JP2005043515A - Developing device for image forming apparatus - Google Patents

Developing device for image forming apparatus Download PDF

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Publication number
JP2005043515A
JP2005043515A JP2003201264A JP2003201264A JP2005043515A JP 2005043515 A JP2005043515 A JP 2005043515A JP 2003201264 A JP2003201264 A JP 2003201264A JP 2003201264 A JP2003201264 A JP 2003201264A JP 2005043515 A JP2005043515 A JP 2005043515A
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Japan
Prior art keywords
magnetic pole
peeling
developer
magnetic
developing
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Abandoned
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JP2003201264A
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Japanese (ja)
Inventor
Norikazu Ochiai
法和 落合
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Toshiba Corp
Toshiba TEC Corp
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Toshiba Corp
Toshiba TEC Corp
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Priority to JP2003201264A priority Critical patent/JP2005043515A/en
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Abandoned legal-status Critical Current

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Abstract

<P>PROBLEM TO BE SOLVED: To obtain a developed image of high quality by preventing a developer of a low toner concentration ratio peeled from magnetic brush rollers by peeling magnetic poles after the end of development from directly readhering to clamping magnetic poles thereby preventing the image defect to bring about the degradation in image density in a part of the toner image. <P>SOLUTION: Peeling assistance magnets 24Y, 24M and 24C which generate the magnetic fields in the direction of parting the developer from the magnetic brush rollers 38Y, 38M and 38C between themselves and the peeling magnetic poles N2 are attached to the external walls of cover sections 23Y, 23M and 23C facing the peeling magnetic poles N2 of developing containers 17Y, 17M and 17C. The developer peeled by the peeling magnetic poles N2 is directed by centrifugal force and the magnetic fields toward the peeling assistance magnets 24Y, 24M and 24C, by which the developer is dropped onto mixing augers 21Y, 21M and 21C parted from the clamping magnetic poles N3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【0001】
【発明の属する技術分野】
この発明は、複写機、プリンタ、ファクシミリ等の画像形成装置に用いられ、磁気ブラシ現像ローラにより現像を行う画像形成装置における現像装置に関する。
【0002】
【従来の技術】
電子写真方式の複写機やプリンタ等の現像装置として、磁気ブラシ現像ローラを用いるものにあっては、近年図5に示すように、現像磁極n1、搬送磁極s1、剥離磁極n2、つかみ磁極n3、及びブレード規制磁極s2を有するマグネットローラ1a周囲のスリーブ1bを矢印q方向に回転する磁気ブラシローラ1を用いて、現像容器3内の現像剤7を矢印q方向にくみ上げながら感光体ドラム4に供給する現像装置6の実用化が図られている。
【0003】
この現像装置6では、現像終了後、現像容器3内に搬送された使用済みの現像剤7は、剥離磁極n2により磁気ブラシローラ1から剥離され、遠心力により磁気ブラシローラ1から離反する方向に向かいながら現像容器3内に落下して、ミキサ7による攪拌後再度現像に用いられる。
【0004】
しかしながら、現像終了後に剥離磁極n2で磁気ブラシローラ1から剥離された現像剤には遠心力が働くものの、その現像容器3内での落下位置はつかみ磁極n3から余り離すことが出来ない。このため剥離された現像剤がつかみ磁極n3の近くに落下し、既に現像に使用されトナー比率が少ない濃度の薄い現像剤がつかみ磁極n3に直接再付着してしまうと、この濃度の薄い現像剤によりトナー画像の一部に画像濃度の低下を来たして画像欠陥を引き起こし、画質を低下するというおそれを有していた。
【0005】
【発明が解決しようとする課題】
そこで本発明は上記課題を解決するものであり、磁気ブラシローラの剥離磁極から剥離した濃度の薄い現像剤が直接つかみ磁極に再付着するのを防止して、画像の位置部に濃度低下を生じるという画像欠陥を防止して、全面にわたり均一濃度の高画質の現像画像を得る画像形成装置の現像装置を提供する事を目的とする。
【0006】
【課題を解決するための手段】
本発明は上記課題を解決するための手段として、像担持体との対向位置に開口部を有する現像容器と、前記現像容器の開口部に位置し、像担持体と対向する現像磁極、前記現像磁極より上方に位置し前記現像磁極通過後の現像剤を前記現像容器内に搬送する搬送磁極、前記搬送磁極で搬送した前記現像剤を剥離する剥離磁極及び前記剥離磁極より下方に位置し現像容器内の前記現像剤をつかむつかみ磁極を有し、前記つかみ磁極にてつかんだ前記現像剤を前記現像磁極にて前記像担持体上の静電潜像に付与する磁気ブラシローラと、前記剥離磁極と対向する位置にて前記現像容器に取着され前記剥離磁極で前記磁気ブラシローラから剥離された前記現像剤を前記磁気ブラシローラから離反する方向の磁界を発生する剥離補助部材とを提供するものである。
【0007】
上記構成により本発明は、剥離補助部材により剥離磁極にて現像剤を磁気ブラシから更に離反する方向の磁界を発生することにより、現像剤をつかみ磁極から遠くに落下して、剥離磁極から剥離した現像剤が直接つかみ磁極に再付着するのを防止し、画像欠陥の無い均一濃度の高画質の現像画像を得るものである。
【0008】
【発明の実施の形態】
以下本発明を図1乃至図3に示す第1の実施の形態を参照して詳細に説明する。図1はこの発明の実施の形態である画像形成装置の画像形成部10を示す概略構成図である。画像形成部10の、像担持体である感光体ドラム11周囲には、感光体ドラム11の矢印s方向の回転に従い順次感光体ドラム11を一様に帯電する帯電器12、帯電された感光体ドラム11に潜像を形成するための潜像形成部であるレーザ書き込みユニット13からのレーザ光13aの照射位置14、イエロー(Y)、マゼンタ(M)、シアン(C)の現像装置16Y、16M、16Cを装着し、矢印t方向に回転するリボルバ装置19、矢印u方向に回転する中間転写ベルト41aを有する中間転写装置41、クリーナ装置42及び、除電ランプ43が配置されている。
【0009】
レーザ書き込みユニット13は、外部のコンピュータ端末等から入力される画像情報に従い、各色毎の書き込み信号に対応したレーザ光を照射して感光体ドラム11上に静電潜像を形成する。図2に示すように、現像装置16Y、16M、16Cは現像容器17Y、17M、17C内に、イエロー(Y)、マゼンタ(M)、シアン(C)の3色のトナー及びキャリアからなる現像剤18Y、18M、18Cをそれぞれ有する。リボルバ装置19は、その回転によりイエロー(Y)、マゼンタ(M)、シアン(C)の現像装置16Y、16M、16Cを一体的に回転して、所望の現像装置16Y、16M、16Cを感光体ドラム11に対向配置する。
【0010】
イエロー(Y)、マゼンタ(M)、シアン(C)の現像装置16Y、16M、16Cは、現像容器17Y、17M、17C内にマグネットローラ36Y、36M、36C及びマグネットローラ36Y、36M、36C周囲を回転する現像スリーブ37Y、37M、37Cからなる磁気ブラシローラ38Y、38M、38Cを有する。更に現像装置16Y、16M、16Cは、トナーカートリッジ31、32、33から供給されるイエロー(Y)、マゼンタ(M)、シアン(C)のトナーと、現像容器17Y、17M、17C内の現像剤を攪拌搬送して磁気ブラシローラ38Y、38M、38Cに供給する搬送オーガ20Y、20M、20C及びミキシングオーガ21Y、21M、21Cを有する。磁気ブラシローラ38Y、38M、38Cの現像スリーブ37Y、37M、37Cは、現像動作時に矢印v方向に回転する。
【0011】
各マグネットローラ36Y、36M、36Cは、感光体ドラム11と対向する位置に、感光体ドラム11上に現像剤を供給して現像を行うN極性の現像磁極N1を有する。マグネットローラ36Y、36M、36Cは、現像磁極N1から、図2の反時計方向回りに順次、現像磁極N1と逆極性で、現像終了後の現像剤を現像容器17Y、17M、17C内に搬送する搬送磁極S1、搬送磁極S1と逆極性で搬送した現像剤を磁気ブラシローラ38Y、38M、38Cから剥離する剥離磁極N2、剥離磁極N2と同極性で現像磁極N1に供給する新たな現像剤をつかむためのつかみ磁極N3及び、つかみ磁極N3と逆極性で、磁気ブラシローラ38Y、38M、38C上の現像剤を薄層にするための現像容器17Y、17M、17Cのドクターブレード22Y、22M、22Cに対向するブレード規制磁極S2を有する。
【0012】
現像容器17Y、17M、17Cの磁気ブラシローラ38Y、38M、38Cを覆うカバー部23Y、23M、23C外壁には、N極性、350[ガウス]の磁力を有する剥離磁極N2に対向する剥離補助部材である板状の剥離補助磁石24Y、24M、24Cが両面テープで取着されている。剥離補助磁石24Y、24M、24Cの剥離磁極N2との対向する面は、剥離磁極N2と逆のS極性、220〜320[ガウス]の磁力を有し、剥離磁極N2との間に、現像剤を磁気ブラシローラ38Y、38M、38Cから遠ざける方向の磁界を発生させている。これにより剥離磁極N2にあっては、図3の点線αで示す搬送磁極S1に向かう磁界と、点線βで示す剥離補助磁石24Y、24M、24Cに向かう磁界を生じている。
【0013】
剥離補助磁石24Y、24M、24Cの上端は、剥離磁極N2から水平方向に7.9mm、垂直方向に4mm離間するようマグネットローラ36Y、36M、36Cの中心を通る水平線に対して57°に傾斜されるカバー部23Y、23M、23Cに取着される。剥離補助磁石24Y、24M、24Cは、マグネットローラ36Y、36M、36Cと同じ長さで、幅5mm、厚さ1mmに形成されている。
【0014】
剥離補助磁石24Y、24M、24Cの取り付け位置は、その上端が剥離磁極N2に近付きすぎると、剥離した現像剤18Y、18M、18Cの落下角度が余り変わらず、つかみ磁極N3への再付着を生じ易く、また剥離補助磁石24Y、24M、24Cの上端が剥離磁極N2から離れすぎても剥離磁極N2と剥離補助磁石24Y、24M、24Cとの間に磁界が発生されず、剥離した現像剤18Y、18M、18Cの落下角度が変わらず、つかみ磁極N3に再付着してしまうことから、剥離補助磁石24Y、24M、24Cの上端位置が、剥離磁極N2から水平方向に6.5〜9.0mm、垂直方向に2.5〜5.8mm程度の距離を隔てることが好ましい。
【0015】
次に画像形成部10によるカラー画像形成プロセスについて説明する。この画像形成部10においては、イエロー(Y)、マゼンタ(M)、シアン(C)の順にトナー像を重ねて、カラー画像を形成する。画像形成開始時、リボルバ装置19に装着されるイエロー(Y)の現像装置16Yの磁気ブラシローラ38Yが感光体ドラム11の現像位置に対向配置される。
【0016】
画像形成プロセスを開始すると、感光体ドラム11は、矢印s方向に回転し、その回転に従い帯電器13により一様に帯電され、照射位置14にてレーザ書き込みユニット13によりイエロー画像信号に応じたレーザ光を照射され、感光体ドラム11上にイエロー画像の静電潜像が形成され、リボルバ装置19に達する。リボルバ装置19にあっては、イエロー(Y)の現像装置16Yの磁気ブラシローラ38Yの現像スリーブ37Yが矢印v方向に回転している。
【0017】
この現像スリーブ37Yの回転により、磁気ブラシローラ38Yは、つかみ磁極N3で現像剤18Yを得た後、ブレード規制磁極S2でドクターブレード22Yにより穂立ちを規制する。次いで現像磁極N1にて感光体ドラム11上の静電潜像にトナーを付与して感光体ドラム11上にイエロー(Y)のトナー像を形成する。現像終了後磁気ブラシローラ38Y上の穂立ちは、搬送磁極S1により現像容器17Y内に搬送され、剥離磁極N2で、磁気ブラシローラ38Yから剥離される。
【0018】
剥離磁極N2では、図3の点線βに示す剥離補助磁石24Yに向かう磁界を生じていることから、剥離磁極N2で磁気ブラシローラ38Yから剥離された現像剤18Yは、遠心力により磁気ブラシローラ38Yから離反する方向に向かうと共に、磁界により磁気ブラシローラ38Yから離間し剥離補助磁石24Y側に引き付けられる矢印w方向に向かいながら、つかみ磁極N3から離れたミキシングオーガ21Y上に落下し、現像容器17Y内で新たに供給される現像剤と混合される。つかみ磁極N3にあっては、剥離磁極N2から剥離された現像剤を直接つかむことが無く、順次ミキシングオーガ21Yから、十分攪拌され所定のトナー濃度比を有する新たな現像剤を供給され、ブレード規制磁極S2を経て現像磁極N1に所定のトナー濃度比の現像剤を供給する事となる。
【0019】
現像終了後、感光体ドラム11上に形成されたイエローのトナー像は矢印u方向に回転される中間転写ベルト41aとの接触位置に達し、中間転写ベルト41a上に静電的に一次転写される。一次転写終了後感光体ドラム11は、クリーナ装置42により残留トナーをクリーニングされ、除電ランプ43により表面電荷を除去される。次いで上記イエローのトナー像形成プロセスと同様に、感光体ドラム11に順次マゼンタ、シアンのトナー像形成プロセスを繰り返して、さらに感光体ドラム11から中間転写ベルト41a上に、イエロー(Y)、マゼンタ(M)、シアン(C)のトナー像を順次中間転写して、中間転写ベルト41a上に3色のトナー像が重なったカラートナー像を形成する。
【0020】
この間リボルバ装置19は、順次矢印t方向に回転し、感光体ドラム11に形成するトナー像の色に応じた磁気ブラシローラ38Y、38M、38Cを感光体ドラム11に対向配置する。中間転写ベルト41aに重ね合わされたイエロー(Y)、マゼンタ(M)、シアン(C)のカラートナー像は、記録紙P等に一括二次転写され記録紙P上にカラー画像を完成される。
【0021】
このように画像形成プロセスを繰り返す間、現像容器17Y、17M、17C内にあっては、現像終了後に剥離磁極N2で磁気ブラシローラ38Y、38M、38Cから剥離された現像剤18Y、18M、18Cは、つかみ磁極N3近くに落下することなく、剥離補助磁石24Y、24M、24C方向に引かれながら、ミキシングオーガ21Y、21M、21C上に確実に落下され、十分攪拌された後、再度つかみ磁極N3に供給される。
【0022】
この第1の実施の形態によれば、現像容器17Y、17M、17Cの剥離磁極N2と対向するカバー部23Y、23M、23C外壁に剥離補助磁石24Y、24M、24Cを取着して、剥離磁極N2から剥離補助磁石24Y、24M、24Cに向かう磁界を発生している。従って剥離磁極N2で磁気ブラシローラ38Y、38M、38Cから剥離した現像剤18Y、18M、18Cを、下方のつかみ磁極N3近くに落下することなく、遠心力と磁界とにより剥離補助磁石24Y、24M、24C方向に向かわせながら、つかみ磁極N3から離れたミキシングオーガ21Y、21M、21C上に落下出来る。
【0023】
この結果、つかみ磁極N3に、現像終了後のトナー比率が少ない濃度の薄い現像剤が直接再付着することが無く、つかみ磁極N3には、ミキシングオーガ21Y、21M、21Cにより十分攪拌され、所定のトナー濃度比率を有する現像剤18Y、18M、18Cが供給されるので、現像磁極N1により現像されるトナー画像は、全面にわたり、十分な画像濃度を有し且つ全面にわたり画像濃度が均一な高画質を得られる。
【0024】
又この第1の実施の形態によれば、剥離補助磁石24Y、24M、24Cをカバー部23Y、23M、23C外壁に取り付けることにより磁力を弱められるので、剥離した現像剤18Y、18M、18Cがカバー部23Y、23M、23Cの剥離補助磁石24Y、24M、24C部分に付着してしまうことなく、且つ磁界により現像剤18Y、18M、18Cを適度に引き付けることが出来る。
【0025】
次に本発明を図4に示す第2の実施の形態を参照して説明する。この第2の実施の形態は第1の実施の形態と現像装置の構造が異なるものであり、他は第1の実施の形態と同様であることから、同一部分については同一符号を付しその説明を省略する。
【0026】
この第2の実施の形態の現像容器17Y、17M、17Cのカバー部23Y、23M、23C外壁には、剥離補助部材である板状の剥離補助鉄板28Y、28M、28Cが取着されている。剥離補助鉄板28Y、28M、28Cは、剥離磁極N2により剥離磁極N2と逆のS極性に磁化される。これにより剥離磁極N2にあっては、剥離補助鉄板28Y、28M、28Cに向かう磁界を生じる。
【0027】
剥離補助鉄板28Y、28M、28Cの上端は、剥離磁極N2から水平方向に7.9mm、翠帳方向に4mm離間するようマグネットローラ36Y、36M、36Cの中心を通る水平線に対して57°に傾斜されるカバー部23Y、23M、23Cに取着される。剥離補助磁石24Y、24M、24Cは、マグネットローラ36Y、36M、36Cと同じ長さで、幅5mm、厚さ1mmに形成されている。
【0028】
更に現像容器17Y、17M、17C内の剥離磁極N2とつかみ磁極N3との間には、傾斜プレート26Y、26M、26Cが設置されている。傾斜プレート26Y、26M、26Cはミキシングオーガ21Y、21M、21Cに向かって傾斜され、その上端27Y、27M、27Cは、磁気ブラシローラ38Y、38M、38Cから約0.5mm離間されている。傾斜プレート26Y、26M、26Cの磁気ブラシローラ38Y、38M、38Cからの距離は、磁気ブラシローラ38Y、38M、38Cに接触しない範囲であればよい。
【0029】
そして現像プロセス時に、例えばイエロー(Y)の現像装置16Yにあって、現像磁極N1での現像終了後に搬送磁極S1により現像容器17Y内に搬送された現像剤18Yは、剥離磁極N2で、磁気ブラシローラ38Yから剥離される。剥離磁極N2では、剥離補助鉄板28Yに向かう磁界を生じていることから、剥離磁極N2で磁気ブラシローラ38Yから剥離された現像剤18Yは、遠心力と磁界とにより磁気ブラシローラ38Yから遠ざかり剥離補助鉄板28Y側に引き付けられる矢印x方向に向かいながら落下する。
【0030】
現像剤18Yは傾斜プレート26Y上に落下し、更に傾斜プレート26Yの傾斜に沿ってミキシングオーガ21Y、21M、21C方向に送られ、ミキシングオーガ21Y、21M、21C上に落下して、現像容器17Y内で新たに供給される現像剤18Yと混合される。つかみ磁極N3は、順次ミキシングオーガ21Yから、十分攪拌され所定のトナー濃度比を有する新たな現像剤18Yを供給され、ブレード規制磁極S2を経て現像磁極N1に所定のトナー濃度比の現像剤を供給する事となる。
【0031】
即ち、画像形成プロセスを繰り返す間、現像容器17Y、17M、17C内にあっては、現像終了後に剥離磁極N2で磁気ブラシローラ38Y、38M、38Cから剥離された現像剤18Y、18M、18Cは、つかみ磁極N3近くに落下することなく、剥離補助鉄板28Y、28M、28C方向に引かれながら傾斜プレート26Y、26M、26C上に落下した後、ミキシングオーガ21Y、21M、21C上に確実に落下され、十分攪拌された後、再度つかみ磁極N3に供給される。
【0032】
この第2の実施の形態によれば、剥離磁極N2にあっては、剥離磁極N2から剥離補助鉄板28Y、28M、28Cに向かう磁界を発生している。従って剥離磁極N2で磁気ブラシローラ38Y、38M、38Cから剥離した現像剤18Y、18M、18Cを、遠心力と磁界とにより剥離補助鉄板28Y、28M、28C方向に向かわせながら落下出来る。しかも剥離磁極N2とつかみ磁極N3との間に傾斜プレート26Y、26M、26Cを設けることにより剥離した現像剤がつかみ磁極N3近くに落下するのをより確実に防止し、つかみ磁極N3から離れたミキシングオーガ21Y、21M、21C上に落下出来る。
【0033】
この結果、つかみ磁極N3には、現像終了後のトナー比率が少ない濃度の薄い現像剤がそのまま再付着することが無く、つかみ磁極N3には、ミキシングオーガ21Y、21M、21Cにより十分攪拌され、所定のトナー濃度比率を有する現像剤が供給されるので、現像磁極N1により現像されるトナー画像は、全面にわたり、十分且つ均一な画像濃度を有する高画質を得られる。更に剥離補助鉄板28Y、28M、28Cをカバー部23Y、23M、23C外壁に取り付けることにより現像剤がカバー部23Y、23M、23Cの剥離補助磁石24Y、24M、24C部分に付着してしまうことなく、且つ磁界により現像剤を適度に引き付けることが出来る。
【0034】
尚この発明は、上記実施の形態に限られるものではなく、この発明の範囲内で種々変更可能であり、例えば現像装置はリボルバ装置に装着されるものに限らず、固定の現像装置であっても良いし、使用されるトナーの色等限定されない。また剥離補助部材は、剥離磁極との間に、現像剤を剥離補助部材方向に引き付ける磁界を生じるものであればその材質や形状等限定されない。更に剥離補助部材の取り付け位置や取り付け方法も任意であり、例えば現像容器の形状により、剥離磁極とカバー部との間隔が広く、現像剤が付着しない程度に剥離補助部材との間の磁界を設定出来れば、カバー部の内壁に剥離補助部材を取り付ける等しても良い。又傾斜プレートの取り付け位置等も限定されない。
【0035】
【発明の効果】
以上詳述したようにこの発明によれば、剥離補助部材を設けて剥離磁極との間に磁界を発生する事により、剥離磁極で剥離した現像剤を剥離補助部材方向に引き付けながら、現像容器内に落下出来る。従って、剥離された現像剤は、つかみ磁極から離れた位置に落下して、つかみ磁極に直接再付着することによる画像欠陥を生じる事が無い。つかみ磁極は所定のトナー濃度比率を有する十分攪拌された現像剤をつかむことが出来、十分且つ均一な画像濃度を有する高画質のトナー像を得られる
【図面の簡単な説明】
【図1】本発明の第1の実施の形態の画像形成装置の画像形成部を示す概略構成図である。
【図2】本発明の第1の実施の形態の現像装置を示す概略構成図である。
【図3】本発明の第1の実施の形態の剥離磁極における磁界を示す概略説明図である。
【図4】本発明の第2の実施の形態の現像装置を示す概略構成図である。
【図5】従来の現像装置を示す概略説明図である。
【符号の説明】
10…画像形成部
11…感光体ドラム
12…帯電器
13…レーザ露光装置
16Y、16M、16C…現像装置
17Y、17M、17C…現像容器
18Y、18M、18C…現像剤
20Y、20M、20C…搬送オーガ
21Y、21M、21C…ミキシングオーガ
22Y、22M、22C…ドクターブレード
23Y、23M、23C…カバー部
24Y、24M、24C…剥離補助磁石
36Y、36M、36C…マグネットローラ
37Y、37M、37C…現像スリーブ
38Y、38M、38C…磁気ブラシローラ
[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing device in an image forming apparatus that is used in an image forming apparatus such as a copying machine, a printer, and a facsimile machine, and performs development by a magnetic brush developing roller.
[0002]
[Prior art]
As a developing device such as an electrophotographic copying machine or printer, which uses a magnetic brush developing roller, as shown in FIG. 5, in recent years, a developing magnetic pole n1, a conveying magnetic pole s1, a peeling magnetic pole n2, a gripping magnetic pole n3, And the magnetic brush roller 1 rotating the sleeve 1b around the magnet roller 1a having the blade regulating magnetic pole s2 in the direction of the arrow q, and supplying the developer 7 in the developing container 3 to the photosensitive drum 4 while pumping up the developer 7 in the direction of the arrow q. The developing device 6 is being put to practical use.
[0003]
In the developing device 6, after the development is completed, the used developer 7 conveyed into the developing container 3 is peeled off from the magnetic brush roller 1 by the peeling magnetic pole n2, and separated from the magnetic brush roller 1 by centrifugal force. It falls into the developing container 3 while facing, and is used again for development after stirring by the mixer 7.
[0004]
However, although centrifugal force acts on the developer peeled off from the magnetic brush roller 1 by the peeling magnetic pole n2 after the development is completed, the dropping position in the developing container 3 cannot be separated from the gripping magnetic pole n3. For this reason, if the peeled developer falls near the gripping magnetic pole n3, and a thin developer having a low toner ratio already used for development and directly adheres to the gripping magnetic pole n3, the developer having a thin concentration is used. As a result, there is a risk that the image density is lowered in a part of the toner image, causing an image defect, and the image quality is lowered.
[0005]
[Problems to be solved by the invention]
Accordingly, the present invention solves the above-described problem, and prevents the developer having a low concentration peeled from the peeled magnetic pole of the magnetic brush roller from directly adhering to the magnetic pole, thereby reducing the density at the position of the image. An object of the present invention is to provide a developing device for an image forming apparatus which prevents image defects and obtains a high-quality developed image having a uniform density over the entire surface.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a developing container having an opening at a position facing the image carrier, a developing magnetic pole located at the opening of the developing container and facing the image carrier, and the development A transport magnetic pole that is positioned above the magnetic pole and transports the developer that has passed through the developing magnetic pole into the developer container, a peeling magnetic pole that peels off the developer transported by the transport magnetic pole, and a developer container that is positioned below the peeling magnetic pole A magnetic brush roller that has a grabbing magnetic pole for grabbing the developer therein, and applies the developer grabbed by the grabbing magnetic pole to the electrostatic latent image on the image carrier by the developing magnetic pole, and the peeling magnetic pole And a peeling assisting member that generates a magnetic field in a direction away from the magnetic brush roller when the developer is peeled off from the magnetic brush roller by the peeling magnetic pole at a position opposite to the developing container. Than it is.
[0007]
With the above-described configuration, the present invention generates a magnetic field in a direction in which the developer is further separated from the magnetic brush by the separation magnetic pole by the separation assisting member, so that the developer is grabbed and dropped far from the magnetic pole and separated from the separation magnetic pole. The developer is prevented from being directly gripped and reattached to the magnetic pole, thereby obtaining a high-quality developed image having a uniform density free from image defects.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the first embodiment shown in FIGS. FIG. 1 is a schematic configuration diagram showing an image forming unit 10 of an image forming apparatus according to an embodiment of the present invention. Around the photosensitive drum 11 that is an image carrier of the image forming unit 10, a charger 12 that uniformly charges the photosensitive drum 11 sequentially in accordance with the rotation of the photosensitive drum 11 in the direction of arrow s, and a charged photosensitive member. An irradiation position 14 of a laser beam 13a from a laser writing unit 13 which is a latent image forming unit for forming a latent image on the drum 11, developing devices 16Y and 16M for yellow (Y), magenta (M), and cyan (C). , 16C, and a revolver device 19 that rotates in the direction of arrow t, an intermediate transfer device 41 having an intermediate transfer belt 41a that rotates in the direction of arrow u, a cleaner device 42, and a static elimination lamp 43.
[0009]
The laser writing unit 13 forms an electrostatic latent image on the photosensitive drum 11 by irradiating laser light corresponding to a writing signal for each color in accordance with image information input from an external computer terminal or the like. As shown in FIG. 2, the developing devices 16Y, 16M, and 16C are developers including three color toners of yellow (Y), magenta (M), and cyan (C) and a carrier in the developing containers 17Y, 17M, and 17C. 18Y, 18M, and 18C, respectively. The revolver 19 rotates the yellow (Y), magenta (M), and cyan (C) developing devices 16Y, 16M, and 16C as a result of the rotation, so that the desired developing devices 16Y, 16M, and 16C are transferred to the photoconductor. Opposing to the drum 11.
[0010]
The developing devices 16Y, 16M, and 16C for yellow (Y), magenta (M), and cyan (C) are arranged around the magnet rollers 36Y, 36M, and 36C and the magnet rollers 36Y, 36M, and 36C in the developing containers 17Y, 17M, and 17C. Magnetic brush rollers 38Y, 38M, and 38C including rotating developing sleeves 37Y, 37M, and 37C are provided. Further, the developing devices 16Y, 16M, and 16C include yellow (Y), magenta (M), and cyan (C) toners supplied from the toner cartridges 31, 32, and 33, and developers in the developing containers 17Y, 17M, and 17C. Are transported and fed to the magnetic brush rollers 38Y, 38M, and 38C, and the feeding augers 20Y, 20M, and 20C and the mixing augers 21Y, 21M, and 21C are provided. The developing sleeves 37Y, 37M, and 37C of the magnetic brush rollers 38Y, 38M, and 38C rotate in the arrow v direction during the developing operation.
[0011]
Each of the magnet rollers 36 </ b> Y, 36 </ b> M, 36 </ b> C has an N-polar developing magnetic pole N <b> 1 that performs development by supplying a developer onto the photosensitive drum 11 at a position facing the photosensitive drum 11. The magnet rollers 36Y, 36M, and 36C sequentially transfer the developer after the development into the developing containers 17Y, 17M, and 17C from the developing magnetic pole N1 in the counterclockwise direction of FIG. Grasp new developer supplied to the developing magnetic pole N1 with the same polarity as the separating magnetic pole N2 and the separating magnetic pole N2 for separating the developer conveyed with the opposite polarity to the conveying magnetic pole S1 and the conveying magnetic pole S1 from the magnetic brush rollers 38Y, 38M and 38C. For the gripping magnetic pole N3 and the doctor blades 22Y, 22M, and 22C of the developing containers 17Y, 17M, and 17C for making the developer on the magnetic brush rollers 38Y, 38M, and 38C into a thin layer with a polarity opposite to that of the gripping magnetic pole N3 It has an opposing blade regulating magnetic pole S2.
[0012]
The outer wall of the cover portions 23Y, 23M, and 23C covering the magnetic brush rollers 38Y, 38M, and 38C of the developing containers 17Y, 17M, and 17C is a peeling auxiliary member that faces the peeling magnetic pole N2 having N polarity and a magnetic force of 350 [Gauss]. A certain plate-like peeling auxiliary magnet 24Y, 24M, 24C is attached with a double-sided tape. The surfaces of the separation assisting magnets 24Y, 24M, and 24C that face the separation magnetic pole N2 have an S polarity opposite to the separation magnetic pole N2 and a magnetic force of 220 to 320 [Gauss], and the developer is between the separation magnetic pole N2. Is generated in a direction away from the magnetic brush rollers 38Y, 38M, and 38C. As a result, in the separation magnetic pole N2, a magnetic field directed toward the transport magnetic pole S1 indicated by a dotted line α in FIG. 3 and a magnetic field directed toward separation auxiliary magnets 24Y, 24M, and 24C indicated by a dotted line β are generated.
[0013]
The upper ends of the auxiliary peeling magnets 24Y, 24M, 24C are inclined at 57 ° with respect to a horizontal line passing through the centers of the magnet rollers 36Y, 36M, 36C so as to be 7.9 mm in the horizontal direction and 4 mm in the vertical direction from the peeling magnetic pole N2. Are attached to the cover portions 23Y, 23M, and 23C. The peeling auxiliary magnets 24Y, 24M, and 24C have the same length as the magnet rollers 36Y, 36M, and 36C, and are formed with a width of 5 mm and a thickness of 1 mm.
[0014]
When the upper end of the auxiliary peeling magnets 24Y, 24M, and 24C is too close to the peeling magnetic pole N2, the falling angle of the peeled developers 18Y, 18M, and 18C does not change so much, and reattachment to the gripping magnetic pole N3 occurs. In addition, even if the upper ends of the peeling auxiliary magnets 24Y, 24M, 24C are too far from the peeling magnetic pole N2, no magnetic field is generated between the peeling magnetic pole N2 and the peeling auxiliary magnets 24Y, 24M, 24C, and the separated developer 18Y, Since the drop angles of 18M and 18C do not change and reattach to the gripping magnetic pole N3, the upper end positions of the separation assisting magnets 24Y, 24M and 24C are 6.5 to 9.0 mm in the horizontal direction from the separation magnetic pole N2. It is preferable to separate the distance of about 2.5 to 5.8 mm in the vertical direction.
[0015]
Next, a color image forming process by the image forming unit 10 will be described. In the image forming unit 10, toner images are superimposed in the order of yellow (Y), magenta (M), and cyan (C) to form a color image. At the start of image formation, the magnetic brush roller 38Y of the yellow (Y) developing device 16Y attached to the revolver device 19 is disposed opposite the developing position of the photosensitive drum 11.
[0016]
When the image forming process is started, the photosensitive drum 11 rotates in the direction of the arrow s, and is uniformly charged by the charger 13 according to the rotation, and the laser corresponding to the yellow image signal is output from the laser writing unit 13 at the irradiation position 14. Irradiated with light, an electrostatic latent image of a yellow image is formed on the photosensitive drum 11 and reaches the revolver device 19. In the revolver device 19, the developing sleeve 37Y of the magnetic brush roller 38Y of the yellow (Y) developing device 16Y rotates in the direction of the arrow v.
[0017]
Due to the rotation of the developing sleeve 37Y, the magnetic brush roller 38Y obtains the developer 18Y with the gripping magnetic pole N3, and then regulates the spikes by the doctor blade 22Y with the blade regulating magnetic pole S2. Next, toner is applied to the electrostatic latent image on the photosensitive drum 11 at the developing magnetic pole N 1 to form a yellow (Y) toner image on the photosensitive drum 11. After the completion of development, the spikes on the magnetic brush roller 38Y are transported into the developing container 17Y by the transport magnetic pole S1, and are peeled off from the magnetic brush roller 38Y by the peeling magnetic pole N2.
[0018]
Since the separation magnetic pole N2 generates a magnetic field directed to the separation assisting magnet 24Y indicated by the dotted line β in FIG. 3, the developer 18Y separated from the magnetic brush roller 38Y by the separation magnetic pole N2 is subjected to centrifugal force by the magnetic brush roller 38Y. , While moving in the direction of the arrow w that is separated from the magnetic brush roller 38Y by the magnetic field and attracted to the peeling assisting magnet 24Y side, falls on the mixing auger 21Y away from the gripping magnetic pole N3 and moves in the developing container 17Y. And mixed with newly supplied developer. In the gripping magnetic pole N3, the developer peeled off from the peeling magnetic pole N2 is not directly gripped, and a new developer having a predetermined toner concentration ratio is supplied from the mixing auger 21Y in succession with sufficient agitation. A developer having a predetermined toner concentration ratio is supplied to the developing magnetic pole N1 through the magnetic pole S2.
[0019]
After the development, the yellow toner image formed on the photosensitive drum 11 reaches a contact position with the intermediate transfer belt 41a rotated in the direction of the arrow u, and is electrostatically primary-transferred onto the intermediate transfer belt 41a. . After the primary transfer, the photosensitive drum 11 is cleaned of residual toner by the cleaner device 42 and the surface charge is removed by the charge eliminating lamp 43. Next, similarly to the yellow toner image forming process, the magenta and cyan toner image forming processes are sequentially repeated on the photosensitive drum 11, and further, yellow (Y) and magenta (from the photosensitive drum 11 onto the intermediate transfer belt 41 a. M) and cyan (C) toner images are sequentially intermediate transferred to form a color toner image in which the three color toner images are superimposed on the intermediate transfer belt 41a.
[0020]
During this time, the revolver device 19 is sequentially rotated in the direction of the arrow t, and magnetic brush rollers 38Y, 38M, and 38C corresponding to the color of the toner image formed on the photosensitive drum 11 are disposed to face the photosensitive drum 11. The yellow (Y), magenta (M), and cyan (C) color toner images superimposed on the intermediate transfer belt 41a are collectively secondarily transferred to the recording paper P or the like to complete a color image on the recording paper P.
[0021]
While the image forming process is repeated in this manner, in the developing containers 17Y, 17M, and 17C, the developers 18Y, 18M, and 18C peeled off from the magnetic brush rollers 38Y, 38M, and 38C by the peeling magnetic pole N2 after the development is finished. While being pulled in the direction of the auxiliary peeling magnets 24Y, 24M, and 24C without falling near the gripping magnetic pole N3, it is surely dropped onto the mixing augers 21Y, 21M, and 21C, and after sufficient stirring, is again applied to the gripping magnetic pole N3. Supplied.
[0022]
According to the first embodiment, the peeling auxiliary magnets 24Y, 24M, and 24C are attached to the outer walls of the cover portions 23Y, 23M, and 23C facing the peeling magnetic pole N2 of the developing containers 17Y, 17M, and 17C, and the peeling magnetic poles are attached. A magnetic field is generated from N2 toward the auxiliary peeling magnets 24Y, 24M, and 24C. Accordingly, the separation assisting magnets 24Y, 24M, and 24M are separated by the centrifugal force and the magnetic field without dropping the developers 18Y, 18M, and 18C separated from the magnetic brush rollers 38Y, 38M, and 38C by the separation magnetic pole N2 near the lower gripping magnetic pole N3. It can fall on the mixing augers 21Y, 21M, and 21C away from the gripping magnetic pole N3 while moving in the 24C direction.
[0023]
As a result, a thin developer having a low toner ratio after development is not directly reattached to the gripping magnetic pole N3, and the gripping magnetic pole N3 is sufficiently stirred by the mixing augers 21Y, 21M, and 21C, Since the developers 18Y, 18M, and 18C having the toner density ratio are supplied, the toner image developed by the developing magnetic pole N1 has a sufficient image density over the entire surface and a high image quality with a uniform image density over the entire surface. can get.
[0024]
Further, according to the first embodiment, since the magnetic force can be weakened by attaching the auxiliary peeling magnets 24Y, 24M, and 24C to the outer walls of the cover portions 23Y, 23M, and 23C, the released developers 18Y, 18M, and 18C are covered by the cover. The developers 18Y, 18M, and 18C can be appropriately attracted by the magnetic field without adhering to the peeling auxiliary magnets 24Y, 24M, and 24C of the portions 23Y, 23M, and 23C.
[0025]
Next, the present invention will be described with reference to a second embodiment shown in FIG. The second embodiment is different from the first embodiment in the structure of the developing device, and the other parts are the same as those in the first embodiment. Description is omitted.
[0026]
On the outer walls of the cover portions 23Y, 23M, and 23C of the developing containers 17Y, 17M, and 17C of the second embodiment, plate-like peeling auxiliary iron plates 28Y, 28M, and 28C that are peeling auxiliary members are attached. The peeling auxiliary iron plates 28Y, 28M, and 28C are magnetized by the peeling magnetic pole N2 to the S polarity opposite to the peeling magnetic pole N2. Thereby, in the peeling magnetic pole N2, a magnetic field directed to the peeling auxiliary iron plates 28Y, 28M, and 28C is generated.
[0027]
The upper ends of the peeling auxiliary iron plates 28Y, 28M, and 28C are inclined at 57 ° with respect to a horizontal line passing through the centers of the magnet rollers 36Y, 36M, and 36C so as to be 7.9 mm horizontally and 4 mm apart from the peeling magnetic pole N2. Are attached to the cover portions 23Y, 23M, and 23C. The peeling auxiliary magnets 24Y, 24M, and 24C have the same length as the magnet rollers 36Y, 36M, and 36C, and are formed with a width of 5 mm and a thickness of 1 mm.
[0028]
Further, inclined plates 26Y, 26M, and 26C are installed between the separation magnetic pole N2 and the gripping magnetic pole N3 in the developing containers 17Y, 17M, and 17C. The inclined plates 26Y, 26M, and 26C are inclined toward the mixing augers 21Y, 21M, and 21C, and their upper ends 27Y, 27M, and 27C are spaced from the magnetic brush rollers 38Y, 38M, and 38C by about 0.5 mm. The distances of the inclined plates 26Y, 26M, and 26C from the magnetic brush rollers 38Y, 38M, and 38C may be in a range that does not contact the magnetic brush rollers 38Y, 38M, and 38C.
[0029]
In the developing process, for example, in the yellow (Y) developing device 16Y, the developer 18Y transported into the developing container 17Y by the transport magnetic pole S1 after the completion of the development at the developing magnetic pole N1 is separated from the magnetic brush by the separation magnetic pole N2. It is peeled off from the roller 38Y. Since the separation magnetic pole N2 generates a magnetic field directed toward the separation assisting iron plate 28Y, the developer 18Y separated from the magnetic brush roller 38Y by the separation magnetic pole N2 is moved away from the magnetic brush roller 38Y by the centrifugal force and the magnetic field. It falls while facing the direction of the arrow x attracted to the iron plate 28Y side.
[0030]
The developer 18Y falls on the inclined plate 26Y, and is further fed along the inclination of the inclined plate 26Y in the direction of the mixing augers 21Y, 21M, and 21C, falls on the mixing augers 21Y, 21M, and 21C, and enters the developing container 17Y. And mixed with the newly supplied developer 18Y. The gripping magnetic pole N3 is sequentially supplied from the mixing auger 21Y with a new developer 18Y sufficiently stirred and having a predetermined toner concentration ratio, and supplied with a predetermined toner concentration ratio to the developing magnetic pole N1 via the blade regulating magnetic pole S2. Will be.
[0031]
That is, while the image forming process is repeated, in the developing containers 17Y, 17M, and 17C, the developers 18Y, 18M, and 18C peeled off from the magnetic brush rollers 38Y, 38M, and 38C by the peeling magnetic pole N2 after the development is completed. After falling on the inclined plates 26Y, 26M, and 26C while being pulled in the direction of the peeling auxiliary iron plates 28Y, 28M, and 28C without falling near the gripping magnetic pole N3, it is surely dropped on the mixing augers 21Y, 21M, and 21C, After sufficiently stirring, it is supplied again to the gripping magnetic pole N3.
[0032]
According to the second embodiment, the separation magnetic pole N2 generates a magnetic field from the separation magnetic pole N2 toward the separation auxiliary iron plates 28Y, 28M, 28C. Accordingly, the developers 18Y, 18M, and 18C separated from the magnetic brush rollers 38Y, 38M, and 38C by the separation magnetic pole N2 can be dropped while being directed toward the separation assisting iron plates 28Y, 28M, and 28C by centrifugal force and magnetic field. In addition, by providing the inclined plates 26Y, 26M, and 26C between the separation magnetic pole N2 and the gripping magnetic pole N3, it is possible to more reliably prevent the separated developer from dropping near the gripping magnetic pole N3, and mixing away from the gripping magnetic pole N3. Can drop on augers 21Y, 21M, 21C.
[0033]
As a result, a thin developer having a small toner ratio after development is not reattached to the gripping magnetic pole N3 as it is, and the gripping magnetic pole N3 is sufficiently stirred by the mixing augers 21Y, 21M, and 21C, Since the developer having the toner density ratio is supplied, the toner image developed by the developing magnetic pole N1 can obtain a high image quality having a sufficient and uniform image density over the entire surface. Further, by attaching the peeling auxiliary iron plates 28Y, 28M, and 28C to the outer walls of the cover portions 23Y, 23M, and 23C, the developer does not adhere to the peeling auxiliary magnets 24Y, 24M, and 24C portions of the cover portions 23Y, 23M, and 23C. In addition, the developer can be appropriately attracted by the magnetic field.
[0034]
The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the developing device is not limited to the one mounted on the revolver device, The color of the toner used is not limited. Further, the material and shape of the peeling assisting member are not limited as long as it generates a magnetic field that attracts the developer in the direction of the peeling assisting member between the peeling magnetic poles. The mounting position and mounting method of the peeling auxiliary member are also arbitrary. For example, depending on the shape of the developing container, the gap between the peeling magnetic pole and the cover portion is wide, and the magnetic field between the peeling auxiliary member is set to the extent that the developer does not adhere If possible, a peeling assisting member may be attached to the inner wall of the cover portion. Also, the mounting position of the inclined plate is not limited.
[0035]
【The invention's effect】
As described above in detail, according to the present invention, a separation assisting member is provided and a magnetic field is generated between the separation magnetic pole and the developer separated by the separation magnetic pole is attracted in the direction of the separation assisting member. It can fall into. Therefore, the peeled developer does not drop to a position away from the gripping magnetic pole and cause image defects due to direct reattachment to the gripping magnetic pole. The gripping magnetic pole can grab a well-stirred developer having a predetermined toner density ratio and obtain a high-quality toner image having a sufficient and uniform image density.
FIG. 1 is a schematic configuration diagram illustrating an image forming unit of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic configuration diagram illustrating a developing device according to a first embodiment of the present invention.
FIG. 3 is a schematic explanatory diagram showing a magnetic field in a separation magnetic pole according to the first embodiment of this invention.
FIG. 4 is a schematic configuration diagram illustrating a developing device according to a second embodiment of the present invention.
FIG. 5 is a schematic explanatory view showing a conventional developing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Image formation part 11 ... Photoconductor drum 12 ... Charger 13 ... Laser exposure apparatus 16Y, 16M, 16C ... Developing device 17Y, 17M, 17C ... Developing container 18Y, 18M, 18C ... Developer 20Y, 20M, 20C ... Conveyance Auger 21Y, 21M, 21C ... Mixing auger 22Y, 22M, 22C ... Doctor blade 23Y, 23M, 23C ... Cover 24Y, 24M, 24C ... Peeling auxiliary magnet 36Y, 36M, 36C ... Magnet roller 37Y, 37M, 37C ... Developing sleeve 38Y, 38M, 38C ... Magnetic brush roller

Claims (5)

像担持体との対向位置に開口部を有する現像容器と、
前記現像容器の開口部に位置し、像担持体と対向する現像磁極、前記現像磁極より上方に位置し前記現像磁極通過後の現像剤を前記現像容器内に搬送する搬送磁極、前記搬送磁極で搬送した前記現像剤を剥離する剥離磁極及び前記剥離磁極より下方に位置し現像容器内の前記現像剤をつかむつかみ磁極を有し、前記つかみ磁極にてつかんだ前記現像剤を前記現像磁極にて前記像担持体上の静電潜像に付与する磁気ブラシローラと、
前記剥離磁極と対向する位置にて前記現像容器に取着され前記剥離磁極で前記磁気ブラシローラから剥離された前記現像剤を前記磁気ブラシローラから離反する方向の磁界を発生する剥離補助部材とを具備する事を特徴とする画像形成装置における現像装置。
A developer container having an opening at a position facing the image carrier;
A developing magnetic pole located at the opening of the developing container and facing the image carrier, a conveying magnetic pole located above the developing magnetic pole and carrying developer after passing through the developing magnetic pole into the developing container; A separation magnetic pole for separating the conveyed developer and a gripping magnetic pole located below the separation magnetic pole for gripping the developer in the developer container, and the developer gripped by the gripping magnetic pole at the development magnetic pole A magnetic brush roller for applying an electrostatic latent image on the image carrier;
A peeling auxiliary member that generates a magnetic field in a direction away from the magnetic brush roller when the developer is peeled off from the magnetic brush roller by the peeling magnetic pole and attached to the developer container at a position facing the peeling magnetic pole; A developing device in an image forming apparatus.
前記剥離補助部材を前記現像容器の外壁に取着して、前記磁界を前記現像容器を介して前記剥離磁極と前記剥離補助部材との間で発生する事を特徴とする請求項1記載の画像形成装置における現像装置。2. The image according to claim 1, wherein the peeling auxiliary member is attached to an outer wall of the developing container, and the magnetic field is generated between the peeling magnetic pole and the peeling auxiliary member through the developing container. A developing device in the forming apparatus. 前記剥離補助部材は磁石であり、前記剥離磁極との対向面の磁気が前記剥離磁極と逆極性であることを特徴とする請求項1又は請求項2のいずれか記載の画像形成装置における現像装置。3. The developing device in an image forming apparatus according to claim 1, wherein the peeling assisting member is a magnet, and a magnetism of a surface facing the peeling magnetic pole is opposite to that of the peeling magnetic pole. . 前記剥離補助部材は、前記剥離磁極により磁化される磁性体であることを特徴とする請求項1又は請求項2のいずれか記載の画像形成装置における現像装置。3. The developing device in an image forming apparatus according to claim 1, wherein the peeling assisting member is a magnetic body magnetized by the peeling magnetic pole. 前記剥離磁極と前記つかみ磁極との間に設けられ、前記剥離磁極で前記磁気ブラシローラから剥離された前記現像剤を前記つかみ磁極から離れる方向に落下搬送する傾斜プレートを設けることを特徴とする請求項1乃至請求項4のいずれか記載の画像形成装置における現像装置。An inclined plate is provided between the separation magnetic pole and the gripping magnetic pole, and drops and conveys the developer separated from the magnetic brush roller by the separation magnetic pole in a direction away from the gripping magnetic pole. The developing device in the image forming apparatus according to claim 1.
JP2003201264A 2003-07-24 2003-07-24 Developing device for image forming apparatus Abandoned JP2005043515A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008256830A (en) * 2007-04-03 2008-10-23 Fuji Xerox Co Ltd Developing body, developing device, and image forming apparatus
JP2013057808A (en) * 2011-09-08 2013-03-28 Ricoh Co Ltd Developing device, image forming apparatus, and process cartridge
JP2018205619A (en) * 2017-06-08 2018-12-27 京セラドキュメントソリューションズ株式会社 Developing device and image forming apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008256830A (en) * 2007-04-03 2008-10-23 Fuji Xerox Co Ltd Developing body, developing device, and image forming apparatus
JP2013057808A (en) * 2011-09-08 2013-03-28 Ricoh Co Ltd Developing device, image forming apparatus, and process cartridge
JP2018205619A (en) * 2017-06-08 2018-12-27 京セラドキュメントソリューションズ株式会社 Developing device and image forming apparatus

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