JP2005049377A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which suppresses the noise due to the friction between a photoreceptor and a cleaning blade and is small in size and low in cost. <P>SOLUTION: The image forming device has the photoreceptor which has a photosensitive layer formed on a cylindrical substrate of ≤60 mm in external diameter, 0.3 to 2 mm in thickness and ≥310 mm in length, in which the photoreceptor and the cleaning blade are in contact with each other while an image is not formed. In the image forming device, the cleaning blade is fixed onto a surface of one tabular portion forming an L-shape of a metallic plate holder having a section of an L shape and a board thickness of 1.0 go 2.5 mm and the other tabular portion forming an L-shaped portion of the metallic plate is so formed that its width is ≥10 mm and its outer peripheral portion is flat and that a region higher by ≥0.5 mm than the outer peripheral portion exists in its inner portion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２５】
（式中、Ｒ_１は低級アルキル基を表し、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す。ｌは０〜４、ｍは０〜２、ｎは０〜２の整数を表し、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す。）
（８）前記一般式（Ｉ）で表される化合物がビスベンジルベンゼン誘導体であり、該ビスベンジルベンゼン誘導体を感光層中に０．５〜７％含有することを特徴とする上記（７）記載の画像形成装置。
（９）帯電装置と感光体の距離が１００μｍ以下であることを特徴とする上記（７）〜（８）のいずれかに記載の画像形成装置。
【００２６】
（１０）上記（１）〜（９）のいずれかに記載の画像形成装置において用いられる、少なくともクリーニング手段を一体に支持し、該画像形成装置本体に着脱自在としたプロセスカートリッジにおいて、該クリーニング手段が、断面がＬ字型で板厚が１．０〜２．５ｍｍの金属製ブレードホルダーと、該金属製ブレードホルダーのＬ字を形成する一方の板状部分の面上に固定されたクリーニングブレードとからなり、該金属製ブレードホルダーのＬ字を形成する他方の板状部分には、幅が１０ｍｍ以上であり、その外周部分が平坦で、内側部分に該外周部分よりも０．５ｍｍ以上高い領域が存在することを特徴とするプロセスカートリッジ。
以下では、上記の発明を、本発明（１）〜（１０）という。
【００２７】
まず、本発明の画像形成装置およびこれを用いた画像形成方法を図１に基づいて説明する。図１は、本発明の画像形成装置およびそれによる画像形成方法を説明するための電子写真装置の模式断面図であるが、その変形例も当然本発明の範囲内である。
【００２８】
図中１は感光体ドラムである。まず接触帯電装置２により、感光体ドラム１は帯電する。感光体ドラム１が帯電した後、レーザー光によるイメージ露光３を受け、露光された部分で、電荷が発生し、感光体ドラム１表面に静電潜像が形成される。感光体ドラム１表面に静電潜像を形成した後、現像手段４を介して現像剤と接触し、トナー像を形成する。感光体ドラム表面に形成されたトナー像は、転写手段６により紙などの転写部材５へ転写され、定着手段９を通過してハードコピーとなる。感光体ドラム１上の残留トナーは金属製ブレードホルダー１０に固定されたクリーニングブレード７からなるクリーニング手段により除去され、残留電荷は除電手段８で除かれて、次の電子写真サイクルに移る。
【００２９】
本発明の画像形成装置は帯電手段、現像手段、クリーニング手段等が、一体構成となっているプロセスカートリッジを構成していても良い。プロセスカートリッジにすることにより画像形成装置を小型化でき、取り付け、取り外しなどが簡便となる。クリーニング手段により除去された廃トナーはトナー回収装置１１内に収納され、スクリュー型搬送装置１２で搬送され、最終的には現像手段４へ移動し、リサイクルされる。このとき、クリーニングブレード７を固定している金属製ブレードホルダー１０のクリーニングブレード７を固定していない側の板状部分はトナー回収装置の蓋を兼ねている。
【００３０】
本発明の画像形成装置に用いる感光体の円筒型支持体の外形としては６０ｍｍ以下、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形が６０ｍｍを超えると、感光体及びクリーニングブレードの温度が高温になり難いため、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、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。
【００３１】
本発明の画像形成装置に用いる感光体の円筒型支持体の厚みは０．３〜２ｍｍ、好ましくは０．４〜１．２ｍｍである。感光体の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。感光体の円筒型支持体の厚みが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ともに、感光体の温度上昇が小さく、感光体の回転ムラも発生し難いため、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。
【００３２】
本発明の画像形成装置に用いる感光体の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未満では、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。
【００３３】
本発明の画像形成装置におけるクリーニング装置を図２に基づいて説明する。クリーニング装置はクリーニングブレード７とこのクリーニングブレードを支持する金属製ブレードホルダー１０とからなる。金属製ブレードホルダー１０は図２に示すようにＬ字型の形状をしており、Ｌ字を形成する一方の板状部分の表面にはクリーニングブレード７が固定されている。図３は、Ｌ字を形成する他方の板状部分（クリーニングブレード７が固定されていない側の板状部分）をトナー回収装置の蓋としても用いた例を示している。
【００３４】
本発明の画像形成装置においては、クリーニングブレードを固定している金属製ブレードホルダーの板厚としては１．０〜２．５ｍｍ、好ましくは１．２〜２．２ｍｍ、さらに好ましくは１．４〜２．０ｍｍである。板厚が１．０ｍｍ未満では、金属性ホルダーの強度が十分でなく、クリーニング不良によるスジ状の異常画像、画像形成を繰り返すに従って、クリーンングブレードによる感光体の摩耗の仕方が不規則になりやすいため、帯状の異常画像を発生しやすく、また、感光体停止時の騒音も大きく好ましくない。板厚が２．５ｍｍを超えると、ブレードホルダーの加工がプレス、打ち抜きで行い難くなるため加工コストが高くなってしまい好ましくない。
【００３５】
図２（ｂ）において、Ｌ字型金属製ブレードホルダー１０のＬ字の曲げ角度（θ）は７０〜１３５°、好ましくは８０〜１２０°、さらに好ましくは８５〜１１０°である。θが７０°未満では、感光体とクリーニングブレードとの当接角を最適な状態に制御させながら、トナー回収装置の蓋を兼用させるには、トナー回収装置の形状や、クリーニングブレードを固定している金属製ブレードホルダーを固定する筐体の形状が複雑になり、好ましくない。θが１２０°を超えると、金属製ブレードホルダーの強度が弱くなるため、クリーニング不良によるスジ状の異常画像、画像形成を繰り返すに従って、クリーンングブレードによる感光体の摩耗の仕方が不規則になりやすいため、帯状の異常画像を発生しやすく、また、感光体停止時の騒音も大きく好ましくない。
【００３６】
本発明のクリーニングブレード７を固定している金属性ホルダー１０は、感光体１上に残存するトナーをクリーニングブレード７がかき落とした後、そのトナーを回収するトナー回収装置１１の蓋としても用いることにより、装置の小型化を図りながら、トナーのリサイクルを行うことができるので好ましい。
【００３７】
図１における金属性ホルダー１０のクリーニングブレード７が固定されていない板状部分の幅（ｗ）は、１０ｍｍ以上、好ましくは１２ｍｍ以上、さらに好ましくは１４〜２０ｍｍである。トナー回収装置１１はトナーを移動させるためのスクリュー型搬送装置１２等を配置しているので、幅（ｗ）が１０ｍｍ未満ではスクリュー等の設置が難しい。また、金属製ブレードホルダー１０のクリーニングブレード７が固定されていない板状部分の外周は平坦となっている。
【００３８】
金属製ブレードホルダーのクリーニングブレードが固定されていない板状部分がトナー回収装置の蓋を兼ねる場合には、該板状部分の外周部分が平坦でないと、トナー回収装置のシールが不十分になるため、回収されるトナーがトナー回収装置より飛散する可能性が高くなってしまう。平坦な部分は端部から２ｍｍ以上、好ましくは３ｍｍ以上である。平坦な部分が端部から２ｍｍ未満であるとトナー回収装置のシールが不十分になりやすいため、回収されるトナーがトナー回収装置より飛散しやすくなり好ましくない。
【００３９】
本発明における金属性ホルダーのクリーニングブレードが固定されていない板状部分の表面には外周よりも０．５ｍｍ以上、好ましくは０．７ｍｍ以上、さらに好ましくは０．８ｍｍ〜３ｍｍ高い部分１３が存在している。外周より高い部分の高さが０．５ｍｍ未満では感光体停止時にクリーニングブレードが固定されていない板状部分の振動が大きく、感光体停止時の騒音を防止することはできない。外周よりも０．５ｍｍ以上の部分の占める面積はクリーニングブレードが固定されていない板状部分の面積全体の１５〜７０％、好ましくは１８〜６０％、さらに好ましくは２０〜５０％である。該面積が１５％未満では、感光体停止時にクリーニングブレードが固定されていない板状部分の振動が大きく、感光体停止時の騒音を防止することはできない。該面積が７０％を超えると加工精度を高めることが難しいため、取扱いの際に、回収されるトナーがトナー回収装置より飛散する可能性が高くなってしまうので好ましくない。
【００４０】
本発明における金属性ホルダーのクリーニングブレードが固定されていない板状部分の端部を上方あるいは下方に曲げた形状を併用することで、クリーニングブレードと感光体の摩擦により発生する騒音を非常に小さくすることができる。
【００４１】
図２では外周より０．５ｍｍ以上高い部分１３を半円柱状の連続した形状として示したが、外周より０．５ｍｍ以上高い部分の断面は楕円の円弧、三角形、多角形であっても良く、連続していなくても良いが、加工のし易さ、再現性のよさを、感光体停止時の騒音の抑制効果を考慮すると断面は円弧あるいは楕円の円弧で、連続した形状であることが好ましい。外周より０．５ｍｍ以上高い部分の幅としては１〜７ｍｍ、好ましくは２〜６ｍｍである。外周より０．５ｍｍ以上高い部分の幅が１ｍｍ未満では感光体停止時の騒音の抑制効果が小さく、７ｍｍを超えると加工精度を高めることが難しいため、取扱いの際に、回収されるトナーがトナー回収装置より飛散する可能性が高くなってしまい好ましくない。
【００４２】
本発明における金属性ホルダーのクリーニングブレードを固定していない板状部分の下側には０．５〜３ｍｍ、好ましくは０．８〜２．５ｍｍの厚みのウレタン発泡体やモルトプレーン，フエルト，フィルム，軟質プラスチックなどの軟弱部材を両面テープ、接着剤等により接着することにより、取扱いの際に、回収されるトナーがトナー回収装置より飛散することが殆どなくなり好ましい。
【００４３】
本発明の画像形成装置においては、感光体停止時の騒音をさらに抑制するため、感光体内部に挿入物を挿入し、感光体の回転ムラを防止することが好ましい。
本発明の画像形成装置における感光体内部への挿入物としては、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。
【００４４】
挿入物の形状としては、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、感光体内部への挿入は容易に行うことができ、円筒型支持体内部との接触も良く好ましい。挿入物は円筒型基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。
挿入物にバネ性がない場合には、接着剤により挿入物を固定することができる。
【００４５】
本発明の画像形成装置においては、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が０．２秒以上、好ましくは０．３秒以上、さらに好ましくは０．４秒から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。
【００４６】
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。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ると、クリーニングブレードと感光体との接触面積が大きくなって摩擦力が大きくなるため発生しやすくなる。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ような場合、例えば、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を用いる場合や、２０℃以下の室温環境で画像形成を行う場合等においては、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。また、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。
【００４７】
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が０〜１００μｍである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あるため好ましい。
【００４８】
感光体と帯電器との距離が０〜１００μｍである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である帯電方式は、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。
【００４９】
感光体の感光層に、特開平９−２６５１９４号公報公報に開示されるビフェニル系化合物や下記一般式（Ｉ）で表さ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て画像劣化を発生するの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殆どないため特に好ましい。
【００５０】
【化３】

【００５１】
ここで、Ｒ_１は低級アルキル基を表し、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し、Ａｒ_１及び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す。また、ｌは０〜４の整数であり、ｍは０〜２の整数であり、ｎは０〜２の整数を表し、ｍ＋ｎは２以上であり、ｌ＋ｍ＋ｎは６以下の整数である。一般式（Ｉ）で表されるベンゼン環の未置換部位は、水素原子を表す。Ｒ_１の低級アルキル基としては、メチル基、エチル基等が挙げられ、炭素数１以上６以下の低級アルキル基が好ましい。また、Ｒ_２及びＲ_３の置換基としては、メチル基、エチル基等のアルキル基、ベンジル基等のアラルキル基、フェニル基等のアリール基が挙げられる。さらに、Ａｒ_１及びＡｒ_２のアリール基としては、フェニル基、ビスフェニル基、ナフチル基等が挙げられ、その置換基としては、メチル基、エチル基、プロピル基等のアルキル基、ベンジル基等のアラルキル基が挙げられる。
なお、上記のビフェニル系化合物及び一般式（Ｉ）で表される化合物からなる群から選択される物質のうち、ビスベンジルベンゼン誘導体が好ましい。ここに、ビスベンジルベンゼン誘導体とは、一般式（Ｉ）で表される化合物のうち、ｌが０であり、Ｒ_２及びＲ_３が、互いに独立な、置換又は無置換のメチレン基であり、Ａｒ_１及びＡｒ_２が、互いに独立な、置換又は無置換のアリール基である。
【００５２】
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ル系化合物や前記一般式（Ｉ）で表される化合物の含有量としては０．５〜７％、好ましくは０．７〜６％、さらに好ましくは１〜５％である。含有量が０．５％未満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％を超えると静電特性が劣化しやすく、経済的にも不利である。
感光体の感光層中のビフェニル系化合物や下記化合物（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。
【００５３】
本発明の画像形成システムにおける感光体の導電性基体としては、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。
【００５４】
本発明の画像形成システムにおける感光体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。
【００５５】
本発明の画像形成装置における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。
【００５６】
本発明の画像形成システムにおける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。
【００５７】
上記電荷発生層、電荷輸送層の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。
【００５８】
【実施例】
以下に、実施例及び比較例を示すことにより、本発明をより詳細に説明するが、本発明は下記の具体例に限定されるものではない。
【００５９】
［実施例１、比較例１］
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重量部を加え、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。アルミニウム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の下引層をアルミニウムドラム上に形成した。
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。
【００６０】
【化４】

【００６１】
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ニウムドラムを浸漬し、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。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。
【００６２】
【化５】

【００６３】
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ニウムドラムを浸漬し、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た。
作製した感光体の中に、長さ６０ｍｍのアルミニウムの制振材１本を感光体中の中心部に配置し、アクリル系接着剤で固定した。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。
【００６４】
このとき、プロセスカートリッジは図１に示した形状であり、クリーニングブレード７を固定したスチール製ホルダー１０のＬ字型に曲げた角度θを９３°とした。
図４は、金属製ブレードホルダーのクリーニングブレードを固定していない板状部分を上方から見たものであるが、図４に示したように幅５ｍｍで、高さ２ｍｍの断面が半円で連続した凸部を設けた。
比較のため、比較例１として凸部を全く設けない以外は同様にしてプロセスカートリッジを作製した。
【００６５】
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６０分間繰り返した。６０分後、感光体の温度は４２℃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、騒音として問題となる音であった。５００Ｈｚ付近の最大音量を騒音の尺度とした。５００Ｈｚ付近の最大音量を表１に示した。
【００６６】
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。
【００６７】
【表１】

【００６８】
［実施例２］
実施例１において、スチール製ホルダーのクリーニングブレードを図５に示したようにした以外は実施例１と同様にして画像形成装置を作製し、実施例１と同様に５００Ｈｚ付近の騒音を評価した。その結果を表２に示す。
【００６９】
【表２】

【００７０】
［実施例３〜５、比較例２］
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、０．５重量部、１．１重量部、０重量部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重量部の感光体を用いた画像形成装置のスチール製ホルダーには、図６に示すような凸部を設けた（実施例３〜５）。
また、電荷輸送層塗工液中の１，４−ビス（２，５−ジメチルベンジル）ベンゼンの量を０重量部とした感光体には、比較例１と同じスチール製ホルダーを用いて、これを比較例２とした。
実施例２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。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評価した。評価結果を表３に示す。
【００７１】
【表３】

【００７２】
［実施例６、比較例３］
実施例４で用いた感光体を用い、実施例１で用いたスチール製ホルダーを用い、実施例３で用いた画像形成装置にプロセスカートリッジを組み込んだ。
また、実施例６において、スチール製ホルダーとして比較例１と同じスチール製ホルダー、感光体を用いたものを比較例３とした。
３０℃、４０％の環境でＡ４ 横画像を１５秒間隔で１枚づつ画像形成を６０分間繰り返した。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評価した。評価結果を表４に示す。
【００７３】
【表４】

【００７４】
これら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６の画像形成装置では正常な画像が得られたが、比較例３の画像形成装置は画像の一部に像流れ（ボケ）が発生した。
【００７５】
【発明の効果】
本発明（１）〜（３）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。
本発明（４）によれば、トナーが飛散することなく、廃トナーの有効活用が可能で、コンパクトで、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。
本発明（５）によれば、画像形成後、感光体を急停止させる特別な装置を用いることなく、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。
本発明（６）によれば、画像形成装置内に特別な冷却機構を用いることなく、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。
本発明（７）〜（９）によれば、高湿下での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。
本発明（１０）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】本発明の画像形成装置の構成を示す模式断面図である。
【図２】本発明の画像形成装置において用いるクリーニング装置の概略図である。
【図３】本発明の画像形成装置において、クリーニングブレードをトナー回収装置の蓋として兼用した例を示す図である。
【図４】実施例１において用いたクリーニングブレードの形状を表す図である。
【図５】実施例２において用いたクリーニングブレードの形状を表す図である。
【図６】実施例３において用いたクリーニングブレードの形状を表す図である。
【符号の説明】
１ 感光体ドラム
２ 接触帯電装置
３ イメージ露光
４ 現像手段
５ 転写部材
６ 転写手段
７ クリーニングブレード
８ 除電手段
９ 定着手段
１０ 金属製ブレードホルダー
１１ トナー回収装置
１２ スクリュー型搬送装置
１３ 外周よりも高い部分
１４ シール部
Ｗ 幅
θ Ｌ字の曲げ角度[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copy, a printer, and a fax machine, and more particularly to an image forming apparatus that reduces vibration noise when rotation of a photosensitive drum is stopped.
[0002]
[Prior art]
From the viewpoint of effective use of office space, it has become very difficult to provide a space for image formation such as a copy room in the office space, and the image forming apparatus is installed in the immediate vicinity of the user's seat. The demand to use them is getting stronger. For this reason, downsizing of an image forming apparatus such as a copy, a printer, and a fax machine is required, so that the photosensitive member used in the image forming apparatus is also required to be reduced in diameter and weight. In addition, since there is a high demand for cost reduction, it has been studied to simplify or omit various devices conventionally provided in the image forming apparatus.
[0003]
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 the paper feeding sound and motor rotating sound that occur during image formation cannot be generated to some extent when performing image formation. As long as it is not sound, it is unlikely to be a problem. However, the noise generated immediately after the completion of image formation and immediately before the photosensitive member stops is 400 to 1500 Hz, which is much lower than the frequency of the sound generated when the machine is in operation, and is unfamiliar to the user. Or the user may feel uneasy about whether the image forming device is out of order or make a complaint. In particular, if the time in which the rotational speed of the photosensitive drum is in the rotation range of 1 to 10 rpm continues for 0.2 seconds or more, it will be heard as a very disturbing sound.
[0004]
This noise is caused by an increase in frictional force between the photoconductor and the cleaning blade when the photoconductor rotates at a low speed just before stopping, causing the cleaning blade to chatter, and the vibration vibrates the blade holder and the sheet metal that fixes the cleaning blade. Caused by that. This noise is lower in volume than the noise during paper feeding or the rotation of the motor, but it occurs after the image formation is completed and the noise for image formation is reduced. Often felt loud.
[0005]
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 grows larger, users are surprised by this noise.
[0006]
Since the noise generated by the increased friction between the photosensitive member and the cleaning blade when the photosensitive member is stopped is generated after the image formation is completed, the contact between the photosensitive member and the cleaning blade is released immediately after the image formation. Of course, this noise does not occur, but it is difficult to provide such a contact release mechanism between the photosensitive member and the cleaning blade because of demands for reduction in size and cost of the image forming apparatus. Further, if the temperature in the vicinity of the cleaning blade can be lowered, the generation of this noise can be suppressed. However, there is a limit to the suppression of the temperature rise inside the image forming apparatus due to the demand for downsizing the image forming apparatus. .
[0007]
Further, in the case of a small photoconductor having a small photoconductor outer shape and a thin photoconductor support, the inner volume of the image forming apparatus using the photoconductor is small, and therefore the photoconductor and the cleaning blade are likely to be hot. Therefore, the chatter noise is likely to occur early and the sound is likely to be loud. Further, when the length of the photosensitive member is increased, rotation unevenness of the photosensitive member is likely to occur, and accordingly, uneven friction between the cleaning blade and the photosensitive member is likely to occur, and chatter noise is likely to increase.
[0008]
Prior art related to an image forming apparatus aimed at reducing noise will be described below with reference to Patent Documents 1 to 7.
(1) Patent Document 1
(Structure) A charging member to which an oscillating voltage is applied to charge the photosensitive drum in contact with the photosensitive drum, and a cleaning device having a cleaning blade for cleaning the photosensitive drum are provided, and the cleaning device absorbs vibration. An absorbing portion is provided to reduce charging noise generated between the charging member and the photosensitive drum.
(Problem) The vibration of the blade holder itself cannot be suppressed only by the vibration absorbing portion of the cleaning device.
[0009]
(2) Patent Document 2
(Structure) The electrostatic latent image formed on the organic photoconductor is developed with a developer containing toner, and the toner image visualized by the development is transferred from the organic photoconductor to a transfer material. In an image forming method having a cleaning device for removing toner remaining on the body, the organic photoreceptor is an organic photoreceptor having a siloxane resin layer as a surface layer, and a cleaning blade of the cleaning device and a support member for the cleaning blade are provided. Even when polymerized toner is used by bonding a part of each other in parallel and using a damping material on the cleaning blade, good cleaning performance is maintained over a long period of time, and there is no image defect. An image forming method and an image forming apparatus capable of forming an electrophotographic image are provided.
(Problem) When a damping material is bonded to a cleaning blade, the rigidity of the cleaning blade is increased and the noise of the blade is increased.
[0010]
(3) Patent Document 3
(Configuration) Without reducing the rigidity of the holder bracket by providing a magnet on the blade holder that holds the blade that is pressed against the surface of the photoreceptor to clean the surface residue, or the holder bracket that supports the blade holder, It is an object of the present invention to provide a cleaning device for an image forming apparatus in which the pressure contact state of the cleaning blade with respect to the surface of the photosensitive member does not change and unnecessary vibration of the entire device does not occur.
(Problem) Since the magnet and the holder bracket cannot be completely brought into close contact with each other, minute vibrations are generated at the contact portion between them.
[0011]
(4) Patent Document 4
(Structure) In a photosensitive drum built in a process cartridge of an image forming apparatus, a metal cylindrical member, an elastic material surrounding at least a part of the outer surface of the cylindrical member, and an elastic material are closely attached to the outer surface of the cylindrical member An anti-vibration material provided with a coating layer is disposed in the drum cylinder to absorb the vibration of the photosensitive drum and reliably absorb the vibration generated when the photosensitive drum rotates, and to adhere the anti-vibration material to the photosensitive drum. The noise generated by improving the performance is suppressed.
(Problem) Even if a damping material is simply inserted into the photoconductor, the noise cannot be completely suppressed, and sometimes a large noise is generated.
[0012]
(5) Patent Document 5
(Configuration) In an electrophotographic photosensitive member having a photosensitive layer on a conductive cylindrical support having an outer diameter of 50 mm or less and having a vibration suppressing member inside the cylindrical support, the cylindricity of the electrophotographic photosensitive member is determined. By setting it to 0.03 mm or less, vibration noise generated by the contact charging method and vibration noise of the cleaning blade are reduced, and a high-quality image without image unevenness is obtained.
(Problem) Although this image forming apparatus is effective against noise because an almost uniform vibration is applied to the entire photosensitive member by AC contact charging, friction between the photosensitive member and the cleaning blade is not necessarily photosensitive. Since the entire body is not uniform, the vibration of the photoconductor in the image forming apparatus is often much larger than the value measured by the cylindricity, and as a result, the noise problem has not been solved.
[0013]
(6) Patent Document 6
(Structure) A silencer molded using a damping resin molding pellet in which an active ingredient that increases the amount of dipole moment in the base resin and an inorganic filler is blended with a base resin is used as a photoreceptor in an image forming apparatus. By applying it to the inner or outer peripheral surface of the drum, vibration generated on the photoconductor during AC contact charging is attenuated and removed, thereby achieving higher image quality and lower noise.
(Problem) Although this image forming apparatus is effective in suppressing noise during AC contact charging of several kHz, it is relatively low such as noise generated by friction between the photosensitive member and the cleaning blade. The effect on frequency noise was low.
[0014]
(7) Patent Document 7
(Configuration) Noise due to friction between the photosensitive member and the cleaning blade is generated when the photosensitive member is stopped at a low speed. Therefore, the toner is supplied to the surface of the photosensitive member immediately before the photosensitive member is stopped, and the photosensitive member is lubricated by the lubricating effect of the toner. The friction between the cleaning blade and the cleaning blade is lowered to suppress noise.
(Problem) It is difficult to provide such a toner supply mechanism because of the demand for lower cost of the image forming apparatus.
[0015]
Another method for reducing noise is to reduce the time of noise generation by providing a brake mechanism to stop the photoconductor after image formation and shortening the low-speed rotation time at which photoconductor noise is generated. It is possible to prevent the user from noticing the noise. 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 There is a problem that it is difficult to provide this control mechanism because of the demand for lower price.
[0016]
[Patent Document 1]
JP-A-5-341701 (Canon: [0004] to [0006],
[0014] to [0016])
[Patent Document 2]
JP 2002-244521 A (Konica: [0005], [0006])
[Patent Document 3]
JP-A-5-188833 (Ricoh: [0003], [0006])
[Patent Document 4]
JP 2001-235971 A ([0008], [0012], [0014])
[Patent Document 5]
JP 2002-116661 (Ricoh: [0005] to [0015])
[Patent Document 6]
International Publication No. 00/49466 Pamphlet
[Patent Document 7]
Japanese Patent Laid-Open No. 10-161426
[0017]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small-sized and low-cost image forming apparatus that suppresses noise caused by friction between a photoreceptor and a cleaning blade.
[0018]
[Means for Solving the Problems]
The present inventors have observed in detail how noise caused by friction between the photosensitive member and the cleaning blade is generated, and obtained the following knowledge.
When the friction between the photoconductor and the cleaning blade increases during low-speed rotation just before the photoconductor stops, the photoconductor presses the urethane rubber cleaning blade and the cleaning blade is compressed and distorted. When it becomes larger, the cleaning blade quickly returns to the original state to release the strain energy.
[0019]
When the cleaning blade returns to its original state, the cleaning blade rubs the photoconductor violently, and the rubbing method does not occur uniformly throughout the cleaning blade, but occurs irregularly and partially, so it can be heard as a chatter sound. Come. In most cases, the cleaning blade is used while being fixed to a metal plate, but when the friction between the photosensitive member and the cleaning blade increases, the photosensitive member pushes the cleaning blade, and the cleaning blade is compressed and distorted. If the metal plate with the cleaning blade fixed is bent and deformed, the energy of deformation of the metal plate is added when the cleaning blade returns to its original state. Since the distance that the cleaning blade rubs the photoconductor also becomes long, the chatter noise becomes very large.
[0020]
It is common practice to bend a metal plate to which a cleaning blade is fixed into an L-shape to suppress bending of the metal plate. The cleaning blade is provided to remove the toner remaining on the photoconductor. In order to collect and transport the toner in order to return the removed toner to the waste toner bottle or developer for reuse. Toner recovery device is required. At this time, the metal plate is bent into an L-shape, the cleaning blade is fixed to one plate-shaped portion that forms the L-shape, and the other plate-shaped portion that forms the L-shape where the cleaning blade is not fixed. Use as a lid for a toner recovery device is preferable because it saves space and reduces the number of parts.
[0021]
In order to use the other plate-like portion as a lid of the toner recovery device, the other plate-like portion needs to have a certain width or more, and when the width becomes large, the cleaning blade is fixed. It has been found that the other plate-like portion that is not vibrated is transmitted to the one plate-like portion that fixes the cleaning blade, and chatter noise becomes very loud. Therefore, in order to suppress chatter noise, when the width of the plate-like portion where the cleaning blade is not fixed increases, the plate-like portion where the cleaning blade is not fixed does not vibrate itself. As a result, the present invention has been found.
That is, the present invention made to solve the above problems is as follows.
[0022]
(1) It has a photoconductor in which a photosensitive layer is formed on a cylindrical support having an outer diameter of 60 mm or less, a thickness of 0.3 to 2 mm, and a length of 310 mm or more. In the image forming apparatus that is still in contact with each other, the cleaning blade is one plate-like portion that forms an L-shape of a metal blade holder having an L-shaped cross section and a plate thickness of 1.0 to 2.5 mm The other plate-like portion forming the L-shape of the metal blade holder has a width of 10 mm or more, the outer peripheral portion is flat, and the inner portion is less than the outer peripheral portion. An image forming apparatus characterized in that a region higher than 5 mm exists.
(2) The image forming apparatus according to (1), wherein the region higher by 0.5 mm or more exists continuously in an inner portion of the other plate-like portion.
(3) The image forming apparatus as described in (1) or (2) above, wherein the area higher by 0.5 mm or more is 15 to 70% of the area of the other plate-like portion.
[0023]
(4) The image forming apparatus according to any one of (1) to (3), wherein the other plate-like portion of the metal blade holder also serves as a lid of a toner collecting device.
(5) After image formation is performed while rotating the photoconductor, the time during which the rotation speed of the photoconductor is 1 to 10 rpm is 0.2 seconds or longer in the process of stopping the rotation of the photoconductor. The image forming apparatus as described in any one of (1) to (4) above.
(6) The image forming apparatus as described in any one of (1) to (5) above, wherein the maximum temperature reached by the photoconductor during image formation is 38 to 53 ° C.
(7) The image forming apparatus as described in any one of (1) to (6) above, wherein the photosensitive layer of the photoreceptor contains a biphenyl compound and a compound represented by the following general formula (I): .
[0024]
[Chemical 2]

[0025]
(Wherein R ₁ Represents a lower alkyl group 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. )
(8) The above-mentioned (7), wherein the compound represented by the general formula (I) is a bisbenzylbenzene derivative, and the bisbenzylbenzene derivative is contained in the photosensitive layer in an amount of 0.5 to 7%. Image forming apparatus.
(9) The image forming apparatus as described in any one of (7) to (8) above, wherein the distance between the charging device and the photosensitive member is 100 μm or less.
[0026]
(10) In the process cartridge used in the image forming apparatus according to any one of (1) to (9), at least the cleaning unit is integrally supported and is detachable from the main body of the image forming apparatus. Is a metal blade holder having an L-shaped cross section and a plate thickness of 1.0 to 2.5 mm, and a cleaning blade fixed on the surface of one plate-like portion forming the L shape of the metal blade holder The other plate-like portion forming the L-shape of the metal blade holder has a width of 10 mm or more, a flat outer peripheral portion, and an inner portion higher than the outer peripheral portion by 0.5 mm or more. A process cartridge having a region.
Below, said invention is called this invention (1)-(10).
[0027]
First, an image forming apparatus of the present invention and an image forming method using the same will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of an electrophotographic apparatus for explaining an image forming apparatus of the present invention and an image forming method using the image forming apparatus, and modifications thereof are naturally within the scope of the present invention.
[0028]
In the figure, reference numeral 1 denotes a photosensitive drum. First, the photosensitive drum 1 is charged by the contact charging device 2. After the photosensitive drum 1 is charged, it receives image exposure 3 by laser light, and an electric charge is generated in the exposed portion, and an electrostatic latent image is formed on the surface of the photosensitive drum 1. After forming an electrostatic latent image on the surface of the photosensitive drum 1, the toner image is formed by contacting the developer via the developing unit 4. The toner image formed on the surface of the photosensitive drum is transferred to the transfer member 5 such as paper by the transfer unit 6 and passes through the fixing unit 9 to become a hard copy. Residual toner on the photosensitive drum 1 is removed by a cleaning unit comprising a cleaning blade 7 fixed to a metal blade holder 10, and the residual charge is removed by a neutralizing unit 8, and the next electrophotographic cycle is started.
[0029]
The image forming apparatus of the present invention may constitute a process cartridge in which a charging unit, a developing unit, a cleaning unit, and the like are integrated. By using a process cartridge, the image forming apparatus can be reduced in size and can be easily attached and detached. The waste toner removed by the cleaning means is stored in the toner collecting device 11, conveyed by the screw type conveying device 12, and finally moved to the developing means 4 for recycling. At this time, the plate-like portion on the side where the cleaning blade 7 is not fixed of the metal blade holder 10 fixing the cleaning blade 7 also serves as a lid of the toner recovery device.
[0030]
The outer shape of the cylindrical support of the photosensitive member used in the image forming apparatus of the present invention is 60 mm or less, preferably 50 mm or less, and more preferably 20 to 40 mm. If the outer shape of the cylindrical support of the photoconductor exceeds 60 mm, the temperature of the photoconductor and the cleaning blade is difficult to be high, so that noise due to friction between the photoconductor and the cleaning blade is very small, and there is little problem. It is not necessary to take the form of the present invention.
[0031]
The thickness of the cylindrical support of the photosensitive member used in the image forming apparatus of the present invention is 0.3 to 2 mm, preferably 0.4 to 1.2 mm. If the thickness of the cylindrical support of the photosensitive member is less than 0.3 mm, the mechanical strength of the photosensitive member is not sufficient, and when actually used, a backup roller or the like is required inside the photosensitive member. If the thickness of the cylindrical support of the photoreceptor exceeds 2 mm, the weight of the photoreceptor is heavy, which is economically disadvantageous, the temperature rise of the photoreceptor is small, and rotation unevenness of the photoreceptor is less likely to occur. Noise due to friction between the photosensitive member and the cleaning blade is very small, and it is not necessary to take the form of the present invention.
[0032]
The length of the cylindrical support of the photosensitive member used in the image forming apparatus 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 less than 310 mm, the precession force of the photoconductor is not large, so 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.
[0033]
A cleaning device in the image forming apparatus of the present invention will be described with reference to FIG. The cleaning device includes a cleaning blade 7 and a metal blade holder 10 that supports the cleaning blade. The metal blade holder 10 has an L shape as shown in FIG. 2, and a cleaning blade 7 is fixed to the surface of one plate-like portion forming the L shape. FIG. 3 shows an example in which the other plate-shaped portion forming the L-shape (the plate-shaped portion on the side where the cleaning blade 7 is not fixed) is also used as a lid of the toner recovery device.
[0034]
In the image forming apparatus of the present invention, the thickness of the metal blade holder to which the cleaning blade is fixed is 1.0 to 2.5 mm, preferably 1.2 to 2.2 mm, and more preferably 1.4 to 2.5 mm. 2.0 mm. If the plate thickness is less than 1.0 mm, the strength of the metallic holder is not sufficient, and as the streaky abnormal image due to poor cleaning and the image formation are repeated, the manner in which the photoconductor is worn by the cleaning blade tends to become irregular. Therefore, a belt-like abnormal image is likely to be generated, and noise at the time of stopping the photosensitive member is not preferable. If the plate thickness exceeds 2.5 mm, it is difficult to perform processing of the blade holder by pressing and punching, which increases the processing cost.
[0035]
In FIG.2 (b), the L-shaped bending angle ((theta)) of the L-shaped metal blade holder 10 is 70-135 degrees, Preferably it is 80-120 degrees, More preferably, it is 85-110 degrees. If θ is less than 70 °, the shape of the toner recovery device and the cleaning blade can be fixed in order to use the lid of the toner recovery device while controlling the contact angle between the photosensitive member and the cleaning blade to an optimum state. The shape of the housing for fixing the metal blade holder is complicated, which is not preferable. If θ exceeds 120 °, the strength of the metal blade holder will be weak, and as a result of repeated streaky abnormal images and image formation due to poor cleaning, the way the photoconductor is worn by the cleaning blade tends to become irregular. Therefore, a belt-like abnormal image is likely to be generated, and noise at the time of stopping the photosensitive member is not preferable.
[0036]
The metallic holder 10 to which the cleaning blade 7 of the present invention is fixed is also used as a lid of a toner collecting device 11 that collects toner remaining on the photoreceptor 1 after the cleaning blade 7 scrapes off the toner. The toner can be recycled while reducing the size of the apparatus, which is preferable.
[0037]
The width (w) of the plate-like portion where the cleaning blade 7 of the metallic holder 10 in FIG. 1 is not fixed is 10 mm or more, preferably 12 mm or more, more preferably 14 to 20 mm. Since the toner collecting device 11 is provided with a screw type conveying device 12 for moving the toner, etc., it is difficult to install a screw or the like if the width (w) is less than 10 mm. Further, the outer periphery of the plate-like portion where the cleaning blade 7 of the metal blade holder 10 is not fixed is flat.
[0038]
When the plate-like portion where the cleaning blade of the metal blade holder is not fixed also serves as the lid of the toner collecting device, the seal of the toner collecting device becomes insufficient unless the outer peripheral portion of the plate-like portion is flat. Therefore, there is a high possibility that the recovered toner will be scattered from the toner recovery device. A flat part is 2 mm or more from an edge part, Preferably it is 3 mm or more. If the flat portion is less than 2 mm from the end, the toner collecting device is likely to be insufficiently sealed, and the collected toner tends to scatter more than the toner collecting device.
[0039]
The surface of the plate-like portion where the cleaning blade of the metallic holder in the present invention is not fixed has a portion 13 higher than the outer periphery by 0.5 mm or more, preferably 0.7 mm or more, more preferably 0.8 mm to 3 mm. ing. If the height of the portion higher than the outer periphery is less than 0.5 mm, vibration of the plate-like portion where the cleaning blade is not fixed when the photosensitive member is stopped is large, and noise when the photosensitive member is stopped cannot be prevented. The area occupied by 0.5 mm or more from the outer periphery is 15 to 70%, preferably 18 to 60%, more preferably 20 to 50% of the entire area of the plate-like portion where the cleaning blade is not fixed. If the area is less than 15%, the vibration of the plate-like portion where the cleaning blade is not fixed when the photosensitive member is stopped is large, and noise when the photosensitive member is stopped cannot be prevented. If the area exceeds 70%, it is difficult to increase the processing accuracy, which is not preferable because the possibility that the collected toner will be scattered from the toner collecting device during handling becomes high.
[0040]
The noise generated by the friction between the cleaning blade and the photosensitive member is extremely reduced by using a shape in which the end of the plate-like portion where the cleaning blade of the metallic holder is not fixed in the present invention is bent upward or downward. be able to.
[0041]
In FIG. 2, the portion 13 higher than the outer periphery by 0.5 mm or more is shown as a semi-cylindrical continuous shape, but the cross section of the portion higher than the outer periphery by 0.5 mm or more may be an elliptical arc, a triangle, or a polygon. It is not necessary to be continuous, but considering the ease of processing and reproducibility, considering the noise suppression effect when the photoconductor is stopped, the cross section is preferably an arc or an elliptical arc, and is preferably continuous. . The width of the portion 0.5 mm or more higher than the outer periphery is 1 to 7 mm, preferably 2 to 6 mm. If the width of the portion higher than the outer periphery by 0.5 mm or more is less than 1 mm, the effect of suppressing noise when the photosensitive member is stopped is small, and if it exceeds 7 mm, it is difficult to improve the processing accuracy. The possibility of scattering from the recovery device is increased, which is not preferable.
[0042]
Under the plate-like portion where the cleaning blade of the metallic holder in the present invention is not fixed, a urethane foam, malt plain, felt or film having a thickness of 0.5 to 3 mm, preferably 0.8 to 2.5 mm is provided. By adhering a soft member such as soft plastic with a double-sided tape, an adhesive or the like, it is preferable that the collected toner hardly scatters from the toner collecting device during handling.
[0043]
In the image forming apparatus of the present invention, in order to further suppress noise when the photoconductor is stopped, it is preferable to insert an insert into the photoconductor to prevent uneven rotation of the photoconductor.
Any material can be used as an insert into the photoreceptor in the image forming apparatus 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 iron, stainless steel, phosphor bronze, and rubbers and plastics mixed with fillers to increase density are used.
[0044]
The shape of the insert may be any shape as long as it is easy to insert the photoreceptor into the cylindrical support and has high adhesion, but particularly if the cross section is C-shaped. Further, it can be easily inserted into the photoconductor, and contact with the inside of the cylindrical support is also preferable. The insert may be inserted by being compressed smaller than the cross-sectional area inside the cylindrical base body, and may be brought into close contact with its own springiness or restoring force, but the adhesiveness may be further enhanced using an adhesive. .
If the insert is not springy, it can be secured with an adhesive.
[0045]
In the image forming apparatus of the present invention, in the process of stopping the rotation of the photoconductor, the time during which the rotation speed of the photoconductor is 1 to 10 rpm is 0.2 seconds or longer, preferably 0.3 seconds or longer, Preferably, it is 0.4 seconds 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.
[0046]
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. As described above, noise due to friction between the photosensitive member and the cleaning blade is likely to be generated when the cleaning blade is softened because a contact area between the cleaning blade and the photosensitive member is increased and a frictional force is increased. Accordingly, when image formation is performed at a maximum temperature of the photoreceptor during image formation of less than 38 ° C., for example, when an image forming apparatus provided with a mechanism for strongly cooling the inside of the image forming apparatus is used, or 20 In the case where image formation is performed in a room temperature environment of less than or equal to 0 ° C., noise due to friction between the photoconductor and the cleaning blade does not occur, and therefore it is not necessary to take the form of the present invention. Further, 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 liable to deteriorate, which is not preferable.
[0047]
As a 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 photosensitive member and the charger is 0 to 100 μm, preferably 0 to 60 μm or less, more preferably 0 to 30 μm. In particular, the charging method in which the distance between the photoconductor and the charger is 0 to 100 μm generates less oxidizing substances such as ozone and NOx as the whole image forming apparatus, and further, the charging method in which alternating current is superimposed on the bias current. Is preferable because it is easy to control the charging potential of the photoreceptor.
[0048]
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. 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 is high. Therefore, image degradation such as a decrease in resolution and image blur is likely to occur.
[0049]
When the photosensitive layer of the photoreceptor contains a biphenyl compound disclosed in JP-A-9-265194 or a compound represented by the following general formula (I), an oxidizing substance such as ozone or NOx is exposed to the photosensitive layer. It is preferable because it can suppress the occurrence of image degradation due to intrusion into the toner, and among them, the bisbenzylbenzene derivative is particularly effective in suppressing the occurrence of image degradation and has almost no adverse effect on the electrostatic characteristics of the photoreceptor. preferable.
[0050]
[Chemical 3]

[0051]
Where R ₁ Represents a lower alkyl group and R ₂ , R ₃ Represents the same or different, substituted or unsubstituted methylene group or ethylene group, Ar ₁ And Ar ₂ Represent the same or different, substituted or unsubstituted aryl groups. L is an integer of 0 to 4, m is an integer of 0 to 2, n is an integer of 0 to 2, m + n is 2 or more, and l + m + n is an integer of 6 or less. The unsubstituted part of the benzene ring represented by the general formula (I) represents a hydrogen atom. R ₁ Examples of the lower alkyl group include a methyl group and an ethyl group, and a lower alkyl group having 1 to 6 carbon atoms is preferred. R ₂ And R ₃ Examples of the substituent include an alkyl group such as a methyl group and an ethyl group, an aralkyl group such as a benzyl group, and an aryl group such as a phenyl group. Furthermore, Ar ₁ And Ar ₂ Examples of the aryl group include a phenyl group, a bisphenyl group, and a naphthyl group, and examples of the substituent include an alkyl group such as a methyl group, an ethyl group, and a propyl group, and an aralkyl group such as a benzyl group.
Of the substances selected from the group consisting of the above biphenyl compounds and the compounds represented by the general formula (I), bisbenzylbenzene derivatives are preferred. Here, the bisbenzylbenzene derivative is a compound represented by the general formula (I), wherein l is 0, R ₂ And R ₃ Are independently substituted or unsubstituted methylene groups, Ar ₁ And Ar ₂ Are independently substituted or unsubstituted aryl groups.
[0052]
The content of the biphenyl compound or the compound represented by the general formula (I) in the photosensitive layer of the photoreceptor used in the image forming apparatus of the present invention is 0.5 to 7%, preferably 0.7 to 6%. More preferably, it is 1 to 5%. If the content is less than 0.5%, the effect of suppressing the intrusion 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 exceeds 7%. Electrostatic properties are likely to deteriorate, and this is economically disadvantageous.
A photosensitive member containing a biphenyl compound in the photosensitive layer of the photosensitive member or a compound selected from the following compound (I) generates noise due to friction between the photosensitive member and the cleaning blade as compared with other photosensitive members. Is big. Therefore, it is essential to provide an image forming apparatus having the configuration of the present invention.
[0053]
As the conductive substrate of the photoreceptor in the image forming system 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.
[0054]
As the undercoat layer of the photoreceptor in the image forming system of the present invention, a resin or a material mainly composed of a white pigment and a resin, a metal oxide film obtained by chemically or electrochemically oxidizing the surface of a conductive substrate, and the like. Although it can illustrate, what has a white pigment and resin as a main component is 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 many of these Mixtures can be exemplified.
[0055]
Examples of the charge generating material used for the photoreceptor in the image forming apparatus of the present invention include monoazo pigments, bisazo pigments, trisazo pigments, tetrakisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, and xanthenes. Dyes, cyanine dyes, styryl dyes, pyrylium dyes, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indanthrone pigments, squarylium pigments, phthalocyanine pigments Organic pigments and dyes such as pigments, inorganic materials such as selenium, selenium-arsenic, selenium-tellurium, cadmium sulfide, zinc oxide, titanium oxide, and amorphous silicon can be used. Can be used.
[0056]
Examples of the charge transport material used for the photoreceptor in the image forming system 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, butadiene compounds, distyryl compounds, oxazole compounds, oxadiazole compounds, thiazole compounds, imidazole compounds, triphenylamine derivatives, phenylenediamine derivatives, aminostilbene derivatives, triphenylmethane derivatives, etc. can do.
[0057]
The binder resin used to form the photosensitive layer of the charge generation layer and the charge transport layer is electrically insulating and is a known thermoplastic resin, thermosetting resin, photocurable resin, and photoconductive material. 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 butyral, polyvinyl acetal, polyester, phenoxy resin, (meth) acrylic resin, polystyrene, polycarbonate, polyarylate, thermoplastic resin such as polysulfone, polyethersulfone, ABS resin, phenol resin , Epoxy resin, urethane resin, melamine resin, isocyanate resin, alkyd resin, Examples thereof include a thermosetting resin such as a ricone resin, a thermosetting acrylic resin, a type of binder resin such as a photoconductive resin such as polyvinyl carbazole, polyvinyl anthracene, and polyvinyl pyrene, or a mixture of various types of binder resins. In particular, it is not limited to these.
[0058]
【Example】
Hereinafter, the present invention will be described in more detail by showing examples and comparative examples, but the present invention is not limited to the following specific examples.
[0059]
[Example 1, Comparative Example 1]
15 parts by weight of acrylic resin (Acridic A-460-60: manufactured by Dainippon Ink & Chemicals), 10 parts by weight of melamine resin (Super Becamine L-121-60: manufactured by Dainippon Ink & Chemicals) 80 parts by weight of methyl ethyl ketone 90 parts by weight of titanium oxide powder (TM-1: manufactured by Fuji Titanium Industry Co., Ltd.) was added thereto and dispersed with a ball mill for 12 hours 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, the aluminum drum 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.
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.
[0060]
[Formula 4]

[0061]
The aluminum drum on which the undercoat layer was formed was immersed in the coating solution for charge generation layer thus obtained, and the coating was carried out 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. 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.
[0062]
[Chemical formula 5]

[0063]
An aluminum drum on which the undercoat layer / charge generation layer was formed was immersed in the thus obtained charge transport layer coating solution, and the coating was carried out 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 transport layer having a thickness of about 32 μm on the charge generation layer.
In the produced photoreceptor, one aluminum damping material having a length of 60 mm was placed in the center of the photoreceptor and fixed with an acrylic adhesive. Improving imgio MF-200 (manufactured by Ricoh), the produced photoreceptor is incorporated into an image forming apparatus in which the rotation time of the photoreceptor is 1 to 10 rpm when the rotation is stopped and the time 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.
[0064]
At this time, the process cartridge had the shape shown in FIG. 1, and the angle θ bent to the L-shape of the steel holder 10 to which the cleaning blade 7 was fixed was 93 °.
FIG. 4 is a top view of the plate-like portion where the cleaning blade of the metal blade holder is not fixed. As shown in FIG. 4, the cross section of 5 mm in width and 2 mm in height is continuous in a semicircle. Convex parts were provided.
For comparison, a process cartridge was prepared in the same manner as Comparative Example 1 except that no protrusion was provided.
[0065]
Image formation was repeated for 60 minutes for each A4 landscape image at 15-second intervals in an environment of room temperature of 32 ° C. in the image forming apparatus. After 60 minutes, the temperature of the photoreceptor was 42 ° 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 this sound was measured with a sound monitor FFT, the frequency characteristics of the sound were measured, and there was a large peak near 500 Hz at the time of noise. When only 450 to 550 Hz sound was extracted and heard, it was a problem sound. The maximum volume around 500 Hz was used as a measure of noise. Table 1 shows the maximum volume around 500 Hz.
[0066]
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.
[0067]
[Table 1]

[0068]
[Example 2]
In Example 1, an image forming apparatus was produced in the same manner as in Example 1 except that the cleaning blade of the steel holder was as shown in FIG. 5, and noise in the vicinity of 500 Hz was evaluated in the same manner as in Example 1. The results are shown in Table 2.
[0069]
[Table 2]

[0070]
[Examples 3 to 5, Comparative Example 2]
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, 0.5 parts by weight, 1.1 parts by weight, and 0 parts by weight. A photosensitive member was prepared.
Image formation using a photoreceptor 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 The steel holder of the apparatus was provided with convex portions as shown in FIG. 6 (Examples 3 to 5).
In addition, the same steel holder as in Comparative Example 1 was used for the photoreceptor in which the amount of 1,4-bis (2,5-dimethylbenzyl) benzene in the charge transport layer coating solution was 0 part by weight. Was referred to as Comparative Example 2.
The charging system of the image forming apparatus used in Example 2 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 20 minutes, the temperature of the photoreceptor was 43 ° C. A microphone was brought close to the right side of the image forming apparatus, and the noise immediately before stopping the photoreceptor was evaluated. The evaluation results are shown in Table 3.
[0071]
[Table 3]

[0072]
[Example 6, Comparative Example 3]
A process cartridge was incorporated into the image forming apparatus used in Example 3 using the photoreceptor used in Example 4 and the steel holder used in Example 1.
In Example 6, the same steel holder and photoconductor as those of Comparative Example 1 were used as Comparative Example 3 as the steel holder.
Image formation was repeated for 60 minutes for each A4 landscape image at 15 second intervals in an environment of 30 ° C. and 40%. A microphone was brought close to the right side of the image forming apparatus, and the noise immediately before stopping the photoreceptor was evaluated. The evaluation results are shown in Table 4.
[0073]
[Table 4]

[0074]
Using these image forming apparatuses, 99 continuous A4 images were formed 200 times (total 19800 sheets). 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 3 displayed an image on a part of the image. A flow (blurred) occurred.
[0075]
【The invention's effect】
According to the present invention (1) to (3), it is possible to provide an image forming apparatus that can prevent noise generated by friction between the photosensitive member and the cleaning blade.
According to the present invention (4), it is possible to provide an image forming apparatus that can effectively use waste toner without scattering toner, is compact, and prevents noise generated by friction between a photosensitive member and a cleaning blade. Can do.
According to the present invention (5), it is possible to provide an image forming apparatus that prevents noise generated by friction between the photosensitive member and the cleaning blade without using a special device that suddenly stops the photosensitive member after image formation. it can.
According to the present invention (6), 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 using a special cooling mechanism in the image forming apparatus.
According to the present invention (7) to (9), it is possible to provide an image forming apparatus in which abnormal images are not generated under high humidity and noise generated by friction between the photosensitive member and the cleaning blade is prevented.
According to the present invention (10), 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 schematic cross-sectional view showing a configuration of an image forming apparatus of the present invention.
FIG. 2 is a schematic view of a cleaning device used in the image forming apparatus of the present invention.
FIG. 3 is a diagram illustrating an example in which a cleaning blade is also used as a lid of a toner recovery device in the image forming apparatus of the present invention.
4 is a diagram illustrating the shape of a cleaning blade used in Example 1. FIG.
5 is a diagram illustrating the shape of a cleaning blade used in Example 2. FIG.
6 is a diagram illustrating the shape of a cleaning blade used in Example 3. FIG.
[Explanation of symbols]
1 Photosensitive drum
2 Contact charging device
3 Image exposure
4 Development means
5 Transfer member
6 Transfer means
7 Cleaning blade
8 Static elimination means
9 Fixing means
10 Metal blade holder
11 Toner recovery device
12 Screw type conveyor
13 Higher than the outer circumference
14 Sealing part
W width
θ L-shaped bending angle

Claims (10)

It has a photoconductor having a photosensitive layer formed on a cylindrical support having an outer diameter of 60 mm or less, a thickness of 0.3 to 2 mm, and a length of 310 mm or more. In the image forming apparatus in a contact state, the cleaning blade is on the surface of one plate-like portion forming an L-shape of a metal blade holder having an L-shaped cross section and a plate thickness of 1.0 to 2.5 mm. The other plate-like portion forming the L-shape of the metal blade holder is 10 mm or more in width, the outer peripheral portion is flat, and the inner portion is 0.5 mm or more than the outer peripheral portion. An image forming apparatus having a high area. 2. The image forming apparatus according to claim 1, wherein the region having a height of 0.5 mm or more is continuously present in an inner portion of the other plate-like portion. 3. The image forming apparatus according to claim 1, wherein the region having a height of 0.5 mm or more is 15 to 70% of the area of the other plate-like portion. The image forming apparatus according to claim 1, wherein the other plate-like portion of the metal blade holder also serves as a lid of a toner recovery device. After image formation while rotating the photoconductor, in the process of stopping the rotation of the photoconductor, the time for which the rotation speed of the photoconductor becomes a rotation region of 1 to 10 rpm is 0.2 seconds or more. The image forming apparatus according to claim 1. 6. The image forming apparatus according to claim 1, wherein the maximum temperature reached by the photoconductor during image formation is 38 to 53 [deg.] C. 7. The image forming apparatus according to claim 1, wherein the photosensitive layer of the photoreceptor contains a biphenyl compound and a compound represented by the following general formula (I).

(Wherein R ₁ represents a lower alkyl group, R ₂ and R ₃ represent the same or different, substituted or unsubstituted methylene group or ethylene group, Ar ₁ and Ar ₂ represent the same or different, substituted or unsubstituted 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. Represents a hydrogen atom.) 8. The image forming apparatus according to claim 7, wherein the compound represented by the general formula (I) is a bisbenzylbenzene derivative, and the bisbenzylbenzene derivative is contained in the photosensitive layer in an amount of 0.5 to 7%. . The image forming apparatus according to claim 7, wherein a distance between the charging device and the photosensitive member is 100 μm or less. 10. The process cartridge used in the image forming apparatus according to claim 1, wherein at least the cleaning unit is integrally supported and is detachable from the image forming apparatus main body. The cleaning unit has an L-shaped cross section. A metal blade holder having a plate thickness of 1.0 to 2.5 mm and a cleaning blade fixed on the surface of one plate-like portion forming the L-shape of the metal blade holder. The other plate-like part forming the L-shape of the blade holder made of steel has a width of 10 mm or more, its outer peripheral part is flat, and an inner part has a region higher than the outer peripheral part by 0.5 mm or more. Feature process cartridge.

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