JP2004138891A

JP2004138891A - Method and device for analyzing potential distribution in transfer region and program for analyzing the same

Info

Publication number: JP2004138891A
Application number: JP2002304548A
Authority: JP
Inventors: Masafumi Kadonaga; 門永　雅史
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2002-10-18
Filing date: 2002-10-18
Publication date: 2004-05-13

Abstract

<P>PROBLEM TO BE SOLVED: To accurately compute potential distribution of practical value by taking into consideration: the resistance, dielectric constant, thickness of each layer constituting an intermediate transfer device; processing speed; and the thickness, dielectric constant, resistance, etc., of a photoreceptor. <P>SOLUTION: A potential distribution analyzing method in which potential distribution is computed corresponding to parameters affecting the potential distribution has: a computation region dividing process in which the computation region is divided to form a plurality of cells; a potential calculating process in which the potential of each cell obtained in the computation region dividing process is calculated; a process for calculating the amount of transfer charge in which the amount of electric charge flowing in or out of each cell obtained in the computation region dividing process is calculated; a process for calculating potential difference transfer charge in which the amount of electric charge flowing in or out of each cell obtained in the computation region dividing process is calculated; and a process for calculating the amount of discharge charge in which the amount of electric charge flowing in or out of each cell obtained in the computation region dividing process is calculated. A potential distribution analyzing device has a first toner layer that remains on the photoreceptor and a second toner layer that is transferred to a transfer material. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、抵抗、放電、物体等の移動によって電位が変化する領域の電位分布、電荷量分布を算出するために、計算領域に対応する計算対象モデルについて、電位分布に影響を及ぼすパラメータに応じた電位分布または電荷量分布を算出する、転写領域の電位分布解析方法、解析装置、解析プログラムに関するものである。
【０００２】
【従来の技術】
複写機、プリンタ、ファクシミリ等の画像形成装置では、像担持体上に形成されるトナー像を転写材に転写する転写工程を行う。高解像度の画像を得るためには、トナー像を用紙へ転写する際の転写効率を上げることが重要課題となっている。そのためには、像担持体、転写材、トナー、転写条件といった各種パラメータを最適化することが重要となる。特に、近年、カラー電子写真における転写プロセスでは、中間転写ベルト等の中間転写体を使用する転写方式が主流となりつつある。この転写方式では、感光体上に形成される４色のトナー画像を一旦中間転写ベルト上に１次転写し、最後に一括して転写紙等の最終転写材上に２次転写することで最終画像を形成するので、最終画像を得るためには２回の転写工程が必要となる。この場合、２回の転写工程における転写性は、感光体、中間転写ベルト、転写紙、トナー、１次転写及び２次転写の転写条件といった更に多くのパラメータが絡み合って決定される。
【０００３】
転写工程における各種パラメータを最適化するため、近年では、試作機等による実験だけではなく、コンピュータ等によるシミュレーションも行われるようになっている。例えば、シミュレーションにより１次転写工程における各種パラメータの最適化を試みる場合、従来、感光体（像担持体）と中間転写ベルト（転写材）とが対向し、かつ、感光体上のトナーを中間転写ベルト上に転写させるための転写領域について、その中間転写ベルトの厚さ方向に注目し、抵抗とコンデンサで近似した１次元の解析対象モデルを用いる方法が知られている。
【０００４】
【参考文献１】
「カラー電子写真プロセスにおける中間転写方式の検討」、宮坂徹，山本雅志，島田昭著、日本画像会誌３８，１，ｐ９（１９９９）
【参考文献２】
「電子写真のローラ転写プロセスシミュレーション」伊藤朋之，川本広行著、日本機械学会論文集（ｃ編），６５，６３７，ｐ８１（１９９９）
【０００５】
【発明が解決しようとする課題】
ところが、上記計算モデルでは、現象のおおまかな傾向は１次元モデルで解析可能ではあるが、感光体や紙、ローラの移動や、中抵抗部材内部の表面や内部における電荷移動を考慮できないため、実際の転写現象に即した解析を行うことができなかった。このため、シミュレーションによって転写工程における各種パラメータの最適化を行っても、実用上の開発課題に対処できないといった問題があった。
【０００６】
そこで、本出願人は、このような状況に対して、ベルトや感光体、装置の試作・実験を行うことなく、電位分布、電荷量分布、転写電界を２次元シミュレーションによって算出し、開発課題の解決策を検討するための有力なツールを先に提案している。
この解析ツールは、電位算出工程、移流電荷量算出工程、電位差移動電荷量算出工程、放電電荷量算出工程を有し、像担持体表面の接線方向であって、像担持体の表面移動方向に対して垂直方向から上記転写領域を見たときの解析対象モデルを計算領域とし、上記移流電荷量算出工程では、上記像担持体及び上記転写材の表面移動方向により移流して、各セルに流入または流出する電荷量を算出し、上記放電電荷量算出工程では、上記像担持体表面と上記転写材との間で生じる放電により各セルに流入または流出する電荷量を算出する転写領域電位分布解析装置である。
【０００７】
図１は、シミュレータでの解析手順である。ステップＳ１において、ファイルもしくはキーボードから、計算条件である入力データを読み込む、ステップＳ２で変数初期化を行い、その後、ステップＳ３において計算領域をメッシュに分割する。図２は転写ローラシステム（図３）をメッシュ分割した例であり、図３に示す破線四角領域を計算対象としている。ただしトナー層は電荷量だけを考慮しているため、厚さを無視してメッシュ分割を行っている。その後、ポアソン方程式、オームの法則、パッシェンの法則を考慮して、ステップＳ４において電位分布計算、ステップＳ５において移流と抵抗の影響考慮、ステップＳ６で電位分布を計算し、ステップＳ７において放電電荷量算出を行う。
【０００８】
図４は、シミュレーション装置の概略構成を示すブロック図である。このシミュレーション装置は、データ入力部１１、電界計算部１２及び計算結果表示部１３を有している。データ入力部１１は、シミュレーションに必要な入力パラメータを入力するためのものである。電界計算部１２は、オームの法則、２次元ポアソン方程式、パッシェンの放電則により、計算領域の電位分布、電荷量分布、電界を算出するものである。また結果表示部１３は、電界計算部１２で算出した結果をオペレータ等が視認できる状態で表示するものである。
【０００９】
図５は、上記電界計算部１２を構成するマイクロコンピュータを示すブロック図である。このマイクロコンピュータ２０は、各種判断および処理を行う計算領域分割手段、電位算出手段、移流電荷量算出手段、電位差移動電荷量算出手段及び放電電荷量算出手段としての中央処理装置（ＣＰＵ）２１と、各処理プログラム及び固定データを格納した処理工程記憶手段としてのＲＯＭ２２と、処理データを格納するデータメモリであるパラメータ記憶手段としてのＲＡＭ２３と、パラメータ入力手段としての入出力回路（Ｉ／Ｏ）２４とから構成されている。
【００１０】
このマイクロコンピュータ２０には、データ入力部１１からの出力データがＩ／Ｏ２４を介して入力され、このマイクロコンピュータ２０により処理された処理結果がＩ／Ｏ２４を介して結果表示部１３に出力される。ここで、データ入力部１１からの処理信号は、上述した入力パラメータのデータである。
転写領域では、入口において感光体上に存在したトナーは、転写領域で転写部材に移動し、出口ではその大部分が転写部材上に存在する。ただし一部のトナーは転写残トナーとして、感光体に残留するが、この影響を考慮してメッシュ分割することは、困難であるため、従来の解析ではトナーは１００％転写すると考え、さらにトナーの大きさを無視して電荷のみを考慮するといった方法を用いたものである。
【００１１】
しかしながら、この前述のシミュレーションツールでは、前記１次元解析モデルよりも精度が向上したものの、未だトナーの扱いが不十分であり、トナー付着量やトナー層厚さの影響については十分に解析できないといった問題が残っていた。
また、トナーは、ある転写率で転写材に移動するため、トナー層は、転写入口では像担持体（感光体）上、出口では転写材と感光体上に分裂するが、この従来の解析方法では、転写率１００％と仮定しているため、この点からも解析精度の劣化が懸念されていた。
なお、これらの問題は、転写領域の電位分布解析の精度が悪いことに原因がある。よって、この原因を解決することは、像担持体、転写材、転写装置等の試作・実験を行うことなく転写工程における実用上の開発課題の解決策を検討するために有効であるばかりでなく、広く抵抗と放電、物体の移動によって電位分布が変化する領域の解析に有効となる。
【００１２】
本発明は、以上の問題に鑑みなされたものであり、その目的とするところは、抵抗、放電、または物体の移動が伴う領域で、かつ複雑な形状の領域であっても、現実に即した値の電位分布を精度よく算出することであり、例えば複写機の転写領域での実用上の開発課題の解決策を検討するために有効な電位分布解析方法、解析装置、及び解析プログラムを提供することである。
また、このように、各種変動の影響を考慮して解析することにより、装置の試作、実験が低減することを狙いとする。
【００１３】
【課題を解決するための手段】
上記目的を達成するために、請求項１の発明は、抵抗と放電、物体の移動によって電位分布が変化する領域の解析を行う際に、該領域に対応する解析対象モデルに対し、電位分布に影響を及ぼすパラメータに応じた電位分布を算出する電位分布解析方法において、計算領域を分割して複数のセルを形成する計算領域分割工程と、上記パラメータに基づき、上記計算領域分割工程で得た各セルの電位を算出する電位算出工程と、上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、上記物体の移動方向により移流して、各セルに流入又は流出する電荷量を算出する移流電荷量算出工程と、上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、隣接するセルとの電位差により各セルに流入又は流出する電荷量を算出する電位差移動電荷量算出工程と、上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、空気を間にはさむ物体間で生じる放電により各セルに流入又は流出する電荷量を算出する放電電荷量算出工程とを有し、感光体上に残留する第１トナー層と転写材へ転写する第２トナー層とを有したことを特徴とするものである。
【００１４】
また、請求項２の発明は、請求項１の電位分布解析方法において、転写材と第２トナー層の間、第２トナー層と第１トナー層の間に薄い空気層、または前記第１トナー層及び前記第２トナー層よりも薄い第３トナー層を設けることを特徴とするものである。
また、請求項３の発明は、請求項１の電位分布解析方法において、トナー層を均一層と考えた誘電率ε_１、ε_２、厚さｈ_１、ｈ_２、層体積電荷密度Ｑ_ｖ１、Ｑ_ｖ２を、以下の式で規定することを特徴とするものである。
ｈ＝Ｍａ／（α×ρ）
ｈ_１＝ｈ×（１−η）
ｈ_２＝ｈ×η
ε_１＝α（１−η）εｔ＋（１＋η）α
ε_２＝αηεｔ＋（１−ηα）
Ｑ_ｖ１＝Ｑ_ｖ２＝Ｑｍ×Ｍａ／ｈ
（ただし、単位質量当たりのトナー帯電量Ｑｍ、像担持体上の単位面積あたりのトナー付着量Ｍａ、トナー層の充填率α、トナー密度ρ、転写率η、転写前像担持体上トナー層高さｈである。）
【００１５】
また、請求項４の発明は、請求項３の電位分布解析方法において、トナー転写率ηを、転写ニップ出口でのトナー層に働く電界強度から算出することを特徴とするものである。
また、請求項５の発明は、請求項３の電位分布解析方法において、トナー転写率ηを、転写ニップ出口でのトナー層に働く電界強度から算出し、そこから算出される転写率ηにしたがって、計算途中でメッシュを再分割しながら計算をすすめることを特徴とするものである。
【００１６】
また、請求項６の発明は、抵抗と放電、物体の移動によって電位分布が変化する領域の解析を行う際に、該領域に対応する解析対象モデルに対し、電位分布に影響を及ぼすパラメータに応じた電位分布を算出する解析装置において、計算領域を分割して複数のセルを形成する計算領域分割手段と、上記パラメータに基づき、上記計算領域分割手段により得た各セルの電位を算出する電位算出手段と、上記パラメータに基づき、上記計算領域分割手段により得た各セルについて、上記物体の移動方向により移流して、各セルに流入又は流出する電荷量を算出する移流電荷量算出手段と、上記パラメータに基づき、上記計算領域分割手段により得た各セルについて、隣接するセルとの電位差により各セルに流入又は流出する電荷量を算出する電位差移動電荷量算出手段と、上記パラメータに基づき、上記計算領域分割手段により得た各セルについて、空気を間にはさむ物体間で生じる放電により各セルに流入又は流出する電荷量を算出する放電電荷量算出手段とを有し、転写材へ転写する第１トナー層と感光体上に残留する第２トナー層を有したことを特徴とするものである。
また、請求項７の発明は、請求項６の電位分布解析装置において、上記計算領域分割手段、上記電位算出手段、上記移流電荷量算出手段、上記電位差移動電荷量算出手段及び上記放電電荷量算出手段により、請求項２〜５の電位分布解析方法における上記計算領域分割工程、上記電位算出工程、上記移流電荷量算出工程、上記電位差移動電荷量算出工程及び上記放電電荷量算出工程を実行することを特徴とするものである。
【００１７】
また、請求項８の発明は、抵抗と放電、物体の移動によって電位分布が変化する領域の解析を行う際に、該領域に対応する解析対象モデルに対し、電位分布に影響を及ぼすパラメータに応じた電位分布を算出することをコンピュータに実行させるための解析プログラムであって、計算領域を分割して複数のセルを形成する計算領域分割工程、上記パラメータに基づき、上記計算領域分割工程で得た各セルの電位を算出する電位算出工程、上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、上記物体の移動方向により移流して、各セルに流入又は流出する電荷量を算出する移流電荷量算出工程、上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、隣接するセルとの電位差により各セルに流入又は流出する電荷量を算出する電位差移動電荷量算出工程、及び上記パラメータに基づき、上記計算領域分割工程で得た各セルについて、空気を間にはさむ物体間で生じる放電により各セルに流入又は流出する電荷量を算出する放電電荷量算出工程を、上記コンピュータに実行させることを特徴とするものである。
また、請求項９の発明は、請求項８の解析プログラムにおいて、請求項２〜５の電位分布解析方法を、上記コンピュータに実行させることを特徴とするものである。
【００１８】
従って、本発明によれば、中間転写装置を構成する各層の抵抗・誘電率・厚さ、プロセススピード、感光体厚さ・誘電率・抵抗等を考慮にいれた計算を行い、電位分布、電荷量分布、電界強度分布を算出する電位分布解析装置において、転写率や付着量、トナー層の厚さを考慮して、計算領域内にトナー層を最適に配置することができる。
尚、上記請求項８又は９の解析プログラムは、ＣＤ−ＲＯＭ等の記録媒体に記録された状態で配布したり、入手したりすることができる。また、このプログラムを乗せ、所定の送信装置により送信された信号を、公衆電話回線や専用線、その他の通信網等の伝送媒体を介して配信したり、受信したりすることでも、配布、入手が可能である。この配信の際、伝送媒体中には、コンピュータプログラムの少なくとも一部が伝送されていればよい。すなわち、コンピュータプログラムを構成するすべてのデータが、一時に伝送媒体上に存在している必要はない。このプログラムを乗せた信号とは、コンピュータプログラムを含む所定の搬送波に具現化されたコンピュータデータ信号である。また、所定の送信装置からコンピュータプログラムを送信する送信方法には、プログラムを構成するデータを連続的に送信する場合も、断続的に送信する場合も含まれる。
【００１９】
【発明の実施の形態】
以下、本発明の実施の形態について図面と共に説明する。
本発明は、抵抗と放電、物体の移動が伴う転写領域において、電位分布、電荷量分布を、精度よく算出するための電位分布解析方法である。
特に、中間転写装置を構成する各層の抵抗・誘電率・厚さ、プロセススピード、感光体厚さ・誘電率・抵抗等を考慮にいれた計算を行い、電位分布、電荷量分布、電界強度分布を算出する電位分布解析装置において、転写率や付着量、トナー層厚さを考慮して、計算領域内にトナー層を最適に配置するものである。
従ってここでは、前述した図１〜図５における電位分布解析方法において、本発明の要部である感光体上に残留する第１トナー層Ｔ_１と転写材へ転写する第２トナー層Ｔ_２の厚さｈ_１、ｈ_２と誘電率ε_１、ε_２及び体積電荷密度Ｑ_ｖ１、Ｑ_ｖ２の決定方法について詳述する。
まず、本実施形態に係るシミュレーションを行う対象の画像形成装置の構成及び動作について説明する。ここでは特に本実施形態におけるシミュレーションを、画像形成装置の転写ローラ周囲の電位分布解析シミュレーションに適用した場合について説明する。なお、本実施形態における画像形成装置は、像担持体としての感光体ドラム上に形成されるトナー画像を、直接、転写紙等の最終転写材上に転写することで最終画像を形成するものである。
【００２０】
図３は、本実施形態のシミュレーションの対象となる画像形成装置の要部を示す概略構成図であり、図６は、図３中破線で囲まれた領域の拡大図である。この画像形成装置は、図中矢印の方向に回転駆動する感光体ドラム１０１と、これに対向するように配置され感光体ドラム１０１上のトナー像Ｔ（Ｔ_１、Ｔ_２）を転写紙１０２に転写するための転写ローラ１０３とを備えている。
なお、図６において、感光体１０１、紙１０２、ローラ１０３は右から左へ移動もしくは回転している。トナー像Ｔを像担持体としての感光体１０１側から第１トナー層Ｔ_１および第２トナー層Ｔ_２と２つの層に分割する。
第１トナー層Ｔ_１は転写出口でも感光体１０１上に配置し、第２トナー層Ｔ_２は転写出口では転写材としての紙１０２上に配置する。これにより、第１トナー層Ｔ_１は転写残トナー、第２トナー層Ｔ_２は転写トナーと考えることができる。第１トナー層Ｔ_１と第２トナー層Ｔ_２の間には、薄い空気層Ａ１が存在し、入口（図６右側）では第１トナー層Ｔ_１の厚さに比べて十分に小さな厚さとなっている。また同様に第２トナー層Ｔ_２と紙１０２間にも薄い空気層Ａ２が存在し、出口では第２トナー層Ｔ_２の厚さに比べて十分に小さな厚さとする。本実施形態では、空気層Ａ_１、空気層Ａ_２ともに１μｍとした。この入口領域における空気層Ａ_１、出口領域における空気層Ａ_２は、現実には存在せず上下の層は接触しているため、この領域での放電は考慮しないものとする。トナー層Ｔは通常絶縁層とみなせるため、この空気層Ａ_１を介しての電荷移動は考える必要がないが、トナーが中抵抗の場合にはこの空気層Ａ_１を第１トナー層Ｔ_１及び第２トナー層Ｔ_２よりも薄い第３トナー層Ｔ_３と置き換えて、電荷移動を適用してもよい。
【００２１】
次に第１トナー層Ｔ_１、第２トナー層Ｔ_２の厚さや誘電率、体積電荷密度の決定方法を説明する。転写前の像担持体上の単位面積あたりのトナー付着量ｍ／ａをＭａ、転写前像担持体上トナー層高さ（層１と層２の厚さの和）をｈ、トナー層中のトナーの体積割合（充填率）をα、トナーの密度をρとおくと、
ｈ＝Ｍａ／（α×ρ）
が成立する。
転写率がη（１００％を１．０、０％を０．０とする）であれば、第２トナー層Ｔ_２の厚さは、ｈのη倍となり、逆に転写残第１トナー層Ｔ_１は１−η倍となる。よって
ｈ_１＝ｈ×（１−η）
ｈ_２＝ｈ×η
が成立する。
【００２２】
各層の誘電率ε_１、ε_２は、トナーと空気の体積割合に応じて平均的な値をとると仮定すると、
ε_１＝α（１−η）εｔ＋（１＋η）α
ε_２＝αηεｔ＋（１−ηα）
となる。
またこのとき各層の体積電荷密度Ｑ_ｖ１、Ｑ_ｖ２は同じになり、
Ｑ_ｖ１＝Ｑ_ｖ２＝Ｑｍ×Ｍａ／ｈ
となる。
このように第１トナー層Ｔ_１、第２トナー層Ｔ_２を分割して設定することによって、転写率を考慮してトナー層Ｔを設定することが可能となり、従来よりも、より精度の高い解析が可能となる。
【００２３】
以下本発明を適用した場合の計算結果を示す。図７のように転写ニップ領域でｙ座標を定義する。図８は転写ニップ領域でのｙ方向電位分布である。転写バイアス１０００Ｖと２０００Ｖの場合であり、図中央の□で囲った領域がトナー層である。また、図９は転写電界であり、図８と同様にトナー層を□で囲っている。
図１０は図９のトナー層部分電界強度とｈ_１、ｈ_２を模式的に表した図である。ここでＥ_ｔｈはトナーが転写する電界強度（臨界転写電界強度）である。トナー感光体間付着力をＦ、トナー１個の帯電量をｑとすると、
Ｆ＝ｑ×Ｅ_ｔｈ
で計算可能である。
つまり、この臨界転写電界強度Ｅ_ｔｈよりも大きな電界強度領域ではトナーが転写すると考えられるため、図中でのｈ_２の部分のトナーが転写され、ｈ_１部分のトナーは感光体に残ると考えられる。
よって、転写率η＝ｈ_２／（ｈ_１＋ｈ_２）となる。従って電界強度分布がわかればトナー転写率が計算可能であり、これよりｈ_１、ｈ_２が算出可能である。
【００２４】
ある転写条件で計算を行う際、当初転写率は不明であっても、このように転写電界強度分布がわかれば転写率が算出可能となり、それに従ってｈ_１、ｈ_２を求め、再度メッシュを再分割することで、より精度の高い計算が可能となる。
メッシュを再分割して計算を行う場合、メッシュが大きく変わらなかった領域でも、最初から収束計算、時間発展計算を行う必要がある。しかしながら大部分の電位分布は、メッシュを作成し直す前と大差ないと考えられるため、無駄な計算を行ってしまい、計算処理の時間短縮化に影響を与える場合がある。
そこで、転写率を算出した後、メッシュだけを変更して計算を続行すると、このような無駄な計算がなくなり、効率を向上することができる。
よって本発明では、最初トナーが１００％転写する（またはまったく転写しない）と仮定して、電界計算を行い、電界分布から転写率を算出し、そのままメッシュだけ分割しなおして計算を続行する。
また、トナーが転写するかどうかを決定するのは、ニップ出口であるため、ニップ出口での転写電界強度分布から転写率を計算するのが効率がよい。
以上の実施形態の構造によれば、トナー層の体積や付着量、転写率の影響を考慮することが可能となり、付着量の増加によるトナー層厚さの増加、転写率の低下等まで考慮できるようになる。
【００２５】
さらには転写率による出口側放電の違い等も考慮できるようになり、より精度の高い解析が可能となる。
また、特に本実施形態によれば、転写領域入口から出口まで、連続的にトナー層を配置することができ、しかも転写残トナーも考慮可能となり、より現実に近い、精度の高い解析が可能となる。
また、トナー付着量が多くても少なくても、同じトナー層厚さで計算を行うと、転写電界強度や放電電流を正しく見積もることができないが、転写後トナー層（第２トナー層Ｔ_２）や転写残トナー層（第１トナー層Ｔ_１）の厚さｈ_１、ｈ_２は、転写率によって変化するために、転写条件によって変える必要があるが上記数式を用いることで、転写率や付着量が変わった場合の、トナー層を均一層と考えた誘電率ε_１、ε_２、厚さｈ_１、ｈ_２、層体積電荷密度Ｑ_ｖ１、Ｑ_ｖ２が一意に決定されるため、これらの影響を排除し、より精度の高いモデルで考慮可能となる。
例えば、転写率によって転写領域出口側での放電量が変動する影響を考慮可能となり、転写後トナー帯電量を高い精度で予測可能となる。
【００２６】
さらに、抵抗値の制御、帯電量制御等が容易でない条件の場合には、実験が困難となり、転写率がわからないために、解析ができないといった問題が発生する。しかしながら転写率は、転写領域出口での電界強度分布Ｅ_ｏｕｔと相関があることが判明したため、この値から転写率を予測することが可能となった。
また、実験が困難な条件でも転写率を算出することができ、より広範囲の条件での解析が可能となる。
また、転写率を算出した後、再度メッシュを作成しなおして、解析を実行する場合、メッシュだけを変更して計算を続行するようにしてあるため、解析時間の大幅な短縮と効率向上が期待できる。
なお、前述の実施形態では、電位分布解析の具体的方法については前述の図１〜図５によるものとして詳細な説明を省略したが、電位分布解析方法としてはこれに限るものではなく、本発明を適用することにより第１トナー層Ｔ_１と第２トナー層Ｔ_２の厚さｈ_１、ｈ_２と誘電率ε_１、ε_２及び体積電荷密度Ｑ_ｖ１、Ｑ_ｖ２を求めることができるので、これらをパラメータとして利用すれば、精度の高い電位分布の解析を行うことができる。
【００２７】
【発明の効果】
以上説明したように、本発明では、ベルトや感光体、装置の試作・実験を行うことなく、電位分布、電荷量分布、電界をシミュレーションによって算出することが可能となり、開発上の課題解決が加速され、開発期間の短縮、試作低減、実験回数低減が可能となる。特に転写率や付着量の影響が精度よく解析可能となる。
特に、現実に即した条件で転写特性の解析を行うことが可能なので、像担持体、転写材、転写装置等の試作・実験を行うことなく、シミュレーションにより転写工程における実用上の開発課題の解決策を有効に検討することが可能となり、開発課題を迅速に解決でき、開発期間の短縮化を図ることが可能となるという優れた効果を得ることができる。
【図面の簡単な説明】
【図１】電位分布解析装置による処理の流れを示すフローチャート。
【図２】転写ローラをメッシュ分割した例。
【図３】電位分布解析装置により行われるシミュレーションの対象となる画像形成装置の要部を示す概略構成図。
【図４】同解析装置の概略構成を示すブロック図。
【図５】同解析装置の電界計算部を構成するマイクロコンピュータを示すブロック図。
【図６】図３中破線で囲まれた領域の拡大図。
【図７】転写ニップ領域におけるｙ座標の定義図。
【図８】転写ニップ領域におけるｙ方向電位分布図。
【図９】トナー層の部分電界強度を示す転写電解図。
【図１０】部分電界強度とトナー層厚ｈ_１、ｈ_２の相関図。
【符号の説明】
１１　　データ入力部
１２　　電界計算部
１３　　結果表示部
２０　　マイクロコンピュータ
１０１　感光体ドラム
１０２　転写紙
１０３　転写ローラ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention calculates a potential distribution and a charge amount distribution in a region where a potential changes due to resistance, discharge, movement of an object or the like. The present invention relates to a method, an analyzing apparatus, and an analyzing program for analyzing a potential distribution of a transfer region for calculating a potential distribution or a charge amount distribution.
[0002]
[Prior art]
2. Description of the Related Art In an image forming apparatus such as a copying machine, a printer, and a facsimile, a transfer process of transferring a toner image formed on an image carrier to a transfer material is performed. In order to obtain a high-resolution image, it is important to increase the transfer efficiency when transferring a toner image onto paper. For that purpose, it is important to optimize various parameters such as an image carrier, a transfer material, a toner, and transfer conditions. In particular, in recent years, in a transfer process in color electrophotography, a transfer method using an intermediate transfer member such as an intermediate transfer belt is becoming mainstream. In this transfer method, a four-color toner image formed on a photoreceptor is once primarily transferred onto an intermediate transfer belt, and finally is collectively secondarily transferred onto a final transfer material such as transfer paper. Since an image is formed, two transfer steps are required to obtain a final image. In this case, the transferability in the two transfer steps is determined by intermingling more parameters such as the photoconductor, the intermediate transfer belt, the transfer paper, the toner, and the transfer conditions of the primary transfer and the secondary transfer.
[0003]
In recent years, in order to optimize various parameters in the transfer process, not only experiments using prototypes and the like, but also simulations using a computer and the like have been performed. For example, when trying to optimize various parameters in the primary transfer process by simulation, conventionally, a photoconductor (image carrier) and an intermediate transfer belt (transfer material) are opposed to each other, and the toner on the photoconductor is subjected to intermediate transfer. A method is known in which a transfer area to be transferred onto a belt is focused on in a thickness direction of the intermediate transfer belt, and a one-dimensional analysis target model approximated by a resistor and a capacitor is used.
[0004]
[Reference 1]
"Investigation of Intermediate Transfer Method in Color Electrophotographic Process", Toru Miyasaka, Masashi Yamamoto, Akira Shimada, Nihon Image Society, 38, 1, p9 (1999)
[Reference 2]
"Simulation of Roller Transfer Process of Electrophotography" by Tomoyuki Ito and Hiroyuki Kawamoto, Transactions of the Japan Society of Mechanical Engineers (ed.c), 65, 637, p81 (1999)
[0005]
[Problems to be solved by the invention]
However, in the above calculation model, the general tendency of the phenomenon can be analyzed with a one-dimensional model. However, since the movement of the photoconductor, paper, and rollers, and the charge movement on the surface and inside of the medium resistance member cannot be considered, the actual tendency is not considered. Could not be analyzed according to the transcription phenomenon. For this reason, there is a problem that even if optimization of various parameters in the transfer process is performed by simulation, practical development problems cannot be solved.
[0006]
Accordingly, the present applicant has calculated the potential distribution, the charge distribution, and the transfer electric field by a two-dimensional simulation without performing the trial production and the experiment of the belt, the photoconductor, and the apparatus in such a situation. We have already suggested a powerful tool for considering a solution.
This analysis tool includes a potential calculation step, an advection charge amount calculation step, a potential difference transfer charge amount calculation step, and a discharge charge amount calculation step, and is a tangential direction of the surface of the image carrier, and a direction in which the surface of the image carrier moves. On the other hand, the model to be analyzed when the transfer area is viewed from the vertical direction is defined as a calculation area, and in the advection charge amount calculation step, advection occurs in the surface movement direction of the image carrier and the transfer material, and flows into each cell. Alternatively, the amount of charge flowing out is calculated, and in the discharge charge amount calculation step, a transfer region potential distribution analysis for calculating the amount of charge flowing into or out of each cell due to a discharge generated between the image carrier surface and the transfer material is performed. Device.
[0007]
FIG. 1 shows an analysis procedure in the simulator. In step S1, input data, which is a calculation condition, is read from a file or a keyboard. In step S2, variables are initialized. In step S3, the calculation area is divided into meshes. FIG. 2 shows an example in which the transfer roller system (FIG. 3) is divided into meshes, and the calculation is performed on a broken-line square area shown in FIG. However, since the toner layer takes into account only the amount of charge, the mesh division is performed ignoring the thickness. Thereafter, in consideration of Poisson's equation, Ohm's law, and Paschen's law, the potential distribution is calculated in step S4, the influence of advection and resistance is considered in step S5, the potential distribution is calculated in step S6, and the discharge charge amount is calculated in step S7. I do.
[0008]
FIG. 4 is a block diagram showing a schematic configuration of the simulation device. This simulation device has a data input unit 11, an electric field calculation unit 12, and a calculation result display unit 13. The data input unit 11 is for inputting input parameters necessary for the simulation. The electric field calculation unit 12 calculates a potential distribution, a charge amount distribution, and an electric field in a calculation region according to Ohm's law, two-dimensional Poisson equation, and Paschen's discharge law. The result display unit 13 displays the result calculated by the electric field calculation unit 12 in a state where an operator or the like can visually recognize the result.
[0009]
FIG. 5 is a block diagram showing a microcomputer constituting the electric field calculator 12. The microcomputer 20 includes a central processing unit (CPU) 21 as a calculation area dividing unit for performing various determinations and processes, a potential calculation unit, an advection charge amount calculation unit, a potential difference transfer charge amount calculation unit, and a discharge charge amount calculation unit. ROM 22 as processing process storage means storing each processing program and fixed data, RAM 23 as parameter storage means as a data memory for storing processing data, and input / output circuit (I / O) 24 as parameter input means It is composed of
[0010]
Output data from the data input unit 11 is input to the microcomputer 20 via the I / O 24, and the processing result processed by the microcomputer 20 is output to the result display unit 13 via the I / O 24. . Here, the processing signal from the data input unit 11 is the data of the input parameter described above.
In the transfer area, the toner existing on the photoconductor at the entrance moves to the transfer member in the transfer area, and most of the toner exists on the transfer member at the exit. However, some toner remains on the photoreceptor as transfer residual toner, but it is difficult to divide into meshes in consideration of this effect. This method uses a method in which only the charge is considered ignoring the size.
[0011]
However, with the above-described simulation tool, although the accuracy is improved compared to the one-dimensional analysis model, the handling of the toner is still insufficient, and the effect of the toner adhesion amount and the toner layer thickness cannot be sufficiently analyzed. Was left.
Also, since the toner moves to the transfer material at a certain transfer rate, the toner layer splits on the image carrier (photoconductor) at the transfer entrance and splits on the transfer material and photoconductor at the exit. In this case, since the transfer rate is assumed to be 100%, the analysis accuracy is also degraded from this point.
Note that these problems are caused by the fact that the accuracy of the potential distribution analysis of the transfer region is poor. Therefore, solving this cause is not only effective for examining solutions to practical development issues in the transfer process without conducting trial production and experiments of the image carrier, transfer material, transfer device, etc. This is effective for analyzing a region in which the potential distribution changes widely due to resistance, discharge, and movement of an object.
[0012]
The present invention has been made in view of the above problems, and aims at realizing resistance, discharge, or an area accompanied by movement of an object, and even an area having a complicated shape. The present invention provides a potential distribution analysis method, an analysis device, and an analysis program which are effective in accurately calculating a potential distribution of values, for example, for examining a solution to a practical development problem in a transfer area of a copying machine. That is.
In addition, by performing analysis in consideration of the influence of various fluctuations as described above, the aim is to reduce the number of prototypes and experiments of the apparatus.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention according to claim 1, when analyzing a region in which the potential distribution changes due to resistance, discharge, and movement of an object, a potential distribution is applied to an analysis target model corresponding to the region. In a potential distribution analysis method for calculating a potential distribution according to an influencing parameter, a calculation region dividing step of dividing a calculation region to form a plurality of cells, and each of a plurality of cells obtained in the calculation region dividing step based on the parameter. A potential calculating step of calculating the potential of the cell, and calculating the amount of charge flowing into or out of each cell based on the parameter, for each cell obtained in the calculation region dividing step in the moving direction of the object. Advection charge amount calculation step, and based on the parameters, for each cell obtained in the calculation area division step, the charge flowing into or out of each cell due to the potential difference between adjacent cells. Calculating the amount of charge transferred to each cell obtained in the calculation region dividing step based on the above parameters, and calculating the amount of charge flowing into or out of each cell due to a discharge generated between objects sandwiching air. And a second toner layer for transferring to a transfer material, the first toner layer remaining on the photoconductor and a second toner layer for transferring to a transfer material.
[0014]
According to a second aspect of the present invention, in the potential distribution analyzing method of the first aspect, a thin air layer between the transfer material and the second toner layer, a thin air layer between the second toner layer and the first toner layer, or the first toner. And a third toner layer thinner than the second toner layer.
According to a third aspect of the present invention, in the potential distribution analysis method of the first aspect, the toner layer is considered to be a uniform layer, and the dielectric constants ε ₁ and ε ₂ , the thicknesses h ₁ and h ₂ , the layer volume charge density Q _v1 , Q _v2 is defined by the following equation.
h = Ma / (α × ρ)
h ₁ = h × (1−η)
h ₂ = h × η
ε ₁ = α (1−η) εt + (1 + η) α
ε ₂ = αηεt + (1−ηα)
Q _v1 = Q _v2 = Qm × Ma / h
(However, the toner charge amount Qm per unit mass, the toner adhesion amount Ma per unit area on the image carrier, the toner layer filling rate α, the toner density ρ, the transfer rate η, the toner layer height on the image carrier before transfer) H.)
[0015]
According to a fourth aspect of the present invention, in the potential distribution analysis method of the third aspect, the toner transfer rate η is calculated from an electric field intensity acting on the toner layer at the transfer nip exit.
According to a fifth aspect of the present invention, in the potential distribution analyzing method of the third aspect, the toner transfer rate η is calculated from the electric field intensity acting on the toner layer at the transfer nip exit, and according to the transfer rate η calculated therefrom. In addition, the calculation is performed while subdividing the mesh during the calculation.
[0016]
Further, according to the present invention, when analyzing a region where the potential distribution changes due to resistance, discharge, and movement of an object, an analysis target model corresponding to the region is subjected to a parameter which affects the potential distribution. A calculation area dividing means for dividing a calculation area to form a plurality of cells, and a potential calculating means for calculating a potential of each cell obtained by the calculation area dividing means based on the parameters. Means, advection charge amount calculation means for calculating a charge amount flowing in or out of each cell in the moving direction of the object for each cell obtained by the calculation area dividing means based on the parameter; A potential for calculating the amount of charge flowing into or out of each cell based on the potential difference between adjacent cells for each cell obtained by the calculation region dividing means based on the parameters. A moving charge amount calculating unit, and a discharge charge amount for calculating a charge amount flowing into or out of each cell due to a discharge generated between objects sandwiching air for each cell obtained by the calculation region dividing unit based on the parameter. A first toner layer to be transferred to a transfer material and a second toner layer remaining on the photoreceptor.
According to a seventh aspect of the present invention, in the potential distribution analyzer according to the sixth aspect, the calculation area dividing means, the potential calculating means, the advection charge amount calculating means, the potential difference moving charge amount calculating means, and the discharge charge amount calculating means. Means for executing the calculation region dividing step, the potential calculation step, the advection charge amount calculation step, the potential difference transfer charge amount calculation step, and the discharge charge amount calculation step in the potential distribution analysis method according to claim 2. It is characterized by the following.
[0017]
Further, the invention according to claim 8 is characterized in that when analyzing a region where the potential distribution changes due to resistance, discharge, and movement of an object, an analysis target model corresponding to the region responds to a parameter affecting the potential distribution. An analysis program for causing a computer to calculate the calculated potential distribution, wherein the calculation region is divided into calculation cells to form a plurality of cells. A potential calculating step of calculating a potential of each cell, and calculating an amount of charge flowing into or out of each cell based on the parameters, for each cell obtained in the calculation region dividing step in the moving direction of the object. Advection charge amount calculation step, based on the above parameters, for each cell obtained in the above calculation area dividing step, flow into or out of each cell depending on the potential difference between adjacent cells. The potential difference moving charge amount calculating step of calculating the charge amount, and the charge flowing into or out of each cell due to the discharge generated between the objects sandwiching the air for each cell obtained in the calculation region dividing step based on the parameter. The computer is caused to execute a discharge charge amount calculating step of calculating the amount.
According to a ninth aspect of the present invention, in the analysis program of the eighth aspect, the computer executes the potential distribution analysis methods of the second to fifth aspects.
[0018]
Therefore, according to the present invention, the resistance, permittivity, and thickness of each layer constituting the intermediate transfer device, process speed, photoconductor thickness, permittivity, resistance, etc. are taken into account, and the potential distribution, charge In the potential distribution analyzer for calculating the amount distribution and the electric field intensity distribution, the toner layer can be optimally arranged in the calculation region in consideration of the transfer rate, the amount of adhesion, and the thickness of the toner layer.
The analysis program according to claim 8 or 9 can be distributed or obtained while being recorded on a recording medium such as a CD-ROM. The distribution and acquisition can also be performed by loading the program and distributing or receiving the signal transmitted by a predetermined transmitting device via a transmission medium such as a public telephone line, a dedicated line, or another communication network. Is possible. At the time of this distribution, it is sufficient that at least a part of the computer program is transmitted in the transmission medium. That is, it is not necessary that all data constituting the computer program exist on the transmission medium at one time. The signal carrying the program is a computer data signal embodied on a predetermined carrier including the computer program. The transmission method for transmitting a computer program from a predetermined transmission device includes a case where data constituting the program is transmitted continuously and a case where the data is transmitted intermittently.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The present invention is a potential distribution analysis method for accurately calculating a potential distribution and a charge amount distribution in a transfer region involving resistance, discharge, and movement of an object.
In particular, calculations are performed taking into account the resistance, dielectric constant, thickness, process speed, photoconductor thickness, dielectric constant, resistance, etc. of each layer constituting the intermediate transfer device, and the potential distribution, charge amount distribution, electric field intensity distribution In the potential distribution analysis apparatus for calculating, the toner layer is optimally arranged in the calculation area in consideration of the transfer rate, the amount of adhesion, and the thickness of the toner layer.
Here, therefore, the potential distribution analysis method in FIGS. 5 described above, the present invention is a main part of the second toner layer T ₂ for transferring the first toner layer T ₁ and the transfer material remaining on the photoreceptor A method for determining the thicknesses h ₁ and h ₂ , the dielectric constants ε ₁ and ε _2, and the volume charge densities Q _v1 and Q _v2 will be described in detail.
First, the configuration and operation of an image forming apparatus to be simulated according to the present embodiment will be described. Here, a case in which the simulation according to the present embodiment is applied to a potential distribution analysis simulation around the transfer roller of the image forming apparatus will be particularly described. The image forming apparatus according to the present embodiment forms a final image by directly transferring a toner image formed on a photosensitive drum as an image carrier onto a final transfer material such as transfer paper. is there.
[0020]
FIG. 3 is a schematic configuration diagram illustrating a main part of an image forming apparatus to be simulated according to the present embodiment, and FIG. 6 is an enlarged view of a region surrounded by a broken line in FIG. The image forming apparatus includes a photosensitive drum 101 that is driven to rotate in a direction indicated by an arrow in the drawing, and a toner image T (T ₁ , T ₂ ) disposed on the photosensitive drum 101 and opposed to the photosensitive drum 101, on a transfer paper 102. And a transfer roller 103 for transferring.
In FIG. 6, the photosensitive member 101, the paper 102, and the roller 103 are moving or rotating from right to left. Splitting the toner image T from the photosensitive member 101 side of the image carrier to the first toner layer T ₁ and the second toner layer T ₂ of the two layers.
First toner layer T ₁ is disposed on the photosensitive member 101 at the transfer outlet, the second toner layer T ₂ are the transfer outlet disposed on the paper 102 as a transfer material. Thus, the first toner layer T ₁ may be considered residual toner, second toner layer T ₂ are the transferred toner. Between the first toner layer T ₁ and the second toner layer T _2, thin and there is an air layer A1, an inlet (6 right side) in a sufficiently small thickness compared to the thickness of the first toner layer T ₁ and Has become. Similarly thin air layer A2 is also present between the second toner layer T ₂ and the paper 102, at the exit is sufficiently small thickness compared to the thickness of the second toner layer T _2. In this embodiment, both the air layer A ₁ and the air layer A _{2 have a} thickness of 1 μm. Since the air layer A _{1 in} the inlet area and the air layer A ₂ in the outlet area do not actually exist and the upper and lower layers are in contact with each other, the discharge in this area is not considered. Since the toner layer T can be regarded as normally insulating layer, there is no need to consider charge transfer through the air layer A _1, the air layer A ₁ first toner layer T ₁ and when the toner is medium resistance by replacing the third toner layer T ₃ thinner than the second toner layer T _2, it may be applied charge transfer.
[0021]
Next, a method for determining the thickness, the dielectric constant, and the volume charge density of the first toner layer T ₁ and the second toner layer T ₂ will be described. Ma is the toner adhesion amount m / a per unit area on the image carrier before transfer, Ma is the height of the toner layer on the image carrier before transfer (the sum of the thicknesses of layers 1 and 2), and If the volume ratio (filling ratio) of the toner is α and the density of the toner is ρ,
h = Ma / (α × ρ)
Holds.
If the transfer rate is eta (a 100% 1.0, 0% to 0.0), the thickness of the second toner layer _{T 2} are, becomes eta times h, transferred to a reversed residual first toner layer T ₁ becomes 1−η times. Therefore, h ₁ = h × (1−η)
h ₂ = h × η
Holds.
[0022]
Assuming that the dielectric constants ε ₁ and ε ₂ of each layer take an average value according to the volume ratio of toner and air,
ε ₁ = α (1−η) εt + (1 + η) α
ε ₂ = αηεt + (1−ηα)
It becomes.
At this time, the volume charge densities Q _v1 and Q _v2 of each layer are the same,
Q _v1 = Q _v2 = Qm × Ma / h
It becomes.
By dividing and setting the first toner layer T ₁ and the second toner layer T ₂ in this manner, it is possible to set the toner layer T in consideration of the transfer rate, and the accuracy is higher than in the related art. Analysis becomes possible.
[0023]
The calculation results when the present invention is applied are shown below. The y coordinate is defined in the transfer nip area as shown in FIG. FIG. 8 shows the y-direction potential distribution in the transfer nip region. In the case of the transfer bias of 1000 V and 2000 V, the area surrounded by the square in the center of the figure is the toner layer. FIG. 9 shows a transfer electric field, in which the toner layer is surrounded by squares as in FIG.
FIG. 10 is a diagram schematically illustrating the electric field intensity of the toner layer and h ₁ and h ₂ of FIG. Here, _Eth is the electric field intensity at which the toner is transferred (critical transfer electric field intensity). Assuming that the adhesion between the toner photoconductors is F and the charge amount of one toner is q,
F = q × E _th
Can be calculated by
In other words, this is a large electric field intensity regions than the critical transfer electric field strength E _th because the toner is considered to transfer the toner of h ₂ portion in a drawing is transferred, the toner of h ₁ part considered to remain on the photoreceptor Can be
Therefore, the transfer rate η = h ₂ / (h ₁ + h ₂ ). Therefore, if the electric field intensity distribution is known, the toner transfer rate can be calculated, and h ₁ and h ₂ can be calculated from this.
[0024]
When the calculation is performed under certain transfer conditions, even if the transfer rate is initially unknown, the transfer rate can be calculated if the transfer electric field intensity distribution is known in this way, h ₁ and h ₂ are calculated accordingly, and the mesh is re-created again. The division enables more accurate calculation.
When the calculation is performed by subdividing the mesh, it is necessary to perform the convergence calculation and the time evolution calculation from the beginning even in a region where the mesh has not changed significantly. However, most of the potential distribution is considered to be not much different from that before the mesh is re-created, so that a useless calculation is performed, which may affect a reduction in calculation processing time.
Therefore, if the calculation is continued after changing only the mesh after calculating the transfer rate, such useless calculation can be eliminated, and the efficiency can be improved.
Therefore, in the present invention, assuming that 100% of the toner is first transferred (or not transferred at all), the electric field is calculated, the transfer rate is calculated from the electric field distribution, the mesh is divided again, and the calculation is continued.
Since it is the nip exit that determines whether or not the toner is transferred, it is efficient to calculate the transfer rate from the transfer electric field intensity distribution at the nip exit.
According to the structure of the above-described embodiment, it is possible to consider the influence of the volume, the amount of adhesion of the toner layer, and the transfer rate, and it is possible to consider the increase in the thickness of the toner layer due to the increase in the amount of adhesion, the decrease in the transfer rate, and the like. Become like
[0025]
Furthermore, it is possible to take into consideration the difference in the discharge on the outlet side due to the transfer rate, and it is possible to perform more accurate analysis.
Further, according to the present embodiment, in particular, the toner layer can be continuously arranged from the entrance to the exit of the transfer area, and the transfer residual toner can be considered, so that a more realistic and accurate analysis can be performed. Become.
Further, if the calculation is performed with the same toner layer thickness regardless of whether the amount of adhered toner is large or small, the transfer electric field strength and the discharge current cannot be estimated correctly, but the post-transfer toner layer (second toner layer T ₂ ) And the thickness h ₁ and h ₂ of the transfer residual toner layer (first toner layer T ₁ ) need to be changed depending on the transfer conditions because they change depending on the transfer rate. When the amount is changed, the dielectric constants ε ₁ and ε ₂ , the thicknesses h ₁ and h ₂ , and the layer volume charge densities Q _v1 and Q _v2 are uniquely determined _assuming that the toner layer is a uniform layer. Eliminate the effects and allow for more accurate models.
For example, it is possible to consider the influence of the variation in the discharge amount at the transfer area exit side depending on the transfer rate, and it is possible to predict the toner charge amount after transfer with high accuracy.
[0026]
Further, in the case where the control of the resistance value, the control of the charge amount, and the like are not easy, the experiment becomes difficult, and there is a problem that the analysis cannot be performed because the transfer rate is not known. However, since the transfer rate was found to be correlated with the electric field intensity distribution E _out at the transfer area exit, it was possible to predict the transfer rate from this value.
Further, the transfer rate can be calculated even under conditions where experiments are difficult, and analysis under a wider range of conditions becomes possible.
In addition, when calculating the transfer rate and then re-creating the mesh and executing the analysis, the calculation is continued by changing only the mesh, so significant reduction in analysis time and improvement in efficiency can be expected. it can.
In the above-described embodiment, the detailed description of the specific method of the potential distribution analysis is omitted as being based on FIGS. 1 to 5 described above. However, the potential distribution analysis method is not limited to this, and the present invention is not limited thereto. Is applied, the thicknesses h ₁ and h ₂ of the first toner layer T ₁ and the second toner layer T ₂ , the dielectric constants ε ₁ and ε _2, and the volume charge densities Q _v1 and Q _v2 can be obtained. If these are used as parameters, highly accurate analysis of the potential distribution can be performed.
[0027]
【The invention's effect】
As described above, according to the present invention, it is possible to calculate a potential distribution, a charge amount distribution, and an electric field by simulation without trial production and experiment of a belt, a photoreceptor, and an apparatus, thereby accelerating the solution of development problems. As a result, the development period, the number of prototypes, and the number of experiments can be reduced. In particular, the effects of the transfer rate and the amount of adhesion can be analyzed with high accuracy.
In particular, since transfer characteristics can be analyzed under real-world conditions, simulations can be used to solve practical development issues in the transfer process without conducting prototypes and experiments on image carriers, transfer materials, and transfer devices. It is possible to effectively examine the measures, to solve the development problem quickly, and to obtain an excellent effect that the development period can be shortened.
[Brief description of the drawings]
FIG. 1 is a flowchart showing the flow of processing by a potential distribution analyzer.
FIG. 2 is an example in which a transfer roller is divided into meshes.
FIG. 3 is a schematic configuration diagram illustrating a main part of an image forming apparatus that is a target of a simulation performed by the potential distribution analyzer.
FIG. 4 is a block diagram showing a schematic configuration of the analyzer.
FIG. 5 is a block diagram showing a microcomputer constituting an electric field calculator of the analyzer.
FIG. 6 is an enlarged view of a region surrounded by a broken line in FIG. 3;
FIG. 7 is a definition diagram of a y coordinate in a transfer nip area.
FIG. 8 is a y-direction potential distribution diagram in a transfer nip region.
FIG. 9 is a transfer electrolytic diagram showing a partial electric field strength of a toner layer.
FIG. 10 is a correlation diagram between partial electric field intensity and toner layer thicknesses h ₁ and h ₂ .
[Explanation of symbols]
Reference Signs List 11 Data input unit 12 Electric field calculation unit 13 Result display unit 20 Microcomputer 101 Photoconductor drum 102 Transfer paper 103 Transfer roller

Claims

When analyzing a region where the potential distribution changes due to resistance, discharge, and movement of an object, a potential distribution analysis that calculates a potential distribution corresponding to a parameter affecting the potential distribution for an analysis target model corresponding to the region. In the method,
A calculation region dividing step of dividing the calculation region to form a plurality of cells;
A potential calculating step of calculating a potential of each cell obtained in the calculation area dividing step based on the parameters;
Based on the parameters, for each cell obtained in the calculation area dividing step, advection in the moving direction of the object, advection charge amount calculation step of calculating the charge amount flowing into or out of each cell,
Based on the parameters, for each cell obtained in the calculation region dividing step, a potential difference moving charge amount calculating step of calculating the amount of charge flowing into or out of each cell based on the potential difference between adjacent cells,
Based on the parameters, for each cell obtained in the calculation region dividing step, having a discharge charge amount calculation step of calculating the charge amount flowing into or out of each cell by a discharge generated between objects sandwiching air,
A method for analyzing a potential distribution in a transfer area, comprising: a first toner layer remaining on a photoreceptor; and a second toner layer transferring to a transfer material.

The potential distribution analysis method according to claim 1,
A thin air layer or a third toner layer thinner than the first and second toner layers is provided between the transfer material and the second toner layer, between the second toner layer and the first toner layer. Potential distribution analysis method of the transfer region to be used.

The potential distribution analysis method according to claim 1,
The electric potential of the transfer region, wherein the dielectric constants ε ₁ , ε ₂ , the thicknesses h ₁ , h ₂ , and the layer volume charge densities Q _v1 , Q _v2 are defined by the following equations, considering the toner layer as a uniform layer. Distribution analysis method.
h = Ma / (α × ρ)
h ₁ = h × (1−η)
h ₂ = h × η
ε ₁ = α (1−η) εt + (1 + η) α
ε ₂ = αηεt + (1−ηα)
Q _v1 = Q _v2 = Qm × Ma / h
(However, the toner charge amount per unit mass Q _m, the toner adhesion amount Ma per unit area on the image bearing member, the filling of the toner layer alpha, toner density [rho, transfer rate eta, the pre-transfer image bearing member toner layer Height h.)

The potential distribution analysis method according to claim 3,
A potential distribution analysis method for a transfer area, wherein the toner transfer rate η is calculated from an electric field intensity acting on a toner layer at a transfer nip exit.

The potential distribution analysis method according to claim 3,
The toner transfer rate η is calculated from the electric field strength acting on the toner layer at the exit of the transfer nip, and the potential of the transfer area is calculated according to the calculated transfer rate η while subdividing the mesh during the calculation. Distribution analysis method.

Resistance and discharge, when analyzing an area where the potential distribution changes due to the movement of an object, an analysis device that calculates a potential distribution according to a parameter that affects the potential distribution for an analysis target model corresponding to the area. ,
Calculation region dividing means for dividing the calculation region to form a plurality of cells,
A potential calculating unit that calculates a potential of each cell obtained by the calculation region dividing unit based on the parameter;
For each cell obtained by the calculation area dividing means based on the parameters, advection in the moving direction of the object, advection charge amount calculation means for calculating the amount of charge flowing into or out of each cell,
Based on the parameters, for each cell obtained by the calculation region dividing means, a potential difference moving charge amount calculating means for calculating the amount of charge flowing into or out of each cell based on the potential difference between adjacent cells,
Based on the parameters, for each cell obtained by the calculation region dividing means, having a discharge charge amount calculation means for calculating the amount of charge flowing into or out of each cell due to discharge generated between objects sandwiching air,
An apparatus for analyzing a potential distribution in a transfer area, comprising: a first toner layer to be transferred to a transfer material; and a second toner layer remaining on a photoconductor.

The analysis device according to claim 6,
The calculation area dividing step in the potential distribution analysis method according to any one of claims 2 to 5, by the calculation area dividing means, the potential calculating means, the advection charge amount calculating means, the potential difference moving charge amount calculating means, and the discharge charge amount calculating means. An analyzing apparatus for executing the potential calculation step, the advection charge amount calculation step, the potential difference transfer charge amount calculation step, and the discharge charge amount calculation step.

When analyzing a region where the potential distribution changes due to resistance, discharge, and movement of an object, a computer calculates a potential distribution according to a parameter affecting the potential distribution for an analysis target model corresponding to the region. An analysis program for causing
A calculation region dividing step of dividing the calculation region to form a plurality of cells,
A potential calculating step of calculating a potential of each cell obtained in the calculation area dividing step based on the parameters;
Based on the parameters, for each cell obtained in the calculation region dividing step, advection in the moving direction of the object, advection charge amount calculation step of calculating the charge amount flowing into or out of each cell,
On the basis of the parameters, for each cell obtained in the calculation region dividing step, a potential difference moving charge amount calculating step of calculating the amount of charge flowing into or out of each cell based on a potential difference with an adjacent cell; and For each cell obtained in the calculation area dividing step, the computer executes a discharge charge amount calculation step of calculating a charge amount flowing into or out of each cell due to a discharge generated between objects sandwiching air. Analysis program to do.

The analysis program according to claim 8, wherein
An analysis program for causing the computer to execute the potential distribution analysis method according to claim 2.