JP4003033B2

JP4003033B2 - Developing device and electrophotographic apparatus using the same

Info

Publication number: JP4003033B2
Application number: JP2000394085A
Authority: JP
Inventors: 一臣大西; 徹宮坂; 雅彦斉藤; 知史吉田; 正治竹谷
Original assignee: リコープリンティングシステムズ株式会社
Priority date: 2000-12-26
Filing date: 2000-12-26
Publication date: 2007-11-07
Anticipated expiration: 2020-12-26
Also published as: JP2002196582A

Description

【０００１】
【発明の属する技術分野】
本発明は、プリンタやファクシミリおよび複写機などに用いられる電子写真装置の現像装置に関わり、特にトナーのみを現像剤として用いる非磁性一成分現像装置に関する。
【０００２】
【従来の技術】
従来の一成分現像装置では、一例として特開平４−８０７７４号公報に記載のように、トナー担持体上に摩擦帯電したトナー薄層を形成するために、トナー担持体上に圧接されるトナー規制部材を平板とする例が知られており、この構成が最も一般的な構成である。また、この他に特開平４−３３６５６４号公報に記載のように、トナー規制部材をトナー担持体の回転軸方向に平行に折り曲げ、トナ−担持体への圧接面と支持面を分けた構成や、特開平６−２１７２７０号公報に記載のように、折り曲げたトナー規制部材のトナー担持体への圧接位置と曲げ位置の中間の圧接面と反対側の面が支持部材の角部に接触する構成とした例が知られている。また、トナ−担持体上のトナー層厚を均一化させるための一例として、特開平８−１９４３７３号公報に記載のように、トナー担持体とトナー規制部材の圧接部において、トナー規制部材のトナー担持体に対して背向する面側に、トナー規制部材の機械強度を補強する補強部材を配設する構成等が知られている。
【０００３】
【発明が解決しようとする課題】
近年の電子写真装置は画像の高解像度化に伴い、微小着色紛体であるトナーの小粒径化が進んでいるが、トナー担持体上のトナー薄層の層厚が最終的な画像品質に大きな影響を与えるため、このトナー層厚を均一にする必要がある。
【０００４】
トナーをトナー担持体により搬送し、トナー規制部材をトナ−担持体に圧接することによりトナーの層厚を規制しながらトナー担持体上に摩擦帯電したトナーを形成する現像装置においては、トナー規制部材のトナー担持体への圧接が不均一であるとトナー層厚が不均一となり、またトナーの帯電量も不均一となる。その結果、画像の濃度ムラや背景部のカブリが発生し画像品位を著しく損なってしまう。
【０００５】
そのため、トナー担持体上にトナー薄層の層厚を均一に形成するためには、トナー担持体上にトナー規制部材をトナー担持体の回転軸方向に、適当な一定の均一な加圧力として圧接しなければならないが、そのためには、トナー規制部材の面精度を良くする必要がある。
【０００６】
前に述べた従来技術では、トナー規制部材は面制度を良くしやすい平板とするのが最も一般的な構成となっていた。
【０００７】
しかしながら、トナー規制部材を平板とすると、トナー規制部材のトナー担持体への圧接面と支持部材への支持面は同一面となるため、トナー規制部材が支持される支持部材のトナー規制部材への接触面の面制度がそのままトナ−規制部材のトナー担持体への圧接面の面制度に影響を及ぼすことになる。
【０００８】
そのため、支持部材のトナー規制部材への接触面の面制度も良くしなければならず、高精度加工が必要となるために低価格化が困難となる。
【０００９】
一方、これとは別に、トナー規制部材をトナー担持体の回転軸方向に折り曲げ、トナー担持体への圧接面と支持面を分けた構成とした場合、トナー規制部材が支持される支持部材のトナー規制部材への接触面の面制度がトナー規制部材のトナー担持体への圧接面の面精度に与える影響は少なくなる。
【００１０】
しかしながら、トナー担持体が回転駆動することにより発生するトナー規制部材のトナー担持体の圧接位置と支持位置の間に働く圧接面内の応力と支持部材の抑え方向が一致しないために、圧接位置が変動したりトナー規制部材が振動したりしてしまい、トナー担持体上にトナー薄層の層厚を均一に形成することができず、画像品位を損なってしまうことがある。
【００１１】
特開平６−２１７２７０号公報に記載の現像装置においても同様の課題があり、またさらに折り曲げたトナー規制部材のトナー担持体への圧接位置と、曲げ位置の中間の圧接面と反対側の面が支持部材の角部に接触する構成としたために、現像装置を小型化するのも困難となる。
【００１２】
また、特開平８−１９４３７３号公報に記載のように、トナー担持体とトナー規制部材の圧接部において、トナー規制部材のトナー担持体に対して背向する面側に、トナー規制部材の機械強度を補強する補強部材を配設する構成では、トナー規制部材がトナー担持体に均一に圧接することが可能となるが、構成が複雑となるために装置が大型化になるとともに高価になってしまう。
【００１３】
本発明の目的は、トナー担持体上に摩擦帯電したトナー薄層を均一に形成することができる構成を、簡単な構成により可能とし、高品位な画像が得られ、更に小型，低価格を実現した現像装置を提供することにある。
【００１４】
【課題を解決するための手段】
上記の目的を達成するために、本発明では、トナー担持体と、現像剤のトナーを格納するトナー格納室と、前記トナーを前記トナー担持体に供給する供給部と、前記トナー担持体上に均一なトナー薄層を形成するトナー規制部材と、前記トナー規制部材を固定するトナー規制部材支持体とを有し、前記トナー規制部材は、前記供給部に対して前記トナー担持体回転方向下流側でかつ前記トナー担持体の回転軸と垂直方向にある支持面で前記トナー規制部材支持体により支持され、前記供給部の方向に少なくとも１回折り曲げられ、圧接面で前記トナー担持体に圧接されている現像装置において、前記トナー規制部材支持体は、前記支持面を支持するトナー規制部材支持部が、前記トナー担持体の回転軸方向の両端部に対し中央部が前記トナー格納室側に凸型に変位するように構成される。
【００１５】
このような構成にすることで、トナー規制部材のトナー担持体への圧接部における圧接面を均一にすることができる。そのため、トナー担持体上に形成されるトナー薄層の層厚を均一にすることができ、その結果、濃度ムラや背景部カブリの少ない高品位な画像を得ることが可能な非磁性一成分現像装置を提供することができる。
【００１６】
また、トナー規制部材を折り曲げることによって、トナー規制部材をトナー担持体への圧接面と支持体との支持面とに分けることができるため、トナー規制部材と支持体を直線上に配設する必要がなくなり、設計の自由度が上がり、現像装置を小型化できる。
【００１７】
【発明の実施の形態】
以下、図１から図５を用いて本発明の実施例を説明する。
【００１８】
図２は、本発明の現像装置の一実施例を示す図である。
【００１９】
トナー格納室４には、現像に用いられる一成分の現像剤であるトナー１１が格納されている。トナー格納室４に配置された搬送羽根６の回転で順次トナー担持体１側にトナー１１を搬送して供給するように構成されている。トナー格納室４の前側（トナー担持体１の配置側）に、必要以上にトナー１１が偏らないように、トナー格納室４の後方（トナー担持体１が配置されている側とは反対側）の図示しない搬送羽根は最前部（トナー担持体１に最も近い側）の搬送羽根６に比較して搬送力が小さくなるようにすることが好ましい。つまり、トナー担持体１の配置位置から離れた位置に配置された搬送羽根ほど搬送力が小さくなるようにする。
【００２０】
本実施例では、トナー格納室４の最前部の搬送羽根６に対して、後方に配置されたほど回転速度が遅くなるようにし、かつ羽根面積の小さい搬送羽根としている。
【００２１】
トナー格納室４内のトナー１１は、これらの羽根の回転によってトナー担持体１側に搬送される。トナー担持体１の手前には、経路分離部材１２が配置され、これによってトナーの供給経路と回収経路とに上下に分離している。図２の実施例における経路分離部材１２は現像装置筐体とは別体であり、所定の位置に設置した後、両端で固定している。経路分離部材１２を別体に構成することで、現像装置筐体３よりも強度の大きい材質の樹脂を用いることができ、経路分離部材
１２をより撓みにくくすることができる。
【００２２】
経路分離部材１２上方の供給経路には、トナー担持体１へトナーを供給する供給部である導電性発泡弾性材を有する供給ロール２が配置されており、トナー格納室４内のトナー１１が最前部の搬送羽根６によって供給ロール２に供給される。供給ロール２は、現像作用を終えて戻ってきたトナー担持体１の表面に新しいトナーを擦り付けることにより、トナー担持体１へ新たなトナーを供給するとともにトナー担持体１上のトナー層を均一化する。トナー担持体１に供給されたトナー１１は、トナー担持体１に圧接されたトナー薄層規制部であるトナー規制部材９にて規制されて薄層化されるとともに、トナー規制部材９との摩擦により帯電される。
【００２３】
図１は、本発明の具体的な一実施例を示す図である。
【００２４】
トナー規制部材９はトナー担持体の回転軸方向に平行に鋭角で１３０度程度に折り曲げられており、一面がトナー担持体上１に圧接され、他の面がトナー規制部材支持体７によって支持されている。トナー規制部材９は、厚さ０.１mm 程度のステンレス，リン青銅等の弾性薄板状部材で構成する。このトナー規制部材９は、直接トナー担持体１に圧接してもよいし、圧接位置において厚さ１mm程度のウレタンゴム，シリコンゴム等を弾性薄板状部材に貼り合わせた二層構造として圧接してもよい。
【００２５】
トナー規制部材支持体７によるトナー規制部材９の支持方法としては、本実施例ではトナー規制部材支持体７および内面支持部材８によってトナー規制部材９の支持面を挟持するようにネジ１０によって固定する構成としているが、内面支持部材８を使用せずトナー規制部材支持体７に接着剤、両面テープまたは溶接等によって直接トナー規制部材９の支持面を固定してもよい。
【００２６】
更に、トナー規制部材支持体７は、トナー規制部材９の支持面を支持するトナー規制部材支持部が、トナー担持体１の回転軸方向の両端部に対し中央部がトナー格納室４側に凸型に変位している（図１矢印Ａ方向）。このように、変位させることにより、トナー規制部材９の先端部が引張られるため、トナー規制部材９先端の歪みが抑制される。その結果、トナー規制部材９とトナー担持体１との圧接部が均一化され、トナー規制部材９によって規制後にトナー担持体１上に形成されるトナー薄層の付着量及び帯電量を均一化することが可能となる。
以上
【００２７】
図３は、図１におけるトナー規制部材支持体を、真上から（図１矢印Ｂ）見た図である。トナー規制部材支持体７の両端部に対する変位量１３は、トナー規制部材支持体７におけるトナー規制部材支持部全長１４の中央部で一番大きくなっていることが好ましい。更には、トナー規制部材支持体７の両端部に対する変位量１３は、トナー規制部材支持体７におけるトナー規制部材支持部全長１４の中央部を頂点として滑らかに変位していることが好ましい。すなわち、トナー規制部材支持体７におけるトナー規制部材支持部は、図４のように波型になっていないことが好ましい。トナー規制部材支持体７におけるトナー規制部材支持部の変位形状が、図４に示すような波型になった場合、凹形状部Ｃの頂点部において、トナー規制部材の先端部に圧縮応力が生じてしまう。そのため、トナー規制部材支持体７の凹形状部Ｃの位置でトナー規制部材に歪みが生じ、その結果トナー規制部材９とトナー担持体１との圧接部が不均一になり、トナー規制部材９によって規制後にトナー担持体１上に形成されるトナー薄層の付着量及び帯電量が不均一になってしまう。
【００２８】
トナー規制部材支持体７における変位量の測定方法としては、ハイトゲージ等による接触式の測定方式、またはレーザ変位計等による非接触の測定方式が考えられる。いずれの測定方法でも、トナー規制部材支持体７の長手方向に対して少なくとも３箇所以上、もっとも好ましくはネジ締結個所およびネジ締結個所間に対して測定し、トナー規制部材支持体７の変位形状を確認するのがよい。
【００２９】
ここで、図１におけるトナー規制部材支持体７の変位量１３は、トナー規制部材９の厚みによっても異なるが、トナー規制部材支持体７におけるトナー規制部材支持部全長の０.０１〜０.３％であることが好ましく、もっとも好ましくは
０.０２〜０.２％の範囲である。トナー規制部材支持体７の中央部における変位量１３が、トナー規制部材支持部全長の０.０１％未満の場合、トナー規制部材９の先端部が十分に引張られず、その結果トナー規制部材９の平滑度が十分に得られない。また、トナー規制部材支持体７の中央部における変位量が、トナー規制部材支持部全長の０.３％より大きい場合、トナー規制部材９の先端部に発生する応力が大きくなってしまい、トナー規制部材９のトナー担持体１に対する圧接力が変動してしまうため好ましくない。
【００３０】
図５に、本発明の一実施例に係る現像装置を備えた画像形成装置の構成を示す。
【００３１】
図５に示すように、この画像形成装置は、静電潜像担持体である感光ベルト
１５が垂直方向に長く設置され、感光ベルト１５を境にして、その感光ベルトの一方側面（図中左側）に中間転写体である転写ドラム１６，転写装置１７，定着器１８が配置され、他方側面（図中右側）には４色の異なる色のトナーを充填された現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋが配置された構成とした。
【００３２】
さらに、現像装置１９Ｃの下部には、感光ベルト１５に潜像を形成するための露光装置２０が配置され、さらにその下には、記録媒体を格納しておく給紙カセット２１が配置されている。転写ドラム１６周辺には、転写装置１７，除電剥離装置２２，中間転写体クリーナ２３が配置され、感光ベルト１５周辺には帯電装置２４，感光体クリーナ２５が配置されている。
【００３３】
縦方向に張られた感光ベルト１５は、図示しない駆動装置により矢印Ｑの方向に駆動される。以下現像プロセスについて説明する。
【００３４】
最初に、駆動される感光ベルト１５表面の感光層が帯電装置２４によって一様に帯電される。次に、露光装置２０によりパソコン，イメージスキャナ等による画像，文字情報をドット単位で露光が行われ、感光ベルト１５上に静電潜像が形成される。その後、感光ベルト１５上の静電潜像は現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋの何れかにより現像されることによってトナー像として可視像化される。
【００３５】
感光ベルト１５は図示しない電源によりある電位を与えられており、転写ドラム１６はアースに接続されている。このため、これらの電位差により感光ベルト１５から転写ドラム１６へのトナー像の転写が行われる。
【００３６】
画像転写後の感光ベルト１５は、感光体クリーナ２５により第一転写で転写されずに残った感光ベルト１５上の残トナーが清掃され、次のトナー像形成が可能な状態となる。
【００３７】
前述した１サイクルの動作を、転写ドラム１６の１周のタイミングに合わせて各色現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋに対して順次行うことにより、転写ドラム１３上に単色トナー像を重ね合わせた複数色トナー画像が形成される。
【００３８】
尚、単色の現像装置の場合は、転写ドラム１６は必要なく、感光ベルト１５に形成されたトナー像を給紙カセット２１から搬送されてきた記録媒体に転写装置１７によって転写するようにしても良い。つまり静電潜像担持体である感光ベルト１５と、感光ベルト１５上に均一に帯電する帯電装置２４と、感光ベルト１５上に静電潜像を形成する露光装置２０と、その感光ベルト１５上にトナー画像を形成する現像装置１９と、トナー画像を記録媒体上に転写する転写装置１７と、記録媒体上にそのトナー画像を定着する定着器１８とを設ける構成とする。
【００３９】
一方、用紙，ＯＨＰシート等の記録媒体が、タイミングを取って転写装置１７に供給され、転写ドラム１６上に形成された単色あるいは複数色のトナー画像が転写装置１６の働きにより記録媒体に転写される。
【００４０】
記録媒体へのトナー像転写後、記録媒体は、除電剥離装置２２により転写ドラム１６より剥離され、定着器１８によりトナーを溶融定着され、排紙装置２６により本体上面に排紙される。
【００４１】
一方、記録媒体への転写終了後、転写されずに転写ドラム１６上に残った残トナーは中間転写体クリーナ２３により清掃され、次のトナー像重ね合わせが可能な状態となる。
【００４２】
記録媒体の給紙から排紙までの搬送経路をできるだけ簡略化し（転写装置１７，定着器１８，排紙装置２６の配置間隔を短くする）、給紙カセット２１からピックされた記録媒体に折り目がつかないように搬送経路の曲率半径を大きくすることによって、搬送途中での紙詰まりが防止でき、信頼性を向上させることができる。また、紙詰まり時の処理も簡単に行うことができる。さらに、厚紙等の多種記録媒体にも対応できる。
【００４３】
本実施例では、記録媒体搬送経路を略円弧状に配置し、転写ドラム１６，感光ベルト１５，現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋ、露光装置２２等を記録媒体搬送経路の内側に配置することによって空間を有効利用して本体を小型化し、搬送経路を簡略化し、記録媒体排出時、印字面を下向きに排出する構成としている。
【００４４】
上記のように配置にすることによって搬送経路を簡略化でき、かつ、ほとんどのユニットが搬送経路よりも本体内側に配置されるため、搬送経路が機枠体１９（外枠）に近く、搬送経路を開放しやすいため、紙詰まり時の処理も簡単に行うことができる。また、排出時印字面を下向きに排出することは印字面側から印刷順に並んで排出される利点がある。
【００４５】
また、感光体をベルト状の構成にすることによって、複数色の現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋをほぼ同一の形状で感光ベルト１５の同一平面に配置することができ、現像する色に合わせて現像装置３Ｙ，３Ｍ，３Ｃ，３Ｋを交替させるための機構や各色毎に現像装置形状を変更する等の必要がないので、小型化，低価格化を図ることができる。
【００４６】
また、感光ベルト１５を垂直方向に長く配置することによって同一周長での感光ベルトの占有する空間を小さくすることができるため、本体を小型化することができると共に、感光ベルト１５の交換時、そのまま上方へ引き出して交換することが可能となり、メンテナンス性を良くすることができる。
【００４７】
また、記録媒体を本体下部から上部に向けて搬送する時、転写ドラム１６は矢印Ｕの方向に回転し、感光ベルト１５は矢印Ｑの方向に回転することによって各接点でそれぞれ順方向に動作することになり、現像効率が良く、振動等の問題の少ない構成が得られる。
【００４８】
また、転写ドラム１６を感光ベルト１５に対して従動とすることができ色ズレの少ない構成とすることができる。
【００４９】
【発明の効果】
以上述べたように、本実施例の構成によれば、簡単な構成で、トナー層規制部材とトナー担持体を均一で安定に接触させることができる。従って、トナー担持体上のトナー層の帯電量および付着量を均一化できるため、濃度むら等のない安定な画像を得る事が可能な、小型・低価格・高性能な現像装置及びそれを用いた電子写真装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示すトナー規制部材およびトナー規制部材支持体の図である。
【図２】本発明の一実施例を用いた現像装置の断面図である。
【図３】本発明の現像装置の、トナー規制部材支持体の一実施例を示す図である。
【図４】トナー規制部材支持体の他の形状を示す図である。
【図５】本発明の適用可能な多色画像形成装置の一実施例を示す図である。
【符号の説明】
１…トナー担持体、２…供給ロール、３…現像装置、３Ｋ…現像装置（黒）、３Ｙ…現像装置（イエロー）、３Ｍ…現像装置（マゼンタ）、３Ｃ…現像装置
（シアン）、４…トナー格納室、５…トナー掻出し部材、６…トナー搬送部材、７…トナー規制部材支持体、８…内面支持部材、９…トナー規制部材、１０…ネジ、１１…トナー、１２…経路分離部材、１３…トナー規制部材支持体変位量、１４…トナー規制部材支持体におけるトナー規制部材支持範囲、１５…感光体、１６…中間転写体、１７…転写装置、１８…定着装置、１９…機枠体（外枠）、２０…露光装置、２１…用紙カセット、２２…除電剥離装置、２３…中間転写体クリーナ、２４…帯電器、２５…感光体クリーナ、２６…排紙装置。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device of an electrophotographic apparatus used for a printer, a facsimile, a copying machine, and the like, and more particularly, to a non-magnetic one-component developing device using only toner as a developer.
[0002]
[Prior art]
In a conventional one-component developing device, as described in Japanese Patent Application Laid-Open No. 4-80774, for example, a toner regulation that is pressed onto a toner carrier to form a frictionally charged thin toner layer is formed on the toner carrier. The example which makes a member a flat plate is known, and this structure is the most common structure. In addition, as described in JP-A-4-336564, the toner regulating member is bent in parallel with the rotation axis direction of the toner carrier, and the pressure contact surface and the support surface to the toner carrier are separated. As described in JP-A-6-217270, the surface of the bent toner regulating member on the side opposite to the pressure contact surface between the pressure contact position and the bending position of the toner carrying member is in contact with the corner of the support member. Examples are known. Further, as an example for making the toner layer thickness on the toner carrier uniform, as described in Japanese Patent Application Laid-Open No. 8-194373, the toner of the toner regulating member is used in the pressure contact portion between the toner carrier and the toner regulating member. A configuration in which a reinforcing member that reinforces the mechanical strength of the toner regulating member is disposed on the side facing away from the carrier is known.
[0003]
[Problems to be solved by the invention]
In recent years, with the increase in image resolution, the electrophotographic apparatus has been made to reduce the particle size of toner, which is a finely colored powder, but the thickness of the toner thin layer on the toner carrier is large in the final image quality. In order to exert an influence, it is necessary to make the toner layer thickness uniform.
[0004]
In a developing device that forms toner that is frictionally charged on a toner carrier while regulating the layer thickness of the toner by conveying toner by the toner carrier and pressing the toner regulating member against the toner carrier, the toner regulating member If the pressure contact with the toner carrier is not uniform, the toner layer thickness is non-uniform, and the toner charge amount is also non-uniform. As a result, the density unevenness of the image and the fogging of the background occur, and the image quality is remarkably impaired.
[0005]
Therefore, in order to form a uniform thickness of the toner thin layer on the toner carrier, the toner regulating member is pressed onto the toner carrier as an appropriate constant uniform pressure in the direction of the rotation axis of the toner carrier. For this purpose, it is necessary to improve the surface accuracy of the toner regulating member.
[0006]
In the prior art described above, the most common configuration is that the toner regulating member is a flat plate that facilitates improving the surface system.
[0007]
However, if the toner restricting member is a flat plate, the pressure contact surface of the toner restricting member to the toner carrier and the support surface to the support member are the same surface, and therefore the support member on which the toner restricting member is supported is attached to the toner restricting member. The surface system of the contact surface directly affects the surface system of the pressure contact surface of the toner regulating member to the toner carrier.
[0008]
Therefore, the surface system of the contact surface of the support member to the toner regulating member must be improved, and high-precision machining is required, so that it is difficult to reduce the cost.
[0009]
On the other hand, when the toner regulating member is bent in the direction of the rotation axis of the toner carrier and the pressure contact surface to the toner carrier and the support surface are separated, the toner of the support member that supports the toner regulating member The influence of the surface system of the contact surface with the restriction member on the surface accuracy of the pressure contact surface of the toner restriction member with the toner carrier is reduced.
[0010]
However, since the stress in the pressure contact surface between the pressure-contact position of the toner-carrying member and the support position of the toner-carrying member generated when the toner-carrying member is driven to rotate does not match the pressing direction of the support member. The toner regulating member may fluctuate or the toner regulating member may vibrate, so that the thickness of the toner thin layer cannot be uniformly formed on the toner carrier, and the image quality may be impaired.
[0011]
The developing device described in JP-A-6-217270 has the same problem, and further, the pressed position of the bent toner regulating member to the toner carrying member and the surface opposite to the pressed face in the middle of the bent position are provided. Since the structure contacts the corners of the support member, it is difficult to reduce the size of the developing device.
[0012]
Further, as described in Japanese Patent Laid-Open No. 8-194373, the mechanical strength of the toner restricting member is provided on the surface of the pressure contact portion between the toner carrying member and the toner restricting member facing away from the toner carrying member. In the configuration in which the reinforcing member that reinforces the toner is provided, the toner regulating member can be uniformly pressed against the toner carrier. However, since the configuration is complicated, the apparatus becomes large and expensive. .
[0013]
The object of the present invention is to enable a simple structure to form a thin layer of toner that is triboelectrically charged on a toner carrier, to obtain a high-quality image, and to achieve a smaller size and a lower price. Another object of the present invention is to provide a developing device.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a toner carrier, a toner storage chamber for storing developer toner, a supply unit for supplying the toner to the toner carrier, and a toner carrier are provided on the toner carrier. possess a toner regulating member for forming a uniform thin toner layer, the toner regulating member support for fixing the toner regulating member, the toner regulating member, the toner carrying member rotation direction downstream side with respect to the supply part And supported by the toner regulating member support at a support surface perpendicular to the rotation axis of the toner carrier, bent at least once in the direction of the supply unit, and pressed against the toner carrier at the pressure contact surface. In the developing device, the toner restricting member support includes a toner restricting member supporting portion that supports the support surface, and a center portion of the toner restricting member supporting portion is opposite to both ends of the toner carrying member in the rotation axis direction. To pay chamber side Ru is configured so as to be displaced in a convex shape.
[0015]
With this configuration, the pressure contact surface of the pressure contact portion of the toner regulating member to the toner carrier can be made uniform. As a result, the layer thickness of the toner thin layer formed on the toner carrying member can be made uniform, and as a result, non-magnetic one-component development capable of obtaining a high-quality image with less density unevenness and background fogging. An apparatus can be provided.
[0016]
Further, by bending the toner regulating member, the toner regulating member can be divided into a pressure contact surface to the toner carrying member and a supporting surface of the supporting member, so that it is necessary to arrange the toner regulating member and the supporting member on a straight line. This increases the degree of freedom in design and makes it possible to downsize the developing device.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to FIGS.
[0018]
FIG. 2 is a diagram showing an embodiment of the developing device of the present invention.
[0019]
The toner storage chamber 4 stores toner 11 which is a one-component developer used for development. The toner 11 is sequentially transported and supplied to the toner carrier 1 side by the rotation of the transport blade 6 disposed in the toner storage chamber 4. Behind the toner storage chamber 4 (on the side opposite to the side on which the toner carrier 1 is disposed) so that the toner 11 is not biased to the front side of the toner storage chamber 4 (on the side where the toner carrier 1 is disposed). It is preferable that the conveyance blade (not shown) has a smaller conveyance force than the conveyance blade 6 at the foremost part (the side closest to the toner carrier 1). That is, the conveyance force is reduced as the conveyance blade is arranged at a position away from the arrangement position of the toner carrier 1.
[0020]
In this embodiment, with respect to the transport blade 6 at the foremost part of the toner storage chamber 4, the rotational speed decreases as the rear blade is disposed, and the transport blade has a small blade area.
[0021]
The toner 11 in the toner storage chamber 4 is transported to the toner carrier 1 side by the rotation of these blades. A path separating member 12 is disposed in front of the toner carrier 1, thereby separating the toner supply path and the recovery path vertically. The path separating member 12 in the embodiment of FIG. 2 is a separate body from the developing device casing, and is fixed at both ends after being installed at a predetermined position. By configuring the path separating member 12 as a separate body, it is possible to use a resin having a strength higher than that of the developing device housing 3 and to make the path separating member 12 more difficult to bend.
[0022]
In the supply path above the path separation member 12, a supply roll 2 having a conductive foamed elastic material, which is a supply unit for supplying toner to the toner carrier 1, is disposed, and the toner 11 in the toner storage chamber 4 is at the forefront. It is supplied to the supply roll 2 by the conveying blade 6 of the part. The supply roll 2 rubs new toner against the surface of the toner carrier 1 that has returned after completion of the developing operation, thereby supplying new toner to the toner carrier 1 and making the toner layer on the toner carrier 1 uniform. To do. The toner 11 supplied to the toner carrier 1 is regulated and thinned by a toner regulation member 9 which is a toner thin layer regulation part pressed against the toner carrier 1 and is also frictioned with the toner regulation member 9. Is charged by.
[0023]
FIG. 1 is a diagram showing a specific embodiment of the present invention.
[0024]
The toner regulating member 9 is bent at an acute angle of about 130 degrees parallel to the rotation axis direction of the toner carrying member, one surface is pressed against the toner carrying member 1, and the other surface is supported by the toner regulating member support 7. ing. The toner regulating member 9 is made of an elastic thin plate member such as stainless steel or phosphor bronze having a thickness of about 0.1 mm. The toner regulating member 9 may be in direct pressure contact with the toner carrier 1 or in a pressure contact position as a two-layer structure in which urethane rubber, silicon rubber or the like having a thickness of about 1 mm is bonded to an elastic thin plate member. Also good.
[0025]
As a method of supporting the toner regulating member 9 by the toner regulating member support 7, in this embodiment, the toner regulating member support 7 and the inner surface supporting member 8 are fixed with screws 10 so that the supporting surface of the toner regulating member 9 is sandwiched. Although it is configured, the support surface of the toner regulating member 9 may be directly fixed to the toner regulating member support 7 without using the inner surface supporting member 8 by an adhesive, a double-sided tape, welding or the like.
[0026]
Further, in the toner regulating member support 7, the toner regulating member supporting portion that supports the supporting surface of the toner regulating member 9 has a central portion that protrudes toward the toner storage chamber 4 with respect to both ends in the rotation axis direction of the toner carrier 1. Displaced in the mold (direction of arrow A in FIG. 1). In this way, by varying position, the tip portion of the toner regulating member 9 is pulled, the distortion of the toner regulating member 9 the tip is prevented. As a result, the pressure contact portion between the toner regulating member 9 and the toner carrier 1 is made uniform, and the adhesion amount and the charge amount of the toner thin layer formed on the toner carrier 1 after regulation are made uniform by the toner regulating member 9. It becomes possible.
[0027]
3 is a view of the toner regulating member support in FIG. 1 as viewed from directly above (arrow B in FIG. 1). It is preferable that the displacement amount 13 with respect to both end portions of the toner regulating member support 7 is the largest at the central portion of the toner regulating member support portion full length 14 in the toner regulating member support 7. Further, it is preferable that the displacement amount 13 with respect to both ends of the toner regulating member support 7 is smoothly displaced with the central portion of the total length 14 of the toner regulating member support portion 7 in the toner regulating member support 7 as a vertex. That is, it is preferable that the toner regulating member support portion in the toner regulating member support 7 is not wave-shaped as shown in FIG. When the displacement shape of the toner restricting member support in the toner restricting member support 7 has a corrugated shape as shown in FIG. 4, a compressive stress is generated at the tip of the toner restricting member at the apex of the recessed portion C. End up. For this reason, the toner regulating member is distorted at the position of the concave portion C of the toner regulating member support 7, and as a result, the pressure contact portion between the toner regulating member 9 and the toner carrier 1 becomes non-uniform. The adhesion amount and the charge amount of the toner thin layer formed on the toner carrier 1 after the regulation are not uniform.
[0028]
As a method for measuring the amount of displacement in the toner regulating member support 7, a contact measurement method using a height gauge or the like, or a non-contact measurement method using a laser displacement meter or the like can be considered. In any measurement method, measurement is performed at least at three or more positions in the longitudinal direction of the toner restricting member support 7, most preferably between screw tightening positions and screw tightening positions, and the displacement shape of the toner restricting member support 7 is determined. It is good to check.
[0029]
Here, the amount of displacement 13 of the toner regulating member support 7 in FIG. 1 varies depending on the thickness of the toner regulating member 9, but is 0.01 to 0.3 of the total length of the toner regulating member support in the toner regulating member support 7. %, And most preferably in the range of 0.02 to 0.2%. When the amount of displacement 13 at the center of the toner regulating member support 7 is less than 0.01% of the total length of the toner regulating member support, the tip of the toner regulating member 9 is not sufficiently pulled, and as a result, the toner regulating member 9 The smoothness of is not sufficiently obtained. Further, when the amount of displacement at the central portion of the toner regulating member support 7 is larger than 0.3% of the total length of the toner regulating member support, the stress generated at the tip of the toner regulating member 9 becomes large, and the toner regulating member 9 becomes large. This is not preferable because the pressing force of the member 9 against the toner carrier 1 varies.
[0030]
FIG. 5 shows a configuration of an image forming apparatus including a developing device according to an embodiment of the present invention.
[0031]
As shown in FIG. 5, in this image forming apparatus, a photosensitive belt 15 serving as an electrostatic latent image carrier is installed long in the vertical direction, and one side surface (left side in the figure) of the photosensitive belt with the photosensitive belt 15 as a boundary. ), A transfer drum 16, which is an intermediate transfer member, a transfer device 17, and a fixing device 18, are arranged on the other side (right side in the drawing), and developing devices 3Y, 3M, 3C, which are filled with toners of four different colors. It was set as the structure by which 3K is arrange | positioned.
[0032]
Further, an exposure device 20 for forming a latent image on the photosensitive belt 15 is disposed below the developing device 19C, and a paper feed cassette 21 for storing a recording medium is disposed below the exposure device 20. . Around the transfer drum 16, a transfer device 17, a charge / separation device 22, and an intermediate transfer body cleaner 23 are arranged, and around the photosensitive belt 15, a charging device 24 and a photoconductor cleaner 25 are arranged.
[0033]
The photosensitive belt 15 stretched in the vertical direction is driven in the direction of arrow Q by a driving device (not shown). The development process will be described below.
[0034]
First, the photosensitive layer on the surface of the driven photosensitive belt 15 is uniformly charged by the charging device 24. Next, the exposure device 20 exposes image and character information by a personal computer, an image scanner or the like in dot units, and an electrostatic latent image is formed on the photosensitive belt 15. Thereafter, the electrostatic latent image on the photosensitive belt 15 is developed by any of the developing devices 3Y, 3M, 3C, and 3K to be visualized as a toner image.
[0035]
The photosensitive belt 15 is given a potential by a power source (not shown), and the transfer drum 16 is connected to the ground. Therefore, the toner image is transferred from the photosensitive belt 15 to the transfer drum 16 by these potential differences.
[0036]
After the image transfer, the photosensitive belt 15 is cleaned by the photoreceptor cleaner 25 and the remaining toner on the photosensitive belt 15 remaining without being transferred by the first transfer is ready for the next toner image formation.
[0037]
The above-described one-cycle operation is sequentially performed with respect to the color developing devices 3Y, 3M, 3C, and 3K in accordance with the timing of one rotation of the transfer drum 16, so that a plurality of monochromatic toner images are superimposed on the transfer drum 13. A color toner image is formed.
[0038]
In the case of a monochromatic developing device, the transfer drum 16 is not necessary, and the toner image formed on the photosensitive belt 15 may be transferred to the recording medium conveyed from the paper feed cassette 21 by the transfer device 17. . That is, the photosensitive belt 15 that is an electrostatic latent image carrier, the charging device 24 that uniformly charges the photosensitive belt 15, the exposure device 20 that forms an electrostatic latent image on the photosensitive belt 15, and the photosensitive belt 15 A developing device 19 for forming a toner image, a transfer device 17 for transferring the toner image onto a recording medium, and a fixing device 18 for fixing the toner image on the recording medium are provided.
[0039]
On the other hand, a recording medium such as paper or an OHP sheet is supplied to the transfer device 17 in a timely manner, and a single-color or multi-color toner image formed on the transfer drum 16 is transferred to the recording medium by the operation of the transfer device 16. The
[0040]
After the transfer of the toner image to the recording medium, the recording medium is peeled off from the transfer drum 16 by the static eliminator 22, the toner is melted and fixed by the fixing device 18, and discharged onto the upper surface of the main body by the paper discharge device 26.
[0041]
On the other hand, after the transfer to the recording medium is completed, the residual toner that is not transferred and remains on the transfer drum 16 is cleaned by the intermediate transfer body cleaner 23, so that the next toner image can be superimposed.
[0042]
The conveyance path from the feeding of the recording medium to the paper discharge is simplified as much as possible (the arrangement interval of the transfer device 17, the fixing device 18 and the paper discharge device 26 is shortened), and the crease is formed in the recording medium picked from the paper feed cassette 21. By increasing the radius of curvature of the transport path so as not to connect, paper jams during transport can be prevented, and reliability can be improved. In addition, processing at the time of paper jam can be easily performed. Furthermore, it can be used for various recording media such as cardboard.
[0043]
In this embodiment, the recording medium conveyance path is arranged in a substantially arc shape, and the transfer drum 16, the photosensitive belt 15, the developing devices 3Y, 3M, 3C, 3K, the exposure device 22 and the like are arranged inside the recording medium conveyance path. Thus, the space is effectively used to reduce the size of the main body, simplify the conveyance path, and discharge the printing surface downward when the recording medium is discharged.
[0044]
By arranging as described above, the conveyance path can be simplified, and since most units are arranged inside the main body with respect to the conveyance path, the conveyance path is close to the machine frame 19 (outer frame), and the conveyance path Since it is easy to release the paper, processing at the time of paper jam can be easily performed. Further, discharging the printing surface downward at the time of discharging has an advantage of discharging in order of printing from the printing surface side.
[0045]
Further, by forming the photosensitive member in a belt-like configuration, the developing devices 3Y, 3M, 3C, and 3K of a plurality of colors can be arranged on the same plane of the photosensitive belt 15 with substantially the same shape, and match the color to be developed. Thus, there is no need to change the developing device 3Y, 3M, 3C, 3K, or to change the shape of the developing device for each color, so that the size and cost can be reduced.
[0046]
In addition, since the space occupied by the photosensitive belt having the same circumference can be reduced by arranging the photosensitive belt 15 long in the vertical direction, the main body can be reduced in size, and when the photosensitive belt 15 is replaced, As it is possible to replace it by pulling it upward as it is, maintenance can be improved.
[0047]
Further, when the recording medium is conveyed from the lower part of the main body toward the upper part, the transfer drum 16 rotates in the direction of arrow U, and the photosensitive belt 15 rotates in the direction of arrow Q, so that each contact point operates in the forward direction. In other words, a structure with good development efficiency and less problems such as vibration can be obtained.
[0048]
Further, the transfer drum 16 can be driven with respect to the photosensitive belt 15, and a configuration with little color misregistration can be achieved.
[0049]
【The invention's effect】
As described above, according to the configuration of this embodiment, the toner layer regulating member and the toner carrier can be brought into uniform and stable contact with a simple configuration. Therefore, since the charge amount and adhesion amount of the toner layer on the toner carrier can be made uniform, a small, low-cost, high-performance developing device capable of obtaining a stable image without density unevenness and the like are used. An electrophotographic apparatus can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram of a toner regulating member and a toner regulating member support showing an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a developing device using an embodiment of the present invention.
FIG. 3 is a view showing an embodiment of a toner regulating member support of the developing device of the present invention.
FIG. 4 is a view showing another shape of the toner regulating member support.
FIG. 5 is a diagram showing an embodiment of a multicolor image forming apparatus to which the present invention is applicable.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Toner carrier, 2 ... Supply roll, 3 ... Developing device, 3K ... Developing device (black), 3Y ... Developing device (yellow), 3M ... Developing device (magenta), 3C ... Developing device (cyan), 4 ... Toner storage chamber, 5 ... toner scraping member, 6 ... toner conveying member, 7 ... toner regulating member support, 8 ... inner surface supporting member, 9 ... toner regulating member, 10 ... screw, 11 ... toner, 12 ... path separating member , 13: Toner regulating member support displacement amount, 14 ... Toner regulating member support range in toner regulating member support, 15 ... Photoconductor, 16 ... Intermediate transfer member, 17 ... Transfer device, 18 ... Fixing device, 19 ... Machine frame Body (outer frame), 20 ... exposure device, 21 ... paper cassette, 22 ... static discharge peeling device, 23 ... intermediate transfer body cleaner, 24 ... charger, 25 ... photoconductor cleaner, 26 ... discharge device.

Claims

トナー担持体と、現像剤のトナーを格納するトナー格納室と、前記トナーを前記トナー担持体に供給する供給部と、前記トナー担持体上に均一なトナー薄層を形成するトナー規制部材と、前記トナー規制部材を固定するトナー規制部材支持体とを有し、前記トナー規制部材は、前記供給部に対して前記トナー担持体回転方向下流側でかつ前記トナー担持体の回転軸と垂直方向にある支持面で前記トナー規制部材支持体により支持され、前記供給部の方向に少なくとも１回折り曲げられ、圧接面で前記トナー担持体に圧接されている現像装置において、前記トナー規制部材支持体は、前記支持面を支持するトナー規制部材支持部が、前記トナー担持体の回転軸方向の両端部に対し中央部が前記トナー格納室側に凸型に変位していることを特徴とする現像装置。A toner carrier, a toner storage chamber for storing developer toner, a supply unit for supplying the toner to the toner carrier, a toner regulating member for forming a uniform toner thin layer on the toner carrier, have a toner regulating member support for fixing the toner regulating member, the toner regulating member, the toner carrying member rotation direction downstream side and the rotation shaft perpendicular direction of said toner carrying member with respect to the supply unit In the developing device that is supported by the toner regulating member support at a certain support surface, bent at least once in the direction of the supply unit, and is pressed against the toner carrier at the pressure contact surface, the toner regulation member support includes: and wherein the toner regulating member support portion for supporting the support surface, the central portion to both end portions in the rotation axis direction of the toner carrier is displaced in a convex type in the toner storage chamber side That the developing device.

請求項１記載の現像装置において、前記トナー規制部材支持部が凸型に変位した変位量は、前記トナー規制部材支持部全長の０The developing device according to claim 1, wherein a displacement amount of the toner regulating member supporting portion displaced in a convex shape is 0 of a total length of the toner regulating member supporting portion. .. ０１〜０01-0 .. ３％の範囲であることを特徴とする現像装置。A developing device characterized by being in the range of 3%.

請求項１または２記載の現像装置において、前記トナー格納室は、経路分離部材によりトナー供給経路と回収経路に分離され、前記供給経路には前記トナー担持体へトナーを供給する供給ローラが配置されていることを特徴とする現像装置。3. The developing device according to claim 1, wherein the toner storage chamber is separated into a toner supply path and a recovery path by a path separating member, and a supply roller for supplying toner to the toner carrier is disposed in the supply path. A developing device.

請求項１、２または請求項３記載の現像装置を備えたことを特徴とする電子写真装置。An electrophotographic apparatus comprising the developing device according to claim 1.