JP4176921B2

JP4176921B2 - Charging device

Info

Publication number: JP4176921B2
Application number: JP20909399A
Authority: JP
Inventors: 貴彦徳増; 雅史門永; 健治杉浦; 真小夫; 雅之平野
Original assignee: Hamamatsu Photonics KK; Ricoh Co Ltd
Current assignee: Hamamatsu Photonics KK; Ricoh Co Ltd
Priority date: 1999-07-23
Filing date: 1999-07-23
Publication date: 2008-11-05
Anticipated expiration: 2019-07-23
Also published as: JP2001034042A

Description

【０００１】
【発明の属する技術分野】
本発明は、複写機、ファクシミリ、プリンタ等の電子写真技術を利用した画像形成装置の帯電装置や転写装置、除電装置等に応用される帯電装置に係り、特に像担持体等の被帯電体を非接触で均一に帯電するための帯電装置に関する。
【０００２】
【従来の技術】
電子写真技術を利用した複写機、ファクシミリ、プリンタ等の画像形成装置における作像プロセスでは、静電潜像担持体である感光体を帯電させるプロセスが存在する。この帯電プロセスとしては、従来は非接触で帯電安定性にも優れているコロナチャージャーによって行われていたが、この方式ではオゾンが多く発生するため、最近では接触帯電方式が検討されており、例えば、特開昭６３−１４９６６９号公報に開示されているような接触帯電方法（導電性ローラを用いたローラ帯電方式であり、ＤＣ電圧にＡＣ電圧を重畳させて導電性ローラに印加する方法）や、特開平６−１７５４６９号公報に開示されているようなブラシ帯電装置（導電性ブラシを用いたブラシ帯電方式であり、導電性ブラシと芯金の間に低抵抗の中間導電部材を設けて、帯電の環境依存性を無くし、被帯電物を一定に帯電させる）が実用化されてきている。
【０００３】
しかし接触帯電方式では、帯電部材が感光体等の静電潜像担持体に接触しているために、帯電部材がトナーなどで汚れやすく、その結果、帯電ムラ等の帯電性能の劣化が生じてしまう。
以上のことから、オゾンレスの非接触帯電方式が帯電手段としては理想的であると言える。
【０００４】
そこで本発明者らは、電磁波照射装置と電界形成手段を備え、電磁波照射装置により静電潜像担持体上の空間に電磁波を照射すると共に電界形成手段で電界を形成することによって、静電潜像担持体を所望の電位に帯電させる新規な帯電方式の帯電装置を提案している。
図９は本発明者らが先に提案した帯電装置の一例を示す図であり、帯電装置と被帯電体である静電潜像担持体（例えば感光体）２を、静電潜像担持体２の軸方向（側面）から見た状態を示している。図９に示す帯電装置では、被帯電体である静電潜像担持体２の上部に近接して電磁波照射装置１を配置し、この電磁波照射装置１の近傍に平板状の電界制御部品６ａ，６ｂを配置して静電潜像担持体２を均一に帯電させるものである。その帯電原理は、電磁波照射装置１から照射された電磁波によって空気中にイオンを発生させ、電界制御部品６ａ，６ｂ及び／または静電潜像担持体２に電圧（Ｖｃ，Ｖｐ）を印加して電界を形成することで、上記の発生させたイオンを静電潜像担持体２に移動させ、付着させることで静電潜像担持体２を帯電するものである。この例の場合、電界制御部品６ａ，６ｂが静電潜像担持体２の上面側全体を覆うように配設されているため、静電潜像担持体２との間に比較的均一な電界を形成することができるので、静電潜像担持体２を均一にムラ無く帯電することができる。
また、図１０は本発明者らが先に提案した帯電装置の別の例を示しており、図９の構成に加えて、電磁波照射装置１と静電潜像担持体２の間にグリッド３を追加したものであり、電界制御部品６ａ，６ｂとグリッド３によってイオンを静電潜像担持体２へ導くことにより、静電潜像担持体２のより均一な帯電を可能にしたものである。
【０００５】
【発明が解決しようとする課題】
図９や図１０に示す構成の帯電装置では、電磁波によって生成されたイオンを電界の作用により効率よく静電潜像担持体に付着させ、静電潜像担持体を非接触で均一に帯電させることができる。
しかしながら、図９や図１０に示す構成の帯電装置では、電磁波照射装置１からの電磁波が被帯電体である静電潜像担持体２に直接照射されてしまい、経時的に悪影響を与えるという不具合があることが判明した。すなわち本発明者らは、電磁波が静電潜像担持体に与える影響を調べるため、電磁波照射装置１からの電磁波を静電潜像担持体（例えば感光体）へ連続照射する実験を実施したところ、静電潜像担持体への照射部位において、正常な帯電ができなくなるという経時劣化の問題が発生した。
【０００６】
本発明は上記事情に鑑みなされたものであって、静電潜像担持体等の被帯電体をオゾンレス・非接触でかつ均一に帯電することができると共に、電磁波が被帯電体に照射されるのを防止し、被帯電体の経時劣化の問題も解消した帯電装置を提供することを目的（課題）としている。
より具体的には、請求項１に係る発明は、電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体を均一に帯電することができる帯電装置を提供することを目的としている。
請求項２に係る発明は、請求項１の目的に加え、一つ以上の電磁波照射装置を被帯電体と平行に配置した場合に、各電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体をより均一に帯電することができる帯電装置を提供することを目的としている。
請求項３〜５に係る発明は、請求項１または２の目的に加え、より安価に電磁波の照射方向を制御すると共に、被帯電体を均一に帯電することを目的とし、さらには部品のコストダウンを図ることを目的としている。
請求項６に係る発明は、請求項１〜５のいずれか一つの目的に加え、部品のコストダウンを図ると共に、他部品への電磁波の影響を抑えることを目的としている。
【０００７】
【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に係る発明は、被帯電体を非接触で均一に帯電する帯電装置であって、上記被帯電体上の空間に電磁波を照射する少なくとも一つ以上の電磁波照射装置と、該電磁波照射装置から照射される電磁波の照射方向を制御する照射方向制御部材と、上記電磁波照射装置から照射された電磁波によって生成されたイオンを上記被帯電体に導くための電界制御部品と、上記被帯電体の帯電電位をより安定させるためのグリッドとを有し、上記照射方向制御部材によって電磁波が被帯電体へ照射されないようにし、上記電界制御部品及びグリッドによってイオンを被帯電体へ導くことにより、被帯電体を帯電させる帯電装置において、上記被帯電体の上部に近接して一つ以上の電磁波照射装置を電磁波照射方向が上記被帯電体の上部表面と平行になるように配置し、上記電磁波照射装置と一体に上記照射方向制御部材を配置し、上記電磁波照射装置の電磁波照射方向の上下に配設される平板状の電界制御部品とグリッドを上記被帯電体の上部表面及び上記電磁波照射装置の電磁波照射方向に対して平行に配置し、上記電界制御部品に印加される電圧をＶｃ、上記グリッドに印加される電圧をＶｇ、上記被帯電体に印加される電圧をＶｐとしたとき、各電圧Ｖｃ，Ｖｐ，Ｖｇの大きさの関係が、
｜Ｖｃ｜＞｜Ｖｇ｜＞｜Ｖｐ｜
となる構成としたものである。このように被帯電体の上部に近接して一つ以上の電磁波照射装置を電磁波照射方向が被帯電体の上部表面と平行になるように配置し、電磁波照射装置と一体に照射方向制御部材を配置し、電磁波照射装置の電磁波照射方向の上下に配設される平板状の電界制御部品とグリッドを被帯電体の上部表面及び電磁波照射装置の電磁波照射方向に対して平行に配置し、上記の電圧関係を満たすようにすることにより、電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体を均一に帯電することが可能となる。
【０００８】
請求項２に係る発明は、請求項１記載の帯電装置において、上記電磁波照射装置は上記被帯電体の軸方向に一つ以上平行に等間隔で配設され、各電磁波照射装置ごとに上記照射方向制御部材を配置した構成としたものである。このように電磁波照射装置は被帯電体の軸方向に一つ以上平行に等間隔で配設され、各電磁波照射装置ごとに照射方向制御部材を配置することにより、各電磁波照射装置ごとに電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体をより均一に帯電することが可能となる。
【０００９】
請求項３に係る発明は、請求項２記載の帯電装置において、上記照射方向制御部材は、各電磁波照射装置と一体の部材でできている構成としたものである。このように照射方向制御部材を電磁波照射装置の一部の形状を変更した一体部品で作成することにより、コストダウンを図ることができ、より安価に電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体を均一に帯電することが可能となる。
【００１０】
請求項４に係る発明は、請求項２または３記載の帯電装置において、上記電磁波照射装置と一体に設けられた外装部品を変形して上記照射方向制御部材としての機能を持たせた構成としたものである。このように電磁波照射装置と一体に設けられた外装部品を変形して照射方向制御部材としての機能を持たせることにより、コストダウンを図ることができ、より安価に電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを確実に防止すると共に、像担持体を均一に帯電することが可能となる。
【００１１】
請求項５に係る発明は、請求項３または４記載の帯電装置において、上記照射方向制御部材は、上記電磁波照射装置の形状に対応した円弧状の形状をしている構成としたものである。
【００１２】
請求項６に係る発明は、請求項１〜５のいずれか一つに記載の帯電装置において、上記電界制御部品が電磁波遮蔽部品を兼ねる構成としたものである。このように電界制御部品が電磁波遮蔽部品を兼ねることで、部品のコストダウンを図るとともに、他部品への電磁波の影響を抑えることが可能となる。
【００１３】
【発明の実施の形態】
以下、本発明の構成、動作を図面を参照して詳細に説明する。
まず本発明による非接触帯電方式の原理について述べる。電磁波が空気中に照射されると、照射された領域の空気が電離され、正負両極性のイオンが生成される。したがって静電潜像担持体等の被帯電体上の空間に電磁波照射装置により電磁波を照射して空気の電離を行い、その空間に電界形成手段（電界制御部品、グリッド、被帯電体側の電極、電源等）で電界を作用させることで、所望の極性のイオンのみを被帯電体に付着させることができ、被帯電体を非接触で帯電させることができる。
尚、電磁波照射装置により照射される電磁波としては紫外線、Ｘ線、軟Ｘ線、γ線等が使用できるが、電離効率や安全性の面を考慮するとＸ線か軟Ｘ線が好ましい。
【００１４】
本発明に係る帯電装置は、例えば、複写機、ファクシミリ、プリンタ等の電子写真技術を利用した画像形成装置の帯電部に応用され、被帯電体である静電潜像担持体（例えば感光体）を非接触で均一に帯電するものである。また、帯電部の他、転写部や除電部等にも応用可能である。ここで図８に本発明に係る帯電装置を帯電部に用いた画像形成装置の一例を示す。
【００１５】
図８において、符号２は静電潜像担持体であるドラム状の感光体であり、例えば金属製の円筒からなる芯金２ｂの上に感光層２ａを形成したものである。この感光体２の周囲には、帯電、露光、現像、転写、クリーニング及び除電の各機能を有する単体あるいは共通のユニットが配設されている。また、転写部より記録紙Ｓ搬送方向下流側には定着装置１８が配設されている。
ここで帯電には、通常は帯電ローラや帯電チャージャが用いられていたが、本発明では電磁波照射装置１と電界制御部品６等を使用してオゾンレスの非接触帯電を行う帯電装置１１を用いている。
露光には、例えばレーザ光１２等で画像信号に応じた光書込を行う光書込装置が用いられ、感光体２上に静電潜像を形成する。
現像を行う現像装置１３には一成分現像剤を用いるものや二成分現像剤を用いるものがあるが、いずれの場合も感光体２上の静電潜像に帯電したトナーを付着させることで、静電潜像を現像し顕像化する。
転写では、現像により感光体上で顕像化されたトナー像を、転写ローラ等の転写装置１５で記録紙Ｓに転写する。
クリーニングでは、クリーニングブレードやクリーニングブラシ等を用いたクリーニング装置１６により、転写後に感光体２上に残った残トナーを除去する。除電では、除電ランプや除電チャージャ等の除電装置１７により、感光体２上の残電位を除去する。
【００１６】
図８に示す構成の画像形成装置では、画像形成プロセスが開始されると、まず感光体２が帯電装置１１により均一に帯電された後、図示しない光書込装置からのレーザ光１２により感光体２上に静電潜像が形成され、感光体２上の静電潜像は、現像装置１３のトナーにより現像され顕像化される。この潜像形成、現像のタイミングに合わせて、記録紙Ｓが図示しない給紙カセット等から給紙ローラや搬送ローラ等によりレジストローラ１４まで搬送され、感光体上のトナー像が転写部に来るタイミングに合わせてレジストローラ１４により記録紙Ｓが送り出され、ガイド板の間等を通り転写部へ搬送される。そして転写部の転写ローラ等からなる転写装置１５により、感光体２上のトナー像が記録紙Ｓへ転写される。その後、トナー像が転写された記録紙Ｓは定着部に搬送され、定着装置１８によりトナーを記録紙Ｓに定着した後、図示しない排紙トレイ等へ排出される。一方、転写後の感光体２はクリーニング装置１６により残トナーを除去され、除電装置１７により残電位を除電される。
【００１７】
本発明では以上のような構成の画像形成装置に用いる帯電装置の一例として、感光体２上の空間に電磁波を照射する少なくとも一つ以上の電磁波照射装置１と、該電磁波照射装置１から照射される電磁波の照射方向を制御する照射方向制御部材４と、上記電磁波照射装置１から照射された電磁波によって生成されたイオンを感光体２に導くための電界制御部品６とを少なくとも有し（必要に応じて感光体の近傍にグリッドが配設される）、上記照射方向制御部材４によって電磁波が感光体２へ照射されないようにし、上記電界制御部品６によってイオンを感光体２へ導くことにより、感光体２を帯電させる構成の帯電装置１１を用いている。以下、本発明に係る帯電装置の具体的な実施例を図１〜７を参照して詳細に説明する。尚、図１，２が請求項１に対応し、図４，５，６が請求項１〜５に対応し、図７が請求項６に対応した実施例を示す図である。
【００１８】
（実施例１）
図１は本発明の一実施例を示す帯電装置の概略構成図であり、帯電装置１１ａ及び感光体２を、感光体２の軸方向（側面）から見た状態を示している。また図２は図１の帯電装置を右手方向から見たときの正面図である。
図１に示す実施例の帯電装置１１ａでは、被帯電体である感光体２の上部に近接して少なくとも一つ以上の電磁波照射装置１を感光体２と平行に配置し（例えば図２に示すように、電磁波照射装置１は感光体２の軸方向に一つ以上平行に等間隔に配設されている）、この電磁波照射装置１の近傍に照射方向制御部材４ａを配置して電磁波の照射方向を制限しつつ、電磁波照射装置１の電磁波照射方向の上下に配設された平板状の電界制御部品６とグリッド３によって所望の電界を形成して、感光体２を均一に帯電させるものである。その帯電原理は前述したように、電磁波照射装置１から照射された電磁波によって空気中にイオンを発生させ、電界制御部品６、グリッド３及び／または感光体２に電圧（Ｖｃ，Ｖｇ，Ｖｐ）を印加して電界を形成することで、上記の発生させたイオンを感光体２に移動させ、付着させることで感光体２を帯電するものである。本実施例の場合、電界制御部品６が感光体２の上面側を覆うように配設されているため、感光体２との間に比較的均一な電界を形成することができ、さらには感光体２の帯電電位をより安定させるためのグリッド３を設けているので、感光体２を均一にムラ無く帯電することができる。
【００１９】
図１の実施例では、感光体２をマイナス帯電させるべく、電界制御部品６に直流電源５ａによりマイナスのバイアス電圧Ｖｃを印加し、グリッド３には直流電源５ｂによりマイナスのバイアス電圧Ｖｇを印加し、感光体２の裏面側金属（芯金）２ｂにはＶｐなる電圧（図の例ではアース電位）を印加している。すなわち電磁波照射装置１の近くに電界制御部品６を配置し、例えば直流電源５ａにより電界制御部品６にマイナス電位Ｖｃを与えると共に、感光体２の芯金２ｂをアース電位（Ｖｐ＝０）とし、さらにグリッド３に直流電源５ｂによりマイナスのバイアス電圧Ｖｇを印加することで、電磁波照射装置１から照射された電磁波によって空気中に発生したマイナスイオンは、アース電位の感光体２側に引き寄せられて感光体２の表面に付着し、空気中に発生したプラスイオンはマイナス電位の電界制御部品６やグリッド３側に引き寄せられることになるので、感光体２はマイナスに帯電される。尚、上記の各電圧Ｖｃ，Ｖｐ，Ｖｇの大きさの関係は以下のようになる。
｜Ｖｃ｜＞｜Ｖｇ｜＞｜Ｖｐ｜（但し、図１ではＶｐ＝０）
【００２０】
また、当然ながら、極性が逆の電界をかければ、感光体２をプラスに帯電させることができる。すなわち、感光体２をプラス帯電させる場合は、電界制御部品６とグリッド３に直流電源５ａ，５ｂによりプラスのバイアス電圧Ｖｃ，Ｖｇを印加して、電界制御部品６、グリッド３、感光体２間に極性が逆の電界を形成すればよく、電磁波によって空気中に発生したプラスイオンを感光体２に付着させることができる。
【００２１】
ここで図３（ａ），（ｂ）は、照射方向制御部材４ａが無い場合と有る場合の電磁波照射装置１による電磁波の照射領域７ａ，７ｂを示したものであり、電界制御部品やグリッドの図示は省略している。図３（ａ）のように、電磁波照射装置１を感光体２と平行に配置しただけでは、電磁波が感光体２に照射されるので、感光体２への電磁波照射部位において、正常な帯電ができなくなるという経時劣化の問題が発生する。そこで図３（ｂ）のように、電磁波照射装置１の下部近傍に照射方向制御部材４ａを配置することで、電磁波が感光体２に照射されなくすることができる。ところで、電磁波照射装置１を感光体２から離せば、または電磁波の照射方向を上方向に変更すれば、照射方向制御部材４ａを設けなくても電磁波が感光体２に当たらなくすることができるが、電磁波の照射角度が結構広く現状でも１２０度を超えているので、帯電効率を考えるとイオンを移動させる距離が長くなり得策ではない。従って、電磁波が感光体２に照射されないようにし、且つ帯電効率を向上させるには、図１、図３（ｂ）のように、電磁波照射装置１の下部近傍に照射方向制御部材４ａを配置する必要がある。尚、図２の例では、照射方向制御部材４ａは複数の電磁波照射装置１とグリッド３の間に一つの部品として配設され、複数の電磁波照射装置１の保持部材を兼ねるように設けられているが、照射方向制御部材は、別に複数の部品であっても何ら構わない。
【００２２】
（実施例２）
次に図４は本発明の別の実施例を示す帯電装置の概略構成図であり、帯電装置１１ｂ及び感光体２を、感光体２の軸方向（側面）から見た状態を示している。また、図５は図４に示す帯電装置の一つの電磁波照射装置と放射方向制御部材を拡大して示す図、図６は図４の帯電装置を右手方向から見たときの正面図である。
図４に示す実施例の帯電装置１１ｂでは、被帯電体である感光体２の上部に近接して少なくとも一つ以上の電磁波照射装置１を感光体２と平行に配置し（例えば図６に示すように、電磁波照射装置１は感光体２の軸方向に一つ以上平行に等間隔に配設されている）、各電磁波照射装置１に一体に照射方向制御部材４ｂを配置して電磁波の照射方向を制限しつつ、電磁波照射装置１の電磁波照射方向の上下に配設された平板状の電界制御部品６とグリッド３によって所望の電界を形成して、感光体２を均一に帯電させるものである。尚、帯電原理は実施例１と同様であり、電磁波照射装置１から照射された電磁波によって空気中にイオンを発生させ、電界制御部品６、グリッド３及び／または感光体２に電圧（Ｖｃ，Ｖｇ，Ｖｐ）を印加して電界を形成することで、上記の発生させたイオンを感光体２に移動させ、付着させることで感光体２を帯電するものである。
【００２３】
図４〜６に示す実施例の帯電装置１１ｂでは、図１で示した照射方向制御部材４ａと同様の役割を持つものとして、電磁波照射装置１と一体に設けられた外装部品を変形して照射方向制御部材４ｂとしての機能を持たせたものであり、このように照射方向制御部材４ｂを電磁波照射装置１の一部の形状を変更した一体部品で作成することによりコストダウンを図ることができる。
尚、照射方向制御部材４ｂの形状としては、図５や図６に示すように円筒を長手方向に切断した円弧状の形状をしているが、円筒を斜めに切断したような形でも良いし、他の形状でも構わない。要するに、電磁波照射装置１からの電磁波が感光体２に当たらないような形状であればよい。
【００２４】
（実施例３）
次に図７は本発明のさらに別の実施例を示す帯電装置の概略構成図であり、帯電装置１１ｃ及び感光体２を、感光体２の軸方向（側面）から見た状態を示している。
図７に示す実施例の帯電装置１１ｃでは、被帯電体である感光体２の上部に近接して少なくとも一つ以上の電磁波照射装置１を感光体２と平行に配置し、その電磁波照射装置１の近傍（あるいは一体）に照射方向制御部材４ｃを配置して電磁波の照射方向を制限しつつ、電磁波照射装置１の電磁波照射方向の上下に配設された電界制御部品６とグリッド３によって所望の電界を形成して、感光体２を均一に帯電させるものである。尚、帯電原理は実施例１と同様であり、電磁波照射装置１から照射された電磁波によって空気中にイオンを発生させ、電界制御部品６、グリッド３及び／または感光体２に電圧（Ｖｃ，Ｖｇ，Ｖｐ）を印加して電界を形成することで、上記の発生させたイオンを感光体２に移動させ、付着させることで感光体２を帯電するものである。
【００２５】
図７に示す実施例の帯電装置１１ｃでは、平板状の電界制御部品６の一端側に鉛直下方に向けて延在する電磁波遮蔽部品８を設けて、電磁波照射装置１からの電磁波が外部に洩れることを防止したものである。また、図７に示す構成の場合、電界制御部品６の一端側を鉛直下方に折り曲げて電磁波遮蔽部品８を兼ねる構成とすることができ、このように構成することにより、部品のコストダウンを図るとともに、他部品への電磁波の影響を抑えることができる。尚、図７において照射方向制御部材４ｃとしては、図１，２のような構成でも、図４〜６のような構成でもよい。
【００２６】
【発明の効果】
以上説明したように、請求項１記載の帯電装置においては、被帯電体の上部に近接して一つ以上の電磁波照射装置を電磁波照射方向が被帯電体の上部表面と平行になるように配置し、電磁波照射装置と一体に照射方向制御部材を配置し、電磁波照射装置の電磁波照射方向の上下に配設される平板状の電界制御部品とグリッドを被帯電体の上部表面及び電磁波照射装置の電磁波照射方向に対して平行に配置し、電界制御部品に印加される電圧をＶｃ、グリッドに印加される電圧をＶｇ、被帯電体に印加される電圧をＶｐとしたとき、各電圧Ｖｃ，Ｖｐ，Ｖｇの大きさの関係が、
｜Ｖｃ｜＞｜Ｖｇ｜＞｜Ｖｐ｜
となる構成としたので、電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体を均一に帯電することができる。
請求項２記載の帯電装置においては、請求項１の構成に加えて、電磁波照射装置は被帯電体の軸方向に一つ以上平行に等間隔で配設され、各電磁波照射装置ごとに照射方向制御部材を配置することにより、各電磁波照射装置ごとに電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体をより均一に帯電することができる。
請求項３記載の帯電装置においては、請求項２の構成に加えて、照射方向制御部材を各電磁波照射装置の一部の形状を変更した一体部品で作成することにより、コストダウンを図ることができ、より安価に電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを防止すると共に、被帯電体を均一に帯電することができる。
請求項４記載の帯電装置においては、請求項２または３の構成に加えて、電磁波照射装置と一体に設けられた外装部品を変形して照射方向制御部材としての機能を持たせることにより、コストダウンを図ることができ、より安価に電磁波の照射方向を制御して電磁波が被帯電体に照射されるのを確実に防止すると共に、像担持体を均一に帯電することができる。
請求項５記載の帯電装置においては、請求項３または４の構成に加えて、照射方向制御部材が電磁波照射装置の形状に対応した円弧状の形状をしていることにより、電磁波が被帯電体に照射されるのを確実に防止することができる。
請求項６記載の帯電装置においては、請求項１〜５のいずれか一つの構成に加えて、電界制御部品が電磁波遮蔽部品を兼ねることで、部品のコストダウンを図るとともに、他部品への電磁波の影響を抑えることができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示す帯電装置の概略構成図である。
【図２】図１に示す帯電装置を右手方向から見たときの帯電装置の正面図である。
【図３】本発明に係る帯電装置において、照射方向制御部材が無い場合と有る場合の電磁波照射装置による電磁波の照射領域を示す図である。
【図４】本発明の別の実施例を示す帯電装置の概略構成図である。
【図５】図４に示す帯電装置の一つの電磁波照射装置と照射方向制御部材を拡大して示す図である。
【図６】図４に示す帯電装置を右手方向から見たときの帯電装置の正面図である。
【図７】本発明のさらに別の実施例を示す帯電装置の概略構成図である。
【図８】本発明に係る帯電装置を帯電部に用いた画像形成装置の一例を示す概略構成図である。
【図９】電磁波照射装置を用いた帯電装置の従来例を示す概略構成図である。
【図１０】電磁波照射装置を用いた帯電装置の別の従来例を示す概略構成図である。
【符号の説明】
１：電磁波照射装置
２：感光体（静電潜像担持体（被帯電体））
３：グリッド
４，４ａ，４ｂ，４ｃ：照射方向制御部材
５ａ，５ｂ：直流電源
６：電界制御部品
７ａ，７ｂ：電磁波照射領域
８：電磁波遮蔽部品
１１，１１ａ，１１ｂ，１１ｃ：帯電装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a charging device applied to a charging device, a transfer device, a static eliminator, etc. of an image forming apparatus using electrophotographic technology such as a copying machine, a facsimile, and a printer, and more particularly to a charged body such as an image carrier. The present invention relates to a charging device for uniformly charging without contact.
[0002]
[Prior art]
In an image forming process in an image forming apparatus such as a copying machine, a facsimile machine, or a printer using an electrophotographic technique, there is a process of charging a photosensitive member that is an electrostatic latent image carrier. This charging process has been conventionally performed by a corona charger that is non-contact and excellent in charging stability. However, since this system generates a lot of ozone, a contact charging system has recently been studied. A contact charging method (a roller charging method using a conductive roller, in which an AC voltage is superimposed on a DC voltage and applied to the conductive roller) as disclosed in JP-A-63-149669, , A brush charging device as disclosed in JP-A-6-175469 (a brush charging method using a conductive brush, and an intermediate conductive member having a low resistance is provided between the conductive brush and the metal core, (Eliminating the environmental dependency of charging and charging the object to be charged uniformly) has been put into practical use.
[0003]
However, in the contact charging method, since the charging member is in contact with the electrostatic latent image carrier such as a photoconductor, the charging member is easily contaminated with toner, and as a result, the charging performance such as charging unevenness is deteriorated. End up.
From the above, it can be said that the ozone-less non-contact charging method is ideal as the charging means.
[0004]
Therefore, the inventors of the present invention have an electromagnetic wave irradiation device and an electric field forming unit. The electromagnetic wave irradiation device irradiates an electromagnetic wave to the space on the electrostatic latent image carrier and forms an electric field by the electric field forming unit. There has been proposed a novel charging system charging device for charging an image carrier to a desired potential.
FIG. 9 is a diagram showing an example of a charging device previously proposed by the present inventors. An electrostatic latent image carrier (for example, a photoreceptor) 2 as a charging device and a member to be charged is connected to the electrostatic latent image carrier. The state seen from the axial direction (side surface) of 2 is shown. In the charging device shown in FIG. 9, the electromagnetic wave irradiation device 1 is disposed in the vicinity of the upper portion of the electrostatic latent image carrier 2 that is the object to be charged, and the flat electric field control component 6a, 6b is arranged to uniformly charge the electrostatic latent image carrier 2. The charging principle is that ions are generated in the air by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1, and voltage (Vc, Vp) is applied to the electric field control components 6 a and 6 b and / or the electrostatic latent image carrier 2. By forming an electric field, the generated ions are moved to and attached to the electrostatic latent image carrier 2 to charge the electrostatic latent image carrier 2. In this example, since the electric field control components 6a and 6b are disposed so as to cover the entire upper surface side of the electrostatic latent image carrier 2, a relatively uniform electric field is formed between the electrostatic latent image carrier 2 and the electric field control components 6a and 6b. Therefore, the electrostatic latent image carrier 2 can be uniformly charged without unevenness.
FIG. 10 shows another example of the charging device previously proposed by the present inventors. In addition to the configuration of FIG. 9, a grid 3 is provided between the electromagnetic wave irradiation device 1 and the electrostatic latent image carrier 2. The electrostatic latent image carrier 2 can be more uniformly charged by guiding ions to the electrostatic latent image carrier 2 by the electric field control parts 6a and 6b and the grid 3. .
[0005]
[Problems to be solved by the invention]
9 and 10, ions generated by electromagnetic waves are efficiently attached to the electrostatic latent image carrier by the action of an electric field, and the electrostatic latent image carrier is uniformly charged in a non-contact manner. be able to.
However, in the charging device having the configuration shown in FIG. 9 or FIG. 10, the electromagnetic wave from the electromagnetic wave irradiation device 1 is directly applied to the electrostatic latent image carrier 2 that is a member to be charged, which has an adverse effect over time. Turned out to be. That is, the present inventors have conducted an experiment in which electromagnetic waves from the electromagnetic wave irradiation device 1 are continuously irradiated to an electrostatic latent image carrier (for example, a photoreceptor) in order to investigate the influence of electromagnetic waves on the electrostatic latent image carrier. As a result, there was a problem of deterioration over time such that normal charging could not be performed at the site irradiated to the electrostatic latent image carrier.
[0006]
  The present invention has been made in view of the above circumstances, and can charge an object to be charged such as an electrostatic latent image bearing member in an ozone-less, non-contact and uniform manner, and be irradiated with electromagnetic waves. It is an object (problem) to provide a charging device that prevents the deterioration of the object to be charged with the lapse of time.
  More specifically, the invention according to claim 1 controls the irradiation direction of the electromagnetic wave to prevent the electromagnetic wave from being irradiated to the object to be charged, and can charge the object to be charged uniformly. The purpose is to provide.
  The invention according to claim 2In addition to the object of claim 1, when one or more electromagnetic wave irradiation devices are arranged in parallel with the body to be charged,An object of the present invention is to provide a charging device that can control the irradiation direction of electromagnetic waves to prevent the electromagnetic waves from being irradiated on the object to be charged and can more uniformly charge the objects to be charged.
  Claim 3~ 5In addition to the object of the first or second aspect of the invention, the object of the invention is to control the irradiation direction of the electromagnetic wave at a lower cost and to uniformly charge the object to be charged.,MoreoverThe purpose is to reduce the cost of parts.
  In addition to the object of any one of claims 1 to 5, the invention according to claim 6 aims to reduce the cost of parts and to suppress the influence of electromagnetic waves on other parts.
[0007]
[Means for Solving the Problems]
  In order to achieve the above object, an invention according to claim 1 is a charging device that uniformly charges a member to be charged in a non-contact manner, and at least one electromagnetic wave that irradiates the space on the member to be charged with electromagnetic waves. Irradiation device, irradiation direction control member for controlling the irradiation direction of the electromagnetic wave irradiated from the electromagnetic wave irradiation device, and electric field control for guiding ions generated by the electromagnetic wave irradiated from the electromagnetic wave irradiation device to the object to be charged A component and a grid for further stabilizing the charged potential of the charged body, the irradiation direction control member prevents the electromagnetic wave from being irradiated to the charged body, and the electric field control component and the grid are charged with ions. In the charging device for charging the object to be charged by guiding it to the body, one or more electromagnetic wave irradiation devices are provided close to the upper part of the object to be charged.The direction of electromagnetic wave irradiation isThe above objectTop surface ofIn parallel withTo beAnd the irradiation direction control member is disposed integrally with the electromagnetic wave irradiation device, and is disposed above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation device.FlatElectric field control component and grid are to be chargedTop surface ofas well asthe aboveElectromagnetic irradiation deviceDirection of electromagnetic wave irradiationThe voltage applied to the electric field control component is Vc, the voltage applied to the grid is Vg, and the voltage applied to the member to be charged is Vp. , Vg magnitude relationship is
  | Vc |> | Vg |> | Vp |
It becomes the composition which becomes. In this way, one or more electromagnetic wave irradiation devices are placed close to the top of the object to be charged.The direction of electromagnetic wave irradiation isCharged objectTop surface ofIn parallel withTo beArrange the irradiation direction control member integrally with the electromagnetic wave irradiation device, and are arranged above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation deviceFlatElectric field control component and grid to be chargedTop surface ofAnd electromagnetic wave irradiation deviceDirection of electromagnetic wave irradiationIs arranged in parallel to satisfy the above voltage relationship, thereby controlling the irradiation direction of the electromagnetic wave to prevent the electromagnetic wave from being irradiated on the charged body and charging the charged body uniformly. It becomes possible to do.
[0008]
  The invention according to claim 2Claim 1In the charging device,One or more of the electromagnetic wave irradiation devices are arranged at equal intervals in parallel to the axial direction of the object to be charged, and the irradiation direction control member is arranged for each electromagnetic wave irradiation device.It is a configuration. in this wayOne or more electromagnetic wave irradiation devices are arranged at equal intervals in parallel to the axial direction of the object to be charged, and an irradiation direction control member is provided for each electromagnetic wave irradiation device.By placingFor each electromagnetic wave irradiation deviceIt is possible to control the irradiation direction of the electromagnetic wave to prevent the electromagnetic wave from being applied to the object to be charged, and to charge the object to be charged more uniformly.
[0009]
  The invention according to claim 3 is claimed in claim2In the charging device described above, the irradiation direction control member includes:eachThe structure is made of a member integrated with the electromagnetic wave irradiation device. By creating the irradiation direction control member as an integral part in which the shape of the electromagnetic wave irradiation device is partially changed, the cost can be reduced, and the electromagnetic wave is charged by controlling the irradiation direction of the electromagnetic wave at a lower cost. It is possible to prevent the body from being irradiated and to uniformly charge the body to be charged.
[0010]
  The invention according to claim 4 is claimed in claim2Or3In the charging device described,The exterior part provided integrally with the electromagnetic wave irradiation device is modified to have the function as the irradiation direction control member.It is a configuration. in this wayThe exterior parts provided integrally with the electromagnetic wave irradiation device are deformed to have a function as an irradiation direction control member.ByCosts can be reduced and cheaperIt is possible to control the irradiation direction of the electromagnetic wave to reliably prevent the electromagnetic wave from being irradiated to the charged body and to uniformly charge the image carrier.
[0011]
  The invention according to claim 5 is claimed in claim3 or4. The charging device according to claim 4, wherein the irradiation direction control member is a member of the electromagnetic wave irradiation device.It has an arc shape corresponding to the shapeIt is a compositionThe
[0012]
According to a sixth aspect of the invention, in the charging device according to any one of the first to fifth aspects, the electric field control component also serves as an electromagnetic shielding component. As described above, the electric field control component also serves as the electromagnetic wave shielding component, thereby reducing the cost of the component and suppressing the influence of the electromagnetic wave on other components.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration and operation of the present invention will be described in detail with reference to the drawings.
First, the principle of the non-contact charging method according to the present invention will be described. When the electromagnetic wave is irradiated into the air, the air in the irradiated region is ionized, and positive and negative ions are generated. Therefore, an electromagnetic wave irradiation device irradiates an electromagnetic wave into a space on a charged body such as an electrostatic latent image carrier to ionize the air, and an electric field forming means (electric field control component, grid, electrode on the charged body side, By applying an electric field with a power source or the like, only ions having a desired polarity can be attached to the member to be charged, and the member to be charged can be charged in a non-contact manner.
In addition, as electromagnetic waves irradiated by the electromagnetic wave irradiation device, ultraviolet rays, X-rays, soft X-rays, γ-rays and the like can be used, but X-rays or soft X-rays are preferable in view of ionization efficiency and safety.
[0014]
The charging device according to the present invention is applied to, for example, a charging portion of an image forming apparatus using electrophotographic technology such as a copying machine, a facsimile machine, a printer, and the like, and an electrostatic latent image carrier (for example, a photoreceptor) that is a charged body. Is uniformly charged in a non-contact manner. In addition to the charging unit, the present invention can also be applied to a transfer unit, a charge removal unit, and the like. Here, FIG. 8 shows an example of an image forming apparatus in which the charging device according to the present invention is used as a charging unit.
[0015]
In FIG. 8, reference numeral 2 denotes a drum-shaped photoconductor which is an electrostatic latent image carrier, and is obtained by forming a photosensitive layer 2a on a cored bar 2b made of, for example, a metal cylinder. A single unit or a common unit having functions of charging, exposure, development, transfer, cleaning, and charge removal is disposed around the photoreceptor 2. In addition, a fixing device 18 is disposed on the downstream side in the conveyance direction of the recording paper S from the transfer unit.
Here, a charging roller or a charger is normally used for charging. However, in the present invention, a charging device 11 that performs ozone-less non-contact charging using the electromagnetic wave irradiation device 1 and the electric field control component 6 is used. Yes.
For the exposure, for example, an optical writing device that performs optical writing according to an image signal with a laser beam 12 or the like is used, and an electrostatic latent image is formed on the photosensitive member 2.
The developing device 13 that performs development includes one using a one-component developer and one using a two-component developer. In any case, by attaching a charged toner to the electrostatic latent image on the photoreceptor 2, The electrostatic latent image is developed and visualized.
In the transfer, the toner image visualized on the photoreceptor by development is transferred onto the recording paper S by a transfer device 15 such as a transfer roller.
In cleaning, residual toner remaining on the photosensitive member 2 after transfer is removed by a cleaning device 16 using a cleaning blade, a cleaning brush, or the like. In the static elimination, the residual potential on the photosensitive member 2 is removed by a static elimination device 17 such as a static elimination lamp or a static elimination charger.
[0016]
In the image forming apparatus having the configuration shown in FIG. 8, when the image forming process is started, first, the photosensitive member 2 is uniformly charged by the charging device 11, and then the photosensitive member is irradiated with a laser beam 12 from an optical writing device (not shown). An electrostatic latent image is formed on the photosensitive member 2, and the electrostatic latent image on the photosensitive member 2 is developed with the toner of the developing device 13 to be visualized. The timing at which the recording sheet S is conveyed from a paper feed cassette (not shown) to the registration roller 14 by a paper feed roller, a transport roller, etc., and the toner image on the photosensitive member arrives at the transfer unit in synchronization with the latent image formation and development timing. At the same time, the recording paper S is sent out by the registration roller 14 and is conveyed between the guide plates and the like to the transfer unit. The toner image on the photosensitive member 2 is transferred to the recording paper S by a transfer device 15 including a transfer roller or the like in the transfer unit. Thereafter, the recording sheet S to which the toner image has been transferred is conveyed to a fixing unit, and after the toner is fixed on the recording sheet S by the fixing device 18, it is discharged to a discharge tray (not shown) or the like. On the other hand, after the transfer, the residual toner is removed by the cleaning device 16 and the residual potential is removed by the neutralization device 17.
[0017]
  In the present invention, as an example of the charging device used in the image forming apparatus having the above-described configuration, at least one electromagnetic wave irradiation device 1 that irradiates the space on the photoconductor 2 with an electromagnetic wave, and the electromagnetic wave irradiation device 1 emits the electromagnetic wave. At least an irradiation direction control member 4 for controlling the irradiation direction of the electromagnetic wave and an electric field control component 6 for guiding ions generated by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1 to the photoreceptor 2 (necessary) Accordingly, a grid is disposed in the vicinity of the photosensitive member), the irradiation direction control member 4 prevents the electromagnetic wave from being irradiated to the photosensitive member 2, and the electric field control component 6 guides ions to the photosensitive member 2, thereby exposing the photosensitive member. A charging device 11 configured to charge the body 2 is used. Hereinafter, specific embodiments of the charging device according to the present invention will be described in detail with reference to FIGS. 1 and 2 are claims.14, 5 and 6 are claims.1-5FIG. 7 is a diagram showing an embodiment corresponding to claim 6.is there.
[0018]
Example 1
FIG. 1 is a schematic configuration diagram of a charging device showing an embodiment of the present invention, and shows a state in which the charging device 11a and the photosensitive member 2 are viewed from the axial direction (side surface) of the photosensitive member 2. FIG. 2 is a front view of the charging device of FIG. 1 when viewed from the right hand direction.
In the charging device 11a of the embodiment shown in FIG. 1, at least one electromagnetic wave irradiation device 1 is disposed in parallel with the photosensitive member 2 in the vicinity of the upper portion of the photosensitive member 2 that is a member to be charged (for example, as shown in FIG. 2). Thus, the electromagnetic wave irradiation device 1 is disposed at equal intervals in parallel with one or more axial directions of the photosensitive member 2), and an irradiation direction control member 4 a is disposed in the vicinity of the electromagnetic wave irradiation device 1 to irradiate the electromagnetic waves. A desired electric field is formed by the plate-shaped electric field control component 6 and the grid 3 disposed above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation device 1 while restricting the direction, and the photosensitive member 2 is uniformly charged. is there. As described above, the charging principle is that ions are generated in the air by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1, and voltage (Vc, Vg, Vp) is applied to the electric field control component 6, the grid 3 and / or the photoreceptor 2. By applying and forming an electric field, the generated ions are moved to and adhered to the photosensitive member 2 to charge the photosensitive member 2. In the case of the present embodiment, since the electric field control component 6 is disposed so as to cover the upper surface side of the photoconductor 2, a relatively uniform electric field can be formed between the photoconductor 2 and the photoconductor. Since the grid 3 for further stabilizing the charging potential of the body 2 is provided, the photoreceptor 2 can be uniformly charged without unevenness.
[0019]
In the embodiment of FIG. 1, in order to negatively charge the photosensitive member 2, a negative bias voltage Vc is applied to the electric field control component 6 from the DC power source 5a, and a negative bias voltage Vg is applied to the grid 3 from the DC power source 5b. A voltage Vp (ground potential in the example shown in the figure) is applied to the back side metal (core metal) 2b of the photosensitive member 2. That is, the electric field control component 6 is disposed near the electromagnetic wave irradiation device 1, and a negative potential Vc is applied to the electric field control component 6 by, for example, a DC power source 5a, and the cored bar 2b of the photosensitive member 2 is set to the ground potential (Vp = 0). Further, by applying a negative bias voltage Vg to the grid 3 from the DC power source 5b, negative ions generated in the air by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1 are attracted to the photosensitive member 2 side of the ground potential and are photosensitive. Since positive ions attached to the surface of the body 2 and generated in the air are attracted to the electric field control component 6 or the grid 3 side having a negative potential, the photosensitive member 2 is negatively charged. The relationship between the magnitudes of the voltages Vc, Vp, and Vg is as follows.
| Vc |> | Vg |> | Vp | (in FIG. 1, Vp = 0)
[0020]
Of course, if an electric field having a reverse polarity is applied, the photosensitive member 2 can be positively charged. That is, when the photosensitive member 2 is positively charged, positive bias voltages Vc and Vg are applied to the electric field control component 6 and the grid 3 by the DC power supplies 5a and 5b, so that the electric field control component 6, the grid 3, and the photosensitive member 2 are electrically connected. It is only necessary to form an electric field having a reverse polarity, and positive ions generated in the air by electromagnetic waves can be attached to the photoreceptor 2.
[0021]
Here, FIGS. 3A and 3B show electromagnetic wave irradiation regions 7a and 7b by the electromagnetic wave irradiation apparatus 1 when there is no irradiation direction control member 4a and when there is no irradiation direction control member 4a. Illustration is omitted. As shown in FIG. 3A, since the electromagnetic wave is irradiated onto the photoconductor 2 only by arranging the electromagnetic wave irradiation device 1 in parallel with the photoconductor 2, normal charging is performed at the site where the electromagnetic wave is applied to the photoconductor 2. The problem of deterioration over time that it cannot be generated occurs. Therefore, as shown in FIG. 3B, by arranging the irradiation direction control member 4 a in the vicinity of the lower part of the electromagnetic wave irradiation device 1, it is possible to prevent the electromagnetic wave from being irradiated on the photoconductor 2. By the way, if the electromagnetic wave irradiation device 1 is separated from the photosensitive member 2 or the electromagnetic wave irradiation direction is changed upward, the electromagnetic wave can be prevented from hitting the photosensitive member 2 without providing the irradiation direction control member 4a. Since the irradiation angle of the electromagnetic wave is fairly wide and exceeds 120 degrees even in the present situation, the distance for moving the ions becomes long when charging efficiency is considered, which is not a good idea. Therefore, in order to prevent the electromagnetic wave from being irradiated to the photosensitive member 2 and to improve the charging efficiency, the irradiation direction control member 4a is disposed in the vicinity of the lower part of the electromagnetic wave irradiation device 1 as shown in FIGS. There is a need. In the example of FIG. 2, the irradiation direction control member 4 a is disposed as a single component between the plurality of electromagnetic wave irradiation devices 1 and the grid 3, and is provided so as to also serve as a holding member for the plurality of electromagnetic wave irradiation devices 1. However, the irradiation direction control member may be a plurality of parts separately.
[0022]
(Example 2)
Next, FIG. 4 is a schematic configuration diagram of a charging device showing another embodiment of the present invention, and shows a state where the charging device 11b and the photosensitive member 2 are viewed from the axial direction (side surface) of the photosensitive member 2. 5 is an enlarged view showing one electromagnetic wave irradiation device and a radiation direction control member of the charging device shown in FIG. 4, and FIG. 6 is a front view of the charging device shown in FIG. 4 as viewed from the right hand direction.
In the charging device 11b of the embodiment shown in FIG. 4, at least one electromagnetic wave irradiation device 1 is arranged in parallel with the photosensitive member 2 in the vicinity of the upper portion of the photosensitive member 2 which is a member to be charged (for example, as shown in FIG. 6). Thus, one or more electromagnetic wave irradiation devices 1 are arranged at equal intervals in parallel with the axial direction of the photosensitive member 2), and an irradiation direction control member 4 b is integrally arranged in each electromagnetic wave irradiation device 1 to irradiate electromagnetic waves. A desired electric field is formed by the plate-shaped electric field control component 6 and the grid 3 disposed above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation device 1 while restricting the direction, and the photosensitive member 2 is uniformly charged. is there. The charging principle is the same as that of the first embodiment, and ions are generated in the air by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1, and the voltage (Vc, Vg) is applied to the electric field control component 6, the grid 3 and / or the photoreceptor 2. , Vp) is applied to form an electric field, whereby the generated ions are moved to and adhered to the photoconductor 2 to charge the photoconductor 2.
[0023]
In the charging device 11b of the embodiment shown in FIGS. 4 to 6, assuming that it has a role similar to that of the irradiation direction control member 4a shown in FIG. 1, the external parts provided integrally with the electromagnetic wave irradiation device 1 are deformed and irradiated. The function as the direction control member 4b is given, and thus the irradiation direction control member 4b is made of an integral part in which the shape of the electromagnetic wave irradiation device 1 is partially changed, so that the cost can be reduced. .
The irradiation direction control member 4b has an arcuate shape obtained by cutting the cylinder in the longitudinal direction as shown in FIGS. 5 and 6. However, the irradiation direction control member 4b may have a shape in which the cylinder is cut obliquely. Other shapes may be used. In short, any shape may be used as long as the electromagnetic wave from the electromagnetic wave irradiation device 1 does not hit the photoreceptor 2.
[0024]
(Example 3)
Next, FIG. 7 is a schematic configuration diagram of a charging device showing still another embodiment of the present invention, and shows a state in which the charging device 11c and the photosensitive member 2 are viewed from the axial direction (side surface) of the photosensitive member 2. .
In the charging device 11 c of the embodiment shown in FIG. 7, at least one electromagnetic wave irradiation device 1 is arranged in parallel with the photosensitive member 2 in the vicinity of the upper portion of the photosensitive member 2 that is a member to be charged. An electromagnetic field control component 6 and a grid 3 disposed above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation apparatus 1 are arranged while limiting the irradiation direction of the electromagnetic wave by disposing the irradiation direction control member 4c in the vicinity (or integrally) of the electromagnetic wave. An electric field is formed to uniformly charge the photosensitive member 2. The charging principle is the same as that of the first embodiment, and ions are generated in the air by the electromagnetic wave irradiated from the electromagnetic wave irradiation device 1, and the voltage (Vc, Vg) is applied to the electric field control component 6, the grid 3 and / or the photoreceptor 2. , Vp) is applied to form an electric field, whereby the generated ions are moved to and adhered to the photoconductor 2 to charge the photoconductor 2.
[0025]
In the charging device 11c of the embodiment shown in FIG. 7, an electromagnetic wave shielding component 8 extending vertically downward is provided on one end side of the flat electric field control component 6, and electromagnetic waves from the electromagnetic wave irradiation device 1 leak to the outside. This has been prevented. In the case of the configuration shown in FIG. 7, one end side of the electric field control component 6 can be bent vertically downward to serve also as the electromagnetic wave shielding component 8. By configuring in this way, the cost of the component can be reduced. In addition, the influence of electromagnetic waves on other parts can be suppressed. In FIG. 7, the irradiation direction control member 4c may be configured as shown in FIGS. 1 and 2 or as shown in FIGS.
[0026]
【The invention's effect】
  As described above, in the charging device according to claim 1, one or more electromagnetic wave irradiation devices are provided in the vicinity of the upper portion of the member to be charged.The direction of electromagnetic wave irradiation isCharged objectTop surface ofIn parallel withTo beArrange the irradiation direction control member integrally with the electromagnetic wave irradiation device, and are arranged above and below the electromagnetic wave irradiation direction of the electromagnetic wave irradiation deviceFlatElectric field control component and grid to be chargedTop surface ofAnd electromagnetic wave irradiation deviceDirection of electromagnetic wave irradiationThe voltage applied to the electric field control component is Vc, the voltage applied to the grid is Vg, and the voltage applied to the member to be charged is Vp, and the voltages Vc, Vp and Vg are The size relationship
  | Vc |> | Vg |> | Vp |
Therefore, it is possible to control the irradiation direction of the electromagnetic wave to prevent the electromagnetic wave from being irradiated to the object to be charged and to uniformly charge the object to be charged.
  According to a second aspect of the present invention, in addition to the structure of the first aspect, one or more electromagnetic wave irradiation devices are arranged at equal intervals in parallel to the axial direction of the object to be charged, and the irradiation direction for each electromagnetic wave irradiation device. By arranging the control member, it is possible to control the irradiation direction of the electromagnetic wave for each electromagnetic wave irradiation device to prevent the electromagnetic wave from being irradiated to the charged body, and to charge the charged body more uniformly.
  In the charging device according to claim 3, in addition to the configuration of claim 2, it is possible to reduce the cost by forming the irradiation direction control member as an integral part in which the shape of a part of each electromagnetic wave irradiation device is changed. In addition, it is possible to control the irradiation direction of the electromagnetic wave at a lower cost to prevent the electromagnetic wave from being irradiated to the object to be charged, and to charge the object to be charged uniformly.
  In the charging device according to claim 4, in addition to the configuration of claim 2 or 3, the exterior part provided integrally with the electromagnetic wave irradiation device is deformed to have a function as an irradiation direction control member, thereby reducing the cost. In addition, it is possible to control the irradiation direction of the electromagnetic wave at a lower cost and reliably prevent the electromagnetic wave from being irradiated to the charged body, and to uniformly charge the image carrier.
  In the charging device according to claim 5, in addition to the configuration of claim 3 or 4, the irradiation direction control member has an arc shape corresponding to the shape of the electromagnetic wave irradiation device, so that the electromagnetic wave is to be charged. Can be reliably prevented.
  In the charging device according to claim 6, in addition to the configuration of any one of claims 1 to 5, the electric field control component also serves as an electromagnetic shielding component, so that the cost of the component is reduced and electromagnetic waves to other components are also achieved. The influence of can be suppressed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a charging device showing an embodiment of the present invention.
FIG. 2 is a front view of the charging device when the charging device shown in FIG. 1 is viewed from the right hand direction.
FIGS. 3A and 3B are diagrams illustrating an electromagnetic wave irradiation region by an electromagnetic wave irradiation device when an irradiation direction control member is not provided and when there is an irradiation direction control member. FIGS.
FIG. 4 is a schematic configuration diagram of a charging device showing another embodiment of the present invention.
5 is an enlarged view showing one electromagnetic wave irradiation device and an irradiation direction control member of the charging device shown in FIG. 4. FIG.
6 is a front view of the charging device when the charging device shown in FIG. 4 is viewed from the right-hand direction. FIG.
FIG. 7 is a schematic configuration diagram of a charging device showing still another embodiment of the present invention.
FIG. 8 is a schematic configuration diagram illustrating an example of an image forming apparatus using a charging device according to the present invention in a charging unit.
FIG. 9 is a schematic configuration diagram illustrating a conventional example of a charging device using an electromagnetic wave irradiation device.
FIG. 10 is a schematic configuration diagram showing another conventional example of a charging device using an electromagnetic wave irradiation device.
[Explanation of symbols]
1: Electromagnetic wave irradiation device
2: Photoconductor (electrostatic latent image carrier (charged body))
3: Grid
4, 4a, 4b, 4c: Irradiation direction control member
5a, 5b: DC power supply
6: Electric field control parts
7a, 7b: electromagnetic wave irradiation area
8: Electromagnetic wave shielding parts
11, 11a, 11b, 11c: charging device

Claims

A charging device that uniformly charges an object to be charged in a non-contact manner, and at least one electromagnetic wave irradiation device that irradiates an electromagnetic wave to a space on the charged body, and irradiation of an electromagnetic wave irradiated from the electromagnetic wave irradiation device An irradiation direction control member for controlling the direction, an electric field control component for guiding ions generated by the electromagnetic waves irradiated from the electromagnetic wave irradiation device to the charged body, and for further stabilizing the charged potential of the charged body A charging device that charges the object to be charged by guiding the ions to the object to be charged by the electric field control component and the grid. ,
One or more electromagnetic radiation direction of electromagnetic waves irradiation device in proximity to an upper portion of the member to be charged is arranged parallel to the upper surface of the member to be charged, the irradiation direction control member integrally with the electromagnetic wave irradiation device was placed, parallel to the plate-shaped electric-field control component and the grid disposed above and below the electromagnetic radiation direction of the electromagnetic wave irradiation device to electromagnetic waves irradiation direction of the upper surface and the electromagnetic wave irradiation device of the member to be charged When the voltage applied to the electric field control component is Vc, the voltage applied to the grid is Vg, and the voltage applied to the member to be charged is Vp, the magnitudes of the voltages Vc, Vp, and Vg Relationship
| Vc |> | Vg |> | Vp |
A charging device characterized by:

The charging device according to claim 1.
One or more said electromagnetic wave irradiation apparatuses are arrange | positioned at equal intervals in parallel with the axial direction of the said to-be-charged body, The said irradiation direction control member is arrange | positioned for every electromagnetic wave irradiation apparatus.

3. The charging device according to claim 2, wherein the irradiation direction control member is made of a member integrated with each electromagnetic wave irradiation device.

4. The charging device according to claim 2, wherein an exterior part provided integrally with the electromagnetic wave irradiation device is deformed to have a function as the irradiation direction control member.

5. The charging device according to claim 3, wherein the irradiation direction control member has an arc shape corresponding to a shape of the electromagnetic wave irradiation device.

6. The charging device according to claim 1, wherein the electric field control component also serves as an electromagnetic shielding component.