JPH09281819A - Electrophotographic device - Google Patents
Electrophotographic deviceInfo
- Publication number
- JPH09281819A JPH09281819A JP9668896A JP9668896A JPH09281819A JP H09281819 A JPH09281819 A JP H09281819A JP 9668896 A JP9668896 A JP 9668896A JP 9668896 A JP9668896 A JP 9668896A JP H09281819 A JPH09281819 A JP H09281819A
- Authority
- JP
- Japan
- Prior art keywords
- transfer roller
- image carrier
- transfer
- roller
- region
- 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
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は電子写真装置に関
し、特に転写ローラを使用する電子写真装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic apparatus, and more particularly to an electrophotographic apparatus using a transfer roller.
【０００２】[0002]
【従来の技術】従来、この種の電子写真装置は、現像さ
れたトナー等の現像剤を印字用紙等の転写媒体に転写す
る場合、現像剤と逆極性の電界を転写媒体の裏面から加
える必要がある。逆極性の電界を発生する方式として、
主にコロナ放電によるスコロトロン帯電が用いられてい
るが、近年では装置の小型化、高速化、オゾンレス化を
考慮してスポンジ等の弾性部材を用いた転写ローラによ
り逆極性電界を発生し、転写媒体に転写する方式が主流
となってきている。2. Description of the Related Art Conventionally, in the case of transferring a developer such as developed toner to a transfer medium such as printing paper, this type of electrophotographic apparatus requires an electric field having a polarity opposite to that of the developer to be applied from the back surface of the transfer medium. There is. As a method of generating an electric field of opposite polarity,
Scorotron charging by corona discharge is mainly used, but in recent years, a transfer roller using an elastic member such as a sponge generates a reverse polarity electric field in consideration of downsizing, speeding up, and ozonelessness of the transfer medium. The method of transferring to is becoming mainstream.
【０００３】転写ローラによる転写方式は、スコロトロ
ン帯電による転写方式と異なり、転写手段である転写ロ
ーラを像担持体に接触して配置する。転写ローラは、像
担持体表面の移動方向と対面する方向に回転し、像担持
体上に現像されている現像剤に電界を加え、像担持体−
転写ローラ間に搬送される転写媒体に、像担持体上の現
像剤の転写を行う。この場合、転写媒体および像担持体
上に現像された現像剤に対して均一な電界が長時間加え
られるときに最大の転写効率が得られる。そのためには
像担持体の周速（表面速度）と転写ローラの周速とが周
速比１：１に設定する必要がある。The transfer method using a transfer roller differs from the transfer method using scorotron charging in that a transfer roller, which is a transfer means, is disposed in contact with the image carrier. The transfer roller rotates in a direction facing the moving direction of the surface of the image bearing member, applies an electric field to the developer developed on the image bearing member, and
The developer on the image carrier is transferred to the transfer medium conveyed between the transfer rollers. In this case, the maximum transfer efficiency is obtained when a uniform electric field is applied to the developer developed on the transfer medium and the image carrier for a long time. For that purpose, it is necessary to set the peripheral speed (surface speed) of the image carrier and the peripheral speed of the transfer roller to a peripheral speed ratio of 1: 1.
【０００４】この転写ローラによる転写方式の概要を示
す図５を参照して説明すると、通常、転写ローラ２は弾
性部材で構成され、不図示の転写媒体を介して像担持体
１との間にニップを形成するため、周速比１：１を実現
するには、像担持体１による転写ローラ２のゆがみを考
慮し、予めゆがんだときの転写ローラ２の半径方向にお
ける周速と、像担持体の周速との周速比が１：１になる
ように像担持体ギア３と転写ローラギア４とのギア比を
設定する必要がある。The transfer method by the transfer roller will be described with reference to FIG. 5. Usually, the transfer roller 2 is composed of an elastic member, and is formed between the transfer roller 2 and the image carrier 1 via a transfer medium (not shown). Since the nip is formed, in order to realize the peripheral speed ratio of 1: 1, the distortion of the transfer roller 2 due to the image carrier 1 is taken into consideration, and the peripheral speed of the transfer roller 2 in the radial direction when the image carrier 1 is distorted in advance and the image carrier It is necessary to set the gear ratio between the image carrier gear 3 and the transfer roller gear 4 so that the peripheral speed ratio to the peripheral speed of the body becomes 1: 1.
【０００５】これに対して、たとえば特開平４−３６２
６７８号公報には、図６に示すように、像担持体１に転
写ローラ２を接触させて配置し、像担持体１からの摩擦
力を利用して転写ローラ２を駆動させ、像担持体１と転
写ローラ２との周速差を無くす転写ローラによる転写方
式が提案されている。On the other hand, for example, JP-A-4-362
In Japanese Patent Laid-Open No. 678, as shown in FIG. 6, a transfer roller 2 is arranged in contact with the image carrier 1 and the transfer roller 2 is driven by using a frictional force from the image carrier 1 to form an image carrier. A transfer method using a transfer roller that eliminates the difference in peripheral speed between the transfer roller 1 and the transfer roller 2 has been proposed.
【０００６】[0006]
【発明が解決しようとする課題】上述した従来の転写ロ
ーラをギアで駆動させる場合、像担持体−転写ローラ間
の軸間距離を設定し、その軸間距離に従って転写ローラ
と像担持体との周速比が１：１になるようにギア比を選
択する。しかしながら、転写ローラは弾性部材で構成さ
れ、転写媒体を介して像担持体との間にニップを形成す
るため、像担持体−転写ローラ間の軸間距離が変化する
場合には実際の周速比が１：１ではなくなり、転写効率
が減少するという欠点がある。When the above-described conventional transfer roller is driven by a gear, the axial distance between the image carrier and the transfer roller is set, and the axial distance between the transfer roller and the image carrier is set according to the axial distance. The gear ratio is selected so that the peripheral speed ratio becomes 1: 1. However, since the transfer roller is composed of an elastic member and forms a nip with the image carrier via the transfer medium, when the axial distance between the image carrier and the transfer roller changes, the actual peripheral speed is changed. The ratio is not 1: 1 and there is a drawback that the transfer efficiency is reduced.
【０００７】転写ローラにより転写を行う電子写真装置
のうち、大型機や高速機は転写媒体の搬送等の駆動系に
精度を要求されるので像担持体−転写ローラ間の軸間距
離は固定されているためこのような問題は発生し難い。
一方、中、低速機のような低価格の電子写真装置では、
転写ローラが設置された装置に対して、像担持体が設置
された交換可能なカートリッジを組み込むことで転写ロ
ーラと像担持体とを接触させている。そのためカートリ
ッジの位置精度が出難く、像担持体−転写ローラ間の軸
間距離が変動する可能性が高い。またカートリッジに組
み込まれた可動部分に動力を伝える際に、駆動トルクの
変動により起こるカートリッジの変形等の影響で像担持
体−転写ローラ間の軸間距離が変動する可能性がある。Among electrophotographic apparatuses that perform transfer using a transfer roller, a large-sized machine or a high-speed machine is required to have high accuracy in a drive system for conveying a transfer medium, so that the axial distance between the image carrier and the transfer roller is fixed. Therefore, such problems are unlikely to occur.
On the other hand, in low-priced electrophotographic devices such as medium and low speed machines,
The transfer roller and the image carrier are brought into contact with each other by incorporating a replaceable cartridge in which the image carrier is installed in the apparatus in which the transfer roller is installed. Therefore, it is difficult to obtain the positional accuracy of the cartridge, and the axial distance between the image carrier and the transfer roller is likely to change. Further, when power is transmitted to a movable part incorporated in the cartridge, the axial distance between the image carrier and the transfer roller may vary due to deformation of the cartridge caused by variation of driving torque.
【０００８】本発明の目的は、像担持体から転写媒体へ
の現像剤の転写効率を１００％に近づける手段、および
その際に発生する問題を回避する手段を備える電子写真
装置を提供することにある。An object of the present invention is to provide an electrophotographic apparatus provided with means for making the transfer efficiency of the developer from the image carrier to the transfer medium close to 100%, and means for avoiding the problems that occur at that time. is there.
【０００９】[0009]
【課題を解決するための手段】本発明の電子写真装置
は、像担持体上の静電潜像を現像剤により現像を行い、
現像したこの現像剤を転写ローラを用いて前記像担持体
と前記転写ローラとの間に搬送される転写媒体へ転写を
行うことを特徴とする電子写真装置において、前記転写
ローラは駆動する前記像担持体表面との摩擦により従動
し、前記転写ローラを前記像担持体が従動させるために
必要な摩擦力が、前記転写ローラと前記像担持体との接
触面の内、前記転写媒体が搬送される領域外で得られる
手段を備える。The electrophotographic apparatus of the present invention develops an electrostatic latent image on an image bearing member with a developer,
In the electrophotographic apparatus, wherein the developed developer is transferred onto a transfer medium conveyed between the image carrier and the transfer roller by using a transfer roller, the transfer roller drives the image. The transfer medium is conveyed by the friction between the transfer medium and the surface of the transfer roller, and the friction force required for the image carrier to move the transfer roller is driven by the friction between the transfer medium and the surface of the transfer roller. Means to be obtained outside the area.
【００１０】また、本発明の電子写真装置は、像担持体
上の静電潜像を現像剤により現像を行い、現像したこの
現像剤を転写ローラを用いて前記像担持体と前記転写ロ
ーラとの間に搬送される転写媒体へ転写を行うことを特
徴とする電子写真装置において、前記転写ローラは駆動
する前記像担持体表面との摩擦により従動し、前記転写
ローラと前記像担持体との摩擦力が低下し前記転写ロー
ラがスリップするときのみに直接動力を与える駆動手段
を備える。In the electrophotographic apparatus of the present invention, the electrostatic latent image on the image carrier is developed with a developer, and the developed developer is transferred to the image carrier and the transfer roller by using a transfer roller. In an electrophotographic apparatus, which performs transfer to a transfer medium conveyed between the transfer roller and the transfer medium, the transfer roller is driven by friction with the surface of the image carrier that is driven, and the transfer roller and the image carrier are separated from each other. Drive means is provided to directly apply power only when the frictional force is reduced and the transfer roller slips.
【００１１】[0011]
【発明の実施の形態】次に、本発明の実施の形態につい
て図面を参照して詳細に説明する。Next, embodiments of the present invention will be described in detail with reference to the drawings.
【００１２】本発明の第１の実施の形態の概要を示す図
１を参照すると、この電子写真装置において、像担持体
１は一定速度で回転している。像担持体１と接触してい
る転写ローラ２は、像担持体１の表面との摩擦により従
動し、回転する。このとき、像担持体１と転写ローラ２
との接触面において、不図示の転写媒体が搬送される領
域Ｐの外側に転写媒体が搬送される領域外Ｐ’が存在す
る。これにより転写媒体が搬送される領域Ｐにおいて摩
擦力が低下した場合でも、転写媒体が搬送される領域外
Ｐ’における摩擦力によって、像担持体１の駆動力が転
写ローラ２に伝達される。また、像担持体１と転写ロー
ラ２との接触面において、転写媒体が搬送される領域外
Ｐ’の像担持体１に高摩擦材７を、転写ローラ２に高摩
擦材７’を設置すると、これにより転写媒体が搬送され
る領域Ｐにおいて摩擦力が低下した場合でも、転写媒体
が搬送される領域外Ｐ’における摩擦力によって、像担
持体１の駆動力が転写ローラ２に伝達される。Referring to FIG. 1 showing the outline of the first embodiment of the present invention, in this electrophotographic apparatus, the image carrier 1 is rotating at a constant speed. The transfer roller 2 that is in contact with the image carrier 1 is driven and rotated by friction with the surface of the image carrier 1. At this time, the image carrier 1 and the transfer roller 2
On the contact surface with, there is an area P ′ outside the area where the transfer medium is conveyed outside the area P where the transfer medium (not shown) is conveyed. As a result, even if the frictional force decreases in the area P where the transfer medium is conveyed, the driving force of the image carrier 1 is transmitted to the transfer roller 2 by the frictional force outside the area P ′ where the transfer medium is conveyed. Further, on the contact surface between the image carrier 1 and the transfer roller 2, when the high friction material 7 is installed on the image carrier 1 outside the region P ′ where the transfer medium is conveyed and the high friction material 7 ′ is installed on the transfer roller 2. Therefore, even if the frictional force is reduced in the area P where the transfer medium is conveyed, the driving force of the image carrier 1 is transmitted to the transfer roller 2 by the frictional force outside the area P ′ where the transfer medium is conveyed. .
【００１３】なお、高摩擦材７は、シリコンゴム、ウレ
タンゴム、天然ゴム等の弾性部材のソリッドもしくはス
ポンジ状の材質とし、転写ローラ２と同程度の弾性を持
ち、像担持体１と同じ直径のローラか、あるいはシリコ
ンゴム、ウレタンゴム、天然ゴム等の弾性部材の薄膜を
像担持体１の表面に張り付けて使用するものが好まし
い。また、高摩擦材７’は、シリコンゴム、ウレタンゴ
ム、天然ゴム等の弾性部材のソリッドもしくはスポンジ
状の材質とし、転写ローラ２と同程度の弾性を持ち、転
写ローラ２と同じ直径のローラか、あるいはシリコンゴ
ム、ウレタンゴム、天然ゴム等の弾性部材の薄膜を転写
ローラ２の表面に張り付けて使用するものが好ましい。The high-friction material 7 is made of an elastic material such as silicone rubber, urethane rubber, natural rubber or the like in the form of a solid or sponge, has elasticity similar to that of the transfer roller 2, and has the same diameter as the image carrier 1. It is preferable to use the above roller or a thin film of an elastic member such as silicone rubber, urethane rubber or natural rubber attached to the surface of the image carrier 1. The high-friction material 7'is a solid or sponge material made of an elastic member such as silicon rubber, urethane rubber, or natural rubber, and has elasticity about the same as that of the transfer roller 2 and has the same diameter as the transfer roller 2. Alternatively, it is preferable to use a thin film of an elastic member such as silicone rubber, urethane rubber or natural rubber attached to the surface of the transfer roller 2 for use.
【００１４】図１においては、高摩擦材７および７’は
像担持体１および転写ローラ２の両端部分の転写媒体が
搬送される領域外Ｐ’に設置するとしてあるが、転写ロ
ーラ２または像担持体１のどちらか一方に設置する構造
でもよい。また、高摩擦材７および７’は像担持体１お
よび転写ローラ２のどちらか一方の端の転写媒体が搬送
される領域外Ｐ’に設置する構造でもよい。In FIG. 1, the high-friction materials 7 and 7 ′ are arranged outside the area P ′ on both ends of the image carrier 1 and the transfer roller 2 where the transfer medium is conveyed. The structure may be such that it is installed on either one of the carriers 1. Further, the high-friction materials 7 and 7 ′ may have a structure in which one end of the image carrier 1 and the transfer roller 2 is installed outside the region P ′ where the transfer medium is conveyed.
【００１５】本発明の第２の実施の形態概要を示す図２
を参照すると、この電子写真装置において、像担持体１
は一定速度で回転している。像担持体１と接触している
転写ローラ２は、像担持体１の表面との摩擦により従動
し、回転する。このとき、転写ローラ２の不図示の転写
媒体が搬送される領域外Ｐ’に転写ローラ２より径が大
きく転写ローラ２と同じ材質の転写ローラ大径部８を設
置する。これにより転写媒体が搬送される領域Ｐにおい
て摩擦力が低下した場合でも、転写媒体が搬送される領
域外Ｐ’における摩擦力によって、像担持体１の駆動力
が転写ローラ２に伝達される。図２においては、転写ロ
ーラ大径部８は転写ローラ２の一端部の転写媒体が搬送
される領域外Ｐ’に設置するとしてあるが、転写ローラ
２の他の一端部または両端部に設置する構造でもよい。FIG. 2 showing the outline of the second embodiment of the present invention.
In this electrophotographic apparatus, the image carrier 1
Is rotating at a constant speed. The transfer roller 2 that is in contact with the image carrier 1 is driven and rotated by friction with the surface of the image carrier 1. At this time, a transfer roller large-diameter portion 8 having a diameter larger than that of the transfer roller 2 and made of the same material as that of the transfer roller 2 is provided outside the region P ′ of the transfer roller 2 where the transfer medium (not shown) is conveyed. As a result, even if the frictional force decreases in the area P where the transfer medium is conveyed, the driving force of the image carrier 1 is transmitted to the transfer roller 2 by the frictional force outside the area P ′ where the transfer medium is conveyed. In FIG. 2, the large diameter portion 8 of the transfer roller is set outside the area P ′ where the transfer medium is conveyed at one end of the transfer roller 2, but it is set at the other end or both ends of the transfer roller 2. It may be a structure.
【００１６】本発明の第３の実施の形態の概要を示す図
３を参照すると、像担持体１は一定速度で回転してい
る。像担持体１と接触している転写ローラ２は、像担持
体１の表面との摩擦により従動し、回転する。また像担
持体ギア３によって駆動する転写ローラギア４は、転写
ローラ２の回転速度よりも低速で回転しており、転写ロ
ーラ２の回転方向に対して自由な構造を持つラチェット
部５によって転写ローラ２の回転軸と接続している。こ
れにより転写ローラ２の回転が転写ローラギア４の回転
より遅くなったときに転写ローラギア４の回転が転写ロ
ーラ２に伝達される。Referring to FIG. 3 showing the outline of the third embodiment of the present invention, the image carrier 1 is rotating at a constant speed. The transfer roller 2 that is in contact with the image carrier 1 is driven and rotated by friction with the surface of the image carrier 1. The transfer roller gear 4 driven by the image carrier gear 3 rotates at a speed lower than the rotation speed of the transfer roller 2, and the transfer roller 2 is rotated by the ratchet portion 5 having a free structure in the rotation direction of the transfer roller 2. It is connected to the rotating shaft of. Thus, when the rotation of the transfer roller 2 is slower than the rotation of the transfer roller gear 4, the rotation of the transfer roller gear 4 is transmitted to the transfer roller 2.
【００１７】本発明の第４の実施の形態概要を示す図４
を参照すると、この電子写真装置において、像担持体１
は一定速度で回転している。像担持体１と接触している
転写ローラ２は、像担持体１の表面との摩擦により従動
し、回転する。また像担持体１の端部で、不図示の転写
媒体が搬送される領域外に設置された像担持体小径部９
に圧接され駆動する高摩擦材ローラ６は、転写ローラ２
の回転速度よりも低速で回転しており、転写ローラ２の
回転方向に対して自由な構造を持つラチェット部５によ
って転写ローラ２の回転軸と接続している。これにより
転写ローラ２の回転が高摩擦材ローラ６の回転より遅く
なったときに高摩擦材ローラ６の回転が転写ローラ２に
伝達される。なお、高摩擦材ローラ６の材質としては、
シリコンゴム、ウレタンゴム、天然ゴム等の弾性部材の
ソリッドローラ、もしくはスポンジ状ローラの使用が好
ましい。FIG. 4 showing the outline of the fourth embodiment of the present invention.
In this electrophotographic apparatus, the image carrier 1
Is rotating at a constant speed. The transfer roller 2 that is in contact with the image carrier 1 is driven and rotated by friction with the surface of the image carrier 1. Further, at the end of the image carrier 1, the small diameter part 9 of the image carrier installed outside the region where the transfer medium (not shown) is conveyed.
The high-friction material roller 6 that is pressed against and driven by the transfer roller 2 is
The rotational speed of the transfer roller 2 is lower than that of the transfer roller 2, and the ratchet portion 5 having a free structure with respect to the rotational direction of the transfer roller 2 is connected to the rotary shaft of the transfer roller 2. Thus, when the rotation of the transfer roller 2 becomes slower than the rotation of the high friction material roller 6, the rotation of the high friction material roller 6 is transmitted to the transfer roller 2. In addition, as a material of the high friction material roller 6,
It is preferable to use a solid roller made of an elastic material such as silicone rubber, urethane rubber, or natural rubber, or a sponge roller.
【００１８】本発明の電子写真装置は、像担持体１とそ
れに接触して配置された転写ローラ２とを有し、ギア等
による恒常的な駆動を行わずに、転写ローラ２は像担持
体表面の摩擦により従動し、回転するため、常に像担持
体１の周速と転写ローラ２の周速との比率は１：１とな
る。また、像担持体１と転写ローラ２との接触面の内、
転写媒体が搬送される領域外の接触面において、像担持
体１および転写ローラ２のいずれかに像担持体１の駆動
力が充分に転写ローラ２に伝わる手段を有することによ
り、転写媒体が搬送される領域において、摩擦力が低下
しても、転写ローラがスリップすることを防止できる。
さらに、像担持体１とそれに接触して配置された転写ロ
ーラ２との他に、転写ローラ２と同軸上に配置され転写
ローラ２の回転方向に対して自由なラチェット構造をも
つギアとを有することにより、像担持体１の周速に対し
て転写ローラ２の周速が遅くなった際にギアにより転写
ローラ２を駆動する。The electrophotographic apparatus of the present invention has an image carrier 1 and a transfer roller 2 arranged in contact therewith, and the transfer roller 2 is an image carrier without being constantly driven by a gear or the like. Since it is driven and rotated by the friction of the surface, the ratio between the peripheral speed of the image carrier 1 and the peripheral speed of the transfer roller 2 is always 1: 1. In addition, of the contact surfaces between the image carrier 1 and the transfer roller 2,
On the contact surface outside the area where the transfer medium is transported, the transfer medium is transported by providing a means for sufficiently transmitting the driving force of the image carrier 1 to the transfer roller 2 to either the image carrier 1 or the transfer roller 2. Even if the frictional force is reduced in the area, the transfer roller can be prevented from slipping.
Further, in addition to the image carrier 1 and the transfer roller 2 arranged in contact therewith, the image carrier 1 has a gear arranged coaxially with the transfer roller 2 and having a ratchet structure which is free in the rotational direction of the transfer roller 2. Thus, the transfer roller 2 is driven by the gear when the peripheral speed of the transfer roller 2 becomes slower than the peripheral speed of the image carrier 1.
【００１９】[0019]
【発明の効果】以上説明したように、本発明によれば、
駆動する像担持体の表面との摩擦により転写ローラを従
動し、回転させることにより像担持体の周速と転写ロー
ラの周速は常に１：１になる。そのとき、転写効率は最
大となり、像担持体上に残留する未転写の現像剤が減少
するため、未転写の現像剤を回収するクリーナの小容量
化、クリーナの削除が可能になる等の効果がある。As described above, according to the present invention,
The peripheral speed of the image carrier and the peripheral speed of the transfer roller are always 1: 1 by following and rotating the transfer roller by friction with the surface of the driven image carrier. At that time, the transfer efficiency becomes maximum and the amount of the untransferred developer remaining on the image carrier is reduced. Therefore, it is possible to reduce the capacity of the cleaner that collects the untransferred developer and to remove the cleaner. There is.
【００２０】また、転写ローラあるいは像担持体上に、
転写媒体が搬送される領域外で摩擦力が得られる手段を
持つことにより、像担持体から転写ローラに対して安定
して駆動力を与えることができるため、転写媒体が搬送
される領域において、大面積、厚みが薄い、あるいは表
面の摩擦抵抗が低い転写媒体が像担持体と転写ローラと
の間に搬送される場合、あるいは転写媒体、現像剤によ
り転写ローラが汚れる場合に生じる摩擦力の低下により
発生する転写ローラのスリップ、あるいは転写媒体の搬
送障害を防止する効果がある。更に、本発明の実施例で
挙げた摩擦力が得られる手段を構成する材料は安価に入
手可能であり、現行機種においても大きく構造を変更す
る必要が無いので容易に採用できる。Further, on the transfer roller or the image carrier,
By having a means for obtaining a frictional force outside the area where the transfer medium is conveyed, a stable driving force can be applied to the transfer roller from the image carrier, so that in the area where the transfer medium is conveyed, Reduction of frictional force that occurs when a transfer medium having a large area, a small thickness, or a low surface friction resistance is conveyed between the image carrier and the transfer roller, or when the transfer medium or developer stains the transfer roller. There is an effect of preventing the transfer roller from slipping or the transfer medium conveyance failure caused by the above. Further, the materials constituting the means for obtaining the frictional force mentioned in the embodiments of the present invention can be obtained at low cost, and even in the current model, there is no need to make a large change in structure, so that they can be easily adopted.
【００２１】また、転写ローラと同軸上にギア、あるい
は高摩擦材ローラを設置し、ラチェット部によって接続
することにより、大面積、厚みが薄い、あるいは表面の
摩擦抵抗が低い転写媒体が像担持体と転写ローラとの間
に搬送された場合、あるいは転写媒体、現像剤により転
写ローラが汚れる場合に生じる摩擦力の低下により発生
する転写ローラのスリップ、あるいは転写媒体の搬送障
害を防止する効果がある。更に、最近はラチェット構造
を持つギアが安価に入手可能であり、現行機種において
も大きく構造を変更する必要が無いので容易に採用でき
る。Further, by installing a gear or a high friction material roller coaxially with the transfer roller and connecting them by a ratchet portion, a transfer medium having a large area, a small thickness or a low surface frictional resistance is used as an image carrier. Between the transfer roller and the transfer roller, or when the transfer roller or the transfer roller is contaminated by the developer, the slippage of the transfer roller caused by the reduction of the frictional force or the transfer medium transfer failure is prevented. . Further, recently, gears having a ratchet structure are available at low cost, and even in the current model, there is no need to change the structure significantly, so that it can be easily adopted.
【図１】本発明の第１の実施の形態の概要を示す図であ
る。FIG. 1 is a diagram showing an outline of a first embodiment of the present invention.
【図２】本発明の第２の実施の形態の概要を示す図であ
る。FIG. 2 is a diagram showing an outline of a second embodiment of the present invention.
【図３】本発明の第３の実施の形態の概要を示す図であ
る。FIG. 3 is a diagram showing an outline of a third embodiment of the present invention.
【図４】本発明の第４の実施の形態の概要を示す図であ
る。FIG. 4 is a diagram showing an outline of a fourth embodiment of the present invention.
【図５】従来例を説明する図である。FIG. 5 is a diagram illustrating a conventional example.
【図６】従来例を説明する図である。FIG. 6 is a diagram illustrating a conventional example.
１ 像担持体 ２ 転写ローラ ３ 像担持体ギア ４ 転写ローラギア ５ ラチェット部 ６ 高摩擦材ローラ ７，７’ 高摩擦材 ８ 転写ローラ大径部 ９ 像担持体小径部 Ｐ 転写媒体が搬送される領域 Ｐ’ 転写媒体が搬送される領域外 1 image carrier 2 transfer roller 3 image carrier gear 4 transfer roller gear 5 ratchet part 6 high friction material roller 7,7 'high friction material 8 transfer roller large diameter part 9 image carrier small diameter part P transfer area P ′ Outside the area where the transfer medium is transported
Claims (3)
像を行い、現像したこの現像剤を転写ローラを用いて前
記像担持体と前記転写ローラとの間に搬送される転写媒
体へ転写を行うことを特徴とする電子写真装置におい
て、前記転写ローラは駆動する前記像担持体表面との摩
擦により従動し、前記転写ローラを前記像担持体が従動
させるために必要な摩擦力が、前記転写ローラと前記像
担持体との接触面の内、前記転写媒体が搬送される領域
外で得られる手段を備えることを特徴とする電子写真装
置。1. A transfer medium in which an electrostatic latent image on an image carrier is developed with a developer, and the developed developer is conveyed between the image carrier and the transfer roller by using a transfer roller. In the electrophotographic apparatus, the transfer roller is driven by friction with the surface of the image carrier to be driven, and a friction force necessary for the image carrier to follow the transfer roller is generated. An electrophotographic apparatus comprising means for obtaining the contact surface between the transfer roller and the image carrier outside the area where the transfer medium is conveyed.
像を行い、現像したこの現像剤を転写ローラを用いて前
記像担持体と前記転写ローラとの間に搬送される転写媒
体へ転写を行うことを特徴とする電子写真装置におい
て、前記転写ローラは駆動する前記像担持体表面との摩
擦により従動し、前記転写ローラと前記像担持体との摩
擦力が低下し前記転写ローラがスリップするときのみに
直接動力を与える駆動手段を備えることを特徴とする電
子写真装置。2. A transfer medium in which an electrostatic latent image on an image carrier is developed with a developer, and the developed developer is conveyed between the image carrier and the transfer roller by using a transfer roller. In the electrophotographic apparatus, the transfer roller is driven by friction with the surface of the image carrier that is driven, and the frictional force between the transfer roller and the image carrier is reduced to reduce the transfer roller. An electrophotographic apparatus comprising a driving unit that directly gives power only when the vehicle slips.
せるために必要な摩擦力が、前記転写ローラと前記像担
持体との接触面の内、前記転写媒体が搬送される領域外
で得られる手段を持つことを特徴とする請求項２記載の
電子写真装置。3. The frictional force required for the image carrier to follow the transfer roller is obtained within the contact surface between the transfer roller and the image carrier and outside the region where the transfer medium is conveyed. The electrophotographic apparatus according to claim 2, further comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9668896A JPH09281819A (en) | 1996-04-18 | 1996-04-18 | Electrophotographic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9668896A JPH09281819A (en) | 1996-04-18 | 1996-04-18 | Electrophotographic device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09281819A true JPH09281819A (en) | 1997-10-31 |
Family
ID=14171741
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9668896A Pending JPH09281819A (en) | 1996-04-18 | 1996-04-18 | Electrophotographic device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09281819A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6208826B1 (en) * | 1998-06-08 | 2001-03-27 | Ricoh Company, Ltd. | Transfer device having notches, method and image forming apparatus using the same transfer device or method |
| JP2007121553A (en) * | 2005-10-26 | 2007-05-17 | Fuji Xerox Co Ltd | Transfer roll and image forming apparatus |
-
1996
- 1996-04-18 JP JP9668896A patent/JPH09281819A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6208826B1 (en) * | 1998-06-08 | 2001-03-27 | Ricoh Company, Ltd. | Transfer device having notches, method and image forming apparatus using the same transfer device or method |
| JP2007121553A (en) * | 2005-10-26 | 2007-05-17 | Fuji Xerox Co Ltd | Transfer roll and image forming apparatus |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 19981013 |