JP3870622B2

JP3870622B2 - Development device

Info

Publication number: JP3870622B2
Application number: JP26300599A
Authority: JP
Inventors: 彰一吉川; 日出幸温
Original assignee: Konica Minolta Business Technologies Inc
Current assignee: Konica Minolta Business Technologies Inc
Priority date: 1999-09-17
Filing date: 1999-09-17
Publication date: 2007-01-24
Anticipated expiration: 2019-09-17
Also published as: JP2001083800A

Description

【０００１】
【発明の属する技術分野】
本発明は潜像担持体が担持している潜像を複数の現像器を切替え使用して現像し、単色画像や複数の色の合成画像、カラー画像が形成できるようにする現像装置に関するものである。
【０００２】
【従来の技術】
現像器はその現像ローラと潜像担持体との間の距離を一定にする技術として、例えば特開平８−２７２１８０号公報、特開平９−２８１８００号公報は、図11に示すように現像ローラａの両端部に設けた間隔保持ローラｂを介して現像器ｃを潜像担持体である感光体ドラムｄに圧接させることにより高精度に位置決めできるようにすることを開示している。また、複数の現像器ｃを切替え使用するため、必要数の現像器を往復移動や特開平１０−３０１４６３号公報に開示のもののように回転する支持体により支持し、支持体の往復移動や回転によりその時々に必要な現像器ｃを感光体ドラムｄと対向する現像位置に切替え位置させて使用するようにしている。
【０００３】
一方、現像器ｃは、現像剤を消費し切ったときに交換をしたり、あるいは必要なメンテナンスをしたりするのに、支持体に対し着脱できるように支持されるが、ユーザでも容易に着脱できるようにすることが望まれ、特開平１０−３０１４６３号公報に開示のように、支持体の現像器ｃを駆動する駆動機構を持たない非駆動側となる機体の側面において、現像器ｃを現像ローラａに平行な方向に出し入れして着脱することが知られている。
【０００４】
複数の現像器ｃを切替え使用する場合、非使用位置にて着脱すると感光体ドラムｄとの間で干渉することはない。そこで、このような着脱できる支持構造において、使用位置とされた現像器ｃが感光体ドラムｄとの間で間隔保持ローラｂを介し高精度に位置決めされるようにするため、従来、現像器ｃの駆動側の固定支点ｅを感光体ドラムｄと離接するｘ方向に可動なように長孔ｆなどで支持しておき、現像器ｃを感光体ドラムｄの側にばねｇで付勢することが第１の方法として行われている。
【０００５】
しかし、駆動側の固定支点ｅを感光体ドラムｄと離接するｘ方向に可動にすることは、現像器ｃの被駆動ギヤｈの前記駆動ギヤｊに対する噛み合い向きが、前記離接方向ｘと直角なｙ方向の向きとされ、ｘ方向に互いに相対移動できるようにする必要がある。
【０００６】
このような駆動機構では、駆動ギヤｊから被駆動ギヤｈへの駆動伝達において、その回転方向に従った駆動ギヤｊと被駆動ギヤｈとのｘ方向の相対移動に伴い現像器ｃを感光体ドラムｄに押圧しあるいは感光体ドラムｄから引き離す方向の力として影響しやすく、現像器ｃの現像剤の残量の変化などによる駆動トルクの変動によって現像器ｃの感光体ドラムｄへの圧接力に変化をもたらし、現像ギャップｋが変動して現像むら、画像濃度むらの原因になる。また、このとき、被駆動ギヤｈが駆動ギヤｊに対しｘ方向に移動する分だけ駆動ギヤｊとの噛み合いピッチが変化し、噛み合い周波数が変動するので画像ノイズが発生する。
【０００７】
これを解消するのに従来、現像器の駆動側の固定支点を軸直角方向に支持して固定し、被駆動側の固定支点を像担持体と離接する方向に支持して、現像器を潜像担持体の側に付勢することが、第２の方法として行われている。
【０００８】
【発明が解決しようとする課題】
しかし、上記のような第２の方法でも、現像器を支持する支持体のフレームに振動などによる歪が生じたり、現像器の駆動側および非駆動側の固定支点位置や、支持体のフレームの前記固定支点を支持する孔などの製造上の精度が低い場合に、駆動側および非駆動側の固定支点を結ぶ線と現像ローラとが平行にならず、現像ギャップが駆動側と非駆動側とで異なり画像濃度差としてあらわれることがあるので問題となる。これは第１の方法の場合も同様に生じ得る。
【０００９】
本発明の目的は、被駆動ギヤの駆動ギヤとの噛み合いが変動しにくく、かつ現像器の潜像担持体との間の現像ギャップが変動したり長手方向に不均一になったりしにくい信頼性の高い現像装置を提供することにある。
【００１０】
【課題を解決するための手段】
本発明の現像装置は、潜像担持体と現像ローラとの間の距離を一定にする間隔保持部材を介して現像器を潜像担持体に圧接させたものであり、
上記のような目的を達成するために、特に、一端側にのみ配置され、駆動ギヤと噛み合って駆動の伝達を受ける被駆動ギヤ、この被駆動ギヤを持った駆動側に配置された固定支点、非駆動側に配置され現像ローラとの間の距離が可変な可動支点を有した、複数の現像器と、複数の現像器をそれらの被駆動ギヤが駆動ギヤに噛み合うようにして支持し、それら現像器を潜像担持体と現像ローラが対向する現像位置に切替え位置させるとともに、各現像器を駆動ギヤを持たない非駆動側から駆動ギヤを持った駆動側に現像ローラに平行な方向で受入れ着脱できるようにするガイド、現像器の装着最終段階で現像器を現像位置での潜像担持体との対向側に付勢する付勢手段、を有し、現像器の装着最終段階でその駆動側の固定支点および非駆動側の可動支点を軸直角方向に支持する支持体と、を備えたことを特徴としている。
【００１１】
このような構成では、現像器は非現像位置にて潜像担持体との干渉なしに現像ローラと平行な方向にて容易に着脱できるようにしながら、支持体への装着最終段階にて駆動側の固定支点が軸直角方向に支持されることにより、駆動負荷が変動しても駆動側の固定支点は変位せず、被駆動ギヤが支持体の駆動ギヤと一定位置にて噛み合い続けられるようにして、噛み合いピッチが変化し噛み合い周波数が変動するのを防止するとともに、前記駆動負荷が現像器の潜像担持体への圧接状態に影響するのを抑えることができ、しかも、現像器の非駆動側は支持体に軸直角方向に支持されながら現像ローラとの間の距離が可変な可動支点により、この可変な範囲で現像器の非駆動側を支持体への支持から遊びを持たせて、現像器の固定支点や支持体の支点支持孔などに製造上の位置誤差や支持体のフレームに振動などによる歪みがあっても、現像器は前記遊びの範囲でそのような位置誤差や歪みを吸収して潜像担持体に馴染みよく圧接されて間隔保持部材による設定通りの現像ギャップを確保しやすくするので、被駆動ギヤの駆動ギヤとの噛み合いの変動による画像ノイズや現像器の潜像担持体との間の現像ギャップが変動したり長手方向に不均一になったりすることによる画像の濃度変化や濃度むらが生じにくく、信頼性の高いものとなる。
【００１４】
本発明の現像装置は、また、一端側にのみ配置され、駆動ギヤと噛み合って駆動の伝達を受ける被駆動ギヤ、この被駆動ギヤを持った駆動側およびその反対の非駆動側に現像ローラと平行な同一軸線上に配置された固定支点、非駆動側に配置され非駆動側の固定支点を軸直角方向に支持するように嵌り合うとともに現像ローラとの間の距離が可変な可動支点を持つ支持部材、を備えた複数の現像器と、複数の現像器をそれらの被駆動ギヤが駆動ギヤに噛み合うようにして支持し、それら現像器を潜像担持体と現像ローラが対向する現像位置に切替え位置させるとともに、各現像器を駆動ギヤを持たない非駆動側から駆動ギヤを持った駆動側に現像ローラに平行な方向で受入れ着脱できるようにするガイド、現像器の装着最終段階で現像器を現像位置での潜像担持体との対向側に付勢する付勢手段、を有し、現像器の装着最終段階でその駆動側の固定支点および支持部材の可動支点を軸直角方向に支持し、現像器が駆動側および非駆動側の固定支点のまわりの回動で間隔保持部材を介し潜像担持体に圧接されるようにする支持体と、を備えたことを今１つの特徴としている。
【００１５】
このような構成では、上記の発明に加え、さらに、現像器は非現像位置にて潜像担持体との干渉なしに現像ローラと平行な方向にて容易に着脱できるようにしながら、支持体への装着最終段階にて少なくとも駆動側の固定支点が軸直角方向に支持されることにより、駆動負荷が変動しても駆動側および固定支点は変位せず、被駆動ギヤが支持体の駆動ギヤと一定位置にて噛み合い続けられるようにして、噛み合いピッチが変化し噛み合い周波数が変動するのを防止するとともに、現像器は駆動側および非駆動側の固定支点まわりの回動で潜像担持体への間隔保持部材を介した圧接を固定支点を結ぶ軸線と現像ローラとの平行度を確保して像担持体への馴染み性よく達成しながら、駆動ギヤ側の回転を固定支点が変位せずに被駆動ギヤの回転に効率よく変換されるようにして、前記駆動負荷が変動してもこれが固定支点まわりの回動により潜像担持体に圧接される現像器の圧接状態に影響するのを防止しやすくするので、被駆動ギヤの駆動ギヤとの噛み合いの変動による画像ノイズや現像器の潜像担持体との間の現像ギャップが変動したり長手方向に不均一になったりすることによる画像の濃度変化や濃度むらが生じにくく、信頼性の高いものとなる。
【００１６】
本発明の現像装置は、上記発明において、さらに、現像器の非駆動側の固定支点は、現像器が現像位置にて対向する潜像担持体とのほぼ離接方向の遊びを持って支持するようにすると、駆動側および非駆動側の固定支点を結ぶ軸線と現像ローラとの平行度を保ったまま、非駆動側の固定支点につき現像器が現像位置で対向する潜像担持体との離接方向に限って自由度を与えることにより、圧接による間隔保持部材を介した潜像担持体との馴染み性を向上して、非駆動側の固定支点やこれを支持する側の部材の製造上の精度や歪の影響をさらに防止し、間隔保持部材により規制する現像ギャップがさらに適正に確保されやすくすることができる。
【００１７】
本発明の現像器は、また、上記各発明において、さらに、駆動側の固定支点は駆動ギヤと同軸上にあると、現像器が駆動側の固定支点まわりに回動して潜像担持体に圧接されるのに圧接位置が仮に変動して被駆動ギヤが移動してもそれは駆動ギヤと同心上の動きとなるので駆動ギヤとの噛み合いピッチなど噛み合い状態が変化することを回避でき、噛み合いの変動による画像ノイズを発生させない利点がある。しかも、駆動ギヤは現像器の回動中心となる駆動側の固定支点と同軸上で回転して現像器上の被駆動ギヤに動力を伝達するため、そのときに被駆動ギヤに伝達する駆動トルクは、被駆動ギヤを現像器の駆動側の固定支点まわりの回動を伴い駆動ギヤまわりに移動させる負荷と、被駆動ギヤをその支持軸まわりに回動させる負荷との格段の相違により、軽負荷となる被駆動ギヤの駆動力として優先的に消費されて、現像器を駆動側の固定支点まわりに回動させる力にはならないので、駆動負荷に変動があってもこれが現像器の潜像担持体への圧接状態に影響して現像ギャップが変動するようなことをより回避して、画像の濃度が変化したり不均一になるのをさらに防止することができる。
【００１８】
本発明のそれ以上の目的および特徴は、以下の詳細な説明および図面の記載によって明らかになる。本発明の各特徴は、できる限りにおいてそれ単独で、あるいは種々な組み合わせで複合して用いることができる。
【００１９】
【発明の実施の形態】
以下、本発明の幾つかの実施の形態についてその実施例とともに図１〜図１０を参照しながら詳細に説明し、本発明の理解に供する。
【００２０】
本実施の形態は、図９に示すように、電子写真方式で潜像担持体としてのドラムタイプの感光体１、４つの現像器２〜５、および像担持体ベルトとしての中間転写ベルト７ａを用いカラー画像を形成するカラープリンタに本発明を適用した場合の一例である。しかし、本発明はこれに限られることはなく、複数の現像器をその現像ローラに平行な方向で着脱できるように支持体に支持して切替え使用するものであれば、プリンタのほか複写機やファクシミリ、マイクロフィルムリーダプリンタなど、各種用途の画像形成装置全般に適用して有効である。また、現像器による像担持体上への画像の形成も、粉体や液体、あるいは双方を含む各種のトナーを用いた各種の現像方式で行うものでもよい。また、潜像担持体はドラムタイプのものに限定されることはなくベルトタイプのものであってもよい。
【００２１】
本実施の形態のカラープリンタは図９に示すように、画像形成のために例えば回転移動される像担持体の一例としてのドラム型の感光体１と、複数の、例えば４つの現像器２〜５を感光体１の移動面まわりに設定される現像位置Ａに切り替え位置させるように例えば回転移動させて感光体１の移動面上に現像によりトナー像を形成する現像ユニット６と、感光体１と同期した例えば周回移動して感光体１の移動面まわりに設定される一次転写位置Ｂにて前記感光体１の移動面上に順次形成されるトナー像を順次に積層して転写される中間転写ユニット７とを備えている。
【００２２】
感光体１はレーザプリントヘッド８からの画像信号により変調されたレーザ光９による画像露光、つまり光学的な印字を受けて画像信号通りの電気的な潜像、つまり静電潜像を色ごとに形成し、これが前記現像によって顕像化したトナー像に形成される。電気的な潜像を現像することに関連して、感光体１上のトナー像は中間転写ユニット７の中間転写ベルト７ａ上に一次転写器としての転写ローラ１１からの電荷付与によって静電的な吸引により静電転写するようにしている。また、中間転写ベルト７ａに順次に積層して静電転写され合成し終わったトナー像は、その移動面まわりに設定される二次転写位置Ｃに給紙部１２ａ、１２ｂなどから給送されてくる転写材１３の上に二次転写器としての転写ローラ１４からの静電的な吸引によって静電的に一括して二次転写し、二次転写後の転写材１３を定着器１５を通して画像形成を終了し排紙トレー１６上に排出する。
【００２３】
一次転写および二次転写の双方とも画像形成に採用する現像方式に対応して静電転写以外の転写方式で転写されてもよい。また、定着器１５も現像方式に対応したものを用いればよく、不要な場合もある。カラー画像形成のために複数の現像器２〜５のそれぞれはイエロー、マゼンタ、シアン、ブラックの各色トナーで静電潜像を現像し、本実施の形態では粉体樹脂トナーを用いることに関連して加熱または加圧、あるいはそれら双方を採用した定着器１５を用いる。なお、ブラックの現像器５の使用は必須ではない。また、カラー画像は４つ以上の現像器を用いて形成するものでもよい。さらにカラー画像を形成するものに限られることはなく、２以上の現像器を切り替え使用するものであれば本発明を適用して有効である。
【００２４】
感光体１は帯電チャージャ３４、クリーナ３５を有したプロセスユニット３６をなし、ガイドレール２１ａなどを利用した第１の案内機構２１により案内されて、装置本体４５に対し軸線方向、つまり紙面に直角な方向の手前側から出し入れして着脱できるようにしている。
【００２５】
中間転写ユニット７は、感光体１と離接するように例えば一点を中心とした回動方向に案内する回転中心軸２２ａなどを利用した第２の案内機構２２によって感光体１の着脱の際に干渉し合わない位置に退避しておけるようにされるとともに、感光体１の取り外し後に回転中心軸２２ａまわりに下動されたとき、左右一対のガイドレール２９ａ、２９ｂなどを利用した第３の案内機構２９により案内して装置本体４５に対し紙面に直角な方向の手前側から出し入れして着脱できるようにしている。
【００２６】
現像ユニット６は支持体としての現像ラック２５を軸２４などを利用した第４の案内機構２３により感光体１と平行な軸線まわりに回動させるように案内して、各現像器２〜５を現像位置Ａとこれから外れた非現像位置との間で切り替え移動させ、その都度必要な現像器を現像位置Ａに位置させて選択使用できるようにしてある。現像器２〜５の選択使用は現像ラック２５の回転方式に限らず直線往復移動など各種に移動して選択使用できるようなものも本発明の範疇に属する。
【００２７】
現像ラック２５は、図４、図５、図７、図９に示すように、レールタイプのガイド１０１ａ、１０１ｂなどを利用した第５の案内機構１０１により各現像器２〜５のそれぞれを現像ローラ２ａ〜５ａに平行な方向、つまり紙面に直角な方向の手前側から個別に出し入れして着脱されるようにしている。
【００２８】
図１〜図６、図８〜図１０に示す現像器２〜５は、非現像位置の１つである感光体１から外れた例えば図１０に示す左側回転位置にて、装置本体４５の正面板８７に設けられた着脱窓８８に対向し、この着脱窓８８を通じて着脱されるようにしている。
【００２９】
なお、現像ラック２５を各現像器２〜５が感光体１と対向する各現像位置Ａに、係止レバー４９と係止ピン５１との係合によって係止する係止状態とこの係止を解除する係止解除状態とに切り替えできる係止機構２６と、中間転写ユニット７を第２の案内機構２２の案内のもとに図９に示すように感光体１と離間する回動方向に付勢するのと連動して、前記係止機構２６が係止解除状態にあり、かつ現像器２〜５の１つである例えば現像器５が現像位置Ａに位置する際に、その現像器５をその現像位置Ａから図９に示すように少し外れた非現像位置に移動するよう第４の案内機構２３を介して付勢する操作入力機構２７とが設けられている。
【００３０】
一方、操作入力機構２７が中間転写ユニット７を感光体１から離間させない非操作入力状態にあり、係止機構２６が現像器２〜５の１つを現像位置Ａに係止しているとき、操作レバー６１は図１０に示すようにプロセスユニット３６の引き出し経路上に位置することにより、そのような状態でプロセスユニット３６の引き出しを阻止し、プロセスユニット３６を引き出すには操作入力機構２７により中間転写ユニット７が感光体１から離間され、これに連動して現像位置Ａにあった現像器５などが非現像位置に移動されていることが条件になるようにして、感光体１とそのまわりの機構との干渉を防止するようにしてある。
【００３１】
さらに、中間転写ユニット７もまたクリーナ３７を持ち二次転写後の移動面をクリーニングする。プロセスユニット３６および中間転写ユニット７の各クリーナ３５、３７は感光体１および中間転写ベルト７ａの移動面から除去した残留トナーを回収する回収容器４１、４２を持ち、それぞれの底部に設けられたスクリュウ４１ａ、４２ａにより排出される。それぞれの図１０に示す排出口４１ｂ、４２ｂには共通の廃トナー容器４３が着脱できるように接続され、接続状態では前記排出される廃トナーを収容し貯留する。満杯になれば取り外して廃棄し新しいものを接続しなおす。あるいは収容した廃トナーを廃棄して空にし再度接続して使用する。排出口４１ｂ、４２ｂには図示しないシャッタが設けられ、廃トナー容器４３を接続するとシャッタは開かれ排出される廃トナーを廃トナー容器４３に受け入れ、廃トナー容器４３を外すとシャッタは閉じられ排出口４１ｂ、４２ｂから回収トナーが漏れでるのを防止する。
【００３２】
廃トナー容器４３は図１０に示すように、前記操作レバー６１の作業者が対面する手前側を覆うように配置されている。つまり、図示しない前カバーの直ぐ内側に廃トナー容器４３が位置していて、感光体１を着脱すべく前カバーを開放しても、操作レバー６１は廃トナー容器４３のさらに内側に隠れているので操作できない。
【００３３】
そこで、邪魔な廃トナー容器４３を中間転写ユニット７およびプロセスユニット３６との接続を外して取り外さないと、操作入力機構２７の操作レバー６１は操作できないので、廃トナー容器４３を取り外さずに操作入力機構２７が操作されることによって、中間転写ユニット７が感光体１から離間される際に接続した状態のままの廃トナー容器４３が従動せず邪魔になったり、無理な力が働いて各部が損傷するようなことが解消する。
【００３４】
ところで、複数の現像器２〜５のうち、ブラックのトナーを収容した現像器５の使用頻度が高く、装置停止時はブラックの現像器を現像位置Ａに位置決めして係止機構２６により係止しておき、カラー画像はそのブラックの現像器５の次のイエローの現像器２による現像から開始し、最終にブラックの現像器５による現像を行って形成し、画像形成終了後はブラックの現像器５が現像位置Ａにあるまま係止機構２６により係止しておく。従って、モノクロの画像、特に頻度の高いブラックのモノクロ画像形成時は、ブラックの現像器５が現像位置Ａに位置しているので、現像器２〜５の切り替え移動なくそのまま即座に画像形成ができる。
【００３５】
本実施の形態は特に図１〜図６に示す現像器２〜５のそれぞれにおいて、感光体１と現像ローラ２ａ〜５ａとの間の距離、つまり現像ギャップＧを一定にする間隔保持部材としての現像ローラ２ａ〜５ａの両端部外側に設ける一対のスペーサローラ１０３、１０４を介して現像器２〜５を感光体１に圧接させる構成を採用し、図３に示すように一端側にのみ配置され、駆動ギヤ１０５と噛み合って駆動の伝達を受ける被駆動ギヤ１０６、この被駆動ギヤ１０６を持った駆動側に配置された固定支点１０７、現像器２〜５の非駆動側の固定支点１１２と長孔１１３でその長手方向に遊びを持って嵌り合って支持する可動支持部材１１４上に一体に設けられるなどして、非駆動側に配置され現像ローラ２ａ〜５ａとの間の距離が可変な可動支点１０８を有している。
【００３６】
可動支点１０８の現像ローラ２ａ〜５ａに対する可動範囲は前記固定支点１１２と長孔１１３との間の遊びと、図４に示すような可動支持部材１１４上のストッパ１１４ａと現像器２〜５の非駆動側に設けた図４、図５に示すような位置規制凹部１０９との間の遊びで規定されている。しかし、可動支点１０８を設ける意味では固定支点１１２と長孔１１３との間の遊びは省略することができる。
【００３７】
これに対し現像ユニット６は、図４、図５に示すように複数の現像器２〜５をそれらの被駆動ギヤ１０６が駆動ギヤ１０５に噛み合うようにして支持し、それら現像器２〜５を感光体１と現像ローラ２ａ〜５ａが対向する現像位置Ａに切替え位置させるとともに、各現像器２〜５を駆動ギヤ１０５を持たない非駆動側から駆動ギヤ１０５を持った駆動側に現像ローラ２ａ〜５ａに平行な方向で受入れ着脱できるようにするガイドである前記第５の案内機構１０１、現像器２〜５の装着最終段階で現像器２〜５を現像位置Ａでの感光体１との対向側に付勢する付勢手段としてのばね１１１を有し、現像器２〜５の装着最終段階でその駆動側の固定支点１０７および非駆動側の可動支点１０８を、支点受け１００、１０２により軸直角方向に支持する支持体である前記現像ラック２５を備えている。
【００３８】
このようにして、現像器２〜５は非現像位置にて感光体１との干渉なしに現像ローラ２ａ〜５ａと平行な方向にて容易に着脱できるようにしながら、現像ラック２５への装着最終段階にて駆動側の固定支点１０７が軸直角方向に支持されることにより、駆動負荷が変動しても駆動側の固定支点１０７は変位せず、被駆動ギヤ１０６が現像ラック２５の駆動ギヤ１０５と一定位置にて噛み合い続けられるようにして、噛み合いピッチが変化し噛み合い周波数が変動するのを防止するとともに、前記駆動負荷が現像器２〜５の感光体１への圧接状態に影響するのを抑えることができ、しかも、現像器２〜５の非駆動側は可動支点１０８が支点受け１０２に軸直角方向に支持されながら現像ローラ２ａ〜５ａとの間の距離が、上記のように可変であることにより、この可変な範囲で現像器２〜５の非駆動側を現像ラック２５への支持から遊びを持たせて、現像器２〜５の固定支点１０７や現像ラック２５の支点受け１００、１０２などに製造上の位置誤差や現像ラック２５のフレームに振動などによる歪みがあっても、現像器２〜５は前記遊びの範囲でそのような位置誤差や歪みを吸収して感光体１に馴染みよく圧接されてスペーサローラ１０３、１０４による設定通りの現像ギャップＧを確保しやすくするので、被駆動ギヤ１０６の駆動ギヤ１０５との噛み合いの変動による画像ノイズや現像器２〜５の感光体１との間の現像ギャップＧが変動したり長手方向に不均一になったりすることによる濃度変化や濃度むらが生じにくく、信頼性の高いものとなる。なお、可動支点１０８の現像ローラ２ａ〜５ａに対し可動とする具体的な設け方は特に限定されない。
【００３９】
以上述べた実施の形態とは別に、図４に示すような可動支持部材１１４上のストッパ１１４ａと現像器２〜５の非駆動側に設けた位置規制凹部１０９との間による遊びを規定せず、現像器２〜５の装着最終段階にて可動支持部材１１４を、現像ラック２５に対しそれ自体ないしはそれに設けた支点部を軸直角方向に支持し、可動支持部材１１４により固定支点１１２を回動のみできるように単に支持する構造を利用するようにしても有効であり、この場合、駆動側および非駆動側の固定支点１０７、１１２を結ぶ軸線１２１が現像ローラ２ａ〜５ａに平行とし、かつこのような関係を利用してさらに、現像器２〜５が駆動側および非駆動側の固定支点１０７、１１２を結ぶ軸線１２１のまわりの回動でスペーサローラ１０３、１０４を介し感光体１に圧接されるようにする
このような図示しない実施の形態では、前述の場合と同様に、現像器２〜５は非現像位置にて感光体１との干渉なしに現像ローラ２ａ〜５ａと平行な方向にて容易に着脱できるようにしながら、現像ラック２５への装着最終段階にて少なくとも駆動側の固定支点１０７が支点受け１００によって軸直角方向に支持されることにより、駆動負荷が変動しても駆動側の固定支点は変位せず、被駆動ギヤ１０６が現像ラック２５の駆動ギヤ１０５と一定位置にて噛み合い続けられるようにして、噛み合いピッチが変化し噛み合い周波数が変動するのを防止するのに加え、特に、現像器２〜５は駆動側および非駆動側の固定支点１０７、１１２まわりの回動で感光体１へのスペーサローラ１０３、１０４を介した圧接を固定支点１０７、１１２を結ぶ軸線１２１と現像ローラ２ａ〜５ａとの平行度を確保して感光体１への馴染み性よく達成しながら、駆動ギヤ１０５側の回転を固定支点１０７、１１２が変位せずに被駆動ギヤ１０６の回転に効率よく変換されるようにして、前記駆動負荷が変動してもこれが固定支点１０７、１１２まわりの回動により感光体１に圧接される現像器２〜５の圧接状態に影響するのを防止しやすくするので、被駆動ギヤ１０６の駆動ギヤ１０５との噛み合いの変動による画像ノイズや現像器２〜５の感光体１との間の現像ギャップＧが変動したり長手方向に不均一になったりすることによる濃度変化や濃度むらが生じにくく、信頼性の高いものとなる。
【００４０】
ここで、図に示す実施例では、上記のような２つの実施の形態における構成を複合して持っていることにより、上記２つの実施の形態が奏する双方の作用効果を併せ発揮することができる。しかも、この場合の実施の形態において、さらに、図示する実施例のように現像器２〜５の非駆動側の固定支点１１２は、可動支持部材１１４の長孔１１３により現像器２〜５が現像位置Ａにて対向する感光体１とのほぼ離接方向の遊びを持って支持するようにしてあるので、駆動側および非駆動側の固定支点１０７、１１２を結ぶ軸線１２１と現像ローラ２ａ〜５ａとの平行度を保ったまま、非駆動側の固定支点１１２につき現像器２ａ〜５ａが現像位置Ａで対向する感光体１とのほぼ離接方向に限って自由度を与えることにより、圧接によるスペーサローラ１０３、１０４を介した感光体１との馴染み性を向上して、非駆動側の固定支点１１２やこれを支持する側の部材である可動支持部材１１４や現像ラック２５などの製造上の精度や歪の影響をさらに防止し、スペーサローラ１０３、１０４により規制する現像ギャップＧがさらに適正に確保されやすくすることができる。
【００４１】
また、駆動側の固定支点１０７は駆動ギヤ１０５と同軸上にある。これにより、現像器２〜５が駆動側の固定支点１０７まわりに回動して感光体１に圧接されるのに圧接位置が仮に変動して被駆動ギヤ１０６が移動してもそれは駆動ギヤ１０５と同心上の動きとなるので駆動ギヤ１０５との噛み合いピッチなど噛み合い状態が変化することを回避でき、噛み合いの変動による画像ノイズを発生させない利点がある。
【００４２】
しかも、駆動ギヤ１０５は現像器２〜５の回動中心となる駆動側の固定支点１０７と同軸上で回転して現像器２〜５上の被駆動ギヤ１０６に動力を伝達するため、そのときに被駆動ギヤ１０６に伝達する駆動トルクは、被駆動ギヤ１０６を現像器２〜５の駆動側の固定支点１０７まわりの回動を伴い駆動ギヤ１０５まわりに移動させる負荷と、被駆動ギヤ１０６をその支持軸まわり１４２に回動させる負荷との格段の相違により、軽負荷となる被駆動ギヤ１０６の駆動力として優先的に消費されて、現像器２〜５を駆動側の固定支点１０７まわりに回動させる力にはならないので、駆動負荷に変動があってもこれが現像器２〜５の感光体１への圧接状態に影響して現像ギャップＧが変動するようなことをより回避して、画像の濃度が変化したり不均一になるのをさらに防止することができる。
【００４３】
なお、図に示す実施例では駆動側の固定支点１０７は孔タイプとして駆動ギヤ１０５と同軸の軸タイプの支点受け１００と嵌め合わせてある。また、非駆動側の固定支点１１２、非駆動側の可動支点１０８のそれぞれは軸タイプとして、前記のように固定支点１１２は孔タイプの支点受けとしての長孔１１３と嵌め合わせ、可動支点１０８は孔タイプの支点受け１０２と嵌め合わせてある。しかし、どちらの側を軸タイプにし、孔タイプにしてもよい。被駆動ギヤ１０６は現像器２〜５の側面に前記支持軸１４２により支持されて、現像ローラ２ａ〜５ａに直結のギヤ１４３に噛み合っており、現像器２〜５の装着最終段階で被駆動ギヤ１０６が駆動ギヤ１０５に噛み合って駆動力の伝達が受けられ、受けた駆動力はギヤ１４３を介して現像ローラ２ａ〜５ａに伝達できるようにしている。
【００４４】
ばね１１１は図５、図６に示すように、現像ラック２５の各現像器２〜５を受け入れる部分の現像器２〜５と対向する壁面に、現像器２〜５を出し入れする方向の前後、つまり駆動側と非駆動側とに、軸１４５により軸支して設けた一対のレバー部材１４６ａ、１４６ｂに働かせ、各レバー部材１４６ａ、１４６ｂが装着最終段階にある現像器２〜５に対してほぼ同時に働くようにしてある。このため、現像器２〜５のレバー部材１４６ａ、１４６ｂの押動を受ける受動壁１４７は、駆動側の受動面１４７ａに対し非駆動側の受動面１４７ｂを感光体１との対向方向における後方側に寄って形成されている。同時に駆動側のレバー部材１４６ａに対し非駆動側のレバー部材１４６ｂを感光体１との対向方向における後方側に寄って配置され、ストッパ１４８ａ、１４８ｂにより待機位置に係止されている。これにより、現像器２〜５の装着最終段階で受動壁１４７の駆動側の受動面１４７ａと非駆動側の受動面１４７ｂとは、図６（ａ）に示す段階から図６（ｂ）に示す段階に変化して、斜面１４７ａ１、１４７ｂ１を経てレバー部材１４６ａ、１４６ｂと同時に当接し合うことにより感光体１の側に押動されて、固定支点１０７、１１２まわりに回動し、スペーサローラ１０３、１０４を介して感光体１に圧接されるようにする。
【００４５】
第５の案内機構１０１は、図４に示すように受け入れる現像器２〜５との間に遊びＳを持ち、それらを現像ラック２５に対し出し入れしやすくしている。しかし、前記駆動側の固定支点１０７と支点受け１００、非駆動側の可動支点１０８と支点受け１０２の、それぞれの組は軸タイプの側である支点受け１００および非駆動側の可動支点１０８の先端にテーパ状のガイド部１５１を設け、前記遊びＳを持った現像ラック２５へ嵌め合わせて装着するのに、この遊びＳ内において支点受け１００および非駆動側の可動支点１０８が固定支点１０７および支点受け１０２に対し、装着最終段階で確実に嵌り合えるようにしている。これにはガイド部１５１を孔タイプの側に設けても同様な働きが得られる。もっとも、軸タイプ側と孔タイプ側との双方にテーパを形成してもよい。
【００４６】
【発明の効果】
本発明によれば、上記の説明から明らかなように、駆動負荷が変動しても駆動側およびの固定支点は変位せず、被駆動ギヤが支持体の駆動ギヤと一定位置にて噛み合い続けられるとともに、駆動負荷が変動してもこれが固定支点まわりの回動により潜像担持体に圧接される現像器の圧接状態に影響するのを防止しやすくするので、被駆動ギヤの駆動ギヤとの噛み合いの変動による画像ノイズや現像器の潜像担持体との間の現像ギャップが変動したり長手方向に不均一になったりすることによる濃度変化や濃度むらが生じにくく、信頼性の高いものとなる。
【図面の簡単な説明】
【図１】本発明の代表的な１つの実施の形態に係る現像装置の現像位置にある現像器と感光体との関係を非駆動側から見て示す非駆動側側面図である。
【図２】図１の現像装置の駆動側から見て示す駆動側側面図である。
【図３】図１、図２の現像装置を模式的に示す斜視図である。
【図４】図１、図２の現像装置における現像器の着脱できる支持構造を非駆動側から見て示す側面図である。
【図５】図４の現像器の着脱できる支持構造での横断面図である。
【図６】図４の現像器の押圧機構の平面状態図で、その（ａ) は装着最終段階より少し手前の未押圧状態、その（ｂ）は装着最終段階での押圧状態をそれぞれ示している。
【図７】図１、図２の現像装置に係る現像ラックの駆動側部分を示す斜視図
【図８】図１、図２の現像器の非駆動側部分の斜視図である。
【図９】図１、図２の現像装置を装備したカラープリンタを示す全体構成図である。
【図１０】図９のカラープリンタの正面パネルを開放した状態で示す正面図である。
【図１１】従来の現像装置を示す駆動側側面図である。
【符号の説明】
１感光体
２〜５現像器
２ａ〜５ａ現像ローラ
６現像ユニット
２３第４の案内機構
２４軸
２５現像ラック
８８着脱窓
１００、１０２支点受け
１０１ａ、１０１ｂガイド
１０１第５の案内機構
１０３、１０４スペーサローラ
１０５駆動ギヤ
１０６被駆動ギヤ
１０７駆動側の固定支点
１０８非駆動側の可動支点
１０９位置規制凹部
１１１ばね
１１２非駆動側の固定支点
１１３長孔
１１４可動支持部材
１１４ａストッパ
Ａ現像位置
Ｇ現像ギャップ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device that develops a latent image carried by a latent image carrier by switching a plurality of developing devices to form a single color image, a composite image of a plurality of colors, or a color image. is there.
[0002]
[Prior art]
As a technique for making the distance between the developing roller and the latent image carrier constant, for example, Japanese Patent Application Laid-Open Nos. 8-272180 and 9-281800 are disclosed in FIG. It is disclosed that the developing device c can be positioned with high accuracy by being brought into pressure contact with the photosensitive drum d which is a latent image carrier through the gap maintaining rollers b provided at both ends of the image forming apparatus. Further, since a plurality of developing devices c are used by switching, the required number of developing devices are supported by a reciprocating support or a rotating support as disclosed in Japanese Patent Laid-Open No. 10-301463, and the reciprocating or rotating of the support is performed. Therefore, the developing device c required at that time is switched to the developing position facing the photosensitive drum d and used.
[0003]
On the other hand, the developer c is supported so that it can be attached to and detached from the support for replacement or when necessary maintenance is performed when the developer has been consumed. As disclosed in Japanese Patent Laid-Open No. 10-301463, the developing device c is provided on the side surface of the machine body on the non-driving side that does not have a driving mechanism for driving the developing device c of the support. It is known to put it in and out in a direction parallel to the developing roller a.
[0004]
When a plurality of developing devices c are switched and used, they do not interfere with the photosensitive drum d if they are attached and detached at non-use positions. Therefore, in such a detachable support structure, in order to position the developing device c in the use position with high accuracy through the gap maintaining roller b with respect to the photosensitive drum d, conventionally, the developing device c The driving side fixed fulcrum e is supported by a long hole f so as to be movable in the x direction so as to be in contact with and away from the photosensitive drum d, and the developing device c is biased by the spring g toward the photosensitive drum d. Is performed as the first method.
[0005]
However, making the fixed fulcrum e on the driving side movable in the x direction to be separated from and in contact with the photosensitive drum d means that the meshing direction of the driven gear h of the developing device c with the driving gear j is perpendicular to the separating direction x. It is necessary to be able to move relative to each other in the x direction.
[0006]
In such a drive mechanism, in the drive transmission from the drive gear j to the driven gear h, the developing device c is connected to the photosensitive member as the drive gear j and the driven gear h move in the x direction according to the rotation direction. It is easily influenced as a force in the direction of pressing against the drum d or pulling away from the photosensitive drum d, and the pressing force of the developing device c against the photosensitive drum d due to a change in driving torque due to a change in the remaining amount of developer in the developing device c. The development gap k fluctuates, causing uneven development and uneven image density. At this time, the meshing pitch with the driving gear j is changed by the amount that the driven gear h moves in the x direction with respect to the driving gear j, and the meshing frequency fluctuates, so that image noise is generated.
[0007]
In order to solve this problem, conventionally, the fixed fulcrum on the driving side of the developing device is supported and fixed in the direction perpendicular to the axis, and the fixed fulcrum on the driven side is supported in the direction to be in contact with and separated from the image carrier, and the developing device is Energizing the image carrier side is performed as a second method.
[0008]
[Problems to be solved by the invention]
However, even in the second method as described above, distortion due to vibration or the like occurs in the frame of the support that supports the developing device, the fixed fulcrum positions on the driving side and non-driving side of the developing device, and the support frame. When the manufacturing accuracy of the hole for supporting the fixed fulcrum is low, the line connecting the fixed fulcrum on the driving side and the non-driving side is not parallel to the developing roller, and the developing gap is between the driving side and the non-driving side. This is a problem because it may appear as an image density difference. This can also occur in the case of the first method as well.
[0009]
The object of the present invention is to ensure that the meshing of the driven gear with the drive gear does not fluctuate easily, and the development gap between the developing unit and the latent image carrier is not fluctuated or non-uniform in the longitudinal direction. It is to provide a developing device having a high level.
[0010]
[Means for Solving the Problems]
In the developing device of the present invention, the developing device is brought into pressure contact with the latent image carrier through an interval holding member that makes the distance between the latent image carrier and the developing roller constant.
In order to achieve the above object, in particular, a driven gear that is arranged only on one end side and meshes with the driving gear to receive driving transmission, a fixed fulcrum arranged on the driving side having the driven gear, A plurality of developing units having a movable fulcrum arranged on the non-driving side and having a variable distance from the developing roller, and supporting the plurality of developing units so that their driven gears mesh with the driving gears, The developing device is switched to the developing position where the latent image carrier and the developing roller face each other, and each developing device is received in a direction parallel to the developing roller from the non-driving side having no driving gear to the driving side having the driving gear. A guide that can be attached and detached, and an urging means that urges the developing device to the opposite side of the latent image carrier at the developing position in the final stage of mounting the developing unit, and drives the developing unit in the final stage of mounting the developing unit. Side fixed fulcrum and non-drive side A support for supporting the moving fulcrum in the axis-perpendicular direction, and comprising the.
[0011]
In such a configuration, the developing unit can be easily attached and detached in the direction parallel to the developing roller without interference with the latent image carrier at the non-developing position, while at the final stage of attachment to the support. By supporting the fixed fulcrum in the direction perpendicular to the axis, the fixed fulcrum on the drive side does not displace even when the drive load fluctuates so that the driven gear can keep meshing with the drive gear of the support at a fixed position. This prevents the meshing pitch from changing and the meshing frequency from fluctuating, and suppresses the influence of the driving load on the pressure contact state of the developing device to the latent image carrier, and the developer is not driven. With the movable fulcrum whose distance from the developing roller is variable while being supported by the support in the direction perpendicular to the axis, the non-driving side of the developing device is allowed to play from the support to the support within this variable range, The fixed fulcrum of the developer and the support Even if there is a manufacturing position error in the point support hole or the distortion of the support frame due to vibration or the like, the developer absorbs such a position error or distortion within the range of the play and becomes familiar with the latent image carrier. Because it is well pressed and it is easy to secure the development gap as set by the spacing member, image noise due to fluctuations in meshing of the driven gear with the drive gear and development gap between the latent image carrier of the developer and fluctuation Therefore, it is difficult to cause a change in density or unevenness of the image due to the non-uniformity in the longitudinal direction, resulting in high reliability.
[0014]
The developing device of the present invention is also arranged only on one end side, and is a driven gear that meshes with the driving gear and receives driving transmission, and the developing roller on the driving side having the driven gear and the opposite non-driving side. A fixed fulcrum arranged on the same parallel axis, and a movable fulcrum that fits so as to support the non-driving side fixed fulcrum in the direction perpendicular to the axis and the distance from the developing roller is variable. A plurality of developing units each having a support member; and the plurality of developing units supported with their driven gears engaged with the driving gears, and the developing units are placed at a developing position where the latent image carrier and the developing roller face each other. A guide that allows each developing device to be received and attached in a direction parallel to the developing roller from the non-driving side that does not have a driving gear to the driving side that has a driving gear, and the developing device at the final stage of mounting the developing device. Present Urging means for urging to the opposite side of the latent image carrier at the position, and supporting the fixed fulcrum on the driving side and the movable fulcrum of the support member in the direction perpendicular to the axis at the final stage of mounting of the developing device, Another feature is that the developing device includes a support member that rotates around the fixed fulcrum on the driving side and the non-driving side so as to be pressed against the latent image carrier via the interval holding member.
[0015]
In such a configuration,In addition to the above invention, the developing device can be easily attached and detached in the direction parallel to the developing roller without interference with the latent image carrier at the non-developing position, and at the final stage of attachment to the support. Since at least the fixed fulcrum on the drive side is supported in the direction perpendicular to the axis, the drive side and fixed fulcrum will not be displaced even if the drive load fluctuates, and the driven gear will continue to mesh with the drive gear of the support at a fixed position. In this way, the meshing pitch is changed and the meshing frequency is prevented from fluctuating, and the developing device is rotated about the fixed fulcrum on the driving side and the non-driving side via the interval holding member to the latent image carrier. While ensuring the parallelism between the axis connecting the fixed fulcrum and the developing roller and the familiarity with the image carrier, the rotation on the drive gear side is efficient in rotating the driven gear without the fixed fulcrum being displaced. Well converted Thus, even if the driving load fluctuates, it is easy to prevent this from affecting the pressure contact state of the developing device pressed against the latent image carrier due to the rotation about the fixed fulcrum. The image noise due to fluctuations in meshing and the development gap with the latent image carrier of the developing device fluctuates or becomes uneven in the longitudinal direction, and image density changes and density irregularities are less likely to occur. It will be expensive.
[0016]
The developing device of the present invention isThe above inventionIn addition, the fixed fulcrum on the non-driving side of the developing device is configured so that the developing device supports the driving side and the non-driving when it is supported with play in the direction of contact with the latent image carrier facing the developing device. While maintaining the parallelism between the axis connecting the fixed fulcrum on the side and the developing roller, the developing unit gives a degree of freedom to the non-driving side fixed fulcrum only in the direction of contact with the latent image carrier facing the developing position. This improves the familiarity with the latent image carrier via the spacing member by pressure contact, and further prevents the influence of manufacturing precision and distortion of the fixed fulcrum on the non-driving side and the member that supports it. In addition, the development gap regulated by the spacing member can be more easily secured.
[0017]
In the developing device of the present invention, in each of the above inventions, if the driving-side fixed fulcrum is coaxial with the driving gear, the developing device rotates around the driving-side fixed fulcrum to form a latent image carrier. Even if the pressure contact position fluctuates and the driven gear moves, it moves concentrically with the drive gear, so that it is possible to avoid changes in the meshing condition such as the meshing pitch with the drive gear. There is an advantage that image noise due to fluctuations is not generated. In addition, since the drive gear rotates coaxially with the fixed fulcrum on the drive side that becomes the rotation center of the developing device and transmits power to the driven gear on the developing device, the driving torque transmitted to the driven gear at that time Is light due to the marked difference between the load that moves the driven gear around the fixed fulcrum on the drive side of the developing device and the load that rotates the driven gear around its support shaft. Since it is preferentially consumed as the driving force of the driven gear, which is the load, and does not turn the developing device around the fixed fulcrum on the driving side, even if the driving load varies, this is the latent image of the developing device. It is possible to further prevent the development gap from fluctuating due to the influence of the pressure contact state with the carrier, and further prevent the image density from changing or becoming non-uniform.
[0018]
Further objects and features of the present invention will become apparent from the following detailed description and drawings. Each feature of the present invention can be used alone or in combination in various combinations as much as possible.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, several embodiments of the present invention will be described in detail with reference to FIGS. 1 to 10 together with the examples thereof for the understanding of the present invention.
[0020]
In the present embodiment, as shown in FIG. 9, a drum type photosensitive member 1 as a latent image carrier, four developing devices 2 to 5 and an intermediate transfer belt 7a as an image carrier belt in an electrophotographic system. This is an example when the present invention is applied to a color printer that forms a color image. However, the present invention is not limited to this, and a printer, a copier, and the like can be used as long as a plurality of developers are supported by a support so that they can be attached and detached in a direction parallel to the developing roller. It is effective when applied to general image forming apparatuses for various uses such as facsimiles and microfilm reader printers. Further, the image formation on the image carrier by the developing device may be performed by various developing methods using various toners including powder, liquid, or both. The latent image carrier is not limited to a drum type, but may be a belt type.
[0021]
As shown in FIG. 9, the color printer according to the present embodiment includes a drum-type photosensitive member 1 as an example of an image carrier that is rotated and moved for image formation, and a plurality of, for example, four developing units 2. A developing unit 6 that forms a toner image on the moving surface of the photosensitive member 1 by developing, for example, a rotational movement so that 5 is switched to a developing position A set around the moving surface of the photosensitive member 1; The toner images formed on the moving surface of the photosensitive member 1 are sequentially stacked and transferred at the primary transfer position B set around the moving surface of the photosensitive member 1 by, for example, rotating around the surface. And a transfer unit 7.
[0022]
The photosensitive member 1 receives an image exposure by a laser beam 9 modulated by an image signal from a laser print head 8, that is, optical printing, and generates an electrical latent image according to the image signal, that is, an electrostatic latent image for each color. This is formed into a toner image visualized by the development. In connection with the development of the electrical latent image, the toner image on the photosensitive member 1 is electrostatically applied to the intermediate transfer belt 7a of the intermediate transfer unit 7 by applying a charge from a transfer roller 11 as a primary transfer device. Electrostatic transfer is performed by suction. Further, the toner images that have been sequentially laminated and electrostatically transferred and synthesized on the intermediate transfer belt 7a are fed from the paper feeding units 12a and 12b to the secondary transfer position C set around the moving surface. A secondary transfer is electrostatically and collectively performed on the transfer material 13 by electrostatic suction from a transfer roller 14 as a secondary transfer device, and the transfer material 13 after the secondary transfer is imaged through a fixing device 15. The formation is completed and discharged onto the paper discharge tray 16.
[0023]
Both primary transfer and secondary transfer may be transferred by a transfer method other than electrostatic transfer, corresponding to the development method used for image formation. Further, the fixing device 15 may be one corresponding to the developing method, and may be unnecessary. In order to form a color image, each of the plurality of developing devices 2 to 5 develops an electrostatic latent image with toners of yellow, magenta, cyan, and black, and this embodiment relates to using powder resin toner. Then, a fixing device 15 employing heating or pressurization or both of them is used. The use of the black developing device 5 is not essential. A color image may be formed using four or more developing devices. Further, the present invention is not limited to the one that forms a color image, and the present invention is effective if the two or more developing devices are switched and used.
[0024]
The photosensitive member 1 includes a process unit 36 having a charging charger 34 and a cleaner 35, and is guided by the first guide mechanism 21 using a guide rail 21a and the like, and is axially directed to the apparatus main body 45, that is, perpendicular to the paper surface. It can be removed from the front side of the direction.
[0025]
The intermediate transfer unit 7 interferes when the photosensitive member 1 is attached or detached by the second guide mechanism 22 using, for example, a rotation center shaft 22 a that guides in a rotational direction centered on one point so as to be in contact with the photosensitive member 1. A third guide mechanism using a pair of left and right guide rails 29a and 29b when the photosensitive member 1 is moved down around the rotation center axis 22a after being removed. It is guided by 29 and can be attached to and detached from the apparatus main body 45 from the front side in a direction perpendicular to the paper surface.
[0026]
The developing unit 6 guides the developing units 2 to 5 by rotating the developing rack 25 as a support member around the axis parallel to the photosensitive member 1 by a fourth guide mechanism 23 using a shaft 24 or the like. The developer is switched between the development position A and the non-development position deviated from the development position A, and the required developing device is positioned at the development position A each time so that it can be selectively used. The selection and use of the developing devices 2 to 5 is not limited to the rotation method of the developing rack 25, and those that can be selectively used by moving in various ways such as linear reciprocation also belong to the category of the present invention.
[0027]
As shown in FIGS. 4, 5, 7, and 9, the developing rack 25 uses a fifth guide mechanism 101 that uses rail-type guides 101 a, 101 b, etc. It is designed to be inserted and removed individually from the front side in the direction parallel to 2a to 5a, that is, the direction perpendicular to the paper surface.
[0028]
The developing devices 2 to 5 shown in FIGS. 1 to 6 and FIGS. 8 to 10 are moved from the photosensitive member 1 which is one of the non-developing positions, for example, at the left rotation position shown in FIG. It faces a detachable window 88 provided on the face plate 87, and is detachable through this detachable window 88.
[0029]
It is to be noted that the developing rack 25 is locked at each developing position A where the developing devices 2 to 5 face the photoreceptor 1 by the engagement of the locking lever 49 and the locking pin 51, and this locking is performed. As shown in FIG. 9, the locking mechanism 26 that can be switched to the unlocking state to be released and the intermediate transfer unit 7 are attached in the rotational direction away from the photosensitive member 1 as shown in FIG. In conjunction with the energization, when the locking mechanism 26 is in the unlocked state and one of the developing devices 2 to 5, for example, the developing device 5 is positioned at the developing position A, the developing device 5 As shown in FIG. 9, an operation input mechanism 27 is provided to urge the toner through a fourth guide mechanism 23 so as to move to a non-development position slightly deviated from the development position A.
[0030]
On the other hand, when the operation input mechanism 27 is in a non-operation input state in which the intermediate transfer unit 7 is not separated from the photosensitive member 1 and the locking mechanism 26 locks one of the developing devices 2 to 5 at the developing position A, The operation lever 61 is positioned on the drawing path of the process unit 36 as shown in FIG. 10 to prevent the drawing of the process unit 36 in such a state. The transfer unit 7 is separated from the photosensitive member 1, and in conjunction with this, the developing unit 5 and the like at the developing position A are moved to the non-developing position, so that the photosensitive member 1 and its surroundings are provided. Interference with this mechanism is prevented.
[0031]
Further, the intermediate transfer unit 7 also has a cleaner 37 to clean the moving surface after the secondary transfer. The cleaners 35 and 37 of the process unit 36 and the intermediate transfer unit 7 have recovery containers 41 and 42 for recovering residual toner removed from the moving surfaces of the photosensitive member 1 and the intermediate transfer belt 7a, and screws provided at the bottoms thereof. It is discharged by 41a and 42a. A common waste toner container 43 is detachably connected to the discharge ports 41b and 42b shown in FIG. 10, and the discharged waste toner is stored and stored in the connected state. When it is full, remove it, discard it, and reconnect a new one. Alternatively, the stored waste toner is discarded, emptied, and reconnected for use. The discharge ports 41b and 42b are provided with shutters (not shown). When the waste toner container 43 is connected, the shutter is opened and the waste toner discharged is received into the waste toner container 43. When the waste toner container 43 is removed, the shutter is closed and discharged. The collected toner is prevented from leaking from the outlets 41b and 42b.
[0032]
As shown in FIG. 10, the waste toner container 43 is disposed so as to cover the front side of the operation lever 61 facing the operator. That is, the waste toner container 43 is located immediately inside the front cover (not shown), and the operation lever 61 is hidden further inside the waste toner container 43 even when the front cover is opened to attach or detach the photosensitive member 1. So I can not operate.
[0033]
Therefore, the operation lever 61 of the operation input mechanism 27 cannot be operated unless the disturbing waste toner container 43 is disconnected and removed from the intermediate transfer unit 7 and the process unit 36. Therefore, the operation input can be performed without removing the waste toner container 43. When the mechanism 27 is operated, when the intermediate transfer unit 7 is separated from the photosensitive member 1, the waste toner container 43 that is in a connected state does not follow and gets in the way, or an unreasonable force is applied to cause each part to move. The damage is resolved.
[0034]
By the way, among the plurality of developing devices 2 to 5, the developing device 5 containing black toner is frequently used, and when the apparatus is stopped, the black developing device is positioned at the developing position A and locked by the locking mechanism 26. The color image is formed by starting development with the yellow developing device 2 next to the black developing device 5 and finally developing with the black developing device 5 and developing black after the image formation is completed. The container 5 is locked by the locking mechanism 26 while being in the developing position A. Therefore, when forming a monochrome image, particularly a black monochrome image having a high frequency, since the black developing device 5 is located at the developing position A, an image can be formed immediately without switching the developing devices 2 to 5. .
[0035]
In this embodiment, in particular, in each of the developing devices 2 to 5 shown in FIGS. 1 to 6, the distance between the photosensitive member 1 and the developing rollers 2a to 5a, that is, as a spacing holding member for making the developing gap G constant. A configuration is adopted in which the developing devices 2 to 5 are pressed against the photosensitive member 1 through a pair of spacer rollers 103 and 104 provided outside both ends of the developing rollers 2a to 5a, and are arranged only on one end side as shown in FIG. A driven gear 106 that meshes with the driving gear 105 and receives driving force, a fixed fulcrum 107 disposed on the driving side having the driven gear 106, and a fixed fulcrum 112 on the non-driving side of the developing devices 2 to 5. Movable with a variable distance between the developing rollers 2a to 5a disposed on the non-driving side, such as being integrally provided on a movable support member 114 that fits and supports the hole 113 with play in the longitudinal direction. Fulcrum 1 It has 8.
[0036]
The movable range of the movable fulcrum 108 with respect to the developing rollers 2a to 5a is the play between the fixed fulcrum 112 and the long hole 113, and the non-contact between the stopper 114a on the movable support member 114 and the developing devices 2 to 5 as shown in FIG. It is defined by play between the position restricting recess 109 as shown in FIGS. 4 and 5 provided on the driving side. However, in the sense of providing the movable fulcrum 108, play between the fixed fulcrum 112 and the long hole 113 can be omitted.
[0037]
On the other hand, as shown in FIGS. 4 and 5, the developing unit 6 supports a plurality of developing devices 2 to 5 so that their driven gears 106 are engaged with the driving gears 105, and these developing devices 2 to 5 are supported. The developing roller 2a is switched from the non-driving side having no driving gear 105 to the driving side having the driving gear 105, while the photosensitive member 1 and the developing rollers 2a to 5a are switched to the developing position A facing each other. In the final stage of mounting of the fifth guide mechanism 101 and the developing devices 2 to 5 which are guides that can be received and attached in a direction parallel to .about.5a, the developing devices 2 to 5 are connected to the photoreceptor 1 at the developing position A. A spring 111 is provided as a biasing means for biasing to the opposite side, and the fixed fulcrum 107 on the driving side and the movable fulcrum 108 on the non-driving side are supported by the fulcrum supports 100 and 102 at the final stage of mounting of the developing devices 2 to 5. Supported in the direction perpendicular to the axis It includes the development rack 25 is that the support.
[0038]
In this way, the developing devices 2 to 5 can be easily attached and detached in the direction parallel to the developing rollers 2 a to 5 a without interference with the photosensitive member 1 at the non-developing position, and finally attached to the developing rack 25. Since the driving-side fixed fulcrum 107 is supported in a direction perpendicular to the axis in the stage, the driving-side fixed fulcrum 107 is not displaced even when the driving load varies, and the driven gear 106 is driven by the driving gear 105 of the developing rack 25. The meshing pitch is changed to prevent the meshing frequency from fluctuating, and the driving load affects the pressure contact state of the developing devices 2 to 5 with respect to the photosensitive member 1. In addition, on the non-driving side of the developing devices 2 to 5, the distance between the developing rollers 2 a to 5 a is variable as described above while the movable fulcrum 108 is supported by the fulcrum support 102 in the direction perpendicular to the axis. Ah Accordingly, the non-driving side of the developing devices 2 to 5 is allowed to play from the support to the developing rack 25 within this variable range, so that the fixed fulcrum 107 of the developing devices 2 to 5 and the fulcrum supports 100 and 102 of the developing rack 25 are provided. Even if there is a manufacturing position error or distortion in the frame of the developing rack 25 due to vibration or the like, the developing devices 2 to 5 absorb the position error and distortion within the range of the play and become familiar with the photoreceptor 1. Since it is well pressed and it is easy to secure the developing gap G as set by the spacer rollers 103 and 104, image noise due to the change in meshing of the driven gear 106 with the driving gear 105 and the photosensitive member 1 of the developing devices 2 to 5 can be obtained. The change in density and uneven density due to fluctuations in the development gap G between the two and non-uniformity in the longitudinal direction are unlikely to occur, resulting in high reliability. In addition, the specific method of making the movable fulcrum 108 movable with respect to the developing rollers 2a to 5a is not particularly limited.
[0039]
Apart from the embodiment described above, play between the stopper 114a on the movable support member 114 as shown in FIG. 4 and the position restricting recess 109 provided on the non-driving side of the developing devices 2 to 5 is not defined. The movable support member 114 is supported on the developing rack 25 by itself or at a fulcrum provided on the developing rack 25 at the final stage of mounting of the developing devices 2 to 5, and the fixed support point 112 is rotated by the movable support member 114. In this case, the axis 121 connecting the fixed fulcrums 107 and 112 on the driving side and the non-driving side is parallel to the developing rollers 2a to 5a. By utilizing such a relationship, the developing devices 2 to 5 are sensed via the spacer rollers 103 and 104 by rotating around the axis 121 connecting the fixed fulcrums 107 and 112 on the driving side and the non-driving side. To be pressed against the body 1
In such an embodiment (not shown), as in the case described above, the developing devices 2 to 5 can be easily attached and detached in the direction parallel to the developing rollers 2 a to 5 a without interference with the photoreceptor 1 at the non-developing position. In the final stage of mounting on the developing rack 25, the fixed fulcrum 107 on the drive side is supported by the fulcrum support 100 in the direction perpendicular to the axis so that the fixed fulcrum on the drive side does not change even if the drive load varies. In particular, the driven gear 106 keeps meshing with the driving gear 105 of the developing rack 25 at a fixed position without being displaced, in addition to preventing the meshing pitch from changing and the meshing frequency from fluctuating. Reference numerals 2 to 5 connect the fixed fulcrums 107 and 112 to the photoreceptor 1 via the spacer rollers 103 and 104 by rotating around the fixed fulcrums 107 and 112 on the driving side and the non-driving side. While ensuring the parallelism between the line 121 and the developing rollers 2a to 5a and achieving good adaptability to the photosensitive member 1, the rotation of the driving gear 105 side does not displace the fixed fulcrums 107 and 112, and the driven gear 106 is not displaced. Even if the driving load fluctuates so as to be efficiently converted into rotation, this influences the pressure contact state of the developing units 2 to 5 that are pressed against the photosensitive member 1 by the rotation around the fixed fulcrums 107 and 112. Since it is easy to prevent, the image noise due to the change in meshing of the driven gear 106 with the driving gear 105 and the developing gap G between the developing devices 2 to 5 and the photosensitive member 1 fluctuate or become uneven in the longitudinal direction. Therefore, the density change and density unevenness due to the occurrence of the problem are less likely to occur, and the reliability becomes high.
[0040]
Here, in the example shown in the figure, by combining the configuration in the two embodiments as described above, it is possible to exhibit both the effects of the two embodiments. . Moreover, in the embodiment in this case, as in the illustrated example, the fixed fulcrum 112 on the non-driving side of the developing devices 2 to 5 is developed by the developing devices 2 to 5 through the long holes 113 of the movable support member 114. Since it is supported at a position A with play in the direction of contact with the opposing photosensitive member 1, the axis 121 connecting the driving side and non-driving side fixed fulcrums 107 and 112 and the developing rollers 2 a to 5 a. The developing devices 2a to 5a give the degree of freedom to the fixed fulcrum 112 on the non-driving side while maintaining the degree of parallelism with the photosensitive member 1 facing the developing position A. The compatibility with the photosensitive member 1 via the spacer rollers 103 and 104 is improved, and the non-driving side fixed fulcrum 112 and the movable support member 114 and the developing rack 25 which are members supporting the non-driving side are manufactured. Accuracy and Can be of influence further prevents easy development gap G for regulating is further properly ensured by a spacer roller 103.
[0041]
The fixed fulcrum 107 on the drive side is coaxial with the drive gear 105. As a result, even if the developing devices 2 to 5 rotate around the fixed fulcrum 107 on the driving side and are pressed against the photosensitive member 1, even if the pressed position fluctuates and the driven gear 106 moves, the driving gear 105 does not move. Therefore, it is possible to avoid changes in the meshing state such as the meshing pitch with the drive gear 105, and there is an advantage that image noise due to the meshing variation is not generated.
[0042]
In addition, the drive gear 105 rotates coaxially with the fixed fulcrum 107 on the drive side, which is the rotation center of the developing devices 2 to 5, and transmits power to the driven gear 106 on the developing devices 2 to 5. The driving torque transmitted to the driven gear 106 is a load that moves the driven gear 106 around the driving fulcrum 107 around the fixed fulcrum 107 on the driving side of the developing devices 2 to 5, and the driven gear 106. Due to the great difference from the load rotated around the support shaft 142, it is preferentially consumed as the driving force of the driven gear 106, which is a light load, and the developing devices 2 to 5 are moved around the fixed fulcrum 107 on the driving side. Since the rotation force is not used, even if the driving load varies, it can be avoided that the development gap G fluctuates due to the pressure contact state of the developing devices 2 to 5 with respect to the photosensitive member 1. Image density has changed It can be further prevented from becoming nonuniform.
[0043]
In the embodiment shown in the figure, the fixed fulcrum 107 on the drive side is fitted with a fulcrum support 100 of a shaft type coaxial with the drive gear 105 as a hole type. Each of the non-driving side fixed fulcrum 112 and the non-driving side movable fulcrum 108 is a shaft type, and the fixed fulcrum 112 is fitted with the elongated hole 113 as a hole type fulcrum support as described above. It is fitted with a hole type fulcrum support 102. However, either side may be a shaft type and a hole type. The driven gear 106 is supported on the side surfaces of the developing units 2 to 5 by the support shaft 142 and meshes with the gear 143 directly connected to the developing rollers 2a to 5a. 106 is engaged with the drive gear 105 to receive the driving force, and the received driving force can be transmitted to the developing rollers 2 a to 5 a via the gear 143.
[0044]
As shown in FIGS. 5 and 6, the spring 111 is disposed on the wall facing the developing devices 2 to 5 in the portion of the developing rack 25 that receives the developing devices 2 to 5. That is, a pair of lever members 146a and 146b provided to be supported by the shaft 145 on the driving side and the non-driving side are made to work, and the lever members 146a and 146b are almost the same as the developing devices 2 to 5 at the final stage of mounting. I try to work at the same time. For this reason, the passive wall 147 that receives the pushing force of the lever members 146a and 146b of the developing units 2 to 5 has the non-driving side passive surface 147b behind the driving side passive surface 147a in the direction facing the photosensitive member 1. It is formed near. At the same time, the non-driving lever member 146b is disposed closer to the rear side in the direction facing the photoreceptor 1 with respect to the driving lever member 146a, and is locked at the standby position by the stoppers 148a and 148b. Accordingly, the driving-side passive surface 147a and the non-driving-side passive surface 147b of the passive wall 147 at the final stage of mounting of the developing devices 2 to 5 are shown in FIG. 6 (a) to FIG. 6 (b). By changing in stages, the lever members 146a and 146b are simultaneously brought into contact with each other through the slopes 147a1 and 147b1, and are pushed toward the photosensitive member 1 to rotate around the fixed fulcrums 107 and 112. The photosensitive member 1 is pressed through 104.
[0045]
As shown in FIG. 4, the fifth guide mechanism 101 has a play S between the receiving developing units 2 to 5 and makes it easy to put them in and out of the developing rack 25. However, the fixed fulcrum 107 and the fulcrum support 100 on the driving side, the movable fulcrum 108 and the fulcrum support 102 on the non-driving side, each pair is a shaft type side fulcrum receiving 100 and the tip of the non-driving side movable fulcrum 108. In this play S, the fulcrum support 100 and the movable fulcrum 108 on the non-driving side are fixed to the fixed fulcrum 107 and the fulcrum. The receiver 102 can be securely fitted in the final stage of mounting. A similar function can be obtained by providing the guide portion 151 on the hole type side. However, a taper may be formed on both the shaft type side and the hole type side.
[0046]
【The invention's effect】
According to the present invention, as is apparent from the above description, the driving side and the fixed fulcrum are not displaced even when the driving load fluctuates, and the driven gear continues to mesh with the driving gear of the support at a fixed position. At the same time, even if the driving load fluctuates, it is easy to prevent this from affecting the pressure contact state of the developing device pressed against the latent image carrier due to the rotation about the fixed fulcrum, so that the driven gear meshes with the driving gear. It is highly reliable because image noise due to fluctuations in image density and development gaps with the latent image carrier of the developing device fluctuate or become uneven in the longitudinal direction are less likely to cause density changes and uneven density. .
[Brief description of the drawings]
FIG. 1 is a non-driving side view showing a relationship between a developing device and a photosensitive member at a developing position of a developing device according to a typical embodiment of the present invention as viewed from the non-driving side.
2 is a driving side view of the developing device of FIG. 1 as viewed from the driving side.
FIG. 3 is a perspective view schematically showing the developing device of FIGS. 1 and 2. FIG.
4 is a side view showing a support structure to which a developing device can be attached and detached in the developing device of FIGS. 1 and 2, as viewed from the non-driving side. FIG.
FIG. 5 is a cross-sectional view of the support structure to which the developing device of FIG. 4 can be attached and detached.
6A is a plan view showing the pressing mechanism of the developing device of FIG. 4, wherein FIG. 6A shows an unpressed state slightly before the final mounting stage, and FIG. 6B shows a pressing state in the final mounting stage. Yes.
7 is a perspective view showing a drive side portion of a developing rack according to the developing device of FIGS. 1 and 2. FIG.
8 is a perspective view of a non-driving side portion of the developing device of FIGS. 1 and 2. FIG.
9 is an overall configuration diagram showing a color printer equipped with the developing device of FIGS. 1 and 2. FIG.
10 is a front view showing a state in which a front panel of the color printer shown in FIG. 9 is opened.
FIG. 11 is a drive side view showing a conventional developing device.
[Explanation of symbols]
1 Photoconductor
2-5 Developer
2a-5a Developing roller
6 Development unit
23 Fourth guide mechanism
24 axes
25 Development rack
88 Removable window
100, 102 fulcrum
101a, 101b guide
101 Fifth guide mechanism
103, 104 Spacer roller
105 Drive gear
106 Driven gear
107 Fixed fulcrum on the drive side
108 Movable fulcrum on the non-drive side
109 Position restriction recess
111 spring
112 Non-drive side fixed fulcrum
113 long hole
114 Movable support member
114a stopper
A Development position
G Development gap

Claims

In the developing device in which the developing device is brought into pressure contact with the latent image carrier through an interval holding member that makes the distance between the latent image carrier and the developing roller constant,
A driven gear that is arranged only on one end side and meshes with the driving gear to receive driving transmission, a fixed fulcrum arranged on the driving side having the driven gear, and a distance between the developing roller arranged on the non-driving side A plurality of developing devices having movable fulcrums,
A plurality of developing devices are supported so that their driven gears mesh with the driving gears, and the developing devices are switched to a developing position where the latent image carrier and the developing roller face each other. A guide that allows the drive side with a drive gear to be received and attached in a direction parallel to the developing roller from the non-drive side that has no drive gear, the developer unit facing the latent image carrier at the development position at the final stage of installation of the developer unit A support that biases the drive side fixed fulcrum and the non-drive side movable fulcrum in a direction perpendicular to the axis at the final stage of mounting of the developing device;
A developing device comprising:

In the developing device in which the developing device is brought into pressure contact with the latent image carrier through an interval holding member that makes the distance between the latent image carrier and the developing roller constant,
Arranged only on one end side, driven gear that meshes with the driving gear and receives driving transmission, arranged on the same axis parallel to the developing roller on the driving side having the driven gear and on the opposite non-driving side A plurality of developments including a fixed fulcrum and a support member that is disposed on the non-drive side and fits so as to support the non-drive side fixed fulcrum in a direction perpendicular to the axis and has a movable fulcrum whose distance from the developing roller is variable. And
A plurality of developing devices are supported so that their driven gears mesh with the driving gears, and the developing devices are switched to a developing position where the latent image carrier and the developing roller face each other. A guide that allows the drive side with a drive gear to be received and attached in a direction parallel to the developing roller from the non-drive side that has no drive gear, the developer unit facing the latent image carrier at the development position at the final stage of installation of the developer unit Urging means for urging to the side, and supporting the fixed fulcrum of the driving side and the movable fulcrum of the support member in the direction perpendicular to the axis at the final stage of mounting of the developing unit. A support that is brought into pressure contact with the latent image carrier via a spacing member by rotation around a fixed fulcrum;
A developing device comprising:

The developing device according to claim 2 , wherein the fixed fulcrum on the non-driving side of the developing device is supported by the developing device with a play in a substantially contacting / separating direction with a latent image carrier facing the developing device.

The developing device according to claim 2 , wherein the driving-side fixed fulcrum is coaxial with the driving gear.