JPH04275566A - Electrophotographic recorder - Google Patents
Electrophotographic recorderInfo
- Publication number
- JPH04275566A JPH04275566A JP3037487A JP3748791A JPH04275566A JP H04275566 A JPH04275566 A JP H04275566A JP 3037487 A JP3037487 A JP 3037487A JP 3748791 A JP3748791 A JP 3748791A JP H04275566 A JPH04275566 A JP H04275566A
- Authority
- JP
- Japan
- Prior art keywords
- voltage
- transfer
- charging
- photoreceptor
- developing
- 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
- 108091008695 photoreceptors Proteins 0.000 claims description 36
- 238000000034 method Methods 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract description 17
- 229910052782 aluminium Inorganic materials 0.000 abstract description 16
- 239000004411 aluminium Substances 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Developing For Electrophotography (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Control Or Security For Electrophotography (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、反転現像方式の電子写
真プロセスにより画像の記録を行う電子写真記録装置に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording apparatus for recording images using a reversal development type electrophotographic process.
【０００２】0002
【従来の技術】図３は従来の電子写真記録装置の概略構
成を示す図である。図中、１は感光ドラムである。この
感光ドラム１は、円筒状のアルミ素管１ａの周面に光導
電材料を塗布して光導電層１ｂをなして構成されている
。この感光ドラム１の周辺にはその周面に沿って、帯電
装置２、露光装置３、現像装置４、転写装置５およびク
リーニング装置６が設けられている。2. Description of the Related Art FIG. 3 is a diagram showing a schematic configuration of a conventional electrophotographic recording apparatus. In the figure, 1 is a photosensitive drum. The photosensitive drum 1 is constructed by applying a photoconductive material to the circumferential surface of a cylindrical aluminum tube 1a to form a photoconductive layer 1b. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are provided around the photosensitive drum 1 along its circumferential surface.
【０００３】この電子写真記録装置では、帯電装置２に
よって例えば−５００Ｖに帯電された感光ドラム１の感
光面を露光装置３によって記録すべき画像に応じて露光
する。感光ドラム１の光導電層１ｂは、光が入射した部
分にあった電荷は除去され、感光ドラム１の感光面に静
電潜像が形成される。そして、この感光ドラム１の感光
面に形成された静電潜像の現像を現像装置４で行う。こ
の現像は、感光ドラム１の帯電電位と同極性に帯電した
トナーに感光ドラム１の帯電電位と同極性かつ低電圧（
例えば−２００Ｖ）な現像バイアスを作用させることに
より、感光ドラム１上の帯電部分には、感光ドラム１側
が高電位であるためにトナーが付着せず、また露光され
除電された部分には、感光ドラム１側が低電位であるた
めにトナーが付着する。In this electrophotographic recording apparatus, the photosensitive surface of the photosensitive drum 1, which is charged to, for example, -500V by the charging device 2, is exposed to light by the exposure device 3 in accordance with the image to be recorded. In the photoconductive layer 1b of the photosensitive drum 1, the charge existing at the portion where the light is incident is removed, and an electrostatic latent image is formed on the photosensitive surface of the photosensitive drum 1. Then, the electrostatic latent image formed on the photosensitive surface of the photosensitive drum 1 is developed by a developing device 4. In this development, the toner charged to the same polarity as the charged potential of the photosensitive drum 1 is applied at a low voltage (
By applying a developing bias (for example, -200 V), toner does not adhere to the charged portions of the photosensitive drum 1 because the photosensitive drum 1 side has a high potential, and the exposed and neutralized portions are exposed to the photosensitive drum 1. Since the drum 1 side has a low potential, toner adheres to it.
【０００４】次に、感光ドラム１の感光面に記録紙（図
示せず）を重ねる。そして、転写装置５より記録紙に対
して、トナーと逆極性の電荷（例えば＋５００Ｖ）を与
えることによって、前記感光ドラム１の感光面に付着し
たトナーを記録紙へと転写する。その後、感光ドラム１
の感光面は、記録紙が剥離された後、転写されずに残留
しているトナーをクリーニング装置６で除去される。Next, recording paper (not shown) is placed on the photosensitive surface of the photosensitive drum 1. Then, by applying an electric charge (for example, +500 V) of opposite polarity to the toner to the recording paper from the transfer device 5, the toner adhering to the photosensitive surface of the photosensitive drum 1 is transferred onto the recording paper. After that, photosensitive drum 1
After the recording paper is peeled off, the toner remaining on the photosensitive surface without being transferred is removed by a cleaning device 6.
【０００５】ところで以上のように構成された電子写真
記録装置において、動作停止時に着目すると、感光ドラ
ム１表面の電位は不定となっている。このように感光ド
ラム１の電位が不定である状態では、記録開始時におい
て現像装置４の位置を通過する際に、電位が低くなって
いる部分ではトナーが付着してしまう。In the electrophotographic recording apparatus constructed as described above, when the operation is stopped, the potential on the surface of the photosensitive drum 1 is unstable. In such a state where the potential of the photosensitive drum 1 is unstable, toner will adhere to the portion where the potential is low when the photosensitive drum 1 passes the position of the developing device 4 at the start of recording.
【０００６】そこで、感光ドラム１の回転を開始すると
同時に帯電装置２による帯電を開始し、感光ドラム１表
面の電位が不定となっている部分を可能な限り小さくし
ている。[0006] Therefore, charging by the charging device 2 is started at the same time as the rotation of the photosensitive drum 1 is started, and the portion where the potential on the surface of the photosensitive drum 1 is unstable is made as small as possible.
【０００７】しかし、感光ドラム１の停止時に帯電装置
２での帯電位置（図３中のＡ点）と現像装置４での現像
位置（図３中のＢ点）との間は帯電させることができず
、この部分（図３中にイで示す部分）にトナーが付着す
ることを防止することができない。このような感光ドラ
ム１へのトナーの付着が生じると、感光ドラム１に付着
したトナーはクリーニング装置６で回収されて廃トナー
となるため、トナーの浪費となる。また転写装置５にロ
ーラやブラシのような接触式のものを用いた場合には、
感光ドラム１に付着したトナーが転写装置にまで付着し
てしまい、記録紙の背面を汚してしまったり、また転写
効率が低下して転写不良を起こしてしまうという不具合
があった。However, when the photosensitive drum 1 is stopped, charging cannot be performed between the charging position in the charging device 2 (point A in FIG. 3) and the developing position in the developing device 4 (point B in FIG. 3). Therefore, it is not possible to prevent toner from adhering to this portion (the portion indicated by A in FIG. 3). When such adhesion of toner to the photosensitive drum 1 occurs, the toner adhering to the photosensitive drum 1 is collected by the cleaning device 6 and becomes waste toner, resulting in wasted toner. Furthermore, if a contact type device such as a roller or brush is used as the transfer device 5,
There have been problems in that the toner adhering to the photosensitive drum 1 also adheres to the transfer device, staining the back surface of the recording paper, and reducing transfer efficiency and causing transfer defects.
【０００８】[0008]
【発明が解決しようとする課題】以上のように従来の電
子写真記録装置は、記録動作の開始時において、停止時
に帯電位置と現像位置との間に位置していた感光体上の
部分が電位不定となっているため、この部分に多量の現
像剤付着が生じるという不具合があった。[Problems to be Solved by the Invention] As described above, in the conventional electrophotographic recording device, at the start of the recording operation, the portion on the photoreceptor that was located between the charging position and the developing position at the time of stopping has a low potential. Since it is not fixed, there is a problem that a large amount of developer adheres to this part.
【０００９】本発明はこのような事情を考慮してなされ
たものであり、その目的とするところは、感光体への無
駄な現像剤付着を極力抑え、これにより経済的かつ高画
質に記録を行うことができる電子写真記録装置を提供す
ることにある。The present invention has been made in consideration of the above circumstances, and its purpose is to minimize wasteful adhesion of developer to the photoreceptor, thereby achieving economical and high-quality recording. The object of the present invention is to provide an electrophotographic recording device that can perform the following steps.
【００１０】0010
【課題を解決するための手段】第１の発明は、感光体を
なす例えばアルミ素管などの導電性部材に、現像バイア
スと同極性で、かつその絶対値が０より大きく前記現像
バイアスの電圧の絶対値より低い所定電圧を印加してお
き、前記感光体の回転開始時に、帯電手段による前記感
光体の帯電が開始された時点に前記帯電手段の帯電位置
に位置していた前記感光体上の所定点が現像手段の現像
位置に至るのに要する時間が経過するまでは前記現像バ
イアスをオフしておき、こののちに前記現像バイアスを
オンするようにした。[Means for Solving the Problems] The first invention applies a voltage of the developing bias which has the same polarity as the developing bias and whose absolute value is greater than 0 to a conductive member such as an aluminum tube forming the photoreceptor. A predetermined voltage that is lower than the absolute value of The developing bias is kept off until the time required for the predetermined point to reach the developing position of the developing means has elapsed, and then the developing bias is turned on.
【００１１】第２の発明は、転写手段として帯電電位と
は逆極性の所定電圧の転写電圧により転写を行うものを
有した第１の発明の電子写真記録装置において、帯電電
圧、現像バイアスおよび前記転写電圧のそれぞれの値を
、導電性部材を接地した場合における前記帯電電圧、前
記現像バイアスおよび前記転写電圧のそれぞれの値に前
記導電性部材に印加する電圧値を加えた値とした。A second aspect of the present invention is the electrophotographic recording apparatus of the first aspect, which has a transfer means that performs transfer using a transfer voltage having a predetermined polarity opposite to that of the charging potential. Each value of the transfer voltage was determined by adding the voltage value applied to the conductive member to the respective values of the charging voltage, the developing bias, and the transfer voltage when the conductive member was grounded.
【００１２】第３の発明は、転写手段として感光体に重
ねられた記録紙に接触し、現像剤の帯電電位とは逆極性
の所定電圧の転写電圧により転写を行うものを有した第
１の発明の電子写真記録装置において、前記転写電圧と
逆極性で所定電圧の逆電圧を発生する逆電圧発生手段を
備え、前記感光体の回転開始時に、帯電手段による前記
感光体の帯電が開始された時点に前記帯電手段の帯電位
置に位置していた前記感光体上の所定点が前記転写手段
の転写位置に至るのに要する時間が経過するまでは前記
転写手段に前記逆電圧を印加しておき、こののちに前記
転写手段への前記逆電圧の印加を停止するとともに前記
転写電圧をオンするようにした。[0012] The third invention is the first invention, which has a transfer means that contacts the recording paper stacked on the photoreceptor and performs transfer with a predetermined transfer voltage having a polarity opposite to the charging potential of the developer. The electrophotographic recording apparatus of the invention includes a reverse voltage generating means for generating a reverse voltage of a predetermined voltage with a polarity opposite to that of the transfer voltage, and charging of the photoreceptor by the charging means is started when the rotation of the photoreceptor starts. The reverse voltage is applied to the transfer means until a time period required for a predetermined point on the photoreceptor, which was located at the charging position of the charging means at the time, to reach the transfer position of the transfer means has elapsed. After that, application of the reverse voltage to the transfer means was stopped and the transfer voltage was turned on.
【００１３】[0013]
【作用】このような手段を講じたことにより、感光体を
なす例えばアルミ素管などの導電性部材に、現像バイア
スと同極性で、かつその絶対値が０より大きく前記現像
バイアスの電圧の絶対値より低い所定電圧を印加されて
いる。また、帯電手段による前記感光体の帯電が開始さ
れた時点に前記帯電手段の帯電位置に位置していた前記
感光体上の所定点が現像手段の現像位置に至るのに要す
る時間が経過するまでは前記現像バイアスがオフされて
いる。[Operation] By taking such a measure, the absolute voltage of the developing bias is applied to the conductive member such as an aluminum tube forming the photoreceptor, with the same polarity as the developing bias and whose absolute value is greater than 0. A predetermined voltage lower than the value is applied. Further, until the time required for a predetermined point on the photoreceptor located at the charging position of the charging means to reach the developing position of the developing means at the time when charging of the photoreceptor by the charging means is started elapses. The developing bias is turned off.
【００１４】従って、帯電手段による前記感光体の帯電
が開始された時点に前記帯電手段の帯電位置に位置して
いた前記感光体上の所定点が現像手段の現像位置に至る
のに要する時間が経過するまでは、感光体側の電位が現
像手段側の電位より常に高くなっており、感光体への現
像剤の付着が生じない。[0014] Therefore, the time required for a predetermined point on the photoreceptor, which was located at the charging position of the charging means at the time when charging of the photoreceptor by the charging means was started, to reach the developing position of the developing means. Until the time elapses, the potential on the photoreceptor side is always higher than the potential on the developing means side, and no developer adheres to the photoreceptor.
【００１５】さらに、感光体の回転開始時に、帯電手段
による前記感光体の帯電が開始された時点に前記帯電手
段の帯電位置に位置していた前記感光体上の所定点が前
記転写手段の転写位置に至るのに要する時間が経過する
までは前記転写電圧をオフするとともに前記転写手段に
前記逆電圧が印加されることにより、当該期間には転写
手段は転写能力を有さず、転写手段への現像剤の付着は
生じない。Furthermore, when the photoreceptor starts rotating, a predetermined point on the photoreceptor that was located at the charging position of the charging means at the time when the charging means started charging the photoreceptor is transferred by the transfer means. By turning off the transfer voltage and applying the reverse voltage to the transfer means until the time required to reach the position has elapsed, the transfer means does not have transfer ability during this period, and the transfer means does not transfer. No adhesion of developer occurs.
【００１６】[0016]
【実施例】以下、図面を参照して本発明の一実施例に付
き説明する。図１は本実施例に係る電子写真記録装置の
構成を示す図である。なお、図３と同一部分には同一符
号を付し、その詳細な説明は省略する。DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of an electrophotographic recording apparatus according to this embodiment. Note that the same parts as in FIG. 3 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.
【００１７】図中、７は帯電装置である。この帯電装置
７は、放電器７１、高圧電源７２、スイッチ７３、グリ
ッド７４およびツェナダイオード７５により構成された
周知のスコロトロン方式の帯電器となっている。In the figure, 7 is a charging device. The charging device 7 is a well-known scorotron type charger composed of a discharger 71, a high-voltage power source 72, a switch 73, a grid 74, and a Zener diode 75.
【００１８】８は現像装置である。この現像装置８は、
トナー（図示せず）を担持した現像スリーブ８１、現像
スリーブ８１に高電圧を印加する高圧電源８２および現
像スリーブ８１への高電圧の印加をＯＮ／ＯＦＦするス
イッチ８３よりなる。8 is a developing device. This developing device 8 is
It consists of a developing sleeve 81 carrying toner (not shown), a high voltage power supply 82 that applies a high voltage to the developing sleeve 81, and a switch 83 that turns on/off the application of the high voltage to the developing sleeve 81.
【００１９】９は転写装置である。この転写装置９は、
感光ドラム１とで記録紙（図示せず）を挾持する状態で
設けられた転写ローラ９１、この転写ローラ９１に正極
性の高電圧を印加する高圧電源９２、転写ローラ９１に
負極性の高電圧を印加する高圧電源９３、転写ローラ９
１への高電圧の印加のＯＮ／ＯＦＦおよび転写ローラ９
１へ高電圧を印加する高圧電源９２，９３の選択を行う
スイッチ９４よりなる。9 is a transfer device. This transfer device 9 is
A transfer roller 91 is provided to sandwich a recording paper (not shown) with the photosensitive drum 1, a high voltage power source 92 applies a positive high voltage to the transfer roller 91, and a negative high voltage is applied to the transfer roller 91. A high-voltage power supply 93 that applies
ON/OFF of high voltage application to 1 and transfer roller 9
It consists of a switch 94 that selects between high voltage power supplies 92 and 93 that apply a high voltage to 1.
【００２０】１０はツェナダイオードである。このツェ
ナダイオード１０は、アノードがツェナダイオード７５
のカソードおよび感光ドラム１のアルミ素管１ａに接続
されている。またカソードは接地されている。10 is a Zener diode. This Zener diode 10 has a Zener diode 75 as an anode.
and the aluminum tube 1a of the photosensitive drum 1. Also, the cathode is grounded.
【００２１】１１は制御部である。この制御部１１は、
スイッチ７３，８３，９４をそれぞれ所定のタイミング
でＯＮ／ＯＦＦするとともに、モータやギヤよりなる感
光ドラム駆動系１２を制御する。11 is a control section. This control section 11 is
The switches 73, 83, and 94 are turned on and off at predetermined timings, and the photosensitive drum drive system 12 consisting of a motor and gears is controlled.
【００２２】次に以上のように構成された電子写真記録
装置の動作を制御部１１の制御手順に従って説明する。
なおここでは、感光ドラム１上において、帯電装置７で
の帯電位置、現像装置８での現像位置および転写装置９
での転写位置をそれぞれＡ点、Ｂ点、Ｃ点とする。また
感光ドラム１上の任意の点がＡ点からＢ点まで移動する
時間およびＢ点からＣ点まで移動する時間をそれぞれＴ
Ａ、ＴＢとする。Next, the operation of the electrophotographic recording apparatus configured as described above will be explained according to the control procedure of the control section 11. Here, on the photosensitive drum 1, the charging position in the charging device 7, the developing position in the developing device 8, and the transfer device 9 are shown.
Let the transfer positions at these points be point A, point B, and point C, respectively. Also, the time it takes for any point on the photosensitive drum 1 to move from point A to point B, and the time it takes for it to move from point B to point C, are both T.
A, TB.
【００２３】まず制御部１１は、記録動作の開始時にお
いて、感光ドラム駆動系１２に対して感光ドラム１の回
転駆動の開始を指示する。これに応じ、感光ドラム駆動
系１２は感光ドラム１の回転駆動を開始し、感光ドラム
１が回転する（図２中のＴ１時点）。First, the control section 11 instructs the photosensitive drum drive system 12 to start rotating the photosensitive drum 1 at the start of a recording operation. In response to this, the photosensitive drum drive system 12 starts rotating the photosensitive drum 1, and the photosensitive drum 1 rotates (time T1 in FIG. 2).
【００２４】また制御部１１は、感光ドラム駆動系１２
に対して感光ドラム１の回転駆動の開始を指示するのと
同時に、帯電装置７のスイッチ７３をＯＮする。帯電装
置７では、スイッチ７２がＯＮされると、放電器７１に
高圧電源７２が発生する高電圧が印加されて放電器７１
から放電がなされ、感光ドラム１の表面が帯電される。
このとき、感光ドラム１の帯電電位は、グリッド７４と
ツェナダイオード７５とにより、ツェナダイオード７５
の降伏電圧（ここでは−５００Ｖ）に一定に保たれる。The control section 11 also controls the photosensitive drum drive system 12.
At the same time, the switch 73 of the charging device 7 is turned on. In the charging device 7, when the switch 72 is turned on, a high voltage generated by the high voltage power supply 72 is applied to the discharger 71, and the discharger 71
A discharge is generated, and the surface of the photosensitive drum 1 is charged. At this time, the charged potential of the photosensitive drum 1 is controlled by the grid 74 and the Zener diode 75.
The breakdown voltage (here -500V) is kept constant.
【００２５】さらに制御部１１は、感光ドラム駆動系１
２に対して感光ドラム１の回転駆動の開始を指示するの
と同時に、転写装置９のスイッチ９４を高圧電源９３側
にＯＮする。Furthermore, the control section 11 controls the photosensitive drum drive system 1.
At the same time, the switch 94 of the transfer device 9 is turned on to the high voltage power source 93 side.
【００２６】次に制御部１１は、Ｔ１時点からＴＡの時
間が経過した時点（図２中のＴ２時点）に現像装置８の
スイッチ８３をＯＮする。すなわち、帯電の開始時に帯
電位置Ａに位置していた感光ドラム１上の所定点が現像
位置Ｂに到達した時点にスイッチ８３をＯＮする。これ
により、現像スリーブ８１に高圧電源８２が発生する高
電圧（現像バイアス：ここでは−２００Ｖ）が印加され
、従来と同様な作用により現像が開始される。Next, the control section 11 turns on the switch 83 of the developing device 8 when the time TA has elapsed from the time T1 (time T2 in FIG. 2). That is, the switch 83 is turned on when the predetermined point on the photosensitive drum 1 that was located at the charging position A at the start of charging reaches the developing position B. As a result, a high voltage (developing bias: -200V in this case) generated by the high-voltage power supply 82 is applied to the developing sleeve 81, and development is started in the same manner as in the conventional case.
【００２７】しかし、感光ドラム１の回転および帯電が
開始されてからスイッチ８３がＯＮされるまでの間、す
なわち、感光ドラム１の停止時に帯電位置Ａと現像位置
Ｂとの間に位置していた感光ドラム１上の部分（電位が
不定である部分）が現像位置Ｂを通過する期間にはスイ
ッチ８３はＯＦＦとなっており、現像スリーブ８１には
現像バイアスが印加されていない。つまり、現像スリー
ブ８１の電位は０Ｖとなっている。一方感光ドラム１は
、アルミ素管１ａがツェナダイオード１０を介して接地
されているため、アルミ素管１ａの電位がツェナダイオ
ード１０の降伏電圧（ここでは−１００Ｖ）とされてい
る。なお、アルミ素管１ａの電位は、現像バイアスと同
極性で、かつその絶対値が０より大きく現像バイアスの
電圧の絶対値より低い値とする。すなわち本実施例では
、アルミ素管１ａの電位をＶｂとすると、［０＞Ｖｂ＞
−２００］の範囲となる。However, the photosensitive drum 1 was located between the charging position A and the developing position B during the period from the start of rotation and charging until the switch 83 was turned on, that is, when the photosensitive drum 1 was stopped. During the period when the portion on the photosensitive drum 1 (the portion where the potential is undefined) passes through the development position B, the switch 83 is OFF, and no development bias is applied to the development sleeve 81. In other words, the potential of the developing sleeve 81 is 0V. On the other hand, in the photosensitive drum 1, since the aluminum tube 1a is grounded through the Zener diode 10, the potential of the aluminum tube 1a is set to the breakdown voltage of the Zener diode 10 (-100V in this case). The potential of the aluminum tube 1a has the same polarity as the developing bias, and its absolute value is greater than 0 and lower than the absolute value of the developing bias voltage. That is, in this embodiment, if the potential of the aluminum tube 1a is Vb, [0>Vb>
-200].
【００２８】以上のように、現像スリーブ８１の電位が
０Ｖであるのに対し、感光ドラム１は最も電位が低い部
分でも電位が−１００Ｖとなっており、感光ドラム１側
の方が高電位となっている。これにより、現像スリーブ
８１に担持されているトナーを感光ドラム１側に付着さ
せる力が生じておらず、感光ドラム１の電位が不定であ
っても感光ドラム１へのトナー付着が生じない。As described above, while the potential of the developing sleeve 81 is 0V, the potential of the photosensitive drum 1 is -100V even at the lowest potential part, and the potential of the photosensitive drum 1 side is higher. It has become. As a result, no force is generated that causes the toner carried on the developing sleeve 81 to adhere to the photosensitive drum 1 side, and toner does not adhere to the photosensitive drum 1 even if the potential of the photosensitive drum 1 is unstable.
【００２９】続いて制御部１１は、Ｔ２時点からＴＢの
時間が経過した時点（図２中のＴ３時点）に転写装置９
のスイッチ９４を高圧電源９２側に切り換える。すなわ
ちスイッチ９４は、感光ドラム１の停止時に帯電位置Ａ
と現像位置Ｂとの間に位置していた感光ドラム１上の部
分（電位が不定である部分）が転写位置Ｃを通過するま
での期間には高圧電源９３側に、またこれ以降は高圧電
源９２側にそれぞれＯＮされる。従って、感光ドラム１
上の電位が不定である部分が転写位置Ｃを通過するまで
の期間には高圧電源９３が発生する負極性の高電圧が、
またこれ以降では高圧電源９２が発生する正極性の高電
圧（例えば＋５００Ｖ）がそれぞれ転写ローラ９１に印
加される。Subsequently, the control unit 11 starts the transfer device 9 at a time point TB when time TB has elapsed from time point T2 (time point T3 in FIG. 2).
switch 94 to the high voltage power supply 92 side. That is, the switch 94 is set to the charging position A when the photosensitive drum 1 is stopped.
Until the part of the photosensitive drum 1 located between the development position B and the development position B (the part where the potential is undefined) passes the transfer position C, it is connected to the high-voltage power supply 93 side, and from then on to the high-voltage power supply 93 side. 92 side are respectively turned ON. Therefore, photosensitive drum 1
During the period until the part where the upper potential is unstable passes the transfer position C, the high voltage of negative polarity generated by the high voltage power supply 93 is
After this, a positive high voltage (for example, +500 V) generated by the high voltage power supply 92 is applied to the transfer roller 91, respectively.
【００３０】ここで、転写ローラ９１に正極性の高電圧
が印加された状態では、従来と同様な作用によって、感
光ドラム１と転写ローラ９１との間を搬送される記録紙
に対するトナーの転写が行われる。一方、転写ローラ９
１に負極性の高電圧が印加された状態では、感光ドラム
１に付着しているトナーは負極性の高電圧の作用によっ
て反発し、転写ローラ９１には付着しない。従って、現
像装置８において、感光ドラム１へのトナーの物理的な
付着が生じたとしても、このように感光ドラム１に付着
したトナーが転写ローラ９１には付着しないから、転写
ローラ９１の汚れが生じることはない。Here, when a positive high voltage is applied to the transfer roller 91, toner is not transferred to the recording paper conveyed between the photosensitive drum 1 and the transfer roller 91 by the same action as in the conventional case. It will be done. On the other hand, the transfer roller 9
When a negative high voltage is applied to the photosensitive drum 1 , the toner adhering to the photosensitive drum 1 is repelled by the action of the negative high voltage and does not adhere to the transfer roller 91 . Therefore, even if toner physically adheres to the photosensitive drum 1 in the developing device 8, the toner that has adhered to the photosensitive drum 1 in this way does not adhere to the transfer roller 91, so that the transfer roller 91 is not contaminated. It will never occur.
【００３１】以上のように本実施例によれば、感光ドラ
ム１のアルミ素管１ａの電位を、現像バイアスと同極性
で、かつその絶対値が０より大きく現像バイアスの電圧
の絶対値より低い値（−１００Ｖ）とするとともに、記
録動作の開始時において、感光ドラム１上の電位が不定
である部分が現像位置Ｂを通過する期間には現像スリー
ブ８１への現像バイアスの印加をＯＦＦしているので、
当該期間には感光ドラム１の電位が不定であっても常に
感光ドラム１側の電位を現像スリーブ８１側の電位より
も高くすることができ、感光ドラム１へのトナー付着を
防止できる。As described above, according to this embodiment, the electric potential of the aluminum tube 1a of the photosensitive drum 1 has the same polarity as the developing bias, and its absolute value is greater than 0 and lower than the absolute value of the developing bias voltage. value (-100V), and at the start of the recording operation, the application of the development bias to the development sleeve 81 is turned off during the period when the part of the photosensitive drum 1 where the potential is unstable passes the development position B. Because there are
During this period, even if the potential of the photosensitive drum 1 is unstable, the potential on the photosensitive drum 1 side can always be made higher than the potential on the developing sleeve 81 side, and toner adhesion to the photosensitive drum 1 can be prevented.
【００３２】また本実施例では、感光ドラム１上の電位
が不定である部分が転写位置Ｃを通過する期間には転写
ローラ９１への印加高電圧を感光ドラム１の帯電極性と
同極性としているので、転写ローラ９１は転写作用を有
しておらず、たとえ感光ドラム１に若干のトナー付着が
生じていたとしても、このトナーは転写ローラ９１には
付着せず、転写ローラ９１の汚れはより確実に防止され
る。Furthermore, in this embodiment, the high voltage applied to the transfer roller 91 is set to have the same polarity as the charged polarity of the photosensitive drum 1 during a period when a portion of the photosensitive drum 1 where the potential is undefined passes through the transfer position C. Therefore, the transfer roller 91 does not have a transfer function, and even if some toner adheres to the photosensitive drum 1, this toner will not adhere to the transfer roller 91 and the transfer roller 91 will become more dirty. Definitely prevented.
【００３３】なお上記実施例では、帯電電位、現像バイ
アス、転写電圧のそれぞれをアルミ素管１ｂを接地して
いる従来と同一値に設定しているが、最適条件での良好
な記録を行う場合には、これらの帯電電位、現像バイア
ス、転写電圧のそれぞれの値をアルミ素管１ａに印加す
る電位分シフトすることが望ましい。具体的には、上述
のようにアルミ素管１ａの電位を−１００Ｖとすると、
帯電電位は−６００Ｖ、現像バイアスは−３００Ｖ、転
写電圧は＋４００Ｖとする。In the above embodiment, the charging potential, developing bias, and transfer voltage are set to the same values as in the conventional case where the aluminum tube 1b is grounded. However, when good recording is performed under optimal conditions, For this reason, it is desirable to shift the respective values of the charging potential, developing bias, and transfer voltage by the potential applied to the aluminum tube 1a. Specifically, if the potential of the aluminum tube 1a is -100V as mentioned above,
The charging potential is -600V, the developing bias is -300V, and the transfer voltage is +400V.
【００３４】また上記実施例では、、転写ローラ９１に
印加する高電圧を転写電圧とは逆極性とする期間を、帯
電装置７による帯電を開始してからＴＡ＋ＴＢの時間が
経過するまでの間としているが、記録紙の先端が転写位
置Ｃに至る時点までとしておけば、帯電がなされた感光
ドラム１上にトナー付着が生じた場合に、このトナーの
転写ローラ９１への付着をも防止できるようになる。Further, in the above embodiment, the period during which the high voltage applied to the transfer roller 91 is of opposite polarity to the transfer voltage is set as the period from when the charging device 7 starts charging until the time TA+TB has elapsed. However, if the leading edge of the recording paper reaches the transfer position C, even if toner adheres to the charged photosensitive drum 1, this toner can be prevented from adhering to the transfer roller 91. become.
【００３５】このほか本発明は上記実施例に限定される
ものではなく、例えば転写装置はローラによるものには
限らず、ブラシを用いたもの、あるいは放電器のような
非接触型のものであっても良い。また転写ローラへの転
写電圧とは逆極性の電圧の印加は必ずしも必要なもので
はなく、省略が可能である。また感光ドラムの基体はア
ルミ素管に限らず、導電性部材によりなっていれば良い
。このほか、本発明の要旨を逸脱しない範囲で種々の変
形実施が可能である。In addition, the present invention is not limited to the above embodiments; for example, the transfer device is not limited to one using a roller, but may also be one using a brush or a non-contact type such as a discharger. It's okay. Further, application of a voltage having a polarity opposite to that of the transfer voltage to the transfer roller is not necessarily necessary and can be omitted. Further, the base of the photosensitive drum is not limited to an aluminum tube, but may be made of a conductive member. In addition, various modifications can be made without departing from the gist of the present invention.
【００３６】[0036]
【発明の効果】第１の発明は、感光体をなす例えばアル
ミ素管などの導電性部材に、現像バイアスと同極性で、
かつその絶対値が０より大きく前記現像バイアスの電圧
の絶対値より低い所定電圧を印加しておき、前記感光体
の回転開始時に、帯電手段による前記感光体の帯電が開
始された時点に前記帯電手段の帯電位置に位置していた
前記感光体上の所定点が現像手段の現像位置に至るのに
要する時間が経過するまでは前記現像バイアスをオフし
ておき、こののちに前記現像バイアスをオンするように
した。[Effects of the Invention] The first invention provides a conductive member, such as an aluminum tube, which forms the photoreceptor, with the same polarity as the developing bias.
A predetermined voltage whose absolute value is greater than 0 and lower than the absolute value of the voltage of the developing bias is applied, and when the photoreceptor starts rotating, the charging means starts charging the photoreceptor. The developing bias is turned off until the time required for a predetermined point on the photoreceptor located at the charging position of the means to reach the developing position of the developing means has elapsed, and then the developing bias is turned on. I decided to do so.
【００３７】第２の発明は、転写手段として帯電電位と
は逆極性の所定電圧の転写電圧により転写を行うものを
有した第１の発明の電子写真記録装置において、帯電電
圧、現像バイアスおよび前記転写電圧のそれぞれの値を
、導電性部材を接地した場合における前記帯電電圧、前
記現像バイアスおよび前記転写電圧のそれぞれの値に前
記導電性部材に印加する電圧値を加えた値とした。A second aspect of the invention is the electrophotographic recording apparatus of the first aspect, which has a transfer means that performs the transfer using a predetermined transfer voltage having a polarity opposite to that of the charging potential, in which the charging voltage, the developing bias, and the Each value of the transfer voltage was determined by adding the voltage value applied to the conductive member to the respective values of the charging voltage, the developing bias, and the transfer voltage when the conductive member was grounded.
【００３８】第３の発明は、転写手段として感光体に重
ねられた記録紙に接触し、現像剤の帯電電位とは逆極性
の所定電圧の転写電圧により転写を行うものを有した第
１の発明の電子写真記録装置において、前記転写電圧と
逆極性で所定電圧の逆電圧を発生する逆電圧発生手段を
備え、前記感光体の回転開始時に、帯電手段による前記
感光体の帯電が開始された時点に前記帯電手段の帯電位
置に位置していた前記感光体上の所定点が前記転写手段
の転写位置に至るのに要する時間が経過するまでは前記
転写手段に前記逆電圧を印加しておき、こののちに前記
転写手段への前記逆電圧の印加を停止するとともに前記
転写電圧をオンするようにした。これらにより、感光体
への無駄な現像剤付着を極力抑え、これにより経済的か
つ高画質に記録を行うことができる電子写真記録装置と
なる。[0038] The third invention is the first invention, which has a transfer means that contacts the recording paper stacked on the photoreceptor and performs transfer with a predetermined transfer voltage having a polarity opposite to the charging potential of the developer. The electrophotographic recording apparatus of the invention includes a reverse voltage generating means for generating a reverse voltage of a predetermined voltage with a polarity opposite to that of the transfer voltage, and charging of the photoreceptor by the charging means is started when the rotation of the photoreceptor starts. The reverse voltage is applied to the transfer means until a time period required for a predetermined point on the photoreceptor, which was located at the charging position of the charging means at the time, to reach the transfer position of the transfer means has elapsed. After that, application of the reverse voltage to the transfer means was stopped and the transfer voltage was turned on. As a result, wasteful adhesion of developer to the photoreceptor can be suppressed as much as possible, resulting in an electrophotographic recording apparatus that can perform economical and high-quality recording.
【図１】本発明の一実施例に係る電子写真記録装置の構
成を示す図。FIG. 1 is a diagram showing the configuration of an electrophotographic recording apparatus according to an embodiment of the present invention.
【図２】図１中の各部の動作タイミングを示すタイミン
グ図。FIG. 2 is a timing chart showing the operation timing of each part in FIG. 1;
【図３】従来技術を説明する図。FIG. 3 is a diagram illustrating a prior art.
１…感光ドラム、１ａ…アルミ素管、１ｂ…光導電層、
７…帯電装置、７１…放電器、７２…高圧電源、７３…
スイッチ、８…現像装置、８１…現像スリーブ、８２…
高圧電源、８３…スイッチ、９…転写装置、９１…転写
ローラ、９２…高圧電源、９３…高圧電源、９４…スイ
ッチ、１０…ツェナダイオード、１１…制御部、１２…
感光ドラム駆動系。1... Photosensitive drum, 1a... Aluminum tube, 1b... Photoconductive layer,
7...Charging device, 71...Discharger, 72...High voltage power supply, 73...
Switch, 8...Developing device, 81...Developing sleeve, 82...
High voltage power supply, 83...Switch, 9...Transfer device, 91...Transfer roller, 92...High voltage power supply, 93...High voltage power supply, 94...Switch, 10...Zena diode, 11...Control unit, 12...
Photosensitive drum drive system.
Claims (3)
行うものであり、感光体として、無端状の導電性部材上
に光導電材料を塗布してなるもの、帯電手段として、所
定電圧の帯電電圧により前記感光体の表面を所定の帯電
電位に帯電するもの、また現像手段として、前記感光体
に形成された静電潜像に対し、前記帯電電位と同極性か
つ前記帯電電位より低い所定電位の現像バイアスにより
現像剤を付着させるものをそれぞれ有した電子写真記録
装置において、前記導電性部材に、前記現像バイアスと
同極性で、かつその絶対値が０より大きく前記現像バイ
アスの電圧の絶対値より低い所定電圧を印加する導電性
部材電圧印加手段と、前記感光体の回転開始時に、前記
帯電手段による前記感光体の帯電が開始された時点に前
記帯電手段の帯電位置に位置していた前記感光体上の所
定点が前記現像手段の現像位置に至るのに要する時間が
経過するまでは前記現像バイアスをオフしておき、この
のちに前記現像バイアスをオンする現像バイアス制御手
段とを具備したことを特徴とする電子写真記録装置。Claim 1: An image is recorded by an electrophotographic process, and the photoreceptor is an endless conductive member coated with a photoconductive material, and the charging means is a device using a predetermined charging voltage. A device that charges the surface of the photoreceptor to a predetermined charging potential, and a developing means that develops the electrostatic latent image formed on the photoreceptor at a predetermined potential that is the same polarity as the charging potential and lower than the charging potential. In an electrophotographic recording device each having a device for adhering a developer using a bias, the conductive member has a voltage having the same polarity as the developing bias, and an absolute value of which is greater than 0 and lower than the absolute value of the voltage of the developing bias. a conductive member voltage applying means for applying a predetermined voltage; and the photoreceptor that is located at a charging position of the charging means at the time when the charging means starts charging the photoreceptor when the photoreceptor starts rotating. and a developing bias control means for turning off the developing bias until the time required for the predetermined point on the top to reach the developing position of the developing means and then turning on the developing bias. Characteristic electrophotographic recording device.
所定電圧の転写電圧により転写を行うものを有し、帯電
電圧、現像バイアスおよび前記転写電圧のそれぞれの値
を、導電性部材を接地した場合における前記帯電電圧、
前記現像バイアスおよび前記転写電圧のそれぞれの値に
前記導電性部材に印加する電圧値を加えた値としたこと
を特徴とする請求項１に記載の電子写真記録装置。2. The transfer means includes one that performs transfer using a predetermined transfer voltage having a polarity opposite to the charging potential, and each value of the charging voltage, the developing bias, and the transfer voltage is set by connecting a conductive member to a ground. The charging voltage in the case,
2. The electrophotographic recording apparatus according to claim 1, wherein the value is a value obtained by adding a voltage value applied to the conductive member to the respective values of the developing bias and the transfer voltage.
録紙に接触し、現像剤の帯電電位とは逆極性の所定電圧
の転写電圧により転写を行うものを有し、前記転写電圧
と逆極性で所定電圧の逆電圧を発生する逆電圧発生手段
と、前記感光体の回転開始時に、帯電手段による前記感
光体の帯電が開始された時点に前記帯電手段の帯電位置
に位置していた前記感光体上の所定点が前記転写手段の
転写位置に至るのに要する時間が経過するまでは前記転
写手段に前記逆電圧を印加しておき、こののちに前記転
写手段への前記逆電圧の印加を停止するとともに前記転
写電圧をオンする転写制御手段とを具備したことを特徴
とする請求項１に記載の電子写真記録装置。3. The transfer means includes one that contacts the recording paper stacked on the photoreceptor and performs the transfer with a transfer voltage of a predetermined voltage having a polarity opposite to that of the charging potential of the developer, the transfer voltage having a polarity opposite to that of the transfer voltage. a reverse voltage generating means for generating a reverse voltage of a predetermined voltage at a voltage, and a photoreceptor positioned at a charging position of the charging means when the photoreceptor starts to be charged by the charging means when the photoreceptor starts rotating; The reverse voltage is applied to the transfer means until the time required for a predetermined point on the body to reach the transfer position of the transfer means, and then the reverse voltage is applied to the transfer means. 2. The electrophotographic recording apparatus according to claim 1, further comprising transfer control means for stopping the transfer voltage and turning on the transfer voltage.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3037487A JPH04275566A (en) | 1991-03-04 | 1991-03-04 | Electrophotographic recorder |
| CA002062230A CA2062230C (en) | 1991-03-04 | 1992-03-03 | Electrophotographic printing apparatus capable of printing images by electrophotographic processing and its start-up method |
| KR1019920003542A KR950003006B1 (en) | 1991-03-04 | 1992-03-04 | Electrophotographic printing apparatus and its start-up method |
| US08/216,370 US5404213A (en) | 1991-03-04 | 1994-03-23 | Electrophotographic printing apparatus capable of printing images by electrophotographic processing and its start-up method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3037487A JPH04275566A (en) | 1991-03-04 | 1991-03-04 | Electrophotographic recorder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04275566A true JPH04275566A (en) | 1992-10-01 |
Family
ID=12498882
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3037487A Pending JPH04275566A (en) | 1991-03-04 | 1991-03-04 | Electrophotographic recorder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04275566A (en) |
-
1991
- 1991-03-04 JP JP3037487A patent/JPH04275566A/en active Pending
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