JPH06316349A - Pressure control device for pressure member - Google Patents

Abstract

PURPOSE:To prevent changing with time owing to a pressure contact state by a method wherein during the non-use of a pressure, a pressure member is separated from a member to be pressurized and brought into pressure contact therewith through energization of a solenoid as occasion demands. CONSTITUTION:In an image forming device, a toner image formed on a photo- sensitive body 1 is transferred to the back of a properly conveyed transfer sheet by bringing a transfer roller 5 into pressure contact with the photo-sensitive body 1. A pressure control device 10 is provided so that the transfer roller 5 is caused to approach and part from the photo-sensitive substance 1. In the pressure control device 10, during the stop of image forming operation, i.e., during waiting, a solenoid 15 is in a non-energized state, and a moving member 13 is movable. A rotary lever 11 is rotated clockwise under gravity and the transfer roller 5 is separated away from the photo-sensitive body 1. Meanwhile, when the solenoid 15 is energized in linkage with image forming operation, the rotary lever 11 is rotated counterclockwise and the transfer roller 5 is moved to the photo-sensitive body 1 side.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、画像形成装置における
記録媒体に対し接触帯電（除電を含む）する帯電部材、
用紙搬送系における定着装置及び搬送ローラ等の加圧部
材を被加圧部材に圧接する際に、その圧力制御、特に圧
接又は離間を行うための圧力制御装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging member for contact charging (including discharging) a recording medium in an image forming apparatus.
The present invention relates to a pressure control device for pressure-contacting a pressure-applying member such as a fixing device and a conveyance roller in a paper-conveying system, and particularly for performing pressure-contact or separation.

【０００２】[0002]

【従来の技術】電子写真方式を利用してなる画像形成装
置は、記録媒体であるドラム状の感光体を均一帯電し、
光学情報を露光（照射）することで、該感光体表面に静
電潜像を形成し、該像はトナー像として現像された後
に、適宜搬送されてくる転写紙上に静電的に転写され、
トナー像が転写された転写紙を一対の加熱ローラからな
る定着装置へと送り込むことで、トナーを加熱定着して
いる。また、転写後の感光体表面には転写されなかった
トナーが残留しており、この残留トナーを除去した後
に、感光体表面を均一な電位状態にするための除電を行
っている。2. Description of the Related Art An image forming apparatus using an electrophotographic system uniformly charges a drum-shaped photoconductor, which is a recording medium,
By exposing (irradiating) optical information, an electrostatic latent image is formed on the surface of the photoconductor, the image is developed as a toner image, and then electrostatically transferred onto a transfer paper that is appropriately conveyed,
The transfer paper on which the toner image is transferred is sent to a fixing device including a pair of heating rollers to heat and fix the toner. In addition, the untransferred toner remains on the surface of the photoconductor after the transfer, and after removing the residual toner, the charge is removed to bring the surface of the photoconductor to a uniform potential state.

【０００３】以上のように、感光体上に画像を形成する
ための、除電を含めて感光体に対向させて複数の帯電手
段を必要とする。つまり、感光体を均一に帯電するため
の帯電部、転写紙にトナー像を静電転写する転写部及び
感光体の表面電荷を除電する除電部等の各種の帯電手段
が設けられている。これたの帯電手段としては、例えば
オゾンの発生を防止すると同時に装置の小型化を目的と
して、感光体表面に接触し帯電を行うローラ方式やブラ
シ方式による帯電が知られる。As described above, in order to form an image on the photoconductor, a plurality of charging means are required to face the photoconductor, including static elimination. That is, various charging means such as a charging unit for uniformly charging the photoconductor, a transfer unit for electrostatically transferring a toner image onto a transfer sheet, and a charge eliminating unit for eliminating surface charges of the photoconductor are provided. As such a charging means, for example, roller type charging or brush type charging is known in which charging is performed by contacting the surface of the photoconductor for the purpose of preventing ozone generation and reducing the size of the apparatus.

【０００４】上記ローラ方式やブラシ方式による帯電部
材は、例えばローラを感光体表面に圧接させた状態で破
壊電圧以上の高電圧を印加することで帯電を（除電も含
む）行っている。The roller type or brush type charging member is charged (including static elimination) by applying a high voltage equal to or higher than the breakdown voltage in a state where the roller is pressed against the surface of the photosensitive member.

【０００５】そのために、帯電ローラ（又はブラシ）を
感光体に圧接させるための圧力手段が設けられており、
また必要に応じて圧接状態を解除し、感光体より離間さ
せる必要があり、そのための圧力制御装置が備わってい
る。To this end, pressure means for pressing the charging roller (or brush) to the photosensitive member is provided,
In addition, it is necessary to release the pressure contact state and separate it from the photoconductor as necessary, and a pressure control device for that purpose is provided.

【０００６】図７にその一例を示すように、感光体１の
下方に設けられた転写ローラ５を支点３０を中心に回動
自在に設けられたレバー３１に回転可能に支持し、レバ
ー３１の転写ローラ２の支持部と反対側をスプリング３
２による付勢力にて、レバー３１を図中時計方向に回転
させることで、転写ローラ５を感光体１表面に圧接して
いる。そして、その部分で転写紙がジャム（詰まり）す
れば、レバー３１をスプリング３２の付勢力に抗して回
動させることで、転写ローラ５を感光体１表面より離間
できる。この方法によれば、人為的にレバー３１を回動
させる必要があるため、ジャム処理が面倒である。ま
た、転写ローラ５は常に感光体１に圧接されるため、画
像形成装置の不使用時にも圧接され、転写ローラ５の変
形による均一帯電を行えなくなる等の問題点があった。As shown in FIG. 7, an example of the transfer roller 5 provided below the photoconductor 1 is rotatably supported by a lever 31 rotatably provided around a fulcrum 30. A spring 3 is provided on the side opposite to the supporting portion of the transfer roller 2.
The transfer roller 5 is pressed against the surface of the photoconductor 1 by rotating the lever 31 in the clockwise direction in the figure by the urging force of 2. If the transfer paper is jammed at that portion, the transfer roller 5 can be separated from the surface of the photoconductor 1 by rotating the lever 31 against the urging force of the spring 32. According to this method, since it is necessary to manually rotate the lever 31, the jam processing is troublesome. Further, since the transfer roller 5 is constantly in pressure contact with the photosensitive member 1, it is in pressure contact even when the image forming apparatus is not in use, and there is a problem that uniform charging due to deformation of the transfer roller 5 cannot be performed.

【０００７】そこで、特開平４−２１６５８３号公報に
記載されるような圧力制御装置が提案された。この圧力
制御装置は、転写ローラを通常は感光体より離間させて
おり、必要時に転写ローラを感光体に圧接させるため
に、ソレノイドを駆動（通電）することで、転写ローラ
を回転可能に支持してなるレバーを回動させ、かつ該ソ
レノイドによる転写ローラの感光体への圧接力を強くす
るために、ソレノイド自体を移動させるために、移動手
段を同時に駆動させている。この移動手段の駆動を行う
ためにクラッチ等を必要としている。Therefore, a pressure control device as described in JP-A-4-216583 has been proposed. This pressure control device normally separates the transfer roller from the photoconductor, and in order to press the transfer roller against the photoconductor when necessary, a solenoid is driven (energized) to rotatably support the transfer roller. The moving means is simultaneously driven in order to move the lever itself and to move the solenoid itself in order to increase the pressing force of the transfer roller to the photoconductor by the solenoid. A clutch or the like is required to drive the moving means.

【０００８】そこで、転写ローラが感光体に圧接してい
る状態でジャム等が生じた時には、ソレノイドへの通電
が断たれることから、ソレノイドの付勢力が作用せず
に、転写ローラが離間する。従ってジャム処理が簡単に
なると共に、画像形成装置の非使用時には転写ローラが
離間するので、転写ローラの変形等の問題は解消され
る。Therefore, when a jam or the like occurs while the transfer roller is in pressure contact with the photosensitive member, the energization of the solenoid is cut off, and the transfer roller is separated without the urging force of the solenoid acting. . Therefore, the jam processing is simplified and the transfer roller is separated when the image forming apparatus is not used, so that the problem such as the deformation of the transfer roller is solved.

【０００９】また、圧力制御装置としては、転写ローラ
に利用させるだけでなく、画像形成装置において、圧接
状態を解除してローラの被加圧部材より離間する必要が
る部分に適用できる。例えば、搬送手段を一部を構成す
る定着装置の加熱定着ローラの一方の加圧ローラ側を上
記転写ローラと同様の構成とする。また、搬送ローラに
おいても同様である。Further, the pressure control device can be applied not only to the transfer roller but also to a portion of the image forming apparatus which needs to be released from the pressure contact state and separated from the pressure-applied member of the roller. For example, one pressure roller side of the heat fixing roller of the fixing device that forms a part of the conveying unit has the same configuration as the transfer roller. The same applies to the transport roller.

【００１０】[0010]

【発明が解決しようとする課題】ところが、特開平４−
２１６５８３号記載の圧力制御装置によれば、ソレノイ
ド等を保持し、移動させるための移動体及び、該移動体
を移動させるための駆動手段からの駆動力を連結又は遮
断するクラッチ等が必要となり構成が複雑化し、大型化
する。そのため、コスト高になる欠点がある。However, Japanese Unexamined Patent Application Publication No.
According to the pressure control device described in Japanese Patent No. 216583, a moving body for holding and moving a solenoid and the like, and a clutch for connecting or disconnecting a driving force from a driving means for moving the moving body are required. Becomes complicated and large. Therefore, there is a drawback that the cost becomes high.

【００１１】本発明は、上述の欠点を解消するために、
不使用時には被圧接部材に対し離間させておき、必要に
応じて圧接させ、電源供給が断たれた状態では確実に離
間しておく簡単な構成の圧力制御装置を提供することを
目的とする。The present invention, in order to overcome the above-mentioned drawbacks,
An object of the present invention is to provide a pressure control device having a simple configuration in which the pressure contact member is separated from the pressure contact member when not in use, and is pressed into contact with the member to be pressed when necessary, and is reliably separated when the power supply is cut off.

【００１２】[0012]

【課題を解決するための手段】上記課題を解決するため
の本発明は、加圧部材を移動可能に設け、該加圧部材を
被加圧部材に圧接又は離間させる圧力制御装置におい
て、上記加圧部材を支持し該加圧部材の自重より上記被
加圧部材に対し離間する位置に移動し、また圧接位置に
移動させるため支持部材と、該支持部材を圧接方向に駆
動するための電磁ソレノイドと、該電磁ソレノイドの通
電時に一方向に駆動されて上記支持部材を圧接方向への
移動させ、非通電時に自由に移動可能であって、上記支
持部材に連結された可動部材と、上記電磁ソレノイドを
固定支持し、該電磁ソレノイドの通電時に上記可動部材
の駆動方向と同方向に往復移動可能に設けられた移動部
材と、該移動部材を往復移動させると共に、上記可動部
材の移動量の最大位置でその状態を維持させる駆動部
と、を備え上記電磁ソレノイドに通電し上記可動部材を
一方向駆動し、且つ上記移動部材を上記駆動部を介して
同方向へ移動させることで上記加圧部材を被加圧部材に
圧接させ、上記電磁ソレノイドの通電の解除により上記
可動部材の自由移動により上記加圧接部材を被加圧部材
離間させることを特徴とする。The present invention for solving the above-mentioned problems provides a pressure control device in which a pressing member is movably provided, and the pressing member is pressed against or separated from a member to be pressed. A support member for supporting the pressure member, moving to a position separated from the member to be pressed by the weight of the pressure member, and moving to the pressure contact position, and an electromagnetic solenoid for driving the support member in the pressure contact direction. And a movable member which is driven in one direction when the electromagnetic solenoid is energized to move the support member in the pressure contact direction and is freely movable when not energized, and which is connected to the support member, and the electromagnetic solenoid. A movable member that is fixedly supported and is capable of reciprocating in the same direction as the driving direction of the movable member when the electromagnetic solenoid is energized, and the moving member reciprocates, and the maximum amount of movement of the movable member. And a drive unit for maintaining that state by energizing the electromagnetic solenoid to drive the movable member in one direction and move the moving member in the same direction via the drive unit to move the pressing member. It is characterized in that the pressure contact member is pressed against the pressure member, and the pressure contact member is separated from the pressure member by the free movement of the movable member when the energization of the electromagnetic solenoid is released.

【００１３】また、上記被加圧部材は画像形成装置の記
録媒体、つまり感光体であり、加圧部材は感光体を帯電
又は除電する帯電部材、あるいは上記被加圧部材及び加
圧部材は画像形成装置の用紙を搬送するための手段であ
り、特に搬送ローラ及び定着ローラであることを特徴と
する。Further, the pressure-applied member is a recording medium of the image forming apparatus, that is, a photoconductor, the pressure member is a charging member for charging or discharging the photoconductor, or the pressure-applied member and the pressurization member are images. It is a means for conveying a sheet of the forming apparatus, and is characterized in particular by a conveying roller and a fixing roller.

【００１４】[0014]

【作用】以上の構成の本発明の加圧部材の圧力制御装置
によれば、加圧部材を被加圧部材に圧接する必要がある
場合、例えば画像を形成する時には、被加圧部材である
感光体を帯電（除電を含む）させるために、加圧部材で
ある帯電部材の帯電ローラ又はブラシを感光体に圧接さ
せる。そのため、電磁ソレノイドが通電される。これに
より、可動部材が磁力により吸引され一方向に駆動され
る。この時のストローク量（移動量）は、電磁ソレノイ
ドの能力で決まる。また同時に駆動部を介して電磁ソレ
ノイドを固定支持してなる移動部材が、可動部材の駆動
方向と同方向に移動されるため、支持部材を介して上記
帯電部材が感光体に圧接される。この状態で感光体の帯
電（除電も含む）を行うことができる。According to the pressure control device for a pressure member of the present invention having the above-described structure, when the pressure member needs to be pressed against the pressure member, for example, when an image is formed, the pressure member is the pressure member. In order to charge the photoreceptor (including charge removal), the charging roller or brush of the charging member, which is a pressing member, is brought into pressure contact with the photoreceptor. Therefore, the electromagnetic solenoid is energized. As a result, the movable member is attracted by the magnetic force and is driven in one direction. The stroke amount (movement amount) at this time is determined by the capacity of the electromagnetic solenoid. At the same time, the moving member, which fixes and supports the electromagnetic solenoid via the drive unit, is moved in the same direction as the driving direction of the movable member, so that the charging member is pressed against the photoconductor via the support member. In this state, the photoconductor can be charged (including static elimination).

【００１５】一方、帯電部材の圧接状態を解除する場
合、つまり帯電を必要としなくなる非画形成時には、上
記電磁ソレノイドへの通電が断たれる。この時、可動部
材の移動が拘束されずに自由になるため、帯電部材の自
重により感光体より離間させる。On the other hand, when the pressure contact state of the charging member is released, that is, at the time of non-image formation where the charging is not required, the electromagnetic solenoid is de-energized. At this time, the movement of the movable member is not restricted and is free, so that the movable member is separated from the photosensitive member by its own weight.

【００１６】また、加圧部材が帯電部材でなく、用紙を
搬送する手段である場合には、画像形成動作に関連させ
て、電磁ソレノイドへの通電、及び電磁ソレノイドを移
動させることで、搬送ローラの一方を他方のローラに圧
接させ、用紙の搬送状態を設定する。そして、非画像形
成時には電磁ソレノイドの通電を解除することで一方の
ローラが離間する。If the pressure member is not a charging member but a means for conveying the sheet, the conveying roller is energized and moved by moving the electromagnetic solenoid in association with the image forming operation. One of the rollers is pressed against the other roller to set the sheet conveyance state. Then, at the time of non-image formation, by de-energizing the electromagnetic solenoid, one roller is separated.

【００１７】[0017]

【実施例】本発明を、実施例について以下に説明する。The present invention will be described below with reference to examples.

【００１８】図１は本発明による圧力制御装置を転写ロ
ーラに適用してなる画像形成装置の概略を示す側面図で
ある。FIG. 1 is a side view showing the outline of an image forming apparatus in which the pressure control device according to the present invention is applied to a transfer roller.

【００１９】図において、矢印Ａ方向に回転駆動される
記録媒体であるドラム形状の感光体１に対向して、画像
形成を行うための各種プロセス部が配置されている。In the figure, various process units for forming an image are arranged so as to face a drum-shaped photoconductor 1 which is a recording medium which is rotationally driven in the direction of arrow A.

【００２０】まず、第１のプロセス部としては、感光体
１表面を均一にする帯電器２であって、コロナ放電器に
て構成されている。この帯電器２はローラ方式又はブラ
シ方式による帯電部材であってもよい。First, the first process section is a charger 2 for uniformizing the surface of the photoreceptor 1 and is constituted by a corona discharger. The charger 2 may be a roller type or brush type charging member.

【００２１】第２のプロセス部は、矢印Ｂ方向より感光
体１表面を光照射する露光部３である。該露光部３は、
複写装置にあっては複写原稿からの反射光像であって、
結像光学系を介して画像露光する。また、プリンタ等に
あっては、必要な情報、例えば文字や図形等を光情報に
変換してなるレーザービームや発光ダイオード、あるい
は多数の液晶シャッター等を利用して、所望の光情報を
露光する。The second process section is the exposure section 3 which irradiates the surface of the photoreceptor 1 with light in the direction of arrow B. The exposure unit 3 is
In the copying machine, it is the reflected light image from the copy original,
Image exposure is performed via the imaging optical system. Also, in a printer or the like, desired optical information is exposed by using necessary information, for example, a laser beam or a light emitting diode formed by converting characters or figures into optical information, or a large number of liquid crystal shutters. .

【００２２】さらに第３のプロセス部は、上記露光部３
にて露光したことにより、感光体１表面に露光された画
像に応じて形成される潜像（静電潜像）を、可視像化す
るための現像装置４である。該現像装置４は、例えば磁
気ブラシ現像方式を利用しており、磁気の作用によりト
ナー及びキャリアからなる現像剤、磁性トナーからなる
現像剤を磁気によりブラシ状に穂立を形成し、これを感
光体１表面に摺擦させるこあとで現像を行う。Further, the third process unit is the exposure unit 3 described above.
The developing device 4 is used to visualize the latent image (electrostatic latent image) formed on the surface of the photoreceptor 1 according to the exposed image. The developing device 4 uses, for example, a magnetic brush developing system, and a developer composed of a toner and a carrier and a developer composed of a magnetic toner are magnetically formed into a brush-like spike by the action of magnetism, and this is exposed to light. Development is performed after rubbing the surface of the body 1.

【００２３】次に、現像装置にて現像されることで、静
電潜像はトナー像となり、該トナー像は図示していない
転写紙に転写するために、感光体１に圧接される転写ロ
ーラ５が第４のプロセス部として配置されている。転写
ローラ５は、保持部材６にて軸部５ａが回転可能に支持
されており、該保持部材６は軸５ａを回転可能に支持す
る軸受であり、上下移動可能に画像形成装置本体の例え
ばフレーム等に移動可能に支持されている。また保持部
材６は、圧縮スプリング７を介して転写ローラ５を感光
体１へと圧接させる。しかも、転写ローラ５は感光体１
より離間する構成である。この転写ローラ５には、上述
のように感光体１への圧接又は離間を行うための圧力制
御装置１０が設けられている。Next, by being developed by a developing device, the electrostatic latent image becomes a toner image, and the toner image is transferred to a transfer sheet (not shown) so that the transfer roller is pressed against the photosensitive member 1. 5 is arranged as a fourth process section. A shaft 5a of the transfer roller 5 is rotatably supported by a holding member 6, and the holding member 6 is a bearing that rotatably supports the shaft 5a. It is supported so as to be movable. Further, the holding member 6 presses the transfer roller 5 against the photoconductor 1 via the compression spring 7. Moreover, the transfer roller 5 is the photosensitive member 1.
It is a structure further separated. The transfer roller 5 is provided with the pressure control device 10 for performing pressure contact with or separation from the photoconductor 1 as described above.

【００２４】上記転写ローラ５は、画像形成装置本体よ
り電気的に絶縁された状態で支持されており、図示して
いない電圧供給源より所望の電圧が印加される構成であ
って、適宜搬送されてくる転写紙の背面よりトナー像が
転写紙に転移するように、静電転写する。また、転写ロ
ーラ１０の材質等については、均一帯電、つまり転写す
るために種々検討されているが、本発明とは関係のなこ
とであって説明は省略する。The transfer roller 5 is supported in a state of being electrically insulated from the main body of the image forming apparatus, has a structure in which a desired voltage is applied from a voltage supply source (not shown), and is appropriately conveyed. Electrostatic transfer is performed so that the toner image is transferred to the transfer paper from the back surface of the transfer paper. Various studies have been made on the material of the transfer roller 10 for uniform charging, that is, for transfer, but the description is omitted because it is not related to the present invention.

【００２５】そして、転写ローラ５の転写位置を通過す
る転写紙は、感光体１表面より剥離され、図示していな
い搬送手段を介して一対の加熱ローラからなる定着装置
へと送られる。これにより、転写紙上のトナー像は、熱
により溶融され、ローラによる圧力にて転写紙上に加熱
定着される。Then, the transfer sheet passing through the transfer position of the transfer roller 5 is peeled off from the surface of the photosensitive member 1 and sent to a fixing device composed of a pair of heating rollers via a conveying means (not shown). As a result, the toner image on the transfer paper is melted by heat and is heated and fixed on the transfer paper by the pressure of the roller.

【００２６】一方、転写ローラ５の転写プロセス部の下
流の感光体１の対向位置には、第５のプロセス部を構成
するクリーニング装置８が配置されている。このクリー
ニング装置８は、例えば弾性部材よりなるブレード８ａ
の先端を感光体１表面に圧接させる構成であって、ブレ
ード８ａ先端にて、感光体１に残留するトナーを掻き落
としている。また、図示していないが、クリーニング装
置の上流側又は下流側には感光体１に残る残留電荷を除
去するための除電手段が設けられる。On the other hand, a cleaning device 8 constituting a fifth process section is arranged at a position facing the photoconductor 1 downstream of the transfer process section of the transfer roller 5. The cleaning device 8 includes, for example, a blade 8a made of an elastic member.
The tip of the blade is pressed against the surface of the photoreceptor 1, and the toner remaining on the photoreceptor 1 is scraped off by the tip of the blade 8a. Further, although not shown, a charge removing unit for removing residual charges remaining on the photoconductor 1 is provided on the upstream side or the downstream side of the cleaning device.

【００２７】以上のような構成の画像形成装置によれ
ば、帯電器２、露光部３、現像装置４にて形成されたト
ナー像を、適宜搬送されてくる転写紙に転写ローラ５の
位置で転写紙を感光体１へと圧接させることで転写を行
う。この時、転写紙は、図示していない給紙手段にて１
枚給紙され、レジストローラ等の搬送ローラを介して、
感光体１の回転と同期して、転写ローラ５の転写位置へ
と搬送制御される。また、転写後の転写後は、上述のよ
うに定着装置を経て、画像形成装置本体外へと排出され
る。この転写紙の給紙、搬送、定着等の用紙搬送系が画
像形成装置に備わっている。According to the image forming apparatus having the above-described structure, the toner image formed by the charger 2, the exposure section 3, and the developing device 4 is appropriately transferred onto the transfer sheet at the position of the transfer roller 5. Transfer is performed by bringing the transfer paper into pressure contact with the photoconductor 1. At this time, the transfer paper is
Sheets of paper are fed, and through conveyance rollers such as registration rollers,
The conveyance is controlled to the transfer position of the transfer roller 5 in synchronization with the rotation of the photoconductor 1. After the transfer, after the transfer, it is discharged to the outside of the image forming apparatus main body through the fixing device as described above. The image forming apparatus is provided with a sheet conveying system for feeding, conveying, fixing, etc. the transfer sheet.

【００２８】次に、本発明による転写ローラ５を感光体
１に圧接又は離間させるための圧力制御装置の構成につ
いて詳細に明記する。Next, the structure of the pressure control device for pressing or separating the transfer roller 5 from the photosensitive member 1 according to the present invention will be described in detail.

【００２９】圧力制御装置１０は、転写ローラ５を上下
移動するためのＬ字形状の回動レバー１１及び該回動レ
バー１１の回動を制御する手段１２とからなる。回動レ
バー１１は画像形成装置本体側に取付けられている軸部
１１ａを中心に回動可能に支持されており、一端部に転
写ローラ５を圧縮スプリング７を介して支持する。この
支持部分には圧縮スプリング７の一端が固定されてい
る。また、回動レバー１１の転写ローラの支持部と反対
側は、回動制御手段１２の可動部材１３とピン１１１ａ
にて回転可能に連結されている。この回動レバー１１及
び保持部材６等にて転写ローラ５の支持手段を構成して
いる。The pressure control device 10 comprises an L-shaped rotary lever 11 for moving the transfer roller 5 up and down, and means 12 for controlling the rotation of the rotary lever 11. The rotating lever 11 is supported rotatably around a shaft portion 11a attached to the image forming apparatus main body side, and supports the transfer roller 5 at one end portion thereof via a compression spring 7. One end of the compression spring 7 is fixed to this support portion. Further, on the side opposite to the supporting portion of the transfer roller of the rotation lever 11, the movable member 13 of the rotation control means 12 and the pin 111a are provided.
It is rotatably connected with. The rotation lever 11, the holding member 6 and the like constitute a support means for the transfer roller 5.

【００３０】上記可動部材１３は、電磁的に吸引し図中
左方向に移動させる電磁ソレノイド１４の駆動部材であ
る。従って、可動部材１３は電磁ソレノイド１４の可動
片であり、電磁的に電磁ソレノイド１４と連結されてい
る。また可動部材は電磁ソレノイド１４への通電が断た
れた状態（ＯＦＦ）では、拘束されることなく自由に移
動可能であり、転写ローラ５の自重により、図中時計方
向に回動レバー１１が回転され、転写ローラ５が感光体
１より離間される。The movable member 13 is a driving member of an electromagnetic solenoid 14 which is electromagnetically attracted and moved leftward in the drawing. Therefore, the movable member 13 is a movable piece of the electromagnetic solenoid 14, and is electromagnetically connected to the electromagnetic solenoid 14. Further, the movable member can freely move without being restrained when the electromagnetic solenoid 14 is de-energized (OFF), and the rotating lever 11 is rotated clockwise in the drawing by the weight of the transfer roller 5. Then, the transfer roller 5 is separated from the photoconductor 1.

【００３１】また、電磁ソレノイド１４は、移動可能に
設けられている移動部材１５に固定支持されており、移
動部材の移動に応じて移動される。この移動部材１５は
図示していないガイド部材によって移動方向が規制され
ており、スプリング１５ｂの付勢力により、図中右方向
へと付勢されている。Further, the electromagnetic solenoid 14 is fixedly supported by a movable member 15 which is movably provided, and is moved according to the movement of the movable member. The movement direction of the moving member 15 is regulated by a guide member (not shown), and is biased rightward in the figure by the biasing force of the spring 15b.

【００３２】上記移動部材１５には、該移動部材１５を
左右方向へ往復移動させるための突起部１５ａが一体的
に形成されいる。この突起部１５ａに対向（対接）して
移動部材１５の移動のための駆動部を構成する回転駆動
される第１カム１６が設けられている。該第１ガム１６
は、回転軸１６ａが画像形成装置本体の感光体１や搬送
系等を駆動する駆動モータ２１の回転力が伝達手段２２
を介して伝達されており、画像形成時には一定速度で回
転される。従って、移動部材１５に固定支持された電磁
ソレノイド１４は、第１カム１６の周面に合わせた形状
に応じて、左右方向に往復移動される。しかしながら、
電磁ソレノイド１４が非通電状態においては、可動部材
１４が解放されていることから転写ローラ５は感光体１
に圧接されることはない。The moving member 15 is integrally formed with a protrusion 15a for reciprocating the moving member 15 in the left-right direction. A first cam 16 that is driven to rotate is provided so as to face (contact) the protrusion 15a and configure a drive unit for moving the moving member 15. The first gum 16
The rotational force of the drive motor 21 that drives the photoconductor 1 of the image forming apparatus main body, the conveyance system, and the like by the rotary shaft 16a is transmitted by the transmission means 22
And is rotated at a constant speed during image formation. Therefore, the electromagnetic solenoid 14 fixedly supported by the moving member 15 is reciprocally moved in the left-right direction according to the shape of the first cam 16 that matches the peripheral surface of the first cam 16. However,
When the electromagnetic solenoid 14 is de-energized, the transfer member 5 is released because the movable member 14 is released.
Will not be pressed against.

【００３３】上記可動部材１３の途中にはレバー１７を
連結するためにレバー１７の一端がピン１３ａにて回転
可能に支持されている。レバー１７は画像形成装置本体
側のフレーム等に取り付けられた軸部１７ａにて回転可
能に軸支されており、可動部材１３と連結された端部と
は反対側に凸部１７ｂを有している。この凸部１７ｂに
対向して、軸部１８ａにて回転可能に軸支されたカム移
動用のカムレバー１８が設けられている。In the middle of the movable member 13, one end of the lever 17 is rotatably supported by a pin 13a for connecting the lever 17. The lever 17 is rotatably supported by a shaft portion 17a attached to a frame or the like on the image forming apparatus main body side, and has a convex portion 17b on the side opposite to the end portion connected to the movable member 13. There is. A cam lever 18 for cam movement, which is rotatably supported by a shaft portion 18a, is provided facing the convex portion 17b.

【００３４】カムレバー１８は、少なくとも軸部１８ａ
を中心にして上記レバー１７と対向する反対側が、少な
くとも弾性変形可能な部材にて一体形成されている。こ
の弾性変形可能部分の端部１８ｂは、第１カム１６の回
転軸１６ａ方向への移動が可能で、かつ回転不可能に回
転軸１６ａに設けられた第２カム１９の底面（第１カム
１６と対向する面と反対面）に当接している。該第２カ
ム１９と第１カム１６との間には復帰スプリング２０が
介在され、両カム１６，１９を離間させるように付勢し
ている。復帰スプリング２０の付勢力に抗して、カムレ
バー１８が回動されると、第２カム１９は第１カム側へ
と移動する。The cam lever 18 has at least a shaft portion 18a.
The opposite side facing the lever 17 is integrally formed of at least an elastically deformable member. The end portion 18b of this elastically deformable portion is capable of moving the first cam 16 in the direction of the rotation shaft 16a, and is non-rotatably provided on the bottom surface of the second cam 19 (the first cam 16). And the opposite surface). A return spring 20 is interposed between the second cam 19 and the first cam 16 and urges the cams 16 and 19 to separate from each other. When the cam lever 18 is rotated against the biasing force of the return spring 20, the second cam 19 moves to the first cam side.

【００３５】上記第１カム１６と第２カム１９は、その
周面が両方合わせて真円となるように、その周面が形成
されており、第１カム１６は、回転軸１６ａに固定さ
れ、第２カム１９は回転軸１６ａに対し軸方向へのみ移
動可能に設けれている。そして、第１カム１６は移動部
材１５に一体形成された突起部１５ａと常に当接してお
り、第２カム１９はスプリング２０に抗して第１カム１
６側に移動された状態で、その周面が突起部１５ａに当
接可能になる。とくに、第１カム１６の大径面が突起部
１５ａと当接した状態において、第２カム１９の小径面
が突起部１５ａと対向するようにカムの周面が形成され
ていることから、この時にカムレバー１８の回動に応じ
て第２カム１９の周面が突起部１５ａに対向することが
できる。The peripheral surfaces of the first cam 16 and the second cam 19 are formed so that the peripheral surfaces thereof both match and form a perfect circle, and the first cam 16 is fixed to the rotary shaft 16a. The second cam 19 is provided so as to be movable only in the axial direction with respect to the rotary shaft 16a. The first cam 16 is always in contact with the projection 15a formed integrally with the moving member 15, and the second cam 19 resists the spring 20 and the first cam 1
When moved to the 6 side, its peripheral surface can come into contact with the protrusion 15a. In particular, since the peripheral surface of the cam is formed so that the small diameter surface of the second cam 19 faces the protruding portion 15a when the large diameter surface of the first cam 16 is in contact with the protruding portion 15a. At times, the peripheral surface of the second cam 19 can face the protrusion 15a according to the rotation of the cam lever 18.

【００３６】以上のように回動レバー１１を回動制御す
るための手段が構成されており、その構成をより理解し
よいように、以下にその動作を図面と共に説明する。The means for controlling the rotation of the rotation lever 11 is configured as described above, and its operation will be described below with reference to the drawings so that the configuration can be better understood.

【００３７】図において、図２は画像形成装置の画像形
成動作が停止中、つまり待機中であって、電磁ソレノイ
ド１４は非通電状態である。そのため可動部材１３は吸
入されることなく自由に移動可能であり、よって転写ロ
ーラ５及び保持部材６等の自重にて回動レバー１１が図
中時計方向に回動し、転写ローラ５は感光体１より離間
している。In FIG. 2, the image forming operation of the image forming apparatus is stopped, that is, in the standby state, and the electromagnetic solenoid 14 is in a non-energized state. Therefore, the movable member 13 can freely move without being sucked, so that the rotating lever 11 is rotated clockwise in the drawing by the weight of the transfer roller 5, the holding member 6 and the like, and the transfer roller 5 is a photosensitive member. It is separated from 1.

【００３８】そこで、画像形成動作が開始されると、感
光体１及び搬送系の搬送ローラ等が駆動され、必要に応
じて給紙ローラが駆動されて１枚給紙が行われ、給紙さ
れ転写紙は一旦レジストローラ等の待機される。そし
て、画像形成動作に応じて、感光体１に形成されたトナ
ー像が所定の位置まで回転してくると、上記レジストロ
ーラの回転が開始され、転写位置へと送り込まれる。Therefore, when the image forming operation is started, the photoconductor 1 and the carrying rollers of the carrying system are driven, and the paper feeding rollers are driven as needed to carry out one paper feeding and paper feeding. The transfer paper is once put on standby by a registration roller or the like. Then, when the toner image formed on the photoconductor 1 rotates to a predetermined position according to the image forming operation, the rotation of the registration roller is started and the toner image is sent to the transfer position.

【００３９】この画像形成動作に合わせて、転写ローラ
５は感光体１表面に転写動作を行う以前に圧接される。
つまり、電磁ソレノイド１４に通電されることで、可動
部材１３が吸入され図中左方向に移動する。この可動部
材１３の移動に応動して、ピン１１ｂにて連結された回
動レバー１１が反時計方向に回動され、圧縮スプリング
７を介して保持部材６を上方へと移動させ、転写ローラ
５を感光体１側へと移動させる。その状態を図３の
（ａ）および（ｂ）に示している。In accordance with this image forming operation, the transfer roller 5 is pressed against the surface of the photosensitive member 1 before the transfer operation is performed.
That is, when the electromagnetic solenoid 14 is energized, the movable member 13 is sucked and moved leftward in the drawing. In response to the movement of the movable member 13, the rotation lever 11 connected by the pin 11b is rotated in the counterclockwise direction to move the holding member 6 upward via the compression spring 7, and the transfer roller 5 Are moved to the photoconductor 1 side. The state is shown in FIGS. 3 (a) and 3 (b).

【００４０】そして、上述の動作と同時に、可動部材１
３にピン１３ａにて連結されたレバー１７が反時計方向
に回動され、あわせてカムレバー１８が時計方向に回動
される。これにより、カムレバー１８の第２カム１９と
当接する端部１８ｂにて、第２カム１９が第１カム１６
側へスプリング２０の付勢力に抗して移動される。そし
て、移動部材１５の突起部１５ａの端部に当接する。At the same time as the above operation, the movable member 1
The lever 17 connected to the pin 3 by the pin 13a is rotated counterclockwise, and the cam lever 18 is also rotated clockwise. As a result, the second cam 19 is moved to the first cam 16 at the end portion 18b of the cam lever 18 that comes into contact with the second cam 19.
It is moved to the side against the biasing force of the spring 20. Then, it abuts on the end of the protrusion 15a of the moving member 15.

【００４１】以上の動作と共に、駆動モータ２１の回転
により、伝達手段２２を介して回転軸１６ａも回転する
ことから、第１カム１６の周面の小径部が突起部１５ａ
に当接している状態から、徐々に大径部が当接すること
で、移動部材１５が左方向へと移動される。この移動に
より可動部材１３は、電磁ソレノイド１４による吸引駆
動より更に左側に移動されるため、回動レバー１１を介
して更に転写ローラ５を感光体１側へと押し上げる。In addition to the above operation, the rotation of the drive motor 21 also rotates the rotary shaft 16a via the transmission means 22, so that the small diameter portion of the peripheral surface of the first cam 16 is the protrusion 15a.
The moving member 15 is moved leftward by gradually abutting the large-diameter portion from the state in which the moving member 15 abuts. By this movement, the movable member 13 is moved further to the left side than the suction drive by the electromagnetic solenoid 14, so that the transfer roller 5 is further pushed up toward the photoconductor 1 side via the turning lever 11.

【００４２】図４の（ａ）及び（ｂ）には、第１カム１
６の周面の大径部が突起部１５ａに対応した状態を示
し、この状態において移動部材１５の左方向の移動量が
最大となり、回動レバー１１を介して転写ローラ５を感
光体１に圧接させる。この時、圧縮スプリング７の付勢
力による一定圧力で転写ローラ５が感光体１に圧接され
る。The first cam 1 is shown in FIGS. 4 (a) and 4 (b).
The large-diameter portion of the peripheral surface of 6 corresponds to the protrusion 15a. In this state, the movement amount of the moving member 15 in the left direction is maximized, and the transfer roller 5 is moved to the photoconductor 1 via the turning lever 11. Press it. At this time, the transfer roller 5 is pressed against the photoconductor 1 with a constant pressure by the urging force of the compression spring 7.

【００４３】また、第２カム１９の小径部は、上述の可
動部材１３の移動に合わせて、レバー１７及びカムレバ
ー１８を介して第１カム１６へと更に移動され、突起部
１５ａに対応することになる。従って、以後は上記第１
カム１６及び第２カム１９の周面が合わせて円形状にな
るため、駆動モータ２１の回転が回転軸１６ａに伝達さ
れ回転を継続しても、移動部材１５の移動がなく、該移
動量の最大位置が維持されることになる。そのため、転
写ローラ５の感光体１への圧接状態には変化なく、転写
ローラ５は一定の圧力で感光体１に加圧される。この状
態を図５の（ａ）及び（ｂ）に示す。なお、カムレバー
１８は第２カム１９を移動させる時に、それ以上の作用
力が生じた時には、弾性変形することで第２カム１９の
移動を行う作用力以外の力を吸収することになる。Further, the small diameter portion of the second cam 19 is further moved to the first cam 16 via the lever 17 and the cam lever 18 in accordance with the movement of the movable member 13 described above, and corresponds to the protrusion 15a. become. Therefore, after that, the first
Since the circumferential surfaces of the cam 16 and the second cam 19 are combined into a circular shape, even if the rotation of the drive motor 21 is transmitted to the rotating shaft 16a and continues to rotate, the moving member 15 does not move and the amount of movement is The maximum position will be maintained. Therefore, the transfer roller 5 remains pressed against the photoconductor 1, and the transfer roller 5 is pressed against the photoconductor 1 with a constant pressure. This state is shown in FIGS. 5 (a) and 5 (b). It should be noted that the cam lever 18 absorbs a force other than the action force for moving the second cam 19 by elastically deforming when a further action force is generated when the second cam 19 is moved.

【００４４】画像形成動作が終了すれば、電磁ソレノイ
ド１４への通電状態が断たれる。また、回転軸１６ａの
回転も停止する。これにより、可動部材１３が自由に移
動できる状態となり、転写ローラ５等の自重により、回
動レバー１１が下方に押下げられ、よって感光体１より
転写ローラ５が離間される。この時、回転軸１６ａが回
転されていても、上述のように電磁ソレノイド１４への
通電を解除することで、簡単に転写ローラ５の感光体１
への加圧状態が解除される。When the image forming operation is completed, the power supply to the electromagnetic solenoid 14 is cut off. Further, the rotation of the rotary shaft 16a also stops. As a result, the movable member 13 becomes free to move, and the rotating lever 11 is pushed downward by the weight of the transfer roller 5 and the like, so that the transfer roller 5 is separated from the photoconductor 1. At this time, even if the rotary shaft 16a is rotated, by deenergizing the electromagnetic solenoid 14 as described above, the photoconductor 1 of the transfer roller 5 can be easily operated.
The pressure applied to is released.

【００４５】しかも、電磁ソレノイド１４の通電解除に
より、レバー１７によるカムレバー１８の回動付勢が同
時に解かれるため、第２カム１９を復帰スプリング２０
の付勢力に抗して移動させていたカムレバー１８の作用
解除により、復帰スプリング２０により図３の（ａ）に
示す状態に第２カム１９が復帰する。Moreover, since the turning bias of the cam lever 18 by the lever 17 is released at the same time when the electromagnetic solenoid 14 is de-energized, the second cam 19 is returned to the return spring 20.
The second spring 19 is returned to the state shown in FIG. 3A by the return spring 20 by releasing the action of the cam lever 18 that has been moved against the urging force of the second cam 19.

【００４６】以上動作説明したように、電磁ソレノイド
１４及び可動部材１３は電磁的に吸引された後（ストロ
ーク０）で転写ローラ５の加圧動作を行うことにより、
図６に示すように、電磁ソレノイド１４を吸引力最大点
で利用できるため、電磁ソレノイド自体、小型でかつ低
コストの電磁ソレノイドを利用できる。また電磁ソレノ
イドへの通電を解除すれば、画像形成動作に関係なく移
動部材１５を移動させる駆動源が停止しても、感光体１
への転写ローラ５の圧接状態を解除し、離間させること
ができる。そのため、画像形成装置の電源断の状態にお
いても、転写ローラ５を感光体１より離間させることが
確実になる。As described above, the electromagnetic solenoid 14 and the movable member 13 are pressed by the transfer roller 5 after being electromagnetically attracted (stroke 0).
As shown in FIG. 6, since the electromagnetic solenoid 14 can be used at the maximum attraction force, the electromagnetic solenoid itself and the small-sized and low-cost electromagnetic solenoid can be used. Further, if the electromagnetic solenoid is de-energized, even if the drive source for moving the moving member 15 stops regardless of the image forming operation, the photoconductor 1
It is possible to release the pressure contact state of the transfer roller 5 with respect to and separate them. Therefore, it is ensured that the transfer roller 5 is separated from the photoconductor 1 even when the image forming apparatus is powered off.

【００４７】とくに、本発明の圧力制御装置によれば、
電磁ソレノイド１４を設け、該電磁ソレノイドを移動さ
せるための駆動部を構成する第１カム１６及び第２カム
１９からなるカム機構を設けることで、転写ローラ５の
感光体１への圧接又は離間制御を行えるため、簡単で小
型化でき、さらに低コスト化を可能にできる。Particularly, according to the pressure control device of the present invention,
By providing the electromagnetic solenoid 14 and the cam mechanism composed of the first cam 16 and the second cam 19 which constitute the drive unit for moving the electromagnetic solenoid, the contact or separation of the transfer roller 5 to the photoconductor 1 is controlled. Therefore, the size can be reduced easily and the cost can be further reduced.

【００４８】なお、本実施例によれば、圧力制御装置を
画像形成装置の転写ローラ５に利用した例を示した。し
かしながら、感光体１を均一帯電するために帯電ローラ
や帯電ブラシを利用する場合や、除電を除電ローラ等を
用いる場合には、同様にして実施できる。According to this embodiment, the pressure controller is used as the transfer roller 5 of the image forming apparatus. However, when a charging roller or a charging brush is used to uniformly charge the photoconductor 1 or when a charge eliminating roller or the like is used, the same process can be performed.

【００４９】また、画像形成を行うプロセス部だけでな
く、転写紙を搬送する搬送系においても利用できる。例
えば、搬送ローラの一方を加圧ローラとして他方のロー
ラに対し移動可能に設け、加圧ローラを転写紙の搬送時
に圧接させ、不要時、つまり非画像形成時には離間させ
ることもできる。そのための構成としては、上述に説明
した圧力制御装置をそのまま利用できる。Further, it can be used not only in the process section for forming an image, but also in the conveying system for conveying the transfer paper. For example, one of the transport rollers may be provided as a pressure roller so as to be movable with respect to the other roller, and the pressure roller may be brought into pressure contact when transporting the transfer paper and may be separated when unnecessary, that is, at the time of non-image formation. As the configuration for that, the pressure control device described above can be used as it is.

【００５０】また、搬送系を構成する定着装置、つまり
加熱ローラ等からなる一対のローラを、一方を他方に対
し加圧可能に設けておき、画像形成動作中に加圧状態と
して、非画像形成動作中に離間させるように、本発明の
圧力制御装置を利用して実施できる。In addition, a fixing device constituting the conveying system, that is, a pair of rollers including a heating roller and the like is provided so that one of the rollers can be pressed against the other, and a non-image forming operation is performed by applying a pressure during the image forming operation. It can be implemented utilizing the pressure control device of the present invention to be spaced apart during operation.

【００５１】しかも、ローラ部材でなく、例えば感光体
１に圧接されるクリーニングブレード８ａの加圧状態を
解除する必要がある場合には、本発明による圧力制御装
置を適用できる。Moreover, when it is necessary to release the pressing state of the cleaning blade 8a that is pressed against the photosensitive member 1 instead of the roller member, the pressure control device according to the present invention can be applied.

【００５２】[0052]

【発明の効果】以上の説明から明らかになったように、
本発明の圧力制御装置によれば、加圧部材を被加圧部材
より必要に応じて離間及び加圧することができる。特
に、装置本体の不使用時には、必ず離間することがで
き、圧接状態による経時的な変化を解消できる。また、
そのための構成が非常に簡単であり、装置の小型化と共
に低コストが可能になる。As is apparent from the above description,
According to the pressure control device of the present invention, the pressing member can be separated from and pressed by the member to be pressed as necessary. In particular, when the main body of the apparatus is not used, the main body can be separated from each other, and the change over time due to the pressure contact state can be eliminated. Also,
The configuration therefor is very simple, and the device can be downsized and the cost can be reduced.

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

【図１】本発明の圧力制御装置を転写ローラに実施した
画像形成装置の概略を示す側面図。FIG. 1 is a side view showing an outline of an image forming apparatus in which a pressure control device of the present invention is applied to a transfer roller.

【図２】本発明の圧力制御装置の一実施例による細を示
す構成図であり、（ａ）は上面図、（ｂ）は側面図。2A and 2B are configuration diagrams showing details of an embodiment of a pressure control device of the present invention, in which FIG. 2A is a top view and FIG. 2B is a side view.

【図３】本発明の圧力制御装置の動作説明にかかる転写
ローラの加圧過程を示す動作図であり、（ａ）は上面
図、（ｂ）は側面図。3A and 3B are operation diagrams illustrating a pressing process of the transfer roller according to the operation of the pressure control device of the present invention, in which FIG. 3A is a top view and FIG. 3B is a side view.

【図４】本発明の圧力制御装置の動作説明にかかる転写
ローラの加圧状態を示す動作図であり、（ａ）は上面
図、（ｂ）は側面図。4A and 4B are operation diagrams showing a pressing state of the transfer roller according to the operation description of the pressure control device of the present invention, in which FIG. 4A is a top view and FIG. 4B is a side view.

【図５】本発明の圧力制御装置の動作説明にかかる転写
ローラの加圧状態を維持状態を示す動作図であり、
（ａ）は上面図、（ｂ）は側面図。FIG. 5 is an operation diagram showing a pressurizing state and a maintaining state of the transfer roller according to the operation explanation of the pressure control device of the present invention;
(A) is a top view and (b) is a side view.

【図６】本発明にかかる電磁ソレノイドの吸引力特性を
示す特性図。FIG. 6 is a characteristic diagram showing attraction force characteristics of an electromagnetic solenoid according to the present invention.

【図７】従来の圧力制御の一態様を示す図。FIG. 7 is a diagram showing one mode of conventional pressure control.

【符号の説明】[Explanation of symbols]

１ 感光体 ５ 転写ローラ ６ 保持部材 １０ 圧力制御装置 １１ 回動レバー １２ 圧力制御手段 １３ 可動部材 １４ 電磁ソレノイド １５ 移動部材 １６ 第１カム １６ａ カム回転軸 １９ 第２カム ２１ 駆動モータ DESCRIPTION OF SYMBOLS 1 Photoconductor 5 Transfer roller 6 Holding member 10 Pressure control device 11 Rotating lever 12 Pressure control means 13 Movable member 14 Electromagnetic solenoid 15 Moving member 16 First cam 16a Cam rotation shaft 19 Second cam 21 Drive motor

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.⁵ 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｇ０３Ｇ 15/20 １０７ ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location G03G 15/20 107

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】加圧部材を移動可能に設け、該加圧部材を
被加圧部材に圧接又は離間させる圧力制御装置におい
て、 上記加圧部材を支持し該加圧部材の自重より上記被加圧
部材に対し離間する位置に移動し、また圧接位置に移動
させるため支持部材と、 該支持部材を圧接方向に駆動するための電磁ソレノイド
と、 該電磁ソレノイドの通電時に一方向に駆動されて上記支
持部材を圧接方向への移動させ、非通電時に自由に移動
可能であって、上記支持部材に連結された可動部材と、 上記電磁ソレノイドを固定支持し、該電磁ソレノイドの
通電時に上記可動部材の駆動方向と同方向に往復移動可
能に設けられた移動部材と、 該移動部材を往復移動させると共に、上記可動部材の移
動量の最大位置でその状態を維持させる駆動部と、を備
え上記電磁ソレノイドに通電し上記可動部材を一方向駆
動し、且つ上記移動部材を上記駆動部を介して同方向へ
移動させることで上記加圧部材を被加圧部材に圧接さ
せ、上記電磁ソレノイドの通電の解除により上記可動部
材の自由移動により上記加圧接部材を被加圧部材離間さ
せてなる加圧部材の圧力制御装置。1. A pressure control device, wherein a pressure member is movably provided, and the pressure member is brought into pressure contact with or separated from a pressure member, the pressure member being supported by the weight of the pressure member. The support member is moved to a position separated from the pressure member and is moved to the pressure contact position, an electromagnetic solenoid for driving the support member in the pressure contact direction, and the electromagnetic solenoid is driven in one direction when energized. The support member is moved in the pressure contact direction, and is freely movable when not energized. The movable member coupled to the support member and the electromagnetic solenoid are fixedly supported, and the movable member of the movable member is energized when the electromagnetic solenoid is energized. The moving member is provided so as to be able to reciprocate in the same direction as the driving direction, and the driving unit that reciprocates the moving member and maintains the state at the maximum position of the moving amount of the movable member. The solenoid is energized to drive the movable member in one direction, and the moving member is moved in the same direction via the driving unit to bring the pressure member into pressure contact with the member to be pressed, thereby energizing the electromagnetic solenoid. A pressure control device for a pressing member, wherein the pressing contact member is separated from the member to be pressed by free movement of the movable member when released. 【請求項２】上記加圧部材及び被加圧部材は、画像形成
装置における帯電部材及び記録媒体からなり、帯電部材
の記録媒体への圧接時に帯電を行うことを特徴とする請
求項１記載の加圧部材の圧力制御装置。2. The pressing member and the pressed member are composed of a charging member and a recording medium in an image forming apparatus, and are charged when the charging member is pressed against the recording medium. Pressure control device for pressure member. 【請求項３】上記加圧部材及び被加圧部材は、画像形成
装置における用紙の搬送するために一方のローラに対し
て他方のローラを圧接又は離間させる構成の搬送手段で
あることを特徴とする請求項１記載の加圧部材の圧力制
御装置。3. The pressurizing member and the pressurized member are conveying means configured to press or separate one roller from another roller in order to convey a sheet in an image forming apparatus. The pressure control device for the pressure member according to claim 1.