JP2003098847A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JP2003098847A JP2003098847A JP2001288383A JP2001288383A JP2003098847A JP 2003098847 A JP2003098847 A JP 2003098847A JP 2001288383 A JP2001288383 A JP 2001288383A JP 2001288383 A JP2001288383 A JP 2001288383A JP 2003098847 A JP2003098847 A JP 2003098847A
- Authority
- JP
- Japan
- Prior art keywords
- toner
- transfer
- intermediate transfer
- adhesive force
- discharge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000463 material Substances 0.000 claims abstract description 34
- 239000002245 particle Substances 0.000 claims abstract description 7
- 239000000654 additive Substances 0.000 claims abstract description 4
- 230000000996 additive effect Effects 0.000 claims abstract description 4
- 239000011347 resin Substances 0.000 claims abstract description 4
- 229920005989 resin Polymers 0.000 claims abstract description 4
- 239000000853 adhesive Substances 0.000 claims description 26
- 230000001070 adhesive effect Effects 0.000 claims description 26
- 230000007547 defect Effects 0.000 abstract description 7
- 241000519995 Stachys sylvatica Species 0.000 description 22
- 238000010586 diagram Methods 0.000 description 12
- 239000010410 layer Substances 0.000 description 11
- 230000005684 electric field Effects 0.000 description 9
- 150000002500 ions Chemical class 0.000 description 4
- 239000011229 interlayer Substances 0.000 description 3
- 230000002265 prevention Effects 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 125000001153 fluoro group Chemical group F* 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
Landscapes
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Color Electrophotography (AREA)
- Developing Agents For Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は樹脂母粒子表面に外
添剤を被覆したトナーを用いた画像形成装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using a toner having resin mother particle surfaces coated with an external additive.
【０００２】[0002]
【従来の技術】カラー電子写真においては、感光体の摩
耗を防止し、カラー像の重ね合わせを容易にするために
中間転写体が使用されている。また、２０μｍ以下、あ
るいは１０μｍ以下の小粒径トナーを用いて解像度を向
上させることが行われている。しかし、小粒径トナーは
大粒径トナーに比して転写性が悪く、転写性向上のため
に転写電界を強めると絶縁破壊が発生し、像欠陥が生じ
てしまうという問題がある。この転写性はトナーと感光
体、トナーと中間転写体との間の付着力（ファンデルワ
ース力、鏡像力）に大きく依存している。2. Description of the Related Art In color electrophotography, an intermediate transfer member is used to prevent abrasion of a photoconductor and facilitate superposition of color images. Further, resolution is improved by using a toner having a small particle diameter of 20 μm or less, or 10 μm or less. However, the toner having a small particle size has poor transferability as compared with the toner having a large particle size, and if the transfer electric field is strengthened to improve the transfer property, dielectric breakdown occurs and an image defect occurs. This transfer property largely depends on the adhesive force (van der Worth force, mirror image force) between the toner and the photoconductor and between the toner and the intermediate transfer body.
【０００３】そこで、転写性を向上させるために、感光
体とトナーの付着力よりも中間転写体とトナーの付着力
を大きくし、さらに中間転写体とトナーの付着力よりも
トナーと転写枚葉紙との付着力を大きくするものが提案
されている（特表平５ー５０３３７号公報）。Therefore, in order to improve transferability, the adhesive force between the intermediate transfer member and the toner is made larger than the adhesive force between the photosensitive member and the toner, and further, the toner and the transfer sheet are separated from each other than the adhesive force between the intermediate transfer member and the toner. It has been proposed to increase the adhesive force to paper (Japanese Patent Publication No. 5-50337).
【０００４】[0004]
【発明が解決しようとする課題】ところで、中間転写体
から記録材へトナーを転写させる２次転写において、転
写残りが起こらないように転写バイアスを付与した時、
転写部において放電が起こり易く、記録材へ移行したト
ナーがこの放電により生じたイオンで逆極性に帯電し、
転写電界により中間転写体へ戻ってしまい（逆転写）、
中間転写体側では転写残りが生じ、一方、記録材上では
トナーが欠落して白抜けが発生し、重大画像欠陥を生ず
る場合がある。By the way, in the secondary transfer for transferring the toner from the intermediate transfer member to the recording material, when a transfer bias is applied so as not to cause a residual transfer,
Discharge is likely to occur in the transfer section, and the toner transferred to the recording material is charged to the opposite polarity by the ions generated by this discharge,
It returns to the intermediate transfer body due to the transfer electric field (reverse transfer),
Transfer residue may occur on the intermediate transfer body side, and on the other hand, toner may be missing on the recording material and white spots may occur, resulting in serious image defects.
【０００５】[0005]
【課題を解決するための手段】本発明は上記課題を解決
するためのもので、転写部における放電によって生ずる
白抜けを防止し、重大な画像欠陥が生じないようにす
る。そのために、請求項１の発明は、樹脂母粒子表面に
外添剤が被覆されたトナーを用いた中間転写体を有する
画像形成装置において、像担持体または中間転写体とト
ナーとの付着力を、トナー間の付着力よりも大きくした
ことを特徴とする。請求項２の発明は、画像形成装置
は、それぞれ像担持体を有する複数の画像形成ユニット
を備えたタンデム構成であることを特徴とする。SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and prevents white spots caused by discharge in a transfer portion and prevents serious image defects. Therefore, according to the invention of claim 1, in an image forming apparatus having an intermediate transfer body using a toner in which the surface of a resin mother particle is coated with an external additive, the adhesion force between the toner and the image carrier or the intermediate transfer body is improved. It is characterized in that it is larger than the adhesive force between the toners. The invention according to claim 2 is characterized in that the image forming apparatus has a tandem structure including a plurality of image forming units each having an image carrier.
【０００６】[0006]
【発明の実施の形態】以下、本発明の実施の形態を図面
を参照しつつ説明する。図１は本発明が適用される画像
形成装置の構成例を示す図である。感光体１の周囲に
は、帯電器２、露光ユニット３、ロータリ型現像器４が
配置され、ロータリ型現像器４で現像されたトナー像
は、感光体１と中間転写体５を挟んで対向配置された転
写帯電器６による転写電界で中間転写体５に転写され、
転写後の残留電位は除電ユニット７により除電され、再
度静電潜像が形成されてトナー現像が行われる。ロータ
リ型現像器４はイエロー現像器４Ｙ、マゼンタ現像器４
Ｍ、シアン現像器４Ｃ、ブラック現像器４Ｋを有し、各
色毎の現像器がロータリ式に間欠的に現像位置にもたら
されて現像を行い、トナー像は中間転写体５上で色重ね
される。中間転写体上のカラー画像は、中間転写体を挟
んでバックアップローラ８と対向する２次転写ローラ９
による転写電界により転写材１０に転写され、中間転写
材の残留トナーはクリーナ１１によりクリーニングされ
る。なお、画像形成装置としては、それぞれ像担持体を
有する複数の画像形成ユニットを備えたタンデム構成で
あってもよい。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of an image forming apparatus to which the present invention is applied. A charger 2, an exposure unit 3, and a rotary developing device 4 are arranged around the photoconductor 1, and the toner image developed by the rotary developing device 4 faces the photoconductor 1 with the intermediate transfer member 5 interposed therebetween. It is transferred to the intermediate transfer body 5 by the transfer electric field by the transfer charger 6 arranged,
The residual potential after the transfer is removed by the charge removing unit 7, an electrostatic latent image is formed again, and toner development is performed. The rotary developing device 4 includes a yellow developing device 4Y and a magenta developing device 4.
M, a cyan developing unit 4C, and a black developing unit 4K. The developing units for each color are rotary-typed intermittently brought to the developing position for development, and the toner image is color-superposed on the intermediate transfer member 5. It The color image on the intermediate transfer member is a secondary transfer roller 9 facing the backup roller 8 with the intermediate transfer member interposed therebetween.
Is transferred to the transfer material 10 by the transfer electric field, and the residual toner on the intermediate transfer material is cleaned by the cleaner 11. The image forming apparatus may have a tandem structure including a plurality of image forming units each having an image carrier.
【０００７】図２は転写ニップ通過前の放電による白抜
け発生を模式的に示す図である。中間転写体５上に付着
しているマイナス帯電トナー３０が、転写材１０と接触
するニップ部に接近し、中間転写体と転写材が所定間隔
になったとき、転写電界によって放電が生じ、放電によ
り生じたイオンで転写材に面した最表層のトナーがプラ
ス帯電（もしくは低帯電化）する傾向がある。例えば、
転写材に面した最表層のトナー３１がプラス帯電（もし
くは低帯電化）した場合を考えると、プラス帯電（もし
くは低帯電化）したトナーは中間転写体側へ引きつけら
れて記録材へ移行しにくくなり、ニップ部通過後にマイ
ナス帯電したトナーと一体になって３層のトナー３２
が、中間転写体側へ移行（逆転写）し、中間転写体上で
は転写残りとなり、一方、転写材上では白抜け部３３が
発生して重大画像欠陥となる。FIG. 2 is a diagram schematically showing occurrence of white spots due to discharge before passing through the transfer nip. When the negatively charged toner 30 adhering on the intermediate transfer body 5 approaches the nip portion in contact with the transfer material 10 and the intermediate transfer body and the transfer material are at a predetermined distance, discharge is generated by the transfer electric field, and the discharge is generated. The toner generated in the outermost layer facing the transfer material tends to be positively charged (or reduced in charge) by the ions generated by the above. For example,
Considering the case where the toner 31 on the outermost layer facing the transfer material is positively charged (or low charged), the positively charged (or low charged) toner is attracted to the intermediate transfer body side and is less likely to transfer to the recording material. , The three-layered toner 32 is integrated with the negatively charged toner after passing through the nip portion.
However, it moves to the side of the intermediate transfer body (reverse transfer) and remains untransferred on the intermediate transfer body, while white spots 33 occur on the transfer material, resulting in a serious image defect.
【０００８】図３は転写ニップ通過後の放電による白抜
け発生を模式的に示す図である。中間転写体５上に、例
えばマイナス帯電トナー２０が３層に付着し、ニップ部
において転写材（記録材）１０に転写される場合を想定
すると、ニップ部を通過して所定の空隙が発生したとき
に、転写電界によって放電が生じ、放電により生じたイ
オンにより、中間転写体に面した最表層のトナーがプラ
ス帯電（もしくは低帯電化）する傾向がある。例えば、
中間転写体に面した最表層のトナー２１がプラス帯電に
なったと仮定すると、トナー２１が転写電界で中間転写
体５の方へ引きつけられ、トナー間の付着力によってマ
イナス帯電トナーも一緒に引きつけられて３層のトナー
２２が逆転写して中間転写体では転写残りが生し、一
方、転写材では白抜け部２３が発生して重大画像欠陥と
なる。FIG. 3 is a diagram schematically showing occurrence of white spots due to discharge after passing through the transfer nip. Assuming that, for example, three layers of negatively charged toner 20 are attached on the intermediate transfer member 5 and transferred to the transfer material (recording material) 10 at the nip portion, a predetermined gap is generated after passing through the nip portion. Occasionally, a discharge is generated by the transfer electric field, and ions generated by the discharge tend to positively charge (or lower the charge) the toner on the outermost layer facing the intermediate transfer member. For example,
Assuming that the outermost surface toner 21 facing the intermediate transfer body is positively charged, the toner 21 is attracted toward the intermediate transfer body 5 by the transfer electric field, and the negatively charged toner is also attracted together by the adhesive force between the toners. As a result, the three layers of toner 22 are reversely transferred and transfer residue is generated on the intermediate transfer member, while white spots 23 are generated on the transfer material, resulting in a serious image defect.
【０００９】このような転写部における放電により白抜
けが発生するのを防止することについて図４により説明
する。図４は転写部の放電による白抜け防止を説明する
ための模式図である。図４において、中間転写体５と転
写材１０との間の転写電界で転写されたトナーのうち、
中間転写体に面した最表層のトナー４０がニップ部通過
後の放電によりプラス帯電し（図４（ａ））、あるいは
転写材１０に面した最表層のトナー４２がニップ部通過
前の放電によりプラス帯電したとき（図４（ｂ））、プ
ラス帯電したトナー４０あるいは４２と、マイナス帯電
トナー４１との付着力で一体となって逆転写を起こすこ
とがないようにするためには、トナーと中間転写体との
付着力をＦ１、トナー同士の付着力をＦ２、トナーと転
写材との付着力をＦ３としたとき、
Ｆ１＜Ｆ２＜Ｆ３ ……（１）
の関係が成立するようにする。（１）式の関係が成立す
ると、転写部の放電によりプラス帯電したトナーに中間
転写体側へ引きつける力が働いても、トナー同士の付着
力が大きい（Ｆ１＜Ｆ２）ためトナーが層間分離を起こ
さず、さらにトナーと転写材との付着力がトナー同士の
付着力より大きい（Ｆ２＜Ｆ３）ため、転写材上のトナ
ーが引き戻されて白抜けとなることはあり得ず、さらに
トナーと転写材との付着力がトナーと中間転写体との付
着力より大きい（Ｆ１＜Ｆ３）ため、３層トナー全体が
中間転写体側へ移行することはない。結局、（１）式の
関係が満たされることにより、放電による逆転写は生ぜ
ず、従って白抜けの発生が防止される。The prevention of the occurrence of white spots due to the discharge in the transfer portion will be described with reference to FIG. FIG. 4 is a schematic diagram for explaining white spot prevention due to discharge of the transfer portion. In FIG. 4, among the toner transferred by the transfer electric field between the intermediate transfer member 5 and the transfer material 10,
The outermost surface toner 40 facing the intermediate transfer member is positively charged by the discharge after passing through the nip portion (FIG. 4A), or the outermost surface toner 42 facing the transfer material 10 is discharged before passing through the nip portion. When positively charged (FIG. 4B), in order to prevent the reverse transfer from being integrally caused by the adhesive force of the positively charged toner 40 or 42 and the negatively charged toner 41, the When the adhesive force with the intermediate transfer member is F1, the adhesive force between the toners is F2, and the adhesive force between the toner and the transfer material is F3, the relationship of F1 <F2 <F3 (1) is established. . When the relation of the expression (1) is established, even if a force of attracting the positively charged toner to the intermediate transfer body side by the discharge of the transfer portion is exerted, the adhesion between the toners is large (F1 <F2), so that the toner causes interlayer separation. In addition, since the adhesive force between the toner and the transfer material is larger than the adhesive force between the toners (F2 <F3), the toner on the transfer material cannot be pulled back to cause white voids. Since the adhesive force between the toner and the intermediate transfer body is larger than that between the toner and the intermediate transfer body (F1 <F3), the entire three-layer toner does not move to the intermediate transfer body side. Eventually, by satisfying the relationship of the expression (1), reverse transfer due to discharge does not occur, and therefore white spots are prevented from occurring.
【００１０】このようにして図２、図３における白抜け
発生を防止する様子を図５、図６により説明する。The manner in which the occurrence of white spots in FIGS. 2 and 3 is thus prevented will be described with reference to FIGS. 5 and 6.
【００１１】図５は転写ニップ部直前の放電による白抜
けの発生防止を模式的に示す図である。図２で説明した
と同様に、中間転写体上に付着している３層のマイナス
帯電トナー３０がニップ部直前で生じた放電により、そ
の最表層トナー３１がプラス帯電、もしくは低帯電量状
態となり、このトナー３１が転写電界により、中間転写
体の方へ引きつけられたとしても、（１）式の関係が成
立していると、放電によりプラス帯電したトナーが中間
転写体側へ引きつけられたときに、トナー同士の付着力
の方が大きいためトナーは層間分離を起こさず、さらに
トナーと転写材との付着力がトナー同士の付着力より大
きいため、３層トナー全体が転写材へ移行して転写さ
れ、逆転写が生ずることなく、白抜けは発生しない。図
６はニップ部通過後の放電により生ずる白抜け防止を模
式的に説明する図である。図３の場合と同様に、中間転
写体５上に３層にマイナス帯電したトナー２０が付着し
ており、ニップ部通過直後の放電により最表層のトナー
がイオンにより正帯電してプラストナー２１になった場
合を想定すると、このプラス帯電トナーに対して転写電
界により、中間転写体５の方へ引きつける力が働くが、
（１）式の関係が成立していると、放電によりプラス帯
電したトナーが中間転写体側へ引きつけられたときに、
トナー同士の付着力の方が大きいためトナーが層間分離
を起こさず、さらにトナーと転写材との付着力がトナー
同士の付着力より大きいため、トナーは転写材へ移行
し、逆転写が生ずることがなく、白抜けは発生しない。FIG. 5 is a diagram schematically showing how white spots are prevented from occurring due to electric discharge just before the transfer nip portion. As described with reference to FIG. 2, the three layers of negatively charged toner 30 adhering on the intermediate transfer member are discharged just before the nip portion, and the outermost surface layer toner 31 is positively charged or is in a low charge amount state. Even if the toner 31 is attracted toward the intermediate transfer body by the transfer electric field, when the relation of the expression (1) is established, when the toner positively charged by the discharge is attracted toward the intermediate transfer body. Since the adhesion between the toners is larger, the toner does not cause interlayer separation, and because the adhesion between the toner and the transfer material is larger than the adhesion between the toners, the entire three-layer toner is transferred to the transfer material and transferred. As a result, reverse transfer does not occur, and blank areas do not occur. FIG. 6 is a diagram schematically illustrating white spot prevention that occurs due to discharge after passing through the nip portion. As in the case of FIG. 3, three layers of negatively charged toner 20 are attached on the intermediate transfer member 5, and the toner at the outermost layer is positively charged by the ions by the discharge immediately after passing through the nip portion to become positive toner 21. Assuming that the positively charged toner is generated, a force that attracts the positively charged toner toward the intermediate transfer body 5 acts.
If the relation of the expression (1) is established, when the positively charged toner is attracted to the intermediate transfer body side by the discharge,
Since the adhesive force between the toners is larger, the toner does not cause interlayer separation, and the adhesive force between the toner and the transfer material is larger than the adhesive force between the toners, so that the toner is transferred to the transfer material and reverse transfer occurs. No white spots occur.
【００１２】次に、（１）式のような条件を設立させる
ための中間転写体の例について説明すると、中間転写体
のベルト材質をウレタン、ポリエステル、ポリカーボネ
ート、ＰＥＴ等の構成とし、ＰＥＴはフッ素、シリコン
含有基などを含んでもよい。また、表面粗さＲａを０．
１μｍ以上とする。Ｒａが小さいことにより、摩擦（付
着）力を小さくすることができる。Next, an example of the intermediate transfer member for establishing the condition of the formula (1) will be explained. The belt material of the intermediate transfer member is made of urethane, polyester, polycarbonate, PET or the like, and PET is fluorine. , A silicon-containing group, etc. may be included. Further, the surface roughness Ra is 0.
It is 1 μm or more. Since Ra is small, the friction (adhesion) force can be reduced.
【００１３】以上のようなトナーと中間転写体を用い、
トナーをタブレット化して中間転写体との摩擦係数、ト
ナータブレット同士の摩擦係数、トナーと転写材との摩
擦係数を求めた実施例を以下に説明する。
〔実施例〕トナーＸを１００〜５００ｋｇｆ／ｃｍ2 で
圧縮し、タブレット化したものを２０ｇｆ／ｃｍ2 〜４
００ｇｆ／ｃｍ2 で中間転写体と表面材質が同じシート
に押圧し、シート（固定）上でトナータブレットを滑ら
せたときの摩擦係数μ１が一番小さく、トナータブレッ
ト同士を一方を固定し、同様に滑らせたときの摩擦係数
μ２、転写材とトナータブレットを２０ｇｆ／ｃｍ2 〜
４００ｇｆ／ｃｍ2で押圧し滑らせたときの摩擦係数μ
３の順に大きくなる（μ１＜μ２＜μ３）トナー、中間
転写体を用いると、２次転写部で高転写効率が実現し、
かつ出力画像の２次転写部で発生する白抜けが起こって
いないことが確認できた。Using the toner and the intermediate transfer member as described above,
An example in which the toner is made into a tablet and the friction coefficient between the intermediate transfer member, the friction coefficient between the toner tablets, and the friction coefficient between the toner and the transfer material is obtained will be described below. [Example] Toner X was compressed at 100 to 500 kgf / cm 2 and tableted to obtain 20 gf / cm 2 to 4
The friction coefficient μ1 is the smallest when the toner tablet is slid on the sheet (fixed) by pressing it to a sheet having the same surface material as the intermediate transfer member at 00 gf / cm 2 , and one of the toner tablets is fixed, and the same. Coefficient of friction when slipped on, transfer material and toner tablet 20 gf / cm 2 ~
Friction coefficient when pressed and slid at 400 gf / cm 2 μ
Higher transfer efficiency is achieved in the secondary transfer section by using toner and intermediate transfer member that increase in order of 3 (μ1 <μ2 <μ3).
In addition, it was confirmed that white spots did not occur in the secondary transfer portion of the output image.
【００１４】[0014]
【発明の効果】転写ニップ直前では放電によるトナー極
性の反転、帯電量変化等による転写効率への影響を考慮
しなければならないが、トナー間の付着力がトナーと中
間転写体との付着力よりも大きく、トナーと記録材との
付着力がトナー間の付着力よりも大きいという条件を満
たすことで、トナー極性が反転、もしくは低帯電量に変
化しても、付着力が小さいためトナーは中間転写体から
離れ易く、トナー同士の付着力が大きいことから、放電
の影響を受けたトナーも周りのトナーと一緒に転写する
ことができ、転写効率を上げて白抜け発生を防止するこ
とができる。EFFECTS OF THE INVENTION It is necessary to consider the influence on the transfer efficiency due to the reversal of the polarity of the toner due to the discharge, the change in the charge amount, etc. immediately before the transfer nip. Is large, and the adhesion force between the toner and the recording material is larger than the adhesion force between the toners, the toner has a small adhesion force even if the toner polarity is reversed or the charge amount is changed to a low charge amount. Since the toner is easily separated from the transfer body and the adhesive force between the toners is large, the toner affected by the discharge can be transferred together with the surrounding toner, and the transfer efficiency can be improved and the occurrence of white spots can be prevented. .
【００１５】また、転写ニップ直後の放電により、中間
転写体上の画像部が転写部で逆転写（一度転写されたト
ナーがニップ部通過直後に放電によってトナーの極性が
反転するなどの影響で中間転写体側に移ってしまう現
象）を起こすと、画像部のトナーが転写材から中間転写
体へと移り、白抜け画像という重大な画像欠陥になる。
そこで、トナー間の付着力がトナーと中間転写体との付
着力よりも大きく、トナーと記録材との付着力がトナー
間の付着力より大きいという条件を満たすことで、トナ
ーは層間分離を起こさず、逆転写が生じないため中間転
写体上での転写残りが発生することがなく、また記録材
上での白抜けの発生を防止することができる。Further, due to the electric discharge immediately after the transfer nip, the image portion on the intermediate transfer member is reverse-transferred at the transfer portion (the toner once transferred has the polarity reversed due to the electric discharge immediately after passing through the nip portion). (A phenomenon in which the toner is transferred to the transfer body side), the toner in the image area is transferred from the transfer material to the intermediate transfer body, resulting in a serious image defect called a blank image.
Therefore, by satisfying the condition that the adhesive force between the toners is larger than the adhesive force between the toners and the intermediate transfer member and the adhesive force between the toners and the recording material is larger than the adhesive force between the toners, the toners are separated from each other. Since reverse transfer does not occur, transfer residue does not occur on the intermediate transfer member, and white spots on the recording material can be prevented.
【図１】 本発明が適用される画像形成装置の構成例を
示す図である。FIG. 1 is a diagram showing a configuration example of an image forming apparatus to which the present invention is applied.
【図２】 ニップ部前の放電による白抜け発生の例を模
式的に示す図である。FIG. 2 is a diagram schematically showing an example of white spot occurrence due to electric discharge in front of a nip portion.
【図３】 ニップ部後の放電による白抜け発生の例を模
式的に示す図である。FIG. 3 is a diagram schematically showing an example of white spot occurrence due to discharge after a nip portion.
【図４】 放電による白抜け発生防止を説明するための
模式図である。FIG. 4 is a schematic diagram for explaining how white spots are prevented from occurring due to discharge.
【図５】 ニップ部通過前の放電による白抜け発生の防
止を模式的に示す図である。FIG. 5 is a diagram schematically showing how white spots are prevented from occurring due to discharge before passing through a nip portion.
【図６】 ニップ部通過後の放電による白抜け発生の防
止を模式的に示す図である。FIG. 6 is a diagram schematically showing how white spots are prevented from occurring due to discharge after passing through a nip portion.
１…感光体、２…帯電器２、３…露光ユニット、４…ロ
ータリ型現像器、５…中間転写体、６…転写帯電器、７
…除電ユニット、８…バックアップローラ、９…２次転
写ローラ、１０…転写材１０、１１…クリーナ１１、２
０…マイナス帯電トナー２０、２１…プラス帯電トナ
ー、２２…逆転写した３層のトナー、２３…白抜け部。DESCRIPTION OF SYMBOLS 1 ... Photosensitive member, 2 ... Charging device 2, 3 ... Exposure unit, 4 ... Rotary type developing device, 5 ... Intermediate transfer member, 6 ... Transfer charging device, 7
... Static elimination unit, 8 ... Backup roller, 9 ... Secondary transfer roller, 10 ... Transfer material 10, 11 ... Cleaner 11, 2
0 ... Negatively charged toner 20, 21, ... Positively charged toner, 22 ... Reversely transferred three-layer toner, 23 ... White spots.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2H005 AA08 AA21 2H030 AB02 AD01 BB24 BB42 2H200 FA05 GA12 GA23 GA44 GA47 GB02 HA02 HA12 HB12 HB22 JA02 JB06 JB16 JC03 JC07 JC12 JC15 JC17 MA04 MA11 MC05 MC06 ─────────────────────────────────────────────────── ─── Continued front page F-term (reference) 2H005 AA08 AA21 2H030 AB02 AD01 BB24 BB42 2H200 FA05 GA12 GA23 GA44 GA47 GB02 HA02 HA12 HB12 HB22 JA02 JB06 JB16 JC03 JC07 JC12 JC15 JC17 MA04 MA11 MC05 MC06
Claims (2)
ナーを用いた中間転写体を有する画像形成装置におい
て、トナー間の付着力はトナーと中間転写体との付着力
よりも大きく、トナーと記録材との付着力はトナー間の
付着力より大きいことを特徴とする画像形成装置。1. In an image forming apparatus having an intermediate transfer member using a toner having a resin mother particle surface coated with an external additive, the adhesive force between the toners is larger than the adhesive force between the toner and the intermediate transfer member. An image forming apparatus characterized in that the adhesive force between the toner and the recording material is larger than the adhesive force between the toners.
を有する複数の画像形成ユニットを備えたタンデム構成
であることを特徴とする請求項１または２記載の画像形
成装置。2. The image forming apparatus according to claim 1, wherein the image forming apparatus has a tandem structure including a plurality of image forming units each having an image carrier.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001288383A JP2003098847A (en) | 2001-09-21 | 2001-09-21 | Image forming device |
| CN02142969A CN1405642A (en) | 2001-09-14 | 2002-09-13 | Image-forming apparatus |
| US10/244,135 US6813458B2 (en) | 2001-09-14 | 2002-09-16 | Image forming apparatus |
| EP02020526A EP1306731A3 (en) | 2001-09-14 | 2002-09-16 | Cleanerless image forming apparatus and toner particles coated with external additives |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001288383A JP2003098847A (en) | 2001-09-21 | 2001-09-21 | Image forming device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003098847A true JP2003098847A (en) | 2003-04-04 |
Family
ID=19111043
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001288383A Pending JP2003098847A (en) | 2001-09-14 | 2001-09-21 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003098847A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7504696B2 (en) | 2020-07-28 | 2024-06-24 | キヤノン株式会社 | Image forming device |
| JP7504695B2 (en) | 2020-07-28 | 2024-06-24 | キヤノン株式会社 | Image forming device |
-
2001
- 2001-09-21 JP JP2001288383A patent/JP2003098847A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7504696B2 (en) | 2020-07-28 | 2024-06-24 | キヤノン株式会社 | Image forming device |
| JP7504695B2 (en) | 2020-07-28 | 2024-06-24 | キヤノン株式会社 | Image forming device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3470472B2 (en) | Transfer device | |
| JP4829661B2 (en) | Cleaning device and image forming apparatus having the same | |
| JP4929829B2 (en) | Image forming apparatus | |
| JP2004280053A (en) | Image forming device | |
| US20020146260A1 (en) | Cleaning unit and image formation apparatus using it | |
| JP2003098847A (en) | Image forming device | |
| JP4320958B2 (en) | Image forming apparatus and image forming method | |
| JPH10333514A (en) | Image forming device | |
| JP2003098846A (en) | Image forming device | |
| JP2001215809A (en) | Belt carrying device and image forming apparatus | |
| JP3524423B2 (en) | Image forming device | |
| JP2001075331A (en) | Color image forming device | |
| JPH11249459A (en) | Image forming device | |
| JPS6295571A (en) | Transfer fixing device | |
| JPH10333523A (en) | Image forming device | |
| JPH1145010A (en) | Image forming device | |
| JP2752886B2 (en) | Toner image transfer device | |
| JP3012016B2 (en) | Color image recording device | |
| JPH11311907A (en) | Image forming device | |
| JP2001265134A (en) | Image forming device | |
| JP2012083565A (en) | Image forming device | |
| JP2002268404A (en) | Image forming device | |
| JP2003098730A (en) | Image forming device | |
| JPH034273A (en) | Image forming device | |
| JPH06175510A (en) | Method and device for forming image |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20040121 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20061006 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20061101 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20061215 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20070328 |