JPH0996970A - Transfer belt device - Google Patents
Transfer belt deviceInfo
- Publication number
- JPH0996970A JPH0996970A JP7278399A JP27839995A JPH0996970A JP H0996970 A JPH0996970 A JP H0996970A JP 7278399 A JP7278399 A JP 7278399A JP 27839995 A JP27839995 A JP 27839995A JP H0996970 A JPH0996970 A JP H0996970A
- Authority
- JP
- Japan
- Prior art keywords
- transfer belt
- transfer
- belt
- roller
- drive roller
- 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
Landscapes
- Cleaning In Electrography (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Delivering By Means Of Belts And Rollers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は電子写真式複写機、
プリンタ、ファクシミリ装置等の画像形成装置であっ
て、感光体上のトナー像を転写紙上に転写する際に転写
ベルトを用いるタイプのものにおいて、転写ベルトを張
設、駆動するローラと、該転写ベルトとの間のスリップ
と、スリップに起因した不具合を解決することができる
転写ベルト装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine,
An image forming apparatus, such as a printer or a facsimile machine, of a type that uses a transfer belt when transferring a toner image on a photoconductor onto a transfer sheet, in which a transfer belt is stretched and driven, and the transfer belt. The present invention relates to a transfer belt device capable of solving a slip between the slip and a defect caused by the slip.
【０００２】[0002]
【従来の技術】複写機、プリンタ、ファクシミリ装置等
の静電転写方式を用いた画像形成装置においては、予め
一様に帯電された感光体を暗所中に於て原稿反射光等の
光学的な画像情報によって露光することにより静電潜像
を形成し、この静電潜像を現像装置からのトナーにより
現像することによって得たトナー像を転写装置によって
転写紙上に転写した後で定着することにより、画像形成
を行っている。ところで、上記転写装置としては、感光
体表面と直接コロナチャージャを対面させて、感光体と
の間を通過する転写紙に対して、コロナ放電によりトナ
ー像と逆極性の電荷を付与することにより静電転写を行
うコロナ転写方式と、中抵抗材料等から成る転写ベルト
を介して転写手段たるバイアスローラを感光体と対面せ
しめ、転写ベルトにより転写紙が転写位置に搬送されて
きた時に転写バイアスを印加してトナー像を転写紙上に
転写せしめる接触転写方式とが知られている。転写ベル
トを用いてベルトにバイアスを印加する接触タイプの転
写方式には、上記従来のコロナ転写方式にくらべて、
オゾンの発生量が少ない、電源容量が小さくて済む、
転写紙の分離搬送性能が良好等、のメリットがある。2. Description of the Related Art In an image forming apparatus using an electrostatic transfer system such as a copying machine, a printer, a facsimile machine, etc., a photoconductor which is uniformly charged in advance is subjected to an optical reflection such as reflected light of a document in a dark place. To form an electrostatic latent image by exposing it with various image information, and to develop the electrostatic latent image with toner from a developing device to transfer the toner image onto a transfer paper by a transfer device and then fix it. In this way, image formation is performed. By the way, as the transfer device, the surface of the photoconductor is directly opposed to the corona charger, and the transfer paper passing between the photoconductor and the photoconductor is electrostatically charged by applying a charge having a polarity opposite to that of the toner image by corona discharge. A corona transfer method that performs electro-transfer and a bias roller that is a transfer means are faced to the photoconductor through a transfer belt made of a medium resistance material, and a transfer bias is applied when the transfer paper is conveyed to the transfer position by the transfer belt. Then, a contact transfer method is known in which a toner image is transferred onto a transfer paper. Compared to the above conventional corona transfer method, the contact type transfer method in which a bias is applied to the belt using a transfer belt is
Low ozone generation, small power supply capacity,
There are merits such as good separation and transport performance of the transfer paper.
【０００３】従来の転写ベルト装置は、実開平３−２９
９４７号公報、特開平３−２１６６８９号公報等に開示
されているように、駆動ロ−ラと従動ロ−ラに転写ベル
トをエンドレスに張架して駆動する構成を有している。
この構成であると、製造時の寸法誤差等に起因して発生
する駆動ロ−ラのロ−ラ径のバラツキと、転写ベルトの
ベルト厚のバラツキに起因して、転写紙搬送速度が機械
によって一様とならず、機械毎にバラツキを有する結果
をもたらす。また、上記各公報記載の発明の目的から明
らかなように、転写位置に転写紙を供給するレジストロ
−ラ、転写ベルト、定着装置内の定着ロ−ラ、感光体の
各線速は、非常に微妙な関係を維持することが必要であ
る。また、上記２つの公報記載の発明とは異なり、特開
昭５９−２０４０６９号公報記載の技術の様に、駆動ロ
−ラを転写ベルトの直線搬送部に設け、ベルトの搬送速
度変動を抑えるものが考案されている。いずれにして
も、従来の転写ベルトは大径の２つの主ローラによって
張設される結果として長円を描くようにベルトの移動経
路が設定されていた。すなわち、両端に位置する２つの
ローラに巻き掛けられたベルト部分だけが円弧状の経路
であり、残りのベルト部分は直線状の経路を形成し、２
つの直線状の経路はほぼ平行な状態で対向しあってい
る。A conventional transfer belt device is a 3-29 actual open flat belt.
As disclosed in Japanese Patent Application No. 947, Japanese Patent Application Laid-Open No. 3-216689, etc., the transfer belt is endlessly stretched around a driving roller and a driven roller and driven.
With this configuration, the transfer paper transport speed varies depending on the machine due to variations in the roller diameter of the driving roller and variations in the transfer belt thickness that occur due to dimensional errors during manufacturing. It is not uniform, resulting in variations from machine to machine. Further, as is apparent from the object of the invention described in each of the above publications, the linear velocity of the resist roller for supplying the transfer paper to the transfer position, the transfer belt, the fixing roller in the fixing device, and the linear velocity of the photoconductor are very delicate. It is necessary to maintain a good relationship. Further, unlike the inventions described in the above-mentioned two publications, a drive roller is provided in the linear conveyance portion of the transfer belt to suppress fluctuations in the conveyance speed of the transfer belt, as in the technique described in JP-A-59-204069. Has been devised. In any case, in the conventional transfer belt, the moving path of the belt is set so as to draw an ellipse as a result of being stretched by the two main rollers of large diameter. That is, only the belt portion wound around the two rollers located at both ends has an arc-shaped path, and the remaining belt portions form a linear path.
The two linear paths face each other in a substantially parallel state.
【０００４】[0004]
【発明の解決しようとする課題】ところで、画像形成装
置においては、転写紙の搬送速度、即ち転写紙の搬送に
関わる各種部材、ユニットの動作速度の制御に関して、
非常に高精度なものが要求されている。特に、レジスト
ロ−ラの線速、感光体線速、転写ベルト線速、定着線速
は重要であり、これらの線速の設定の適否が画質の良否
に大きく影響する。具体的には倍率誤差や、倍率誤差偏
差、画像ブレ、潜像ブレ等の画質劣化が上記線速差のバ
ランスがくずれると惹起される。ところで、これらの各
部材、ユニットの線速の中で、必ず線速を同速としなけ
ればならないのは、感光体線速と転写ベルト線速であ
る。この２つの線速がずれている場合には、他の部材、
ユニットの線速の制御がいかに高精度に仕上がったとし
ても、倍率誤差、倍率誤差偏差、画像ブレ等が必ず発生
し、画質低下の原因となる。なお、上記２つの線速のう
ち感光体線速は、感光体単品の精度と装置全体の駆動負
荷変動に起因するところが大きく、現在では狙いの線速
を確保することはさほど難しいものではなくなってい
る。一方、転写ベルトの線速は、実開平３−２９９４７
号、特開平３−２１６６８９号公報記載の技術の様に転
写ベルト裏面に巻き掛けられた駆動ロ−ラにより転写ベ
ルトを駆動する構成では、駆動ロ−ラ径、転写ベルト厚
さの精度によってほぼ決定される。駆動ロ−ラ径を、加
工上高精度に仕上げるのは比較的容易であるが、転写ベ
ルト厚さを全面に渡って均一化し、しかも高精度に仕上
げることは非常に困難である。By the way, in the image forming apparatus, with respect to the control of the transfer speed of the transfer paper, that is, the operation speed of various members and units related to the transfer of the transfer paper,
Very high precision is required. In particular, the linear velocity of the resist roller, the linear velocity of the photosensitive member, the linear velocity of the transfer belt, and the linear velocity of the fixing are important, and the suitability of these linear velocity settings greatly affects the quality of the image. Specifically, image quality deterioration such as magnification error, magnification error deviation, image blur, and latent image blur is caused when the balance of the linear velocity difference is lost. By the way, among the linear velocities of these members and units, the linear velocities that must always be the same are the linear velocity of the photoconductor and the linear velocity of the transfer belt. If the two linear velocities are deviated, another member,
No matter how highly accurate the linear velocity of the unit is controlled, magnification errors, magnification error deviations, image blurring, etc. will always occur, which causes deterioration of image quality. Of the two linear velocities, the linear velocity of the photosensitive member largely depends on the accuracy of the photosensitive member alone and the fluctuation of the driving load of the entire apparatus, and it is not so difficult to secure the target linear velocity at present. There is. On the other hand, the linear velocity of the transfer belt is 3-29947
Japanese Patent Laid-Open No. 3-216689 discloses a structure in which the transfer belt is driven by a drive roller wound around the back surface of the transfer belt, the drive roller diameter and the transfer belt thickness are almost accurate. It is determined. Although it is relatively easy to finish the drive roller diameter with high precision in processing, it is very difficult to make the transfer belt thickness uniform over the entire surface and to finish with high precision.
【０００５】一般的に転写ベルトは図５に示す様に中抵
抗ゴムから成る基材１００の表面にＰＴＦＥ１０１を約
１０〜２０μｍの肉厚でコ−ティングしたものから成っ
ており、このような複数層の構成も均一で狙い通りの厚
さを得ることを難しくしている一因である。また、別の
要因として基材１００の中抵抗ゴム厚を狙い通り仕上げ
ることが加工上非常に難しいということを挙げることが
できる。また、経時で転写ベルト厚が摩耗、伸び等によ
り変化した場合も、当然転写ベルト線速は狙いの値をは
ずれてしまう。また、特開昭５９−２０４０６９号公報
記載の技術の様に転写ベルトの直線部に駆動ロ−ラを設
ければ、転写ベルト厚のバラツキを一切無視できるが、
転写ベルト駆動を転写ベルトと駆動ロ−ラとの摩擦力に
よって行うため、直線部において転写ベルトを駆動する
ためには、従動ロ−ラ等の押圧部材を必要とし、しかも
押圧力としてかなりの力を加える必要が生じる。なぜな
ら、転写ベルト周囲には、駆動負荷となるクリ−ニング
ブレ−ドに代表されるクリ−ニング部材を設ける必要性
があり、また、感光体と転写ベルトとのニップ部により
形成される転写部に転写紙が進入した後も正確に転写紙
を搬送するには、転写ベルトと駆動ロ−ラとの間におい
てスリップを生じさせてはならず、ベルトの直線経路に
おいては、転写ベルトと駆動ロ−ラとの接触面積が非常
に小さいため、スリップを生じさせない為には押圧力を
高くする必要があるからである。本発明は上記に鑑みて
なされたものであり、転写ベルトと、転写ベルトを張設
支持するローラとのスリップを防止する為の強力な押圧
手段等を設けることなく、転写ベルトと感光体の各線速
を一致させて倍率誤差や、倍率誤差偏差、画像ブレ、潜
像ブレ等の画質劣化を惹起しないようにした転写ベルト
装置を提供することを目的としている。As shown in FIG. 5, a transfer belt generally comprises a substrate 100 made of medium resistance rubber coated with PTFE 101 in a thickness of about 10 to 20 .mu.m. This is one of the reasons why it is difficult to obtain the desired thickness because the layer structure is uniform. Another factor is that it is very difficult in processing to finish the medium resistance rubber thickness of the base material 100 as intended. Also, when the transfer belt thickness changes over time due to wear, elongation, etc., the transfer belt linear velocity naturally deviates from the target value. Further, if a driving roller is provided in the linear portion of the transfer belt as in the technique described in JP-A-59-204069, the variations in the transfer belt thickness can be completely ignored.
Since the transfer belt is driven by the frictional force between the transfer belt and the driving roller, in order to drive the transfer belt in the straight portion, a pressing member such as a driven roller is required, and a considerable pressing force is required. Will need to be added. This is because it is necessary to provide a cleaning member represented by a cleaning blade, which is a driving load, around the transfer belt, and a transfer portion formed by a nip portion between the photoconductor and the transfer belt is required. In order to convey the transfer paper accurately even after the transfer paper has entered, no slip should occur between the transfer belt and the drive roller, and in the linear path of the belt, the transfer belt and the drive roller should not be moved. This is because the contact area with the la is very small, and the pressing force must be increased in order to prevent slippage. The present invention has been made in view of the above, and each line of the transfer belt and the photoconductor is provided without providing a strong pressing means or the like for preventing slip between the transfer belt and a roller that stretches and supports the transfer belt. An object of the present invention is to provide a transfer belt device in which speeds are matched so as not to cause image quality deterioration such as magnification error, magnification error deviation, image blur, and latent image blur.
【０００６】[0006]
【課題を解決する為の手段】請求項１の発明は、複数の
ローラによりエンドレスに張設されて駆動される転写ベ
ルトと、該転写ベルトの表面側走行面に接して該転写ベ
ルト表面により吸着搬送される転写紙にトナー像を転写
する感光体とを備えた画像形成装置において、前記転写
ベルトを張設するロ−ラの内の少なくとも一つのローラ
は、該転写ベルトの表面に接すると共に、他の従動ロー
ラにより形成される直線状の下側走行経路をベルト内側
へ向けて変形させるように配置されている駆動ローラで
あり、該駆動ローラの外周面に対して転写ベルトが巻き
付くように巻き掛けられていることを特徴とする。この
ように、従動ローラ以外の駆動ローラを転写ベルト表面
に接触させ、且つ巻き付くように接触させたので、ロー
ラと転写ベルトとの間のスリップを防止することがで
き、感光体と転写ベルトとの間の線速の不一致がなくな
る。請求項２の発明は、請求項１の画像形成装置におい
て、前記駆動ロ−ラが前記転写ベルト表面と接触する部
分の材質は、ゴム材より成っていることを特徴とする。
この為、ローラと転写ベルト間のスリップの発生防止を
更に確実化することができる。請求項３の発明は、請求
項１、２の画像形成装置において、前記転写ベルトの表
面に摺接して清掃する清掃部材を、前記転写ベルトの周
動方向において前記駆動ロ−ラよりも上流側に少なくと
も１つ配置したことを特徴とする。このため、転写ベル
ト上に残留するトナ−を極力取り除き、転写ベルトと駆
動ロ−ラの間にトナ−が介在することによりスリップが
発生することを防止できる。請求項４の発明は、請求項
１、２、３の画像形成装置において、前記駆動ロ−ラに
摺接して前記駆動ロ−ラ表面を清掃する部材を配置した
ことを特徴とする。このため、駆動ロ−ラに付着したト
ナ−を取り除き、確実に転写ベルトを搬送することがで
きる。According to a first aspect of the present invention, there is provided a transfer belt which is endlessly stretched by a plurality of rollers and driven, and a transfer belt which is in contact with a surface side running surface of the transfer belt and is attracted by the transfer belt surface. In an image forming apparatus including a photoconductor that transfers a toner image to a transfer sheet that is conveyed, at least one roller of rollers that stretches the transfer belt is in contact with the surface of the transfer belt, and A drive roller arranged so as to deform the linear lower running path formed by another driven roller toward the inner side of the belt, so that the transfer belt is wound around the outer peripheral surface of the drive roller. Characterized by being wrapped around. As described above, since the driving roller other than the driven roller is brought into contact with the surface of the transfer belt so as to be wound around, the slip between the roller and the transfer belt can be prevented, and the photosensitive member and the transfer belt can be prevented. There is no discrepancy in the linear velocity between. According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the material of the portion where the drive roller comes into contact with the surface of the transfer belt is a rubber material.
Therefore, it is possible to further ensure the prevention of the slip between the roller and the transfer belt. According to a third aspect of the present invention, in the image forming apparatus according to the first and second aspects, a cleaning member, which is in sliding contact with the surface of the transfer belt to be cleaned, is located upstream of the drive roller in the circumferential direction of the transfer belt. It is characterized in that at least one is arranged. Therefore, the toner remaining on the transfer belt can be removed as much as possible, and the occurrence of slip due to the toner intervening between the transfer belt and the driving roller can be prevented. According to a fourth aspect of the invention, in the image forming apparatus of the first, second and third aspects, a member for slidingly contacting the drive roller and cleaning the surface of the drive roller is arranged. For this reason, the toner adhered to the drive roller can be removed, and the transfer belt can be reliably conveyed.
【０００７】[0007]
【発明の実施の形態】以下、本発明を添付図面に示した
形態例により説明する。図１は本発明の第１実施例の概
略構成説明図であり、電子写真プロセスに基づいた画像
形成に関与する他の構成要素の図示及び説明は省略す
る。図１のドラム状感光体１の周囲には図示していない
がカ−ルソンプロセスとして知られている画像形成原理
に基づいた、必要な装置が配置されている。まず、矢印
方向に回転する感光体１上に形成されたトナ−像の移動
に同期して、転写紙Ｐを感光体１と転写ベルト２より成
る転写部６に搬送するレジストロ−ラ対５により送り出
された転写紙Ｐは、レジストロ−ラ径によって決定され
る線速ＶR にて、転写部６に搬送される。次に所定のタ
イミングをもって帯電させられた転写ベルト２に静電的
に吸着し、転写ベルト線速Ｖb をもって転写紙Ｐは搬送
される。この時感光体線速ＶO と転写ベルト速度Ｖb と
レジストロ−ラ線速ＶR は、ＶO ＝Ｖb ＜ＶR の関係に
あることが望ましい。以上の構成は、図２、図３、図４
に示した他の実施例についても共通するものである。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the accompanying drawings. FIG. 1 is a schematic configuration explanatory diagram of a first embodiment of the present invention, and illustration and description of other components involved in image formation based on an electrophotographic process are omitted. Around the drum-shaped photoreceptor 1 shown in FIG. 1, although not shown, necessary devices based on the image forming principle known as the Carson process are arranged. First, in synchronization with the movement of the toner image formed on the photoconductor 1 rotating in the direction of the arrow, by the registration roller pair 5 that conveys the transfer paper P to the transfer unit 6 including the photoconductor 1 and the transfer belt 2. the fed transfer sheet P is Rejisutoro - at a linear velocity V R determined by La diameter, is conveyed to the transfer section 6. Next, it is electrostatically adsorbed to the charged transfer belt 2 at a predetermined timing, and the transfer paper P is conveyed at the transfer belt linear velocity V b . At this time, it is desirable that the linear velocity V O of the photoconductor, the velocity V b of the transfer belt, and the linear velocity V R of the registration roller have a relation of V O = V b <V R. The above configuration is shown in FIGS.
It is common to the other embodiments shown in FIG.
【０００８】＜請求項１に対応する形態例の構成動作＞
本発明の転写ベルト装置は、駆動ロ−ラ３と、従動ロー
ラ４群と、転写ベルト２等から成り、駆動ロ−ラ３、従
動ロ−ラ４、４、４間に転写ベルト２がエンドレスに張
架され、駆動ローラ３の駆動力によって駆動される。つ
まり、図示していない駆動源により駆動ロ−ラ３を回す
ことにより、それに接触している転写ベルト２をＶb の
速さで走行させる。転写ベルト２が駆動ロ−ラ３と接触
する面（表面）は、転写紙が転写ベルトに静電的に吸
着、搬送される面と同一面であり、転写ベルト２と駆動
ロ−ラ３間でスリップしないような所定の巻き付け角を
もって駆動ロ−ラ３と接触している。この時、駆動ロ−
ラ径と回転数は、狙い値となる転写ベルト速度Ｖb によ
って任意に選択できる。即ち、転写ベルト厚さは転写ベ
ルト速度Ｖb に一切無関係で、転写ベルト速度Ｖb は駆
動ロ−ラ径と回転数により決定される駆動ロ−ラ線速Ｖ
r と同速となる。従来一般の転写ベルトは、２つの大径
のローラ（４ａ，４ｂ）間に巻き掛けられることによ
り、ほぼ長円形状の走行経路を形成しているが、本形態
例では、図示のように下側の走行面の適所裏面に第３の
従動ローラ４ｃを配置すると共に、該従動ローラ４ｃの
上流側近接位置に駆動ローラ３を配置している。駆動ロ
ーラ３と従動ローラ４ｃの位置関係は、駆動ローラ３が
ベルトの本来の下側走行面（一点鎖線で示す）の内側へ
変位し、従動ローラ４ｃが該下側走行面の外側へ変位す
るように上下位置関係をずらしてある。この為、下側走
行面は、２つの従動ローラ４ａ，４ｂだけによりベルト
が張設されている場合に想定される経路（一点鎖線）か
ら傾斜した経路Ａ、Ｂと、両傾斜経路Ａ、Ｂ間に位置し
て本来の下側走行面とほぼ直交する中間経路Ｃとから構
成されることとなる。つまり、第３の従動ローラ４ｃを
用いて転写ベルトが駆動ローラ３の外周面に巻き付く様
にしている。符号、７は上ガイド、８は下ガイド、１１
は定着ローラ対、１５は第３の従動ローラ４ｃを矢印方
向に付勢するバネである。<Structure operation of form example corresponding to claim 1>
The transfer belt device of the present invention comprises a drive roller 3, a group of driven rollers 4, a transfer belt 2 and the like. The transfer belt 2 is endless between the drive roller 3, the driven rollers 4, 4 and 4. And is driven by the driving force of the driving roller 3. That is, by rotating the drive roller 3 by a drive source (not shown), the transfer belt 2 in contact therewith is caused to travel at the speed of Vb . The surface (front surface) where the transfer belt 2 contacts the drive roller 3 is the same surface as the surface on which the transfer paper is electrostatically adsorbed and conveyed by the transfer belt, and between the transfer belt 2 and the drive roller 3. Is in contact with the drive roller 3 with a predetermined winding angle so as not to slip. At this time, the drive roll
The radius and the number of revolutions can be arbitrarily selected according to the transfer belt speed V b that is a target value. That is, the transfer belt is thickness in all independent of the transfer belt velocity V b, the transfer belt speed V b driven Russia - drive B is determined by a La diameter rpm - La linear velocity V
It becomes the same speed as r . A conventional transfer belt is wound around two large-diameter rollers (4a, 4b) to form a substantially elliptical traveling path. The third driven roller 4c is arranged on the rear surface of the proper running surface on the side, and the drive roller 3 is arranged on the upstream side adjacent position of the driven roller 4c. As for the positional relationship between the driving roller 3 and the driven roller 4c, the driving roller 3 is displaced to the inside of the original lower running surface of the belt (shown by a chain line), and the driven roller 4c is displaced to the outside of the lower running surface. As described above, the vertical positional relationship is shifted. Therefore, the lower traveling surface has paths A and B inclined from the path (one-dot chain line) assumed when the belt is stretched only by the two driven rollers 4a and 4b, and both inclined paths A and B. The intermediate path C is located between and is substantially orthogonal to the original lower traveling surface. That is, the transfer belt is wound around the outer peripheral surface of the drive roller 3 by using the third driven roller 4c. Reference numeral, 7 is an upper guide, 8 is a lower guide, 11
Is a fixing roller pair, and 15 is a spring for urging the third driven roller 4c in the arrow direction.
【０００９】このように、第１の形態例では、従動ロー
ラ４によって張架された転写ベルト２の転写紙を静電吸
着し搬送する面（表面）に、駆動ロ−ラ３を接触させ、
かつ転写ベルト２と駆動ロ−ラ３間でスリップが生じな
い様に転写ベルト２を駆動ロ−ラ３に巻付ける様に配い
回している。このため、転写ベルト２は駆動ロ−ラ３と
スリップせずに駆動され、その時の搬送速度、即ちベル
トの線速Ｖb は、駆動ロ−ラ３の直径と回転数によって
のみ決定されることとなり、転写ベルト２の厚さのバラ
ツキに起因した線速のバラツキは一切生じない。従っ
て、レジストローラ、感光体、転写ベルト、定着ローラ
の各線速差のバランスを保ちやすく、異常画像の発生を
防ぐことができる。As described above, in the first embodiment, the drive roller 3 is brought into contact with the surface (front surface) of the transfer belt 2 stretched by the driven roller 4 that electrostatically attracts and conveys the transfer paper.
In addition, the transfer belt 2 is arranged so as to be wound around the drive roller 3 so that slip does not occur between the transfer belt 2 and the drive roller 3. Therefore, the transfer belt 2 is driven without slipping with the driving roller 3, and the transport speed at that time, that is, the linear velocity Vb of the belt is determined only by the diameter and the number of rotations of the driving roller 3. Therefore, there is no variation in the linear velocity due to the variation in the thickness of the transfer belt 2. Therefore, it is easy to maintain the balance of the linear velocity differences among the registration roller, the photoconductor, the transfer belt, and the fixing roller, and it is possible to prevent the occurrence of an abnormal image.
【００１０】＜請求項２に対応する形態例の構成動作＞
本発明の第２の形態例は、請求項１における転写ベルト
装置において、駆動ロ−ラ３が転写ベルト２と接触する
面をゴム材質としている点が特徴的である。従って、駆
動ロ−ラ３の摩擦係数を高くして転写ベルト２との摩擦
抵抗を大きくすることができ、駆動ロ−ラ３により転写
ベルト２を駆動した場合にスリップが生じなくなる。従
って、狙いの転写ベルト線速Ｖb を得ることが可能とな
る。また、駆動ロ−ラがゴムのため、転写ベルト表面を
キズつけることが無くなり、ベルト表面にキズ、ピンホ
−ル等が形成されることに起因したリ−ク、異常画像等
が発生することがなくなる。<Structure operation of the embodiment corresponding to claim 2>
The second embodiment of the present invention is characterized in that, in the transfer belt device according to the first aspect, the surface of the drive roller 3 in contact with the transfer belt 2 is made of a rubber material. Therefore, the friction coefficient of the drive roller 3 can be increased to increase the frictional resistance with the transfer belt 2, and when the transfer roller 2 is driven by the drive roller 3, no slip occurs. Therefore, it becomes possible to obtain the target transfer belt linear velocity V b . Further, since the driving roller is made of rubber, the transfer belt surface is not scratched, and a leak, an abnormal image or the like due to the formation of scratches, pinholes or the like on the belt surface may occur. Disappear.
【００１１】＜請求項３に対応する形態例の構成動作＞
図２は本発明の第３の形態例の構成を示す図であり、請
求項１、２に対応する形態例と異なる点は、転写ベルト
２の周動方向において、駆動ロ−ラ３よりも上流側位置
に清掃部材９、１０を少なくとも１つ配置してあること
である。図では一方の清掃部材９をブレードとし、他方
１０をブラシとしているが、これら以外の清掃手段であ
ってもよいし、ブレード９とブラシ１０の位置関係が異
なってもよい。いずれにしても、第１の従動ローラ４ａ
の外周面に接する位置に各清掃部材を設ける。転写ベル
ト２上には、感光体１と転写ベルト２が直に接触し、回
転している最中に、感光体に付着しているトナ−の何割
かがベルト２上に転移するため、ベルト２上にはトナ−
が少量存在する。また、原稿サイズ（原稿スキャンサイ
ズ）と転写紙サイズ及び倍率のアンマッチのために、転
写ベルト上にトナ−が転写されてしまうこともある。こ
の様に転写ベルトがトナ−で汚れていると、次の紙の裏
面を汚してしまうことになる。そこで、清掃部材９、１
０により次の転写前に付着したトナーを除去することが
必要となる。清掃部材としては、ブレ−ド、ファ−ブラ
シ等が考えられ、これらは転写ベルトに圧接されてい
る。<Constitutional operation of the embodiment corresponding to claim 3>
FIG. 2 is a diagram showing the configuration of the third embodiment of the present invention. The difference from the embodiment corresponding to the first and second aspects is that, in the circumferential direction of the transfer belt 2, it is more than the drive roller 3. That is, at least one cleaning member 9, 10 is arranged at the upstream side position. In the figure, one cleaning member 9 is a blade and the other is a brush, but cleaning means other than these may be used, or the positional relationship between the blade 9 and the brush 10 may be different. In any case, the first driven roller 4a
Each cleaning member is provided at a position in contact with the outer peripheral surface of the. Since the photoconductor 1 and the transfer belt 2 are in direct contact with each other on the transfer belt 2 and some of the toner adhering to the photoconductor is transferred onto the belt 2 while the photoconductor 1 and the transfer belt 2 are rotating, Toner on 2
There is a small amount. Further, the toner may be transferred onto the transfer belt due to the mismatch between the original size (original scan size) and the transfer paper size and magnification. When the transfer belt is soiled with toner as described above, the back surface of the next paper is soiled. Therefore, the cleaning members 9, 1
When 0, it is necessary to remove the attached toner before the next transfer. As the cleaning member, a blade, a fur brush or the like can be considered, and these are pressed against the transfer belt.
【００１２】＜請求項４に対応する形態例の構成動作＞
本発明の第４の形態例は、上記各形態例の転写ベルト装
置において、駆動ロ−ラ３に圧接して駆動ロ−ラ３を清
掃する清掃部材１２、１３を配置した構成が特徴的であ
る。駆動ローラ３の周面は転写ベルトの表面と接触する
為、ベルト上の残留トナーが付着し易い。上流側にベル
ト用の清掃部材を配置しない場合は勿論、配置したとし
ても、少量残留することがあるので、ベルト上のトナー
を除去しておかないと、後続の転写動作に不具合をもた
らすこととなる。清掃部材１２、１３としては、不織布
（１３）、ブレ−ド、ロ−ラ（１２）等が考えられる。
これらの清掃部材は、必要時のみ圧接させる様に接離自
在に構成しても良い。この形態例の清掃部材は、駆動ロ
−ラに付着したトナ−を取り除き、確実に転写ベルトを
搬送することを可能とする。このため、経時においても
安定して狙いの転写ベルト線速Ｖb を得ることが可能と
なる。なお、図４に示した形態例は、図１の例と組み合
わせてもよいし、図２の例と組み合わせてもよい。<Construction operation of the embodiment corresponding to claim 4>
The fourth embodiment of the present invention is characterized in that the transfer belt device of each of the above embodiments is provided with cleaning members 12 and 13 which press the drive roller 3 to clean the drive roller 3. is there. Since the peripheral surface of the drive roller 3 contacts the surface of the transfer belt, the residual toner on the belt is easily attached. When the cleaning member for the belt is not arranged on the upstream side, of course, a small amount may remain even if it is arranged. Therefore, if the toner on the belt is not removed, it may cause a problem in the subsequent transfer operation. Become. As the cleaning members 12 and 13, a nonwoven fabric (13), a blade, a roller (12), etc. can be considered.
These cleaning members may be configured to be contactable and separable so that they are brought into pressure contact only when necessary. The cleaning member of this embodiment removes the toner adhering to the drive roller, and makes it possible to reliably convey the transfer belt. For this reason, it is possible to stably obtain the target transfer belt linear velocity V b even over time. The example of the form shown in FIG. 4 may be combined with the example of FIG. 1 or may be combined with the example of FIG.
【００１３】[0013]
【発明の効果】以上のように、本発明では、転写ベルト
と、転写ベルトを張設支持するローラとのスリップを防
止する為の強力な押圧手段等を設けることなく、転写ベ
ルトと感光体の各線速を一致させて倍率誤差や、倍率誤
差偏差、画像ブレ、潜像ブレ等の画質劣化を防止でき
る。即ち、請求項１の転写装置においては、エンドレス
に張架された転写ベルトの転写紙を静電吸着し搬送する
面（表面）に、駆動ロ−ラを接触させ、かつ転写ベルト
２と駆動ロ−ラ３間でスリップが生じない様に転写ベル
ト２を駆動ロ−ラ３に巻き付く様に配い回している。こ
のため、転写ベルト２は駆動ロ−ラ３とスリップせずに
駆動され、その時の搬送速度、即ち転写ベルト線速Ｖb
は、駆動ロ−ラ３の直径と回転数によってのみ決定さ
れ、転写ベルト２の厚さのバラツキによる線速のバラツ
キは一切生じない。従って、レジストローラ、感光体、
転写ベルト、定着ローラの各線速差のバランスを保ちや
すく、異常画像の発生を防ぐことができる。As described above, according to the present invention, the transfer belt and the photoconductor are not provided with strong pressing means for preventing slip between the transfer belt and the roller that stretches and supports the transfer belt. By making the respective linear velocities equal, it is possible to prevent image quality deterioration such as magnification error, magnification error deviation, image blur, and latent image blur. That is, in the transfer device according to the first aspect, the drive roller is brought into contact with the surface (front surface) of the transfer belt stretched endlessly for electrostatically adsorbing and conveying the transfer paper, and the transfer belt 2 and the drive roller. The transfer belt 2 is arranged so as to be wound around the driving roller 3 so that a slip does not occur between the rollers 3. Therefore, the transfer belt 2 is driven without slipping with the drive roller 3, and the transport speed at that time, that is, the transfer belt linear velocity V b.
Is determined only by the diameter of the drive roller 3 and the number of rotations, and there is no variation in linear velocity due to variation in the thickness of the transfer belt 2. Therefore, the registration roller, the photoconductor,
It is easy to maintain the balance of the linear velocity difference between the transfer belt and the fixing roller, and it is possible to prevent the occurrence of abnormal images.
【００１４】請求項２の転写装置においては、駆動ロ−
ラの少なくとも表面をゴム材質にて成形しているので、
駆動ロ−ラと転写ベルトとの摩擦係数を高くすることが
でき、駆動ロ−ラ３にて転写ベルト２を駆動した場合に
スリップが生じなくなる。よって狙いの転写ベルト線速
Ｖb を得ることが可能となる。また、駆動ロ−ラがゴム
製であるため、転写ベルト表面をキズつけることが無く
なる。その結果、ベルト表面のキズ、ピンホ−ル等に起
因したリ−ク、異常画像等の発生を防止できる。In the transfer device of the second aspect, the drive roller is
At least the surface of the la is molded with a rubber material,
The friction coefficient between the driving roller and the transfer belt can be increased, and slipping does not occur when the transfer belt 2 is driven by the driving roller 3. Therefore, it is possible to obtain the target transfer belt linear velocity V b . Further, since the driving roller is made of rubber, the transfer belt surface is not scratched. As a result, it is possible to prevent the occurrence of leaks, abnormal images and the like due to scratches on the belt surface, pinholes and the like.
【００１５】請求項３の転写装置においては、転写ベル
トの周動方向において、駆動ロ−ラよりも上流側位置に
転写ベルト表面を清掃し、転写ベルト表面上のトナ−を
除去するための清掃部材を少なくとも１つ配置している
ので、転写ベルトと駆動ロ−ラの間にトナ−が介在し、
それらの間の摩擦係数が低下し、スリップが発生するこ
とを防止できる。よって、経時においても転写ベルト線
速Ｖb を得ることが可能となる。請求項４の転写装置に
おいては、駆動ロ−ラに圧接し、駆動ロ−ラ表面を清掃
する部材を設けているので、駆動ロ−ラ表面に付着した
トナ−を除去でき、経時においても安定して狙いの線速
Ｖb を得ることが可能となる。In the transfer device according to the third aspect of the present invention, the transfer belt surface is cleaned at a position upstream of the drive roller in the circumferential direction of the transfer belt, and cleaning is performed to remove the toner on the transfer belt surface. Since at least one member is arranged, the toner is interposed between the transfer belt and the driving roller,
The friction coefficient between them is lowered, and it is possible to prevent the occurrence of slip. Therefore, it is possible to obtain the transfer belt linear velocity V b even over time. In the transfer device according to the fourth aspect, since the member for pressing the drive roller and cleaning the surface of the drive roller is provided, the toner adhering to the surface of the drive roller can be removed, and it is stable over time. Then, it becomes possible to obtain the target linear velocity V b .
【図１】本発明の第１の形態例のベルト転写装置の概略
構成説明図。FIG. 1 is a schematic configuration explanatory diagram of a belt transfer device according to a first embodiment of the present invention.
【図２】本発明の第２の形態例のベルト転写装置の概略
構成説明図。FIG. 2 is a schematic configuration explanatory diagram of a belt transfer device according to a second embodiment of the present invention.
【図３】本発明の第３の形態例のベルト転写装置の概略
構成説明図。FIG. 3 is a schematic configuration explanatory diagram of a belt transfer device according to a third embodiment of the present invention.
【図４】本発明の第４の形態例のベルト転写装置の概略
構成説明図。FIG. 4 is a schematic configuration explanatory diagram of a belt transfer device according to a fourth embodiment of the present invention.
【図５】転写ベルトの断面図。FIG. 5 is a sectional view of a transfer belt.
１ 感光体、２ 転写ベルト、３ 駆動ローラ、４（４
ａ，４ｂ，４ｃ） 従動ローラ、５ レジストローラ、
６ 転写部、７ 上ガイド、８ 下ガイド、１１定着ロ
ーラ対、１５ バネ、1 photoconductor, 2 transfer belt, 3 drive roller, 4 (4
a, 4b, 4c) driven roller, 5 registration roller,
6 transfer unit, 7 upper guide, 8 lower guide, 11 fixing roller pair, 15 spring,
Claims (4)
れて駆動される転写ベルトと、該転写ベルトの表面側走
行面に接して該転写ベルト表面により吸着搬送される転
写紙にトナー像を転写する感光体とを備えた画像形成装
置において、前記転写ベルトを張設するロ−ラの内の少
なくとも一つのローラは、該転写ベルトの表面に接する
と共に、他の従動ローラにより形成される直線状の下側
走行経路をベルト内側へ向けて変形させるように配置さ
れている駆動ローラであり、該駆動ローラの外周面に対
して転写ベルトが巻き付くように巻き掛けられているこ
とを特徴とする転写ベルト装置。1. A transfer belt, which is endlessly stretched and driven by a plurality of rollers, and a toner image is transferred onto a transfer paper which is in contact with a front running surface of the transfer belt and is adsorbed and conveyed by the transfer belt surface. In an image forming apparatus including a photoconductor, at least one roller of rollers that stretches the transfer belt is in contact with the surface of the transfer belt and is a linear roller formed by another driven roller. A transfer roller arranged so as to deform the lower traveling path toward the inner side of the belt, wherein the transfer belt is wound around the outer peripheral surface of the drive roller so that the transfer belt is wound around the transfer roller. Belt device.
駆動ロ−ラが前記転写ベルト表面と接触する部分の材質
は、ゴム材より成っていることを特徴とする転写ベルト
装置。2. The transfer belt device according to claim 1, wherein a material of a portion of the drive roller that contacts the transfer belt surface is a rubber material.
前記転写ベルトの表面に摺接して清掃する清掃部材を、
前記転写ベルトの周動方向において前記駆動ロ−ラより
も上流側に少なくとも１つ配置したことを特徴とする転
写ベルト装置。3. The image forming apparatus according to claim 1,
A cleaning member for slidingly cleaning the surface of the transfer belt,
At least one transfer belt device is arranged on the upstream side of the drive roller in the circumferential direction of the transfer belt.
て、前記駆動ロ−ラに摺接して前記駆動ロ−ラ表面を清
掃する部材を配置したことを特徴とする転写ベルト装
置。4. The transfer belt apparatus according to claim 1, wherein a member for slidingly contacting the drive roller to clean the surface of the drive roller is arranged.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7278399A JPH0996970A (en) | 1995-10-02 | 1995-10-02 | Transfer belt device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7278399A JPH0996970A (en) | 1995-10-02 | 1995-10-02 | Transfer belt device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0996970A true JPH0996970A (en) | 1997-04-08 |
Family
ID=17596811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7278399A Pending JPH0996970A (en) | 1995-10-02 | 1995-10-02 | Transfer belt device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0996970A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009178965A (en) * | 2008-01-31 | 2009-08-13 | Canon Inc | Printer |
-
1995
- 1995-10-02 JP JP7278399A patent/JPH0996970A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009178965A (en) * | 2008-01-31 | 2009-08-13 | Canon Inc | Printer |
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