JPH02156279A - Transfer device for image forming device - Google Patents

Transfer device for image forming device

Info

Publication number
JPH02156279A
JPH02156279A JP63308787A JP30878788A JPH02156279A JP H02156279 A JPH02156279 A JP H02156279A JP 63308787 A JP63308787 A JP 63308787A JP 30878788 A JP30878788 A JP 30878788A JP H02156279 A JPH02156279 A JP H02156279A
Authority
JP
Japan
Prior art keywords
transfer
drum
charger
plane
shielding plate
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
JP63308787A
Other languages
Japanese (ja)
Inventor
Makoto Hasegawa
真 長谷川
▲ゆ▼ 英雄
Hideo Yuu
Yasunori Kawaishi
河石 康則
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.)
Ricoh Co Ltd
Original Assignee
Ricoh 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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP63308787A priority Critical patent/JPH02156279A/en
Publication of JPH02156279A publication Critical patent/JPH02156279A/en
Pending legal-status Critical Current

Links

Landscapes

  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
  • Color Electrophotography (AREA)

Abstract

PURPOSE:To prevent the fault of an image by making a space between a 1st plane passing both center axis lines of a photosensitive drum and a transfer drum and the contact line of both drums and the charge wire of a charger for transfer and a space between a 2nd plane which is in parallel with the 1st plane and includes the charger wire and the end part of a shielding plate nearest to the 2nd plane specified ones. CONSTITUTION:It is assumed that the space (a) between the 1st plane passing both center axis lines 10a and 1a of the photosensitive drum 10 and the transfer drum 1 and the contact line of both drums 10 and 1 and the charger wire of the charger 2 for transfer is <=2.0mm and the space (b) between the 2nd plane which is in parallel with the 1st plane and includes the charger wire and the end part of the shielding plate 5 which is the nearest to the 2nd plate is >=0mm and <=3.0mm. Thus, the stable transfer processing is secured in spite of the change of environment and the fault of the image such as the missing of the image caused by the over or shot discharge of the transfer charger is prevented from occurring.

Description

【発明の詳細な説明】 産業上の 本発明は、トナー像を担持する感光体ドラムと転写ドラ
ムとを対向配置し、転写ドラム内にその回転方向に見て
両ドラムの接触線の上流にチャージワイヤが位置するよ
うに転写チャージャを配置し、更に上記転写チャージャ
に転写ドラムの回転方向に見て上流側に転写入口遮蔽板
を設け、該転写チャージャにより感光体ドラム上のトナ
ー像を転写ドラム上のシートに転写するようにした画像
形成装置の転写装置に関する。
DETAILED DESCRIPTION OF THE INVENTION According to the present invention, a photoreceptor drum carrying a toner image and a transfer drum are disposed facing each other, and a charge is placed in the transfer drum upstream of a contact line between the two drums when viewed in the direction of rotation of the transfer drum. A transfer charger is arranged so that the wire is located, and a transfer entrance shielding plate is provided on the upstream side of the transfer charger when viewed in the rotational direction of the transfer drum, and the transfer charger transfers the toner image on the photoreceptor drum onto the transfer drum. The present invention relates to a transfer device for an image forming apparatus that transfers images onto a sheet.

灸末立技先 画像形成装置の上述せる形式の転写装置では、転写チャ
ージワイヤが転写ドラムと感光体ドラムとの接触線に位
置し、かつ転写入口遮蔽板を設置しないことが、基本的
には最も転写効率を上げる方法である。しかし、実際に
は転写チャージ電界はワイヤから放射状にか1っており
、上記のような配置では様々な副作用が生ずる。このた
め、チャージワイヤは両ドラムの接触線に近接して転写
ドラム内部に配置される。しかしながら、単に転写用チ
ャージを転写ドラム内部に配置するものでは、チャージ
ャの放電状態が周囲環境に影響され易くかつ安定性にか
け、その結果画像不良を発生している。これに対し、転
写チャージャのチャージワイヤを感光体ドラムと転写ド
ラムのそれぞれの中心軸線を結び両ドラムの接触線を通
る面よりも感光体ドラムの回転方向に見て上流側にてチ
ャージャに配置し、それによって転写条件の余裕度を増
すことは当業者に知られている。しかし、周囲の環境温
度が低温から高温まで変更する場合、上記の対策では不
充分である。
In the transfer device of the above-mentioned type, the transfer charge wire is located at the contact line between the transfer drum and the photoreceptor drum, and the transfer entrance shielding plate is not installed. This is the method that maximizes transfer efficiency. However, in reality, the transfer charge electric field radiates from the wire, and the above arrangement causes various side effects. For this purpose, the charge wire is placed inside the transfer drum close to the line of contact between both drums. However, if the transfer charge is simply placed inside the transfer drum, the discharge state of the charger is easily affected by the surrounding environment and the stability is affected, resulting in image defects. On the other hand, the charge wire of the transfer charger is placed in the charger on the upstream side of the plane that connects the center axes of the photoreceptor drum and the transfer drum and passes through the contact line of both drums when viewed in the rotational direction of the photoreceptor drum. , thereby increasing latitude in transfer conditions is known to those skilled in the art. However, when the surrounding environment temperature changes from low to high temperature, the above measures are insufficient.

明が解決しようとする課題 本発明は、産業上の利用分野に記した形式の転写装置に
おいて1周囲環境の変動に対し転写条件の余裕度を大き
くすることを課題とする。
SUMMARY OF THE INVENTION An object of the present invention is to increase the latitude of transfer conditions against changes in the surrounding environment in a transfer apparatus of the type described in the field of industrial application.

課題を解決するための手 上記の課題は1本発明により、感光体ドラムと転写ドラ
ムの両中心軸線および両ドラムの接触線を通る第1の面
と、転写用チャージャのチャージワイヤとの間の間隔を
2.0mm以下とし、上記第1の面に平行でかつチャー
ジワイヤを含む第2の面とこれに最も近い遮蔽板端部と
の間の間隔を0m以上にして3.0mm以下とすること
により解決される。
Means for Solving the Problems According to the present invention, the above-mentioned problem can be solved by one aspect of the present invention. The distance is 2.0 mm or less, and the distance between the second surface parallel to the first surface and containing the charge wire and the end of the shielding plate closest to this is 0 m or more and 3.0 mm or less. This is solved by

ヌ〕1汁 第1図には、本発明を適用した転写ドラム1および感光
体ドラム10を設けた電子写真複写機を示す。この電子
複写機pは、黒色複写およびカラー複写の2通りの複写
を行うことが出来る。同電子写真複写機のその他の構成
および上記の各複写動作を、以下に説明する。
[1] Figure 1 shows an electrophotographic copying machine equipped with a transfer drum 1 and a photosensitive drum 10 to which the present invention is applied. This electronic copying machine p can perform two types of copying: black copying and color copying. Other configurations of the electrophotographic copying machine and each copying operation described above will be explained below.

瓜へ農工 帯電チャージャ16の放電により感光体ドラム10の表
面が一様に帯電する。露光装置17の画像露光により感
光体ドラム表面に静電潜像が形成され、その潜像が黒現
像器11内の黒色トナーで現像されて黒色トナー像とさ
れる。この黒色トナー像は、その後転写チャージャ2の
所まで運ばれ、該転写チャージャ2の放電、例えば(−
)極性の放電の下に、転写ベルト1の外表面に巻き付け
られた転写紙上に転写される。転写が終了すると。
The surface of the photosensitive drum 10 is uniformly charged by the discharge of the agricultural/industrial charger 16 to the melon. An electrostatic latent image is formed on the surface of the photoreceptor drum by the image exposure of the exposure device 17, and the latent image is developed with black toner in the black developing device 11 to form a black toner image. This black toner image is then carried to the transfer charger 2, and the discharge of the transfer charger 2, for example (-
) is transferred onto a transfer paper wrapped around the outer surface of the transfer belt 1 under a polar discharge. Once the transcription is finished.

転写紙は分離ユニット7によって転写ドラム1から分離
され、搬送装置8により送られ、更に定着器9による定
着処理を受けた後に機外へ排出される。転写後に感光体
ドラム10上に残留するトナーは、磁性ブラシクリーニ
ング装置15によって口取される。
The transfer paper is separated from the transfer drum 1 by a separation unit 7, sent by a conveyance device 8, and further subjected to a fixing process by a fixing device 9, and then discharged to the outside of the machine. Toner remaining on the photoreceptor drum 10 after the transfer is removed by a magnetic brush cleaning device 15.

転写紙が分離された後の転写ドラム1は、転写チャージ
ャ2の放電極性と逆極性、すなわち(+)極性で放電す
る内側DCチャージャ4b及びそれと逆極性、すなわち
(−)極性で放電する外側DCチャージャ4aの両チャ
ージャによって除電され、更にAC除電チャージャ3a
、3bにより交流除電される。転写ドラム1は(−)極
性放電を行なう転写チャージャ2によって、その内側が
(−)極性にIF電し、一方その外側が(+)極性に帯
電する。本実施例では、転写ドラム1の内側を(十)極
性放電の内側DCチャージャ4bで除電し、その外側を
(−)極性放電の外側DCチャージャ4aで除電するよ
うにしているので、転写チャージャ2によった帯電した
転写ドラム1はDCチャージャ4a、4bによって確実
に除電される。DCチャージャによる転写ドラム1の除
電後の電位が(+)極性あるいは(−)極性にシフトす
ることもあるが、AC除電チャージャ3a、3bによっ
てこのシフトが補償されて転写ドラム1がゼロ電位に調
整される9 カラー複写 黒現像器11による現像が行なわれないで、感光体ドラ
ム10が3回転する間にシアン現像器12、マゼンタ現
像器13、そしてイエロー現像器14による各色現像が
順次に行なわれる。現像が1回行なわれるごとに、磁気
ブラシクリーニング装置15により感光体ドラム10の
表面がクリーニングされる。転写紙が巻き付けられてい
る転写ドラム1は、感光体ドラム10の回転に同期して
3回転する。転写ドラム1が1回転するごとに、シアン
トナー像、マゼンタトナー像、そしてイエロートナー像
が順次1枚の転写紙上に重ねて転写される。3回の転写
が終わると1分離ユニット7等による転写紙の分離及び
定着器9による定着が行なわれる。
After the transfer paper is separated, the transfer drum 1 has an inner DC charger 4b that discharges with a polarity opposite to that of the transfer charger 2, that is, (+) polarity, and an outer DC charger 4b that discharges with the opposite polarity, that is, (-) polarity. Static electricity is removed by both chargers of the charger 4a, and then the AC static electricity removal charger 3a
, 3b, the AC static electricity is removed. The inside of the transfer drum 1 is IF-charged to a (-) polarity, while the outside thereof is charged to a (+) polarity by a transfer charger 2 that performs a (-) polarity discharge. In this embodiment, the inside of the transfer drum 1 is charged with an inner DC charger 4b with a (10) polarity discharge, and the outside with a (-) polarity discharge with an outer DC charger 4a. The charged transfer drum 1 is reliably neutralized by the DC chargers 4a and 4b. The potential of the transfer drum 1 after static elimination by the DC charger may shift to (+) polarity or (-) polarity, but this shift is compensated for by the AC static elimination chargers 3a and 3b, and the transfer drum 1 is adjusted to zero potential. 9 Color Copying Development by the black developer 11 is not performed, and each color is developed in sequence by the cyan developer 12, magenta developer 13, and yellow developer 14 while the photosensitive drum 10 rotates three times. . Each time development is performed, the surface of the photosensitive drum 10 is cleaned by the magnetic brush cleaning device 15. The transfer drum 1 around which the transfer paper is wound rotates three times in synchronization with the rotation of the photosensitive drum 10. Each time the transfer drum 1 rotates once, a cyan toner image, a magenta toner image, and a yellow toner image are sequentially transferred onto a sheet of transfer paper in an overlapping manner. After the three transfers are completed, the transfer paper is separated by the 1-separation unit 7 or the like and fixed by the fixing device 9.

転写紙が分離された後の転写ドラム1に対して、黒色複
写の場合と同様に、DCチャージャ4a。
After the transfer paper has been separated, a DC charger 4a is applied to the transfer drum 1 as in the case of black copying.

4b、AC除電チャージャ3a、3bによる除電及び帯
電が行なわれる。
4b, static elimination and charging are performed by AC static elimination chargers 3a and 3b.

第2図において、転写ドラム1の中心軸線1aと感光体
ドラム10の中心軸線LOaとを結ぶ第1の面は、両ド
ラムの接触線を通過する。転写チャージャ2のチャージ
ワイヤ2aは、転写ドラム内部にその回転方向に見て上
記第1の面の上流に位置するように配置され、このチャ
ージワイヤ2aと上記せる第1の面とは、間隔aを隔て
て位置している。更に、転写チャージャ2には、転写ド
ラムの回転方向に見て上流側に転写入口遮蔽板5が取付
けてあり、チャージワイヤ2aを通り第1の面に平行な
第2の面とこれに最も近い転写入口遮蔽板の端部5aと
は1間隔すを有している。この場合、上記端部5aは、
第1の面に関しチャージワイヤ2aと同じ側にありかつ
第1の面からチャージワイヤ2aよりも離れている。
In FIG. 2, a first surface connecting the central axis 1a of the transfer drum 1 and the central axis LOa of the photoreceptor drum 10 passes through a contact line between both drums. The charge wire 2a of the transfer charger 2 is disposed inside the transfer drum so as to be located upstream of the first surface when viewed in the rotation direction of the transfer drum, and the charge wire 2a and the first surface are spaced apart by a distance a. It is located across from. Furthermore, a transfer inlet shielding plate 5 is attached to the transfer charger 2 on the upstream side when viewed in the rotational direction of the transfer drum, and the transfer inlet shielding plate 5 passes through the charge wire 2a and connects the second surface parallel to the first surface and the closest surface thereto. It has one interval from the end 5a of the transfer entrance shielding plate. In this case, the end portion 5a is
It is on the same side as the charge wire 2a with respect to the first surface and is further away from the first surface than the charge wire 2a.

本発明により、上記間隔aの値は2.0m以下に、そし
て上記間隔すの値は01以上3.On+以下に選択され
る。
According to the present invention, the value of the distance a is 2.0 m or less, and the value of the distance a is 01 or more and 3.0 m or less. Selected below On+.

上記の値aおよびbをいろいろの値となして実験し、感
光体ドラムに与える転写チャージャの放電過多あるいは
放電不足等による転写後側像のいわゆる部分的なトナー
ρ「抜け」を評価した結果を、第3図の表に示す。但し
、表中の記号は1周囲温度を低温度から高温度まで変化
させた時の総合評価であり、Oを良、Δを可、モして×
を不可とする。
We experimented with various values of a and b above, and evaluated the so-called partial toner ρ "missing" of the image after transfer due to excessive or insufficient discharge of the transfer charger applied to the photoreceptor drum. , shown in the table of FIG. However, the symbols in the table are the overall evaluation when the ambient temperature is changed from low to high.
is not allowed.

a>2.0anのとき: 転写領域(転写ドラムと感光体ドラムとの間の接触面)
へのチャージ電界が弱くなり、転写不良が発生する。
When a>2.0an: Transfer area (contact surface between transfer drum and photosensitive drum)
The charging electric field becomes weaker and transfer defects occur.

b < Omのとき: 転写チャージャから感光体ドラムへの電界が大幅に遮断
され、転写不良が発生する。
When b < Om: The electric field from the transfer charger to the photoreceptor drum is significantly interrupted, causing a transfer failure.

b>3.0mmのとき: 転写入口遮蔽板を設けない場合、転写チャージャから感
光体ドラムへ向って放射状にかさっている電界により、
感光体ドラム上に現像されたトナー粒子が転写領域より
上流にて転写紙に引き寄せられ、散乱して転写されてし
まう。この問題の解決のために転写入口遮蔽板を設け、
転写領域より上流にか)る転写電界を遮断しているので
あるが、b > 30 mmとすると、転写入口遮蔽板
を設けた効果がなくなってしまう。
When b > 3.0 mm: If no transfer entrance shielding plate is provided, the electric field radiating from the transfer charger toward the photoconductor drum causes
Toner particles developed on the photoreceptor drum are attracted to the transfer paper upstream from the transfer area, and are scattered and transferred. To solve this problem, we installed a transfer entrance shielding plate.
However, if b > 30 mm, the effect of providing the transfer entrance shielding plate is lost.

結局、本発明に従って両間隔aとbの値を決めることに
より、良好な転写が行われる。
After all, good transfer can be achieved by determining the values of both distances a and b according to the present invention.

効果 本発明により、周囲の環境変化にか\わらず安定した転
写プロセスの行われることが保証され、転写チャージの
放′11過多あるいは放電不足による画像抜は等の画像
不良発生が防止される。
Effects According to the present invention, a stable transfer process is guaranteed regardless of changes in the surrounding environment, and occurrence of image defects such as image deletion due to excessive discharge or insufficient discharge of transfer charge is prevented.

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

第1図は本発明を適用した電子写真複写機の図式図、第
2図は本発明の主要部を示す説明図、第3図は本発明の
評価を示す表である。 1・・・転写ドラム 1a・・・転写ドラム中心軸線 2・・・転写チャージャ 5・・・転写入口遮蔽板 10・・・感光体ドラム 10a・・感光体ドラム中心軸線 a・・・転写チャージワイヤと両トラムの中心軸線を結
び両ドラムの接触線を通る第1の面との間隔 b・・チャージワイヤを含み上記の第1の面に平行な第
2の面とこれに最も近い転写入口遮蔽板端部との間隔 第 図 ]4 第 図 第 閃
FIG. 1 is a schematic diagram of an electrophotographic copying machine to which the present invention is applied, FIG. 2 is an explanatory diagram showing the main parts of the present invention, and FIG. 3 is a table showing evaluation of the present invention. 1...Transfer drum 1a...Transfer drum center axis line 2...Transfer charger 5...Transfer entrance shielding plate 10...Photoconductor drum 10a...Photoconductor drum center axis a...Transfer charge wire and a first surface that connects the central axes of both trams and passes through the contact line of both drums. Distance b... A second surface that includes the charge wire and is parallel to the first surface and the transfer inlet shield closest to this. Diagram of distance from plate edge] 4 Diagram No. 4

Claims (1)

【特許請求の範囲】[Claims]  トナー像を担持する感光体ドラムと転写ドラムとを対
向配置し、転写ドラム内にその回転方向に見て両ドラム
の接触線の上流にチャージワイヤが位置するように転写
チャージャを配置し、更に上記転写チャージャに転写ド
ラムの回転方向に見て上流側に転写入口遮蔽板を設け、
該転写チャージャにより感光体ドラム上のトナー像を転
写ドラム上のシートに転写するようにした画像形成装置
の転写装置において、感光体ドラムと転写ドラムの両中
心軸線および両ドラムの接触線を通る第1の面と、転写
用チャージャのチャージワイヤとの間の間隔を2.0m
m以下とし、上記第1の面に平行でかつチャージワイヤ
を含む第2の面とこれに最も近い遮蔽板端部との間の間
隔を0mm以上にして3.0mm以下としたことを特徴
とする転写装置。
A photosensitive drum carrying a toner image and a transfer drum are disposed facing each other, and a transfer charger is disposed within the transfer drum so that a charge wire is located upstream of a contact line between both drums when viewed in the direction of rotation of the transfer drum. A transfer inlet shielding plate is provided in the transfer charger on the upstream side when viewed in the rotational direction of the transfer drum,
In a transfer device of an image forming apparatus in which a toner image on a photoreceptor drum is transferred to a sheet on a transfer drum by the transfer charger, a line passing through both central axes of the photoreceptor drum and the transfer drum and a contact line between the two drums is provided. The distance between the surface of 1 and the charge wire of the transfer charger is 2.0 m.
m or less, and the distance between the second surface parallel to the first surface and including the charge wire and the end of the shielding plate closest to this is 0 mm or more and 3.0 mm or less. transfer device.
JP63308787A 1988-12-08 1988-12-08 Transfer device for image forming device Pending JPH02156279A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP63308787A JPH02156279A (en) 1988-12-08 1988-12-08 Transfer device for image forming device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP63308787A JPH02156279A (en) 1988-12-08 1988-12-08 Transfer device for image forming device

Publications (1)

Publication Number Publication Date
JPH02156279A true JPH02156279A (en) 1990-06-15

Family

ID=17985301

Family Applications (1)

Application Number Title Priority Date Filing Date
JP63308787A Pending JPH02156279A (en) 1988-12-08 1988-12-08 Transfer device for image forming device

Country Status (1)

Country Link
JP (1) JPH02156279A (en)

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