JP4116833B2 - Mounting / detaching structure of a plurality of toner cartridges, developing unit and image forming apparatus provided with the same - Google Patents

Description

【０１０６】
表１において、外添処理した初期トナーとして、Ｎｏ．１のトナーを使用し、該Ｎｏ．１が消費された後に補充する補充トナーとしては、Ｎｏ．２〜Ｎｏ．6のトナーを使用し、加速試験的にトータルで４万枚ずつの現像を行った。
【０１０７】
この現像後のトナー画像を用紙に転写し、定着後の画像状態を確認した結果を下記の表２に示した。ここで、比較のために、トナーＮｏ．１のトナーを初期トナーとして、補充トナーを初期トナーと同一のＮｏ．１のトナーを用いた場合の結果を合わせて付記している。
【０１０８】
【表２】

【０１０９】
表２において、画像カブリは白紙を白色コピーすることで、コピー前の用紙と、排出された用紙の濃度を白度計で測定し、その測定値の差で評価を行った。つまり、数値が大きくなれば、画像カブリが大きくなる。また、トナー飛散については、現像装置の下部に溜まったトナー量である。さらに、画像ボケについては、ライン画像を形成し、それを目視にて評価した。この時、コピーのために、白色部分及びライン部分を有するテストチャートを容易して画像形成を行った。
【０１１０】
表２から理解できるように、トナーＮｏ．１に代えて補充トナーとして、Ｎｏ．２〜Ｎｏ．６のトナーを使用した時には、画像のカブリが軽減でき、またトナー飛散等も軽減できた。従って、初期トナー（Ｎｏ．１）と補充トナー（Ｎｏ．２）のように、外添剤の量、特にシリカの量を多くすることで、画像カブリ、画質劣化の生じることのない良好な安定した画質の画像を得られることが判る。
【０１１１】
また、初期トナー（トナーＮｏ．１）と補充トナー（トナーＮｏ．３〜６）のように、外添剤の材料を変更することによっても、つまり初期トナーの外添剤とは別の外添剤をさらに加えることによっても、量的な調整とほぼ同様の効果が得られた。
【０１１２】
これに対し、初期トナー（Ｎｏ．１）と補充トナー（Ｎｏ．１）のように、補充トナーを初期トナーの外添剤と全く同一量、及び同一材料を用いると、画像カブリが増し、しかもトナー飛散の量も多くなる。そして、画像ボケが生じ、安定した画質を得られなかった。
【０１１３】
トナー表面の流動性に影響を及ぼす外添剤の欠落、埋没により流動性が劣化し、特に２成分系の現像剤を継続して使用し、トナー濃度検出用の透磁率センサを用いてトナー濃度制御を行うと、トナー濃度が上昇し、画像カブリやトナー飛散を生じる原因となり、表２に示すような結果となる。
【０１１４】
これに対して、補充トナーの外添剤としてのシリカの量を初期トナーより多くすることで、流動性低下を補い、結果として表２のトナーＮｏ．２に示すように画像カブリを防止し、画質を安定させることができた。また、外添剤としてシリカ及びマグネタイトを同一量とし、この外添剤の外に酸化チタン、酸化亜鉛等を別に加えたトナーＮｏ．３及び４を補充トナーとした時にも同等の効果を得ることができる。
【０１１５】
また、トナーの帯電性に影響を及ぼす外添剤として、イミダゾール誘電体やアルカマイザーを別に加えたトナーＮｏ．５や６を補充トナーとして使用した場合には、特に効果的であった。
【０１１６】
一方、画質を良好に保つために、感光体ドラム１の表面を研磨し、常に良好な状態にすることを目的としてトナーに添加する外添剤として、マグネタイトがよく用いられる。この外添剤の添加により、感光体ドラム１の研磨効果が低下するのを補い、良好な画質状態に保つことができる。
【０１１７】
特に、感光体ドラム１は、帯電器２や転写チャージャ１０等において発生した窒素酸化物が付着し、これを除去するために、マグネタイトが外添剤として用いられている。マグネタイトは感光体ドラム１の研磨効果を維持し、それにより画質の劣化、特に画像ボケ等を阻止し、画像ボケのない良好なる画質状態を維持することができる。特に、感光体ドラム１としては、ＯＰＣ感光体において効果が顕著になる。
【０１１８】
以上より、トナーカートリッジ４２Ａ〜４２Ｃに充填するトナーＮｏ．の組合わせの一例として、表３のような設定が可能である。
【０１１９】
【表３】

【０１２０】
〔第２の実施形態〕
本実施形態では、初期トナーと補充トナーとで異なるものを使用して、定着性を安定させることで画質の劣化を阻止するようにしている。つまり、初期トナーと補充トナーとで定着性に影響を及ぼす材料を異ならせ、良好な画質状態を維持させるようにする。
【０１２１】
現像剤中のトナーが受けるストレスにより定着性が悪くなり、定着部１３の定着ローラ（ヒートローラ等）にトナーが付着し、これが用紙に転写されるといったオフセット現象が生じ、画質を劣化することがある。しかも、定着性が劣化し、定着後の画像が剥離され画像が乱れ、またユーザーの手を汚すこともある。すなわち、現像剤中のトナーは、各種ストレスを与えられ、外添剤の消失や微粉トナーが増加する。これにより、用紙への定着強度や定着オフセットが生じ、用紙表面の画像、つまりトナー像が剥がれ易くなると同時に、オフセット現象により用紙が汚され画質が悪くなる。
【０１２２】
このような問題を解消するために、本実施形態においては、トナーホッパー部に初期に充填されている初期トナーがなくなり新たに補充する補充トナーによって定着性が良好になり、定着オフセットが生じない特性を有するトナーとする。そのために、補充トナーとしては、ガラス転移点及びトナー溶融粘度を定着強度が向上する方向にシフトさせたものを使用する。これにより、微粉砕されたトナーが現像部へ搬送・供給に寄与された時に、定着性等が悪くなり画質が劣化するのを防止することができる。
【０１２３】
トナーのガラス転移点を変える方法としては、トナーを構成する結着樹脂等の分子量分布を異ならせる方法がある。例えば、トナーを構成する組成の一つの結着樹脂の分子量を低くすることで、ガラス転移点を下げ、溶融温度が下がるため用紙への定着強度が上がる。従って、結着樹脂の分子量を初期トナーと補充トナーとで異なるものを選定し、これを使用するようにすればよい。
【０１２４】
また、分子量を異ならせる方法としては、予め分子量の異なるものを選択するだけではなく、トナーを製造する過程においても容易に行える。例えば、トナーを製造する時の混練過程において、その条件を変更すればよく、例えば、温度や押し出し速度等を変えればよい。すなわち、混練温度を下げて材料にストレスをかけた状態で混練することで、分子が切断され、分子量が低い状態に移行する。
【０１２５】
また、定着部１３を構成する定着ローラ等にトナーが付着し、これが用紙に再転写されるといった定着オフセットの現象を押さえるには、粘着防止剤であるワックスの量を変えればよい。すなわち、初期トナーに対して補充トナーのワックス量を多くすれば、リサイクルトナーが微粉トナーとして回収される時にも、定着ローラへのトナーの付着を抑制し、定着オフセットによる画質の劣化を防止できる。
【０１２６】
以上のように、初期トナーと補充トナーとで、ガラス転移点及びトナー溶融粘度を、定着強度を向上させる方向にシフトさせるようにする。つまり、初期トナーのガラス転移点の温度に比べて補充トナーのガラス転移点の温度を低く設定している。また、分子量を変化させることで、トナー溶融粘度が定着強度を向上させる方向にシフトさせ、定着強度を向上させている。
【０１２７】
以下に、実施例を通じて、本実施形態による作用・効果をより具体的に説明する。
（実施例２）
使用する現像剤としては、（実施例１）と同様に、２成分系の現像剤を用い、画像形成装置は、電子写真方式によるものを採用した。トナーの組成としては、結着樹脂であるポリスチレンを９０重量部、着色剤であるカーボンブラックを５重量部、帯電制御剤を２重量部、そして粘着防止剤であるポリエチレンワックスを３重量部又は５重量部、とし、これをミキサーで十分に撹拌混合し、この混合物を加熱下において、スクリュー押し出し機で混練し、この混練物を冷却後に粗粉砕し、粗粉砕物をジェット粉砕機で微粉砕し、その微粉砕物を分級処理して平均粒径約９μｍ程度の外添前のトナーを製造した。
【０１２８】
このようにして得た外添前のトナー１００重量部に対して、シリカ０．３重量部、マグネタイト０．２重量部の外添剤をミキサーで撹拌混合し、外添処理を施した。また、使用したトナーの物性及び粘着防止剤であるワックス量は下掲の表４の通りである。この場合、トナーを構成する結着樹脂であるポリエチレンの分子量を種々選択して使用した。
【０１２９】
ここで、トナーＮｏ．８（Ａ）とトナーＮｏ．９（Ｂ）とでは、結着樹脂である分子量分布を異ならせている。つまり、トナーＮｏ．９（Ｂ）の分子量の数平均分子量（Ｍｎ）を低くし、よってガラス転移点の温度を低く設定するようにした。また、トナーＮｏ．１０（Ｃ）の結着樹脂の分布量の重量平均分子量（Ｍｗ）を多くし、さらにトナーＮｏ．１１（Ｄ）を構成するワッスク量を、Ｎｏ．１０（Ｃ）のトナーのワックス量より多くした。
【０１３０】
【表４】

【０１３１】
表４において、トナーＮｏ．８（Ａ）を初期トナーとして使用し、該初期トナーがなくなった後に、補充するトナーを、トナーＮｏ．８（Ａ）の同一のトナーを使用した時を比較例とし、その他トナーＮｏ．９（Ｂ）〜１１（Ｄ）のトナーを補充トナーとして使用し、それぞれにおい加速試験的に４万枚の画像形成、特に現像（コピー）を行った結果を下記の表５に示す。
【０１３２】
【表５】

【０１３３】
表５におていは、定着ローラの汚れを、白紙を定着ローラに通過させる時の、通過前と通過後の白度計の測定値の差で評価した。この場合、画像形成においては、白色部と文字やその他の画像によるテストチャートを用いて画像形成を行った。ここで、数値が大きいほど定着ローラの汚れが甚だしいことが判る。
【０１３４】
表５に示す結果から、定着ローラは、トナーＮｏ．Ａのトナーを初期トナーとし、かつ、該初期トナーがなくなった後の補充トナーとした時には、甚だしく汚れることとなった。この点、初期トナーと補充トナーがそれぞれ異なる場合（トナーＮｏ．Ｂ〜Ｄ）には、定着ローラの汚れは少なくなり、トナーＮｏ．Ｄに示すように、ワックス量を多くしたものを補充トナーとして利用することで、定着ローラの汚れを顕著に軽減できることが判った。
【０１３５】
また、定着性能を確認した結果につき、特に初期トナーをトナーＮｏ．Ａ（ＲＥＦ）とし、その後に補充する補充トナーを、トナーＮｏ．Ａ（ＲＥＦ）とした比較例の場合（一点鎖線で示す）と、補充トナーとしてトナーＮｏ．９（Ｂ）を使用した場合（実線で示す）と、トナーＮｏ．１０（Ｃ）のトナーを使用した場合（点線で示す）と、を図１０に示す。
【０１３６】
この図１０において、定着強度を確認するために、中間調の画像を形成した部分を、消しゴムで擦った後の濃度と、擦る前の濃度との比で評価した。この時の濃度は、マクベス濃度計で測定した。同図において、縦座標における数値が高いほど、消しゴムで擦った前後での濃度（ＩＤ）差がなく、定着強度が良好であることを示す。
【０１３７】
同図から判るように、初期トナーと補充トナーの結着樹脂の分子量が異なるようにして定着強度を上げる方向に設定しているため、定着不良等による画質低下も合わせて解消された。すなわち、初期トナーと補充トナーとを異ならせることで定着ローラの汚れも軽減でき、定着オフセットによる画質の低下を防止することができる。この時、初期トナーと補充トナーのワックス量を異ならせるようにし、かつ、補充トナーの方のワックス量を多くすることで、画質の低下を免れることができる。
【０１３８】
ここで、初期の状態から表４に示したトナーＮｏ．Ｂ，Ｃ，Ｄ等のトナーを使用すれば、初期の状態での定着等において問題が生じる。つまり、初期においては却って定着ローラに初期のストレスを受けていないトナーが付着し、オフセット現象や、定着ローラを汚すことにもなる。
【０１３９】
そのため、表５に示したように初期トナーと補充トナーとを区分して使用することによって、同表及び図１０で確認できるような良好な結果を得ることができる。以上から、トナーカートリッジ４２Ａ〜４２Ｃに充填するトナーＮｏ．の組合わせの好ましい一例として次の表６に示すような設定が可能となる。
【０１４０】
【表６】

【０１４１】
なお、本発明は、画像形成装置を、図１に示す構成に限定するものではなく、トナー等の消耗品が充填された交換可能なトナーカートリッジ等の筐体状部材と、前記筐体状部材を着脱可能に装着するための受容部と、を有して、少なくとも前記筐体状部材よりも長い耐用期間または稼動期間を設定された装置ユニットを備える画像形成装置であれば、その構成や形式の如何を問わず、本発明を適用することができる。
【０１４２】
また、本実施形態では、現像ユニットを装置ユニットとして説明しているが、本発明は、これに限定されるものではなく、少なくとも、消耗品が充填された交換可能な筐体状部材と、前記筐体状部材を着脱可能に装着するための受容部と、を有し、かつ、前記筐体状部材よりも長い耐用期間または稼動期間を設定された装置ユニットであれば、その機能や目的、構成、形式等の如何を問わず、本発明を適用することができる。
【０１４３】
【発明の効果】
以上の説明から明らかなように、本発明は、以下の効果を奏する。
【０１４４】
（１）装置ユニットの受容部に着脱自在に装着されている筐体状部材が取り外される度毎に、前記受容部には、前記筐体状部材に充填された消耗品とは特性の異なる消耗品が充填された筐体状部材が装着されるので、一基の装置ユニットと複数個の筐体状部材を１セットとして取り扱うことができる。
【０１４５】
従って、予め製造段階において、使用段階を経て進行する筐体状部材の性能の低下の程度に応じて、逐次、これに適合する特性の異なる消耗品が充填された筐体状部材を段階的に取り揃えて用意しておき、装置ユニットとセットとしてユーザーに提供することで、ユーザー側にて、筐体状部材の交換が必要になった時点で、適合する筐体状部材と適宜取り換えることができるため、装置ユニットの性能を所定の水準に維持することができる。
【０１４６】
その取り換え操作は、受容部への筐体状部材の着脱交換作業のみであるから、特別の操作や熟練を要することもなく、ユーザーサイドで、メンテナンスを容易におこなうことができるため、装置ユニットを備えた画像形成装置にデッドタイムを発生させることなく、装着の高い稼働率を維持することができる。
【０１４７】
（２）現像ユニットの受容部に着脱自在に装着されているトナーカートリッジが取り外される度毎に、前記受容部には、前記現像ユニット内で保有する現像剤の性能低下に適合する特性の異なるトナーが充填されたトナーカートリッジが装着されるので、一基の現像ユニットと複数個のトナーカートリッジを１セットとして取り扱うことができる。
【０１４８】
従って、予め製造段階において、使用段階を経て進行する現像剤の性能の低下の程度に応じて、逐次、これに適合する特性のトナーが充填された複数のトナーカートリッジを段階的に取り揃えて用意しておき、現像ユニットとセットとしてユーザーに提供することで、ユーザー側にて、トナーカートリッジの交換が必要になった時点で、適合するトナー特性を内蔵したトナーカートリッジと適宜取り換えることにより、現像ユニットの性能を所定の水準に維持することができる。
【０１４９】
その取り換え操作は、受容部へのトナーカートリッジの着脱交換作業のみであるから、特別の操作や熟練を要することもなく、ユーザーサイドで、メンテナンスを容易におこなうことができるため、現像ユニットを備えた画像形成装置にデッドタイムを発生させることなく、装着の高い稼働率を維持することができる。
【０１５０】
現像剤、特にトナーにおいては、組成そのものを変えることなく、流動性、帯電性等の特性を、所定状態に保つための外添剤の量や種類を変更する等により対処することができ、現像剤のコストアップにはつながらずに、耐久使用でも画質状態を使用初期の状態と同程度に維持することができる。
【０１５１】
（３）現像ユニットの受容部に装着されているトナーカートリッジが取り外される度毎に、前記受容部の形状が更新されるとともに、前記受容部には、特性の異なるトナーが充填されたトナーカートリッジが装着されるので、一基の現像ユニットと複数個のトナーカートリッジを１セットとして取り扱うことができる。従って、予め製造段階において、使用段階を経て進行する現像剤の性能の低下の程度に応じて、逐次、取り換えの度毎に、段階的に更新される受容部に適合する形状を具備し、かつ、特性の異なるトナーが充填された複数のトナーカートリッジを取り揃えて用意し、これを現像ユニットとセットとしてユーザーに提供することで、ユーザー側では、トナーカートリッジの交換が必要になった時点で、装着されているトナーカートリッジを取り外して、更新された受容部に適合する形状を具備したトナーカートリッジと適宜取り換えることにより、現像ユニットの性能を所定の水準に維持することができる。
【０１５２】
その取り換え操作は、受容部へのトナーカートリッジの着脱交換作業のみであるから、特別の操作や熟練を要することもなく、ユーザーサイドで、メンテナンスを容易におこなうことができるため、現像ユニットにデッドタイムを発生させることなく、高い稼働率を維持することができる。
【０１５３】
現像剤、特にトナーにおいては、組成そのものを変えることなく、流動性、帯電性等の特性を、所定状態に保つための外添剤の量や種類を変更する等することで対処することができ、現像剤のコストアップにはつながらずに、耐久使用でも画質状態を使用初期の状態と同程度に維持することができる。
【０１５４】
（４）受容部が、トナーカートリッジを交換される毎に縮小されるので、先に装着されるトナーカートリッジを、後から装着されるトナーカートリッジより大きく形成することで、所定の使用順序に基づいて未使用トナーカートリッジを間違いなく装着できる。
【０１５５】
（５）現像ユニットより使用済トナーカートリッジを取り外す際に、前記第１の部材が使用済トナーカートリッジより分離されて現像ユニット側へ残留し、前記受容部の形状、あるいは、前記受容部および該受容部に未使用トナーカートリッジを挿入するための挿入開口部の断面形状が更新され、これらの形状に嵌合可能な未使用トナーカートリッジのみが装着されるので、簡易な構成によって、所定の使用順序に基づいて未使用トナーカートリッジを間違いなく装着できる。
【０１５６】
（６）第１の部材は現像ユニット側へ係止され、現像ユニットより使用済トナーカートリッジを取り外す際に、第１の部材は使用済トナーカートリッジより分離され、現像ユニット側に残留するので、簡易な構成によって、所定の使用順序に基づいて未使用トナーカートリッジを間違いなく装着できる。
【０１５７】
（７）現像ユニットから使用済トナーカートリッジが取り外される度毎に、前記受容部の形状あるいは、受容部および挿入開口部の断面形状が更新され、これらの形状に嵌合可能な未使用トナーカートリッジを装着させるようにした簡易な構成により、確実に所定の使用順序に基づいて未使用トナーカートリッジを間違いなく装着できる。
【０１５８】
また、例えば、各々が異なる形状を有した複数個のトナーカートリッジを交換した時点で１基の現像ユニットが耐用寿命に到達すると設定することで、使用限度を越えた現像ユニットの誤使用を確実に防止できる。さらに、トナーカートリッジの挿入順序を誤ることによって現像ユニットの残寿命を間違って認識してしまうようなトラブルの発生を未然に防止できる。
【図面の簡単な説明】
【図１】本発明の実施形態にかかる画像形成装置の構成説明図である。
【図２】同装置ユニットとしての現像ユニットの分解斜視図である。
【図３】同トナーカートリッジの斜視図と断面図である。
【図４】同第１の部材と一体のトナーカートリッジの斜視図と要部断面図である。
【図５】同第１の部材にトナーカートリッジを組み合わせる工程の説明図である。
【図６】同トナーカートリッジ挿入時の説明図である。
【図７】同異なるトナーカートリッジの要部断面図である。
【図８】同トナーカートリッジ挿入時の説明図である。
【図９】同現像ユニットの交換時期に達するまでの流れの説明図である。
【図１０】同実施例における定着強度を比較例と比較して示す説明図である。
【符号の説明】
４−装置ユニット，現像ユニット
４２−筐体状部材，トナーカートリッジ
４６−受容部
６１−第１の部材[0001]
BACKGROUND OF THE INVENTION
The present invention includes a replaceable consumable part and a receiving part for mounting the consumable part, and includes at least a functional part that can be used for a longer period of time than the consumable part.Loading and unloading structure of a plurality of toner cartridgesThe present invention relates to a developing unit and an image forming apparatus.
[0002]
[Prior art]
An image forming apparatus using an electrophotographic system develops an electrostatic latent image formed on a surface of a photoreceptor to form a toner image, and transfers the toner image to a recording medium to form an image (apparatus unit). ). The developing unit includes a developing housing part (functional part) having a developing device including a sponge roller, a stirring roller, a developing roller, and the like, and a toner cartridge (consumable part).
[0003]
As the image formation is repeated, the toner in the toner cartridge is consumed. When a certain period of time is reached, the toner cartridge must be replaced and new toner must be replenished. However, the life of the developing housing portion having the developing device is exhausted. Until used continuously. That is, a mechanism is used in which a plurality of toner cartridges are exchanged for one (one) development unit.
[0004]
[Problems to be solved by the invention]
As described above, when a plurality of toner cartridges and a developing unit are used in combination, the toner cartridge is appropriately replaced when the toner filled in the cartridge is exhausted as the image forming operation progresses. Thus, it is replaced with an unused toner cartridge.
[0005]
On the other hand, the developer filled in the developing unit is subjected to mechanical stress (mixing and stirring between the developer and the toner) that occurs due to frictional charging of the developer and the toner in the developing unit due to long-term use. (Contact, collision, sliding, friction) between the developing container wall surface, the stirring member or the carriers.
[0006]
As for the toner in the developer, the external additive on the toner surface is peeled, detached, or buried, and the external additive on the toner surface is substantially lost, and the fluidity is deteriorated, the charging performance is deteriorated, etc. And the image quality gradually deteriorates as the number of image formations or the number of developments increases.
[0007]
Accordingly, a plurality of toner cartridges filled with toner having different characteristics to be newly supplied to one (one) development unit in accordance with changes in developer characteristics accompanying the progress of image formation during the service life. When the user replaces the toner cartridge, the toner cartridge filled with the toner having characteristics suitable for changing the characteristics of the developer is appropriately selected, and the characteristics of the developer are selected. If it is possible to apply a usage pattern such as replacement to compensate for the deterioration, the above-described problem of image quality deterioration should be avoided.
[0008]
However, even if the order of use of the toner cartridges is defined by means such as number display or color marking, the shapes of the plurality of toner cartridges are all very similar, and the user himself / herself selects an appropriate toner cartridge. This imposes a burden of managing the order of use and is not practically applicable.
[0009]
SUMMARY An advantage of some aspects of the invention is that it provides an apparatus unit, a developing unit, and an image forming apparatus capable of maintaining the initial performance even during long-term use by simple maintenance on the user side. For the purpose.
[0010]
[Means for Solving the Problems]
In the present invention, means for solving the above-described problems are configured as follows.
[0011]
  A plurality of toner cartridges of the present inventionLoading and unloading structureIs,In the receiving space formed in the development unitA loading / unloading structure for loading / unloading a plurality of toner cartridges in a predetermined order,A first toner cartridge and a second toner cartridge are provided. A first locking hole and a second locking hole are provided on the back side surface of the receiving space in the loading direction. The first toner cartridge has a first main body portion filled with the first toner, and a first housing formed so as to be able to be inserted into the receiving space. The first main body is provided with a first handle on a first surface that intersects the loading direction on the near side of the loading direction. The first housing is detachably attached to the first main body, and is engaged with the first locking hole on the second surface intersecting the loading direction on the far side in the loading direction of the first main body. A stopper and a second through hole formed at a position facing the second locking hole are provided. The second toner cartridge has a second handle provided on a surface corresponding to the first surface, a second main body portion filled with the second toner, and a second housing formed to be inserted into the first housing. And having a body. The second housing is provided with a second locking portion that penetrates the second through hole in a surface corresponding to the second surface and engages with the second locking hole.The first toner cartridge is loaded into and removed from the receiving space, and then the second toner cartridge is loaded.
[0012]
  This configurationThen, when the first toner cartridge is loaded in the receiving space formed in the developing unit, the first housing is engaged with the receiving space. When the first toner cartridge is pulled out from the receiving space, the first housing is detached from the main body because the first locking portion of the first housing is engaged with the first locking hole. Further, the second toner cartridge is loaded in the receiving space with which the first housing is engaged. Therefore, the first toner cartridge and the second toner cartridge can be sequentially loaded into the receiving space of the developing unit.
[0015]
  In this configuration, a third toner cartridge may be further provided. The third toner cartridge is formed to be insertable into the second housing and has a third main body portion filled with the third toner.Alternatively, the third toner cartridge may be loaded after the second toner cartridge is inserted into and removed from the receiving space.For this reason, the second toner cartridge can be pulled out of the receiving space, and the third toner cartridge can be loaded into the receiving space.
[0020]
  Further, the second toner may contain more external additives than the first toner. For this reason, it is possible to suppress the deterioration of the toner performance of the developing unit, which has been deteriorated by repeated development processing, by the external additive contained in the second toner.
[0025]
  The first toner may contain a first external additive containing silica and magnetite. The second toner may contain a second external additive that further contains any one of titanium oxide, zinc oxide, imidazole, alkamidizer, and a hydrosartite compound. Thereby, it is possible to prevent the chargeability and fluidity of the toner stored in the developing unit from being lowered.
[0027]
  The developing unit of the present invention can be loaded with a plurality of toner cartridges in a predetermined order and may include a housing portion. The housing part is a developing device for stirring the toner, according to any one of the above inventionsMultiple toner cartridge loading / unloading structureYou may have. When the first toner cartridge loaded in the receiving space is pulled out of the receiving space, the first housing is locked in the receiving space, and when the second toner cartridge is further loaded in the receiving space, the first housing locked in the receiving space. A second housing is inserted into the body. For this reason, in the developing unit, the same effect as that of the plurality of toner cartridges according to any of the above inventions can be obtained.
[0029]
  The image forming apparatus according to the present invention may include a paper feeding unit that feeds the recording paper, and an image forming unit that includes the developing unit according to the invention and performs image forming processing on the recording paper. Therefore, in the image forming apparatus, it is possible to obtain the same effect as the developing unit according to the above invention.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an apparatus unit according to an embodiment of the present invention and an image forming apparatus including the apparatus unit will be described in detail with reference to the drawings.
[0035]
[Description of operation of image forming apparatus to which apparatus unit is applied]
FIG. 1 shows a configuration of an electrophotographic image forming apparatus 14, which includes an image forming unit 20, a sheet feeding unit 5, and a sheet feeding unit 6, and the sheet feeding unit 5 and the sheet feeding unit. 6 includes a paper feed roller 7 and a separation roller 8, and recording paper (recording medium) is stored in each paper feed unit. The image forming unit 20 includes a photosensitive drum 1, a charger 2, a laser writing system 3, a developing unit (device unit) 4, a registration roller 9, a transfer charger 10, a separation charger 11, a transport belt 12, and a fixing unit 13. Then, an operation related to image formation is performed.
[0036]
Specifically, the outer peripheral surface of the photosensitive drum 1 is uniformly charged by the charger 2 in the process in which the photosensitive drum 1 rotates clockwise as indicated by an arrow in FIG. This charged portion is irradiated with a laser beam from the laser writing system 3 based on the document image information, and an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 1. Next, toner is supplied to the electrostatic latent image by the developing unit 4 disposed so as to face the peripheral surface of the photosensitive drum 1 to form a toner image.
[0037]
On the other hand, the recording paper (recording medium) stored in the paper supply unit 5 or 6 is pulled out by the paper supply roller 7 and separated and conveyed one by one by the separation roller 8. Thereafter, the recording paper comes into contact with the nip portion of the registration roller 9 in a stopped state and stands by. When the registration roller 9 rotates in synchronization with the rotation cycle of the photosensitive drum 1, the recording paper is conveyed toward the outer periphery of the photosensitive drum 1. Is done.
[0038]
The toner image on the peripheral surface of the photosensitive drum 1 is transferred to the recording paper by the transfer charger 10, and the recording paper is separated from the photosensitive drum 1 by the separation charger 11. The recording paper separated from the photosensitive drum 1 is conveyed to the fixing unit 13 by the conveying belt 12. The fixing unit 13 fixes the transferred image on the recording paper. Then, the recording paper is conveyed by a paper discharge roller 15 to a discharge unit (not shown).
[0039]
[Developing unit as device unit]
Next, the developing unit 4 will be described with reference to FIG. The developing unit 4 includes a developing housing part (functional component) 41 having a developing device 47 and a toner cartridge (housing member) 42 having a cover-shaped member (first member, outer frame) 63. . The developing housing portion 41 is formed by injection molding a thermoplastic resin such as polystyrene (PS), acrylonitrile butadiene styrene (ABS), or modified polyphenylene oxide (M-PPO) to a thickness of about 2 to 4 mm.
[0040]
The developing housing portion 41 includes a developing device 47, a toner cartridge receiving portion 46 (hereinafter referred to as a receiving portion 46), and a toner hopper portion (not shown) that supplies toner to the developing device 47. The developing device 47 includes a sponge roller (not shown), a stirring roller (not shown), a developing roller 43, a layer thickness regulating blade 44, and a driving gear 48.
[0041]
The developing roller 43 is for supplying toner to the electrostatic latent image on the photosensitive drum 1 (see FIG. 1), and the layer thickness regulating blade 44 regulates the layer thickness of the toner on the developing roller 43 to drive the drive gear. 48 receives a driving force from a driving source such as a driving motor (not shown) and rotates the developing roller 43.
[0042]
The receiving portion 46 is for mounting the toner cartridge 42 in the upper surface opening of the toner hopper portion. Specifically, the receiving portion 46 includes an insertion opening 45 in the end wall of the development housing portion 41, and the toner cartridge 42 is mounted on the upper surface of the toner hopper portion by inserting the toner cartridge 42 from the insertion opening 45. It is configured to be.
[0043]
The toner supplied from the toner cartridge 42 to the toner hopper is put into the developing device via the sponge roller. Although details of the inside of the developing device are not shown, the toner and the carrier (iron powder) are stirred by the stirring roller, and the toner held on the carrier appears on the surface of the developing roller 43 with a predetermined thickness, The toner is electrodeposited on the peripheral surface of the photosensitive drum 1 in accordance with the electrostatic latent image on the photosensitive drum 1 to form a toner image.
[0044]
[Toner cartridge as a housing-like member that can be attached to the device unit]
Next, the toner cartridge 42 will be described with reference to FIGS. The toner cartridge 42 is a container for storing toner having a rectangular or trapezoidal cross-sectional shape, and is formed by injection molding a thermoplastic resin such as PS or M-PPO to a thickness of about 1 to 3 mm. The opening 51 is provided in the opening 51, and a flange 53 is formed over the entire circumference of the opening 51.
[0045]
The flange portion 53 improves the rigidity of the entire toner cartridge 42 and serves as a mounting surface when a film seal 52 (to be described later) is adhered or welded to the toner cartridge 42. The toner cartridge 42 is attached to the developing housing portion 41. It also functions as an engagement guide surface when performing.
[0046]
After the toner cartridge 42 configured in this manner is filled with a predetermined amount of powder toner, the opening 51 is adhered by a film seal 52 (sealing member), for example, by adhering a double-sided tape or applying an adhesive. Alternatively, it is closed by a method such as heat welding by a hot plate welding method or ultrasonic welding method, and the toner inside is sealed.
[0047]
The film seal 52 has an extra length portion (becomes a grip when peeling) that is not adhered or thermally welded to the opening surface of the toner cartridge 42, and the tip portion is folded back, and the leading end portion is peeled off by a release tape or the like. The cartridge 42 is fixed in place. The film seal 52 is made of a flexible material having a thickness of about 50 to 200 μm (microns) such as low density polyethylene (PE) or polyethylene terephthalate (PET).
[0048]
On the other hand, a cover-shaped member 63 provided in the toner cartridge 42 is for attaching the toner cartridge 42 to the developing housing portion 41, and is configured to cover the entire toner cartridge 42 in close contact.
[0049]
On the other hand, the cover-shaped member 63 is formed in a lid shape having an opening 66 at one end and the other end closed as a wall surface 65, and the toner cartridge 42 has an opening 66 relative to the cover-shaped member 63. More removable.
[0050]
A handle portion 61 is provided on one side surface of the toner cartridge 42, and a hook-like claw (holding claw) 62 is provided on the wall surface 65 opposite to the opening 66 of the cover-shaped member 63. A pair of protrusions are provided.
[0051]
The handle 61 inserts the toner cartridge 42 with the cover-shaped member 63 from the insertion opening 45 of the developing housing 41 into the receiving portion 46 (see FIG. 2). This is for removing only the toner cartridge 42, leaving it in the receiving portion 46).
[0052]
On the other hand, the claw 62 of the cover-shaped member 63 engages the cover-shaped member 63 in the receiving portion 46 of the developing housing portion 41, and when the toner cartridge 42 is pulled out after using the toner, only the cover-shaped member 63 is removed from the developing housing. This is to keep it in the part 41.
[0053]
As shown in FIG. 4C, in the outer frame 63A attached to the first toner cartridge 42A, a pair of claws 62A are provided on the wall surface 65A of the cover-shaped member 63A. Are fitted and latched in two slot-like small holes 64A provided on the corresponding wall surface (one end wall surface) 46B of the developing housing portion 41 in accordance with the arrangement interval (pitch) P1, thereby forming a cover-shaped member. 63 </ b> A is locked in the receiving portion 46 of the developing housing portion 41. 4C is a cross-sectional view of the fitting latching portion viewed from above the developing housing portion 41. FIG.
[0054]
Here, the total number of toner cartridges 42 used in one new developing unit 4 is set in advance, and when the set number of toner cartridges 42 is used, the developing device 47 provided in the developing housing portion 41 is used. Is reached, and it is determined that the developing unit 4 is in a replacement period.
[0055]
The toner cartridge 42 used last in one developing unit 4 does not have the cover-shaped member 63, and only the toner cartridge 42 is inserted into the developing housing portion 41.
[0056]
In the above description, the toner cartridge 42 and the cover-shaped member 63 are combined. However, FIG. 5A shows a state where the independent toner cartridge 42 and the cover-shaped member 63 are combined together. ) And (b), the individual structure becomes more apparent.
[0057]
That is, FIGS. 5A and 5B show a process in which the toner cartridge 42 is combined with the cover-shaped member 63 before the toner cartridge 2 is inserted into the developing unit 4. As shown in FIG. The toner cartridge 42 may be fitted through the opening 66 of the cover-shaped member 63 by holding the handle portion 61 of the cartridge 42 and integrated as shown in FIGS.
[0058]
FIGS. 6A and 6B show how the claw 62B is locked when the second toner cartridge 42B is inserted. On one end wall surface 46B of the developing housing portion 41, the arrangement interval (pitch) P1 of the claws 62A provided on the wall surface 65A of the outer frame 63A of the toner cartridge 42A to be inserted the first time and the toner cartridge to be inserted the second time. Two pairs of slot-like small holes 64A and 64B are provided in accordance with the arrangement interval (pitch) P2 of the claws 62B provided on the wall surface 65B of the outer frame 63B of 42B (see FIG. 4C).
[0059]
Of these two pairs of slot-like small holes 64A and 64B, the outer small hole pair 64A remains fitted when the first toner cartridge 42A is inserted (FIG. 4 ( c)), the claw 62B is fitted into the inner small hole pair 64B when the second toner cartridge 42B is inserted.
[0060]
The wall surface 65A of the outer frame 63A of the toner cartridge 42A that is inserted the first time matches the arrangement interval (pitch) P2 of the claws 62B provided on the outer frame 63B of the toner cartridge 42B that is inserted the second time. A pair of slot-shaped small holes 64B ′ are provided.
[0061]
Therefore, when the second toner cartridge 42B is inserted, the claw 62B provided on the wall surface 65B of the outer frame 63B of the toner cartridge 42B is connected to the slot-like small hole 64B on the one end wall surface 46B of the developing housing portion 41, To be fitted through a slot-like small hole 64B ′ provided on one side wall surface 65A of the outer frame 63A (that is, the claw 62B is fitted through two wall surfaces which are overlapped in close contact with each other). (See FIG. 6B), the tip of the hook-shaped claw 62B is hooked on one end wall surface 46B, and the outer frame 63B is locked.
[0062]
Therefore, even if the outer frame 63A is inserted in a state associated with the first toner cartridge 42A and is retained by being locked to the one end wall surface 46B of the developing housing portion 41 as the toner cartridge 42A is removed. The wall surface 65A of the outer frame 63A does not hinder the insertion operation of the second toner cartridge 42B. In the third toner cartridge 42C, only the toner cartridge main body (having the same shape as the second toner cartridge main body) is inserted without the outer frame 63.
[0063]
If the order of the cartridges to be inserted into the developing housing 41 is incorrect, the cartridges are not properly positioned in the receiving portion 46, so that there is a problem that the toner cannot be properly supplied (the first toner cartridge 42A has a problem). Since it can be shipped in a state where it is mounted on the developing housing, this mounting order is unlikely to be erroneous).
[0064]
However, when the second toner cartridge 42B is to be mounted, if the third toner cartridge 42C is mounted, it is mounted along with the first toner cartridge 42A and retained in the developing housing 41. Since the cross-sectional shape of the third toner cartridge 42C is too small with respect to the cross-sectional shape of the outer frame 63A, excessive backlash occurs, and the operator recognizes that the cartridge mounting order is incorrect at this point. It will be.
[0065]
In the above description, the arrangement interval P1 of the claws 62A provided on the wall surface 65A of the outer frame 63A associated with the toner cartridge 42A inserted the first time and the outer frame 63B associated with the toner cartridge 42B inserted the second time. With respect to the arrangement interval P2 of the claws 62B provided on the wall surface 65B, the opposed spaces (pitch) in the horizontal direction of the pairs of claws are made different, and small holes 64A and 64B on the wall surface of the developing housing are provided in accordance with the opposed spaces. However, it can also be dealt with by making the magnitude relationship between the arrangement intervals P1 and P2 opposite to that in the above description.
[0066]
Further, in addition to the method of changing the facing interval of the claws 62, as different embodiments, the attachment positions in the height direction of the claws 62A on the wall surface 65A of the outer frame 63A and the wall surfaces 65A of the outer frame 63B are different, Correspondingly, small holes 64A and 64B on the wall surface of the developing housing can be provided in accordance with the claw mounting position.
[0067]
See FIGS. 7 and 8 for this case. 7 and 8 are cross-sectional views of the fitting portion viewed from the side of the developing housing portion 41. FIG. For example, regarding the mounting position H in the height direction of the claw 62 with the lower surface of the flange portion 53 of the cartridge 42 as a reference in the height direction, the outer frame 63A of the toner cartridge 42A to be mounted first is set to H1, and the second mounting is performed. The outer frame 63B of the toner cartridge 42B to be used may be set to H2, and a magnitude relationship may be given to H1 and H2.
[0068]
Furthermore, when the above description is combined, it is clear that the arrangement of the claws 62 on the wall surface 65 may be set so that the facing interval (pitch) P and the mounting height H from the reference surface are different at the same time. .
[0069]
[Flow until development unit reaches replacement time]
Next, the flow until the plurality of toner cartridges 42 used in one new developing unit 4 are replaced and the developing unit 4 reaches the replacement time will be described with reference to FIG. FIG. 9A shows the developing housing 41 before the first toner cartridge 42a is mounted, and FIG. 9B shows the toner cartridge before use having a cover-shaped member 63a dedicated to the first toner cartridge. 42a is shown.
[0070]
FIG. 9C shows the developing housing portion 41 before the second toner cartridge 42b is mounted, and FIG. 9D shows the used toner cartridge 42a and the cover shape member 63b dedicated to the second toner cartridge. 2 shows a toner cartridge 42b before use.
[0071]
FIG. 9E shows the developing housing 41 before the third toner cartridge 42c is mounted, and FIG. 9F shows the used toner cartridge 42b and the third toner cartridge 42c before use. . FIG. 9G shows the developing housing portion 41 in which the toner cartridge 42c is mounted.
[0072]
Here, the number of toner cartridges 42 used in one new developing unit 4 is set to three, and when the set number of toner cartridges 42 is used, a developing device provided in the developing housing portion 41 is used. Assume that 47 reaches the end of its life and it is determined that the developing unit 4 is in the replacement period. In this case, for example, one new developing housing part 41 and three unused toner cartridges 42 are shipped as one set.
[0073]
The first toner cartridge 42a and the second toner cartridge 42b have a cover-shaped member 63a and a cover-shaped member 63b, respectively, when they are not used, that is, before being attached to the developing housing portion 41. On the other hand, the third toner cartridge 42c that is finally attached to the developing housing portion 41 does not have the cover-shaped member 63 even when it is not used.
[0074]
Here, the widths of the upper surfaces of the cover-shaped member 63a provided on the toner cartridge 42a, the cover-shaped member 63b provided on the toner cartridge 42b, and the toner cartridge 42c are set to W0, W1, and W2, respectively. Assuming that the widths of the lower surfaces of H0, H1, and H2 are B0, B1, and B2, the respective cross-sectional shapes are formed to have the following relationship.
[0075]
W0> W1> W2, H0> H1> H2, B0> B1> B2
That is, the cross-sectional shape of the cover-shaped member 63a provided in the toner cartridge 42a is maximized, and thereafter, the cross-sectional shape is gradually reduced.
[0076]
Further, the cross-sectional shape of the cover-shaped member 63a is the cross-sectional shape of the receiving portion 46 and the insertion opening 45 in the new developing housing portion 41 in which the toner cartridge 42 has never been mounted (hereinafter simply referred to as the cross-sectional shape of the receiving portion 46). The cover-shaped member 63a is formed so as to substantially coincide with the description. Strictly speaking, however, the cross-sectional shape of the receiving portion 46 is set to be slightly larger and the cross-sectional shape of the cover-shaped member 63a is set to be slightly smaller in order to smoothly perform the fitting operation between them.
[0077]
Accordingly, only the toner cartridge 42a having the cover-shaped member 63a can be attached to the new developing housing portion 41. That is, the other toner cartridges are too small in cross-sectional shape, so that proper positioning within the developing housing portion 41 cannot be performed. Accordingly, it is recognized that the backlash of the toner cartridge with respect to the developing housing portion is excessive, and it is possible to prevent the operator from mounting the toner cartridge out of the normal mounting order by mistake.
[0078]
When the unused toner cartridge 42a is attached to the developing housing portion 41 and pushed into a predetermined position, the cover-shaped member 63a is locked by the claw 62. When all of the toner filled in the toner cartridge 42a is consumed during the image forming operation, for example, the display unit provided in the image forming apparatus 14 displays that the toner cartridge 42b is replaced with the next unused toner cartridge 42b. Instruct the operator.
[0079]
In order to replace the toner cartridge 42a with the toner cartridge 42b, first, the used toner cartridge 42a is removed from the developing housing 41. Here, since the cover-shaped member 63 a is in the locked state with the developing housing portion 41, it remains in the developing housing portion 41. As a result, the cross-sectional shape of the receiving portion 46 is reduced by an amount corresponding to the thickness of the cover-shaped member 63a than the cross-sectional shape of the receiving portion 46 before the toner cartridge 42a is mounted.
[0080]
Next, the second toner cartridge 42 b is inserted into the developing housing portion 41. Here, the cross-sectional shape of the cover-shaped member 63b that covers the toner cartridge 42b containing the toner, and the reception in a state where the toner cartridge 42a is removed from the developing housing portion 41 and the cover-shaped member 63a remains in the developing housing portion 41. The cover-shaped member 63b is formed so as to substantially match the cross-sectional shape of the portion 46. As a result, the toner cartridge 42 b is fitted into the developing housing portion 41. Strictly speaking, the cross-sectional area of the receiving portion 46 is set to be slightly large and the cross-sectional shape of the cover-shaped member 63b is set to be slightly small in order to smoothly fit the two.
[0081]
The used toner cartridge 42a can also be attached to the developing housing 41 at this point, but can be easily recognized as a used toner cartridge. That is, even if the used toner cartridge 42a is mounted, for example, the display unit provided in the image forming apparatus 14 is output as an error message or instructed to replace the toner cartridge.
[0082]
On the other hand, since the unused third toner cartridge 42c has a smaller cross-sectional shape than the toner cartridge 42b, it cannot be attached to the developing housing portion 41 at this point (dimensionally passing through the opening). Although it is possible, proper positioning of the cartridge in the developing housing portion 41 cannot be performed).
[0083]
When the unused toner cartridge 42b is pushed into a predetermined position of the receiving portion 46, the cover-shaped member 63b is locked by the claw 62, and the toner cartridge 42b is attached to the developing housing portion 41. The claw 62 of the cover-shaped member 63b is narrower than the mounting interval (pitch) of the claw 62 of the cover-shaped member 63a, and the mounting position is set closer to the center of the toner cartridge 42b. Slot-shaped small holes provided on the end wall surface of the developing unit with which the claw 62 of the cover-shaped member 63b is fitted are also provided so as to match the mounting interval of the claw 62 of the cover-shaped member 63b.
[0084]
When all of the toner filled in the toner cartridge 42b is consumed during the image forming operation, for example, the display unit provided in the image forming apparatus 14 displays that the toner cartridge 42c should be replaced with the next unused toner cartridge 42c. Instruct the operator.
[0085]
In order to replace the toner cartridge 42b with the toner cartridge 42c, first, the used toner cartridge 42b is removed from the developing housing 41. Here, the cover-shaped member 63 b remains in the developing housing portion 41 because it is locked to the developing housing portion 41. As a result, the cross-sectional shape of the receiving portion 46 is reduced by an amount corresponding to the thickness of the cover-shaped member 63b than the cross-sectional shape of the receiving portion 46 before the toner cartridge 42b is mounted.
[0086]
Next, the third toner cartridge 42 c is inserted into the developing housing portion 41. The third toner cartridge 42c does not have the cover-shaped member 63 like the toner cartridges 42a and 42b, but the cross-sectional shape of the toner cartridge 42c and the toner cartridge 42b are removed from the developing housing portion 41, The toner cartridge 42c is formed so as to substantially match the cross-sectional shape of the receiving portion 46 in a state where the cover-shaped member 63b remains in the developing housing portion 41.
[0087]
As a result, the toner cartridge 42 c is fitted into the developing housing portion 41. Strictly speaking, the cross-sectional area of the receiving portion 46 is set to be slightly large and the cross-sectional shape of the cover-shaped member 63b is set to be slightly small in order to smoothly fit the two.
[0088]
On the other hand, the used toner cartridge 42b can be attached to the developing housing 41 at this point, but can be easily recognized as a used toner cartridge. That is, even if the used toner cartridge 42b is mounted, for example, the display unit provided in the image forming apparatus 14 is output as an error message or instructed to replace the toner cartridge.
[0089]
When the unused toner cartridge 42 c is pushed to a predetermined position of the receiving portion 46, the toner cartridge 42 b is mounted on the developing housing portion 41. The toner cartridge 42c is configured such that the cover-shaped member 63b is removed from the toner cartridge 42b in order to be attached to the developing housing portion 41.
[0090]
When all of the toner filled in the toner cartridge 42c is consumed during the image forming operation, the operator replaces the next unused developing unit 4 with the display means provided in the image forming apparatus 14, for example. To instruct.
[0091]
If one new developing housing portion 41 and three unused toner cartridges 42 are set as one set as described above, the toner cartridge 42 is replaced and attached three times, and the third toner cartridge 42 is attached. When it is exhausted, the operator can recognize that the developing device 47 provided in the developing housing portion 41 in use has reached the end of its life, and by using the developing unit 4 beyond the life limit of the developing device 47. It is possible to prevent the occurrence of defects.
[0092]
[First Embodiment]
In the toner hopper (not shown), new toner for replenishing toner in the developing tank is replenished in advance via the toner cartridge 42, and this toner is replenished to the developing tank when necessary. Although not shown in the drawing, the toner concentration sensor is disposed at an appropriate position on the bottom surface of the developing tank and the toner concentration sensor detects that the toner concentration is insufficient. That is, a toner supply roller (not shown) is rotated, and the toner attracted and held by the toner supply roller is supplied into the developing tank.
[0093]
In the present embodiment, when the image forming apparatus 14 is newly arranged, when the developing apparatus is newly replaced, or when the developer in the developing tank of the developing apparatus is replaced with a new developer, the developing apparatus is used. In the developer used in the initial development, for example, in the two-component developer, the initial toner and the initial toner in the toner hopper are lost, and the replenishment toner for the additional replenishment uses a new toner as an external additive. Different amounts or materials of external additives are used. That is, for example, the external additive is different between the initial toner and the replenishment toner that is newly replenished after the initial toner is lost.
[0094]
Thus, in the image forming apparatus 14, the initial toner when the electrostatic latent image on the photosensitive drum 1 is first developed by the developing device is filled in the toner hopper through the toner cartridge 42, and the initial toner is used as the initial toner. As the development proceeds, the initial toner in the toner hopper is gradually reduced. When the amount of toner in the toner hopper is below a predetermined amount, the image forming apparatus 14 informs the user or the like to newly fill the toner. As a result, the user replenishes the toner hopper with new toner.
[0095]
The replenishment toner at this time differs in the amount and material of the external additive added to the initial toner. That is, an external additive is added to the toner in order to improve fluidity and chargeability. For example, if the amount of the external additive of the new toner to be replenished to the toner hopper is made larger than the amount of the external additive of the initial toner, the toner is introduced into the developing device 47 at the start of use of the image forming apparatus 14. Even when the developer is stressed, the external additive is sufficiently added, so that it is possible to suppress the deterioration of the image quality due to the decrease in fluidity and chargeability.
[0096]
Further, the materials of the external additive for the new toner and the replenishing toner may be different. For example, by adding an external additive of a different material that is not externally added to the external toner to the replenishing toner, the external additive can be sufficiently added to prevent deterioration of chargeability and fluidity. Thereby, it is possible to prevent the deterioration of the image quality.
[0097]
Examples of the external additive externally added to the toner include silica, titanium oxide, zinc oxide and the like that improve the fluidity of the toner and prevent toner aggregation. Examples of the external additive that affects the charging performance include imidazole dielectrics and hydrosartite compounds.
[0098]
Examples of the external additive include magnetite as a material that affects the polishing of the surface of the photosensitive drum 1. By adding such an external additive to the toner, in order to eliminate image quality deterioration, particularly image blurring, etc., when the toner adheres to the surface of the photosensitive drum 1 or is oxidized, the photosensitive drum 1 The surface is polished.
[0099]
Accordingly, when silica is added as an external additive for the initial toner, the amount of silica may be increased, or zinc oxide or hydrosulitic compounds may be added in addition to silica. . Such external additives may be used singly or in combination, and the addition amount may be set as necessary.
[0100]
Hereinafter, the operations and effects of the present embodiment will be described more specifically through examples.
Example 1
The composition of the toner before adding the external additive to the developer contained in the developing tank of the developing device is 90 parts by weight of polystyrene as the binder resin, 5 parts by weight of carbon black as the colorant, and charge control. 2 parts by weight of the agent and 3 parts by weight of polyethylene wax as an anti-blocking agent are mixed thoroughly with a mixer, and the mixture is kneaded with a screw extruder under heating. The kneaded product was coarsely pulverized after cooling, the coarsely pulverized product was finely pulverized with a jet pulverizer, and the finely pulverized product was classified to obtain a toner before external addition having an average particle size of about 9 μm.
[0101]
The binder resin that is a composition constituting the toner is not limited to the above-mentioned ones, but styrene copolymers such as styrene / butadiene copolymer and styrene / acrylic copolymer, polyethylene, polyethylene vinyl acetate copolymer, An ethylene polymer such as a polyethylene vinyl alcohol copolymer, a phenol resin, an epoxy resin, an allyl phthalate resin, a polyamide resin, a polyester resin, and a maleic acid resin can be used.
[0102]
In addition to carbon black, as a colorant, for example, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine yellow, methylene blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green, oxalate, Lamp black, rose belgar, and mixtures thereof can be used.
[0103]
Further, as the charge control agent, amino compounds, quaternary ammonium compounds and organic dyes, particularly basic dyes and salts thereof are known, such as benzyldimethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, nigrosine base Nigrosine hydrochloride, safranin, crystal violet, and the like can be used.
[0104]
In addition to polyethylene wax, polypropylene wax, paraffin wax, and the like can be used as the anti-adhesive agent, which works extremely effectively for improving the releasability of the toner from the fixing device (fixing roller). On the other hand, various external additives shown in Table 1 below were agitated and mixed in the toner manufactured as described above with a mixer, and external addition processing was performed. The amount of the external additive indicates a ratio with respect to 100 parts by weight of the toner before the external addition.
[0105]
[Table 1]

[0106]
In Table 1, as an initial toner subjected to external addition processing, No. No. 1 toner is used. No. 1 is a replenishing toner that is replenished after consumption of No. 1. 2-No. A total of 40,000 sheets were developed in an accelerated test using 6 toners.
[0107]
The developed toner image was transferred to a sheet of paper, and the result of confirming the image state after fixing was shown in Table 2 below. Here, for comparison, the toner No. No. 1 is the initial toner, and the replenishment toner is the same No. as the initial toner. The results for the case of using 1 toner are also shown.
[0108]
[Table 2]

[0109]
In Table 2, the image fog was measured by measuring the density of a sheet before copying and the discharged sheet with a whiteness meter by copying a white sheet in white, and evaluating the difference between the measured values. That is, as the numerical value increases, the image fog increases. The toner scattering is the amount of toner accumulated in the lower part of the developing device. Further, regarding the image blur, a line image was formed and visually evaluated. At this time, for copying, a test chart having a white portion and a line portion was easily formed to form an image.
[0110]
As can be understood from Table 2, the toner No. As a replenishing toner instead of No. 1, 2-No. When toner No. 6 was used, image fogging could be reduced and toner scattering could be reduced. Therefore, as in the case of the initial toner (No. 1) and the replenishing toner (No. 2), by increasing the amount of the external additive, particularly the amount of silica, it is possible to achieve good stability without causing image fog and image quality deterioration. It can be seen that an image of the same quality can be obtained.
[0111]
Further, by changing the material of the external additive such as the initial toner (toner No. 1) and the replenishing toner (toner No. 3 to 6), that is, the external additive different from the external additive of the initial toner is used. The effect similar to that of quantitative adjustment was also obtained by further adding the agent.
[0112]
On the other hand, if the same amount and the same material as the external additive of the initial toner are used as in the case of the initial toner (No. 1) and the replenishment toner (No. 1), the image fog increases. The amount of toner scattering also increases. Then, image blur occurs and stable image quality cannot be obtained.
[0113]
Fluidity deteriorates due to missing or buried external additives that affect the fluidity of the toner surface. In particular, the two-component developer is used continuously, and the toner concentration is measured using a magnetic permeability sensor for toner concentration detection. When the control is performed, the toner density increases, causing image fogging and toner scattering, and the results shown in Table 2 are obtained.
[0114]
On the other hand, the amount of silica as the external additive of the replenishing toner is made larger than that of the initial toner to compensate for the decrease in fluidity. As shown in FIG. 2, image fogging was prevented and the image quality was stabilized. In addition, toner No. 1 was prepared by using the same amount of silica and magnetite as external additives, and separately adding titanium oxide, zinc oxide or the like to the external additives. The same effect can be obtained when 3 and 4 are used as replenishing toners.
[0115]
In addition, as an external additive that affects the chargeability of the toner, Toner No. containing imidazole dielectric and alkamizer separately added. This was particularly effective when 5 or 6 was used as a replenishing toner.
[0116]
On the other hand, in order to maintain good image quality, magnetite is often used as an external additive to be added to the toner for the purpose of polishing the surface of the photosensitive drum 1 to always maintain a good state. By adding this external additive, it is possible to compensate for a reduction in the polishing effect of the photosensitive drum 1 and to maintain a good image quality state.
[0117]
In particular, on the photosensitive drum 1, magnetite is used as an external additive in order to remove nitrogen oxides generated in the charger 2, the transfer charger 10, and the like and remove them. Magnetite maintains the polishing effect of the photosensitive drum 1, thereby preventing deterioration of image quality, particularly image blurring, and maintaining a good image quality state free from image blurring. In particular, as the photosensitive drum 1, the effect becomes remarkable in the OPC photosensitive member.
[0118]
As described above, the toner No. to be filled in the toner cartridges 42A to 42C. As an example of the combination, the settings shown in Table 3 are possible.
[0119]
[Table 3]

[0120]
[Second Embodiment]
In the present embodiment, the initial toner and the replenishment toner are different from each other, and the fixing property is stabilized to prevent the deterioration of the image quality. That is, the material that affects the fixing property is made different between the initial toner and the replenishing toner so as to maintain a good image quality state.
[0121]
Fixing properties deteriorate due to stress received by the toner in the developer, and an offset phenomenon occurs in which the toner adheres to the fixing roller (heat roller or the like) of the fixing unit 13 and is transferred to a sheet, thereby degrading the image quality. is there. In addition, the fixability is deteriorated, the image after fixing is peeled off, the image is disturbed, and the user's hand may be soiled. That is, the toner in the developer is subjected to various stresses, and the loss of external additives and the amount of fine powder toner increase. As a result, the fixing strength and fixing offset on the sheet are generated, and the image on the sheet surface, that is, the toner image is easily peeled off.
[0122]
In order to solve such a problem, in the present embodiment, the initial toner filled in the toner hopper portion is eliminated, and the replenishment toner newly replenished improves the fixability and does not cause a fixing offset. A toner having Therefore, as the replenishing toner, a toner in which the glass transition point and the toner melt viscosity are shifted in the direction of improving the fixing strength is used. Thereby, when finely pulverized toner is contributed to conveyance and supply to the developing unit, it is possible to prevent deterioration of image quality due to poor fixability and the like.
[0123]
As a method of changing the glass transition point of the toner, there is a method of changing the molecular weight distribution of the binder resin or the like constituting the toner. For example, by lowering the molecular weight of one binder resin having a composition constituting the toner, the glass transition point is lowered and the melting temperature is lowered, so that the fixing strength to the paper is increased. Therefore, it is only necessary to select a binder resin having a different molecular weight between the initial toner and the replenishing toner and use it.
[0124]
In addition, as a method of changing the molecular weight, not only those having different molecular weights are selected in advance, but also easily in the process of producing the toner. For example, in the kneading process when the toner is manufactured, the conditions may be changed. For example, the temperature, the extrusion speed, etc. may be changed. That is, by kneading in a state where stress is applied to the material by lowering the kneading temperature, the molecules are cut and the molecular weight shifts to a low state.
[0125]
Further, in order to suppress the phenomenon of fixing offset such that the toner adheres to the fixing roller or the like constituting the fixing unit 13 and is retransferred to the paper, the amount of the wax as an anti-adhesive agent may be changed. That is, if the amount of the replenishing toner wax is increased with respect to the initial toner, even when the recycled toner is collected as the fine powder toner, the adhesion of the toner to the fixing roller can be suppressed and the deterioration of the image quality due to the fixing offset can be prevented.
[0126]
As described above, the glass transition point and the toner melt viscosity are shifted in the direction of improving the fixing strength between the initial toner and the replenishing toner. That is, the glass transition temperature of the replenishing toner is set lower than the glass transition temperature of the initial toner. Also, by changing the molecular weight, the toner melt viscosity is shifted in the direction of improving the fixing strength, and the fixing strength is improved.
[0127]
Hereinafter, the operations and effects of the present embodiment will be described more specifically through examples.
(Example 2)
As the developer to be used, a two-component developer was used as in (Example 1), and an electrophotographic system was used as the image forming apparatus. The toner composition is 90 parts by weight of polystyrene as a binder resin, 5 parts by weight of carbon black as a colorant, 2 parts by weight of a charge control agent, and 3 parts by weight of polyethylene wax as an anti-adhesive agent. The mixture was sufficiently stirred and mixed with a mixer, and the mixture was kneaded with a screw extruder under heating. Then, the finely pulverized product was classified to produce a toner before external addition having an average particle size of about 9 μm.
[0128]
The external additive of 0.3 parts by weight of silica and 0.2 parts by weight of magnetite was stirred and mixed with a mixer with respect to 100 parts by weight of the toner before external addition thus obtained, and subjected to external addition treatment. Further, the physical properties of the toner used and the amount of wax as an anti-adhesive agent are shown in Table 4 below. In this case, various molecular weights of polyethylene as a binder resin constituting the toner were selected and used.
[0129]
Here, toner No. 8 (A) and toner no. 9 (B) has a different molecular weight distribution which is a binder resin. That is, the toner No. The number average molecular weight (Mn) of the molecular weight of 9 (B) was lowered, and thus the temperature of the glass transition point was set low. In addition, toner No. The weight average molecular weight (Mw) of the distribution amount of the binder resin 10 (C) is increased, and toner No. 11 (D), the amount of washes constituting No. 11 (D). More than the wax amount of the toner of 10 (C).
[0130]
[Table 4]

[0131]
In Table 4, the toner No. 8 (A) is used as the initial toner, and after the initial toner runs out, the toner to be replenished is toner No. The same toner of No. 8 (A) was used as a comparative example. Table 5 below shows the results of performing 40,000 image formation, particularly development (copying) in an accelerated test using the toners 9 (B) to 11 (D) as replenishing toners.
[0132]
[Table 5]

[0133]
In Table 5, the fouling of the fixing roller was evaluated by the difference between the measured values of the whiteness meter before and after passing the white paper through the fixing roller. In this case, in the image formation, the image formation was performed using a white portion and a test chart with characters and other images. Here, it can be seen that the larger the numerical value, the more dirty the fixing roller.
[0134]
From the results shown in Table 5, the fixing roller has toner No. When the toner A was used as the initial toner and the replenished toner after the initial toner was used up, the toner became extremely dirty. In this regard, when the initial toner and the replenishment toner are different from each other (toner Nos. B to D), the fouling of the fixing roller is reduced. As shown in D, it has been found that using a toner with a large amount of wax as a replenishing toner can significantly reduce the fouling of the fixing roller.
[0135]
Further, as a result of confirming the fixing performance, in particular, the initial toner is the toner No. The replenishing toner to be replenished thereafter is designated as toner No. A (REF). In the case of the comparative example indicated by A (REF) (indicated by the alternate long and short dash line), toner no. No. 9 (B) is used (indicated by a solid line), and toner No. FIG. 10 shows the case where the toner of 10 (C) is used (indicated by a dotted line).
[0136]
In FIG. 10, in order to confirm the fixing strength, the portion where the halftone image was formed was evaluated by the ratio between the density after rubbing with an eraser and the density before rubbing. The concentration at this time was measured with a Macbeth densitometer. In the figure, the higher the numerical value on the ordinate, the better the fixing strength, with no difference in density (ID) before and after rubbing with an eraser.
[0137]
As can be seen from the figure, since the fixing strength is set so that the molecular weights of the binder resin of the initial toner and the replenishment toner are different, the deterioration of image quality due to fixing failure or the like is also eliminated. That is, by making the initial toner different from the replenishing toner, the fouling of the fixing roller can be reduced, and the deterioration of the image quality due to the fixing offset can be prevented. At this time, it is possible to avoid deterioration of image quality by making the wax amount of the initial toner and the replenishment toner different and increasing the amount of wax of the replenishment toner.
[0138]
Here, the toner No. shown in Table 4 from the initial state. If toners such as B, C, and D are used, problems arise in fixing in the initial state. That is, in the initial stage, toner that has not been subjected to the initial stress adheres to the fixing roller, thereby causing an offset phenomenon and fouling of the fixing roller.
[0139]
Therefore, by using the initial toner and the replenishing toner separately as shown in Table 5, it is possible to obtain a good result that can be confirmed in the same table and FIG. From the above, the toner Nos. To be filled in the toner cartridges 42A to 42C. As a preferred example of the combination, the settings shown in Table 6 below can be made.
[0140]
[Table 6]

[0141]
The present invention does not limit the image forming apparatus to the configuration shown in FIG. 1, but a case-like member such as a replaceable toner cartridge filled with consumables such as toner, and the case-like member. If the image forming apparatus has a receiving unit for detachably mounting the image forming apparatus, and includes an apparatus unit in which a lifetime or operating period longer than that of the housing-like member is set, the configuration and type of the image forming apparatus The present invention can be applied regardless of the case.
[0142]
In the present embodiment, the developing unit is described as an apparatus unit. However, the present invention is not limited to this, and at least the replaceable casing-shaped member filled with consumables, If it is a device unit having a receiving part for detachably mounting the housing-like member, and having a longer service life or operation period than the housing-like member, its function and purpose, The present invention can be applied regardless of the configuration, form, and the like.
[0143]
【The invention's effect】
As is clear from the above description, the present invention has the following effects.
[0144]
(1) Each time the housing-like member that is detachably attached to the receiving portion of the apparatus unit is removed, the receiving portion has a consumable characteristic different from that of the consumables filled in the housing-like member. Since the case-like member filled with the product is mounted, one device unit and a plurality of case-like members can be handled as one set.
[0145]
Therefore, in the manufacturing stage, the casing-like member filled with consumables having different characteristics conforming to the grade of the deterioration of the performance of the casing-like member that progresses through the use stage in advance is stepwise. Prepared and provided to the user as a set together with the device unit, so that when the user needs to replace the housing-like member, it can be replaced with a suitable housing-like member as appropriate. Therefore, the performance of the device unit can be maintained at a predetermined level.
[0146]
Since the replacement operation is only the attachment / detachment / replacement operation of the housing-like member to the receiving portion, no special operation or skill is required, and maintenance can be easily performed on the user side. A high operating rate of mounting can be maintained without causing dead time in the provided image forming apparatus.
[0147]
(2) Each time the toner cartridge detachably attached to the receiving portion of the developing unit is removed, the receiving portion has a toner having different characteristics suitable for performance deterioration of the developer held in the developing unit. Since the toner cartridge filled with is mounted, one developing unit and a plurality of toner cartridges can be handled as one set.
[0148]
Therefore, in the manufacturing stage, depending on the degree of deterioration in the developer performance that progresses through the use stage, a plurality of toner cartridges filled with toners having characteristics suitable for this are prepared in stages. By providing it to the user as a set together with the developing unit, when the user needs to replace the toner cartridge, it is possible to replace the developing unit with a toner cartridge that incorporates suitable toner characteristics. The performance can be maintained at a predetermined level.
[0149]
Since the replacement operation is only an operation for attaching and detaching the toner cartridge to the receiving portion, a special operation and skill are not required, and maintenance can be easily performed on the user side. A high operating rate of mounting can be maintained without causing dead time in the image forming apparatus.
[0150]
Developers, especially toners, can be dealt with by changing the amount and type of external additives to maintain the fluidity, chargeability and other characteristics without changing the composition itself. Without increasing the cost of the agent, the image quality state can be maintained at the same level as the initial use state even in durable use.
[0151]
(3) Each time the toner cartridge attached to the receiving portion of the developing unit is removed, the shape of the receiving portion is updated, and a toner cartridge filled with toner having different characteristics is stored in the receiving portion. Since it is mounted, one developing unit and a plurality of toner cartridges can be handled as one set. Therefore, in the manufacturing stage, it has a shape that conforms to the receiving portion that is updated step by step in accordance with the degree of deterioration in the performance of the developer that progresses through the use stage. By preparing multiple toner cartridges filled with toners with different characteristics and providing them to the user as a set with the development unit, the user installs them when the toner cartridge needs to be replaced. The performance of the developing unit can be maintained at a predetermined level by removing the used toner cartridge and appropriately replacing it with a toner cartridge having a shape adapted to the updated receiving portion.
[0152]
Since the replacement operation is only the operation of attaching and detaching the toner cartridge to and from the receiving portion, no special operation or skill is required, and maintenance can be easily performed on the user side. High operating rate can be maintained without generating
[0153]
Developers, especially toners, can be dealt with by changing the amount and type of external additives to maintain the properties such as fluidity and chargeability without changing the composition itself. Further, the cost of the developer is not increased, and the image quality state can be maintained at the same level as the initial use state even in durable use.
[0154]
(4) Since the receiving portion is reduced every time the toner cartridge is replaced, the toner cartridge to be mounted first is formed larger than the toner cartridge to be mounted later, so that the toner cartridge can be installed based on a predetermined order of use. Unused toner cartridges can be installed without fail.
[0155]
(5) When removing the used toner cartridge from the developing unit, the first member is separated from the used toner cartridge and remains on the developing unit side, and the shape of the receiving portion, or the receiving portion and the receiving portion The cross-sectional shape of the insertion opening for inserting the unused toner cartridge into the part is updated, and only the unused toner cartridge that can be fitted into these shapes is mounted. Based on this, an unused toner cartridge can be definitely installed.
[0156]
(6) The first member is locked to the developing unit side, and when the used toner cartridge is removed from the developing unit, the first member is separated from the used toner cartridge and remains on the developing unit side. With this configuration, unused toner cartridges can be definitely mounted based on a predetermined order of use.
[0157]
(7) Each time the used toner cartridge is removed from the developing unit, the shape of the receiving portion or the cross-sectional shape of the receiving portion and the insertion opening is updated, and an unused toner cartridge that can be fitted into these shapes is installed. With a simple configuration to be mounted, it is possible to reliably mount an unused toner cartridge based on a predetermined order of use.
[0158]
In addition, for example, by setting that one developing unit reaches the end of its useful life when a plurality of toner cartridges each having a different shape is replaced, it is possible to ensure that the developing unit is not misused beyond the usage limit. Can be prevented. Further, it is possible to prevent the occurrence of a trouble that erroneously recognizes the remaining life of the developing unit by mistakenly inserting the toner cartridges.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view of a developing unit as the apparatus unit.
FIG. 3 is a perspective view and a sectional view of the toner cartridge.
FIG. 4 is a perspective view and a cross-sectional view of a main part of a toner cartridge integrated with the first member.
FIG. 5 is an explanatory diagram of a process of combining a toner cartridge with the first member.
FIG. 6 is an explanatory diagram when the toner cartridge is inserted.
FIG. 7 is a cross-sectional view of a main part of the different toner cartridge.
FIG. 8 is an explanatory diagram when the toner cartridge is inserted.
FIG. 9 is an explanatory diagram of a flow until the development unit replacement time is reached.
FIG. 10 is an explanatory diagram showing the fixing strength in the embodiment in comparison with a comparative example.
[Explanation of symbols]
4-Device unit, development unit
42-Housing member, toner cartridge
46-Receptor
61-first member

Claims (6)

A loading / unloading structure for loading and unloading a plurality of toner cartridges in a predetermined order in a receiving space formed in the developing unit, wherein a first locking hole and a second lock are formed on a side surface on the far side in the loading direction of the receiving space. A blind hole,
A first handle provided on a first surface intersecting a loading direction on the near side of the loading direction, a first main body portion filled with a first toner;
It is formed so that it can be inserted in the receiving space, and is detachably attached to the first main body portion, and the first surface on a second surface that intersects the loading direction on the back side of the loading direction in the first main body portion. A first housing provided with a first locking portion that engages with the locking hole and a second through hole formed at a position facing the second locking hole;
A first toner cartridge having
A second handle provided on a surface corresponding to the first surface, and a second main body portion filled with a second toner;
A second locking portion that penetrates the second through hole and engages with the second locking hole is provided on a surface corresponding to the second surface, and is formed to be insertable into the first housing. A second housing detachably attached to the second body portion;
A second toner cartridge having
Equipped with a,
A plurality of toner cartridge loading / unloading structures in which the second toner cartridge is loaded after the first toner cartridge is loaded into and removed from the receiving space . A third toner cartridge that is formed to be insertable into the second housing and has a third main body filled with the third toner ;
2. The mounting structure of a plurality of toner cartridges according to claim 1, wherein the third toner cartridge is loaded after the second toner cartridge is loaded into and removed from the receiving space . Wherein the second toner includes many external additive than the first toner,
The mounting / removal structure of a plurality of toner cartridges according to claim 1. Wherein the first toner, silica, includes a first external additive containing magnetite, a,
The second toner includes a second external additive further containing any one of titanium oxide, zinc oxide, imidazole, alkamidizer, and a hydrosartite compound.
The mounting / removal structure of a plurality of toner cartridges according to any one of claims 1 to 3. A developing unit capable of loading a plurality of toner cartridges in a predetermined order;
A developer unit for agitating the toner, and a housing portion having a plurality of toner cartridge loading / unloading structures according to any one of claims 1 to 4,
When the first toner cartridge loaded in the receiving space is pulled out of the receiving space, the first housing is locked in the receiving space, and when the second toner cartridge is loaded in the receiving space, the receiving space The second casing is inserted into the first casing locked in the space.
Development unit. A paper feed unit for feeding out recording paper;
An image forming unit that has the developing unit according to claim 5 and performs image forming processing on the recording paper;
An image forming apparatus.

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