JP3710170B2 - Sheet storage device - Google Patents

Description

【０１０２】
なお、（３）式においてａ１１〜ａ３３はマスキング係数、Ｍ１，Ｃ１，Ｙ１はＵＣＲ回路１０５から出力されたＭＣＹ画像信号、Ｍ０，Ｃ０，Ｙ０はマスキング回路１０６から出力されるＭＣＹ画像信号であり、マスキング係数ａ１１〜ａ３３はリーダコントローラ７００から指定されるマスキング係数制御信号によって決定される。
【０１０３】
１０７はセレクタであり、リーダコントローラ７００から選択端子Ｓへ入力された色選択信号に応じて、マスキング回路１０６と黒抽出回路１０４から入力されたＭ、Ｃ、Ｙ、Ｂｋの画像信号の中から１色の画像信号を選択して画像信号Ｖ１を出力する。
【０１０４】
１０８はリーダ階調補正回路であり、セレクタ１０７から入力された画像信号Ｖ１に図４に示すような階調補正を施して、画像信号Ｖ２を出力する。例えば、リーダ階調補正回路１０８は、リーダコントローラ７００から指定された階調補正選択信号に基づいて選択された図４の変換特性ａ〜ｅの何れかによって、画像信号に濃度補正を施す。このリーダ階調補正回路１０８での設定は、後述する操作部の画像濃度設定によって決定される。
【０１０５】
１０９はプリンタ階調補正回路であり、プリンタ部２０２の出力特性を各色ごとにリニアにするために、プリンタコントローラ７０１から入力されたプリンタ色選択信号に応じて、図５に一例を示すガンマ変換特性のｍ，ｃ，ｙ，ｂｋの何れかを選択して画像信号に補正を施す。
【０１０６】
１１０はレーザドライバであり、前述のレーザ露光光学系３（図１参照）に含まれる。レーザドライバ１１０は、プリンタ階調補正回路１０９から入力された画像信号Ｖ３に基づいて半導体レーザを変調駆動することにより、感光ドラム１上に潜像を形成する。
【０１０７】
図６は、本発明のカラー画像形成装置の操作部を示したものである。図６において３５１はテンキーであり、画像形成枚数の設定やモード設定の数値入力に使用する。３５２はクリア／ストップキーであり、設定された画像形成枚数や画像形成動作の停止を行うために使用する。３５３はリセットキーであり、設定された画像形成枚数や動作モードや選択給紙段等のモードを規定値に戻すためのものである。３５４はスタートキーであり、このスタートキー３５４の押下により画像形成動作を開始する。
【０１０８】
３６９は液晶等で構成される表示パネルであり、詳細なモード設定を容易にすべく、設定モードに応じて表示内容が変わる。本実施例では、カーソルキー３６６〜３６８で表示パネル３６９のカーソルを移動させ、ＯＫキー３６４によって設定を決定させる。このような設定方法はタッチパネルで構成することも可能である。
【０１０９】
３７１は紙種設定キーであり、標準より厚い記録材へ画像形成を行うときに設定する。紙種設定キー３７１によって厚紙モードが設定されると、ＬＥＤ３７０が点灯するように制御される。本実施例では、厚紙モードの設定のみ可能であるが、必要に応じて、ＯＨＰやその他の特殊用紙用のモードの設定が可能となるように機能を拡張することもできる。
【０１１０】
３７５は両面モード設定キーであり、例えば、片面原稿から片面出力を行う「片−片モード」、片面原稿から両面出力を行う「片−両モード」、両面原稿から両面出力を行う「両−両モード」、両面原稿から２枚の片面出力を行う「両−片モード」の４種類の両面モードの設定が可能である。ＬＥＤ３７２〜３７４は、設定された両面モードに応じて点灯し、「片−片モード」ではＬＥＤ３７２〜３７４はすべて消灯し、「片−両モード」ではＬＥＤ３７２のみが点灯、「両−両モード」ではＬＥＤ３７３のみが点灯、「両−片モード」ではＬＥＤ３７４のみが点灯するように制御される。
【０１１１】
（画像形成の具体例）
以下、具体例として、自動原稿送り装置ＲＤＦ６００を使用しない「片−片モード」で、厚紙モードの設定がされていない普通紙に対しての４色の画像形成動作について説明を行う。
【０１１２】
この場合、画像形成を行う記録材が普通紙であるため、定着駆動モータドライバ７６１に対してのスピード設定は感光ドラム１の画像形成スピード（プロセススピード）ＶＰと同じＶＦＮとなるように設定する。
【０１１３】
オペレータがテンキー３５１によって画像形成枚数を設定した後、用紙選択キー３０３で給紙段を選択し、スタートキー３５４で動作スタートを指示すると、プリンタコントローラ７０１は、画像形成に必要な駆動モータ、例えば、感光ドラム駆動モータ、定着駆動モータ、給紙駆動モータ、およびメイン駆動モータの各ドライバに駆動を指示する。次に、それらの駆動モータの駆動状態が安定化してから、指定された給紙段（記録材カセット７ａ，７ｂなど）から記録材Ｐの給紙動作を開始する。このとき、略同時にリーダ部２０１は、４色モードの第１色目の現像色であるマゼンタ用の画像信号を生成できるように、前述のシフト量、黒抽出量、ＵＣＲ量、およびリーダ色選択信号等を画像処理部２０３の各ブロックに設定する。また、リーダ階調補正回路１０８は、操作部７０４の濃度キー３０４，３０６の指定内容に対応した図４に示すａ〜ｅの変換特性のいずれかを選択する。また、プリンタ階調補正回路１０９には図５に示すｍの変換特性が選択される。
【０１１４】
指定給紙段から給紙された記録材Ｐは、レジストローラ５０によって、リーダ部２０１の光学スキャン動作とタイミングを合わせるようにして送られ、吸着帯電器５ｃと対抗電極である吸着ローラ５ｇにより転写シート５ｆに吸着される。
【０１１５】
また、リーダ部２０１で読み取られた原稿情報は、画像処理部２０３で処理され、そして帯電器２により一様に帯電された感光ドラム１に、レーザ光として照射されて潜像を成し、まずはマゼンタ現像器４ｍにより現像される。現像された画像情報は、先ほど吸着された記録材Ｐ上に転写帯電器５ｂにより転写される。このＭ（マゼンタ）原稿読み取り、潜像形成、現像、転写の画像形成動作は、感光ドラム１と転写ドラム５ａが１回転する間に実行され、同様に、残りの３色のＣ（シアン）、Ｙ（イエロー）、Ｂｋ（ブラック）の各色についても実行する。また、このとき画像処理部２０３に対しての設定は画像形成毎に行うものとする。
【０１１６】
このように４色の画像が転写された記録材Ｐは転写シート５ｆから分離される。その際、分離帯電器５ｈにより転写シート５ｆと記録材Ｐの吸着力を弱め、分離押し上げコロ８ｂにより転写シート５ｆを変形させて曲率分離を行い、分離爪８ａにより転写シート５ｆから記録材Ｐを分離する。
【０１１７】
このように分離された記録材Ｐは、転写ドラム５ａと同一のスピード（ＶＰ）で搬送動作する記録材搬送部９ｇにより、熱ローラ定着器９に搬送され、そして定着スピードＶＦＮ＝ＶＰで定着されてから、排紙カール補正部５００でカール補正された後ソータ４００に排出される。
【０１１８】
次に、オイル清掃部材のための制御について詳細に説明する。オイル清掃制御は、定着スピードが異なると制御方法が異なるため、はじめに普通紙でのオイル清掃制御について説明する。
【０１１９】
最初に、普通紙モードでのオイル清掃部材の非動作時の制御（オイル清掃不実施時の制御）について説明し、その後普通紙モードでのオイル清掃部材の動作時の制御（オイル清掃実施時の制御）について説明する。
【０１２０】
（普通紙モードでのオイル清掃不実施の制御）
図７は、最終紙（同一原稿の画像が形成される複数枚の用紙の内の最終のもの）に対する最終色の転写動作開始から画像形成動作停止までの制御を示したフローチャートであり、通常、このような制御は「後回転制御」といわれる。この後回転制御により、記録材把持手段である転写ドラム５ａの「通常清掃制御」が実行される。その通常清掃制御は、後述するようにファーブラシ１４とファーバッファブラシ１５を用いた通常の清掃制御である。
【０１２１】
図８は、図７のフローチャートにおいて、転写ドラム５ａが２枚貼り制御可能サイズであるときに後述する「定着（Ｎ）回転制御によって１枚貼り制御を行ったときのタイミングチャート、図９は、図７のフローチャートにおいて、後述する「定着（Ｎ＋１）回転制御」によって１枚貼り制御または２枚貼り制御を行ったときのタイミングチャートである。
【０１２２】
図７の後回転制御のフローチャートにおいて、色モードによって決定される画像形成色の最終色の転写が開始されると（ステップＳ１０００）、まず、同一原稿に対する最終用紙つまり最終紙であるか否かを判断する（ステップＳ１００１）。これにより、転写終了後、後回転制御を行うかどうかを判断する。最終用紙に対する画像形成（以下、「最終画像形成」という）でない場合は画像形成動作を続行し（ステップＳ１００２）、本制御は終了する（ステップＳ１００３）。
【０１２３】
最終画像形成である場合には、記録材の搬送方向のサイズと、転写位置から転写シート清掃位置までの距離ＬＴＣＬＮとを比較する（ステップＳ１００４）。これは、転写位置と転写シート清掃位置の両方に記録材がかかった場合（本実施例では転写位置から転写シート清掃位置までの距離ＬＴＣＮは２５０ｍｍ）、その記録材に対する転写中に転写ドラム５ａの清掃動作や記録材の分離動作を行うと画像乱れが発生することを防止するためであり、転写位置と転写シート清掃位置の両方に記録材がかかる場合には、転写動作を終了させるべく転写ドラム５ａを１回転だけ空回転させて（ステップＳ１００５）後に、分離動作（ステップＳ１００６）と清掃動作（ステップＳ１００８）を行う。
【０１２４】
ステップＳ１００７での通常清掃制御では、ファーブラシ１４を不図示のモータで回転させ、かつこのファーブラシ１４に対向するファーバックアップブラシ１５を有効にして、ファーブラシ１４を転写シート５ｆに当接させればよい。このときは、１枚貼り制御や２枚貼り制御の如何にかかわらず、転写ドラム５ａの１周分の転写シート５ｆの清掃を行い、転写シート５ｆの清掃動作を終了する（ステップＳ１００９）。その後、動作中のモータ等の負荷や高圧を停止し（ステップＳ１００９）、画像形成動作を終了する（ステップＳ１０１０）。
【０１２５】
（普通紙モードでのオイル清掃実施時の制御）
普通紙の両面に単色画像を形成する際における両面２面目の画像形成時（以下、「普通紙単色両面２面時」ともいう）には、以下のように転写シート５ｆのオイル清掃動作を実行する。
【０１２６】
いずれかのカセットから給紙され１面目に画像が形成された記録材は、一旦、中間トレイ２２に格納されてから再給紙される。再給紙された記録材は、２面目の画像形成のために転写ドラム５ａに担持される。このとき、記録材の転写シート５ｆの表面は記録材の１面目の画像形成面に接しており、その１面目の画像形成時に定着器９において付着したオイルが転写シート５ｆの表面に再付着することになる。このオイルが感光ドラム１に付着することは避けなければならず、そのためには、両面２面目の画像形成中の転写シート５ｆが転写位置を通過するときに、その転写位置を通過する転写シート５ｆの表面を事前にオイル清掃するか、あるいは転写シート５ｆと感光ドラム１の間に記録材を存在させるように制御しなくてはならない。定着スピードがプロセススピードと同じ普通紙単色両面２面時では、連続的に複数の記録材に画像形成しているときの転写位置において、転写シート５ｆと感光ドラム１との間に記録材が常に存在するため、例えば、前述の後回転制御時にのみオイル清掃を行えば足りる。
【０１２７】
ところで、両面２面目の画像形成の記録材は、中間トレイ２２から給紙される場合と、記録材トレイ７ｍから給紙される場合とが考えられる。記録材トレイ７ｍには、ユーザが画像形成し終えた記録材を両面画像出力するために再セットする場合があり、この場合には、中間トレイ２２からの給紙と同じように、１面目に画像が形成されている両面２面目用の記録材が存在するとして制御する。
【０１２８】
次に、具体的にオイル清掃制御を図１０のフローチャートにより説明する。この図１０は、両面２面目時にオイル清掃と通常清掃とを実施し、それ以外の時は通常清掃のみを実施する場合の例を示す。
【０１２９】
転写ドラム清掃開始し（ステップＳ１５００）、給紙位置が中間トレイ２２もしくは記録材トレイ７ｍである場合には、ステップＳ１５０１において両面２面目の画像形成であると判断し、オイル清掃動作を行うために、オイル清掃バックアップブラシ１７を有効にし（ステップＳ１５０２）、オイル清掃ローラ１６を駆動して、転写シート５ｆに当接させる（ステップＳ１５０３）。オイル清掃ローラ１６はオイルを吸い取る材質で構成されているため、転写シート５ｆに当接することにより、その転写シート５ｆ上に付着したオイルを除去する。次に、通常清掃を行うために、ファーバックアップブラシ１５を有効にし（ステップＳ１５０４）、ファーブラシ１４を駆動して、それを転写シート５ｆに当接させて（ステップＳ１５０５）清掃動作を終了する（ステップＳ１５０６）。また、ステップＳ１５０１において、給紙位置が中間トレイ２２もしくは記録材トレイ７ｍではない場合には、オイル清掃が不要なためファーブラシ１４のみを駆動して通常清掃制御をする（ステップＳ１５０４，Ｓ１５０５）。
【０１３０】
ところで、図１０のステップＳ１５００〜Ｓ１５０６を図７中の転写ドラム清掃制御（ステップＳ１００７）にて実行した場合には、後回転制御において、必要に応じてオイル清掃を実施することができる。また、図１０のステップＳ１５００〜１５０６を図７中のステップＳ１００１とステップＳ１００２との間にて実行した場合には、記録材を転写ドラム５ａから分離する毎に必要に応じてオイル清掃や通常清掃を実施することができる。さらに、図１０のステップＳ１５００〜ステップＳ１５０３を図７中のステップＳ１００１とステップＳ１００２との間にて実行した場合には、記録材を転写ドラム５ａから分離する毎に必要に応じてオイル清掃のみを実施することができる。
【０１３１】
（厚紙モードでの定着スピードの特殊性）
厚紙上にトナーを定着させるためには、普通紙に比べてより多くのエネルギーが必要となるため、定着スピードを普通紙に比べて遅くして、単位面積／時間当たりのエネルギーを増やすことで厚紙の定着性を確保している。その場合、従来では、分離爪８ａから上下定着ローラ９ａ、９ｂの当接位置までの距離を厚紙の画像形成可能最大サイズより大きくすることにより、画像形成スピード（プロセススピード）ＶＰである転写ドラム５ａの周速を一定にしたまま、記録材搬送部９ｇにて、記録材を転写ドラム５ａのスピードとは異なる定着スピードＶＦに減速し、その記録材搬送部９ｇを速度変換領域として使用していた。このためには、厚紙の画像形成可能最大サイズに相当する大きさの記録材搬送部９ｇを確保しなくてはならず、装置が大型化するという欠点があった。
【０１３２】
そこで、本実施例では、転写ドラム５ａのスピードを定着スピードと同様に可変できる構成とし、定着スピードＶＦを画像形成スピードＶＰより遅くしなくてはならないときには、最終色の転写終了後は、転写ドラム５ａのスピードを定着スピードにまで減速する。これにより、記録材搬送部９ｇに速度変換領域としての大きさを確保する必要をなくして、装置の大型化を回避する。
【０１３３】
ところで、図１における転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣよりも記録材の搬送方向サイズが大きい場合には、転写ドラム５ａの定着スピードまでの減速が次の記録材の分離動作のタイミングに間に合わない。このような場合には、転写ドラム５ａを余分に１回転させ、その後の分離動作のタイミングで記録材の分離動作をする。このように、厚紙モードでの最終色の転写終了後に転写ドラム５ａをもう１回転させてから分離動作を行い、さらに定着を行う制御を以下では「定着厚紙（Ｎ＋１）回転制御」という。また、転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣ、もしくは記録材搬送部９ｇが速度変換領域として使用できる場合、つまり転写ドラム５ａを余分に１回転させる必要のない時の制御を以下では「定着厚紙（Ｎ）回転制御」という。
【０１３４】
ここで、説明を分かりやすくするために、図１における転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣを２５０ｍｍであるとすると、代表的な記録材サイズによる厚紙モードでは以下に示すように制御される。
【０１３５】
Ａ４横送りサイズ（送り方向２１０ｍｍ）１枚貼り：定着厚紙（Ｎ）回転制御
Ａ４縦送りサイズ（送り方向２９７ｍｍ）１枚貼り：定着厚紙（Ｎ＋１）回転制御
Ａ３縦送りサイズ（送り方向４２０ｍｍ）１枚貼り：定着厚紙（Ｎ＋１）回転制御
Ａ４横送りサイズ（送り方向２１０ｍｍ）２枚貼り：定着厚紙（Ｎ＋１）回転制御
【０１３６】
（厚紙モードでのオイル清掃の特殊性）
次に、このように定着スピードを遅くする必要のある厚紙モードでのオイル清掃制御について説明する。
【０１３７】
前述したように、普通紙のオイル清掃制御の場合には、転写ドラム５ａの画像形成終了後、転写ドラム５ａのスピードを変えないため、連続的に画像形成動作が実行でき、オイル清掃制御は、原稿に対する最終紙の画像形成動作終了時に実施するだけでよい。
【０１３８】
これに対し、厚紙モードでは、定着制御のために転写ドラム５ａと感光ドラム１のスピードを定着スピードＶＦＴと同じにするため、次の用紙の画像形成のためには、転写ドラム５ａと感光ドラム１を元のスピードＶＰに再び戻さなくてはならず、記録材が異なると連続的な画像形成動作ができなくなる。そのため、厚紙の２面目の画像形成を行っている場合に、転写位置において、転写シート５ｆ上の付着オイルが感光ドラム１に付着することになってしまい、各記録材に対する最終色の転写動作終了ごとにオイル清掃制御が必要になる。そこで、厚紙モードでの画像の形成時には、以下のように、各記録材に対する最終色の転写動作終了毎にオイル清掃制御を実施する。
【０１３９】
（厚紙モードでの画像の形成制御）
以下に、厚紙モードでのカラー画像の形成制御を図１１のフローチャートを参照しながら説明する。図１１のフローチャートは厚紙モード、普通紙モード、ＯＨＰモードの全ての記録材に対応するものとなっている。そこで図１１では、定着厚紙（Ｎ＋１）回転制御、および定着厚紙（Ｎ）回転制御に相当する制御を定着（Ｎ＋１）回転制御、および定着（Ｎ）回転制御として、全ての記録材に共通するものとして表している。
【０１４０】
前述したように、給紙、吸着を含む潜像、現像、転写動作（ステップＳ２０００）を、最終色を転写するまで繰り返す（ステップＳ２００１）。最終色の転写後は、定着スピードＶＦと画像形成スピードＶＰとを比較する（ステップＳ２００２）。ここで、厚紙モードの場合は、定着スピードＶＦが厚紙用の遅い定着スピードＶＦＴであって、その定着スピードＶＦが画像形成スピードＶＰとは異なるため、ステップＳ２００２からステップＳ２００３へ移行する。
【０１４１】
ステップＳ２００３では、転写シート５ｆに対して複数枚の記録材を保持するモードか否かの判断を行う。本実施例では、記録材担持手段として静電吸着を用いているため、転写シート５ｆの全周の１／２以下の記録材の場合には、２枚の記録材に対して同時に画像形成が可能である。本例では、２枚の記録材に同時に画像形成する場合（２枚貼）には、その２枚の記録材を、それらの紙間距離を含む１枚の記録材として扱うため、その１枚の記録材として扱った記録材搬送方向サイズよりも、転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣが小さくなり、転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣが速度変換領域として使用できなくなるものとする。そこで、この場合には、「定着（Ｎ＋１）回転制御」を行う（ステップＳ２００６）。
【０１４２】
次に、転写シート５ｆに記録材を１枚だけ担持して画像形成動作を行う場合（１枚貼）には、転写位置から記録材搬送部９ｇの先端位置までの距離ＬＴＣと記録材の記録材搬送方向のサイズＰＸを比較する（ステップＳ２００４）。そのサイズＰＸが距離ＬＴＣより大きい場合には、転写位置から記録材搬送部９ｇの先端位置までの距離を定着スピードの変換領域として使用することができないため、「定着（Ｎ＋１）回転制御」を行う（ステップＳ２００６）。逆に、サイズＰＸが距離ＬＴＣより小さい場合には（ステップＳ２００４）、「定着（Ｎ）回転制御」を行う（ステップＳ２００５）。
【０１４３】
本例では、距離ＬＴＣと記録材の搬送方向サイズを比較するが、ドラムモータの性能などのために速度変化に時間がかかる場合には、その速度変化に要する時間を考慮するように判断ステップ（ステップＳ２００３，ステップＳ２００４）を改良することも可能である。また、定着（Ｎ）回転制御において、記録材の分離動作と略同時に転写シート５ｆの清掃を行う場合には、転写シート５ｆの清掃動作が転写中の記録材に悪影響を与える可能性があるため、記録材搬送方向サイズと転写位置から転写シート清掃位置までの距離によっては制御を変える必要がある。なお、本実施例では、距離ＬＴＣと、転写位置から転写シート清掃位置までの距離ＬＴＣＬＮは、それぞれ２５０ｍｍで等しく設定されている。
【０１４４】
（厚紙モードでの定着（Ｎ）回転制御）
以下、図１２のタイミングチャートにより、厚紙モードでの定着（Ｎ）回転制御について説明する。図１２において、Ｃはシアン、Ｙはイエロー、Ｋはブラックの画像に対応し、また転写ドラムの基準信号は、転写ドラム５ａの回転速度に対応する間隔となり、感光ドラムスピードは転写ドラムスピードと同様に変化する。
【０１４５】
定着（Ｎ）回転制御（ステップＳ２００５）は、最終色転写開始（ステップＳ２００１）後に動作が開始される。分離動作は、厚紙モードではない普通紙モードの場合と同じである。すなわち、分離動作開始タイミングｔ１になるまで待ち、その分離開始タイミングｔ１になったときに、分離爪８ａ、分離押し上げコロ８ｂを動作させて、分離動作を開始する。
【０１４６】
次に、記録材の搬送方向サイズＰＸから決定される転写終了タイミングｔ２になるまで待つ。その転写終了タイミングｔ２になったときに転写帯電器の出力をＯＦＦに設定し、感光ドラムモータドライバ７６０に対して、転写ドラム５ａの周速を厚紙用の定着スピードＶＦＴと同じにするような設定を行う。その後、分離動作終了タイミングｔ３になるまで待ち、分離爪８ａをＯＦＦして分離動作を終了する。
【０１４７】
ところで、このような転写が厚紙モードでの両面２面目である場合には、前述したように、分離後の転写シート５ｆの表面に記録材の１面目の定着オイルが付着することになるため、図１１のステップＳ２００８においてオイル清掃が必要と判断し、その定着オイルが付着した転写シート５ｆの領域が再び転写位置に到達する前にオイル清掃制御を行う（ステップＳ２００９）。そのオイル清掃は、前述した図１０のステップＳ１５０２、Ｓ１５０３と同様に、オイル清掃バックアップブラシ１７を有効にして、オイル清掃ローラ１６を駆動して転写シート５ｆに当接させる制御である。結局、厚紙モードでの両面２面目時には、記録材を分離する毎にオイル清掃制御が行われることになる。
【０１４８】
そして、厚紙用の定着スピードＶＦＴで駆動されている記録材搬送部９ｇに記録材の先端が到達する前に、転写ドラム５ａの周速が定着スピードＶＦＴと同じとなって、記録材が正常に分離、搬送され、厚紙用の定着スピードＶＦＴで定着される。そして、その記録材の排紙終了まで待った後（ステップＳ２０１０）、次の記録材に対する画像形成のために、ドラムモータのスピードで決定される転写ドラム５ａのスピードを画像形成用であるスピードＶＰに設定する（ステップＳ２０１１）。
【０１４９】
このような動作を設定枚数行った後（ステップＳ２０１２）、画像形成動作を終了する。
【０１５０】
（厚紙モードでの定着（Ｎ＋１）回転制御）
以下、図１３のタイミングチャートにより厚紙モードでの定着（Ｎ＋１）回転制御について説明する。図１３は２枚貼のときの例であり、同図において、Ｋ１は１枚目の記録材に対するブラックの画像に対応し、Ｙ２とＫ２は２枚目の記録材に対するイエローとブラックの画像に対応する。
【０１５１】
この定着（Ｎ＋１）回転制御は、前述したように、記録材の搬送方向サイズが転写位置から記録材搬送部先端までの距離ＬＴＣ（＝２５０ｍｍ）より大きく、この間の距離を定着スピードの速度変換領域として用いることができない場合に、転写動作の終了後、転写ドラム５ａを１回転させてから分離動作を行うものである。
【０１５２】
このため、２枚貼の記録材の２枚目における最終色の転写終了時ｔ１１になるまで待ち、その転写終了タイミングｔ１１になったときに転写帯電器の高圧をＯＦＦし、転写動作を終了する。次に、転写ドラム５ａの周速を厚紙用の定着スピードＶＦＴと同じになるように設定し、この定着スピードＶＦＴのまま次の回転における分離開始タイミングｔ１２になるまで待つ。分離開始タイミングｔ１２になったときに分離動作を行い、分離動作終了後、分離爪８ａをＯＦＦし、動作を終了する。
【０１５３】
ところで、このような転写が厚紙モードでの両面２面目である場合には、前述したように、分離後の転写シート５ｆの表面に記録材の１面目の定着オイルが付着することになるため、図１１のステップＳ２００８においてオイル清掃が必要であると判断し、その定着オイルが付着した転写シート５ｆの領域が再び転写位置に到達する前にオイル清掃制御を行う（ステップＳ２００９）。結局、厚紙モードでの定着（Ｎ＋１）回転制御における両面２面目時には、記録材を分離する毎にオイル清掃制御が行われることになる。
【０１５４】
このようにして、転写ドラム５ａが余分に１回転することによって速度変換領域を構成することになり、通常動作の画像形成最大サイズまでの記録材に対しての厚紙モードでの定着動作が可能となる。また、２枚貼りの動作でも厚紙モードの実現が可能となる。
【０１５５】
そして、記録材の排紙終了まで待ったのち（ステップＳ２０１０）、次の記録材に対する画像形成のために、転写ドラム５ａのスピードを画像形成用のスピードＶＰに設定する（ステップＳ２０１１）。
【０１５６】
このような動作を設定枚数分行ってから（ステップＳ２０１２）、画像形成動作を終了する。
【０１５７】
（普通紙モードでの定着通常回転制御）
前述した厚紙モードに対して普通紙モードの場合には、画像形成スピードＶＰと定着スピードが等しいため、図１１のステップＳ２００２からステップＳ２００７へ移行し、「定着通常回転制御」を行う（ステップＳ２００７）。この定着通常回転制御では、定着スピードが画像形成スピードＶＰと等しいため、転写シート５ｆに対して連続的に画像形成が行われ、両面２面目の画像形成であってもオイル清掃制御は設定枚数分の画像形成終了後に実行される（ステップＳ２０１３〜Ｓ２０１５）。
【０１５８】
このような制御を前述した厚紙モードの場合の図１２、図１３と対比して表現したものが図１４，図１５のタイミングチャートである。図１４は、前述した図１２の厚紙モードの場合と同様の１枚貼、図１５は、前述した図１３の厚紙モードの場合と同様の２枚貼のときのタイミングチャートである。
【０１５９】
普通紙では、設定枚数分の画像形成後のステップＳ２０１４においてオイル清掃が必要であると判断したときに、オイル清掃制御（ステップＳ２０１５）を行ってから制御を終了する。そのオイル清掃は、前述したように中間トレイ２２または記録材トレイ７ｍから給紙された両面２面目時に必要と判断される。
【０１６０】
ところで、厚紙モードとは定着スピードが異なるＯＨＰシートに対する記録モード（ＯＨＰモード）では、定着スピードをＶＦＯに設定すれば、厚紙の場合と同様にＯＨＰ用紙に対しての適用も可能である。また、両面２面目で単色モードでない場合には、定着スピードＶＦＤがプロセススピードＶＰと異なるため、厚紙モード両面２面目と同様なオイル清掃制御を行えばよい。
【０１６１】
また、記録材の１面目に付着したトナーなどが２面目の定着時に及ぼす影響を考慮し、両面２面目時には両面１面目時よりも定着スピードを遅らせるように制御してもよい。このような制御は、普通紙モード、厚紙モード、あるいはＯＨＰモードの如何に拘らず実行することができる。
【０１６２】
（リカバリ制御）
次に、このように実現した画像形成装置における紙づまり検知（以下、「ジャム検知」と略す）後のリカバリ制御について図１６のフローチャートを用いて説明する。公知のようにジャムが発生したときは（ステップＳ３０００）、記録材の搬送を停止し、操作部にジャムの発生を表示する（ステップＳ３００１）。
【０１６３】
その後、つまった記録材を取り除くために開かれるドアが開閉されたならば（ステップＳ３００２，Ｓ３００３）、不図示の用紙搬送センサにより記録材が用紙搬送路または転写ドラムから取り除かれたか否かを確認する（ステップＳ３００４）。取り除かれた記録材に、両面２面目の用紙が含まれているときは、停止時の転写シート５ｆの表面に、記録材の１面目に形成された画像上の定着オイルが付着している。そこで、この場合には、ステップＳ３００５からステップＳ３００６に進み、オイル清掃制御を行いかつ転写シート５ｆの清掃動作を行う。一方、両面２面目の用紙が含まれない場合には、オイル清掃制御を行わず、ファーブラシ１４とファーバックアップブラシ１５のみによる転写シート５ｆの清掃を行って（ステップＳ３００７）、その後、リカバリ動作するように制御する（ステップＳ３００８，ステップＳ３００９，ステップＳ３０１０）。
【０１６４】
また、ステップＳ３００５での判断はオイル清掃制御が必要かどうかの判断でもよく、オイル清掃制御画必要な用紙ジャム検知があった場合は、リカバリ制御前にオイル清掃制御を行うことによって、リカバリ制御時の定着オイルの感光ドラム１への付着を防止できる。本実施例では、定着スピードや給紙場所に応じてオイル清掃制御の有無を決定しているため、これらの判断条件を拡張することによって、全ての場合におけるリカバリ制御前のオイル清掃制御が可能となる。
【０１６５】
（研磨ローラ１８の制御）
次に、研磨ローラ１８の制御について、図１７のフローチャートを用いて説明する。
【０１６６】
研磨ローラ１８は、対向する研磨ローラバックアップブラシ１９と共に動作する。研磨ローラ１８は、ファーブラシ１４で清掃しても取れないトナーや用紙からの付着物を削り落とすために用いられる。そのため、研磨ローラ１８の外周には紙やすりと同様な効果を果たす部材が巻き付けられており、この部材により、ファーブラシ１４で清掃できない付着物を削り落とすことが可能となる。研磨ローラ１８の動作は転写シート５ａの寿命に関係するため、例えば、２０００枚の画像形成動作ごとに研磨制御が行われるように制御されている。
【０１６７】
本実施例における研磨制御は、研磨ローラ１８と研磨ローラバックアップブラシ１９を駆動し、転写ドラム５ａを２０回転分回転させることで実現している。そのため、約数分間の実行時間がかかり、この間の画像形成動作は実行できなくなる。そこで、ユーザを拘束する画像形成動作禁止時間を増加させないように、電源投入直後（ステップＳ４０００）の定着ローラが冷えている場合に、この研磨制御を行うように制御している。このことにより、定着ローラの温度が画像形成するために必要な温度となる間に研磨制御を行って、画像形成動作禁止時間の短縮を図っている。
【０１６８】
具体的には、定着上サーミスタ７８１と定着下サーミスタ７８２で検出したそれぞれの定着ローラ（９ａ，９ｂ）の検知温度が両方とも１００度以下の場合に、前述した研磨制御を行う（ステップＳ４００１，Ｓ４００２）。なお、電源投入時に研磨制御を実行するか否かの判断は、これだけに限定されるものではなく、定着ローラの検知温度と研磨実行後の枚数等により研磨制御の有無を決定すればよい。
【０１６９】
定着ローラが加熱されて、画像形成動作画可能になり、そして操作部より所望のモード設定がされて、スタートキー３５４が押されると（ステップＳ４００３）、前述の画像形成動作を開始する（ステップＳ４００４）。用紙１枚ごとの画像形成動作終了時には、研磨制御用カウンタがディクリメントされる（ステップＳ４００５）。この動作を設定枚数分繰り返し（ステップＳ４００６）、自動原稿送り装置ＲＤＦを使用している場合には、最終原稿に対する設定枚数分の画像形成動作を繰り返す（ステップＳ４００７，ステップＳ４００８）。この時点では、全ての画像形成動作が終了しているため、画像形成動作に合わせてディクリメントされた研磨制御用カウンタをチェックする（ステップＳ４００６）。このカウンタが０になっている場合には、前回の研磨動作から所定枚数分の画像形成がされており、研磨動作が必要であることを意味している。そこで、そのカウンタが０となっている場合には、研磨動作を行うための研磨制御を行う（ステップＳ４００９，Ｓ４０１０）。研磨制御中の画像形成動作はできないため、操作部にその旨のメッセージを表示しておく。このようにすれば一連の画像形成動作として研磨制御をユーザに提供できる。
【０１７０】
次に、ステップＳ４０１０での研磨制御の内容について、図１８のフローチャートを用いて説明する。研磨制御瓦解しされたならば（ステップＳ４１００）、ファーブラシ１４だけで転写ドラム５ａの１回転分の清掃を行い、転写シート５ｆ上のトナーを清掃する（ステップＳ４１０１）。その後、研磨ローラ１８と研磨バックアップブラシ１９を駆動し（ステップＳ４１０２）、転写シート５ｆが所定回転分（本例では２０回転分）だけ回転する毎の研磨動作を行う（ステップＳ４１０３）。このような所定回転分毎の研磨動作の終了後は、研磨ブラシ１８と研磨バックアップブラシ１９の駆動を停止し（ステップＳ４１０４）、再び転写ドラム５ａの１回転分野ファーブラシ１４のみによる清掃を行い（ステップＳ４１０５）、研磨動作によって生じたり削り粉を清掃する。その後、枚数管理用の研磨制御用カウンタに初期値である数（本例では２０００）を設定し（ステップＳ４１０６）、研磨制御を終了する（ステップＳ４１０７）。
【０１７１】
ところで、本例では、前回からの研磨制御時からの記録材の枚数管理を行うが、前述のファーブラシ清掃やオイル清掃の場合にもこのような枚数管理のためのカウンタを独立に設けることによって、用紙の種類を設定する際におけるユーザの設定ミスや、出力済み用紙をカセットへ追加することによるオイル付着のような操作ミス等による装置への悪影響も防止可能となる。
【０１７２】
（転写ドラムに対する清掃動作）
次に、操作部からの転写ドラムに対する清掃動作の実行について説明する。本実施例では、ユーザではなくサービスマンのみが実行できる環境を提供するが、必要に応じてユーザからも実行できるようにしてもよい。
【０１７３】
操作部７０４を所定操作することによって、サービスマンのみが使用するサービスモードの入力画面が表示パネル３６９に表示される。転写ドラムに対する清掃動作関連のサービスモードを表示している状態を図１９に示す。この状態でカーソルキー（３６５，３６６，３６７，３６８）とＯＫキー３６４を用いて清掃モードを選択し、実行する。図１９ではオイル除去モードが選択されているため、この状態でＯＫキー３６４を押すとオイル除去モードが実行される。
【０１７４】
以下、図２０のフローチャートを用いて転写ドラムに対する清掃関連のサービスモードについて説明する。まず、サービスモードであり、かつそれが図１９に示されている転写ドラム清掃関連サービスモードであるか否かをチェックする（ステップＳ５０００）。それが肯定されたときには、ＯＫキー３６４の入力を監視し（ステップＳ５００１）、それが入力された時点で清掃モードが確定する。そして、選択された清掃モードの種類を判定し（ステップＳ５００２，Ｓ５００３）、クリーニングが選択された場合には、からステップＳ５００６に進み、オイル除去なしの転写クリーニングを実行する。これは、前述した図１６におけるステップＳ３００７と同じ制御であり、ファーブラシ１４とファーバックアップブラシ１５のみによる転写シート５ｆの清掃を行う。一方、オイル除去が選択された場合には、ステップＳ５００３からステップＳ５００５に進み、オイル除去あり転写クリーニングを実行する。これは、前述した図１６におけるステップＳ３００６と同じ制御であり、ファーブラシ１４とファーバックアップブラシ１５に加え、オイル清掃バックアップブラシ１７、およびオイル清掃ローラ１６を駆動して、転写シート５ｆの清掃を行う。
【０１７５】
また、前記２つ以外の清掃モードが選択された場合には研磨制御を実行する（ステップＳ５００４）。これは、前述した図１８に示したオイル除去制御そのものを実行することになる。
【０１７６】
このように、サービスモードによって選択的に転写ドラムに対する清掃動作を実行することにより、サービス作業の短縮、効率の向上、及び品質の高い画像を形成できることになる。
【０１７７】
【発明の効果】
以上説明した様に、本発明によれば、画像形成装置の画像形成動作終了または中断に応じて、シートが収納されていないトレイと隣のトレイとの間隔を広げ、シートが収納されているトレイと隣のトレイとの間隔をせばめ、画像形成動作を開始することに応じて、元のトレイの位置に復帰させるように制御するので、画像形成装置からシートが排出されない状態のときに長時間シートが放置され、シートが収納されているトレイと隣のトレイとの間隔が広げられたままでシートのカールが成長してしまうことを防止できる。
【図面の簡単な説明】
【図１】本発明の実施例としてのカラー画像形成装置の概略断面図である。
【図２】図１のカラー画像形成装置の制御系のブロック図である。
【図３】図２に示す画像形成処理部の制御系のブロック図である。
【図４】図３のリーダ階調補正回路における入力／出力信号の一例を示す階調補正特性図である。
【図５】図３のプリンタ階調補正回路における入力／出力信号の一例を示す階調補正特性図である。
【図６】図２に示す操作部の概略平面図である。
【図７】図１に示すカラー画像形成装置における最終紙の最終色転写動作開始から画像形成動作停止までの動作を説明するためのフローチャートである。
【図８】図７のフローチャートにおいて定着（Ｎ）回転制御によって１枚貼り制御を行ったときのタイミングチャートである。
【図９】図７のフローチャートにおいて定着（Ｎ＋１）回転制御によって１枚貼り制御または２枚貼り制御を行ったときの制御タイミングチャートである。
【図１０】図７のフローチャートにおいて適用可能な転写ドラム清掃動作を説明するためのフローチャートである。
【図１１】図１のカラー画像形成装置における定着制御を説明するためのフローチャートである。
【図１２】図１１のフローチャートにおいて厚紙モードでの定着（Ｎ）回転動作を説明するためのタイミングチャートである。
【図１３】図１１のフローチャートにおいて厚紙モードでの定着（Ｎ＋１）回転動作を説明するためのタイミングチャートである。
【図１４】図１１のフローチャートにおいて普通紙モードでの定着（Ｎ）回転動作を説明するためのタイミングチャートである。
【図１５】図１１のフローチャートにおいて普通紙モードでの定着（Ｎ＋１）回転動作を説明するためのタイミングチャートである。
【図１６】図１のカラー画像形成装置におけるジャム時の処理を説明するためのフローチャートである。
【図１７】図１のカラー画像形成装置における研磨制御処理を示すフローチャートである。
【図１８】図１のカラー画像形成装置における研磨制御を説明するためのフローチャートである。
【図１９】図１のカラー画像形成装置におけるサービスモード時の表示パネルの表示例を説明するための概略平面図である。
【図２０】図１のカラー画像形成装置における転写ドラム清掃モードの処理を説明するためのフローチャートである。
【図２１】図１のカラー画像形成装置において使用可能なＯＨＰ用紙の平面図である。
【図２２】カール補正部を示す図である。
【図２３】カール補正のフローチャートである。
【図２４】カール補正の制御を説明する図である。
【図２５】自動原稿送り装置の構成を表す断面図である。
【図２６】ソータ部の構成図である。
【図２７】ソータ部の構成図である。
【図２８】ＲＤＦ制御部を示すブロック図である。
【図２９】ソータ制御部を示すブロック図である。
【図３０】制御フローチャートである。
【図３１】制御フローチャートである。
【図３２】制御フローチャートである。
【図３３】制御フローチャートである。
【図３４】制御フローチャートである。
【図３５】制御フローチャートである。
【図３６】制御フローチャートである。
【図３７】制御フローチャートである。
【図３８】制御フローチャートである。
【図３９】制御フローチャートである。
【図４０】制御フローチャートである。
【図４１】制御フローチャートである。
【図４２】制御フローチャートである。
【図４３】制御フローチャートである。
【図４４】制御フローチャートである。
【図４５】制御フローチャートである。
【図４６】制御フローチャートである。
【図４７】制御を説明する図である。
【図４８】制御を説明する図である。
【符号の説明】
２０２ プリンタ部
４００ ソータ
Ｂ ビン[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet storage device having a plurality of trays for storing sheets.
[0002]
[Prior art]
Conventionally, as a sheet storage device that stores sheets discharged from an image forming apparatus, a bin moving type sorter provided with a plurality of bins movable, or after an image is formed in a plurality of fixed bins There is a sorter with a fixed bin that sorts sheets.
[0003]
[Problems to be solved by the invention]
However, when the image forming apparatus to which the conventional sorter is mounted is, for example, a color copying machine, there are the following problems.
[0004]
That is, in general, a manuscript copied by a color copier is often an image such as a photograph, and the toner is applied to the entire surface of the sheet after passing through the fixing device after the image is transferred. Will be established. The thermally expanded toner immediately after the fixing is cooled as time passes, the toner contracts on the sheet, and the sheet is largely curled. As the sheet cools, its curl increases. When the curled sheet is discharged from the color copying machine onto the sorter bin, there is a problem that the rear end of the sheet blocks the sheet discharge port of the sorter, leading to a jam.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a conveying unit that conveys a sheet discharged from an image forming apparatus, a plurality of trays that store sheets conveyed by the conveying unit, and a plurality of trays. In order to store the sheets, the positions of the plurality of trays with respect to the conveying unit are moved, and a tray moving unit that widens the interval between the tray in which the sheets are stored and an adjacent tray, and the image forming operation of the image forming apparatus is completed or interrupted. And a control means for controlling the tray moving means so as to press the sheets on the tray by widening the gap between the trays not containing the sheets and narrowing the gap between the trays containing the sheets. The control unit controls the sheet to return to the original tray position in response to the image forming apparatus starting an image forming operation. There is provided a pay system.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic sectional view of a color image forming apparatus as an embodiment of the present invention.
[0007]
In this example, a digital color image reader unit 201 (hereinafter abbreviated as “reader unit”) at the top, a digital color image printer unit 202 (hereinafter abbreviated as “printer unit”) at the bottom, a reader unit 201 and a printer unit 202. An image processing unit 203 is provided therebetween.
[0008]
In the reader unit 201, the original 30 is placed on the original platen glass 31 and exposed and scanned by the exposure lamp 32, whereby the reflected light image from the original 30 is integrated with the RGB three-color separation filter by the lens 33. To obtain a color separation image analog signal. The color-separated image analog signal is digitized through an amplifier circuit (not shown), processed by the image processing unit 203, and sent to the printer unit 202.
[0009]
In the printer unit 202, the photosensitive drum 1 as an image carrier is rotatably supported in the direction of the arrow, and around the photosensitive drum 1, a pre-exposure lamp 11, a corona charger 2, a laser exposure optical system 3, and a potential sensor. 12, a developing device 4 (developing devices 4y, 4c, 4m, and 4Bk), an on-drum light amount detection sensor 13, a transfer device 5, and a cleaning device 6 are disposed.
[0010]
In the laser exposure optical system 3, the image signal from the reader unit 201 is converted into an optical signal by a laser output unit (not shown), the converted laser beam is reflected by the polygon mirror 3a, and the lens 3b and the mirror 3c are transmitted. Then, the light is projected onto the surface of the photosensitive drum 1.
[0011]
At the time of image formation by the printer unit 202, the photosensitive drum 1 is rotated in the direction of the arrow, and the photosensitive drum 1 after being neutralized by the pre-exposure lamp 11 is uniformly charged by the charger 2, and then an optical image for each separation color. E is irradiated to form a latent image.
[0012]
Next, a predetermined developing device is operated to develop the latent image on the photosensitive drum 1, and a toner image using a resin as a base is formed on the photosensitive drum 1. The developing unit is made to approach the photosensitive drum 1 alternatively according to each separation color by the operation of the eccentric cams 24y, 24c, 24m, and 24Bk.
[0013]
The developed toner image on the photosensitive drum 1 is supplied from the recording material cassettes 7a, 7b, 7c, the intermediate tray 22 or the recording material tray 7m to the position facing the photosensitive drum 1 through the transport system and the transfer device 5. It is transferred to the recording material. The transfer device 5 of this example includes a transfer drum 5a serving as a recording material holding unit, a transfer charger 5b, an adsorption roller 5g opposed to an adsorption charger 5c for electrostatically adsorbing a recording material, an inner charger 5d, and an outer charger. A recording material-carrying sheet 5f made of a dielectric material is integrally stretched in a cylindrical shape in an opening area of a peripheral surface of a transfer drum 5a that is rotatably supported. As the recording material carrying sheet 5f, a dielectric sheet such as a polycarbonate film is used (hereinafter referred to as “transfer sheet 5f”).
[0014]
In this embodiment, since electrostatic adsorption is used as the recording material holding means, in the case of a recording material (250 mm) of ½ or less of the entire circumference of the transfer sheet 5f, two recording materials are simultaneously applied. Image formation is possible. The case where images are formed simultaneously on these two recording sheets is hereinafter referred to as “two-sheet pasting control”, and the case where image formation is performed by electrostatically attracting one recording material to the transfer sheet 5f is referred to as “one-sheet pasting control”. "
[0015]
As the drum-shaped transfer device, that is, the transfer drum 5a is rotated, the toner image on the photosensitive drum 1 is transferred onto the recording material carried on the transfer sheet 5f by the transfer charger 5b. In this way, a desired number of color images are transferred to the recording material attracted and conveyed by the transfer sheet 5f to form a full color image. In the case of full-color image formation, the recording material after the transfer of the four color toner images is separated from the transfer sheet 5f from the transfer drum 5a by the action of the separation claw 8a, separation push-up roller 8b, and separation charger 5h. Then, after curl correction control is performed by a paper discharge curl correction unit 500, which will be described later, via the heat roller fixing device 9, it is sent to a paper discharge post-processing unit (sorter) 400 for post-processing such as desired collation and stapling. The
[0016]
On the other hand, after the transfer, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned by the cleaning device 6.
[0017]
When images are formed on both sides of the recording material, the recording material on which the image is formed on one surface is discharged from the fixing device 9 and immediately after that, the conveyance path switching guide 19 is driven to convey the recording material in the vertical direction. After passing through the path 20, it is once guided to the reversing path 21 a, and then with the reverse rotation of the reversing roller 21 b, it is withdrawn in the direction opposite to the feeding direction with the rear end when it is fed in and stored in the intermediate tray 22. Thereafter, an image is formed on the other surface again by the image forming process described above. When images are formed on both the front and back sides of the recording material in this way, the first surface on which the image is first formed is “the first side of both surfaces”, and the second surface on which the image is formed next is “ It is called "both sides and second side".
[0018]
Further, in order to prevent the powder from scattering and adhering on the recording material carrying sheet 5f of the transfer drum 5a and the later-described oil from adhering to the recording material, the fur brush 14 and the fur facing each other through the recording material carrying sheet 5f are used. Using the backup brush 15, the oil cleaning roller 16 and the oil cleaning backup brush 17 that are opposed via the recording material carrying sheet 5f, and the polishing roller 18 and the polishing roller backup brush 19 that are opposed via the recording material carrying sheet 5f, Clean. Such cleaning is performed before or after image formation, and at any time when a jam (paper jam) occurs.
[0019]
Further, in this example, the gap between the recording material carrying sheet 5f and the photosensitive drum 1 is arbitrarily set by operating the eccentric cam 25 at a desired timing and operating the cam follower 5i integrated with the transfer drum 5a. It has a possible configuration. For example, the distance between the transfer drum 5a and the photosensitive drum 1 is increased during standby or when the power is turned off.
[0020]
Next, toner density control in the developing device 4 will be described. Each toner in the magenta developing unit 4m, the cyan developing unit 4c, and the yellow developing unit 4y reflects near-infrared light having a wavelength of about 960 nm. This reflected light is detected by a developer density detector 780 (see FIG. 2) disposed in the printer, and converted to a toner density signal by an A / D converter 752 (see FIG. 2), and toner for the toner density signal is not shown. Supply the developer from the hopper.
[0021]
On the other hand, black toner absorbs near-infrared light having a wavelength of about 960 nm. Therefore, the toner density is not detected in the black developing device 4Bk, and the black toner image developed on the photosensitive drum 1 is not detected. Near infrared light having a wavelength of about 960 nm is irradiated, the developed black toner density is detected from the ratio of the reflection component on the photosensitive drum 1 surface and the absorption component by the black toner, and the toner density in the developing device is calculated from this.
[0022]
The on-drum light amount detection sensor 13 is arranged between the black developing device 4Bk and the transfer charging device 5b, and is configured to detect a black toner image developed by the black developing device 4Bk before transfer. Detection is possible in the absence of density fluctuation.
[0023]
Next, the heat roller fixing device 9 will be described in detail. The heat roller fixing device 9 includes an upper fixing roller 9a, a lower fixing roller 9b, a fixing web 9c, and a fixing oil application 9d.
[0024]
The heat roller fixing device 9 melts the toner on the recording material by the heat energy of the fixing rollers 9a and 9b, and fixes the melted toner to the recording material by the pressure between the fixing rollers 9a and 9b. Note that the surfaces of the upper fixing roller 9a and the lower fixing roller 9b are the upper fixing heater 9e and the lower fixing heater 9f incorporated in substantially the center thereof, the upper fixing thermistor 781 for detecting the respective roller surface temperatures, and the lower fixing thermistor. 782 and independently controlled so as to obtain an optimum surface temperature.
[0025]
The fixing web 9c contacts the upper fixing roller 9a when necessary to remove dirt on the upper fixing roller 9a or offset toner. At that time, a winding device built in the fixing web 9c can improve the cleaning performance by bringing the new surface of the fixing web 9c into contact with the fixing upper roller 9a. In addition, a fixing oil application roller 9d for supplying silicon oil to the surface of the cleaned upper fixing roller 9a is prepared, so that the toner on the recording material does not adhere to the upper fixing roller 9a when necessary. Oil is applied to the fixing upper roller 9a.
[0026]
Further, the heat roller fixing device 9 drives the fixing rollers 9a and 9b and the recording material conveying portion 9g by a fixing driving motor (not shown in FIG. 1). The fixing drive motor is driven by a fixing drive motor driver 761 (see FIG. 2). In this embodiment, in order to eliminate the difference in fixability depending on the type of recording material, the fixing speed corresponding to four types of recording materials can be realized.
[0027]
If the peripheral speed at the time of image formation on the photosensitive drum 1 is VP (hereinafter referred to as “process speed”), the plain paper fixing speed VFN = VP, and the fixing speed VFD for the second side of both sides is smaller than VFN, The fixing speed for thick paper VFT is smaller than VFD, and the fixing speed for OHP VFO is smaller than VFT. Therefore, the relationship of VP = VFN>VFD>VFT> VFO is established, and the fixing drive motor driver 761 (see FIG. 2) is configured to realize these four types of fixing speeds. The conveyance speed of the recording material conveyance unit 9g is set to be the same as the peripheral speed of the fixing rollers 9a and 9b. Also, the fixing speed VFD for double-sided and double-sided is used for double-sided and double-sided that fixes two or more colors of toner, and is not used in the single-color mode in which only one-color toner is fixed on both sides of the double-sided. The fixing operation is performed at the fixing speed VFN.
[0028]
Next, the curl correction unit 500 will be described. It is known that when a toner image formed by electrophotography is fixed on a sheet, the sheet curls. It is also a well-known fact that this curl adversely affects alignment quality when performing post-discharge processing. For this reason, in this embodiment, the curl correction unit 500 corrects the curl, and the paper is post-processed so as not to adversely affect the paper discharge post-processing unit 400.
[0029]
FIG. 22 shows a main part of the curl correction unit 500 shown in FIG. In FIG. 22, the curling portion 501 is composed of a soft large-diameter upper roller 502 and a metallic small-diameter lower roller 503 made of an elastic body such as silicon sponge.
[0030]
By pressing the metal lower roller 503 against the elastic upper roller 502, a convex nip is formed along the outer diameter of the metal lower roller 503, and the positive curl (convex downward) of the paper P passing through the nip is formed. Make corrections.
[0031]
The curl correcting ability can be adjusted by changing the penetration amount x of the metal lower roller 503 with respect to the elastic upper roller 502. The change of the penetration amount x causes the pressure arm 504 supporting the metal lower roller 503 to be supported on the support shaft 505. The center cam is pivoted by the rotation of the eccentric cam 506. In order to rotationally drive the eccentric cam 506, an eccentric cam motor 507 composed of a stepping motor or the like is driven.
[0032]
B. RDF (circulating automatic document feeder) (600)
As shown in detail in FIG. 25, the RDF 600 is equipped with a stacking tray 610 as a first document tray on which the document bundle S is set. The stacking tray 610 is equipped with a feeding unit 300 constituting one part of the document feeding unit. The feeding means includes a half-moon roller 631, a separation conveyance roller 632, a separation motor SPRMTR (not shown), a registration roller 635, an entire belt 636, a belt motor BELTMTR (not shown), and a large conveyance roller. 637, a conveyance motor FEEDMTR (not shown), a paper discharge roller 640, a flapper 641, a recycle lever 642, a paper feed sensor ENTS, a reverse sensor TRNS, a paper discharge sensor EJTS (not shown), and the like. .
[0033]
Here, the half-moon roller 631 and the separation conveying roller 632 are rotated by a separation motor SPRMTR to separate the documents one by one from the lowermost part of the sheets S on the stacking tray 610.
[0034]
The registration roller 635 and the entire surface belt 636 convey the original separated by rotation by the belt motor BELTMTR to the exposure position (sheet path c) on the original table glass 101 via the sheet paths a and b. The large conveyance roller 637 is rotated by a conveyance motor FEEDMTR to convey the original on the platen glass 31 from the sheet path c to the sheet path e. The document conveyed to the sheet path e is returned to the document bundle S on the stacking tray 610 by the paper discharge roller 640.
[0035]
The recycle lever 642 detects the circulation of the document. When the document feed starts, the recycle lever 642 is placed on the top of the document bundle S, the documents are sequentially fed, and the rear end of the final document exits the recycle lever 642. Sometimes it detects one cycle of the document by dropping by its own weight.
[0036]
In the feeding unit 630, when a double-sided document is used, the document is once guided from the sheet paths a and b to c, and then the large conveying roller 637 is rotated and the flapper 641 is switched to guide the leading edge of the document to the sheet path d. The sheet is passed through the sheet path b by the registration roller 635, and then the entire surface belt 636 conveys the document onto the document table glass 31 and stops, thereby reversing the document. That is, the original is reversed along the sheet paths c to d and b.
[0037]
It is possible to count the number of originals by conveying the originals of the original bundle S through the sheet paths ab to c to de until one cycle is detected by the recycle lever 642. it can.
[0038]
C. Sheet processing device (sorter) (400)
Next, the sorter unit will be described with reference to FIGS. In both figures, the sorter unit 400 includes a machine body 402 and a bin unit 403, and the machine body 402 is provided with a carry-in roller pair 405 in the vicinity of the carry-in entrance 404. A flapper 409 that switches the sheet conveyance direction to the conveyance path 406 or 407 is disposed downstream of the carry-in roller pair 405. One conveyance path 406 extends substantially in the horizontal direction, and a conveyance roller pair 408 is disposed downstream thereof, while the other conveyance path 406 extends downward and the conveyance roller pair 411 is disposed downstream thereof. Further, staplers 412 (a, 412b) are disposed in the vicinity of the roller pair 411.
[0039]
The carry-in roller pair 405 and the conveyance roller pairs 408 and 411 are driven by a conveyance motor 413 (not shown). The transport path 406 is provided with a non-sort path sensor S401 that detects passage of a sheet, and the transport path 407 is provided with a sort path sensor S402. Further, a bin unit 403 having a large number of bins B is disposed on the downstream side of the pair of conveying rollers 408 and 411. One end of the bin unit 403 is engaged with the hook of the bin unit 403 and the other end is connected to the body 402. By holding the weight with a fixed spring, the bin unit 403 is supported to be movable up and down.
[0040]
Guide rollers 417 and 419 are rotatably supported on the upper and lower portions of the base end side of the bin unit 403, and the guide rollers 417 and 419 are guide grooves provided in the machine body 402 so as to extend in the vertical direction. The bottle unit 403 is guided by rolling in the inside 402. Further, a shift motor 421 is disposed on the body 402. A lead cam 423 is fixed to a rotating shaft 422 pivotally supported by the body 402. A chain 426 is stretched around the output shaft of the shift motor 421 so that the rotation of the motor 421 is transmitted to the rotary shaft 422 via the chain 426.
[0041]
Further, the bin unit 403 includes a bottom frame 427 having an inclined portion and a vertical portion, and a frame 429 and a cover supported by the frame 429 that are vertically provided on the front and back sides of the bottom frame 427. A unit main body 431 configured by 430 is included. On the front side of the unit main body 431, a reference plate is provided which can abut against the sheet S and align it.
[0042]
A lower arm that is rotated by an alignment motor a is rotatably supported on the rear side of the base end of the bottom frame 427 (not shown). Further, the upper arm a is fixed to a shaft that is rotatably supported by the cover 430 at a position facing the lower arm a of the cover 430. The rotation center of the upper arm a and the lower arm a are A shaft a is installed at the center of rotation. An alignment rod 439a is installed between the tip of the lower arm a and the tip of the upper arm a, and the alignment rod 439a is configured to be rotated by an alignment motor. Is aligned with the front side.
[0043]
Similarly, a lower arm b that is rotated by an alignment motor b is rotatably supported on the front side of the base end of the bottom frame 427 (not shown). Further, the upper arm b is fixed to a shaft b that is rotatably supported by the cover 430 at a position facing the lower arm b of the cover 430. An alignment rod 439b is provided between the tip of the lower arm b and the tip of the upper arm b, and the alignment rod 439b is configured to be rotated by an alignment motor. Is aligned to the back side.
[0044]
The alignment motors a and b are stepping motors, and the positions of the alignment rods 439a and 439b can be accurately controlled by the number of pulses applied to the stepping motor. Reference numerals S403a and S403b (not shown) are alignment bar home sensors for detecting the positions of the alignment bars 439a and 439b. The alignment bars 439a and 439b are positioned at the alignment bar home sensor and the alignment motors a and b. Can be controlled by the number of pulses given to
[0045]
The bin B is formed with an engagement plate on the front side and the back side, and the engagement plate is engaged with a support plate provided inside the frame 429 so that the bin B is supported on the front side. It is like that. Further, the bin B has a long hole 443a which is longer than the rotation distance of the alignment bar 439a at a predetermined distance from the axis a and sufficiently wider than the width of the alignment bar 439a, and the rotation of the alignment bar 439b at a predetermined distance from the axis b. A long hole 443b longer than the distance and sufficiently wider than the alignment bar 439b is provided. The base end portion Ba of the bin rises perpendicular to the sheet storage surface Bb. The bin B is inclined at a predetermined angle upward with respect to the machine body 402. By this inclination, the sheet S slides on the sheet storage surface Bb and abuts the rear end against the base end portion Ba and is aligned in the front-rear direction. It has become so.
[0046]
The bin B is provided with a notch at a portion where the stapler 412 enters so as not to interfere with the stapler 412. The alignment bar 439a is fitted in the long hole 443a of the bins B1, B2,..., And the alignment bar 439a rotates in the long hole 443a to align the sheet S on the bin B to the near side. Is configured to do. Similarly, the alignment bar 439b is inserted into the long hole 443b of the bins B1, B2,..., And the alignment bar 439b rotates in the long hole 443b to bring the sheet S on the bin B to the back side. Configured to match.
[0047]
The lead cam 423 is engaged with a part of the bin, and the bin unit moves up and down along the groove 423a by the rotation of the lead cam 423. One rotation of the lead cam 423 is detected by a lead cam sensor S404 disposed in the vicinity of the lead cam 423. The position of the bin unit 403 is detected by a bin home position sensor S405.
[0048]
The presence of the sheet S on the sort bin B can be detected by a sort tray paper presence / absence detection sensor (sheet post-processing position selection unit) S407.
[0049]
In the vicinity of the lower discharge roller pair 411, an electric stapler 412 for binding the sheet S stored in the bin B is disposed at a position orthogonal to the carrying-in direction of the sheet S so as to be advanced and retracted by a driving unit. In order to prevent interference when B moves up and down, it is retracted to position a, and when binding a bundle of sheets S on the bin B, the sheet S is moved to position B to bind the bundle of sheets S. After the end of binding, the electric stapler is returned to the position A by driving means (not shown).
[0050]
The electric stapler 412 performs a stapling operation by rotation of a motor (not shown), and when the sheets S of a plurality of bins B are bound, after the stapling operation of the sheets S of one bin B is finished, the bin unit 403 is moved to a predetermined bin. The sheet S is moved to the position and the sheet S stored in the bin B is bound.
[0051]
Note that S406 is a manual stapling key. When the manual stepping key S406 is pressed after sorting, a stapling operation is performed.
[0052]
Further, the position of the sheet bundle on the bin can be pushed forward by the rotation operation of the alignment bar 439a on the back side of the sorter 400.
[0053]
FIG. 2 is a block diagram of a control system in the color image forming apparatus according to the embodiment of the present invention. The color image forming apparatus is roughly divided into two blocks for control. One is a reader controller 700 that mainly controls the reader unit 201 and the image processing unit 203, and the other is a printer controller 701 that controls the printer unit 202.
[0054]
An optical motor driver 702 drives an optical motor (not shown) that moves the scanning mirrors 32a, 32b, and 32c and the exposure lamp 32, and 703 controls an automatic document feeder RDF600 that automatically replaces the document. RDF control unit 900, an operation unit 900 for setting the operation mode of the color image forming apparatus, 705 a ROM storing a control program of the reader controller 700, 706 a RAM storing data such as control values, Reference numeral 707 denotes an I / O for driving a load such as the exposure lamp 32. The RAM 706 is backed up by a battery so that data can be retained even when the power is turned off.
[0055]
Next, the peripheral control unit of the printer controller 701 will be described. A ROM 750 stores a control program for the printer controller 701, a RAM 751 stores data such as control values, and 752 converts analog signals from the potential sensor 12 and the on-drum light amount detection sensor 13 into digital data. An A / D converter, 753 is a D / A converter that outputs an analog set value to the high voltage control unit 770, and 754 is an I / O that drives a load such as a motor and a clutch.
[0056]
G. RDF controller (900)
FIG. 28 is a block diagram showing a circuit configuration of the RDF control unit 900. The apparatus includes a central processing unit (CPU) 901, a read only memory (ROM) 902, a random access memory (RAM) 903, an output port 904, an input port 905, and the like. A control program is stored, and input data and work data are stored in the RAM 903. Also, the output port 904 is connected to various motors such as the separation motor described above and solenoid driving means, the input port 905 is connected to a paper feed sensor and the like, and the CPU 901 is connected via a bus according to a control program stored in the ROM 902. Control each part. Further, the CPU 901 has a serial interface function, performs serial communication with the CPU of the reader control unit 700, and exchanges control data with the reader control unit. The data transmitted from the RDF control unit 900 to the reader control unit 700 is a paper feed completion signal indicating completion of paper feeding on the platen glass.
[0057]
H. Sorter control unit (1000)
FIG. 29 is a block diagram showing a circuit configuration of the sorter control unit 1000. The apparatus includes a central processing unit (CPU) 1001, a read only memory (ROM) 1002, a random access memory (RAM) 1003, an output port 1004, an input port 1005, and the like. A control program is stored, and input data and work data are stored in the RAM 1003. Also, the output port 1004 is connected to various motors such as the shift motor 416 described above, the input port 1005 is connected to each sensor and switch from S401 to S406 such as the non-sort path sensor S401, and the CPU 1001 is a ROM 1002. The units connected via the bus are controlled in accordance with the control program stored in. The CPU 1001 has a serial interface function, performs serial communication with the CPU of the printer control unit 701, and controls each unit by a signal from the printer control unit 701.
[0058]
Next, the control flow of the sorter control unit 1000 in this embodiment will be described with reference to the flowcharts of FIGS. 30 to 46 and FIGS. 47 and 48.
[0059]
(1) Mode processing
First, referring to FIG. 30, the mode process which is the overall process of this embodiment will be described. In step 101, it is determined whether or not there is a “sorter start signal” indicating that sheet discharge from the copying machine main body is started. If yes, the process proceeds to step 103. When there is no “sorter start signal” at step 101, it is checked at step 125 that the manual stapling key is turned on. When it is turned on, manual stapling processing (step 800: described later) (FIG. 38) is performed, and when it is off, step 900 (FIG. 39). , The bin save request is checked (step 130), and if there is, the save sequence is executed (step 131). Also, the bin return request is checked (step 133), and if there is, the return sequence is performed (step 135). Thereafter, the processing is returned to step 101. The bin evacuation request at step 130 is issued after the copying machine main body finishes the copying operation, when the copying machine main body stops abnormally, or when the copying machine main body stops the copying operation. Also, the bin return request at step 133 is issued when the copying machine main body starts a copying operation.
[0060]
At step 137, the presence or absence of the recording paper in the bin B is monitored by the sensor S407, and when it is detected that there is no recording paper in all the bins B, the bin position is initialized (step 139) and the retreat state flag is cleared. (Step 141), the process proceeds to step 101. The initialization of the bin position is to move the bin to a state where it can be discharged to the bin B1.
[0061]
In steps 130 to 107, the mode relating to the storage of the sheet discharged from the copying machine is determined, and the process proceeds to each process described later. That is, non-sort processing (step 103, step 200) described later in the non-sort mode, sort processing (step 105, step 300) described later in the sort mode, group processing (step 107, step 400) described later in the group mode, other than the above In this case, the process proceeds to stack processing (step 500) described later. Then, after each of the above processes, when the mode is the staple mode (step 117), a stapling process (step 600) described later is performed, and the process returns to step 101.
[0062]
(2) Non-sort processing
Next, the operation in the above-described non-sort mode will be described with reference to FIG. First, in order to store sheets in the uppermost bin, the bin unit is lowered to the non-sort home position as initialization of the bin (step 201). Then, the flapper 409 is switched to select the conveyance path 406 as the sheet conveyance path inside the sorter (step 203). The flapper 409 has a drive solenoid (not shown) for switching the flapper 409. When the flapper 409 is normally off, the conveyance path 407 is at a position to be selected. When the flapper 409 is turned on, the conveyance path 406 is selected. . After step 203, the conveyance motor that conveys the sheet is turned on in step 205, the pass sensor is checked on / off (step 207), and the process proceeds to the stored sheet count process (described later) in step 1050 (FIG. 40). That is, it is for counting the number of sheets passing through the transport path and stored in the bin. Thereafter, after performing the overload monitoring process (step 1100: described later) (FIG. 41), the presence / absence of the “sorter start signal” is checked (step 209). If the “sorter start signal” is on, the process returns to step 207. If it is off, the transport motor is stopped at step 211, the flapper is turned off at step 213, and the non-sort process is terminated.
[0063]
(3) Sort processing
Next, the operation in the sort mode will be described with reference to FIG. First, it is determined whether or not the bin position where the operation is to be started is specified (step 327). If specified, the position is moved to that position (step 329). If there is no designation, the presence / absence of a “bin initial signal” for storing sheets from the top bin is checked (step 301). If there is no “bin initial signal”, the process proceeds to step 305, and if there is, the process proceeds to step 303. In step 303, the bin unit is lowered to the non-sort home position as the bin initialization. In step 305, the transport motor is turned on, and then the pass sensor is checked (step 307). If the path sensor is not turned on in step 307, the process proceeds to step 323. If it is turned on, in step 309, the alignment bar is retracted to perform the alignment operation later on the discharged sheet. Thereafter, when it is detected that the path sensor has been turned off, an alignment operation to the storage sheet is performed (step 313), the number counting process (step 1050) (FIG. 40), and the overload monitoring process (step 1100) (FIG. 41) are performed. Then, in step 315, the alignment bars are retracted depending on the presence or absence of the shift direction inversion signal (step 317), one bin shift (step 319) and inversion processing (step 321) are performed. In the inversion process, the subsequent bin shift direction is inverted, and the bin shift operation is not performed. If the “sorter start signal” is turned on in step 323, the process returns to step 307. If the “sorter start signal” is turned off, the transport motor is stopped in step 325, and the sorter process is terminated.
[0064]
(4) Group processing
Next, the operation of the group mode will be described with reference to FIG. First, it is determined whether or not the bin position where the operation is to be started is specified (step 427), and if it is specified, the position is moved to that position (step 429). If there is no designation, the presence / absence of a “bin initial signal” for storing sheets from the highest bin is checked (step 401). If there is no “bin initial signal”, the process proceeds to step 405, and if there is, the process proceeds to step 403. In step 403, the bin unit is lowered to the non-sort home position as the bin initialization. In step 405, the transport motor is turned on, and then the pass sensor is checked on (step 407). If the path sensor is not turned on in step 407, the process proceeds to step 423. If it is turned on, in step 409, the alignment rod is retracted to perform the alignment operation later on the discharged sheet. Thereafter, when it is detected that the path sensor is turned off, a sheet alignment operation is performed (step 413), a sheet count process (step 1050) (FIG. 40), and an overload monitoring process (step 1100) (FIG. 41) are performed. If there is a bin shift signal at step 415, the alignment bar is retracted (step 417) and 1 bin shift (step 419), and if not, the process proceeds to step 423. If the “sorter start signal” is turned on at step 423, the process returns to step 407. If the “sorter start signal” is turned off, the transport motor is stopped at step 425, and the sort process is terminated.
[0065]
(5) Stack processing
Next, the operation in the above-described stack mode will be described with reference to FIG. First, it is determined whether or not the bin position where the operation is to be started is specified (step 527). If specified, the position is moved to that position (step 529). If there is no designation, first, the presence or absence of a “bin initial signal” for storing sheets from the top bin is checked (step 501). If there is no “bin initial signal”, the process proceeds to step 505, and if present, the process proceeds to step 503. . In step 503, the bin unit is lowered to the non-sort home position as the bin initialization. In step 505, the transport motor is turned on, and then the pass sensor is checked on (step 507). If the path sensor is not turned on in step 507, the process proceeds to step 523. If it is turned on, in step 509, the alignment bar is retracted in order to perform the alignment operation later on the discharged sheet. Thereafter, when it is detected that the path sensor is turned off (step 511), the sheet alignment operation is performed (step 513), the sheet count process (step 1050) (FIG. 40), and the overload monitoring process (step 1100) (FIG. 41) is performed. If the number of bins being stored in step 515 has not reached the upper limit number, step 523 is performed, and if it has reached, the alignment bar is retracted (step 517) and one bin shift (step 519) is performed. If the “sorter start signal” is turned on in step 523, the process is returned to step 507. If the “sorter start signal” is turned off, the transport motor is stopped in step 525, and the stack process is terminated.
[0066]
(6) Staple processing
Next, the stapling process will be described with reference to FIG. FIG. 36 is a flowchart showing the flow of the stapling process. First, in step 601, the bin position is initialized for a series of stapling processes. The bin position to be initialized is the position of the uppermost or lowermost bin among the used bins. When the movement is completed, the shift direction is set downward when the position is the upper position, and the shift direction is set upward when the position is the lower position. Then, the process proceeds to step 700 and a stapling operation process is performed. Details of the staple operation processing step 700 will be described later. When the stapling operation process is completed, the program proceeds to step 609 to determine whether or not the bundle that has finished stapling is the final bundle of a series of stapling processes. If it is the final bundle, the stapling process is terminated. If it is not the final bundle, a 1-bin shift is performed, and then the process returns to step 700 to continue the process.
[0067]
Details of the stapling operation processing will be described with reference to the flowchart of FIG. First, in step 901, it is determined whether or not there is a staple for stapling the stapler. If there is a needle, the program proceeds to step 903, and the bundle is restrained by an alignment bar so that the bundle does not shift. Next, the process proceeds to step 905, where stapling is performed. In step 907, the alignment bar is retracted, and the one-point stapling process is completed. If it is determined in step 901 that there is no needle, the process proceeds to step 913, a needle-free alarm is output to the main body, and the process is terminated.
[0068]
(7) Manual stapling process
Next, the manual stapling operation will be described with reference to FIG. Manual stapling is a mode for stapling an already loaded paper bundle on the bin or a paper bundle inserted into the bin by the user, and stapling only one bin. First, in step 801, the stapler is moved to the staple position. When the movement is completed, it is determined whether or not there is paper in the stapler portion by the stapler paper sensor a in the vicinity of the stapler (step 803). If there is paper, the program proceeds to step 805, and staples are made with the stapler a. When it is determined in step 803 that there is no paper in the portion of the stapler a, or after the staple driving in the stapler a is completed in step 805, the program proceeds to step 811. Then, the stapler is moved to the retracted position and the process is terminated.
[0069]
(8) Loading status monitoring process
Next, the loading state monitoring process will be described with reference to FIG. First, the program counter: i is cleared (step 901). In step 903, the counter is incremented by 1 and the sheet detection sensor in the i-th bin from the highest bin is checked (step 905). If there is no paper, the process proceeds to step 909. The set stack number counter: Ni is cleared to 0 (step 907). Thereafter, the same process is performed for all bins (step 903 to step 909), and after the final bin is completed (step 909), the process is completed.
[0070]
Next, the stored number counting process will be described with reference to FIG. In step 1001, the program counter: i is set to the bin number from which the sheet is to be discharged, and in step 1003, the stacking number counter corresponding to i is incremented by 1, and the processing is terminated.
[0071]
Next, the overload monitoring process will be described with reference to FIG. In step 1103, it is determined whether or not the number of sheet sheets currently stored in the bin is larger than a preset stacking upper limit number. If it is not larger than the upper limit number of sheets, the process is terminated, and if it is larger than the upper limit number of sheets, a stacking over alarm is output to the printer body (step 1105). This overload alarm is communication data used to inform the printer that more than the set sheet paper has been stored in the sorter. When this data is received on the printer side, the sheet for image formation is promptly received. Is stopped and sheet discharge to the sorter is stopped (continuous operation is performed after the alarm is released).
[0072]
Next, the storage process will be described with reference to FIG. First, it is determined whether the output is a copy (step 1201). If the determination is affirmative, the process proceeds to step 1203. If the determination is negative, the process proceeds to step 1221. In step 1203, the bin counter k is initialized to zero. In step 1205, the counter k is incremented by 1, and it is determined whether a sheet is stored in the k-th bin (step 1207). At this time, if stored, the process returns to step 1205, and if not stored, the k-th bin is stored (step 1209). If the stored sheet is the final sheet, the process is terminated. If not, it is determined whether there is a storage bin change request (step 1213). If there is no request, the process returns to step 1209. Is incremented by 1 (step 1215), and the process returns to step 1209.
[0073]
In step 1221, the bin counter k is initialized to N + 1. In step 1223, the counter k is decremented by 1, and it is determined whether or not a sheet is stored in the k-th bin (step 1225). At this time, if stored, the process returns to step 1223, and if not stored, the k-th bin is stored (step 1227). If the stored sheet is the final sheet, the process is terminated. If not, it is determined whether there is a storage bin change request (step 1231). If there is no request, the process returns to step 1227. Is decremented by 1 (step 1233), and the process returns to step 1227.
[0074]
Next, the save sequence process will be described with reference to FIG. In step 2051, the target retraction position is calculated, and if the result (step 2053) is the same as that of the current bin, there is no need to retreat, so a retreat alarm is set (step 2061) and the process is terminated. In this case, the current bin position (BIN_POS) is stored in the return position (RET_BIN) (step 2055), and the movement operation is performed to the retreat position (ESC_BIN) (step 2057). Then, after the moving operation ends, the evacuation alarm is cleared and the evacuation state flag is set (step 2059).
[0075]
Next, the return sequence process will be described with reference to FIG. In step 2101, it is checked whether or not it is in the evacuation state. If it is not in the evacuation state, it is not necessary to return, so the evacuation alarm is set (step 2109) to finish the process. RET_BIN) (step 2103, step 2105). Then, the evacuation alarm is cleared and the evacuation state flag is set (step 2107).
[0076]
Next, the movement operation will be described with reference to FIG. First, the current bin position (BIN_POS) and the movement destination (MOV_BIN) are compared (step 2201). If they are the same, the process ends. If they are different, the process moves to step 2203. In step 2203, the magnitude relationship between the current bin position (BIN_POS) and the movement target position is determined. If the movement target bin is smaller, the bin is shifted down by 1 bin (step 2205) and the current position counter is decremented by 1 (step 2207). To do. If the movement target bin is larger, the bin is shifted up by 1 (step 2209) and the current position counter is incremented by 1 (step 2211).
[0077]
Next, calculation of the retracted position will be described with reference to FIG. First, 20 (a number representing the position of the lowest bin in this configuration) is set in the bin position counter (BIN_CN) (step 2301).
[0078]
Then, the number of sheets stacked in the bin indicated by the bin position counter (BIN_CN) (VOL (BIN_CN)) is confirmed. If the number is “0”, the process proceeds to step 2309, and the bin at that time The position counter (BIN_CN) is stored in the retreat position (ESC_BIN). If the number of stacked sheets is other than “0”, it is confirmed whether the bin position counter is “1” (step 2305), and if it is not “1”, the bin position counter (BIN_CN) is decremented by 1 for processing. The process returns to step 2303 and the process continues. If “1”, the process moves to step 2309 and the calculation process ends.
[0079]
Next, the save sequence will be schematically described with reference to FIGS. In the present embodiment, a sorting mode of three originals and a set number of 3 is shown. FIG. 47 shows the bin state and the sheet stacking state at the time when the sort mode processing is finished. The bin II-III between the bin from which the sheet III- (1) is finally discharged and the bin above it is I. -Wider than between II bins. Therefore, the sheet III- (1) does not receive the clamping force from the bins II and III. For this reason, the paper curls in the process of cooling the toner on the hot paper.
[0080]
On the other hand, FIG. 48 shows a bin state and a paper stacking state at the time when the retreat sequence is performed, and a state in which the bins of each bin are fixed and the paper is nipped. As a result, the curling can be reduced because the sheet is pressed in the process of cooling the toner on the sheet.
[0081]
Curl motor driver
Reference numeral 763 denotes a curl motor driver which drives a curl motor which is a drive source of a curl correction unit 500 (not shown) and an eccentric cam motor 507 shown in FIG.
[0082]
Next, the control method for the curl correction unit 500 and the sorter 400 in this embodiment will be described in detail. First, an outline of curl correction control in the curl correction unit 500 will be described, and details will be described using a flowchart.
[0083]
The sheet output on one side is often discharged from the heat roller fixing device 9 in a normal curled (convex downward) state, as shown in FIG. It is known that the positive curl of the paper is caused by shrinkage of the toner heated and melted by the heat roller fixing device 9 due to air cooling after being discharged. The curl amount is the image density (toner amount), It is known that there is a correlation between the above-mentioned change factors and the curl amount, depending on the type of paper (material, rigidity, thickness, size, direction of the gap, etc.) and the surrounding temperature and humidity environment.
[0084]
In the present invention, in addition to the above factors, the operation mode of the sorter 400, the presence / absence of stapling, and the partial image density (toner amount) are comprehensively determined, and optimal curl correction control is provided, resulting in output. An improvement in the quality of the final form of the paper is achieved.
[0085]
First, a method of calculating the partial image density (toner amount) in the first embodiment will be described. In order to simplify the description, the partial image density (toner amount) will be described as an example divided into two in the paper conveyance direction, and the description will be made assuming that the intrusion amount x in FIG. Do.
[0086]
The following will be described with reference to the flowchart of FIG. 23 and FIG. FIG. 23 is a flowchart of the curl correction control unit, and the control is started when the final color image formation is completed (S6000).
[0087]
The image density (toner amount) is sampled by the potential sensor 12 at the time of image formation, averaged, and then converted into a toner amount from the relationship between the potential amount and the toner amount obtained from the experiment. If the toner amount here is a toner amount per unit area and a uniform density, the same value will be shown even if the paper size changes. In the case of forming a color image (four colors), the toner amount is expressed as a sum of a magenta toner amount, a cyan toner amount, a yellow toner amount, and a black toner amount.
[0088]
This toner amount calculation operation is performed after the image formation of the final color black is completed, and three toner amounts of the first half average toner amount TNRtop, the second half average toner amount TNRbottom, and the total average toner amount TNRtotal are calculated (S6001). .
[0089]
Next, the calculated toner amount is selectively used according to the stacking mode for the sorter 400. In the non-sort mode (S6002), since there is no alignment operation, the loading amount is more important than the loading quality, so the total average toner amount TNRtotal is used as the toner amount for determining the intrusion amount ( S6004).
[0090]
Next, in the sort mode and the staple sort mode in which stapling is performed at the end of the job (S6003), the portion to be stapled is the second half of the sheet, so the second half average toner amount TNRbottom is used as the toner amount for determining the intrusion amount (S6005). ).
[0091]
Next, in the case of neither the non-sort mode nor the staple sort mode, that is, in the sort mode or the group mode, the intrusion amount is determined with the larger one of the first half average toner amount TNRtop and the second half average toner amount TNRbottom for improving the stacking quality. It is used as the amount of toner to be used (S6006). In this case, the curl correction quality particularly when the toner amount is shifted is significantly improved as compared with the case where the total average toner amount TNRtotal is used.
[0092]
Thus, the toner amount for determining the intrusion amount for determining the curl correction performance is determined. A method for determining the toner amount and the intrusion amount X will be described with reference to FIG. In this embodiment, the intrusion amount x can be switched between three levels, which are expressed as a small intrusion amount, a medium intrusion amount, and a large intrusion amount. Since the curl amount is proportional to the toner amount as described above, when the total toner amount is taken on the horizontal axis, the switching point data 1 for the small intrusion amount and the intrusion amount and the switching point data for the intrusion amount and the large intrusion amount. 2 exists. Further, since the curl amount depends on the paper size and the size, data 1 and data 2 corresponding to each paper size are determined. This is expressed in Table 28. Since the curl amount also depends on the paper type, thickness, and the like, data corresponding to the table in FIG. 24 is prepared depending on the plain paper on which image can be formed, the OHP paper type, and thick paper.
[0093]
Intrusion amount switching data for each paper size is determined from this table 28, and the intrusion amount is determined from the above-described intrusion amount determination toner amount (S6006).
[0094]
FIG. 3 is a block diagram illustrating a configuration example of the image processing unit 203 in the present embodiment. In FIG. 3, reference numeral 101 denotes a CCD reading unit, which is an amplifier for amplifying the analog RGB signals inputted from the full-color sensor 34 (see FIG. 1), and for converting the analog RGB signals into, for example, 8-bit digital signals. A / D converter, a known shading correction circuit for performing shading correction, and the like, and outputs a digital RGB image signal of a document image.
[0095]
Reference numeral 102 denotes a shift memory, which corrects, for example, a color shift or a pixel shift of the RGB image signal input from the CCD reading unit 101 in accordance with a shift amount control signal from the reader controller 700. Reference numeral 103 denotes a complementary color conversion circuit that converts the RGB image signal input from the shift memory 102 into an MCY image signal. A black extraction circuit 104 extracts a black region of the image from the MCY (magenta, cyan, yellow) image signal input from the complementary color conversion circuit 103 in accordance with the black extraction signal input from the reader controller 700 and extracts the black region. A Bk (black) image signal for the black area is output.
[0096]
A UCR circuit 105 removes the under color from the MCY image signal input from the complementary color conversion circuit 103 in accordance with the Bk image signal input from the black extraction circuit 104 and the UCR amount control signal input from the reader controller 700. (UCR) processing is performed. That is, the black extraction circuit 104 and the UCR circuit 105 improve the color reproducibility by replacing the extracted black region with Mk three-color toner and performing image formation by replacing it with Bk toner.
[0097]
The Bk image signal output from the black extraction circuit 104 is determined by the following equation (1).
[0098]
BK = A · min (C2, Y2, M2) (1)
In Equation (1), A is a black extraction coefficient, and C2, Y2, and M2 are MCY image signals output from the complementary color conversion circuit 103. The black extraction coefficient A is determined by a black extraction amount control signal designated from the reader controller 700.
[0099]
The MCY image signal output from the UCR circuit 105 is determined by the following equation (2).
M1 = B1. (M2-D1.Bk)
C1 = B2 · (C2−D2 · Bk) (2)
Y1 = B3. (Y2-D3.Bk)
In Equation (2), M2, C2, and Y2 are MCY image signals output from the complementary color conversion circuit 103, and M1, C1, and Y1 are MCY image signals output from the UCR circuit 105, and coefficients B1, B2, and B3 , D1, D2, D3 are determined by the UCR amount control signal from the reader controller 700.
[0100]
Next, reference numeral 106 denotes a masking circuit, which removes the turbid component of the toner to be used and corrects the RGB filter characteristics of the CCD from the UCR circuit 105 in accordance with a masking coefficient control signal input from the reader controller 700. Masking processing is performed on the input MCY image signal. The MCY image signal output from the masking circuit 106 is expressed by the following expression (3).
[0101]
[Outside 1]

[0102]
In Equation (3), a11 to a33 are masking coefficients, M1, C1, and Y1 are MCY image signals output from the UCR circuit 105, and M0, C0, and Y0 are MCY image signals output from the masking circuit 106. The masking coefficients a11 to a33 are determined by a masking coefficient control signal designated from the reader controller 700.
[0103]
Reference numeral 107 denotes a selector. One of the M, C, Y, and Bk image signals input from the masking circuit 106 and the black extraction circuit 104 in accordance with the color selection signal input from the reader controller 700 to the selection terminal S. The color image signal is selected and the image signal V1 is output.
[0104]
A reader gradation correction circuit 108 performs gradation correction as shown in FIG. 4 on the image signal V1 input from the selector 107, and outputs an image signal V2. For example, the reader gradation correction circuit 108 performs density correction on the image signal according to any of the conversion characteristics a to e shown in FIG. 4 selected based on the gradation correction selection signal designated by the reader controller 700. The setting in the reader gradation correction circuit 108 is determined by the image density setting of the operation unit described later.
[0105]
Reference numeral 109 denotes a printer gradation correction circuit. In order to make the output characteristic of the printer unit 202 linear for each color, a gamma conversion characteristic shown as an example in FIG. 5 in accordance with a printer color selection signal input from the printer controller 701. Is selected from among m, c, y, and bk, and the image signal is corrected.
[0106]
A laser driver 110 is included in the above-described laser exposure optical system 3 (see FIG. 1). The laser driver 110 forms a latent image on the photosensitive drum 1 by modulating and driving the semiconductor laser based on the image signal V3 input from the printer gradation correction circuit 109.
[0107]
FIG. 6 shows an operation unit of the color image forming apparatus of the present invention. In FIG. 6, reference numeral 351 denotes a numeric keypad which is used for setting the number of images to be formed and inputting numerical values for mode setting. Reference numeral 352 denotes a clear / stop key, which is used for stopping the set number of image forming sheets and the image forming operation. Reference numeral 353 denotes a reset key for returning the set number of image forming sheets, operation mode, selected paper feed stage, etc. to a specified value. Reference numeral 354 denotes a start key. When the start key 354 is pressed, an image forming operation is started.
[0108]
Reference numeral 369 denotes a display panel composed of a liquid crystal or the like, and the display content changes according to the setting mode in order to facilitate detailed mode setting. In this embodiment, the cursor keys 366 to 368 are used to move the cursor on the display panel 369 and the OK key 364 is used to determine the setting. Such a setting method can also be configured by a touch panel.
[0109]
A paper type setting key 371 is set when an image is formed on a recording material thicker than the standard. When the thick paper mode is set by the paper type setting key 371, the LED 370 is controlled to be lit. In this embodiment, only the thick paper mode can be set, but the function can be expanded so that the mode for OHP and other special paper can be set as necessary.
[0110]
Reference numeral 375 denotes a duplex mode setting key. For example, “single-single mode” for single-sided output from a single-sided document, “single-both mode” for double-sided output from a single-sided document, and “both-both” for double-sided output from a double-sided document It is possible to set four types of duplex modes, “mode” and “both-single mode” in which two-sided originals are output from a double-sided document. The LEDs 372 to 374 are turned on according to the set duplex mode. In the “single-single mode”, the LEDs 372 to 374 are all turned off. In the “single-both mode”, only the LED 372 is turned on. Only the LED 373 is lit, and in the “both-single mode”, only the LED 374 is lit.
[0111]
(Specific examples of image formation)
Hereinafter, as a specific example, a four-color image forming operation for plain paper in which the automatic paper feeder RDF 600 is not used and the thick paper mode is not set will be described.
[0112]
In this case, since the recording material on which image formation is performed is plain paper, the speed setting for the fixing drive motor driver 761 is set to be the same VFN as the image formation speed (process speed) VP of the photosensitive drum 1.
[0113]
After the operator sets the number of images to be formed using the numeric keypad 351, the printer controller 701 selects a paper feed stage using the paper selection key 303 and instructs the start of operation using the start key 354. The driver is instructed to drive the photosensitive drum drive motor, the fixing drive motor, the paper feed drive motor, and the main drive motor. Next, after the drive state of these drive motors is stabilized, the feeding operation of the recording material P is started from the designated paper feed stage (recording material cassettes 7a, 7b, etc.). At this time, the reader unit 201 generates the magenta image signal that is the first development color in the four-color mode almost simultaneously, so that the shift amount, black extraction amount, UCR amount, and reader color selection signal are generated. Are set in each block of the image processing unit 203. The reader gradation correction circuit 108 selects any one of the conversion characteristics a to e shown in FIG. 4 corresponding to the contents specified by the density keys 304 and 306 of the operation unit 704. Further, m conversion characteristics shown in FIG. 5 are selected for the printer gradation correction circuit 109.
[0114]
The recording material P fed from the designated paper feed stage is fed by the registration roller 50 so as to coincide with the optical scanning operation of the reader unit 201, and transferred by the suction charging device 5c and the suction roller 5g which is a counter electrode. Adsorbed on the sheet 5f.
[0115]
The document information read by the reader unit 201 is processed by the image processing unit 203, and is irradiated as a laser beam onto the photosensitive drum 1 uniformly charged by the charger 2 to form a latent image. It is developed by a magenta developing device 4m. The developed image information is transferred by the transfer charger 5b onto the recording material P adsorbed earlier. This M (magenta) document reading, latent image formation, development, and transfer image forming operations are performed while the photosensitive drum 1 and the transfer drum 5a rotate once, and similarly, the remaining three colors C (cyan), The process is also executed for each color of Y (yellow) and Bk (black). At this time, the setting for the image processing unit 203 is performed for each image formation.
[0116]
The recording material P onto which the four color images have been transferred in this manner is separated from the transfer sheet 5f. At that time, the separation charger 5h weakens the attracting force between the transfer sheet 5f and the recording material P, the transfer sheet 5f is deformed by the separation push-up roller 8b to perform curvature separation, and the recording material P is removed from the transfer sheet 5f by the separation claw 8a. To separate.
[0117]
The separated recording material P is transported to the heat roller fixing device 9 by the recording material transporting section 9g that transports at the same speed (VP) as the transfer drum 5a, and is fixed at the fixing speed VFN = VP. Then, after the paper curl correction unit 500 corrects the curl, the paper is discharged to the sorter 400.
[0118]
Next, the control for the oil cleaning member will be described in detail. Since the oil cleaning control has a different control method for different fixing speeds, the oil cleaning control for plain paper will be described first.
[0119]
First, the control during non-operation of the oil cleaning member in the plain paper mode (control when oil cleaning is not performed) will be described, and then the control during operation of the oil cleaning member in the plain paper mode (when oil cleaning is performed). Control) will be described.
[0120]
(Control of non-oil cleaning in plain paper mode)
FIG. 7 is a flowchart showing control from the start of the final color transfer operation to the stop of the image forming operation on the final paper (the final one of a plurality of sheets on which images of the same document are formed). Such control is called “post-rotation control”. Thereafter, the “normal cleaning control” of the transfer drum 5a as the recording material gripping means is executed by the rotation control. The normal cleaning control is normal cleaning control using the fur brush 14 and the fur buffer brush 15 as described later.
[0121]
FIG. 8 is a timing chart when “one sheet sticking control is performed by fixing (N) rotation control”, which will be described later, when the transfer drum 5a has a size capable of two sheet sticking control in the flowchart of FIG. FIG. 8 is a timing chart when one-sheet pasting control or two-sheet pasting control is performed by “fixing (N + 1) rotation control” to be described later in the flowchart of FIG. 7.
[0122]
In the flowchart of post-rotation control in FIG. 7, when the transfer of the final color of the image forming color determined by the color mode is started (step S1000), it is first determined whether or not it is the final paper, that is, the final paper for the same document. Judgment is made (step S1001). Thus, it is determined whether or not post-rotation control is performed after the transfer is completed. If it is not image formation on the final sheet (hereinafter referred to as “final image formation”), the image forming operation is continued (step S1002), and this control is ended (step S1003).
[0123]
In the case of final image formation, the size of the recording material in the conveyance direction is compared with the distance LTCLN from the transfer position to the transfer sheet cleaning position (step S1004). This is because, when the recording material is applied to both the transfer position and the transfer sheet cleaning position (in this embodiment, the distance LTCN from the transfer position to the transfer sheet cleaning position is 250 mm), the transfer drum 5a is being transferred during the transfer to the recording material. This is to prevent image disturbance when the cleaning operation or the recording material separation operation is performed. When the recording material is applied to both the transfer position and the transfer sheet cleaning position, the transfer drum is used to end the transfer operation. After 5a is rotated by one revolution (step S1005), a separation operation (step S1006) and a cleaning operation (step S1008) are performed.
[0124]
In the normal cleaning control in step S1007, the fur brush 14 is rotated by a motor (not shown) and the fur backup brush 15 opposed to the fur brush 14 is made effective so that the fur brush 14 is brought into contact with the transfer sheet 5f. That's fine. At this time, the transfer sheet 5f for one rotation of the transfer drum 5a is cleaned regardless of whether the one-sheet pasting control or the two-sheet pasting control is performed, and the cleaning operation for the transfer sheet 5f is finished (step S1009). Thereafter, the load and high voltage of the motor and the like that are operating are stopped (step S1009), and the image forming operation is terminated (step S1010).
[0125]
(Control when performing oil cleaning in plain paper mode)
When forming a single-color image on both sides of plain paper, when performing image formation on the second side of both sides (hereinafter, also referred to as “regular paper side-by-side two sides”), an oil cleaning operation of the transfer sheet 5f is executed as follows. To do.
[0126]
The recording material fed from one of the cassettes and having an image formed on the first side is temporarily stored in the intermediate tray 22 and then fed again. The re-recorded recording material is carried on the transfer drum 5a for image formation on the second side. At this time, the surface of the transfer sheet 5f of the recording material is in contact with the first image forming surface of the recording material, and the oil adhered in the fixing device 9 at the time of image formation of the first surface reattaches to the surface of the transfer sheet 5f. It will be. This oil must be prevented from adhering to the photosensitive drum 1, and for this purpose, when the transfer sheet 5f on the second and second surfaces forming the image passes through the transfer position, the transfer sheet 5f passes through the transfer position. The surface must be cleaned in advance with oil or controlled so that a recording material exists between the transfer sheet 5f and the photosensitive drum 1. When the plain speed is the same as the process speed and the printing speed is the same, the recording material is always between the transfer sheet 5f and the photosensitive drum 1 at the transfer position when images are continuously formed on a plurality of recording materials. Therefore, for example, it is only necessary to clean the oil only during the post-rotation control described above.
[0127]
By the way, it is conceivable that the recording material for image formation on the second and second surfaces is fed from the intermediate tray 22 and fed from the recording material tray 7m. In some cases, the recording material tray 7m may be reset to output the double-sided image of the recording material that has been formed by the user. In this case, as in the case of paper feeding from the intermediate tray 22, Control is performed assuming that there is a recording material for the second and second sides on which images are formed.
[0128]
Next, the oil cleaning control will be specifically described with reference to the flowchart of FIG. FIG. 10 shows an example in which oil cleaning and normal cleaning are performed on the second side of both surfaces, and only normal cleaning is performed at other times.
[0129]
When transfer drum cleaning is started (step S1500) and the paper feed position is the intermediate tray 22 or the recording material tray 7m, it is determined in step S1501 that the image formation is on the second and second surfaces, and the oil cleaning operation is performed. Then, the oil cleaning backup brush 17 is activated (step S1502), and the oil cleaning roller 16 is driven to contact the transfer sheet 5f (step S1503). Since the oil cleaning roller 16 is made of a material that absorbs oil, the oil adhering to the transfer sheet 5f is removed by contacting the transfer sheet 5f. Next, in order to perform normal cleaning, the fur backup brush 15 is enabled (step S1504), the fur brush 14 is driven, and is brought into contact with the transfer sheet 5f (step S1505), thereby completing the cleaning operation (step S1505). Step S1506). If the paper feed position is not the intermediate tray 22 or the recording material tray 7m in step S1501, normal cleaning control is performed by driving only the fur brush 14 because oil cleaning is unnecessary (steps S1504 and S1505).
[0130]
By the way, when steps S1500 to S1506 in FIG. 10 are executed in the transfer drum cleaning control (step S1007) in FIG. 7, oil cleaning can be performed as necessary in the post-rotation control. Further, when steps S1500 to 1506 in FIG. 10 are executed between steps S1001 and S1002 in FIG. 7, oil cleaning or normal cleaning is performed as necessary every time the recording material is separated from the transfer drum 5a. Can be implemented. Furthermore, when steps S1500 to S1503 in FIG. 10 are executed between steps S1001 and S1002 in FIG. 7, only oil cleaning is performed as necessary every time the recording material is separated from the transfer drum 5a. Can be implemented.
[0131]
(Specificity of fixing speed in cardboard mode)
In order to fix the toner on the cardboard, more energy is required compared to the plain paper. Therefore, the fixing speed is slower than that of the plain paper and the energy per unit area / time is increased. Is secured. In that case, conventionally, the distance from the separation claw 8a to the contact position of the upper and lower fixing rollers 9a and 9b is made larger than the maximum image formable size of thick paper, whereby the transfer drum 5a which is the image forming speed (process speed) VP. In the recording material conveying section 9g, the recording material is decelerated to a fixing speed VF different from the speed of the transfer drum 5a, and the recording material conveying section 9g is used as a speed conversion area. . For this purpose, it is necessary to secure a recording material conveying portion 9g having a size corresponding to the maximum image-capable size of cardboard, and there is a drawback that the apparatus becomes large.
[0132]
Therefore, in this embodiment, the speed of the transfer drum 5a can be changed in the same manner as the fixing speed, and when the fixing speed VF must be slower than the image forming speed VP, the transfer drum after the final color transfer is completed. Decrease the speed of 5a to the fixing speed. As a result, it is not necessary to secure the size as the speed conversion area in the recording material conveyance unit 9g, and the enlargement of the apparatus is avoided.
[0133]
By the way, when the recording material conveyance direction size is larger than the distance LTC from the transfer position in FIG. 1 to the leading end position of the recording material conveyance unit 9g, the deceleration to the fixing speed of the transfer drum 5a causes the separation of the next recording material. The operation timing is not in time. In such a case, the transfer drum 5a is rotated once more and the recording material is separated at the timing of the subsequent separation operation. In this way, after the transfer of the final color in the thick paper mode, the transfer drum 5a is rotated one more time before the separation operation is performed, and the fixing operation is further referred to as “fixed thick paper (N + 1) rotation control”. Further, the distance LTC from the transfer position to the leading end position of the recording material conveyance unit 9g, or when the recording material conveyance unit 9g can be used as a speed conversion region, that is, control when the transfer drum 5a does not need to be rotated once more. Hereinafter, this is referred to as “fixed cardboard (N) rotation control”.
[0134]
Here, in order to make the explanation easy to understand, assuming that the distance LTC from the transfer position in FIG. 1 to the leading end position of the recording material transport unit 9g is 250 mm, the following is shown in the thick paper mode with a typical recording material size. To be controlled.
[0135]
A4 side feed size (feed direction 210mm) 1 sheet pasting: Fixed cardboard (N) rotation control
A4 vertical feed size (feed direction 297 mm) 1 sheet pasted: Fixed cardboard (N + 1) rotation control
A3 vertical feed size (feed direction 420 mm) 1 sheet pasting: fixing cardboard (N + 1) rotation control
A4 horizontal feed size (feed direction 210 mm) 2 sheets pasted: Fixed cardboard (N + 1) rotation control
[0136]
(Special characteristics of oil cleaning in cardboard mode)
Next, oil cleaning control in the thick paper mode in which the fixing speed needs to be slowed in this way will be described.
[0137]
As described above, in the case of oil cleaning control of plain paper, after the image formation on the transfer drum 5a is completed, the speed of the transfer drum 5a is not changed, so that the image forming operation can be executed continuously. It only needs to be performed at the end of the image forming operation of the final sheet for the document.
[0138]
On the other hand, in the thick paper mode, the transfer drum 5a and the photosensitive drum 1 are set to the same speed as the fixing speed VFT for fixing control. Therefore, the transfer drum 5a and the photosensitive drum 1 are used for image formation on the next sheet. Must be restored again to the original speed VP, and if the recording materials are different, continuous image forming operations cannot be performed. For this reason, when image formation on the second side of thick paper is performed, the adhered oil on the transfer sheet 5f adheres to the photosensitive drum 1 at the transfer position, and the transfer operation of the final color for each recording material is completed. Oil cleaning control is required every time. Therefore, when an image is formed in the thick paper mode, oil cleaning control is performed every time the transfer operation of the final color for each recording material is completed as follows.
[0139]
(Image formation control in cardboard mode)
Hereinafter, color image formation control in the thick paper mode will be described with reference to the flowchart of FIG. The flowchart of FIG. 11 corresponds to all recording materials in the thick paper mode, the plain paper mode, and the OHP mode. Therefore, in FIG. 11, the control equivalent to the fixing cardboard (N + 1) rotation control and the fixing cardboard (N) rotation control is common to all the recording materials as the fixing (N + 1) rotation control and the fixing (N) rotation control. It represents as.
[0140]
As described above, the latent image including paper feeding and suction, development, and transfer operation (step S2000) are repeated until the final color is transferred (step S2001). After the final color is transferred, the fixing speed VF is compared with the image forming speed VP (step S2002). Here, in the thick paper mode, the fixing speed VF is the slow fixing speed VFT for thick paper, and the fixing speed VF is different from the image forming speed VP. Therefore, the process proceeds from step S2002 to step S2003.
[0141]
In step S2003, it is determined whether or not the transfer sheet 5f is in a mode for holding a plurality of recording materials. In this embodiment, since electrostatic adsorption is used as the recording material holding means, in the case of a recording material that is 1/2 or less of the entire circumference of the transfer sheet 5f, image formation is simultaneously performed on two recording materials. Is possible. In this example, when images are simultaneously formed on two recording materials (two sheets pasted), the two recording materials are handled as one recording material including the distance between them, so that one sheet The distance LTC from the transfer position to the leading end position of the recording material transport unit 9g is smaller than the recording material transport direction size handled as the recording material, and the distance LTC from the transfer position to the leading end position of the recording material transport unit 9g is the speed. It is assumed that it cannot be used as a conversion area. Therefore, in this case, “fixing (N + 1) rotation control” is performed (step S2006).
[0142]
Next, when an image forming operation is performed with only one recording material held on the transfer sheet 5f (one sheet is attached), the distance LTC from the transfer position to the leading end position of the recording material conveyance unit 9g and the recording of the recording material are recorded. The sizes PX in the material conveyance direction are compared (step S2004). When the size PX is larger than the distance LTC, the distance from the transfer position to the leading end position of the recording material transport unit 9g cannot be used as a fixing speed conversion area, and therefore, “fixing (N + 1) rotation control” is performed. (Step S2006). Conversely, when the size PX is smaller than the distance LTC (step S2004), “fixing (N) rotation control” is performed (step S2005).
[0143]
In this example, the distance LTC and the conveyance direction size of the recording material are compared. When the speed change takes time due to the performance of the drum motor, etc., a determination step (in consideration of the time required for the speed change) It is also possible to improve step S2003 and step S2004). In the fixing (N) rotation control, when the transfer sheet 5f is cleaned substantially simultaneously with the recording material separation operation, the transfer sheet 5f cleaning operation may adversely affect the recording material being transferred. The control needs to be changed depending on the recording material conveyance direction size and the distance from the transfer position to the transfer sheet cleaning position. In this embodiment, the distance LTC and the distance LTCLN from the transfer position to the transfer sheet cleaning position are set to be equal to 250 mm.
[0144]
(Fixing (N) rotation control in cardboard mode)
Hereinafter, the fixing (N) rotation control in the thick paper mode will be described with reference to the timing chart of FIG. In FIG. 12, C corresponds to a cyan image, Y corresponds to a yellow image, and K corresponds to a black image. The transfer drum reference signal corresponds to the rotation speed of the transfer drum 5a, and the photosensitive drum speed is the same as the transfer drum speed. To change.
[0145]
The fixing (N) rotation control (step S2005) is started after the final color transfer is started (step S2001). The separation operation is the same as in the plain paper mode that is not the thick paper mode. That is, the process waits until the separation operation start timing t1, and when the separation start timing t1 is reached, the separation claw 8a and the separation push-up roller 8b are operated to start the separation operation.
[0146]
Next, the process waits until the transfer end timing t2 determined from the recording material conveyance direction size PX. When the transfer end timing t2 is reached, the output of the transfer charger is set to OFF, and the photosensitive drum motor driver 760 is set so that the peripheral speed of the transfer drum 5a is the same as the fixing speed VFT for thick paper. I do. Thereafter, the process waits until the separation operation end timing t3, and the separation claw 8a is turned off to complete the separation operation.
[0147]
By the way, when such transfer is on the second side on both sides in the cardboard mode, as described above, the fixing oil on the first side of the recording material adheres to the surface of the transfer sheet 5f after separation. In step S2008 of FIG. 11, it is determined that oil cleaning is necessary, and oil cleaning control is performed before the area of the transfer sheet 5f to which the fixing oil has adhered reaches the transfer position again (step S2009). The oil cleaning is a control in which the oil cleaning backup brush 17 is activated and the oil cleaning roller 16 is driven to come into contact with the transfer sheet 5f, similarly to steps S1502 and S1503 in FIG. After all, when the second side of both sides in the thick paper mode, oil cleaning control is performed every time the recording material is separated.
[0148]
The peripheral speed of the transfer drum 5a becomes the same as the fixing speed VFT before the leading edge of the recording material reaches the recording material conveyance unit 9g driven at the fixing speed VFT for cardboard, so that the recording material is normally operated. Separated, conveyed, and fixed at a fixing speed VFT for cardboard. After waiting for the recording material to be discharged (step S2010), the speed of the transfer drum 5a determined by the speed of the drum motor is set to the image forming speed VP for image formation on the next recording material. It sets (step S2011).
[0149]
After performing the set number of such operations (step S2012), the image forming operation is terminated.
[0150]
(Fixing in thick paper mode (N + 1) rotation control)
Hereinafter, the fixing (N + 1) rotation control in the thick paper mode will be described with reference to the timing chart of FIG. FIG. 13 shows an example when two sheets are pasted. In FIG. 13, K1 corresponds to a black image for the first recording material, and Y2 and K2 represent yellow and black images for the second recording material. Correspond.
[0151]
In the fixing (N + 1) rotation control, as described above, the size of the recording material in the conveyance direction is larger than the distance LTC (= 250 mm) from the transfer position to the front end of the recording material conveyance unit. In the case where the transfer drum 5a cannot be used, after the transfer operation is completed, the transfer drum 5a is rotated once and then the separation operation is performed.
[0152]
For this reason, the process waits until the final color transfer time t11 for the second sheet of the two-ply recording material is reached, and when the transfer end timing t11 is reached, the high voltage of the transfer charger is turned off to complete the transfer operation. . Next, the peripheral speed of the transfer drum 5a is set to be the same as the fixing speed VFT for thick paper, and the process waits until the separation start timing t12 in the next rotation remains at the fixing speed VFT. When the separation start timing t12 is reached, the separation operation is performed. After the separation operation is finished, the separation claw 8a is turned off and the operation is finished.
[0153]
By the way, when such transfer is on the second side on both sides in the cardboard mode, as described above, the fixing oil on the first side of the recording material adheres to the surface of the transfer sheet 5f after separation. In step S2008 of FIG. 11, it is determined that oil cleaning is necessary, and oil cleaning control is performed before the area of the transfer sheet 5f to which the fixing oil has adhered reaches the transfer position again (step S2009). Eventually, in the second side of both sides of the fixing (N + 1) rotation control in the thick paper mode, the oil cleaning control is performed every time the recording material is separated.
[0154]
In this way, an extra rotation of the transfer drum 5a constitutes a speed conversion area, and a fixing operation in a thick paper mode can be performed on a recording material up to the maximum image forming size in a normal operation. Become. Further, the cardboard mode can be realized even when two sheets are pasted.
[0155]
After waiting for the recording material to be discharged (step S2010), the speed of the transfer drum 5a is set to the image forming speed VP for image formation on the next recording material (step S2011).
[0156]
After performing such an operation for the set number of sheets (step S2012), the image forming operation is terminated.
[0157]
(Fixing normal rotation control in plain paper mode)
In the case of the plain paper mode with respect to the above-described thick paper mode, since the image forming speed VP and the fixing speed are equal, the process proceeds from step S2002 of FIG. 11 to step S2007, and “fixing normal rotation control” is performed (step S2007). . In this normal fixing rotation control, since the fixing speed is equal to the image forming speed VP, image formation is continuously performed on the transfer sheet 5f, and the oil cleaning control is performed for the set number of sheets even in the image formation on the second side of both sides. This is executed after the image formation is completed (steps S2013 to S2015).
[0158]
The timing charts of FIGS. 14 and 15 express such control in contrast to FIGS. 12 and 13 in the thick paper mode described above. FIG. 14 is a timing chart when one sheet is pasted as in the thick paper mode of FIG. 12 described above, and FIG. 15 is a timing chart when two sheets are pasted as in the thick paper mode of FIG. 13 described above.
[0159]
For plain paper, when it is determined that oil cleaning is necessary in step S2014 after image formation for the set number of sheets, the control is ended after performing oil cleaning control (step S2015). As described above, the oil cleaning is determined to be necessary for the second side of both sides of the sheet fed from the intermediate tray 22 or the recording material tray 7m.
[0160]
By the way, in the recording mode (OHP mode) for an OHP sheet having a fixing speed different from that of the thick paper mode, if the fixing speed is set to VFO, it can be applied to the OHP paper as in the case of the thick paper. Further, when the second side is not the single color mode, the fixing speed VFD is different from the process speed VP. Therefore, the same oil cleaning control as that of the second side of the thick paper mode may be performed.
[0161]
Further, in consideration of the influence of the toner adhering to the first surface of the recording material on the fixing of the second surface, control may be performed so that the fixing speed is delayed for the second surface of both surfaces than for the first surface of both surfaces. Such control can be executed regardless of the plain paper mode, the thick paper mode, or the OHP mode.
[0162]
(Recovery control)
Next, recovery control after paper jam detection (hereinafter abbreviated as “jamming detection”) in the image forming apparatus thus realized will be described with reference to the flowchart of FIG. As is known, when a jam occurs (step S3000), the conveyance of the recording material is stopped, and the occurrence of the jam is displayed on the operation unit (step S3001).
[0163]
Thereafter, if the door that is opened to remove the jammed recording material is opened and closed (steps S3002 and S3003), it is confirmed whether or not the recording material is removed from the paper conveyance path or the transfer drum by a paper conveyance sensor (not shown). (Step S3004). When the removed recording material includes the paper on the second surface on both sides, the fixing oil on the image formed on the first surface of the recording material adheres to the surface of the transfer sheet 5f when stopped. Therefore, in this case, the process proceeds from step S3005 to step S3006, where oil cleaning control is performed and the transfer sheet 5f is cleaned. On the other hand, when the second and second sheets are not included, the oil cleaning control is not performed, and the transfer sheet 5f is cleaned only by the fur brush 14 and the fur backup brush 15 (step S3007), and then the recovery operation is performed. (Step S3008, Step S3009, Step S3010).
[0164]
The determination in step S3005 may be a determination as to whether or not oil cleaning control is necessary. If a paper jam detection that requires an oil cleaning control image is detected, the oil cleaning control is performed before the recovery control. Can be prevented from adhering to the photosensitive drum 1. In this embodiment, since the presence or absence of oil cleaning control is determined according to the fixing speed and the paper feeding location, it is possible to perform oil cleaning control before recovery control in all cases by extending these determination conditions. Become.
[0165]
(Control of polishing roller 18)
Next, control of the polishing roller 18 will be described with reference to the flowchart of FIG.
[0166]
The polishing roller 18 operates with an opposing polishing roller backup brush 19. The polishing roller 18 is used to scrape off toner or paper deposits that cannot be removed by the fur brush 14. Therefore, a member that performs the same effect as sandpaper is wound around the outer periphery of the polishing roller 18, and this member makes it possible to scrape off deposits that cannot be cleaned by the fur brush 14. Since the operation of the polishing roller 18 is related to the life of the transfer sheet 5a, for example, it is controlled so that polishing control is performed every 2000 image forming operations.
[0167]
The polishing control in this embodiment is realized by driving the polishing roller 18 and the polishing roller backup brush 19 and rotating the transfer drum 5a by 20 rotations. Therefore, it takes about several minutes to execute, and the image forming operation during this time cannot be executed. Therefore, in order not to increase the image forming operation prohibition time that restrains the user, control is performed so that this polishing control is performed when the fixing roller immediately after power-on (step S4000) is cold. As a result, polishing control is performed while the temperature of the fixing roller reaches a temperature necessary for image formation, thereby shortening the image formation operation inhibition time.
[0168]
Specifically, when the detected temperatures of the fixing rollers (9a, 9b) detected by the upper fixing thermistor 781 and the lower fixing thermistor 782 are both 100 degrees or less, the above-described polishing control is performed (steps S4001, S4002). ). The determination as to whether or not the polishing control is executed when the power is turned on is not limited to this. The presence or absence of the polishing control may be determined based on the detected temperature of the fixing roller and the number of sheets after the polishing is performed.
[0169]
When the fixing roller is heated so that an image forming operation image can be obtained, and a desired mode is set from the operation unit and the start key 354 is pressed (step S4003), the above-described image forming operation is started (step S4004). ). At the end of the image forming operation for each sheet, the polishing control counter is decremented (step S4005). This operation is repeated for the set number of sheets (step S4006). When the automatic document feeder RDF is used, the image forming operation for the set number of sheets for the final document is repeated (steps S4007 and S4008). At this point, since all the image forming operations have been completed, the polishing control counter decremented in accordance with the image forming operation is checked (step S4006). When this counter is 0, it means that a predetermined number of images have been formed since the previous polishing operation, and the polishing operation is necessary. Therefore, when the counter is 0, polishing control for performing the polishing operation is performed (steps S4009 and S4010). Since an image forming operation cannot be performed during polishing control, a message to that effect is displayed on the operation unit. In this way, polishing control can be provided to the user as a series of image forming operations.
[0170]
Next, the details of the polishing control in step S4010 will be described using the flowchart of FIG. If the polishing control tile is defrosted (step S4100), the transfer drum 5a is cleaned for one rotation only with the fur brush 14, and the toner on the transfer sheet 5f is cleaned (step S4101). Thereafter, the polishing roller 18 and the polishing backup brush 19 are driven (step S4102), and a polishing operation is performed each time the transfer sheet 5f rotates by a predetermined rotation (20 rotations in this example) (step S4103). After the completion of the polishing operation for every predetermined rotation, the driving of the polishing brush 18 and the polishing backup brush 19 is stopped (step S4104), and the transfer drum 5a is again cleaned only by the one-turn field fur brush 14 ( Step S4105), the shavings generated by the polishing operation are cleaned. Thereafter, the initial value (2000 in this example) is set in the polishing control counter for managing the number of sheets (step S4106), and the polishing control is terminated (step S4107).
[0171]
By the way, in this example, the number of recording materials is managed from the previous polishing control. However, in the case of the above-mentioned fur brush cleaning and oil cleaning, a counter for such number management is provided independently. In addition, it is possible to prevent adverse effects on the apparatus due to a user's setting mistake when setting the paper type or an operation error such as oil adhesion caused by adding the output paper to the cassette.
[0172]
(Cleaning operation for the transfer drum)
Next, execution of the cleaning operation for the transfer drum from the operation unit will be described. In this embodiment, an environment is provided that can be executed only by a service person, not a user, but may be executed by a user as necessary.
[0173]
By performing a predetermined operation on the operation unit 704, an input screen for a service mode used only by a service person is displayed on the display panel 369. FIG. 19 shows a state in which the service mode related to the cleaning operation for the transfer drum is displayed. In this state, the cleaning mode is selected and executed using the cursor keys (365, 366, 367, 368) and the OK key 364. In FIG. 19, since the oil removal mode is selected, when the OK key 364 is pressed in this state, the oil removal mode is executed.
[0174]
Hereinafter, the cleaning-related service mode for the transfer drum will be described with reference to the flowchart of FIG. First, it is checked whether it is the service mode and whether it is the transfer drum cleaning related service mode shown in FIG. 19 (step S5000). If the determination is affirmative, the input of the OK key 364 is monitored (step S5001), and the cleaning mode is determined when the input is received. Then, the type of the selected cleaning mode is determined (steps S5002 and S5003). If cleaning is selected, the process proceeds to step S5006 to perform transfer cleaning without oil removal. This is the same control as step S3007 in FIG. 16 described above, and the transfer sheet 5f is cleaned only by the fur brush 14 and the fur backup brush 15. On the other hand, if oil removal is selected, the process advances from step S5003 to step S5005 to execute transfer cleaning with oil removal. This is the same control as step S3006 in FIG. 16 described above, and in addition to the fur brush 14 and the fur backup brush 15, the oil cleaning backup brush 17 and the oil cleaning roller 16 are driven to clean the transfer sheet 5f. .
[0175]
If a cleaning mode other than the two is selected, polishing control is executed (step S5004). This executes the oil removal control itself shown in FIG.
[0176]
As described above, by selectively performing the cleaning operation on the transfer drum in the service mode, it is possible to shorten the service work, improve the efficiency, and form a high quality image.
[0177]
【The invention's effect】
As described above, according to the present invention, in accordance with the end or interruption of the image forming operation of the image forming apparatus, the interval between the tray that does not store the sheet and the adjacent tray is widened, and the tray that stores the sheet. And the adjacent tray, the sheet is controlled to be restored to the original tray position in response to the start of the image forming operation. , And curling of the sheet can be prevented from growing while the interval between the tray in which the sheet is stored and the adjacent tray is widened.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a color image forming apparatus as an embodiment of the present invention.
FIG. 2 is a block diagram of a control system of the color image forming apparatus of FIG.
FIG. 3 is a block diagram of a control system of the image forming processing unit shown in FIG.
4 is a gradation correction characteristic diagram showing an example of an input / output signal in the reader gradation correction circuit of FIG. 3; FIG.
5 is a gradation correction characteristic diagram showing an example of an input / output signal in the printer gradation correction circuit of FIG. 3; FIG.
6 is a schematic plan view of the operation unit shown in FIG. 2. FIG.
7 is a flowchart for explaining operations from the final color transfer operation of the final paper to the stop of the image formation operation in the color image forming apparatus shown in FIG. 1;
FIG. 8 is a timing chart when one sheet sticking control is performed by fixing (N) rotation control in the flowchart of FIG. 7;
9 is a control timing chart when one-sheet pasting control or two-sheet pasting control is performed by fixing (N + 1) rotation control in the flowchart of FIG. 7;
10 is a flowchart for explaining a transfer drum cleaning operation applicable in the flowchart of FIG. 7;
FIG. 11 is a flowchart for explaining fixing control in the color image forming apparatus of FIG. 1;
12 is a timing chart for explaining a fixing (N) rotation operation in a thick paper mode in the flowchart of FIG.
13 is a timing chart for explaining a fixing (N + 1) rotation operation in a thick paper mode in the flowchart of FIG.
14 is a timing chart for explaining a fixing (N) rotation operation in the plain paper mode in the flowchart of FIG.
15 is a timing chart for explaining the fixing (N + 1) rotation operation in the plain paper mode in the flowchart of FIG.
FIG. 16 is a flowchart for explaining processing at the time of jam in the color image forming apparatus of FIG. 1;
17 is a flowchart showing a polishing control process in the color image forming apparatus of FIG. 1;
FIG. 18 is a flowchart for explaining polishing control in the color image forming apparatus of FIG. 1;
19 is a schematic plan view for explaining a display example of the display panel in the service mode in the color image forming apparatus of FIG.
20 is a flowchart for explaining processing in a transfer drum cleaning mode in the color image forming apparatus of FIG. 1;
FIG. 21 is a plan view of OHP paper that can be used in the color image forming apparatus of FIG. 1;
FIG. 22 is a diagram illustrating a curl correction unit.
FIG. 23 is a flowchart of curl correction.
FIG. 24 is a diagram for explaining curl correction control;
FIG. 25 is a cross-sectional view illustrating a configuration of an automatic document feeder.
FIG. 26 is a configuration diagram of a sorter unit.
FIG. 27 is a configuration diagram of a sorter unit.
FIG. 28 is a block diagram showing an RDF control unit.
FIG. 29 is a block diagram illustrating a sorter control unit.
FIG. 30 is a control flowchart.
FIG. 31 is a control flowchart.
FIG. 32 is a control flowchart.
FIG. 33 is a control flowchart.
FIG. 34 is a control flowchart.
FIG. 35 is a control flowchart.
FIG. 36 is a control flowchart.
FIG. 37 is a control flowchart.
FIG. 38 is a control flowchart.
FIG. 39 is a control flowchart.
FIG. 40 is a control flowchart.
FIG. 41 is a control flowchart.
FIG. 42 is a control flowchart.
FIG. 43 is a control flowchart.
FIG. 44 is a control flowchart.
FIG. 45 is a control flowchart.
FIG. 46 is a control flowchart.
FIG. 47 is a diagram illustrating control.
FIG. 48 is a diagram illustrating control.
[Explanation of symbols]
202 Printer section
400 Sorter
B Bin

Claims (3)

Conveying means for conveying the sheet discharged from the image forming apparatus;
A plurality of trays for storing sheets conveyed by the conveying means;
A tray moving means for moving a position of the plurality of trays with respect to the conveying means and for expanding a gap between a tray to be stored and an adjacent tray in order to store sheets in each of the plurality of trays;
In response to the end or interruption of the image forming operation of the image forming apparatus, the interval between the trays in which sheets are not stored is widened, the intervals between the trays in which sheets are stored are narrowed, and the sheets on the tray are pressed down. Control means for controlling the moving means;
The sheet storage device is characterized in that the control means controls the image forming apparatus to return to the original tray position in response to the image forming apparatus starting an image forming operation . A detecting means for detecting presence or absence of sheets on the plurality of trays;
The sheet storage device according to claim 1, wherein the control unit controls the plurality of trays to move to an initial position in response to detection of no sheet by the detection unit.   The sheet storage apparatus according to claim 1, wherein the image forming apparatus forms an image by an electrophotographic process.

Images