JP2005004005A - Electrophotographic photoreceptor, image forming apparatus mounted with the same, and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drum-like electrophotographic photoreceptor of a small diameter in which the noise by the friction between itself and a cleaning blade is suppressed. <P>SOLUTION: The electrophotographic photoreceptor is provided with a photoreceptor layer on a cylindrical conductive support of an external diameter ≤65 mm, a thickness 0.3 to 1.2 mm, and length ≥310 mm and is used in the state of bringing its surface in contact with the cleaning blade at all times. A plurality of damping materials are inserted into the support and the damping materials are not present in the positions 45/100 to 55L/100 apart from the ends of the support when the length in the axial direction of the support is defined as L. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（式中、Ｒ_１は炭素数１〜４の低級アルキル基を表わし、Ｒ_２、Ｒ_３は同一又は異なる、置換又は無置換のメチレン基又はエチレン基を表わし、Ａｒ_１、Ａｒ_２は同一又は異なる、置換又は無置換のアリール基を表わす。ｌは０〜４、ｍは０〜２、ｎは０〜２の整数を表わし、ｍ＋ｎは２以上、ｌ＋ｍ＋ｎは６以下の整数である。又、ベンゼン環の未置換部位は水素原子を表わす。）
【００２７】
（１０）感光層がビスベンジルベンゼン誘導体を０．５〜７重量％含有していることを特徴とする前記（１）〜（９）のいずれかに記載の電子写真感光体。
【００２８】
（１１）電子写真感光体とクリーニングブレードが常時接触した状態の画像形成装置において、該電子写真感光体として前記（１）〜（１０）のいずれかに記載の電子写真感光体を搭載したことを特徴とする画像形成装置。
【００２９】
（１２）電子写真感光体を回転させながら画像形成を行った後、感光体が回転を停止する過程で該感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．２秒以上３．５秒以下であることを特徴とする前記（１１）記載の画像形成装置。
【００３０】
（１３）画像形成中における電子写真感光体表面の軸方向中央の位置で測定したときの最高到達温度が３８〜５３℃であることを特徴とする前記（１１）又は（１２）記載の画像形成装置。
【００３１】
（１４）電子写真感光体と、帯電手段、露光手段、現像手段、転写手段の少なくとも１つとを具備した画像形成装置用プロセスカートリッジにおいて、該電子写真感光体が前記（１）〜（９）のいずれかに記載の電子写真感光体であることを特徴とする画像形成装置用プロセスカートリッジ。
【００３２】
【発明の実施の形態】
以下本発明をさらに詳細に説明する。
本発明の感光体に用いる円筒型支持体の外径は６５ｍｍ以下、より好ましくは５０ｍｍ以下、さらに好ましくは２０〜４０ｍｍである。感光体の円筒型支持体の外径が６５ｍｍを超える大型の画像形成装置の場合には、感光体とクリーニングブレードとの摩擦による騒音が非常に小さいため、問題になることは少なく、本発明のような形態をとる必要がない。
【００３３】
本発明の感光体に用いる円筒型支持体の厚みは０．３〜１．２ｍｍ、好ましくは０．４〜１．０ｍｍである。円筒型支持体の厚みが０．３ｍｍ未満では感光体の機械的強度が十分でなく、実際に使用する場合には、感光体内部にバックアップローラー等の配置が必要となる。また、円筒型支持体の厚みが１．２ｍｍを超えると感光体の重量が重く、経済的にも不利であると共に、感光体とクリーニングブレードとの摩擦による騒音が非常に小さく、本発明のような形態をとる必要がない。
【００３４】
本発明の感光体に用いる円筒型支持体の長さは３１０ｍｍ以上、好ましくは３２０ｍｍ以上、さらに好ましくは３３０〜３９０ｍｍである。感光体の円筒型支持体の長さが３１０ｍｍ以下では、感光体の歳差運動の力が大きくないため、感光体とクリーニングブレードとの摩擦による騒音が非常に小さく、本発明のような形態をとる必要がない。
【００３５】
本発明における感光体の円筒型支持体の内部に挿入される制振材は、▲１▼図１及び図２の感光体断面図に示されるような、円筒型支持体９０の長手方向中心に存在させないで配置される複数の制振材１１からなるもの、▲２▼図３及び図４に示されるような、円筒型支持体９０の長手方向中心には接触しないで配置される単一の制振材２１又は２２からなるもの、あるいは▲３▼図５及び図６に示されるような、円筒型支持体９０の長手方向中心は接触しないで配置される複数の制振材３１又は３２からなるものである。
【００３６】
上記▲１▼の制振材１１について説明する。
ここでの制振材１１は複数個が使用される。円筒型支持体９０に挿入される制振材１１が１本では、騒音を防止するためその長さを長くしなければならず、制振材の挿入が難しく、また、円筒型支持体の軸線方向中心に制振材が存在しやすくなり、その結果、感光体ドラムとクリーニングブレードとの摩擦による騒音が発生しやすくなる。更にまた、感光体の軸線方向（長さ方向）の重量のバランスが悪くなりやすいため、感光体の歳差運動が発生すると、その運動の大きさを増幅する方向に働きやすく、ときとして感光体とクリーニングブレードとの摩擦による騒音が発生しやすくなり好ましくない。
【００３７】
挿入する制振材１１の本数としては、感光体の円筒型支持体９０の軸線方向の長さ中心部に制振材１１が存在しなければ、２本以上で良いが、経済的、挿入工程の容易性を考慮すると、２〜４本の範囲が特に好ましい。
なお以降、特に断らない限り、“円筒型支持体の長さ”とは円筒型支持体の軸線方向の長さを意味する。
【００３８】
本発明の感光体の円筒型支持体内部に制振材１１が存在してはならない領域は、円筒型支持体の軸線方向の長さをＬとしたとき、その支持体端部から４５Ｌ／１００〜５５Ｌ／１００離れたところ、好ましくは４３Ｌ／１００〜５７Ｌ／１００離れたところ、さらに好ましくは４０Ｌ／１００〜６０Ｌ／１００離れたところ、表現を変えて言えば、感光体の円筒型支持体の長さを１００％としたとき、支持体端部（一方の端部で０％となる位置）から４５〜５５％、好ましくは４３〜５７％、さらに好ましくは４０〜６０％位置に支持体内部に挿入した制振材１１が存在してはならない。支持体端部から４５〜５５％の位置に挿入物が存在すると、感光体とクリーニングブレードとの摩擦による騒音を防止することができない。
【００３９】
制振材１１の形状としては、感光体の円筒型支持体内部への挿入が容易で、支持体内壁との密着性が高いものであればどのような形状であっても良いが、特に断面がＣ字状であれば、円筒型支持体内部への挿入は容易に行うことができ、円筒型支持体内壁との接触も良く好ましい。制振材１１は円筒型支持体内部の内部空間の断面積よりも小さく圧縮して挿入し、それ自身が持つバネ性や、復元力により密着させても良いが、接着剤を用いて密着性をさらに高めても良い。
【００４０】
制振材１１の長さとしては、円筒型支持体の長さの１５〜４０％、好ましくは２０〜４２％、さらに好ましくは２５〜４０％である。制振材１１の長さが円筒型支持体の長さの１５％以下では、騒音を防止するための挿入物の数が多数必要となるため、挿入工程が複雑になり好ましくない。制振材１１の長さが円筒型支持体の長さの４０％以上では、制振材１１の挿入における位置精度を高くしないと、感光体の中央部に制振材１１が存在しやすくなるため、感光体とクリーニングブレードとの摩擦による騒音が発生することがあり好ましくない。
【００４１】
次に、上記▲２▼の制振材２１、２２について説明する。
これらの制振材２１、２２はともに或るところから中央部にかけて外径が小さくなっていることで共通しているが、制振材２１は中央部が断面漏斗上に狭まっているのに対して、制振材２２は中央部が断面腕状に狭まっていることの違いだけである。このため、ここでは代表的として制振材２１について説明することにする。
【００４２】
制振材２１は単一のものである。制振材２１は前述のように感光体内部に挿入した際に、感光体の中央部で円筒型支持体内壁と接していない。具体的に円筒型支持体内壁と制振材２１が接しない領域は、先に▲１▼の制振材１１について説明したのと同じである。すなわち、感光体の円筒型支持体の軸線方向の長さを１００％としたとき、支持体端部（一方の端部で０％とする位置）から４５〜５５％、好ましくは４３〜５７％、さらに好ましくは４０〜６０％位置で円筒型支持体内壁と挿入した制振材２１が接してはならない。この位置で円筒型支持体内壁と挿入した制振材２１が接していると、感光体とクリーニングブレードとの摩擦による騒音を防止することができない。
【００４３】
また、制振材２１は、感光体の円筒型支持体の長さ方向中央部で接してはならないため、制振材２１を挿入し、制振材２１が感光体中央部に固定された場合、感光体の中央部、即ち、感光体の円筒型支持体の長さを１００％としたとき、支持体端部から４５〜５５％、好ましくは４３〜５７％、さらに好ましくは４６〜６０％の位置に当たる制振材２１の外径は円筒型支持体の内径の５〜９８％、好ましくは１０〜９５％、さらに好ましくは２０〜９２％とすれば、感光体の中央部で感光体の円筒型支持体と制振材２１が接することなく、感光体とクリーニングブレードとの摩擦による騒音を防止することができる。
【００４４】
制振材２１の窪んでいるところ（円筒型支持体の内壁に接しないところ）の外径が円筒型支持体の内径の５％以下では、制振材２１の機械的強度が不足するため、感光体内部への制振材２１の挿入がスムーズに行うことが難しくなる。また、制振材２１の窪んでいるところの外径が円筒型支持体の内径の９８％以上では、制振材２１の挿入の仕方によっては、感光体の中央部で円筒型支持体の内壁と制振材２１が接する場合が生じる危険が生じるため、感光体とクリーニングブレードとの摩擦による騒音を防止することができない場合があり好ましくない。
【００４５】
制振材２１の外径が円筒型支持体の内径の５〜９８％であるところは、制振材２１が感光体支持体に挿入され、固定されたとき、感光体中央部で円筒型支持体９０と制振材２１が接しなければ良く、例えば、制振材２１の中央部に円筒型支持体の内径の５〜９８％がなくても、制振材２１を感光体支持体に挿入し、固定される位置を調整し、感光体中央で、制振材２１と円筒型支持体とが接していなければ良い。
【００４６】
制振材２１の形状としては、感光体の円筒型支持体内部への挿入が容易で、密着性が高く、上記の条件を満たしていればどのような形状であっても良いが、特に断面がＣ字状であれば、感光体内部への挿入は容易に行うことができ、円筒型支持体内壁との接触も良く好ましい。制振材２１は円筒型支持体内部の断面積よりも小さく圧縮して挿入し、それ自身が持つバネ性や、復元力により密着させても良いが、接着剤を用いて密着性をさらに高めても良い。しかし、接着剤が制振材２１の細くなっている部分（窪んでいる部分）に侵入し、接着剤を介して、感光体中央部で、制振材２１と円筒型支持体内壁とが接着されると、感光体とクリーニングブレードとの摩擦による騒音を防止することができない場合があり好ましくない。
【００４７】
本発明の制振材２１の長さとしては、円筒型支持体の長さの３０〜９８％、好ましくは３５〜８０％、さらに好ましくは４０〜７０％である。制振材２１の長さが円筒型支持体の長さの３０％未満では、制振材２１の重量が小さいため、感光体の歳差運動を防止することが難しく、感光体とクリーニングブレードとの摩擦による騒音を防止することができず好ましくない。制振材２１の長さが円筒型支持体の長さの９８％を超える場合には、制振材２１と感光体におけるフランジとが接する可能性があるため、アース不良や感光体の回転ムラを生じやすく、経済的にも好ましくない。
【００４８】
さらに、上記▲３▼の制振材３１、３２について説明する。
ここでの制振材３１、３２は各々その複数個が互いに接した状態で円筒型支持体内に挿入されるものである。これらの制振材３１、３２はともにその複数個が互いに接した状態にあるときは、図５及び図６に示したように、中央部にかけて外径が小さくなっている。そして、この複数個の制振材３１、３２が接している状態は図３、図４に示したものと同一ないしほぼ同一である。ここでも代表として制振材３１について説明する。
【００４９】
制振材３１は前述のように感光体内部に挿入した際に、感光体の中央部では円筒型支持体内壁と接していない。具体的に円筒型支持体内壁と挿入物が接しない領域は、先に▲１▼の制振材１１について説明したのと同じである。すなわち、感光体の円筒型支持体の長さを１００％としたとき、支持体端部（一方の端部で０％とする位置）から４５〜５５％、好ましくは４３〜５７％、さらに好ましくは４０〜６０％位置で円筒型支持体内壁と挿入した制振材３１と接してはならない。この位置で円筒型支持体内壁と挿入した制振材３１が接していると、感光体とクリーニングブレードとの摩擦による騒音を防止することができない。
【００５０】
制振材３１は、感光体の円筒型支持体の長さ方向中央部で接してはならないため、制振材３１を挿入し、制振材３１が感光体中央部に固定された場合、感光体の中央部、即ち、感光体の円筒型支持体の長さを１００％としたとき、支持体端部から４５〜５５％、好ましくは４３〜５７％、さらに好ましくは４０〜６０％の位置に当たる制振材３１の外径は円筒型支持体の内径の５〜９８％、好ましくは１０〜９５％、さらに好ましくは２０〜９２％とすれば、感光体の中央部で感光体の円筒型支持体と制振材３１が接することなく、感光体とクリーニングブレードとの摩擦による騒音を防止することができる。
【００５１】
制振材３１の円筒型支持体内壁と接しないところの外径が円筒型支持体の内径の５％以下では、制振材３１の機械的強度が不足するため、感光体内部への制振材３１の挿入がスムーズに行うことが難しくなる。また、制振材３１の円筒型支持体内壁と接しないところの外径が円筒型支持体の内径の９８％以上では、制振材３１の挿入の仕方によっては、感光体の中央部で感光体の円筒型支持体と制振材３１が接する場合が生じる危険が生じるため、感光体とクリーニングブレードとの摩擦による騒音を防止することができない場合があり好ましくない。
【００５２】
制振材３１の外径が円筒型支持体の内径の５〜９８％であるところは、挿制振材３１が感光体支持体に挿入され、固定されたとき、感光体中央部で円筒型支持体と制振材３１が接しなければ良く、例えば、制振材３１の中央部に円筒型支持体の内径の５〜９８％がなくても、制振材３１を感光体支持体に挿入し、固定される位置を調整し、感光体中央で、制振材３１と円筒型支持体とが接していなければ良い。
【００５３】
制振材３１の形状としては、感光体の円筒型支持体内部への挿入が容易で、密着性が高く、上記の条件を満たしていればどのような形状であっても良いが、特に断面がＣ字状であれば、感光体内部への挿入は容易に行うことができ、円筒型支持体内壁との接触も良く好ましい。制振材３１は円筒型支持体内部の断面積よりも小さく圧縮して挿入し、それ自身が持つバネ性や、復元力により密着させても良いが、接着剤を用いて密着性をさらに高めても良い。しかし、接着剤が制振材３１の径が小さくなっている部分に侵入し、接着剤を介して、感光体中央部で、制振材３１と円筒型支持体内壁とが接着されると、感光体とクリーニングブレードとの摩擦による騒音を防止することができない場合があり好ましくない。なお、図７は別の制振材３３の例である。
【００５４】
制振材３１が複数個が接した状態にある場合の長さとしては、円筒型支持体の長さの３０〜９８％、好ましくは３５〜８０％、さらに好ましくは４０〜７０％である。制振材３１の長さが円筒型支持体の長さの３０％未満では、制振材３１の重量が小さいため、感光体の歳差運動を防止することが難しく、感光体とクリーニングブレードとの摩擦による騒音を防止することができず好ましくない。制振材３１の長さが円筒型支持体の長さの９８％を超える場合には、制振材３１と感光体におけるフランジとが接する可能性があるため、アース不良や感光体の回転ムラを生じやすく、経済的にも好ましくない。
【００５５】
本発明の感光体内部へ挿入される制振材の素材としては、密度が高く、感光体の円筒型支持体との密着性が高ければ、どのようなものでも用いることができるが、例えば、アルミニウム、鉄、ステンレス、リン青銅等の金属や合金、密度を高めるために充填剤を混合させたゴムやプラスチック類等が用いられる。
【００５６】
本発明のこのような制振材を有する感光体が搭載された画像形成装置において、感光体が回転を停止する過程で、感光体の回転数が１〜１０ｒｐｍの回転領域となる時間は０．２〜３．５秒、好ましくは０．３〜２．５秒、さらに好ましくは０．４〜１．５秒である。感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．２秒未満では感光体とクリーニングブレードとの摩擦による騒音が発生する時間が非常に短いため、騒音として問題になり難いため、本発明の形態をとる必要がない。
【００５７】
本発明の画像形成装置における画像形成中の感光体の最高到達温度は３８〜５３℃、好ましくは３９〜５２℃、さらに好ましくは４０〜５１℃である。この温度は感光体の表面の軸方向中央の位置で測定される温度である。前述のように、感光体とクリーニングブレードとの摩擦による騒音は、クリーニングブレードが柔らかくなり、反発弾性率が高くなって発生する。
従って、画像形成中の感光体の最高到達温度が３８℃未満で画像形成を行うかぎりは感光体とクリーニングブレードとの摩擦による騒音は発生しないため、本発明の形態をとる必要がない（画像形成装置内部を強力に冷却する機構を設けている画像形成装置や、２０℃以下の室温環境での画像形成等）。
感光体の最高到達温度が５３℃を超えると、感光体の静電特性が変化しやすく、またトナーや画像形成装置内部の部品に劣化が生じやすく好ましくない。
【００５８】
本発明の画像形成装置の帯電方式としては、コロトロン、スコロトロンの他、感光体と帯電器との距離を０〜１００μｍ、好ましくは０〜６０μｍ以下、さらに好ましくは０〜３０μｍとした帯電方式が用いられ、特に感光体と帯電器との距離を０〜１００μｍの帯電方式は画像形成装置全体としてオゾン、ＮＯｘ等の酸化性物質の発生が少なく、さらにバイアス電流に交流を重畳させた帯電方式は感光体の帯電電位の制御が容易で好ましい。感光体と帯電器との距離を０〜１００μｍの帯電方式の具体的な帯電方式としては、ローラー帯電方式、ブラシ帯電方式、ブレード帯電方式、磁気ブラシ帯電方式等の接触帯電方式、微小空隙面帯電方式、感光体と帯電ローラーとを微小空隙を保って帯電する帯電方式等を例示することができる。しかしながら、感光体と帯電器との距離が０〜１００μｍの帯電方式は、帯電器と感光体との距離が非常に近いため、感光体表面のオゾン、ＮＯｘ等の酸化性物質の濃度は高くなってしまい、解像度の低下、画像ボケ等の画像劣化を発生させやすい。
【００５９】
本発明の感光体はその感光層にビフェニール誘導体や下記化合物（Ｉ）から選ばれる化合物を含有させると、オゾン、ＮＯｘ等の酸化性物質が感光層に侵入し、画像劣化の発生を抑制することができるために好ましく、中でもビスベンジルベンゼン誘導体が画像劣化の発生を抑制する効果が高く、感光体の静電特性に悪影響がほとんどないため特に好ましい。
【化３】

（式中、Ｒ_１は炭素数１〜４の低級アルキル基を表わし、Ｒ_２、Ｒ_３は同一又は異なる、置換又は無置換のメチレン基又はエチレン基を表わし、Ａｒ_１、Ａｒ_２は同一又は異なる、置換又は無置換のアリール基を表わす。ｌは０〜４、ｍは０〜２、ｎは０〜２の整数を表わし、ｍ＋ｎは２以上、ｌ＋ｍ＋ｎは６以下の整数である。又、ベンゼン環の未置換部位は水素原子を表わす。）
【００６０】
本発明の画像形成装置に用いる感光体の感光層中のビフェニール誘導体や上記化合物（Ｉ）から選ばれる化合物の含有量としては０．５〜７重量％、好ましくは０．７〜６重量％、さらに好ましくは１〜５重量％である。含有量が０．５重量％以下では酸化性物質の感光層への侵入を抑制する効果が十分でないため、解像度の低下、画像ボケ等の画像劣化を発生しやすくなり、含有量が７重量％以上では静電特性が劣化しやすく、経済的にも不利である。
【００６１】
感光層中のビフェニール誘導体や上記化合物（Ｉ）から選ばれる化合物を含有させた感光体は、他の感光体と比較して感光体とクリーニングブレードとの間の摩擦により発生する騒音が大きい。そのため、本発明の構成の画像形成装置とすることが必須となる。
【００６２】
本発明の感光体の導電性基体（円筒型支持体）としては、銅、アルミニウム、金、銀、白金、鉄、パラジウム、ニッケル等の金属あるいはこれら金属を主成分とする合金をドラム状に形成したものを例示することができる。
【００６３】
導電性基体と感光層との間には必要に応じて下引層が設けられ、この下引層としては樹脂、あるいは白色顔料と樹脂を主成分としたもの、及び導電性基体表面を化学的あるいは電気化学的に酸化させた酸化金属膜等が例示できるが、白色顔料と樹脂を主成分とするものが好ましい。
白色顔料としては、酸化チタン、酸化アルミニウム、酸化ジルコニウム、酸化亜鉛等の金属酸化物が挙げられ、中でも導電性基体からの電荷の注入防止性が優れる酸化チタンを含有させることが最も好ましい。
下引層に用いる樹脂としてはポリアミド、ポリビニルアルコール、カゼイン、メチルセルロース等の熱可塑性樹脂、アクリル、フェノール、メラミン、アルキッド、不飽和ポリエステル、エポキシ等の熱硬化性樹脂、これらの中の一種あるいは多種の混合物を例示することができる。
【００６４】
本発明の感光体に用いる電荷発生物質としては、例えば、モノアゾ系顔料、ビスアゾ系顔料、トリスアゾ系顔料、テトラキスアゾ顔料、トリアリールメタン系染料、チアジン系染料、オキサジン系染料、キサンテン系染料、シアニン系色素、スチリル系色素、ピリリウム系染料、キナクリドン系顔料、インジゴ系顔料、ペリレン系顔料、多環キノン系顔料、ビスベンズイミダゾール系顔料、インダスロン系顔料、スクアリリウム系顔料、フタロシアニン系顔料等の有機系顔料及び染料や、セレン、セレン−ヒ素、セレン−テルル、硫化カドミウム、酸化亜鉛、酸化チタン、アモルファスシリコン等の無機材料を使用することができ、電荷発生物質は一種あるいは多種混合して使用することができる。
【００６５】
本発明の感光体に用いる電荷輸送物質としては、例えば、アントラセン誘導体、ピレン誘導体、カルバゾール誘導体、テトラゾール誘導体、メタロセン誘導体、フェノチアジン誘導体、ピラゾリン化合物、ヒドラゾン化合物、スチリル化合物、スチリルヒドラゾン化合物、エナミン化合物、ブタジエン化合物、ジスチリル化合物、オキサゾール化合物、オキサジアゾール化合物、チアゾール化合物、イミダゾール化合物、トリフェニルアミン誘導体、フェニレンジアミン誘導体、アミノスチルベン誘導体、トリフェニルメタン誘導体等の一種あるいは多種を混合して使用することができる。
【００６６】
上記電荷発生物質、電荷輸送物質を有する感光層はこれを物質を含む単層であっても、また、電荷発生物質を主成分として含有する電荷発生層と、電荷輸送物質を主成分として含有する電荷輸送層との積層であってもよい。
【００６７】
感光層を形成するのに使用する結着樹脂としては、電気絶縁性であり、それ自体公知の熱可塑性樹脂、熱硬化性樹脂、光硬化性樹脂及び光導電性樹脂等を使用することができ、適当な結着樹脂としては、例えば、ポリ塩化ビニル、ポリ塩化ビニリデン、塩化ビニル−酢酸ビニル共重合体、塩化ビニル−酢酸ビニル−無水マレイン酸共重合体、エチレン−酢酸ビニル共重合体、ポリビニルブチラール、ポリビニルアセタール、ポリエステル、フェノキシ樹脂、（メタ）アクリル樹脂、ポリスチレン、ポリカーボネ−ト、ポリアリレート、ポリスルホン、ポリエーテルスルホン、ＡＢＳ樹脂等の熱可塑性樹脂、フェノール樹脂、エポキシ樹脂、ウレタン樹脂、メラミン樹脂、イソシアネート樹脂、アルキッド樹脂、シリコーン樹脂、熱硬化性アクリル樹脂等の熱硬化性樹脂、ポリビニルカルバゾール、ポリビニルアントラセン、ポリビニルピレン等の光導電性樹脂など一種の結着樹脂あるいは多種と結着樹脂の混合物を挙げることができるが、特にこれらのものに限定されるものではない。
【００６８】
次に図面を用いて本発明の画像形成方法ならびに画像形成装置を詳しく説明する。
図１１は、本発明の画像形成プロセスおよび画像形成装置を説明するための概略図であり、以下に示すような変形例も本発明の範疇に属するものである。
図１１において、感光体１は本発明の感光層が設けられてなる。感光体１はドラム状の形状を示しているが、シート状、エンドレスベルト状のものであっても良い。帯電ローラー３、転写前チャージャ７、転写チャージャ１０、分離チャージャ１１、クリーニング前チャージャ１３には、コロトロン、スコロトロン、固体帯電器（ソリッド・ステート・チャージャー）、帯電ローラを始めとする公知の手段が用いられる。
転写手段には、一般に上記の帯電器が使用できるが、図に示されるように転写チャージャーと分離チャージャーを併用したものが効果的である。
【００６９】
また、画像露光部５、除電ランプ２等の光源には、蛍光灯、タングステンランプ、ハロゲンランプ、水銀灯、ナトリウム灯、発光ダイオード（ＬＥＤ）、半導体レーザー（ＬＤ）、エレクトロルミネッセンス（ＥＬ）などの発光物全般を用いることができる。そして、所望の波長域の光のみを照射するために、シャープカットフィルター、バンドパスフィルター、近赤外カットフィルター、ダイクロイックフィルター、干渉フィルター、色温度変換フィルターなどの各種フィルターを用いることもできる。
かかる光源等は、図１１に示される工程の他に光照射を併用した転写工程、除電工程、クリーニング工程、あるいは前露光などの工程を設けることにより、感光体に光が照射される。
【００７０】
現像ユニット６により感光体１上に現像されたトナーは、転写紙９に転写されるが、全部が転写されるわけではなく、感光体１上に残存するトナーも生ずる。このようなトナーは、ファーブラシ１４およびクリーニングブレード１５により、感光体より除去される。クリーニングは、クリーニングブラシだけで行なわれることもあり、クリーニングブラシにはファーブラシ、マグファーブラシを始めとする公知のものが用いられる。
【００７１】
感光体に正（負）帯電を施し、画像露光を行なうと、感光体表面上には正（負）の静電潜像が形成される。
これを負（正）極性のトナー（検電微粒子）で現像すれば、ポジ画像が得られるし、また正（負）極性のトナーで現像すれば、ネガ画像が得られる。
かかる現像手段には、公知の方法が適用されるし、また、除電手段にも公知の方法が用いられる。
【００７２】
以上の図示した画像形成プロセスは、本発明における実施形態を例示するものであって、もちろん他の実施形態も可能である。
以上に示すような画像形成手段は、複写装置、ファクシミリ、プリンター内に固定して組み込まれていてもよいが、プロセスカートリッジの形でそれら装置内に組み込まれてもよい。プロセスカートリッジとは、感光体を内蔵し、他に帯電手段、露光手段、現像手段、転写手段、クリーニング手段、除電手段の少なくとも１つを含んだ装置（部品）である。プロセスカートリッジの形状等は多く挙げられるが、一般的な例として、図１２に示すものが挙げられる。
【００７３】
【実施例】
次に実施例をあげて本発明を具体的に説明する。
【００７４】
（実施例１、２及び比較例１、２）
アクリル樹脂（アクリディックＡ−４６０−６０、大日本インキ化学工業製）１５重量部、メラミン樹脂（スーパーベッカミンＬ−１２１−６０、大日本インキ化学工業製）１０重量部をメチルエチルケトン８０重量部に溶解し、これに酸化チタン粉末（ＴＭ−１、富士チタン工業製）９０重量部加え、ボールミルで１２時間分散し、下引層塗布液を作製した。
外径３０ｍｍ、厚み０．６ｍｍ、長さ３３０ｍｍのアルミニウムドラムを上記下引層塗工液に浸漬した後、速度一定で垂直に引き上げて塗工した。アルミドラムの方向を維持したまま、乾燥室に移動させ１４０℃で２０分乾燥し、厚さ３．５μｍの下引層をアルミドラム上に形成した。
【００７５】
次にブチラール樹脂（エスレックＢＬＳ、積水化学製）１５重量部をシクロヘキサノン１５０重量部に溶解し、これに下記構造式のトリスアゾ顔料１０重量部を加えてボールミルで４８時間分散した。
【化４】

こうして得られた電荷発生層用塗工液に、下引層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い約０．２μｍの電荷発生層を形成した。
【００７６】
さらに下記構造式の電荷輸送材料６重量部、ポリカーボネート樹脂（パンライトＫ−１３００、帝人化成製）１０重量部、１，４−ビス（２，５−ジメチルベンジル）ベンゼン０．７重量部、シリコンオイル（ＫＦ−５０、信越化学工業製）０．００２重量部を塩化メチレン９０重量部に溶解した。
【化５】

こうして得られた電荷輸送層塗工液に、下引層／電荷発生層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い電荷発生層上に厚さ約３２μｍの電荷輸送層を形成して感光体ドラムを作製した。
【００７７】
作製した感光体の中に、長さ６０ｍｍ、外径２７．７ｍｍのアルミニウムの円柱（制振材１１）を二本、感光体中に図１（実施例１）、図２（実施例２）、図８（比較例１）に示すような位置に配置し、制振材１１をエポキシ樹脂で固定した。また、上記と同じ制振材１１、１本を感光体中の中心部に配置し、固定したもの（図９）を比較例２とした。
【００７８】
作製した感光体をｉｍａｇｉｏ ＭＦ−２００（リコー製）を改良し、停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．６〜０．７秒とした画像形成装置に組み込んだ。このとき、感光体は帯電ローラー（直流接触帯電方式）、現像装置、クリーニングブレードを搭載したｉｍａｇｉｏ ＭＦ−２００用プロセスカートリッジに搭載した。
【００７９】
画像形成装置を室温３２℃の環境でＡ４横画像を１５秒間隔で１枚づつ画像形成を２０分間繰り返した。２０分後、感光体の温度は４３℃であった。画像形成装置の右側面にマイクを近づけ、感光体停止直前の騒音を測定した。マイクはエレクトレットコンデンサーマイクＷＣＭ−Ｔ１１５（ソニー製）を用い、録音ソフトには、サウンドモニターＦＦＴ Ｖｅｒ．７．０（Ｅ．Ｎ．Ｓｏｆｔｗａｒｅ製）を用いてＰＣに録音した。録音を行った後、ＳｏｕｎｄＥｎｇｉｎｅ Ｆｒｅｅ Ｖｅｒ．２．９０（Ｃｙｃｌｅ ｏｆ ５ｔｈ製）にて音量をボリューム１７ｄＢで拡大した。この音をサウンドモニターＦＦＴで音の周波数特性を測定したところ、騒音がする時刻には５００Ｈｚ付近に大きなピークが存在した。４５０〜５５０Ｈｚの音のみを抜き出し、聞いたところ、問題とする騒音の音であった。５００Ｈｚ付近の最大音量を騒音の尺度とした。
【００８０】
ちなみに、官能評価から、５００Ｈｚ付近の最大音量が−２０ｄＢ以下では、画像形成装置の直ぐ側にいても騒音が全く気が付かないレベルであり、−１６ｄＢ以下では空調が止まっているオフィス環境で画像形成装置から１ｍ離れると騒音が気が付かないレベル、−１４ｄＢ以下では空調が働いているオフィス環境で画像形成装置から１ｍ離れると騒音がほとんど気が付かないレベル、−１０ｄＢ以下では空調が働いているオフィス環境で画像形成装置から１ｍ離れて騒音が聞こえるものの不快に感じないレベル、−１０ｄＢ以上では空調が働いているオフィス環境で画像形成装置から１ｍ離れていても騒音が不快に感じ始めるレベルである。
【００８１】
５００Ｈｚ付近の最大音量を測定したところ、実施例１では−１７．３ｄＢ、実施例２では−１６．９ｄＢ、比較例１では−３．７ｄＢ、比較例２では−２．１ｄＢであった。
【００８２】
（実施例３、４及び比較例３）
外径３０ｍｍ、厚さ４．５ｍｍ、長さ６０ｍｍで軸線方向に幅２ｍｍのスリットを有し、断面形状がＣ字型の制振材を作製した。制振材は、フィラーとして雲母を４５重量％含有したＡＢＳ樹脂である。
この制振材を実施例１、２、比較例２と同様に配置して、それぞれ実施例３、実施例４、比較例３とした。
実施例１で用いた画像形成装置を改良し、停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．５〜０．６秒とした画像形成装置に組み込んだ。
実施例１と同様に５００Ｈｚ付近の最大音量を測定したところ、実施例３では−１８．５ｄＢ、実施例４では−１７．３ｄＢ、比較例３では−２．２ｄＢであった。
【００８３】
（実施例５、６、７及び比較例４）
実施例１において、電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量を０．１重量部（実施例５）、０．５重量部（実施例６）、１．１重量部（実施例７）、０重量部（比較例４）とした感光体を作製した。
【００８４】
電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量が０．１重量部、０．５重量部、１．１重量部の感光体には実施例３と同じ制振材を同じ場所に配置した（実施例５，６，７）。
電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量が０重量部の感光体には、比較例３と同じ制振材を同じ場所に配置した（比較例４）。
【００８５】
また、実施例１で用いた画像形成装置の帯電方式を交流帯電方式に改良した。画像形成装置を２７℃のオフィス環境でＡ４横画像を１５秒間隔で１枚づつ画像形成を２０分間繰り返した。１５分後、感光体の温度は３９℃であった。画像形成装置の右側面にマイクを近づけ、感光体停止直前の騒音を測定した。
５００Ｈｚ付近の最大音量は、実施例５では−１９．１ｄＢ、実施例６では−１８．４ｄＢ、実施例７では−１６．１ｄＢ、比較例４では−１４．５ｄＢであった。
実施例６、比較例４の画像形成装置で、さらに４５分間画像形成を行ったところ、感光体の温度は４１℃であった。５００Ｈｚ付近の最大音量は実施例６では−１６．３ｄＢ、比較例４では−５．７ｄＢであった。
【００８６】
実施例６、比較例４の画像形成装置を用い、Ａ４横画像を９９枚連続で１００回画像形成を行った。画像形成装置を３０℃、９０％の環境で画像形成を行ったところ、実施例６の画像形成装置では正常な画像が得られたが、比較例４の画像形成装置は画像の一部に像流れ（ボケ）が発生してしまった。
【００８７】
（実施例８、９及び比較例５）
アクリル樹脂（アクリディックＡ−４６０−６０、大日本インキ化学工業製）１５重量部、メラミン樹脂（スーパーベッカミンＬ−１２１−６０、大日本インキ化学工業製）１０重量部をメチルエチルケトン８０重量部に溶解し、これに酸化チタン粉末（ＴＭ−１、富士チタン工業製）９０重量部加え、ボールミルで１２時間分散し、下引層塗布液を作製した。外径３０ｍｍ、厚み０．６ｍｍ、長さ３３０ｍｍのアルミニウムドラムを上記下引層塗工液に浸漬した後、速度一定で垂直に引き上げて塗工した。アルミドラムの方向を維持したまま、乾燥室に移動させ１４０℃で２３分乾燥し、厚さ３．４μｍの下引層をアルミドラム上に形成した。
【００８８】
次にブチラール樹脂（エスレックＢＬＳ 積水化学製）１５重量部をシクロヘキサノン１５０重量部に溶解し、これに下記構造式のトリスアゾ顔料１０重量部を加えてボールミルで４８時間分散した。
【化６】

こうして得られた電荷発生層用塗工液に、下引層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い約０．２μｍの電荷発生層を形成した。
【００８９】
さらに下記構造式の電荷輸送材料６重量部、ポリカーボネート樹脂（パンライトＫ−１３００、帝人化成製）１０重量部、１，４−ビス（２，５−ジメチルベンジル）ベンゼン０．７重量部、シリコンオイル（ＫＦ−５０、信越化学工業製）０．００２重量部を塩化メチレン９０重量部に溶解した。
【化７】

こうして得られた電荷輸送層塗工液に、下引層／電荷発生層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い電荷発生層上に厚さ約３２μｍの電荷輸送層を形成して感光体ドラムを作製した。
【００９０】
作製した感光体中に、図３に示すように中央部で径が小さくなっている長さ２００ｍｍのアルミニウム製制振材２１（実施例８）、又は図４に示すように中央部で径が小さくなっている長さ２００ｍｍの制振材（実施例９）を配置し、各々の制振材をエポキシ樹脂で固定した。
また、作製した感光体中に、図１０に示すように中央部の径が小さくなっている箇所の幅が小さい長さ１７０ｍｍのアルミニウム製制振材５０（比較例５）をエポキシ樹脂で固定した。
【００９１】
これらを実施例１と同様な画像形成装置（停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．６〜０．７秒となる画像形成装置）に組み込んで、５００Ｈｚ付近の最大音響を測定したところ、実施例８では−１７．７ｄＢ、実施例９では−１６．８ｄＢ、比較例５では−２．２ｄＢであった。
【００９２】
（実施例１０、１１及び比較例６）
中央部が窪んでいる箇所を外したところの外径が３０ｍｍ、厚さが４．５ｍｍ、長さが２００ｍｍで軸線方向に幅２ｍｍのスリットを有し、断面形状がＣ字型の制振材を作製した。制振材はフィラーとして雲母を４５重量％含有したＡＢＳ樹脂である。
これらを実施例１と同様な画像形成装置（停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．５〜０．６秒となる画像形成装置）に組み込んで、５００Ｈｚ付近の最大音響を測定したところ、実施例１０では−１８．９ｄＢ、実施例１１では−１７．７ｄＢ、比較例６では−２．４ｄＢであった。
【００９３】
（実施例１２〜１４及び比較例７）
実施例１において、電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量を０．１重量部（実施例１２）、０．５重量部（実施例１３）、１．１重量部（実施例１４）、０重量部（比較例７）とした感光体を作製した。
電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量が０．１重量部、０．５重量部、１．１重量部の感光体には実施例１０と同じ制振材を同じ場所に配置した（実施例１２、１３、１４）。電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量が０重量部の感光体には、比較例３と同じ制振材を同じ場所に配置した（比較例７）。
【００９４】
実施例１で用いた画像形成装置の帯電方式を交流帯電方式に改良した。画像形成装置を２７℃のオフィス環境でＡ４横画像を１５秒間隔で１枚づつ画像形成を２０分間繰り返した。１５分後、感光体の温度は３９℃であった。画像形成装置の右側面にマイクを近づけ、感光体停止直前の騒音を測定した。
５００Ｈｚ付近の最大音量は、実施例１２では−１９．３ｄＢ、実施例１３では−１８．３ｄＢ、実施例１４では−１６．５ｄＢ、比較例７では−１４．２ｄＢであった。
実施例１３、比較例７の画像形成装置で、さらに３０分間画像形成を行ったところ、感光体の温度は４０℃であった。５００Ｈｚ付近の最大音量は実施例では−１７．１ｄＢ、比較例４では−７．２ｄＢであった。
【００９５】
さらに実施例１２、比較例７の画像形成装置を用い、Ａ４横画像を９９枚連続で１００回画像形成を行った。画像形成装置を３０℃、９０％の環境で画像形成を行ったところ、実施例１２の画像形成装置では正常な画像が得られたが、比較例７の画像形成装置は画像の一部に像流れ（ボケ）が発生してしまった。
【００９６】
（実施例１５、１６）
アクリル樹脂（アクリディックＡ−４６０−６０、大日本インキ化学工業製）１５重量部、メラミン樹脂（スーパーベッカミンＬ−１２１−６０、大日本インキ化学工業製）１０重量部をメチルエチルケトン８０重量部に溶解し、これに酸化チタン粉末（ＴＭ−１、富士チタン工業製）９０重量部加え、ボールミルで１２時間分散し、下引層塗布液を作製した。外径３０ｍｍ、内径２８．５ｍｍ、長さ３３０ｍｍのアルミニウムドラムを上記下引層塗工液に浸漬した後、速度一定で垂直に引き上げて塗工した。アルミドラムの方向を維持したまま、乾燥室に移動させ１４０℃で２３分乾燥し、厚さ３．４μｍの下引層をアルミドラム上に形成した。
【００９７】
次にブチラール樹脂（エスレックＢＬＳ、積水化学製）１５重量部をシクロヘキサノン１５０重量部に溶解し、これに下記構造式のトリスアゾ顔料１０重量部を加えてボールミルで４８時間分散した。
【化８】

こうして得られた電荷発生層用塗工液に、下引層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い約０．２μｍの電荷発生層を形成した。
【００９８】
さらに下記構造式の電荷輸送材料６重量部、ポリカーボネート樹脂（パンライトＫ−１３００、帝人化成製）１０重量部、１，４−ビス（２，５−ジメチルベンジル）ベンゼン０．７重量部、シリコンオイル（ＫＦ−５０、信越化学工業製）０．００２重量部を塩化メチレン９０重量部に溶解した。
【化９】

こうして得られた電荷輸送層塗工液に、下引層／電荷発生層を形成したアルミドラムを浸漬し、速度一定で垂直に引き上げて塗工した。１２０℃、２０分間下引層と同様に乾燥を行い電荷発生層上に厚さ約３２μｍの電荷輸送層を形成して感光体ドラムを作製した。
【００９９】
作製した感光体中に、図５に示すようにアルミニウム制振材４１を互いに接触させ（実施例１５）、又は図６に示すようにアルミニウム製の制振材４２を互いに接触させ（実施例６）を配置し、各々エポキシ樹脂で固定した。
【０１００】
これらを実施例１と同様な画像形成装置（停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．６〜０．７秒となる画像形成装置）に組み込んで、５００Ｈｚ付近の最大音響を測定したところ、実施例１５では−１８．２ｄＢ、実施例１６では−１７．３ｄＢであった。
【０１０１】
（実施例１７）
外径２８．５５ｍｍ、厚さ３．５ｍｍ、長さ６０ｍｍで制振材の縦方向に幅１．５ｍｍのスリットを有し、断面形状がＣ字型の図７のような制振材３３を作製した。制振材３３は、フィラーとして雲母を４５重量％含有したＡＢＳ樹脂であり、制振材左側には凸部を有し、制振材右側には制振材左側凸部と同型状の凹部を有しており、二つの制振材の凸部と凹部を接続することで一つの制振材とすることができる。基準台より５８ｍｍ上方に、直径２６ｍｍの円盤を有し、基準台に垂直に立った直径２１ｍｍの円柱に、円柱上方より下図の制振材の右側を下になるようにし、二つの制振材を連結して突き刺した。円柱の上方より上方より感光体を下方に移動させ、感光体内部に制振材が入るように、感光体を基準台に接するまで下方に移動させた。その後、感光体を上方に移動させることで、感光体内部に連結した制振材を感光体の端部より制振材の端部から５８ｍｍの位置になった感光体を作製した。
実施例１と同様な画像形成装置（停止時に感光体の回転数が１〜１０ｒｐｍの回転領域となる時間が０．５〜０．６秒とした画像形成装置）に組み込んで５００Ｈｚ付近の最大音量を測定したところ、−１９．０ｄＢであった。
【０１０２】
（実施例１８〜２０）
実施例１５において、電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量を０．１重量部（実施例１８）、０．５重量部（実施例１９）、１．１重量部（実施例２０）とした感光体を作製した。
電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量が０．１重量部、０．５重量部、１．１重量部の感光体には実施例１７と同じ制振材を同じ場所に配置した（実施例１８、１９、２０）。
実施例１で用いた画像形成装置の帯電方式を交流帯電方式に改良した。画像形成装置を２７℃のオフィス環境でＡ４横画像を１５秒間隔で１枚づつ画像形成を２０分間繰り返した。３０分後、感光体の温度は４３℃であった。画像形成装置の右側面にマイクを近づけ、感光体停止直前の騒音を測定した。５００Ｈｚ付近の最大音量を測定したところ、実施例１８では−１９．０ｄＢ、実施例１９では−１８．９ｄＢ、実施例２０では−１７．２ｄＢであった。
【０１０３】
実施例２０の画像形成装置を用い、Ａ４横画像を９９枚連続で２００回（トータル１９８００枚）画像形成を行った。画像形成装置を３０℃、９０％の環境で画像形成を行ったところ、実施例２０の画像形成装置では正常な画像が得られた。
【０１０４】
【発明の効果】
（１）請求項１の発明によれば、感光体とクリーニングブレードとの摩擦で発生する騒音を防止した画像形成装置を提供することができる。
（２）請求項２〜８の発明によれば、感光体内部への挿入物の挿入を容易に行うことができ、感光体とクリーニングブレードとの摩擦で発生する騒音を防止した画像形成装置を提供することができる。
（３）請求項９〜１１の発明によれば、酸化性ガスの発生量が少なく、異常画像の発生がなく、感光体とクリーニングブレードとの摩擦で発生する騒音を防止した画像形成装置を提供することができる。
（４）請求項１２の発明によれば、感光体を急速停止させる装置を設けなくても、感光体とクリーニングブレードとの摩擦で発生する騒音を防止した画像形成装置を提供することができる。
（５）請求項１３の発明によれば、特別画像形成装置内部を冷却せず、特別な設置環境を要求することなく、感光体とクリーニングブレードとの摩擦で発生する騒音を防止した画像形成装置を提供することができる。
（６）請求項１４の発明によれば、感光体とクリーニングブレードとの摩擦で発生する騒音を防止したプロセスカートリッジを提供することができる。
【図面の簡単な説明】
【図１】本発明の電子写真感光体を説明するための図。
【図２】本発明の他の電子写真感光体を説明するための図。
【図３】本発明の他の電子写真感光体を説明するための図。
【図４】本発明の他の電子写真感光体を説明するための図。
【図５】本発明の他の電子写真感光体を説明するための図。
【図６】本発明の他の電子写真感光体を説明するための図。
【図７】制振材の一例を説明するための図。
【図８】比較の電子写真感光体を説明するための図。
【図９】比較の電子写真感光体を説明するための図。
【図１０】比較の電子写真感光体を説明するための図。
【図１１】電子写真方式による画像形成プロセスを説明するための図。
【図１２】画像形成装置用プロセスカートリッジの一例の図。
【符号の説明】
（図１〜図９において）
１１ 制振材
２１ 制振材
２２ 制振材
３１ 制振材
３２ 制振材
３３ 制振材
５０ 比較の制振材
９０ 円筒型支持体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, an image forming apparatus including the same, and a process cartridge for the image forming apparatus.
[0002]
[Prior art]
An image forming apparatus such as an electrophotographic copying machine, a facsimile, or a printer forms an electrostatic latent image on an electrophotographic photosensitive member, develops the latent image with toner, transfers the toner image onto a sheet, and fixes it. An image is obtained, and toner (transfer residual toner) which is not transferred onto the sheet and remains on the photosensitive member is removed by a cleaning means (cleaning blade or the like).
[0003]
By the way, from the effective use of office space, it has become very difficult to allocate a space for installing an image forming apparatus such as a copy room. The demand to install and use in the vicinity is getting higher. For this reason, downsizing of an image forming apparatus such as a copy, a printer, a facsimile or the like is required. Therefore, a photosensitive member mounted on the image forming apparatus is also required to have a small diameter and light weight. Furthermore, since there is a high demand for cost reduction, it has been examined whether various devices conventionally provided in the image forming apparatus can be simplified or omitted.
[0004]
When the image forming apparatus is installed in the immediate vicinity of the user, noise generated by the image forming apparatus may give an unpleasant impression to the user. The user feels that there is little noise when performing image formation against the sound of paper feeding that occurs during image formation and the sound of motor rotation. As far as there is little problem. However, after the image formation is completed, the noise generated immediately before the photoconductor stops is 400-1500 Hz, which is much lower than the frequency of the sound generated when the machine is in operation. The image forming apparatus may feel uneasy that it has failed, and may become a complaint.
[0005]
This noise is a blade holder in which the photosensitive drum is in the form of a drum and the friction between the photosensitive drum and the cleaning blade increases during low-speed rotation just before it stops, the cleaning blade chatters, and the vibration fixes the cleaning blade. This occurs when the sheet metal is vibrated. This noise is lower in volume than the sound during paper feeding or the rotation of the motor, but it occurs after the image formation is finished and the noise for image formation is reduced. Often felt loud.
In addition, this noise hardly occurs immediately after the image forming apparatus is turned on, but as the image formation is repeated, the temperature inside the image forming apparatus rises, the cleaning blade becomes soft, and the amplitude of the cleaning blade becoming erratic. Because it only occurs when it grows up, users were surprised by this noise.
[0006]
Since noise generated by friction between the photosensitive member and the cleaning blade when the photosensitive member is stopped is generated after the image formation is completed, it is natural that the contact between the photosensitive member and the cleaning blade is released immediately after the image formation. Although this noise does not occur, it is difficult to provide such a contact release mechanism between the photosensitive member and the cleaning blade because of demands for downsizing and cost reduction of the image forming apparatus. In addition, if the temperature in the vicinity of the cleaning blade can be lowered, the generation of this noise can be suppressed. However, due to the demand for downsizing of the image forming apparatus, consideration is given so that the heat of the fixing device does not reach the vicinity of the photosensitive member. In addition, there are limits to suppressing the temperature inside the image forming apparatus (the temperature of the photoconductor) by arranging a large number of ventilation devices and cooling devices.
[0007]
In order to prevent these noises, for example, in Japanese Patent Application Laid-Open No. 2001-235971 (Patent Document 1), a damping material in which a metal cylindrical member is wrapped with an elastic body is inserted and fixed inside a photosensitive drum, and photosensitive It is disclosed to suppress noise generated by body vibration. However, even if the damping material is simply inserted into the photoreceptor, the noise cannot be completely suppressed, and sometimes a large amount of noise is generated.
[0008]
In WO00 / 49466 (Patent Document 2), a damping material manufactured using a pellet in which an active ingredient that increases the amount of dipole moment in the same base resin and an inorganic filler is blended with the base resin is used. Thus, there is disclosed an image forming apparatus that is generated by vibration of a photosensitive member during AC contact charging. Although this image forming apparatus is effective in suppressing noise during AC contact charging of several kHz, it is effective against relatively low frequency noise such as noise generated by friction between the photosensitive member and the cleaning blade. Was less effective.
[0009]
Japanese Patent Laid-Open No. 2002-116661 (Patent Document 3) discloses an image forming apparatus using a photoconductor having a cylindricity of 0.03 mm or less in order to prevent noise generated by vibration of the photoconductor. . However, although it is effective against noise generated when an almost uniform vibration of several KHz is applied to the entire photoconductor due to AC contact charging, friction between the photoconductor and the cleaning blade is not always required. Since it is not uniform as a whole, the vibration of the photosensitive member in the image forming apparatus is often much larger than the measured value of the cylindricity, and as a result, the noise problem has not been solved.
[0010]
Japanese Patent Application Laid-Open No. 6-19230 (Patent Document 4) discloses a process cartridge in which a damping material is disposed at a position displaced to one side from the axial center of the photosensitive member in order to prevent noise generated during AC contact charging. It is disclosed. This process cartridge is effective in preventing noise generated during AC contact charging. Further, although it has an effect on noise due to friction between the photosensitive member and the cleaning blade, when the temperature of the cleaning blade becomes high, the noise cannot often be prevented.
[0011]
In Japanese Patent Laid-Open No. 10-161426 (Patent Document 5), noise due to friction between the photoconductor and the cleaning blade is generated during low-speed rotation when the photoconductor is stopped. An image forming apparatus that supplies toner, reduces friction between the photosensitive member and the cleaning blade by a lubricating effect, and suppresses noise is disclosed. However, it is difficult to provide these toner supply mechanisms because of the low cost requirement of the image forming apparatus.
[0012]
In addition, a brake mechanism is provided to stop the photoconductor after image formation, thereby shortening the low-speed rotation time during which photoconductor noise is generated, thereby shortening the noise generation time and preventing the user from being aware of the noise. It is also possible to do so. However, since the rotational speed of the photoconductor during image formation tends to increase due to the demand for high-speed image formation, the cost for the control mechanism for preventing the user from noticing noise is large, and the image forming apparatus It is difficult to provide this control mechanism because of the demand for lower prices.
[0013]
[Patent Document 1]
JP 2001-235971 A
[Patent Document 2]
WO00 / 49466
[Patent Document 3]
JP 2002-116661 A
[Patent Document 4]
JP-A-6-19230
[Patent Document 5]
Japanese Patent Laid-Open No. 10-161426
[0014]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a small-sized and low-cost image forming apparatus that suppresses noise caused by friction between a drum-shaped electrophotographic photosensitive member and a cleaning blade.
[0015]
[Means for Solving the Problems]
The present inventors have observed in detail how noise is generated by friction between the photosensitive member and the cleaning blade. Generally, the photosensitive member generally has flanges inserted at both ends, and the flanges at both ends are In many cases, a photosensitive drum is rotated by fixing a part to a process cartridge or the like and connected to one flange drive side. Of course, the process cartridge and the flanges at both ends of the photosensitive drum are played in order to rotate the photosensitive drum. There is.
In addition, there is a play, and only one flange generates a force that accelerates (starts) or suppresses (stops) rotation. It is easy to shake like a drum around the center (center in the axial direction of the photoconductor), and the degree of contact between the photoconductor and the cleaning blade partially changes due to so-called precession, and chattering of the cleaning blade It was found that it is likely to occur. This precession of the photosensitive member is likely to occur when the outer diameter of the photosensitive member is 65 mm or less, the thickness is 1.2 mm or less, and the length (axial length) is 310 mm or more.
[0016]
When the photosensitive drum starts, the motor reaches a constant rotation at a high speed in a very short time, so even if the chattering of the cleaning blade occurs, it is very short time, and the generated noise is the noise driven by the motor. Therefore, the user of the image forming apparatus does not feel the noise generated by the friction between the photosensitive member and the cleaning blade.
However, in the image forming apparatus provided with a mechanism for suddenly stopping the photosensitive member when the photosensitive member is stopped, the problem of noise is small. However, in the case of an image forming apparatus having a mechanism in which the low-speed rotation region of the photosensitive member continues for a certain time, Since noise is generated for a long time and there is almost no noise driven by the motor (the motor is not driven), it is relatively easy to feel the noise generated by the friction between the photosensitive member and the cleaning blade.
[0017]
Since the precession of the photoconductor during low-speed rotation occurs around the center of the photoconductor, when a damping material is inserted in the center of the photoconductor, the effect of suppressing the precession is small. Has become a node of the entire photoconductor, and has been found to often promote precession.
In order to suppress the noise generated by the friction between the photosensitive member and the cleaning blade, it is essential to insert a vibration damping material inside the photosensitive member. In addition, it has been found that the arrangement of a plurality of vibration damping materials at a certain distance from the center of the photoconductor significantly improves the noise generated by the friction between the photoconductor and the cleaning blade. Furthermore, even if the damping material is arranged in the central portion of the photosensitive member, the same noise can be obtained if the damping material has a shape with a small diameter at the central portion and a portion that does not contact the inner surface of the cylindrical support. We have found that the suppression is significantly improved.
The present invention has been made based on this. Therefore, the said subject is achieved by following (1)-(14).
[0018]
(1) An electron used in a state where a photosensitive layer is provided on a cylindrical conductive support having an outer diameter of 65 mm or less, a thickness of 0.3 to 1.2 mm, and a length of 310 mm or more, and the surface is always in contact with a cleaning blade. A photographic photosensitive member, wherein a plurality of damping materials are inserted into the support, and the damping material is 45 L from the end of the support when the length in the axial direction of the support is L. An electrophotographic photosensitive member that does not exist at positions separated from / 100 to 55 L / 100.
[0019]
(2) The electrophotographic photosensitive member according to (1), wherein the length of one damping material is 15 to 40% of the length of the cylindrical support.
[0020]
(3) The electrophotographic photosensitive member according to (1) or (2), wherein the vibration damping material has a C-shaped cross-section.
[0021]
(4) Electrons used with a photosensitive layer provided on a cylindrical conductive support having an outer diameter of 65 mm or less, a thickness of 0.3 to 1.2 mm, and a length of 310 mm or more, and whose surface is always in contact with a cleaning blade. It is a photographic photoreceptor, and a damping material is inserted into the support, and the damping material is 45 L / 100 to 45 L / 100 to the end of the support when the length in the axial direction of the support is L. An electrophotographic photosensitive member, wherein the inner surface of the support and the damping material do not contact at a distance of 55 L / 100.
[0022]
(5) The electrophotographic photosensitive member according to (4), wherein the vibration damping material is a single material or a plurality of vibration damping materials are inserted into the cylindrical support while being in contact with each other.
[0023]
(6) The outer diameter of the damping material that does not contact the inner surface of the cylindrical support is 5 to 98% of the inner diameter of the cylindrical support, as described in (4) or (5) above Electrophotographic photoreceptor.
[0024]
(7) The damping material inserted into the inside of the cylindrical support in a state where a plurality are in contact with each other can be fitted into each other, as described in (5) or (6) above Electrophotographic photoreceptor.
[0025]
(8) The electrophotographic photosensitive member according to any one of (4) to (7), wherein the vibration damping material has a C-shaped cross-section at a portion in contact with the inner peripheral surface of the cylindrical support. .
[0026]
(9) The photosensitive layer contains at least one selected from a biphenyl derivative and a compound represented by the following general formula compound (I), according to any one of (1) to (8), Electrophotographic photoreceptor.
[Chemical 2]

(Wherein R ₁ Represents a lower alkyl group having 1 to 4 carbon atoms, and R ₂ , R ₃ Represents the same or different, substituted or unsubstituted methylene group or ethylene group, Ar ₁ , Ar ₂ Represent the same or different substituted or unsubstituted aryl groups. l represents an integer of 0 to 4, m represents an integer of 0 to 2, and n represents an integer of 0 to 2. m + n is an integer of 2 or more, and l + m + n is an integer of 6 or less. The unsubstituted part of the benzene ring represents a hydrogen atom. )
[0027]
(10) The electrophotographic photosensitive member according to any one of (1) to (9), wherein the photosensitive layer contains 0.5 to 7% by weight of a bisbenzylbenzene derivative.
[0028]
(11) In an image forming apparatus in which the electrophotographic photosensitive member and the cleaning blade are always in contact, the electrophotographic photosensitive member according to any one of (1) to (10) is mounted as the electrophotographic photosensitive member. An image forming apparatus.
[0029]
(12) After image formation is performed while rotating the electrophotographic photosensitive member, the time during which the rotational speed of the photosensitive member is in the rotation region of 1 to 10 rpm in the process of stopping the rotation of the photosensitive member is 0.2 seconds or more 3 (5) The image forming apparatus as described in (11) above, wherein it is 5 seconds or less.
[0030]
(13) The image formation as described in (11) or (12) above, wherein the maximum temperature reached is 38 to 53 ° C. when measured at a position in the center in the axial direction of the surface of the electrophotographic photosensitive member during image formation. apparatus.
[0031]
(14) In a process cartridge for an image forming apparatus comprising an electrophotographic photosensitive member and at least one of a charging unit, an exposing unit, a developing unit, and a transferring unit, the electrophotographic photosensitive member is as described in (1) to (9) above. A process cartridge for an image forming apparatus, which is the electrophotographic photosensitive member according to any one of the above.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in further detail below.
The outer diameter of the cylindrical support used for the photoreceptor of the present invention is 65 mm or less, more preferably 50 mm or less, and still more preferably 20 to 40 mm. In the case of a large-sized image forming apparatus in which the outer diameter of the cylindrical support of the photoconductor exceeds 65 mm, noise due to friction between the photoconductor and the cleaning blade is very small, so that there is little problem, and the present invention There is no need to take such a form.
[0033]
The thickness of the cylindrical support used for the photoreceptor of the present invention is 0.3 to 1.2 mm, preferably 0.4 to 1.0 mm. When the thickness of the cylindrical support is less than 0.3 mm, the mechanical strength of the photoconductor is not sufficient, and when actually used, a backup roller or the like is required inside the photoconductor. Further, if the thickness of the cylindrical support exceeds 1.2 mm, the weight of the photoconductor is heavy, which is disadvantageous from an economical point of view, and noise caused by friction between the photoconductor and the cleaning blade is extremely small. There is no need to take any form.
[0034]
The length of the cylindrical support used for the photoreceptor of the present invention is 310 mm or more, preferably 320 mm or more, and more preferably 330 to 390 mm. When the length of the cylindrical support of the photoconductor is 310 mm or less, the precession force of the photoconductor is not large, so that noise due to friction between the photoconductor and the cleaning blade is very small, and the configuration of the present invention is achieved. There is no need to take.
[0035]
The damping material inserted into the cylindrical support of the photosensitive member in the present invention is as follows: (1) The longitudinal direction center of the cylindrical support 90 as shown in the sectional view of the photosensitive member in FIGS. A plurality of damping members 11 arranged without being present, (2) a single unit arranged without contacting the longitudinal center of the cylindrical support 90 as shown in FIGS. 3 and 4 From the vibration damping material 21 or 22, or from a plurality of vibration damping materials 31 or 32 arranged without contacting the longitudinal center of the cylindrical support 90 as shown in FIG. 5 and FIG. It will be.
[0036]
The vibration damping material 11 of the above (1) will be described.
A plurality of damping materials 11 are used here. If one damping material 11 is inserted into the cylindrical support 90, its length must be increased to prevent noise, making it difficult to insert the damping material, and the axis of the cylindrical support. A damping material is likely to be present in the center of the direction, and as a result, noise due to friction between the photosensitive drum and the cleaning blade is likely to occur. Furthermore, since the balance of the weight in the axial direction (length direction) of the photosensitive member is likely to be deteriorated, when the precession of the photosensitive member occurs, it tends to work in the direction of amplifying the magnitude of the movement, and sometimes the photosensitive member. This is not preferable because noise due to friction between the cleaning blade and the cleaning blade tends to be generated.
[0037]
The number of damping members 11 to be inserted may be two or more if the damping member 11 does not exist at the center of the axial length of the cylindrical support 90 of the photosensitive member. In view of the ease of the above, the range of 2 to 4 is particularly preferable.
Hereinafter, unless otherwise specified, “the length of the cylindrical support” means the length of the cylindrical support in the axial direction.
[0038]
The region where the damping material 11 should not be present inside the cylindrical support of the photosensitive member of the present invention is 45 L / 100 from the end of the support when the length in the axial direction of the cylindrical support is L. At a distance of ~ 55 L / 100, preferably at a distance of 43 L / 100 to 57 L / 100, more preferably at a distance of 40 L / 100 to 60 L / 100, the expression of the cylindrical support of the photosensitive member can be changed. When the length is 100%, the inside of the support is positioned 45 to 55%, preferably 43 to 57%, more preferably 40 to 60% from the end of the support (the position at which one end is 0%). There must be no damping material 11 inserted in. If an insert is present at a position of 45 to 55% from the edge of the support, noise due to friction between the photoreceptor and the cleaning blade cannot be prevented.
[0039]
The shape of the damping material 11 may be any shape as long as it can be easily inserted into the cylindrical support of the photosensitive member and has high adhesion to the wall of the support body, and in particular, the cross section If it is C-shaped, the insertion into the cylindrical support can be easily performed, and the contact with the wall of the cylindrical support is good and preferable. The damping material 11 may be inserted by being compressed to be smaller than the cross-sectional area of the internal space inside the cylindrical support, and may be brought into close contact by its own springiness or restoring force. May be further increased.
[0040]
The length of the damping material 11 is 15 to 40%, preferably 20 to 42%, more preferably 25 to 40% of the length of the cylindrical support. If the length of the damping material 11 is 15% or less of the length of the cylindrical support, a large number of inserts are required to prevent noise, which is not preferable because the insertion process becomes complicated. If the length of the damping material 11 is 40% or more of the length of the cylindrical support, the damping material 11 tends to exist at the center of the photosensitive member unless the positional accuracy in inserting the damping material 11 is increased. Therefore, noise due to friction between the photosensitive member and the cleaning blade may occur, which is not preferable.
[0041]
Next, the vibration damping materials 21 and 22 of the above (2) will be described.
Both of these damping materials 21 and 22 are common in that the outer diameter decreases from a certain point to the center, whereas the damping material 21 is narrowed on the cross-sectional funnel. Thus, the vibration damping material 22 is only different in that the central portion is narrowed in a cross-sectional arm shape. For this reason, here, the damping material 21 will be described as a representative.
[0042]
The damping material 21 is a single material. The damping material 21 is not in contact with the cylindrical support inner wall at the center of the photosensitive member when inserted into the photosensitive member as described above. Specifically, the region where the cylindrical support inner wall does not contact the damping material 21 is the same as that described for the damping material 11 of (1) above. That is, when the length in the axial direction of the cylindrical support of the photosensitive member is 100%, it is 45 to 55%, preferably 43 to 57% from the end of the support (position where 0% is set at one end). More preferably, the inserted damping material 21 should not contact the wall of the cylindrical support body at a position of 40 to 60%. If the inserted damping member 21 is in contact with the cylindrical support body wall at this position, noise due to friction between the photosensitive member and the cleaning blade cannot be prevented.
[0043]
In addition, since the vibration damping material 21 should not be in contact with the central portion in the length direction of the cylindrical support of the photosensitive member, the vibration damping material 21 is inserted and the vibration damping material 21 is fixed to the central portion of the photosensitive member. When the length of the central portion of the photoreceptor, that is, the length of the cylindrical support of the photoreceptor is 100%, it is 45 to 55%, preferably 43 to 57%, more preferably 46 to 60% from the end of the support. If the outer diameter of the damping material 21 corresponding to the position is 5 to 98%, preferably 10 to 95%, more preferably 20 to 92% of the inner diameter of the cylindrical support, Noise due to friction between the photosensitive member and the cleaning blade can be prevented without contacting the cylindrical support and the damping material 21.
[0044]
Since the mechanical strength of the damping material 21 is insufficient when the outer diameter of the place where the damping material 21 is recessed (where it does not contact the inner wall of the cylindrical support) is 5% or less of the inner diameter of the cylindrical support, It becomes difficult to smoothly insert the damping material 21 into the photoreceptor. In addition, when the outer diameter of the vibration damping material 21 in the recessed portion is 98% or more of the inner diameter of the cylindrical support, the inner wall of the cylindrical support at the center of the photosensitive member depends on how the vibration damping material 21 is inserted. Therefore, there is a risk that the vibration damping material 21 may come into contact with the vibration damping material 21, and noise due to friction between the photosensitive member and the cleaning blade may not be prevented.
[0045]
Where the outer diameter of the damping material 21 is 5 to 98% of the inner diameter of the cylindrical support, the cylindrical support is provided at the center of the photosensitive member when the damping material 21 is inserted and fixed to the photosensitive support. For example, even if the central portion of the vibration damping material 21 does not have 5 to 98% of the inner diameter of the cylindrical support, the vibration damping material 21 is inserted into the photosensitive member support. Then, the position to be fixed is adjusted, and it is sufficient that the damping material 21 and the cylindrical support are not in contact with each other at the center of the photosensitive member.
[0046]
The shape of the damping material 21 may be any shape as long as the photoreceptor can be easily inserted into the cylindrical support, has high adhesion, and satisfies the above conditions. If it is C-shaped, it can be easily inserted into the photoreceptor, and contact with the cylindrical support body wall is also preferable. The damping material 21 may be inserted by being compressed to be smaller than the cross-sectional area inside the cylindrical support, and may be brought into close contact by its own springiness or restoring force, but the adhesiveness is further enhanced by using an adhesive. May be. However, the adhesive enters the narrowed portion (the recessed portion) of the vibration damping material 21, and the vibration damping material 21 and the cylindrical support body wall are bonded to each other at the center of the photoreceptor via the adhesive. In this case, noise due to friction between the photosensitive member and the cleaning blade may not be prevented, which is not preferable.
[0047]
The length of the damping material 21 of the present invention is 30 to 98%, preferably 35 to 80%, more preferably 40 to 70% of the length of the cylindrical support. If the length of the damping material 21 is less than 30% of the length of the cylindrical support, the weight of the damping material 21 is so small that it is difficult to prevent precession of the photoreceptor, and the photoreceptor, the cleaning blade, This is not preferable because noise due to friction cannot be prevented. When the length of the damping material 21 exceeds 98% of the length of the cylindrical support, the damping material 21 and the flange of the photosensitive member may come into contact with each other. It is easy to produce and it is not preferable economically.
[0048]
Further, the vibration damping materials 31 and 32 of the above (3) will be described.
The damping materials 31 and 32 here are each inserted into the cylindrical support body in a state where a plurality of the damping materials 31 and 32 are in contact with each other. When a plurality of these damping materials 31 and 32 are in contact with each other, the outer diameter decreases toward the center as shown in FIGS. The state where the plurality of damping materials 31 and 32 are in contact is the same as or substantially the same as that shown in FIGS. Here, the damping material 31 will be described as a representative.
[0049]
When the damping material 31 is inserted into the photoreceptor as described above, the damping member 31 is not in contact with the cylindrical support body wall at the center of the photoreceptor. Specifically, the region where the cylindrical support inner wall does not contact the insert is the same as that described for the damping material 11 of (1) above. That is, when the length of the cylindrical support of the photosensitive member is 100%, it is 45 to 55%, preferably 43 to 57%, more preferably from the end of the support (the position at which one end is 0%). Should not contact the wall of the cylindrical support body and the inserted damping material 31 at a position of 40 to 60%. If the inserted damping material 31 is in contact with the cylindrical support body wall at this position, noise due to friction between the photosensitive member and the cleaning blade cannot be prevented.
[0050]
Since the vibration damping material 31 should not contact at the central portion in the length direction of the cylindrical support of the photosensitive member, when the vibration damping material 31 is inserted and the vibration damping material 31 is fixed to the central portion of the photosensitive member, the photosensitive member When the length of the central portion of the body, that is, the length of the cylindrical support of the photoconductor is 100%, the position is 45 to 55%, preferably 43 to 57%, more preferably 40 to 60% from the end of the support. If the outer diameter of the damping material 31 corresponding to the above is 5 to 98%, preferably 10 to 95%, more preferably 20 to 92% of the inner diameter of the cylindrical support, the cylindrical shape of the photosensitive member is at the center of the photosensitive member. Noise due to friction between the photosensitive member and the cleaning blade can be prevented without contacting the support and the damping material 31.
[0051]
If the outer diameter of the damping material 31 that does not contact the wall of the cylindrical support body is 5% or less of the inner diameter of the cylindrical support body, the mechanical strength of the damping material 31 is insufficient. It becomes difficult to insert the material 31 smoothly. Further, when the outer diameter of the vibration damping material 31 that does not contact the wall of the cylindrical support body is 98% or more of the inner diameter of the cylindrical support body, depending on the insertion method of the vibration damping material 31, the photosensitive member may be exposed at the center of the photosensitive member. Since there is a danger that the vibration damping material 31 may come into contact with the cylindrical support body, noise due to friction between the photosensitive member and the cleaning blade may not be prevented.
[0052]
Where the outer diameter of the damping material 31 is 5 to 98% of the inner diameter of the cylindrical support, when the insertion damping material 31 is inserted into and fixed to the photoreceptor support, it is cylindrical at the center of the photoreceptor. For example, even if the central portion of the damping material 31 does not have 5 to 98% of the inner diameter of the cylindrical support, the damping material 31 is inserted into the photosensitive member support. Then, the position to be fixed is adjusted, and it is sufficient that the damping material 31 and the cylindrical support are not in contact with each other at the center of the photosensitive member.
[0053]
The shape of the damping material 31 may be any shape as long as the photoreceptor can be easily inserted into the cylindrical support, has high adhesion, and satisfies the above conditions. If it is C-shaped, it can be easily inserted into the photoreceptor, and contact with the cylindrical support body wall is also preferable. The damping material 31 may be compressed and inserted smaller than the cross-sectional area inside the cylindrical support, and may be brought into close contact by its own springiness or restoring force, but the adhesiveness is further enhanced by using an adhesive. May be. However, when the adhesive enters the portion where the diameter of the damping material 31 is small and the damping material 31 and the cylindrical support body wall are bonded to each other at the center of the photoreceptor via the adhesive, Noise due to friction between the photosensitive member and the cleaning blade may not be prevented, which is not preferable. FIG. 7 shows another example of the damping material 33.
[0054]
The length when a plurality of damping materials 31 are in contact with each other is 30 to 98%, preferably 35 to 80%, more preferably 40 to 70% of the length of the cylindrical support. If the length of the damping material 31 is less than 30% of the length of the cylindrical support, the weight of the damping material 31 is so small that it is difficult to prevent precession of the photoconductor. This is not preferable because noise due to friction cannot be prevented. When the length of the damping material 31 exceeds 98% of the length of the cylindrical support, there is a possibility that the damping material 31 and the flange of the photosensitive member are in contact with each other. It is easy to produce and it is not preferable economically.
[0055]
Any material can be used as the material of the vibration damping material inserted into the photoreceptor of the present invention as long as the density is high and the adhesion of the photoreceptor to the cylindrical support is high. Metals and alloys such as aluminum, iron, stainless steel and phosphor bronze, and rubbers and plastics mixed with a filler to increase density are used.
[0056]
In the image forming apparatus on which the photoconductor having such a vibration damping material of the present invention is mounted, in the process of stopping the rotation of the photoconductor, the time during which the rotation speed of the photoconductor is in the rotation region of 1 to 10 rpm is 0. It is 2 to 3.5 seconds, preferably 0.3 to 2.5 seconds, and more preferably 0.4 to 1.5 seconds. If the time for which the rotational speed of the photosensitive member is in the rotation range of 1 to 10 rpm is less than 0.2 seconds, the time for generating noise due to friction between the photosensitive member and the cleaning blade is very short, so it is difficult to cause a problem as noise. There is no need to take the form of the present invention.
[0057]
The maximum temperature reached by the photoreceptor during image formation in the image forming apparatus of the present invention is 38 to 53 ° C, preferably 39 to 52 ° C, and more preferably 40 to 51 ° C. This temperature is a temperature measured at the center position in the axial direction of the surface of the photoreceptor. As described above, noise caused by friction between the photosensitive member and the cleaning blade is generated when the cleaning blade is soft and the resilience elastic modulus is high.
Therefore, as long as the image formation is performed when the maximum temperature of the photoconductor during image formation is less than 38 ° C., noise due to friction between the photoconductor and the cleaning blade does not occur, and thus it is not necessary to take the form of the present invention (image formation). Image forming apparatus provided with a mechanism for strongly cooling the inside of the apparatus, image forming in a room temperature environment of 20 ° C. or less, and the like).
If the maximum temperature reached by the photoreceptor exceeds 53 ° C., the electrostatic characteristics of the photoreceptor are likely to change, and the toner and components inside the image forming apparatus are likely to deteriorate, which is not preferable.
[0058]
As the charging method of the image forming apparatus of the present invention, in addition to corotron and scorotron, a charging method in which the distance between the photoreceptor and the charger is 0 to 100 μm, preferably 0 to 60 μm or less, more preferably 0 to 30 μm is used. In particular, the charging method in which the distance between the photosensitive member and the charger is 0 to 100 μm generates less oxidizing substances such as ozone and NOx in the entire image forming apparatus, and the charging method in which alternating current is superimposed on the bias current is photosensitive. It is preferable because the charge potential of the body is easily controlled. Specific charging methods in which the distance between the photoconductor and the charger is 0 to 100 μm include a roller charging method, a brush charging method, a blade charging method, a contact charging method such as a magnetic brush charging method, and a minute gap surface charging. Examples thereof include a charging method and a charging method in which the photosensitive member and the charging roller are charged while maintaining a minute gap. However, in the charging method in which the distance between the photoconductor and the charger is 0 to 100 μm, since the distance between the charger and the photoconductor is very close, the concentration of oxidizing substances such as ozone and NOx on the surface of the photoconductor becomes high. Therefore, it tends to cause image degradation such as a decrease in resolution and image blur.
[0059]
When the photosensitive layer of the present invention contains a biphenyl derivative or a compound selected from the following compounds (I) in the photosensitive layer, an oxidizing substance such as ozone or NOx enters the photosensitive layer and suppresses the occurrence of image deterioration. In particular, a bisbenzylbenzene derivative is particularly preferable because it has a high effect of suppressing the occurrence of image deterioration and hardly adversely affects the electrostatic characteristics of the photoreceptor.
[Chemical 3]

(Wherein R ₁ Represents a lower alkyl group having 1 to 4 carbon atoms, and R ₂ , R ₃ Represents the same or different, substituted or unsubstituted methylene group or ethylene group, Ar ₁ , Ar ₂ Represent the same or different substituted or unsubstituted aryl groups. l represents an integer of 0 to 4, m represents an integer of 0 to 2, and n represents an integer of 0 to 2. m + n is an integer of 2 or more, and l + m + n is an integer of 6 or less. The unsubstituted part of the benzene ring represents a hydrogen atom. )
[0060]
The content of the biphenyl derivative in the photosensitive layer of the photoreceptor used in the image forming apparatus of the present invention or the compound selected from the above compound (I) is 0.5 to 7% by weight, preferably 0.7 to 6% by weight, More preferably, it is 1 to 5% by weight. If the content is 0.5% by weight or less, the effect of suppressing the invasion of the oxidizing substance into the photosensitive layer is not sufficient, so that it tends to cause resolution deterioration and image deterioration such as image blur, and the content is 7% by weight. Above, the electrostatic characteristics are easily deteriorated, which is disadvantageous economically.
[0061]
A photoconductor containing a biphenyl derivative in the photosensitive layer or a compound selected from the above-mentioned compound (I) has a larger noise generated by friction between the photoconductor and the cleaning blade than other photoconductors. Therefore, it is essential to provide an image forming apparatus having the configuration of the present invention.
[0062]
As the conductive substrate (cylindrical support) of the photoreceptor of the present invention, a metal such as copper, aluminum, gold, silver, platinum, iron, palladium, nickel, or an alloy containing these metals as a main component is formed in a drum shape. Can be illustrated.
[0063]
If necessary, an undercoat layer is provided between the conductive substrate and the photosensitive layer. As the undercoat layer, a resin or a material mainly composed of a white pigment and a resin and a surface of the conductive substrate are chemically treated. Alternatively, an electrochemically oxidized metal oxide film and the like can be exemplified, but those containing a white pigment and a resin as main components are preferable.
Examples of the white pigment include metal oxides such as titanium oxide, aluminum oxide, zirconium oxide, and zinc oxide. Among them, it is most preferable to contain titanium oxide that is excellent in preventing charge injection from the conductive substrate.
As the resin used for the undercoat layer, thermoplastic resins such as polyamide, polyvinyl alcohol, casein, and methyl cellulose, thermosetting resins such as acrylic, phenol, melamine, alkyd, unsaturated polyester, and epoxy, one or various kinds of these Mixtures can be exemplified.
[0064]
Examples of the charge generating material used in the photoreceptor of the present invention include monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, and cyanine. Organic dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments, phthalocyanine pigments, etc. Inorganic materials such as selenium pigments and dyes, selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, amorphous silicon, etc. can be used. be able to.
[0065]
Examples of the charge transport material used in the photoreceptor of the present invention include anthracene derivatives, pyrene derivatives, carbazole derivatives, tetrazole derivatives, metallocene derivatives, phenothiazine derivatives, pyrazoline compounds, hydrazone compounds, styryl compounds, styryl hydrazone compounds, enamine compounds, butadienes A compound, distyryl compound, oxazole compound, oxadiazole compound, thiazole compound, imidazole compound, triphenylamine derivative, phenylenediamine derivative, aminostilbene derivative, triphenylmethane derivative, etc. .
[0066]
The photosensitive layer having the charge generation material and the charge transport material may be a single layer containing the material, or may include a charge generation layer containing the charge generation material as a main component and a charge transport material as the main component. It may be a laminate with a charge transport layer.
[0067]
The binder resin used to form the photosensitive layer is electrically insulating, and known thermoplastic resins, thermosetting resins, photocurable resins and photoconductive resins can be used. Suitable binder resins include, for example, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, ethylene-vinyl acetate copolymer, polyvinyl Thermoplastic resins such as butyral, polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, polysulfone, polyethersulfone, ABS resin, phenol resin, epoxy resin, urethane resin, melamine resin , Isocyanate resin, alkyd resin, silicone resin, thermosetting active resin One kind of binder resin or a mixture of various kinds of binder resins, such as thermosetting resins such as polyvinyl resins, photoconductive resins such as polyvinyl carbazole, polyvinyl anthracene, polyvinyl pyrene, etc., are particularly limited to these. Is not to be done.
[0068]
Next, the image forming method and the image forming apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 11 is a schematic diagram for explaining the image forming process and the image forming apparatus of the present invention, and the following modifications also belong to the category of the present invention.
In FIG. 11, the photoreceptor 1 is provided with the photosensitive layer of the present invention. The photosensitive member 1 has a drum shape, but may be a sheet shape or an endless belt shape. For the charging roller 3, the pre-transfer charger 7, the transfer charger 10, the separation charger 11, and the pre-cleaning charger 13, known means such as a corotron, a scorotron, a solid state charger, and a charging roller are used. It is done.
As the transfer means, the above charger can be generally used. However, as shown in the figure, a combination of a transfer charger and a separation charger is effective.
[0069]
The light source such as the image exposure unit 5 and the charge removal lamp 2 emits light such as a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL). All things can be used. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
Such a light source or the like irradiates the photosensitive member with light by providing a process such as a transfer process, a charge eliminating process, a cleaning process, or a pre-exposure using light irradiation in addition to the process shown in FIG.
[0070]
The toner developed on the photoreceptor 1 by the developing unit 6 is transferred to the transfer paper 9, but not all is transferred, and some toner remains on the photoreceptor 1. Such toner is removed from the photoreceptor by the fur brush 14 and the cleaning blade 15. Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.
[0071]
When the photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member.
A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.
[0072]
The above-described image forming process illustrated exemplifies an embodiment of the present invention, and other embodiments are of course possible.
The image forming means as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. The process cartridge is an apparatus (part) that contains a photosensitive member and includes at least one of charging means, exposure means, developing means, transfer means, cleaning means, and charge eliminating means. There are many shapes and the like of the process cartridge, but a general example is the one shown in FIG.
[0073]
【Example】
Next, the present invention will be specifically described with reference to examples.
[0074]
(Examples 1 and 2 and Comparative Examples 1 and 2)
15 parts by weight of acrylic resin (Acridic A-460-60, manufactured by Dainippon Ink & Chemicals) and 10 parts by weight of melamine resin (Super Becamine L-121-60, manufactured by Dainippon Ink & Chemicals) in 80 parts by weight of methyl ethyl ketone After dissolution, 90 parts by weight of titanium oxide powder (TM-1, manufactured by Fuji Titanium Industry Co., Ltd.) was added thereto, and dispersed for 12 hours by a ball mill to prepare an undercoat layer coating solution.
An aluminum drum having an outer diameter of 30 mm, a thickness of 0.6 mm, and a length of 330 mm was immersed in the undercoat layer coating solution, and then applied by pulling it up vertically at a constant speed. While maintaining the direction of the aluminum drum, it was moved to a drying chamber and dried at 140 ° C. for 20 minutes to form a subbing layer having a thickness of 3.5 μm on the aluminum drum.
[0075]
Next, 15 parts by weight of a butyral resin (ESREC BLS, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 150 parts by weight of cyclohexanone, and 10 parts by weight of a trisazo pigment having the following structural formula was added thereto and dispersed in a ball mill for 48 hours.
[Formula 4]

The aluminum drum having the undercoat layer was immersed in the coating solution for charge generation layer thus obtained, and the coating was performed by pulling it up vertically at a constant speed. Drying was performed in the same manner as the undercoat layer at 120 ° C. for 20 minutes to form a charge generation layer of about 0.2 μm.
[0076]
Furthermore, 6 parts by weight of charge transport material having the following structural formula, 10 parts by weight of polycarbonate resin (Panlite K-1300, manufactured by Teijin Chemicals), 0.7 part by weight of 1,4-bis (2,5-dimethylbenzyl) benzene, silicon 0.002 part by weight of oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 90 parts by weight of methylene chloride.
[Chemical formula 5]

An aluminum drum on which the undercoat layer / charge generation layer was formed was immersed in the charge transport layer coating solution thus obtained, and the coating was carried out by pulling it up vertically at a constant speed. Drying was performed at 120 ° C. for 20 minutes in the same manner as the undercoat layer, and a charge transport layer having a thickness of about 32 μm was formed on the charge generation layer to prepare a photosensitive drum.
[0077]
Two aluminum cylinders (damping material 11) having a length of 60 mm and an outer diameter of 27.7 mm are produced in the produced photoreceptor, and FIGS. 1 (Example 1) and 2 (Example 2) are provided in the photoreceptor. 8 was arranged at a position as shown in FIG. 8 (Comparative Example 1), and the damping material 11 was fixed with an epoxy resin. In addition, Comparative Example 2 was obtained by disposing and fixing one damping material 11 as described above in the center of the photosensitive member (FIG. 9).
[0078]
Improving imgio MF-200 (manufactured by Ricoh), the produced photoreceptor is incorporated into an image forming apparatus in which the time during which the rotation speed of the photoreceptor is in the rotation region of 1 to 10 rpm is 0.6 to 0.7 seconds. It is. At this time, the photoconductor was mounted on a process cartridge for imgio MF-200 equipped with a charging roller (DC contact charging system), a developing device, and a cleaning blade.
[0079]
Image formation was repeated for 20 minutes for each A4 landscape image at 15 second intervals in an environment where the image forming apparatus was at room temperature of 32 ° C. After 20 minutes, the temperature of the photoreceptor was 43 ° C. A microphone was brought close to the right side surface of the image forming apparatus, and the noise immediately before the photoreceptor was stopped was measured. The electret condenser microphone WCM-T115 (manufactured by Sony) was used as the microphone, and the sound monitor FFT Ver. The sound was recorded on a PC using 7.0 (manufactured by E.N. Software). After recording, SoundEngine Free Ver. The volume was increased with a volume of 17 dB at 2.90 (manufactured by Cycle of 5th). When the sound frequency characteristics of this sound were measured with a sound monitor FFT, a large peak was present around 500 Hz at the time of noise. When only the sound of 450 to 550 Hz was extracted and heard, it was the sound of the noise in question. The maximum volume around 500 Hz was used as a measure of noise.
[0080]
By the way, from sensory evaluation, when the maximum volume near 500 Hz is −20 dB or less, the noise level is not noticeable even at the immediate side of the image forming apparatus, and when it is −16 dB or less, the image forming apparatus is in an office environment where air conditioning is stopped. 1 m away from the image, noise is not noticed at -14 dB or less, in an office environment where air conditioning is working 1 m away from the image forming device, noise is almost noticeable after 1 m from the image forming apparatus, and air conditioning is working at -10 dB or less Noise is heard at a distance of 1 m from the apparatus, but it does not feel uncomfortable. Above -10 dB, the noise starts to feel uncomfortable even if it is 1 m away from the image forming apparatus in an office environment where air conditioning is working.
[0081]
When the maximum volume around 500 Hz was measured, it was -17.3 dB in Example 1, -16.9 dB in Example 2, -3.7 dB in Comparative Example 1, and -2.1 dB in Comparative Example 2.
[0082]
(Examples 3 and 4 and Comparative Example 3)
A damping material having an outer diameter of 30 mm, a thickness of 4.5 mm, a length of 60 mm, a slit having a width of 2 mm in the axial direction, and a C-shaped cross section was produced. The damping material is an ABS resin containing 45% by weight of mica as a filler.
The vibration damping materials were arranged in the same manner as in Examples 1 and 2 and Comparative Example 2, and were set as Example 3, Example 4, and Comparative Example 3, respectively.
The image forming apparatus used in Example 1 was improved and incorporated in the image forming apparatus in which the time during which the rotation speed of the photosensitive member was 1 to 10 rpm when stopped was 0.5 to 0.6 seconds.
When the maximum volume around 500 Hz was measured in the same manner as in Example 1, it was -18.5 dB in Example 3, -17.3 dB in Example 4, and -2.2 dB in Comparative Example 3.
[0083]
(Examples 5, 6, 7 and Comparative Example 4)
In Example 1, the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0.1 parts by weight (Example 5) and 0.5 parts by weight (Example 6). ), 1.1 parts by weight (Example 7), and 0 parts by weight (Comparative Example 4).
[0084]
Example 3 was applied to a photoreceptor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0.1 parts by weight, 0.5 parts by weight, and 1.1 parts by weight. The same damping material was placed in the same place (Examples 5, 6 and 7).
The same damping material as in Comparative Example 3 was placed in the same place on the photoconductor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0 parts by weight (comparison) Example 4).
[0085]
In addition, the charging method of the image forming apparatus used in Example 1 was improved to an AC charging method. Image formation was repeated for 20 minutes for each A4 landscape image at 15-second intervals in an office environment at 27 ° C. After 15 minutes, the temperature of the photoreceptor was 39 ° C. A microphone was brought close to the right side surface of the image forming apparatus, and the noise immediately before the photoreceptor was stopped was measured.
The maximum volume around 500 Hz was -19.1 dB in Example 5, -18.4 dB in Example 6, -16.1 dB in Example 7, and -14.5 dB in Comparative Example 4.
When image formation was further performed for 45 minutes with the image forming apparatuses of Example 6 and Comparative Example 4, the temperature of the photoreceptor was 41 ° C. The maximum volume around 500 Hz was -16.3 dB in Example 6 and -5.7 dB in Comparative Example 4.
[0086]
Using the image forming apparatuses of Example 6 and Comparative Example 4, 99 A4 horizontal images were continuously formed 100 times. When image formation was performed in an environment of 30 ° C. and 90% in the image forming apparatus, a normal image was obtained with the image forming apparatus of Example 6, but the image forming apparatus of Comparative Example 4 showed an image on a part of the image. Flow (blurred) has occurred.
[0087]
(Examples 8 and 9 and Comparative Example 5)
15 parts by weight of acrylic resin (Acridic A-460-60, manufactured by Dainippon Ink & Chemicals) and 10 parts by weight of melamine resin (Super Becamine L-121-60, manufactured by Dainippon Ink & Chemicals) in 80 parts by weight of methyl ethyl ketone After dissolution, 90 parts by weight of titanium oxide powder (TM-1, manufactured by Fuji Titanium Industry Co., Ltd.) was added thereto, and dispersed for 12 hours by a ball mill to prepare an undercoat layer coating solution. An aluminum drum having an outer diameter of 30 mm, a thickness of 0.6 mm, and a length of 330 mm was immersed in the undercoat layer coating solution, and then applied by pulling it up vertically at a constant speed. While maintaining the direction of the aluminum drum, it was moved to a drying chamber and dried at 140 ° C. for 23 minutes to form a subbing layer having a thickness of 3.4 μm on the aluminum drum.
[0088]
Next, 15 parts by weight of a butyral resin (manufactured by SREC BLS Sekisui Chemical Co., Ltd.) was dissolved in 150 parts by weight of cyclohexanone, and 10 parts by weight of a trisazo pigment having the following structural formula was added thereto and dispersed in a ball mill for 48 hours.
[Chemical 6]

The aluminum drum having the undercoat layer was immersed in the coating solution for charge generation layer thus obtained, and the coating was performed by pulling it up vertically at a constant speed. Drying was performed in the same manner as the undercoat layer at 120 ° C. for 20 minutes to form a charge generation layer of about 0.2 μm.
[0089]
Furthermore, 6 parts by weight of charge transport material having the following structural formula, 10 parts by weight of polycarbonate resin (Panlite K-1300, manufactured by Teijin Chemicals), 0.7 part by weight of 1,4-bis (2,5-dimethylbenzyl) benzene, silicon 0.002 part by weight of oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 90 parts by weight of methylene chloride.
[Chemical 7]

An aluminum drum on which the undercoat layer / charge generation layer was formed was immersed in the charge transport layer coating solution thus obtained, and the coating was carried out by pulling it up vertically at a constant speed. Drying was performed at 120 ° C. for 20 minutes in the same manner as the undercoat layer, and a charge transport layer having a thickness of about 32 μm was formed on the charge generation layer to prepare a photosensitive drum.
[0090]
In the produced photoreceptor, a 200 mm long aluminum damping material 21 (Example 8) having a small diameter at the center as shown in FIG. 3, or a diameter at the center as shown in FIG. A damping material (Example 9) having a reduced length of 200 mm was disposed, and each damping material was fixed with an epoxy resin.
Further, in the produced photoreceptor, as shown in FIG. 10, an aluminum damping material 50 (Comparative Example 5) having a length of 170 mm and having a small width at the central portion is fixed with an epoxy resin. .
[0091]
These are incorporated in an image forming apparatus similar to that in the first embodiment (an image forming apparatus in which the rotation speed of the photosensitive member is 1 to 10 rpm when the rotation is stopped is 0.6 to 0.7 seconds), and is around 500 Hz. As a result of measurement, the maximum sound was -17.7 dB in Example 8, -16.8 dB in Example 9, and -2.2 dB in Comparative Example 5.
[0092]
(Examples 10 and 11 and Comparative Example 6)
Damping material with an outer diameter of 30 mm, a thickness of 4.5 mm, a length of 200 mm, a slit with a width of 2 mm in the axial direction, and a C-shaped cross-section, with the central portion removed. Was made. The damping material is an ABS resin containing 45% by weight of mica as a filler.
These are incorporated into an image forming apparatus similar to that of the first embodiment (an image forming apparatus in which the rotation speed of the photosensitive member is 1 to 10 rpm when the rotation is stopped is 0.5 to 0.6 seconds), and is around 500 Hz. As a result of measurement, the maximum sound was -18.9 dB in Example 10, -17.7 dB in Example 11, and -2.4 dB in Comparative Example 6.
[0093]
(Examples 12 to 14 and Comparative Example 7)
In Example 1, the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0.1 parts by weight (Example 12) and 0.5 parts by weight (Example 13). ), 1.1 parts by weight (Example 14), and 0 parts by weight (Comparative Example 7).
A photoconductor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution is 0.1 parts by weight, 0.5 parts by weight, and 1.1 parts by weight is shown in Example 10. The same damping material was placed in the same place (Examples 12, 13, and 14). The same damping material as in Comparative Example 3 was placed in the same place on the photoconductor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0 parts by weight (Comparison Example 7).
[0094]
The charging system of the image forming apparatus used in Example 1 was improved to an AC charging system. Image formation was repeated for 20 minutes for each A4 landscape image at 15-second intervals in an office environment at 27 ° C. After 15 minutes, the temperature of the photoreceptor was 39 ° C. A microphone was brought close to the right side surface of the image forming apparatus, and the noise immediately before the photoreceptor was stopped was measured.
The maximum volume around 500 Hz was -19.3 dB in Example 12, -18.3 dB in Example 13, -16.5 dB in Example 14, and -14.2 dB in Comparative Example 7.
When image formation was further performed for 30 minutes with the image forming apparatuses of Example 13 and Comparative Example 7, the temperature of the photoreceptor was 40 ° C. The maximum volume around 500 Hz was −17.1 dB in the example and −7.2 dB in Comparative Example 4.
[0095]
Furthermore, using the image forming apparatuses of Example 12 and Comparative Example 7, 99 A4 horizontal images were continuously formed 100 times. When image formation was performed in an environment of 30 ° C. and 90% in the image forming apparatus, a normal image was obtained with the image forming apparatus of Example 12, but the image forming apparatus of Comparative Example 7 showed an image on a part of the image. Flow (blurred) has occurred.
[0096]
(Examples 15 and 16)
15 parts by weight of acrylic resin (Acridic A-460-60, manufactured by Dainippon Ink & Chemicals) and 10 parts by weight of melamine resin (Super Becamine L-121-60, manufactured by Dainippon Ink & Chemicals) in 80 parts by weight of methyl ethyl ketone After dissolution, 90 parts by weight of titanium oxide powder (TM-1, manufactured by Fuji Titanium Industry Co., Ltd.) was added thereto, and dispersed for 12 hours by a ball mill to prepare an undercoat layer coating solution. An aluminum drum having an outer diameter of 30 mm, an inner diameter of 28.5 mm, and a length of 330 mm was immersed in the undercoat layer coating solution, and then applied by pulling it up vertically at a constant speed. While maintaining the direction of the aluminum drum, it was moved to a drying chamber and dried at 140 ° C. for 23 minutes to form a subbing layer having a thickness of 3.4 μm on the aluminum drum.
[0097]
Next, 15 parts by weight of a butyral resin (ESREC BLS, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 150 parts by weight of cyclohexanone, and 10 parts by weight of a trisazo pigment having the following structural formula was added thereto and dispersed in a ball mill for 48 hours.
[Chemical 8]

The aluminum drum having the undercoat layer was immersed in the coating solution for charge generation layer thus obtained, and the coating was performed by pulling it up vertically at a constant speed. Drying was performed in the same manner as the undercoat layer at 120 ° C. for 20 minutes to form a charge generation layer of about 0.2 μm.
[0098]
Furthermore, 6 parts by weight of charge transport material having the following structural formula, 10 parts by weight of polycarbonate resin (Panlite K-1300, manufactured by Teijin Chemicals), 0.7 part by weight of 1,4-bis (2,5-dimethylbenzyl) benzene, silicon 0.002 part by weight of oil (KF-50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 90 parts by weight of methylene chloride.
[Chemical 9]

An aluminum drum on which the undercoat layer / charge generation layer was formed was immersed in the charge transport layer coating solution thus obtained, and the coating was carried out by pulling it up vertically at a constant speed. Drying was performed at 120 ° C. for 20 minutes in the same manner as the undercoat layer, and a charge transport layer having a thickness of about 32 μm was formed on the charge generation layer to prepare a photosensitive drum.
[0099]
As shown in FIG. 5, aluminum damping materials 41 are brought into contact with each other in the produced photoreceptor (Example 15), or aluminum damping materials 42 are brought into contact with each other as shown in FIG. 6 (Example 6). ), And each was fixed with an epoxy resin.
[0100]
These are incorporated in an image forming apparatus similar to that in the first embodiment (an image forming apparatus in which the rotation speed of the photosensitive member is 1 to 10 rpm when the rotation is stopped is 0.6 to 0.7 seconds), and is around 500 Hz. As a result of measurement of the maximum sound, it was -18.2 dB in Example 15, and -17.3 dB in Example 16.
[0101]
(Example 17)
A damping material 33 as shown in FIG. 7 having an outer diameter of 28.55 mm, a thickness of 3.5 mm, a length of 60 mm, a slit having a width of 1.5 mm in the longitudinal direction of the damping material, and a C-shaped cross section. Produced. The damping material 33 is an ABS resin containing 45% by weight of mica as a filler. The damping material 33 has a convex portion on the left side of the damping material, and a concave portion having the same shape as the left convex portion of the damping material on the right side of the damping material. It has one, and it can be set as one damping material by connecting the convex part and recessed part of two damping materials. Two dampers with a disk with a diameter of 26 mm above the reference table and a cylinder with a diameter of 21 mm standing perpendicular to the reference table, with the right side of the damping material in the figure below from below the cylinder. Were connected and pierced. The photosensitive member was moved downward from above the cylinder, and the photosensitive member was moved downward until it contacted the reference table so that the damping material was placed inside the photosensitive member. Thereafter, the photoconductor was moved upward to produce a photoconductor in which the damping material connected to the inside of the photoconductor was positioned 58 mm from the end of the damping material from the end of the photoconductor.
Built in an image forming apparatus similar to that of the first embodiment (image forming apparatus in which the rotation speed of the photosensitive member is 1 to 10 rpm when the rotation is stopped is 0.5 to 0.6 seconds), and the maximum volume around 500 Hz. Was measured to be -19.0 dB.
[0102]
(Examples 18 to 20)
In Example 15, the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0.1 parts by weight (Example 18) and 0.5 parts by weight (Example 19). ), 1.1 parts by weight (Example 20).
Example 17 was used for a photoreceptor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0.1, 0.5, and 1.1 parts by weight. The same damping material was placed in the same place (Examples 18, 19, and 20).
The charging system of the image forming apparatus used in Example 1 was improved to an AC charging system. Image formation was repeated for 20 minutes for each A4 landscape image at 15-second intervals in an office environment at 27 ° C. After 30 minutes, the temperature of the photoreceptor was 43 ° C. A microphone was brought close to the right side surface of the image forming apparatus, and the noise immediately before the photoreceptor was stopped was measured. When the maximum volume around 500 Hz was measured, it was -19.0 dB in Example 18, -18.9 dB in Example 19, and -17.2 dB in Example 20.
[0103]
Using the image forming apparatus of Example 20, 99 sheets of A4 horizontal images were continuously formed 200 times (total 19800 sheets). When image formation was performed in an environment of 30 ° C. and 90%, a normal image was obtained with the image forming apparatus of Example 20.
[0104]
【The invention's effect】
(1) According to the first aspect of the present invention, it is possible to provide an image forming apparatus in which noise generated by friction between the photosensitive member and the cleaning blade is prevented.
(2) According to the inventions of claims 2 to 8, there is provided an image forming apparatus capable of easily inserting an insert into the photoreceptor and preventing noise generated by friction between the photoreceptor and the cleaning blade. Can be provided.
(3) According to the inventions of claims 9 to 11, there is provided an image forming apparatus in which the generation amount of oxidizing gas is small, no abnormal image is generated, and noise generated by friction between the photosensitive member and the cleaning blade is prevented. can do.
(4) According to the twelfth aspect of the present invention, it is possible to provide an image forming apparatus in which noise generated by friction between the photosensitive member and the cleaning blade is prevented without providing a device for rapidly stopping the photosensitive member.
(5) According to the thirteenth aspect of the present invention, the inside of the special image forming apparatus is not cooled, a special installation environment is not required, and the image forming apparatus that prevents noise generated by friction between the photosensitive member and the cleaning blade is prevented. Can be provided.
(6) According to the fourteenth aspect of the present invention, it is possible to provide a process cartridge in which noise generated by friction between the photosensitive member and the cleaning blade is prevented.
[Brief description of the drawings]
FIG. 1 is a view for explaining an electrophotographic photosensitive member of the present invention.
FIG. 2 is a view for explaining another electrophotographic photosensitive member of the present invention.
FIG. 3 is a view for explaining another electrophotographic photosensitive member of the present invention.
FIG. 4 is a view for explaining another electrophotographic photosensitive member of the present invention.
FIG. 5 is a view for explaining another electrophotographic photosensitive member of the present invention.
FIG. 6 is a view for explaining another electrophotographic photosensitive member of the present invention.
FIG. 7 is a view for explaining an example of a damping material.
FIG. 8 is a diagram for explaining a comparative electrophotographic photosensitive member.
FIG. 9 is a view for explaining a comparative electrophotographic photosensitive member.
FIG. 10 is a diagram for explaining a comparative electrophotographic photosensitive member.
FIG. 11 is a diagram for explaining an image forming process by an electrophotographic method.
FIG. 12 is a diagram illustrating an example of a process cartridge for an image forming apparatus.
[Explanation of symbols]
(In FIGS. 1 to 9)
11 Damping material
21 Damping material
22 Damping material
31 Damping material
32 Damping material
33 Damping material
50 Comparative damping material
90 Cylindrical support

Claims (14)

An electrophotographic photosensitive member having a photosensitive layer provided on a cylindrical conductive support having an outer diameter of 65 mm or less, a thickness of 0.3 to 1.2 mm, and a length of 310 mm or more, and having the surface always in contact with a cleaning blade A plurality of damping materials are inserted into the support, and the damping material is 45 L / 100 to 45 L / 100 to the end of the support when the axial length of the support is L. An electrophotographic photosensitive member which does not exist at a position 55 L / 100 away. 2. The electrophotographic photosensitive member according to claim 1, wherein the length of one damping material is 15 to 40% of the length of the cylindrical support. The electrophotographic photosensitive member according to claim 1, wherein the vibration damping material has a C-shaped cross-section. An electrophotographic photosensitive member having a photosensitive layer provided on a cylindrical conductive support having an outer diameter of 65 mm or less, a thickness of 0.3 to 1.2 mm, and a length of 310 mm or more, and having the surface always in contact with a cleaning blade The damping material is inserted into the support, and the damping material is 45 L / 100 to 55 L / 100 from the end of the support when the length of the support in the axial direction is L. An electrophotographic photosensitive member, characterized in that the inner surface of the support and the damping material do not come into contact with each other at a distant position. 5. The electrophotographic photosensitive member according to claim 4, wherein the damping material is a single member or a plurality of damping members are inserted into the cylindrical support in a state where they are in contact with each other. 6. The electrophotographic photosensitive member according to claim 4, wherein an outer diameter of the vibration damping material not contacting the inner surface of the cylindrical support is 5 to 98% of an inner diameter of the support. 7. The electrophotographic photosensitive member according to claim 5, wherein the vibration damping materials inserted into the cylindrical support in a state where a plurality of them are in contact with each other can be fitted into each other. The electrophotographic photosensitive member according to any one of claims 4 to 7, wherein the damping material has a C-shaped cross-section at a portion in contact with the inner peripheral surface of the cylindrical support. 9. The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer contains at least one selected from a biphenyl derivative and a compound represented by the following general formula compound (I).

(Wherein R ₁ represents a lower alkyl group having 1 to 4 carbon atoms, R ₂ and R ₃ represent the same or different, a substituted or unsubstituted methylene group or ethylene group, and Ar ₁ and Ar ₂ are the same or Represents a different substituted or unsubstituted aryl group, 1 represents an integer of 0 to 4, m represents an integer of 0 to 2, n represents an integer of 0 to 2, m + n represents an integer of 2 or more, and l + m + n represents an integer of 6 or less. (The unsubstituted part of the benzene ring represents a hydrogen atom.) The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer contains 0.5 to 7% by weight of a bisbenzylbenzene derivative. 11. An image forming apparatus in which the electrophotographic photosensitive member and the cleaning blade are always in contact with each other, wherein the electrophotographic photosensitive member according to claim 1 is mounted as the electrophotographic photosensitive member. . After image formation is performed while rotating the electrophotographic photosensitive member, the time during which the rotational speed of the photosensitive member is in the rotation range of 1 to 10 rpm in the process of stopping the rotation of the photosensitive member is 0.2 seconds to 3.5 seconds. The image forming apparatus according to claim 11, wherein: The image forming apparatus according to claim 11 or 12, wherein the maximum temperature reached when measured at a position in the center in the axial direction of the surface of the electrophotographic photosensitive member during image formation is 38 to 53 ° C. 10. The process cartridge for an image forming apparatus comprising an electrophotographic photosensitive member and at least one of a charging unit, an exposing unit, a developing unit, and a transferring unit. A process cartridge for an image forming apparatus, which is a photographic photosensitive member.

Images