JP2004303513A

JP2004303513A - Power feed member, electrical connection structure, and image formation device

Info

Publication number: JP2004303513A
Application number: JP2003093463A
Authority: JP
Inventors: Akira Tagami; 亮田上
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2003-03-31
Filing date: 2003-03-31
Publication date: 2004-10-28
Anticipated expiration: 2023-03-31
Also published as: JP4167104B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power feed member and an electrical connection structure for stably establishing electrical contact between the power feed member and a power-fed member with time without using conductive grease, and to provide an image formation device having them. <P>SOLUTION: In this power feed member 22, the electrical connection structure 30 and the image formation device having them, engagement parts 26a and 26b engaging with the power-fed member 11 to feed power to the member are formed of conductive resins each having a low friction coefficient and wear resistance. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、被給電部材に係合し給電を行う給電部材、これを備えこの給電部材が係合し同給電部材により給電を行なわれる被給電部材を有する電気的接続構造およびこれらを備えた複写機、ファクシミリ、プリンタ等の画像形成装置に関する。
【０００２】
【従来の技術】
従来より、電気的な接続を行なう構造であって、給電部材と被給電部材とが擦れる構成となっている構造が知られている。このような構造においては、給電部材、被給電部材はそれぞれ、他方に接触する部分が磨耗し、接触不良となって、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等の不具合が生じる。そこで従来は、互いの接触部分に導電性グリスを塗布することで、かかる接触部分の磨耗を防止し、接触状態を安定させて、かかる不具合を防止してきた。
【０００３】
【発明が解決しようとする課題】
しかし、導電性グリスは経時的に乾燥、変質、消耗するため、かかる接触状態の安定を保ちつづけることが困難であって、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等のかかる不具合を回避しつづけることが困難であるという問題があった。また、給電部材と被給電部材との相対的な振動等によっても、同様の不具合が生じるという問題があった。さらに、かかる電気的接続構造を、複写機、プリンタ、ファクシミリ等の画像形成装置に適用した場合、かかる不具合に起因して画像形成の不良が生じるという問題があった。
【０００４】
本発明は、導電性グリスを用いることなく、給電部材と被給電部材との電気的な接触を経時的に安定して行なう給電部材、電気的接続構造およびこれらを有する画像形成装置を提供するものである。
【０００５】
【課題を解決するための手段】
上記目的を達成するため、請求項１記載の発明は、被給電部材に係合し給電を行う係合部を有する給電部材において、少なくとも上記係合部を低摩擦係数で耐磨耗性を備える導電性樹脂としたことを特徴とする。
【０００６】
請求項２記載の発明は、請求項１記載の給電部材において、上記係合部が、被給電部材に対し所定の加圧力にて圧接していることを特徴とする。
【０００７】
請求項３記載の発明は、請求項２記載の給電部材において、上記係合部を被給電部材に対し所定の加圧力にて圧接させるための板ばね構造を有することを特徴とする。
【０００８】
請求項４記載の発明は、請求項１ないし３の何れか１つに記載の給電部材において、上記係合部を複数有することを特徴とする。
【０００９】
請求項５記載の発明は、請求項１ないし４の何れか１つに記載の給電部材と、この給電部材が係合し同給電部材により給電を行なわれる被給電部材とを有する電気的接続構造にある。
【００１０】
請求項６記載の発明は、請求項５記載の電気的接続構造において、上記被給電部材が、回転するローラ状の部材であることを特徴とする。
【００１１】
請求項７記載の発明は、請求項６記載の電気的接続構造であって、上記係合部を複数有し、同係合部が上記被給電部材に対し所定の加圧力にて圧接している電気的接続構造において、上記係合部の少なくとも１つが、上記被給電部材の軸方向を含む方向から同被給電部材に係合することを特徴とする。
【００１２】
請求項８記載の発明は、請求項６記載の電気的接続構造であって、上記係合部を複数有し、同係合部が上記被給電部材に対し所定の加圧力にて圧接している電気的接続構造において、上記係合部の少なくとも１つが、上記被給電部材の軸方向に垂直な方向を含む方向から同被給電部材に係合することを特徴とする。
【００１３】
請求項９記載の発明は、請求項５ないし８の何れか１つに記載の電気的接続構造において、上記給電部材が上記被給電部材により高電圧を印加させることを特徴とする。
【００１４】
請求項１０記載の発明は、請求項９記載の電気的接続構造において、画像形成装置に備えられるためのものであって、上記被給電部材がバイアスローラであることを特徴とする。
【００１５】
請求項１１記載の発明は、請求項１ないし４記載の給電部材または請求項５ないし１０記載の電気的接続構造を備えた画像形成装置にある。
【００１６】
請求項１２記載の発明は、請求項１１記載の画像形成装置であって、上記被給電部材がバイアスローラである画像形成装置において、像担持体を有し、同バイアスローラが、上記像担持体上のトナー像を記録媒体に転写するための転写バイアスを印加するための転写バイアス印加手段に備えられていることを特徴とする。
【００１７】
請求項１３記載の発明は、請求項１２記載の画像形成装置であって、上記係合部が、上記被給電部材に対し所定の加圧力にて圧接している画像形成装置において、上記所定の加圧力ｎが、２Ｎ≦ｎ≦７Ｎの範囲であることを特徴とする。
【００１８】
【実施例】
図１に本発明を適用した画像形成装置の概略を示す。画像形成装置は複写機、ファクシミリ、プリンタ等、何れでもよい。本実施例の画像形成装置は単色の画像を形成するものであるが、カラー画像を形成するものであっても良い。画像形成装置１００は、一般にコピー等に用いられる普通紙と、フィルム、ＯＨＰシートや、カード、ハガキといった９０Ｋ紙、坪量約１００ｇ／ｍ^２相当以上の厚紙や、封筒等の、普通紙よりも熱容量が大きないわゆる特殊シートとの何れに対しても、シート状の記録媒体である転写紙として、画像形成を行うことが可能である。転写紙の大きさは、Ａ４サイズやＡ３サイズ等の一般的な規格をなす大きさが一般的であるが、規格外の大きさであっても良い。
【００１９】
画像形成装置１００は、矢印Ｃ方向に回転駆動される円筒状に形成された像担持体としての感光体ドラム（以下、「感光体」という。）３と、感光体３を帯電する帯電手段としての帯電装置１０２と、帯電後の感光体３に画像信号に応じた潜像を形成する図示しないレーザー光を発して光走査を行う露光手段としての図示しない光電装置である露光装置と、露光後の感光体３上の静電潜像を現像する現像手段としての現像ユニットである現像装置１０４とを有している。
【００２０】
画像形成装置１００はまた、感光体３の下方において感光体３に対向して配置され現像装置１０４による現像によって得られた感光体３上のトナー像を転写紙に転写する転写手段であり感光体３からトナー像を転写された転写紙を搬送する搬送装置である転写搬送装置１と、転写後の感光体３をクリーニングするクリーニング手段としてのクリーニングユニットであるクリーニング装置１０６と、帯電装置１０２で帯電を行う前に感光体３の除電を行う除電手段としての除電装置１１０とを有している。感光体３、帯電装置１０２、露光装置、現像装置１０４、クリーニング装置１０６及び除電装置１１０等は、プロセスユニットを構成している。
【００２１】
画像形成装置１００はまた、記録紙を積載している図示しない給紙トレイと、給紙トレイに積載した記録紙を感光体３と転写搬送装置１との対向部に向けて送り出す給紙手段としての図示しない給紙ローラと、給紙ローラによって給紙トレイから送られてきた転写紙を所定のタイミングで感光体３と転写搬送装置１との対向部である転写ニップ部２０に搬送するレジストローラ１０と、転写搬送装置１により感光体３上のトナー像を転写された転写紙に、かかるトナー像の定着を行う定着手段としての図示しない定着装置と、転写後の転写紙を感光体３から強制的に分離する分離爪２１とを有している。
【００２２】
現像装置１０４は、感光体３に対向して配設された被給電部材としての現像ローラ１０４ａ、１０４ｂを有している。現像ローラ１０４ａ、１０４ｂは帯電しており、静電的に吸着したトナーを感光体３に供給することで現像を行なうものである。クリーニング装置１０６は、Ｃ方向における感光体３と転写搬送装置１との対向部の下流側で感光体３に対向して配置されている。クリーニング装置１０６は、感光体３に対向して配設された被給電部材としてのクリーニングブラシ１０６ａを有しており、帯電したクリーニングブラシ１０６ａにより転写後の感光体３の表面に残留付着しているトナーや、微細な紙粉などを除去するものである。
【００２３】
図１または図２に示すように、転写搬送装置１は、ベルトユニット２を本体１Ａに対して着脱自在に支持している。ベルトユニット２は、駆動ローラ４と、従動ローラ５と、感光体３からの現像画像を転写するために駆動ローラ４及び従動ローラ５に巻き掛けられており、図２において矢印Ａで示す方向に回転駆動される転写ベルト６と、転写ベルト６を感光体３に対して接離させるためのＤＣソレノイド８及び接離レバー９とを備えている。
【００２４】
転写搬送装置１はまた、転写ベルト６に転写バイアスを印加する転写バイアスローラとしての被給電部材であるバイアスローラ１１と、バイアスローラ１１に係合し給電を行う給電部材２２と、給電部材２２を介してバイアスローラ１１に給電する図示しない高圧電源と、駆動ローラ４、従動ローラ５及び転写ベルト６とともにバイアスローラ１１及び給電部材２２を支持する図示しないフレームとを備えている。
【００２５】
転写搬送装置１はまた、高圧電源と給電部材２２とを備え感光体３上のトナー像を転写紙に転写するための転写バイアスを印加するための転写バイアス印加手段と、給電部材２２とバイアスローラ１１とを備え給電部材２２がバイアスローラ１１により２ｋＶ〜７ｋＶの高電圧を印加させる図３、４に示す電気的接続構造３０とを有している。なお、給電部材２２は図示しないハーネス等を介して高圧電源に電気的に接続されており、かかるハーネス等も転写バイアス印加手段、転写搬送装置１に備えられている。
【００２６】
転写搬送装置１はまた、転写ベルト６の表面に付着した残留トナーや転写紙の紙屑を掻き落とすクリーニングブレード１６と、転写ベルト６にバイアスを印加して転写ベルト６の表面に付着した残留トナーや転写紙の紙屑を吸着するクリーニングバイアスローラ１７と、クリーニングバイアスローラ１７に当接しクリーニングバイアスローラ１７に吸着された残留トナーや紙粉をクリーニングバイアスローラ１７から除去するためのバイアスローラクリーニングブレード１８と、クリーニングブレード１６やバイアスローラクリーニングブレード１８から落下した残留トナーや紙粉を回収するトナー回収コイル１９とを有している。
【００２７】
転写ベルト６は、図示しないが、２層構造であり、ＪＩＳＫ６９１１に準拠した電気抵抗の測定で、ＤＣ１００Ｖ印加時において、表面層は表面抵抗率が１×１０^８Ω〜１×１０^１２Ω、内側層の表面抵抗率が１×１０^７Ω〜１×１０^９Ωに、そして、その体積抵抗率が５×１０^８Ω・ｃｍ〜５×１０^１０Ω・ｃｍとなるよう設定されている。なお、これら抵抗値は一例であり、他の抵抗値にすることも可能である。
【００２８】
バイアスローラ１１は、図示しない駆動手段によって回転駆動されるローラ状の部材である。バイアスローラ１１は、転写ベルト６の移動方向Ａにおいて従動ローラ５及び転写ニップ部２０の下流側、すなわち転写ニップ部２０から駆動ローラ４の方へ所定距離だけ離れた位置、言い替えると図２において従動ローラ５及び転写ニップ部２０の左側に位置し、また転写ベルト６の内側に接触するように設けられている。
【００２９】
バイアスローラ１１は、転写ベルト６に電圧を印加して、感光体３上のトナーを、転写ベルト６によって搬送されている転写紙に転写するためのものである。バイアスローラ１１は、直径が６ｍｍであり、周面の速度が５００ｍｍ／ｓｅｃであって、回転数が１５９２ｒｐｍとされている。
【００３０】
図３または図４に給電部材２２及びこれを備えた電気的接続構造３０を示す。給電部材２２は、基体２３とこの基体２３から２箇所において延出した２つの板ばね構造としての板ばね部２４ａ、２４ｂとを有する本体２５と、板ばね部２４ａ、２４ｂのそれぞれの先端部に配設されバイアスローラ１１に係合した係合部としてのシート材２６ａ、２６ｂとを備えている。基体２３は、フレームにネジ２７、２８によりネジ止めされている。
【００３１】
シート材２６ａはバイアスローラ１１の周面に当接している。すなわちシート材２６ａは、図３において矢印Ｂで示すバイアスローラ１１の軸方向に垂直な方向を含む方向からバイアスローラ１１に係合している。シート材２６ｂはバイアスローラ１１の端面に当接している。すなわちシート材２６ｂはバイアスローラ１１の軸方向Ｂを含む方向からバイアスローラ１１に係合している。
【００３２】
シート材２６ａ、２６ｂは、低摩擦係数で耐磨耗性を備える導電性樹脂である。シート材２６ａ、２６ｂの厚さは０．１３ｍｍであって、物性は以下のようになっている。

【００３３】
このような特性を備えるシート材２６ａ、２６ｂの材料として、本実施例においては、超高分子量ポリエチレンを採用しているが、上述のような低摩擦係数で耐磨耗性を備える導電性樹脂であれば、他の材料を使用してもよい。シート材２６ａ、２６ｂは板ばね部２４ａ、２４ｂによりバイアスローラ１１に対し、以下説明する所定の圧力で圧接され係合しているが、このような特性を備えることで、バイアスローラ１１及びシート材２６ａ、２６ｂ自身の経時的な磨耗が防止され、バイアスローラ１１とシート材２６ａ、２６ｂとの接触状態は常に安定した状態となる。
【００３４】
板ばね部２４ａ、２４ｂによるシート材２６ａ、２６ｂのバイアスローラ１１に対する圧接力、すなわち加圧力について説明する。図５に、板ばね部２４ａ、２４ｂによるシート材２６ａ、２６ｂのバイアスローラ１１に対する加圧力と、バイアスローラ１１のトルクと、これら加圧力、トルクと電磁波ノイズ発生、異常画像発生の条件との関係とを示す。
【００３５】
図５から明らかなように、電磁波ノイズが発生するのは、かかる加圧力が２Ｎを下回ったときである。また、異常画像が発生するのは、バイアスローラ１１のトルクが１６Ｎ・ｍを上回ったときであり、これは図５に示されたかかるトルクとかかる加圧力との関係、すなわち、かかるトルクとかかる加圧力とがほぼ比例するという関係から、かかる加圧力が７Ｎを上回るときである。
【００３６】
そこで、シート材２６ａ、２６ｂのバイアスローラ１１に対する加圧力ｎは、２Ｎ≦ｎ≦７Ｎの範囲が適切であり、この範囲内で決定される。かかる加圧力ｎは、シート材２６ａ、２６ｂそれぞれのバイアスローラ１１に対する接触がほぼ点接触で行なわれることから、板ばね部２４ａ、２４ｂによる加圧力すなわち板ばね部２４ａ、２４ｂの弾性力によって規定される。
【００３７】
そして、かかる加圧力ｎをかかる範囲とすることで、シート材２６ａ、２６ｂとバイアスローラ１１との相対的な振動を防止し、シート材２６ａ、２６ｂとバイアスローラ１１との電気的な接触を安定して行なうことができ、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、またバイアスローラ１１のトルクが過大になることを防止することで、転写搬送装置１による記録紙搬送の負荷を抑制すること等により、画像ぶれ等の異常画像の発生を防止し、良好な画像形成に寄与している。
【００３８】
なお、本実施例においては、ｎ＝４Ｎとされ、バイアスローラ１１の外周の周速度が上述のように５００ｍｍ／ｓｅｃであるとき、３０００ｈの耐久性すなわち耐磨耗性が確認された。また、加圧力ｎが２Ｎ≦ｎ≦７Ｎの範囲であることをバイアスローラ１１のトルクｔで規定すれば、５Ｎ・ｍ≦ｔ≦１６Ｎ・ｍである。
【００３９】
シート材２６ａは、板ばね部２４ａのかかる加圧力により、バイアスローラ１１の軸方向Ｂに垂直な方向を含む方向からバイアスローラ１１の周面に係合しているため、バイアスローラ１１が方向Ｂに垂直な方向に振動することを防止するとともに、このような振動が生じた場合にあっても、接触不良となることがなく、耐磨耗性等をも有することから、確実に導通を行ない、導通不良が発生することがなく確実に給電し、常に適正なバイアス印加を行なうとともに、異音の発生、導通不良に起因する電磁波ノイズの発生等の不具合を防止する。
【００４０】
同様に、シート材２６ｂは、板ばね部２４ｂのかかる加圧力により、バイアスローラ１１の軸方向Ｂを含む方向からバイアスローラ１１の端面に係合しているため、バイアスローラ１１が方向Ｂに振動することを防止するとともに、このような振動が生じた場合にあっても、接触不良となることがなく、耐磨耗性等をも有することから、確実に導通を行ない、導通不良が発生することがなく確実に給電し、常に適正なバイアス印加を行なうとともに、異音の発生、導通不良に起因する電磁波ノイズの発生等の不具合を防止する。
【００４１】
また、このように複数箇所、特に互いに直交する２方向から、２箇所においてシート材２６ａ、２６ｂが係合していることで、かりに、何れか１箇所において、給電部材２２やバイアスローラ１１の振動等により、接触不良が生じても、他方においては接触状態が良好に維持されるため、給電が確実に行なわれ、バイアスが適正に印加される。
【００４２】
図示を省略するが、給電部材２２と同様の構成の給電部材が現像装置１０４及びクリーニング装置１０６に備えられている。現像装置１０４においては、バイアスローラたる現像ローラ１０４ａ、１０４ｂのそれぞれに対してかかる給電部材が係合しており、この給電部材と現像ローラ１０４ａ、１０４ｂのそれぞれとは、電気的接続構造３０と同様の電気的接続構造を構成している。
【００４３】
クリーニング装置１０６においては、バイアスローラたるクリーニングブラシ１０６ａに対してかかる給電部材が係合しており、この給電部材とクリーニングブラシ１０６ａとは、電気的接続構造３０と同様の電気的接続構造を構成している。また、現像ローラ１０４ａ、現像ローラ１０４ｂはそれぞれ、現像ローラ１０４ａ、現像ローラ１０４ｂ上のトナーを感光体３上に供給するための現像バイアス印加手段に備えられており、クリーニングブラシ１０６ａは、感光体３上の残留トナーや紙粉を除去するためのクリーニングバイアス印加手段に備えられている。転写バイアス印加手段、現像バイアス印加手段、クリーニングバイアス印加手段は、何れもバイアス引火手段である点において共通している。
【００４４】
転写搬送装置１においては、レジストローラ１０から転写紙が繰り出されるのに合わせて、図２に示すように、転写ベルト６が感光体３に接近させる態位とされ、感光体３との間で転写紙の搬送方向Ａに沿った長さに相当する幅４〜８ｍｍ程度の転写ニップ部２０が形成される。
【００４５】
感光体３からの画像転写すなわちトナー像の転写が行われると、これと同時に転写紙も帯電する。従って、転写ベルト６の真電荷と転写紙側に発生する分極電荷との関係により、転写紙を転写ベルト６上に静電的に吸着して感光体３からの転写紙の分離が行える。そして、感光体３の曲率分離を利用した転写紙自らの腰の強さによる剥離動作によって分離が助長される。
【００４６】
静電吸着は、環境条件の変化により、高湿度の場合には、転写紙に電流が流れやすくなるので転写紙の分離がうまく行かなくなることがある。このため、転写ベルト６の表面層の抵抗値が若干高めに設定してあり、さらには、バイアスローラ１１を転写ニップ部２０よりも転写紙搬送方向Ａで下流側に位置させている。これにより、転写ベルト６から転写紙への真電荷の移行を遅らせて、転写紙と感光体３との間での静電的な吸着関係を回避するようになっている。これらによっても分離されない場合には分離爪２１により分離が行われる。なお図２において分離爪２１の図示は省略している。
【００４７】
転写ニップ部２０を通過した転写紙は、転写ベルト６の移動にあわせて静電吸着搬送され、駆動ローラ４での曲率分離が行われる。このため、駆動ローラ４の直径は１６ｍｍ以下に設定されている。駆動ローラ４で転写ベルト６から分離された転写紙は、定着装置に進入し、定着装置では、転写紙上のトナーを加熱溶解して転写紙に圧着し、トナーを転写紙上に定着させる。
【００４８】
転写紙への画像転写および分離が完了した転写ベルト６は、ＤＣソレノイド８の励磁が解除されるのに応じて接離レバー９が解除され、感光体３から離間される。そして、クリーニングブレード１６とクリーニングバイアスローラ１７とにより表面を清掃される。転写ベルト６の表面から掻き採られたトナーあるいは紙粉は、回収コイル１９によって図示しない廃トナー回収容器に収容される。
【００４９】
画像形成装置１００は以上のような構成であるので、操作者による所定の操作により、画像形成装置１００の電源が投入され、又は待機状態から動作状態に移行した後、操作者が画像形成を開始する周知の操作を行うと、帯電装置１０２による帯電工程によって均一に帯電された感光体３は、矢印Ｃ方向の回転により、外部から入力されるデータ等に応じて照射されるレーザ光による露光工程における潜像形成、現像装置１０４による現像によって行われる現像工程、転写搬送装置１による転写工程、クリーニング装置１０６によるクリーニング工程、除電装置１１０による除電工程を経て再び帯電工程に移る。
【００５０】
転写工程によって転写紙上に転写されたトナー像は、転写搬送装置１によって定着装置に搬送され、定着装置における定着工程によって転写紙上に定着される。トナー像を定着された転写紙は、画像形成装置１００の外に排出される。このような画像形成工程において、給電部材、被給電部材たるバイアスローラ１１、現像ローラ１０４ａ、１０４ｂ、クリーニングブラシ１０６ａは、磨耗することなく、接触不良となることがなく、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等の不具合が防止されている。
【００５１】
ここで、給電部材、被給電部材との係合とは、直接係合していることを意味しており、これらの部材に導電性グリスは塗布されていない。したがって、導電性グリスの経時的乾燥、変質、消耗は生じず、接触状態の安定が保ちつづけるられる。これにより、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等のかかる不具合が回避される。
【００５２】
また、係合部が板ばね構造により被給電部材に対して加圧され弾性的に係合していることから、給電部材と被給電部材との相対的な振動等によっても、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等の不具合が生じることはない。したがって、かかる給電部材、電気的接続構造を適用されていることで、画像形成装置１００においてはかかる不具合に起因する画像形成の不良が生じることはなく、常に良好な画像形成が行なわれる。
【００５３】
以上、本発明を適用した給電部材、電気的接続構造及び画像形成装置を説明したが、給電部材は、少なくとも被給電部材に係合して給電を行う係合部が低摩擦係数で耐磨耗性を備える導電性樹脂であればよい。すなわち、上記実施例においては、係合部すなわちシート材２６ａ、２６ｂとし、このシート材２６ａ、２６ｂを低摩擦係数で耐磨耗性を備える導電性樹脂としたが、より多くの部分を低摩擦係数で耐磨耗性を備える導電性樹脂として、この導電性樹脂が、係合部以外の他の部分を含むようにしてもよい。
【００５４】
係合部は、複数であることが望ましいが、単数であってもよく、また複数である場合にも、上述した２箇所に限らず、２箇所以上備えられていてもよい。係合部を複数有する場合には、その係合部の少なくとも１つが、被給電部材の軸方向を含む方向や、この軸方向に垂直な方向を含む方向から被給電部材に係合することが望ましい。上記実施例においては、係合部が、被給電部材の軸方向とほぼ同一の方向、この軸方向に垂直な方向とほぼ同一の方向から被給電部材に係合しているが、これに限らず、これらの方向を含む方向から係合していればよい。
【００５５】
本発明を適用した給電部材、電気的接続構造は、給電部材と被給電部材とが相対的に移動することを前提とした技術であり、かかる移動には、外乱による振動等のみならず、給電部材、被給電部材の何れか一方又は両方が、他方に対して相対移動するように駆動され擦れる場合を含むが、特に駆動され擦れる場合において安定した係合状態を保つのに有効である。また、かかる給電部材、電気的接続構造は、その適用が画像形成装置に限られるものではなく、また画像形成装置に適用する場合にあっても、上述した部位に適用するのみならず、他の部位に適用可能である。
【００５６】
【発明の効果】
本発明は、被給電部材に係合し給電を行う係合部を有する給電部材において、少なくとも上記係合部を低摩擦係数で耐磨耗性を備える導電性樹脂としたので、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができる給電部材を提供することができる。
【００５７】
係合部が、被給電部材に対し所定の加圧力にて圧接していることとすれば、給電部材、被給電部材の振動が生じた場合であっても、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができる給電部材を提供することができる。
【００５８】
係合部を被給電部材に対し所定の加圧力にて圧接させるための板ばね構造を有することとすれば、給電部材自身に備えられた簡易な構造により、被給電部材の振動が生じた場合であっても、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができる給電部材を提供することができる。
【００５９】
係合部を複数有することとすれば、給電部材、被給電部材の振動が生じた場合であっても、すべての係合部が被給電部材との係合を解除されることを抑制して、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や導通不良に起因する電磁波ノイズの発生等を防止することができる給電部材を提供することができる。
【００６０】
本発明は、請求項１ないし４の何れか１つに記載の給電部材と、この給電部材が係合し同給電部材により給電を行なわれる被給電部材とを有する電気的接続構造にあるので、上述の各効果を奏し、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができる電気的接続構造を提供することができる。
【００６１】
被給電部材が、回転するローラ状の部材であることとすれば、給電部材と被給電部材とが相対的に移動する構成において、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができる電気的接続構造を提供することができる。
【００６２】
係合部を複数有し、同係合部が被給電部材に対し所定の加圧力にて圧接している電気的接続構造において、上記係合部の少なくとも１つが、被給電部材の軸方向を含む方向から同被給電部材に係合することとすれば、被給電部材の軸方向において、給電部材、被給電部材の振動が生じた場合であっても、被給電部材の軸方向を含む方向から同被給電部材に係合する係合部が被給電部材への係合状態を保つことで、すべての係合部が被給電部材との係合を解除されることを抑制して、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や導通不良に起因する電磁波ノイズの発生等を防止することができる電気的接続構造を提供することができる。
【００６３】
係合部を複数有し、同係合部が被給電部材に対し所定の加圧力にて圧接している電気的接続構造において、上記係合部の少なくとも１つが、被給電部材の軸方向に垂直な方向を含む方向から同被給電部材に係合することとすれば、被給電部材の軸方向と垂直な方向において、給電部材、被給電部材の振動が生じた場合であっても、被給電部材の軸方向と垂直な方向を含む方向から同被給電部材に係合する係合部が被給電部材への係合状態を保つことで、すべての係合部が被給電部材との係合を解除されることを抑制して、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や導通不良に起因する電磁波ノイズの発生等を防止することができる電気的接続構造を提供することができる。
【００６４】
給電部材が被給電部材により高電圧を印加させることとすれば、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な高圧での接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、被給電部材によって良好に高電圧を印加させることができる電気的接続構造を提供することができる。
【００６５】
画像形成装置に備えられるためのものであって、被給電部材がバイアスローラであることとすれば、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な高圧での接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、被給電部材によって良好に高電圧のバイアスを印加させることができ、良好な画像形成に資することができる電気的接続構造を提供することができる。
【００６６】
本発明は、請求項１ないし４記載の給電部材または請求項５ないし１０記載の電気的接続構造を備えた画像形成装置にあるので、上述の各効果を奏し、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、良好な画像形成を行うことができる画像形成装置を提供することができる。
【００６７】
被給電部材がバイアスローラである画像形成装置において、像担持体を有し、同バイアスローラが、上記像担持体上のトナー像を記録媒体に転写するための転写バイアスを印加するための転写バイアス印加手段に備えられていることとすれば、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止して、給電部材と被給電部材との電気的な接触を経時的に安定して行なうことができ、経時にわたって導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、被給電部材によって良好に転写バイアスを印加させることができ、良好な転写を行うことにより画像形成を行うことができる画像形成装置を提供することができる。
【００６８】
係合部が、被給電部材に対し所定の加圧力にて圧接している画像形成装置において、上記所定の加圧力ｎが、２Ｎ≦ｎ≦７Ｎの範囲であることとすれば、導電性グリスを用いることなく、給電部材、被給電部材の磨耗を防止するとともに、係合部と被給電部材との相対的な振動を防止することで、給電部材と被給電部材との電気的な接触を安定して行なうことができ、導通不良や異音の発生、導通不良に起因する電磁波ノイズの発生等を防止することができ、また、バイアスローラのトルクが過大になることを防止することで、画像ぶれ等の異常画像の発生を防止し、さらに良好な画像形成を行うことができる画像形成装置を提供することができる。
【図面の簡単な説明】
【図１】本発明を適用した画像形成装置の概略図である。
【図２】図１に示した転写搬送装置の概略図である。
【図３】図２に示した転写搬送装置に備えられた、本発明を適用した給電部材及び電気的接続構造の平面図である。
【図４】図２に示した転写搬送装置に備えられた、本発明を適用した給電部材及び電気的接続構造の側面図である。
【図５】給電部材の被給電部材に対する加圧力と、被給電部材のトルクと、これら加圧力、トルクと電磁波発生、異常画像発生の条件との関係とを示す相関図である。
【符号の説明】
３像担持体
１１被給電部材であり、回転するローラ状の部材としてのバイアスローラ
２２給電部材
２４ａ、２４ｂ板ばね構造
２６ａ、２６ｂ係合部、導電性樹脂
１００画像形成装置
１０４ａ、１０４ｂ被給電部材としての現像ローラ
１０６ａ被給電部材としてのクリーニングブラシ
Ｂ被給電部材の軸方向[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply member that engages with a power-supplied member to supply power, an electric connection structure including the power-supplied member that includes the power-supply member and that is supplied with power by the same power-supply member, and a copy provided with the same. And an image forming apparatus such as a facsimile, a printer, and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been known a structure for performing electrical connection, in which a power supply member and a power supplied member are rubbed. In such a structure, the power-supplying member and the power-supplied member each wear at a portion in contact with the other, resulting in poor contact, resulting in poor conduction, generation of abnormal noise, generation of electromagnetic noise due to poor conduction, and the like. Failure occurs. Therefore, conventionally, conductive grease has been applied to the contact portions of each other to prevent the wear of the contact portions, stabilize the contact state, and prevent such a problem.
[0003]
[Problems to be solved by the invention]
However, since the conductive grease is dried, deteriorated, and consumed with time, it is difficult to maintain such a stable contact state, and over time, poor conduction, generation of abnormal noise, and electromagnetic noise caused by poor conduction are caused. There is a problem that it is difficult to avoid such problems such as occurrence. In addition, there has been a problem that a similar problem occurs due to relative vibration between the power supply member and the power supply receiving member. Further, when such an electrical connection structure is applied to an image forming apparatus such as a copying machine, a printer, a facsimile, or the like, there is a problem that such a defect causes a defect in image formation.
[0004]
The present invention provides a power supply member, an electric connection structure, and an image forming apparatus having the same, which stably perform electric contact between a power supply member and a power-supplied member over time without using conductive grease. It is.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a power supply member having an engagement portion that engages with a power-supplied member and supplies power, wherein at least the engagement portion has a low friction coefficient and wear resistance. It is characterized by using a conductive resin.
[0006]
According to a second aspect of the present invention, in the power supply member according to the first aspect, the engaging portion is pressed against the power-supplied member with a predetermined pressure.
[0007]
According to a third aspect of the present invention, in the power supply member of the second aspect, the power supply member has a leaf spring structure for pressing the engagement portion against the power-supplied member with a predetermined pressing force.
[0008]
According to a fourth aspect of the present invention, in the power supply member according to any one of the first to third aspects, the power supply member includes a plurality of the engaging portions.
[0009]
According to a fifth aspect of the present invention, there is provided an electrical connection structure comprising the power supply member according to any one of the first to fourth aspects, and a power-supplied member to which the power supply member is engaged and power is supplied by the power supply member. It is in.
[0010]
According to a sixth aspect of the present invention, in the electrical connection structure according to the fifth aspect, the power-supplied member is a rotating roller-shaped member.
[0011]
The invention according to claim 7 is the electrical connection structure according to claim 6, comprising a plurality of the engaging portions, and the engaging portions are pressed against the power-supplied member with a predetermined pressure. In the electrical connection structure, at least one of the engaging portions engages the power-supplied member from a direction including an axial direction of the power-supplied member.
[0012]
An eighth aspect of the present invention is the electrical connection structure according to the sixth aspect, wherein the electrical connection structure has a plurality of the engaging portions, and the engaging portions are pressed against the power-supplied member with a predetermined pressure. In the electrical connection structure, at least one of the engaging portions engages the power-supplied member from a direction including a direction perpendicular to an axial direction of the power-supplied member.
[0013]
According to a ninth aspect of the present invention, in the electrical connection structure according to any one of the fifth to eighth aspects, the power supply member applies a high voltage to the power supplied member.
[0014]
According to a tenth aspect of the present invention, in the electrical connection structure according to the ninth aspect, the power supply member is a bias roller provided in the image forming apparatus.
[0015]
According to an eleventh aspect of the present invention, there is provided an image forming apparatus including the power supply member according to the first to fourth aspects or the electrical connection structure according to the fifth to tenth aspects.
[0016]
According to a twelfth aspect of the present invention, in the image forming apparatus according to the eleventh aspect, in the image forming apparatus, wherein the power-supplied member is a bias roller, the image forming apparatus includes an image carrier, and the bias roller includes the image carrier. It is characterized in that it is provided in a transfer bias applying means for applying a transfer bias for transferring the upper toner image to a recording medium.
[0017]
According to a thirteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, the engaging portion is pressed against the power-supplied member with a predetermined pressing force. The pressure n is in the range of 2N ≦ n ≦ 7N.
[0018]
【Example】
FIG. 1 schematically shows an image forming apparatus to which the present invention is applied. The image forming apparatus may be any of a copier, a facsimile, a printer, and the like. Although the image forming apparatus of this embodiment forms a single color image, it may form a color image. The image forming apparatus 100 includes plain paper generally used for copying and the like, 90K paper such as a film, an OHP sheet, a card, and a postcard, and a basis weight of about 100 g / m. ² It is possible to form an image as transfer paper, which is a sheet-shaped recording medium, on any of so-called special sheets having a larger heat capacity than plain paper, such as considerable thick paper and envelopes. The size of the transfer paper is generally a size conforming to a general standard such as A4 size or A3 size, but may be a size outside the standard.
[0019]
The image forming apparatus 100 includes a photosensitive drum (hereinafter, referred to as “photosensitive member”) 3 as a cylindrical image carrier that is driven to rotate in the direction of arrow C, and charging means for charging the photosensitive member 3. Charging device 102, an exposing device that is a not-shown photoelectric device as an exposing unit that emits a laser beam (not shown) for forming a latent image corresponding to an image signal on the charged photoconductor 3, and performs optical scanning. And a developing device 104 which is a developing unit as a developing unit for developing the electrostatic latent image on the photoconductor 3.
[0020]
The image forming apparatus 100 is a transfer unit that is disposed below the photoconductor 3 so as to face the photoconductor 3 and that transfers a toner image on the photoconductor 3 obtained by development by the developing device 104 to transfer paper. A transfer device 1 as a transfer device for transferring the transfer paper onto which the toner image has been transferred from the transfer member 3, a cleaning device 106 as a cleaning unit as a cleaning unit for cleaning the photoreceptor 3 after the transfer, and a charging device 102. And a static eliminator 110 as static elimination means for neutralizing the photoconductor 3 before performing the operation. The photoreceptor 3, the charging device 102, the exposure device, the developing device 104, the cleaning device 106, the charge removing device 110, and the like constitute a process unit.
[0021]
The image forming apparatus 100 also serves as a paper feed tray (not shown) on which recording papers are loaded, and a paper feed unit for sending the recording papers loaded on the paper feed tray toward the opposing portion of the photoconductor 3 and the transfer / transport device 1. And a registration roller that conveys the transfer paper sent from the paper supply tray by the paper supply roller to a transfer nip portion 20 which is an opposing portion of the photoconductor 3 and the transfer conveyance device 1 at a predetermined timing. 10, a fixing device (not shown) as a fixing unit for fixing the toner image onto the transfer paper on which the toner image on the photoconductor 3 has been transferred by the transfer conveyance device 1, and the transfer paper after transfer from the photoconductor 3 And a separation claw 21 forcibly separating.
[0022]
The developing device 104 has developing

rollers

104 a and 104 b as power-supplied members disposed to face the photoconductor 3. The developing

rollers

104a and 104b are charged and perform development by supplying electrostatically attracted toner to the photoconductor 3. The cleaning device 106 is disposed to face the photoconductor 3 on the downstream side of the opposing portion between the photoconductor 3 and the transfer / transport device 1 in the C direction. The cleaning device 106 has a cleaning brush 106 a as a power-supplied member disposed opposite to the photoconductor 3, and the cleaning brush 106 a remains on the surface of the photoconductor 3 after transfer by the charged cleaning brush 106 a. It removes toner and fine paper powder.
[0023]
As shown in FIG. 1 or FIG. 2, the transfer conveyance device 1 supports the belt unit 2 detachably from the main body 1A. The belt unit 2 is wound around the drive roller 4, the driven roller 5, and the drive roller 4 and the driven roller 5 to transfer a developed image from the photoconductor 3, and is moved in a direction indicated by an arrow A in FIG. The transfer belt 6 includes a transfer belt 6 that is driven to rotate, a DC solenoid 8 for moving the transfer belt 6 toward and away from the photoconductor 3, and a contact / separation lever 9.
[0024]
The transfer conveyance device 1 further includes a bias roller 11 that is a power-supplied member as a transfer bias roller that applies a transfer bias to the transfer belt 6, a power supply member 22 that engages with the bias roller 11 to supply power, and a power supply member 22. A high-voltage power supply (not shown) that supplies power to the bias roller 11 via the power supply unit, and a frame (not shown) that supports the bias roller 11 and the power supply member 22 together with the driving roller 4, the driven roller 5, and the transfer belt 6 are provided.
[0025]
The transfer conveyance device 1 further includes a high-voltage power supply and a power supply member 22, a transfer bias application unit for applying a transfer bias for transferring a toner image on the photoreceptor 3 to transfer paper, a power supply member 22 and a bias roller. The power supply member 22 includes an electrical connection structure 30 shown in FIGS. 3 and 4 for applying a high voltage of 2 kV to 7 kV by the bias roller 11. The power supply member 22 is electrically connected to a high-voltage power supply via a harness or the like (not shown), and the harness or the like is also provided in the transfer bias applying unit and the transfer conveyance device 1.
[0026]
The transfer conveyance device 1 also includes a cleaning blade 16 for scraping off residual toner and transfer paper debris adhered to the surface of the transfer belt 6, and a residual toner adhered to the surface of the transfer belt 6 by applying a bias to the transfer belt 6. A cleaning bias roller 17 for adhering paper debris of the transfer paper, a bias roller cleaning blade 18 for contacting the cleaning bias roller 17 and removing residual toner and paper dust adsorbed on the cleaning bias roller 17 from the cleaning bias roller 17; It has a toner collecting coil 19 that collects residual toner and paper dust dropped from the cleaning blade 16 and the bias roller cleaning blade 18.
[0027]
Although not shown, the transfer belt 6 has a two-layer structure, and has a surface layer having a surface resistivity of 1 × 10 when a voltage of 100 V DC is applied by measuring electric resistance in accordance with JIS K6911. ⁸ Ω ~ 1 × 10 ¹² Ω, surface resistivity of inner layer is 1 × 10 ⁷ Ω ~ 1 × 10 ⁹ Ω and its volume resistivity is 5 × 10 ⁸ Ω · cm to 5 × 10 ¹⁰ Ω · cm is set. Note that these resistance values are merely examples, and other resistance values can be used.
[0028]
The bias roller 11 is a roller-shaped member that is driven to rotate by a driving unit (not shown). The bias roller 11 is located downstream of the driven roller 5 and the transfer nip 20 in the moving direction A of the transfer belt 6, that is, at a position separated by a predetermined distance from the transfer nip 20 toward the drive roller 4, that is, in FIG. The transfer belt 6 is provided on the left side of the roller 5 and the transfer nip portion 20 and is in contact with the inside of the transfer belt 6.
[0029]
The bias roller 11 applies a voltage to the transfer belt 6 to transfer the toner on the photoreceptor 3 to the transfer paper conveyed by the transfer belt 6. The bias roller 11 has a diameter of 6 mm, a peripheral speed of 500 mm / sec, and a rotation speed of 1592 rpm.
[0030]
FIG. 3 or FIG. 4 shows the power supply member 22 and the electrical connection structure 30 including the same. The power supply member 22 includes a main body 25 having a base 23 and two

leaf springs

24 a and 24 b as a leaf spring structure extending at two locations from the base 23, and a distal end of each of the

leaf springs

24 a and 24 b. And

sheet members

26a and 26b as engaging portions that are disposed and engaged with the bias roller 11. The base 23 is fixed to the frame by

screws

27 and 28.
[0031]
The sheet material 26a is in contact with the peripheral surface of the bias roller 11. That is, the sheet material 26a is engaged with the bias roller 11 from a direction including a direction perpendicular to the axial direction of the bias roller 11 indicated by an arrow B in FIG. The sheet material 26b is in contact with the end surface of the bias roller 11. That is, the sheet material 26b is engaged with the bias roller 11 from a direction including the axial direction B of the bias roller 11.
[0032]
The

sheet members

26a and 26b are conductive resins having a low friction coefficient and abrasion resistance. The thickness of the

sheet materials

26a and 26b is 0.13 mm, and the physical properties are as follows.

[0033]
In the present embodiment, ultrahigh molecular weight polyethylene is used as the material of the

sheet materials

26a and 26b having such characteristics. However, the conductive resin having a low friction coefficient and abrasion resistance as described above is used. If so, other materials may be used. The

sheet members

26a, 26b are pressed against and engaged with the bias roller 11 by

leaf spring portions

24a, 24b at a predetermined pressure described below. With such characteristics, the bias roller 11 and the sheet member are provided. The wear of the

members

26a and 26b over time is prevented, and the contact state between the bias roller 11 and the

sheet members

26a and 26b is always stable.
[0034]
The pressing force of the

sheet materials

26a, 26b against the bias roller 11 by the

leaf spring portions

24a, 24b, that is, the pressing force will be described. FIG. 5 shows the pressing force of the

sheet materials

26a and 26b applied to the bias roller 11 by the

leaf spring portions

24a and 24b, the torque of the bias roller 11, and the relationship between the pressing force, the torque, and the conditions of generation of electromagnetic noise and abnormal image. And
[0035]
As is apparent from FIG. 5, the electromagnetic noise is generated when the applied pressure falls below 2N. An abnormal image is generated when the torque of the bias roller 11 exceeds 16 N · m, which corresponds to the relationship between the torque and the applied pressure shown in FIG. 5, that is, the applied torque. Since the pressure is almost proportional to the pressure, the pressure is more than 7N.
[0036]
Therefore, the pressing force n of the

sheet materials

26a and 26b to the bias roller 11 is appropriately in a range of 2N ≦ n ≦ 7N, and is determined within this range. The pressing force n is defined by the pressing force of the

leaf spring portions

24a, 24b, that is, the elastic force of the

leaf spring portions

24a, 24b, since the contact of the

sheet members

26a, 26b with the bias roller 11 is substantially performed by point contact. You.
[0037]
By setting the pressing force n within the above range, relative vibration between the

sheet members

26a and 26b and the bias roller 11 is prevented, and electrical contact between the

sheet members

26a and 26b and the bias roller 11 is stabilized. It is possible to prevent occurrence of conduction failure, abnormal noise, generation of electromagnetic noise due to conduction failure, and the like, and to prevent the torque of the bias roller 11 from becoming excessively large. By suppressing the load of recording paper conveyance by the conveyance device 1, occurrence of an abnormal image such as image blur is prevented, thereby contributing to good image formation.
[0038]
In this example, when n = 4N and the peripheral speed of the outer periphery of the bias roller 11 is 500 mm / sec as described above, the durability of 3000 hours, that is, the abrasion resistance, was confirmed. If the torque n of the bias roller 11 specifies that the pressing force n is in the range of 2N ≦ n ≦ 7N, then 5N · m ≦ t ≦ 16N · m.
[0039]
The sheet material 26a is engaged with the peripheral surface of the bias roller 11 from a direction including a direction perpendicular to the axial direction B of the bias roller 11 by the pressing force of the leaf spring portion 24a. In addition to preventing vibration in a direction perpendicular to the direction, even if such vibration occurs, there is no poor contact, and since it also has abrasion resistance, etc., conduction is ensured. In addition, power is supplied reliably without occurrence of conduction failure, proper bias is always applied, and problems such as generation of abnormal noise and generation of electromagnetic noise due to conduction failure are prevented.
[0040]
Similarly, the sheet material 26b is engaged with the end surface of the bias roller 11 from the direction including the axial direction B of the bias roller 11 by the pressing force applied by the leaf spring portion 24b. In addition, when such vibrations occur, even if such vibrations occur, contact failure does not occur, and since it also has abrasion resistance, etc., conduction is ensured and conduction failure occurs. The power supply is performed without fail, the proper bias is always applied, and problems such as generation of abnormal noise and generation of electromagnetic noise due to poor conduction are prevented.
[0041]
In addition, since the

sheet members

26a and 26b are engaged at a plurality of places, particularly at two places from two directions orthogonal to each other, the vibration of the power supply member 22 and the bias roller 11 can be made at any one place. For example, even if a contact failure occurs, the contact state is maintained in a favorable state on the other hand, so that power supply is reliably performed and a bias is appropriately applied.
[0042]
Although not shown, a power supply member having the same configuration as the power supply member 22 is provided in the developing device 104 and the cleaning device 106. In the developing device 104, the power supply members engage with each of the developing

rollers

104 a and 104 b serving as bias rollers. The power supply member and each of the developing

rollers

104 a and 104 b are similar to the electrical connection structure 30. Of the electrical connection structure.
[0043]
In the cleaning device 106, the power supply member engages with the cleaning brush 106a serving as a bias roller, and the power supply member and the cleaning brush 106a form an electrical connection structure similar to the electrical connection structure 30. ing. The developing roller 104a and the developing roller 104b are provided in a developing bias applying unit for supplying the toner on the developing roller 104a and the developing roller 104b onto the photosensitive member 3, respectively. The cleaning bias applying means for removing the residual toner and paper dust is provided. The transfer bias applying unit, the developing bias applying unit, and the cleaning bias applying unit are all common in that they are bias ignition units.
[0044]
In the transfer conveyance device 1, as shown in FIG. 2, the transfer belt 6 is brought close to the photoconductor 3 as the transfer paper is fed out from the registration roller 10, and the transfer belt 6 is brought into contact with the photoconductor 3. A transfer nip portion 20 having a width of about 4 to 8 mm corresponding to the length of the transfer sheet along the transport direction A is formed.
[0045]
When the image transfer from the photoconductor 3, that is, the transfer of the toner image, is performed, the transfer paper is also charged at the same time. Therefore, the transfer paper is electrostatically attracted onto the transfer belt 6 and the transfer paper can be separated from the photoconductor 3 by the relationship between the true charge of the transfer belt 6 and the polarization charge generated on the transfer paper side. Then, separation is promoted by a peeling operation based on the strength of the transfer paper itself utilizing the curvature separation of the photoconductor 3.
[0046]
In the case of electrostatic attraction, in a case of high humidity due to a change in environmental conditions, current easily flows through the transfer paper, so that the transfer paper may not be properly separated. For this reason, the resistance value of the surface layer of the transfer belt 6 is set slightly higher, and the bias roller 11 is located downstream of the transfer nip portion 20 in the transfer paper transport direction A. As a result, the transfer of the true charges from the transfer belt 6 to the transfer sheet is delayed, so that the electrostatic attraction relationship between the transfer sheet and the photoconductor 3 is avoided. If the separation is not performed by these, the separation is performed by the separation claw 21. In FIG. 2, the illustration of the separation claw 21 is omitted.
[0047]
The transfer paper that has passed through the transfer nip 20 is electrostatically attracted and conveyed in accordance with the movement of the transfer belt 6, and the drive roller 4 separates the curvature. For this reason, the diameter of the driving roller 4 is set to 16 mm or less. The transfer paper separated from the transfer belt 6 by the drive roller 4 enters a fixing device, where the toner on the transfer paper is heated and melted and pressed against the transfer paper to fix the toner on the transfer paper.
[0048]
The transfer belt 6 on which the image transfer to the transfer paper and the separation have been completed is released from the photoreceptor 3 by releasing the contact / separation lever 9 in response to the release of the excitation of the DC solenoid 8. Then, the surface is cleaned by the cleaning blade 16 and the cleaning bias roller 17. The toner or paper dust scraped off from the surface of the transfer belt 6 is stored in a waste toner collecting container (not shown) by a collecting coil 19.
[0049]
Since the image forming apparatus 100 is configured as described above, the power of the image forming apparatus 100 is turned on by a predetermined operation by the operator, or after the image forming apparatus 100 shifts from the standby state to the operation state, the image forming apparatus 100 starts image formation. When a known operation is performed, the photoconductor 3 uniformly charged by the charging process by the charging device 102 is exposed to a laser beam irradiated by rotation in the direction of arrow C in accordance with externally input data or the like. , A developing process performed by development by the developing device 104, a transfer process by the transfer / conveyance device 1, a cleaning process by the cleaning device 106, and a static elimination process by the static elimination device 110, and then the charging process is started again.
[0050]
The toner image transferred on the transfer paper in the transfer process is transported to the fixing device by the transfer transport device 1, and is fixed on the transfer paper by the fixing process in the fixing device. The transfer paper on which the toner image has been fixed is discharged out of the image forming apparatus 100. In such an image forming process, the power supply member, the power supply member, the bias roller 11, the developing

rollers

104a and 104b, and the cleaning brush 106a do not wear out, do not cause a contact failure, and cause poor conduction and abnormal noise. In addition, problems such as generation of electromagnetic noise due to poor conduction are prevented.
[0051]
Here, the engagement with the power supply member and the power-supplied member means that they are directly engaged, and the conductive grease is not applied to these members. Therefore, the conductive grease is not dried, deteriorated or consumed over time, and the contact state is kept stable. This avoids such troubles as poor conduction and abnormal noise over time, and generation of electromagnetic noise due to poor conduction.
[0052]
In addition, since the engaging portion is pressed against the power-supplied member by the leaf spring structure and is elastically engaged with the power-supplied member, poor conduction or abnormalities may occur due to relative vibration between the power-supplying member and the power-supplied member. Problems such as generation of sound and generation of electromagnetic noise due to poor conduction do not occur. Therefore, by applying such a power supply member and the electrical connection structure, in the image forming apparatus 100, image formation failure due to such a defect does not occur, and good image formation is always performed.
[0053]
As described above, the power supply member, the electrical connection structure, and the image forming apparatus to which the present invention is applied have been described. Any conductive resin having properties can be used. That is, in the above embodiment, the engaging portions, that is, the

sheet members

26a and 26b are made of the conductive resin having a low friction coefficient and abrasion resistance. As the conductive resin having abrasion resistance by a coefficient, the conductive resin may include a portion other than the engaging portion.
[0054]
It is desirable that the number of the engaging portions is plural, but the number of the engaging portions may be singular, and even in the case of plural, the number of engaging portions is not limited to the above-mentioned two, but may be two or more. When a plurality of engaging portions are provided, at least one of the engaging portions may engage with the power-supplied member from a direction including the axial direction of the power-supplied member or a direction including a direction perpendicular to the axial direction. desirable. In the above embodiment, the engaging portion is engaged with the power-supplied member from a direction substantially the same as the axial direction of the power-supplied member, and substantially the same direction as a direction perpendicular to the axial direction. However, it is only necessary to engage from directions including these directions.
[0055]
The power supply member and the electrical connection structure to which the present invention is applied are technologies based on the premise that the power supply member and the power-supplied member move relatively. Such movement includes not only vibration due to disturbance, but also power supply. This includes the case where one or both of the member and the power-supplied member are driven and rubbed so as to relatively move with respect to the other. However, it is effective to maintain a stable engagement state particularly when the member is driven and rubbed. Further, the application of the power supply member and the electric connection structure is not limited to the image forming apparatus. Applicable to the site.
[0056]
【The invention's effect】
The present invention provides a power supply member having an engagement portion that engages with a power-supplied member and performs power supply, since at least the engagement portion is made of a conductive resin having a low friction coefficient and abrasion resistance. Without using, the power supply member and the power supplied member can be prevented from being worn, and the electric contact between the power supply member and the power supplied member can be stably performed with time, resulting in poor conduction and abnormal noise over time. In addition, it is possible to provide a power supply member capable of preventing generation of electromagnetic noise due to poor conduction.
[0057]
Assuming that the engaging portion is pressed against the power-supplied member with a predetermined pressing force, the power-supplying member and the power-supplied member can be connected even if the power-supplying member vibrates. It is possible to provide a power supply member capable of performing stable electrical contact and preventing occurrence of poor conduction, abnormal noise, generation of electromagnetic noise due to poor conduction, and the like.
[0058]
If the power receiving member has a leaf spring structure for pressing the engaging portion against the power receiving member with a predetermined pressing force, the vibration of the power receiving member occurs due to the simple structure provided in the power feeding member itself. Even in this case, electrical contact between the power supply member and the power supplied member can be stably performed, and occurrence of poor conduction, abnormal noise, generation of electromagnetic noise due to poor conduction, and the like can be prevented. A power supply member can be provided.
[0059]
By having a plurality of engaging portions, even when the power supply member and the power-supplied member vibrate, it is possible to suppress all the engagement portions from being disengaged from the power-supplied member. In addition, it is possible to provide a power supply member capable of stably making electrical contact between the power supply member and the power-supplied member and preventing poor conduction and generation of electromagnetic noise due to poor conduction.
[0060]
The present invention is an electrical connection structure having a power supply member according to any one of claims 1 to 4 and a power-supplied member to which the power supply member is engaged and power is supplied by the power supply member. With the above-described effects, the power supply member and the power-supplied member can be prevented from being worn without using conductive grease, and the electric contact between the power-supply member and the power-supplied member can be stably performed with time. Thus, it is possible to provide an electrical connection structure capable of preventing occurrence of conduction failure or abnormal noise over time, generation of electromagnetic noise due to conduction failure, and the like.
[0061]
Assuming that the power-supplied member is a rotating roller-shaped member, the power-supplying member and the power-supplied member wear in a configuration in which the power-supplying member and the power-supplied member relatively move without using conductive grease. , Electrical contact between the power supply member and the power-supplied member can be stably performed over time, and the occurrence of poor conduction or abnormal noise over time, the occurrence of electromagnetic noise due to the poor conduction, etc. An electrical connection structure that can be prevented can be provided.
[0062]
In an electrical connection structure in which a plurality of engaging portions are provided, and the engaging portions are pressed against the power-supplied member at a predetermined pressure, at least one of the engaging portions is arranged in the axial direction of the power-supplied member. If the power-supplying member is engaged with the power-supplying member from the direction including the power-supplying member, even if the power-supplying member vibrates in the axial direction of the power-supplying member, the direction including the axial direction of the power-supplying member. Since the engaging portions that engage with the power-supplied member maintain the state of engagement with the power-supplied member, it is possible to prevent all the engaging portions from being disengaged from the power-supplied member, and It is possible to provide an electrical connection structure capable of stably making electrical contact between the member and the power-supplied member, and preventing poor conduction and generation of electromagnetic noise due to poor conduction.
[0063]
In an electrical connection structure in which a plurality of engaging portions are provided, and the engaging portions are pressed against the power-supplied member at a predetermined pressure, at least one of the engaging portions is arranged in the axial direction of the power-supplied member. If the power-supplying member is engaged with the power-supplying member from a direction including the vertical direction, even if the power-supplying member and the power-supplying member vibrate in a direction perpendicular to the axial direction of the power-supplying member, the power-supplying member can be engaged. The engaging portions that engage with the power-supplied member from the direction including the direction perpendicular to the axial direction of the power-supplying member maintain the engagement state with the power-supplied member, so that all the engaging portions engage with the power-supplied member. The electrical connection between the power-supplying member and the power-supplied member can be stably performed by suppressing the release of the connection, and the occurrence of electromagnetic noise due to poor conduction or poor conduction can be prevented. A possible electrical connection structure can be provided.
[0064]
If the power supply member applies a high voltage to the power supply member, wear of the power supply member and the power supply member can be prevented without using conductive grease, and the electrical high voltage between the power supply member and the power supply member can be reduced. Can be stably performed with time, and the occurrence of poor conduction or abnormal noise over time, the occurrence of electromagnetic noise due to the poor conduction, and the like can be prevented. Can be provided.
[0065]
It is intended to be provided in the image forming apparatus, and if the power-supplied member is a bias roller, without using conductive grease, the power-supplying member, preventing wear of the power-supplied member, Electrical high-voltage contact with the power-supplied member can be stably performed over time, and the occurrence of poor conduction, abnormal noise, and electromagnetic noise due to the poor conduction can be prevented over time. In addition, a high-voltage bias can be satisfactorily applied by the power-supplied member, and an electrical connection structure that can contribute to good image formation can be provided.
[0066]
The present invention resides in an image forming apparatus provided with the power supply member according to claims 1 to 4 or the electrical connection structure according to claims 5 to 10, so that the above-described effects can be obtained without using conductive grease. By preventing wear of the power supply member and the power supply receiving member, electrical contact between the power supply member and the power supply receiving member can be stably performed over time, resulting in poor conduction, abnormal noise, and poor conduction over time. Thus, it is possible to provide an image forming apparatus that can prevent generation of electromagnetic wave noise and the like and can perform favorable image formation.
[0067]
In an image forming apparatus in which a power-supplied member is a bias roller, the image forming apparatus includes an image carrier, and the bias roller includes a transfer bias for applying a transfer bias for transferring a toner image on the image carrier to a recording medium. If the power supply member is provided in the application unit, the power supply member and the power supply target member are prevented from being worn without using conductive grease, and the electrical contact between the power supply member and the power supply target member is stabilized with time. It is possible to prevent the occurrence of conduction failure and abnormal noise over time, the occurrence of electromagnetic noise due to the conduction failure, and the like, and to apply the transfer bias satisfactorily with the power-supplied member. It is possible to provide an image forming apparatus capable of forming an image by performing a proper transfer.
[0068]
In the image forming apparatus in which the engaging portion is pressed against the power-supplied member with a predetermined pressing force, if the predetermined pressing force n is in a range of 2N ≦ n ≦ 7N, the conductive grease may be used. Without using the power supply member and the power-supplied member, the electrical contact between the power-supply member and the power-supplied member can be prevented by preventing the wear of the power-supplying member and the power-supplied member, and by preventing the relative vibration between the engaging portion and the power-supplied member. It can be performed in a stable manner, and can prevent the occurrence of conduction failure and abnormal noise, the generation of electromagnetic noise due to the conduction failure, and the like, and also prevent the torque of the bias roller from becoming excessive, It is possible to provide an image forming apparatus capable of preventing abnormal images such as image blurring from occurring and performing better image formation.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an image forming apparatus to which the present invention is applied.
FIG. 2 is a schematic view of the transfer / conveyance device shown in FIG.
FIG. 3 is a plan view of a power supply member and an electrical connection structure to which the present invention is applied, provided in the transfer / conveyance device shown in FIG. 2;
FIG. 4 is a side view of a power supply member and an electrical connection structure to which the present invention is applied, provided in the transfer / conveyance device shown in FIG. 2;
FIG. 5 is a correlation diagram showing a pressing force of the power supply member to the power-supplied member, a torque of the power-supplied member, and a relationship between the pressing force, the torque, and conditions of generation of electromagnetic waves and abnormal images.
[Explanation of symbols]
3 Image carrier
11 A bias roller which is a member to be supplied with power and is a rotating roller-shaped member
22 Power supply member
24a, 24b leaf spring structure
26a, 26b engaging portion, conductive resin
100 Image forming apparatus
104a, 104b Developing roller as power-supplied member
106a Cleaning Brush as Powered Member
B Axial direction of power-supplied member

Claims

A power supply member having an engagement portion that engages with a power-supplied member to supply power, wherein at least the engagement portion is made of a conductive resin having a low friction coefficient and wear resistance.

2. The power supply member according to claim 1, wherein the engagement portion is pressed against the power-supplied member with a predetermined pressure.

3. The power supply member according to claim 2, wherein the power supply member has a leaf spring structure for pressing the engagement portion against the power-supplied member with a predetermined pressing force.

The power supply member according to claim 1, wherein the power supply member includes a plurality of the engagement portions.

An electrical connection structure comprising: the power supply member according to any one of claims 1 to 4; and a power-supplied member to which the power supply member engages and is supplied with power by the power supply member.

The electrical connection structure according to claim 5, wherein the power-supplied member is a rotating roller-shaped member.

7. The electrical connection structure according to claim 6, wherein the plurality of engagement portions include a plurality of the engagement portions, and the engagement portions are pressed against the power-supplied member with a predetermined pressure. An electrical connection structure, wherein at least one of the engaging portions engages the power-supplied member from a direction including an axial direction of the power-supplied member.

7. The electrical connection structure according to claim 6, wherein the plurality of engagement portions include a plurality of the engagement portions, and the engagement portions are pressed against the power-supplied member with a predetermined pressure. An electrical connection structure, wherein at least one of the engagement portions engages the power-supplied member from a direction including a direction perpendicular to the axial direction of the power-supplied member.

The electrical connection structure according to any one of claims 5 to 8, wherein the power supply member applies a high voltage to the power-supplied member.

The electrical connection structure according to claim 9, wherein the power supply member is a bias roller, provided in the image forming apparatus.

An image forming apparatus comprising the power supply member according to claim 1 or 4 or the electrical connection structure according to claim 5.

12. The image forming apparatus according to claim 11, wherein the power-supplied member is a bias roller, the image forming apparatus including an image carrier, wherein the bias roller applies a toner image on the image carrier to a recording medium. An image forming apparatus provided in transfer bias applying means for applying a transfer bias for transfer.

13. The image forming apparatus according to claim 12, wherein the engaging portion is pressed against the power-supplied member with a predetermined pressing force, wherein the predetermined pressing force n is 2N ≦ n. ≦ 7N. An image forming apparatus, wherein: