JPH04204876A - Reversal development controller - Google Patents

Reversal development controller

Info

Publication number
JPH04204876A
JPH04204876A JP2337711A JP33771190A JPH04204876A JP H04204876 A JPH04204876 A JP H04204876A JP 2337711 A JP2337711 A JP 2337711A JP 33771190 A JP33771190 A JP 33771190A JP H04204876 A JPH04204876 A JP H04204876A
Authority
JP
Japan
Prior art keywords
bias
developing
exposure
voltage
bias voltage
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
Application number
JP2337711A
Other languages
Japanese (ja)
Inventor
Akihiro Kondo
昭浩 近藤
Yoshihiro Nakajima
中嶋 義弘
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kyocera Mita Industrial Co Ltd
Original Assignee
Mita Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mita Industrial Co Ltd filed Critical Mita Industrial Co Ltd
Priority to JP2337711A priority Critical patent/JPH04204876A/en
Priority to US07/754,949 priority patent/US5179411A/en
Priority to DE69115611T priority patent/DE69115611T2/en
Priority to EP91115224A priority patent/EP0475334B1/en
Publication of JPH04204876A publication Critical patent/JPH04204876A/en
Pending legal-status Critical Current

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  • Developing For Electrophotography (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Dry Development In Electrophotography (AREA)
  • Control Or Security For Electrophotography (AREA)

Abstract

PURPOSE:To prevent the scattering of toner and carrier by making a light quantity control means for an exposure means vary the quantity of exposed light applied by the use of the exposure means, from the prescribed value to 0 gradually and making a bias control means for a bias applying means vary a bias voltage applied by the use of the bias imparting means to the prescribed voltage value gradually. CONSTITUTION:A high voltage power source circuit 11 which applies a high voltage to a developing unit 4 is connected to the developing unit 4. A control circuit 12 which controls the intensity of a voltage produced by the high voltage power source circuit 11 is connected to the high voltage power source circuit 11. Further, a control circuit 14 which controls the quantity of exposed light is connected to a LED array 3. A CPU(central processing circuit) 13 which gives instructions concerning the contents of controls by the control circuits 9, 12, and 14, instructs the circuit to vary the quantity of exposed light, applied by use of the LED array 3, from the prescribed value to 0, and also instructs the circuit so as to vary a bias voltage, applied to the developing unit 4, to the prescribed voltage value gradually. Thus, scattering of toner and carrier is prevented.

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は、静電写真複写機等の画像形成装置に適用され
ている反転現像装置に関し、さらに詳しくは反転現像装
置の反転現像制御装置に関するものである。
DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reversal developing device applied to an image forming apparatus such as an electrostatographic copying machine, and more particularly to a reversing developing control device for a reversing developing device. It is something.

(従来の技術) 一般に、2成分現像剤を使用する反転現像方式の複写機
においては、例えば帯電手段によって感光体ドラム表面
を負に帯電し、露光によって零電位となった部分(露光
領域)に現像剤のうち負帯電したトナーを付着させ現像
している。このときキャリアは正帯電している。
(Prior Art) In general, in a reversal development type copying machine that uses a two-component developer, the surface of the photoreceptor drum is negatively charged, for example, by a charging means, and the portion (exposed area) that has a zero potential due to exposure is Among the developer, negatively charged toner is attached for development. At this time, the carrier is positively charged.

詳述すると、この反転現像方式では、第4図に示すよう
に、帯電器1により感光体ドラム2の表面を−700ボ
ルト程度の負電位に印加し、この負に帯電した部分が露
光手段3による露光位置に回転移動して露光される。そ
の後、感光体ドラム2はさらに回転して現像ローラ41
と対向する現像位置に到達し、この時点で現像ローラ4
1に−400ボルト程度の負のバイアス電圧が印加され
、その静電気的反発力で負に帯電したトナーが飛び出し
、感光体ドラム2の零電位の露光部分に付着する。
To be more specific, in this reversal development method, as shown in FIG. is rotated to the exposure position and exposed. Thereafter, the photoreceptor drum 2 further rotates and the developing roller 41
At this point, the developing roller 4 reaches the developing position opposite the developing roller 4.
A negative bias voltage of about -400 volts is applied to the photoreceptor drum 2, and the negatively charged toner flies out due to the electrostatic repulsion and adheres to the exposed portion of the photoreceptor drum 2, which has a zero potential.

(発明が解決しようとする問題) ところで、現像ローラ41へのバイアス電圧は、感光体
ドラム2の帯電・露光された部分が現像ローラ41と対
向する現像位置へ到達すると同時に印加されるのが好ま
しいが、このタイミングの制御は容易ではなく、バイア
ス電圧の印加タイミングがずれてしまうことがあった。
(Problem to be Solved by the Invention) Incidentally, it is preferable that the bias voltage to the developing roller 41 be applied at the same time as the charged and exposed portion of the photosensitive drum 2 reaches the developing position facing the developing roller 41. However, it is not easy to control this timing, and the timing of applying the bias voltage may shift.

したがって、例えば、その現像ローラ41に=400ボ
ルトのバイアス電圧が印加されるタイミングが感光体ド
ラム2の一700ボルトに帯電した部分が現像ローラ4
1との現像位置へ到達する時点よりも早すぎると、感光
体ドラム2表面の電位が現像ローラ41のバイアス電圧
値よりも大きくなって、トナーが感光体ドラム2へ飛ん
でしまう。すなわち、第5図(a)に示すように、現像
位置に到達した感光体ドラム2に対して現像ローラ41
に印加されるバイアス電圧のタイミングがずれると、第
5図(b)(バイアス電圧値をOボルトとしての相対的
差)に示すように、許容される相対的差をその電圧差が
越えてしまう。
Therefore, for example, the timing at which a bias voltage of 400 volts is applied to the developing roller 41 is such that the portion of the photosensitive drum 2 charged to 700 volts is the timing when the developing roller 41 is charged with a voltage of 700 volts.
If the toner reaches the developing position with 1 too early, the potential on the surface of the photosensitive drum 2 will become larger than the bias voltage value of the developing roller 41, and the toner will fly to the photosensitive drum 2. That is, as shown in FIG. 5(a), the developing roller 41 is moved against the photosensitive drum 2 that has reached the developing position.
If the timing of the bias voltage applied to the voltage is off, the voltage difference will exceed the allowable relative difference, as shown in Figure 5(b) (relative difference assuming the bias voltage value is O volts). .

逆に、その現像ローラ41に一400ボルトのバイアス
電圧を印加するタイミングが、感光体ドラム2の一70
0ボルトに帯電した部分が現像ローラ41との現像位置
に到達した時点よりも遅すぎると、その間、−700ボ
ルトに帯電した感光体ドラム部分が現像ローラ41との
現像位置に到達しているにもかかわらず、現像ローラ4
1にバイアス電圧が印加されていないので、正に帯電し
たキャリアが感光体ドラム2の表面に引き寄せられる。
Conversely, the timing at which a bias voltage of 1,400 volts is applied to the developing roller 41 is 170 volts on the photosensitive drum 2.
If it is too late than the point at which the portion charged to 0 volts reaches the developing position with the developing roller 41, the photosensitive drum portion charged at -700 volts will have reached the developing position with the developing roller 41 during that time. Despite this, developing roller 4
Since no bias voltage is applied to the photoreceptor drum 1, positively charged carriers are attracted to the surface of the photoreceptor drum 2.

すなわち、第6図(a)に示すように、現像領域に到達
した感光体ドラム2に対して現像ローラ41に印加され
るバイアス電圧のタイミングがずれると、第6図(b)
(バイアス電圧値をOボルトとしての相対的差)に示す
ように、許容される相対的差をその電圧差が越えてしま
うのである。
That is, as shown in FIG. 6(a), if the timing of the bias voltage applied to the developing roller 41 is shifted with respect to the photosensitive drum 2 reaching the developing area, the bias voltage applied to the developing roller 41 is shifted as shown in FIG. 6(b).
As shown in (relative difference assuming bias voltage value as O volts), the voltage difference exceeds the allowable relative difference.

これに対し、バイアス電圧を急激に印加しない発明もさ
れているが、それでもやはり、両電圧の印加のタイミン
グが悪いと、電圧差が許容範囲を越えて、トナーやキャ
リアが飛散してしまう。
On the other hand, although some inventions have been made in which the bias voltage is not applied suddenly, if the timing of application of both voltages is inappropriate, the voltage difference will exceed the allowable range and the toner and carrier will be scattered.

本発明は、このような従来の反転現像制御装置の課題を
考慮し、感光体ドラムへの電圧の印加のタイミングある
いは、現像手段へのバイアス電圧の印加のタイミングが
正常なタイミングよりずれても、トナーやキャリアが飛
散しない反転現像制御装置を提供することを目的とする
ものである。
The present invention takes into consideration the problems of the conventional reversal development control device, and even if the timing of applying voltage to the photoreceptor drum or the timing of applying bias voltage to the developing means deviates from the normal timing, It is an object of the present invention to provide a reversal development control device in which toner and carrier do not scatter.

(問題点を解決するための手段) 本発明の反転現像制御装置は、潜像が形成される感光体
と、この感光体に電圧を印加して所定の表面電位に帯電
する帯電手段と、この帯電手段により帯電された感光体
を露光して潜像を形成するための露光手段と、前記潜像
を反転現像する現像手段と、この現像手段に所定のバイ
アス電圧を印加するバイアス付与手段とを有する画像形
成装置の反転現像装置において、前記露光手段は露光光
量を所定値からOまで徐々に変化させるように制御する
光量制御手段を備え、さらに前記バイアス付与手段はバ
イアス電圧値を所定電圧値まで徐々に変化させるバイア
ス制御手段を具備することを特徴とするものである。
(Means for Solving the Problems) The reversal development control device of the present invention includes: a photoreceptor on which a latent image is formed; a charging means for applying a voltage to the photoreceptor to charge it to a predetermined surface potential; An exposure means for exposing a photoreceptor charged by the charging means to form a latent image, a developing means for reversing and developing the latent image, and a bias applying means for applying a predetermined bias voltage to the developing means. In the reversal developing device of the image forming apparatus, the exposure means includes a light amount control means for controlling the exposure light amount to gradually change from a predetermined value to O, and the bias applying means changes the bias voltage value to a predetermined voltage value. The present invention is characterized in that it includes a bias control means that gradually changes the bias.

(作用) 本発明は、帯電手段によって感光体を帯電し、その帯電
した感光体が露光手段による露光位置に到達した際に露
光により潜像を形成する。そして、この潜像が形成され
た感光体が現像手段による現像位置に到達した際にバイ
アス付与手段によって現像手段に所定のバイアス電圧を
印加して、トナーを感光体へ付着させる。
(Function) In the present invention, a photoreceptor is charged by a charging means, and a latent image is formed by exposure when the charged photoreceptor reaches an exposure position by an exposure means. Then, when the photoreceptor on which the latent image is formed reaches a developing position by the developing means, a predetermined bias voltage is applied to the developing means by the bias applying means to cause the toner to adhere to the photoreceptor.

このとき、露光手段の光量制御手段は、その露光光量を
所定値からOまで徐々に変化させるように制御し、バイ
アス付与手段のバイアス制御手段は、印加電圧を所定電
圧値まで徐々に変化させるように制御する。
At this time, the light amount control means of the exposure means controls the exposure light amount so as to gradually change from a predetermined value to O, and the bias control means of the bias applying means gradually changes the applied voltage to a predetermined voltage value. to control.

従って、現像位置における感光体の表面電位と現像手段
のバイアス電圧値との差は、その印加のタイミングが多
少、正規のタイミングからずれても、許容範囲内に収ま
るため、不必要なトナーやキャリアの飛散が防止される
Therefore, the difference between the surface potential of the photoreceptor at the developing position and the bias voltage value of the developing means is within the allowable range even if the timing of application is slightly off from the regular timing, so unnecessary toner and carrier scattering is prevented.

(実施例) 以下、本発明の実施例について図面を参照して説明する
(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

第1図は、本発明にかかる反転現像制御装置の一実施例
が適用された複写機の要部の概略断面図である。
FIG. 1 is a schematic cross-sectional view of the main parts of a copying machine to which an embodiment of the reversal development control device according to the present invention is applied.

同図において、潜像が形成される感光体の一例としての
感光体ドラム2の周辺には、図面上、反時計回りの方向
に順に、帯電器1、表面電位センサー6、露光位置に設
けられた露光手段としてのLEDアレイ3、現像手段の
一例としての現像器4とその現像ローラ41、そして残
留したトナーを除去するクリーニング手段5等が配置さ
れている。
In the figure, a charger 1, a surface potential sensor 6, and an exposure position are installed around a photoconductor drum 2, which is an example of a photoconductor on which a latent image is formed, in order counterclockwise in the drawing. An LED array 3 as an exposure means, a developing device 4 and its developing roller 41 as an example of a developing means, a cleaning means 5 for removing residual toner, and the like are arranged.

前記帯電器1には、感光体ドラム2を−700ボルト程
度に帯電させるための高圧電源回路10が接続されてい
る。また、この高圧電源回路10には、その高圧電源回
路10の発生する電圧の大きさを制御する制御回路9が
接続されている。
A high voltage power supply circuit 10 is connected to the charger 1 for charging the photoreceptor drum 2 to about -700 volts. Further, a control circuit 9 that controls the magnitude of the voltage generated by the high voltage power supply circuit 10 is connected to the high voltage power supply circuit 10.

一方、現像器4にはその現像器4に高圧を印加するため
の高圧電源回路11が接続されている。
On the other hand, a high voltage power supply circuit 11 for applying high voltage to the developing device 4 is connected to the developing device 4 .

また、この高圧電源回路11には、その高圧電源回路1
1の発生する電圧の大きさを制御する制御回路12が接
続されている。さらに、LEDアレイ3には、露光光量
を制御する制御回路14が接続されている。
In addition, this high voltage power supply circuit 11 includes the high voltage power supply circuit 1
A control circuit 12 for controlling the magnitude of the voltage generated by 1 is connected. Furthermore, the LED array 3 is connected to a control circuit 14 that controls the amount of exposure light.

そして、これら制御回路9.12.14の制御内容を指
示するためのCPU (中央演算処理装置)13が設け
られ、そこへ前記表面電位センサー6の出力信号が入力
されるようになっている。
A CPU (Central Processing Unit) 13 is provided for instructing the control contents of these control circuits 9, 12, and 14, and the output signal of the surface potential sensor 6 is input thereto.

このCPU13は、LEDアレイ3の露光光量を所定値
からOまで徐々に変化させるように指示するとともに、
現像器4へのバイアス印加電圧も所定電圧値まで徐々に
変化させるように指示するようになっている。
This CPU 13 instructs to gradually change the exposure light amount of the LED array 3 from a predetermined value to O, and
An instruction is also given to gradually change the bias voltage applied to the developing device 4 up to a predetermined voltage value.

次に、上記実施例の動作について説明する。Next, the operation of the above embodiment will be explained.

まずその概略を説明する。ここで感光体ドラム2は第1
図に示すように、反時計方向に回転しているとする。帯
電器1は感光体ドラム2を高電圧で帯電し、表面電位セ
ンサー6はその帯電した感光体ドラム2の表面電位を測
定し、その帯電した部分が露光位1に到達すると、LE
Dアレイ3によって露光−され、潜像が形成される。さ
らに回転して、現像器4の現像位置に到達すると、高圧
電源回路11が高電圧を現像器4の現像ローラ41に印
加して、トナーを飛ばせて現像する。その後、現像され
た部分は転写(図示省略)され、残留したトナーはクリ
ーニング装置5により除去される。
First, I will explain the outline. Here, the photosensitive drum 2 is the first
Assume that it is rotating counterclockwise as shown in the figure. The charger 1 charges the photoreceptor drum 2 with a high voltage, the surface potential sensor 6 measures the surface potential of the charged photoreceptor drum 2, and when the charged portion reaches the exposure position 1, the LE
It is exposed by the D array 3 and a latent image is formed. When the toner rotates further and reaches the developing position of the developing device 4, the high voltage power supply circuit 11 applies a high voltage to the developing roller 41 of the developing device 4, thereby causing the toner to fly off and developing. Thereafter, the developed portion is transferred (not shown), and the remaining toner is removed by the cleaning device 5.

次に、上記動作における露光光量変化及びバイアス電圧
印加のタイミングについて詳しく説明する。
Next, the timing of changing the amount of exposure light and applying the bias voltage in the above operation will be explained in detail.

帯電器1により電圧を印加された感光体ドラム2の部分
P1が回転して、LEDアレイ3の露光位置P2及び現
像器4の現像ローラ41の現像位置P3へ到達するまで
一定の時間がかかる。たとえば、PIからP2までに要
する時間を0.2秒、PlからP3までに要する時間を
0.4秒とする。
It takes a certain amount of time for the portion P1 of the photoreceptor drum 2 to which a voltage is applied by the charger 1 to rotate and reach the exposure position P2 of the LED array 3 and the development position P3 of the developing roller 41 of the developer 4. For example, assume that the time required from PI to P2 is 0.2 seconds, and the time required from P1 to P3 is 0.4 seconds.

まず、CPU13は制御回路9を駆動して高圧電源回路
10によって帯電器1により感光体ドラム2が一700
ボルトに帯電されるように印加される0次いで、その0
.2秒後に制御回路14を駆動してLEDアレイ3によ
る露光光量が所定値から0に向かってステップ状に減少
するように露光し始める。このことにより、感光体の帯
電電位は一700ボルトと一定であるために露光後の感
光体ドラムの表面電位はステップ状に増加することにな
る。そのさらに0.2秒後に制御回路12を駆動して高
圧電源回路11によってバイアス電圧を現像ローラ41
に+100ボルトから所定電圧に向かってステップ状に
印加する。
First, the CPU 13 drives the control circuit 9 so that the high-voltage power supply circuit 10 charges the photosensitive drum 1 by the charger 1.
0 applied so that the volt is charged, then that 0
.. After 2 seconds, the control circuit 14 is driven to start exposing the LED array 3 such that the amount of exposure light from the LED array 3 decreases stepwise from a predetermined value toward 0. As a result, since the charged potential of the photoreceptor is constant at 1,700 volts, the surface potential of the photoreceptor drum after exposure increases stepwise. After another 0.2 seconds, the control circuit 12 is driven and the high voltage power supply circuit 11 applies a bias voltage to the developing roller 41.
The voltage is applied in steps from +100 volts to a predetermined voltage.

上記した露光後の感光体の表面電位、すなわち現像位置
に達したときの感光体ドラム2の表面電位および現像ロ
ーラ41のバイアス電圧は、第2図に示すように、感光
体ドラム2の表面電位が=100ボルト→−200ボル
ト→−300ボルト→−400ポルト→−500ボルト
→−600ボルト→−700ボルトと変化し、現像ロー
ラ41のバイアス電圧が+100ボルト→0ボルト→−
100ボルト→−200ボルト→−300ボルト→−4
00ボルトと変化する。なお、第2図における感光体ド
ラム2の表面電位のグラフのタイミング(横軸)は露光
した時間より0.2秒遅れで描かれている。
As shown in FIG. changes as =100 volts → -200 volts → -300 volts → -400 volts → -500 volts → -600 volts → -700 volts, and the bias voltage of the developing roller 41 changes from +100 volts → 0 volts → -
100 volts → -200 volts → -300 volts → -4
It changes to 00 volts. The timing (horizontal axis) of the graph of the surface potential of the photosensitive drum 2 in FIG. 2 is drawn 0.2 seconds later than the exposure time.

この結果、現像位置における感光体ドラム2の表面電位
と現像ローラ41のバイアス電圧値との差は、第3図に
示すようになる。同図は、バイアス電圧値を零としてそ
れに対する感光体ドラム2の表面電位の相対的差を示し
ている。
As a result, the difference between the surface potential of the photosensitive drum 2 and the bias voltage value of the developing roller 41 at the developing position is as shown in FIG. The figure shows the relative difference in surface potential of the photosensitive drum 2 with respect to the bias voltage value of zero.

すなわち、図のようなタイミングで徐々に変化させると
、現像ローラ41のバイアス電圧値に対する感光体ドラ
ム2の表面電位の相対的差は許容範囲におさまることに
なる。ここで、万が一1LEDアレイ3の露光のタイミ
ングが前後にずれたとしても、感光体ドラム2の表面電
位と現像ローラ41のバイアス電圧値との相対的差は変
化するが、双方の電位は徐々に変化しているので許容範
囲内の300ボルト程度に収まる。したがって、トナー
やキャリアが飛散するような不都合は発生しない。
That is, if the voltage is gradually changed at the timing shown in the figure, the relative difference in the surface potential of the photosensitive drum 2 with respect to the bias voltage value of the developing roller 41 will fall within an allowable range. Here, even if the timing of exposure of the LED array 3 is shifted back or forth, the relative difference between the surface potential of the photoreceptor drum 2 and the bias voltage value of the developing roller 41 will change, but the potentials of both will gradually change. Since the voltage is changing, it falls within the allowable range of about 300 volts. Therefore, inconveniences such as toner and carrier scattering do not occur.

なお、上記実施例においては、現像手段に所定のバイア
ス電圧を印加するバイアス付与手段として高圧電源回路
11を、またバイアス制御手段として制御回路12およ
びCPU13等で構成していたが、これに限らず要する
にバイアス電圧値を徐々に変化させて所定電圧値に到達
できるものであればよい、また、上記実施例においては
、露光手段はLEDアレイ3で構成されていたが、これ
に限らず要するに帯電された感光体ドラムへの露光光量
を徐々に変化させ感光体ドラムの表面電位を徐々に変化
させるものであればよい。さらに、上記実施例において
は各電圧の印加の仕方はステップ状に印加していたが、
これに限らず連続的に徐々に変化させるようにしてもよ
い、また、上記実施例においては、2成分現像剤の反転
現像装置を適用していたが、1成分現像剤の反転現像装
置に適用することも可能である。
In the above embodiment, the high-voltage power supply circuit 11 is used as a bias applying means for applying a predetermined bias voltage to the developing means, and the control circuit 12 and the CPU 13 are used as bias control means, but the present invention is not limited to this. In short, any device that can reach a predetermined voltage value by gradually changing the bias voltage value will suffice.Also, in the above embodiment, the exposure means is composed of the LED array 3, but is not limited to this. Any method may be used as long as it gradually changes the amount of exposure light applied to the photoreceptor drum to gradually change the surface potential of the photoreceptor drum. Furthermore, in the above embodiment, each voltage was applied in steps, but
The invention is not limited to this, and it may be changed continuously and gradually.Also, in the above embodiment, a reversal developing device using a two-component developer was applied, but it can be applied to a reversing developing device using a one-component developer. It is also possible to do so.

(発明の効果) 本発明は露光手段の光量制御手段が、その露光光量を所
定値から0まで徐々に変化させるように制御し、バイア
ス付与手段のバイアス制御手段が、そのバイアス付与手
段によるバイアス電圧印加を所定電圧値まで徐々に変化
させるように制御することにより、バイアス電圧を印加
するタイミングや表面電位を印加するタイミングが多少
ずれてもトナーやキャリアが飛散することがない。
(Effects of the Invention) In the present invention, the light amount control means of the exposure means controls the exposure light amount to gradually change from a predetermined value to 0, and the bias control means of the bias applying means controls the bias voltage applied by the bias applying means. By controlling the application so that it gradually changes to a predetermined voltage value, toner and carriers will not be scattered even if the timing of applying the bias voltage or the timing of applying the surface potential is slightly shifted.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明にかかる反転現像制御装置の一実施例を
示すブロック図、第2図は同実施例の露光後の感光体の
表面電位とバイアス電圧値の時間的変化を示すグラフ、
第3図は同実施例の露光後の感光体の表面電位とバイア
ス電圧値との相対的差を示すグラフ、第4図は従来の複
写機の要部を示す模式的断面図、第5図は従来の感光体
の表面電位とバイアス電圧値の関係を示すグラフ、第6
図は他の従来の感光体の表面電位とバイアス電圧値の関
係を示すグラフである。 1・・・帯電器、2・・・感光体ドラム、3・・・LE
Dアレイ、4・・・現像器、41・・・現像ローラ、1
1・・・高圧電源回路、12・・・制御回路、13・・
・CPU
FIG. 1 is a block diagram showing an embodiment of the reversal development control device according to the present invention, and FIG. 2 is a graph showing temporal changes in the surface potential and bias voltage value of the photoreceptor after exposure in the same embodiment.
FIG. 3 is a graph showing the relative difference between the surface potential of the photoreceptor and the bias voltage value after exposure in the same example, FIG. 4 is a schematic cross-sectional view showing the main parts of a conventional copying machine, and FIG. 5 is a graph showing the relationship between the surface potential and bias voltage value of a conventional photoreceptor;
The figure is a graph showing the relationship between the surface potential and bias voltage value of another conventional photoreceptor. 1... Charger, 2... Photosensitive drum, 3... LE
D array, 4...Developing device, 41...Developing roller, 1
1... High voltage power supply circuit, 12... Control circuit, 13...
・CPU

Claims (3)

【特許請求の範囲】[Claims] (1)潜像が形成される感光体と、この感光体に電圧を
印加して所定の表面電位に帯電する帯電手段と、この帯
電手段により帯電された感光体を露光して潜像を形成す
るための露光手段と、前記潜像を反転現像する現像手段
と、この現像手段に所定のバイアス電圧を印加するバイ
アス付与手段とを有する画像形成装置の反転現像装置に
おいて、前記露光手段は露光光量を所定値から0まで徐
々に変化させるように制御する光量制御手段を備え、 さらに前記バイアス付与手段はバイアス電圧値を所定電
圧値まで徐々に変化させるバイアス制御手段を具備する
ことを特徴とする反転現像制御装置。
(1) A photoreceptor on which a latent image is formed, a charging means that applies a voltage to the photoreceptor to charge it to a predetermined surface potential, and a latent image is formed by exposing the photoreceptor charged by the charging means to light. In a reversal developing device of an image forming apparatus, the exposure means has an exposure means for reversing the latent image, a developing means for reversing developing the latent image, and a bias applying means for applying a predetermined bias voltage to the developing means. The invention further comprises a light amount control means for gradually changing the bias voltage value from a predetermined value to 0, and the bias applying means further comprises a bias control means for gradually changing a bias voltage value to a predetermined voltage value. Development control device.
(2)前記光量制御手段は、露光光量を所定値から0ま
で徐々に変化させる際、ステップ状に変化させるもので
あることを特徴とする請求項(1)記載の反転現像制御
装置。
(2) The reversal development control device according to claim 1, wherein the light amount control means changes the exposure light amount in steps when gradually changing the exposure light amount from a predetermined value to 0.
(3)前記バイアス制御手段は、所定電圧値を印加させ
る際、ステップ状に印加させるものであることを特徴と
する請求項(1)記載の反転現像制御装置。
(3) The reversal development control device according to claim (1), wherein the bias control means applies the predetermined voltage value in steps.
JP2337711A 1990-09-11 1990-11-30 Reversal development controller Pending JPH04204876A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2337711A JPH04204876A (en) 1990-11-30 1990-11-30 Reversal development controller
US07/754,949 US5179411A (en) 1990-09-11 1991-09-04 Inversion development controller
DE69115611T DE69115611T2 (en) 1990-09-11 1991-09-09 Image generating device and method for generating images
EP91115224A EP0475334B1 (en) 1990-09-11 1991-09-09 Image forming device and method of forming images

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2337711A JPH04204876A (en) 1990-11-30 1990-11-30 Reversal development controller

Publications (1)

Publication Number Publication Date
JPH04204876A true JPH04204876A (en) 1992-07-27

Family

ID=18311246

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2337711A Pending JPH04204876A (en) 1990-09-11 1990-11-30 Reversal development controller

Country Status (1)

Country Link
JP (1) JPH04204876A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09311607A (en) * 1996-05-17 1997-12-02 Oki Data:Kk Electrophotographic printer
EP0709747A3 (en) * 1994-10-31 1998-04-29 Mita Industrial Co. Ltd. Electrophotographic method using photosensitive material
KR100389442B1 (en) * 2000-02-25 2003-06-27 후지제롯쿠스 가부시끼가이샤 Potential control apparatus in image forming device
US11435675B2 (en) * 2019-03-27 2022-09-06 Canon Kabushiki Kaisha Image forming apparatus with fog suppression feature

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0709747A3 (en) * 1994-10-31 1998-04-29 Mita Industrial Co. Ltd. Electrophotographic method using photosensitive material
JPH09311607A (en) * 1996-05-17 1997-12-02 Oki Data:Kk Electrophotographic printer
KR100389442B1 (en) * 2000-02-25 2003-06-27 후지제롯쿠스 가부시끼가이샤 Potential control apparatus in image forming device
US11435675B2 (en) * 2019-03-27 2022-09-06 Canon Kabushiki Kaisha Image forming apparatus with fog suppression feature

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