JP3635864B2

JP3635864B2 - Noble gas discharge lamp

Info

Publication number: JP3635864B2
Application number: JP13848797A
Authority: JP
Inventors: 敏田村
Original assignee: Ushio Denki KK
Current assignee: Ushio Denki KK
Priority date: 1997-05-28
Filing date: 1997-05-28
Publication date: 2005-04-06
Anticipated expiration: 2017-05-28
Also published as: JPH10334858A

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内面にアパ−チャ部を有する発光層を形成すると共に、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、安定した動作状態の得られる外部電極の構造の改良に関する。
【０００２】
【従来の技術】
本出願人は、先に、図１７〜図１９に示す希ガス放電灯を提案した。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１種又は２種以上の蛍光体を含む発光層２が形成されている。特に、この発光層２には所定の開口角を有するアパ−チャ部２ａがほぼ全長に亘って形成されている。そして、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の封入が望ましい。
【０００３】
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絶縁性の透光性シ−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た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、それと電気的な接続関係を有し、かつ導出端が透光性シ−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、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。
【０００４】
特に、このシ−ト構体３において、透光性シ−ト４としては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他の樹脂も利用できる。又、外部電極５，６としては帯状のアルミニウム箔が好適するが、導電性に優れ、かつ不透光性の金属部材であれば、ニッケルなどのように他の金属部材も利用できる。端子５１，６１としてはほぼ短冊状の銅が好適するが、銀，ステンレス，Ｃｕ−Ｎｉ合金など他の金属部材も利用できる。尚、端子５１，６１は外部電極５，６と同一部材にて構成し、その端部から外方に向けて延在させることもできる。さらに、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他の接着剤も使用できる。
【０００５】
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の一方の側縁部間には第１の開口部７が、外部電極５，６の他方の側縁部間には第２の開口部８がそれぞれ形成されており、発光層２からの放射光は主としてアパ−チャ部２ａを介して第１の開口部７から外部に放出される。
【０００６】
この希ガス放電灯は、例えば次のように製造される。まず、例えば青色領域，緑色領域，赤色領域にそれぞれ発光スペクトルを有する蛍光体を含む蛍光体塗布液をガラスバルブよりなる外囲器１の内面に塗布・乾燥し、焼成することにより発光層２が形成される。次に、例えば図示しないスクレ−パを利用して発光層２の一部を強制的に所定の開口角を以て剥離・除去することにより、アパ−チャ部２ａが形成される。次に、この外囲器１を密閉状に構成し、かつ内部空間にキセノンなどの希ガスを所定量封入する。
【０００７】
次に、図１８〜図１９に示すように、透光性シ−ト４の所定部分に一対の外部電極５，６を互いに離隔して配置すると共に、外部電極５，６の端部から端子５１，６１を導出し、かつ透光性シ−ト４及び外部電極５，６に接着層９を形成してシ−ト構体３を構成する。次に、図２０に示すように、シ−ト構体３を展開した状態で組み立てステ−ジ１０に載置する。引き続き、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に従動ロ−ラ１１，１１を、外囲器１が透光性シ−ト４に若干押しつけるように配置する。この状態で、ステ−ジ１０を若干Ｍ方向に移動させた後、Ｎ方向に移動させる。これによって、シ−ト構体３は、図１７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によって接着されて希ガス放電灯が完成する。
【０００８】
この希ガス放電灯は、端子５１，６１を介して外部電極５，６に高周波高電圧を印加することにより放電が生じ、希ガスの励起線によって発光層２が励起されて発光するものであり、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。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、ファクシミリ，イメ−ジスキャナ，複写機などのＯＡ機器における原稿読取用の光源として好適するものであり、例えば原稿照射装置に適用した場合には、原稿面照度を高めることができ、原稿の読み取り精度を向上させることができる。
【０００９】
又、この希ガス放電灯の組み立てに上述の方法を採用すれば、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ために、作業能率を著しく改善できるのみならず、機械化が可能となり、量産性を高めることができるなどの優れた効果が期待できる。
【００１０】
【発明が解決しようとする課題】
ところで、この希ガス放電灯は、例えば図２１に示すように、高周波高電圧が出力されるインバ−タ回路１２によって点灯動作される。希ガス放電灯の外部電極５，６にはインバ−タ回路１２から端子５１，６１を介して、例えば周波数が３０ＫＨｚ，電圧が２５００Ｖ_O-P程度の高周波高電圧が印加されることによって点灯するものである。例えば外囲器１の外径が８ｍｍ，全長が３６０ｍｍ程度の希ガス放電灯では、外部電極５，６に印加する電圧はほぼ２５００Ｖ_O-Pを定格電圧としている。
【００１１】
この希ガス放電灯は、熱陰極や冷陰極を用いた放電灯のように外囲器の長手方向に沿った１つの放電路によって点灯するものとは異なり、外部電極５，６の間（外囲器１の長手方向に対してほぼ直角方向）に無数の放電路が形成されることによって縞状の状態で点灯するものであり、正常な点灯状態では縞状の放電状態は目視することはできない。
【００１２】
しかしながら、電源ラインの電圧変動などによってインバ−タ回路１２の出力電圧が例えば１０％程度も低下したりすると、縞状の放電状態が目視できるようになるのみならず、放電位置（放電点）が一定化せず、絶えず外囲器の長手方向に移動したりしてアパ−チャ部２ａから放出される光にチラツキが生ずるようになる。
【００１３】
特に、この希ガス放電灯がファクシミリ，イメ−ジスキャナなどにおける原稿照射装置に適用される場合には、アパ−チャ部２ａの長手方向におけるそれぞれの位置の輝度が絶えず変動することによって、原稿の読み取り精度が著しく損なわれ、再生品位が低下するという問題が生ずることがある。
【００１４】
それ故に、本発明の目的は、比較的に簡単な構成によってチラツキの抑制された安定した放電状態が得られ、かつ光出力も改善できる希ガス放電灯を提供することにある。
【００１５】
【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外囲器と、外囲器の外周面に、それのほぼ全長に亘って第１，第２の開口部が形成されるように互いに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を具備し、前記第１の開口部及び／又は第２の開口部を形成する外部電極の側縁部に、三角状，矩形状，波形を含むほぼ半円状などの形状を有する同一形状が繰り返し形成されてなる異形部を、互いに対向するように形成すると共に、互いに対向する異形部の、同一形状が繰り返し形成される方向への位置ずれ量を、異形部ピッチの２０％以下に設定したことを特徴とする。
【００１６】
又、本発明の第２の発明は、内面に発光層を有する外囲器と、外囲器の外周面に、それのほぼ全長に亘って第１，第２の開口部が形成されるように互いに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を具備し、前記第２の開口部を形成する一対の外部電極の側縁部に、三角状，矩形状，波形を含むほぼ半円状などの形状を有する同一形状が繰り返し形成されてなる異形部を互いに対向するように形成すると共に、互いに対向する異形部の、同一形状が繰り返し形成される方向への位置ずれ量を異形部ピッチの２０％以下に設定したことを特徴とし、第３の発明は、前記発光層からの放射光を、主として第１の開口部から外部に放出するように構成すると共に、第１の開口部を形成する一対の外部電極のそれぞれの側縁部をストレ−ト状に形成したことを特徴とする。
【００１７】
又、本発明の第４の発明は、内面に発光層を有する外囲器と、外囲器の外周面に、それのほぼ全長に亘って第１，第２の開口部が形成されるように互いに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、外部電極が被覆されるように装着した絶縁部材とを具備し、
前記第２の開口部を形成する一対の外部電極の側縁部に、三角状，矩形状，波形を含むほぼ半円状などの形状を有する同一形状が繰り返し形成されてなる異形部を互いに対向するように形成すると共に、
互いに対向する異形部の、同一形状が繰り返し形成される方向への位置ずれ量を異形部ピッチの２０％以下に設定したことを特徴とし、第５の発明は、前記絶縁部材を、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。
【００１８】
又、本発明の第６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−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、第１，第２の開口部が形成されるように互いに離隔して配置し、かつ外部電極の位置する側の透光性シ−ト面に接着層を形成してなるシ−ト構体とを具備し、前記第２の開口部を形成する一対の外部電極の側縁部に、三角状，矩形状，波形を含むほぼ半円状などの形状を有する同一形状が繰り返し形成されてなる異形部を互いに対向するように形成すると共に、互いに対向する異形部の、同一形状が繰り返し形成される方向へ位置ずれ量を異形部ピッチの２０％以下に設定し、かつ外囲器の外周面にシ−ト構体を、外囲器と透光性シ−トとの間に外部電極が位置するように巻回し接着したことを特徴とする。
【００１９】
さらには、本発明の第７の発明は、前記異形部を、周期性を有するようにほぼ全長に亘って形成したことを特徴とし、第８の発明は、前記異形部を、三角状，台形を含む矩形状，波形を含むほぼ半円状のいずれかにて構成したことを特徴とし、第９の発明は、前記第１の開口部にほぼ対応する外囲器の内面部分に、発光層の形成されないアパ−チャ部を形成したことを特徴とし、第１０の発明は、前記外囲器に希ガスを８３〜２００トルの圧力範囲で封入したことを特徴とし、さらに、第１１の発明は、前記外囲器の肉厚を０．２〜０．７ｍｍの範囲に設定したことを特徴とする。
【００２０】
【発明の実施の形態】
次に、本発明にかかる希ガス放電灯の第１の実施例について図１〜図３を参照して説明する。尚、図１７〜図２１に示す先行技術と同一部分には同一参照符号を付し、その詳細な説明は省略する。同図において、この実施例の特徴部分は、第２の開口部８を形成する外部電極５，６の側縁部５ｂ，６ｂにほぼ同一形状である三角状の異形部５Ａ，６Ａを互いに対向するように形成すると共に、互いに対向する異形部５Ａ，６Ａの位置ずれ量ΔＰを異形部ピッチＰの２０％以下に設定したことと、第１の開口部７を形成する外部電極５，６の側縁部５ａ，６ａをストレ−ト状に形成したことである。
【００２１】
この異形部５Ａ，６Ａは外部電極５，６における側縁部５ｂ，６ｂのほぼ全長に亘って周期性を有するように形成されており、異形部５Ａの先端部（三角部分の頂点）５Ａａ，５Ａａ間の異形部ピッチＰと異形部６Ａの先端部（三角部分の頂点）６Ａａ，６Ａａ間の異形部ピッチＰとはほぼ等しくなるように設定されている。そして、互いに対向する異形部５Ａ，６Ａの位置ずれ量ΔＰは異形部ピッチＰの２０％以下に設定されている。しかしながら、位置ずれ量ΔＰが異形部ピッチＰの２０％を超えると、電源ラインの電圧が定格電圧の１０％以上低下した場合、始動特性が損なわれ、仮に点灯しても縞状の放電状態が目視されるようになって、アパ−チャ部２ａから放出される光にチラツキが生ずるようになる。従って、通常、この種ＯＡ機器についてはライン電圧の変動が定格電圧の１０％以内では正常に動作することが求められていることから、かかる位置ずれ量ΔＰは上記範囲内に設定しなければならない。
【００２２】
しかも、互いに対向する異形部５Ａ，６Ａの先端部５Ａａ，６Ａａの対向間隔はほぼ全長に亘ってほぼ同一となるように設定されている。そして、この異形部５Ａ（６Ａ）は、例えば外囲器１の外径が８ｍｍの場合には異形部５Ａ（６Ａ）を含めた幅が８ｍｍ，異形部５Ａ（６Ａ）のピッチが４ｍｍ，異形部５Ａ（６Ａ）の三角部分の頂点５Ａａ（６Ａａ）までの高さが１．８ｍｍ程度の寸法に設定することが望ましいが、希ガス放電灯，点灯装置の仕様によっては適宜に変更できる。尚、第１の開口部７の開口幅（間隔）は全長に亘ってほぼ同一となるように設定されている。
【００２３】
上述の外囲器１の構成部材としては、誘電率が大きく、かつ気密性が確実に保持でき、透光性を有する材料であれば一応適用が可能であるが、例えばガラスの中でも比較的に誘電率の大きい鉛ガラスなどが好適するものである。これの肉厚は０．２〜０．７ｍｍの範囲（好ましくは０．４〜０．７ｍｍの範囲）に設定されており、この範囲では所望の生産性，光特性が得られる。しかしながら、肉厚が０．４ｍｍ未満、特に０．２ｍｍ未満になると、外囲器１の機械的な強度が極端に低下するために、量産設備による生産工程でのガラス破損に伴う不良率が増加するようになるし、逆に、肉厚が０．７ｍｍを超えると、縞状の放電状態が目視され、アパ−チャ部２ａから放出される光にチラツキが生ずることがある。従って、外囲器１の肉厚は上記範囲内に設定することが望ましい。
【００２４】
又、この外囲器１の内部空間にはキセノン（Ｘｅ），クリプトン（Ｋｒ），ネオン（Ｎｅ），ヘリウム（Ｈｅ）などの希ガスが１種又は２種以上を混合して封入されており、その封入圧力は例えば８３〜２００トル（Ｔｏｒｒ）の範囲に設定されている。この範囲では始動特性，光出力（原稿面照度），チラツキに関する改善効果が得られる。しかしながら、封入圧力が８３トル未満になると、光出力に対する改善効果が不十分になるし、逆に、封入圧力が２００トルを超えると、始動特性が損なわれるのみならず、縞状の放電状態が目視され、アパ−チャ部２ａから放出される光にチラツキが生ずるようになる。従って、特段の事由がなければ、希ガスの封入圧力は上記範囲内に設定することが望ましい。
【００２５】
又、発光層２は、希ガス放電灯の用途によって、使用する蛍光体が１種のみにて構成したり、２種以上を混合して構成されたりする。例えば三波長域発光形の場合には、例えば青色領域に発光スペクトルを有するユ−ロピウム付活アルミン酸バリウム・マグネシウム蛍光体，緑色領域に発光スペクトルを有するセリウム・テルビウム付活リン酸ランタン蛍光体，赤色領域に発光スペクトルを有するユ−ロピウム付活硼酸イットリウム・ガドリウム蛍光体を混合してなる混合蛍光体にて形成され、その付着量は１ｃｍ²当たり５〜３０ｍｇの範囲に設定されている。この範囲では十分の光量（光出力）が得られるものの、その付着量が５ｍｇ未満になると、光量不足によって原稿面照度が不十分になるし、逆に、付着量が３０ｍｇを超えると、均質な発光層の形成が困難になる。従って、発光層２の付着量は上記範囲内に設定することが望ましい。
【００２６】
さらに、外部電極５，６のそれぞれの側縁部間には第１，第２の開口部７，８が形成されており、それぞれの開口角θ₁，θ₂はθ₁＞θ₂の関係に設定されている。第１の開口部７の開口角θ₁は６０〜９０°の範囲が、第２の開口部８の開口角θ₂は５５°程度がそれぞれ望ましい。しかしながら、第１の開口部７の開口角θ₁は用途によっては上記範囲外に設定することも可能であり、第２の開口部８は絶縁破壊しない程度に狭いことが望ましく、例えば最低２ｍｍ程度の離隔距離を確保することが推奨される。尚、上述のアパ−チャ部２ａの開口角は第１の開口部７の開口角θ₁とほぼ同程度に設定されている。
【００２７】
この実施例によれば、第２の開口部８を形成する外部電極５，６の側縁部５ｂ，６ｂには三角状の異形部５Ａ，６Ａが周期性を有し、それぞれの先端部５Ａａ，６Ａａが互いに対向するように形成されており、その上、互いに対向する異形部５Ａ，６Ａの位置ずれ量ΔＰは異形部ピッチＰの２０％以下に設定されているために、外部電極５，６に高周波高電圧を印加した場合、異形部５Ａ，６Ａの先端部分５Ａａ，６Ａａに電界が集中し、異形部５Ａ，６Ａ間で容易に放電する。従って、例えば１０％以内の電源変動によって外部電極５，６への印加電圧が低くなっても、チラツキのない状態で確実に点灯させることができる。このために、この希ガス放電灯を上述のＯＡ機器の原稿照射装置に適用した場合、原稿の読み取り精度，再生品位の向上が期待できる。
【００２８】
しかも、外囲器１の肉厚は０．２〜０．７ｍｍの範囲に設定されており、外部電極５，６に高周波高電圧を印加した場合、肉厚の厚い範囲では抵抗成分の増加に伴う外囲器自身への電圧分配の増加に関連してチラツキが発生し易くなるものの、上述のように外部電極５，６の側縁部５ｂ，６ｂに異形部５Ａ，６Ａが互いに対向するように形成され、異形部５Ａ，６Ａの位置ずれ量ΔＰが異形部ピッチＰの２０％以下に設定されていることと相俟って肉厚の厚い領域においてもチラツキの発生を効果的に抑制できるし、アパ−チャ部２ａを介して第１の開口部７から放出される光出力も効果的に改善できる。
【００２９】
その上、第２の開口部８を形成する外部電極５，６の側縁部５ｂ，６ｂには三角状の異形部５Ａ，６Ａが形成されているものの、第１の開口部７を形成する外部電極５，６の側縁部５ａ，６ａは光の放出に影響を与えないストレ−ト状に構成されているために、例えば原稿照射装置に適用した場合、原稿面の照度分布の均一化が容易になる。従って、簡単な構成で原稿の読み取り精度を高めることが可能になる。
【００３０】
特に、希ガスの封入圧力を高くすると、光出力は増加する反面、始動特性は損なわれるようになるが、外部電極５，６の側縁部５ｂ，６ｂに三角状の異形部５Ａ，６Ａを互いに対向するように形成し、かつ異形部５Ａ，６Ａの位置ずれ量ΔＰを異形部ピッチＰの２０％以下に設定することによって、希ガスの封入圧力の上限を２００トルにまで拡大しても、実用に供し得る始動特性が確保でき、移動縞（チラツキ）の発生も効果的に抑制でき、その上、光出力を有効に改善できる。従って、原稿照射装置に適用した場合には、安定した放電状態が得られる上に、原稿面照度を高めることができることから、読み取り品位の向上が期待できる。
【００３１】
又、発光層２の付着量が１ｃｍ²当たり５〜３０ｍｇの範囲に設定されれば、外囲器１の肉厚を０．２〜０．７ｍｍの範囲に設定すること及び希ガスの封入圧力を８３〜２００トルに設定することと相俟ってアパ−チャ部２ａを介して第１の開口部７から放出される光出力を効果的に増加できる。
【００３２】
特に、発光層２の付着量は通常の照明用蛍光ランプに比較すると２〜１０倍程度に設定されており、通常の照明用蛍光ランプでは特性的に好ましいものではないと考えられている量であるにも拘らず、希ガス放電灯では光出力が有効に増加している。この原因については明らかではないが、外部電極５，６の間（外囲器１の長手方向に対してほぼ直角方向）に無数の放電路が形成されることによって縞状の状態で点灯する希ガス放電灯に特有の現象と考えられる。
【００３３】
さらには、外囲器１の肉厚及び外部電極の構造を、好ましくは発光層２の付着量，希ガスの封入圧力をも上述の範囲に設定した上で、第１の開口部７の開口角θ₁を６０〜９０°の範囲に設定すれば、第１の開口部７から放出される光出力を一層に増加させることができる。この際に、第２の開口部８の離隔長さ（異形部５Ａ，６Ａの先端部５Ａａ，６Ａａ間の間隔）を２ｍｍ程度に設定すれば、第２の開口部８からの光の漏洩が抑制され、第１の開口部７から放出される光出力の一層の改善効果が期待できる。
【００３４】
図４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３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の内面部分に形成されているアパ−チャ部２ａの開口角θ₃を第１の開口部７の開口角θ₁より大きく設定したことである。このアパ−チャ部２ａの開口角θ₃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。尚、第１の開口部７の開口角θ₁と第２の開口部８の開口角θ₂はθ₁＞θ₂に設定することが望ましい。
【００３５】
この実施例によれば、外囲器１の外周面にシ−ト構体３を巻回する際に、第１の開口部７とアパ−チャ部２ａとのセンタ−が若干ずれても、第１の開口部７から放出される光の光軸のずれを緩和できる。このために、例えば原稿照射装置に適用しても、十分に高い読み取り精度を得ることができる。
【００３６】
図５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１〜図３に示す希ガス放電灯と同じである。異なる点は、透光性シ−ト４のそれぞれの端部４ａ，４ｂを外部電極５の上において重ね合わせ、この重ね合わせ部分を超音波溶着したことである。
【００３７】
この実施例によれば、重ね合わせ部分４ａ，４ｂの超音波溶着が外部電極５の外側面において行われるために、外囲器内面の発光層２に作用する超音波振動が緩和される。従って、第１，第２の実施例に比較すると、発光層２の外囲器内面の開口部７とアパ−チャ部２ａとのセンタ−が若干ずれても、第１の開口部７から放出される光の光軸のずれを緩和できる。このために、例えば原稿照射装置に適用しても、十分に高い読み取り精度を得ることができる。
【００３８】
図５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１〜図３に示す希ガス放電灯と同じである。異なる点は、透光性シ−ト４のそれぞれの端部４ａ，４ｂを外部電極５の上において重ね合わせ、この重ね合わせ部分を超音波溶着したことである。
【００３９】
この実施例によれば、重ね合わせ部分４ａ，４ｂの超音波溶着が外部電極５の外側面において行われるために、外囲器内面の発光層２に作用する超音波振動が緩和される。従って、第１，第２の実施例に比較すると、発光層２の外囲器内面からの剥離を抑制でき、光出力の改善が可能となる。
【００４０】
図６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３に示す希ガス放電灯と同じである。異なる点は、外囲器１の外周面に、側縁部５ｂ，６ｂに三角状の異形部５Ａ，６Ａを互いに対向するように形成した一対の外部電極５，６を接着層を利用して貼着した後に、外囲器１の外周面にＰＥＴ樹脂などの透光性シ−ト４Ａを、外部電極５，６が被覆されるように巻回して接着したことである。
【００４１】
この実施例によれば、外囲器１の外周面に透光性シ−ト４Ａを巻回するに先立って、外囲器１の外周面にシリコ−ンワニスなどの透光性の絶縁被膜を形成しておけば、外部電極間の絶縁耐力を改善できる。
【００４２】
図７は本発明の第５の実施例を示すものであって、基本的な構成は図１〜図３に示す希ガス放電灯と同じである。異なる点は、外囲器１の外周面に、側縁部５ｂ，６ｂに三角状の異形部５Ａ，６Ａを互いに対向するように形成した一対の外部電極５，６を接着層を利用して貼着した後に、外囲器１の外周面にＰＥＴ樹脂などの熱収縮性樹脂よりなる保護チュ−ブ１３を、外部電極５，６が被覆されるように装着し、熱収縮させたことである。尚、この保護チュ−ブ１３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外囲器１の外周面に密着される。
【００４３】
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、保護チュ−ブ１３に接着層を使用しないために、例えば端子の構成部材と接着剤成分との反応による腐食がなく、長期間に亘って安定した動作状態を維持できる上、保護チュ−ブ１３に継目がないために、上述の実施例のように透光性シ−ト４の端部の重ね合わせ部分の剥がれを完全に防止できる。
【００４４】
特に、外囲器１の外周面に保護チュ−ブ１３を装着するに先立って、外囲器１の外周面にシリコ−ンワニスなどの透光性の絶縁被膜を形成しておけば、外部電極間の絶縁耐力を一層高めることができる。
【００４５】
図８は本発明の第６の実施例を示すものであって、基本的な構成は図１〜図３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ＰＥＴ樹脂などの熱収縮性樹脂よりなる保護チュ−ブ１３を装着した後に、熱収縮させたことである。尚、この保護チュ−ブ１３はシ−ト構体３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透光性シ−ト４の外周面に密着される。
【００４６】
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１３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。
【００４７】
特に、この実施例の構造は、図４，図５，図６，図７に示す実施例にも適用することができる。
【００４８】
図９は本発明の第７の実施例を示すものであって、特に、外囲器１を展開した状態を示しており、基本的な構成は図１〜図３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を形成する外部電極５，６の側縁部５ａ，６ａにも周期性を有する三角状の異形部５Ａ，６Ａを互いに対向するように形成したことである。
【００４９】
図１０は本発明の第８の実施例を示すものであって、外部電極５（６）における異形部５Ａ（６Ａ）の先端形状の異なった状態を示すものである。同図（ａ）に示す先端部５Ａａ（６Ａａ）には丸味が形成されており、同図（ｂ）に示す先端部５Ａａ（６Ａａ）には先端を切除した台形部が形成されている。尚、基本的な構成は図１〜図３に示す希ガス放電灯と同じである。
【００５０】
この実施例によれば、例えば長尺状の導電性シ−トから外部電極５，６をプレス機などによって打ち抜く場合、異形部５Ａ，６Ａの先端部分５Ａａ，６Ａａのように細かい部分を所望通りの形状に形成でき、安定した放電を確保することが可能となる。
【００５１】
図１１は本発明の第９の実施例を示すものであって、特に、外囲器１を展開した状態を示しており、基本的な構成は図２〜図３（図１）に示す希ガス放電灯と同じである。異なる点は、第２の開口部８を形成する外部電極５，６の側縁部５ｂ，６ｂに周期性を有する同形状のほぼ半円状の異形部５Ｂ，６Ｂを互いは対向するように形成したことである。尚、外部電極５，６の側縁部５ａ，６ａにも異形部５Ｂ，６Ｂを形成することもできるし、この異形部５Ｂ，６Ｂの形態において、半円状は例えば楕円状，その類似形状なども含むものである。
【００５２】
図１２は本発明の第１０の実施例を示すものであって、特に、外囲器１を展開した状態を示しており、基本的な構成は図２〜図３（図１）に示す希ガス放電灯と同じである。異なる点は、第２の開口部８を形成する外部電極５，６の側縁部５ｂ，６ｂに周期性を有する同形状のほぼ台形を含むほぼ矩形状の異形部５Ｃ，６Ｃを互いに対向するように形成したことである。尚、外部電極５，６の側縁部５ａ，６ａにも異形部５Ｃ，６Ｃを形成することもできる。
【００５３】
特に、図９〜図１２に示すそれぞれ異なった異形部を有する外部電極構造は、図１〜図８に示すそれぞれの希ガス放電灯に適宜に組み合わせて適用することができる。
【００５４】
尚、本発明は、何ら上記実施例にのみ制約されることなく、例えば発光層に含まれる蛍光体としては、セリウム・テルビウム付活リン酸ランタン蛍光体（ＬａＰＯ₄：Ｃｅ，Ｔｂ），ユ−ロピウム付活硼酸イットリウム・ガドリウム蛍光体などの他に、錫付活リン酸ストロンチウム・マグネシウム蛍光体（（ＳｒＭｇ）₃（ＰＯ₄）₂：Ｓｎ），ユ−ロピウム付活リンバナジン酸イットリウム蛍光体（Ｙ（ＰＶ）Ｏ₄：Ｅｕ），ユ−ロピウム付活硼リン酸ストロンチウム蛍光体（２ＳｒＯ・（Ｐ₂Ｏ₇・Ｂ₂Ｏ₃）：Ｅｕ）などのリン酸塩蛍光体，硼酸塩蛍光体の他、例えばセリウム・テルビウム付活アルミン酸マグネシウム蛍光体（ＭｇＡｌ₁₁Ｏ₁₉：Ｃｅ，Ｔｂ），セリウム・テルビウム付活イットリウム・シリケ−ト蛍光体（Ｙ₂ＳｉＯ₅：Ｃｅ，Ｔｂ），ユ−ロピウム付活アルミン酸バリウム・マグネシウム蛍光体（ＢａＭｇ₂Ａｌ₁₆Ｏ₂₇：Ｅｕ），ユ−ロピウム付活酸化イットリウム蛍光体（Ｙ₂Ｏ₃：Ｅｕ）なども使用でき、これらの蛍光体は単独ないし複数を混合して使用することもできる。又、外囲器の内面全体に発光層を形成することもできる。又、透光性シ−トの端部の重ね合わせ部分は単に接着の他に、熱溶着したり，超音波溶着したり，接着と溶着を併用したりすることもできるし、透光性シ−ト，保護チュ−ブなどの絶縁部材は省略することもできる。異形部のピッチ，高さなどは希ガス放電灯のサイズに応じて適宜に変更できる。さらには、外囲器の内面全体に発光層を形成してアパ−チャ部を省略することもできる。
【００５５】
【実施例】
次に、第１の実験例について説明する。まず、イエロ−グリ−ンの発光色を有するセリウム・テルビウム付活イットリウム・シリケ−ト蛍光体（Ｙ₂ＳｉＯ₅：Ｃｅ，Ｔｂ）を含む水溶性の蛍光体塗布液を外径が８ｍｍ，肉厚が０．５ｍｍ，長さが３６０ｍｍの鉛ガラスよりなる外囲器の内面に塗布し発光層を形成する。次に、スクレ−パを用いて発光層の一部を強制的に剥がすことによって開口角７５°のアパ−チャ部を形成する。尚、発光層の付着量は１５ｍｇ／ｃｍ²である。次に、外囲器を封止し、内部空間にキセノンガスを７０〜２３０トルの封入圧力で封入する。然る後、この外囲器の外周面にシ−ト構体を図１８〜図２０に示す先行技術と同様の方法にて希ガス放電灯を製造した。尚、一対の外部電極には幅が８ｍｍのアルミニウム箔を用い、第２の開口部を形成する外部電極のそれぞれの側縁部にピッチが４ｍｍで頂点の高さが１．８ｍｍの三角状の異形部を形成し、互いに対向する異形部の先端部における位置ずれ量ΔＰを０％に設定した（図２〜図３参照）。
【００５６】
これらの希ガス放電灯を図２１に示す点灯回路に組み込み、インバ−タ回路１２の出力電圧（定格は周波数が３０ＫＨｚで、電圧が２５００Ｖ_0-P）を徐々に上昇させ、移動縞（チラツキ）が目視されない状態での放電開始電圧（始動電圧）を測定したところ、図１３に示す結果が得られた。
【００５７】
同図から明らかなように、キセノンガスの封入圧力が２００トルまでの範囲では定格電圧の９０％電圧でもチラツキのない状態で点灯し、点灯後も安定した放電状態が得られており、外部電極に異形部を形成しない以外は同仕様の希ガス放電灯（先行技術）に比較すると、始動電圧を３００〜６００Ｖ程度改善できた。又、先行技術では封入圧力が８３トルを超えるとチラツキが認められ、１００トルにもなると実用上支障を生ずるようになる。しかしながら、封入圧力が２００トルを超え、２１０，２３０トルでは２５００Ｖ_0-Pで点灯するものの、電源電圧が低下するような変動が生じた場合には確実な始動が保証できなくなる。
【００５８】
次に、上述の希ガス放電灯を定格電圧の９０％電圧で点灯させた状態において、外囲器から８ｍｍ離隔した原稿照射面の照度及び移動縞（チラツキ）の発生の有無について評価したところ、図１４に示す結果が得られた。尚、同図のチラツキの評価項目において、○はチラツキが発生していないことを、△は若干のチラツキは認められるものの、実用上支障がないことを、×はチラツキの発生が顕著であり、実用上問題になることを示している。
【００５９】
同図から明らかなように、キセノンガスの封入圧力が１５０トルまでの範囲ではチラツキのない安定した放電状態が得られているが、２００トルでは若干のチラツキが認められるものの、実用的には問題ないものである。しかしながら、封入圧力が２００トルを超え、２１０，２３０トルではチラツキの発生が顕著となり、原稿照射装置への適用は読み取り品位の観点から難しい。
【００６０】
又、原稿面照度はキセノンガスの封入圧力が高くなるほど増加しているものの、チラツキのない安定した照度はキセノンガスの封入圧力が２００トルまでの範囲で得られることがわかる。従って、希ガスの封入圧力は、上述の各種評価結果によれば、８３〜２００トルの範囲に設定することが望ましい。
【００６１】
次に、第２の実験例について説明する。第１の実験例（図１３）において、キセノンガスの封入圧力を１２０トルに固定し、外囲器の肉厚を０．１８〜０．８ｍｍの範囲で変化させた希ガス放電灯を製造した。
【００６２】
これらの希ガス放電灯を図２１に示す点灯回路に組み込み、インバ−タ回路１２の出力電圧を定格電圧の９０％電圧に設定し、移動縞（チラツキ）の発生の有無及び生産工程での破損の有無（強度）を観察したところ、図１５に示す結果が得られた。尚、同図において、チラツキの評価項目では、○はチラツキが発生していないことを、△は若干のチラツキは認められるものの、実用上支障がないことを、×はチラツキの発生が顕著であり、実用上問題になることを示している。又、外囲器の強度の評価項目では、○は外囲器の破損がなく十分の強度であることを、△は生産工程で若干の破損事故が発生しているものの、一応実用に供し得ることを、×は強度不足により破損事故が多く実用に供し得ないことを示している。
【００６３】
同図から明らかなように、外囲器の肉厚が０．１８〜０．６ｍｍの範囲では外部電極への印加電圧が低いにも拘らず、チラツキの発生は観測されなかったが、肉厚が０．７ｍｍでは若干のチラツキが認められたものの、実用上は問題ないものである。しかしながら、肉厚が０．８ｍｍではチラツキの発生が顕著となり、異形部によるチラツキ抑制効果の希釈が認められた。又、肉厚が０．４ｍｍ以上では生産工程での破損は認められなかったが、０．４ｍｍ未満の０．２５ｍｍ，０．２ｍｍでは生産工程での破損が認められるようになり、特に、０．１８ｍｍでは機械的強度の低下によってクラックなどの破損事故が急激に増加し、量産に不向きであることがわかる。従って、外囲器の肉厚は、それぞれの評価項目の評価結果に基づいて、０．２〜０．７ｍｍの範囲（好ましくは０．４〜０．７ｍｍの範囲）に設定することが望ましい。
【００６４】
次に、第３の実験例について説明する。第１の実験例において、キセノンガスの封入圧力を１２０トルに固定し、互いに対向する異形部の先端部における位置ずれ量ΔＰ（図２〜図３参照）を異形部ピッチＰの０〜２５％の範囲で変化させた希ガス放電灯を製造した。
【００６５】
これらの希ガス放電灯を図２１に示す点灯回路に組み込み、インバ−タ回路１２の出力電圧（定格は周波数が３０ＫＨｚで、電圧が２５００Ｖ_0-P）を徐々に上昇させ、移動縞（チラツキ）が目視されない状態での放電開始電圧（始動電圧）を測定したところ、図１６に示す結果が得られた。
【００６６】
同図から明らかなように、位置ずれ量ΔＰが０〜１８％までの範囲では定格電圧の８０％程度の２０００Ｖ_0-Pでもチラツキのない状態で点灯しており、位置ずれ量ΔＰが１９〜２０％の範囲でも定格電圧の９０％程度の２２５０Ｖ_0-Pでチラツキのない状態で点灯し、点灯後も安定した放電状態が得られている。しかしながら、位置ずれ量ΔＰが２１％以上では始動電圧が２４００Ｖ_0-P以上となり、ライン電圧の９０％でのチラツキのない安定した始動特性が保証できなくなる。従って、対向する異形部の位置ずれ量ΔＰは異形部ピッチＰの２０％以下に設定しなければならない。
【００６７】
【発明の効果】
以上のように本発明によれば、第１の開口部及び／又は第２の開口部を形成する外部電極の側縁部には周期性を有する異形部が互いに対向するように形成されており、その上、互いに対向する異形部の位置ずれ量が異形部ピッチの２０％以下に設定されているために、外部電極に高周波高電圧を印加した場合、異形部の先端部分に電界が集中し、異形部間で容易に放電するようになる。従って、例えば１０％以内の電源変動によって外部電極への印加電圧が低くなっても、チラツキのない状態で確実に点灯させることができる。このために、この希ガス放電灯をＯＡ機器の原稿照射装置に適用した場合、原稿の読み取り精度，再生品位の向上が期待できる。
【００６８】
特に、外囲器の肉厚を０．２〜０．７ｍｍの範囲に、希ガスの封入圧力を８３〜２００トルの範囲に設定すれば、上述の外部電極構造と相俟って移動縞（チラツキ）の発生を効果的に抑制できるのみならず、第１の開口部から放出される光出力をも改善できる。従って、原稿照射装置に適用した場合には安定した放電状態が得られる上に、原稿面照度を高めることができ、読み取り精度の向上が期待できる。
【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に示す外囲器及び外部電極の展開図。
【図３】図１に示す外部電極の異形部の位置ずれ状態を説明する要部拡大図。
【図４】本発明の第２の実施例を示す縦断面図。
【図５】本発明の第３の実施例を示す縦断面図。
【図６】本発明の第４の実施例を示す縦断面図。
【図７】本発明の第５の実施例を示す縦断面図。
【図８】本発明の第６の実施例を示す縦断面図。
【図９】本発明の第７の実施例を示す外囲器及び外部電極の展開図。
【図１０】本発明の第８の実施例を示す外部電極の要部拡大図であって、同図（ａ）は異形部の先端部分に丸味を形成した状態を示す図、同図（ｂ）は異形部の先端部分を切除して台形部を形成した状態を示す図。
【図１１】本発明の第９の実施例を示す外囲器及び外部電極の展開図。
【図１２】本発明の第９の実施例を示す外囲器及び外部電極の展開図。
【図１３】キセノンガスの封入圧力に対する始動特性の関係を示す図。
【図１４】キセノンガスの封入圧力に対するチラツキの発生の有無及び原稿面照度の関係を示す図。
【図１５】外囲器の肉厚に対するチラツキの発生の有無及び強度の関係を示す図。
【図１６】対向する異形部の位置ずれ量に対する始動特性の関係を示す図。
【図１７】先行技術にかかる希ガス放電灯の縦断面図。
【図１８】先行技術にかかるシ−ト構体の展開図。
【図１９】図１８のＸ−Ｘ断面図。
【図２０】先行技術にかかる希ガス放電灯の製造方法を説明するための縦断面図。
【図２１】先行技術にかかる希ガス放電灯の点灯回路図。
【符号の説明】
１外囲器
２発光層
２ａアパ−チャ部
３シ−ト構体
４，４Ａ透光性シ−ト（絶縁部材）
４ａ，４ｂ端部
５，６外部電極
５ａ，５ｂ，６ａ，６ｂ側縁部
５Ａ，５Ｂ，５Ｃ異形部
５Ａａ，５Ｂａ，５Ｃａ，６Ａａ，６Ｂａ，６Ｃａ先端部
７第１の開口部
８第２の開口部
９接着層
１２インバ−タ回路
１３保護チュ−ブ（絶縁部材）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rare gas discharge lamp, and in particular, in a rare gas discharge lamp having a light emitting layer having an aperture on the inner surface of a glass bulb and a pair of strip-shaped external electrodes on the outer peripheral surface, The present invention relates to improvement of the structure of the obtained external electrode.
[0002]
[Prior art]
The present applicant has previously proposed the rare gas discharge lamp shown in FIGS. In the figure, reference numeral 1 denotes a straight tube envelope that is hermetically sealed with, for example, a glass bulb, and has one or more kinds of fluorescent light such as a rare earth phosphor and a halophosphate phosphor on the inner surface thereof. A light emitting layer 2 including a body is formed. In particular, the light emitting layer 2 is formed with an aperture 2a having a predetermined opening angle over almost the entire length. The sealing structure of the envelope 1 is formed by sealing a disc-shaped sealing glass plate at the end of the glass bulb. For example, the glass bulb is simply heated while the glass bulb is heated and melted. It can also be configured. In addition, a rare gas such as xenon (Xe), krypton (Kr), neon (Ne), helium (He), which does not contain a metal vapor such as mercury, is contained in the sealed space of the envelope 1 singly or mixedly. Although a predetermined amount is enclosed, it is desirable to enclose a rare gas mainly containing xenon.
[0003]
The 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, an insulating translucent sheet 4 having a length substantially equal to the entire length of the envelope 1 and a thickness set in a range of 20 to 100 μm. A pair of translucent metal electrodes 5 and 6 made of a translucent metal member adhered to one surface of the translucent sheet 4 with a predetermined distance from each other, and the external electrode 5 , 6 and terminals 51, 61 which have an electrical connection relationship therewith and are led out such that the lead-out end protrudes from the edge portion of the translucent sheet 4; -It is comprised from the adhesion layer 9 which has the adhesion | attachment thru | or adhesion | attachment function provided to one side of G4.
[0004]
In particular, in the sheet structure 3, a polyethylene terephthalate (PET) resin is suitable as the translucent sheet 4, but other resins such as a polyester resin can also be used. As the external electrodes 5 and 6, a strip-shaped aluminum foil is suitable. However, other metal members such as nickel can be used as long as they are excellent in electrical conductivity and opaque. Although the strips of copper are suitable for the terminals 51 and 61, other metal members such as silver, stainless steel, and Cu—Ni alloy can also be used. The terminals 51 and 61 are made of the same member as the external electrodes 5 and 6 and can extend outward from the end portions thereof. Furthermore, a silicone-based adhesive is suitable as the adhesive layer 9, but other adhesives such as an acrylic adhesive can also be used.
[0005]
The above-described sheet structure 3 is mounted on the outer peripheral surface of the envelope 1 so that the external electrodes 5 and 6 are positioned between the envelope 1 and the translucent sheet 4. In the second opening (8), the other end 4b is superposed on one end 4a of the translucent sheet 4 and bonded. In particular, when the seat structure 3 is attached to the envelope 1, the first opening 7 is provided between one side edge of the external electrodes 5, 6 and the other side edge of the external electrodes 5, 6. A second opening 8 is formed between the portions, and the emitted light from the light emitting layer 2 is emitted to the outside mainly from the first opening 7 via the aperture 2a.
[0006]
This rare gas discharge lamp is manufactured as follows, for example. First, for example, a phosphor coating solution containing a phosphor having an emission spectrum in each of a blue region, a green region, and a red region is applied to the inner surface of the envelope 1 made of a glass bulb, dried, and baked to form the light emitting layer 2. It is formed. Next, for example, by using a scraper (not shown), a part of the light emitting layer 2 is forcibly peeled and removed with a predetermined opening angle to form the aperture portion 2a. Next, the envelope 1 is configured to be hermetically sealed, and a predetermined amount of a rare gas such as xenon is sealed in the internal space.
[0007]
Next, as shown in FIGS. 18 to 19, a pair of external electrodes 5, 6 are arranged on a predetermined portion of the translucent sheet 4 so as to be spaced apart from each other, and terminals are connected from the ends of the external electrodes 5, 6. 51 and 61 are led out, and an adhesive layer 9 is formed on the translucent sheet 4 and the external electrodes 5 and 6 to constitute the sheet structure 3. Next, as shown in FIG. 20, the sheet structure 3 is placed on the assembly stage 10 in a developed state. Subsequently, the envelope 1 is placed on 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 as to be parallel). Position). In this state, the driven rollers 11 and 11 are arranged so that the envelope 1 slightly presses against the translucent sheet 4. In this state, the stage 10 is slightly moved in the M direction and then moved in the N direction. As a result, as shown in FIG. 17, the sheet structure 3 is wound around the outer peripheral surface of the envelope 1, and the other end 4b is overlapped with the one end 4a of the translucent sheet 4 so as to adhere. Bonded by layer 9 completes the noble gas discharge lamp.
[0008]
In this rare gas discharge lamp, discharge is generated by applying a high frequency high voltage to the external electrodes 5 and 6 via terminals 51 and 61, and the light emitting layer 2 is excited by the rare gas excitation line to emit light. The light emitted from the light emitting layer 2 is densified in the envelope and emitted to the outside from the aperture 2a through the first opening 7. In particular, since no mercury is used in this rare gas discharge lamp, the amount of light rising after lighting is steep, and the amount of light reaches nearly 100% simultaneously with lighting. For this reason, it is suitable as a light source for reading a document in office automation equipment such as a facsimile, an image scanner, and a copying machine. Reading accuracy can be improved.
[0009]
Further, if the above-described method is adopted for the assembly of the rare gas discharge lamp, the adhesive layer 9 is formed on one surface of the translucent sheet 4, so that the envelope 1 is sealed. Since the sheet structure 3 can be wound and adhered to the outer peripheral surface of the envelope 1 by a simple operation by rolling on the structure 3, not only the work efficiency can be remarkably improved but also mechanization can be achieved. Therefore, it is possible to expect an excellent effect such as increasing mass productivity.
[0010]
[Problems to be solved by the invention]
By the way, the rare gas discharge lamp is turned on by an inverter circuit 12 that outputs a high frequency high voltage as shown in FIG. 21, for example. For example, the frequency is 30 KHz and the voltage is 2500 V from the inverter circuit 12 via the terminals 51 and 61 to the external electrodes 5 and 6 of the rare gas discharge lamp. _OP It is lit when a high frequency high voltage of a certain level is applied. For example, in a rare gas discharge lamp having an outer diameter of the envelope 1 of 8 mm and a total length of about 360 mm, the voltage applied to the external electrodes 5 and 6 is approximately 2500V. _OP Is the rated voltage.
[0011]
Unlike a discharge lamp using a hot cathode or a cold cathode, this rare gas discharge lamp is lit by a single discharge path along the longitudinal direction of the envelope, and between the external electrodes 5 and 6 (outside The myriad discharge paths are formed in a direction substantially perpendicular to the longitudinal direction of the envelope 1 to light up in a striped state. In a normal lighting state, the striped discharge state can be visually observed. Can not.
[0012]
However, if the output voltage of the inverter circuit 12 is reduced by, for example, about 10% due to voltage fluctuation of the power supply line, etc., not only the striped discharge state can be seen but also the discharge position (discharge point). The light emitted from the aperture portion 2a is flickered by constantly moving in the longitudinal direction of the envelope without being stabilized.
[0013]
In particular, when this rare gas discharge lamp is applied to a document irradiating apparatus such as a facsimile or an image scanner, the luminance of each position in the longitudinal direction of the aperture portion 2a constantly fluctuates, thereby reading a document. There may be a problem that accuracy is remarkably impaired and reproduction quality is lowered.
[0014]
SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a rare gas discharge lamp that can obtain a stable discharge state with reduced flicker and can improve light output with a relatively simple structure.
[0015]
[Means for Solving the Problems]
Therefore, in order to achieve the above-mentioned object, the present invention has an envelope having a light emitting layer on the inner surface, and first and second openings on the outer peripheral surface of the envelope over almost the entire length thereof. A pair of strip-shaped external electrodes made of metal members that are spaced apart from each other so as to be formed, on the side edges of the external electrodes forming the first opening and / or the second opening The same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform is repeatedly formed. The deformed parts are formed so as to face each other, and the deformed parts facing each other , In the direction that the same shape is repeatedly formed The positional deviation amount is set to 20% or less of the deformed portion pitch.
[0016]
According to the second aspect of the present invention, an envelope having a light emitting layer on the inner surface, and first and second openings are formed on the outer peripheral surface of the envelope over almost the entire length thereof. A pair of strip-shaped external electrodes made of metal members spaced apart from each other on the side edges of the pair of external electrodes forming the second opening The same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform is repeatedly formed. The deformed parts are formed so as to face each other, and the deformed parts facing each other , In the direction that the same shape is repeatedly formed The misregistration amount is set to 20% or less of the deformed portion pitch, and the third invention is configured to emit the radiated light from the light emitting layer to the outside mainly from the first opening. The side edges of each of the pair of external electrodes forming the first opening are formed in a straight shape.
[0017]
According to a fourth aspect of the present invention, an envelope having a light emitting layer on the inner surface, and first and second openings are formed on the outer peripheral surface of the envelope over almost the entire length thereof. A pair of strip-shaped external electrodes made of metal members that are spaced apart from each other, and an insulating member mounted so as to cover the external electrodes,
At the side edges of the pair of external electrodes that form the second opening The same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform is repeatedly formed. While forming the deformed parts to face each other,
Of the deformed parts facing each other , In the direction that the same shape is repeatedly formed The misalignment amount is set to 20% or less of the deformed portion pitch, and the fifth invention comprises the protective member made of a translucent sheet or a heat-shrinkable resin. It is characterized by that.
[0018]
According to a sixth aspect of the present invention, there is provided a straight tubular envelope having a light emitting layer on the inner surface and a translucent sheet having a length substantially the same as the entire length of the envelope. A pair of strip-shaped external electrodes made of a metal member are arranged apart from each other so that the first and second openings are formed, and are adhered to the translucent sheet surface on the side where the external electrodes are located. A sheet structure formed with a layer, on the side edges of a pair of external electrodes forming the second opening The same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform is repeatedly formed. The deformed parts are formed so as to face each other, and the deformed parts facing each other In the direction where the same shape is repeatedly formed The amount of positional deviation is set to 20% or less of the deformed portion pitch, and the sheet structure is arranged on the outer peripheral surface of the envelope so that the external electrode is positioned between the envelope and the translucent sheet. It is characterized by being wound and adhered.
[0019]
Further, the seventh invention of the present invention is characterized in that the deformed portion is formed over substantially the entire length so as to have periodicity, and the eighth invention is characterized in that the deformed portion is triangular, trapezoidal. In the ninth aspect, the light emitting layer is formed on the inner surface portion of the envelope substantially corresponding to the first opening. The tenth invention is characterized in that a rare gas is sealed in the envelope in a pressure range of 83 to 200 torr, and the eleventh invention is further provided. Is characterized in that the thickness of the envelope is set in the range of 0.2 to 0.7 mm.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, a first embodiment of a rare gas discharge lamp according to the present invention will be described with reference to FIGS. The same reference numerals are given to the same parts as those of the prior art shown in FIGS. 17 to 21, and the detailed description thereof will be omitted. In this figure, the characteristic part of this embodiment is that the triangular deformed portions 5A and 6A having substantially the same shape are opposed to the side edges 5b and 6b of the external electrodes 5 and 6 that form the second opening 8. The positional deviation amount ΔP of the deformed portions 5A and 6A facing each other is set to 20% or less of the deformed portion pitch P, and the external electrodes 5 and 6 forming the first opening 7 That is, the side edges 5a and 6a are formed in a straight shape.
[0021]
The deformed portions 5A and 6A are formed so as to have a periodicity over substantially the entire length of the side edges 5b and 6b of the external electrodes 5 and 6, and the tip portions (apex of triangular portions) 5Aa, The deformed portion pitch P between 5Aa and the deformed portion pitch P between the front end portions (apex of triangular portions) 6Aa and 6Aa of the deformed portion 6A are set to be substantially equal. The positional deviation amount ΔP between the deformed portions 5A and 6A facing each other is set to 20% or less of the deformed portion pitch P. However, if the positional deviation amount ΔP exceeds 20% of the deformed portion pitch P, if the voltage of the power supply line decreases by 10% or more of the rated voltage, the starting characteristics are impaired, and a striped discharge state is generated even if the lamp is lit. As a result, the light emitted from the aperture portion 2a is flickered. Therefore, since this type of OA equipment is normally required to operate normally when the fluctuation of the line voltage is within 10% of the rated voltage, the positional deviation amount ΔP must be set within the above range. .
[0022]
In addition, the facing interval between the tip portions 5Aa and 6Aa of the deformed portions 5A and 6A facing each other is set to be substantially the same over substantially the entire length. For example, when the outer diameter of the envelope 1 is 8 mm, the deformed portion 5A (6A) has a width including the deformed portion 5A (6A) of 8 mm, and the deformed portion 5A (6A) has a pitch of 4 mm. Although it is desirable to set the height to the apex 5Aa (6Aa) of the triangular portion of the portion 5A (6A) to a dimension of about 1.8 mm, it can be changed as appropriate depending on the specifications of the rare gas discharge lamp and the lighting device. In addition, the opening width (interval) of the 1st opening part 7 is set so that it may become substantially the same over the full length.
[0023]
As a constituent member of the envelope 1 described above, any material can be used as long as it is a material having a large dielectric constant, a reliable airtightness, and a light-transmitting property. Lead glass having a high dielectric constant is suitable. The thickness of this is set in the range of 0.2 to 0.7 mm (preferably in the range of 0.4 to 0.7 mm). In this range, desired productivity and optical characteristics can be obtained. However, when the wall thickness is less than 0.4 mm, particularly less than 0.2 mm, the mechanical strength of the envelope 1 is extremely reduced, and the defect rate associated with glass breakage in the production process by the mass production equipment increases. On the contrary, when the thickness exceeds 0.7 mm, the striped discharge state is visually observed, and flickering may occur in the light emitted from the aperture portion 2a. Therefore, it is desirable to set the thickness of the envelope 1 within the above range.
[0024]
In addition, a rare gas such as xenon (Xe), krypton (Kr), neon (Ne), helium (He) is mixed in the inner space of the envelope 1 in a mixture of one or more. The sealing pressure is set, for example, in the range of 83 to 200 Torr. In this range, improvement effects regarding start characteristics, light output (document surface illumination), and flicker can be obtained. However, when the sealing pressure is less than 83 Torr, the improvement effect on the light output becomes insufficient. Conversely, when the sealing pressure exceeds 200 Torr, not only the starting characteristics are impaired, but also the striped discharge state is The light that is visually observed and emitted from the aperture portion 2a flickers. Therefore, it is desirable to set the rare gas filling pressure within the above range unless there is a special reason.
[0025]
Moreover, the light emitting layer 2 is comprised only by 1 type of fluorescent substance used according to the use of a rare gas discharge lamp, or is comprised by mixing 2 or more types. For example, in the case of a three-wavelength emission type, for example, a europium activated barium magnesium aluminate phosphor having an emission spectrum in the blue region, a cerium terbium activated lanthanum phosphate phosphor having an emission spectrum in the green region, It is formed of a mixed phosphor formed by mixing a europium-activated yttrium borate / gadolinium phosphor having an emission spectrum in the red region, and its adhesion amount is 1 cm. ² The range is set to 5 to 30 mg per unit. In this range, a sufficient amount of light (light output) can be obtained, but if the amount of adhesion is less than 5 mg, the illuminance on the original surface becomes insufficient due to insufficient amount of light, and conversely, if the amount of adhesion exceeds 30 mg, it is homogeneous. Formation of the light emitting layer becomes difficult. Therefore, it is desirable to set the amount of the light emitting layer 2 to be within the above range.
[0026]
Further, first and second openings 7 and 8 are formed between the side edges of the external electrodes 5 and 6, respectively. ₁ , Θ ₂ Is θ ₁ > Θ ₂ The relationship is set. Opening angle θ of first opening 7 ₁ Is in the range of 60 to 90 °, the opening angle θ of the second opening 8 ₂ Is preferably about 55 °. However, the opening angle θ of the first opening 7 ₁ Depending on the application, it may be set outside the above range, and it is desirable that the second opening 8 is narrow enough not to cause dielectric breakdown. For example, it is recommended to secure a separation distance of at least about 2 mm. Note that the opening angle of the aperture 2a is the opening angle θ of the first opening 7. ₁ Is set to about the same level.
[0027]
According to this embodiment, the side edge portions 5b and 6b of the external electrodes 5 and 6 forming the second opening 8 have the triangular deformed portions 5A and 6A having periodicity, and the respective front end portions 5Aa. , 6Aa are formed so as to face each other, and the positional deviation amount ΔP of the deformed portions 5A, 6A facing each other is set to 20% or less of the deformed portion pitch P. When a high frequency high voltage is applied to 6, the electric field concentrates on the tip portions 5Aa and 6Aa of the deformed portions 5A and 6A, and discharge is easily performed between the deformed portions 5A and 6A. Therefore, for example, even if the voltage applied to the external electrodes 5 and 6 is lowered due to power supply fluctuation within 10%, it can be surely turned on without flickering. For this reason, when this rare gas discharge lamp is applied to the above-described original irradiating apparatus for OA equipment, it is expected to improve the reading accuracy and reproduction quality of the original.
[0028]
Moreover, the thickness of the envelope 1 is set in the range of 0.2 to 0.7 mm. When a high frequency high voltage is applied to the external electrodes 5 and 6, the resistance component increases in the thick range. Although flickering is likely to occur in association with the increase in voltage distribution to the envelope itself, the deformed portions 5A and 6A are opposed to the side edges 5b and 6b of the external electrodes 5 and 6 as described above. And the occurrence of flickering can be effectively suppressed even in a thick region in combination with the fact that the positional deviation amount ΔP of the deformed portion 5A, 6A is set to 20% or less of the deformed portion pitch P. In addition, the light output emitted from the first opening 7 via the aperture 2a can be effectively improved.
[0029]
In addition, the side edges 5b and 6b of the external electrodes 5 and 6 that form the second opening 8 are provided with the first opening 7 although triangular shaped parts 5A and 6A are formed. Since the side edges 5a and 6a of the external electrodes 5 and 6 are formed in a straight shape that does not affect light emission, for example, when applied to a document irradiating device, the illuminance distribution on the document surface is made uniform. Becomes easier. Accordingly, it is possible to increase the reading accuracy of the document with a simple configuration.
[0030]
In particular, when the noble gas sealing pressure is increased, the light output increases, but the starting characteristics are impaired. However, the triangular shaped portions 5A and 6A are provided on the side edges 5b and 6b of the external electrodes 5 and 6, respectively. Even if the upper limit of the rare gas filling pressure is increased to 200 torr by setting the position deviation amount ΔP of the deformed portions 5A and 6A to be 20% or less of the deformed portion pitch P, they are formed so as to face each other. Thus, it is possible to secure start-up characteristics that can be put to practical use, to effectively suppress the occurrence of moving stripes (flicker), and to effectively improve the light output. Therefore, when applied to a document irradiation apparatus, a stable discharge state can be obtained and the illuminance on the document surface can be increased, so that improvement in reading quality can be expected.
[0031]
Moreover, the adhesion amount of the light emitting layer 2 is 1 cm. ² If it is set in the range of 5 to 30 mg per unit, the thickness of the envelope 1 is set in the range of 0.2 to 0.7 mm and the enclosure pressure of the rare gas is set in the range of 83 to 200 torr. As a result, the light output emitted from the first opening 7 via the aperture 2a can be effectively increased.
[0032]
In particular, the amount of the light-emitting layer 2 attached is set to about 2 to 10 times that of a normal illumination fluorescent lamp, and is an amount that is considered to be characteristically unpreferable in a normal illumination fluorescent lamp. Nevertheless, the light output is effectively increased in rare gas discharge lamps. Although the cause of this is not clear, a rare light that is lit in a striped state is formed by forming innumerable discharge paths between the external electrodes 5 and 6 (substantially perpendicular to the longitudinal direction of the envelope 1). This phenomenon is thought to be unique to gas discharge lamps.
[0033]
Further, the thickness of the envelope 1 and the structure of the external electrode are preferably set in the above-mentioned range with the light emitting layer 2 deposition amount and the noble gas sealing pressure being set within the above-mentioned range. Angle θ ₁ Is set in the range of 60 to 90 °, the light output emitted from the first opening 7 can be further increased. At this time, if the separation length of the second opening 8 (the interval between the tip portions 5Aa and 6Aa of the deformed portions 5A and 6A) is set to about 2 mm, light leakage from the second opening 8 is prevented. A further improvement effect of the light output that is suppressed and emitted from the first opening 7 can be expected.
[0034]
FIG. 4 shows a second 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 the opening angle θ of the aperture 2a formed on the inner surface of the envelope 1 corresponding to the first opening 7 is different. _Three Is the opening angle θ of the first opening 7. ₁ This is a larger setting. Opening angle θ of the aperture 2a _Three Is set in the range of 70 to 110 degrees, for example, but can be changed as appropriate according to the application and purpose. The opening angle θ of the first opening 7 ₁ And the opening angle θ of the second opening 8 ₂ Is θ ₁ > Θ ₂ It is desirable to set to.
[0035]
According to this embodiment, when the sheet structure 3 is wound around the outer peripheral surface of the envelope 1, even if the center of the first opening 7 and the aperture 2a is slightly shifted, the first The shift of the optical axis of the light emitted from one opening 7 can be alleviated. For this reason, even when applied to, for example, a document irradiation apparatus, sufficiently high reading accuracy can be obtained.
[0036]
FIG. 5 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 the end portions 4a and 4b of the translucent sheet 4 are superposed on the external electrode 5, and the superposed portion is ultrasonically welded.
[0037]
According to this embodiment, since the ultrasonic welding of the overlapping portions 4a and 4b is performed on the outer surface of the external electrode 5, the ultrasonic vibration acting on the light emitting layer 2 on the inner surface of the envelope is reduced. Therefore, as compared with the first and second embodiments, even if the center of the opening 7 on the inner surface of the envelope of the light emitting layer 2 and the aperture 2a is slightly shifted, the light is emitted from the first opening 7. The shift of the optical axis of the emitted light can be alleviated. For this reason, even when applied to, for example, a document irradiation apparatus, sufficiently high reading accuracy can be obtained.
[0038]
FIG. 5 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 the end portions 4a and 4b of the translucent sheet 4 are superposed on the external electrode 5, and the superposed portion is ultrasonically welded.
[0039]
According to this embodiment, since the ultrasonic welding of the overlapping portions 4a and 4b is performed on the outer surface of the external electrode 5, the ultrasonic vibration acting on the light emitting layer 2 on the inner surface of the envelope is reduced. Therefore, as compared with the first and second embodiments, peeling of the light emitting layer 2 from the inner surface of the envelope can be suppressed, and the light output can be improved.
[0040]
FIG. 6 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 pair of external electrodes 5 and 6 are formed on the outer peripheral surface of the envelope 1 so that the side edge portions 5b and 6b have triangular deformed portions 5A and 6A facing each other by using an adhesive layer. After sticking, the translucent sheet | seat 4A, such as PET resin, was wound around the outer peripheral surface of the envelope 1 so that the external electrodes 5 and 6 were covered and adhered.
[0041]
According to this embodiment, prior to winding the translucent sheet 4A around the outer peripheral surface of the envelope 1, a translucent insulating film such as a silicon varnish is applied to the outer peripheral surface of the envelope 1. If formed, the dielectric strength between the external electrodes can be improved.
[0042]
FIG. 7 shows a fifth 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 pair of external electrodes 5 and 6 are formed on the outer peripheral surface of the envelope 1 so that the side edge portions 5b and 6b have triangular deformed portions 5A and 6A facing each other by using an adhesive layer. After sticking, the outer tube 5 was covered with a protective tube 13 made of a heat-shrinkable resin such as PET resin so that the external electrodes 5 and 6 were covered, and heat-shrinked. is there. After the protective tube 13 is mounted on the envelope 1, it is brought into close contact with the outer peripheral surface of the envelope 1 by heating to, for example, about 150 to 200 ° C. and contracting.
[0043]
According to this embodiment, compared with the above-mentioned embodiments, although it is inferior in mechanization and work efficiency, in order not to use an adhesive layer for the protective tube 13, for example, a terminal component and an adhesive component In addition to being able to maintain a stable operating state over a long period of time without corrosion due to the reaction of the above, the protective tube 13 has no seam, so that the end portion of the light-transmitting sheet 4 as in the above-described embodiment Can be completely prevented from peeling off.
[0044]
In particular, prior to mounting the protective tube 13 on the outer peripheral surface of the envelope 1, if a translucent insulating film such as silicon varnish is formed on the outer peripheral surface of the envelope 1, the external electrode The dielectric strength between them can be further increased.
[0045]
FIG. 8 shows a sixth 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 after the protective tube 13 made of a heat-shrinkable resin such as PET resin is mounted on the outer peripheral surface of the sheet structure 3, the sheet is heat-shrinked. The protective tube 13 is attached to the outer surface of the translucent sheet 4 after being attached to the sheet structure 3 and then heated to, for example, about 150 to 200 ° C. and contracted.
[0046]
According to this embodiment, when the environmental conditions at the application site of the rare gas discharge lamp are severe, the safety standard is high, etc., for example, the protective tube 13 is excellent in heat resistance and has translucency. By coating the sheet structure 3, the product of higher quality can be provided.
[0047]
In particular, the structure of this embodiment can be applied to the embodiments shown in FIGS. 4, 5, 6 and 7.
[0048]
FIG. 9 shows a seventh embodiment of the present invention. In particular, FIG. 9 shows a state in which the envelope 1 is developed, and the basic configuration is the rare gas discharge lamp shown in FIGS. The same. A different point is that triangular side-shaped portions 5A and 6A having periodicity are formed so as to face each other also on the side edges 5a and 6a of the external electrodes 5 and 6 forming the first opening 7. .
[0049]
FIG. 10 shows an eighth embodiment of the present invention and shows a state in which the tip shape of the deformed portion 5A (6A) in the external electrode 5 (6) is different. The tip 5Aa (6Aa) shown in FIG. 5A is rounded, and the tip 5Aa (6Aa) shown in FIG. The basic configuration is the same as that of the rare gas discharge lamp shown in FIGS.
[0050]
According to this embodiment, for example, when the external electrodes 5 and 6 are punched out of a long conductive sheet by a press or the like, fine portions such as the tip portions 5Aa and 6Aa of the deformed portions 5A and 6A are obtained as desired. Therefore, stable discharge can be ensured.
[0051]
FIG. 11 shows a ninth embodiment of the present invention. In particular, FIG. 11 shows a state in which the envelope 1 is developed. The basic configuration is a rare configuration shown in FIGS. 2 to 3 (FIG. 1). Same as gas discharge lamp. The difference is that the side edges 5b and 6b of the external electrodes 5 and 6 forming the second opening 8 have the same semi-circular deformed parts 5B and 6B having the same shape facing each other. It is formed. The deformed portions 5B and 6B can also be formed on the side edges 5a and 6a of the external electrodes 5 and 6, and in the form of the deformed portions 5B and 6B, the semicircular shape is, for example, an ellipse, or a similar shape thereof. And so on.
[0052]
FIG. 12 shows a tenth embodiment of the present invention. In particular, FIG. 12 shows a state in which the envelope 1 is developed, and the basic configuration is a rare configuration shown in FIGS. Same as gas discharge lamp. The difference is that the substantially rectangular deformed portions 5C and 6C including the substantially trapezoidal shape of the same shape having periodicity are opposed to the side edges 5b and 6b of the external electrodes 5 and 6 that form the second opening 8. That is how it was formed. The deformed portions 5C and 6C can also be formed on the side edges 5a and 6a of the external electrodes 5 and 6.
[0053]
In particular, the external electrode structures having different shapes shown in FIGS. 9 to 12 can be applied in appropriate combinations to the respective rare gas discharge lamps shown in FIGS.
[0054]
The present invention is not limited to the above-described embodiments. For example, phosphors contained in the light emitting layer include cerium / terbium activated lanthanum phosphate phosphors (LaPO). _Four : Ce, Tb), europium-activated yttrium borate and gadolinium phosphor, etc., and tin-activated strontium magnesium phosphate phosphor ((SrMg)) _Three (PO _Four ) ₂ : Sn), europium-activated yttrium phosphovanadate phosphor (Y (PV) O) _Four : Eu), europium-activated strontium borophosphate phosphor (2SrO. (P ₂ O ₇ ・ B ₂ O _Three ): Eu) and other phosphate phosphors and borate phosphors, for example, cerium terbium activated magnesium aluminate phosphor (MgAl) ₁₁ O ₁₉ : Ce, Tb), cerium terbium activated yttrium silicate phosphor (Y ₂ SiO _Five : Ce, Tb), europium activated barium magnesium aluminate phosphor (BaMg) ₂ Al ₁₆ O ₂₇ : Eu), europium activated yttrium oxide phosphor (Y ₂ O _Three : Eu) or the like can be used, and these phosphors can be used alone or in combination. In addition, a light emitting layer can be formed on the entire inner surface of the envelope. In addition, the overlapping portion of the end portions of the light-transmitting sheet can be heat-welded, ultrasonically welded, or a combination of bonding and welding in addition to simply bonding. -Insulating members such as totes and protective tubes may be omitted. The pitch, height, and the like of the deformed portion can be appropriately changed according to the size of the rare gas discharge lamp. Furthermore, the light emitting layer may be formed on the entire inner surface of the envelope, and the aperture portion may be omitted.
[0055]
【Example】
Next, a first experimental example will be described. First, a cerium terbium activated yttrium silicate phosphor having a yellow green emission color (Y ₂ SiO _Five : A water-soluble phosphor coating solution containing Ce, Tb) is applied to the inner surface of an envelope made of lead glass having an outer diameter of 8 mm, a thickness of 0.5 mm, and a length of 360 mm to form a light emitting layer. Next, an aperture portion with an opening angle of 75 ° is formed by forcibly peeling off a part of the light emitting layer using a scraper. In addition, the adhesion amount of the light emitting layer is 15 mg / cm. ² It is. Next, the envelope is sealed, and xenon gas is sealed in the internal space at a sealing pressure of 70 to 230 Torr. Thereafter, a rare gas discharge lamp was manufactured by the same method as the prior art shown in FIGS. 18 to 20 with the sheet structure on the outer peripheral surface of the envelope. The pair of external electrodes is made of aluminum foil having a width of 8 mm, and each side edge of the external electrode forming the second opening has a triangular shape with a pitch of 4 mm and a vertex height of 1.8 mm. A deformed portion was formed, and the positional deviation amount ΔP at the tip portion of the deformed portions facing each other was set to 0% (see FIGS. 2 to 3).
[0056]
These rare gas discharge lamps are incorporated in the lighting circuit shown in FIG. 21, and the output voltage of the inverter circuit 12 (the rating is a frequency of 30 KHz and the voltage is 2500 V). _0-P ) Was gradually increased, and the discharge start voltage (starting voltage) was measured in a state where no moving stripes (flickering) were visually observed. The result shown in FIG. 13 was obtained.
[0057]
As can be seen from the figure, when the xenon gas filling pressure is up to 200 torr, the lamp is lit without flickering even at 90% of the rated voltage, and a stable discharge state is obtained even after lighting. Compared with the rare gas discharge lamp (prior art) of the same specification except that no deformed portion is formed, the starting voltage can be improved by about 300 to 600V. Further, in the prior art, flickering is recognized when the sealing pressure exceeds 83 torr, and when it reaches 100 torr, practical problems will occur. However, the enclosed pressure exceeds 200 Torr, 2500V at 210,230 Torr _0-P However, if a fluctuation occurs that causes the power supply voltage to drop, reliable starting cannot be guaranteed.
[0058]
Next, when the above rare gas discharge lamp was turned on at a voltage of 90% of the rated voltage, the illuminance of the document irradiation surface separated by 8 mm from the envelope and the presence or absence of movement fringes (flicker) were evaluated. The result shown in FIG. 14 was obtained. In addition, in the evaluation item of flickering in the figure, ◯ indicates that no flickering occurred, △ indicates that although some flickering is observed, there is no practical problem, × indicates that flickering is remarkable, It shows that it becomes a problem in practical use.
[0059]
As is clear from the figure, a stable discharge state with no flicker is obtained when the sealed pressure of the xenon gas is up to 150 torr, but a slight flicker is observed at 200 torr, but there is a problem in practical use. There is nothing. However, when the sealing pressure exceeds 200 torr, and 210 and 230 torr, flickering becomes prominent, and application to the document irradiation apparatus is difficult from the viewpoint of reading quality.
[0060]
Further, although the illuminance on the original surface increases as the sealing pressure of xenon gas increases, it can be seen that a stable illuminance without flickering can be obtained when the sealing pressure of xenon gas is up to 200 torr. Therefore, it is desirable that the rare gas sealing pressure is set in the range of 83 to 200 Torr according to the above-described various evaluation results.
[0061]
Next, a second experimental example will be described. In the first experimental example (FIG. 13), a rare gas discharge lamp was manufactured in which the sealed pressure of xenon gas was fixed at 120 torr and the thickness of the envelope was changed in the range of 0.18 to 0.8 mm. .
[0062]
These rare gas discharge lamps are incorporated into the lighting circuit shown in FIG. 21, the output voltage of the inverter circuit 12 is set to 90% of the rated voltage, and the presence or absence of movement fringes (flickering) and breakage in the production process. When the presence or absence (strength) was observed, the results shown in FIG. 15 were obtained. In the same figure, in the evaluation item of flicker, ○ indicates that no flicker has occurred, △ indicates that there is slight flicker, but there is no practical problem, and × indicates that flicker is prominent. It shows that it becomes a problem in practical use. In addition, in the evaluation items of the strength of the envelope, ○ indicates that the envelope is not damaged and is sufficiently strong, and Δ indicates that although there is a slight damage accident in the production process, it can be put to practical use. That is, x indicates that there are many breakage accidents due to insufficient strength and cannot be put to practical use.
[0063]
As is clear from the figure, no flickering was observed in the range where the envelope thickness was 0.18 to 0.6 mm although the applied voltage to the external electrode was low. Although a slight flicker was observed at 0.7 mm, there was no problem in practical use. However, when the wall thickness was 0.8 mm, flickering was prominent and dilution of the flicker-suppressing effect due to the deformed portion was observed. In addition, when the wall thickness is 0.4 mm or more, no damage was observed in the production process. However, when the thickness is less than 0.4 mm, 0.25 mm and 0.2 mm, damage in the production process is recognized. It can be seen that at .18 mm, breakage accidents such as cracks rapidly increase due to a decrease in mechanical strength, which is not suitable for mass production. Therefore, it is desirable to set the thickness of the envelope within the range of 0.2 to 0.7 mm (preferably within the range of 0.4 to 0.7 mm) based on the evaluation results of the respective evaluation items.
[0064]
Next, a third experimental example will be described. In the first experimental example, the sealed pressure of xenon gas is fixed at 120 torr, and the positional deviation amount ΔP (see FIGS. 2 to 3) at the tip portions of the deformed portions facing each other is set to 0 to 25% of the deformed portion pitch P. Noble gas discharge lamps were manufactured with varying the range.
[0065]
These rare gas discharge lamps are incorporated in the lighting circuit shown in FIG. 21, and the output voltage of the inverter circuit 12 (the rating is a frequency of 30 KHz and the voltage is 2500 V). _0-P ) Was gradually raised, and the discharge start voltage (starting voltage) was measured in a state where no moving stripes (flickering) were visually observed. The result shown in FIG. 16 was obtained.
[0066]
As is apparent from the figure, when the positional deviation amount ΔP is in the range of 0 to 18%, 2000V, which is about 80% of the rated voltage. _0-P However, it is lit without flickering, and 2250V, which is about 90% of the rated voltage, even if the positional deviation amount ΔP is in the range of 19-20%. _0-P It is lit without flickering, and a stable discharge state is obtained even after lighting. However, when the displacement ΔP is 21% or more, the starting voltage is 2400V. _0-P Thus, stable starting characteristics without flicker at 90% of the line voltage cannot be guaranteed. Therefore, the positional deviation amount ΔP of the opposing deformed portion must be set to 20% or less of the deformed portion pitch P.
[0067]
【The invention's effect】
As described above, according to the present invention, the odd-shaped portions having periodicity are formed so as to face each other at the side edges of the external electrodes forming the first opening and / or the second opening. In addition, since the amount of misalignment between the deformed portions facing each other is set to 20% or less of the deformed portion pitch, when a high frequency high voltage is applied to the external electrode, the electric field concentrates on the tip portion of the deformed portion. It becomes easy to discharge between the deformed parts. Therefore, for example, even if the voltage applied to the external electrode is lowered due to a power supply fluctuation within 10%, the light can be reliably turned on without flickering. For this reason, when this rare gas discharge lamp is applied to a document irradiating apparatus for OA equipment, it can be expected to improve document reading accuracy and reproduction quality.
[0068]
In particular, if the thickness of the envelope is set in the range of 0.2 to 0.7 mm and the enclosure pressure of the rare gas is set in the range of 83 to 200 Torr, the moving stripe ( It is possible not only to effectively suppress the occurrence of flicker) but also to improve the light output emitted from the first opening. Therefore, when applied to a document irradiating apparatus, a stable discharge state can be obtained, the illuminance on the document surface can be increased, and an improvement in reading accuracy can be expected.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
FIG. 2 is a development view of an envelope and external electrodes shown in FIG.
FIG. 3 is an enlarged view of a main part for explaining a misalignment state of a deformed portion of the external electrode shown in FIG.
FIG. 4 is a longitudinal sectional view showing a second embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing a third embodiment of the present invention.
FIG. 6 is a longitudinal sectional view showing a fourth embodiment of the present invention.
FIG. 7 is a longitudinal sectional view showing a fifth embodiment of the present invention.
FIG. 8 is a longitudinal sectional view showing a sixth embodiment of the present invention.
FIG. 9 is a development view of an envelope and external electrodes showing a seventh embodiment of the present invention.
FIG. 10 is an enlarged view of a main part of an external electrode showing an eighth embodiment of the present invention, in which FIG. 10 (a) is a diagram showing a state in which a rounded portion is formed at the tip of the deformed part; ) Is a diagram showing a state in which a trapezoidal portion is formed by cutting off the tip portion of the deformed portion.
FIG. 11 is a development view of an envelope and external electrodes showing a ninth embodiment of the present invention.
FIG. 12 is a development view of an envelope and external electrodes showing a ninth embodiment of the present invention.
FIG. 13 is a diagram showing a relationship of starting characteristics with respect to a sealing pressure of xenon gas.
FIG. 14 is a diagram showing the relationship between occurrence of flicker and document surface illuminance with respect to the sealing pressure of xenon gas.
FIG. 15 is a diagram showing the relationship between presence / absence of flicker and strength with respect to the thickness of the envelope.
FIG. 16 is a diagram showing a relationship of starting characteristics with respect to a positional deviation amount of opposing deformed portions.
FIG. 17 is a longitudinal sectional view of a rare gas discharge lamp according to the prior art.
FIG. 18 is a development view of a sheet structure according to the prior art.
19 is a sectional view taken along line XX in FIG.
FIG. 20 is a longitudinal sectional view for explaining a method for manufacturing a rare gas discharge lamp according to the prior art.
FIG. 21 is a lighting circuit diagram of a rare gas discharge lamp according to the prior art.
[Explanation of symbols]
1 Envelope
2 Light emitting layer
2a Aperture part
3 Sheet structure
4,4A Translucent sheet (insulating member)
4a, 4b end
5,6 External electrode
5a, 5b, 6a, 6b Side edge
5A, 5B, 5C deformed part
5Aa, 5Ba, 5Ca, 6Aa, 6Ba, 6Ca Tip
7 First opening
8 Second opening
9 Adhesive layer
12 Inverter circuit
13 Protection tube (insulating member)

Claims

An envelope having a light emitting layer on the inner surface, and a metal member spaced apart from each other so that first and second openings are formed on the outer circumferential surface of the envelope over almost the entire length thereof. A pair of external electrodes in a strip shape,
The same shape having a triangular shape, a rectangular shape, a substantially semicircular shape including a waveform, or the like is repeatedly formed on the side edge of the external electrode forming the first opening and / or the second opening. the profiled section made, as well as formed to face each other,
A rare gas discharge lamp characterized in that the amount of positional deviation in the direction in which the same shape is repeatedly formed between the deformed portions facing each other is set to 20% or less of the deformed portion pitch.

An envelope having a light emitting layer on the inner surface, and a metal member spaced apart from each other so that first and second openings are formed on the outer circumferential surface of the envelope over almost the entire length thereof. A pair of external electrodes in a strip shape,
The side portions of the pair of external electrodes forming the second opening are opposed to each other with deformed portions formed by repeatedly forming the same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform. As well as forming
A rare gas discharge lamp characterized in that the amount of positional deviation in the direction in which the same shape is repeatedly formed between the deformed portions facing each other is set to 20% or less of the deformed portion pitch.

The radiated light from the light emitting layer is mainly emitted to the outside from the first opening, and the side edges of the pair of external electrodes forming the first opening are formed in a straight shape. The rare gas discharge lamp according to claim 2, which is formed.

An envelope having a light emitting layer on the inner surface, and a metal member spaced apart from each other so that first and second openings are formed on the outer circumferential surface of the envelope over almost the entire length thereof. A pair of strip-shaped external electrodes, and an insulating member mounted so that the external electrodes are covered;
The side portions of the pair of external electrodes forming the second opening are opposed to each other with deformed portions formed by repeatedly forming the same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform. As well as forming
A rare gas discharge lamp characterized in that the amount of positional deviation in the direction in which the same shape is repeatedly formed between the deformed portions facing each other is set to 20% or less of the deformed portion pitch.

5. The rare gas discharge lamp according to claim 4, wherein the insulating member is constituted by a protective 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 strip-like external electrodes made of a metal member on one surface of a translucent sheet having a length substantially the same as the entire length of the envelope. A sheet structure which is arranged so as to be spaced apart from each other so as to form first and second openings, and which has an adhesive layer formed on a translucent sheet surface on the side where the external electrode is located; Comprising
The side portions of the pair of external electrodes forming the second opening are opposed to each other with deformed portions formed by repeatedly forming the same shape having a triangular shape, a rectangular shape, or a substantially semicircular shape including a waveform. As well as forming
The amount of positional deviation of the deformed portions facing each other in the direction in which the same shape is repeatedly formed is set to 20% or less of the pitch of the deformed portions, and the sheet structure is placed on the outer peripheral surface of the envelope. A rare gas discharge lamp characterized by being wound and bonded so that an external electrode is positioned between the light-sensitive sheet.

The rare gas discharge lamp according to claim 1, wherein the deformed portion is formed over substantially the entire length so as to have periodicity.

The deformed portion is formed of any one of a triangular shape, a rectangular shape including a trapezoid, and a substantially semicircular shape including a waveform. A rare gas discharge lamp according to claim 1.

An aperture portion in which a light emitting layer is not formed is formed on the inner surface portion of the envelope substantially corresponding to the first opening portion. A rare gas discharge lamp according to any one of the above.

The rare gas discharge lamp according to claim 1, wherein a rare gas is sealed in the envelope in a pressure range of 83 to 200 Torr.

The rare gas discharge lamp according to any one of claims 1, 2, 4, and 6, wherein a thickness of the envelope is set in a range of 0.2 to 0.7 mm. .