JP4294238B2

JP4294238B2 - Developing device, process cartridge and image forming apparatus using the same

Info

Publication number: JP4294238B2
Application number: JP2001241778A
Authority: JP
Inventors: 篤哉大慈彌
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2001-08-09
Filing date: 2001-08-09
Publication date: 2009-07-08
Anticipated expiration: 2021-08-09
Also published as: JP2003057932A

Description

【０００１】
【発明の属する技術分野】
本発明は、複写機、ファクシミリ、プリンター等の画像形成装置に用いられる現像装置に関し、詳しくは、現像剤担持体上にトナーと磁性キャリアとを含む現像剤を担持して画像形成装置の像担持体に対向する領域へ該現像剤を搬送し、該像担持体に形成された潜像を現像する現像装置及びこの現像装置を用いたプロセスカートリッジと画像形成装置に関する。
【０００２】
【従来の技術】
従来、トナーを用いて静電潜像を現像する方法として、トナーと磁性キャリアを用いた現像剤を利用する２成分現像法が知られている。この二成分現像法においては、トナー不足による画像のかすれやトナー過多による地汚れなどの現像不良を防止するため、トナーと磁性キャリアとの間の摩擦による静電気力を適正に保つこと、また、トナーと磁性キャリアとの混合比（トナー濃度）を一定範囲に保つ制御が必要となる。このため従来の現像装置は、現像剤を帯電あるいは攪拌するための攪拌搬送機構や、トナー濃度センサと該センサからの検知信号により制御されるトナー補給部材などを必要としていた。
【０００３】
これに対し、現像装置を含む画像形成装置全体の低コスト化及び小型化を図るため、図１示すような、攪拌搬送機構やトナー濃度センサなどを省略した現像装置が提案されている。
この現像装置は像担持体である円筒状の感光体ドラム１の側方に配置され、この感光体ドラム１に向けて開口部が形成された現像ケーシング２の内部に、該開口部から一部が露出した、トナー及び磁性キャリアからなる現像剤３aを表面に担持する現像剤担持体としての非磁性材質からなる現像スリーブ４、現像スリーブ４の内部に固定配置された磁界発生手段としてのマグネットローラ５、現像スリーブ４上に担持されて搬送されている現像剤の量を規制する第一の現像剤規制部材としてのドクタ（ドクターブレード）６、現像剤収納ケース７、トナー収容部としてのトナーホッパ８等を備えている。
【０００４】
現像剤収納ケース７は、現像スリーブ４との間に、感光体ドラム１との対向部の現像位置に供給されずにドクタ６で進行が阻止された現像剤を収容する現像剤収容部Ａを形成している。そして、現像剤スリーブ４の内部に固定配置されているマグネットローラ５のうち、現像剤収容部Ａに対向する位置には、現像剤収容部Ａ内の現像剤３ａを現像スリーブ４上に担持させるための磁極５ａを配置している。
また、トナーホッパ８は、現像スリーブ４の現像剤搬送方向における現像剤収容部Ａの上流側に隣接して、現像スリーブ４表面と対向するトナー補給口８ａを有する。このトナー補給口８ａに隣り合ったスペースには、トナーホッパ８内の新しいトナー１１ａをトナー補給口８ａに向けて攪拌しながら送り出すトナー補給部材としてのアジテータ９が配置されている。そしてこのアジテータ９は、回転軸の位置、羽の長さが調節され、図中破線で示すように、アジテータの最外周軌道が、現像スリーブ４の周辺に位置している現像剤（トナー及び磁性キャリアで構成）に振れないように設定されている。
【０００５】
上記構成の現像装置において、現像スリーブ４上に担持された現像剤３ａは、図中の矢印ａ方向に回転する現像スリーブ４の回転に伴ってスリーブ上をドクタ６側に搬送され、ドクタ６により規制されて薄層化される。薄層化された現像剤３ａは、図中の矢印ｂ方向に回転している感光体ドラム１と対向する現像領域に搬送される。そして、該現像領域では、感光体ドラム１上に形成されている静電潜像にトナーが接触あるいは非接触で供給され、該静電潜像の可視化が行われる。なお、この静電潜像を、感光体ドラム１の周囲に配置された、帯電装置、光書込装置などの潜像形成手段により形成される。
その後、現像剤３ａは、現像スリーブ４の回転に伴ってスリーブ上をトナー補給口８ａ側に搬送され、トナーホッパ８内のアジテータ９によりトナー補給口８ａを通じて供給された新しいトナー１１ａを取り込んだあと、現像剤収容部Ａに戻る。
【０００６】
一方、上記現像領域に供給されずにドクタ６で進行が阻止された現像剤３ａの一部は、現像剤収容部Ａ内で現像剤３ａ自身の内圧及び重力によってトナーホッパ８のトナー補給口８ａに向かって移動する。トナー補給口８ａ付近まで移動してきた現像剤３ａは、現像剤収容部とトナー収容部との間に設けられ該現像剤担持体と所定の間隔を隔て配置された第二の現像剤規制部材であるプレドクタ１０により規制される。
そして、プレドクタ１０により規制された現像剤３ａは、トナー補給口８ａ側から進入してきた新しいトナー１１ａを含む現像剤３ａと合流して、磁極５ａの磁力により現像スリーブ４側に引き寄せられ、再び現像スリーブ４の回転に伴ってドクタ６側に搬送される。
このような現像剤３ａによる現像剤収容部Ａ内の循環は、トナーと磁性キャリアとの間で摩擦帯電を発生させることを可能とするため、従来の現像装置に設けられた現像剤を帯電あるいは攪拌するためのパドルやスクリュー等のような複雑な攪拌搬送機構が不要となる。
【０００７】
また、上記構成の現像装置においては、現像剤３ａに補給されたトナーが多くなってトナー濃度が高まると、それに従って現像剤収容部Ａ内の現像剤３ａの嵩が増加するため、現像剤３ａが第二の現像剤規制部材であるプレドクタ１０に向かって移動し、プレドクタ１０により規制しきれない現像剤３ａが現像剤滞留部３ｂを形成して、トナー補給口８ａの開口をおおってしまう。このため、現像スリーブ４上の現像剤３ａに対するトナー１１ａの取り込み量が少なくなる。このトナー１１ａ取り込み量の減少により、現像剤３ａのトナー濃度が減少するため、現像剤３ａのトナー濃度が常に一定濃度以下に保たれることとなる。
逆に、現像剤３ａのトナー濃度が低くなると現像剤収容部Ａ内の現像剤３ａの嵩が減少するため、プレドクタ１０により規制しきれずに現像剤収容部Ａからはみ出す現像剤３ａの量が減少する。このため、現像剤滞留部３ｂがトナー補給口８ａを塞がなくなるので、現像スリーブ４上の現像剤３ａへ所定量のトナー１１ａが取り込まれ、現像剤３ａのトナー濃度が常に一定濃度以上に保たれる。
【０００８】
また、トナー濃度を変化させたい場合は、現像剤収容部Ａ内に収容される磁性キャリアの量を変化させることで現像剤３ａの嵩が変わりコントロールできる。例えば、キャリア量をある一定量から減らすと現像剤３ａの嵩が減少するため、現像剤滞留部３ｂが減少し、トナー補給口８ａからのトナー１１ａの取り込みが増加して現像剤３ａのトナー濃度は高くなる。
このようにトナー濃度をほぼ一定範囲内にコントロールできるため、トナー濃度センサやトナー補給部材などを用いた複雑なトナー濃度制御機構が不要となる。さらに、このような現像装置では、現像剤収容部Ａ内に収容される磁性キャリアとトナーからなる二成分現像剤３ａの量が少量であり、現像スリーブ４の軸方向に均一に現像剤３ａが担持されている。このため、通常の二成分現像方式に比較して磁性キャリアが少なく、現像装置の現像スリーブ４を回転させるためのトルクが大幅に減少し、駆動系の省電力化も達成することが可能となる。
図１のようにトナー濃度を自律制御をする機能を有する現像装置を、以下では、「トナー濃度自律制御型現像装置」という。
【０００９】
【発明が解決しようとする課題】
トナー濃度自律制御型現像装置は、当該装置を初めて使用する際、現像スリーブ４上に現像剤３ａを、該現像スリーブ４の軸方向に対して略均一になるように担持させる必要がある。
他方、現像剤収容部Ａ近傍に現像剤を収容した初期現像剤収容部を設けて、ユーザーが使用する際に該現像剤収容部と該初期現像剤収容部を隔てるシール部材を剥がして、初期現像剤収容部に収容されている現像剤を現像剤収容部内にセットする様になっている。また、トナー補給開口にトナーを供給するためのトナー補給口を有するトナー収容部があり、トナー補給口内のトナーの凝集やトナー収容部からのトナー飛散をさけるためにトナー補給口とトナー収容部を隔てるシール部材も設けており、これもユーザーが使用する際に剥がす様になっている。そして、前記した様にユーザーが使用する際に各シールを剥がした後、本体にセットして現像スリーブやトナー収容部内に設けられたトナー補給部材がギヤを介して同時に回転し、初期現像剤の現像スリーブへのセットやトナー補給が開始される。
【００１０】
しかしながら、このような現像装置は、ユーザーの使用場所までの搬送途中に初期現像剤収容部内の現像剤が一部に偏る、あるいは、初めて現像装置を含む画像形成装置を使用するために、前記の各シール部材を剥がす際に現像装置を傾けて行うなどの原因から、初期現像剤が現像剤収容部内ににおいて現像スリーブの長手方向の一方側に偏ってしまい、該初期現像剤が長手方向に不均一な状態で現像スリーブ上にセットされることとなる。このため、現像スリーブの長手方向において、現像剤が少ない部分では、図１のような現像剤滞留部３ｂが減少するためトナーが過剰に供給され、他方、現像剤が多い部分では、現像剤滞留部３ｂが増加するためトナー供給が抑制されることとなり、画像濃度ムラなどが現像スリーブの長手方向で発生する。
【００１１】
本発明の課題は、上述した問題を解決し、初期現像剤の現像剤坦持体上へのセットを、現像剤坦持体の長手方向において均一化し、画像濃度ムラなどのない良好な画像を形成できる現像装置、及びそれを利用したプロセスカートリッジと画像形成装置を提供することである。
【００１２】
【課題を解決するための手段】
上記課題を解決するため、請求項１に係る発明は、トナーと磁性キャリアとを含む現像剤を担持して搬送するための現像剤担持体及び該現像剤担持体の内部に配置した磁界発生手段と、該現像剤担持体に供給される現像剤が収容される現像剤収容部とを有する現像装置において、前記現像剤収容部の近傍に前記現像剤担持体の軸方向に取り除くことが可能なシール部材を介在させて初期現像剤を収容する初期現像剤収容部を設け、該初期現像剤収容部内は仕切り板により前記シール部材の取り除き方向で複数に分割され、かつ、前記現像剤収容部内には、前記取り除き方向において上端の位置が前記仕切り板の下端の位置を取り、該上端よりも下方の箇所ほど前記取り除き方向の下流側になるように傾斜したガイド板を配置し、前記シール部材を取り除いた際に、前記初期現像剤収容部内の現像剤が前記現像剤収容部内の前記ガイド板を経て前記現像剤担持体上に供給されるように構成したことを特徴とする。
【００１３】
請求項１に係る発明によれば、初期現像剤収容部が仕切り板によって複数に分割されているため、例えば、現像装置を初めて使用するためシール部材を現像剤担持体の軸線方向に取り除く際に、現像装置を傾けてシール部材を取り除いた場合においても、初期現像剤収容部内において初期現像剤が各仕切り板を越えて水平方向で大きく偏ることはなく、しかも、現像剤収容部のガイド板が、複数に分割された初期現像剤を水平方向で大きく移動させずに、現像剤担持体上に案内するため、現像剤担持体の長手方向において均一な状態で初期現像剤を現像剤担持体上にセットできる。
【００１５】
更に、前記ガイド板が、前記取り除き方向において上端の位置が前記仕切り板の下端の位置であり、該上端よりも下方の箇所ほど前記取り除き方向の下流側になるように傾斜しているので、シール部材を取り除くときに現像装置が傾いている場合でも、初期現像剤が現像剤収容室に移動する際にガイド板にせき止められる。そして、現像装置を本体にセットする際に現像装置が水平になったときガイド板にせき止められていた初期現像剤が現像剤収容室内にセットされ、より均一に現像剤が現像剤担持体長手方向にセットされる。
以上により、画像濃度ムラなどのない良好な画像を形成する現像装置を提供できる。
また、請求項２に係る発明は、請求項１に記載の現像装置において、前記ガイド板の傾斜は、前記取り除き方向に対する角度が４５度以上９０度未満の傾斜であることを特徴とする。
また、請求項３に係る発明は、請求項１又は２の現像装置において、該現像剤担持体に担持されて搬送される現像剤の量を規制する現像剤規制部材と、トナーを収容するトナー収容部と、該トナー収容部からのトナーを、前記現像剤担持体上での現像剤搬送方向で前記現像剤収容部よりも上流に位置する前記現像剤担持体の表面部分に向けて供給するためのトナー補給口とを備え、該現像剤収容部は、該現像剤規制部材で阻止された現像剤を収容することを特徴とする。
また、請求項４に係る発明は、請求項３の現像装置において、前記現像剤担持体上のトナー濃度の変化により、現像剤とトナーの接触状態を変化させて、前記現像剤担持体上の現像剤の該トナー収容部からのトナー取り込み状態を変化させる。
【００１６】
また、請求項５に係る発明は、現像手段と、像担持体、帯電手段、クリーニング手段より選ばれる少なくとも１つの手段とを一体に支持し、かつ画像形成装置本体に着脱自在に構成されたプロセスカートリッジにおいて、該現像手段として、請求項１〜４のいずれか一に記載された現像装置を用いたことを特徴とする。
【００１７】
請求項５に係る発明によれば、プロセスカートリッジを現像剤担持体の長手方向を水平方向としない状態で搬送する場合や、プロセスカートリッジを画像形成装置本体にセットする際に、プロセスカートリッジをある程度傾けて、現像装置に設けられた初期現像剤収容部と現像剤収容部とを隔てるシール部材を剥がす場合でも、現像剤担持体の長手方向に均一に初期現像剤がセットされるため、画像濃度ムラなどのない良好な画像を形成するプロセスカートリッジを提供できる。
【００１８】
また、請求項６に係る発明は、現像手段を有する画像形成装置において、該現像手段として、請求項１〜４のいずれか一に記載された現像装置を用いたことを特徴とする。
【００１９】
請求項６に係る発明によれば、画像形成装置の現像手段において、上述したように現像剤担持体の長手方向に均一に初期現像剤がセットされるため、現像装置に起因する画像濃度ムラなどのない良好な画像を形成する画像形成装置を提供できる。
【００２０】
【発明の実施の形態】
以下、本発明の好適な実施例について説明する。本発明の現像装置においても、従来の技術の欄において説明した、トナー濃度自律制御型現像装置を用いているため、トナー濃度を一定の範囲に保つ基本的な構成は同様であるため、その詳細な説明は省略する。また、以下の説明及び図面については、図１に示した各部材の番号を参考に、共通の機能を有する部材については、同じ番号を付与している。
【００２１】
第１の実施例について、図２、３、４を参考に説明する。
図２は、本発明の現像装置における未使用時の側面図であり、図３は、同じ時点の正面図を示す。また、図４は、本発明の現像装置の使用時の側面図である。
図２が示すように、本発明の現像装置は、現像剤収容部Ａの上方に初期現像剤収容部Ｂ、現像剤収容部Ａと初期現像剤収容部Ｂを隔てるシールＣ、輸送時のトナー補給口内のトナーの凝集やトナー収容部からのトナー飛散をさけるためにトナー補給口８ａとトナーホッパ８を隔てるシール８ｂを具備している。
初期の現像剤１２は均一に現像スリーブ４上にセットする必要があるため前記の様に現像剤収容部Ａの近傍に初期現像剤収容部Ｂを設けて、ユーザーが使用する際にシールＣを剥がして初期現像剤１２を現像剤収容部Ａ内にセットする様になっている。また、トナー補給口８ａとトナーホッパ８を隔てるシール８ｂもユーザーが使用する際に剥がす様になっている。
【００２２】
前述した様にユーザーが使用する際に、現像装置の各シールを剥がした後、画像形成装置本体に該現像装置をセットすることにより、図４に示すように、現像スリーブ４やトナーホッパ８内に設けられたアジテータ９がギヤ１３、９ａなどを介して同時に回転し、初期現像剤１２の現像スリーブへのセットやトナー補給が開始される。
このように、トナー濃度自律制御型現像装置では、初期現像剤１２の現像スリーブ４へのセットやトナー補給が同時に行われるために、各シールを剥がす際に装置を傾けて行った場合には、初期現像剤が現像剤収容部Ａ内を現像スリーブ４の長手方向に移動してしまい、初期現像剤は該長手方向に不均一に現像スリーブ４上にセットされることとなる。
【００２３】
本発明では、図３に示すように、初期現像剤収容部Ｂを複数に分割する仕切り板Ｂ１を設け、また、現像剤収容室Ａ内には、前記仕切り板Ｂ１に対応する位置に初期現像剤１２ａをガイドするガイド板Ｅを設けている。また、仕切り板Ｂ１で複数に分割された初期現像剤収容部Ｂと、ガイド板Ｅで分割された現像剤収容室Ａ１を有する現像剤収容部Ａとを連結するため、スペーサ部材Ｄが設けられる。
これにより仕切り板Ｂ１で分割された初期現像剤１２ａは、シ−ルＣが剥がされると初期現像剤収容部Ｂから各々の現像剤収容室Ａ１にスペーサ部材Ｄを介して移動することが可能となり、シールＣを剥がす際に現像装置を傾けて行った場合でも、初期現像剤１２が現像剤収容室内Ａを現像スリーブ４の長手方向に移動することを抑制でき、ほぼ均一に初期現像剤１２が現像スリーブ４上にセットされる。
【００２４】
なお、この仕切り板Ｂ１とガイド板Ｅの設置数は多い方が、より効果的な結果が得られる。
また、仕切り板Ｂ１とガイド板Ｅとは、図３のように連続するように配置する場合に限らず、例えば、隣接する仕切り板Ｂ１の間にガイド板Ｅを配置することも可能である。
さらに、現像スリーブ４に対するガイド板Ｅの下端の位置については、適切なトナー濃度に現像剤が制御されている状態で、現像剤収容部Ａにおける現像剤が現像スリーブの長手方向において均一に分布できるように、現像剤の該長手方向への移動を妨げないように設けることが必要である。
【００２５】
本発明の現像装置の効果を確認するため、従来の現像装置と図３に示すような本発明の現像装置との比較実験を行った。
まず、従来の現像装置を使って、まず初期現像剤収容部Ｂ内に収容されるトナー濃度１０ｗｔ％の現像剤を５０ｇ、トナーホッパ８内に５００ｇのトナーを充填し、初めは現像装置を水平にしてシ−ルＣとシ−ル８ｂを剥がして、画像形成装置本体に現像装置をセットして画像形成を行った。３枚画像形成後に現像剤３ａのトナー濃度測定を行ったところ１２ｗｔ％になり、良好な画像を得る事ができた。
【００２６】
次に、同手順で同じ現像装置を準備して、今度は現像装置を４５°傾けてシ−ルＣとシ−ル８ｂを剥がして、画像形成装置本体に現像装置をセットして画像形成を行った。３枚画像形成後に現像剤３ａのトナー濃度測定を行ったところ現像スリーブ長手方向の一部が２０ｗｔ％になり、部分的に地汚れ画像が発生した。
【００２７】
本発明の現像装置を用いて、同様に現像装置を４５°傾けてシ−ルＣとシ−ル８ｂを剥がして、本体に現像装置をセットして画像形成を行った。３枚画像形成後に現像剤３ａのトナー濃度測定を行ったところ１２ｗｔ％になり、良好な画像を得る事ができた。
【００２８】
上記実験に際しての主な実験条件を、参考までに以下に示す。
（機械的条件）
・感光体線速：１２０mm/sec
・現像スリーブと感光体ドラムのギャップＧｐ：０．３〜０．５ｍｍ
・現像スリーブとドクタのギャップＧｄ１：０．３〜０．５ｍｍ
・現像スリーブとプレドクタのギャップＧｄ２：０．３〜１．５ｍｍ
・現像スリーブ径：１６φ
・感光体線速に対する現像ローラの線速比：１．５〜３．０
・現像剤収容室の分割数（仕切り板数）：３〜２０（２〜１９）
（現像剤）
・キャリア：マグネタイトｏｒ鉄で４０〜５０μｍのサイズ
・トナー：磁性体量（１５〜４０ｗｔ％）、シリカ量（０．５〜１．０ｗｔ％）
・トナーのキャリアに対する被覆率：５０〜１２０％
・Ｑ／Ｍ：１０〜３０μｃ／ｇ
・現像剤収容部内に収容される磁性キャリアの量：３０〜１５０ｇ
【００２９】
次に、第２の実施例について、図５を参考に説明する。
図５は、本発明の現像装置における未使用時の正面図であり、図３に代るものである。
第２の実施例と第１の実施例との違いは、第１の実施例の現像装置における現像剤収容室Ａ内の初期現像剤１２をガイドするガイド板Ｅ１が、該現像剤坦持体の長手方向であるシールＣの剥がし方向から角度θで傾いて取り付けられている。この角度θは４５°≦θ＜９０°が望ましい。
これによりシールＣを剥がす際に装置を傾けて行った場合でも初期現像剤１２ａが現像剤収容室Ａ１に移動する際にガイド板Ｅ１にせき止められ、装置を本体にセットする際に装置が水平になった時にガイド板Ｅ１にせき止められていた初期現像剤１２ａは現像剤収容室内Ａにセットされ、より均一に現像剤が現像スリーブ長手方向にセットされるという仕組みである。
【００３０】
また、画像形成装置のメンテナンスフリー化などを反映して、感光体、帯電手段、現像手段、クリーニング手段等の構成要素のうち、少なくとも１つの手段を一体に支持し画像形成装置本体に着脱自在であるプロセスカートリッジとして構成することが行われている。しかも、プロセスカートリッジにおいても、小型化や低コスト化が求められ、トナー濃度自律制御型現像装置は、これらの課題に適合するものである。
本発明のプロセスカートリッジは、上述した第１または２の実施例のような現像装置を利用しているため、プロセスカートリッジにおいてシールＣを剥がす際にカートリッジを傾けて行った場合でも、初期現像剤が現像スリーブの長手方向渡って均一にセットされ、画像濃度ムラなどを防止した高画質な画像形成装置を提供することが可能となる。
【００３１】
【発明の効果】
請求項１乃至２に係る発明によれば、初期現像剤収容部が仕切り板によって複数に分割されているため、例えば、現像装置を初めて使用するためシール部材を取り除く際に、現像装置を傾けてシール部材を現像剤担持体の軸方向に取り除いた場合においても、初期現像剤収容部内において初期現像剤が各仕切り板を越えて水平方向で大きく偏ることはなく、しかも、現像剤収容部のガイド板が、複数に分割された初期現像剤を水平方向に大きく移動させずに、現像剤担持体上に案内するため、現像剤担持体の長手方向において均一な状態で初期現像剤を現像剤担持体上にセットできる。
【００３２】
更に、初期現像剤を現像剤担持体上へ案内するガイド板が所定の傾斜を有しているため、シール部材を取り除くときに現像装置が傾いている場合でも、初期現像剤が現像剤収容室に移動する際にガイド板にせき止められ、そして、現像装置を本体にセットする際に現像装置が水平になったときガイド板にせき止められていた初期現像剤が現像剤収容室内にセットされ、より均一に現像剤が現像剤担持体長手方向にセットされる。
以上により、画像濃度ムラなどのない良好な画像を形成する現像装置を提供できる。
【００３３】
また、請求項５に係る発明によれば、プロセスカートリッジを現像剤担持体の長手方向を水平方向としない状態で搬送する場合や、プロセスカートリッジを画像形成装置本体にセットする際に、プロセスカートリッジをある程度傾けて、現像装置に設けられた初期現像剤収容部と現像剤収容部とを隔てるシール部材を剥がす場合でも、現像剤担持体の長手方向に均一に初期現像剤がセットされるため、画像濃度ムラなどのない良好な画像を形成するプロセスカートリッジを提供できる。
【００３４】
また、請求項６に係る発明によれば、画像形成装置の現像手段において、上述したように現像剤担持体の長手方向に均一に初期現像剤がセットされるため、現像装置に起因する画像濃度ムラなどのない良好な画像を形成する画像形成装置を提供できる。
【図面の簡単な説明】
【図１】トナー濃度自律制御型現像装置の概略図
【図２】本発明の現像装置の未使用時の側面図
【図３】本発明の第１の実施例に係る現像装置の未使用時の正面図
【図４】本発明の現像装置の使用時の側面図
【図５】本発明の第２の実施例に係る現像装置の未使用時の正面図
【符号の説明】
１感光体
２現像装置
３ａ現像剤
３ｂ現像剤滞留部
４現像スリーブ
５マグネットローラ
６ドクタ（ドクターブレード）
７現像剤収納ケース
８トナーホッパ
８ａトナー補給口
８ｂシール
９アジテータ
１０プレドクタ
１１ａトナー
１２初期現像剤
Ａ現像剤収容部
Ｂ初期現像剤収容部
Ｂ１仕切り板
Ｃシール
Ｄスペーサ部材
Ｅガイド板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer. More specifically, the present invention relates to an image carrier of an image forming apparatus by carrying a developer containing toner and a magnetic carrier on a developer carrier. The present invention relates to a developing device that transports the developer to a region facing the body and develops a latent image formed on the image carrier, and a process cartridge and an image forming apparatus using the developing device.
[0002]
[Prior art]
Conventionally, as a method for developing an electrostatic latent image using toner, a two-component development method using a developer using toner and a magnetic carrier is known. In this two-component development method, the electrostatic force due to friction between the toner and the magnetic carrier is properly maintained in order to prevent development defects such as blurring of the image due to toner shortage and background contamination due to excessive toner. It is necessary to control the mixing ratio (toner concentration) of the toner and the magnetic carrier within a certain range. For this reason, the conventional developing device requires a stirring / conveying mechanism for charging or stirring the developer, a toner concentration sensor and a toner replenishing member controlled by a detection signal from the sensor.
[0003]
On the other hand, in order to reduce the cost and size of the entire image forming apparatus including the developing device, there has been proposed a developing device in which an agitating / conveying mechanism and a toner density sensor are omitted as shown in FIG.
This developing device is disposed on the side of a cylindrical photosensitive drum 1 as an image carrier, and a part of the developing device 2 is formed inside the developing casing 2 in which an opening is formed toward the photosensitive drum 1. A developing sleeve 4 made of a non-magnetic material as a developer carrying member for carrying a developer 3a comprising toner and a magnetic carrier on the surface, and a magnet roller as a magnetic field generating means fixedly arranged inside the developing sleeve 4 5. A doctor (doctor blade) 6 as a first developer regulating member for regulating the amount of developer carried and conveyed on the developing sleeve 4, a developer accommodating case 7, and a toner hopper 8 as a toner accommodating portion Etc.
[0004]
The developer storage case 7 includes a developer storage portion A that stores the developer that is not supplied to the development position of the portion facing the photosensitive drum 1 and is prevented from advancing by the doctor 6 between the developer sleeve 4 and the developing sleeve 4. Forming. In the magnet roller 5 fixedly arranged inside the developer sleeve 4, the developer 3 a in the developer accommodating portion A is carried on the developing sleeve 4 at a position facing the developer accommodating portion A. The magnetic pole 5a for this is arrange | positioned.
The toner hopper 8 has a toner replenishing port 8 a facing the surface of the developing sleeve 4 adjacent to the upstream side of the developer accommodating portion A in the developer conveying direction of the developing sleeve 4. In a space adjacent to the toner replenishing port 8a, an agitator 9 as a toner replenishing member for sending new toner 11a in the toner hopper 8 while stirring toward the toner replenishing port 8a is disposed. The agitator 9 is adjusted in the position of the rotating shaft and the length of the wing, and as shown by the broken line in the figure, the outermost peripheral track of the agitator is located in the periphery of the developing sleeve 4 (toner and magnetic It is set so that it does not swing to (composed of carriers).
[0005]
In the developing device configured as described above, the developer 3a carried on the developing sleeve 4 is conveyed to the doctor 6 side on the sleeve as the developing sleeve 4 rotates in the direction of arrow a in the figure. It is regulated and thinned. The thinned developer 3a is conveyed to a developing region facing the photosensitive drum 1 rotating in the direction of arrow b in the figure. In the developing area, toner is supplied to the electrostatic latent image formed on the photosensitive drum 1 in contact or non-contact, and the electrostatic latent image is visualized. The electrostatic latent image is formed by latent image forming means such as a charging device or an optical writing device disposed around the photosensitive drum 1.
Thereafter, the developer 3a is conveyed to the toner replenishing port 8a side as the developing sleeve 4 rotates, and after taking in the new toner 11a supplied through the toner replenishing port 8a by the agitator 9 in the toner hopper 8, Return to developer container A.
[0006]
On the other hand, a part of the developer 3a, which is not supplied to the developing area and is prevented from advancing by the doctor 6, enters the toner replenishing port 8a of the toner hopper 8 due to the internal pressure and gravity of the developer 3a itself in the developer container A. Move towards. The developer 3a that has moved to the vicinity of the toner supply port 8a is a second developer regulating member that is provided between the developer accommodating portion and the toner accommodating portion and is disposed at a predetermined interval from the developer carrier. It is regulated by a certain predoctor 10.
Then, the developer 3a regulated by the predoctor 10 merges with the developer 3a containing the new toner 11a that has entered from the toner supply port 8a side, and is attracted to the developing sleeve 4 side by the magnetic force of the magnetic pole 5a, and developed again. As the sleeve 4 rotates, it is conveyed to the doctor 6 side.
Such circulation in the developer accommodating portion A by the developer 3a makes it possible to generate frictional charge between the toner and the magnetic carrier, so that the developer provided in the conventional developing device is charged or A complicated stirring and conveying mechanism such as a paddle or a screw for stirring is not required.
[0007]
Further, in the developing device having the above configuration, when the amount of toner supplied to the developer 3a increases and the toner density increases, the volume of the developer 3a in the developer accommodating portion A increases accordingly. Moves toward the pre-doctor 10 which is the second developer regulating member, and the developer 3a which cannot be regulated by the pre-doctor 10 forms the developer retaining portion 3b and covers the opening of the toner supply port 8a. For this reason, the amount of toner 11a taken into the developer 3a on the developing sleeve 4 is reduced. Since the toner concentration of the developer 3a decreases due to the reduction in the amount of toner 11a taken in, the toner concentration of the developer 3a is always kept below a certain concentration.
On the contrary, when the toner concentration of the developer 3a is lowered, the volume of the developer 3a in the developer accommodating portion A is reduced, and therefore the amount of the developer 3a protruding from the developer accommodating portion A without being regulated by the predoctor 10 is reduced. To do. For this reason, the developer retaining portion 3b does not block the toner supply port 8a, so that a predetermined amount of the toner 11a is taken into the developer 3a on the developing sleeve 4, and the toner concentration of the developer 3a is always kept at a certain level or higher. Be drunk.
[0008]
Further, when it is desired to change the toner density, the volume of the developer 3a can be changed and controlled by changing the amount of the magnetic carrier accommodated in the developer accommodating portion A. For example, if the carrier amount is reduced from a certain amount, the volume of the developer 3a is reduced, so that the developer retention portion 3b is reduced, the toner 11a is taken in from the toner supply port 8a, and the toner concentration of the developer 3a is increased. Becomes higher.
Thus, since the toner density can be controlled within a substantially constant range, a complicated toner density control mechanism using a toner density sensor, a toner replenishing member, or the like is not required. Further, in such a developing device, the amount of the two-component developer 3a composed of the magnetic carrier and the toner accommodated in the developer accommodating portion A is small, and the developer 3a is uniformly distributed in the axial direction of the developing sleeve 4. It is supported. For this reason, there are few magnetic carriers compared with a normal two-component developing system, the torque for rotating the developing sleeve 4 of the developing device is greatly reduced, and it is possible to achieve power saving of the drive system. .
A developing device having a function of autonomously controlling the toner density as shown in FIG. 1 is hereinafter referred to as “toner density autonomous control type developing device”.
[0009]
[Problems to be solved by the invention]
When the developing device of the toner density autonomous control type is used for the first time, it is necessary to carry the developer 3 a on the developing sleeve 4 so as to be substantially uniform with respect to the axial direction of the developing sleeve 4.
On the other hand, an initial developer containing portion that contains developer is provided in the vicinity of the developer containing portion A, and when the user uses, the seal member that separates the developer containing portion from the initial developer containing portion is peeled off, The developer accommodated in the developer accommodating portion is set in the developer accommodating portion. There is also a toner container having a toner replenishing port for supplying toner to the toner replenishing opening, and the toner replenishing port and the toner container are provided in order to prevent toner aggregation and toner scattering from the toner replenishing port. A seal member is also provided, which is also removed when the user uses it. Then, as described above, after each seal is peeled off when the user uses it, the toner replenishing member set in the main body and provided in the developing sleeve and the toner containing portion is simultaneously rotated via the gear, and the initial developer Setting on the developing sleeve and toner supply are started.
[0010]
However, in such a developing device, the developer in the initial developer accommodating portion is partially biased while being transported to the user's place of use, or the image forming apparatus including the developing device is used for the first time. The initial developer is biased to one side in the longitudinal direction of the developing sleeve in the developer accommodating portion due to, for example, tilting the developing device when peeling each seal member, and the initial developer is not longitudinally aligned. It is set on the developing sleeve in a uniform state. For this reason, in the longitudinal direction of the developing sleeve, in the portion where the developer is small, the developer retention portion 3b as shown in FIG. 1 is reduced, so that the toner is excessively supplied. On the other hand, in the portion where the developer is large, the developer retention Since the portion 3b increases, toner supply is suppressed, and uneven image density and the like occur in the longitudinal direction of the developing sleeve.
[0011]
The object of the present invention is to solve the above-mentioned problems, uniformize the setting of the initial developer on the developer carrier in the longitudinal direction of the developer carrier, and obtain a good image without uneven image density. It is an object of the present invention to provide a developing device that can be formed, and a process cartridge and an image forming apparatus using the developing device.
[0012]
[Means for Solving the Problems]
To solve the above problems, the invention according to claim 1, a magnetic field generating disposed inside the developer carrying member and a developer responsible lifting member for carrying and conveying a developer containing a toner and a magnetic carrier the developing device that Yusuke means and, and a developer accommodating portion in which the developer is accommodated to be supplied to the developer in charge bearing member is removed in the axial direction of said developer carrying member in the vicinity of the developer containing portion it is interposed a sealing member which can be an initial developer accommodating portion for accommodating the initial developer is provided, the initial developer housing is divided into a plurality at removing direction of the seal member by the partition plate, and the developing In the agent container, a guide plate that is inclined so that the position of the upper end in the removal direction takes the position of the lower end of the partition plate, and the position below the upper end is on the downstream side of the removal direction , said sealing portion When removal of the, characterized in that the developer in the initial developer accommodating portion is configured to be supplied to the guide plate on the developer carrying member through in the developer containing portion.
[0013]
According to the invention of claim 1, since the initial developer accommodating portion is divided into a plurality by a partition plate, for example, when removing the sealing member for use of the developing device for the first time in the axial direction of the developer carrying member , in case of removing the sealing member by tilting the developing device is also the initial developer initial developer in the accommodating portion is not being biased large in horizontal direction beyond the respective partition plates, moreover, of the developer accommodating portion guide developing plates, without moving greatly initial developer is divided into a plurality horizontally, for guiding the developer responsible lifting member, the initial developer in a uniform state in the longitudinal direction of the developer responsible lifting body It can be set on the agent responsible lifting body.
[0015]
Furthermore, the guide plate is inclined so that the upper end position in the removal direction is the lower end position of the partition plate, and the lower part of the guide plate is downstream in the removal direction. Even when the developing device is inclined when the member is removed, the initial developer is blocked by the guide plate when it moves to the developer storage chamber. Then, when the developing device is set to the main body, the initial developer blocked by the guide plate when the developing device becomes horizontal is set in the developer containing chamber, and the developer is more evenly distributed in the longitudinal direction of the developer carrier. Set to
More than it can be provided a developing device to form a good image free from such image density unevenness.
According to a second aspect of the present invention, in the developing device according to the first aspect, the inclination of the guide plate is an inclination with respect to the removal direction of 45 degrees or more and less than 90 degrees .
According to a third aspect of the present invention, there is provided the developer according to the first or second aspect, wherein a developer regulating member that regulates the amount of the developer carried on the developer carrying member and a toner containing the toner. The storage unit and the toner from the toner storage unit are supplied toward a surface portion of the developer carrying member positioned upstream of the developer containing unit in the developer transport direction on the developer carrying unit. And a developer replenishing port, wherein the developer accommodating portion accommodates the developer blocked by the developer regulating member.
According to a fourth aspect of the present invention, in the developing device of the third aspect, the contact state between the developer and the toner is changed by the change in the toner density on the developer carrier, and the developer on the developer carrier is changed. The toner intake state of the developer from the toner container is changed.
[0016]
According to a fifth aspect of the present invention, there is provided a process in which the developing unit and at least one unit selected from an image carrier, a charging unit, and a cleaning unit are integrally supported and detachably attached to the main body of the image forming apparatus. The cartridge is characterized in that the developing device according to any one of claims 1 to 4 is used as the developing means.
[0017]
According to the invention of claim 5, or when conveying the process cartridge in a state without the longitudinal direction of the developer responsible lifting member and the horizontal direction, when setting the process cartridge into the image forming apparatus main body, the process cartridge somewhat tilted, because even when peeling off the seal member separating the initial developer accommodating portion provided in the developing device and the developer storage portion, uniform initial developer in the longitudinal direction of the developer responsible lifting body is set, the image It is possible to provide a process cartridge that forms a good image without density unevenness.
[0018]
According to a sixth aspect of the present invention, in the image forming apparatus having the developing means, the developing device according to any one of the first to fourth aspects is used as the developing means.
[0019]
According to the invention of claim 6, in the developing unit of the image forming apparatus, since the uniform initial developer in the longitudinal direction of the developer responsible lifting member as described above is set, the image density unevenness due to developing device It is possible to provide an image forming apparatus that forms a good image without any problem.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described. Since the developing device of the present invention also uses the toner density autonomous control type developing device described in the section of the prior art, the basic configuration for keeping the toner density within a certain range is the same, and the details thereof are as follows. Detailed explanation is omitted. In the following description and drawings, the same numbers are assigned to members having common functions with reference to the numbers of the members shown in FIG.
[0021]
The first embodiment will be described with reference to FIGS.
FIG. 2 is a side view when the developing device of the present invention is not used, and FIG. 3 is a front view at the same time point. FIG. 4 is a side view when the developing device of the present invention is used.
As shown in FIG. 2, the developing device of the present invention includes an initial developer container B above the developer container A, a seal C that separates the developer container A and the initial developer container B, and toner during transportation. A seal 8b that separates the toner replenishing port 8a and the toner hopper 8 is provided to prevent toner aggregation in the replenishing port and toner scattering from the toner container.
Since the initial developer 12 needs to be uniformly set on the developing sleeve 4, the initial developer accommodating portion B is provided in the vicinity of the developer accommodating portion A as described above, and the seal C is used when the user uses it. The initial developer 12 is peeled off and set in the developer accommodating portion A. The seal 8b separating the toner supply port 8a and the toner hopper 8 is also peeled off when the user uses it.
[0022]
As described above, after the user removes each seal of the developing device, the developing device is set in the main body of the image forming apparatus, and as shown in FIG. The provided agitator 9 is simultaneously rotated via gears 13 and 9a and the like, and the initial developer 12 is set on the developing sleeve and toner supply is started.
As described above, in the toner concentration autonomous control type developing device, the initial developer 12 is set on the developing sleeve 4 and the toner is replenished at the same time. Therefore, when the device is tilted when removing each seal, The initial developer moves in the developer accommodating portion A in the longitudinal direction of the developing sleeve 4, and the initial developer is set on the developing sleeve 4 unevenly in the longitudinal direction.
[0023]
In the present invention, as shown in FIG. 3, a partition plate B1 for dividing the initial developer accommodating portion B into a plurality of parts is provided, and the initial development is performed in the developer accommodating chamber A at a position corresponding to the partition plate B1. A guide plate E for guiding the agent 12a is provided. In addition, a spacer member D is provided to connect the initial developer containing portion B divided into a plurality by the partition plate B1 and the developer containing portion A having the developer containing chamber A1 divided by the guide plate E. .
Thus, the initial developer 12a divided by the partition plate B1 can be moved from the initial developer accommodating portion B to each developer accommodating chamber A1 via the spacer member D when the seal C is peeled off. Even when the developing device is tilted when the seal C is peeled off, the initial developer 12 can be prevented from moving in the longitudinal direction of the developing sleeve 4 in the developer accommodating chamber A, and the initial developer 12 is almost uniformly distributed. It is set on the developing sleeve 4.
[0024]
A more effective result can be obtained when the number of the partition plates B1 and the guide plates E is larger.
Further, the partition plate B1 and the guide plate E are not limited to being arranged continuously as shown in FIG. 3, and for example, the guide plate E can be arranged between the adjacent partition plates B1.
Further, with respect to the position of the lower end of the guide plate E with respect to the developing sleeve 4, the developer in the developer accommodating portion A can be uniformly distributed in the longitudinal direction of the developing sleeve while the developer is controlled to an appropriate toner concentration. Thus, it is necessary to provide the developer so as not to hinder the movement of the developer in the longitudinal direction.
[0025]
In order to confirm the effect of the developing device of the present invention, a comparative experiment was conducted between the conventional developing device and the developing device of the present invention as shown in FIG.
First, using a conventional developing device, 50 g of a toner having a toner concentration of 10 wt% contained in the initial developer containing portion B and 500 g of toner are filled in the toner hopper 8, and the developing device is initially leveled. Then, the seal C and the seal 8b were peeled off, and a developing device was set in the image forming apparatus main body to form an image. When the toner density of developer 3a was measured after the three-sheet image was formed, it was 12 wt%, and a good image could be obtained.
[0026]
Next, the same developing device is prepared according to the same procedure, this time the developing device is inclined by 45 °, the seal C and the seal 8b are peeled off, and the developing device is set on the image forming apparatus main body to form an image. went. When the toner density of the developer 3a was measured after the three-sheet image was formed, a part of the developing sleeve in the longitudinal direction was 20 wt%, and a scumming image was partially generated.
[0027]
Using the developing device of the present invention, similarly, the developing device was inclined by 45 ° to peel off the seal C and the seal 8b, and the developing device was set on the main body to form an image. When the toner density of developer 3a was measured after the three-sheet image was formed, it was 12 wt%, and a good image could be obtained.
[0028]
The main experimental conditions for the above experiment are shown below for reference.
(Mechanical conditions)
-Photoconductor linear velocity: 120mm / sec
・ Gap Gp between developing sleeve and photosensitive drum: 0.3 to 0.5 mm
・ Gap Gd1 between developing sleeve and doctor: 0.3 to 0.5 mm
・ Gap Gd2 between developing sleeve and predoctor: 0.3 to 1.5 mm
・ Developing sleeve diameter: 16φ
The ratio of the developing roller linear velocity to the photosensitive member linear velocity: 1.5 to 3.0
-Number of divisions of developer storage chamber (number of partition plates): 3 to 20 (2 to 19)
(Developer)
・ Carrier: magnetite or iron, 40-50 μm size ・ Toner: magnetic substance (15-40 wt%), silica quantity (0.5-1.0 wt%)
-Coverage ratio of toner to carrier: 50 to 120%
Q / M: 10-30 μc / g
-Amount of magnetic carrier accommodated in developer accommodating portion: 30 to 150 g
[0029]
Next, a second embodiment will be described with reference to FIG.
FIG. 5 is a front view of the developing device of the present invention when not used, and is a substitute for FIG.
The difference between the second embodiment and the first embodiment is that the guide plate E1 for guiding the initial developer 12 in the developer storage chamber A in the developing device of the first embodiment is provided with the developer carrier. The seal C is attached at an angle θ from the peeling direction of the seal C, which is the longitudinal direction. This angle θ is preferably 45 ° ≦ θ <90 °.
As a result, even when the apparatus is tilted when the seal C is peeled off, the initial developer 12a is blocked by the guide plate E1 when it moves to the developer accommodating chamber A1, and the apparatus becomes horizontal when the apparatus is set on the main body. At this time, the initial developer 12a that has been blocked by the guide plate E1 is set in the developer containing chamber A, and the developer is more uniformly set in the longitudinal direction of the developing sleeve.
[0030]
Reflecting the maintenance-free operation of the image forming apparatus, at least one of the constituent elements such as the photosensitive member, the charging unit, the developing unit, and the cleaning unit is integrally supported and is detachable from the image forming apparatus main body. Configuration as a certain process cartridge is performed. Moreover, the process cartridge is also required to be downsized and reduced in cost, and the toner density autonomous control type developing device is suitable for these problems.
Since the process cartridge of the present invention uses the developing device as in the first or second embodiment described above, even when the process cartridge is tilted when the seal C is peeled off, the initial developer is not removed. It is possible to provide a high-quality image forming apparatus that is set uniformly over the longitudinal direction of the developing sleeve and prevents image density unevenness.
[0031]
【The invention's effect】
According to the invention according to claim 1 or 2, since the initial developer accommodating portion is divided into a plurality by a partition plate, for example, when removing a sealing member for use of the developing device for the first time, tilting the developing device Te in the case of removing the sealing member in the axial direction of the developer carrying member is also not the initial developer is biased largely in the horizontal direction beyond the respective partition plates in the initial developer accommodating portion, moreover, a developer accommodating portion of the guide plate, without moving greatly multiple the divided initial developer in the horizontal direction, for guiding the developer responsible lifting member, the initial developer in a uniform state in the longitudinal direction of the developer responsible lifting body It can be set on the developer responsible lifting body.
[0032]
Furthermore, since the guide plate for guiding the initial developer to the developer responsible lifting body on has a predetermined inclination, even when the developing device is tilted when removing the sealing member, the initial developer accommodating developer The initial developer that was damped to the guide plate when moving to the chamber, and dammed to the guide plate when the developing device was leveled when the developing device was set on the main body was set in the developer containing chamber, The developer is set more uniformly in the longitudinal direction of the developer carrier.
More than it can be provided a developing device to form a good image free from such image density unevenness.
[0033]
Further, the invention according to claim 5, or when conveying the process cartridge in a state without the longitudinal direction of the developer responsible lifting member and the horizontal direction, when setting the process cartridge into the image forming apparatus main body, the process cartridge the tilted to some extent, even if peeling off the seal member separating the initial developer accommodating portion provided in the developing device and the developer storage portion, since the uniform initial developer in the longitudinal direction of the developer responsible lifting body is set Thus, it is possible to provide a process cartridge that forms a good image without image density unevenness.
[0034]
Further, according to the invention of claim 6, in the developing unit of the image forming apparatus, since the uniform initial developer in the longitudinal direction of the developer responsible lifting member as described above is set, the image caused by the developing device It is possible to provide an image forming apparatus that forms a good image without density unevenness.
[Brief description of the drawings]
FIG. 1 is a schematic view of a developing device of toner density autonomous control type. FIG. 2 is a side view of the developing device of the present invention when not used. FIG. 3 is a diagram of when the developing device according to the first embodiment of the present invention is not used. FIG. 4 is a side view when the developing device of the present invention is used. FIG. 5 is a front view when the developing device according to the second embodiment of the present invention is not used.
DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developing device 3a Developer 3b Developer retention part 4 Developing sleeve 5 Magnet roller 6 Doctor (doctor blade)
7 Developer storage case 8 Toner hopper 8a Toner supply port 8b Seal 9 Agitator 10 Predoctor 11a Toner 12 Initial developer A Developer storage section B Initial developer storage section B1 Partition plate C Seal D Spacer member E Guide plate

Claims

A magnetic field generating means disposed inside the developer carrying member and a developer responsible lifting member for carrying and conveying a developer containing a toner and a magnetic carrier, the developer supplied to the developer in charge bearing member the developing device that but having a developing agent storage unit to be accommodated,
Said sealing member which can be removed in the axial direction of said developer carrying member in the vicinity of the developer accommodating portion is interposed initial developer accommodating portion for accommodating the initial developer provided, initial developer housing partition It is divided into a plurality to at removing direction of the seal member by the plate, and wherein the developer housing, takes the position of the lower end position of the upper end in the removing direction is the partition plate, the more points below the upper end place a guide plate which is inclined so that the downstream side of the removing direction, the when removal of the sealing member, the developer in the initial developer accommodating portion through said guide plate in said developer accommodating portion developing A developing device configured to be supplied onto an agent carrier.

The developing device according to claim 1,
The developing device according to claim 1, wherein the guide plate is inclined at an angle of 45 degrees to less than 90 degrees with respect to the removing direction .

The developing device according to claim 1 or 2,
A developer regulating member that regulates the amount of the developer carried on the developer carrying member, a toner containing unit that contains toner, and toner from the toner containing unit on the developer carrying member. A toner replenishing port for supplying toward the surface portion of the developer carrying member located upstream of the developer accommodating portion in the developer transport direction of
The developer storage unit stores the developer blocked by the developer regulating member.

The developing device according to claim 3.
A developing device that changes the contact state between the developer and the toner according to a change in toner density on the developer carrying member, thereby changing the toner intake state of the developer on the developer carrying member from the toner container.

In a process cartridge that integrally supports a developing unit and at least one unit selected from an image carrier, a charging unit, and a cleaning unit and is configured to be detachable from an image forming apparatus main body,
A process cartridge using the developing device according to any one of claims 1 to 4 as the developing means.

In an image forming apparatus having a developing unit,
An image forming apparatus using the developing device according to any one of claims 1 to 4 as the developing means.