JPH0420185B2 - - Google Patents
Info
- Publication number
- JPH0420185B2 JPH0420185B2 JP16070681A JP16070681A JPH0420185B2 JP H0420185 B2 JPH0420185 B2 JP H0420185B2 JP 16070681 A JP16070681 A JP 16070681A JP 16070681 A JP16070681 A JP 16070681A JP H0420185 B2 JPH0420185 B2 JP H0420185B2
- Authority
- JP
- Japan
- Prior art keywords
- corona discharge
- transfer
- constant current
- corona
- image
- 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.)
- Expired
Links
- 108091008695 photoreceptors Proteins 0.000 description 15
- 230000003068 static effect Effects 0.000 description 11
- 230000008030 elimination Effects 0.000 description 6
- 238000003379 elimination reaction Methods 0.000 description 6
- 238000004140 cleaning Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
- G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
- G03G15/163—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap
- G03G15/1635—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using the force produced by an electrostatic transfer field formed between the second base and the electrographic recording member, e.g. transfer through an air gap the field being produced by laying down an electrostatic charge behind the base or the recording member, e.g. by a corona device
- G03G15/1645—Arrangements for controlling the amount of charge
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
Description
【発明の詳細な説明】
本発明はコロナ放電手段を備えた画像形成装
置、特に像担持体上に形成されたトナー像を転写
部材に転写するためにコロナ帯電器からのコロナ
放電を利用する画像形成装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming apparatus equipped with a corona discharge means, and particularly to an image forming apparatus that utilizes corona discharge from a corona charger to transfer a toner image formed on an image carrier to a transfer member. The present invention relates to a forming device.
上記のコロナ帯電器を定電圧電源で駆動する
と、温度・湿度・気圧等の外部環境の変化によ
り、コロナ放電量が変化し転写が非常に不安定で
あつた。また、定電流電源あるいは定電流回路を
用いてコロナ帯電器に一定電流を与えて駆動する
場合、コロナ放電量の総量は外部環境変動に対し
て補正されるが、実際に転写のために必要とされ
る転写部材上へのコロナ放電量は、コロナ帯電器
のシールド板へ流れ込むコロナ放電流の影響を受
け、外部環境変動並びにそれに伴う転写部材の抵
抗率変化により不安定となる。 When the above-mentioned corona charger was driven with a constant voltage power supply, the amount of corona discharge changed due to changes in the external environment such as temperature, humidity, and atmospheric pressure, making the transfer extremely unstable. In addition, when driving a corona charger by applying a constant current using a constant current power supply or constant current circuit, the total amount of corona discharge is corrected for external environmental fluctuations, but it is not necessary to actually transfer the corona charger. The amount of corona discharge onto the transfer member is affected by the corona discharge current flowing into the shield plate of the corona charger, and becomes unstable due to changes in the external environment and accompanying changes in the resistivity of the transfer member.
本発明は上記の点に鑑み提案されたもので、外
部環境変動に対して安定した画像を形成すること
ができる画像形成装置を提供することを目的とす
る。 The present invention has been proposed in view of the above points, and an object of the present invention is to provide an image forming apparatus that can form images that are stable against changes in the external environment.
即ち本発明は、像担持体と、この像担持体に対
向するコロナ放電手段とを有する画像形成装置に
おいて、上記コロナ放電手段のコロナ放電電極に
は定電流電源が接続されているとともに上記コロ
ナ放電電極を囲むシールド部材とアースとの間に
定電流回路を接続したことを特徴とするものであ
る。 That is, the present invention provides an image forming apparatus having an image carrier and a corona discharge means facing the image carrier, in which a constant current power source is connected to the corona discharge electrode of the corona discharge means, and the corona discharge This device is characterized in that a constant current circuit is connected between the shield member surrounding the electrode and the ground.
以下図面に示す実施例について説明する。第１
図は本発明画像形成装置の１実施例を適用した電
子写真複写機の概要を示す正面図であつて、像担
持体たるドラム状感光体１はその軸１ａによつて
不図示の機枠に矢示方向に回転自在に軸支されて
いる。このドラム状感光体１の周囲にはコロナ帯
電器２・光像露光光学系３・現像器４・転写用の
コロナ帯電器８・転写後ドラム状感光体１の表面
に残留するトナーを除去するためのクリーニング
ブレード１１等の公知の電子写真プロセスが配置
されている。本実施例は上記のコロナ帯電器８の
コロナ放電電極たるワイヤ８ａとアースＥとの間
には定電流電源７ａを、また、コロナ帯電器８の
シールド部材たるシールド板８ｂ及び放電尖端を
有する除電手段たる除電針９（転写時のコロナ放
電による帯電電荷を転写部材上から除去するため
のもの）とアースＥとの間は定電流回路７ｂを接
続したものである。 The embodiments shown in the drawings will be described below. 1st
The figure is a front view showing an outline of an electrophotographic copying machine to which an embodiment of the image forming apparatus of the present invention is applied, in which a drum-shaped photoreceptor 1 serving as an image carrier is attached to a machine frame (not shown) by its shaft 1a. It is supported rotatably in the direction of the arrow. Around this drum-shaped photoreceptor 1, there are a corona charger 2, a photoimage exposure optical system 3, a developing device 4, a corona charger 8 for transfer, and a toner remaining on the surface of the drum-shaped photoreceptor 1 after transfer is removed. A known electrophotographic process, such as a cleaning blade 11, is provided for the cleaning. In this embodiment, a constant current power source 7a is connected between the wire 8a which is the corona discharge electrode of the corona charger 8 and the earth E, and a shield plate 8b which is the shield member of the corona charger 8 and a static eliminator having a discharge tip are provided. A constant current circuit 7b is connected between the static eliminating needle 9 (for removing charged charges caused by corona discharge during transfer from the transfer member) and the earth E.
転写部材６はレジスタローラ５によつてドラム
状感光体１と転写用のコロナ帯電器８との間に移
送されると、コロナ帯電器８のコロナ放電を受け
てドラム状感光体１上の画像が転写される。転写
後、ドラム状感光体１から分離された転写部材６
は搬送ローラ１０によつて不図示の定着器に向つ
て移送される。上記の転写時、コロナ帯電器８か
らのコロナ放電流Iaはシールド板８ｂ、除電針
９、転写部材６およびそれを突き抜けてドラム状
感光体１へ流れる。このとき、シールド板８ｂ、
除電針９に流れるコロナ放電流Ib・Icが外部環境
変動およびワイヤ８ａの振動による除電針９とワ
イヤ８ａ間、シールド板８ｂとワイヤ８ａ間の距
離変動等により大きく変わることから、画像ム
ラ、低湿時の画像飛び散り、紙跡等の現象が生
じ、これ等の問題に対してラチチユードがきわめ
て狭くなる。 When the transfer member 6 is transferred between the drum-shaped photoreceptor 1 and the transfer corona charger 8 by the register roller 5, the image on the drum-shaped photoreceptor 1 is affected by corona discharge from the corona charger 8. is transcribed. Transfer member 6 separated from drum-shaped photoreceptor 1 after transfer
is transported by a transport roller 10 toward a fixing device (not shown). During the above-described transfer, the corona discharge current I a from the corona charger 8 flows through the shield plate 8 b, the static eliminating needle 9, the transfer member 6, and the drum-shaped photoreceptor 1. At this time, the shield plate 8b,
The corona discharge currents I b and I c flowing through the static elimination needle 9 vary greatly due to changes in the external environment and distance changes between the static elimination needle 9 and the wire 8a due to vibrations of the wire 8a, and between the shield plate 8b and the wire 8a, resulting in image unevenness. Phenomena such as image scattering and paper marks occur at low humidity, and the latitude becomes extremely narrow in response to these problems.
なお、上記の紙跡は次のような現象をいう。即
ち、転写用のコロナ帯電器から感光体へ流れる電
流はこれ等両者間を転写部材が通じるときと通ら
ないときでは異なる。このため、感光体表面に帯
電電位差が生じ、この電位差を前除電で消去しき
れないと次のコピー時に悪影響をおよぼす。特
に、ハーフトーン時は電位差に基ずく濃度差が顕
著に目立つことになる。 The paper marks mentioned above refer to the following phenomenon. That is, the current flowing from the transfer corona charger to the photoreceptor differs when the transfer member passes between them and when it does not. For this reason, a charging potential difference is generated on the surface of the photoreceptor, and if this potential difference cannot be completely erased by pre-discharge, it will have an adverse effect on the next copying process. In particular, during halftone, the density difference based on the potential difference becomes conspicuous.
しかるに、本実施例装置はコロナ帯電器８のワ
イヤ８ａに定電流電源７ａから常に一定の電流Ia
を供給するので、外部環境変動による影響が抑え
られる。また、ワイヤ８ａからシールド板８ｂへ
流れるコロナ放電流Ibおよびワイヤ８ａから除電
針９へ流れるコロナ放電流Icは定電流回路７ｂに
よつて常にその和が一定に保たれる。この結果、
転写部材６並びにドラム感光体へ流れるコロナ放
電流の強さ及び向きを一定に保つことができ、転
写時に生ずる画像ムラ、画像飛び散り、紙跡等に
対してラチチユードの広い転写が行なえる。 However, in the device of this embodiment, a constant current I a is always applied to the wire 8 a of the corona charger 8 from the constant current power source 7 a .
supply, the effects of external environmental fluctuations can be suppressed. Further, the sum of the corona discharge current I b flowing from the wire 8a to the shield plate 8b and the corona discharge current I c flowing from the wire 8a to the static eliminating needle 9 is always kept constant by the constant current circuit 7b. As a result,
The strength and direction of the corona discharge current flowing to the transfer member 6 and the drum photoreceptor can be kept constant, and transfer with a wide latitude can be performed against image unevenness, image scattering, paper marks, etc. that occur during transfer.
第２図は他の実施例を示すもので、転写用のコ
ロナ帯電器８のワイヤ８ａとアースＥとの間に定
電流電源７ａ、シールド板８ｂおよび除電針９と
アースＥとの間に定電流回路７ｂ，７ｃを夫々接
続した構成である。 FIG. 2 shows another embodiment, in which a constant current power source 7a is connected between the wire 8a of the corona charger 8 for transfer and the earth E, a constant current power source 7a is connected between the shield plate 8b, and the static elimination needle 9 and the earth E. This configuration has current circuits 7b and 7c connected to each other.
第３図、第４図は上記定電流電源７ａおよび定
電流回路７ｂ，７ｃの具体的回路例を示すもので
ある。第３図例回路はワイヤ８ａの定電流電源７
ａとシールド板８ｂおよび除電針９に対する定電
流回路７ｂを共に発振回路を利用したもので、
T1、T2はトランス、OA1、OA2はいずれもオペ
アンプである。第４図例回路はワイヤ８ａの定電
流電源として発振回路を利用したもので、T3は
トランス、OA3はオペアンプである。一方、シー
ルド板８ｂおよび除電針９に対しては、トランジ
スタTr1、Tr2にて放電流量を定常化したもので
ある。上記の構成により、ワイヤ８ａから感光体
１へのコロナ放電流、除電針９へのコロナ放電
流、シールド板８ｂへのコロナ放電流の関係が一
定し、その流れる方向および強さも一定となり、
より安定に画像転写が行なわれる。 FIGS. 3 and 4 show specific circuit examples of the constant current power supply 7a and constant current circuits 7b and 7c. The example circuit in Figure 3 is a constant current power supply 7 of wire 8a.
a, the shield plate 8b, and the constant current circuit 7b for the static elimination needle 9, both of which utilize oscillation circuits,
T 1 and T 2 are transformers, and OA 1 and OA 2 are operational amplifiers. The example circuit in FIG. 4 uses an oscillation circuit as a constant current power source for the wire 8a, T3 is a transformer, and OA 3 is an operational amplifier. On the other hand, for the shield plate 8b and the static eliminating needle 9, the amount of discharge is made constant by transistors Tr 1 and Tr 2 . With the above configuration, the relationship among the corona discharge current from the wire 8a to the photoreceptor 1, the corona discharge current to the static elimination needle 9, and the corona discharge current to the shield plate 8b is constant, and the direction and strength of the flow are also constant.
Image transfer is performed more stably.
以上説明したように、本発明のコロナ放電手段
によれば、外部環境の変動に対して常に安定した
コロナ放電を行なうことができ、特に本発明のコ
ロナ放電手段を転写用コロナ放電手段として使用
した場合には、転写時、コロナ放電手段からの転
写部材上へのコロナ放電量を一定に保ち、外部環
境変動に対して安定した転写画像を得ることがで
きる効果がある。 As explained above, according to the corona discharge means of the present invention, stable corona discharge can always be performed against changes in the external environment, and in particular, the corona discharge means of the present invention can be used as a corona discharge means for transfer. In this case, during transfer, the amount of corona discharge from the corona discharge means onto the transfer member is kept constant, and a transferred image that is stable against changes in the external environment can be obtained.
なお、図示例はドラム状感光体を例示して説明
したが、平板感光体、無端状感光体についても同
様に適用できる。 Note that although the illustrated example has been described using a drum-shaped photoreceptor, the present invention can be similarly applied to a flat photoreceptor and an endless photoreceptor.
第１図は本発明画像形成装置の１実施例を適用
した電子写真複写機の概要を示す正面図、第２図
は本発明画像形成装置の他の実施例を示す正面
図、第３図、第４図は本発明画像形成装置の回路
図である。
１はドラム状感光体、２はコロナ帯電器、３は
光像露光光学系、４は現像器、５はレジスタロー
ラ、６は転写部材、７ａ，７ｂ，７ｃは定電流回
路、８は転写用のコロナ帯電器、９は除電針、１
０は搬送ローラ。
1 is a front view showing an outline of an electrophotographic copying machine to which one embodiment of the image forming apparatus of the present invention is applied; FIG. 2 is a front view showing another embodiment of the image forming apparatus of the present invention; FIG. FIG. 4 is a circuit diagram of the image forming apparatus of the present invention. 1 is a drum-shaped photoreceptor, 2 is a corona charger, 3 is a photoimage exposure optical system, 4 is a developer, 5 is a register roller, 6 is a transfer member, 7a, 7b, 7c are constant current circuits, 8 is for transfer corona charger, 9 is static elimination needle, 1
0 is a conveyance roller.
Claims (1)
放電手段とを有する画像形成装置において、上記
コロナ放電手段のコロナ放電電極には定電流電源
が接続されているとともに上記コロナ放電電極を
囲むシールド部材とアースとの間に定電流回路を
接続したことを特徴とする画像形成装置。 ２ 上記コロナ放電手段は像担持体に形成される
像を転写材に転写する転写用コロナ放電手段であ
る特許請求の範囲第１項に記載の画像形成装置。[Scope of Claims] 1. An image forming apparatus having an image carrier and a corona discharge means facing the image carrier, wherein a constant current power source is connected to a corona discharge electrode of the corona discharge means, and the corona discharge means is connected to a constant current power source. An image forming apparatus characterized in that a constant current circuit is connected between a shield member surrounding a corona discharge electrode and ground. 2. The image forming apparatus according to claim 1, wherein the corona discharge means is a transfer corona discharge means for transferring the image formed on the image carrier to a transfer material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16070681A JPS5862673A (en) | 1981-10-08 | 1981-10-08 | Transfer device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16070681A JPS5862673A (en) | 1981-10-08 | 1981-10-08 | Transfer device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5862673A JPS5862673A (en) | 1983-04-14 |
| JPH0420185B2 true JPH0420185B2 (en) | 1992-03-31 |
Family
ID=15720699
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16070681A Granted JPS5862673A (en) | 1981-10-08 | 1981-10-08 | Transfer device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5862673A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6126068A (en) * | 1984-07-16 | 1986-02-05 | Fuji Xerox Co Ltd | Transfer form peeling device of copying machine |
| EP0473161B1 (en) * | 1990-08-31 | 1995-08-09 | Sharp Kabushiki Kaisha | A recording paper separating device |
-
1981
- 1981-10-08 JP JP16070681A patent/JPS5862673A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5862673A (en) | 1983-04-14 |
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