JPS5848073A - Flat type electric discharger for electrophotographic copier - Google Patents

Abstract

PURPOSE:To charge only the image areas of a photoreceptor electrostatically with a single electric charger by dividing excitation electrodes according to paper sizes and applying a driving power source selctively thereto. CONSTITUTION:Electric discharging electrodes 3 of a rectangular strip shape are provided via an insulator 2 of glass or the like on exciting electrodes 11, 12. which are divided to a plurality according to paper sizes and of which the divided parts are made like belts so as to prevent generation of irregular charging, whereby a flat type electric discharger is formed. According to the sizes of copying originals, a driving power source 4 is applied selectively upon the electrodes 11, 12.. Thus a photoreceptor is charged locally to a single polarity by the single discharger and the charging to unnecessary non-image parts is surely prevented by the simple constitution requiring no erasers, etc.

Description

【発明の詳細な説明】 この発明は励起電極を用紙サイズに合せて分割し、かつ
これら励起電極を選択的に使用することによシ感光体の
非画像部の帯電を防止する電子複写機の平型放電装置に
関する。DETAILED DESCRIPTION OF THE INVENTION The present invention provides an electronic copying machine which divides excitation electrodes according to paper size and selectively uses these excitation electrodes to prevent charging of non-image areas of a photoreceptor. This invention relates to a flat discharge device.

そしてこの発明の目的とするところは、単一の放電装置
により感光体の非画像領域、すなわち、複写すべき原稿
の露光により形成される潜像領域外やインタイメージな
どを帯電せずに感光体の帯電が可能な電子複写機の放電
装置を提供しようとするものである。An object of the present invention is to use a single discharge device to charge the non-image area of the photoreceptor, that is, the outside of the latent image area formed by exposure of the original to be copied, the inter-image, etc., without charging the photoreceptor. An object of the present invention is to provide a discharging device for an electronic copying machine that is capable of charging.

以下この発明を詳述すると、第１図は平型放電装置の原
理図で、平板状の励起用電極１上・にガラス等の絶縁物
２を介して短冊状の放電電極３が設けられており、これ
ら放電電極３と励起用電極１０間に交流駆動用電源４が
印加されて、各放電電極３の間に沿面放電によるプラズ
マ状のイオンが発生される。また上記放電電極３に対向
する位置には感光体５が設けられていて、この感光体５
と上記放電電極３の間にイオン引出し用電源６が印加さ
れ、これによシイオンが感光体５側へ吸引されて感光体
５の表面が単一極性に帯電される。以上が平型放電装置
の原理であるが、上記放電装置では感光体５の全面を単
一極性に帯電することは可能であるが、一部を選択的に
帯電することは困難である。そこでとの発明では次の方
法で感光体５の必要な部分のみを帯電可能としたもので
ある。To explain this invention in detail below, FIG. 1 is a diagram showing the principle of a flat discharge device, in which a strip-shaped discharge electrode 3 is provided on a flat excitation electrode 1 with an insulating material 2 such as glass interposed therebetween. An AC driving power source 4 is applied between these discharge electrodes 3 and excitation electrodes 10, and plasma-like ions are generated between each discharge electrode 3 by creeping discharge. Further, a photoreceptor 5 is provided at a position facing the discharge electrode 3, and this photoreceptor 5
An ion extraction power source 6 is applied between the discharge electrode 3 and the discharge electrode 3, whereby ions are attracted toward the photoreceptor 5, and the surface of the photoreceptor 5 is charged to a single polarity. The above is the principle of the flat discharge device. Although it is possible to charge the entire surface of the photoreceptor 5 to a single polarity in the above-mentioned discharge device, it is difficult to charge a portion selectively. Therefore, in the second invention, only the necessary portions of the photoreceptor 5 can be charged by the following method.

以下にこの発明の一実施例を第２図以下に示す図面を参
照して詳述すると、第２図において１１．＋２・・・・
・・は用紙サイズに応じて複数分割された励起用電極で
、各励起用電極１＋、１２・・・・・・毎に選択的に駆
動用電源４が印加できるようになっており、各励起用電
極１１．＋２・・・・・・の各分割部は帯電むらが生じ
ないよう第３図に示すように階段状に形成されている。An embodiment of the present invention will be described below in detail with reference to the drawings shown in FIG. 2 and below. +2...
. . . are excitation electrodes divided into multiple parts according to the paper size, and the driving power source 4 can be selectively applied to each excitation electrode 1+, 12, . . . Electrode 11. The divided portions +2, . . . are formed in a step-like manner as shown in FIG. 3 to prevent uneven charging.

また」二記分割された励起用電源１１．＋２・・・・・
・上にガラス等の絶縁物２を介して短冊状の放電電極３
が設けられておシ、これら放電電極３と上記励起用電＠
ｔ、Ｉ＋。In addition, two divided excitation power sources 11. +2...
・A strip-shaped discharge electrode 3 is placed on top through an insulating material 2 such as glass.
are provided, and these discharge electrodes 3 and the above-mentioned excitation electrode @
t, I+.

１２　・・・・・・間に駆動用電源４が印加されるよう
になっている。12... The driving power source 4 is applied between them.

上記構成された放電装置を使用するに当っては、複写す
べき原稿サイズに応じて励起用電極１１、”＋２・・・
・・・を選択して駆動用電源４を印加することによシ、
駆動用電源４の印加された励起用電極１１．１２・・・
・・パのみがプラズマを発生し、イオン引き出し電源６
の印加された感光体５側へイオン流として引き出される
ため、感光体５の表面を局部的に単一極性に帯電できる
と共に、帯電の不用な非画像部の帯電を防止することが
できるようになる。When using the discharge device configured as described above, depending on the size of the original to be copied, the excitation electrodes 11, ``+2...''
By selecting ... and applying the driving power source 4,
Excitation electrodes 11, 12, to which the driving power source 4 is applied
・Only PA generates plasma, and ion extraction power supply 6
Since the ions are drawn out as an ion flow toward the photoreceptor 5 side to which the ion is applied, the surface of the photoreceptor 5 can be locally charged to a single polarity, and it is possible to prevent non-image areas from being charged where charging is unnecessary. Become.

一方第４図は放電電極３とアース間に直流電源７を重畳
した交流駆動用電源４を印加し、また励起用電極ｌ＋、
１２・・・・・・に電圧の異なる直流′電源８を選択的
に印加するようにした別の実施例を示すもので、直流電
源７の′重圧ＶＥを変えることにより、駆動用電源４と
の位相をずらすようにしたものである。すなわち、放電
電極３に印加される′直圧と、感光体５との作る電界に
よりイオンが感光体５側へ引き出されるが、励起用電極
Ｉｔ、１２・・・・・・に印加される電圧ｖｕが小さい
ときにに駆動用電源４の正のとき（第５図Ｔ＋）に■の
イオンが感光体５　■Ｉへ引き出されるが、電圧Ｖｍが
Ｖｉ’に高くなると、駆動用電源４のＴ２のときにイオ
ンが発生されるが、このとき感光体５との間に電界が生
じていかいため感光体５は帯電されず、電圧ＶＦＩを変
化させることにより帯電状態を制御することが可能とな
る。On the other hand, in FIG. 4, an AC drive power source 4 with a DC power source 7 superimposed is applied between the discharge electrode 3 and the ground, and the excitation electrode l+,
This shows another embodiment in which DC' power supplies 8 with different voltages are selectively applied to 12..., and by changing the heavy pressure VE of the DC power supply 7, the drive power supply 4 and This is to shift the phase of the . That is, ions are drawn out to the photoreceptor 5 side by the direct pressure applied to the discharge electrode 3 and the electric field created by the photoreceptor 5, but the voltage applied to the excitation electrodes It, 12... When vu is small and the driving power source 4 is positive (T+ in FIG. 5), the ions of ■ are drawn out to the photoreceptor 5 ■I, but when the voltage Vm increases to Vi', T2 of the driving power source 4 Ions are generated at this time, but since an electric field is generated between the photoreceptor 5 and the photoreceptor 5, the photoreceptor 5 is not charged, and the charging state can be controlled by changing the voltage VFI. .

またこの発明の放電装置は予備電器や帯電器、除電器な
どに利用でき、予備電器に使用した場合選択転写が可能
であシ、さらに除電器に用いた場合、画像領域と非画像
領域のトナーチャージ処理を、１本の電極で最適電流値
にすることができる。Further, the discharge device of the present invention can be used as a standby charger, a charger, a static eliminator, etc. When used as a standby charger, selective transfer is possible, and when used as a static eliminator, toner in image areas and non-image areas can be transferred. The charging process can be performed at the optimum current value using one electrode.

この発明は以上詳述したように、励起用電極を用紙サイ
ズに合せて分割し、かつこれら励起用電極に選択的に駆
動用電源を印加することにより、感光体の画像領域のみ
を単一の放電装置で帯電することができるようになり、
従来のような非画像部の帯電を消去する手段を必要とし
ないので経済的である。As described in detail above, this invention divides the excitation electrodes according to the paper size and selectively applies driving power to these excitation electrodes, thereby dividing only the image area of the photoreceptor into a single image area. It is now possible to charge with a discharge device,
It is economical because it does not require a means for erasing the charge in the non-image area as in the conventional method.

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

第１図は平型放電装置の原理図、第２図はこの発明の一
実施例になる平型放電装置の斜視図、第３図は分割部の
拡大図、第４図は他の実施例を示す説明図、第５図は同
作用説明図である。 １は励起用電源、２は絶縁物、３は放電電極、４は交流
駆動用電源。Fig. 1 is a principle diagram of a flat discharge device, Fig. 2 is a perspective view of a flat discharge device which is an embodiment of the present invention, Fig. 3 is an enlarged view of a divided part, and Fig. 4 is another embodiment. FIG. 5 is an explanatory diagram showing the same action. 1 is an excitation power source, 2 is an insulator, 3 is a discharge electrode, and 4 is an AC drive power source.

Claims (1)

【特許請求の範囲】[Claims] 励起用電源１に絶縁物２を介して短冊状の放電電極３を
設け、これら放電電極３と上記励起電極１０間に交流駆
動用電源４を印加したものにおいて、上記励起用電源１
を用紙サイズに合せて複数分割すると共に、各励起用電
極り、Ｉｚ・・−・・・・・毎に駆動用電源４が印加で
きるようにしてなる電子複写機の平型放電装置。In the excitation power source 1, a strip-shaped discharge electrode 3 is provided via an insulator 2, and an AC drive power source 4 is applied between these discharge electrodes 3 and the excitation electrode 10.
A flat discharge device for an electronic copying machine, which is divided into a plurality of parts according to paper size, and a driving power source 4 can be applied to each excitation electrode, Iz, . . . .