JPH09160395A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JPH09160395A JPH09160395A JP7322667A JP32266795A JPH09160395A JP H09160395 A JPH09160395 A JP H09160395A JP 7322667 A JP7322667 A JP 7322667A JP 32266795 A JP32266795 A JP 32266795A JP H09160395 A JPH09160395 A JP H09160395A
- Authority
- JP
- Japan
- Prior art keywords
- resistance
- transfer
- primary transfer
- secondary transfer
- conductive layer
- 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.)
- Granted
Links
Landscapes
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Color Electrophotography (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、感光体等の潜像担
持体に形成された潜像を、順次、色の異なるカラートナ
ーにより現像し、現像されたトナー像を一旦中間転写媒
体に転写し、全色のトナー像を中間転写媒体上に重ね合
わせた後まとめて記録紙に転写する画像形成装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention sequentially develops latent images formed on a latent image carrier such as a photoconductor with different color toners and transfers the developed toner images to an intermediate transfer medium. The present invention relates to an image forming apparatus that superimposes toner images of all colors on an intermediate transfer medium and then collectively transfers the toner images onto recording paper.
【０００２】[0002]
【従来の技術】カラーレーザープリンター、カラー複写
機として使用される画像形成装置のひとつとして、感光
体に形成された潜像を、順次、色の異なるカラートナー
により現像し、現像されたトナー像を一旦中間転写媒体
に転写し、全色のトナー像を中間転写媒体上に重ね合わ
せた後、まとめて記録紙に転写する中間転写方式があ
る。一般的に、トナーを静電的に転写する方式が用いら
れている。この静電的に転写する中間転写方式におい
て、中間転写媒体が電気的に均一な抵抗体で形成される
ものや中間転写媒体中に導電体が導電層を有し更に表面
層として抵抗層が形成されているもの等種々の構成が提
案されている。2. Description of the Related Art As one of image forming apparatuses used as color laser printers and color copying machines, latent images formed on a photoconductor are successively developed with color toners of different colors, and the developed toner images are formed. There is an intermediate transfer system in which the toner images of all colors are once transferred onto an intermediate transfer medium, and the toner images of all colors are superimposed on the intermediate transfer medium, and then collectively transferred onto a recording paper. Generally, a method of electrostatically transferring toner is used. In this electrostatic intermediate transfer method, the intermediate transfer medium is formed of an electrically uniform resistor, or the intermediate transfer medium has a conductive layer in which a conductive layer is formed, and a resistance layer is formed as a surface layer. Various configurations such as the existing ones have been proposed.
【０００３】さて電気的に均一な抵抗体で形成される中
間転写媒体を有する画像形成装置においては、一般的に
転写電界は転写部裏面に当接する導電性のローラにより
付与されるが、中間転写媒体に歪み等が発生したり導電
性のローラにごみが付着した場合、部分的に電界が付与
できなくなり転写部の電界が不均一となり転写された画
像にむらが発生する。一方導電層を有する中間転写媒体
から構成される画像形成装置は、中間転写媒体に歪みが
発生したり、転写部のローラーにごみが付着した場合に
も、転写部全域に均一な転写の電界が付与できるため、
転写に起因する画像むらが無くなるという長所を有す
る。In an image forming apparatus having an intermediate transfer medium formed of an electrically uniform resistor, a transfer electric field is generally applied by a conductive roller that contacts the back surface of the transfer portion. When the medium is distorted or dust is attached to the conductive roller, the electric field cannot be partially applied, and the electric field at the transfer portion becomes non-uniform, causing unevenness in the transferred image. On the other hand, in the image forming apparatus including the intermediate transfer medium having the conductive layer, even when the intermediate transfer medium is distorted or dust adheres to the roller of the transfer section, a uniform transfer electric field is generated in the entire transfer section. Because it can be given
It has an advantage that image unevenness due to transfer is eliminated.
【０００４】しかしながら導電層を有する中間転写媒体
から構成される画像形成装置では、一次転写の動作のみ
行う時に最適に設定された一次転写部に流れる電流が、
一次転写と二次転写の動作を同時に行った時に回路に二
次転写部の電流が流入し変化してしまうため、一次転写
部の転写効率が変化し良好な画像が形成できないという
欠点があった。However, in the image forming apparatus composed of the intermediate transfer medium having the conductive layer, the current flowing through the primary transfer portion which is optimally set when only the primary transfer operation is performed,
When the primary transfer operation and the secondary transfer operation are performed at the same time, the current of the secondary transfer portion flows into the circuit and changes. Therefore, the transfer efficiency of the primary transfer portion changes and there is a drawback that a good image cannot be formed. .
【０００５】これを防ぐため従来一次転写と二次転写の
動作を同時に行なわないという対策がとられている。例
えば、特開平１−２８８８７７号公報では、中間転写媒
体のトナー像を形成する表面と反対側に導電層が形成さ
れており、相互の動作を同時に行わないで、一次転写二
次転写それぞれの動作時に、電極の電位状態を非接地、
地接地と切り替えている。In order to prevent this, conventionally, a measure has been taken in which the operations of primary transfer and secondary transfer are not performed at the same time. For example, in Japanese Unexamined Patent Publication No. 1-288877, a conductive layer is formed on the side of the intermediate transfer medium opposite to the surface on which a toner image is formed, and the operations of the primary transfer and the secondary transfer are performed without performing mutual operations at the same time. Sometimes the potential state of the electrode is not grounded,
Switching to ground contact.
【０００６】[0006]
【発明が解決しようとする課題】しかし、上述の従来技
術においては、一次転写と二次転写の動作が同時に行わ
れないようにするために、一次転写部から二次転写部ま
での中間転写媒体の長さを記録紙の搬送方向の長さより
長くしたり、あるいは一次転写が完全に終了するまで二
次転写動作を行わず、一次転写終了以前に二次転写部を
通過してしまった画像先端部を再度二次転写部まで搬送
するための空回しを行ってから二次転写を開始する必要
があった。この結果中間転写媒体が大型化したり、転写
動作に長い時間を必要とする問題点を有していた。However, in the above-mentioned prior art, in order to prevent the operations of the primary transfer and the secondary transfer from being performed at the same time, the intermediate transfer medium from the primary transfer portion to the secondary transfer portion is formed. The length of the image is longer than the length of the recording paper in the conveyance direction, or the secondary transfer operation is not performed until the primary transfer is completely completed, and the leading edge of the image that has passed the secondary transfer section before the primary transfer is completed. It was necessary to start the secondary transfer after performing idling to convey the part to the secondary transfer part again. As a result, there are problems that the intermediate transfer medium becomes large and that the transfer operation requires a long time.
【０００７】さらに従来技術の装置構成においては、導
電層とそれにバイアス印加するために導電層に接触する
接触電極との間に遊離トナー等のごみが蓄積され、導電
層と接触電極の抵抗値が大きくなり良好な転写が継続で
きなくなるという問題点を有していた。Furthermore, in the prior art device configuration, dust such as free toner is accumulated between the conductive layer and the contact electrode that contacts the conductive layer for applying a bias thereto, and the resistance value of the conductive layer and the contact electrode is reduced. There is a problem in that it becomes large and good transfer cannot be continued.
【０００８】そこで本発明は、かかる問題点を解決する
ためになされたものであり、その目的とするところは、
一次転写、二次転写の動作が同時に実行でき、転写動作
が短く小型の電源を有する画像形成装置を提供すること
にある。また本発明の第二の目的は、使用にともなう接
触抵抗の変化を防ぎ、良好な転写動作を継続的に得るこ
とにある。Therefore, the present invention has been made to solve the above problems, and its purpose is to:
An object of the present invention is to provide an image forming apparatus which can perform primary transfer and secondary transfer operations at the same time, has a short transfer operation, and has a small power source. A second object of the present invention is to prevent a change in contact resistance due to use and continuously obtain a good transfer operation.
【０００９】[0009]
【課題を解決するための手段】本発明の画像形成装置
は、順次色の異なるカラートナーにより現像されたトナ
ー像を中間転写媒体に転写する一次転写部と、一次転写
部においてバイアスを印加するための一次転写バイアス
印加電源と、前記全色中間転写媒体にて重ね合わせられ
た全色カラートナー像を記録紙に転写する二次転写部
と、二次転写部においてバイアスを印加するための二次
転写バイアス印加電源を有する画像形成装置において、
前記中間転写媒体が導電層を有し、かつ、前記一次転写
バイアス印加電源から前記導電層までの抵抗ＲTと一次
転写部の見かけの抵抗Ｒ1が、 ＲT＜Ｒ1 なる関係を有することを特徴とする。In the image forming apparatus of the present invention, a primary transfer portion for transferring a toner image sequentially developed with color toners of different colors to an intermediate transfer medium, and a bias is applied in the primary transfer portion. Primary transfer bias application power source, a secondary transfer section for transferring all color color toner images superposed on the all color intermediate transfer medium onto recording paper, and a secondary transfer section for applying a bias at the secondary transfer section. In an image forming apparatus having a transfer bias applying power source,
The intermediate transfer medium has a conductive layer, and the resistance RT from the primary transfer bias applying power source to the conductive layer and the apparent resistance R1 of the primary transfer portion have a relationship of RT <R1. .
【００１０】さらに ＲT／Ｒ1≦０．１ なる関係を有することを特徴とする。Further, it is characterized by having a relationship of RT / R1 ≦ 0.1.
【００１１】[0011]
【発明の実施の形態】以下に本発明の実施の形態を図面
に基づいて説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.
【００１２】図１は本発明の画像形成装置の断面概観図
である。まず、装置の動作を説明する。帯電ローラ１０
２は感光体１０１を均一にある電位（例えば−７００
Ｖ）に帯電する。レーザー走査光学系である露光手段１
０３によって形成された６００ｄｐｉ（ｄｏｔ ｐｅｒ
ｉｎｃｈ）の解像度のレーザービームは折り返しミラ
ー１０４により感光体１０１上に導かれ静電潜像（例え
ば−１００Ｖ）が形成される。次に図中矢印方向に接離
可能な一成分接触方式の現像器１０５の内、イエロー現
像器１０５Ｙを接触させ他の現像器は離間させるととも
に図では示していない電源の電界作用によって負帯電性
イエロートナーが反転現像され感光体上１０１において
顕像化される。顕像化されたイエロートナーは、中間転
写媒体に静電転写される。FIG. 1 is a schematic sectional view of the image forming apparatus of the present invention. First, the operation of the device will be described. Charging roller 10
2 is a potential at which the photoconductor 101 is even (for example, -700).
V). Exposure means 1 which is a laser scanning optical system
600 formed by 03 (dot per
The laser beam having the (inch) resolution is guided onto the photoconductor 101 by the folding mirror 104 to form an electrostatic latent image (for example, −100 V). Next, of the one-component contact type developing device 105 which can be contacted and separated in the direction of the arrow in the figure, the yellow developing device 105Y is brought into contact with the other developing devices and the other developing devices are separated from each other, and the negative charging property is caused by the electric field effect of a power source (not shown) The yellow toner is reversely developed and visualized on the photoconductor 101. The visualized yellow toner is electrostatically transferred to the intermediate transfer medium.
【００１３】中間転写媒体はＰＥＴ（ポリエチレンテレ
フタレート）の基材上に、導電層としてアルミ蒸着膜を
有し、さらにその上部を適当な抵抗に調整された表面抵
抗層により被覆されている。中間転写媒体の表面は、全
て表面抵抗層に被覆されておらず、端部において導電層
が露出している。The intermediate transfer medium comprises a PET (polyethylene terephthalate) base material, an aluminum vapor deposition film as a conductive layer, and the upper part thereof is covered with a surface resistance layer adjusted to have an appropriate resistance. The surface of the intermediate transfer medium is not entirely covered with the surface resistance layer, and the conductive layer is exposed at the end.
【００１４】定電圧制御可能な一次転写バイアス印加電
源１０８によりトナーと逆極性のバイアスが発生され、
電源１０８に接続された接触電極１２１から中間転写媒
体１０６の導電層露出部を介し、中間転写媒体１０６上
に転写電圧が印加される。感光体１０１上のトナーは、
感光体１０１と一次転写ローラー１０７に挟み込まれた
中間転写媒体１０６上に静電転写される。感光体１０１
上の転写残りトナーは、ブレードを接触させてクリーニ
ングする感光体クリーナー１０９で回収され、続いて感
光体電位は除電ランプ１１０によりリセットされる。同
様の動作を中間転写体１０６の位置と露光手段１０３の
発光タイミングの同期を取りマゼンタ現像器１０５Ｍ、
シアン現像器１０５Ｃ、ブラック現像器１０５Ｋについ
ても繰り返すことにより、中間転写媒体１０６上に各色
のトナーが重ねられフルカラー画像が形成される。この
間、二次転写ローラ１１６、および中間転写媒体クーリ
ナー１１９は離間状態とする。一方、転写材１１３は給
紙カセット１１２から給紙手段１１１によりレジストロ
ーラ対１１４まで搬送されたのち、中間転写体１０６上
のフルカラー画像と同期をとって駆動ローラ１１５と図
中矢印方向に接離可能な二次転写ローラ１１６にて形成
される二次転写部に搬送される。二次転写部では転写材
１１３と同期して二次転写ローラ１１６が中間転写体１
０６に接触してニップ部を形成するとともに二次転写バ
イアス印加電源１１７により定電流制御されその電界の
作用で転写材１１３上にフルカラートナー像が形成され
る。また、この時中間転写体媒体クリーナー１１９は中
間転写媒体１０６に接触する。その後、転写材１１３は
定着手段１２０によって定着され装置外へ排出される。
二次転写後の転写残りトナーは図中矢印方向に動くテン
ションローラ１１８を通過後、中間転写媒体クリーナー
１１９にて回収される。A primary transfer bias applying power source 108 capable of constant voltage control generates a bias having a polarity opposite to that of the toner,
A transfer voltage is applied to the intermediate transfer medium 106 from the contact electrode 121 connected to the power supply 108 through the exposed portion of the conductive layer of the intermediate transfer medium 106. The toner on the photoconductor 101 is
It is electrostatically transferred onto the intermediate transfer medium 106 sandwiched between the photoconductor 101 and the primary transfer roller 107. Photoconductor 101
The transfer residual toner on the upper part is collected by the photoconductor cleaner 109 which is brought into contact with a blade for cleaning, and subsequently, the photoconductor potential is reset by the discharging lamp 110. The same operation is performed by synchronizing the position of the intermediate transfer member 106 and the light emission timing of the exposure unit 103, and the magenta developing device 105M
By repeating the steps for the cyan developing device 105C and the black developing device 105K, the toners of the respective colors are superposed on the intermediate transfer medium 106 to form a full-color image. During this time, the secondary transfer roller 116 and the intermediate transfer medium cooler 119 are in the separated state. On the other hand, the transfer material 113 is conveyed from the paper feeding cassette 112 to the registration roller pair 114 by the paper feeding means 111, and then is brought into contact with and separated from the driving roller 115 in the direction of the arrow in the figure in synchronization with the full-color image on the intermediate transfer body 106. It is conveyed to a secondary transfer portion formed by a possible secondary transfer roller 116. In the secondary transfer portion, the secondary transfer roller 116 is synchronized with the transfer material 113 and the secondary transfer roller 116
A full-color toner image is formed on the transfer material 113 by the action of the electric field under the control of a constant current by the secondary transfer bias applying power source 117 while forming a nip portion in contact with the contact point 06. At this time, the intermediate transfer medium cleaner 119 contacts the intermediate transfer medium 106. Thereafter, the transfer material 113 is fixed by the fixing unit 120 and discharged out of the apparatus.
The untransferred toner after the secondary transfer passes through the tension roller 118 that moves in the direction of the arrow in the figure, and is collected by the intermediate transfer medium cleaner 119.
【００１５】本発明では、一次転写部と二次転写部間の
中間転写媒体長さが、形成された画像長さより短い場合
は、最後の色の画像の一次転写が完全に終了する前に二
次転写が同時に行なわれ、この時点では二次転写ローラ
ー１１６は中間転写媒体に接触している。According to the present invention, when the length of the intermediate transfer medium between the primary transfer portion and the secondary transfer portion is shorter than the length of the formed image, the secondary transfer is completed before the primary transfer of the image of the last color is completed. The secondary transfer is performed at the same time, and the secondary transfer roller 116 is in contact with the intermediate transfer medium at this point.
【００１６】図２〜４に、上記画像形成装置の転写動作
に対応した、本発明の簡単な等価回路図を示す。2 to 4 show simple equivalent circuit diagrams of the present invention corresponding to the transfer operation of the image forming apparatus.
【００１７】図２は、本発明において、一次転写のみが
行われる場合の等価回路図である。一次転写だけが行わ
れる場合は、二次転写ローラーは離間しており等価回路
的には二次転写に関わることは考慮しなくともよい。図
中Ｖ1は一次転写バイアス印加電源のから発生される定
電圧であり、抵抗ＲTを介し中間転写媒体の導電層Ａに
印加される。感光体と導電層の間の一次転写部には一次
転写電流Ｉ11が流れるが、この場合は電源Ｖ1に流れる
電流と同じである。導電層Ａの電位を測定して、前記Ｉ
11で除することにより一次転写部の見かけの抵抗Ｒ1が
計算できる。また抵抗ＲTは電源から導電層までの抵抗
で、主に導電層と接触電極との間の接触抵抗であると考
えられるが、一次転写バイアス印加電源Ｖ1と導電層Ａ
の電位の差分をＩ11で除することにより算出できる。FIG. 2 is an equivalent circuit diagram when only the primary transfer is performed in the present invention. When only the primary transfer is performed, it is not necessary to consider that the secondary transfer rollers are spaced apart and are involved in the secondary transfer in terms of an equivalent circuit. In the figure, V1 is a constant voltage generated from the primary transfer bias applying power source, and is applied to the conductive layer A of the intermediate transfer medium via the resistor RT. A primary transfer current I11 flows through the primary transfer portion between the photoconductor and the conductive layer, and in this case, it is the same as the current flowing through the power supply V1. The electric potential of the conductive layer A is measured to obtain the I
By dividing by 11, the apparent resistance R1 of the primary transfer portion can be calculated. The resistance RT is the resistance from the power source to the conductive layer, and is considered to be mainly the contact resistance between the conductive layer and the contact electrode.
It can be calculated by dividing the potential difference of I by I11.
【００１８】図３は本発明において一次転写、二次転写
が同時に行われる場合の等価回路図である。定電流Ｉ2
が流れるように制御された二次転写バイアス印加電源Ｖ
2は、二次転写部を介して中間転写媒体の導電層Ａに接
続されている。導電層Ａ点の電位より電源Ｖ2の出力電
圧を減じ、二次転写部に流れる定電流Ｉ2で除すること
により二次転写部の見かけの抵抗Ｒ2が算出できる。二
次転写部が接続されたことにより一次転写部に流れる電
流は変化しＩ12となる。Ｉ12は、Ｉ2から一次転写電源
に流れる電流を減ずることにより算出できる。FIG. 3 is an equivalent circuit diagram when the primary transfer and the secondary transfer are simultaneously performed in the present invention. Constant current I2
Secondary transfer bias application power source V controlled to flow
2 is connected to the conductive layer A of the intermediate transfer medium via the secondary transfer portion. The apparent resistance R2 of the secondary transfer portion can be calculated by subtracting the output voltage of the power source V2 from the potential of the conductive layer A and dividing by the constant current I2 flowing in the secondary transfer portion. Since the secondary transfer portion is connected, the current flowing through the primary transfer portion changes and becomes I12. I12 can be calculated by subtracting the current flowing to the primary transfer power source from I2.
【００１９】図４は、本発明において、二次転写のみが
行われる場合の等価回路図である。一次転写部では、ト
ナーの転写がなくなり、従って見かけの抵抗が非常に大
きくなるため一次転写部の回路は考慮しなくともよい。FIG. 4 is an equivalent circuit diagram when only secondary transfer is performed in the present invention. At the primary transfer portion, the toner is not transferred, and therefore the apparent resistance becomes very large, so the circuit of the primary transfer portion need not be considered.
【００２０】一次転写と二次転写を同時に行っても良好
な画像を得るためには、各転写動作のみが行われる場合
と同時に行われる場合、それぞれの転写効率が等しくな
れば良い。一般的に転写部を定電流制御を行なうと転写
効率が変化せず良好な転写が行われることが知られてい
る。前記本発明の等価回路において二次転写部は定電流
制御が可能のため、同時転写行なう場合も、二次転写だ
け行なう場合も転写効率は一定である。一方一次転写部
へのバイアス印加電源は、転写部に直接電源が接続でき
ないため定電流制御を行えず定電圧制御となる。前記等
価回路において一次転写部に流れる電流は、一次転写だ
けが行われる時と、一次転写二次転写同時に行われる時
でそれぞれ下式（１）式（２）であらわされる。In order to obtain a good image even if the primary transfer and the secondary transfer are performed at the same time, it is sufficient that the transfer efficiencies are equal when the respective transfer operations are performed at the same time. It is generally known that when constant current control is performed on a transfer portion, good transfer is performed without changing transfer efficiency. In the equivalent circuit of the present invention, since the secondary transfer portion is capable of constant current control, the transfer efficiency is constant both when performing simultaneous transfer and when performing only secondary transfer. On the other hand, the bias applying power supply to the primary transfer portion cannot be directly connected to the transfer portion, so that constant current control cannot be performed and constant voltage control is performed. The current flowing through the primary transfer portion in the equivalent circuit is expressed by the following equations (1) and (2) when only the primary transfer is performed and when the primary transfer and the secondary transfer are simultaneously performed.
【００２１】[0021]
【数１】 [Equation 1]
【００２２】[0022]
【数２】 (Equation 2)
【００２３】各式でＲT＜Ｒ1なる関係を実現すると、Ｉ
11とＩ12がほぼ同じとなり、一次転写の動作のみ行う場
合と、一次転写と二次転写の動作を同時に行う場合の一
次転写部における転写効率がほぼ等しくなり、一次転写
と二次転写を同時に行うことが可能となる。When the relation RT <R1 is realized in each equation, I
11 and I12 are almost the same, and the transfer efficiencies in the primary transfer portion when only the primary transfer operation is performed and when the primary transfer and secondary transfer operations are performed at the same time are substantially the same, and the primary transfer and the secondary transfer are performed at the same time. It becomes possible.
【００２４】本発明により一次転写と二次転写が同時に
できることになり、例えば最大Ｂ４縦サイズ以上の画像
が形成できる装置の場合、一次転写部と二次転写部間の
中間転写媒体長さはＡ４縦サイズより短くすることがで
きる。従って、中間転写媒体の長さは、従来の構成の画
像形成装置より短くなり装置構成は簡単且つ小型となっ
ている。According to the present invention, the primary transfer and the secondary transfer can be performed at the same time. For example, in the case of an apparatus capable of forming an image having a maximum size of B4 vertical size or more, the length of the intermediate transfer medium between the primary transfer portion and the secondary transfer portion is A4. It can be shorter than the vertical size. Therefore, the length of the intermediate transfer medium is shorter than that of the image forming apparatus having the conventional configuration, and the apparatus configuration is simple and compact.
【００２５】本発明ではベルトの基材としてＰＥＴを使
用したが、プラスチックフィルム等の同等の性質を有す
る材質ならいかなる基材でもよい。ＰＥＴ基材とアルミ
ニウム蒸着層の替わりに金属材料の単体の厚膜、例えば
ニッケル電鋳ベルト等を使用しても良いが、これらの膜
は多数の回転に伴う折り曲げにより、金属疲労を引き起
こし破断してしまうため、プラスチックフィルムにより
張力を支えるのがより望ましい。また本発明の構成では
中間転写媒体としてベルト状のものを使用したが、金属
ドラム等のドラム状の構成に置いても本発明が有効であ
る。しかし装置構成の点から形状の自由度が高いベルト
状のものが望ましい。Although PET is used as the base material of the belt in the present invention, any base material may be used as long as it has the same properties such as a plastic film. A thick film of a metal material alone, such as a nickel electroformed belt, may be used instead of the PET base material and the aluminum vapor deposition layer, but these films cause metal fatigue due to bending due to many rotations and break. Therefore, it is more desirable to support the tension with a plastic film. Further, although a belt-shaped medium is used as the intermediate transfer medium in the configuration of the present invention, the present invention is also effective when placed in a drum-shaped configuration such as a metal drum. However, a belt-shaped member having a high degree of freedom in shape is desirable from the viewpoint of the device configuration.
【００２６】（実施例１）以下に前記、本発明の装置構
成にて、電源から導電層までの抵抗ＲT、一次転写部の
見かけの抵抗Ｒ1を変化させその画像を評価した。(Embodiment 1) In the device constitution of the present invention, the resistance RT from the power source to the conductive layer and the apparent resistance R1 of the primary transfer portion were changed to evaluate the image.
【００２７】電源から導電層までの抵抗ＲTは、その抵
抗成分は主として電極と導電層の接触部の接触抵抗に起
因している。そこでアルミニウム導電層の不動体膜厚を
変化させまた、電極の接触圧を変化させることにより接
触抵抗を変化させることにより、ＲTを変化させた。The resistance component of the resistance RT from the power source to the conductive layer is mainly due to the contact resistance of the contact portion between the electrode and the conductive layer. Therefore, RT is changed by changing the film thickness of the unmoving body of the aluminum conductive layer and by changing the contact pressure of the electrode.
【００２８】一次転写部の見かけ抵抗はＲ1は、感光体
の帯電電位Ｖ0、中間転写媒体の回転線速であるプロセ
ス速度ｖ、トナー厚みｄ、画像形成領域の広さｌ、中間
転写媒体のin-situ抵抗Ｒm等により可変である。これら
の要因を変化させることにより、一次転写部の見かけの
抵抗Ｒ1を変化させた。The apparent resistance R1 of the primary transfer portion is the charging potential V 0 of the photosensitive member, the process speed v which is the rotational linear velocity of the intermediate transfer medium, the toner thickness d, the width l of the image forming area, and the intermediate transfer medium. It is variable by the in-situ resistance R m and the like. By changing these factors, the apparent resistance R 1 of the primary transfer portion was changed.
【００２９】評価方法は、画像形成装置にてＡ４サイズ
の画像を全面ベタ印字を行い転写紙に印字された像を目
視にて評価した。本装置においては、一次転写部と二次
転写部間の中間転写媒体長さがＡ４サイズの画像長さよ
り短い。従って、二次転写が行がまだ始まらないとき一
次転写が実行された画像領域が転写紙の先端に、二次転
写と同時に行われた一次転写の領域が転写紙の後端に形
成される。印字した転写紙の先端、後端を目視により比
較し、後端が先端と区別できない場合は一次転写、二次
転写同時におこなっても良いことが分かる。下表１の画
像評価の項目に、先端後端が全然区別できない場合は
◎、若干濃度差が認められるものの実用上差しつかえな
い場合は○、はっきり区別できる場合は×と示す。As an evaluation method, an A4 size image was solidly printed on the entire surface by an image forming apparatus, and the image printed on the transfer paper was visually evaluated. In this apparatus, the length of the intermediate transfer medium between the primary transfer portion and the secondary transfer portion is shorter than the image length of A4 size. Therefore, when the secondary transfer is not yet started, the image area where the primary transfer is executed is formed at the front end of the transfer paper, and the area of the primary transfer performed simultaneously with the secondary transfer is formed at the rear end of the transfer paper. By visually comparing the front end and the rear end of the printed transfer paper, it can be understood that the primary transfer and the secondary transfer may be performed simultaneously when the rear end cannot be distinguished from the front end. In the image evaluation items of Table 1 below, ⊚ indicates that the front end and rear end cannot be distinguished at all, “◯” indicates that there is a slight difference in density but it is practically acceptable, and “X” indicates that they can be clearly distinguished.
【００３０】上記Ｒt、Ｒ1をそれぞれ変化させた組み合
わせにおいて画像を評価した結果を下表１に示す。Table 1 below shows the results of image evaluation in the combinations in which Rt and R1 are changed.
【００３１】[0031]
【表１】 [Table 1]
【００３２】前記表１よりＲT／ Ｒ1を小さくした場合
場合は画像先端と、画像後端の区別ができず良好な印字
が得られることが判明した。従って上記本発明の関係を
満たすことにより一次転写二次転写同時転写が可能とな
る。From Table 1 above, it was found that when RT / R1 was reduced, the leading edge of the image and the trailing edge of the image could not be distinguished and good printing could be obtained. Therefore, the primary transfer, the secondary transfer, and the simultaneous transfer can be performed by satisfying the above relationship of the present invention.
【００３３】一般的に接触抵抗は、不動体膜表面に、導
電性でかつ酸化しずらい被覆層を広範囲に形成すること
により低減できる。また電極の接触圧だけを増大させて
も抵抗値は低減するが、電極が硬い物質だと、導電膜が
摩耗してしまうので、耐摩耗性という観点からも被覆層
を形成することが望ましい。このような被覆層の形成法
としては、導電性のカーボンあるいは銀などを分散させ
た塗料を塗布する方法、また金、銅、ＩＴＯなどを、メ
ッキ、真空プロセス等で成膜する方法などが存在する。Generally, the contact resistance can be reduced by forming a conductive and hard-to-oxidize coating layer on the surface of the passive film in a wide range. Although the resistance value decreases even if only the contact pressure of the electrode is increased, if the electrode is a hard substance, the conductive film is worn away, so it is desirable to form the coating layer also from the viewpoint of wear resistance. As a method of forming such a coating layer, there are a method of applying a coating material in which conductive carbon or silver is dispersed, a method of forming gold, copper, ITO or the like by plating, a vacuum process or the like. To do.
【００３４】（実施例２）前記実施例１では、ＲTとＲ1
の関係の具体例を述べてきたが、本実施例２では特に電
極部の耐久性を向上させＲT／Ｒ1を常に小さく保つする
方法例について述べる。(Second Embodiment) In the first embodiment, RT and R1
Although a specific example of the above relationship has been described, the second embodiment will particularly describe an example of a method for improving durability of the electrode portion and keeping RT / R1 always small.
【００３５】図５に実施例２における中間転写媒体端部
の断面図を示す。中間転写媒体をその進行方向方向に垂
直に切った概略図である。ＰＥＴの基材層２０１上にア
ルミニウムを蒸着した導電層２０２を設け、その上部に
適当な抵抗値を有する中間転写媒体の表面抵抗層２０３
が形成されており、その上に画像が形成される。導電層
２０２は、導電性被覆層２０４により被覆されており、
ブラシで構成される接触電極１２１に接触し回路を形成
している。導電性被覆層２０４が感光体１０１に当接す
るような構成をする場合、感光体表面の材料、遊離トナ
ー、紙粉等の固有抵抗値の大きい物質が導電性被覆層２
０４に強く付着し接触抵抗が大きくなってしまう。そこ
で本実施例では、中間転写媒体の表面抵抗層２０３が導
電性被覆層２０４と接触する端部を、他の領域より厚く
形成することにより、導電性被覆層２０４が感光体１０
１に直接接触する事を妨げ表面被覆層２０３の抵抗値を
低く保つことができる。FIG. 5 shows a sectional view of the end portion of the intermediate transfer medium in the second embodiment. It is the schematic which cut | interrupted the intermediate transfer medium perpendicular | vertical to the advancing direction. A conductive layer 202 formed by vapor deposition of aluminum is provided on a base material layer 201 of PET, and a surface resistance layer 203 of an intermediate transfer medium having an appropriate resistance value is provided thereon.
Are formed, and an image is formed thereon. The conductive layer 202 is covered with a conductive coating layer 204,
A circuit is formed in contact with the contact electrode 121 composed of a brush. When the conductive coating layer 204 is in contact with the photoconductor 101, a material having a large specific resistance value such as a material on the surface of the photoconductor, free toner or paper powder is used as the conductive coating layer 2.
It strongly adheres to 04 and the contact resistance increases. Therefore, in this embodiment, the conductive coating layer 204 is formed thicker than the other regions at the end where the surface resistance layer 203 of the intermediate transfer medium contacts the conductive coating layer 204.
It is possible to prevent the surface coating layer 203 from being brought into direct contact with the surface coating layer 203 and keep the resistance value of the surface coating layer 203 low.
【００３６】また導電層がブラシ等の接触電極により直
接摺擦され、摩耗により導電層自身の導電性が悪くなる
ことを防ぐために、表面抵抗層と導電性被覆層の隙間を
無くすことが望ましく、そのために互いに隣接する端部
が重なり合うように形成される場合がある。このような
場合導電性被覆層を形成後、その端部を覆うように表面
抵抗層を形成すると、表面抵抗層の導電性被覆層と接触
する端部が他の表面抵抗領域より厚く形成でき、導電性
被覆層が感光体に直接接触する事を妨げることが可能と
なり表面被覆層の抵抗値を低く保つことができる。表面
抵抗層に滑材を混入すると、表面抵抗層端部の膜厚が厚
い突出部の耐摩耗性が向上し好ましい。Further, in order to prevent the conductive layer from being directly rubbed by a contact electrode such as a brush and deteriorating the conductivity of the conductive layer itself due to abrasion, it is desirable to eliminate the gap between the surface resistance layer and the conductive coating layer. Therefore, there are cases where adjacent ends are formed so as to overlap each other. In such a case, after forming the conductive coating layer, if the surface resistance layer is formed so as to cover the end portion, the end portion of the surface resistance layer in contact with the conductive coating layer can be formed thicker than other surface resistance regions, It is possible to prevent the conductive coating layer from coming into direct contact with the photoreceptor, and the resistance value of the surface coating layer can be kept low. It is preferable to mix a lubricant in the surface resistance layer because the abrasion resistance of the protrusion having a large film thickness at the end of the surface resistance layer is improved.
【００３７】以上本実施例では接触抵抗が低く保ちつづ
けることができる。一次転写バイアス印加電源１０８か
ら導電層２０２までの抵抗ＲTの大部分は接触抵抗に起
因しており、従って接触抵抗を小さく保つことによりＲ
T／Ｒ1を常に小さく保つことができる。本実施例の前記
構成で、Ｂ４サイズ紙８０００枚相当の画像を連続して
形成したが、画像の劣化、すなわち接触抵抗に起因する
画像濃度むらは認められなかった。As described above, in this embodiment, the contact resistance can be kept low. Most of the resistance RT from the primary transfer bias applying power supply 108 to the conductive layer 202 is caused by the contact resistance, and therefore by keeping the contact resistance small, R
T / R1 can always be kept small. An image corresponding to 8000 sheets of B4 size paper was continuously formed with the above-described configuration of the present example, but no image deterioration, that is, image density unevenness due to contact resistance was not recognized.
【００３８】本実施例では接触電極１２１としてブラシ
を用いて説明したが、このほかにローラ状の回転電極、
固定型の炭素電極、あるいはブラシが回転するタイプの
電極でも接触することにより給電できる電極であればい
ずれを用いても使用可能である。In this embodiment, a brush is used as the contact electrode 121, but in addition to this, a roller-shaped rotating electrode,
A fixed carbon electrode or an electrode of a type in which a brush rotates can be used as long as it can supply power by contact.
【００３９】なおシート材料の両端を継ぎ合わせベルト
状の中間転写媒体を作成する場合、中間転写媒体上にで
きた継ぎ目部の表面に一定の幅を有する凹部が生成され
る。さらに導電層上に導電性被覆層を形成しその後に継
ぎ合わせをする場合は、この継ぎ目部において導電性被
覆層が不連続となる。このような継ぎ目部をブラシ、ロ
ーラ等の接触電極が通過する際、際接触抵抗が変化す
る。一次転写が行われている際に接触抵抗が変化すると
転写効率が変化して濃度むらが発生するので、接触抵抗
の設置位置を調整し、一次転写が行われているときに中
間転写媒体ベルトの継ぎ目部と接触電極が接触すること
が無いようにすることが望ましい。When both ends of the sheet material are spliced together to form a belt-shaped intermediate transfer medium, a recess having a constant width is formed on the surface of the seam portion formed on the intermediate transfer medium. Furthermore, when a conductive coating layer is formed on the conductive layer and then joined together, the conductive coating layer becomes discontinuous at this joint. When a contact electrode such as a brush or a roller passes through such a joint, the contact resistance changes. If the contact resistance changes during the primary transfer, the transfer efficiency changes and density unevenness occurs.Therefore, adjust the contact resistance installation position to adjust the contact resistance of the intermediate transfer medium belt during the primary transfer. It is desirable to prevent contact between the seam and the contact electrode.
【００４０】さらに接触電極が中間転写ベルトの回転周
方向に導電性被覆層に対して接触する長さを、中間転写
媒体ベルトの継ぎ目部の幅以上に設定することにより、
一次転写が行われているときに継ぎ目部と接触電極が接
触しても接触抵抗の変動を押さえることができ、濃度む
らのない画像が得られた。Further, by setting the length of contact between the contact electrode and the conductive coating layer in the circumferential direction of rotation of the intermediate transfer belt to be not less than the width of the seam portion of the intermediate transfer medium belt,
Even if the seam and the contact electrode were in contact with each other during the primary transfer, the fluctuation of the contact resistance could be suppressed, and an image without density unevenness was obtained.
【００４１】（実施例３）図６は実施例３における中間
転写媒体の断面図である。図６では、表面抵抗層２０３
の端部と導電性被覆層２０４の端部は、次第に薄くなる
ように互いに斜めに接触しており、突出している部分は
ない。本実施例では導電性被覆層２０４の端部が表面抵
抗層２０３の端部の上になっているが、表面抵抗層２０
３の端部が導電性被覆層２０４の端部の上になっても良
い。突出している部分がなくなった結果、導電性被覆層
２０４の表面も中間転写媒体クリーナー１１９のクリー
ニングブレードを用いクリーニングが可能となり導電性
被覆層に付着するごみに起因する接触抵抗の増大を防ぐ
ことができた。さらに突出している部分をなくすことに
より、突出部が感光体１０１と強く接触し摩耗する事に
より発生するごみをなくすことができ、ごみに起因する
接触抵抗の増大を防ぐことができた。Example 3 FIG. 6 is a sectional view of an intermediate transfer medium in Example 3. In FIG. 6, the surface resistance layer 203
And the end of the conductive coating layer 204 are obliquely in contact with each other so as to become thinner, and there is no protruding portion. In this embodiment, the end of the conductive coating layer 204 is on the end of the surface resistance layer 203.
The end of 3 may be on the end of the conductive coating layer 204. As a result of eliminating the protruding portion, the surface of the conductive coating layer 204 can be cleaned by using the cleaning blade of the intermediate transfer medium cleaner 119, and an increase in contact resistance due to dust adhering to the conductive coating layer can be prevented. did it. Further, by eliminating the protruding portion, it is possible to eliminate dust generated when the protruding portion is in strong contact with the photoconductor 101 and is worn, and it is possible to prevent an increase in contact resistance due to dust.
【００４２】（実施例４）図７に実施例４における中間
転写媒体端部の断面図を示す。図７においては導電性被
覆層２０４は表面抵抗層２０３より薄く構成される。本
実施例においては、導電性被覆層２０４の厚さを表面抵
抗層２０３の厚さより薄くすることにより、感光体１０
１と導電性被覆層２０４の非接触が達成でき、接触抵抗
はさらに継続的に低く保たれる。また感光体１０１と非
接触にできたことで、感光体の絶縁層にピンホール等が
存在した場合でも、また摩耗に絶縁層が薄くなった場合
でも導電性被覆層から感光体への電流のリークがなくな
るという効果も有する。(Embodiment 4) FIG. 7 shows a sectional view of an end portion of an intermediate transfer medium in Embodiment 4. In FIG. 7, the conductive coating layer 204 is thinner than the surface resistance layer 203. In this embodiment, the thickness of the conductive coating layer 204 is made smaller than that of the surface resistance layer 203, so that the photoconductor 10
1 and non-contact of the conductive coating layer 204 can be achieved, and the contact resistance is continuously kept low. Further, since the photosensitive member 101 can be made non-contact with the photosensitive member, even if a pinhole or the like is present in the insulating layer of the photosensitive member, or if the insulating layer becomes thin due to abrasion, the current from the conductive coating layer to the photosensitive member is It also has the effect of eliminating leaks.
【００４３】本実施例の前記構成で画像を形成し評価し
た結果、良好な画像が実施例３以上に連続して得られ
た。As a result of forming an image with the above-mentioned constitution of this embodiment and evaluating it, a good image was continuously obtained as compared with the third embodiment.
【００４４】（実施例５）図８に実施例５における中間
転写媒体端部の断面図を示す。図８においては、導電性
被覆層２０４として、表面抵抗層と同じ材料を表面層よ
り薄く被覆する事により、導電性被覆層と同等な接触抵
抗を発現することができた。また同時に感光体１０１と
導電性被覆層２０４の非接触が達成でき、接触抵抗は継
続的に低く保たれる。この構成により中間転写媒体の表
面抵抗層と導電被覆層の形成が同時に実行でき製造工程
が簡易化できた。(Embodiment 5) FIG. 8 shows a sectional view of an end portion of an intermediate transfer medium in Embodiment 5. In FIG. 8, as the conductive coating layer 204, by coating the same material as the surface resistance layer to be thinner than the surface layer, the contact resistance equivalent to that of the conductive coating layer could be exhibited. At the same time, non-contact between the photoreceptor 101 and the conductive coating layer 204 can be achieved, and the contact resistance is continuously kept low. With this configuration, the surface resistance layer and the conductive coating layer of the intermediate transfer medium can be simultaneously formed, and the manufacturing process can be simplified.
【００４５】本実施例の前記構成で画像を形成し評価し
た結果、良好な画像が実施例３以上に連続して得られ
た。As a result of forming an image with the above-mentioned constitution of this example and evaluating it, a good image was continuously obtained as in the case of Example 3 and above.
【００４６】（実施例６）図９に実施例６における中間
転写媒体端部の断面図を示す。図９においては、導電性
被覆層２０４を薄く塗りかつ導電性被覆層の表面に部分
的に表面抵抗層２０３と同じ材料のギャップ形成材２０
６を形成した。この結果感光体１０１と導電性被覆層２
０４の非接触がさらに確実に達成でき、接触抵抗は継続
的に低く保たれる。図９においてはギャップ材２０６が
直接、導電層２０２の上部に形成されているが、導電性
被覆層２０４の上部に設置してもよい。(Embodiment 6) FIG. 9 shows a sectional view of an end portion of an intermediate transfer medium in Embodiment 6. In FIG. 9, the conductive coating layer 204 is thinly applied and the gap forming material 20 is partially made of the same material as the surface resistance layer 203 on the surface of the conductive coating layer.
6 was formed. As a result, the photoconductor 101 and the conductive coating layer 2
A non-contact of 04 can be achieved more reliably and the contact resistance is kept low continuously. Although the gap material 206 is formed directly on the conductive layer 202 in FIG. 9, it may be provided on the conductive coating layer 204.
【００４７】本実施例の前記構成で画像を形成し評価し
た結果、良好な画像が実施例４以上に連続して得られ
た。As a result of forming and evaluating an image with the above-mentioned constitution of this example, a good image was continuously obtained as in Example 4 and above.
【００４８】（実施例７）図１０に実施例実施例７にお
ける中間転写媒体端部の断面図を示す。本実施例におい
ては、導電性被覆層２０４の端部を基材層２０１の端部
より中央部側に後退させたことを特徴とする。被覆層を
基材端部を完全に被覆するよう形成すると、被覆層が基
材の端部面を経て基材の内側面まで回り込む場合があ
る。一般的に中間転写媒体を支持するローラーは、剥離
放電を防ぐため、接地されている場合が多い。裏面との
支持ローラーに導電層と同じ電位を付与することも可能
であるが、ケース本体との絶縁性を確保しないといけな
いため装置構成が複雑となり、接地することが望まし
い。(Embodiment 7) FIG. 10 shows a sectional view of an end portion of an intermediate transfer medium in Embodiment 7 of the present invention. The present embodiment is characterized in that the end of the conductive coating layer 204 is set back from the end of the base material layer 201 toward the center. When the coating layer is formed so as to completely cover the end portion of the base material, the coating layer may wrap around the inner surface of the base material through the end surface of the base material. Generally, the roller that supports the intermediate transfer medium is often grounded to prevent peeling discharge. It is possible to apply the same potential as the conductive layer to the support roller on the back side, but since the insulation with the case body must be ensured, the device configuration becomes complicated and it is desirable to ground.
【００４９】例えば中間転写媒体を支持する支持ローラ
ーが接地されている場合には、基材の内側面まで回り込
んだ被覆層が支持ローラと接触すると、導電層から支持
ローラーに導通路が形成され、導電層が接地した状態と
なるので導電層に所定の電位が形成できない。For example, when the support roller supporting the intermediate transfer medium is grounded, when the coating layer wrapping around to the inner surface of the substrate comes into contact with the support roller, a conductive path is formed from the conductive layer to the support roller. Since the conductive layer is grounded, a predetermined potential cannot be formed on the conductive layer.
【００５０】従って本構成にすると中間転写媒体の内周
面へのリークが防止できるので、安定して良好な画像が
形成することができる。Therefore, with this structure, it is possible to prevent the leak to the inner peripheral surface of the intermediate transfer medium, so that it is possible to stably form a good image.
【００５１】（実施例８）図１１に実施例５における電
極接触部の概念図を示す。本実施例は接触部を常に清掃
できる簡易な機構を実現した。図１１は中間転写媒体ベ
ルトを表面からみた概念図であり、図中の矢印の方向に
回転していく。導電性被覆層２０４には、凹状部２０７
が斜めに形成されており、ブラシ状の接触電極１２１に
たまったトナー等は、回転に伴い凹状部で補集され、中
間転写媒体の表面抵抗層２０３上に移動する。表面層に
移動したトナー等は、表層に当接する中間転写媒体クリ
ーナー１１９のクリーナーブレード（本図では図示せ
ず）によって清掃される。これにより電極部は常に清浄
に保たれ、その接触抵抗は一定である。特に前記実施例
３、４、５、６の構成にした場合、導電性被覆層２０４
が表面層より薄いため、ブレードクリーニングでは充分
表面のトナー等が除去できない。本実施例の構成によれ
ば、導電性被覆層に付着したトナーやごみは、接触電極
により回収され、上記実施例と同じメカニズムで回収さ
れる。従って凸凹のある表面構造において非常に有効な
方法である。(Embodiment 8) FIG. 11 shows a conceptual diagram of an electrode contact portion in Embodiment 5. This embodiment realizes a simple mechanism that can constantly clean the contact portion. FIG. 11 is a conceptual view of the intermediate transfer medium belt as viewed from the surface, and the belt rotates in the direction of the arrow in the figure. The conductive coating layer 204 has a concave portion 207.
The toner and the like accumulated on the brush-shaped contact electrode 121 are collected by the concave portion as the toner rotates and move onto the surface resistance layer 203 of the intermediate transfer medium. The toner and the like that have moved to the surface layer are cleaned by a cleaner blade (not shown in the figure) of the intermediate transfer medium cleaner 119 that contacts the surface layer. As a result, the electrode portion is always kept clean and its contact resistance is constant. In particular, in the case of the constitutions of the above-mentioned Examples 3, 4, 5, and 6, the conductive coating layer 204
Since it is thinner than the surface layer, the toner etc. on the surface cannot be sufficiently removed by blade cleaning. According to the configuration of this embodiment, the toner and dust attached to the conductive coating layer are collected by the contact electrode and are collected by the same mechanism as in the above embodiment. Therefore, it is a very effective method for uneven surface structures.
【００５２】本実施例では凹状部の例を示したが凸でも
同様な作用を発現する。これらの凹凸は、表面被覆層に
や他の塗料の印刷により形成できる。また中間転写媒体
のベルトの継ぎ目の段差を利用したり何れの方法で形成
しても良い。In this embodiment, an example of the concave portion is shown, but the same effect is exhibited even when it is convex. These irregularities can be formed on the surface coating layer or by printing with another paint. Further, the step of the seam of the belt of the intermediate transfer medium may be utilized or any method may be used.
【００５３】また接触電極としてローラー状のものを使
用した場合は、中間転写媒体回転の一定間隔において、
ローラーを中間転写媒体表面層と当接させることにより
トナー等を表層に転写しクリナーブレードにより回収す
ることもできる。When a roller-shaped contact electrode is used, at a constant interval of rotation of the intermediate transfer medium,
By bringing the roller into contact with the surface layer of the intermediate transfer medium, the toner or the like can be transferred to the surface layer and collected by a cleaner blade.
【００５４】本実施例の前記構成で画像を形成し評価し
た結果、良好な画像が実施例６以上に連続して得られ
た。As a result of forming an image with the above-mentioned constitution of this embodiment and evaluating it, good images were continuously obtained as in the case of the embodiment 6 and above.
【００５５】なお本実施例においては導電層に導電性被
覆層を施してあるが、導電層が充分強度を有し、初期の
接触抵抗が小さい場合被覆を施す必要がないことは明ら
かである。Although a conductive coating layer is applied to the conductive layer in this embodiment, it is clear that the conductive layer need not be coated if the conductive layer has sufficient strength and the initial contact resistance is small.
【００５６】[0056]
【発明の効果】以上説明した本発明の効果を以下に記
す。The effects of the present invention described above will be described below.
【００５７】本発明の請求項１によれば、二次転写が行
がまだ始まらないとき一次転写が実行された画像領域
と、二次転写と同時に行われた一次転写の領域で得られ
る画像は変わらず良好である。請求項２を実施するとさ
らに良好な画像が得られる。According to claim 1 of the present invention, the image obtained in the image area in which the primary transfer is performed when the secondary transfer is not yet started and the image obtained in the area of the primary transfer performed simultaneously with the secondary transfer are It is still good. By implementing the second aspect, a better image can be obtained.
【００５８】従って一次転写、二次転写同時転写が可能
となり、転写動作が短く小形の小形の電源を有する画像
形成装置を提供することが可能となった。Therefore, the primary transfer and the secondary transfer simultaneous transfer are possible, and it is possible to provide an image forming apparatus which has a short transfer operation and a small power source.
【００５９】また本発明実施例２〜１０の構成を実施す
る事により、中間転写媒体の導電層と、感光体は互いに
強く当接しないため、感光体が導電層に付着して導電層
の接触抵抗が大きくなったり、逆に感光体の絶縁層を破
壊し転写不能となることが起きず、ＲT／Ｒ1が変化せ
ず、一次転写二次転写同時転写が可能な枚数を増加させ
ることが可能となった。By carrying out the structures of Examples 2 to 10 of the present invention, the conductive layer of the intermediate transfer medium and the photosensitive member do not come into strong contact with each other, so that the photosensitive member adheres to the conductive layer and contacts with the conductive layer. It is possible to increase the number of sheets that can be simultaneously transferred by the primary transfer, the secondary transfer and the simultaneous transfer without increasing the resistance or conversely destroying the insulating layer of the photoconductor to make the transfer impossible. Became.
【００６０】また本発明の実施例１１を構成することに
より接触電極部が常に清浄に保たれるため、接触抵抗
値、あるいはＲT／Ｒ1が変化せず一次転写二次転写同時
転写が可能な枚数をさらに増加させることが可能となっ
た。Further, by constructing the eleventh embodiment of the present invention, since the contact electrode portion is always kept clean, the contact resistance value or RT / R1 does not change, and the primary transfer secondary transfer simultaneous transfer is possible. It has become possible to further increase.
【図１】本発明の画像形成装置の断面概観図。FIG. 1 is a schematic cross-sectional view of an image forming apparatus of the present invention.
【図２】一次転写のみが行われる場合の等価回路図。FIG. 2 is an equivalent circuit diagram when only primary transfer is performed.
【図３】一次転写、二次転写が同時に行われる場合の等
価回路図。FIG. 3 is an equivalent circuit diagram when the primary transfer and the secondary transfer are simultaneously performed.
【図４】二次転写のみが行われる場合の等価回路図。FIG. 4 is an equivalent circuit diagram when only secondary transfer is performed.
【図５】実施例２における中間転写媒体端部の断面図。FIG. 5 is a cross-sectional view of an end portion of an intermediate transfer medium according to a second exemplary embodiment.
【図６】実施例３における中間転写媒体端部の断面図。FIG. 6 is a cross-sectional view of an end portion of an intermediate transfer medium in Example 3.
【図７】実施例４における中間転写媒体端部の断面図。FIG. 7 is a cross-sectional view of an end portion of an intermediate transfer medium in Example 4.
【図８】実施例５における中間転写媒体端部の断面図。FIG. 8 is a sectional view of an end portion of an intermediate transfer medium according to the fifth embodiment.
【図９】実施例６における中間転写媒体端部の断面図。FIG. 9 is a sectional view of an end portion of an intermediate transfer medium in Example 6.
【図１０】実施例実施例７における中間転写媒体端部の
断面図。FIG. 10 is a sectional view of an end portion of an intermediate transfer medium in Example 7.
【図１１】実施例８における電極接触部の概念図。FIG. 11 is a conceptual diagram of an electrode contact portion in Example 8.
１０１ 感光体 １０２ 帯電ローラ １０３ 露光手段 １０４ 折り返しミラー １０５Ｙ イエロー現像器 １０５Ｍ マゼンタ現象器 １０５Ｃ シアン現像器 １０５Ｋ ブラック現像器 １０６ 中間転写媒体 １０７ 一次転写ローラ １０８ 一次転写バイアス印加電源 １０９ 感光体クリーナー １１０ 除電ランプ １１１ 給紙手段 １１２ 給紙カセット １１３ 転写材 １１４ レジストローラ対 １１５ 駆動ローラ １１６ 二次転写ローラ １１７ 二次転写バイアス印加電源 １１８ テンションローラ １１９ 中間転写媒体クリーナー １２０ 定着手段 １２１ 接触電極 ２０１ 基材層 ２０２ 導電層 ２０３ 表面抵抗層 ２０４ 導電性被覆層 ２０６ ギャップ形成材 ２０７ 凹状部 101 Photoreceptor 102 Charging Roller 103 Exposure Means 104 Folding Mirror 105Y Yellow Developer 105M Magenta Phenomenon 105C Cyan Developer 105K Black Developer 106 Intermediate Transfer Medium 107 Primary Transfer Roller 108 Primary Transfer Bias Applied Power Supply 109 Photosensitive Cleaner 110 Static Elimination Lamp 111 Paper feeding means 112 Paper feeding cassette 113 Transfer material 114 Registration roller pair 115 Driving roller 116 Secondary transfer roller 117 Secondary transfer bias applying power source 118 Tension roller 119 Intermediate transfer medium cleaner 120 Fixing means 121 Contact electrode 201 Base material layer 202 Conductive layer 203 Surface Resistive Layer 204 Conductive Coating Layer 206 Gap Forming Material 207 Concave Section
Claims (2)
されたトナー像を中間転写媒体に転写する一次転写部
と、一次転写部においてバイアスを印加するための一次
転写バイアス印加電源と、前記全色中間転写媒体にて重
ね合わせられた全色カラートナー像を記録紙に転写する
二次転写部と、二次転写部においてバイアスを印加する
ための二次転写バイアス印加電源を有する画像形成装置
において、前記中間転写媒体が導電層を有し、かつ、前
記一次転写バイアス印加電源から前記導電層までの抵抗
ＲTと一次転写部の見かけの抵抗Ｒ1が、 ＲT＜Ｒ1 なる関係を有することを特徴とする画像形成装置。1. A primary transfer section for transferring toner images developed with color toners of different colors to an intermediate transfer medium, a primary transfer bias application power source for applying a bias in the primary transfer section, and an intermediate for all colors. In an image forming apparatus having a secondary transfer section for transferring all color toner images superimposed on a transfer medium onto a recording sheet, and a secondary transfer bias applying power source for applying a bias in the secondary transfer section, The intermediate transfer medium has a conductive layer, and the resistance RT from the primary transfer bias applying power source to the conductive layer and the apparent resistance R1 of the primary transfer portion have a relationship of RT <R1. Forming equipment.
電層間の抵抗ＲTと一次転写部の見かけの抵抗Ｒ1が、 ＲT／Ｒ1≦０．１ なる関係を有することを特徴とする請求項１記載の画像
形成装置。2. The primary transfer bias applying power source, the resistance RT between the conductive layers, and the apparent resistance R1 of the primary transfer portion have a relationship of RT / R1 ≦ 0.1. Image forming apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32266795A JP3301474B2 (en) | 1995-12-12 | 1995-12-12 | Image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32266795A JP3301474B2 (en) | 1995-12-12 | 1995-12-12 | Image forming device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09160395A true JPH09160395A (en) | 1997-06-20 |
| JP3301474B2 JP3301474B2 (en) | 2002-07-15 |
Family
ID=18146267
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32266795A Ceased JP3301474B2 (en) | 1995-12-12 | 1995-12-12 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3301474B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0919884A2 (en) * | 1997-11-28 | 1999-06-02 | Seiko Epson Corporation | Image forming apparatus |
| US6173139B1 (en) | 1997-01-31 | 2001-01-09 | Seiko Epson Corporation | Recording medium carrier system having a paper feed unit, a transfer unit, a fixing unit and a paper ejecting unit constructed as independent units |
| US6408158B1 (en) | 1997-01-31 | 2002-06-18 | Seiko Epson Corporation | Intermediate transfer unit |
| US6856782B2 (en) | 1997-01-31 | 2005-02-15 | Seiko Epson Corporation | Intermediate transfer unit having a primary and a secondary transfer member |
| US7106997B2 (en) * | 2002-11-29 | 2006-09-12 | Samsung Electronics Co., Ltd. | Intermediate transfer member for carrying intermediate electrophotographic image |
| EP1835359A2 (en) * | 2006-03-17 | 2007-09-19 | Ricoh Company, Ltd. | Image forming apparatus having primary and secondary electric bias transferring means |
| JP2016095435A (en) * | 2014-11-17 | 2016-05-26 | シャープ株式会社 | Transfer device and image forming apparatus |
| JP2020101640A (en) * | 2018-12-20 | 2020-07-02 | キヤノン株式会社 | Intermediate transfer belt and image forming apparatus |
-
1995
- 1995-12-12 JP JP32266795A patent/JP3301474B2/en not_active Ceased
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6957032B2 (en) | 1997-01-31 | 2005-10-18 | Seiko Epson Corporation | Intermediate transfer unit having a primary transfer member and a secondary transfer roller |
| US7187893B2 (en) | 1997-01-31 | 2007-03-06 | Seiko Epson Corporation | Image transfer unit having an intermediate transfer belt to which a toner image is applied |
| US6173139B1 (en) | 1997-01-31 | 2001-01-09 | Seiko Epson Corporation | Recording medium carrier system having a paper feed unit, a transfer unit, a fixing unit and a paper ejecting unit constructed as independent units |
| US6408158B1 (en) | 1997-01-31 | 2002-06-18 | Seiko Epson Corporation | Intermediate transfer unit |
| US6731899B2 (en) | 1997-01-31 | 2004-05-04 | Seiko Epson Corporation | Intermediate transfer unit |
| US6856782B2 (en) | 1997-01-31 | 2005-02-15 | Seiko Epson Corporation | Intermediate transfer unit having a primary and a secondary transfer member |
| EP0919884A3 (en) * | 1997-11-28 | 2000-09-06 | Seiko Epson Corporation | Image forming apparatus |
| EP0919884A2 (en) * | 1997-11-28 | 1999-06-02 | Seiko Epson Corporation | Image forming apparatus |
| US7106997B2 (en) * | 2002-11-29 | 2006-09-12 | Samsung Electronics Co., Ltd. | Intermediate transfer member for carrying intermediate electrophotographic image |
| EP1835359A3 (en) * | 2006-03-17 | 2007-12-19 | Ricoh Company, Ltd. | Image forming apparatus having primary and secondary electric bias transferring means |
| EP1835359A2 (en) * | 2006-03-17 | 2007-09-19 | Ricoh Company, Ltd. | Image forming apparatus having primary and secondary electric bias transferring means |
| US7546074B2 (en) | 2006-03-17 | 2009-06-09 | Ricoh Co., Ltd. | Image forming apparatus |
| JP2016095435A (en) * | 2014-11-17 | 2016-05-26 | シャープ株式会社 | Transfer device and image forming apparatus |
| JP2020101640A (en) * | 2018-12-20 | 2020-07-02 | キヤノン株式会社 | Intermediate transfer belt and image forming apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3301474B2 (en) | 2002-07-15 |
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