JP3822994B2

JP3822994B2 - Development device

Info

Publication number: JP3822994B2
Application number: JP4155899A
Authority: JP
Inventors: 英世渡辺
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 1999-02-19
Filing date: 1999-02-19
Publication date: 2006-09-20
Anticipated expiration: 2019-02-19
Also published as: JP2000242079A

Description

【０００１】
【発明の属する技術分野】
本発明は、電子写真方式の画像形成装置における現像装置に係り、詳しくは、現像ローラの軸方向端部外周面と現像剤容器の現像剤収容部との隙間からの現像剤の溢出を防止するためのシール部材や、該現像ローラの表面に担持された現像剤の層厚を規制する現像剤規制部材の配設部と該シール部材の端部との隙間からの現像剤の溢出を防止するための端部シール部材などを備えた現像装置に関するものである。
【０００２】
【従来の技術】
この種の現像装置の一例を図６に示す。この現像装置は、表面にトナーなどからなる現像剤１０を担持して搬送する現像剤担持体としての現像ローラ１、該現像剤１０を収容するための現像剤収容部２ａと該現像ローラ１の表面の一部を露出するための開口部２ｂとを有する現像剤容器２、該現像剤容器２の現像剤収容部２ａに収容されている現像剤１０を該現像ローラ１に向けて供給する現像剤供給ローラ４、及び、該開口部２ｂの近傍の該現像ローラ１の回転方向上流側に位置するように該現像剤容器２に取り付けられ、該現像ローラ１の表面に担持された現像剤１０を該表面との間に挟み込むことにより、該現像ローラ１の表面に担持された現像剤の層厚を規制する現像剤規制部材としてのドクタタブレード５などを備えている。
【０００３】
また、この現像装置には、現像ローラ１の軸方向端部外周面と現像剤容器２の現像剤収容部２ａとの隙間を塞ぐように配置されて、該隙間からの現像剤１０の溢出（トナー漏れ）を防止するシール部材６や、該ドクタブレード５側の該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間を塞ぐように配置されて、該隙間からの現像剤１０の溢出を防止する端部シール部材７などが設けられている。
【０００４】
図６において、現像剤容器２の現像剤収容部２ａに収容された現像剤１０は、供給ローラ４の回転により現像ローラ１の表面に供給される。これにより、該現像ローラ１の表面に担持された現像剤１０は、該現像ローラ１の回転により該現像剤容器２の開口部２ｂに向けて搬送される。そして、該現像剤１０は、該ドクタブレード５によって所定の層厚になるように、その搬送量が規制された後、該現像ローラ１に対向するように配置された感光体ドラムなどからなる像担持体２０の表面に供給される。これにより、該像担持体２０の表面に形成された潜像が該現像剤１０により顕像化される。
【０００５】
なお、この種の従来の現像装置としては、現像剤担持体（現像ローラ）の回転方向下流側の端部付近に、端部シール部材と同じ幅を有し端部シール部材の端部が入り込む溝部を有するものが知られている（特開平９−２２１８５号公報）。
【０００６】
【発明が解決しようとする課題】
ところで、現像ローラ１の軸方向端部外周面と該現像剤容器２の現像剤収容部２ａとの隙間を塞ぐように配置されるシール部材６としては、現像ローラ１に対する摺動性が高く、且つ、該隙間を確実に塞ぐことができるシール材、例えば、ナイロンやフッ素などの繊維をパイル織りして形成されたパイルシール材６Ａを、弾性スポンジなどで形成されたベース材６Ｂ上に設けた２層構造のシール材が適している。
これに対し、ドクタブレード５側の該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間を塞ぐように配置される端部シール部材７としては、現像ローラ１に対する摺動性を考慮する必要がないので、安価な素材で該隙間を確実に塞ぐことができる例えばスポンジ材のみで構成されたシール材が適している。
【０００７】
ところが、上述のような２層構造のシール材からなるパイル構造のシール部材６と、スポンジ材からなる端部シール部材７とを備えた現像装置においては、該シール部材６の方が該端部シール部材７よりも剛性が大きいため、例えば図７に示すように、該シール部材６の端部６ａが、現像ローラ１の表面の接線方向に沿って、ドクタブレード５側に向けて直線的に伸びてしまう傾向があった。
このため、この従来の現像装置では、上記ドクタブレード５と該ドクタブレード５の基部を挾持する一対のブレードブラケット５Ａ，５Ｂとで構成されたブレードユニット５Ｕを、上記現像剤容器２に取り付ける際に、図７に示したように直線的に伸びた状態の上記シール部材６の端部６ａ、及び、該シール部材６の端部６ａによって押し曲げられた上記端部シール部材７の先端７ａが、例えば図８に示すように、該ブレードユニット５Ｕの取付時に座屈されてしまうことがあった。
【０００８】
従って、この種の従来の現像装置においては、上述のように、シール部材６の端部６ａ及び端部シール部材７の先端７ａが座屈されることにより、該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間を正確に塞ぐことができなくなって、現像剤容器２の現像剤収容部２ａに収容されている現像剤１０が該隙間を通して溢出する不具合があった。
また、この現像装置においては、上記シール部材６の端部６ａ及び上記端部シール部材７の先端７ａが座屈しないように、上記ブレードユニット５Ｕを上記現像剤容器２に対して慎重に取り付ける必要があるため、該ブレードユニット５Ｕの組み付けに手間が掛かり、その生産性が低下する不具合があった。
【０００９】
本発明は、以上の問題に鑑みなされたものであり、その目的とするところは、現像ローラの軸方向端部外周面と現像剤容器の現像剤収容部との隙間からの現像剤の溢出を防止するためのシール部材や、該現像ローラの表面に担持された現像剤の層厚を規制する現像剤規制部材の配設部と該シール部材の端部との隙間からの現像剤の溢出を防止するための端部シール部材などのシール性、及び、該現像剤規制部材の組み付け性を向上させることができる現像装置を提供することである。
【００１０】
【課題を解決するための手段】
上記目的を達成するために、請求項１の発明は、表面に現像剤を担持して搬送する現像ローラと、該現像剤を収容するための現像剤収容部と該現像ローラの表面の一部を露出するための開口部とを有する現像剤容器と、該現像ローラの軸方向端部外周面と、該現像剤容器の側壁の該端部外出面と対向する面部分との隙間を塞ぐように配置されて、該隙間からの現像剤の溢出を防止するシール部材と、該開口部近傍の該現像ローラの回転方向上流側に位置するように基端部が該現像剤容器に取り付けられ、該基端部から該現像ローラ回転方向下流側に延びだした自由端部で該現像ローラの表面に担持された現像剤の層厚を規制する現像剤規制部材と、を備えた現像装置において、該現像剤規制部材側の該シール部材の端部を上記面部分から延出させて自由端部を設けるとともに、基端部が、上記側壁の該現像剤規制部材と対向する面部分と該現像剤規制部材との間を塞ぎ、該面部分から該現像剤担持体側に延出した自由端部の側面が、該シール部材の自由端部の側面と密着して該シール部材の自由端部とともに該現像ローラ周面と該現像剤規制部材基端部との間を塞ぐ端部シール部材を設け、かつ、上記端部シール部材に、該現像剤規制部材を取り付け前の状態で該端部シール部材の配置姿勢を保持するための姿勢保持部材を設けたことを特徴とするものである。
【００１１】
請求項１の発明においては、上記端部シール部材に設けた姿勢保持部材によって、該端部シール部材の配置姿勢が保持されるので、上記現像剤規制部材を上記現像剤容器に取り付ける際の、上記シール部材の端部及び該端部シール部材の先端の座屈が回避される。これにより、該シール部材や端部シール部材のシール性が向上される。また、上記端部シール部材が上記姿勢保持部材によって配置姿勢を保持され、上記座屈が生じにくい状態で、上記現像剤規制部材を取り付けることができるので、上記現像剤規制部材の上記現像剤容器に対する上記座屈を生じさせない取り付けを比較的容易に行うことができ、該現像剤規制部材の組み付け性、及び、現像装置の生産性が向上される。
【００１２】
請求項２の発明は、上記姿勢保持部材が、弾性体からなる薄板で形成されていることを特徴とするものである。
【００１３】
請求項２の発明においては、上記姿勢保持部材が弾性体からなる薄板で形成されているので、該姿勢保持部材を設けたことによって上記端部シール部材が大型化したり複雑化したりすることがない。これにより、現像装置の大型化や複雑化を回避でき、小型で低コストな現像装置の提供が可能になる。
【００１４】
請求項３の発明は、上記姿勢保持部材が、上記端部シール部材と一体的に構成されていることを特徴とするものである。
【００１５】
請求項３の発明においては、上記姿勢保持部材が上記端部シール部材と一体的に構成されているので、上記現像剤容器に対する該端部シール部材の組付け位置精度が向上され、該シール部材や端部シール部材のシール性が向上される。また、上記現像剤容器に対して該姿勢保持部材と該端部シール部材とが同時に組み付けられるので、該現像剤規制部材の組み付け性、及び、現像装置の生産性が向上される。
【００１６】
請求項４の発明は、上記現像剤容器側に向けて上記端部シール部材を押圧する押圧部材を設けたことを特徴とするものである。
【００１７】
請求項４の発明においては、上記押圧部材によって、該現像剤容器側に向けて上記端部シール部材が押圧される。これにより、該現像剤容器からの該端部シール部材の浮き上がり（剥がれ）が防止され、該端部シール部材と該現像剤規制部材の配設部との隙間とのシール性が向上される。ここで、該押圧部材は、該端部シール部材を直接押圧してもよく、あるいは、上記姿勢保持部材を介して間接的に該端部シール部材を押圧してもよい。
【００１８】
【発明の実施の形態】
以下、本発明を適用した現像装置の一実施形態について説明する。
図１は、本実施形態に係る現像装置の概略構成を示す断面図である。この現像装置は、図６に示した現像装置と同様な、現像ローラ１、現像剤容器２、現像剤供給ローラ４、ドクタタブレード５、シール部材６、及び、端部シール部材７などを備えている。
上記現像ローラ１は、図１乃至図３に示すように、その回転軸１ａの両端部に装着された軸受３を介して、現像剤容器２に回転自在に保持されている。該軸受３は、該現像剤容器２の両側部に形成された軸受保持部２ｃに装着されている（図２及び図３参照）。また、現像剤供給ローラ４は、例えばウレタンなどの発泡体で構成されており、その支軸４ａの両端部が、該現像剤容器２の両側部に形成された軸受穴２ｄに挿通されることによって回転自在に保持されている（図２及び図３参照）。該現像ローラ１の回転軸１ａの一方の端部は、該軸受３を貫通して外方に延出しており、該回転軸１ａの端部には駆動ギヤ１１が取り付けられている。また、該現像剤供給ローラ４の支軸４ａの一方の端部は、該軸受穴２ｄを貫通して外方に延出しており、該支軸４ａの端部には、図３に示すように、該現像剤供給ローラ４の駆動ギヤ１２が、該現像ローラ１の駆動ギヤ１１に噛み合うように取り付けられている。
【００１９】
該現像装置は、図示しないプリンタなどの画像形成装置に装着されることによって、該現像ローラ１の駆動ギヤ１１が、該画像形成装置側の駆動ギヤ（不図示）に噛み合うように構成されており、該該画像形成装置側の駆動ギヤが回転することによって、該駆動ギヤ１１，１２を介して、該現像ローラ１及び該現像剤供給ローラ４が、図１において矢印で示す方向にそれぞれ回転される。これにより、現像剤容器２の現像剤収容部２ａに収容された現像剤１０が、供給ローラ４の回転により現像ローラ１の表面に供給され、該現像ローラ１の表面に担持された現像剤１０が、該現像ローラ１の回転により該現像剤容器２の開口部２ｂに向けて搬送される。そして、該開口部２ｂに向けて搬送された現像剤１０は、上記ドクタブレード５によって所定の層厚になるように、その搬送量が規制された後、該現像ローラ１に対向するように配置された像担持体２０（図６参照）の表面に供給される。
【００２０】
上記ドクタブレード５は、例えば、ステンレス製の弾性板で形成されており、該ドクタブレード５と該ドクタブレード５の基部を挾持する一対のブレードブラケット５Ａ，５Ｂとでブレードユニット５Ｕが構成されている。該ブレードユニット５Ｕは、図１及び図３に示すように、そのドクタタブレード５の先端が、現像剤容器２の開口部２ｂの近傍の像ローラ１の回転方向上流側に位置するように、該現像剤容器２の両側部（手前の側部は図示せず）に、止めネジ５Ｃにより取り付けられている。
【００２１】
一方、上記シール部材６は、図１乃至図３に示すように、現像ローラ１の軸方向端部外周面と該現像剤容器２の現像剤収容部２ａとの隙間を塞ぐように、現像剤容器２の両側部（手前側の側部は図示せず）に配置されている。
また、上記端部シール部材７は、図１乃至図３に示すように、ドクタブレード５側の該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間を塞ぐように、現像剤容器２の両側部（手前側の側部は図示せず）に配置されている。この端部シール部材７の現像剤容器２の両側部に対する取付位置は、図４に示すように、該現像剤容器２の両側部に形成された基準ピン２に、該端部シール部材７に穿たれた丸穴７ｂを嵌合させることによって位置決めされるようになっている。
【００２２】
ここで、該シール部材６としては、前述したように、現像ローラ１に対する摺動性が高く、且つ、該隙間を確実に塞ぐことができるシール材、例えば、ナイロンやフッ素などの繊維をパイル織りして形成されたパイルシール材６Ａを、弾性スポンジなどで形成されたベース材６Ｂ上に設けた２層構造のシール材が適している。
これに対し、端部シール部材７としては、現像ローラ１に対する摺動性を考慮する必要がないので、安価な素材で該隙間を確実に塞ぐことができる例えばスポンジ材のみで構成されたシール材が適している。
【００２３】
ところが、このような２層構造のシール材からなるシール部材６と、スポンジ材からなる端部シール部材７とを備えた現像装置においては、該シール部材６の方が該端部シール部材７よりも剛性が大きいため、図７に示したように、該シール部材６の端部６ａが、現像ローラ１の表面の接線方向に沿って、ドクタブレード５側に向けて直線的に伸びてしまう傾向がある。
このため、このような現像装置では、上記ブレードユニット５Ｕを上記現像剤容器２に取り付ける際に、直線的に伸びた状態のシール部材６の端部６ａ及び端部シール部材７の先端７ａが、図８に示したように、該ブレードユニット５Ｕによって座屈されて、該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間が正確に塞がれず、該現像剤容器２の現像剤収容部２ａに収容されている現像剤１０が該隙間を通して溢出することがあった。
また、この現像装置においては、上記シール部材６の端部６ａ及び上記端部シール部材７の先端７ａが座屈しないように、上記ブレードユニット５Ｕを上記現像剤容器２に対して慎重に取り付ける必要があるため、該ブレードユニット５Ｕの組み付けに手間が掛かり、その生産性が低下する不具合があった。
【００２４】
そこで、本実施形態に係る現像装置においては、上記端部シール部材７に、該端部シール部材７の配置姿勢を保持するための姿勢保持部材８を設けた構成とする。
このように構成した現像装置においては、上記端部シール部材７に設けた姿勢保持部材８の先端部８ａによって、図１に示すように、上記シール部材６により上記現像ローラ１の軸方向端部外周面と上記現像剤容器２の現像剤収容部２ａとの隙間が確実に塞がれ、且つ、該端部シール部材７により上記ドクタブレード５側の該シール部材６の端部６ａと該ドクタブレード５の配設部２Ａとの隙間が確実に塞がれるように、すなわち、該シール部材６の端部６ａ及び該端部シール部材７の先端７ａが、該現像ローラ１の表面側に押しつけられるように、該端部シール部材７の配置姿勢が保持される。
【００２５】
従って、この現像装置によれば、上記ブレードユニット５Ｕを上記現像剤容器２に取り付ける際の、上記シール部材６の端部６ａ及び該端部シール部材７の先端７ａの座屈が回避される。これにより、該シール部材６や端部シール部材７のシール性が向上される。また、上記端部シール部材７が上記姿勢保持部材８によって配置姿勢を保持され、上記座屈が生じにくい状態で、上記ブレードユニット５Ｕを取り付けることができるので、該ブレードユニット５Ｕの上記現像剤容器２に対する上記座屈を生じさせない取り付けを比較的容易に行うことができ、該ブレードユニット５Ｕの組み付け性、及び、現像装置の生産性が向上される。
【００２６】
ここで、上記姿勢保持部材８は、弾性体からなる薄板で形成されていることが望ましい。すなわち、該姿勢保持部材８を弾性体からなる薄板で形成することによって、該姿勢保持部材８が設けられることによる上記端部シール部材７の大型化や複雑化が解消される。これにより、現像装置の大型化や複雑化を回避でき、小型で低コストな現像装置の提供が可能になる。このような姿勢保持部材８としては、例えば、厚さｔ＝０．０７５ｍｍ〜０．１８８ｍｍのポリエステルフィルムが有効である。
なお、上記現像剤容器２の開口部２ｂの、上記現像ローラ１の回転方向下流側の部位には、該現像ローラ１の表面と該開口部２ｂとの隙間からの現像剤１０の飛散を防止するための入口シール９が設けられている。この入口シール９は、例えば、厚さｔ＝０．１ｍｍのポリエステルフィルムで形成されている。また、該入口シール９の端面と上記シール部材６の端面との間の僅かな隙間は、該現像ローラ１の回転を阻害しないシリコーン系の充填材１３で埋められている。
【００２７】
上記姿勢保持部材８は、上記端部シール部材７を現像剤容器２の両側部に取り付ける場合と同様、図４に示すように、該現像剤容器２の両側部に形成された基準ピン２に、該姿勢保持部材８に穿った丸穴８ｂを嵌合させることによって位置決めされるようになっている。
従って、上記姿勢保持部材８は、上記端部シール部材７と一体的に構成したものであってもよい。このように、該姿勢保持部材８と該端部シール部材７と一体的に構成することによって、上記現像剤容器２に対する該端部シール部材７の組付け位置精度を向上させることができる。すなわち、該端部シール部材７は、前述したようにスポンジ材で構成されているため、上述のように、該現像剤容器２の両側部に形成された基準ピン２に、該端部シール部材７に穿った丸穴７ｂを嵌合させて位置決めしても、該端部シール部材７の変形によって位置ズレを起こし易い。これに対して、該姿勢保持部材８と該端部シール部材７と一体的に構成し、該現像剤容器２の両側部に形成された基準ピン２に、該姿勢保持部材８に穿った丸穴８ｂを嵌合させることによって位置決めすることにより、該端部シール部材７の面方向の位置ズレが発生しなくなるので、現像剤容器２に対する該端部シール部材７の組付け位置精度が向上される。これにより、該端部シール部材７のシール性が向上される。また、現像剤容器２に対して該姿勢保持部材８と該端部シール部材７とを同時に組み付けることができるので、該ブレードユニット５Ｕの組み付け性、及び、現像装置の生産性が向上される。
【００２８】
このように、上記姿勢保持部材８と上記端部シール部材７と一体的に構成したものとしては、図５（ａ），（ｂ）に示すように、該端部シール部材７の外側に該姿勢保持部材８を接着して（この場合、該端部シール部材７の端部７ａの折れ曲がる部分は接着してもてもしなくてもよい）構成したもの、あるいは、図５（ｃ），（ｄ）に示すように、該端部シール部材７の内側全面に該姿勢保持部材８を接着して、該姿勢保持部材８の弾性作用により該端部シール部材７の先端７ａを内側から引っ張るように構成したものの何れであってもよい。
【００２９】
また、本発明の現像装置としては、図１及び図３に示すように、上記ブレードユニット５Ｕの上記現像剤容器２への取付部（ここでは、ブレードブラケット５Ａ）に、該現像剤容器２側に向けて上記端部シール部材７を押圧する押圧部材５Ｄを設けた構成としてもよい。この現像装置においては、上記押圧部材５Ｄによって、該現像剤容器２側に向けて上記端部シール部材７が押圧されるので、該現像剤容器２からの該端部シール部材７の浮き上がり（剥がれ）が防止され、該端部シール部材７と該ブレードユニット５Ｕとの隙間とのシール性が向上される。ここで、該押圧部材５Ｄは、該端部シール部材７を直接押圧してもよく、あるいは、上記姿勢保持部材８を介して間接的に該端部シール部材７を押圧してもよい。
【００３０】
なお、本実施形態においては、上記シール部材６や端部シール部材７を用いて、現像装置の回転部や開口部からの現像剤の漏れを防止する構成を示したが、この種のシール部材６や端部シール部材７は、粉体を収納する粉体容器の回転部や開口部からの粉体の漏れを防止するための手段として広く応用することができる。従って、本発明は、上記現像装置に限らず、例えばクリーニング装置やトナー補給装置などにも適用することが可能である。
【００３１】
【発明の効果】
請求項１乃至４の発明によれば、端部シール部材に設けた姿勢保持部材によって、該端部シール部材の配置姿勢が保持されるので、現像剤規制部材を現像剤容器に取り付ける際の、シール部材の端部及び該端部シール部材の先端の座屈を回避でき、該シール部材や端部シール部材のシール性を向上させることができる。また、現像剤容器に対して現像剤規制部材を比較的容易に取り付けることができるようになるので、該現像剤規制部材の組み付け性、及び、現像装置の生産性を向上させることができるという優れた効果がある。
【００３２】
特に、請求項２の発明によれば、上記姿勢保持部材が弾性体からなる薄板で形成されているので、該姿勢保持部材を設けたことによって上記端部シール部材が大型化したり複雑化したりすることがなく、小型で低コストな現像装置の提供が可能になるという優れた効果がある。
【００３３】
また、請求項３の発明によれば、上記姿勢保持部材が上記端部シール部材と一体的に構成されているので、上記現像剤容器に対する該端部シール部材の組付け位置精度が向上され、該シール部材や端部シール部材のシール性を向上させることができる。また、上記現像剤容器に対して該姿勢保持部材と該端部シール部材とを同時に組み付けられるので、該現像剤規制部材の組み付け性、及び、現像装置の生産性を向上できるという優れた効果がある。
【００３４】
また、請求項４の発明によれば、上記現像剤規制部材の上記現像剤容器への取付部に設けられた上記押圧部材によって、該現像剤容器側に向けて上記端部シール部材が押圧されるので、該現像剤容器からの該端部シール部材の浮き上がり（剥がれ）を防止でき、該端部シール部材と該現像剤規制部材の配設部との隙間とのシール性を向上させることができるという優れた効果がある。
【図面の簡単な説明】
【図１】本実施形態に現像装置の概略構成を示す断面図。
【図２】上記現像装置における現像剤容器のシール部材及び端部シール部材の取付部の概略構成を示す斜視図。
【図３】上記現像装置における現像ローラ、現像剤供給ローラ、及び、ブレードユニットの取付構造を示す概略斜視図。
【図４】上記シール部材及び端部シール部材の取付構造を示す概略斜視図。
【図５】（ａ），（ｂ），（ｃ），（ｄ）は、上記端部シール部材と姿勢保持部材とを一体的に構成した例を示す概略斜視図及び概略断面図。
【図６】従来の現像装置の概略構成を示す断面図。
【図７】従来の現像装置におけるシール部材及び端部シール部材の取付構造を示す概略斜視図。
【図８】従来の現像装置におけるシール部材及び端部シール部材の取付構造を示す概略断面図。
【符号の説明】
１現像ローラ
１ａ現像ローラの回転軸
２現像剤容器
２ａ現像剤容器の現像剤収容部
2b 現像剤容器の開口部
２ｃ現像剤容器の軸受保持部
２ｄ現像剤容器の軸受穴
２ｅ基準ピン
３軸受
４現像剤供給ローラ
５ドクタブレード
５Ａ，５Ｂブレードブラケット
５Ｃ止めネジ
５Ｄ押圧部材
５Ｕブレードユニット
６シール部材
６ａシール部材の端部
７端部シール部材
７ａ端部シール部材の先端
７ｂ端部シール部材の丸穴
８姿勢保持部材
８ａ姿勢保持部材の先端部
８ｂ姿勢保持部材の丸穴
９入口シール
１０現像剤
１１，１２駆動ギヤ
１３充填材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device in an electrophotographic image forming apparatus, and more specifically, prevents overflow of developer from a gap between an outer peripheral surface of an axial end portion of a developing roller and a developer accommodating portion of a developer container. For preventing the developer from overflowing from the gap between the seal member and the end portion of the seal member and the end portion of the seal member that regulates the layer thickness of the developer carried on the surface of the developing roller. The present invention relates to a developing device provided with an end seal member and the like.
[0002]
[Prior art]
An example of this type of developing device is shown in FIG. The developing device includes a developing roller 1 as a developer carrying member that carries and conveys a developer 10 made of toner on the surface, a developer containing portion 2 a for containing the developer 10, and the developing roller 1. A developer container 2 having an opening 2b for exposing a part of the surface, and development for supplying the developer 10 contained in the developer container 2a of the developer container 2 toward the developing roller 1 The developer supply roller 4 and the developer 10 that is attached to the developer container 2 so as to be positioned upstream of the developing roller 1 in the vicinity of the opening 2b and carried on the surface of the developing roller 1 And a doctor blade 5 as a developer regulating member for regulating the layer thickness of the developer carried on the surface of the developing roller 1.
[0003]
In addition, the developing device is disposed so as to close the gap between the outer peripheral surface of the axial end of the developing roller 1 and the developer accommodating portion 2a of the developer container 2, and the developer 10 overflows from the gap ( The seal member 6 for preventing toner leakage) and the gap between the end portion 6a of the seal member 6 on the doctor blade 5 side and the placement portion 2A of the doctor blade 5 are arranged to close the gap from the gap. An end seal member 7 and the like for preventing the developer 10 from overflowing are provided.
[0004]
In FIG. 6 , the developer 10 accommodated in the developer accommodating portion 2 a of the developer container 2 is supplied to the surface of the developing roller 1 by the rotation of the supply roller 4. As a result, the developer 10 carried on the surface of the developing roller 1 is conveyed toward the opening 2 b of the developer container 2 by the rotation of the developing roller 1. The developer 10 is an image formed of a photosensitive drum or the like disposed so as to face the developing roller 1 after the transport amount is regulated by the doctor blade 5 so as to have a predetermined layer thickness. It is supplied to the surface of the carrier 20. Thereby, the latent image formed on the surface of the image carrier 20 is visualized by the developer 10.
[0005]
In this type of conventional developing device, the end of the end seal member has the same width as the end seal member and enters the vicinity of the end on the downstream side in the rotation direction of the developer carrying member (developing roller). One having a groove is known (Japanese Patent Laid-Open No. 9-22185).
[0006]
[Problems to be solved by the invention]
By the way, as the seal member 6 disposed so as to close the gap between the outer peripheral surface of the axial end portion of the developing roller 1 and the developer accommodating portion 2a of the developer container 2, the sliding property with respect to the developing roller 1 is high. In addition, a seal material that can reliably close the gap, for example, a pile seal material 6A formed by pile weaving of a fiber such as nylon or fluorine, is provided on a base material 6B formed of an elastic sponge or the like. A two-layer sealing material is suitable.
On the other hand, as the end seal member 7 disposed so as to close the gap between the end 6a of the seal member 6 on the doctor blade 5 side and the disposition portion 2A of the doctor blade 5, the slide with respect to the developing roller 1 is used. Since there is no need to consider the mobility, a sealing material composed only of, for example, a sponge material that can reliably close the gap with an inexpensive material is suitable.
[0007]
However, in the developing device including the pile-structured seal member 6 made of the two-layered seal material as described above and the end seal member 7 made of the sponge material, the seal member 6 is the end portion. Since the rigidity is larger than that of the seal member 7, for example, as shown in FIG. 7, the end 6a of the seal member 6 is linearly directed toward the doctor blade 5 along the tangential direction of the surface of the developing roller 1. There was a tendency to grow.
Therefore, in this conventional developing device, when the blade unit 5U composed of the doctor blade 5 and a pair of blade brackets 5A and 5B that hold the base of the doctor blade 5 is attached to the developer container 2, As shown in FIG. 7, the end portion 6a of the seal member 6 in a linearly extended state, and the tip end 7a of the end portion seal member 7 pushed and bent by the end portion 6a of the seal member 6, For example, as shown in FIG. 8, the blade unit 5U may be buckled when attached.
[0008]
Therefore, in the conventional developing device of this type, as described above, the end 6a of the seal member 6 and the tip 7a of the end seal member 7 are buckled, so that the end 6a of the seal member 6 The gap between the doctor blade 5 and the arrangement portion 2A cannot be accurately closed, and the developer 10 contained in the developer containing portion 2a of the developer container 2 overflows through the gap. .
Further, in this developing device, it is necessary to carefully attach the blade unit 5U to the developer container 2 so that the end 6a of the seal member 6 and the tip 7a of the end seal member 7 do not buckle. Therefore, it takes time to assemble the blade unit 5U and there is a problem that the productivity is lowered.
[0009]
The present invention has been made in view of the above problems, and its object is to prevent the developer from overflowing from the gap between the outer peripheral surface of the axial end of the developing roller and the developer container of the developer container. The overflow of the developer from the gap between the seal member for preventing the seal member and the arrangement portion of the developer regulating member for regulating the layer thickness of the developer carried on the surface of the developing roller and the end of the seal member It is an object of the present invention to provide a developing device capable of improving the sealing performance of an end seal member and the like, and the assembling performance of the developer regulating member.
[0010]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention of claim 1 is directed to a developing roller for carrying and transporting a developer on the surface, a developer containing portion for containing the developer, and a part of the surface of the developing roller. A gap between the developer container having an opening for exposing the surface , the outer peripheral surface of the axial end portion of the developing roller, and the surface portion of the side wall of the developer container facing the end protruding surface. A seal member that prevents the developer from overflowing from the gap, and a base end portion attached to the developer container so as to be positioned upstream of the developing roller in the rotation direction in the vicinity of the opening, A developer regulating member that regulates a layer thickness of the developer carried on the surface of the developing roller at a free end extending from the base end to the downstream side in the rotation direction of the developing roller ; the ends of the developer regulating member side of the seal member extending from said surface portion The free end portion is provided, and the base end portion closes a space between the surface portion of the side wall facing the developer restricting member and the developer restricting member, and extends from the surface portion toward the developer carrying member. The end where the side surface of the free end portion that comes out comes into close contact with the side surface of the free end portion of the seal member and closes the space between the developing roller peripheral surface and the developer regulating member base end portion together with the free end portion of the seal member the part sealing member is provided, and, in the end seal member, characterized in that a posture holding member for holding the arrangement orientation of said end sealing member in a state before mounting the developer regulating member Is.
[0011]
In the first aspect of the invention, since the posture of the end seal member is held by the posture holding member provided on the end seal member, the developer regulating member is attached to the developer container. Buckling of the end of the seal member and the tip of the end seal member is avoided. Thereby, the sealing performance of the seal member and the end seal member is improved. Further, the developer regulating member can be attached in a state in which the end seal member is held in the arrangement posture by the posture holding member and the buckling hardly occurs, so the developer container of the developer regulating member can be attached. As a result, it is possible to relatively easily perform the attachment without causing the buckling to occur, and the assembling property of the developer regulating member and the productivity of the developing device are improved.
[0012]
The invention of claim 2 is characterized in that the posture holding member is formed of a thin plate made of an elastic body.
[0013]
In the invention of claim 2, since the posture holding member is formed of a thin plate made of an elastic body, the end seal member is not enlarged or complicated by providing the posture holding member. . As a result, it is possible to avoid an increase in size and complexity of the developing device, and to provide a developing device that is small and low in cost.
[0014]
The invention of claim 3 is characterized in that the posture holding member is integrally formed with the end seal member.
[0015]
In the invention of claim 3, since the posture holding member is integrally formed with the end seal member, the assembly position accuracy of the end seal member with respect to the developer container is improved, and the seal member Further, the sealing performance of the end seal member is improved. In addition, since the posture holding member and the end seal member are assembled to the developer container at the same time, the assembling property of the developer regulating member and the productivity of the developing device are improved.
[0016]
According to a fourth aspect of the present invention, there is provided a pressing member that presses the end seal member toward the developer container.
[0017]
In the invention of claim 4, the end seal member is pressed toward the developer container by the pressing member. Accordingly, the end seal member is prevented from being lifted (peeled) from the developer container, and the sealing performance between the end seal member and the gap between the developer regulating member and the arrangement portion is improved. Here, the pressing member may directly press the end seal member, or may indirectly press the end seal member via the posture holding member.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a developing device to which the present invention is applied will be described.
FIG. 1 is a cross-sectional view illustrating a schematic configuration of a developing device according to the present embodiment. The developing device includes a developing roller 1, a developer container 2, a developer supply roller 4, a doctor blade 5, a seal member 6, an end seal member 7, and the like, similar to the developing device shown in FIG. ing.
As shown in FIGS. 1 to 3, the developing roller 1 is rotatably held in the developer container 2 via bearings 3 attached to both ends of the rotating shaft 1a. The bearing 3 is mounted on a bearing holding portion 2c formed on both sides of the developer container 2 (see FIGS. 2 and 3). Further, the developer supply roller 4 is made of, for example, foam such as urethane, and both end portions of the support shaft 4a are inserted into bearing holes 2d formed on both side portions of the developer container 2. (See FIGS. 2 and 3). One end of the rotating shaft 1a of the developing roller 1 extends outward through the bearing 3, and a driving gear 11 is attached to the end of the rotating shaft 1a. Further, one end portion of the support shaft 4a of the developer supply roller 4 extends outward through the bearing hole 2d, and the end portion of the support shaft 4a has an end as shown in FIG. Further, the drive gear 12 of the developer supply roller 4 is attached so as to mesh with the drive gear 11 of the developer roller 1.
[0019]
When the developing device is mounted on an image forming apparatus such as a printer (not shown), the driving gear 11 of the developing roller 1 is configured to mesh with a driving gear (not shown) on the image forming apparatus side. As the driving gear on the image forming apparatus side rotates, the developing roller 1 and the developer supply roller 4 are rotated in the directions indicated by arrows in FIG. 1 via the driving gears 11 and 12, respectively. The Thereby, the developer 10 accommodated in the developer accommodating portion 2 a of the developer container 2 is supplied to the surface of the developing roller 1 by the rotation of the supply roller 4, and the developer 10 carried on the surface of the developing roller 1. Is conveyed toward the opening 2 b of the developer container 2 by the rotation of the developing roller 1. Then, the developer 10 conveyed toward the opening 2b is disposed so as to face the developing roller 1 after the conveyance amount is regulated by the doctor blade 5 so as to have a predetermined layer thickness. Is supplied to the surface of the image carrier 20 (see FIG. 6).
[0020]
The doctor blade 5 is formed of, for example, an elastic plate made of stainless steel, and a blade unit 5U is configured by the doctor blade 5 and a pair of blade brackets 5A and 5B that hold the base of the doctor blade 5. . As shown in FIGS. 1 and 3, the blade unit 5U is arranged such that the tip of the doctor blade 5 is positioned upstream in the rotation direction of the image roller 1 near the opening 2b of the developer container 2. The developer container 2 is attached to both side portions (the front side portion is not shown) by set screws 5C.
[0021]
On the other hand, as shown in FIGS. 1 to 3, the seal member 6 has a developer so as to close a gap between the outer peripheral surface of the axial end portion of the developing roller 1 and the developer accommodating portion 2 a of the developer container 2. The container 2 is disposed on both sides (the front side is not shown).
Further, as shown in FIGS. 1 to 3, the end seal member 7 closes the gap between the end portion 6a of the seal member 6 on the doctor blade 5 side and the arrangement portion 2A of the doctor blade 5. The developer container 2 is disposed on both sides (the front side is not shown). As shown in FIG. 4, the attachment position of the end seal member 7 to both sides of the developer container 2 is set to the reference pins 2 formed on both sides of the developer container 2, and to the end seal member 7. Positioning is performed by fitting the drilled round hole 7b.
[0022]
Here, as the seal member 6, as described above, a seal material having high slidability with respect to the developing roller 1 and capable of reliably closing the gap, for example, a fiber such as nylon or fluorine is pile woven. A two-layer sealing material in which the pile sealing material 6A formed in this manner is provided on a base material 6B formed of an elastic sponge or the like is suitable.
On the other hand, as the end seal member 7, it is not necessary to consider the slidability with respect to the developing roller 1, so that the gap can be reliably closed with an inexpensive material, for example, a seal material composed only of a sponge material. Is suitable.
[0023]
However, in the developing device provided with the seal member 6 made of such a two-layer seal material and the end seal member 7 made of a sponge material, the seal member 6 is more suitable than the end seal member 7. 7 has a large rigidity, the end 6a of the seal member 6 tends to linearly extend toward the doctor blade 5 along the tangential direction of the surface of the developing roller 1 as shown in FIG. There is.
Therefore, in such a developing device, when the blade unit 5U is attached to the developer container 2, the end portion 6a of the seal member 6 and the tip end 7a of the end seal member 7 in a linearly extended state are As shown in FIG. 8, the developer unit is buckled by the blade unit 5U, and the gap between the end portion 6a of the seal member 6 and the arrangement portion 2A of the doctor blade 5 is not accurately closed, and the developer container In some cases, the developer 10 accommodated in the second developer accommodating portion 2a overflows through the gap.
Further, in this developing device, it is necessary to carefully attach the blade unit 5U to the developer container 2 so that the end 6a of the seal member 6 and the tip 7a of the end seal member 7 do not buckle. Therefore, it takes time to assemble the blade unit 5U and there is a problem that the productivity is lowered.
[0024]
Therefore, the developing device according to the present embodiment is configured such that the end seal member 7 is provided with a posture holding member 8 for holding the arrangement posture of the end seal member 7.
In the developing device configured as described above, the end portion 8a of the posture holding member 8 provided on the end seal member 7 causes the end portion in the axial direction of the developing roller 1 to be formed by the seal member 6 as shown in FIG. The gap between the outer peripheral surface and the developer accommodating portion 2a of the developer container 2 is reliably closed, and the end seal member 7 and the end 6a of the seal member 6 on the doctor blade 5 side and the doctor The gap between the blade 5 and the arrangement portion 2A is surely closed, that is, the end 6a of the seal member 6 and the tip 7a of the end seal member 7 are pressed against the surface side of the developing roller 1. Thus, the arrangement posture of the end seal member 7 is maintained.
[0025]
Therefore, according to this developing device, buckling of the end 6a of the seal member 6 and the tip 7a of the end seal member 7 when the blade unit 5U is attached to the developer container 2 is avoided. Thereby, the sealing performance of the seal member 6 and the end seal member 7 is improved. Further, the blade unit 5U can be mounted in a state in which the end seal member 7 is held in the arrangement posture by the posture holding member 8 and the buckling hardly occurs, so the developer container of the blade unit 5U can be attached. As a result, the blade unit 5U can be easily assembled and the productivity of the developing device can be improved.
[0026]
Here, the posture holding member 8 is preferably formed of a thin plate made of an elastic body. That is, by forming the posture holding member 8 from a thin plate made of an elastic body, the increase in size and complexity of the end seal member 7 due to the provision of the posture holding member 8 is eliminated. As a result, it is possible to avoid an increase in size and complexity of the developing device, and to provide a developing device that is small and low in cost. As such a posture holding member 8, for example, a polyester film having a thickness t = 0.075 mm to 0.188 mm is effective.
Note that the developer 10 is prevented from being scattered from the gap between the surface of the developing roller 1 and the opening 2b at the downstream side of the opening 2b of the developer container 2 in the rotation direction of the developing roller 1. An inlet seal 9 is provided. The inlet seal 9 is made of, for example, a polyester film having a thickness t = 0.1 mm. Further, a slight gap between the end face of the inlet seal 9 and the end face of the seal member 6 is filled with a silicone filler 13 that does not hinder the rotation of the developing roller 1.
[0027]
As shown in FIG. 4, the posture holding member 8 is attached to the reference pins 2 formed on both sides of the developer container 2, as in the case where the end seal member 7 is attached to both sides of the developer container 2. The position holding member 8 is positioned by fitting a round hole 8b.
Therefore, the posture holding member 8 may be configured integrally with the end seal member 7. As described above, by integrally configuring the posture holding member 8 and the end seal member 7, the assembly position accuracy of the end seal member 7 with respect to the developer container 2 can be improved. That is, since the end seal member 7 is made of the sponge material as described above, the end seal member is attached to the reference pins 2 formed on both sides of the developer container 2 as described above. Even if the round hole 7b formed in the hole 7 is fitted and positioned, the end seal member 7 is easily deformed due to deformation. On the other hand, the posture holding member 8 and the end seal member 7 are formed integrally, and the reference pins 2 formed on both sides of the developer container 2 are rounded in the posture holding member 8. By positioning by fitting the hole 8b, positional displacement in the surface direction of the end seal member 7 does not occur, so that the assembly position accuracy of the end seal member 7 with respect to the developer container 2 is improved. The Thereby, the sealing performance of the end seal member 7 is improved. Further, since the posture holding member 8 and the end seal member 7 can be assembled to the developer container 2 at the same time, the assembling property of the blade unit 5U and the productivity of the developing device are improved.
[0028]
As described above, the posture holding member 8 and the end seal member 7 are configured integrally with each other, as shown in FIGS. 5A and 5B, on the outside of the end seal member 7. The posture holding member 8 is bonded (in this case, the bent portion of the end portion 7a of the end seal member 7 may or may not be bonded), or FIG. As shown in d), the posture holding member 8 is bonded to the entire inner surface of the end seal member 7, and the tip 7 a of the end seal member 7 is pulled from the inside by the elastic action of the posture holding member 8. Any of the above may be used.
[0029]
Further, as shown in FIGS. 1 and 3, the developing device of the present invention has a mounting portion (here, the blade bracket 5A) of the blade unit 5U to the developer container 2 on the developer container 2 side. A pressing member 5D that presses the end seal member 7 toward the end may be provided. In this developing device, since the end seal member 7 is pressed toward the developer container 2 by the pressing member 5D, the end seal member 7 is lifted (peeled) from the developer container 2. ) Is prevented, and the sealing performance between the end seal member 7 and the gap between the blade unit 5U is improved. Here, the pressing member 5 </ b> D may directly press the end seal member 7, or may indirectly press the end seal member 7 via the posture holding member 8.
[0030]
In the present embodiment, the configuration in which the seal member 6 and the end seal member 7 are used to prevent the leakage of the developer from the rotating portion and the opening of the developing device is shown. 6 and the end seal member 7 can be widely applied as means for preventing leakage of powder from the rotating portion and the opening of the powder container for storing powder. Therefore, the present invention can be applied not only to the developing device but also to a cleaning device, a toner replenishing device, and the like.
[0031]
【The invention's effect】
According to the first to fourth aspects of the invention, since the arrangement posture of the end seal member is held by the posture holding member provided in the end seal member, when attaching the developer regulating member to the developer container, Buckling of the end of the seal member and the tip of the end seal member can be avoided, and the sealing performance of the seal member and the end seal member can be improved. Further, since the developer regulating member can be attached to the developer container relatively easily, it is possible to improve the assembling property of the developer regulating member and the productivity of the developing device. There is an effect.
[0032]
In particular, according to the second aspect of the present invention, since the posture holding member is formed of a thin plate made of an elastic body, the end seal member is enlarged or complicated by providing the posture holding member. There is an excellent effect that a small-sized and low-cost developing device can be provided.
[0033]
According to the invention of claim 3, since the posture holding member is integrally formed with the end seal member, the assembly position accuracy of the end seal member with respect to the developer container is improved, The sealing performance of the seal member and the end seal member can be improved. Further, since the posture holding member and the end seal member can be assembled at the same time with respect to the developer container, the excellent effect of improving the assembling property of the developer regulating member and the productivity of the developing device can be achieved. is there.
[0034]
According to a fourth aspect of the present invention, the end seal member is pressed toward the developer container by the pressing member provided at the attachment portion of the developer regulating member to the developer container. Therefore, the end seal member can be prevented from lifting (peeling) from the developer container, and the sealing performance between the end seal member and the gap between the developer regulating member and the arrangement portion can be improved. There is an excellent effect of being able to.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a developing device according to the present embodiment.
FIG. 2 is a perspective view illustrating a schematic configuration of a mounting portion for a seal member and an end seal member of a developer container in the developing device.
FIG. 3 is a schematic perspective view showing a mounting structure of a developing roller, a developer supply roller, and a blade unit in the developing device.
FIG. 4 is a schematic perspective view showing a mounting structure of the seal member and the end seal member.
FIGS. 5A, 5B, 5C, and 5D are a schematic perspective view and a schematic cross-sectional view showing an example in which the end seal member and the posture holding member are integrally configured.
FIG. 6 is a cross-sectional view showing a schematic configuration of a conventional developing device.
FIG. 7 is a schematic perspective view showing a mounting structure of a seal member and an end seal member in a conventional developing device.
FIG. 8 is a schematic cross-sectional view showing a mounting structure of a seal member and an end seal member in a conventional developing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Developing roller 1a Rotating shaft 2 of developing roller 2 Developer container 2a Developer container of developer container
2b Developer container opening 2c Developer container bearing holder 2d Developer container bearing hole 2e Reference pin 3 Bearing 4 Developer supply roller 5 Doctor blades 5A, 5B Blade bracket 5C Set screw 5D Press member 5U Blade unit 6 Seal member 6a Seal member end 7 End seal member 7a End seal member tip 7b End seal member round hole 8 Posture holding member 8a Posture hold member tip 8b Posture hold member round hole 9 Inlet seal 10 Developer 11, 12 Drive gear 13 Filler

Claims

A developing roller for carrying and carrying a developer on the surface;
A developer container having a developer accommodating portion for accommodating the developer and an opening for exposing a part of the surface of the developing roller;
Arranged so as to close the gap between the outer peripheral surface of the axial end of the developing roller and the surface portion of the side wall of the developer container facing the end protruding surface, and prevents overflow of the developer from the gap. A sealing member to be
A base end is attached to the developer container so as to be positioned upstream of the developing roller in the rotation direction in the vicinity of the opening, and a free end extending from the base end to the downstream in the developing roller rotation direction. A developer regulating member that regulates a layer thickness of the developer carried on the surface of the developing roller ;
The end of the seal member on the developer regulating member side is extended from the surface portion to provide a free end,
The base end portion closes the space between the developer regulating member and the surface portion of the side wall facing the developer regulating member, and the side surface of the free end portion that extends from the surface portion toward the developer carrying member, Providing an end seal member in close contact with the side surface of the free end portion of the seal member and closing the space between the peripheral surface of the developing roller and the developer regulating member base end portion together with the free end portion of the seal member; and
A developing device, wherein the end seal member is provided with a posture holding member for holding the arrangement posture of the end seal member in a state before the developer regulating member is attached .

The developing device according to claim 1, wherein the posture holding member is formed of a thin plate made of an elastic body.

The developing device according to claim 1, wherein the posture holding member is formed integrally with the end seal member.

4. The developing device according to claim 1, further comprising a pressing member that presses the end seal member toward the developer container.