JP2008105778A

JP2008105778A - Image forming device

Info

Publication number: JP2008105778A
Application number: JP2006288296A
Authority: JP
Inventors: Tatsuya Kobayashi; 竜也小林
Original assignee: Kyocera Mita Corp
Current assignee: Kyocera Document Solutions Inc
Priority date: 2006-10-24
Filing date: 2006-10-24
Publication date: 2008-05-08

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of properly holding a distance from paper, effectively carrying out static elimination and carrying paper with a suitable carrying route. <P>SOLUTION: A paper carrying passage 40 located on a paper carrying direction downstream side of a transfer part 30 for transferring a toner image on a surface of a photoreceptor drum 21 to paper is provided with a carrying guide member 41 for guiding carrying of paper and a static eliminating member 42 arranged on a surface of the carrying guide member 41 to eliminate charged charge of paper. This image forming device is provided with a first driving device 50 for rotating the static eliminating member 42 in a vertical plane along a paper carrying direction. As a result, the position of the static eliminating member 42 can be changed corresponding to a change of pulling of paper to the static eliminating member 42 according to the kind of paper and humidity. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、複写機やプリンタに代表される画像形成装置に関する。 The present invention relates to an image forming apparatus represented by a copying machine or a printer.

複写機やプリンタ等の電子写真方式の画像形成装置には、感光体表面にトナー像を形成する画像形成部（作像部）やそのトナー像を用紙に転写する転写部、用紙に転写されたトナー像を定着させる定着部などといった構成要素が設けられている。用紙は、これらを含めた各構成要素間を、用紙搬送路に沿って搬送せしめられる。用紙搬送路には、その経路を構成する搬送ガイド部材や、用紙に送りを与えるための搬送ローラ、搬送コロ、そして搬送方向を切り替える可動ガイドなどが配置されている。 In an electrophotographic image forming apparatus such as a copying machine or a printer, an image forming unit (image forming unit) that forms a toner image on the surface of a photosensitive member, a transfer unit that transfers the toner image to a sheet, Components such as a fixing unit for fixing the toner image are provided. The sheet is conveyed along the sheet conveyance path between the components including these. In the sheet conveyance path, a conveyance guide member constituting the path, a conveyance roller for feeding the sheet, a conveyance roller, and a movable guide for switching the conveyance direction are arranged.

ここで、用紙は、転写部においてトナー像が転写されたり、搬送中に搬送ガイド部材や搬送ローラと接触したりすることにより、電荷が蓄積し、帯電してしまうことがある。そして、このように帯電した用紙に関して、特に転写部の用紙搬送方向下流側で、搬送ガイド部材などとの間に大きな電位差が生じる場合がある。この用紙が、搬送ガイド部材などと接触すると、急激な電位変化によって放電が生じ、用紙上の未定着トナーが飛散する恐れがある。これにより、トナー像は乱れ、異常画像が発生するといった問題となる。 Here, the sheet may be charged due to charge accumulation due to transfer of the toner image at the transfer unit or contact with the conveyance guide member or the conveyance roller during conveyance. A large potential difference may occur between the charged sheet and the conveyance guide member, particularly on the downstream side of the transfer unit in the sheet conveyance direction. When this sheet comes into contact with a conveyance guide member or the like, a sudden electric potential change may cause a discharge, and unfixed toner on the sheet may be scattered. As a result, the toner image is disturbed and an abnormal image is generated.

また、転写部から排出された用紙は、トナーと同極に帯電している。このまま、用紙に蓄積された電荷を除去することなく、用紙が定着部に進入すると、用紙とトナーとの間で反発が生じて正常にトナーが定着されず、熱ローラ（定着ローラ）にトナーが付着してしまう恐れがある。これにより、画像が、熱ローラの周回ピッチで二重に印刷される定着オフセットという不具合が発生する。 Further, the paper discharged from the transfer unit is charged to the same polarity as the toner. If the sheet enters the fixing unit without removing the electric charge accumulated on the sheet, the repulsion occurs between the sheet and the toner and the toner is not normally fixed, and the toner is not fixed on the heat roller (fixing roller). There is a risk of sticking. As a result, there arises a problem of fixing offset in which an image is printed doubly at a circumferential pitch of the heat roller.

そこで、上記のような画像乱れの原因となる電荷の除去を行う手法として、転写部の用紙搬送方向下流に、除電部材を設けた搬送ガイド部材を配置した画像形成装置が提案され、その一例を特許文献１に見ることができる。
特開２００２−３２８５５２号公報（第４頁、図１） Therefore, as a technique for removing the charge that causes image disturbance as described above, an image forming apparatus is proposed in which a conveyance guide member provided with a charge removal member is arranged downstream of the transfer unit in the sheet conveyance direction. It can be seen in Patent Document 1.
JP 2002-328552 A (4th page, FIG. 1)

ここで、印刷に使用される用紙は、厚さなどのその種類や湿度によっては、帯電量が異なる場合がある。そして、これにより、用紙が除電部材に引っ張られる量も変化する。 Here, the paper used for printing may have different charge amounts depending on its type such as thickness and humidity. As a result, the amount by which the sheet is pulled by the charge removal member also changes.

特許文献１に記載された画像形成装置では、用紙搬送方向、及びこれと直角をなす用紙幅方向に延びる搬送ガイドの表面に、薄い板金で構成された搬送板金（除電部材）が配置され、この搬送板金によって用紙の除電を行っている。しかしながら、この構成では、搬送ガイドや除電部材が固定されているので、上記にように種類や湿度によって変化する、用紙の除電部材への引っ張られ方の違いに対応することができない。つまり、用紙と除電部材との距離が遠い場合に、効果的な用紙の除電を行うことができない恐れがある。また、用紙を除電部材の方へと引っ張ることができないので、下流に続く構成要素、すなわち定着部へと適正に用紙を送り込むことができないといった問題が発生する可能性もある。 In the image forming apparatus described in Patent Document 1, a conveyance sheet metal (static elimination member) made of a thin sheet metal is disposed on the surface of a conveyance guide extending in the sheet conveyance direction and the sheet width direction perpendicular to the sheet conveyance direction. The sheet is neutralized by the conveying sheet metal. However, in this configuration, since the conveyance guide and the charge removal member are fixed, it is not possible to cope with the difference in how the sheet is pulled to the charge removal member, which varies depending on the type and humidity as described above. In other words, when the distance between the sheet and the charge removal member is long, there is a possibility that effective sheet charge removal cannot be performed. In addition, since the sheet cannot be pulled toward the static eliminator, there is a possibility that a problem may occur that the sheet cannot be properly fed to the downstream components, that is, the fixing unit.

本発明は上記の点に鑑みなされたものであり、搬送ガイド部材と、この表面に配置された除電部材とにより、用紙の帯電電荷を除去するに際し、用紙との距離を適正に保持し、効果的な除電を遂行するとともに、好適な搬送経路でもって用紙を搬送することが可能な画像形成装置を提供することを目的とする。 The present invention has been made in view of the above points, and when removing the charged charge on the paper, the conveyance guide member and the charge removing member disposed on the surface appropriately maintain the distance from the paper. An object of the present invention is to provide an image forming apparatus capable of performing static neutralization and transporting paper along a suitable transport path.

上記の課題を解決するため、本発明は、用紙の搬送をガイドする搬送ガイド部材と、この搬送ガイド部材の表面に配置され、用紙の帯電電荷を除去する除電部材とを備えた画像形成装置において、前記除電部材を用紙搬送方向に沿う垂直面内で回転させる第１の駆動装置を設けることとした。 In order to solve the above-described problems, the present invention provides an image forming apparatus including a conveyance guide member that guides conveyance of a sheet, and a charge removal member that is disposed on a surface of the conveyance guide member and removes a charged charge of the sheet. The first driving device is provided for rotating the static elimination member in a vertical plane along the sheet conveyance direction.

また、上記構成の画像形成装置において、前記搬送ガイド部材を用紙搬送方向に沿う垂直面内で回転させる第２の駆動装置を設けることとした。 In the image forming apparatus having the above-described configuration, a second driving device that rotates the conveyance guide member in a vertical plane along the sheet conveyance direction is provided.

また、上記構成の画像形成装置において、前記搬送ガイド部材は、用紙搬送空間に突出する複数のリブを備え、前記除電部材は、搬送ガイド部材の前記リブが貫通する複数のスリットを備えることとした。 In the image forming apparatus having the above configuration, the conveyance guide member includes a plurality of ribs protruding into the sheet conveyance space, and the charge removal member includes a plurality of slits through which the ribs of the conveyance guide member pass. .

また、上記構成の画像形成装置において、前記搬送ガイド部材及び前記除電部材を、像担持体表面のトナー像を用紙に転写する転写部の用紙搬送方向下流側に備えることとした。 In the image forming apparatus having the above-described configuration, the conveyance guide member and the charge removal member are provided on the downstream side in the sheet conveyance direction of the transfer unit that transfers the toner image on the surface of the image carrier to the sheet.

本発明の構成によれば、用紙の搬送をガイドする搬送ガイド部材と、この搬送ガイド部材の表面に配置され、用紙の帯電電荷を除去する除電部材とを備えた画像形成装置において、除電部材を用紙搬送方向に沿う垂直面内で回転させる第１の駆動装置を設けることとしたので、除電部材の位置を変更することが可能である。これにより、用紙と除電部材との距離を適正に保持することができ、種類や湿度によって変化する、用紙の除電部材への引っ張られ方の違いに対応することができる。したがって、効果的な除電を遂行するとともに、好適な搬送経路でもって用紙を搬送することが可能な画像形成装置を得ることができる。 According to the configuration of the present invention, in the image forming apparatus including the conveyance guide member that guides the conveyance of the sheet and the neutralization member that is disposed on the surface of the conveyance guide member and removes the charged charge of the sheet, Since the first drive device that rotates in the vertical plane along the sheet conveyance direction is provided, the position of the charge removal member can be changed. As a result, the distance between the sheet and the charge removal member can be appropriately maintained, and it is possible to cope with the difference in the method of pulling the sheet to the charge removal member, which varies depending on the type and humidity. Therefore, it is possible to obtain an image forming apparatus capable of performing effective static elimination and transporting paper along a suitable transport path.

また、搬送ガイド部材を用紙搬送方向に沿う垂直面内で回転させる第２の駆動装置を設けることとしたので、搬送ガイド部材の位置を変更することが可能である。これにより、種類や湿度によって変化する、用紙の除電部材への引っ張られ方の違いに対応した、搬送性能の向上を図ることができる。したがって、さらに好適な搬送経路でもって用紙を搬送することが可能である。 In addition, since the second driving device that rotates the conveyance guide member in the vertical plane along the sheet conveyance direction is provided, the position of the conveyance guide member can be changed. Thereby, it is possible to improve the conveyance performance corresponding to the difference in how the sheet is pulled to the charge removal member, which varies depending on the type and humidity. Therefore, it is possible to transport the paper along a more preferable transport path.

また、搬送ガイド部材は、用紙搬送空間に突出する複数のリブを備えることとしたので、リブ頂部で用紙を支持することができ、搬送ガイド部材の用紙との接触面積をできるだけ少なくすることができる。これにより、搬送ガイド部材と用紙との摩擦を低減することができ、用紙やトナー像の破損、搬送性能の低下を防止することが可能である。さらに、除電部材は、搬送ガイド部材の前記リブが貫通する複数のスリットを備えることとしたので、用紙に除電部材を直接接触させることなく、搬送ガイド部材表面を通過する用紙の近傍に除電部材を配置することができる。これにより、用紙との距離を適正に保持することが一層簡便になり、さらに効果的な除電を遂行することが可能である。 In addition, since the conveyance guide member includes a plurality of ribs protruding into the sheet conveyance space, the sheet can be supported at the top of the rib, and the contact area between the conveyance guide member and the sheet can be reduced as much as possible. . As a result, friction between the conveyance guide member and the sheet can be reduced, and damage to the sheet and toner image and a decrease in conveyance performance can be prevented. Further, since the neutralizing member includes a plurality of slits through which the ribs of the conveyance guide member pass, the neutralization member is disposed in the vicinity of the sheet passing through the surface of the conveyance guide member without directly contacting the neutralization member with the sheet. Can be arranged. As a result, it becomes easier to maintain the distance from the paper properly, and more effective static elimination can be performed.

また、搬送ガイド部材及び除電部材を、像担持体表面のトナー像を用紙に転写する転写部の用紙搬送方向下流側に備えることとしたので、特に用紙と搬送ガイド部材との間に大きな電位差が生じ易い箇所において、効果的な除電の遂行と、好適な搬送経路での用紙の搬送とが可能になる。これにより、用紙上の未定着トナーの飛散や、定着オフセットといった画像不良の発生を防止することができる。したがって、安定した定着性能を期待することができる。 In addition, since the conveyance guide member and the charge removal member are provided on the downstream side in the sheet conveyance direction of the transfer unit that transfers the toner image on the surface of the image carrier to the sheet, there is a large potential difference between the sheet and the conveyance guide member. It is possible to perform effective static elimination and transport the paper along a suitable transport path at a place where it easily occurs. Thereby, it is possible to prevent the occurrence of image defects such as scattering of unfixed toner on the paper and fixing offset. Therefore, stable fixing performance can be expected.

以下、本発明の実施形態を図１〜図１２に基づき説明する。 Hereinafter, embodiments of the present invention will be described with reference to FIGS.

最初に、本発明の実施形態に係る画像形成装置について、図１を用いてその構造の概略を説明しつつ、画像出力動作を説明する。図１は、画像形成装置の概略構造を示す模型的垂直断面右側面図である。図１において左方が画像形成装置の前面側、右方が背面側である。 First, an image output operation of an image forming apparatus according to an embodiment of the present invention will be described while explaining an outline of the structure with reference to FIG. FIG. 1 is a schematic vertical sectional right side view showing a schematic structure of an image forming apparatus. In FIG. 1, the left side is the front side of the image forming apparatus, and the right side is the back side.

図１に示すように、画像形成装置１の本体２の下部には、用紙カセット３が配置されている。用紙カセット３の内部には、印刷前のカットペーパー等の用紙が積まれて収容される。そして、この用紙は、図１において用紙カセット３の左上方に向けて、１枚ずつ分離されて送り出される。用紙カセット３は、本体２の前面側、すなわち図１において左方から水平に引き出すことが可能である。 As shown in FIG. 1, a paper cassette 3 is disposed at the lower part of the main body 2 of the image forming apparatus 1. Inside the paper cassette 3, paper such as cut paper before printing is stacked and stored. The sheets are separated and sent one by one toward the upper left of the sheet cassette 3 in FIG. The paper cassette 3 can be pulled out horizontally from the front side of the main body 2, that is, from the left side in FIG.

用紙カセット３の用紙搬送方向下流には、給紙用用紙搬送路４、給紙用搬送ローラ５、レジストローラ６、画像形成部２０、及び転写部３０が配置されている。用紙カセット３から送り出された用紙は、給紙用用紙搬送路４に進入し、給紙用搬送ローラ５により搬送されて、レジストローラ６に到達する。レジストローラ６は、用紙の斜め送りを矯正しつつ、画像形成部２０で形成されるトナー像とのタイミングを計り、用紙を転写部３０へと送り出す。 A paper feed path 4, a paper feed transport roller 5, a registration roller 6, an image forming unit 20, and a transfer unit 30 are disposed downstream of the paper cassette 3 in the paper transport direction. The sheet sent out from the sheet cassette 3 enters the sheet feeding sheet conveyance path 4, is conveyed by the sheet feeding conveyance roller 5, and reaches the registration roller 6. The registration roller 6 feeds the paper to the transfer unit 30 by correcting the oblique feeding of the paper and timing the toner image formed by the image forming unit 20.

画像形成部２０には、その中心に、回転体の像担持体である感光体ドラム２１が備えられている。感光体ドラム２１は、図１において反時計方向に回転する。感光体ドラム２１の周囲には、その回転方向に沿って順に帯電装置２２、現像装置２３、及びドラム用クリーニング装置２４が配置されている。 The image forming unit 20 includes a photosensitive drum 21 which is a rotating image carrier at the center thereof. The photosensitive drum 21 rotates counterclockwise in FIG. Around the photosensitive drum 21, a charging device 22, a developing device 23, and a drum cleaning device 24 are sequentially arranged along the rotation direction.

一方、外部コンピュータ（図示せず）からの文字や図形、模様等の画像データ信号が画像形成装置１に送信され、この画像データに基づき、画像形成部２０上方に備えられた光学部７にて制御されるレーザ光Ｌ（図中二点鎖線）が、感光体ドラム２１に向かって照射される。これにより、画像形成部２０においては、感光体ドラム２１表面に原稿画像の静電潜像が形成される。この静電潜像から、感光体ドラム２１に対向して配置された現像装置２３によってトナー像が現像される。トナー像は、前記レジストローラ６によって同期をとって送られてきた用紙に、感光体ドラム２１と転写部３０の転写ローラ３１とが圧接して形成される転写ニップ部にて転写される。 On the other hand, image data signals such as characters, graphics, and patterns from an external computer (not shown) are transmitted to the image forming apparatus 1, and based on this image data, the optical unit 7 provided above the image forming unit 20. Laser light L to be controlled (two-dot chain line in the figure) is irradiated toward the photosensitive drum 21. Thereby, in the image forming unit 20, an electrostatic latent image of the original image is formed on the surface of the photosensitive drum 21. From this electrostatic latent image, a toner image is developed by a developing device 23 arranged to face the photosensitive drum 21. The toner image is transferred to a sheet fed synchronously by the registration roller 6 at a transfer nip portion formed by press contact between the photosensitive drum 21 and the transfer roller 31 of the transfer portion 30.

画像形成部２０、及び転写部３０の用紙搬送方向下流には、定着部８、排出用用紙搬送路９、及び用紙排出部１０が配置されている。転写部３０にて未定着トナー像を担持した用紙は、定着部８へと送られ、熱ローラと加圧ローラとにより加熱、加圧され、トナー像が定着される。定着部８から排出された用紙は、排出用用紙搬送路９を通って上方へ送られ、本体２の上面に設けられた用紙排出部１０に排出される。用紙排出部１０は、本体２の上面に、印刷済みの用紙を外部から取り出し可能な位置に設けられている。 A fixing unit 8, a discharge paper transport path 9, and a paper discharge unit 10 are disposed downstream of the image forming unit 20 and the transfer unit 30 in the paper transport direction. The sheet carrying the unfixed toner image in the transfer unit 30 is sent to the fixing unit 8 and heated and pressed by the heat roller and the pressure roller to fix the toner image. The sheet discharged from the fixing unit 8 is sent upward through the discharge sheet conveyance path 9 and is discharged to the sheet discharge unit 10 provided on the upper surface of the main body 2. The paper discharge unit 10 is provided on the upper surface of the main body 2 at a position where a printed paper can be taken out from the outside.

定着部８、及び転写部３０の下方であって、用紙カセット３との間には、両面印刷用用紙搬送路１１が配置されている。両面印刷用用紙搬送路１１は、排出用用紙搬送路９の途中から分岐し、定着部８の下方、及び転写部３０の下方を通り、給紙用搬送ローラ５のすぐ上流で給紙用用紙搬送路４に合流している。 A paper transport path 11 for double-sided printing is disposed below the fixing unit 8 and the transfer unit 30 and between the paper cassette 3. The double-sided printing paper conveyance path 11 branches from the middle of the discharge paper conveyance path 9, passes under the fixing unit 8 and under the transfer unit 30, and immediately upstream of the paper supply conveyance roller 5. It merges with the conveyance path 4.

両面印刷を行う場合、定着部８から排出された用紙は、排出用用紙搬送路９を通って用紙排出部１０に排出される直前に、その搬送方向が逆方向に切り替えられ、スイッチバックされる。そして、用紙は、両面印刷用用紙搬送路１１に送られ、給紙用搬送ローラ５のすぐ上流で給紙用用紙搬送路４に合流せしめられて、再度転写部３０へと送られる。 When performing double-sided printing, the sheet discharged from the fixing unit 8 is switched to the reverse direction and switched back immediately before being discharged to the sheet discharge unit 10 through the discharge sheet transfer path 9. . Then, the paper is sent to the paper transport path 11 for double-sided printing, joined to the paper feed paper transport path 4 immediately upstream of the paper feed transport roller 5, and sent again to the transfer unit 30.

続いて、上記画像形成装置１の、転写部３０と定着部８との間に設けられた用紙搬送路４０の詳細な構成について、図１に加えて、図２〜図７を用いて説明する。 Subsequently, a detailed configuration of the sheet conveyance path 40 provided between the transfer unit 30 and the fixing unit 8 of the image forming apparatus 1 will be described with reference to FIGS. 2 to 7 in addition to FIG. .

図２は転写部とその下流の用紙搬送路周辺を示す斜視図、図３は図２の用紙搬送路の下側用紙ガイドを示す斜視図、図４は搬送ガイド部材の斜視図、図５は除電部材の斜視図である。図６は搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、上方から見たもの、図７は搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、右側から見たものである。なお、図２〜図５においては、図６、図７に示す搬送ガイド部材及び除電部材の駆動装置の描画を省略している。 2 is a perspective view showing the transfer portion and the periphery of the paper conveyance path downstream thereof, FIG. 3 is a perspective view showing a lower paper guide of the paper conveyance path in FIG. 2, FIG. 4 is a perspective view of the conveyance guide member, and FIG. It is a perspective view of a static elimination member. FIG. 6 is a perspective view showing the conveyance guide member, the charge removal member, and their driving device, as viewed from above, and FIG. 7 is a perspective view showing the conveyance guide member, the charge removal member, and their drive device, Viewed from the right side. 2 to 5, illustrations of the conveyance guide member and the neutralization member driving device shown in FIGS. 6 and 7 are omitted.

図２に示すように、転写部３０の用紙搬送方向下流側であって、定着部８（図１参照）との間に設けられた用紙搬送路４０には、その下側の用紙ガイドとして、搬送ガイド部材４１と、除電部材４２とが備えられている。搬送ガイド部材４１と、除電部材４２とは、図３に示すように、上下に重ね合わせたような形にして、除電部材４２が搬送ガイド部材４１の表面に配置されている。 As shown in FIG. 2, a sheet guide on the downstream side of the transfer unit 30 in the sheet conveyance direction and provided between the transfer unit 30 and the fixing unit 8 (see FIG. 1) A conveyance guide member 41 and a charge removal member 42 are provided. As shown in FIG. 3, the conveyance guide member 41 and the charge removal member 42 are arranged on the surface of the conveyance guide member 41 so as to overlap each other.

搬送ガイド部材４１は、図２及び図３に示すように、用紙搬送方向、及び用紙搬送方向と直角をなす用紙幅方向に延びる略板状の部材である。搬送ガイド部材４１は、合成樹脂で構成されている。 As shown in FIGS. 2 and 3, the conveyance guide member 41 is a substantially plate-like member that extends in the sheet conveyance direction and in the sheet width direction perpendicular to the sheet conveyance direction. The conveyance guide member 41 is made of synthetic resin.

搬送ガイド部材４１は、図３及び図４に示すように、その表面に、上方、すなわち用紙搬送空間に向かって突出し、用紙搬送方向に延びるリブ４１ａを備えている。リブ４１ａは、用紙幅方向に並べて、複数個が設けられている。各リブ４１ａの頂部は、曲面になるように仕上げられている。これにより、用紙との接触箇所が少なく、搬送性能を向上させることができ、且つ用紙の汚れを低減させることができる。 As shown in FIGS. 3 and 4, the transport guide member 41 includes ribs 41 a that protrude upward, that is, toward the paper transport space and extend in the paper transport direction. A plurality of ribs 41a are arranged in the paper width direction. The top of each rib 41a is finished to be a curved surface. Thereby, there are few contact parts with a paper, conveyance performance can be improved, and the stain | pollution | contamination of a paper can be reduced.

除電部材４２は、図２及び図３に示すように、搬送ガイド部材４１と同様に、用紙搬送方向、及び用紙幅方向に延びる薄い略板状の部材である。除電部材４２は、金属製であって、所謂板金で構成されている。 As shown in FIGS. 2 and 3, the static elimination member 42 is a thin, substantially plate-like member that extends in the paper conveyance direction and the paper width direction, like the conveyance guide member 41. The neutralizing member 42 is made of metal and is formed of a so-called sheet metal.

除電部材４２は、図３及び図５に示すように、その表面に、用紙搬送方向に延びるスリット４２ａを備えている。スリット４２ａは、搬送ガイド部材４１のリブ４１ａに対応した箇所に、用紙搬送方向に並べて、複数個が設けられている。各スリット４２ａは、リブ４１ａを受け入れ可能な大きさをなしている。これにより、図３に示すように、搬送ガイド部材４１の上面に除電部材４２を重ねると、すべてのリブ４１ａがスリット４２ａを貫通する。なお、除電部材４２には、図示しないアース線が接続され、用紙に蓄積された帯電電荷を除去する。 As shown in FIGS. 3 and 5, the static eliminating member 42 includes a slit 42 a extending on the surface thereof in the paper transport direction. A plurality of slits 42 a are provided in the paper guide direction at positions corresponding to the ribs 41 a of the transport guide member 41. Each slit 42a is sized to receive the rib 41a. Thereby, as shown in FIG. 3, when the static elimination member 42 is overlapped on the upper surface of the conveyance guide member 41, all the ribs 41a penetrate the slits 42a. Note that a ground wire (not shown) is connected to the charge removal member 42 to remove the charged charges accumulated on the paper.

上記のような搬送ガイド部材４１、除電部材４２はともに、用紙搬送方向に沿う垂直面内で回転が可能である。このため、互いに駆動装置を備えている。図６及び図７に示すように、除電部材４２はその右側に設けられた第１の駆動装置５０に、搬送ガイド部材４１はその左側に設けられた第２の駆動装置６０に、各々接続されている。 Both the conveyance guide member 41 and the charge removal member 42 as described above can rotate in a vertical plane along the sheet conveyance direction. For this reason, a drive device is provided for each other. As shown in FIGS. 6 and 7, the static elimination member 42 is connected to the first driving device 50 provided on the right side thereof, and the conveyance guide member 41 is connected to the second driving device 60 provided on the left side thereof. ing.

除電部材４２を回転させる第１の駆動装置５０は、駆動源であるモータ５１と、減速機構５２と、駆動シャフト５３とを備えている。モータ５１は、ステッピングモータで構成され、複数のギアで構成される減速機構５２を介して、駆動シャフト５３に連結され、駆動シャフト５３に動力を伝達する。駆動シャフト５３は、用紙幅方向に延びる形で除電部材４２の下流端下部に固定され、その軸線を中心として、除電部材４２を垂直面内で回転させる。これにより、除電部材４２の上流部が、上下方向に変位することとなる。 The first drive device 50 that rotates the charge removal member 42 includes a motor 51 that is a drive source, a speed reduction mechanism 52, and a drive shaft 53. The motor 51 is composed of a stepping motor, and is connected to the drive shaft 53 via a speed reduction mechanism 52 composed of a plurality of gears, and transmits power to the drive shaft 53. The drive shaft 53 is fixed to the lower end lower portion of the static elimination member 42 so as to extend in the paper width direction, and rotates the static elimination member 42 in a vertical plane around the axis. Thereby, the upstream part of the static elimination member 42 will be displaced to an up-down direction.

搬送ガイド部材４１を回転させる第２の駆動装置６０は、第１の駆動装置５０と同様に、駆動源であるモータ６１と、減速機構６２と、駆動シャフト６２とを備えている。モータ６１は、ステッピングモータで構成され、複数のギアで構成される減速機構６２を介して、駆動シャフト６３に連結され、駆動シャフト６３に動力を伝達する。駆動シャフト６３は、用紙幅方向に延びる形で搬送ガイド部材４１の下流部に固定され、その軸線を中心として、搬送ガイド部材４１を垂直面内で回転させる。これにより、搬送ガイド部材５１の上流部が、上下方向に変位することとなる。 Similar to the first drive device 50, the second drive device 60 that rotates the conveyance guide member 41 includes a motor 61 that is a drive source, a speed reduction mechanism 62, and a drive shaft 62. The motor 61 is composed of a stepping motor, and is connected to the drive shaft 63 via a speed reduction mechanism 62 composed of a plurality of gears, and transmits power to the drive shaft 63. The drive shaft 63 is fixed to the downstream portion of the conveyance guide member 41 so as to extend in the paper width direction, and rotates the conveyance guide member 41 in the vertical plane around the axis. Thereby, the upstream part of the conveyance guide member 51 will be displaced to an up-down direction.

次に、第１の駆動装置５０及び第２の駆動装置６０による、除電部材４２と搬送ガイド部材４１との回転動作について、図７に加えて、図８〜図１２を用いて説明する。 Next, the rotation operation of the static elimination member 42 and the conveyance guide member 41 by the first driving device 50 and the second driving device 60 will be described with reference to FIGS. 8 to 12 in addition to FIG.

図８は、図７の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。図９は搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、図７の状態から除電部材のみを回転させた状態を示すもの、図１０は図９の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。図１１は搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、図９の状態からさらに搬送ガイド部材も回転させた状態を示すもの、図１２は図１１の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。 FIG. 8 is a right side view of the vertical section of the conveyance guide member and the charge removal member in the state of FIG. FIG. 9 is a perspective view showing the conveyance guide member, the charge removal member, and their driving devices, and shows a state where only the charge removal member is rotated from the state of FIG. 7, and FIG. 10 is the conveyance guide member in the state of FIG. FIG. 5 is a right side view of the vertical cross section of the static elimination member. FIG. 11 is a perspective view showing the conveyance guide member, the charge removal member, and their driving devices, and shows the state where the conveyance guide member is further rotated from the state of FIG. 9, and FIG. 12 is the conveyance guide in the state of FIG. It is a vertical cross section right view of a member and a static elimination member.

図７及び図８は、通常の用紙搬送状態にある搬送ガイド部材４１、除電部材４２を描画している。この状態で、第１の駆動装置５０及び第２の駆動装置６０は、除電部材４２の表面と、搬送ガイド部材４１のリブ４１ａの頂部とが、略平行になるように駆動する。これにより、通常の用紙搬送状態では、除電部材４２と搬送ガイド部材４１の上方を通過する用紙との適正な距離が保持され、用紙の効果的な除電を遂行でき、好適な搬送経路を提供できる。 7 and 8 depict the conveyance guide member 41 and the charge removal member 42 in the normal sheet conveyance state. In this state, the first driving device 50 and the second driving device 60 are driven so that the surface of the static elimination member 42 and the top of the rib 41a of the transport guide member 41 are substantially parallel. As a result, in a normal paper conveyance state, an appropriate distance between the static elimination member 42 and the paper passing above the conveyance guide member 41 is maintained, and effective neutralization of the paper can be performed and a suitable conveyance path can be provided. .

続いて、用紙の種類や湿度の影響により、除電部材４２と用紙との距離が遠くなった場合には、第１の駆動装置５０を駆動させ、図９及び図１０に示すように、除電部材４２の上流側を上昇させるようにして、除電部材４２を回転させる。これにより、除電部材４２と用紙との距離を近づけることができる。 Subsequently, when the distance between the static eliminating member 42 and the paper becomes longer due to the influence of the type of paper and humidity, the first driving device 50 is driven to remove the static eliminating member as shown in FIGS. 9 and 10. The static elimination member 42 is rotated so as to raise the upstream side of 42. Thereby, the distance of the static elimination member 42 and a paper can be shortened.

そして、さらに第２の駆動装置６０は、図１１及び図１２に示すように、搬送ガイド部材４１の上流側を上昇させるようにして、搬送ガイド部材４２を回転させる。これにより、用紙が除電部材４２に直接接触するのを防止しながら、搬送ガイド部材４１と用紙との距離を近づけることができる。 Further, as shown in FIGS. 11 and 12, the second driving device 60 rotates the conveyance guide member 42 so as to raise the upstream side of the conveyance guide member 41. Accordingly, it is possible to reduce the distance between the conveyance guide member 41 and the sheet while preventing the sheet from coming into direct contact with the charge removal member 42.

このようにして、用紙の搬送をガイドする搬送ガイド部材４１と、この搬送ガイド部材４１の表面に配置され、用紙の帯電電荷を除去する除電部材４２とを備えた画像形成装置１において、除電部材４２を用紙搬送方向に沿う垂直面内で回転させる第１の駆動装置５０を設けたので、除電部材４２の位置を変更することが可能である。これにより、用紙と除電部材４２との距離を適正に保持することができ、種類や湿度によって変化する、用紙の除電部材４２への引っ張られ方の違いに対応することができる。したがって、効果的な除電を遂行するとともに、好適な搬送経路でもって用紙を搬送することが可能な画像形成装置１を得ることができる。 Thus, in the image forming apparatus 1 including the conveyance guide member 41 that guides the conveyance of the sheet and the neutralization member 42 that is disposed on the surface of the conveyance guide member 41 and removes the charged charges of the sheet, the neutralization member. Since the first drive device 50 that rotates the surface 42 in a vertical plane along the paper conveyance direction is provided, the position of the charge removal member 42 can be changed. As a result, the distance between the sheet and the charge removal member 42 can be appropriately maintained, and it is possible to cope with the difference in how the sheet is pulled to the charge removal member 42 that varies depending on the type and humidity. Therefore, it is possible to obtain an image forming apparatus 1 that can perform effective static elimination and can transport a sheet along a suitable transport path.

さらに、搬送ガイド部材４１を用紙搬送方向に沿う垂直面内で回転させる第２の駆動装置６０を設けたので、搬送ガイド部材４１の位置を変更することが可能である。これにより、種類や湿度によって変化する、用紙の除電部材４２への引っ張られ方の違いに対応した、搬送性能の向上を図ることができる。したがって、さらに好適な搬送経路でもって用紙を搬送することが可能である。 Furthermore, since the second drive device 60 that rotates the conveyance guide member 41 in a vertical plane along the sheet conveyance direction is provided, the position of the conveyance guide member 41 can be changed. Thereby, it is possible to improve the conveyance performance corresponding to the difference in how the sheet is pulled to the charge removal member 42, which varies depending on the type and humidity. Therefore, it is possible to transport the paper along a more preferable transport path.

また、搬送ガイド部材４１は、用紙搬送空間に突出する複数のリブ４１ａを備えているので、リブ４１ａの頂部で用紙を支持することができ、搬送ガイド部材４１の用紙との接触面積をできるだけ少なくすることができる。これにより、搬送ガイド部材４１と用紙との摩擦を低減することができ、用紙やトナー像の破損、搬送性能の低下を防止することが可能である。さらに、除電部材４２は、搬送ガイド部材４１のリブ４１ａが貫通する複数のスリット４２ａを備えているので、用紙に除電部材４２を直接接触させることなく、搬送ガイド部材４１表面を通過する用紙の近傍に除電部材４２を配置することができる。これにより、用紙との距離を適正に保持することが一層簡便になり、さらに効果的な除電を遂行することが可能である。 Further, since the conveyance guide member 41 includes a plurality of ribs 41a protruding into the sheet conveyance space, the sheet can be supported on the top of the rib 41a, and the contact area of the conveyance guide member 41 with the sheet is minimized. can do. Thereby, friction between the conveyance guide member 41 and the sheet can be reduced, and it is possible to prevent the sheet and the toner image from being damaged and the conveyance performance from being deteriorated. Further, since the static elimination member 42 includes a plurality of slits 42a through which the ribs 41a of the conveyance guide member 41 pass, the vicinity of the paper passing through the surface of the conveyance guide member 41 without directly contacting the static elimination member 42 to the paper. The neutralizing member 42 can be disposed on the surface. As a result, it becomes easier to maintain the distance from the paper properly, and more effective static elimination can be performed.

そして、搬送ガイド部材４１及び除電部材４２を、像担持体である感光体ドラム２１の表面のトナー像を用紙に転写する転写部３０の用紙搬送方向下流側に設けたので、特に用紙と搬送ガイド部材４１との間に大きな電位差が生じ易い箇所において、効果的な除電の遂行と、好適な搬送経路での用紙の搬送とが可能になる。これにより、用紙上の未定着トナーの飛散や、定着オフセットといった画像不良の発生を防止することができる。したがって、安定した定着性能を期待することができる。 Since the conveyance guide member 41 and the charge removal member 42 are provided on the downstream side in the sheet conveyance direction of the transfer unit 30 that transfers the toner image on the surface of the photosensitive drum 21 as an image carrier to the sheet, in particular, the sheet and the conveyance guide. In a place where a large potential difference between the member 41 and the member 41 is likely to occur, it is possible to perform effective static elimination and transport the paper through a suitable transport path. As a result, it is possible to prevent the occurrence of image defects such as scattering of unfixed toner on the paper and fixing offset. Therefore, stable fixing performance can be expected.

以上、本発明の実施形態につき説明したが、本発明の範囲はこれに限定されるものではなく、発明の主旨を逸脱しない範囲で種々の変更を加えて実施することができる。 Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

たとえば、上記実施形態では、第１の駆動装置５０に接続された除電部材４２と、第２の駆動装置６０に接続された搬送ガイド部材４１とを、転写部３０のすぐ下流に位置する用紙搬送路４０に設けることとしたが、それらの部材の配置箇所はこれに限定されるわけではなく、他の用紙搬送路に設けることとしても構わない。 For example, in the above-described embodiment, the static elimination member 42 connected to the first driving device 50 and the conveyance guide member 41 connected to the second driving device 60 are conveyed to the sheet located immediately downstream of the transfer unit 30. Although it is provided in the path 40, the arrangement location of these members is not limited to this, and may be provided in another sheet conveyance path.

本発明は、画像形成装置全般において利用可能である。 The present invention can be used in general image forming apparatuses.

本発明の実施形態に係る画像形成装置の模型的垂直断面右側面図である。1 is a right side view of a schematic vertical section of an image forming apparatus according to an embodiment of the present invention. 図１の転写部とその下流の用紙搬送路周辺を示す斜視図である。FIG. 2 is a perspective view showing a transfer portion in FIG. 1 and a periphery of a sheet conveyance path downstream thereof. 図２の用紙搬送路の下側用紙ガイドを示す斜視図である。FIG. 3 is a perspective view illustrating a lower sheet guide of the sheet conveyance path in FIG. 2. 搬送ガイド部材の斜視図である。It is a perspective view of a conveyance guide member. 除電部材の斜視図である。It is a perspective view of a static elimination member. 搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、上方から見たものである。It is the perspective view which shows a conveyance guide member, a static elimination member, and those drive devices, and is seen from upper direction. 搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、右側から見たものである。It is the perspective view which shows a conveyance guide member, a static elimination member, and those drive devices, and is seen from the right side. 図７の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。FIG. 8 is a right side view of a vertical section of a conveyance guide member and a charge removal member in the state of FIG. 7. 図７と同様の搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、図７の状態から除電部材のみを回転させた状態を示すものである。FIG. 8 is a perspective view showing a conveyance guide member, a charge removal member, and a driving device thereof similar to FIG. 7, and shows a state where only the charge removal member is rotated from the state of FIG. 7. 図９の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。FIG. 10 is a right side view of a vertical section of the conveyance guide member and the charge removal member in the state of FIG. 9. 図９と同様の搬送ガイド部材、除電部材、及びそれらの駆動装置を示す斜視図にして、図９の状態からさらに搬送ガイド部材も回転させた状態を示すものである。FIG. 10 is a perspective view showing the conveyance guide member, the charge removal member, and their drive devices similar to those in FIG. 9, and shows a state where the conveyance guide member is further rotated from the state of FIG. 9. 図１１の状態における搬送ガイド部材及び除電部材の垂直断面右側面図である。FIG. 12 is a right side view of a vertical section of a conveyance guide member and a charge removal member in the state of FIG. 11.

符号の説明Explanation of symbols

１画像形成装置
２０画像形成部
２１感光体ドラム（像担持体）
３０転写部
４０用紙搬送路
４１搬送ガイド部材
４１ａリブ
４２除電部材
４２ａスリット
５０第１の駆動装置
６０第２の駆動装置 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 20 Image forming part 21 Photosensitive drum (image carrier)
DESCRIPTION OF SYMBOLS 30 Transfer part 40 Paper conveyance path 41 Conveyance guide member 41a Rib 42 Static elimination member 42a Slit 50 1st drive device 60 2nd drive device

Claims

用紙の搬送をガイドする搬送ガイド部材と、この搬送ガイド部材の表面に配置され、用紙の帯電電荷を除去する除電部材とを備えた画像形成装置において、
前記除電部材を用紙搬送方向に沿う垂直面内で回転させる第１の駆動装置を設けたことを特徴とする画像形成装置。 In an image forming apparatus including a conveyance guide member that guides conveyance of a sheet, and a charge removal member that is disposed on a surface of the conveyance guide member and removes a charged charge of the sheet
An image forming apparatus, comprising: a first driving device that rotates the charge eliminating member in a vertical plane along a sheet conveyance direction.

前記搬送ガイド部材を用紙搬送方向に沿う垂直面内で回転させる第２の駆動装置を設けたことを特徴とする請求項１に記載の画像形成装置。 The image forming apparatus according to claim 1, further comprising a second driving device configured to rotate the conveyance guide member in a vertical plane along a sheet conveyance direction.

前記搬送ガイド部材は、用紙搬送空間に突出する複数のリブを備え、前記除電部材は、搬送ガイド部材の前記リブが貫通する複数のスリットを備えることを特徴とする請求項１または請求項２に記載の画像形成装置。 The said conveyance guide member is provided with the some rib which protrudes in paper conveyance space, The said static elimination member is provided with the some slit which the said rib of a conveyance guide member penetrates to Claim 1 or Claim 2 characterized by the above-mentioned. The image forming apparatus described.

前記搬送ガイド部材及び前記除電部材を、像担持体表面のトナー像を用紙に転写する転写部の用紙搬送方向下流側に備えることを特徴とする請求項１〜請求項３のいずれか１項に記載の画像形成装置。 The said conveyance guide member and the said static elimination member are provided in the paper conveyance direction downstream of the transfer part which transfers the toner image on the surface of an image carrier to a paper. The image forming apparatus described.