JP3186291B2 - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JP3186291B2 JP3186291B2 JP01325893A JP1325893A JP3186291B2 JP 3186291 B2 JP3186291 B2 JP 3186291B2 JP 01325893 A JP01325893 A JP 01325893A JP 1325893 A JP1325893 A JP 1325893A JP 3186291 B2 JP3186291 B2 JP 3186291B2
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- toner
- transfer belt
- charge
- applying device
- 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.)
- Expired - Lifetime
Links
Description
【０００１】[0001]
【産業上の利用分野】本発明は、プリンタ，ファクシミ
リ，複写機等のトナーを用いて画像を顕像化させる画像
形成装置に係り、特にベルト転写／搬送方式におけるト
ナー汚れ防止に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a facsimile, and a copying machine for visualizing an image using a toner, and more particularly to prevention of toner contamination in a belt transfer / transport system.
【０００２】[0002]
【従来の技術】以下、従来の画像形成装置について説明
する。電子写真方式を用いた画像形成装置は、記録体表
面にトナー像を作像する装置である。その作像過程は、
未作像の記録体を送り出す給紙工程，トナーを記録体表
面に画像として顕像化させる現像／転写工程，顕像化さ
れたトナー画像を記録体に固定する定着工程，定着後の
記録体を排紙する排紙工程，上記各工程間に記録体を搬
送する搬送装置から成る。2. Description of the Related Art A conventional image forming apparatus will be described below. 2. Description of the Related Art An image forming apparatus using an electrophotographic method is an apparatus that forms a toner image on the surface of a recording medium. The imaging process is
A paper feeding process for sending out an unformed recording medium, a developing / transferring process in which toner is visualized as an image on the surface of the recording medium, a fixing process in which the visualized toner image is fixed to the recording medium, and a recording medium after fixing And a transport device for transporting the recording medium between the above steps.
【０００３】本発明では無端ベルトを用い、記録体を搬
送しつつ転写も行うベルト転写／搬送方式を用いた画像
形成装置に関する。図４に従来のベルト転写／搬送方式
を用いた画像形成装置の模式図を示す。一般の電子写真
画像形成装置と同様に感光体１表面にトナー像が顕像化
される。一方、記録体９は給紙ホッパより繰り出され、
転写ベルト１０上にまで搬送される。転写ベルト１０は
駆動ローラあるいは従動ローラ１１，２２，２４を囲ん
で取り付けられており、駆動ローラの回転に従って受け
渡された記録体９を搬送する。転写装置５に対応する位
置において、記録体９が転写ベルト１０と感光体１には
さみ込まれたまま感光体１上のトナー画像は記録体９に
転写される。転写ベルト１０はさらに記録体９を搬送
し、定着装置１２へと送り出す。定着装置１２にて、記
録体９上の未定着トナー画像は記録体９に固定される。
その後、片面印刷の場合は排紙スタッカへ記録体９を排
紙して印刷を終了する。両面印刷では反転搬送工程を経
て記録体９を反転させ、再び転写ベルト１０に記録体９
を受け渡し、上記転写，定着，排紙工程を繰り返して印
刷を終了する。以上が作像の基本的工程である。[0003] The present invention relates to an image forming apparatus using a belt transfer / conveyance system which uses an endless belt and conveys a recording medium while carrying out transfer. FIG. 4 is a schematic diagram of an image forming apparatus using a conventional belt transfer / conveyance system. A toner image is visualized on the surface of the photoconductor 1 as in a general electrophotographic image forming apparatus. On the other hand, the recording medium 9 is fed out from the paper feed hopper,
It is transported onto the transfer belt 10. The transfer belt 10 is attached so as to surround a driving roller or driven rollers 11, 22, 24, and conveys the transferred recording material 9 according to the rotation of the driving roller. At a position corresponding to the transfer device 5, the toner image on the photoconductor 1 is transferred to the recording body 9 while the recording body 9 is sandwiched between the transfer belt 10 and the photoconductor 1. The transfer belt 10 further conveys the recording medium 9 and sends it out to the fixing device 12. The unfixed toner image on the recording medium 9 is fixed to the recording medium 9 by the fixing device 12.
Thereafter, in the case of single-sided printing, the recording medium 9 is discharged to a discharge stacker, and printing is completed. In the double-sided printing, the recording material 9 is reversed through a reversal conveyance process, and the recording material 9 is again placed on the transfer belt 10.
Then, the above-described transfer, fixing, and paper discharging processes are repeated to finish printing. The above is the basic process of image formation.
【０００４】上記、作像工程を繰り返すと、感光体１の
記録体９と記録体９の間隙に対応する領域や記録体９の
搬送方向と直行する奥行き方向の領域より外側の領域な
ど記録体９と接しない領域に存在する微量なトナーが転
写ベルト１０に転写されるため転写ベルト１０が汚れる
という問題を引き起こすことがある。この問題を未然に
防止するため、転写ベルトクリーナ１２が設けられるの
が通常である。転写ベルトクリーナ１２にはトナーと逆
極性の電位を印加してベルト上に残存したトナーを転写
ベルト１０から回収するバイアスクリーニング方式が用
いられることが多い。また、バイアスクリーニング方式
を用いた場合、トナーはより強く帯電していた方がクリ
ーニング性能が高いことは言うまでもない。そのため、
ベルト上のトナーにトナーと同極性の電荷を供給する電
荷付与装置１４をクリーナ１２よりベルト駆動方向前方
に設置し、トナーをより強く帯電させる方法が多く用い
られる。When the above-described image forming process is repeated, the recording medium, such as an area corresponding to the gap between the recording bodies 9 of the photoconductor 1 and an area outside the area in the depth direction perpendicular to the conveying direction of the recording medium 9, is obtained. Since a very small amount of toner existing in an area not in contact with the transfer belt 9 is transferred to the transfer belt 10, the transfer belt 10 may be stained. In order to prevent this problem, a transfer belt cleaner 12 is usually provided. In many cases, a bias cleaning method is used in which a potential having a polarity opposite to that of the toner is applied to the transfer belt cleaner 12 to collect the toner remaining on the belt from the transfer belt 10. When the bias cleaning method is used, it is needless to say that the stronger the toner is charged, the higher the cleaning performance. for that reason,
A method is often used in which a charge applying device 14 for supplying a charge of the same polarity as the toner to the toner on the belt is provided in front of the cleaner 12 in the belt driving direction, and the toner is more strongly charged.
【０００５】また、上記作像工程において、記録体９が
転写ベルト１０と感光体１にはさみ込まれたまま感光体
１上のトナー画像が記録体９に転写される際、転写装置
５はトナーと逆極性の電荷を転写ベルト１０の裏側より
供給する。これにより、感光体１表面に配列したトナー
に転写装置５に向かうクーロン力が作用し、トナーは記
録体９表面に移動し、転写が行われるのである。その
際、感光体１のトナーに被覆されていない部分にもトナ
ーと同極性の電荷が存在しており、この電荷もトナーと
同様に記録体９表面に移動する。転写工程において、記
録体９はトナーと同極性に、転写ベルト１０はトナーと
逆極性に帯電することになる。その後、記録体９が転写
ベルト１０に密着している間は、記録体９と転写ベルト
１０を一体にみれば、記録体９と転写ベルト１０の合計
の電荷量は相互に打消しあっていかにも僅かに見える。
実際には、上述のように、記録体９はトナーと同極性
に、転写ベルト１０はトナーと逆極性に分極した状態に
なっているのである。その後、記録体９が定着装置１２
に向かうため、転写ベルト１０から分離する際、この分
極状態は顕在化し、記録体９と転写ベルト１０はそれぞ
れ逆極性に強く帯電する。これを、分離帯電と呼ぶ。ま
た、転写ベルト１０はローラ１１に沿って移動するた
め、分離帯電した直後に、記録体９と転写ベルト１０と
の間に間隙が発生する。記録体９と転写ベルト１０はそ
れぞれ逆極性に強く帯電しているため、この間隙におい
て両者の間で、火花放電が発生することがある。上記分
離帯電が発生すると、記録体９表面のトナーとトナーが
存在しない部分の記録体９表面の電荷は同極性となる。
そのため、トナーは記録体９表面に存在する周囲の同極
性の電荷から作用するクーロン力により押し出され移動
し、上方の空間に舞散ったり、画像としての配列を乱す
ことがある。また、上記火花放電が発生した場合でもそ
の力学的衝撃により同様の現象がみられ、著しい場合に
はトナーによる放電模様が観察されることもある。In the image forming process, when the toner image on the photosensitive member 1 is transferred to the recording member 9 while the recording member 9 is sandwiched between the transfer belt 10 and the photosensitive member 1, the transfer device 5 Is supplied from the back side of the transfer belt 10. As a result, a Coulomb force directed to the transfer device 5 acts on the toner arranged on the surface of the photoconductor 1, and the toner moves to the surface of the recording medium 9 and transfer is performed. At this time, a charge of the same polarity as that of the toner also exists in a portion of the photoreceptor 1 that is not covered with the toner, and this charge also moves to the surface of the recording medium 9 similarly to the toner. In the transfer step, the recording medium 9 is charged to the same polarity as the toner, and the transfer belt 10 is charged to the opposite polarity to the toner. Thereafter, while the recording medium 9 is in close contact with the transfer belt 10, if the recording medium 9 and the transfer belt 10 are viewed as a unit, the total charge amount of the recording medium 9 and the transfer belt 10 can be canceled out. Slightly visible.
Actually, as described above, the recording body 9 is polarized to the same polarity as the toner, and the transfer belt 10 is polarized to the opposite polarity to the toner. Thereafter, the recording medium 9 is moved to the fixing device 12.
Therefore, when the recording medium 9 and the transfer belt 10 are separated from the transfer belt 10, this polarization state becomes apparent, and the recording body 9 and the transfer belt 10 are strongly charged to opposite polarities. This is called separation charging. Further, since the transfer belt 10 moves along the roller 11, a gap is generated between the recording material 9 and the transfer belt 10 immediately after the separation belt is charged. Since the recording medium 9 and the transfer belt 10 are strongly charged with opposite polarities, spark discharge may occur between the two in this gap. When the above-described separation charging occurs, the toner on the surface of the recording medium 9 and the electric charge on the surface of the recording medium 9 in a portion where the toner does not exist have the same polarity.
Therefore, the toner is pushed and moved by the Coulomb force acting from the surrounding charges of the same polarity existing on the surface of the recording medium 9, and may be scattered in a space above or disturb the arrangement as an image. Further, even when the above-mentioned spark discharge occurs, the same phenomenon is observed due to the mechanical impact. In a remarkable case, a discharge pattern due to the toner may be observed.
【０００６】なお、この種の装置として関連するものに
は例えば特開昭63−83772 号等が挙げられる。[0006] Japanese Patent Application Laid-Open No. 63-83772 and the like relate to this type of apparatus.
【０００７】[0007]
【発明が解決しようとする課題】上記従来技術は、上記
分離帯電や火花放電に配慮がされておらず、トナーが空
間に舞散ったり、画像としての配列を乱すという問題が
あった。In the above prior art, no consideration is given to the above-described separation charging and spark discharge, and there has been a problem that the toner scatters in space and disturbs the arrangement as an image.
【０００８】また、上記従来技術は、転写ベルトクリー
ナのクリーニング性能についても配慮にも欠けており、
クリーニング性能が不十分あるいは高い性能を維持でき
ないという問題があった。Further, the above-mentioned prior art lacks consideration for the cleaning performance of the transfer belt cleaner.
There is a problem that cleaning performance is insufficient or high performance cannot be maintained.
【０００９】そこで、本発明の目的は、上記従来技術に
おける問題を解決し、トナーの空間への舞散りや画像配
列の乱れが無く、転写ベルトクリーナのクリーニング性
能を高く維持する画像形成装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus which solves the above-mentioned problems in the prior art and which maintains the cleaning performance of a transfer belt cleaner at a high level without causing toner scattering in a space or disturbing image arrangement. Is to do.
【００１０】[0010]
【課題を解決するための手段】本発明は、上記目的を達
成するため、転写ベルトの記録体分離位置に対応するロ
ーラにトナーと逆極性のバイアス電位を印加し、かつ上
記ローラに対抗した位置にトナーと逆極性の電荷を記録
体と転写ベルトに供給する電荷付与装置を設置するよう
にしたものである。According to the present invention, in order to achieve the above object, a bias potential having a polarity opposite to that of the toner is applied to a roller corresponding to a recording material separation position of a transfer belt, and a position opposite to the roller is applied. And a charge applying device for supplying a charge having a polarity opposite to that of the toner to the recording medium and the transfer belt.
【００１１】[0011]
【作用】転写ベルトの記録体分離位置に対応するローラ
に対抗した位置に設置された電荷付与装置はトナーと逆
極性の電荷を転写ベルトとの分離後の記録体の裏面と転
写ベルトに供給し、記録体を除電することにより、分離
後の記録体の帯電を防止し、適正な電荷を転写ベルト及
びベルト表面の残存トナーに付与して転写ベルトと残存
トナーの吸着力を緩和する。また、転写ベルトの上記ロ
ーラに印加されたトナーと逆極性のバイアス電位は記録
体との間にクーロン力を作用させ、記録体と転写ベルト
の分離位置をより電荷付与装置側へ移動させ、上記電荷
付与装置と分離位置とをより近接させることにより電荷
付与装置による記録体の除電効果を高める。かつ上記ロ
ーラへのバイアス電位は記録体とトナーとを密着させる
べく記録体表面のトナーとの間にもクーロン力を作用さ
せ、記録体と転写ベルトの分離時におけるトナーの移動
をも防止する。The charge applying device installed at a position opposite to the roller corresponding to the recording material separation position of the transfer belt supplies charges of opposite polarity to the toner to the back surface of the recording material after separation from the transfer belt and to the transfer belt. By eliminating the charge on the recording medium, the recording medium after separation is prevented from being charged, and an appropriate charge is applied to the transfer belt and the residual toner on the surface of the belt to reduce the attraction between the transfer belt and the residual toner. Further, the bias potential having a polarity opposite to that of the toner applied to the roller of the transfer belt causes a Coulomb force to act on the recording medium, thereby moving the separation position between the recording medium and the transfer belt toward the charge applying device side. By bringing the charge applying device closer to the separation position, the charge removing effect of the recording medium by the charge applying device is enhanced. In addition, the bias potential applied to the roller also applies a Coulomb force between the recording medium and the toner on the surface of the recording medium so that the toner adheres to the recording medium, thereby preventing the toner from moving when the recording medium is separated from the transfer belt.
【００１２】これにより、記録体と転写ベルトとの分離
時のトナーの移動と分離後の記録体の帯電を防止し、転
写ベルトと残存トナーの吸着力が緩和されるので、トナ
ーの空間への舞散りや画像配列の乱れが無く、転写ベル
トクリーナのクリーニング性能を高く維持することがで
きる画像形成装置を提供することができる。Thus, the movement of the toner when the recording medium is separated from the transfer belt and the electrification of the recording medium after the separation are prevented, and the adsorbing force between the transfer belt and the residual toner is alleviated. It is possible to provide an image forming apparatus which can maintain high cleaning performance of a transfer belt cleaner without scattering and disturbance of image arrangement.
【００１３】[0013]
〈実施例１〉本発明の一実施例を図１および図２を用い
て説明する。<Embodiment 1> One embodiment of the present invention will be described with reference to FIGS.
【００１４】図１は本実施例の記録体９と転写ベルト１
０の分離位置付近の構成を示す断面側面図である。図２
は本発明における画像形成装置の基本構成を示す断面側
面図である。画像形成プロセスに関与する基本的な部品
は図４と同様であるが、トナー２３とは逆極性の電荷を
発生し、対抗電極を具備しない電荷付与装置１４の開口
部に、遮蔽板２５が設置されている。FIG. 1 shows a recording medium 9 and a transfer belt 1 according to this embodiment.
FIG. 2 is a cross-sectional side view showing a configuration near a separation position of No. 0. FIG.
1 is a sectional side view showing a basic configuration of an image forming apparatus according to the present invention. The basic components involved in the image forming process are the same as those in FIG. 4, but generate a charge having a polarity opposite to that of the toner 23, and a shielding plate 25 is provided at the opening of the charge applying device 14 having no counter electrode. Have been.
【００１５】但しここで、感光体１はマイナス帯電の有
機感光体を用い、現像装置４による現像方式は、二成分
現像剤を用いた反転現像方式で、トナー２３がマイナス
電荷を持つ。また転写装置５はプラスのコロトロン感光
体帯電装置で、そのコロナ電流値を制御しているが、転
写装置５に印加する電位を制御する方法をとることも可
能である。更に転写ベルト１０は常温常室における体積
抵抗が１０の１０乗Ω・cmから１０の１３乗Ω・cmで厚
さが０.０６cm の無端ベルトであり、記録体９及び転写
ベルト１０の静電容量がそれぞれ１０２６ｐＦ及び４７
４ｐＦにおいて、記録体９と転写ベルト１０が重なった
状態でのローラ１１に対する電位は−１８００Ｖ、転写
ベルト１０単独でのローラ１１に対する電位は−６５０
Ｖである。これらの条件は以下の実施例において同一で
ある。Here, the photosensitive member 1 uses a negatively charged organic photosensitive member, and the developing system using the developing device 4 is a reversal developing system using a two-component developer, and the toner 23 has a negative charge. Further, the transfer device 5 is a positive corotron photosensitive member charging device and controls the corona current value. However, a method of controlling the potential applied to the transfer device 5 can be adopted. Further, the transfer belt 10 is an endless belt having a volume resistance of 10 10 Ω · cm to 10 13 Ω · cm and a thickness of 0.06 cm in a normal temperature and normal room. Capacities of 1026 pF and 47 respectively
At 4 pF, the potential with respect to the roller 11 when the recording material 9 and the transfer belt 10 are overlapped is −1800 V, and the potential with respect to the roller 11 when the transfer belt 10 alone is −650.
V. These conditions are the same in the following examples.
【００１６】本装置における画像形成の過程および記録
体９の搬送の過程を図２を用いて詳述すると以下のよう
になる。まず感光体１の表面に感光体帯電装置２により
一様なマイナス電荷を与えた後、露光装置３により形成
すべき所望の画像部分に光を照射することにより光の照
射されないバックグラウンド部分より零電位に近い静電
潜像が形成される。現像装置４の内部に蓄えられたトナ
ー２３は摩擦帯電によりほぼ一定のマイナス電荷が付与
されており、上記バックグラウンド部分の電位と静電潜
像部分の電位の中間にあたる電位を現像装置４に印加す
ることにより、トナー２３が静電潜像のみに吸引され、
感光体１上にトナー２３による可視画像が形成される。
一方記録体９は図示しない記録体供給機から図の矢印Ａ
の向きに供給され、転写ベルト１０上へと搬送され、感
光体１と転写ベルト１０との接するニップ領域に送られ
る。ここにおいて転写ベルト１０には転写装置５からプ
ラス電荷を与えられるため、感光体１上のマイナス電荷
を持つトナー２３は、このニップ領域において記録体９
上に転写される。記録体９がニップ領域を通過する際、
転写ベルト１０上に与えられたプラス電荷の影響で、感
光体１上にあるトナー２３と同極性のマイナス電荷が記
録体９に転移する。このため記録体９は転写ベルト１０
上のプラス電荷、及びローラ１１に印加されているプラ
スのバイアス１７との静電吸着力により転写ベルト１０
に吸着して搬送される。The process of forming an image and the process of transporting the recording medium 9 in this apparatus will be described below in detail with reference to FIG. First, a uniform negative charge is applied to the surface of the photoreceptor 1 by the photoreceptor charging device 2, and then a desired image portion to be formed by the exposing device 3 is irradiated with light so that the background portion which is not irradiated with light becomes zero. An electrostatic latent image close to the potential is formed. The toner 23 stored inside the developing device 4 is given a substantially constant negative charge by frictional charging, and applies a potential intermediate between the potential of the background portion and the potential of the electrostatic latent image portion to the developing device 4. As a result, the toner 23 is attracted only to the electrostatic latent image,
A visible image is formed on the photoconductor 1 by the toner 23.
On the other hand, the recording medium 9 is moved from an unillustrated recording medium feeder to an arrow A in the figure.
, And is conveyed onto the transfer belt 10 and sent to a nip area where the photoconductor 1 and the transfer belt 10 are in contact with each other. Here, since the transfer belt 10 is provided with a positive charge from the transfer device 5, the toner 23 having the negative charge on the photoreceptor 1 is transferred to the recording medium 9 in this nip area.
Transcribed above. When the recording body 9 passes through the nip area,
Due to the influence of the positive charge applied to the transfer belt 10, the negative charge having the same polarity as the toner 23 on the photoconductor 1 is transferred to the recording medium 9. For this reason, the recording body 9 is a transfer belt 10
The transfer belt 10 is moved by the positive charge above and the electrostatic attraction force with the positive bias 17 applied to the roller 11.
Is transported by suction.
【００１７】ローラ１１付近に搬送された記録体９は、
ここで転写ベルト１０がローラ１１の円筒に沿って曲げ
られると、記録体９自身の剛性により前記静電吸着力に
打勝って分離し始める。この際、記録体９と転写ベルト
１０との分離によって急激に記録体９はマイナスに分離
帯電しようとする。The recording medium 9 conveyed near the roller 11 is
Here, when the transfer belt 10 is bent along the cylinder of the roller 11, the recording medium 9 starts to separate by overcoming the electrostatic attraction force due to the rigidity of the recording medium 9 itself. At this time, the recording body 9 suddenly separates negatively due to the separation between the recording body 9 and the transfer belt 10.
【００１８】記録体９とトナー２３とは逆極性のプラス
電荷を発生し、対向電極を具備しない電荷付与装置１４
は記録体９と転写ベルト１０との分離直後で、未固着の
トナー２３が付着している記録体９の面とは逆の面に向
かって設置されている。電荷付与装置１４の開口部に記
録体９が突入しないように、ローラ１１上の転写ベルト
１０と電荷付与装置１４との段差は５mm程度とってい
る。記録体９と転写ベルト１０との分離点と、電荷付与
装置１４のワイヤーとの間は、電荷付与装置１４のシー
ルド部や、または転写ベルト１０等で遮蔽されている
が、より効果的に除電するためには、記録体９が転写ベ
ルト１０から分離する点と、電荷付与装置１４のワイヤ
ーとの間は、電荷付与装置１４のシールド部や、または
転写ベルト１０等で遮蔽されていないことが望ましい。
電荷付与装置１４には＋１μＡ以上の定電流が印加され
ているが、電荷付与装置１４に印加する投入電流を任意
に制御することも可能である。The recording medium 9 and the toner 23 generate positive charges of opposite polarities, and are provided with a charge applying device 14 having no counter electrode.
Is set immediately after the separation of the recording medium 9 from the transfer belt 10 and is directed toward the surface opposite to the surface of the recording medium 9 to which the unfixed toner 23 adheres. The step between the transfer belt 10 on the roller 11 and the charge applying device 14 is about 5 mm so that the recording medium 9 does not enter the opening of the charge applying device 14. The gap between the separation point between the recording medium 9 and the transfer belt 10 and the wire of the charge applying device 14 is shielded by the shield portion of the charge applying device 14 or the transfer belt 10, but more effectively removes electricity. In order to achieve this, the point between the recording medium 9 separating from the transfer belt 10 and the wire of the charge applying device 14 is not shielded by the shield portion of the charge applying device 14 or the transfer belt 10. desirable.
Although a constant current of +1 μA or more is applied to the charge applying device 14, the applied current applied to the charge applying device 14 can be arbitrarily controlled.
【００１９】上記電荷付与装置１４において、記録体９
が転写ベルト１０との分離によって分離帯電しても、記
録体９とトナー２３とは逆極性の電荷を発生し、対向電
極を具備しない電荷付与装置１４を記録体９と転写ベル
ト１０との分離直後で、未固着のトナー２３が付着して
いる記録体９の面とは逆の面に向かって設置されている
ので、電荷付与装置１４が発生させる記録体９とトナー
２３とは逆極性の電荷が記録体９と転写ベルト１０との
分離点に投与され、分離帯電した記録体９が直ちに除電
される。In the charge applying device 14, the recording material 9
However, even if the recording medium 9 is separated and charged by the separation from the transfer belt 10, the recording medium 9 and the toner 23 generate electric charges of opposite polarities, and the charge applying device 14 having no counter electrode separates the recording medium 9 from the transfer belt 10. Immediately after, the recording medium 9 and the toner 23 generated by the charge applying device 14 have opposite polarities because the recording medium 9 and the toner 23 are installed facing the surface opposite to the surface of the recording medium 9 to which the unfixed toner 23 adheres. Electric charges are applied to the separation point between the recording medium 9 and the transfer belt 10, and the separated and charged recording medium 9 is immediately discharged.
【００２０】これによってトナー２３と記録体９とは静
電的に反発しないうえに、トナー２３の電荷の極性と電
荷付与装置１４の電荷の極性は逆であるので、トナー２
３は電荷付与装置１４が設置されている方向に引き付け
られるので、記録体９上のトナー２３は、記録体９と転
写ベルトとの分離点以降で飛散することはない。さらに
トナー２３また記録体９が除電されることによって、記
録体９がガイド部材１５に接触しても記録体９とガイド
部材１５との間で火花放電は発生しないので、記録体９
上に枝状、或いは班点状のトナー２３による模様が発生
せず、記録体９上のトナー２３を乱すことなく、画像品
質が保持される。As a result, the toner 23 and the recording medium 9 do not repel electrostatically, and the polarity of the charge of the toner 23 and the polarity of the charge of the charge applying device 14 are opposite.
3 is attracted in the direction in which the charge applying device 14 is installed, so that the toner 23 on the recording medium 9 does not scatter after the separation point between the recording medium 9 and the transfer belt. Further, since the toner 23 and the recording medium 9 are neutralized, no spark discharge occurs between the recording medium 9 and the guide member 15 even if the recording medium 9 contacts the guide member 15.
An image quality is maintained without causing a pattern of the branch-like or spot-like toner 23 on the upper side and disturbing the toner 23 on the recording medium 9.
【００２１】また、本実施例では、従来技術において図
４を用いて説明した転写ベルトクリーナ１２の電荷付与
装置１４の極性を反転させたため、ベルトクリーニング
性能が低下することが懸念された。しかし、本発明者ら
の実験によれば、ベルト上に残存したトナーに電荷を全
く供給しないより、正電荷であろうとも、適切な範囲で
あれば若干の電荷をベルト上に残存したトナーに供給し
た方が良好なベルトクリーニング性能が得られ、負電荷
を供給した場合に比較してもむしろ良好なベルトクリー
ニング性能が得られ、この性能を維持できることが判っ
た。この理由は、残存トナーに微少な逆特性電荷を付与
することにより転写ベルトクリーナ８と残存トナーとの
クーロン力が弱まる以上に残存トナーと転写ベルト１０
との吸着力を弱める効果が発生するためである。Further, in this embodiment, since the polarity of the charge applying device 14 of the transfer belt cleaner 12 described with reference to FIG. 4 in the related art is reversed, there is a concern that the belt cleaning performance may be deteriorated. However, according to the experiments of the present inventors, even if it is a positive charge, a small amount of charge is applied to the toner remaining on the belt even if it is in an appropriate range, rather than supplying no charge to the toner remaining on the belt. It was found that better belt cleaning performance was obtained when the belt was supplied, and better belt cleaning performance was obtained than when a negative charge was supplied, and this performance could be maintained. The reason for this is that the Coulomb force between the transfer belt cleaner 8 and the residual toner is weakened by imparting a slight reverse characteristic charge to the residual toner, and the residual toner and the transfer belt 10
This is because an effect of weakening the adsorbing force of the pressure occurs.
【００２２】本発明における上記電荷付与装置１４の開
口部に設置された遮蔽板２５によって、電荷付与装置１
４から発生した電荷がローラ１１に流入するのを抑制
し、転写ベルトクリーナ８のクリーニング性能を良好な
状態に保持できる。遮蔽板２５の高さは、転写ベルトク
リーナ８のクリーニング性能が良好な状態になる様に調
整されたものであり、本実施例では電荷付与装置１４の
底面から１０mmとなっており、電荷付与装置１４の上面
との開口幅（図中記号Ｃ寸法）は５mmである。また、残
存トナーに付与される電荷はローラ１１に流れ込む電流
に換算して、５〜１０μＡである。この幅Ｃは電荷付与
装置１４の形状や投入電流により変わるが、通常１〜１
８mmの間に設定される。また、残存トナーに付与される
電荷はローラ１１に流れ込む電流に換算して、０.５〜
２０μＡ であれば良好なクリーニング性能が得られ
る。According to the present invention, the charge applying device 1 is provided by the shielding plate 25 provided at the opening of the charge applying device 14.
4 can be prevented from flowing into the roller 11 and the cleaning performance of the transfer belt cleaner 8 can be maintained in a good state. The height of the shield plate 25 is adjusted so that the cleaning performance of the transfer belt cleaner 8 is in a good state. In the present embodiment, the height of the shield plate 25 is 10 mm from the bottom of the charge applying device 14. The opening width (dimension C in the drawing) with the upper surface of 14 is 5 mm. The charge applied to the residual toner is 5 to 10 μA in terms of the current flowing into the roller 11. The width C varies depending on the shape of the charge applying device 14 and the applied current.
It is set between 8mm. The charge applied to the remaining toner is converted into a current flowing into the roller 11 to be 0.5 to 0.5.
If it is 20 μA, good cleaning performance can be obtained.
【００２３】上記のように、遮蔽板２５が設置された電
荷付与装置１４によって除電された記録体９は、接地さ
れたガイド部材１５を通過し、下流の定着装置１２によ
りトナー２３を溶融し画像の定着が行われ、図の矢印Ｂ
の向きに搬送される。更に、前記感光体１上の電荷はイ
レーズランプ６により除電され、また同様に残存したト
ナー２３は感光体クリーナ７により除去され次の新たな
画像形成に備える。また転写ベルト１０上に飛散したト
ナー２３は遮蔽板２５が設置された電荷付与装置１４に
よってクリーニング性能が常に良好な転写ベルトクリー
ナ８によって除去される。As described above, the recording medium 9 which has been neutralized by the charge applying device 14 provided with the shielding plate 25 passes through the grounded guide member 15 and melts the toner 23 by the downstream fixing device 12 to melt the image. Is fixed, and arrow B in the figure
Transported in the direction of Further, the charge on the photoconductor 1 is eliminated by the erase lamp 6, and the remaining toner 23 is similarly removed by the photoconductor cleaner 7 to prepare for the next new image formation. In addition, the toner 23 scattered on the transfer belt 10 is removed by the transfer belt cleaner 8 having always good cleaning performance by the charge applying device 14 provided with the shielding plate 25.
【００２４】以上のような構成において、トナー２３を
転写された記録体９が定着装置１２を通過するまでの
間、画像劣化を招くトナー２３の飛散を防止でき、放電
模様がなく、長期の使用によっても画像を著しく乱すこ
となく、高品位な画像が得られる画像形成装置を提供で
きると同時に、転写ベルトクリーナ８のクリーニング性
能を常に良好な状態に保持できる。In the above configuration, until the recording material 9 onto which the toner 23 has been transferred passes through the fixing device 12, scattering of the toner 23 which causes image deterioration can be prevented, there is no discharge pattern, and the toner 23 is used for a long time. Accordingly, it is possible to provide an image forming apparatus capable of obtaining a high-quality image without remarkably disturbing the image, and at the same time, always maintain a good cleaning performance of the transfer belt cleaner 8.
【００２５】更に、本実施例で説明した電荷付与装置１
４の電荷を発生するワイヤー側のシールド面や、遮蔽板
２５を一部絶縁することにより、除電効果を高めたり、
ローラ１１に流入する電荷付与装置１４からの電荷を抑
制し、転写ベルトクリーナ８のクリーニング性能を良好
に保持することも可能である。Further, the charge applying device 1 described in the present embodiment.
By partially insulating the shield surface on the wire side that generates the charge of No. 4 and the shield plate 25, the static elimination effect can be enhanced,
It is also possible to suppress the charge from the charge applying device 14 flowing into the roller 11 and maintain the cleaning performance of the transfer belt cleaner 8 satisfactorily.
【００２６】〈実施例２〉次に本発明の他の実施例を説
明する。<Embodiment 2> Next, another embodiment of the present invention will be described.
【００２７】本実施例を図２に示す。図３は実施例２の
記録体９と転写ベルト１０の分離位置付近の構成を示す
断面側面図である。本実施例では、実施例１の場合と同
様な構成であるが、転写ベルトクリーナ８のクリーニン
グ性能を常に良好な状態に保持するための、電荷付与装
置１４の開口部に遮蔽板２５及び、傾斜板２６が設置さ
れている。傾斜板２６を設置することにより、更なる記
録体９の除電効果が得られることが実験によって確認さ
れている。遮蔽板２５と傾斜板２６との空隙Ａは、ロー
ラ１１に流入する電荷付与装置１４からの電荷を抑制
し、転写ベルトクリーナ８のクリーニング性能を良好に
保持する様に調整されたものである。空隙Ａは３mmであ
る。この空隙幅は電荷付与装置１４の形状や投入電流あ
るいは傾斜板２６の長さにより変わるが、通常１〜１０
mmの間に設定される。FIG. 2 shows this embodiment. FIG. 3 is a cross-sectional side view showing a configuration near the separation position between the recording medium 9 and the transfer belt 10 according to the second embodiment. In the present embodiment, the structure is the same as that of the first embodiment, but a shield plate 25 and an inclined plate are provided at the opening of the charge applying device 14 to keep the cleaning performance of the transfer belt cleaner 8 always good. A plate 26 is provided. It has been confirmed by an experiment that by installing the inclined plate 26, a further static elimination effect of the recording medium 9 can be obtained. The gap A between the shielding plate 25 and the inclined plate 26 is adjusted so as to suppress the charge from the charge applying device 14 flowing into the roller 11 and to maintain the cleaning performance of the transfer belt cleaner 8 satisfactorily. The gap A is 3 mm. The gap width varies depending on the shape of the charge applying device 14, the applied current, or the length of the inclined plate 26.
Set between mm.
【００２８】本構成においても実施例１で述べた全ての
効果と同様、トナー２３を転写された記録体９が定着装
置１２を通過するまでの間、画像劣化を招くトナー２３
の飛散を防止でき、放電模様がなく、長期の使用によっ
ても画像を著しく乱すことなく、高品位な画像が得られ
る画像形成装置を提供できると同時に、転写ベルトクリ
ーナ８のクリーニング性能を常に良好な状態に保持でき
る。In this configuration, as in the case of all the effects described in the first embodiment, the toner 23 that causes image deterioration until the recording material 9 onto which the toner 23 has been transferred passes through the fixing device 12.
Of the transfer belt cleaner 8 can be provided, and the cleaning performance of the transfer belt cleaner 8 can be always improved. Can be kept in a state.
【００２９】[0029]
【発明の効果】以上述べた本発明によれば、転写ベルト
の記録体分離位置に対応したローラに対抗した位置にト
ナーと逆極性の電荷を転写ベルトとの分離後の記録体の
裏面と転写ベルトに供給する電荷付与装置を設置して記
録体を除電し、分離後の記録体の帯電を防止し、かつ転
写ベルトクリーナ性能を高め、転写ベルトの上記ローラ
にトナーと逆極性のバイアス電位を印加して記録体と転
写ベルトの分離位置をより電荷付与装置に近接させて電
荷付与装置による記録体の除電効果を高め、かつ上記バ
イアス電位により上記ローラと記録体表面のトナーとの
間にもクーロン力を発生させ記録体とトナーとを密着さ
せるので、記録体と転写ベルトの分離時におけるトナー
の舞散りや移動を防止し、転写ベルトクリーナのクリー
ニング性能を高く維持する効果がある。According to the present invention described above, a charge having a polarity opposite to that of the toner is transferred to the back surface of the recording material after separation from the transfer belt at a position opposite to the roller corresponding to the recording material separation position of the transfer belt. A charge applying device for supplying to the belt is installed to eliminate the charge on the recording material, prevent the charged recording material from being separated, and enhance the transfer belt cleaner performance. By applying the voltage, the separation position of the recording material and the transfer belt is brought closer to the charge applying device to enhance the charge eliminating effect of the recording material by the charge applying device. Coulomb force is generated to make the recording material and toner adhere to each other, preventing toner scattering and movement when separating the recording material and transfer belt, and improving the cleaning performance of the transfer belt cleaner. The effect of equity.
【図１】図１は実施例１の記録体９と転写ベルト１０の
分離位置付近の構成を示す断面側面図。FIG. 1 is a cross-sectional side view illustrating a configuration near a separation position between a recording medium 9 and a transfer belt 10 according to a first embodiment.
【図２】図２は本発明における画像形成装置の基本構成
を示す断面側面図。FIG. 2 is a sectional side view showing a basic configuration of the image forming apparatus according to the present invention.
【図３】図３は実施例２の記録体９と転写ベルト１０の
分離位置付近の構成を示す断面側面図。FIG. 3 is a cross-sectional side view illustrating a configuration near a separation position of a recording medium 9 and a transfer belt 10 according to a second embodiment.
【図４】従来のベルト転写／搬送方式を用いた画像形成
装置の模式図。FIG. 4 is a schematic view of an image forming apparatus using a conventional belt transfer / transport system.
１…感光体、２…感光体帯電装置、３…露光装置、４…
現像装置、５…転写装置、７…感光体クリーナ、８…転
写ベルトクリーナ、９…記録体、１０…転写ベルト、１
１，２２，２４…駆動ローラ，従動ローラ、１２…定着
装置、１４…電荷付与装置、２５…遮蔽板、２６…傾斜
板。REFERENCE SIGNS LIST 1 photoconductor 2 photoconductor charging device 3 exposure device 4
Developing device, 5 ... Transfer device, 7 ... Photoconductor cleaner, 8 ... Transfer belt cleaner, 9 ... Recorded body, 10 ... Transfer belt, 1
1, 22, 24: drive roller, driven roller, 12: fixing device, 14: charge applying device, 25: shielding plate, 26: inclined plate.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三矢 輝章 茨城県日立市大みか町七丁目１番１号 株式会社 日立製作所 日立研究所内 (72)発明者 梅田 高雄 東京都千代田区大手町二丁目６番２号 日立工機株式会社内 (72)発明者 安西 正保 東京都千代田区大手町二丁目６番２号 日立工機株式会社内 (72)発明者 栗林 夏城 東京都千代田区大手町二丁目６番２号 日立工機株式会社内 (72)発明者 三輪 正人 東京都千代田区大手町二丁目６番２号 日立工機株式会社内 (72)発明者 鈴木 貴志 東京都千代田区大手町二丁目６番２号 日立工機株式会社内 (56)参考文献 特開 平６−110338（ＪＰ，Ａ) 特開 平４−29174（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G03G 15/16 G03G 15/14 101 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruaki Sanya 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Takao Umeda 2-6-Otemachi, Chiyoda-ku, Tokyo 2 Hitachi Koki Co., Ltd. (72) Masaho Anzai, Inventor 2-6-2, Otemachi, Chiyoda-ku, Tokyo Hitachi Koki Co., Ltd. (72) Kuribayashi, Natsujo 2-cho, Otemachi, Chiyoda-ku, Tokyo No. 2 within Hitachi Koki Co., Ltd. (72) Inventor Masato Miwa 2-6-2 Otemachi, Chiyoda-ku, Tokyo 2 Within Hitachi Koki Co., Ltd. (72) Takashi Suzuki 2-chome Otemachi, Chiyoda-ku, Tokyo No. 2 Within Hitachi Koki Co., Ltd. (56) References JP-A-6-110338 (JP, A) JP-A-4-29174 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB Name) G03G 15/16 G03G 15/14 101
Claims (4)
搬送過程において、感光体から記録体にトナーを転写す
る電子写真の画像形成装置において、該記録体が該無端
ベルトから分離する位置に対応したローラに該トナーと
逆極性の電位を付与し、該ローラに対抗した位置にトナ
ーと逆極性の電荷を該記録体及び上記無端ベルトに供給
する電荷付与装置を設置することを特徴とする画像形成
装置。An electrophotographic image forming apparatus in which a recording medium is conveyed by using an endless belt and toner is transferred from a photosensitive member to the recording medium during the conveyance process, wherein the recording medium is separated from the endless belt. A charge applying device for applying an electric potential having a polarity opposite to that of the toner to a roller corresponding to the roller and supplying an electric charge having a polarity opposite to that of the toner to the recording medium and the endless belt at a position opposed to the roller. Image forming apparatus.
て、該記録体が該無端ベルトから分離する位置に対応し
たローラと対抗する面に開口を有することを特徴とする
請求項１記載の画像形成装置。2. The apparatus according to claim 1, wherein said charge applying device is a corotron charger, and has an opening on a surface opposed to a roller corresponding to a position where said recording medium is separated from said endless belt. Image forming device.
から分離する位置に対応したローラと対抗する面の一部
分に開口を有することを特徴とする請求項１記載の画像
形成装置。3. An image forming apparatus according to claim 1, wherein said recording medium of said charge applying device has an opening in a part of a surface facing a roller corresponding to a position where said recording medium is separated from said endless belt.
から分離する位置に対応したローラと対抗する面に遮蔽
板を有し、該電荷付与装置と該無端ベルトとの中間位置
に傾斜板を有することを特徴とする請求項２記載の画像
形成装置。4. The charge applying device has a shield plate on a surface opposite to a roller corresponding to a position where the recording medium separates from the endless belt, and is inclined at an intermediate position between the charge applying device and the endless belt. The image forming apparatus according to claim 2, further comprising a plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01325893A JP3186291B2 (en) | 1993-01-29 | 1993-01-29 | Image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01325893A JP3186291B2 (en) | 1993-01-29 | 1993-01-29 | Image forming device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06230684A JPH06230684A (en) | 1994-08-19 |
| JP3186291B2 true JP3186291B2 (en) | 2001-07-11 |
Family
ID=11828200
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01325893A Expired - Lifetime JP3186291B2 (en) | 1993-01-29 | 1993-01-29 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3186291B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102216087B1 (en) * | 2019-06-05 | 2021-03-12 | 문정혁 | Vapor chamber and method for manufacturing the same |
-
1993
- 1993-01-29 JP JP01325893A patent/JP3186291B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102216087B1 (en) * | 2019-06-05 | 2021-03-12 | 문정혁 | Vapor chamber and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06230684A (en) | 1994-08-19 |
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