JPH07140758A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JPH07140758A JPH07140758A JP29079793A JP29079793A JPH07140758A JP H07140758 A JPH07140758 A JP H07140758A JP 29079793 A JP29079793 A JP 29079793A JP 29079793 A JP29079793 A JP 29079793A JP H07140758 A JPH07140758 A JP H07140758A
- Authority
- JP
- Japan
- Prior art keywords
- roller
- transfer
- diameter
- photosensitive drum
- 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.)
- Pending
Links
Landscapes
- Discharging, Photosensitive Material Shape In Electrophotography (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、主に電子写真方式を用
いて画像形成を行なう画像形成装置に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus which mainly forms an image by using an electrophotographic system.
【０００２】[0002]
【従来の技術】従来、ローラ帯電方式を採用する画像形
成装置においては、帯電ローラの直径は像担持体である
感光ドラムのそれよりも小さく設定されており、又、転
写ローラに関しても同様にその直径は感光ドラムのそれ
よりも小さく設定されていた。2. Description of the Related Art Conventionally, in an image forming apparatus which employs a roller charging system, the diameter of the charging roller is set smaller than that of the photosensitive drum which is an image carrier, and the transfer roller also has the same diameter. The diameter was set smaller than that of the photosensitive drum.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記従
来の画像形成装置では、帯電ローラの直径が感光ドラム
のそれよりも小さいために次のような問題があった。However, the above-mentioned conventional image forming apparatus has the following problems because the diameter of the charging roller is smaller than that of the photosensitive drum.
【０００４】即ち、潜像形成における感光ドラム表面へ
の電荷注入の際に感光ドラムと帯電ローラ間のニップ近
傍の曲率が大きくなるため、帯電領域が狭くなり、放電
リップルや帯電不安定状態が生じた場合にはその影響を
受け易く、白スジや帯電ムラが発生し易い。That is, when a charge is injected onto the surface of the photosensitive drum during latent image formation, the curvature in the vicinity of the nip between the photosensitive drum and the charging roller becomes large, so that the charging area becomes narrow and discharge ripples and unstable charging occur. In that case, white stripes and uneven charging are likely to occur.
【０００５】又、転写ローラの直径が感光ドラムのそれ
よりも小さいと、転写時の転写領域が狭くなり、転写不
良や転写材の搬送経路によっては現像剤の飛び散りが発
生する等の問題があった。If the diameter of the transfer roller is smaller than that of the photosensitive drum, the transfer area at the time of transfer becomes narrow, and there are problems such as defective transfer and scattering of the developer depending on the transfer material transport path. It was
【０００６】本発明は上記問題に鑑みてなされたもの
で、その目的とする処は、十分広い帯電領域及び転写領
域を確保して潜像形成時の白スジや潜像ムラ、転写時の
転写不良や現像剤の飛び散りを防ぐとともに、帯電ロー
ラと転写ローラの寿命延長を図ることができる画像形成
装置を提供することにある。The present invention has been made in view of the above problems, and an object of the present invention is to secure a sufficiently wide charging area and a transfer area so that white streaks and latent image unevenness at the time of latent image formation and transfer at the time of transfer are achieved. An object of the present invention is to provide an image forming apparatus capable of preventing defects and developer scattering and extending the life of the charging roller and the transfer roller.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成すべく本
発明は、少なくとも像担持体と帯電ローラ及び転写ロー
ラを有する画像形成装置において、前記帯電ローラと転
写ローラの直径を前記像担持体の直径又は周長の１／π
よりも大きく設定したことを特徴とする。To achieve the above object, the present invention provides an image forming apparatus having at least an image carrier, a charging roller and a transfer roller, in which the diameters of the charging roller and the transfer roller are the same as those of the image carrier. 1 / π of diameter or circumference
It is characterized in that it is set larger than.
【０００８】[0008]
【作用】本発明によれば、帯電ローラの直径を像担持体
の直径（像担持体が感光ドラムである場合）又は周長の
１／π（像担持体がベルト感光体である場合）よりも大
きくすることで、潜画像形成時に十分な帯電領域を確保
することが可能となり、放電ムラやリップルに対しても
十分なラチチュードを確保することができ、白スジや潜
像ムラの発生を防ぐことができる。According to the present invention, the diameter of the charging roller is determined from the diameter of the image carrier (when the image carrier is a photosensitive drum) or 1 / π of the circumference (when the image carrier is a belt photosensitive member). By also increasing the value, it is possible to secure a sufficient charged area during latent image formation, to secure a sufficient latitude for discharge unevenness and ripples, and to prevent white lines and latent image unevenness from occurring. be able to.
【０００９】又、転写ローラに関しても帯電ローラと同
様に構成したため、転写時の転写領域を十分に確保で
き、転写不良や現像剤の飛び散りを防ぐことができる。Further, since the transfer roller is constructed in the same manner as the charging roller, it is possible to secure a sufficient transfer area at the time of transfer and prevent transfer failure and scattering of the developer.
【００１０】又、帯電ローラと転写ローラの何れについ
ても、その直径を大きくすることで、１コピー動作当り
の回転数を減らすことができ、これら帯電ローラと転写
ローラの寿命延長を図ることができる。Further, by increasing the diameter of both the charging roller and the transfer roller, the number of rotations per copy operation can be reduced, and the life of these charging roller and transfer roller can be extended. .
【００１１】[0011]
【実施例】以下に本発明の実施例を添付図面に基づいて
説明する。Embodiments of the present invention will be described below with reference to the accompanying drawings.
【００１２】＜第１実施例＞図１は本発明の第１実施例
に係る画像形成装置要部の構成図である。<First Embodiment> FIG. 1 is a block diagram of the essential portions of an image forming apparatus according to the first embodiment of the present invention.
【００１３】図１において、１は図示矢印方向（時計方
向）に回転する像担持体である感光ドラムであり、該感
光ドラム１の周囲には帯電ローラ２、現像装置４、搬送
ガイド５、レジストローラ６、転写ローラ７、搬送ガイ
ド８、搬送ベルト９及びクリーナ１０がそれぞれ配設さ
れている。In FIG. 1, reference numeral 1 denotes a photosensitive drum which is an image bearing member which rotates in the direction of the arrow (clockwise direction). Around the photosensitive drum 1, a charging roller 2, a developing device 4, a conveyance guide 5 and a resist. A roller 6, a transfer roller 7, a conveyance guide 8, a conveyance belt 9 and a cleaner 10 are provided.
【００１４】ところで、上記帯電ローラ２は、感光ドラ
ム１に接触しながら図示矢印方向（反時計方向）に回転
することによって感光ドラム１の表面を一様に帯電する
ものであって、その直径ｄ1 は感光ドラム１の直径Ｄも
大きく（ｄ1 ＞Ｄ）設定されている。By the way, the charging roller 2 is adapted to uniformly charge the surface of the photosensitive drum 1 by rotating in the direction of the arrow (counterclockwise) shown in FIG. In the case of 1, the diameter D of the photosensitive drum 1 is also set large (d 1 > D).
【００１５】又、前記転写ローラ７は、感光ドラム１に
接触しながら図示矢印方向（反時計方向）に回転するこ
とによって感光ドラム１上の未定着トナー像を転写材Ｐ
上に転写するものであって、その直径ｄ2 も前記帯電ロ
ーラ２と同様に感光ドラム１の直径Ｄよりも大きく（ｄ
2 ＞Ｄ）設定されている。Further, the transfer roller 7 rotates in the direction of the arrow (counterclockwise) in the figure while being in contact with the photosensitive drum 1 to transfer the unfixed toner image on the photosensitive drum 1 to the transfer material P.
Similarly to the charging roller 2, the diameter d 2 is larger than the diameter D of the photosensitive drum 1 (d
2 > D) It is set.
【００１６】而して、帯電ローラ２によって感光ドラム
１の表面が一様に帯電された後、該感光ドラム１上に画
像情報に対応する露光光が照射されると、感光ドラム１
上に静電潜像が形成され、この静電潜像は前記現像装置
４によって現像されてトナー像として顕画化される。Then, after the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2, when the photosensitive drum 1 is irradiated with exposure light corresponding to image information, the photosensitive drum 1 is exposed.
An electrostatic latent image is formed on the electrostatic latent image, and the electrostatic latent image is developed by the developing device 4 and visualized as a toner image.
【００１７】一方、不図示の給紙カセットからは転写材
Ｐが搬送ガイド５に沿って搬送され、この転写材Ｐは前
記レジストローラ６によって適当なタイミングで感光ド
ラム１と転写ローラ７間のニップ部（転写部）に供給さ
れ、転写ローラ７の作用によって、感光ドラム１上に担
持された前記トナー像の転写を受ける。On the other hand, a transfer material P is conveyed from a sheet feeding cassette (not shown) along a conveyance guide 5, and the transfer material P is nipped between the photosensitive drum 1 and the transfer roller 7 by the registration roller 6 at an appropriate timing. The toner image carried on the photosensitive drum 1 is transferred by the action of the transfer roller 7 that is supplied to the section (transfer section).
【００１８】そして、トナー像の転写を受けた転写材Ｐ
は、搬送ガイド８に沿って前記搬送ベルト９に送られ、
更に搬送ベルト９によって不図示の定着装置に送られ、
定着装置によってトナー像の定着を受けた後、機外へ排
出される。Then, the transfer material P on which the toner image is transferred
Is sent to the conveyor belt 9 along the conveyor guide 8,
Further, it is sent to a fixing device (not shown) by the conveyor belt 9,
After the toner image is fixed by the fixing device, the toner image is discharged to the outside of the machine.
【００１９】尚、転写されないで感光ドラム１上に残留
したトナーはクリーナ１０によって除去され、感光ドラ
ム１は次の画像形成に備えられる。Toner remaining on the photosensitive drum 1 without being transferred is removed by the cleaner 10, and the photosensitive drum 1 is prepared for the next image formation.
【００２０】以上において、本実施例では、感光ドラム
１よりも硬度が低くて柔らな帯電ローラ２の直径ｄ1 を
感光ドラム１の直径Ｄよりも大きく設定したため、該帯
電ローラ２と感光ドラム１の当接のニップ幅を十分広く
取ることができ、そのため、帯電領域の幅が広くなって
放電ムラや放電リップルに対してのラチチュードが広が
り、白スジや潜像ムラの発生が防がれる。そして、上述
のように帯電領域を広く取ることができる結果、プロセ
ススピードをアップした場合でも、十分な帯電量を確保
することができる。As described above, in the present embodiment, the diameter d 1 of the charging roller 2 which is lower in hardness and softer than the photosensitive drum 1 is set to be larger than the diameter D of the photosensitive drum 1, so that the charging roller 2 and the photosensitive drum 1 are set. The contact nip width can be made sufficiently wide, so that the width of the charging region is widened and the latitude for discharge unevenness and discharge ripple is widened, and white stripes and latent image unevenness are prevented from occurring. As a result of the large charging area as described above, a sufficient amount of charge can be secured even when the process speed is increased.
【００２１】又、本実施例では、前述のように転写ロー
ラ７の直径ｄ2 も感光ドラム１の直径Ｄよりも大きく設
定したため、該転写ローラ７と感光ドラム１との間のニ
ップ領域を大きく取ることが可能となり、十分に広い転
写領域を確保でき、転写不良やトナーの飛び散りを防ぐ
ことができる。Further, in this embodiment, since the diameter d 2 of the transfer roller 7 is also set to be larger than the diameter D of the photosensitive drum 1 as described above, the nip area between the transfer roller 7 and the photosensitive drum 1 is increased. Therefore, it is possible to secure a sufficiently large transfer area and prevent transfer failure and toner scattering.
【００２２】更に、１コピー動作は感光ドラム１の回転
数によって決まるが、本実施例では帯電ローラ２と転写
ローラ７の各直径ｄ1 ，ｄ2 の方が感光ドラム１の直径
Ｄよりも大きいため、これらの帯電ローラ２と転写ロー
ラ７の回転数が感光ドラム１のそれよりも小さく抑えら
れ、帯電ローラ２と転写ローラ７の耐久性が向上してこ
れらの寿命が延びるという効果も得られる。Further, although one copy operation is determined by the number of rotations of the photosensitive drum 1, in this embodiment, the diameters d 1 and d 2 of the charging roller 2 and the transfer roller 7 are larger than the diameter D of the photosensitive drum 1. Therefore, the number of rotations of the charging roller 2 and the transfer roller 7 is suppressed to be smaller than that of the photosensitive drum 1, and the durability of the charging roller 2 and the transfer roller 7 is improved, and the life of these is extended. .
【００２３】＜実施例２＞次に、本発明の第２実施例を
図２に基づいて説明する。<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG.
【００２４】本実施例は像担持体としてベルト感光体１
１を用いており、他の基本構成は前記第１実施例のそれ
と同様である。従って、図２においては図１に示したと
同一要素には同一符号を付しており、以下、それらにつ
いての説明は省略する。In this embodiment, the belt photosensitive member 1 is used as an image bearing member.
1 is used, and the other basic structure is the same as that of the first embodiment. Therefore, in FIG. 2, the same elements as those shown in FIG. 1 are designated by the same reference numerals, and description thereof will be omitted below.
【００２５】本実施例においては、帯電ローラ２の直径
ｄ1 と転写ローラ７の直径ｄ2 をベルト感光体１１の周
長Ｌの１／π（πは円周率）よりも大きく設定（ｄ1 ，
ｄ2＞Ｌ／π）している。[0025] In this example, 1 / π (π is the circular constant) set larger than the circumferential length L of the diameter d 2 of the photosensitive belt 11 having a diameter d 1 and the transfer roller 7 of the charging roller 2 (d 1 ,
d 2 > L / π).
【００２６】而して、本実施例においても、十分に広い
帯電領域及び転写領域を確保することができ、前記第１
実施例と同様の効果が得られる。Thus, also in this embodiment, it is possible to secure a sufficiently wide charging area and transfer area.
The same effect as the embodiment can be obtained.
【００２７】[0027]
【発明の効果】以上の説明で明らかな如く、本発明によ
れば、少なくとも像担持体と帯電ローラ及び転写ローラ
を有する画像形成装置において、前記帯電ローラと転写
ローラの直径を前記像担持体の直径又は周長の１／πよ
りも大きく設定したため、十分広い帯電領域及び転写領
域を確保して潜像形成時の白スジや潜像ムラ、転写時の
転写不良や現像剤の飛び散りを防ぐとともに、帯電ロー
ラと転写ローラの寿命延長を図ることができるという効
果が得られる。As is apparent from the above description, according to the present invention, in an image forming apparatus having at least an image carrier, a charging roller and a transfer roller, the diameters of the charging roller and the transfer roller are set to those of the image carrier. Since it is set to be larger than 1 / π of the diameter or circumference, a sufficiently wide charging area and transfer area are secured to prevent white lines and latent image unevenness during latent image formation, transfer failure during transfer, and developer scattering. As a result, it is possible to extend the life of the charging roller and the transfer roller.
【図１】本発明の第１実施例に係る画像形成装置要部の
構成図である。FIG. 1 is a configuration diagram of a main part of an image forming apparatus according to a first embodiment of the present invention.
【図２】本発明の第２実施例に係る画像形成装置要部の
構成図である。FIG. 2 is a configuration diagram of a main part of an image forming apparatus according to a second embodiment of the present invention.
１ 感光ドラム（像担持体） ２ 帯電ローラ ７ 転写ローラ １１ ベルト感光体（像担持体） Ｄ 感光ドラムの直径 ｄ1 帯電ローラの直径 ｄ2 転写ローラの直径 Ｌ ベルト感光体の周長1 photosensitive drum (image bearing member) 2 charging roller 7 transfer roller 11 belt photosensitive member (image bearing member) D diameter of photosensitive drum d 1 diameter of charging roller d 2 diameter of transfer roller L circumference of belt photosensitive member
Claims (3)
写ローラを有する画像形成装置において、前記帯電ロー
ラと転写ローラの直径を前記像担持体の直径又は周長の
１／πよりも大きく設定したことを特徴とする画像形成
装置。1. An image forming apparatus having at least an image carrier, a charging roller, and a transfer roller, wherein the diameter of the charging roller and the transfer roller is set to be larger than 1 / π of the diameter or circumference of the image carrier. An image forming apparatus characterized by.
帯電ローラと転写ローラの直径は該感光ドラムの直径よ
り大きく設定されることを特徴とする請求項１記載の画
像形成装置。2. The image forming apparatus according to claim 1, wherein the image carrier is a photosensitive drum, and the diameters of the charging roller and the transfer roller are set larger than the diameters of the photosensitive drum.
記帯電ローラと転写ローラの直径は該ベルト感光体のベ
ルトの周長の１／πより大きく設定されることを特徴と
する請求項１記載の画像形成装置。3. The image bearing member is a belt photosensitive member, and the diameters of the charging roller and the transfer roller are set to be larger than 1 / π of the circumferential length of the belt of the belt photosensitive member. 1. The image forming apparatus according to 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29079793A JPH07140758A (en) | 1993-11-19 | 1993-11-19 | Image forming device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29079793A JPH07140758A (en) | 1993-11-19 | 1993-11-19 | Image forming device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07140758A true JPH07140758A (en) | 1995-06-02 |
Family
ID=17760625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29079793A Pending JPH07140758A (en) | 1993-11-19 | 1993-11-19 | Image forming device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07140758A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6898401B2 (en) * | 2002-04-23 | 2005-05-24 | Canon Kabushiki Kaisha | Charging system, process cartridge and image forming apparatus |
| US7636100B2 (en) * | 2005-07-08 | 2009-12-22 | Canon Kabushiki Kaisha | Image forming apparatus |
-
1993
- 1993-11-19 JP JP29079793A patent/JPH07140758A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6898401B2 (en) * | 2002-04-23 | 2005-05-24 | Canon Kabushiki Kaisha | Charging system, process cartridge and image forming apparatus |
| EP1357438A3 (en) * | 2002-04-23 | 2007-12-26 | Canon Kabushiki Kaisha | Charging system, process cartridge and image forming apparatus |
| US7636100B2 (en) * | 2005-07-08 | 2009-12-22 | Canon Kabushiki Kaisha | Image forming apparatus |
| US8259143B2 (en) | 2005-07-08 | 2012-09-04 | Canon Kabushiki Kaisha | Image forming apparatus |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11454926B2 (en) | Image forming apparatus | |
| JP4464037B2 (en) | Image forming apparatus | |
| JP3133565B2 (en) | Image forming device | |
| JP3576894B2 (en) | Sheet member conveying device in image forming apparatus | |
| JP4051905B2 (en) | Image forming apparatus | |
| JPH07140758A (en) | Image forming device | |
| JPH1138855A (en) | Cleaner for image forming device | |
| JP4971775B2 (en) | Image forming apparatus | |
| JP4211294B2 (en) | Image forming apparatus | |
| JP2002072574A (en) | Image-forming device | |
| JP3037387B2 (en) | Image forming device | |
| JP2002244386A (en) | Image forming device | |
| JP3576895B2 (en) | Image forming device | |
| JP3146234B2 (en) | Image forming device | |
| JP2003140460A (en) | Developing device | |
| JP2005173075A (en) | Image forming apparatus | |
| JP2018180394A (en) | Image forming apparatus | |
| JP2000155501A (en) | Image forming device | |
| JP2005338700A (en) | Image forming apparatus | |
| JPH08314344A (en) | Image forming device | |
| JP4038405B2 (en) | Image forming apparatus | |
| JPH03249781A (en) | Developer leakage preventing device and process cartridge provided therewith | |
| JPH06236096A (en) | Image forming device provided with corona charging device | |
| JP2019152845A (en) | Cleaning device and image forming apparatus | |
| JPH0545957A (en) | Image forming device |