JP4289807B2 - Developing device, toner regulating roller used therein, method for incorporating toner regulating roller into developing device, and image forming apparatus using the developing device - Google Patents

Description

上記の結果において、「スジ」とは目視で観察しうる現像ローラー３の表面に付着しているトナー薄層をいう。
【００６６】
現像ローラー３を作像時の回転方向（矢印Ａ方向）と逆方向（矢印Ｂ方向）に回転させず、かつ、トナー規制ローラー６を回転させない実験条件１のもとでは、「スジ」の発生が他の実験条件２〜実験条件４に較べて顕著であり、３０サイクルを繰り返した時点で無数のスジが発生した。
【００６７】
実際に実験条件１のもとでは、現像ローラー３とトナー規制ローラー６との間の楔形状領域１１に直径数ｍｍのトナー７の凝集塊が見られた。
【００６８】
これに対して、実験条件２、実験４のもとでは、優位差のほとんどない結果となったが、実験条件１と較べて明らかに現像ローラー３の表面のトナー薄層にはスジがほとんど見られず、外観が良好な結果を得られた。
【００６９】
これは、現像ローラー３とトナー規制ローラー６との間の楔形状領域１１に堆積していたトナー７が非作像時に上流側９に吐き戻されたからであると考えられる。
【００７０】
非作像時に現像ローラー３が作像時の回転方向（矢印Ａ方向）と逆方向（矢印Ｂ方向）に回転され、かつ、トナー規制ローラー６も従動回転される実験条件３のもとでは、１５サイクル、３０サイクルいずれの場合にもスジの発生が全く見られなかった。
【００７１】
これは、現像ローラー３とトナー規制ローラー６との間の楔形状領域１１に堆積していたトナー７が両ローラーの回転により、より一層良好に上流側に吐き戻されたと考えられるからである。
【００７２】
そこで、実験条件３のもとで、耐久試験を行うことにした。
【００７３】
すなわち、現像ローラー３を１分間作像方向に空回しした後、逆回転を０．１秒間行った後、約１０秒間停止させることを１サイクルとした。プロセススピードはＡ４ペーパーで１分間２０枚とした。これを５０００サイクル繰り返した。
【００７４】
耐久枚数は（空回しの時間）÷（２０／分）の計算により、耐久枚数を換算により求めた。
【００７５】
この耐久テスト実験は、感光体ベルトに一様なバイアスを印加し、約２％のトナーを消費しながら行った。
【００７６】
これによって、リコー株式会社、Ｉｐｓｉｏ Ｃｏｌｏｒ ５０００では保ち得なかった現像ローラー３のトナー薄層の安定性について、１０万枚相当まで達成することが確認された。
【００７７】
次に、トナー規制ローラー６の連れ回りを高めるための実験を行った。
【００７８】
ここでは、トナー規制ローラー６の製作には、円筒状芯金６ａの外周に所定ゴム硬度の弾性層６ｂを形成し、弾性層６ｂの材料としてＮＢＲ（ニトロル−ブタジエンゴム）を用いた。その弾性層６ｂの外周に、以下に掲げる各樹脂を用いて表面層６ｃをスプレーコーティングにより形成した。その表面層６ｃの層厚はここでは２０μｍとした。
【００７９】
なお、弾性層６ｂの形成材料としては、エチレンプロピレンゴム、ブタジエンゴム、スチレン−ブタジエンゴム、イソプレンゴム、エピクロルヒドリンゴム、シリコーンゴム、ウレタンゴム、フォーム等の公知のエラストマー（ゴム）を用いても良い。
【００８０】
また、表面層６ｃのコーティング方法としては、スプレーコーティングによる他、ディップ法、ロールコート法等の公知のコーティング方法を用いても良い。この他、表面層６ｃを形成する材料をチューブ状に予め形成してその成形物を用いて弾性層６ｂを被覆する方法を採用することもできる。
【００８１】
トナー規制ローラー６には、比較例１、比較例２、試験例１、試験例２、試験例３の５種類を準備した。この比較例１、比較例２、試験例１、試験例２、試験例３は、弾性層６ｂに形成する表面層６ｃの材料をそれぞれ異ならせたものである。
【００８２】
比較例１は表面層６ｃの形成材料にアクリル樹脂を用い、比較例２は表面層６ｃの形成材料にフッ素樹脂を用い、試験例１では表面層６ｃの形成材料にフッ素樹脂を用いると共にフィラーとしてカーボンブラックを１５重量部加えたものであり、試験例２はフッ素樹脂／メラミン架橋体を用いると共にカーボンブラックを１５重量部加えたものであり、試験例３はフッ素樹脂／イソシアネート架橋体を用いると共にカーボンブラックを１５重量部加えたものである。
【００８３】
そのトナー規制ローラー６の表面層６ｃの現像ローラー３の表面層３ｂに対する静止摩擦係数（μｓ）は、比較例１のトナー規制ローラー６が０．３２、比較例２のトナー規制ローラー６が０．２０、試験例１のトナー規制ローラー６が０．３１、試験例２のトナー規制ローラー６が０．３０、試験例３のトナー規制ローラー６が０．３２であった。
【００８４】
なお、現像ローラー３の表面層３ｂとトナー規制ローラー６ｃとの間の静止摩擦係数μｓはオイラーベルト法により測定した。
【００８５】
すなわち、現像ローラー３の表面層３ｂを形成する塗料（ポリエステル樹脂とグアナミン硬化剤とＩＴＯとを分散した塗料）をポリエステルフィルム基板（ベース）に塗布して硬化させることにより、現像ローラー３の表面層３ｂと等価な表面層をポリエステルフィルム基板に形成して、摩擦試験用ベルトを作成した。その摩擦試験用ベルトの表面層に対する比較例１、比較例２、試験例１〜試験例３の各トナー規制ローラー６の表面層６ｃの静止摩擦係数（μｓ）を測定した。
【００８６】
そして、比較例１、比較例２、試験例１〜試験例３のトナー規制ローラー６を現像装置に組み込んで現像ローラー３に作像時の回転方向とは逆方向の回転を与え時の各トナー規制ローラー６の連れ回り動作を確認した。
【００８７】
また、１００、０００枚の画像出力実験を行い、各トナー規制ローラー６へのトナー７の付着、トナー薄層の状況、出力画像の観察を行った。
【００８８】
その比較結果を表１に示す。
【００８９】
【表１】

【００９０】
表１の結果から、現像ローラー３の表面層３ｂに対するトナー規制ローラー６の表面層６ｃの静止摩擦係数が０．３以上の場合には、トナー規制ローラー６が現像ローラー３に従動回転することが理解できる。
【００９１】
比較例２のトナー規制ローラー６は、現像ローラー３の回転に対してスリップが発生したことから、トナー規制ローラー６の表面層６ｃの同一箇所が常時現像ローラー３の表面層３ｂに接触し、これによって、現像ローラー３への薄層形成が行われたため、トナー規制ローラー６にトナー７が凝集、固着し、トナー薄層のスジが生じ、結果として画像出力を行ったときに、スジ状の濃度むらが発生している。
【００９２】
比較例１では、現像ローラー３の逆回転に伴ってトナー規制ローラー６が従動回転しているにもかかわらず、１００，０００枚の画像出力実験の結果、トナー７の凝集固着が発生しているが、これは、トナー７のアクリル樹脂に対する離型性が良好ではないことによる。
【００９３】
これに対して、フッ素樹脂を材料を用いて表面層６ｃを形成したトナー規制ローラー６の場合には、フッ素樹脂の離型性がアクリル樹脂よりも良好であるので、現像ローラー３の回転に伴って従動回転する試験例１〜試験例３の場合には、トナー規制ローラー６へのトナー７の凝集・固着は見られなかった。
【００９４】
また、試験例１〜試験例３のトナー規制ローラー６の場合に固着が見られなかったのは、表面層６ｃの形成材料に用いるフッ素樹脂にフィラーとしてカーボンブラックを添加して、静止摩擦係数が高められているからである。
【００９５】
なお、フッ素樹脂に添加するフィラーとしては、カーボンブラックの他に、シリカ、金属粉、金属酸化物（例えば、酸化チタン、ＩＴＯ処理チタン）、これらの混合物を用いても良い。
【００９６】
従って、表面層６ｃの形成材料に離型性が良好でかつそれ自体では静止摩擦係数の小さなフッ素樹脂を用いた場合でも、フィラーをフッ素樹脂に添加することにより、表面層６ｃの静止摩擦係数を増大させることができ、従って、表面層６ｃの形成材料にフッ素樹脂を用いた場合でも、フッ素樹脂にカーボンブラックを加えることにより、トナー７に対する離型性が良好でかつ従動性の良好なトナー規制ローラー６を製作することができる。
【００９７】
ところで、作像時に現像ローラー３が回転するのに対して、トナー規制ローラー６はその回転が停止された状態でトナー薄層を現像ローラー３の表面層３ｂに形成する役割を果たすため、作像時における現像ローラー３の周速とトナー規制ローラーとの周速との差が大きく、トナー規制ローラー６の表面層６ｃの摩耗量が大きくなると考えられる。そこで、比較例２、試験例１〜試験例３の各トナー規制ローラー６について、１０万枚画像出力（プリント）後の表面層６ｃの摩耗量を測定してみた。
【００９８】
その結果、比較例２のものの表面層６ｃの摩耗量は１４μｍ、試験例１のものの表面層６ｃの摩耗量は１０μｍ、試験例２のものの表面層６ｃの摩耗量は２μｍ、試験例３のものの表面層６ｃの摩耗量は３μｍであった。比較例２のものでは、表面層６ｃの摩耗量が１４μｍであるので、単純に考えて１,０００，０００枚のプリントに耐え得る現像装置を製作するのに、表面層６ｃの層厚を１４０μｍとしなければならず、このような現像装置を製作することにすると、材料費が嵩み、生産性が低下すると共に、コストアップとなる。
【００９９】
これに対して、試験例２に示すように、表面層６ｃをメラミン架橋剤でフッ素樹脂を架橋したもの、イソシアネート架橋剤でフッ素樹脂を架橋したものでは、著しく耐摩耗性が向上し、１０万枚画像出力（プリント）後の表面層６ｃの摩耗量は、２μｍ、３μｍであり、材料費が嵩むことなく、生産性が低下することなく現像装置１の耐久性の向上を図ることができる。
【０１００】
なお、メラミン架橋剤で架橋した試験例２のトナー規制ローラー６では、現像ローラー３へのトナー規制ローラー６の当接圧力により、１００,０００枚画像出力後に、表面層６にクラックが発生し、トナー規制ローラー６の表面層に微小なスジムラが生じ、従って、出力画像に微小なスジムラが発生した。これは、メラミン架橋剤によりフッ素樹脂を架橋した場合、表面層６ｃの可撓性が低下すると考えられるからである。これに対して、イソシアネート架橋剤で架橋した試験例３のトナー規制ローラー６では、１００,０００枚画像出力後でも、表面層６ｂにクラックが発生しなかった。これは、可撓性を損なうことなく耐摩耗性を向上させることができたからであると考えられる。これは、フッ素樹脂末端の水酸基とイソシアネート化合物との付加反応によって生じるウレタン結合が柔軟性と耐摩耗性とに寄与が大きいことによるものである。
【０１０１】
トナー規制ローラー６の現像ローラー３への弾発付勢力Ｆは、この弾発付勢力Ｆを図５に示すように、現像ローラー３の回転中心Ｏ１とトナー規制ローラー６の回転中心Ｏ２とを結ぶ線分Ｌに沿う方向の方向成分Ｆ１と、この方向成分Ｆ１と直交する直交方向成分Ｆ２とに分解したとき、直交方向成分Ｆ２が現像ローラー３とトナー規制ローラー６との接触箇所において非作像時のトナー規制ローラー６の従動回転方向（矢印Ｃ方向）に向いているのが望ましい。
【０１０２】
このように構成すると、トナー規制ローラー６の摩擦力が小さくともトナー規制ローラー６を現像ローラー３により一層確実に従動させて回転させることができる。
【０１０３】
また、図６に示すように、弾性層６ｂを研削砥石１２で研削すると、図７に示すように、トナー規制ローラー６の弾性層６ｂの表面に目６ｊが生じるが、このトナー規制ローラー６の弾性層６ｂの順目方向に抗する方向に非作像時の現像ローラー３が回転されるようにしてトナー規制ローラー６を現像装置１に組み込む構成とすれば、作像時にはトナー規制ローラー６の現像ローラー３に対する静止摩擦係数を小さくできるため、作像時の現像ローラー３の摩擦発熱を抑制でき、トナー７が現像ローラー３に溶着するのを低減できる。
【０１０４】
その一方、非作像時には、トナー規制ローラー６の現像ローラー３に対する摩擦力を増大させることができるため、非作像時のトナー規制ローラー６の従動回転の確実化を図ることができる。
【０１０５】
また、トナー規制ローラー６の製造時に生じる目６ｊを有効に利用して摩擦力を調節できる。
【０１０６】
更に、図８（ａ）に示すように、弾性層６ｂの外径が円筒状芯金６ａの延びる方向回転軸部６ｄ、６ｄ側から中央に向かって滑らかに直径が増大するクラウン（太鼓）形状とすれば、現像ローラー３に対するトナー規制ローラー６の当接圧力のより一層の均一化を図ることができる。
【０１０７】
その弾性層６ｂを長手方向に沿って断面下ときの輪郭線の形状は、二次曲線又は円弧曲線であることが望ましい。
【０１０８】
すなわち、図８（ｂ）に示すように、例えば、輪郭線の形状が角部ｋ１〜ｋ４を有する弾性層６ｂからなるトナー規制ローラー６の回転軸部６ｄの両側を付勢して現像ローラー３に当接させることにすると、角部ｋ１〜ｋ４の部分のみが現像ローラー３に当接し、角部ｋ１〜ｋ４以外の部分は凹んで現像ローラー３に当接しないが、図８（ａ）に示すような滑らかな輪郭線を有する曲線に形成すると、現像ローラー３の長手方向全ての箇所に弾性層６ｂが均等に当接することになり、当接箇所の均質化を図ることができる。なお、その輪郭線の形状は、図９（ａ）に示すように、トナー規制ローラー６の輪郭線の形状は、弾性層６ｂの長手方向の寸法Ｌ１と高さＨ１とを適宜考慮して実験により定めれば良い。
【０１０９】
【発明の効果】
請求項１、請求項２に記載の発明によれば、現像ローラーが非作像時に作像時の回転方向とは逆方向に回転され、現像ローラーとトナー規制部材との間の楔形状領域（ニップ部）に堆積したトナー凝集粉が上流側に押し戻されるので、現像ローラーの表面、トナー規制ローラーの表面を傷つけることなく、また、トナーを飛散させることなく、トナー凝集粉を楔形状領域から除去できる。
特に、トナー規制ローラーがその回転により現像ローラーと協働して楔形状領域に堆積したトナーを上流側に吐き出すので、現像装置の耐久性が向上する。
【０１１１】
請求項２に記載の発明によれば、トナー規制ローラーを現像ローラーの非作像時の回転に従動回転させるので、小型化、耐久性の向上を図ることができる。
【０１１２】
請求項３に記載の発明によれば、弾発付勢力の直交方向成分が現像ローラーとトナー規制ローラーとの接触箇所で、非作像時のトナー規制ローラーの従動回転方向に向いているので、トナー規制ローラーの静止摩擦係数が小さい場合でも、トナー規制ローラーを確実に従動回転させることができる。
【０１１３】
請求項４に記載の発明によれば、作像時にはトナー規制ローラーの現像ローラーに対する静止摩擦係数を小さくすることができるため、作像時の現像ローラーの摩擦発熱を抑制できると共に、非作像時にはトナー規制ローラーの現像ローラーに対する静止摩擦係数を増大させることができるため、非作像時のトナー規制ローラーの従動回転の確実化を図ることができる。
【０１１４】
請求項５、請求項６に記載の発明によれば、トナー規制ローラーを現像ローラーに均一に当接させることができ、安定したニップ幅を得ることができる。
【０１２３】
請求項７に記載の発明によれば、トナー規制ローラーの製造時に生ずる目を有効に利用して現像ローラーに対する摩擦力を調節できる。
【図面の簡単な説明】
【図１】 本発明に係わる現像装置の概略構成を示す断面図である。
【図２】 図１に示す現像装置のトナー規制ローラーと現像ローラーとの関係を示す概略図である。
【図３】 図１に示すトナー規制ローラーの拡大図である。
【図４】 図２に示すワンウエイクラッチの一例を示す模式図である。
【図５】 トナー規制ローラーの現像ローラーに対する弾発付勢方向を示す説明図である。
【図６】 トナー規制ローラーの製造方法の一例を示す模式図である。
【図７】 トナー規制ローラーの外周面の順目方向と現像ローラーの回転方向との関係を説明するための説明図である。
【図８】 トナー規制ローラーの弾性層の輪郭線の形状を説明するための図であって、（ａ）は弾性層の輪郭線の形状が円弧のトナー規制ローラを示し、（ｂ）は弾性層の輪郭線の形状が角部を有するトナー規制ローラーを示す。
【符号の説明】
１…現像装置
３…現像ローラー
４…トナー供給ローラー
６…トナー規制部材（トナー規制ローラー）
７…トナー[0001]
BACKGROUND OF THE INVENTION
  The present invention is in contact with the image bearing member on which the electrostatic latent image is formed and contacting the developing roller, which is rotated at the time of image formation in order to make the electrostatic latent image visible by attaching toner. And a toner supply roller that supplies the toner to the developing roller, and a toner regulating member that regulates the amount of toner adhering to the developing roller and forms a thin toner layer on the developing roller.Equipment, andIncorporating the toner regulating roller into the developing deviceOn the wayRelated.
[0002]
[Prior art]
Conventionally, a developing device such as a one-component developing device is rotated at the time of image formation in order to make the electrostatic latent image visible by contacting the image carrier on which the electrostatic latent image is formed and attaching toner. A developing roller, a toner supply roller that is disposed in contact with the developing roller and supplies toner to the developing roller, and a toner regulating member that forms a thin toner layer on the developing roller by regulating the amount of toner adhering to the developing roller Are known.
[0003]
[Problems to be solved by the invention]
In this type of one-component developing device, in order to prevent the occurrence of fog, ghost, etc. and maintain the image quality, it is essential to uniformly charge the toner at a high voltage. The selection of the surface material of the part is important.
[0004]
In recent years, due to environmental problems, it has been required to extend the life of a one-component developing device. The surface of each component is the surface of a toner regulating member, the occurrence of toner aggregation / fixation on the surface of the developing roller, and the developing roller. It is necessary to cope with deterioration due to scratches, cracks, peeling, etc. on the surface and the surface of the toner regulating member. Furthermore, there is a need to be able to cope with internal contamination of the image forming apparatus due to toner leakage and scattering for long-term use as a one-component developing device.
[0005]
The reason why the toner agglomerates and adheres to the toner regulating member and the developing roller is thought to be because the toner is clogged in the wedge-shaped region having a wedge-shaped cross section existing at the contact portion of both parts.
[0006]
As a means for preventing the occurrence of toner aggregation, Japanese Patent Laid-Open No. 5-142938 discloses a configuration in which a mechanism for vibrating a flat plate (blade) shaped toner regulating member is provided. There are disadvantages that a large number of components are required, and the developing unit is very complicated and large. Further, in this blade system, since the contact portion with the developing roller is limited, the contact portion is mechanically worn, and it is difficult to extend the life of the developing device due to deterioration due to wear.
[0007]
As means for preventing the occurrence of toner aggregation and fixation, Japanese Patent Application Laid-Open No. 11-84867 proposes a configuration in which the toner regulating member is constituted by a toner regulating roller, and the toner regulating roller is rotated at a predetermined timing during non-development. Has been.
[0008]
In the developing device disclosed in Japanese Patent Application Laid-Open No. 11-84867, since the contact portion between the developing roller and the toner regulating roller is increased as compared with a developing device in which the toner regulating member is a blade type, the surface of the toner regulating roller, This is effective in preventing mechanical wear of the developing roller.
[0009]
However, the developing roller always rotates in a fixed direction during development and non-development, and the toner regulating roller rotates in the direction opposite to the rotation direction of the developing roller, but the toner accumulated in the wedge-shaped region This is a direction in which the agglomerated powder moves to the downstream, and pressure is applied to the toner agglomerated powder, and the surface of the developing roller and the surface of the toner regulating roller are likely to be scratched, which is not preferable as a measure for preventing the occurrence of toner agglomeration and adhesion.
[0010]
Accordingly, an image forming apparatus using this type of developing device has a limit of about 6,000 sheets as the number of image formation, and it is insufficient to expect a long life.
[0011]
  The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent toner aggregation and sticking while extending life.Developing device and toner thereofIncorporation of regulated rollers into development equipmentmethodIt is to provide.
[0012]
[Means for Solving the Problems]
  The developing device according to claim 1, wherein the developing roller is rotated at the time of image formation in order to contact the image carrier on which the electrostatic latent image is formed and to attach the toner to visualize the electrostatic latent image; A toner supply roller that is disposed so as to contact the developing roller and supplies the toner to the developing roller, and a toner regulation that forms a thin toner layer on the developing roller by regulating the amount of toner adhering to the developing roller In a developing device having a member,
  The developing rollerNon-imagingThe toner restricting member is a toner restricting roller, the toner restricting roller is stopped during the image forming, andNon-imagingOf the developing rollerDuring non-imagingIt is characterized by being configured to rotate in the direction opposite to the rotation direction.
  According to a second aspect of the present invention, there is provided the developing device, wherein the toner regulating roller includes a mechanism that is rotated by a frictional resistance with the developing roller.
  The developing device according to claim 3, wherein the toner regulating roller includes a cylindrical cored bar having rotation shaft portions at both ends, and an elastic layer formed on an outer periphery of the cylindrical cored bar, and the toner regulating roller includes A direction component along a line segment that is elastically urged toward the developing roller and connects the elastic urging force between the rotation center of the developing roller and the rotation center of the toner regulating roller, and an orthogonal direction component orthogonal to the direction component. When the image is decomposed, the orthogonal direction component is directed to the driven rotation direction of the toner regulating roller at the time of non-image formation at a contact portion between the developing roller and the toner regulating roller.
  The developing device according to claim 4, wherein the developing roller is rotated at the time of image formation in order to contact the image carrier on which the electrostatic latent image is formed and to attach the toner to visualize the electrostatic latent image; A toner supply roller that is disposed so as to contact the developing roller and supplies the toner to the developing roller, and a toner regulation that forms a thin toner layer on the developing roller by regulating the amount of toner adhering to the developing roller In a developing device having a member,
  The toner regulating member is a toner regulating roller;The developing rollerNon-imagingThe toner is rotated in a direction opposite to the rotation direction at the time of image formation, and the coefficient of static friction of the toner regulating roller with respect to the rotation direction of the development roller at the time of non-image formation has It is characterized by being larger than the coefficient of static friction of the regulating roller.
  The developing device according to claim 5 is characterized in that the hardness of the toner regulating roller is lower than the hardness of the developing roller.
  According to a sixth aspect of the present invention, the toner regulating roller includes a cylindrical metal core made of metal and an elastic layer formed on the outer periphery of the cylindrical metal core.
  8. The method of incorporating a toner regulating roller into a developing device according to claim 7, wherein the electrostatic latent image is visualized by contacting the image carrier on which the electrostatic latent image is formed and attaching toner. A developing roller that is rotated at times and a toner supply roller that is disposed in contact with the developing roller and supplies the toner to the developing roller;Non-imagingIn addition, the toner is incorporated in a developing device that is rotated in a direction opposite to the rotation direction at the time of image formation, and the amount of toner that contacts the developing roller and adheres to the developing roller is regulated so that the toner on the developing roller is thinned. A toner regulating roller used to form a layer is incorporated into the developing device, the toner regulating roller comprising a metal cylindrical cored bar and an elastic layer formed on the outer periphery thereof, The elastic layer is ground with a grinding wheel, and the toner regulating roller is incorporated in the developing device such that the developing roller at the time of non-image formation is rotated in a direction against the forward direction of the elastic layer by the grinding wheel. It is characterized by that.
[0015]
  Claims 1 and 2According to the invention described in the above, the toner aggregation powder accumulated in the wedge-shaped region between the developing roller and the toner regulating member is upstream when the developing roller is rotated in a direction opposite to the rotation direction at the time of image formation when non-image formation is performed. Therefore, the toner agglomerated powder can be removed from the wedge-shaped region without damaging the surface of the developing roller and the surface of the toner regulating roller.
[0017]
  Claim 3According to the invention described in the above, since the orthogonal direction component of the elastic urging force is directed to the driven rotation direction of the toner regulating roller at the time of non-image formation at the contact portion between the toner regulating roller and the toner driving roller, the toner regulating roller Even when the static friction coefficient of the toner is small, the toner regulating roller can be surely driven and rotated.
[0019]
  Claim 4According to the invention described above, since the coefficient of static friction of the toner regulating roller with respect to the developing roller during image formation can be reduced, the frictional heat generation of the developing roller during image formation can be suppressed, and the toner regulating roller during non-image forming Since the coefficient of static friction with respect to the developing roller can be increased, the driven rotation of the toner regulating roller during non-image formation can be ensured.
[0022]
  Claims 5 and 6According to the invention described in (1), the toner regulating roller can be uniformly brought into contact with the developing roller, and a stable nip width can be obtained.
[0043]
  Claim 7According to the invention described in (3), the friction force against the developing roller can be adjusted by effectively utilizing the eyes generated when the toner regulating roller is manufactured.
[0046]
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1, reference numeral 1 denotes a one-component developing device. In the housing 2 of the developing device 1, a developing roller 3, a toner supply roller 4, a toner conveying stirring member 5, and a toner regulating roller 6 as a toner regulating member are provided, and 7 is toner.
[0047]
The developing roller 3 is composed of an aluminum cylinder having a diameter of 26 mm. As shown in FIG. 2, a rotating shaft 3a is formed at both ends of the aluminum cylinder. In FIG. 2, reference numeral 3c denotes a bearing. A surface layer 3b having a thickness of about 10 μm is formed on the surface of the aluminum cylinder. The surface roughness of the developing roller 3 is a smooth surface of 2 μm or less according to the JIS Rz standard.
[0048]
The surface layer 3b is formed by spraying a paint on the surface of an aluminum cylinder and curing it. As the coating material, one prepared by dispersing a polyester resin, a guanamine curing agent, and ITO as conductive particles is used.
[0049]
A guanamine curing agent is a substance containing an amino group and has a polarity opposite to that of a negatively charged toner. ITO is based on alumina powder, and the surface of the alumina powder is coated with indium-doped tin oxide.
[0050]
Since the toner regulating roller 6 has the developing roller 3 rigid, here, it is composed of an elastic roller. The hardness is lower than the hardness of the developing roller 3. Thereby, the durability of the developing roller 3 is relatively improved. Here, as shown in FIG. 3, the toner regulating roller 6 is coated with nitrile-butadiene rubber (NBR), epichlorohydrin rubber (polygon rubber), etc. on the outer periphery of a cylindrical core 6a made of stainless steel (JIS standard S45C). Thus, an elastic layer 6b was formed, and a surface layer 6c made of a fluororesin was formed on the surface of the elastic layer 6b by spray coating. The layer thickness of the surface layer 6c made of the fluororesin is 20 μm.
[0051]
Here, the reason for using the polar rubber is to increase the adhesive strength of the surface layer 6c to the elastic layer 6b and to prevent the peeling. As a result, it is possible to prevent the toner from being fogged onto the paper when the image is printed, and it is possible to form a good image with little background stain.
[0052]
It is desirable to connect the elastic layer 6b and the cylindrical cored bar 6a via an adhesive 6m. When the elastic layer 6b is bonded to the cylindrical cored bar 6a using the adhesive 6m in this way, peeling between the cylindrical cored bar 6a and the elastic layer 6b can be prevented, and the shape of the elastic layer 6b can be kept stable. . The adhesive 6m is preferably conductive. By making the adhesive 6m conductive, a good image with little background stain can be formed.
[0053]
The toner regulating roller 6 has rotating shaft portions 6d at both ends thereof. The rotary shaft portion 6d is rotatably supported on the inner cylinder 6f of the one-way clutch 6e shown in FIG. A ball 6h is provided between the inner cylinder 6f and the outer cylinder 6g of the one-way clutch 6e, and a biting protrusion 6i is provided. In the one-way clutch 6e, when the inner cylinder 6f is rotated in the direction of the arrow D, the ball 6h bites into the biting protrusion 6i and prevents the toner regulating roller 6 from rotating. When the inner cylinder 6f rotates in the direction opposite to the arrow D direction, the bit 6h and the biting protrusion 6i are released, and the toner regulating roller 6 is rotated smoothly. Here, the toner regulating roller 6 in the direction of the arrow D is rotated. The rotation in the direction opposite to the rotation corresponds to the rotation in the direction of arrow C shown in FIG. 1 (the driven rotation direction during non-image formation).
[0054]
The toner regulating roller 6 is urged by a pair of urging springs 8 in a direction (contact direction) in contact with the developing roller 3. Here, the biasing spring 8 is configured to bias the one-way clutch 6e.
[0055]
The developing roller 3 is rotated in the direction of arrow A shown in FIG. 1 at the time of image formation, so that the toner 7 is supplied from the upstream side 9 to the downstream side 10 of the toner. The developing roller 3 is rotated in a direction B opposite to the arrow A direction when the image is not formed. The toner regulating roller 6 stops rotating when the developing roller 3 rotates in the direction of arrow A shown in FIG. 1, and when the developing roller 3 rotates in the direction of arrow B, friction contact with the developing roller 3 causes an arrow C direction. It is driven and rotated.
[0056]
The toner regulating roller 6 can be forced to rotate in the opposite direction (arrow C direction) to the rotation direction (arrow B direction) of the developing roller 3 during non-image formation, but the configuration of the developing device 1 becomes complicated. Also, depending on the configuration of the drive gear, side effects such as banding may occur, so care must be taken.
[0057]
According to the developing device 1, the toner 7 formed by the developing roller 3 and the toner regulating roller 6 and accumulated in the wedge-shaped region 11 existing on the upstream side 9 of the toner 7 can be discharged back to the upstream side 9. Therefore, the wedge-shaped region 11 can be prevented from being clogged and fixed.
[0058]
The following comparative experiment was conducted on the developing device 1 as a preliminary test for confirming durability.
[0059]
Experimental condition 1: Under the condition that the toner regulating roller 6 is fixed, the developing roller 3 is continuously rotated in the image forming direction (arrow A direction) for 1 minute and then paused for 10 seconds. I went two ways.
[0060]
Experiment condition 2: Under the condition that the toner regulating roller 6 is fixed, the developing roller 3 is continuously rotated in the image forming direction for 1 minute, then reversed for 1 minute, and then rested for 10 seconds. And went two ways.
[0061]
Experimental condition 3: Under the condition that the toner regulating roller 6 is rotated (driven) in the rotation direction when the developing roller 3 is not imaged, the developing roller 3 is continuously rotated in the image forming direction for 1 minute, and then 1 Reversing for 10 minutes and then resting for 10 seconds were performed in two ways, 15 cycles and 30 cycles.
[0062]
Experimental condition 4: The developing roller 3 is continuously rotated in the image forming direction for 1 minute, and then paused for 10 seconds. During the pause, the position of the toner regulating roller 6 is forcibly changed. I went there.
[0063]
In this preliminary test, since the developing roller 3 is idled without consuming the toner 7, it is a severe test condition.
[0064]
As a result, the following results were obtained.
[0065]

In the above results, “streak” refers to a thin toner layer adhering to the surface of the developing roller 3 that can be visually observed.
[0066]
Under the experimental condition 1 where the developing roller 3 is not rotated in the direction opposite to the rotation direction (arrow A direction) at the time of image formation (arrow B direction) and the toner regulating roller 6 is not rotated, a “streak” is generated. However, in comparison with the other experimental conditions 2 to 4, innumerable streaks occurred when 30 cycles were repeated.
[0067]
Actually, under the experimental condition 1, an aggregate of toner 7 having a diameter of several millimeters was observed in the wedge-shaped region 11 between the developing roller 3 and the toner regulating roller 6.
[0068]
On the other hand, under experimental conditions 2 and 4, there was almost no difference in the superiority. However, clearly compared with experimental condition 1, the streaks of toner on the surface of the developing roller 3 were hardly observed. The result that the external appearance was favorable was obtained.
[0069]
This is presumably because the toner 7 accumulated in the wedge-shaped region 11 between the developing roller 3 and the toner regulating roller 6 was discharged back to the upstream side 9 during non-image formation.
[0070]
Under the experimental condition 3 in which the developing roller 3 is rotated in the opposite direction (arrow B direction) to the image forming rotation direction (arrow A direction) during non-image formation, and the toner regulating roller 6 is also driven to rotate. No streak was observed in any of 15 cycles and 30 cycles.
[0071]
This is because it is considered that the toner 7 accumulated in the wedge-shaped region 11 between the developing roller 3 and the toner regulating roller 6 is discharged more favorably upstream by the rotation of both rollers.
[0072]
Therefore, it was decided to perform an endurance test under the experimental condition 3.
[0073]
That is, after the developing roller 3 was idled in the image forming direction for 1 minute, the reverse rotation was performed for 0.1 second and then stopped for about 10 seconds as one cycle. The process speed was 20 sheets per minute with A4 paper. This was repeated 5000 cycles.
[0074]
The number of durable sheets was determined by converting the number of durable sheets by calculation of (empty turning time) / (20 / min).
[0075]
This durability test experiment was performed while applying a uniform bias to the photoreceptor belt and consuming about 2% of the toner.
[0076]
As a result, it was confirmed that the stability of the toner thin layer of the developing roller 3 that could not be maintained by Ricoh Co., Ltd., Ipsio Color 5000, was achieved up to 100,000 sheets.
[0077]
Next, an experiment for increasing the rotation of the toner regulating roller 6 was performed.
[0078]
Here, in manufacturing the toner regulating roller 6, an elastic layer 6b having a predetermined rubber hardness is formed on the outer periphery of the cylindrical cored bar 6a, and NBR (nitrol-butadiene rubber) is used as a material of the elastic layer 6b. A surface layer 6c was formed on the outer periphery of the elastic layer 6b by spray coating using the following resins. The layer thickness of the surface layer 6c is 20 μm here.
[0079]
As a material for forming the elastic layer 6b, a known elastomer (rubber) such as ethylene propylene rubber, butadiene rubber, styrene-butadiene rubber, isoprene rubber, epichlorohydrin rubber, silicone rubber, urethane rubber, foam, or the like may be used.
[0080]
As a method for coating the surface layer 6c, a known coating method such as a dip method or a roll coating method may be used in addition to spray coating. In addition, it is also possible to adopt a method in which the material for forming the surface layer 6c is formed in a tube shape in advance and the elastic layer 6b is covered with the molded product.
[0081]
For the toner regulating roller 6, five types of Comparative Example 1, Comparative Example 2, Test Example 1, Test Example 2, and Test Example 3 were prepared. In Comparative Example 1, Comparative Example 2, Test Example 1, Test Example 2, and Test Example 3, the material of the surface layer 6c formed on the elastic layer 6b is different.
[0082]
Comparative Example 1 uses an acrylic resin as a forming material for the surface layer 6c, Comparative Example 2 uses a fluororesin as a forming material for the surface layer 6c, and in Test Example 1 uses a fluororesin as a forming material for the surface layer 6c and serves as a filler. Carbon black was added at 15 parts by weight, Test Example 2 was a fluororesin / melamine crosslinked product and carbon black was added at 15 parts by weight, and Test Example 3 was a fluororesin / isocyanate crosslinked product. Carbon black is added at 15 parts by weight.
[0083]
The coefficient of static friction (μs) of the surface layer 6c of the toner regulating roller 6 with respect to the surface layer 3b of the developing roller 3 is 0.32 for the toner regulating roller 6 of Comparative Example 1, and is 0 for the toner regulating roller 6 of Comparative Example 2. 20. The toner regulation roller 6 of Test Example 1 was 0.31, the toner regulation roller 6 of Test Example 2 was 0.30, and the toner regulation roller 6 of Test Example 3 was 0.32.
[0084]
The static friction coefficient μs between the surface layer 3b of the developing roller 3 and the toner regulating roller 6c was measured by the Euler belt method.
[0085]
That is, a surface layer of the developing roller 3 is formed by applying a coating material (a coating material in which a polyester resin, a guanamine curing agent and ITO are dispersed) forming the surface layer 3b of the developing roller 3 to a polyester film substrate (base) and curing it. A surface layer equivalent to 3b was formed on the polyester film substrate to prepare a friction test belt. The static friction coefficient (μs) of the surface layer 6c of each toner regulating roller 6 of Comparative Example 1, Comparative Example 2, Test Example 1 to Test Example 3 with respect to the surface layer of the friction test belt was measured.
[0086]
Then, the toner regulating rollers 6 of Comparative Example 1, Comparative Example 2, and Test Examples 1 to 3 are incorporated in the developing device, and each toner when the developing roller 3 is rotated in a direction opposite to the rotation direction at the time of image formation is provided. The revolving operation of the regulation roller 6 was confirmed.
[0087]
Further, an image output experiment of 100,000 sheets was performed, and the adhesion of the toner 7 to each toner regulating roller 6, the state of the toner thin layer, and the output image were observed.
[0088]
The comparison results are shown in Table 1.
[0089]
[Table 1]

[0090]
From the results of Table 1, when the static friction coefficient of the surface layer 6c of the toner regulating roller 6 with respect to the surface layer 3b of the developing roller 3 is 0.3 or more, the toner regulating roller 6 may be driven to rotate by the developing roller 3. Understandable.
[0091]
Since the toner regulating roller 6 of Comparative Example 2 slipped with respect to the rotation of the developing roller 3, the same portion of the surface layer 6 c of the toner regulating roller 6 always contacts the surface layer 3 b of the developing roller 3. As a result, a thin layer was formed on the developing roller 3, so that the toner 7 aggregated and fixed on the toner regulating roller 6, resulting in streaks of the toner thin layer. Unevenness has occurred.
[0092]
In Comparative Example 1, although the toner regulating roller 6 is driven to rotate with the reverse rotation of the developing roller 3, as a result of an image output experiment of 100,000 sheets, the toner 7 is agglomerated and fixed. However, this is because the releasability of the toner 7 with respect to the acrylic resin is not good.
[0093]
On the other hand, in the case of the toner regulating roller 6 in which the surface layer 6c is formed using a fluororesin material, the release property of the fluororesin is better than that of the acrylic resin. In the case of Test Example 1 to Test Example 3 in which the toner rotates, the toner 7 does not aggregate or adhere to the toner regulating roller 6.
[0094]
Further, in the case of the toner regulating roller 6 of Test Example 1 to Test Example 3, no sticking was observed because carbon black was added as a filler to the fluororesin used for the material for forming the surface layer 6c, and the static friction coefficient was Because it is raised.
[0095]
In addition to carbon black, silica, metal powder, metal oxide (for example, titanium oxide, ITO-treated titanium), or a mixture thereof may be used as the filler added to the fluororesin.
[0096]
Therefore, even when a fluororesin having a good releasability and a small static friction coefficient is used as the material for forming the surface layer 6c, the static friction coefficient of the surface layer 6c can be reduced by adding a filler to the fluororesin. Therefore, even when a fluororesin is used as a material for forming the surface layer 6c, by adding carbon black to the fluororesin, toner regulation with good releasability with respect to the toner 7 and good followability can be achieved. The roller 6 can be manufactured.
[0097]
By the way, while the developing roller 3 rotates during image formation, the toner regulating roller 6 plays a role of forming a toner thin layer on the surface layer 3b of the developing roller 3 in a state where the rotation is stopped. It is considered that the difference between the peripheral speed of the developing roller 3 and the peripheral speed of the toner regulating roller at that time is large, and the wear amount of the surface layer 6c of the toner regulating roller 6 is increased. Therefore, the amount of wear of the surface layer 6c after 100,000 sheets of image output (printing) was measured for each toner regulating roller 6 of Comparative Example 2 and Test Examples 1 to 3.
[0098]
As a result, the wear amount of the surface layer 6c of Comparative Example 2 was 14 μm, the wear amount of the surface layer 6c of Test Example 1 was 10 μm, the wear amount of the surface layer 6c of Test Example 2 was 2 μm, and that of Test Example 3 The amount of wear of the surface layer 6c was 3 μm. In the comparative example 2, since the wear amount of the surface layer 6c is 14 μm, the thickness of the surface layer 6c is 140 μm in order to manufacture a developing device that can withstand 1,000,000 prints simply. If such a developing device is manufactured, the material cost increases, the productivity decreases, and the cost increases.
[0099]
On the other hand, as shown in Test Example 2, when the surface layer 6c is obtained by cross-linking a fluororesin with a melamine cross-linking agent, or when the fluororesin is cross-linked with an isocyanate cross-linking agent, the wear resistance is remarkably improved. The wear amount of the surface layer 6c after the sheet image output (printing) is 2 μm and 3 μm, and the durability of the developing device 1 can be improved without increasing the material cost and without decreasing the productivity.
[0100]
In the toner regulating roller 6 of Test Example 2 crosslinked with a melamine crosslinking agent, the surface layer 6 cracks after outputting 100,000 sheets due to the contact pressure of the toner regulating roller 6 to the developing roller 3. Fine streaks occurred on the surface layer of the toner regulating roller 6, and therefore fine streaks occurred in the output image. This is because the flexibility of the surface layer 6c is considered to decrease when the fluororesin is crosslinked with a melamine crosslinking agent. On the other hand, in the toner regulating roller 6 of Test Example 3 crosslinked with an isocyanate crosslinking agent, no crack was generated in the surface layer 6b even after outputting 100,000 sheets of images. This is considered to be because the wear resistance could be improved without impairing flexibility. This is because the urethane bond generated by the addition reaction between the hydroxyl group at the terminal of the fluororesin and the isocyanate compound greatly contributes to flexibility and wear resistance.
[0101]
The elastic biasing force F of the toner regulating roller 6 to the developing roller 3 connects the rotational center O1 of the developing roller 3 and the rotational center O2 of the toner regulating roller 6 as shown in FIG. When the direction component F1 in the direction along the line segment L and the orthogonal direction component F2 orthogonal to the direction component F1 are decomposed, the orthogonal direction component F2 is not imaged at the contact point between the developing roller 3 and the toner regulating roller 6. It is desirable that the toner restricting roller 6 is oriented in the driven rotation direction (arrow C direction).
[0102]
If comprised in this way, even if the frictional force of the toner control roller 6 is small, the toner control roller 6 can be driven and rotated more reliably by the developing roller 3.
[0103]
As shown in FIG. 6, when the elastic layer 6 b is ground with the grinding wheel 12, eyes 6 j are formed on the surface of the elastic layer 6 b of the toner regulating roller 6 as shown in FIG. 7. If the toner restricting roller 6 is incorporated in the developing device 1 so that the developing roller 3 at the time of non-image formation is rotated in a direction against the forward direction of the elastic layer 6b, the toner restricting roller 6 of the toner restricting roller 6 is formed at the time of image formation. Since the coefficient of static friction with respect to the developing roller 3 can be reduced, frictional heat generation of the developing roller 3 during image formation can be suppressed, and the welding of the toner 7 to the developing roller 3 can be reduced.
[0104]
On the other hand, since the frictional force of the toner regulating roller 6 against the developing roller 3 can be increased during non-image formation, the driven rotation of the toner regulating roller 6 during non-image formation can be ensured.
[0105]
Further, the frictional force can be adjusted by effectively using the eyes 6j generated when the toner regulating roller 6 is manufactured.
[0106]
Further, as shown in FIG. 8A, the outer diameter of the elastic layer 6b is a crown (drum) shape in which the diameter smoothly increases from the side of the rotating shafts 6d and 6d extending in the cylindrical cored bar 6a toward the center. Then, the contact pressure of the toner regulating roller 6 with respect to the developing roller 3 can be made more uniform.
[0107]
The shape of the contour line when the elastic layer 6b is sectioned along the longitudinal direction is preferably a quadratic curve or an arc curve.
[0108]
That is, as shown in FIG. 8B, for example, the developing roller 3 is energized by urging both sides of the rotating shaft portion 6d of the toner regulating roller 6 formed of an elastic layer 6b whose contour shape has corner portions k1 to k4. 8A, only the corners k1 to k4 are in contact with the developing roller 3, and the portions other than the corners k1 to k4 are recessed and do not contact the developing roller 3, but FIG. If it forms in the curve which has a smooth outline as shown, the elastic layer 6b will contact | abut uniformly to all the locations of the developing roller 3 in the longitudinal direction, and the contact location can be homogenized. As shown in FIG. 9A, the contour shape of the toner regulating roller 6 is determined by appropriately considering the length L1 and the height H1 of the elastic layer 6b in the longitudinal direction. It may be determined by
[0109]
【The invention's effect】
  Claims 1 and 2According to the invention described in the above, the toner accumulated in the wedge-shaped region (nip portion) between the developing roller and the toner regulating member is rotated when the developing roller is rotated in the direction opposite to the rotation direction during the non-image forming. Since the aggregated powder is pushed back to the upstream side, the toner aggregated powder can be removed from the wedge-shaped region without damaging the surface of the developing roller and the surface of the toner regulating roller and without scattering the toner.
  In particular, since the toner regulating roller cooperates with the developing roller by the rotation and discharges the toner accumulated in the wedge-shaped region to the upstream side, the durability of the developing device is improved.
[0111]
  Claim 2According to the invention described in (1), since the toner regulating roller is driven to rotate following the rotation of the developing roller during non-image formation, it is possible to reduce the size and improve the durability.
[0112]
  Claim 3According to the invention described in the above, since the orthogonal direction component of the elastic urging force is directed to the driven rotation direction of the toner restriction roller at the time of non-image formation at the contact portion between the developing roller and the toner restriction roller, the toner restriction roller Even when the static friction coefficient of the toner is small, the toner regulating roller can be surely driven and rotated.
[0113]
  Claim 4According to the invention described above, since the coefficient of static friction of the toner regulating roller with respect to the developing roller during image formation can be reduced, the frictional heat generation of the developing roller during image formation can be suppressed, and the toner regulating roller during non-image forming Since the coefficient of static friction with respect to the developing roller can be increased, the driven rotation of the toner regulating roller during non-image formation can be ensured.
[0114]
  Claims 5 and 6According to the invention described in (1), the toner regulating roller can be uniformly brought into contact with the developing roller, and a stable nip width can be obtained.
[0123]
  Claim 7According to the invention described in (3), the friction force against the developing roller can be adjusted by effectively utilizing the eyes generated when the toner regulating roller is manufactured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic configuration of a developing device according to the present invention.
FIG. 2 is a schematic diagram showing a relationship between a toner regulating roller and a developing roller of the developing device shown in FIG.
FIG. 3 is an enlarged view of the toner regulating roller shown in FIG.
4 is a schematic diagram showing an example of a one-way clutch shown in FIG. 2. FIG.
FIG. 5 is an explanatory diagram showing a direction of urging and energizing a toner regulating roller with respect to a developing roller.
FIG. 6 is a schematic diagram illustrating an example of a method for manufacturing a toner regulating roller.
FIG. 7 is an explanatory diagram for explaining the relationship between the forward direction of the outer peripheral surface of the toner regulating roller and the rotation direction of the developing roller.
8A and 8B are diagrams for explaining the shape of the contour line of the elastic layer of the toner regulating roller, where FIG. 8A shows the toner regulating roller whose contour shape of the elastic layer is an arc, and FIG. The shape of the outline of a layer shows the toner control roller which has a corner | angular part.
[Explanation of symbols]
1 ... Developing device
3 ... Developing roller
4 ... Toner supply roller
6. Toner regulating member (toner regulating roller)
7. Toner

Claims (7)

A developing roller that is rotated at the time of image formation to contact the image carrier on which the electrostatic latent image is formed and to attach the toner to visualize the electrostatic latent image, and to be in contact with the developing roller. A toner supply roller that supplies the toner to the development roller; and a toner regulation member that regulates the amount of toner adhering to the development roller and forms a thin toner layer on the development roller.
The developing roller to the rotating direction during the image formation at the time of non-image formation is rotated in the reverse direction, the toner regulating member is a toner regulating roller, the toner regulating roller is stopped rotating when the image forming and the non A developing device, wherein the developing roller is configured to rotate in a direction opposite to a rotation direction of the developing roller during non-image formation during image formation.   The developing device according to claim 1, wherein the toner regulating roller includes a mechanism that is rotated by frictional resistance with the developing roller.   The toner regulating roller includes a cylindrical cored bar having a rotating shaft at both ends, and an elastic layer formed on an outer periphery of the cylindrical cored bar, and the toner regulating roller is elastically biased toward the developing roller. When the elastic urging force is decomposed into a direction component along a line connecting the rotation center of the developing roller and the rotation center of the toner regulating roller and an orthogonal direction component orthogonal to the direction component, the orthogonal direction component 3. The developing device according to claim 2, wherein the developing device is directed to a driven rotation direction of the toner regulating roller at the time of non-image formation at a contact portion between the developing roller and the toner regulating roller. A developing roller that is rotated at the time of image formation to contact the image carrier on which the electrostatic latent image is formed and to attach the toner to visualize the electrostatic latent image, and to be in contact with the developing roller. A toner supply roller that supplies the toner to the development roller; and a toner regulation member that regulates the amount of toner adhering to the development roller and forms a thin toner layer on the development roller.
The toner regulating member is a toner regulating roller, the developing roller and the rotation direction when the imaging at the time of non-image formation is rotated in the reverse direction, the toner regulating relative rotation direction of the developing roller at the time of non-image formation A developing device, wherein a static friction coefficient of a roller is larger than a static friction coefficient of the toner regulating roller with respect to a rotation direction of the developing roller at the time of image formation.   The developing device according to claim 4, wherein a hardness of the toner regulating roller is lower than a hardness of the developing roller.   The developing device according to claim 5, wherein the toner regulating roller includes a metal cylindrical cored bar and an elastic layer formed on an outer periphery of the cylindrical cored bar. It is arranged to contact the image bearing member on which the electrostatic latent image is formed and to contact the developing roller and the developing roller which are rotated at the time of image formation in order to make the electrostatic latent image visible by attaching toner. A toner supply roller that supplies the toner to the developing roller, and the developing roller is incorporated in a developing device that rotates in a direction opposite to the rotation direction at the time of image formation during non-image formation, and the development A method for assembling a toner regulating roller used to form a thin toner layer on the developing roller by regulating the amount of toner that contacts the roller and adheres to the developing roller. The regulating roller is composed of a metal cylindrical cored bar and an elastic layer formed on the outer periphery thereof. The elastic layer is ground with a grinding wheel and resists the normal direction of the elastic layer by the grinding wheel. EMBEDDING to the developing device of the toner regulating roller, wherein the developing roller at the non-image formation is the toner regulating roller so as to be rotated are incorporated into the developing device.

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