JPH0954503A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable sure destaticization without increasing the scale and cost of a device, to reduce a load to a transfer material carrying means and an intermediate transfer body and to prolong the life by destaticizing the front and rear surfaces of the transfer material carrying means and the intermediate transfer body with a contact type destaticization member, that is, destaticizing the inside and outside on the upstream and downstream sides of a cleaning means respectively. SOLUTION: First and second destaticization means are provided on the upstream and downstream sides of a belt cleaner 20 respectively. The first destaticization means is composed of a conductive destaticization brush 21 which is provided inside a transfer belt 5 and comes into contact with the rear surface of the belt 5 and an earth electrode 23 arranged to face the brush 21, without contacting and an AC voltage is applied to the brush 21 from a power source 22. On the other hand, the second destaticization means is composed of a conductive destaticization brush 24 which is provided outside the transfer belt 5 and comes into contact with the front surface of the belt 5 and a grounded electrode 26 arranged to face the brush 24, without contacting and the AC voltage is applied to the brush 24 from a power source 25.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、複写機やプリンタ
などの電子写真方式を用いた画像形成装置に関し、詳し
くは、トナー像を転写される用紙を担持して搬送する転
写材搬送装置を備えた画像形成装置、及び、ベルトやフ
ィルム上に一旦トナー像を転写した後に用紙へ再転写す
る中間転写体を備え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 electrophotographic image forming apparatus such as a copying machine or a printer, and more specifically, it is provided with a transfer material conveying device for carrying and conveying a sheet on which a toner image is transferred. The present invention also relates to an image forming apparatus having an intermediate transfer member that transfers a toner image onto a belt or a film and then retransfers the toner image onto a sheet.

【０００２】[0002]

【従来の技術】従来、ベルト状の転写材搬送手段に用紙
やＯＨＰシートなどの転写材を保持し、転写、搬送を行
う所謂ベルト転写方式や、円筒ドラム状の転写材搬送手
段に転写材を保持し、転写、搬送を行う所謂転写ドラム
方式が提案されており、また、それらには転写ベルトや
転写ドラムなどの転写材搬送手段の表裏面の除電を行う
ために、転写ベルトや転写ドラムを挟み除電用コロナチ
ャージャや除電ブラシを対向配置させるものが提案され
ている。2. Description of the Related Art Conventionally, a so-called belt transfer method in which a transfer material such as a sheet or an OHP sheet is held and transferred and conveyed by a belt-shaped transfer material conveying means, or a transfer material is transferred to a cylindrical drum-shaped transfer material conveying means. A so-called transfer drum method for holding, transferring, and conveying has been proposed. In addition, there is a transfer belt or a transfer drum for removing charges on the front and back surfaces of a transfer material conveying unit such as a transfer belt or a transfer drum. It has been proposed to dispose a corona charger for static elimination and a static elimination brush to face each other.

【０００３】また、ベルト状の中間転写体上に色の異な
るトナー像を順次転写し、その後これらのトナー像を転
写材上へ一括転写する画像形成装置が提案されており、
この種の装置においても、上述のものと同様に中間転写
体の表裏面の除電を行う必要がある。Further, an image forming apparatus has been proposed in which toner images of different colors are sequentially transferred onto a belt-shaped intermediate transfer member, and then these toner images are collectively transferred onto a transfer material.
In this type of apparatus as well, it is necessary to remove the charge on the front and back surfaces of the intermediate transfer member as in the case of the above.

【０００４】[0004]

【発明が解決しようとする課題】ところが、前記転写材
搬送手段や中間転写体を除電するためにコロナチャージ
ャを設けた場合は、このコロナチャージャにより大量の
オゾンが発生してしまい、そのためオゾンフィルターや
オゾン吸引ファン等を設ける必要があり、装置の大型
化、コストアップ等の問題を有していた。However, when a corona charger is provided in order to neutralize the transfer material conveying means and the intermediate transfer member, a large amount of ozone is generated by the corona charger, so that an ozone filter or an ozone filter is used. It is necessary to provide an ozone suction fan or the like, which causes problems such as an increase in size of the device and an increase in cost.

【０００５】一方、転写材搬送手段や中間転写体を除電
するために、これらの表裏面に接触する一対の導電性ブ
ラシを設け、このブラシに電圧を印加し除電する方法も
あるが、転写材搬送手段や中間転写体の表面に付着して
いるトナー等でブラシが汚れると除電性能が低下するた
め、ブラシは清掃手段の下流に設ける必要がある。その
場合、転写材搬送手段や中間転写体に付着しているトナ
ーはこれらが保持する電荷によってその表面に吸着され
ており、そのトナーを完全に清掃するために清掃手段は
より強く転写材搬送手段に摺擦させる必要があり、その
結果、転写材搬送手段の表面にキズ等が入りやすく寿命
が短くなってしまう問題があった。このために両ブラシ
を回転ブラシとし、回転ブラシにブラシ清掃手段を設け
る方法も考えられるが、回転させる手段やブラシ清掃手
段が必要であり、大型化、コストアップを招来するとい
う問題があった。On the other hand, there is also a method of providing a pair of conductive brushes which come into contact with the front and back surfaces of the transfer material conveying means and the intermediate transfer body, and applying a voltage to the brushes to remove the charge. If the brush is contaminated with the toner or the like adhering to the surface of the conveying unit or the intermediate transfer member, the charge removal performance is deteriorated, so the brush must be provided downstream of the cleaning unit. In that case, the toner adhering to the transfer material conveying means and the intermediate transfer body is adsorbed on the surface by the electric charge held by the transfer material conveying means and the intermediate transfer body, and the cleaning means is stronger to completely clean the toner. Therefore, there is a problem that the surface of the transfer material conveying means is easily scratched and its life is shortened. For this reason, a method in which both brushes are rotary brushes and brush cleaning means is provided on the rotary brush is conceivable. However, there is a problem in that a rotating means and a brush cleaning means are required, resulting in an increase in size and an increase in cost.

【０００６】[0006]

【課題を解決するための課題】本発明の目的は、装置の
大型化、コストアップなどを招来することなく転写材搬
送手段や中間転写体の除電を行うとともに、転写材搬送
手段や中間転写体に対する清掃手段による負荷を軽減
し、より高寿命を達成でき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 remove charge from a transfer material conveying means and an intermediate transfer body without increasing the size of the apparatus and increase the cost, and at the same time, to transfer material conveying means and an intermediate transfer body. An object of the present invention is to provide an image forming apparatus that can reduce the load of the cleaning means on the above and can achieve a longer life.

【０００７】上記目的を達成するために、本発明は、転
写材搬送手段や中間転写体の除電手段としてブラシ等の
接触除電部材を用い、これらの表面を除電する除電手段
は清掃手段の下流側に、裏面を除電する除電手段は清掃
手段の上流側に設けたことを特徴とする。In order to achieve the above object, the present invention uses a contact charge-eliminating member such as a brush as a charge-eliminating unit for a transfer material conveying unit or an intermediate transfer member, and the charge-eliminating unit for eliminating the charge on the surface of these members is located on the downstream side of the cleaning unit. In addition, the discharging means for discharging the back surface is provided upstream of the cleaning means.

【０００８】[0008]

【作用】本発明の構成によると、清掃の前に転写材搬送
手段や中間転写体の裏面の電荷を除去することで、転写
体とトナーとの間の吸着力を弱めることができ清掃の負
荷を軽減できる。また、転写材搬送手段や中間転写体の
清掃の後に表面の除電を行うので、表面の接触除電部材
がトナーで汚れることはなく安定した除電を行うことが
できる。According to the structure of the present invention, by removing the charges on the back surface of the transfer material conveying means or the intermediate transfer member before cleaning, the attraction force between the transfer member and the toner can be weakened, and the cleaning load can be reduced. Can be reduced. Further, since the surface is neutralized after cleaning the transfer material conveying means and the intermediate transfer member, the contact neutralizing member on the surface is not contaminated with the toner, and stable static neutralization can be performed.

【０００９】[0009]

【発明の実施の形態】以下、本発明を図面に示す実施例
に基づいて詳細に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

【００１０】第１図は、本発明を適用した第１実施例の
全体概略構成図であって、図中、感光体ドラム（１）は
矢印ａ方向に回転駆動され、その周囲に、帯電チャージ
ャ（２）、プリントヘッド（３）、現像器（４）、転写
ベルト（５）、クリーナー（６）、イレーサー（７）等
が配置されている。FIG. 1 is an overall schematic configuration diagram of a first embodiment to which the present invention is applied. In the figure, a photosensitive drum (1) is rotationally driven in a direction of an arrow a, around which a charging charger is provided. (2), a print head (3), a developing device (4), a transfer belt (5), a cleaner (6), an eraser (7), etc. are arranged.

【００１１】転写ベルト（５）は感光体ドラム（１）に
同期して矢印ｂ方向に回転駆動されており、ＰＶＤＦ
（ポリフッ化ビニリデン）やＰＣ（ポリカーボネイト）
等を材料とする誘電体フィルムベルト、もしくはＣＲゴ
ムやウレタンゴム等を材料とするゴムベルトで形成さ
れ、駆動ローラ（１８）、及び従動ローラ（１９）によ
って張架されている。The transfer belt (5) is rotationally driven in the direction of arrow b in synchronism with the photosensitive drum (1).
(Polyvinylidene fluoride) and PC (Polycarbonate)
It is formed of a dielectric film belt made of, for example, or a rubber belt made of CR rubber, urethane rubber, or the like, and is stretched by a driving roller (18) and a driven roller (19).

【００１２】転写ベルト（５）の内部には感光体ドラム
（１）と対向して転写ブラシ（１６）が配置されてい
る。この転写ブラシ（１６）は転写ベルト（５）の裏面
に接触して設けられた導電性ブラシからなり、電源（１
７）に接続され、転写時に直流電圧が印加される。転写
ブラシ（１６）の下流側には転写ベルト（５）から用紙
を分離する分離爪（１４）が駆動ローラ（１８）と対向
して設けられ、分離爪（１４）の下流側にベルトクリー
ナ（２０）が設けられている。ベルトクリーナ（２０）
は転写ベルト（５）の表面に当接して配置されたブレー
ドと、転写ベルトを介してブレードと対向するローラを
備えている。A transfer brush (16) is arranged inside the transfer belt (5) so as to face the photosensitive drum (1). The transfer brush (16) is composed of a conductive brush provided in contact with the back surface of the transfer belt (5), and has a power source (1
7), and a DC voltage is applied during transfer. A separation claw (14) for separating the paper from the transfer belt (5) is provided on the downstream side of the transfer brush (16) so as to face the drive roller (18), and a belt cleaner (downstream) is provided on the downstream side of the separation claw (14). 20) is provided. Belt cleaner (20)
Comprises a blade arranged in contact with the surface of the transfer belt (5), and a roller facing the blade via the transfer belt.

【００１３】また、ベルトクリーナ（２０）の上流側に
は第１除電手段が設けられ、下流側には第２除電手段が
設けられている。第１除電手段は、ベルトクリーナ（２
０）と駆動ローラ（１８）の間に位置し、転写ベルト
（５）の内部に設けられベルト（５）の裏面に接触する
導電性の除電ブラシ（２１）と、ベルト（５）を介して
除電ブラシ（２１）と対向して非接触に配置された接地
電極（２３）とから構成され、除電ブラシ（２１）には
電源（２２）から交流電圧が印加されている。一方、第
２除電手段は、ベルトクリーナ（２０）と従動ローラ
（１９）の間に位置し、転写ベルト（５）の外部に設け
られベルト（５）の表面に接触する導電性の除電ブラシ
（２４）と、ベルト（５）を介して除電ブラシ（２４）
と対向して非接触に配置された接地電極（２６）とから
構成され、除電ブラシ（２４）には電源（２５）から交
流電圧が印加されている。即ち、ベルトクリーナ（２
０）の上流側に位置する除電ブラシ（２１）は転写ベル
ト（５）の裏面へ接触するよう配置し、下流側に位置す
る除電ブラシ（２４）は転写ベルト（５）の表面へ接触
するよう配置している。A first static eliminator is provided on the upstream side of the belt cleaner (20) and a second static eliminator is provided on the downstream side. The first charge eliminating means is a belt cleaner (2
0) and the driving roller (18), which is provided inside the transfer belt (5) and has a conductive static elimination brush (21) contacting the back surface of the belt (5) and the belt (5). The static elimination brush (21) is constituted by a ground electrode (23) arranged in a non-contact manner so as to face the static elimination brush (21), and an AC voltage is applied to the static elimination brush (21) from a power source (22). On the other hand, the second static eliminator is located between the belt cleaner (20) and the driven roller (19), is provided outside the transfer belt (5), and is a conductive static eliminator brush (contacting the surface of the belt (5)). 24) and the static elimination brush (24) via the belt (5)
And a ground electrode (26) which is arranged in a non-contact manner so as to face the above, and an AC voltage is applied to the static elimination brush (24) from a power source (25). That is, the belt cleaner (2
0) is arranged so that the static elimination brush (21) located on the upstream side is in contact with the back surface of the transfer belt (5), and the static elimination brush (24) located on the downstream side is in contact with the front surface of the transfer belt (5). It is arranged.

【００１４】上述の構成において、用紙トレイ（１０）
から給紙ローラ（１１）により送り出された用紙Ｐは、
ガイド（１２）でタイミングローラ（９）へ案内され、
タイミングローラ（９）で感光体ドラム（１）と同期さ
れた後、直流電源（２８）に接続された従動ローラ（１
９）と接地された対向ローラ（２４）の間へ送りこま
れ、駆動ローラ（１８）によって駆動される転写ベルト
（５）に静電吸着される。用紙Ｐが感光体ドラム（１）
と転写ベルト（５）の間の転写位置に到達すると、転写
ベルト（５）の内側の転写ブラシ（１６）により転写ベ
ルト（５）に転写電荷が供給され、感光体ドラム（１）
上のトナー像が用紙Ｐ上に静電的に転写される。In the above structure, the paper tray (10)
The paper P sent from the paper by the paper feed roller (11) is
Guided by the guide (12) to the timing roller (9),
The driven roller (1) connected to the DC power source (28) after being synchronized with the photosensitive drum (1) by the timing roller (9)
9) is fed between the grounded opposing roller (24) and electrostatically attracted to the transfer belt (5) driven by the driving roller (18). Paper P is photoconductor drum (1)
When the transfer position between the transfer belt (5) and the transfer belt (5) is reached, transfer charges are supplied to the transfer belt (5) by the transfer brush (16) inside the transfer belt (5), and the photoconductor drum (1).
The upper toner image is electrostatically transferred onto the paper P.

【００１５】トナー像が転写された用紙Ｐは、転写ベル
ト（５）に吸着された状態で搬送され、分離爪（１４）
で転写ベルト（５）から剥離される。そしてガイド（１
５）にて定着部へ案内され、定着ローラ（８）にて定着
され、排紙トレイ（１３）上へ排出される。The sheet P on which the toner image has been transferred is conveyed while being attracted to the transfer belt (5), and the separation claw (14).
Is peeled off from the transfer belt (5). And guide (1
The sheet is guided to the fixing section by 5), is fixed by the fixing roller (8), and is discharged onto the sheet discharge tray (13).

【００１６】用紙Ｐが剥離された転写ベルト（５）は、
まずその裏面が除電ブラシ（２１）により転写ブラシ
（１６）で与えられた転写電荷を除電され、その後、ベ
ルトクリーナ（２０）で転写ベルト（５）の表面が清掃
される。この時既に転写ベルト（５）裏面の電荷は除電
されておりトナーの転写ベルト（５）への吸着力は弱く
なっているので容易に清掃できる。その後、転写ベルト
（５）の表面が除電ブラシ（２４）で除電される。この
時既に転写ベルト（５）の表面は清掃されており、除電
ブラシ（２４）がトナー等で汚れることはない。The transfer belt (5) from which the paper P is peeled off is
First, the back surface of the transfer belt (5) is neutralized by the static elimination brush (21) to eliminate the transfer charges provided by the transfer brush (16), and then the front surface of the transfer belt (5) is cleaned by the belt cleaner (20). At this time, the charge on the back surface of the transfer belt (5) has already been removed, and the attraction force of the toner to the transfer belt (5) is weakened, so that the transfer belt (5) can be easily cleaned. Then, the surface of the transfer belt (5) is neutralized by the static elimination brush (24). At this time, the surface of the transfer belt (5) has already been cleaned, and the static elimination brush (24) is not contaminated with toner or the like.

【００１７】尚、本実施例では除電ブラシ（２１）およ
び（２４）に交流電源を接続したが、直流を重畳した交
流電源でもよいし、直流電源のみを印加してもよい。In this embodiment, an AC power source is connected to the static elimination brushes (21) and (24), but an AC power source in which DC is superimposed may be used, or only a DC power source may be applied.

【００１８】第２図は、本発明を適用した第２実施例の
全体概略構成図である。この装置は所謂転写ドラム方式
のカラー画像形成装置であり、以下に詳細に説明する。FIG. 2 is an overall schematic configuration diagram of a second embodiment to which the present invention is applied. This apparatus is a so-called transfer drum type color image forming apparatus, which will be described in detail below.

【００１９】第２図において、（３０）は感光体ドラム
であり、図中矢印ａ方向に回転駆動され、その周囲に
は、帯電チャージャ（３１）、プリントヘッド（３
２）、イエロー色現像剤を収容する現像器（３３）、マ
ゼンタ色現像剤を収容する現像器（３４）、シアン色現
像剤を収容する現像器（３５）、黒色現像剤を収容する
現像器（３６）、クリーナー（３８）、イレーサー（３
９）等が配置されている。In FIG. 2, reference numeral (30) is a photosensitive drum, which is rotationally driven in the direction of arrow a in the figure, and around which a charger (31) and a print head (3) are provided.
2), a developing device (33) containing a yellow developer, a developing device (34) containing a magenta color developer, a developing device (35) containing a cyan color developer, and a developing device containing a black developer. (36), cleaner (38), eraser (3
9) etc. are arranged.

【００２０】転写ドラム（３７）は枠体にＰＶＤＦ（ポ
リフッ化ビニリデン）やＰＣ（ポリカーボネイト）等の
誘電体フィルムを巻き付け固定した円筒ドラムであっ
て、感光体ドラム（３０）に同期して矢印ｂ方向に回転
駆動される。The transfer drum (37) is a cylindrical drum having a frame body around which a dielectric film such as PVDF (polyvinylidene fluoride) or PC (polycarbonate) is wound and fixed. The transfer drum (37) is synchronized with the photosensitive drum (30) by an arrow b. Driven to rotate.

【００２１】転写ドラム（３７）の内部には感光体ドラ
ム（３０）と対向して転写ブラシ（４６）が配置されて
いる。この転写ブラシ（４６）は転写ドラム（３７）の
裏面に接触して設けられた導電性ブラシからなり、電源
（４７）に接続され、転写時に直流電圧が印加される。
転写ブラシ（４６）の上流側内部には用紙を転写ドラム
（３７）へ吸着させる吸着ブラシ（４３）が転写ドラム
（３７）の裏面に接触して設けられており、転写ドラム
（３７）を介し吸着ブラシ（４３）に対向して接地導電
ローラ（４４）が配設されている。この吸着ブラシは電
源４５に接続されており、用紙の吸着時直流電圧が印加
される。一方、転写ブラシ（４６）の下流側には転写ド
ラム（３７）から用紙を分離する分離爪（５１）が設け
られ、分離爪（１４）の下流側に転写ドラム（３７）表
面を清掃するドラムクリーナ（５３）が設けられてい
る。A transfer brush (46) is arranged inside the transfer drum (37) so as to face the photosensitive drum (30). The transfer brush (46) is a conductive brush provided in contact with the back surface of the transfer drum (37), is connected to a power source (47), and is applied with a DC voltage during transfer.
An adsorption brush (43) for adsorbing the paper to the transfer drum (37) is provided inside the upstream side of the transfer brush (46) in contact with the back surface of the transfer drum (37). A grounding conductive roller (44) is arranged to face the suction brush (43). This suction brush is connected to a power supply 45, and a DC voltage is applied when the paper is sucked. On the other hand, a separation claw (51) for separating the paper from the transfer drum (37) is provided on the downstream side of the transfer brush (46), and a drum for cleaning the surface of the transfer drum (37) on the downstream side of the separation claw (14). A cleaner (53) is provided.

【００２２】また、ドラムクリーナ（５３）の上流側に
は第１除電手段が設けられ、下流側には第２除電手段が
設けられている。第１除電手段は、分離爪（５１）と転
写ブラシ（４６）の間に位置し、転写ドラム（３７）の
内部に設けられドラム（３７）の裏面に接触する導電性
の除電ブラシ（４８）と、ドラム（３７）を介して除電
ブラシ（４８）と対向して非接触に配置された接地電極
（５０）とから構成され、除電ブラシ（４８）には電源
（４９）から交流電圧が印加されている。一方、第２除
電手段は、ドラムクリーナ（５３）と吸着ブラシ（４
３）の間に位置し、転写ドラム（３７）の外部に設けら
れドラム（５）の表面に接触する導電性の除電ブラシ
（５４）と、ドラム（３７）を介して除電ブラシ（５
４）と対向して非接触に配置された接地電極（５６）と
から構成され、除電ブラシ（５４）には電源（２５）か
ら交流電圧が印加されている。分離爪（５１）、転写ド
ラムクリーナ（５３）および除電ブラシ（５４）は、図
示しない機構によってそれぞれ転写ドラム（３７）表面
に対し離隔可能に構成されている。Further, a first static eliminator is provided on the upstream side of the drum cleaner (53), and a second static eliminator is provided on the downstream side. The first static eliminator is located between the separating claw (51) and the transfer brush (46), is provided inside the transfer drum (37), and is a conductive static eliminator brush (48) that contacts the back surface of the drum (37). And a ground electrode (50) arranged in a non-contact manner facing the static elimination brush (48) through the drum (37), and an AC voltage is applied to the static elimination brush (48) from a power source (49). Has been done. On the other hand, the second static eliminator includes the drum cleaner (53) and the suction brush (4
3), which is provided outside the transfer drum (37) and is in contact with the surface of the drum (5), and is a conductive static elimination brush (54), and the static elimination brush (5) via the drum (37).
4) and a ground electrode (56) arranged in a non-contact manner facing each other, and an AC voltage is applied to the static elimination brush (54) from a power source (25). The separation claw (51), the transfer drum cleaner (53) and the static elimination brush (54) are configured to be separated from the surface of the transfer drum (37) by a mechanism (not shown).

【００２３】このようにして、用紙Ｐは図示しない用紙
トレイよりタイミングローラ（４１）へ送られ、タイミ
ングローラ（４１）で感光体ドラム（３０）と同期され
た後、ガイド（４２）により、直流電源（４５）に接続
された吸着ブラシ（４３）と接地された対向ローラ（４
４）の間へ送りこまれ、転写ドラム（３７）に静電吸着
される。用紙Ｐが感光体ドラム（３０）と転写ドラム
（３７）の間の転写位置に到達すると、直流電源（４
７）に接続された導電性転写ブラシ（４６）により転写
ドラム（３７）の内面に転写電荷が供給され、まず感光
体ドラム（３０）上に形成されているイエロー色のトナ
ー像が用紙Ｐに静電的に転写される。In this way, the paper P is sent to the timing roller (41) from the paper tray (not shown), synchronized with the photosensitive drum (30) by the timing roller (41), and then the direct current is fed by the guide (42). A suction brush (43) connected to a power source (45) and an opposing roller (4) grounded
4) and is electrostatically adsorbed to the transfer drum (37). When the paper P reaches the transfer position between the photoconductor drum (30) and the transfer drum (37), the DC power supply (4
Transfer charges are supplied to the inner surface of the transfer drum (37) by the conductive transfer brush (46) connected to 7), and the yellow toner image formed on the photoconductor drum (30) is first transferred onto the paper P. It is electrostatically transferred.

【００２４】イエロートナー像が転写された用紙Ｐは、
転写ドラム（３７）に吸着された状態で搬送され、非作
動の除電ブラシ（４８）、分離爪（５１）、転写ドラム
クリーナ（５３）、除電ブラシ（５４）および吸着ブラ
シ（４３）を通過し、再び転写ドラム（３７）と感光体
ドラム（３０）の間の転写位置に到達する。尚、この
間、分離爪（５１）、転写ドラムクリーナ（５３）およ
び除電ブラシ（５４）は離隔して転写ドラム（３７）と
非接触状態となっており、また、吸着部の対向ローラ
（４４）はもともと転写ドラム（３７）とは非接触状態
で配置されており、用紙Ｐ上のイエロートナー像は乱さ
れない。The paper P on which the yellow toner image has been transferred is
It is conveyed while being attracted to the transfer drum (37) and passes through the non-actuated static elimination brush (48), separation claw (51), transfer drum cleaner (53), static elimination brush (54) and suction brush (43). The transfer position between the transfer drum (37) and the photoconductor drum (30) is again reached. During this time, the separation claw (51), the transfer drum cleaner (53), and the static elimination brush (54) are separated from each other and are in non-contact with the transfer drum (37), and the opposing roller (44) of the suction portion is also provided. Originally, the yellow toner image on the paper P is not disturbed because it is originally arranged in non-contact with the transfer drum (37).

【００２５】転写位置に到達した用紙Ｐは、前述同様転
写ブラシ（４７）の作用により、今度は感光体ドラム
（３０）上に形成されているマゼンタトナー像が転写さ
れる。その後用紙Ｐは、その上に転写されたイエロート
ナー像およびマゼンタトナー像を保持したまま前述同様
に搬送され、今度はシアントナー像が転写される。The magenta toner image formed on the photosensitive drum (30) is transferred to the paper P, which has reached the transfer position, by the action of the transfer brush (47) as described above. After that, the paper P is conveyed in the same manner as described above while holding the yellow toner image and the magenta toner image transferred thereon, and the cyan toner image is transferred this time.

【００２６】同様にして最後に黒トナー像が転写される
と、除電ブラシ（４８）に電圧が印加されるとともに、
分離爪（５１）、転写ドラムクリーナ（５３）および除
電ブラシ（５４）が転写ドラム（３７）と接触する状態
に切り替えられ、用紙Ｐは、除電ブラシ（４８）で、転
写ドラム（３７）の裏面を除電されつつ、分離爪（５
１）で転写ドラム（３７）から剥離される。この時、分
離爪（５１）は、除電ブラシ（４８）で除電されて吸着
力の弱まった用紙Ｐを剥離するため、用紙Ｐにかかる負
荷も軽減され、用紙Ｐ上のトナー像が乱れることむな
い。そして、用紙Ｐはガイド（５２）にて定着部へ案内
され、定着ローラ（４０）にて定着され、図示しない排
紙トレイ上へ排出される。Similarly, when the black toner image is finally transferred, a voltage is applied to the charge eliminating brush (48) and
The separation claw (51), the transfer drum cleaner (53), and the static elimination brush (54) are switched to a state in which they are in contact with the transfer drum (37), and the paper P is removed by the static elimination brush (48) on the back surface of the transfer drum (37). While removing the charge, separate claw (5
In 1), it is separated from the transfer drum (37). At this time, the separation claw (51) peels off the paper P that has been weakened by the static elimination brush (48) and has a weaker adsorption force. Therefore, the load on the paper P is also reduced, and the toner image on the paper P is disturbed. Absent. Then, the paper P is guided to the fixing portion by the guide (52), fixed by the fixing roller (40), and discharged onto a paper discharge tray (not shown).

【００２７】用紙Ｐが剥離された転写ドラム（３７）
は、転写ドラムクリーナ（５３）によりその表面がクリ
ーニングされる。この時既に転写ドラム（３７）の内面
の電荷は、用紙分離に際して除電ブラシ（４８）により
除電されており、トナーの転写ドラム（３７）への吸着
力は弱くなっているので容易に清掃できる。その後、転
写ドラム（３７）の表面が除電ブラシ（５４）で除電さ
れる。この時既に転写ドラム（３７）の表面は清掃され
ており、除電ブラシ（５４）がトナー等で汚れることは
ない。Transfer drum (37) from which the paper P has been peeled off
The surface is cleaned by the transfer drum cleaner (53). At this time, the charge on the inner surface of the transfer drum (37) has already been removed by the charge removal brush (48) when the paper is separated, and the attraction force of the toner to the transfer drum (37) is weakened so that the transfer drum (37) can be easily cleaned. Then, the surface of the transfer drum (37) is neutralized by the static elimination brush (54). At this time, the surface of the transfer drum (37) has already been cleaned, and the charge removal brush (54) is not contaminated with toner or the like.

【００２８】尚、本実施例でも除電ブラシ（４８）およ
び（５４）に交流電源を接続したが、直流を重畳した交
流電源でもよいし、直流電源であってもよい。Although an AC power source was connected to the static elimination brushes (48) and (54) in this embodiment, it may be an AC power source in which DC is superposed or a DC power source.

【００２９】以下に第１図に示す画像形成装置での確認
結果を示す。第１図において転写ベルト（５）として
は、表面および体積抵抗が１０14Ω・ｃｍで厚みが１５
０μｍのＰＶＤＦ（ポリフッ化ビニリデン）を用いた。The results of confirmation by the image forming apparatus shown in FIG. 1 are shown below. In FIG. 1, the transfer belt (5) has a surface and volume resistance of 10 14 Ω · cm and a thickness of 15
PVDF (polyvinylidene fluoride) of 0 μm was used.

【００３０】除電ブラシ（２１）および（２４）は、第
３図に示すように導電性の布地（６１）に導電性ブラシ
糸（６０）を織り込んだ後切断したものを、導電接着剤
にてアルミニウムの基体（６２）に接着した構成であ
り、ブラシ（６０）部は、ブラシ長さＬが５ｍｍ、幅Ｄ
は８ｍｍとした。また、ブラシ（６０）は密度が１０万
Ｆ（フィラー）／ｉｎｃｈ2 であり、電気抵抗が１０4
Ω・ｃｍとなるようにレーヨン系樹脂に導電性カーボン
を入れた材料を用いた。尚、転写ブラシ（１６）の詳細
は省略するが同じ材料のものを用いている。The static elimination brushes (21) and (24) are obtained by weaving the conductive brush thread (60) into the conductive cloth (61) and then cutting it with a conductive adhesive as shown in FIG. The brush (60) has a brush length L of 5 mm and a width D.
Was 8 mm. The brush (60) has a density of 100,000 F (filler) / inch2 and an electric resistance of 104.
A material was used in which conductive carbon was added to a rayon-based resin so as to be Ω · cm. The details of the transfer brush (16) are omitted, but the same material is used.

【００３１】また、第１図の画像形成装置で使用するト
ナーはその摩擦帯電極性が（−）極性のもので、転写ブ
ラシ（１６）には直流電源（１７）より（＋）極性の２
ＫＶの電圧を印加し転写を行っている。Further, the toner used in the image forming apparatus of FIG. 1 has a triboelectrification polarity of (-) polarity, and the transfer brush (16) has a polarity of (+) from the DC power supply (17).
Transfer is performed by applying a voltage of KV.

【００３２】以上の構成で、まず除電ブラシ（２１）お
よび（２４）を非作動状態で画像を形成した場合、転写
ベルト（５）の除電が行われず、結果転写不良が発生し
た。また、ベルトクリーナ（２０）の線圧は、２．５ｇ
／ｍｍ程度にしないとベルトの清掃不良が発生した。With the above structure, when an image was formed with the static elimination brushes (21) and (24) in a non-operating state, the static elimination of the transfer belt (5) was not performed, resulting in defective transfer. The linear pressure of the belt cleaner (20) is 2.5g.
If it is not about / mm, cleaning failure of the belt occurs.

【００３３】この時、線圧が高過ぎベルトクリーナ（２
０）と転写ベルト（５）が強く摺擦されすぎて、転写ベ
ルト（５）の外面に線状のキズが多く入り、その結果ハ
ーフトーン画像にムラが発生してしまった。また、線圧
が高過ぎベルトクリーナー（２０）のブレードのめくれ
現象が発生してしまう場合もあった。At this time, the linear pressure is too high and the belt cleaner (2
0) and the transfer belt (5) were rubbed against each other too much, and many linear scratches were formed on the outer surface of the transfer belt (5), resulting in uneven halftone images. In addition, the linear pressure may be too high and the blade of the belt cleaner (20) may be turned over.

【００３４】そこで、除電ブラシ（２１）および（２
４）に交流電源（２２）および（２５）よりピーク電圧
が２．５ＫＶの交流電圧を印加したところ、転写ベルト
（５）の除電が十分行われ前述した転写不良は発生せ
ず、またベルトクリーナー（２０）の線圧も１．５ｇ／
ｍｍ程度で完全にベルトの清掃を行え、また前記の転写
ベルト（５）のキズやブレードのめくれ現象も発生しな
かった。Therefore, the static elimination brushes (21) and (2
When an AC voltage having a peak voltage of 2.5 KV was applied to 4) from the AC power supplies (22) and (25), the transfer belt (5) was sufficiently neutralized and the above-mentioned transfer failure did not occur, and a belt cleaner was used. The linear pressure of (20) is also 1.5g /
The belt could be completely cleaned at a thickness of about mm, and neither the scratches on the transfer belt (5) nor the curl phenomenon of the blade occurred.

【００３５】また、交流電源（２２）および（２５）を
直流電源に変え、除電ブラシ（２１）に（−）極性の２
ＫＶの電圧を印加し、除電ブラシ（２４）に（＋）極性
の２ＫＶの電圧を印加しても同様の効果が得られた。こ
こで、除電ブラシ（２１）に（−）極性の電圧を印加し
たのは、転写ブラシ（１６）により転写ベルト（５）の
内面に供給された（＋）極性の電荷を除電するためであ
り、また除電ブラシ（２４）に（＋）極性の電圧を印加
したのは、転写ベルト（５）と感光体ドラム（１）の対
向部である転写部の近傍で発生する放電により転写ベル
ト（５）の外面にある（−）電荷を除電するためであ
る。Further, the alternating current power supplies (22) and (25) are changed to direct current power supplies, and the static elimination brush (21) has a negative polarity (2).
The same effect was obtained even when a voltage of KV was applied and a voltage of 2 KV of (+) polarity was applied to the static elimination brush (24). Here, the voltage of the (-) polarity is applied to the charge removal brush (21) to remove the charge of the (+) polarity supplied to the inner surface of the transfer belt (5) by the transfer brush (16). Further, the voltage of the (+) polarity is applied to the charge eliminating brush (24) because the discharge of the transfer belt (5) is caused in the vicinity of the transfer portion, which is the facing portion of the transfer belt (5) and the photosensitive drum (1). This is because the (−) charge on the outer surface of () is eliminated.

【００３６】同様の確認は第２図に示す画像形成装置に
おいても行ったが同様の効果が得られた。The same confirmation was performed in the image forming apparatus shown in FIG. 2, but the same effect was obtained.

【００３７】また以上の実施例は、導電性の除電ブラシ
を用いたものについて説明したが、前記実施例における
除電ブラシに代えて、第４図に示すような導電性あるい
は半導電性のローラ（６３）および（６４）等を用いて
も同様の効果が得られる。Further, in the above-mentioned embodiment, the one using the conductive static eliminating brush was explained, but instead of the static eliminating brush in the above-mentioned embodiment, a conductive or semi-conductive roller as shown in FIG. 4 ( The same effect can be obtained by using 63) and (64).

【００３８】なお、前記実施例は転写ベルトや転写ドラ
ム上に用紙を保持し、保持された用紙上にトナー像を転
写する形態の画像形成装置について述べたが、本発明は
これに限定されるものではなく、例えば特開平１−１６
６０７０号公報に記載されているような、トナー像を感
光体ドラムから一旦中間転写体に転写した後、中間転写
体から用紙へ再度転写する所謂中間転写方式の画像形成
装置にも適応できる。Although the above embodiment describes the image forming apparatus in which the sheet is held on the transfer belt or the transfer drum and the toner image is transferred onto the held sheet, the present invention is not limited to this. However, for example, Japanese Patent Laid-Open No. 1-16
It is also applicable to an image forming apparatus of a so-called intermediate transfer system in which a toner image is once transferred from a photosensitive drum to an intermediate transfer member and then transferred again from the intermediate transfer member to a sheet as described in JP-A-6070.

【００３９】[0039]

【発明の効果】以上説明したように、本発明は、転写材
搬送手段や中間転写体の表裏面の除電を接触タイプの除
電部材により行うもので、内面の除電は清掃手段の上流
側に、また外面の除電は清掃手段の下流側で行うことに
より、装置の大型化・コストアップなく確実に除電を行
えると共に、清掃手段による転写材搬送手段や中間転写
体への負荷を軽減でき転写材搬送手段や中間転写体の長
寿命化を行える。As described above, according to the present invention, the charge removal on the front and back surfaces of the transfer material conveying means and the intermediate transfer member is performed by the contact type charge removing member, and the charge removal on the inner surface is performed on the upstream side of the cleaning means. In addition, since the outer surface is discharged on the downstream side of the cleaning means, it is possible to reliably discharge electricity without increasing the size and cost of the device, and reduce the load on the transfer material conveying means and the intermediate transfer member by the cleaning means. The life of the means and the intermediate transfer member can be extended.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明に係る画像形成装置の第１実施例を示す
概略図FIG. 1 is a schematic view showing a first embodiment of an image forming apparatus according to the present invention.

【図２】本発明に係る画像形成装置の第２実施例を示す
概略図FIG. 2 is a schematic diagram showing a second embodiment of the image forming apparatus according to the present invention.

【図３】接触除電部材の詳細を示す図FIG. 3 is a diagram showing details of a contact static eliminator.

【図４】接触除電部材の別の具体例を示す図FIG. 4 is a diagram showing another specific example of the contact charge-eliminating member.

【符号の説明】[Explanation of symbols]

１，３０・・・・感光体ドラム ５・・・・転写ベルト ３７・・・・転写ドラム １６，４６・・・・転写ブラシ ２１，２４，４８，５４・・・・除電ブラシ ２０・・・・転写ベルトクリーナ ５３・・・・転写ドラムクリーナ ６３，６４・・・・除電ローラ 1, 30 ... Photoconductor drum 5 ... Transfer belt 37 ... Transfer drum 16, 46 ... Transfer brush 21, 24, 48, 54 ... Static elimination brush 20 ...・ Transfer belt cleaner 53 ・ ・ ・ ・ Transfer drum cleaner 63, 64 ・ ・ Electrification elimination roller

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】 トナー像が形成される像担持体と、転写
材を担持し搬送する転写材担持体と、前記転写材担持体
上の転写材に前記トナー像を転写する手段を備えた画像
形成装置において、 前記転写材担持体に接触する除電部材を、転写材担持面
では前記転写材担持体の清掃手段の下流側に、転写材非
担持面では前記清掃手段の上流側に設けたことを特徴と
する画像形成装置。1. An image including an image carrier on which a toner image is formed, a transfer material carrier that carries and conveys a transfer material, and means for transferring the toner image onto the transfer material on the transfer material carrier. In the forming apparatus, a charge removing member that comes into contact with the transfer material carrying member is provided on the transfer material carrying surface on the downstream side of the cleaning means of the transfer material carrying body, and on the transfer material non-bearing surface, on the upstream side of the cleaning means. An image forming apparatus characterized by. 【請求項２】 トナー像が形成される像担持体と、転写
材を表面に担持し搬送する転写材担持体と、前記転写材
担持体上の転写材に前記トナー像を静電的に転写する転
写手段と、転写材担持体の表面を清掃する清掃手段と、
搬送方向において清掃手段の上流側に設けられ、転写材
担持体の裏面に接触する第１除電部材と、搬送方向にお
いて清掃手段の下流側に設けられ、転写材担持体の表面
に接触する第２除電部材とを備えたことを特徴とする画
像形成装置。2. An image carrier on which a toner image is formed, a transfer material carrier that carries and conveys a transfer material on the surface, and the toner image is electrostatically transferred onto a transfer material on the transfer material carrier. Transfer means for cleaning, and a cleaning means for cleaning the surface of the transfer material carrier,
A first charge removing member that is provided on the upstream side of the cleaning unit in the transport direction and contacts the back surface of the transfer material carrier, and a second charge removing member that is provided on the downstream side of the cleaning unit in the transport direction and contacts the surface of the transfer material carrier. An image forming apparatus comprising a charge removing member. 【請求項３】 請求項２に記載の画像形成装置であっ
て、さらに転写材担持体から転写材を分離する分離手段
を備え、第１除電部材は転写材の搬送方向において分離
手段の上流側に配置されていることを特徴とする画像形
成装置。3. The image forming apparatus according to claim 2, further comprising a separating means for separating the transfer material from the transfer material carrier, wherein the first charge removing member is on the upstream side of the separating means in the transfer material conveying direction. An image forming apparatus characterized in that the image forming apparatus is arranged in. 【請求項４】 請求項２に記載の画像形成装置であっ
て、転写材担持体を介して第１除電部材と対向して非接
触に配置された第１接地電極と、転写材担持体を介して
第２除電部材と対向して非接触に配置された第２接地電
極とを備えたことを特徴とする画像形成装置。4. The image forming apparatus according to claim 2, further comprising a first ground electrode, which is arranged in non-contact with the first charge removing member so as to face the first charge eliminating member with the transfer material carrier interposed therebetween. An image forming apparatus, comprising: a second ground electrode that is disposed in a non-contact manner so as to face the second charge eliminating member via the intermediate electrode. 【請求項５】 トナー像が形成される像担持体と、像担
持体と対向して設けられた中間転写体と、像担持体から
中間転写体へ前記トナー像を静電的に転写する第１転写
手段と、中間転写体から転写材へトナー像を静電的に転
写する第２転写手段と、中間転写体の表面を清掃する清
掃手段と、搬送方向において清掃手段の上流側に設けら
れ、中間転写体の裏面に接触する第１除電部材と、搬送
方向において清掃手段の下流側に設けられ、中間転写体
の表面に接触する第２除電部材とを備えたことを特徴と
する画像形成装置。5. An image carrier on which a toner image is formed, an intermediate transfer member provided facing the image carrier, and an electrostatic transfer of the toner image from the image carrier to the intermediate transfer member. 1 transfer means, a second transfer means for electrostatically transferring a toner image from an intermediate transfer body to a transfer material, a cleaning means for cleaning the surface of the intermediate transfer body, and a upstream side of the cleaning means in the transport direction. An image forming device comprising: a first static eliminator member that contacts the back surface of the intermediate transfer member; and a second static eliminator member that is provided downstream of the cleaning unit in the transport direction and that contacts the surface of the intermediate transfer member. apparatus. 【請求項６】 可橈性の誘電体表面に残留したトナーと
電荷を除去する装置であって、移動する誘電体表面に接
触して設けられたクリーナと、誘電体の移動方向におい
てクリーナの上流側に設けられ、誘電体の裏面に接触す
る第１除電部材と、誘電体の移動方向においてクリーナ
の下流側に設けられ、誘電体の表面に接触する第２除電
部材とを備えたことを特徴とする電荷及びトナー除去装
置。6. A device for removing toner and charges remaining on a flexible dielectric surface, the cleaner being provided in contact with a moving dielectric surface, and the cleaner upstream in the moving direction of the dielectric. And a second static eliminator member that is provided on the side and contacts the back surface of the dielectric, and a second static eliminator member that is provided on the downstream side of the cleaner in the moving direction of the dielectric and that contacts the surface of the dielectric. A charge and toner removing device.