JP2004246058A - Image forming apparatus - Google Patents

Image forming apparatus Download PDF

Info

Publication number
JP2004246058A
JP2004246058A JP2003035585A JP2003035585A JP2004246058A JP 2004246058 A JP2004246058 A JP 2004246058A JP 2003035585 A JP2003035585 A JP 2003035585A JP 2003035585 A JP2003035585 A JP 2003035585A JP 2004246058 A JP2004246058 A JP 2004246058A
Authority
JP
Japan
Prior art keywords
image
image forming
electrophotographic photosensitive
photosensitive member
flange
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2003035585A
Other languages
Japanese (ja)
Inventor
Junichi Shibata
順一 柴田
Tetsuya Sakamoto
哲也 坂本
Hidemi Nukada
秀美 額田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujifilm Business Innovation Corp
Original Assignee
Fuji Xerox Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Xerox Co Ltd filed Critical Fuji Xerox Co Ltd
Priority to JP2003035585A priority Critical patent/JP2004246058A/en
Publication of JP2004246058A publication Critical patent/JP2004246058A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Discharging, Photosensitive Material Shape In Electrophotography (AREA)
  • Photoreceptors In Electrophotography (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of surely suppressing the occurrence of an image unevenness to such a degree that the image unevenness is not visually recognized. <P>SOLUTION: The image forming apparatus 1 is provided with an image forming section 2 which has a flanged electrophotographic photoreceptor 3 obtained by fastening flanges 14a, 14b to both end openings in an electrophotographic photoreceptor 13 having a photosensitive layer formed on a cylindrical substrate 19 by a dip coating method, and in which an image formed on the flanged electrophotographic photoreceptor 3 is transferred onto an image output medium 12 to form a black-and-white image, the image forming apparatus 1 achieves resolution R (dpi), and the absolute value Δt (μm) of film thickness difference between the maximum and minimum film thicknesses of a coating film 61 on the inside face of the electrophotographic photoreceptor 13 satisfies Δt≤1,000÷R<SP>0.5</SP>. In this case, with respect to an image formed using the image forming apparatus 1, the occurrence of image unevenness can be surely suppressed to such a degree that image unevenness is not visually recognized. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、プリンタ、複写機等の画像形成装置に係り、より詳細には、フランジ付き電子写真感光体を備えた画像形成装置に関するものである。
【０００２】
【従来の技術】
画像形成装置においては、アルミニウム又はアルミニウム合金からなる導電性の円筒状基体の外周面上に感光層を形成してなる電子写真感光体が用いられており、この電子写真感光体には、従来から、基体の片側又は両側にフランジと呼ばれる樹脂又はアルミニウム合金からなる嵌合物が接着や加締めその他の手段によって嵌合され、電子写真感光体とフランジを一体としたフランジ付き電子写真感光体として使用されることが一般的である（例えば、特許文献１参照）。
【０００３】
【特許文献１】
特開平８−１８４９７７号公報
【０００４】
【発明が解決しようとする課題】
ところで、電子写真感光体の製造過程においては一般に、円筒状基体に感光層を形成するために浸漬塗布法が用いられる。ところが、この浸漬塗布法により感光層を形成する場合には、円筒状基体の下端部内面への感光層形成用塗布液の付着が避けられない。
【０００５】
従って、浸漬塗布法によって得られた電子写真感光体の端部開口にフランジを嵌合すると、開口部近傍の内面に残留した塗布膜の存在により、フランジが電子写真感光体に完璧に嵌合されず、電子写真感光体の中心軸線とフランジの回転軸線とが一致しなくなる場合がある。その場合、フランジ付き電子写真感光体が画像形成装置においてフランジの回転軸線を中心に回転されると、電子写真感光体に振れが生じ、生成される画像にムラが生じることとなる。
【０００６】
そこで、上記のようなフランジ付き電子写真感光体において電子写真感光体の内周面における塗布膜の完全な除去を図る方法が種々考案されている（例えば特開平５−１７３３３９号公報）。同公報に記載の塗布膜除去方法は、内周面に塗布膜が残留している電子写真感光体を、その塗布膜が残留している端部側から軸方向に所定の長さＬ１だけ、塗膜を溶解し得る溶剤中に浸漬した後、ストロークＬ１で軸心方向に往復運動させ、次に、Ｌ１より長いストロークＬ２で軸心方向に往復運動させ、最後に、Ｌ１より短いストロークＬ３で軸心方向に往復運動させることにより塗布膜の除去を図るものである。
【０００７】
しかし、上記公報に記載の塗布膜除去方法で、電子写真感光体の内周面における塗布膜を除去してもなお、上記フランジ付き電子写真感光体を用いた画像形成装置において目視で分かる程度に画像ムラが生じる場合があった。また、フランジ付き電子写真感光体を用いてカラー画像を形成する画像形成装置にあっては、画像ムラが色ムラとして生じるため、よりいっそう欠陥として目立つものとなってしまった。
【０００８】
本発明は、上記事情に鑑みてなされたものであり、画像ムラの発生を目視で分からない程度まで確実に抑えることができる画像形成装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明者等は、上記課題を解決すべく鋭意検討した結果、フランジが嵌合される電子写真感光体において内周に残留した塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値Δｔ（μｍ）が画像形成装置の解像度Ｒ（ｄｐｉ）に対して特定の関係を満たすようにすることで、上記課題を解決し得ることを見出し、本発明を完成するに至った。
【００１０】
即ち本発明は、円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つフランジ付き電子写真感光体に形成される像を画像出力媒体に転写して白黒画像を形成する画像形成部を備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、膜厚差Δｔ（μｍ）が下記式：
Δｔ≦１０００÷Ｒ０．５ ・・・（１）
を満たすことを特徴とする。
【００１１】
この画像形成装置によれば、画像形成部によりフランジ付き電子写真感光体に形成される像が画像出力媒体に転写されて白黒画像が形成される。このとき、その画像上において、濃度ムラ（画像ムラ）を目視で分からない程度まで確実に抑えることが可能となる。
【００１２】
また本発明は、円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つフランジ付き電子写真感光体に形成される像を画像出力媒体に転写してカラー画像を形成することが可能な画像形成部を１つ備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、膜厚差Δｔ（μｍ）が下記式：
Δｔ≦７５０÷Ｒ０．５ ・・・（２）
を満たすことを特徴とする。
【００１３】
この画像形成装置によれば、１つの画像形成部によりフランジ付き電子写真感光体に形成される像が画像出力媒体に転写されてカラー画像が形成されても、その画像上において、色ムラ（画像ムラ）を、目視で分からない程度まで確実に抑えることが可能となる。
【００１４】
また本発明は、円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つフランジ付き電子写真感光体に形成される像を画像出力媒体に転写してカラー画像を形成することが可能な画像形成部を複数備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、膜厚差Δｔ（μｍ）が下記式：
Δｔ≦５００÷Ｒ０．５ ・・・（３）
を満たすことを特徴とする。
【００１５】
この画像形成装置によれば、複数の画像形成部によりフランジ付き電子写真感光体に形成される像が画像出力媒体に転写されてカラー画像が形成されても、その画像上において、色ムラ（画像ムラ）を、目視で分からない程度まで確実に抑えることが可能となる。
【００１６】
上記感光層が、少なくとも１５μｍを超える厚さの下引き層を有することが好ましい。
【００１７】
円筒状基体において、その製造過程での溶着により生ずる継ぎ目がある場合に、下引き層により、その継ぎ目が隠蔽され、画像において筋状模様の画像欠陥が防止される。
【００１８】
【発明の実施の形態】
以下、本発明の実施形態について詳細に説明する。
【００１９】
［第１実施形態］
図１は本発明の画像形成装置にかかる第１実施形態を示す概略図である。図１に示すように、本実施形態に係る画像形成装置１は１つの画像形成部２を有し、画像形成部２は、フランジ付き電子写真感光体３を備えている。フランジ付き電子写真感光体３は、画像形成装置１において回転可能に支持されている。
【００２０】
また画像形成部２は、フランジ付き電子写真感光体３の表面を帯電させる接触帯電装置４と、接触帯電装置４により帯電されるフランジ付き電子写真感光体３を、解像度がＲ（ｄｐｉ）となるように露光する像露光装置６と、像露光装置６により露光された部分を黒色トナーを用いて現像する現像装置７と、現像装置７によりフランジ付き電子写真感光体３に現像された像を紙等の画像出力媒体１２上に転写する転写装置８と、画像形成部２の転写装置８で画像出力媒体１２に転写された未定着の画像を画像出力媒体１２に定着させるための像定着装置１１と、転写装置８により画像出力媒体１２に像を転写した後の感光体表面をクリーニングするクリーニング装置９とを備えている。接触帯電装置４は、電源５から与えられる電位によりフランジ付き電子写真感光体３の表面を帯電させるようになっている。
【００２１】
上記画像形成装置１によれば、フランジ付き電子写真感光体３が矢印Ａ方向に回転させられながら接触帯電装置４により帯電され、像露光装置６により像露光が行われて静電潜像が形成された後、現像装置７２により静電潜像が現像化される。そして、現像化された像は、転写装置８により画像出力媒体１２に転写され、画像出力媒体１２上に白黒画像が形成される。この画像は、像定着装置１１により画像出力媒体１２に定着される。
（フランジ付き電子写真感光体）
図２は、図１のフランジ付き電子写真感光体を示す側面図、図３は、図２のＩＩＩ−ＩＩＩ線に沿った断面図である。
【００２２】
図２、図３に示すように、フランジ付き電子写真感光体３は、円筒状の電子写真感光体１３と、電子写真感光体の両端の開口にそれぞれ嵌合されるフランジ１４ａ，１４ｂとから構成されている。
【００２３】
電子写真感光体１３は、円筒状基体１９と、円筒状基体１９の外周面上に設けられる感光層２０とを備えている。感光層２０は、画像形成装置１においては、電荷発生層及び電荷輸送層を順次積層してなる積層型感光層となっている。フランジ１４ａは、電子写真感光体３の端部開口に嵌合される円筒状の嵌合部１５と、嵌合部１５より大きい外径を有し電子写真感光体３の端面に当接される円盤部１６とにより構成されている。円盤部１６の外周には、ギヤ部１６ａが設けられている。
【００２４】
一方、フランジ１４ｂは、電子写真感光体１３の端部開口に嵌合される円筒状の嵌合部１７と、嵌合部１７より大きい外径を有し電子写真感光体１３の端面に当接される円盤部１８と、円盤部１８に対して嵌合部１７と反対側に設けられるギヤ部６０とから構成されている。円盤部１８の外周には、ギヤ部１８ａが設けられている。両フランジ１４ａ、１４ｂは、回転可能に支持され、ギヤ部１６ａ、１８ａ、６０は画像形成部２の駆動ギア（図示せず）と噛合されている。そして、駆動ギアを回転させることによってフランジ付き電子写真感光体３がフランジ１４ａ，１４ｂの中心軸線を回転中心として回転できるようになっている。
（フランジ付き電子写真感光体の製造方法）
ここで、フランジ付き電子写真感光体３の製造方法について説明する。
【００２５】
まずフランジ付き電子写真感光体３を構成する電子写真感光体１３の製造方法について説明する。
【００２６】
まず円筒状基体１９を用意する。円筒状基体１９の材質は、基本的には導電性を有し且つ円筒状に成型できる材料であれば特に制限はないが、成形性、加工性、強度などの観点からは、金属、特にアルミニウムや、１０００（純アルミニウム）系、３０００（Ａｌ−Ｍｎ）系、５０００（Ａｌ−Ｍｇ）系、６０００（Ａｌ−Ｍｇ−Ｓｉ）系等のアルミニウム合金あるいはステンレス鋼などの材料を用いることができる。
【００２７】
円筒状基体１９は、例えばアルミニウムあるいはアルミニウム合金を原料として円筒状に成型する。成型方法は、円筒状に成型できるものであれば特定のものには限られないが、ビレットを熱間押出した後、冷間抽伸して円筒状の部材とし、その外周面を旋削又は研磨・研削加工する方法が製造安定性やコスト面からよく用いられる。ここで、押出加工法としては、マンドレル方式又はポートホール方式が用いられる。マンドレル方式は、押出機のステムの先端にマンドレルを取り付け、これを中子として用いて円筒を形成する方法であり、これに対しポートホール方式は、金型の中でいったん材料のメタルが分離された後再び溶着させて円筒を形成する方式である。一般に、ポートホール方式の方が、マンドレル方式よりも円筒の薄肉化が容易で偏肉が生じにくいという利点があるため、ポートホール方式を用いて円筒状の部材を製造する方法がよく用いられる。
【００２８】
ここで、ポートホール方式で製造されるポートホール管について説明する。ポートホール管の材料としては、１０００（純アルミニウム）系、３０００（Ａｌ−Ｍｎ）系、５０００（Ａｌ−Ｍｇ）系、６０００（Ａｌ−Ｍｇ−Ｓｉ）系などのアルミニウムまたはアルミニウム合金が用いられる。
【００２９】
これらの材料を用いたポートホール管は、押出し加工、所望の長さへの切断の各工程によって製造される。かかる各工程における加工の条件は、従来普通に行われている範囲内の条件で行う。押出し加工は、偏肉の度合および薄肉化に優れているポートホール方式で行う。なお、押出し加工（ポートホール押出工程）後であって切断加工前に、曲がり矯正装置により、ポートホール管に対して曲がり矯正を施すことが好ましい。この場合、この後工程として行われる旋削・研磨・研削において、加工がしやすくなる。
【００３０】
外径ばらつき、内径ばらつき及び曲がりなどをより小さくするためには、加工率１．１〜１．４程度の抽伸加工をポートホール管に施すことが好ましい。この引抜き加工（抽伸加工）は、内径側にプラグ、外径側にダイと呼ばれる金型を設置し、内径と外径を同時に引き伸ばすことで行われるが、この内側と外側の加工率のバランスが悪いと残留応力の原因となる。また、切断はポートホール管を所定の長さに揃えるために行われるが、切断によって生ずる端面の外側端縁または内側端縁に、切断時に発生したバリが残ることがあり、これが以降の加工に障害となるおそれがある。従って、ポートホール管の切断工程後に、Ｃ面取りやブラシ加工等のバリ取り工程を設けることが望ましい。
【００３１】
ポートホール管の肉厚は、コストおよび画像形成装置１全体の軽量化の点から、好ましくは２ｍｍ以下、より好ましくは１ｍｍ以下の範囲である。また、偏肉は、電子写真感光体１３の円筒状基体１９として用いることを配慮すれば、好ましくは０．０７５ｍｍ以下である。
【００３２】
次に、上記のようにして準備した円筒状基体１９の外周面上に感光層２０を形成する。感光層２０の形成は、電荷発生物質、結着樹脂および溶剤を分散及び混合して調合された電荷発生層形成用塗布液と、電荷輸送物質、結着樹脂および溶剤を分散及び混合して調合された電荷輸送層形成用塗布液とをそれぞれ用意し、まず円筒状基体１９の外周面に電荷発生層形成用塗布液を塗布し乾燥し、次いでその上に、電荷輸送層形成用塗布液を塗布し乾燥することにより行う。こうして円筒状基体１９上に、電荷発生層及び電荷輸送層を順次積層してなる積層型の感光層２０が形成される。
【００３３】
上記電荷発生物質としては、例えばアゾ顔料、ジスアゾ顔料、キノン顔料、キノシアニン顔料、ペリレン顔料、インジゴ顔料、ビスベンジイミダソール顔料、フタロシアニン顔料、キナクリドン顔料、ピリリウム塩、アズレニウム塩、三晶方型セレン等が挙げられる。
【００３４】
上記電荷輸送物質としては、例えば主鎖または側鎖に、アントラセン、ピレン、フェナントレン、コロネン等の多芳香族化合物、または、インドール、カルバゾール、オキサゾール、イソオキサゾールチアオール、イミダゾール、ピラゾール、オキサジアゾール、ピラジリン、ピアジアゾール、トリアゾール等の含窒素環式化合物の骨格を有する化合物や、その他、ヒドラゾン化合物等の正孔輸送物質等が挙げられる。
【００３５】
上記結着樹脂としては、例えばポリカーボネイト、ポリアリレート、ポリスチレン、ポリメタクリ酸エステル類、スチレンーメタクリル酸メチルコポリマー、ポリエステル、スチレンーアクリロニトリルポリマー、ポリサルホン、ポリ酢酸ビニル、ポリアクリルニトリル、ポリビニルブチラール、ポリビニルピロリドン、メチルセルロース、ヒドロキシメチルセルロース、セルロースエステル類等が挙げられる。
【００３６】
上記溶剤（溶媒）としては、揮発性が高く、且つその蒸気の密度が空気より大きい溶剤が好適に用いられ、例えば、ｎ―ブチルアミン、ジエチルアミン、エチレンジアミン、イソプロパノールアミン、トリエタノールアミン、Ｎ，Ｎ−ジメチルホルムアミド、アセトン、メチルエチルケトン、シクロヘキサノン、ベンゼン、４−メトキシ−４−メチルペンタノン、ジメトキシメタン、ジメトキシエタン、２，４−ペンタジオン、アニソール、３−オキソブタン酸メチル、モノクロロベンゼン、トルエン、キシレン、クロロホルム、１，２−ジクロロエタン、ジクロロメタン、テトラヒドロフラン、ジオキサン、メタノール、エタノール、イソプロパノール、１−ブタノール、酢酸エチル、酢酸ブチル、ジメチルスルホキシド、メチルセルソルブ、エチルセルソルブ、メチルセルソルブ、メチルセルソルブアセテート等が挙げられる。
【００３７】
上記電荷発生層形成用塗布液及び電荷輸送層形成用塗布液を円筒状基体１９に塗布するには、浸漬塗布法が用いられる。即ち、電荷発生層は、円筒状基体１９を電荷輸送層形成用塗布液に浸漬した後、その塗布液から引き上げることにより形成され、電荷輸送層は、円筒状基体１９に電荷発生層が形成されたものを電荷輸送層形成用塗布液に浸漬した後、その塗布液から出すことにより形成される。
【００３８】
このように、浸漬塗布法により円筒状基体１９の外周面上に感光層２０を形成することにより電子写真感光体が得られるが、円筒状基体１９を塗布液に浸漬する場合、その下端部内周面への塗布液の付着が避けられない。そのため付着した塗布液が電子写真感光体の端部の内周面に塗布膜６１として形成されてしまう（図４参照）。
【００３９】
この状態で電子写真感光体とフランジ１４ａ又はフランジ１４ｂとを嵌合させても完全に嵌合されず、電子写真感光体の中心軸線とフランジ１４ａの中心軸線が一致しなくなるおそれがある。このため、フランジ付き電子写真感光体３を画像形成部２に装着すると、電子写真感光体を回転させた場合に振れが生じ、生成される画像にムラが生じてしまう。
【００４０】
そこで、円筒状基体１９上に感光層２０を形成した後は、電子写真感光体を所定時間自然乾燥した後であってフランジ１４ａ，１４ｂの嵌合前に、以下のようにして電子写真感光体の内周面に残留した塗布膜６１の拭き取りを行う。塗布膜６１の拭取りは、具体的には、スポンジ状の拭取り部材を電子写真感光体の内周面に密着させた状態で、塗布膜を溶解する溶剤を感光体の内周面と拭取部材との間に供給しながら拭取部材を回転させることにより行うことができる。
【００４１】
塗布膜６１の拭き取りを終えた後は、電子写真感光体１３の端部の内周面における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値Δｔ（μｍ）を測定する。Δｔは、例えば渦電流膜厚計などにより測定することができる。
【００４２】
こうして電子写真感光体についてΔｔを測定し、画像形成装置１の解像度Ｒ（ｄｐｉ）に対して下記式：
Δｔ≦１０００÷Ｒ０．５ ・・・（１）
を満たすΔｔを有する電子写真感光体を、画像形成装置１のフランジ付き電子写真感光体３に用いる電子写真感光体１３として選別する。電子写真感光体が上記（１）式を満たさない場合には、複数本の電子写真感光体についてΔｔの測定を行い、上記（１）式を満たすΔｔを有する電子写真感光体を、フランジ付き電子写真感光体３の電子写真感光体１３として選別する。
【００４３】
一方、電子写真感光体１３の端部開口に嵌合されるフランジ１４ａ，１４ｂを準備する。フランジ１４ａ，１４ｂの材質は熱可塑性樹脂を主成分としており、同一の形状が得られれば成型方法は特定の方法には限られないが、フランジ１４ａ，１４ｂは、例えば射出成形によって得ることができる。上記熱可塑性樹脂としては、例えばポリアセタール樹脂、ＡＢＳ樹脂、ポリカボネード樹脂、ポリプロピレン樹脂、ナイロン樹脂、ＰＢＴ樹脂などが挙げられる。
【００４４】
そして、図４に示すように、こうして準備したフランジ１４ａ，１４ｂをそれぞれ、電子写真感光体１３の各端部の開口に嵌合させる。この場合、フランジ１４ａの嵌合部１５の外周面を電子写真感光体１３の一方の端部の内周面と沿うように嵌合させればよい。またフランジ１４ｂについても、嵌合部１７の外周面を電子写真感光体１３の他方の端部の内周面と沿うように嵌合させる。嵌合方法は、電子写真感光体１３にフランジ１４ａ、１４ｂを固定できるものであれば上記の固定方法に限定されないが、圧入と接着を併用して用いることもできる。この場合、フランジ１４ａ，１４ｂを電子写真感光体１３に圧入させる際の圧入代は、使用環境と、フランジ１４ａ又は１４ｂの線膨張係数との関係に応じて適切な値に設定される。
【００４５】
こうしてフランジ付き電子写真感光体３の製造が完了する。こうして製造されるフランジ付き電子写真感光体３においては、画像形成部２によりフランジ付き電子写真感光体３に形成される像が画像出力媒体１２に転写されて白黒画像が形成される場合でも、その画像上において、濃度ムラ（画像ムラ）を、目視で分からない程度まで確実に抑えることが可能となる。
【００４６】
なお、円筒状基体１９に感光層２０を形成するための浸漬塗布装置及び電子写真感光体１３の端部の内周面における塗布膜６１の拭取り装置の一例についてそれぞれ説明する。
【００４７】
図５は、浸漬塗布装置の概略図である。図５に示すように、浸漬塗布装置２１は、塗布液２６を還流させるための還流装置２３を備えており、還流装置２３は円筒状基体１９を塗布液２６中に浸漬するための開口が上端部に形成された塗布槽２４と、塗布槽２４から流れ込む塗布液２６を貯留する貯留槽２５とを有している。塗布槽２４の上部側面と貯留槽２５の上部側面との間には、塗布槽２４内の塗布液２６を貯留槽２５に導入する受容用パイプ２９が設けられている。さらに、貯留槽２５の底面と塗布槽２４の底面との間には、ポンプ２８を有する還流用パイプ２７が設けられており、ポンプ２８の作動により、貯留槽２５に貯留されている塗布液２６が塗布槽２４に戻されるようになっている。
【００４８】
一方、浸漬塗布装置２１は、円筒状基体１９を昇降させ、塗布槽２４の塗布液２６中に浸漬し塗布液２６から引き上げる昇降装置２２を備えている。昇降装置２２は、モータ３１と、モータ３１の回転軸に連結され鉛直方向に延びる駆動ネジ３２と、駆動ネジ３２にねじ係合され、駆動ネジ３２の回転により昇降する昇降アーム３４と、昇降アーム３４に固定され円筒状基体１９を保持する基体保持部材３５とを備えている。
【００４９】
上記浸漬塗布装置２１を用いて円筒状基体１９に感光層形成用塗布液を形成する場合、まずポンプ２８を作動する。すると、塗布槽２４において塗布液２６の液面が上昇し、塗布槽２４の上部より塗布液２６が受容用パイプ２９を経て貯留槽２５に導入され、貯留槽２５に導入された塗布液２６は、還流用パイプ２７を経て塗布槽２４に戻される。こうして塗布液２６が還流される。この状態で、昇降装置２２のモータ３１の作動により駆動ネジ３２を回転させ、昇降アーム３３を下降させる。すると、円筒状基体１９が下降して塗布槽２４の塗布液２６中に浸漬される。円筒状基体１９を塗布液２６中に浸漬した後、モータ３１の作動により駆動ネジ３２を逆回転させ、昇降アーム３３を上昇させる。すると、円筒状基体１９が上昇して塗布液２６中から引き上げられる。こうして円筒状基体１９の外周面上に塗布液２６が塗布されることとなる。
【００５０】
図６は、塗布膜６１の拭取装置の側面図、図７は、拭取部材の平面図であり、（ａ）は図６の拭取り部材の平面図、図７（ｂ）及び（ｃ）は、図７（ａ）の拭取部材の変形例を示す平面図である。図６に示すように、塗布膜拭取装置３７は、支持板３８と、支持板３８の上面側中央に固定され塗布膜６１を拭き取る拭取部材３９と、支持板３８に固定され支持板３８及び拭取部材３９を貫通する回転駆動軸６２と、拭取部材３９の上面側中央であって回転駆動軸６２の先端に固定され、溶剤吹出口４０ａを有する溶剤吹出部４０とを備えている。拭取部材３９は、材質としてポリエチレン樹脂、ポリプロピレン樹脂等の樹脂材料を発泡させて得られた発泡樹脂が用いられ、その形状は、例えば図７（ａ）に示すように円柱状である。なお、拭取り部材３９の形状は、円柱状に限られるものではない。要するに、拭取り部材３９の形状は、電子写真感光体１３の下端開口に拭取り部材３９を挿入した時に拭取り部材３９が電子写真感光体１３の内面に密着する形状であればよい。従って、拭取り部材３９の形状は、図７（ｂ）に示すように直方体形状であってもよく、図７（ｃ）に示すように十字形状でも構わない。溶剤吹出部４０から吹き出される有機溶剤は、固化した塗布膜６１を溶解させることができるものであればよく、このような有機溶剤として、例えば塩化メチレン、テトラヒドロフラン、トルエン、ハロゲン化ベンゼン等が用いられる。
【００５１】
次に、上記塗布膜拭取装置３７を用いた塗布膜６１の拭き取り方法について説明する。まず、回転駆動軸６２を回転させると同時に、溶剤吹出部４０の溶剤吹出口４０ａから有機溶剤を吹き出させ、拭取部材３９を常に有機溶剤で湿潤させるようにする。次に、電子写真感光体１３を、その下端部内周面を拭取部材３９の外周面と密着させながら下降させる。そして、電子写真感光体１３の下端部が拭取部材３９の上面から所定の距離に達した位置で所定時間電子写真感光体１３を停止させる。次に、所定速度で所定距離上昇させて電子写真感光体１３を停止させる。そして、回転駆動軸６２の回転速度を更に上げる。こうして、電子写真感光体１３の内周面における塗布膜６１の拭取りを行う。
【００５２】
なお、上記実施形態では、感光層２０に下引き層が含まれていないが、円筒状基体１９として、ポートホール管が用いられる場合には、感光層２０は下引き層を含んでもよい。この場合、下引き層の厚さは１５μｍを超えることが好ましい。下引き層の厚さが１５μｍ未満では、ポートホール法で円筒状基体１９を成型した場合に一旦分離されたメタル同士が溶着した跡（ウェルドライン）が残り、電子写真感光体１３を用いて画像形成が行われる場合にこのウェルドラインに起因して画像上に筋状の画像欠陥が現れる。１５μｍを超える厚さの下引き層が感光層２０に含まれることによって、円筒状基体１９のウェルドラインが隠蔽され、電子写真感光体１３を用いて画像が形成された場合にその画像上において筋状の画像欠陥が目視で分からない程度まで抑えられる。
【００５３】
下引き層は、下引き層形成用塗布液を、上述した浸漬塗布法により塗布し乾燥することにより円筒状基体１９上に形成される。
【００５４】
上記下引き層としては、例えばアクリル系樹脂、メクアクリル系樹脂、塩化ビニル系樹脂、酢酸ビニル系樹脂、エポキシ系樹脂、ポリウレタン系樹脂、フェノール系樹脂、ポリエステル系樹脂、アルキッド系樹脂、ポリカーボネイト系樹脂、シリコン系樹脂、メラミン系樹脂等の各種樹脂類や、これら樹脂系にジルコニウム化合物、チタニウム化合物等を含有した物が挙げられる。
【００５５】
また上記実施形態では、感光層２０は積層型感光層となっているが、感光層２０は、単層型感光層であっても構わない。この場合、塗布液としては、電荷発生能および電荷輸送能の双方を併せ持つ感光層形成用塗布液が用いられる。このような感光層形成用塗布液としては、例えば上記電荷発生物質、上記電荷輸送物質および上記結着樹脂を、上記溶剤中に分散させたものを用いることができる。
【００５６】
また上記実施形態においては、フランジ付き電子写真感光体３はフランジ１４ａ，１４ｂを備えているが、本発明のフランジ付き電子写真感光体は、電子写真感光体の両端開口のうちいずれか一方の端部開口にフランジを嵌合してなるものであってもよい。
【００５７】
更に、上記実施形態においては、画像形成装置１がクリーニング装置９を備えているが、クリーニング装置９は、必ずしも必要なものではない。例えば現像装置７２がクリーニング機能を有する場合は、現像装置７２の他に、別途クリーニング装置９を設ける必要はない。また、画像形成部２は必要に応じて更に除電装置（図示せず）を有していてもよい。更に、図１の画像形成部２においては、接触帯電装置４が用いられているが、非接触式の帯電装置を用いることも可能である。更にまた、上記実施形態では、フランジ１４ａにギヤ部１６ａ、フランジ１４ｂにギヤ部１８ａ、６０が設けられているが、フランジ１４ａ、１４ｂの少なくとも一方にギヤ部が形成されていればよい。
【００５８】
［第２実施形態］
次に、本発明の第２実施形態について説明する。なお、第１実施形態と同一又は同等の構成要素については同一符号を付し、重複する説明を省略する。
【００５９】
図８は、本発明の画像形成装置にかかる第２実施形態を示す概略図である。図８に示すように、本実施形態に係る画像形成装置１０１は、いわゆるタンデム方式のカラー画像形成装置であり、以下の点で第１実施形態の画像形成装置１と相違する。
【００６０】
即ち第１に、画像形成装置１０１が４つの画像形成部２ａ〜２ｄを有している点である。ここで、画像形成部２ａ〜２ｄは、トナーの色を除いて第１実施形態の画像形成部２と同様の構成を有する。
【００６１】
第２に、画像形成部２ａ〜２ｄのそれぞれにおけるフランジ付き電子写真感光体３が、下記式：
Δｔ≦５００÷Ｒ０．５ ・・・（３）
（上記式中、Δｔは、電子写真感光体１３の両端開口にフランジ１４ａ，１４ｂを嵌合する前の電子写真感光体１３の下端部内周面における塗布膜の最大厚さと最小厚さとの差の絶対値（μｍ）を、Ｒは、フランジ付き電子写真感光体３が装着される画像形成装置１０１の解像度（ｄｐｉ）を表す）
を満たす点である。
【００６２】
なお、画像形成装置１０１は、画像形成部２に対向した部位に配設されて画像出力媒体１２を搬送するベルト搬送装置４１と、画像出力媒体１２をベルト搬送装置４１に供給する媒体供給装置５４とを備えている。ベルト搬送装置４１は、無端状の搬送ベルト４２を有しており、搬送ベルト４２は、例えば６つの張架ロール４３〜４８及び４つの転写装置８に掛け渡されている。また媒体供給装置５４は、画像出力媒体１２を収容する給紙トレイ５５と、給紙トレイ５５に収容される画像出力媒体１２をベルト搬送装置４１に供給する媒体送り機構５６とを備えている。
【００６３】
そして、搬送ベルト４２が循環搬送され、媒体供給装置５４により画像出力媒体１２がベルト搬送装置４１に供給されると、画像出力媒体１２は、吸着ロール４９で吸着保持されて、各画像形成部２ａ〜２ｄの転写部位に順次移動される。こうして画像出力媒体１２上に、異なる色のトナーが重畳転写されてカラー画像が形成される。４つの画像形成部２ａ〜２ｄを順次通過した画像出力媒体１２は、定着装置１１により、転写されたカラー画像が画像出力媒体１２に定着された後、収容トレイ５１に収容される。なお、符号５２は、搬送ベルト４２に所定の張力を付与するテンションロール、符号５３は、搬送ベルト４８の表面の汚れをクリーニングするベルトクリーナである。
【００６４】
上記画像形成装置１０１によれば、各画像形成部２ａ〜２ｄにおいて、フランジ付き電子写真感光体３が、画像形成装置１０１のフランジ付き電子写真感光体として装着されることにより、画像出力媒体１２にカラー画像が形成されても、色ムラ（画像ムラ）を、目視で分からない程度まで確実に抑えることが可能となる。
【００６５】
［第３実施形態］
次に、本発明の第３実施形態について説明する。なお、第１及び第２実施形態と同一又は同等の構成要素については同一符号を付し、重複する説明を省略する。
【００６６】
図９は、本発明の画像形成装置の第３実施形態を示す概略図である。図９に示すように、本実施形態の画像形成装置２０１は、画像出力媒体１２にカラー画像を形成する画像形成部７１と、この画像形成部７１に画像出力媒体１２を供給する媒体供給装置５４とを備えている。画像形成装置２０１において媒体供給装置５４が、給紙トレイ５５と、媒体送り機構５６とから構成されている点は、第２実施形態の画像形成装置１０１と同様である。なお、本実施形態の画像形成装置２０１は、第２実施形態の画像形成装置１０１と異なり、ベルト搬送装置４１を有していない。
【００６７】
画像形成部７１は、１本のフランジ付き電子写真感光体３と、フランジ付き電子写真感光体３の周囲に沿って順次配置される接触帯電装置４、像露光装置６、現像装置７２、中間転写ユニット７３、二次転写ユニット７４及び像定着装置１１とを備えている。
【００６８】
ここで、現像装置７２について説明する。現像装置７２は、１つのフランジ付き電子写真感光体３に対して４つの現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃを備えている。より具体的には、４つの現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃは、回転軸７２ｏの周囲に配置され、回転軸７２ｏの回転に伴って各４色の現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃが順次フランジ付き電子写真感光体３に対向するように構成されている。各現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃは、フランジ付き電子写真感光体３に形成された静電潜像をＫ，Ｙ，Ｍ，Ｃの各色のトナー像に現像する。現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃに使用するトナー剤としては、磁性若しくは非磁性の一成分系現像剤又は二成分系現像剤を用いることができる。さらに、現像装置７２は、正規現像タイプ又は反転現像タイプの何れでもよい。
【００６９】
現像装置７２による現像工程をより具体的に説明すると、以下の通りである。まず、４つの現像器７２Ｋ，７２Ｙ，７２Ｍ，７２Ｃのうちの現像器７２Ｋにより、ブラックトナーによる現像が行われる。次に、現像装置７２が回転し、現像器７２Ｙがフランジ付き電子写真感光体３に対向する位置に移動する。そしてこの現像器７２Ｙにより、イエロートナーによる現像が行われる。次に、現像装置７２が回転し、現像器７２Ｍがフランジ付き電子写真感光体３に対向する位置に移動する。そしてこの現像器７２Ｍにより、マゼンタトナーによる現像が行われる。次に、現像装置７２が回転し、現像器７２Ｃがフランジ付き電子写真感光体３に対向する位置に移動する。そしてこの現像器７２Ｃにより、シアントナーによる現像が行われる。この結果、４色のトナーによる重畳転写が行われ、目的のカラー画像に対応した合成カラートナー像がフランジ付き電子写真感光体３上に形成される。
【００７０】
なお、以上の４色での現像は１色ごとに独立して行われ、該１色についての現像が行われている間は他の色による現像は行われていないので、該１色についての現像は他の色の現像器の影響を受けることはない。具体的には、目的の画像の第１の色成分像（例えばブラック成分像）に対応した静電潜像がまず形成される。次いで、現像器７２Ｋによりその静電潜像がブラックトナーで現像される。この時、他の現像器７２Ｙ，７２Ｍ，７２Ｃは、オフ状態になっているのでフランジ付き電子写真感光体３には作用せず、ブラックトナーによる現像像は他の現像器７２Ｙ，７２Ｍ，７２Ｃの影響を受けない。
【００７１】
次に、中間転写ユニット７３について説明する。中間転写ユニット７３は、フランジ付き電子写真感光体３上に形成されたトナー像が一次転写位置Ｔ１にて一次転写される無端の中間転写ベルト７５を有している。中間転写ベルト７５は、一次転写位置Ｔ１に配置された一次転写ロール７６、内側二次転写ロール（バイアスロール）７７、及び駆動ロール７８等によって張架されており、図示しない駆動機構によりフランジ付き電子写真感光体３と略同速度で駆動ロール７８を介して図中の矢印方向へ回転する。
【００７２】
一次転写ロール７６としては、フランジ付き電子写真感光体３上のトナー像を中間転写ベルト７５に転写する機能を有している限り特に制限はなく、例えばベルト、ローラー、フィルム、ゴムブレード等を用いた接触型転写帯電器、コロナ放電を利用したスコロトロン転写帯電器やコロトロン転写帯電器等の公知の転写帯電器を用いることができる。これらの中でも、転写帯電補償能力に優れる点では接触型転写帯電器が望ましい。
【００７３】
二次転写ユニット７４は、中間転写ベルト７５に一次転写されたトナー像を媒体供給トレイ５５から媒体送り機構５６によって供給された画像出力媒体１２に二次転写位置Ｔ２にて二次転写するものである。
【００７４】
上述したフランジ付き電子写真感光体３は、下記式：
Δｔ≦７５０÷Ｒ０．５ ・・・（２）
（上記式中、Δｔは、電子写真感光体１３の両端開口にフランジを嵌合する前の電子写真感光体の下端部内周面における塗布膜の最大厚さと最小厚さとの差の絶対値（μｍ）を、Ｒは、フランジ付き電子写真感光体３が装着される画像形成装置２０１の解像度（ｄｐｉ）を表す）
を満たすものである。
【００７５】
このようなフランジ付き電子写真感光体３を有する画像形成装置２０１によれば、画像出力媒体１２にカラー画像が形成されても、その画像上において、色ムラ（画像ムラ）を、目視で分からない程度まで確実に抑えることが可能となる。
【００７６】
以下、実施例を用いて、本発明の内容をより具体的に説明するが、本発明は、これらの実施例に限定されるものではない。
【００７７】
【実施例】
（実施例１）
外径φ３０．３、内径φ２８．５、長さ３４０ｍｍ、Ａ６０６３製アルミニウム素管を用意し、旋盤にて外径φ３０．０に切削加工を施して円筒状基体を得た。
【００７８】
次に、上記のようにして得られた円筒状基体の外周面上に以下のようにして感光層を形成した。
【００７９】
即ち、まず酸化亜鉛（平均粒子径７０μｍ、比表面積値１５ｍ２／ｇ：テイカ社製）１００重量部をトルエン５００重量部と攪拌混合し、更にシランカップリング剤（信越化学社製ＫＢＭ６０３）１．５重量部を添加し、２時間攪拌した。
【００８０】
その後トルエンを減圧蒸留にて留去し、１５０℃で３時間焼き付けを行い、酸化亜鉛に表面処理を施した。
【００８１】
次に、こうして表面処理を施した酸化亜鉛６０重量部、硬化剤であるブロック化イソシアネート（住友バイエルンウレタン社製スミジュール３１７５）１５重量部及びブチラール樹脂 （積水化学社製ＢＭ−１）１５重量部をメチルエチルケトン８５重量部に溶解した溶液３８重量部と、メチルエチルケトン２５重量部とを混合し、１ｍｍφのガラスビーズを用いてサンドミルにて２時間の分散を行い分散液を得た。得られた分散液に触媒としてジオクチルスズジラウレート０．００５重量部及びシリコーンオイル（東レダウコーニングシリコーン社製ＳＨ２９ＰＡ）０．０１重量部を添加し、下引き層形成用塗布液を得た。
【００８２】
この下引き層形成用塗布液を浸漬塗布法により先に準備した円筒状基体上に塗布した。
【００８３】
次に、下引き層形成用塗布液の塗布が終了した導電性基体を５分間自然乾燥させ、図６の拭取装置３７を用いて円筒状基体の下端部内面の拭き取りを行った。その際、溶剤吹出部４０の溶剤吹出口４０ａからブタノールを１５０ｍｌ／分にて連続的に流し、１５倍発泡ポリエチレンからなる拭取部材３９を常に湿潤させておいた。この状態で円筒状基体を２００ｍｍ／分で下降させると同時に支持板３８を３０ｒｐｍで回転させ、円筒状基体の下端部が拭取部３９の上面から１５ｍｍの位置に食い込むまで下降させた。その後、その位置に１０秒間保持した後、５０ｍｍ／分の速度で２０ｍｍ上昇させ、さらに５００ｍｍ／分の速度で上昇させることにより拭き取りを行った。
【００８４】
拭き取りを行った下引き層付き円筒状基体について１６０℃、１００分の乾燥硬化を行い、厚さ２０μｍの下引き層を得た。
【００８５】
次に、下引き層上に以下のようにして電荷発生層を形成した。まず、電荷発生物質として、Ｃｕｋα線を用いたＸ線回折スペクトルのブラッグ角度（２θ±０．２°）が少なくとも７．３゜，１６．０゜，２４．９゜，２８．０゜の位置に回折ピークを有するヒドロキシガリウムフタロシアニン１５部を用意し、これと、結着樹脂としての塩化ビニル−酢酸ビニル共重合体樹脂（日本ユニカー社製ＶＭＣＨ）１０部と、ｎ−酢酸ブチル３００部とからなる混合物を、１ｍｍφのガラスビーズを用いてサンドミルにて４時間分散した。得られた分散液を電荷発生層形成用塗布液として下引き層上に浸漬塗布法により塗布し、１００℃で１０分間乾燥して、厚みが０．２μｍの電荷発生層を形成した。
【００８６】
さらに、Ｎ，Ｎ’−ジフェニル−Ｎ，Ｎ’−ビス（３−メチルフェニル）−［１、１’］ビフェニル−４，４’−ジアミン４部と、ビスフェノールＺポリカーボネート樹脂（分子量４万）６重量部とをクロルベンゼン８０重量部を加えて溶解した塗布液を電荷輸送層形成用塗布液として浸漬塗布法により塗布した。
【００８７】
電荷輸送層形成用塗布液の塗布が終了した円筒状基体を５分間自然乾燥させ、下引き層形成後と同様にして下端部内面のふき取り処置を行い、１３０℃、４０分の乾燥を行うことにより膜厚２５μｍの電荷輸送層を形成し、電子写真感光体を得た。
【００８８】
次に、このようにして得られた電子写真感光体の下端部内面に拭き取り残として存在する塗布膜の厚み評価を行った。測定部位は、電子写真感光体の内周面であって下端より５ｍｍの位置である。測定に用いるセンサーとしては、渦電流膜厚計（フィッシャー社製ＭＰ４０）を用い、複数本の電子写真感光体について、電子写真感光体の内周全体の塗布膜の膜厚を測定した。そして、電子写真感光体の内周において測定された塗布膜の最大膜厚と最小膜厚との膜厚差が３３μｍである電子写真感光体を選別した。
【００８９】
一方、フランジとしては、図３に示すフランジ１４ａ，１４ｂと同様な構成のものをそれぞれ製造した。具体的には、フランジは、フッ素入りポリカボネード樹脂（三菱瓦斯化学社製ユーピロンＬＳ−２０２０）を原料として、射出成形で製造した。
【００９０】
そして、上記のようにして選別した電子写真感光体の両端開口にそれぞれフランジを圧入し接着してフランジ付き電子写真感光体を得た。
【００９１】
続いて、このフランジ付き電子写真感光体を、解像度が６００（ｄｐｉ）で画像形成部を１つのみ有し且つ白黒画像を形成する画像形成装置（富士ゼロックス（株）製ＤｏｃｕＣｅｎｔｒｅ２８０。以下、「白黒画像形成装置」と呼ぶ）のフランジ付き電子写真感光体として装着した。
【００９２】
（実施例２）
下端部内面の塗布膜の膜厚差が２５μｍである電子写真感光体を選別した以外は実施例１と同様にしてフランジ付き電子写真感光体を１本製造した。そして、このフランジ付き電子写真感光体を、解像度を１２００（ｄｐｉ）とした以外は実施例１と同様の構成を有する白黒画像形成装置のフランジ付き電子写真感光体として装着した。
【００９３】
（実施例３）
下端部内面の塗布膜の膜厚差が２５μｍである電子写真感光体を選別した以外は実施例１と同様にしてフランジ付き電子写真感光体を１本製造した。そして、この１本のフランジ付き電子写真感光体を、解像度が６００（ｄｐｉ）で画像形成部を１つのみ有し且つカラー画像を形成することが可能な画像形成装置（以下、「カラー画像形成装置」と呼ぶ）のフランジ付き電子写真感光体として装着した。
【００９４】
（実施例４）
下端部内面の塗布膜の膜厚差が２１μｍである電子写真感光体を選別した以外は実施例１と同様にして１本のフランジ付き電子写真感光体を得た。そして、このフランジ付き電子写真感光体を、解像度を１２００（ｄｐｉ）とした以外は実施例３と同様の構成を有するカラー画像形成装置のフランジ付き電子写真感光体として装着した。
【００９５】
（実施例５）
下端部内面の塗布膜の膜厚差が１７μｍである電子写真感光体を選別した以外は実施例１と同様にしてフランジ付き電子写真感光体を４本製造した。そして、これら４本のフランジ付き電子写真感光体を、解像度が６００（ｄｐｉ）で画像形成部を４つ有し且つカラー画像を形成することが可能な画像形成装置（富士ゼロックス（株）製ＤｏｃｕＰｒｉｎｔＣ２２２１。以下、「タンデム型カラー画像形成装置」と呼ぶ）の４本のフランジ付き電子写真感光体として装着した。
【００９６】
（実施例６）
下端部内面の塗布膜の膜厚差が１０μｍである電子写真感光体を選別した以外は実施例１と同様にしてフランジ付き電子写真感光体を４本製造した。そして、これら４本のフランジ付き電子写真感光体を、解像度を１２００（ｄｐｉ）とした以外は実施例５と同様の構成を有するタンデム型カラー画像形成装置の４本のフランジ付き電子写真感光体として装着した。
【００９７】
（比較例１）
下端部内面の塗布膜の膜厚差が４３μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を１本製造した。そして、この１本のフランジ付き電子写真感光体を、実施例１と同様の構成を有する白黒画像形成装置のフランジ付き電子写真感光体として装着した。
【００９８】
（比較例２）
下端部内面の塗布膜の膜厚差が３３μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を１本製造した。そして、この１本のフランジ付き電子写真感光体を、実施例２と同様の構成を有する白黒画像形成装置のフランジ付き電子写真感光体として装着した。
【００９９】
（比較例３）
下端部内面の塗布膜の膜厚差が３３μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を１本製造した。そして、この１本のフランジ付き電子写真感光体を、実施例３と同様の構成を有するカラー画像形成装置のフランジ付き電子写真感光体として装着した。
【０１００】
（比較例４）
下端部内面の塗布膜の膜厚差が２５μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を４本製造した。そして、これら４本のフランジ付き電子写真感光体を、実施例４と同様の構成を有するカラー画像形成装置のフランジ付き電子写真感光体として装着した。
【０１０１】
（比較例５）
下端部内面の塗布膜の膜厚差が２１μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を４本製造した。そして、これら４本のフランジ付き電子写真感光体を、実施例５と同様の構成を有するタンデム型カラー画像形成装置の４本のフランジ付き電子写真感光体として装着した。
【０１０２】
（比較例６）
下端部内面の塗布膜の膜厚差が１７μｍである電子写真感光体を選別した以外は実施例１と同様にして、フランジ付き電子写真感光体を４本製造した。そして、これら４本のフランジ付き電子写真感光体を、解像度を１２００（ｄｐｉ）とした以外は実施例５と同様の構成を有するタンデム型カラー画像形成装置の４本のフランジ付き電子写真感光体として装着した。
【０１０３】
（画像評価）
【表１】

Figure 2004246058
表１に示すように、白黒画像形成装置にあっては、実施例１，２及び比較例３，４の結果より、フランジ付き電子写真感光体が上記（１）式を満たす場合には、濃度ムラが視認されず、濃度ムラを目視で分からない程度まで確実に抑えることができることが分かった。
【０１０４】
また、カラー画像形成装置にあっては、実施例３，４及び比較例３の結果より、フランジ付き電子写真感光体が上記（２）式を満たす場合には、色ムラが視認されず、色ムラを目視で分からない程度まで確実に抑えることができることが分かった。
【０１０５】
更に、タンデム型カラー画像形成装置にあっては、実施例５，６及び比較例４，５，６の結果より、フランジ付き電子写真感光体が上記（３）式を満たす場合には、色ムラが視認されず、色ムラを目視で分からない程度まで確実に抑えることができることが分かった。
【０１０６】
【発明の効果】
以上説明したように本発明の画像形成装置によれば、画像ムラの発生を目視で分からない程度まで確実に抑えることが可能となる。
【図面の簡単な説明】
【図１】本発明の第１実施形態に係る画像形成装置を示す概略図である。
【図２】図１のフランジ付き電子写真写真感光体の側面図である。
【図３】図２のフランジ付き電子写真感光体のＩＩＩ−ＩＩＩ線に沿った断面図である。
【図４】フランジ取付け前の電子写真感光体とフランジを示す切断面端面図である。
【図５】電子写真感光体の感光層の形成に用いられる浸漬塗布装置の概略図である。
【図６】電子写真感光体の端部内面の塗布膜を除去するために用いられる拭取装置の概略図である。
【図７】（ａ）は、図６の拭取り装置を構成する拭取部材の平面図であり、（ｂ）及び（ｃ）は、（ａ）の拭取部材の変形例を示す平面図である。
【図８】本発明の第２実施形態に係る画像形成装置を示す概略図である。
【図９】本発明の第３実施形態に係る画像形成装置を示す概略図である。
【符号の説明】
１，１０１…画像形成装置、２，２ａ〜２ｄ…画像形成部、３…フランジ付き電子写真感光体、１３…電子写真感光体、１４ａ，１４ｂ…フランジ、１９…円筒状基体、２０…感光層、２１…塗布膜。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus such as a printer and a copying machine, and more particularly, to an image forming apparatus including a flanged electrophotographic photosensitive member.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus, an electrophotographic photosensitive member having a photosensitive layer formed on an outer peripheral surface of a conductive cylindrical substrate made of aluminum or an aluminum alloy is used. A fitting made of a resin or an aluminum alloy called a flange is fitted to one or both sides of the base by bonding, caulking or other means, and used as an electrophotographic photosensitive member with a flange in which the electrophotographic photosensitive member and the flange are integrated. Is generally performed (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-8-184977
[0004]
[Problems to be solved by the invention]
By the way, in the process of manufacturing an electrophotographic photosensitive member, a dip coating method is generally used to form a photosensitive layer on a cylindrical substrate. However, when the photosensitive layer is formed by the dip coating method, it is inevitable that the coating solution for forming the photosensitive layer adheres to the inner surface of the lower end of the cylindrical substrate.
[0005]
Therefore, when the flange is fitted to the end opening of the electrophotographic photosensitive member obtained by the dip coating method, the flange is perfectly fitted to the electrophotographic photosensitive member due to the presence of the coating film remaining on the inner surface near the opening. In some cases, the center axis of the electrophotographic photosensitive member does not coincide with the rotation axis of the flange. In this case, when the electrophotographic photosensitive member with the flange is rotated around the rotation axis of the flange in the image forming apparatus, the electrophotographic photosensitive member shakes, and the generated image becomes uneven.
[0006]
Therefore, various methods have been devised for completely removing the coating film on the inner peripheral surface of the electrophotographic photosensitive member with the flanged electrophotographic photosensitive member as described above (for example, JP-A-5-173339). The coating film removing method described in the publication discloses that an electrophotographic photosensitive member having a coating film remaining on an inner peripheral surface is axially separated by a predetermined length L1 from an end portion where the coating film remains. After being dipped in a solvent capable of dissolving the coating film, the film is reciprocated in the axial direction with a stroke L1, then reciprocated in the axial direction with a stroke L2 longer than L1, and finally, with a stroke L3 shorter than L1. The coating film is removed by reciprocating in the axial direction.
[0007]
However, even if the coating film on the inner peripheral surface of the electrophotographic photosensitive member is removed by the coating film removing method described in the above publication, the image forming apparatus using the electrophotographic photosensitive member with the flange is still visually noticeable. Image unevenness sometimes occurred. Further, in an image forming apparatus that forms a color image using an electrophotographic photoreceptor with a flange, image unevenness occurs as color unevenness, so that it becomes more conspicuous as a defect.
[0008]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus capable of surely suppressing the occurrence of image unevenness to such an extent that it cannot be visually recognized.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to solve the above-described problems, and as a result, in the electrophotographic photoreceptor to which the flange is fitted, the absolute difference of the film thickness between the maximum film thickness and the minimum film thickness of the coating film remaining on the inner periphery is considered. By finding that the value Δt (μm) satisfies a specific relationship with the resolution R (dpi) of the image forming apparatus, it has been found that the above problem can be solved, and the present invention has been completed.
[0010]
That is, the present invention has an electrophotographic photosensitive member with a flange formed by fitting a flange to an opening of at least one end of an electrophotographic photosensitive member having a photosensitive layer formed on a cylindrical substrate by a dip coating method, and An image forming apparatus including an image forming unit that transfers an image formed on a flanged electrophotographic photosensitive member to an image output medium to form a black-and-white image, and has a resolution of R (dpi). When the absolute value of the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface of the body is Δt (μm), the thickness difference Δt (μm) is represented by the following formula:
Δt ≦ 1000 ÷ R 0.5 ... (1)
Is satisfied.
[0011]
According to this image forming apparatus, an image formed on the electrophotographic photosensitive member with a flange by the image forming unit is transferred to an image output medium to form a black and white image. At this time, it is possible to reliably suppress the density unevenness (image unevenness) on the image to such an extent that it cannot be visually recognized.
[0012]
Further, the present invention has an electrophotographic photosensitive member with a flange formed by fitting a flange into an opening at at least one end of an electrophotographic photosensitive member having a photosensitive layer formed on a cylindrical substrate by a dip coating method; An image forming apparatus having one image forming unit capable of forming a color image by transferring an image formed on a flanged electrophotographic photosensitive member to an image output medium, and having a resolution of R (dpi). When the absolute value of the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface of the electrophotographic photosensitive member is Δt (μm), the thickness difference Δt (μm) is as follows. formula:
Δt ≦ 750 ° R 0.5 ... (2)
Is satisfied.
[0013]
According to this image forming apparatus, even if an image formed on a flanged electrophotographic photosensitive member by one image forming unit is transferred to an image output medium to form a color image, color unevenness (image) Unevenness) can be surely suppressed to such an extent that it cannot be visually recognized.
[0014]
Further, the present invention has an electrophotographic photosensitive member with a flange formed by fitting a flange into an opening at at least one end of an electrophotographic photosensitive member having a photosensitive layer formed on a cylindrical substrate by a dip coating method; An image forming apparatus having a plurality of image forming units capable of forming a color image by transferring an image formed on a flanged electrophotographic photosensitive member to an image output medium, and having a resolution of R (dpi). When the absolute value of the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface of the electrophotographic photosensitive member is Δt (μm), the thickness difference Δt (μm) is expressed by the following equation. :
Δt ≦ 500 ÷ R 0.5 ... (3)
Is satisfied.
[0015]
According to this image forming apparatus, even when an image formed on a flanged electrophotographic photosensitive member by a plurality of image forming units is transferred to an image output medium to form a color image, color unevenness (image) Unevenness) can be surely suppressed to such an extent that it cannot be visually recognized.
[0016]
It is preferable that the photosensitive layer has an undercoat layer having a thickness of at least more than 15 μm.
[0017]
When there is a seam caused by welding in the manufacturing process of the cylindrical substrate, the seam is concealed by the undercoat layer, and the image defect of the streak pattern in the image is prevented.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0019]
[First Embodiment]
FIG. 1 is a schematic diagram showing a first embodiment according to the image forming apparatus of the present invention. As shown in FIG. 1, the image forming apparatus 1 according to the present embodiment has one image forming unit 2, and the image forming unit 2 includes an electrophotographic photosensitive member 3 with a flange. The electrophotographic photosensitive member 3 with a flange is rotatably supported in the image forming apparatus 1.
[0020]
The image forming section 2 has a resolution of R (dpi) for a contact charging device 4 for charging the surface of the electrophotographic photosensitive member 3 with a flange and the electrophotographic photosensitive member 3 with a flange charged by the contact charging device 4. Exposure device 6 for exposing as described above, a developing device 7 for developing a portion exposed by the image exposure device 6 using black toner, and an image developed on the electrophotographic photosensitive member 3 with a flange by the developing device 7 on paper. And the like, and an image fixing device 11 for fixing the unfixed image transferred to the image output medium 12 by the transfer device 8 of the image forming unit 2 to the image output medium 12. And a cleaning device 9 for cleaning the surface of the photoconductor after transferring the image to the image output medium 12 by the transfer device 8. The contact charging device 4 charges the surface of the electrophotographic photosensitive member 3 with a flange by a potential applied from a power supply 5.
[0021]
According to the image forming apparatus 1, the electrophotographic photosensitive member 3 with a flange is charged by the contact charging device 4 while being rotated in the direction of arrow A, and the image exposure device 6 performs image exposure to form an electrostatic latent image. Thereafter, the electrostatic latent image is developed by the developing device 72. Then, the developed image is transferred to the image output medium 12 by the transfer device 8, and a black and white image is formed on the image output medium 12. This image is fixed on the image output medium 12 by the image fixing device 11.
(Electrophotographic photoreceptor with flange)
FIG. 2 is a side view showing the electrophotographic photosensitive member with a flange of FIG. 1, and FIG. 3 is a sectional view taken along the line III-III of FIG.
[0022]
As shown in FIGS. 2 and 3, the electrophotographic photosensitive member 3 with a flange includes a cylindrical electrophotographic photosensitive member 13 and flanges 14a and 14b fitted into openings at both ends of the electrophotographic photosensitive member, respectively. Have been.
[0023]
The electrophotographic photosensitive member 13 includes a cylindrical substrate 19 and a photosensitive layer 20 provided on the outer peripheral surface of the cylindrical substrate 19. In the image forming apparatus 1, the photosensitive layer 20 is a laminated photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated. The flange 14 a has a cylindrical fitting portion 15 fitted into an end opening of the electrophotographic photosensitive member 3, and has an outer diameter larger than the fitting portion 15 and is in contact with an end surface of the electrophotographic photosensitive member 3. It is constituted by a disk portion 16. A gear portion 16a is provided on the outer periphery of the disk portion 16.
[0024]
On the other hand, the flange 14 b has a cylindrical fitting portion 17 fitted into an end opening of the electrophotographic photosensitive member 13 and has an outer diameter larger than the fitting portion 17 and abuts on an end face of the electrophotographic photosensitive member 13. And a gear portion 60 provided on the opposite side of the disk portion 18 from the fitting portion 17. A gear portion 18 a is provided on the outer periphery of the disk portion 18. The flanges 14a, 14b are rotatably supported, and the gear portions 16a, 18a, 60 are engaged with a drive gear (not shown) of the image forming unit 2. By rotating the driving gear, the electrophotographic photosensitive member 3 with a flange can be rotated about the center axis of the flanges 14a and 14b as the center of rotation.
(Production method of electrophotographic photoreceptor with flange)
Here, a method for manufacturing the electrophotographic photosensitive member 3 with a flange will be described.
[0025]
First, a method for manufacturing the electrophotographic photosensitive member 13 constituting the electrophotographic photosensitive member 3 with a flange will be described.
[0026]
First, a cylindrical substrate 19 is prepared. The material of the cylindrical substrate 19 is not particularly limited as long as it is basically a material having electrical conductivity and can be molded into a cylindrical shape. However, from the viewpoints of moldability, workability, strength, etc., metals, particularly aluminum Alternatively, a material such as an aluminum alloy of 1000 (pure aluminum), 3000 (Al-Mn), 5000 (Al-Mg), 6000 (Al-Mg-Si), or stainless steel can be used.
[0027]
The cylindrical substrate 19 is formed into a cylindrical shape using, for example, aluminum or an aluminum alloy as a raw material. The molding method is not limited to a specific method as long as it can be molded into a cylindrical shape, but after hot extruding the billet, cold drawing is performed to form a cylindrical member, and the outer peripheral surface thereof is turned or polished. A grinding method is often used in terms of manufacturing stability and cost. Here, a mandrel method or a porthole method is used as the extrusion processing method. The mandrel method is a method in which a mandrel is attached to the tip of the stem of an extruder, and this is used as a core to form a cylinder.In contrast, the porthole method is a method in which the material metal is separated once in a mold. After that, it is welded again to form a cylinder. In general, the porthole method has an advantage that the thickness of the cylinder can be easily reduced and uneven thickness is less likely to occur than the mandrel method. Therefore, a method of manufacturing a cylindrical member using the porthole method is often used.
[0028]
Here, a porthole tube manufactured by the porthole method will be described. As a material of the porthole tube, aluminum or aluminum alloy such as 1000 (pure aluminum), 3000 (Al-Mn), 5000 (Al-Mg), and 6000 (Al-Mg-Si) is used.
[0029]
Porthole tubes made of these materials are manufactured by extrusion and cutting to a desired length. The processing conditions in each of these steps are performed under conditions within the range usually performed conventionally. Extrusion is performed by a porthole method which is excellent in the degree of uneven thickness and thinning. It is preferable that the straightening of the porthole pipe be performed by the straightening device after the extrusion process (porthole extrusion step) and before the cutting process. In this case, in turning, polishing, and grinding performed as a subsequent process, processing is facilitated.
[0030]
In order to further reduce the variation in the outer diameter, the variation in the inner diameter, the bending, and the like, it is preferable to perform a drawing process on the porthole tube at a processing ratio of about 1.1 to 1.4. This drawing (drawing) is performed by installing a plug on the inner diameter side and a die called a die on the outer diameter side, and simultaneously expanding the inner and outer diameters. Poor results in residual stress. Also, cutting is performed to align the porthole pipe to a predetermined length, but burrs generated at the time of cutting may remain on the outer edge or the inner edge of the end face generated by the cutting, and this is used for subsequent processing. It may be an obstacle. Therefore, it is desirable to provide a deburring step such as C chamfering or brushing after the porthole pipe cutting step.
[0031]
The thickness of the porthole tube is preferably 2 mm or less, more preferably 1 mm or less, in view of cost and weight reduction of the entire image forming apparatus 1. The thickness deviation is preferably 0.075 mm or less in consideration of use as the cylindrical substrate 19 of the electrophotographic photosensitive member 13.
[0032]
Next, a photosensitive layer 20 is formed on the outer peripheral surface of the cylindrical substrate 19 prepared as described above. The photosensitive layer 20 is formed by dispersing and mixing a charge generating substance, a binder resin, and a solvent, and dispersing and mixing a charge transporting substance, a binder resin, and a solvent. And a coating solution for forming a charge transport layer, respectively. First, a coating solution for forming a charge transport layer is applied to the outer peripheral surface of the cylindrical substrate 19 and dried, and then a coating solution for forming a charge transport layer is formed thereon. It is performed by coating and drying. In this manner, a laminated photosensitive layer 20 in which the charge generation layer and the charge transport layer are sequentially laminated on the cylindrical substrate 19 is formed.
[0033]
Examples of the charge generating material include azo pigments, disazo pigments, quinone pigments, quinocyanine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, pyrylium salts, azulhenium salts, and tricrystalline selenium. And the like.
[0034]
Examples of the charge transport material include, for example, polyaromatic compounds such as anthracene, pyrene, phenanthrene, and coronene, or indole, carbazole, oxazole, isoxazole thiol, imidazole, pyrazole, oxadiazole, in the main chain or side chain. Examples thereof include compounds having a skeleton of a nitrogen-containing cyclic compound such as pyrazirine, pidiazole, and triazole, and hole transport substances such as hydrazone compounds.
[0035]
As the binder resin, for example, polycarbonate, polyarylate, polystyrene, polymethacrylates, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile polymer, polysulfone, polyvinyl acetate, polyacrylonitrile, polyvinyl butyral, polyvinyl pyrrolidone, Examples include methylcellulose, hydroxymethylcellulose, cellulose esters and the like.
[0036]
As the solvent (solvent), a solvent having high volatility and a vapor density higher than that of air is suitably used. For example, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, N, N- Dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, 4-methoxy-4-methylpentanone, dimethoxymethane, dimethoxyethane, 2,4-pentadione, anisole, methyl 3-oxobutanoate, monochlorobenzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, 1-butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methylcellsol , Ethyl cellosolve, methyl cellosolve, and the like methyl cellosolve acetate.
[0037]
In order to apply the above-mentioned coating liquid for forming a charge generation layer and the coating liquid for forming a charge transport layer to the cylindrical substrate 19, a dip coating method is used. That is, the charge generation layer is formed by immersing the cylindrical substrate 19 in the coating solution for forming a charge transport layer and then pulling up the coating solution. The charge transport layer is formed by forming the charge generation layer on the cylindrical substrate 19. This is immersed in a coating solution for forming a charge transport layer, and then discharged from the coating solution.
[0038]
As described above, an electrophotographic photoreceptor is obtained by forming the photosensitive layer 20 on the outer peripheral surface of the cylindrical substrate 19 by the dip coating method. Adhesion of the coating liquid to the surface is inevitable. Therefore, the applied coating liquid is formed as a coating film 61 on the inner peripheral surface at the end of the electrophotographic photosensitive member (see FIG. 4).
[0039]
In this state, even if the electrophotographic photosensitive member and the flange 14a or the flange 14b are fitted, the fitting is not completely performed, and there is a possibility that the center axis of the electrophotographic photosensitive member does not coincide with the center axis of the flange 14a. For this reason, when the electrophotographic photosensitive member 3 with a flange is mounted on the image forming section 2, when the electrophotographic photosensitive member is rotated, a shake occurs and a generated image becomes uneven.
[0040]
Therefore, after the photosensitive layer 20 is formed on the cylindrical substrate 19, after the electrophotographic photosensitive member is naturally dried for a predetermined time and before the flanges 14a and 14b are fitted, the electrophotographic photosensitive member is formed as follows. Of the coating film 61 remaining on the inner peripheral surface of the substrate is performed. More specifically, the solvent for dissolving the coating film is wiped on the inner peripheral surface of the photoconductor while the sponge-like wiping member is in close contact with the inner peripheral surface of the electrophotographic photoconductor. This can be performed by rotating the wiping member while supplying the material between the wiping member and the wiping member.
[0041]
After the wiping of the coating film 61 is completed, the absolute value Δt (μm) of the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface at the end of the electrophotographic photosensitive member 13 is measured. Δt can be measured by, for example, an eddy current film thickness meter.
[0042]
The Δt of the electrophotographic photoreceptor was measured in this manner, and the following formula was determined with respect to the resolution R (dpi) of the image forming apparatus 1.
Δt ≦ 1000 ÷ R 0.5 ... (1)
The electrophotographic photosensitive member having Δt that satisfies is selected as the electrophotographic photosensitive member 13 used for the flanged electrophotographic photosensitive member 3 of the image forming apparatus 1. When the electrophotographic photosensitive member does not satisfy the above formula (1), Δt is measured for a plurality of electrophotographic photosensitive members, and the electrophotographic photosensitive member having the Δt that satisfies the above formula (1) is replaced with a flanged electronic device. The photoconductor 3 is selected as the electrophotographic photoconductor 13.
[0043]
On the other hand, flanges 14a and 14b to be fitted into the end openings of the electrophotographic photosensitive member 13 are prepared. The material of the flanges 14a and 14b is mainly composed of a thermoplastic resin, and the molding method is not limited to a specific method as long as the same shape is obtained, but the flanges 14a and 14b can be obtained by, for example, injection molding. . Examples of the thermoplastic resin include polyacetal resin, ABS resin, polycarbonate resin, polypropylene resin, nylon resin, and PBT resin.
[0044]
Then, as shown in FIG. 4, the flanges 14a and 14b prepared as described above are fitted into openings at respective ends of the electrophotographic photosensitive member 13. In this case, the outer peripheral surface of the fitting portion 15 of the flange 14a may be fitted along the inner peripheral surface of one end of the electrophotographic photosensitive member 13. The flange 14b is also fitted so that the outer peripheral surface of the fitting portion 17 is along the inner peripheral surface of the other end of the electrophotographic photosensitive member 13. The fitting method is not limited to the above fixing method as long as the flanges 14a and 14b can be fixed to the electrophotographic photoreceptor 13, but it is also possible to use press-fitting and bonding in combination. In this case, the press-fitting margin for press-fitting the flanges 14a and 14b into the electrophotographic photosensitive member 13 is set to an appropriate value according to the relationship between the use environment and the linear expansion coefficient of the flange 14a or 14b.
[0045]
Thus, the manufacture of the electrophotographic photosensitive member 3 with a flange is completed. In the flanged electrophotographic photosensitive member 3 manufactured in this manner, even when an image formed on the flanged electrophotographic photosensitive member 3 by the image forming section 2 is transferred to the image output medium 12 to form a black and white image, On an image, density unevenness (image unevenness) can be reliably suppressed to a level that cannot be visually recognized.
[0046]
An example of a dip coating device for forming the photosensitive layer 20 on the cylindrical substrate 19 and an example of a device for wiping the coating film 61 on the inner peripheral surface at the end of the electrophotographic photosensitive member 13 will be described.
[0047]
FIG. 5 is a schematic view of the dip coating apparatus. As shown in FIG. 5, the dip coating device 21 includes a reflux device 23 for refluxing the coating solution 26. The reflux device 23 has an upper end for immersing the cylindrical substrate 19 in the coating solution 26. It has a coating tank 24 formed in the section and a storage tank 25 for storing a coating liquid 26 flowing from the coating tank 24. Between the upper side surface of the coating tank 24 and the upper side surface of the storage tank 25, a receiving pipe 29 for introducing the coating liquid 26 in the coating tank 24 into the storage tank 25 is provided. Further, a reflux pipe 27 having a pump 28 is provided between the bottom surface of the storage tank 25 and the bottom surface of the coating tank 24, and the application liquid 26 stored in the storage tank 25 is operated by the operation of the pump 28. Is returned to the coating tank 24.
[0048]
On the other hand, the dip coating device 21 includes a lifting device 22 that raises and lowers the cylindrical substrate 19, dipped in the coating liquid 26 in the coating tank 24, and lifts up from the coating liquid 26. The lifting device 22 includes a motor 31, a driving screw 32 connected to a rotating shaft of the motor 31 and extending in a vertical direction, a lifting arm 34 which is screw-engaged with the driving screw 32 and moves up and down by rotation of the driving screw 32, And a base holding member 35 fixed to the base 34 and holding the cylindrical base 19.
[0049]
When the photosensitive layer forming coating liquid is formed on the cylindrical substrate 19 using the dip coating apparatus 21, the pump 28 is first operated. Then, the liquid level of the coating liquid 26 rises in the coating tank 24, and the coating liquid 26 is introduced from above the coating tank 24 into the storage tank 25 via the receiving pipe 29, and the coating liquid 26 introduced into the storage tank 25 is Is returned to the coating tank 24 via the reflux pipe 27. Thus, the coating liquid 26 is refluxed. In this state, the drive screw 32 is rotated by the operation of the motor 31 of the lifting device 22, and the lifting arm 33 is lowered. Then, the cylindrical substrate 19 descends and is immersed in the coating liquid 26 in the coating tank 24. After the cylindrical base 19 is immersed in the coating liquid 26, the drive screw 32 is rotated in reverse by the operation of the motor 31, and the lifting arm 33 is raised. Then, the cylindrical substrate 19 rises and is pulled up from the coating liquid 26. Thus, the coating liquid 26 is applied on the outer peripheral surface of the cylindrical substrate 19.
[0050]
6 is a side view of a device for wiping the coating film 61, FIG. 7 is a plan view of the wiping member, (a) is a plan view of the wiping member of FIG. 6, and (b) and (c) of FIG. 7) is a plan view showing a modification of the wiping member of FIG. As shown in FIG. 6, the coating film wiping device 37 includes a support plate 38, a wiping member 39 fixed to the center of the upper surface of the support plate 38 for wiping the coating film 61, and a support plate 38 fixed to the support plate 38. A rotary drive shaft 62 that penetrates the wiping member 39; and a solvent blowing section 40 that is fixed at the center of the upper surface side of the wiping member 39 and at the tip of the rotary drive shaft 62 and has a solvent outlet 40a. . As the wiping member 39, a foamed resin obtained by foaming a resin material such as a polyethylene resin and a polypropylene resin as a material is used, and the shape thereof is, for example, a columnar shape as shown in FIG. The shape of the wiping member 39 is not limited to a column shape. In short, the shape of the wiping member 39 may be any shape as long as the wiping member 39 is in close contact with the inner surface of the electrophotographic photosensitive member 13 when the wiping member 39 is inserted into the lower end opening of the electrophotographic photosensitive member 13. Therefore, the shape of the wiping member 39 may be a rectangular parallelepiped shape as shown in FIG. 7B, or a cross shape as shown in FIG. 7C. The organic solvent blown out from the solvent blowing section 40 may be any organic solvent that can dissolve the solidified coating film 61. Examples of such an organic solvent include methylene chloride, tetrahydrofuran, toluene, and halogenated benzene. Can be
[0051]
Next, a method of wiping the coating film 61 using the coating film wiping device 37 will be described. First, at the same time as the rotation drive shaft 62 is rotated, the organic solvent is blown out from the solvent blowout port 40a of the solvent blowout unit 40, so that the wiping member 39 is always wetted with the organic solvent. Next, the electrophotographic photosensitive member 13 is lowered while the inner peripheral surface of the lower end portion is in close contact with the outer peripheral surface of the wiping member 39. Then, the electrophotographic photoconductor 13 is stopped for a predetermined time at a position where the lower end of the electrophotographic photoconductor 13 reaches a predetermined distance from the upper surface of the wiping member 39. Next, the electrophotographic photosensitive member 13 is stopped by being raised at a predetermined speed for a predetermined distance. Then, the rotation speed of the rotation drive shaft 62 is further increased. Thus, the coating film 61 on the inner peripheral surface of the electrophotographic photosensitive member 13 is wiped.
[0052]
In the above embodiment, the photosensitive layer 20 does not include an undercoat layer. However, when a porthole tube is used as the cylindrical base 19, the photosensitive layer 20 may include an undercoat layer. In this case, the thickness of the undercoat layer preferably exceeds 15 μm. When the thickness of the undercoat layer is less than 15 μm, when the cylindrical substrate 19 is molded by the porthole method, traces (weld lines) where the metals once separated are welded to each other remain, and the image is formed using the electrophotographic photosensitive member 13. When the formation is performed, a streak-like image defect appears on the image due to the weld line. When the undercoat layer having a thickness of more than 15 μm is included in the photosensitive layer 20, the weld line of the cylindrical substrate 19 is concealed, and when an image is formed using the electrophotographic photosensitive member 13, a stripe is formed on the image. Image defects are suppressed to such an extent that they cannot be visually recognized.
[0053]
The undercoat layer is formed on the cylindrical substrate 19 by applying a coating liquid for forming an undercoat layer by the above-mentioned dip coating method and drying.
[0054]
As the undercoat layer, for example, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, Examples include various resins such as a silicon-based resin and a melamine-based resin, and those containing a zirconium compound, a titanium compound, and the like in these resin systems.
[0055]
In the above embodiment, the photosensitive layer 20 is a laminated photosensitive layer, but the photosensitive layer 20 may be a single-layer photosensitive layer. In this case, as the coating liquid, a coating liquid for forming a photosensitive layer having both charge generation ability and charge transport ability is used. As such a coating liquid for forming a photosensitive layer, for example, a liquid in which the above-mentioned charge generating substance, the above-mentioned charge transporting substance and the above-mentioned binder resin are dispersed in the above-mentioned solvent can be used.
[0056]
In the above embodiment, the flanged electrophotographic photoreceptor 3 includes the flanges 14a and 14b. However, the flanged electrophotographic photoreceptor of the present invention has one of the two end openings of the electrophotographic photoreceptor. The flange may be fitted to the opening of the part.
[0057]
Further, in the above embodiment, the image forming apparatus 1 includes the cleaning device 9, but the cleaning device 9 is not always necessary. For example, when the developing device 72 has a cleaning function, it is not necessary to provide the cleaning device 9 separately in addition to the developing device 72. Further, the image forming section 2 may further include a charge removing device (not shown) as necessary. Further, in the image forming section 2 in FIG. 1, the contact charging device 4 is used, but a non-contact charging device may be used. Further, in the above embodiment, the gear portion 16a is provided on the flange 14a, and the gear portions 18a, 60 are provided on the flange 14b. However, the gear portion may be formed on at least one of the flanges 14a, 14b.
[0058]
[Second embodiment]
Next, a second embodiment of the present invention will be described. Note that the same or equivalent components as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.
[0059]
FIG. 8 is a schematic diagram illustrating a second embodiment according to the image forming apparatus of the present invention. As shown in FIG. 8, the image forming apparatus 101 according to the present embodiment is a so-called tandem type color image forming apparatus, and differs from the image forming apparatus 1 of the first embodiment in the following points.
[0060]
That is, first, the image forming apparatus 101 has four image forming units 2a to 2d. Here, the image forming units 2a to 2d have the same configuration as the image forming unit 2 of the first embodiment except for the color of the toner.
[0061]
Second, the electrophotographic photosensitive member 3 with a flange in each of the image forming units 2a to 2d is represented by the following formula:
Δt ≦ 500 ÷ R 0.5 ... (3)
(In the above equation, Δt is the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface at the lower end portion of the electrophotographic photosensitive member 13 before the flanges 14a and 14b are fitted into the openings at both ends of the electrophotographic photosensitive member 13. (The absolute value (μm) and R represent the resolution (dpi) of the image forming apparatus 101 on which the electrophotographic photosensitive member with flange 3 is mounted.)
That is,
[0062]
The image forming apparatus 101 includes a belt conveying device 41 that is disposed at a portion facing the image forming unit 2 and conveys the image output medium 12, and a medium supply device 54 that supplies the image output medium 12 to the belt conveying device 41. And The belt transport device 41 has an endless transport belt 42, and the transport belt 42 is stretched over, for example, six stretching rolls 43 to 48 and four transfer devices 8. The medium supply device 54 includes a paper feed tray 55 that stores the image output medium 12, and a medium feed mechanism 56 that supplies the image output medium 12 stored in the paper feed tray 55 to the belt transport device 41.
[0063]
Then, when the transport belt 42 is circulated and transported, and the image output medium 12 is supplied to the belt transport apparatus 41 by the medium supply device 54, the image output medium 12 is sucked and held by the suction roll 49, and each image forming unit 2a To 2d transcription sites. In this way, different color toners are superimposedly transferred onto the image output medium 12 to form a color image. The image output medium 12 that has sequentially passed through the four image forming units 2 a to 2 d is stored in the storage tray 51 after the transferred color image is fixed to the image output medium 12 by the fixing device 11. Reference numeral 52 denotes a tension roll that applies a predetermined tension to the transport belt 42, and reference numeral 53 denotes a belt cleaner that cleans the surface of the transport belt 48.
[0064]
According to the image forming apparatus 101, in each of the image forming units 2a to 2d, the flanged electrophotographic photosensitive member 3 is mounted as the flanged electrophotographic photosensitive member of the image forming apparatus 101, so that the image output medium 12 Even when a color image is formed, color unevenness (image unevenness) can be reliably suppressed to a level that cannot be visually recognized.
[0065]
[Third embodiment]
Next, a third embodiment of the present invention will be described. Note that the same or equivalent components as those of the first and second embodiments are denoted by the same reference numerals, and redundant description will be omitted.
[0066]
FIG. 9 is a schematic view showing a third embodiment of the image forming apparatus of the present invention. As shown in FIG. 9, the image forming apparatus 201 of the present embodiment includes an image forming unit 71 that forms a color image on the image output medium 12, and a medium supply device 54 that supplies the image output medium 12 to the image forming unit 71. And The point that the medium supply device 54 in the image forming apparatus 201 includes a paper feed tray 55 and a medium feeding mechanism 56 is similar to the image forming apparatus 101 of the second embodiment. Note that the image forming apparatus 201 of the present embodiment does not include the belt conveying device 41, unlike the image forming apparatus 101 of the second embodiment.
[0067]
The image forming unit 71 includes one electrophotographic photosensitive member 3 with a flange, a contact charging device 4, an image exposing device 6, a developing device 72, and an intermediate transfer, which are sequentially arranged along the periphery of the electrophotographic photosensitive member 3 with a flange. A unit 73, a secondary transfer unit 74, and the image fixing device 11 are provided.
[0068]
Here, the developing device 72 will be described. The developing device 72 includes four developing devices 72K, 72Y, 72M, and 72C for one electrophotographic photosensitive member 3 with a flange. More specifically, the four developing devices 72K, 72Y, 72M, and 72C are arranged around the rotation shaft 72o, and the four color developing devices 72K, 72Y, 72M, and 72C are rotated with the rotation of the rotation shaft 72o. It is configured so as to sequentially face the electrophotographic photosensitive member 3 with a flange. Each of the developing units 72K, 72Y, 72M, and 72C develops the electrostatic latent image formed on the electrophotographic photosensitive member 3 with a flange into a toner image of each color of K, Y, M, and C. As the toner used in the developing units 72K, 72Y, 72M, and 72C, a magnetic or non-magnetic one-component developer or a two-component developer can be used. Further, the developing device 72 may be either a regular development type or a reversal development type.
[0069]
The developing process by the developing device 72 will be described more specifically as follows. First, development with black toner is performed by the developing unit 72K of the four developing units 72K, 72Y, 72M, and 72C. Next, the developing device 72 rotates, and the developing device 72Y moves to a position facing the electrophotographic photosensitive member 3 with a flange. Then, the developing device 72Y performs development with yellow toner. Next, the developing device 72 rotates, and the developing device 72M moves to a position facing the electrophotographic photosensitive member 3 with a flange. The developing unit 72M performs development with magenta toner. Next, the developing device 72 rotates, and the developing device 72C moves to a position facing the electrophotographic photosensitive member 3 with a flange. Then, the developing with the cyan toner is performed by the developing device 72C. As a result, the superimposed transfer is performed using the four color toners, and a synthetic color toner image corresponding to the target color image is formed on the flanged electrophotographic photosensitive member 3.
[0070]
Note that the above-described development with four colors is performed independently for each color, and while development with respect to the one color is performed, development with other colors is not performed. Development is not affected by other color developers. Specifically, an electrostatic latent image corresponding to a first color component image (for example, a black component image) of a target image is first formed. Next, the developing device 72K develops the electrostatic latent image with black toner. At this time, since the other developing units 72Y, 72M, and 72C are in the off state, they do not act on the electrophotographic photosensitive member 3 with the flange, and the image developed by the black toner is not applied to the other developing units 72Y, 72M, and 72C. Not affected.
[0071]
Next, the intermediate transfer unit 73 will be described. The intermediate transfer unit 73 transfers the toner image formed on the flanged electrophotographic photosensitive member 3 to the primary transfer position T. 1 And an endless intermediate transfer belt 75 on which primary transfer is performed. The intermediate transfer belt 75 is moved to the primary transfer position T 1 , And a secondary transfer roll (bias roll) 77, a drive roll 78, and the like, and are driven at substantially the same speed as the flanged electrophotographic photosensitive member 3 by a drive mechanism (not shown). It rotates in the direction of the arrow in FIG.
[0072]
The primary transfer roll 76 is not particularly limited as long as it has a function of transferring the toner image on the electrophotographic photosensitive member 3 with a flange to the intermediate transfer belt 75. For example, a belt, a roller, a film, a rubber blade, or the like is used. A known transfer charger such as a contact-type transfer charger, a scorotron transfer charger using corona discharge, and a corotron transfer charger can be used. Among these, a contact-type transfer charger is desirable in terms of excellent transfer charge compensation ability.
[0073]
The secondary transfer unit 74 transfers the toner image primarily transferred to the intermediate transfer belt 75 to the image output medium 12 supplied from the medium supply tray 55 by the medium feeding mechanism 56 to the secondary transfer position T. 2 Is used for secondary transfer.
[0074]
The above-described electrophotographic photosensitive member 3 with a flange has the following formula:
Δt ≦ 750 ° R 0.5 ... (2)
(In the above formula, Δt is the absolute value (μm) of the difference between the maximum thickness and the minimum thickness of the coating film on the inner peripheral surface at the lower end portion of the electrophotographic photosensitive member before the flanges are fitted into the openings at both ends of the electrophotographic photosensitive member 13. ) And R represents the resolution (dpi) of the image forming apparatus 201 on which the electrophotographic photosensitive member 3 with a flange is mounted.
It satisfies.
[0075]
According to the image forming apparatus 201 having such a flanged electrophotographic photosensitive member 3, even if a color image is formed on the image output medium 12, color unevenness (image unevenness) is not visually recognized on the image. It is possible to reliably suppress to the extent.
[0076]
Hereinafter, the content of the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.
[0077]
【Example】
(Example 1)
An aluminum base tube made of A6063 having an outer diameter of 30.3, an inner diameter of 28.5, and a length of 340 mm was prepared, and the outer diameter of 30.0 was cut with a lathe to obtain a cylindrical substrate.
[0078]
Next, a photosensitive layer was formed on the outer peripheral surface of the cylindrical substrate obtained as described above as follows.
[0079]
That is, first, zinc oxide (average particle diameter 70 μm, specific surface area value 15 m 2 / G: manufactured by Teica Co.) was stirred and mixed with 100 parts by weight of toluene and 500 parts by weight of toluene, and 1.5 parts by weight of a silane coupling agent (KBM603, manufactured by Shin-Etsu Chemical Co., Ltd.) was further added, followed by stirring for 2 hours.
[0080]
Thereafter, toluene was distilled off under reduced pressure and baked at 150 ° C. for 3 hours to subject zinc oxide to a surface treatment.
[0081]
Next, 60 parts by weight of the surface-treated zinc oxide, 15 parts by weight of a blocked isocyanate (Sumijur 3175 manufactured by Sumitomo Bayern Urethane Co., Ltd.) and 15 parts by weight of a butyral resin (BM-1 manufactured by Sekisui Chemical Co., Ltd.) Was dissolved in 85 parts by weight of methyl ethyl ketone, and 25 parts by weight of methyl ethyl ketone were mixed, and the mixture was dispersed in a sand mill for 2 hours using 1 mmφ glass beads to obtain a dispersion. To the obtained dispersion, 0.005 parts by weight of dioctyltin dilaurate and 0.01 part by weight of silicone oil (SH29PA manufactured by Dow Corning Toray Silicone Co., Ltd.) were added as a catalyst to obtain a coating liquid for forming an undercoat layer.
[0082]
The coating liquid for forming an undercoat layer was applied onto the previously prepared cylindrical substrate by a dip coating method.
[0083]
Next, the conductive substrate on which the coating liquid for forming the undercoat layer had been applied was naturally dried for 5 minutes, and the inner surface of the lower end portion of the cylindrical substrate was wiped using the wiping device 37 shown in FIG. At that time, butanol was continuously flowed at a rate of 150 ml / min from the solvent outlet 40a of the solvent outlet 40 to keep the wiping member 39 made of 15-fold foamed polyethylene moist. In this state, the cylindrical base was lowered at 200 mm / min, and at the same time, the support plate 38 was rotated at 30 rpm until the lower end of the cylindrical base was cut into a position 15 mm from the upper surface of the wiping portion 39. Then, after holding at that position for 10 seconds, wiping was performed by increasing the height by 20 mm at a speed of 50 mm / min and further increasing the speed at a speed of 500 mm / min.
[0084]
The wiped cylindrical substrate with an undercoat layer was dried and cured at 160 ° C. for 100 minutes to obtain an undercoat layer having a thickness of 20 μm.
[0085]
Next, a charge generation layer was formed on the undercoat layer as follows. First, the position at which the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα ray as a charge generating material is at least 7.3 °, 16.0 °, 24.9 °, 28.0 °. Is prepared by preparing 15 parts of hydroxygallium phthalocyanine having a diffraction peak, 10 parts of a vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Unicar) as a binder resin, and 300 parts of n-butyl acetate. The resulting mixture was dispersed for 4 hours in a sand mill using 1 mmφ glass beads. The obtained dispersion was applied as a coating liquid for forming a charge generation layer on the undercoat layer by a dip coating method, and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.
[0086]
Further, 4 parts of N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1 '] biphenyl-4,4'-diamine and bisphenol Z polycarbonate resin (molecular weight 40,000) 6 And a coating solution prepared by adding 80 parts by weight of chlorobenzene and dissolving the same as a coating solution for forming a charge transport layer by a dip coating method.
[0087]
The cylindrical substrate on which the coating liquid for forming the charge transport layer has been applied is naturally dried for 5 minutes, and the inner surface of the lower end portion is wiped off in the same manner as after the formation of the undercoat layer, and dried at 130 ° C. for 40 minutes. To form a charge transport layer having a thickness of 25 μm, thereby obtaining an electrophotographic photosensitive member.
[0088]
Next, the thickness of the coating film remaining as a residue after wiping on the inner surface of the lower end portion of the electrophotographic photosensitive member thus obtained was evaluated. The measurement site is on the inner peripheral surface of the electrophotographic photosensitive member and at a position 5 mm from the lower end. As a sensor used for the measurement, an eddy current film thickness meter (MP40 manufactured by Fischer) was used, and the film thickness of the coating film on the entire inner periphery of the electrophotographic photosensitive member was measured for a plurality of electrophotographic photosensitive members. Then, an electrophotographic photosensitive member having a thickness difference of 33 μm between the maximum thickness and the minimum thickness of the coating film measured on the inner periphery of the electrophotographic photosensitive member was selected.
[0089]
On the other hand, as the flanges, those having the same configuration as the flanges 14a and 14b shown in FIG. 3 were manufactured. Specifically, the flange was manufactured by injection molding using a fluorine-containing polycarbonate resin (Iupilon LS-2020 manufactured by Mitsubishi Gas Chemical Company) as a raw material.
[0090]
Then, flanges were press-fitted into the openings at both ends of the electrophotographic photosensitive member selected as described above, and were adhered to obtain an electrophotographic photosensitive member with a flange.
[0091]
Subsequently, the electrophotographic photosensitive member with a flange is provided with an image forming apparatus (DocuCenter 280, manufactured by Fuji Xerox Co., Ltd .; hereinafter referred to as "black and white") having only one image forming unit and having a resolution of 600 (dpi) and forming a black and white image. (Referred to as "image forming apparatus").
[0092]
(Example 2)
One electrophotographic photosensitive member with a flange was manufactured in the same manner as in Example 1 except that an electrophotographic photosensitive member having a thickness difference of 25 μm between the coating films on the inner surface at the lower end was selected. Then, this electrophotographic photosensitive member with a flange was mounted as an electrophotographic photosensitive member with a flange of a black-and-white image forming apparatus having the same configuration as in Example 1 except that the resolution was 1200 (dpi).
[0093]
(Example 3)
One electrophotographic photosensitive member with a flange was manufactured in the same manner as in Example 1 except that an electrophotographic photosensitive member having a thickness difference of 25 μm between the coating films on the inner surface at the lower end was selected. An image forming apparatus (hereinafter, referred to as "color image forming apparatus") capable of forming a color image with only one image forming section at a resolution of 600 (dpi) by using this single electrophotographic photosensitive member with a flange. (Referred to as “device”).
[0094]
(Example 4)
One electrophotographic photosensitive member with a flange was obtained in the same manner as in Example 1, except that an electrophotographic photosensitive member having a thickness difference of 21 μm between the coating films on the inner surface at the lower end was selected. Then, this electrophotographic photosensitive member with a flange was mounted as an electrophotographic photosensitive member with a flange of a color image forming apparatus having the same configuration as in Example 3 except that the resolution was set to 1200 (dpi).
[0095]
(Example 5)
Four electrophotographic photoconductors with flanges were manufactured in the same manner as in Example 1 except that electrophotographic photoconductors in which the difference in the thickness of the coating film on the inner surface at the lower end was 17 μm were selected. An image forming apparatus (DocuPrint C2221 manufactured by Fuji Xerox Co., Ltd.) that can form a color image with these four flanged electrophotographic photosensitive members having a resolution of 600 (dpi), four image forming units, and a color image. (Hereinafter, referred to as "tandem-type color image forming apparatus").
[0096]
(Example 6)
Four electrophotographic photoconductors with flanges were manufactured in the same manner as in Example 1 except that electrophotographic photoconductors in which the difference in the thickness of the coating film on the inner surface at the lower end was 10 μm were selected. The four flanged electrophotographic photosensitive members having the same configuration as in Example 5 except that the resolution was set to 1200 (dpi) were used as the four flanged electrophotographic photosensitive members. I attached it.
[0097]
(Comparative Example 1)
One electrophotographic photosensitive member with a flange was manufactured in the same manner as in Example 1 except that an electrophotographic photosensitive member in which the difference in the thickness of the coating film on the inner surface at the lower end was 43 μm was selected. Then, this one electrophotographic photosensitive member with a flange was mounted as an electrophotographic photosensitive member with a flange of a black-and-white image forming apparatus having the same configuration as in Example 1.
[0098]
(Comparative Example 2)
One electrophotographic photosensitive member with a flange was manufactured in the same manner as in Example 1 except that an electrophotographic photosensitive member having a thickness difference of 33 μm between the coating films on the inner surface at the lower end was selected. Then, this single electrophotographic photosensitive member with a flange was mounted as an electrophotographic photosensitive member with a flange of a black-and-white image forming apparatus having the same configuration as in Example 2.
[0099]
(Comparative Example 3)
One electrophotographic photosensitive member with a flange was manufactured in the same manner as in Example 1 except that an electrophotographic photosensitive member having a thickness difference of 33 μm between the coating films on the inner surface at the lower end was selected. Then, this single electrophotographic photosensitive member with a flange was mounted as an electrophotographic photosensitive member with a flange of a color image forming apparatus having the same configuration as in Example 3.
[0100]
(Comparative Example 4)
Four electrophotographic photoconductors with flanges were manufactured in the same manner as in Example 1 except that electrophotographic photoconductors in which the difference in the thickness of the coating film on the inner surface at the lower end was 25 μm were selected. Then, these four electrophotographic photosensitive members with a flange were mounted as electrophotographic photosensitive members with a flange of a color image forming apparatus having the same configuration as in Example 4.
[0101]
(Comparative Example 5)
Four electrophotographic photoconductors with flanges were manufactured in the same manner as in Example 1 except that electrophotographic photoconductors in which the difference in the thickness of the coating film on the inner surface at the lower end was 21 μm were selected. Then, these four electrophotographic photosensitive members with a flange were mounted as four electrophotographic photosensitive members with a flange of a tandem-type color image forming apparatus having the same configuration as in Example 5.
[0102]
(Comparative Example 6)
Four electrophotographic photoconductors with flanges were manufactured in the same manner as in Example 1 except that electrophotographic photoconductors in which the difference in thickness of the coating film on the inner surface at the lower end was 17 μm were selected. The four flanged electrophotographic photosensitive members having the same configuration as in Example 5 except that the resolution was set to 1200 (dpi) were used as the four flanged electrophotographic photosensitive members. I attached it.
[0103]
(Image evaluation)
[Table 1]
Figure 2004246058
As shown in Table 1, in the black-and-white image forming apparatus, according to the results of Examples 1 and 2 and Comparative Examples 3 and 4, when the flanged electrophotographic photosensitive member satisfies the above expression (1), It was found that unevenness was not visually recognized, and density unevenness could be surely suppressed to the extent that it could not be visually recognized.
[0104]
Further, in the color image forming apparatus, from the results of Examples 3 and 4 and Comparative Example 3, when the electrophotographic photosensitive member with a flange satisfies the above expression (2), color unevenness is not visually recognized, It has been found that unevenness can be reliably suppressed to the extent that it cannot be visually recognized.
[0105]
Further, in the tandem-type color image forming apparatus, the results of Examples 5 and 6 and Comparative Examples 4, 5, and 6 show that if the electrophotographic photosensitive member with a flange satisfies the above-mentioned formula (3), color unevenness may occur. Was not visually recognized, and it was found that color unevenness could be reliably suppressed to the extent that it could not be visually recognized.
[0106]
【The invention's effect】
As described above, according to the image forming apparatus of the present invention, it is possible to reliably suppress the occurrence of image unevenness to such an extent that it is not visually recognized.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is a side view of the electrophotographic photosensitive member with a flange of FIG.
FIG. 3 is a cross-sectional view of the electrophotographic photosensitive member with a flange of FIG. 2 taken along line III-III.
FIG. 4 is a sectional end view showing the electrophotographic photosensitive member and the flange before the flange is mounted.
FIG. 5 is a schematic view of a dip coating apparatus used for forming a photosensitive layer of an electrophotographic photosensitive member.
FIG. 6 is a schematic view of a wiping device used for removing a coating film on an inner surface of an end portion of the electrophotographic photosensitive member.
7A is a plan view of a wiping member included in the wiping device of FIG. 6, and FIGS. 7B and 7C are plan views showing a modification of the wiping member of FIG. It is.
FIG. 8 is a schematic diagram illustrating an image forming apparatus according to a second embodiment of the present invention.
FIG. 9 is a schematic diagram illustrating an image forming apparatus according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 101 ... Image forming apparatus, 2, 2a-2d ... Image forming part, 3 ... Electrophotographic photosensitive member with a flange, 13 ... Electrophotographic photosensitive member, 14a, 14b ... Flange, 19 ... Cylindrical base, 20 ... Photosensitive layer , 21 ... Coating film.

Claims (5)

円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つ前記フランジ付き電子写真感光体に形成される像を画像出力媒体に転写して白黒画像を形成する画像形成部を備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、
前記電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、前記膜厚差Δｔ（μｍ）が下記式：
Δｔ≦１０００÷Ｒ０．５ ・・・（１）
を満たすことを特徴とする画像形成装置。An electrophotographic photosensitive member having a flange formed by fitting a flange to an opening at at least one end of a photosensitive layer having a photosensitive layer formed on a cylindrical substrate by a dip coating method, and the electrophotographic device having the flange. An image forming apparatus including an image forming unit that transfers an image formed on a photoconductor to an image output medium to form a black and white image, and has a resolution of R (dpi).
When the absolute value of the difference between the maximum film thickness and the minimum film thickness of the coating film on the inner peripheral surface of the electrophotographic photosensitive member is Δt (μm), the film thickness difference Δt (μm) is expressed by the following formula. :
Δt ≦ 1000 ÷ R 0.5 (1)
An image forming apparatus characterized by satisfying the following. 円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つ前記フランジ付き電子写真感光体に形成される像を画像出力媒体に転写してカラー画像を形成することが可能な画像形成部を１つ備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、
前記電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、前記膜厚差Δｔ（μｍ）が下記式：
Δｔ≦７５０÷Ｒ０．５ ・・・（２）
を満たすことを特徴とする画像形成装置。An electrophotographic photosensitive member having a flange formed by fitting a flange to an opening at at least one end of a photosensitive layer having a photosensitive layer formed on a cylindrical substrate by a dip coating method, and the electrophotographic device having the flange. An image forming apparatus including one image forming unit capable of forming a color image by transferring an image formed on a photoconductor to an image output medium, and having a resolution of R (dpi),
When the absolute value of the difference between the maximum film thickness and the minimum film thickness of the coating film on the inner peripheral surface of the electrophotographic photosensitive member is Δt (μm), the film thickness difference Δt (μm) is expressed by the following formula. :
Δt ≦ 750 ÷ R 0.5 (2)
An image forming apparatus characterized by satisfying the following. 円筒状基体上に浸漬塗布法により感光層が形成された電子写真感光体の少なくとも一方の端部の開口にフランジを嵌合してなるフランジ付き電子写真感光体を有し且つ前記フランジ付き電子写真感光体に形成される像を画像出力媒体に転写してカラー画像を形成することが可能な画像形成部を複数備えており、解像度がＲ（ｄｐｉ）である画像形成装置であって、
前記電子写真感光体の内周面上における塗布膜の最大膜厚と最小膜厚との膜厚差の絶対値をΔｔ（μｍ）とした場合に、前記膜厚差Δｔ（μｍ）が下記式：
Δｔ≦５００÷Ｒ０．５ ・・・（３）
を満たすことを特徴とする画像形成装置。An electrophotographic photosensitive member having a flange formed by fitting a flange to an opening at at least one end of a photosensitive layer having a photosensitive layer formed on a cylindrical substrate by a dip coating method, and the electrophotographic device having the flange. An image forming apparatus comprising: a plurality of image forming units capable of forming a color image by transferring an image formed on a photoconductor to an image output medium, wherein the resolution is R (dpi);
When the absolute value of the difference between the maximum film thickness and the minimum film thickness of the coating film on the inner peripheral surface of the electrophotographic photosensitive member is Δt (μm), the film thickness difference Δt (μm) is expressed by the following formula. :
Δt ≦ 500 ÷ R 0.5 (3)
An image forming apparatus characterized by satisfying the following. 前記感光層が、少なくとも１５μｍを超える厚さの下引き層を有することを特徴とする請求項１から３のいずれか一項に記載の画像形成装置。The image forming apparatus according to claim 1, wherein the photosensitive layer has an undercoat layer having a thickness of at least more than 15 μm. 前記円筒状基体が、ポートホール押出工程を経て形成されたアルミニウム合金管であることを特徴とする請求項４に記載の画像形成装置。The image forming apparatus according to claim 4, wherein the cylindrical substrate is an aluminum alloy tube formed through a porthole extrusion process.
JP2003035585A 2003-02-13 2003-02-13 Image forming apparatus Pending JP2004246058A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2003035585A JP2004246058A (en) 2003-02-13 2003-02-13 Image forming apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2003035585A JP2004246058A (en) 2003-02-13 2003-02-13 Image forming apparatus

Publications (1)

Publication Number Publication Date
JP2004246058A true JP2004246058A (en) 2004-09-02

Family

ID=33020964

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2003035585A Pending JP2004246058A (en) 2003-02-13 2003-02-13 Image forming apparatus

Country Status (1)

Country Link
JP (1) JP2004246058A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007004089A (en) * 2005-06-27 2007-01-11 Fuji Xerox Co Ltd Method for manufacturing electrophotographic photoreceptor and apparatus for removing excess coating film
US9176468B2 (en) 2006-12-22 2015-11-03 Canon Kabushiki Kaisha Rotational force transmitting part
US9477201B2 (en) 2008-06-20 2016-10-25 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member
US9678471B2 (en) 2006-12-22 2017-06-13 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9703257B2 (en) 2007-03-23 2017-07-11 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member

Cited By (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007004089A (en) * 2005-06-27 2007-01-11 Fuji Xerox Co Ltd Method for manufacturing electrophotographic photoreceptor and apparatus for removing excess coating film
JP4506586B2 (en) * 2005-06-27 2010-07-21 富士ゼロックス株式会社 Electrophotographic photoreceptor manufacturing method and surplus coating film removing apparatus
US11237517B2 (en) 2006-12-22 2022-02-01 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9869960B2 (en) 2006-12-22 2018-01-16 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9733614B2 (en) 2006-12-22 2017-08-15 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9874854B2 (en) 2006-12-22 2018-01-23 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9772602B2 (en) 2006-12-22 2017-09-26 Canon Kabushiki Kaisha Rotational force transmitting part
US9836021B2 (en) 2006-12-22 2017-12-05 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9841728B2 (en) 2006-12-22 2017-12-12 Canon Kabushiki Kaisha Process cartridge having changeable relative positioning of a coupling member and another part of the process cartridge
US9874846B2 (en) 2006-12-22 2018-01-23 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9841729B2 (en) 2006-12-22 2017-12-12 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9841727B2 (en) 2006-12-22 2017-12-12 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10845756B2 (en) 2006-12-22 2020-11-24 Canon Kabushiki Kaisha Rotational force transmitting part
US10877433B2 (en) 2006-12-22 2020-12-29 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9678471B2 (en) 2006-12-22 2017-06-13 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9846408B2 (en) 2006-12-22 2017-12-19 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9746826B2 (en) 2006-12-22 2017-08-29 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10209670B2 (en) 2006-12-22 2019-02-19 Canon Kabushiki Kaisha Rotational force transmitting part
US9857764B2 (en) 2006-12-22 2018-01-02 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10671018B2 (en) 2006-12-22 2020-06-02 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9857765B2 (en) 2006-12-22 2018-01-02 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9864333B2 (en) 2006-12-22 2018-01-09 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9864331B2 (en) 2006-12-22 2018-01-09 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10585391B2 (en) 2006-12-22 2020-03-10 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10551793B2 (en) 2006-12-22 2020-02-04 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US11156956B2 (en) 2006-12-22 2021-10-26 Canon Kabushiki Kaisha Rotational force transmitting part
US10539924B2 (en) 2006-12-22 2020-01-21 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10539923B2 (en) 2006-12-22 2020-01-21 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US9176468B2 (en) 2006-12-22 2015-11-03 Canon Kabushiki Kaisha Rotational force transmitting part
US11720054B2 (en) 2006-12-22 2023-08-08 Canon Kabushiki Kaisha Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit
US10429794B2 (en) 2006-12-22 2019-10-01 Canon Kabushiki Kaisha Rotational force transmitting part
US9841724B2 (en) 2007-03-23 2017-12-12 Canon Kabushiki Kaisha Image forming apparatus cartridge having changeable relative positioning of a coupling member and another part of the image forming apparatus cartridge
US11675308B2 (en) 2007-03-23 2023-06-13 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10520887B2 (en) 2007-03-23 2019-12-31 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9886002B2 (en) 2007-03-23 2018-02-06 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9939776B2 (en) 2007-03-23 2018-04-10 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10788790B2 (en) 2007-03-23 2020-09-29 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9851688B2 (en) 2007-03-23 2017-12-26 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9851685B2 (en) 2007-03-23 2017-12-26 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10620582B2 (en) 2007-03-23 2020-04-14 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9857766B2 (en) 2007-03-23 2018-01-02 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10712709B2 (en) 2007-03-23 2020-07-14 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10712710B2 (en) 2007-03-23 2020-07-14 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10788789B2 (en) 2007-03-23 2020-09-29 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9836015B2 (en) 2007-03-23 2017-12-05 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10795312B2 (en) 2007-03-23 2020-10-06 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US10816931B2 (en) 2007-03-23 2020-10-27 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9817333B2 (en) 2007-03-23 2017-11-14 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9703257B2 (en) 2007-03-23 2017-07-11 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US11204584B2 (en) 2007-03-23 2021-12-21 Canon Kabushiki Kaisha Electrophotographic image forming apparatus, developing apparatus, and coupling member
US9477201B2 (en) 2008-06-20 2016-10-25 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member
US10901360B2 (en) 2008-06-20 2021-01-26 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member
US11209772B2 (en) 2008-06-20 2021-12-28 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassemblying method for coupling member
US10545450B2 (en) 2008-06-20 2020-01-28 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member
US10095179B2 (en) 2008-06-20 2018-10-09 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member
US9594343B2 (en) 2008-06-20 2017-03-14 Canon Kabushiki Kaisha Cartridge, mounting method for coupling member, and disassembling method for coupling member

Similar Documents

Publication Publication Date Title
JP2005154713A (en) Hydroxygallium phthalocyanine pigment and process for production thereof, process for production of photosensitive layer-forming coating solution, electrophotographic photoreceptor, process cartridge, electrophotographic device and image formation method
JP2007219087A (en) Electrifying device and image forming apparatus
JP2009058789A (en) Electrophotographic equipment, and process cartridge
JP2009150958A (en) Method of manufacturing support for electrophotographic photoreceptor
JP2004246058A (en) Image forming apparatus
JP3987040B2 (en) Electrophotographic photoreceptor and image forming apparatus having the same
JP2006267957A (en) Electrophotographic photoreceptor, composite body, manufacturing method for composite body, process cartridge, and electrophotographic device
JPH10177261A (en) Electrophotographic device and image forming method
JP4076596B2 (en) Electrophotographic apparatus and image forming method
JP2006178415A (en) Image forming method and image forming apparatus
JP2001125435A (en) Electrophotographic sensitive body, process cartridge, and image forming device
JPH09187820A (en) Reclaiming method of plastic part and cylinder assembly
US20030073014A1 (en) Electrophotographic photoreceptor and electrophotographic apparatus using same
JP2009186672A (en) Electrophotographic photoreceptor and image forming apparatus equipped with the same
JP2006047870A (en) Electrophotographic photoreceptor and manufacturing method therefor, electrophotographic apparatus, and process cartridge
JP2002006516A (en) Electrophotographic photoreceptor, method for manufacturing the electrophotographic photoreceptor, image forming device and process cartridge
JPH08234471A (en) Electrophotgraphic photoreceptor and image forming method
JP2003167361A (en) Method for manufacturing cylindrical base substance for electrophotographic photoreceptor, cylindrical base substance for electrophotographic photoreceptor, electrophotographic sensitive body, image forming apparatus and process cartridge
JP2010066668A (en) Method of manufacturing electrophotographic photoreceptor unit, electrophotographic apparatus and process cartridge
JPH08314174A (en) Electrophotographic photoreceptor, electrophotographic device and device unit
JP2003091135A (en) Image forming apparatus
JP2000347518A (en) Image forming device
JPH10177262A (en) Electrophotographic device and image forming method
JP2004233674A (en) Electrophotographic apparatus and process cartridge
JPH10177263A (en) Electrophotographic device and image forming method

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20060201

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20071011

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20071113

A02 Decision of refusal

Free format text: JAPANESE INTERMEDIATE CODE: A02

Effective date: 20080408