介して印加する加速試験を行なったところ、１５００時間を経過するも、外部電極と端子との接続部分に腐食は全く認められなかった。しかしながら、端子の幅ｄを３．０ｍｍに設定しアルミ半田で接続した以外は本発明品と同一構成の従来品では、７５０時間を経過した段階で腐食が進行し始めていることが認められた。
【００４４】
これは、本発明品において、腐食電位の高い銅の端子の幅ｄが腐食電位の低いアルミニウムの外部電極の幅Ｗに対してほぼ０．３と十分に狭くなっているために、腐食の進行が抑制されたものと推測される。しかしながら、従来品では、０．６であり、この状態で腐食の進行が認められたことから、端子の幅ｄと外部電極の幅Ｗとの関係はｄ＝０．１Ｗ〜０．５Ｗに設定することが望ましいことが理解できる。
【００４５】
又、本発明品では、外径のバラツキ（最大値−最小値）が０．５ｍｍであったのに対し、従来品ではバラツキが２．６ｍｍであった。このために、本発明品では、小形化されたＯＡ機器への組み込みに何の支障も生じなかったが、従来品では組み込みに支障の生ずるものが発生した。
【００４６】
【発明の効果】
以上のように、本発明によれば、外部電極の端部に端子が導電性接着剤を利用して電気的に接続されているために、その厚みを十分に小さくできる。このために、シ−ト構体を外囲器の外周面に巻回・密着させた状態において、放電灯の外径は全長に亘ってほぼ均斉化され、外囲器端部で局部的に外径が大きくなるということはなくなる。従って、ＯＡ機器において、希ガス放電灯の組み込み空間部がかなり制約された状態であっても、確実に組み込むことができる。
【００４７】
特に、外部電極の幅Ｗと端子の幅ｄとの関係を、０．１Ｗ≦ｄ≦０．５Ｗに設定すれば、外部電極と端子とを導電性接着剤を利用して接続しても、異種金属接触腐食の発生を効果的に抑制できる。従って、長期間に亘って安定した動作状態を維持できる。
【００４８】
又、シ−ト構体を用いる場合には、外囲器をシ−ト構体の上で単に転動させるだけで、外部電極を外囲器の外周面に貼着できるし、外部電極は透光性シ−トに予め所定の間隔で配列されているために、貼り付けの際に外部電極の間隔を所定の間隔となるように調整する必要が全くない。従って、作業能率を飛躍的に改善できるのみならず、機械化が可能となり、一層の量産効果が期待できる。
【００４９】
さらに、外部電極は、シ−ト構体を外囲器に装着する際に、透光性シ−トと外囲器の外周面との間に位置するように配慮されているために、ファクシミリなどのＯＡ機器に適用されて使用時に高電圧が印加されても、外部電極間は勿論のこと、対地間絶縁をも十分に確保することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施例を示す縦断面図。
【図２】図１のＸ−Ｘ断面図。
【図３】図１の一部破断状態の側面図。
【図４】本発明にかかるシ−ト構体の展開図。
【図５】図４のＹ−Ｙ断面図。
【図６】本発明にかかるシ−ト構体の組み立て方法を説明するための平面図であって、同図（ａ）は透光性シ−トに外部電極を配置した状態を示し、同図（ｂ）は端子を配置した状態を示し、同図（ｃ）は導電性接着剤を被着した状態を示す。
【図７】本発明方法を説明するための縦断面図。
【図８】本発明の第２の実施例を示す縦断面図。
【図９】図７の要部断面図。
【図１０】本発明の第３の実施例を示す縦断面図。
【図１１】本発明の第４の実施例を示す縦断面図。
【図１２】従来例の縦断面図。
【図１３】従来方法を説明するための斜視図。
【図１４】図１２のＺ−Ｚ断面図。
【符号の説明】
Ｗ外部電極の幅
ｄ端子の幅
１外囲器
２発光層
２ａアパ−チャ部
３シ−ト構体
４透光性シ−ト
５，６外部電極
５Ａ，６Ａ切欠き
５１，６１端子
５２導電性接着剤
７第１の開口部
８第２の開口部
９接着層
１０保護チュ−ブ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rare gas discharge lamp, and more particularly, to an improvement in a structure in which a terminal is led out from an end of an external electrode in a rare gas discharge lamp having a pair of strip-shaped external electrodes on an outer peripheral surface of a glass bulb.
[0002]
[Prior art]
A conventional rare gas discharge lamp of this type is configured, for example, as shown in FIGS. That is, A is a straight tubular envelope made of, for example, a glass bulb, and a light emitting layer B made of a phosphor such as a rare earth phosphor or a halophosphate phosphor is formed on the inner surface thereof. A predetermined amount of a rare gas mainly containing xenon gas or the like that does not contain a metal vapor such as mercury is sealed in the inner space of the envelope A. On the other hand, a pair of strip-shaped external electrodes C and D made of a non-translucent metal member such as aluminum are attached to the outer peripheral surface of the envelope A so as to face each other. Covered and protected by a protective tube E made of a heat-shrinkable resin. At the ends of the external electrodes C and D, terminals F and F made of, for example, copper are connected to solders (hereinafter referred to as aluminum solder) G and G for aluminum connection made of a quaternary alloy of lead-tin-silver-antimony. Soldered.
[0003]
In this rare gas discharge lamp, when a high frequency high voltage (for example, 2500 Vop at 29 KHz) is applied to the external electrodes C and D, discharge of xenon gas occurs, and the light emitting layer B is excited by the xenon gas excitation line to emit light. The light is emitted from the opening P between the ends Ca and Da of the external electrodes C and D. In particular, since no mercury is used in this rare gas discharge lamp, the light quantity rises sharply after lighting, and the quantity of light reaches almost 100% simultaneously with lighting. For this reason, recently, it has been spotlighted as a light source for reading originals of OA equipment such as a facsimile, an image scanner, and a copying machine.
[0004]
[Problems to be solved by the invention]
However, since this rare gas discharge lamp is manufactured as follows, it is difficult to stabilize the form of the final product, and it is also difficult to improve mass productivity.
[0005]
That is, first, as shown in FIG. 13, external electrodes C and D having an adhesive layer on one surface are manually attached to the outer peripheral surface of the envelope A so as to be separated from each other by a predetermined distance. Then, the terminals F, F are soldered to the ends of the external electrodes C, D with aluminum solders G, G, and an external lead-out harness (not shown) is soldered to the terminals F, F. The external electrodes C, D can be attached to the envelope A after the terminals F, F are soldered to the external electrodes C, D. Next, the envelope A is immersed in a silicone varnish solution, pulled up, and then dried, for example, for about one hour, so that a silicone varnish coating is formed on the surfaces of the envelope A and the external electrodes C and D. You. Thereafter, as shown in FIGS. 12 and 14, the envelope A is covered with a protective tube E made of a heat-shrinkable resin, and the protective tube E is heated to about 150 to 200 ° C. Then, the protective tube E is brought into close contact with the outer peripheral surface of the envelope A to produce a rare gas discharge lamp.
[0006]
As described above, the manufacturing process of the rare gas discharge lamp includes a process of soldering the terminals F, F to the ends of the external electrodes C, D with the aluminum solders G, G. , F are large, the soldering area is large, and since the soldering is performed manually, there is a large variation between workers, and there is a tendency that the swelling form of the aluminum solders G, G is not constant. For example, when the aluminum solders G, G are greatly raised, the area of the terminals F, F is large. Therefore, as shown in FIG. , D is locally larger than the outer diameter of the central portion of the envelope A.
[0007]
Recently, OA equipment such as a facsimile, an image scanner, and a copying machine has been reduced in size in response to a request from a user or the like, and a rare gas discharge as a light source for document reading incorporated in the OA equipment has been advanced. Similarly, miniaturization is required for electric lights. Therefore, the clearance between the rare gas discharge lamp and the OA equipment at the installation part is extremely small.
[0008]
For this reason, there is no problem if the variation in the outer diameter of the rare gas discharge lamp is small over the entire length, but when the outer diameter of the rare gas discharge lamp is locally increased as described above, the predetermined size of the OA equipment is reduced. A problem arises in that it cannot be installed in a position.
[0009]
In addition, in the rare gas discharge lamp, the external electrodes C and D are taken into consideration from the viewpoints of the adhesion and the adhesion of the external electrodes C and D to the envelope A, the connection strength of the terminals F and F to the external electrodes C and D, and the like. , D are made of aluminum having a small thickness, and the terminals F, F are made of strip copper having a width exceeding 50% of the width of the external electrodes C, D. Since the corrosion potential trains of these metal members are far apart from each other, the contact portions of the two members cause dissimilar metal contact corrosion due to long-term use. Particularly, in this rare gas discharge lamp, in use, a high-frequency high voltage is applied to the external electrodes C and D via the terminals F and F, so that dissimilar metal contact corrosion is accelerated. There is a problem in that the electrical connection between F, F and the external electrodes C, D is broken, and it becomes impossible to maintain the lighting of the rare gas discharge lamp.
[0010]
On the other hand, the manufacture of the rare gas discharge lamp includes, for example, a process of manually attaching the external electrodes C and D, a process of applying and drying a silicone varnish, and a process of installing a protective tube E and a heat shrinking process. In addition, there is a problem that it is difficult to improve the mass productivity, because it has to go through many manufacturing steps.
[0011]
Therefore, an object of the present invention is to provide a rare gas discharge lamp that can reduce variation in the form of the final product with a relatively simple configuration, can improve productivity, and can suppress the contact corrosion of dissimilar metals. is there.
[0012]
[Means for Solving the Problems]
Therefore, in order to achieve the above object, the present invention provides a straight tubular envelope having a light-emitting layer on the inner surface, and a metal disposed on the outer peripheral surface of the envelope over substantially the entire length thereof. A pair of band-shaped external electrodes made of a member, a terminal having an electrical connection with the external electrode, and a terminal formed of a metal different from the external electrode derived from an end of the external electrode, and an outer periphery of the envelope A transparent insulating member mounted on the surface so as to cover the external electrode, and the width W of the external electrode and the width d of the terminal are set in a relationship of 0.1 W ≦ d ≦ 0.5 W. The external electrode and the terminal are electrically connected by a conductive adhesive. According to a second aspect of the present invention, the light-transmitting insulating member is made of a light-transmitting sheet or a heat-shrinkable sheet. And a protective tube made of a conductive resin.
[0013]
Further, a third invention of the present invention is directed to a straight tubular envelope having a light emitting layer on an inner surface, and a metal member provided on one surface of a translucent sheet having a length substantially equal to the entire length of the envelope. A sheet structure in which a pair of strip-shaped external electrodes made of a metal material are arranged apart from each other, and a terminal made of a metal different from the external electrode is electrically connected to an end of the external electrode with a conductive adhesive. The width W of the external electrode and the width d of the terminal are set in a relationship of 0.1 W ≦ d ≦ 0.5 W, and a sheet structure is provided on the outer peripheral surface of the envelope, and the outer body is transparent to the envelope. It is characterized by being wound and adhered so that an external electrode is located between the optical sheet and the optical sheet.
[0014]
Further, a fourth invention of the present invention is characterized in that the external electrodes and terminals are arranged on substantially the same plane and are electrically connected to each other by a conductive adhesive. The electrode and the terminal are overlapped, and the external electrode and the terminal are electrically connected by interposing a conductive adhesive in each overlapping portion .
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a first embodiment of the present invention will be described with reference to FIGS. In the figure, reference numeral 1 denotes a straight tubular envelope which is hermetically constituted by a glass bulb, for example, and a light emitting layer 2 made of a phosphor such as a rare earth phosphor or a halophosphate phosphor is provided on the inner surface thereof. Is formed. In particular, the sealing structure of the envelope 1 is configured by sealing the disk-shaped sealing glass plates 1a and 1b to the ends of the glass bulb. It can also be configured by fusing. In the enclosed space of the envelope 1, a rare gas such as xenon (Xe), krypton (Kr), neon (Ne), or helium (He) which does not contain metal vapor such as mercury is used alone or mixed. However, it is preferable to fill a rare gas containing xenon as a main component at a pressure of, for example, 20 to 110 Torr.
[0016]
A sheet structure 3 is wound around the outer peripheral surface of the envelope 1 so as to be in close contact therewith. The sheet structure 3 has, for example, a length substantially equal to the entire length of the envelope 1 and a thickness of 20 to 100 μm. A strip-like member made of a light-transmissive metal member that is adhered to one surface of the light-sensitive sheet 4 at a predetermined distance from each other and has notches 5A and 6A that are substantially U-shaped at the ends. From the pair of external electrodes 5 and 6 and one end of the external electrodes 5 and 6, one end is located in the cutouts 5 </ b> A and 6 </ b> A of the external electrodes 5 and 6, and the other end is a translucent sheath. Terminals 51 and 61 protruding from the edge of the sheet 4, a conductive adhesive 52 for electrically connecting the external electrodes 5 and 6 to the terminals 51 and 61, and a translucent sheet. 4 and an adhesive layer 9 having a sticking or adhering function provided on one surface thereof.
[0017]
In particular, in the sheet structure 3, the conductive adhesive 52 is formed by dispersing a predetermined amount of conductive powder in a resin-based adhesive. For example, a conductive powder in which nickel powder is dispersed in an acrylic adhesive is preferable. However, besides acrylic resin, silicone-based, epoxy-based, and vinyl-based resin adhesives, and conductive powder such as nickel, carbon, copper, silver, and other members as appropriate. They can be used in combination. As the adhesive layer 9, a silicone-based adhesive is suitable, but an acrylic-based adhesive can also be used. In particular, the adhesive layer 9 is also formed on the exposed surfaces of the external electrodes 5 and 6, but is formed in advance only on one surface of the translucent sheet 4 and is formed on the exposed surfaces of the external electrodes 5 and 6. It can also be configured not to form. Further, as the translucent sheet 4, for example, polyethylene terephthalate (PET) resin is preferable, but polyester resin or the like can also be used.
[0018]
The external electrodes 5 and 6 and the terminals 51 and 61 are made of a metal member at a position away from the corrosion potential train. For example, the external electrodes 5 and 6 are formed of strip-shaped aluminum foil. As such, strip-shaped copper is preferable. However, as the external electrodes 5 and 6, a metal member such as nickel or the like other than aluminum can be used as long as it is a metal member that is excellent in conductivity and is opaque. Also, metal members such as silver, stainless steel, and Cu-Ni alloy can be used. In particular, the width W of the external electrodes 5 and 6 and the width d of the terminals 51 and 61 are set such that 0.1 W ≦ d ≦ 0.5 W. In particular, the thickness of the terminals 51 and 61 is preferably in the range of 0.1 to 0.5 mm.
[0019]
The above-mentioned sheet structure 3 is mounted on the outer peripheral surface of the envelope 1 so that the external electrodes 5 and 6 are located between the envelope 1 and the translucent sheet 4, and will be described later. In the second opening (8), one end 4a of the translucent sheet 4 and another end 4b are overlapped and bonded. In particular, when the sheet structure 3 is attached to the envelope 1, a first opening 7 is provided between the one ends 5a and 6a of the external electrodes 5 and 6, and the other ends 5b and 5b of the external electrodes 5 and 6 are provided. The second openings 8 are respectively formed between 6b, and the light from the light emitting layer 2 is mainly emitted from the first openings 7. The opening angles θ ₁ and θ ₂ of the first and second openings 7 and 8 are desirably set in a relationship of θ ₁ > θ ₂ , but may be set the same.
[0020]
This rare gas discharge lamp is manufactured, for example, as follows. First, as shown in FIG. 6 (a), the external electrodes 5 and 6 are provided on the translucent sheet 4 so that the substantially U-shaped notches 5A and 6A are formed on the same side. Place in place and glue. Next, as shown in FIG. 2B, one end of the terminal 51, 61 is located at the notch 5A, 6A, and the other end protrudes from the edge of the translucent sheet 4. And glue them together. Next, as shown in FIG. 3C, a conductive adhesive 52 is applied to the cutout portions 5A and 6A of the external electrodes 5 and 6 including one ends of the terminals 51 and 61, and is solidified. Then, the external electrodes 5 and 6 are electrically and mechanically connected to the terminals 51 and 61, and the sheet structure 3 is completed.
[0021]
Next, as shown in FIG. 7, the sheet structure 3 is placed on a predetermined portion, for example, an assembly stage in a state where the sheet structure 3 is expanded. Next, the envelope 1 is placed parallel to one end 4a of the translucent sheet 4 of the sheet structure 3 so that the longitudinal direction of the envelope 1 is along the longitudinal direction of the external electrodes 5 and 6. So) position. In this state, the envelope 1 is rolled in the direction indicated by the arrow (the direction of the other end 4b of the translucent sheet 4) by slightly pressing the envelope 1 against the translucent sheet 4. As a result, the sheet structure 3 is wound around the outer peripheral surface of the envelope 1 as shown in FIG. 1, and the other end 4b is superimposed on one end 4a of the translucent sheet 4 and adhered. Glued by layer 9. When a thermosetting adhesive is used for the adhesive layer 9, it is desirable to perform a heat treatment.
[0022]
According to this rare gas discharge lamp, one end of each of the terminals 51 and 61 is disposed in the cutouts 5A and 6A of the external electrodes 5 and 6 so as to be substantially flush with the external electrodes 5 and 6 and then conductive. Since they are electrically connected by the conductive adhesive 52, the thickness can be sufficiently reduced. For this reason, in a state where the sheet structure 3 is wound and closely attached to the outer peripheral surface of the envelope 1, the outer diameter of the discharge lamp is substantially equalized over the entire length, and the discharge lamp is locally localized at the end of the envelope. The outer diameter does not become large. Therefore, in the OA equipment, even if the installation space of the rare gas discharge lamp is considerably restricted, it can be reliably installed.
[0023]
In particular, since the relationship between the width W of the external electrodes 5 and 6 and the width d of the terminals 51 and 61 is set to 0.1 W ≦ d ≦ 0.5 W, the external electrodes 5 and 6 and the terminals 51 and 61 are set. Even if they are connected using the conductive adhesive 52, the occurrence of dissimilar metal contact corrosion can be effectively suppressed. Therefore, a stable operation state can be maintained for a long period of time. However, when the width d of the terminals 51 and 61 is less than 0.1 W, the connection strength to the translucent sheet 4 decreases. Conversely, if the width d exceeds 0.5 W, in order to make the terminals 51 and 61 easily follow the outer peripheral surface of the envelope 1 when the sheet structure 3 is wound around the envelope 1. In addition, it is necessary to previously process the outer surface of the envelope 1 into a curved surface, which causes a problem that the processing is extremely troublesome. Therefore, it is desirable that both are set in the above-described relationship.
[0024]
On the other hand, according to the above-described method, the external electrodes 5 and 6 can be adhered to the outer peripheral surface of the envelope 1 simply by rolling the envelope 1 on the sheet structure 3. Since the electrodes 5 and 6 are arranged on the translucent sheet 4 at a predetermined interval in advance, there is no need to adjust the interval between the external electrodes 5 and 6 to a predetermined interval at the time of sticking. Even if manual work is performed, the work efficiency can be significantly improved. Specifically, while the conventional method required 60 minutes for production, the method of the present invention can reduce the time to about 1 minute.
[0025]
In addition, since the adhesive layer 9 is formed on one surface of the translucent sheet 4 in the sheet structure 3, the envelope 1 is simply rolled on the sheet structure 3. The sheet structure 3 can be wound around and adhered to the outer peripheral surface of the envelope 1 by the simple operation of (1). Therefore, not only the work efficiency can be dramatically improved, but also mechanization becomes possible, and a further mass production effect can be expected.
[0026]
In addition, when the sheet structure 3 is wound and adhered to the outer peripheral surface of the envelope 1, the end portions 4a and 4b of the translucent sheet 4 are overlapped and adhered to each other. The coating reliability of the electrodes 5 and 6 can be improved. In particular, when the thickness of the translucent sheet 4 is set in the range of 20 to 100 μm, stable polymerization and adhesion of the ends 4a and 4b can be obtained. However, if the thickness is less than 20 .mu.m, sufficient insulation cannot be ensured. Conversely, if it exceeds 100 .mu.m, the stiffness of the sheet becomes so strong that the overlapped portions of the end portions 4a and 4b tend to peel off. , Winding work is also troublesome. Therefore, it is desirable to set the sheet thickness in the above range.
[0027]
The external electrodes 5 and 6 are arranged so as to be located between the translucent sheet 4 and the outer peripheral surface of the envelope 1 when the sheet structure 3 is mounted on the envelope 1. Therefore, even when applied to an OA device such as a facsimile machine and a high voltage is applied during use, sufficient insulation between the external electrodes as well as between the external electrodes can be ensured.
[0028]
FIGS. 8 and 9 show a second embodiment of the present invention. The basic structure is the same as that of the rare gas discharge lamp shown in FIGS. The difference is that an aperture portion (light emitting portion) 2a in which the light emitting layer 2 is not formed is formed in the inner surface portion of the envelope 1 corresponding to the first opening 7, and the end portions of the external electrodes 5 and 6 are formed. The notches 5A and 6A are omitted, and the terminals 51 and 61 are electrically and mechanically connected to the external electrodes 5 and 6 with a conductive adhesive 52 interposed therebetween in a layered manner. As the conductive adhesive 52, for example, a material obtained by dispersing and mixing nickel powder into an acrylic adhesive is preferable, but other conductive adhesives can also be applied. Further, the aperture angle of the aperture portion 2a is set in a range of, for example, 70 to 110 degrees, but can be appropriately changed according to the use and purpose.
[0029]
According to this embodiment, since the external electrodes 5, 6 and the terminals 51, 61 are connected by interposing a conductive adhesive 52 in a layer between them, the final outer diameter of the terminal portion is equal to that of the terminal. It can be suppressed to about the same as the outer diameter of the part that does not exist. For this reason, even if the OA device is downsized and the installation space is narrowed, it can be reliably installed.
[0030]
In addition, since the conductive adhesive 52 is interposed between the external electrodes 5 and 6 and the terminals 51 and 61, the progress of contact corrosion of dissimilar metals can be suppressed. In particular, if a conductive adhesive containing nickel powder is applied, a further suppression effect can be expected.
[0031]
Further, since the light emitted from the light emitting layer 2 is densified in the envelope and is emitted from the aperture portion 2a to the outside through the first opening 7, the light emitted from the light emitting layer 2 is applied to a document irradiation device. Thus, the illuminance of the document surface can be increased, and the reading accuracy of the document can be improved.
[0032]
In particular, if the surface of the outer electrodes 5 and 6 on the side of the envelope is provided with light reflectivity, the illuminance of the aperture portion 2a can be further increased, and the reading accuracy of the document can be further improved. As a material for this, a metal member having light reflectivity such as an aluminum foil is suitable.
[0033]
FIG. 10 shows a third embodiment of the present invention, and the basic configuration is the same as that of the rare gas discharge lamp shown in FIGS. The difference is that when the sheet structure 3 is wound around and adhered to the envelope 1, the main overlapping portions of the ends 4 a and 4 b of the translucent sheet 4 are connected to the outer surface of the external electrode 5. It is set to. Note that this overlapped portion may be on the outer surface side of the external electrode 4.
[0034]
FIG. 11 shows a fourth embodiment of the present invention, and the basic configuration is the same as that of the rare gas discharge lamp shown in FIGS. The difference is that a protective tube 10 made of a heat-shrinkable resin is placed on the outer peripheral surface of the sheet structure 3. After the protective tube 10 is mounted on the envelope 1, it is heated to, for example, about 150 to 200 ° C. and shrunk to be closely attached to the sheet structure 3.
[0035]
According to this embodiment, when the environmental conditions in the application area of the rare gas discharge lamp are strict or the safety standards are high, for example, the protective tube 10 which is excellent in heat resistance and the like and has translucency. By coating the sheet structure 3 with the above, a higher quality product can be provided.
[0036]
In particular, the structure of this embodiment can be applied to the second and third embodiments shown in FIGS.
[0037]
A fifth embodiment of the present invention will be described with reference to the second and third embodiments shown in FIGS. In this embodiment, after a pair of external electrodes 5 and 6 are adhered to the outer peripheral surface of the envelope 1, the translucent sheet 4 is coated on the outer peripheral surface of the envelope 1 with the external electrodes 5 and 6. In this manner, the ends 4a and 4b of the translucent sheet 4 are overlapped and adhered while being wound and brought into close contact with each other.
[0038]
According to this embodiment, although it is inferior in mechanization and work efficiency as compared with the above-described embodiments, it can be improved as compared with the conventional example. In particular, if an insulating coating such as a silicone varnish is formed on the outer peripheral surface of the envelope 1 before winding the translucent sheet 4, the insulating properties can be further improved. .
[0039]
In addition, the present invention is not limited to the above-described embodiment at all. For example, the connection between the external electrode and the terminal is performed by superposing the two and superposing the conductive adhesive over the surface of the terminal and the external electrode. Can also be carried out. The attachment of the sheet structure to the outer peripheral surface of the envelope can be performed by rolling the envelope on the sheet structure, or by rotating the sheet structure and attaching the sheet structure. Can be used together. In addition, the ends of the sheet structure may be overlapped, butted, or processed to form a slight gap. Further, the width between the external electrode and the terminal can be set to a value other than the above-mentioned relationship in the case where the dissimilar metal contact corrosion is not a problem.
[0040]
【Example】
Next, a first experimental example will be described. The sheet structure shown in FIG. 4 is wound and adhered to an envelope made of lead glass having an outer diameter of 8 mm and a length of 300 mm. The external electrode of this sheet structure is formed of a strip of aluminum having a notch having a width of 3 mm and a length of 4 mm at the end, a thickness of 70 μm, and a width W of 8 mm. Is made of a strip-shaped copper having a width of 0.15 mm and a width d of 2 mm. Both are electrically connected with a two-part cold-setting adhesive 3381 (acrylic conductive adhesive containing nickel powder) manufactured by Three Bond Co. Connected. This rare gas discharge lamp was placed in an atmosphere having an ambient temperature of 60 ° C. and a relative humidity of 90%, and an acceleration test was performed in which a high-frequency high voltage of 25 KHz and 2000 Vo-p was applied to external electrodes via terminals. Even after 1500 hours, no corrosion was observed at the connection between the external electrode and the terminal. However, the width d of the terminal is set to 4.5 mm, and the external electrode and the terminal are made of aluminum made of lead (59%)-tin (40%)-silver (0.5%)-antimony (0.5%). In the conventional product having the same configuration as the product of the present invention except that it was connected by solder, it was recognized that the corrosion started to progress after 700 hours.
[0041]
This is because, in the product of the present invention, the width d of the copper terminal having a high corrosion potential is sufficiently narrow to about 0.25 with respect to the width W of the external electrode made of aluminum having a low corrosion potential. Is assumed to have been suppressed. However, in the conventional product, it is 0.56, and since the progress of corrosion was recognized in this state, the relation between the terminal width d and the external electrode width W was set to d = 0.1 W to 0.5 W. It is desirable to do.
[0042]
Further, in the product of the present invention, the variation in the outer diameter (maximum value-minimum value) was 0.25 mm, whereas in the conventional product, the variation was 2.6 mm. For this reason, the product of the present invention did not cause any trouble in assembling into a miniaturized OA device, but the conventional product caused trouble in assembling. This is presumably because the terminals of the product of the present invention are arranged in the cutouts of the external electrodes.
[0043]
Next, a second experimental example will be described. The sheet structure shown in FIG. 4 is wound and adhered to an envelope made of lead glass having an outer diameter of 6 mm and a length of 280 mm. In this sheet structure, strip-shaped aluminum having a thickness of 70 μm and a width W of 5 mm was used for external electrodes, and strip-shaped copper having a thickness of 0.2 mm and a width d of 1.5 mm was used for terminals. The two are electrically and mechanically connected to each other by a two-part cold-setting adhesive 3381 manufactured by Three Bond Co., Ltd. interposed therebetween. This rare gas discharge lamp was placed in the same atmosphere as in the first experimental example, and an acceleration test in which a high-frequency high voltage of 25 KHz and 1500 Vo-p was applied to the external electrode through a terminal was performed. Also, no corrosion was observed at the connection between the external electrode and the terminal. However, it was recognized that corrosion started to progress after 750 hours in the conventional product having the same configuration as the product of the present invention except that the terminal width d was set to 3.0 mm and connected by aluminum solder.
[0044]
This is because, in the product of the present invention, the width d of the copper terminal having a high corrosion potential is sufficiently narrow to approximately 0.3 with respect to the width W of the external electrode made of aluminum having a low corrosion potential. Is assumed to have been suppressed. However, in the conventional product, it was 0.6, and the progress of corrosion was recognized in this state. Therefore, the relation between the terminal width d and the external electrode width W was set to d = 0.1 W to 0.5 W. It is understood that it is desirable to do.
[0045]
In addition, the variation of the outer diameter (maximum value-minimum value) of the product of the present invention was 0.5 mm, whereas the variation of the conventional product was 2.6 mm. For this reason, the product of the present invention did not cause any trouble in assembling into a miniaturized OA device, but the conventional product caused trouble in assembling.
[0046]
【The invention's effect】
As described above, according to the present invention, since the terminal is electrically connected to the end of the external electrode using the conductive adhesive, the thickness can be sufficiently reduced. For this reason, in a state where the sheet structure is wound and closely attached to the outer peripheral surface of the envelope, the outer diameter of the discharge lamp is substantially equalized over the entire length, and the outer diameter is locally reduced at the end of the envelope. The diameter does not increase. Therefore, in the OA equipment, even if the installation space of the rare gas discharge lamp is considerably restricted, it can be reliably installed.
[0047]
In particular, if the relationship between the width W of the external electrode and the width d of the terminal is set to 0.1 W ≦ d ≦ 0.5 W, even if the external electrode and the terminal are connected using a conductive adhesive, It is possible to effectively suppress the occurrence of dissimilar metal contact corrosion. Therefore, a stable operation state can be maintained for a long period of time.
[0048]
When a sheet structure is used, the external electrodes can be adhered to the outer peripheral surface of the envelope simply by rolling the envelope on the sheet structure, and the external electrodes can be transparent. Since the sex sheets are arranged at predetermined intervals in advance, there is no need to adjust the intervals between the external electrodes at the time of attachment so as to be at the predetermined intervals. Therefore, not only the work efficiency can be dramatically improved, but also mechanization becomes possible, and a further mass production effect can be expected.
[0049]
Further, the external electrode is designed to be located between the translucent sheet and the outer peripheral surface of the envelope when the sheet structure is mounted on the envelope. Even if a high voltage is applied during use by applying to the OA equipment, sufficient insulation between the external electrodes as well as between the external electrodes can be ensured.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
FIG. 2 is a sectional view taken along line XX of FIG.
FIG. 3 is a side view in a partially broken state of FIG. 1;
FIG. 4 is a development view of a sheet structure according to the present invention.
FIG. 5 is a sectional view taken along line YY of FIG. 4;
FIG. 6 is a plan view for explaining a method of assembling a sheet structure according to the present invention, and FIG. 6A shows a state in which external electrodes are arranged on a translucent sheet; (B) shows a state where terminals are arranged, and (c) shows a state where a conductive adhesive is applied.
FIG. 7 is a longitudinal sectional view for explaining the method of the present invention.
FIG. 8 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 9 is a sectional view of a main part of FIG. 7;
FIG. 10 is a longitudinal sectional view showing a third embodiment of the present invention.
FIG. 11 is a longitudinal sectional view showing a fourth embodiment of the present invention.
FIG. 12 is a longitudinal sectional view of a conventional example.
FIG. 13 is a perspective view for explaining a conventional method.
FIG. 14 is a sectional view taken along the line ZZ of FIG. 12;
[Explanation of symbols]
W External electrode width d Terminal width 1 Enclosure 2 Light emitting layer 2a Aperture 3 Sheet structure 4 Transparent sheets 5, 6 External electrodes 5A, 6A Notch 51, 61 Terminal 52 Conductivity Adhesive 7 First opening 8 Second opening 9 Adhesive layer 10 Protective tube

Claims

A straight tubular envelope having a light-emitting layer on the inner surface, a pair of band-shaped external electrodes made of a metal member arranged on the outer peripheral surface of the envelope over substantially the entire length thereof, And a terminal made of a metal different from the external electrode derived from the end of the external electrode, and a light-transmitting device mounted on the outer peripheral surface of the envelope so as to cover the external electrode. And an insulating member of
The width W of the external electrode and the width d of the terminal are set in a relationship of 0.1 W ≦ d ≦ 0.5 W, and the external electrode and the terminal are electrically connected by a conductive adhesive. Rare gas discharge lamp.

2. The rare gas discharge lamp according to claim 1, wherein the light-transmitting insulating member is formed of a protection tube made of a light-transmitting sheet or a heat-shrinkable resin.

A straight tubular envelope having a light-emitting layer on the inner surface, and a pair of band-shaped external electrodes made of a metal member on one surface of a translucent sheet having a length substantially equal to the entire length of the envelope are separated from each other. And a sheet structure formed by electrically connecting terminals made of a metal different from the external electrode to the end of the external electrode with a conductive adhesive, and having a width W of the external electrode. The width d of the terminal is set in a relationship of 0.1 W ≦ d ≦ 0.5 W , a sheet structure is provided on the outer peripheral surface of the envelope, and an external electrode is positioned between the envelope and the translucent sheet. A rare gas discharge lamp characterized by being wound and closely contacted.

The rare gas discharge lamp according to claim 1, wherein the external electrode and the terminal are arranged on substantially the same plane, and each is electrically connected by a conductive adhesive.

The rare gas discharge according to claim 1 or 3, wherein the external electrode and the terminal are overlapped with each other, and the external electrode and the terminal are electrically connected by interposing a conductive adhesive in each overlapping portion. Electric lights.