JP2005157187A - Image forming apparatus - Google Patents

Image forming apparatus Download PDF

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JP2005157187A
JP2005157187A JP2003398788A JP2003398788A JP2005157187A JP 2005157187 A JP2005157187 A JP 2005157187A JP 2003398788 A JP2003398788 A JP 2003398788A JP 2003398788 A JP2003398788 A JP 2003398788A JP 2005157187 A JP2005157187 A JP 2005157187A
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transfer
transfer body
slider
forming apparatus
image forming
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Toshiyuki Nakada
俊行 仲田
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Kyocera Document Solutions Inc
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Kyocera Mita Corp
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  • Dry Development In Electrophotography (AREA)
  • Electrophotography Configuration And Component (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, capable of parting a photoreceptor from a transfer body with a simple configuration upon jam removal to effectively prevent the photoreceptor from damages, surely reducing the impact caused by the collisions between a regulation member of the development unit side and the photoreceptor and holding a developing roller on a regular position, and thereby permitting high-precision image formation. <P>SOLUTION: Only by removing the development unit 12 from a prescribed position in an image forming apparatus body 11 at jam processing, a transfer body moving means 28 allows the transfer roller 5 to move separated from the photoreceptor 4 coupled to the movement of the development unit 12. When the development unit 12 is loaded on the prescribed position in the image forming apparatus body 11, a slider spring 34 of the transfer body moving means 28 mitigates the impact caused by the collision between the regulation member 54 of the development unit 12 and the photoreceptor 4, and the developing roller 13 is held on the regular position by the slider spring 34. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

この発明は、複写機，プリンタ、ファクシミリ等の電子写真方式の画像形成装置に関するものである。   The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile.

従来から一般に知られた電子写真方式の複写機等の画像形成装置は、帯電器によって一様に帯電した感光体の表面に露光デバイスでレーザー光を照射して、感光体表面に静電潜像を形成し、その静電潜像が形成された感光体表面に現像ユニットから現像剤を供給し、感光体表面の静電潜像をトナー像として可視化する。そして、感光体表面に形成したトナー像を転写ローラ等の転写体によってシート状の転写材（コピー紙やＯＨＰフィルム等）に転写する。その後、感光体に残留した現像剤はクリーニングデバイスで取り除かれるようになっている。次いで、このような画像形成装置は、トナー像が転写された転写材を定着手段に送り込み、転写材の表面にトナー像を定着した後、その定着済みの転写材を排紙トレイ等に排出して積載するようになっている。   Conventionally known image forming apparatuses such as electrophotographic copying machines generally irradiate the surface of a photoconductor uniformly charged by a charger with a laser beam using an exposure device, thereby forming an electrostatic latent image on the surface of the photoconductor. The developer is supplied from the developing unit to the surface of the photosensitive member on which the electrostatic latent image is formed, and the electrostatic latent image on the surface of the photosensitive member is visualized as a toner image. Then, the toner image formed on the surface of the photoreceptor is transferred onto a sheet-like transfer material (copy paper, OHP film, etc.) by a transfer body such as a transfer roller. Thereafter, the developer remaining on the photoreceptor is removed by a cleaning device. Next, such an image forming apparatus feeds the transfer material onto which the toner image has been transferred to the fixing unit, fixes the toner image on the surface of the transfer material, and then discharges the fixed transfer material to a discharge tray or the like. To load.

図８〜図９は、このような画像形成装置１００の一例を示すものであり、帯電器，感光体，クリーニングデバイス等から構成される感光体ユニット１０１が画像形成装置本体１０２側に固定されているのに対し、現像ユニット１０３が画像形成装置本体１０２に対して着脱自在に取り付けられるようになっている。なお、図８は、現像ユニット１０３を画像形成装置本体１０２内の所定位置に取り付けた状態を示すものである。また、図９は、現像ユニット１０３を画像形成装置本体１０２内の所定位置から取り外した状態を示す図である。   FIGS. 8 to 9 show an example of such an image forming apparatus 100, in which a photosensitive unit 101 including a charger, a photosensitive member, a cleaning device, and the like is fixed to the image forming apparatus main body 102 side. In contrast, the developing unit 103 is detachably attached to the image forming apparatus main body 102. FIG. 8 shows a state in which the developing unit 103 is attached to a predetermined position in the image forming apparatus main body 102. FIG. 9 is a diagram illustrating a state in which the developing unit 103 is removed from a predetermined position in the image forming apparatus main body 102.

このような画像形成装置１００において、感光体１０４と転写体１０５との間でジャム（紙詰まり）が生じた場合、ユーザーは、図９〜図１１に示すように、現像ユニット１０３のみを画像形成装置本体１０２から取り外した後、感光体１０４と転写体１０５との間にある転写材１０６を引き抜こうとする。しかしながら、感光体１０４と転写体１０５は、互いにニップを形成するように密接しているか、又は、両者の間に非常に狭い隙間を形成し、両者間に転写材１０６を挟持するようになっており、転写材搬送方向と逆の方向に回転しないようになっているため、ユーザーが転写材１０６を転写材搬送方向と逆方向に引き抜こうとすると、感光体１０４及び転写体１０５の表面と転写材１０６とが強い力で摩擦されることになり、感光体１０４や転写体１０５の表面が傷つく虞があった。   In such an image forming apparatus 100, when a jam (paper jam) occurs between the photosensitive member 104 and the transfer member 105, the user forms an image only on the developing unit 103 as shown in FIGS. After removal from the apparatus main body 102, the transfer material 106 between the photoconductor 104 and the transfer body 105 is to be pulled out. However, the photosensitive member 104 and the transfer member 105 are in close contact with each other so as to form a nip, or a very narrow gap is formed between them, and the transfer material 106 is sandwiched between them. Therefore, when the user tries to pull out the transfer material 106 in the direction opposite to the transfer material conveyance direction, the surface of the photosensitive member 104 and the transfer material 105 and the transfer material are removed. 106 is rubbed with a strong force, and the surface of the photosensitive member 104 or the transfer member 105 may be damaged.

このような従来の画像形成装置１００の不具合を回避するためには、画像形成装置本体１０２から現像ユニット１０３を取り外した場合でも、ユーザーがジャムを生じた転写材１０６に触ることができないように、感光体１０４と転写体１０５とが対峙している部分よりも転写材搬送方向上流側にカバー１０７を取り付けて、ユーザーがジャムした転写材１０６に触りにくくすることが考えられる（図１２参照）。しかし、このような工夫をしたとしても、感光体１０４のすぐそばに現像ユニット１０３を配置しなければならない等のレイアウト上の都合により、カバー１０７を感光体１０４の直近まで配置することが困難であるため、ユーザーがジャムした転写材１０６に触るのを確実に防止することが困難であった。   In order to avoid such a problem of the conventional image forming apparatus 100, even when the developing unit 103 is removed from the image forming apparatus main body 102, the user cannot touch the jammed transfer material 106. It is conceivable that a cover 107 is attached on the upstream side in the transfer material conveyance direction with respect to the portion where the photosensitive member 104 and the transfer member 105 are opposed to each other, thereby making it difficult for the user to touch the jammed transfer material 106 (see FIG. 12). However, even with such a contrivance, it is difficult to arrange the cover 107 as close as possible to the photoconductor 104 due to layout reasons such as the development unit 103 having to be arranged next to the photoconductor 104. For this reason, it is difficult to reliably prevent the user from touching the jammed transfer material 106.

そこで、このようなジャム処理時において、感光体１０４が損傷を受けるのを防止するために、転写体１０５を感光体１０４から離し、転写体１０５と感光体１０４との間に十分な隙間（転写材の厚さ以上の隙間）を形成するようにした技術が案出されている。   Therefore, in order to prevent the photosensitive member 104 from being damaged during such a jam processing, the transfer member 105 is separated from the photosensitive member 104, and a sufficient gap (transfer) is formed between the transfer member 105 and the photosensitive member 104. A technique has been devised in which a gap larger than the thickness of the material is formed.

例えば、特許文献１の技術は、画像形成装置本体の前カバーを開いた際に、前カバーに連繋された解除レバーが連動し、この解除レバーに接続されたローラ転接解除機構によって転写体としての転写ローラを感光体から離間させるようになっている。   For example, in the technique of Patent Document 1, when the front cover of the image forming apparatus main body is opened, a release lever linked to the front cover is interlocked, and a roller rolling contact release mechanism connected to the release lever serves as a transfer body. The transfer roller is separated from the photoconductor.

また、特許文献２の技術は、現像ユニットと転写体とをリンク機構で連繋し、リンク機構を作動させることにより、現像ユニットを感光体から離間させると共に、転写体を感光体から離間させるようになっている。   In the technique of Patent Document 2, the developing unit and the transfer member are linked by a link mechanism, and the link mechanism is operated to separate the developing unit from the photosensitive member and to separate the transfer member from the photosensitive member. It has become.

また、上述の特許文献１及び２のように転写体を感光体から離間させるのではなく、画像形成装置本体に取り付けた転写体としての転写ローラに対し、感光体ユニット及び現像ユニットを一体として離間できるようにし、この感光体ユニット及び現像ユニットを画像形成装置本体内の所定位置（画像形成位置）に装着する際に、転写ローラの軸芯に沿った方向と直交する方向から感光体ユニットの感光体ドラムを当接させるようにして、感光体ドラムの表面が損傷しないようにした技術が特許文献３に開示されている。   Further, instead of separating the transfer member from the photosensitive member as in the above-mentioned Patent Documents 1 and 2, the photosensitive member unit and the developing unit are integrally separated from the transfer roller as the transfer member attached to the image forming apparatus main body. When the photosensitive unit and the developing unit are mounted at a predetermined position (image forming position) in the main body of the image forming apparatus, the photosensitive unit unit is exposed from a direction perpendicular to the direction along the axis of the transfer roller. Japanese Patent Application Laid-Open No. H10-228473 discloses a technique in which the surface of the photosensitive drum is not damaged by bringing the body drum into contact therewith.

特開平７−１９１５５７号公報JP 7-191557 A 特開平４−３３１９６０号公報JP-A-4-331960 特開平１−２２９２７０号公報JP-A-1-229270

しかしながら、特許文献１の技術は、現像ユニットを画像形成装置本体に着脱可能にした画像形成装置において、現像ユニットを取り外した状態でジャム処理をする際に、必ず前カバーを開けなければ転写体を感光体から離間させることができず、前カバーを開けるという余分な動作が必要となるという不具合を有している。   However, in the technique of Patent Document 1, in the image forming apparatus in which the developing unit is detachable from the main body of the image forming apparatus, when the jam processing is performed with the developing unit removed, the transfer body must be opened unless the front cover is opened. There is a problem that it cannot be separated from the photoconductor, and an extra operation of opening the front cover is required.

また、特許文献２の技術は、複雑なリンク機構を必要とするため、全体構造が複雑化すると共に、複雑なリンク機構を収容するためのスペースが必要となり、全体構造が大型化するという不具合を有している。   Moreover, since the technique of patent document 2 requires a complicated link mechanism, while the whole structure is complicated, the space for accommodating a complicated link mechanism is needed, and the whole structure becomes large in size. Have.

また、特許文献３の技術は、現像ユニットと感光体ユニットを一体として画像形成装置本体に脱着しなければならず、現像ユニットと感光体ユニットを一体とすると外形形状が大型化すると共に、重量が重くなるため、現像ユニットのみを画像形成装置本体に脱着する場合に比較し、ユーザーのジャム処理時の作業負担が大きくなるという不具合を有している。   In the technique of Patent Document 3, the developing unit and the photosensitive unit must be integrally attached to and detached from the main body of the image forming apparatus. If the developing unit and the photosensitive unit are integrated, the outer shape becomes large and the weight is increased. Therefore, compared with the case where only the developing unit is attached to and detached from the main body of the image forming apparatus, there is a problem in that the burden on the user during the jam processing is increased.

また、従来の画像形成装置において、感光体表面と現像ローラの外周面との間に一定の距離（現像ギャップ）を保持した状態で、現像ローラから感光体表面に向けて現像剤を飛翔させる構成のものがある。このような構成を採用する画像形成装置は、感光体表面と現像ローラとの間の現像ギャップを適正に保つため、図１３及び図１４に示すように、現像ローラ１３の両端部のローラ軸５３に現像ローラ１３よりも大径の略円板状の規制部材５４を設置し、この規制部材５４を感光体１０４表面に当接させるようになっている。その結果、現像ユニット１０３を画像形成装置本体１０２に取り付ける際に（図８参照）、現像ユニット１０３側の規制部材５４が感光体１０４に勢いよく衝突することになり、この規制部材５４の感光体１０４への衝突の衝撃により、感光体１０４の規制部材５４に衝突した部分が変形し、感光体１０４と現像ローラ１３との間の現像ギャップが適正でなくなり、画像不良を生じる虞があった。このような場合、現像ユニット１０３を画像形成装置本体１０２内の所定位置に案内するガイドレール１０８の形状や構造を工夫することも試みられているが、十分な効果を得られていない（図１２参照）。   In addition, in a conventional image forming apparatus, a developer is allowed to fly from the developing roller toward the surface of the photosensitive member while maintaining a certain distance (developing gap) between the surface of the photosensitive member and the outer peripheral surface of the developing roller. There are things. In the image forming apparatus adopting such a configuration, in order to keep an appropriate developing gap between the surface of the photosensitive member and the developing roller, as shown in FIGS. 13 and 14, roller shafts 53 at both ends of the developing roller 13 are used. A restricting member 54 having a substantially disk shape larger than the developing roller 13 is installed on the surface of the photosensitive member 104. As a result, when the developing unit 103 is attached to the image forming apparatus main body 102 (see FIG. 8), the regulating member 54 on the developing unit 103 side collides with the photoconductor 104 vigorously, and the photoconductor of the regulating member 54 Due to the impact of the collision with the photosensitive member 104, the portion of the photosensitive member 104 that has collided with the regulating member 54 is deformed, and the developing gap between the photosensitive member 104 and the developing roller 13 becomes inadequate, which may cause image defects. In such a case, attempts have been made to devise the shape and structure of the guide rail 108 that guides the developing unit 103 to a predetermined position in the image forming apparatus main body 102, but sufficient effects have not been obtained (FIG. 12). reference).

また、上述のように、感光体１０４と現像ローラ１３との間の現像ギャップｄを形成する画像形成装置１００は、現像ユニット１０３を画像形成装置本体１０２内の現像位置に装着した際に、現像ギャップｄを適正な寸法に保持するため、現像ユニット１０３を現像ユニット押し部材（コイルスプリング等）１９で感光体１０４側に向けて付勢し、現像ローラ１３の規制部材５４を感光体１０４の表面に押し付けるようになっている（図１，図１３及び図１４参照）。また、このような画像形成装置１００は、現像ユニット１０３を画像形成装置本体１０２内の現像位置に円滑に装着するため、画像形成装置本体１０２と現像ユニット１０３との間に僅かながら隙間を設けてある。その結果、図１に示すように、現像ユニット１０３の背面側が現像ユニット押し部材１９で水平方向（ほぼ感光体１０４に向かう方向）に押圧されると、現像ローラ１３と感光体１０４との接触位置における接線Ｔが左斜め上方に延びるようになっているため、現像ローラ１３が感光体１０４に押し付けられる力の接線Ｔ方向分力により、現像ローラ１３が転写体１０４から離間するように、現像ローラ１３がその接線Ｔ方向の斜め上方に（矢印方向に）向かってずれ動き（逃げ移動）を生じ、現像ローラ１３側から感光体１０４側に向けて現像剤を飛翔させる位置が正規位置（本来の設計上の位置）からずれてしまい、画像不良等の問題を生じる虞があった。   As described above, the image forming apparatus 100 that forms the developing gap d between the photoconductor 104 and the developing roller 13 develops when the developing unit 103 is mounted at the developing position in the image forming apparatus main body 102. In order to maintain the gap d at an appropriate size, the developing unit 103 is urged toward the photosensitive member 104 by the developing unit pushing member (coil spring or the like) 19, and the regulating member 54 of the developing roller 13 is moved to the surface of the photosensitive member 104. (See FIGS. 1, 13 and 14). Also, in such an image forming apparatus 100, a slight gap is provided between the image forming apparatus main body 102 and the developing unit 103 in order to smoothly mount the developing unit 103 at the developing position in the image forming apparatus main body 102. is there. As a result, as shown in FIG. 1, when the rear side of the developing unit 103 is pressed in the horizontal direction (substantially toward the photosensitive member 104) by the developing unit pressing member 19, the contact position between the developing roller 13 and the photosensitive member 104. Since the tangent line T in FIG. 3 extends obliquely to the left, the developing roller 13 is separated from the transfer member 104 by the tangential T direction component of the force with which the developing roller 13 is pressed against the photosensitive member 104. 13 shifts (escapes) obliquely upward (in the direction of the arrow) in the direction of the tangent T, and the position at which the developer flies from the developing roller 13 side toward the photoconductor 104 side is the normal position (original position). There is a possibility that a problem such as an image defect may occur due to a deviation from the design position.

そこで、本発明は、ジャム処理時に、簡単な構成で感光体と転写体とを離間することができ、感光体の損傷を効果的に防止できると共に、現像ローラと感光体との位置関係を適正に保持できる技術を提供する。   Therefore, the present invention can separate the photosensitive member and the transfer member with a simple configuration at the time of jam processing, can effectively prevent the photosensitive member from being damaged, and has an appropriate positional relationship between the developing roller and the photosensitive member. To provide technology that can be retained.

請求項１の発明は、表面に静電潜像が形成された感光体と、この感光体の表面に現像剤を供給して前記静電潜像をトナー像として可視化する現像ユニットと、前記感光体の表面に形成された前記トナー像を転写材に転写する転写体とを備え、前記現像ユニットを前記感光体に対峙する現像位置に着脱できると共に、前記転写体を前記感光体に対峙する転写位置と前記感光体から十分に離間した退避位置とに転写体移動手段で移動できるようになっている画像形成装置に関するものである。この画像形成装置において、前記転写体移動手段は、（ａ）前記転写体を前記転写位置に弾性力で保持する転写体保持バネと、（ｂ）前記感光体と接触しない位置に配置されて、前記転写体の移動方向に沿って移動するスライダと、（ｃ）このスライダを前記転写体が前記感光体から離間する方向に向けて付勢する転写体退避バネと、を備えている。また、この発明に係る画像形成装置において、前記転写体保持バネが前記転写体を前記感光体に押すバネ力よりも、前記転写体退避バネが前記転写体を前記感光体から離間させる方向に押すバネ力の方が大きくなるように、前記転写体保持バネと前記転写体退避バネのバネ力が設定されている。また、この発明に係る画像形成装置において、前記現像ユニットが前記現像位置に装着される際に、前記現像ユニットが前記現像位置に近づくと、前記スライダに接触し、前記スライダを前記転写体退避バネのバネ力に抗して移動させ、前記転写体保持バネのバネ力によって前記転写体を前記転写位置に保持させることを可能にする一方、前記現像ユニットが前記現像位置から取り外されると、前記スライダから離脱し、前記転写体退避バネのバネ力によるスライダの移動を可能にして、前記転写体が前記退避位置へ移動するのを可能にする、転写体移動手段駆動部を前記現像ユニットに備えたことを特徴としている。   The invention according to claim 1 is a photosensitive member having an electrostatic latent image formed on a surface thereof, a developing unit that supplies a developer to the surface of the photosensitive member to visualize the electrostatic latent image as a toner image, and the photosensitive member. A transfer body for transferring the toner image formed on the surface of the body to a transfer material, the development unit being attachable to and detachable from a development position facing the photoconductor, and a transfer for facing the transfer body to the photoconductor The present invention relates to an image forming apparatus which can be moved by a transfer body moving means between a position and a retracted position sufficiently separated from the photoreceptor. In this image forming apparatus, the transfer body moving means is disposed at (a) a transfer body holding spring that holds the transfer body at the transfer position with an elastic force, and (b) at a position not in contact with the photoconductor. A slider that moves along the moving direction of the transfer member; and (c) a transfer member retracting spring that urges the slider toward a direction in which the transfer member is separated from the photosensitive member. In the image forming apparatus according to the present invention, the transfer body retracting spring pushes the transfer body away from the photoconductor, rather than the spring force that the transfer body holding spring pushes the transfer body against the photoconductor. The spring force of the transfer body holding spring and the transfer body retracting spring is set so that the spring force becomes larger. In the image forming apparatus according to the present invention, when the developing unit is attached to the developing position, when the developing unit approaches the developing position, the developing unit comes into contact with the slider, and the slider is moved to the transfer member retracting spring. When the developing unit is removed from the developing position, the slider can be moved against the spring force of the transfer member, and the transfer member can be held at the transfer position by the spring force of the transfer member holding spring. The transfer unit is provided with a transfer body moving means driving section that allows the slider to move by the spring force of the transfer body retracting spring and allows the transfer body to move to the retracted position. It is characterized by that.

請求項２の発明は、上記請求項１の発明に係る画像形成装置において、前記現像ユニットの前記転写体移動手段駆動部と前記スライダとの接触部分が傾斜面であり、前記転写体移動手段駆動部と前記スライダとの接触動作及び離脱動作が滑らかに行われるようになっていることを特徴としている。   According to a second aspect of the present invention, in the image forming apparatus according to the first aspect of the present invention, the contact portion between the transfer member moving means driving portion of the developing unit and the slider is an inclined surface, and the transfer member moving means is driven. The contact operation and separation operation between the slider and the slider are performed smoothly.

本発明は、ジャム処理時に、現像ユニットを画像形成装置本体内の所定位置から取り外すだけで、転写体移動手段駆動部が転写体移動手段から離脱し、転写体移動手段が現像ユニットの移動に連動して転写体を感光体から離間させることができるため、現像ユニットを取り外してジャム処理を行う場合に、転写材との摩擦接触によって感光体の表面や転写体が損傷を受けることがない。   According to the present invention, at the time of jam processing, the transfer body moving means driving unit is detached from the transfer body moving means simply by removing the developing unit from a predetermined position in the image forming apparatus main body, and the transfer body moving means is interlocked with the movement of the developing unit. Since the transfer member can be separated from the photosensitive member, the surface of the photosensitive member and the transfer member are not damaged by the frictional contact with the transfer material when the developing unit is removed and the jam processing is performed.

また、本発明は、現像ユニットを画像形成装置本体内の所定位置（現像位置）に装着すると、転写体移動手段駆動部がスライダに接触し、現像ユニットが転写体退避バネのバネ力によって転写体退避方向に押されて保持される。その結果、現像ユニットが画像形成装置本体内においてずれ動きを生じることがなく、感光体と現像ユニットとの位置関係を適正に保つことができ、高精度の画像形成が可能になる。   Further, according to the present invention, when the developing unit is mounted at a predetermined position (developing position) in the main body of the image forming apparatus, the transfer body moving unit driving unit comes into contact with the slider, and the developing unit is moved by the spring force of the transfer body retracting spring. It is pushed and held in the retreat direction. As a result, the developing unit does not move in the image forming apparatus main body, the positional relationship between the photoconductor and the developing unit can be maintained appropriately, and high-precision image formation is possible.

また、本発明は、転写体移動手段駆動部とスライダの接触部分を傾斜面とし、転写体移動手段駆動部とスライダの接触動作及び離脱動作を円滑化することができ、現像ユニットの脱着時の衝撃を緩和できる。   In addition, the present invention has a contact portion between the transfer member moving unit driving unit and the slider as an inclined surface, so that the contact operation and the detachment operation of the transfer member moving unit driving unit and the slider can be facilitated. Shock can be mitigated.

以下、本発明の実施の形態を図面に基づき詳述する。   Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

図１〜図２は、本発明の実施の形態に係る画像形成装置１の概略構成を示すものである。これらの図に示すように、本実施の形態の画像形成装置１は、給紙トレイ２から送り出されたシート状の転写材（コピー用紙等の紙やＯＨＰフィルム等のプラスチックフィルム等）３がドラム状の感光体４と転写ローラ（転写体）５との間の転写位置Ｐに送り込まれ、ここで感光体４表面のトナー像が転写材３に転写される。トナー像が転写された転写材３は、転写材搬送路６に沿って定着手段７に送り込まれ、この定着手段７によって加熱・加圧されてトナー像が定着させられた後、排紙トレイ８上に排出されるようになっている。   1 to 2 show a schematic configuration of an image forming apparatus 1 according to an embodiment of the present invention. As shown in these drawings, in the image forming apparatus 1 according to the present embodiment, a sheet-like transfer material (paper such as copy paper or plastic film such as an OHP film) 3 fed from a paper feed tray 2 is a drum. Then, the toner image on the surface of the photosensitive member 4 is transferred to the transfer material 3. The transfer material 3 onto which the toner image has been transferred is sent to the fixing means 7 along the transfer material conveyance path 6 and is heated and pressurized by the fixing means 7 to fix the toner image. It is supposed to be discharged to the top.

感光体４は、この感光体４の表面を一様に帯電させる図示しない帯電デバイスや、転写後に感光体４表面に付着したトナーを取り除く図示しないクリーニングデバイス等と共に感光体ユニット１０を構成しており、画像形成装置本体１１に装着されている。   The photoconductor 4 constitutes a photoconductor unit 10 together with a charging device (not shown) that uniformly charges the surface of the photoconductor 4 and a cleaning device (not shown) that removes toner adhering to the surface of the photoconductor 4 after transfer. The image forming apparatus main body 11 is mounted.

また、感光体４に対峙するように現像ユニット１２が配置されている。この現像ユニット１２は、図４に示すように、現像ローラ１３と感光体４の表面との間の隙間寸法（現像ギャップ）ｄが所定寸法になるように、画像形成装置本体１１内の所定位置に着脱可能に取り付けられている。そして、この現像ユニット１２は、露光デバイス１４によって静電潜像が形成された感光体４表面に向けて現像剤を現像ローラ１３から飛翔させ、感光体４表面の静電潜像をトナー像として可視化するようになっている。このように機能する現像ユニット１２は、図２に示すように、図中右上部の上カバー１５と、図中右上部の側面カバー１６を開き、この画像形成装置本体１１の開口部１７から外部に取り出したり、また、外部から画像形成装置本体１１の開口部１７を介して画像形成装置本体１１内の所定位置（現像位置）に装着することができるようになっている。ここで、現像ユニット１２が画像形成装置本体１１内の所定位置に装着されると、現像ユニット１２が現像ユニット押し部材（コイルスプリング等）１９によって感光体４側に付勢されるようになっている。   Further, a developing unit 12 is disposed so as to face the photoconductor 4. As shown in FIG. 4, the developing unit 12 has a predetermined position in the image forming apparatus main body 11 such that a gap dimension (developing gap) d between the developing roller 13 and the surface of the photoreceptor 4 becomes a predetermined dimension. Is detachably attached. Then, the developing unit 12 causes the developer to fly from the developing roller 13 toward the surface of the photoconductor 4 on which the electrostatic latent image is formed by the exposure device 14, and the electrostatic latent image on the surface of the photoconductor 4 is used as a toner image. It is designed to be visualized. As shown in FIG. 2, the developing unit 12 that functions in this manner opens the upper cover 15 at the upper right portion in the drawing and the side cover 16 at the upper right portion in the drawing, and externally opens from the opening portion 17 of the image forming apparatus main body 11. The image forming apparatus main body 11 can be attached to a predetermined position (developing position) through the opening 17 of the image forming apparatus main body 11 from the outside. Here, when the developing unit 12 is mounted at a predetermined position in the image forming apparatus main body 11, the developing unit 12 is urged toward the photoreceptor 4 by a developing unit pushing member (coil spring or the like) 19. Yes.

転写ローラ５は、図３に示すように、感光体４に向かって開口する断面略矩形形状の転写ローラハウジング１８内において、その軸方向両端部のシャフト２０が軸受け部材２１によって回動可能に支持されている。また、転写ローラ５を回動可能に支持する軸受け部材２１は、転写ローラハウジング１８の底面２２に対して転写体保持バネ２３で弾性的に支持されている。そして、転写ローラ５は、軸受け部材２１を介して作用する転写体保持バネ２３のバネ力によって感光体４に押し付けられ、感光体４との当接部に転写材を挟時するニップＰを形成している。   As shown in FIG. 3, the transfer roller 5 is supported by a bearing member 21 so that the shafts 20 at both ends in the axial direction are rotatably supported in a transfer roller housing 18 having a substantially rectangular cross section that opens toward the photosensitive member 4. Has been. The bearing member 21 that rotatably supports the transfer roller 5 is elastically supported by a transfer body holding spring 23 with respect to the bottom surface 22 of the transfer roller housing 18. The transfer roller 5 is pressed against the photoconductor 4 by the spring force of the transfer body holding spring 23 acting via the bearing member 21 to form a nip P that sandwiches the transfer material at the contact portion with the photoconductor 4. doing.

ここで、軸受け部材２１は、図３に示すように、転写ローラハウジング１８の側面２４に沿って位置するガイド部材２５に案内されて上下動できるようになっており、コイル状の転写体保持バネ２３の上端部に挿入されるバネ係合ピン２６が下方に向けて突出形成されている。なお、転写ローラハウジング１８の底面２２には、軸受け部材２１のバネ係合ピン２６に対向するようにバネ取付ピン２７が突出形成されている。そして、このバネ取付ピン２７には、転写体保持バネ２３の下端部が嵌合されている。   Here, as shown in FIG. 3, the bearing member 21 is guided by a guide member 25 positioned along the side surface 24 of the transfer roller housing 18 so as to move up and down, and a coil-shaped transfer body holding spring. A spring engagement pin 26 to be inserted into the upper end portion of 23 is formed so as to protrude downward. A spring mounting pin 27 protrudes from the bottom surface 22 of the transfer roller housing 18 so as to face the spring engaging pin 26 of the bearing member 21. The lower end portion of the transfer body holding spring 23 is fitted to the spring mounting pin 27.

転写体保持バネ２３は、導電性金属で形成されたコイルスプリングであり、転写時において、転写ローラ５を所定の圧力で感光体４に押圧できるように、圧縮された状態で軸受け部材２１を支持するようになっている。そして、図外の電力供給部から供給される転写電圧が転写体保持バネ２３及び軸受け部材２１を介して転写ローラ５に通電されるようになっている。   The transfer body holding spring 23 is a coil spring made of a conductive metal, and supports the bearing member 21 in a compressed state so that the transfer roller 5 can be pressed against the photoconductor 4 with a predetermined pressure during transfer. It is supposed to be. A transfer voltage supplied from a power supply unit (not shown) is supplied to the transfer roller 5 through the transfer body holding spring 23 and the bearing member 21.

図４〜図７は、このような画像形成装置１の転写ローラ５を感光体４に接触又は離間させるための転写体移動手段２８及びこれに連繋する現像ユニット１２の突起（転写体移動手段駆動部）３０との関係を説明するために用いる図であり、転写体移動手段２８が配置される部分を模式的に簡略化して示す図である。これらの図に示すように、転写移動手段２８は、感光体４及び転写ローラ５の軸端部に位置しており、転写材が転写材搬送路６に沿って搬送されるのを邪魔することがないように、感光体４の両軸端部及び転写ローラ５の両軸端部にそれぞれ配置されている。   FIGS. 4 to 7 show transfer body moving means 28 for bringing the transfer roller 5 of the image forming apparatus 1 into contact with or separating from the photosensitive body 4 and protrusions of the developing unit 12 linked thereto (drive of the transfer body moving means). (Part) 30 is a diagram used for explaining the relationship with 30, and is a diagram schematically showing a portion where the transfer body moving means 28 is arranged. As shown in these drawings, the transfer moving means 28 is located at the shaft end portions of the photosensitive member 4 and the transfer roller 5 and obstructs the transfer material from being conveyed along the transfer material conveyance path 6. Are arranged at both shaft end portions of the photosensitive member 4 and at both shaft end portions of the transfer roller 5, respectively.

これらの図４〜図７に示すように、転写体移動手段２８は、転写ローラ５を上下動させるようになっており、転写ローラ５が感光体４に当接する転写位置（図４，図６参照）と、転写ローラ５が感光体４から十分に離れた退避位置（図５及び図７参照）とに移動（上下動）させる。この転写体移動手段２８は、上述の転写体保持バネ２３と、第１スライダ３１と第２スライダ３２とからなるスライダ３３と、第２スライダ３２の両端側を常時下方に向けて付勢する一対のスライダバネ（転写体退避バネ）３４と、を備えている。   As shown in FIGS. 4 to 7, the transfer body moving means 28 moves the transfer roller 5 up and down, and the transfer position at which the transfer roller 5 contacts the photoconductor 4 (FIGS. 4 and 6). And the transfer roller 5 is moved (moved up and down) to a retracted position (see FIGS. 5 and 7) sufficiently separated from the photosensitive member 4. The transfer member moving means 28 is a pair of members that constantly urge the transfer member holding spring 23, the slider 33 including the first slider 31 and the second slider 32, and the both ends of the second slider 32 downward. The slider spring (transfer body retracting spring) 34 is provided.

このうち、第１スライダ３１は、転写ローラ５のシャフト２０に係合される転写ローラ押圧プレート部３５と、この転写ローラ押圧プレート部３５の両側に位置する一対の第２スライダ突き当てプレート部３６と、転写ローラ押圧プレート部３５と各第２スライダ突き当てプレート部３６とを接続する縦方向壁部３７と、を備えている。そして、転写ローラ押圧プレート部３５は、その転写材搬送方向略中央の下面３８側に、転写ローラ５のシャフト２０に係合する略半円形のシャフト係合溝４０が形成されており、転写体保持バネ２３のバネ力によって転写ローラ５と共に感光体４側に付勢されている。   Among these, the first slider 31 includes a transfer roller pressing plate portion 35 engaged with the shaft 20 of the transfer roller 5 and a pair of second slider abutting plate portions 36 located on both sides of the transfer roller pressing plate portion 35. And a vertical wall portion 37 that connects the transfer roller pressing plate portion 35 and each second slider abutting plate portion 36. The transfer roller pressing plate portion 35 is formed with a substantially semicircular shaft engaging groove 40 that engages with the shaft 20 of the transfer roller 5 on the lower surface 38 side of the transfer material conveyance direction substantially in the center. The spring force of the holding spring 23 is urged to the photosensitive member 4 side together with the transfer roller 5.

第２スライダ３２は、第１スライダ３１の第２スライダ突き当てプレート部３６，３６に接触又は離間する略角柱状の一対の押圧ブロック部４１，４２と、この一対の押圧ブロック部４１，４２の上方に一体に形成されたバネ受けプレート部４３とを備えている。このうち、バネ受けプレート部４３は、図６に示すように、平面形状が略コ字形状を呈しており、第１スライダ３１との接触を回避するようにフロント側に出っ張るように形成されている。そして、このバネ受けプレート部４３は、そのバネ受けプレート部４３の略コ字形状の空間４４内に第１スライダ３１の転写ローラ押圧プレート部３５及び縦方向壁部３７，３７をスライド可能に収容できるようになっている（図４参照）。このように、第２スライダ３２のバネ受けプレート部４３が形成されることにより、転写体移動手段２８の高さ方向寸法（図４乃至図７の上下方向寸法）を小さくすることが可能になり、画像形成装置本体１１内のスペース、特に、感光体４の周辺部のスペースを有効に利用できるようになり、感光体４の周辺部の設計が容易になる。   The second slider 32 includes a pair of substantially rectangular columnar pressing block portions 41 and 42 that contact or separate from the second slider abutting plate portions 36 and 36 of the first slider 31, and the pair of pressing block portions 41 and 42. And a spring receiving plate portion 43 formed integrally therewith. Among these, as shown in FIG. 6, the spring receiving plate portion 43 has a substantially U-shaped planar shape, and is formed to protrude to the front side so as to avoid contact with the first slider 31. Yes. The spring receiving plate portion 43 slidably accommodates the transfer roller pressing plate portion 35 and the vertical wall portions 37 and 37 of the first slider 31 in a substantially U-shaped space 44 of the spring receiving plate portion 43. (See FIG. 4). Thus, by forming the spring receiving plate portion 43 of the second slider 32, it is possible to reduce the height direction dimension (vertical direction dimension in FIGS. 4 to 7) of the transfer body moving means 28. The space in the image forming apparatus main body 11, particularly the space around the periphery of the photoconductor 4 can be used effectively, and the design of the periphery of the photoconductor 4 is facilitated.

この第２スライダ３２の一対の押圧ブロック部４１，４２は、その外側面４５，４６が画像形成装置本体１１側のフレーム４７，４８によってガイドされて、円滑に上下動できるようになっている。このうち、図４及び図５中の右側の押圧ブロック部４１は、現像ユニット１２のハウジング５０に形成された転写体移動手段駆動部としての突起３０に係合するようになっており、その現像ユニット１２の突起３０との接触部分が傾斜面５１になっている。この押圧ブロック部４１の傾斜面５１は、現像ユニット１２の突起３０に形成された右斜め上方に向かって傾斜する傾斜面５２とほぼ合致する形状になっている。その結果、第２スライダ３２の押圧ブロック部４１と現像ユニット１２の突起３０との接触動作及び離脱動作が円滑に行われることになり、この第２スライダ３２の押圧ブロック部４１と現像ユニット１２の突起３０との接触動作及び離脱動作による衝撃や振動が生じにくくなっている。なお、第２スライダ３２の右側の押圧ブロック部４１をガイドするフレーム４７は、現像ユニット１２の突起３０との干渉を避けるように部分的に切り欠き等が施されている。   The pair of pressing block portions 41 and 42 of the second slider 32 can be smoothly moved up and down by the outer surfaces 45 and 46 being guided by the frames 47 and 48 on the image forming apparatus main body 11 side. 4 and 5, the right pressing block portion 41 is engaged with a protrusion 30 as a transfer member moving means driving portion formed in the housing 50 of the developing unit 12. The contact portion of the unit 12 with the protrusion 30 is an inclined surface 51. The inclined surface 51 of the pressing block portion 41 has a shape that substantially coincides with the inclined surface 52 that is formed on the protrusion 30 of the developing unit 12 and is inclined obliquely upward to the right. As a result, the contact operation and the separation operation of the pressing block portion 41 of the second slider 32 and the protrusion 30 of the developing unit 12 are performed smoothly, and the pressing block portion 41 of the second slider 32 and the developing unit 12 are connected. Impacts and vibrations due to contact operation and separation operation with the protrusion 30 are less likely to occur. The frame 47 that guides the right pressure block 41 of the second slider 32 is partially cut away so as to avoid interference with the protrusion 30 of the developing unit 12.

一対のスライダバネ３４は、その上端が画像形成装置本体１１側に取り付けられており、その下端が第２スライダ３２を常時下方に押圧するようになっており、第２スライダ３２を均等に下方に押圧するようになっている。また、一対のスライダバネ３４は、そのバネ力の合力が転写体保持バネ２３のバネ力よりも大きくなるように設定されており、第２スライダ３２の押圧ブロック部４１と現像ユニット１２の突起３０との係合が解除された状態において、図５に示すように、転写体保持バネ２３を押し縮め、スライダ３３及び転写ローラ５を押し下げて、転写ローラ５を退避位置まで移動させるようになっている。   The upper ends of the pair of slider springs 34 are attached to the image forming apparatus main body 11 side, and the lower ends of the pair of slider springs 34 always press the second slider 32 downward, and the second slider 32 is uniformly pressed downward. It is supposed to be. The pair of slider springs 34 is set so that the resultant force of the spring force is larger than the spring force of the transfer body holding spring 23, and the pressing block portion 41 of the second slider 32 and the protrusion 30 of the developing unit 12 5, the transfer body holding spring 23 is compressed and the slider 33 and the transfer roller 5 are pressed down to move the transfer roller 5 to the retracted position, as shown in FIG. .

以上のように構成された本実施の形態によれば、図２に示すように、画像形成装置本体１１内から取り外した現像ユニット１２を画像形成装置本体１１内に装着していき、現像ユニット１２が画像形成装置本体１１内の所定位置（現像位置）に近づくと、現像ユニット１２のハウジング５０の突起３０が第２スライダ３２の押圧ブロック部４１の傾斜面５１に当接する。そして、さらに現像ユニット１２が画像形成装置本体１１内の所定位置に近づけられると、現像ユニット１２の突起３０がスライダバネ３４，３４を押し縮めて第２スライダ３２を押し上げる。この際、第２スライダ３２は、その押圧ブロック部４１の傾斜面５１が現像ユニット１２の突起３０の傾斜面５２に滑らかに接触し、緩やかに持ち上げられることになる。また、この第２スライダ３２の上昇移動に伴い、転写体保持バネ２３によって感光体４に向かって（上方に向かって）付勢された軸受け部材２１が転写ローラ５及び第１スライダ３１と共に連動して上昇移動する（図３及び図４参照）。そして、現像ユニット１２が画像形成装置本体１１内の所定位置に装着されると、第２スライダ３２の押圧ブロック部４１，４２が第１スライダ３１に接触しない位置まで現像ユニット１２の突起３０によって持ち上げられ、転写ローラ５が転写体保持バネ２３のバネ力によって感光体４に押し付けられて、転写ローラ５と感光体４との間にニップＰが形成される（図４及び図６参照）。   According to the present embodiment configured as described above, as shown in FIG. 2, the developing unit 12 removed from the image forming apparatus main body 11 is mounted in the image forming apparatus main body 11, and the developing unit 12 is mounted. 2 approaches the predetermined position (development position) in the image forming apparatus main body 11, the protrusion 30 of the housing 50 of the development unit 12 contacts the inclined surface 51 of the pressing block portion 41 of the second slider 32. When the developing unit 12 is further brought closer to a predetermined position in the image forming apparatus main body 11, the protrusion 30 of the developing unit 12 presses and contracts the slider springs 34 and 34 to push up the second slider 32. At this time, the inclined surface 51 of the pressing block 41 of the second slider 32 smoothly contacts the inclined surface 52 of the protrusion 30 of the developing unit 12 and is gently lifted. As the second slider 32 moves upward, the bearing member 21 urged toward the photosensitive member 4 (upward) by the transfer member holding spring 23 is interlocked with the transfer roller 5 and the first slider 31. (See FIGS. 3 and 4). When the developing unit 12 is mounted at a predetermined position in the image forming apparatus main body 11, the pressing block portions 41 and 42 of the second slider 32 are lifted by the protrusions 30 of the developing unit 12 to a position where they do not contact the first slider 31. Then, the transfer roller 5 is pressed against the photoconductor 4 by the spring force of the transfer body holding spring 23, and a nip P is formed between the transfer roller 5 and the photoconductor 4 (see FIGS. 4 and 6).

この現像ユニット１２が画像形成装置本体１１内の所定位置に装着された状態において、現像ユニット１２の現像ローラ１３は、図１３及び図１４に示すように、その両端部のローラ軸５３に現像ローラ１３よりも大径の円板状の規制部材５４が取り付けられており、現像ユニット１２が画像形成装置本体１１内の所定位置（現像位置）に装着されると（図４参照）、規制部材５４が感光体４の表面に当接し、感光体４の表面と現像ローラ１３の表面との間に所定寸法の隙間（現像ギャップ）ｄが生じるようになっている。   In a state where the developing unit 12 is mounted at a predetermined position in the image forming apparatus main body 11, the developing roller 13 of the developing unit 12 is connected to the developing roller on the roller shafts 53 at both ends thereof as shown in FIGS. When the developing unit 12 is mounted at a predetermined position (developing position) in the image forming apparatus main body 11 (see FIG. 4), a restricting member 54 having a disk shape larger than 13 is attached. Is in contact with the surface of the photosensitive member 4 so that a gap (developing gap) d having a predetermined size is formed between the surface of the photosensitive member 4 and the surface of the developing roller 13.

ここで、現像ユニット１２を画像形成装置本体１１内に装着する際に（図５参照）、現像ユニット１２が画像形成装置本体内１１の所定位置（現像位置）に到達する前において、スライダバネ３４，３４のバネ力で押されたスライダ３３の押圧ブロック部４１に現像ユニット１２のハウジング５０の突起３０が当接し、現像ユニット１２がスライダバネ３４，３４を押し縮めながら所定位置にセットされる。したがって、現像ローラ１３の軸方向両端部に取り付けられた規制部材５４と感光体４との衝突は、その衝撃がスライダバネ３４，３４の弾性変形により緩和される。   Here, when the developing unit 12 is mounted in the image forming apparatus main body 11 (see FIG. 5), before the developing unit 12 reaches a predetermined position (developing position) in the image forming apparatus main body 11, the slider spring 34, The protrusion 30 of the housing 50 of the developing unit 12 contacts the pressing block portion 41 of the slider 33 pressed by the spring force of 34, and the developing unit 12 is set at a predetermined position while pressing and contracting the slider springs 34 and 34. Therefore, the impact between the regulating member 54 attached to both ends of the developing roller 13 in the axial direction and the photosensitive member 4 is reduced by the elastic deformation of the slider springs 34 and 34.

また、現像ユニット１２が画像形成装置本体１１内の所定位置に装着される際に、現像ユニット１２の現像ローラ１３が現像ユニット押し部材１９によって感光体４に押し付けられることになるが、図４及び図６に示すように、現像ユニット１２の突起３０がスライダバネ３４，３４のバネ力で画像形成装置本体１１の現像ユニット支持部５５に押し付けられるため（下方に押圧されるため）、現像ローラ１３が感光体４に対して図１の左斜め上方へずれ動くようなことがなく、現像ローラ１３を感光体４に対して感光体周方向の正規位置に保持することができ、高精度の画像形成が可能になる。   Further, when the developing unit 12 is mounted at a predetermined position in the image forming apparatus main body 11, the developing roller 13 of the developing unit 12 is pressed against the photosensitive member 4 by the developing unit pressing member 19, but FIG. As shown in FIG. 6, since the protrusion 30 of the developing unit 12 is pressed against the developing unit support portion 55 of the image forming apparatus main body 11 by the spring force of the slider springs 34, 34, the developing roller 13 is pressed. The developing roller 13 can be held at a normal position in the circumferential direction of the photosensitive member 4 with respect to the photosensitive member 4 without being shifted from the photosensitive member 4 obliquely upward to the left in FIG. Is possible.

一方、現像ユニット１２が現像位置から取り外される際に、現像ユニット１２の突起３０と第２スライダ３２の押圧ブロック部４１とが傾斜面５１，５２に沿って滑らかに離脱する。この現像ユニット１２の突起３０と第２スライダ３２の押圧ブロック部４１との係合が解除されると、一対のスライダバネ３４のバネ力によって第２スライダ３２，第１スライダ３１，転写ローラ５及び軸受け部材２１が一体として押し下げられ、転写ローラ５が転写体保持バネ２３を押し縮めて退避位置まで下降移動し、感光体４と転写ローラ５の間に十分なスペースが生じる（図３，図５及び図７参照）。   On the other hand, when the developing unit 12 is removed from the developing position, the protrusion 30 of the developing unit 12 and the pressing block portion 41 of the second slider 32 are smoothly separated along the inclined surfaces 51 and 52. When the engagement between the protrusion 30 of the developing unit 12 and the pressing block portion 41 of the second slider 32 is released, the second slider 32, the first slider 31, the transfer roller 5, and the bearing are supported by the spring force of the pair of slider springs 34. The member 21 is pushed down integrally, and the transfer roller 5 pushes and shrinks the transfer body holding spring 23 and moves down to the retracted position, so that a sufficient space is generated between the photoconductor 4 and the transfer roller 5 (FIGS. 3 and 5). (See FIG. 7).

以上のように、本実施の形態の画像形成装置１は、ジャム処理時に、現像ユニット１２を図１及び図４に示す状態から図２及び図５に示す状態まで移動させて、現像ユニット１２を画像形成装置本体１１内から取り外すだけで、転写体移動手段２８のスライダ３３がスライダバネ３４のバネ力でスライド移動して転写ローラ５を転写体保持バネ２３のバネ力に抗して押し下げ、感光体４と転写ローラ５との間に十分な隙間（転写材３の厚み以上の隙間）が形成される。したがって、ユーザーが現像ユニット１２を取り外してできる空間に手を入れて転写材３を引き抜いたとしても、感光体４の表面や転写ローラ５の表面が転写材３との摩擦接触で損傷することがない。   As described above, the image forming apparatus 1 according to the present embodiment moves the developing unit 12 from the state shown in FIGS. 1 and 4 to the state shown in FIGS. By simply removing it from the image forming apparatus main body 11, the slider 33 of the transfer member moving means 28 slides by the spring force of the slider spring 34 and pushes down the transfer roller 5 against the spring force of the transfer member holding spring 23. A sufficient gap (a gap larger than the thickness of the transfer material 3) is formed between the transfer roller 4 and the transfer roller 5. Therefore, even if the user puts a hand in the space formed by removing the developing unit 12 and pulls out the transfer material 3, the surface of the photoreceptor 4 and the surface of the transfer roller 5 may be damaged by frictional contact with the transfer material 3. Absent.

また、上述のように、本実施の形態の画像形成装置１は、現像ユニット１２を画像形成装置本体１１の所定位置に装着する際に、現像ユニット１２の規制部材５４が感光体４に当接する前から第２スライダ３２の押圧ブロック部４１が現像ユニット１２の突起３０に当接し、現像ユニット１２を画像形成装置本体１１内の所定位置に装着する際の衝撃をスライダバネ３４の変形によって緩衝することができる。その結果、本実施の形態の画像形成装置１は、現像ユニット１２の規制部材５４が緩衝された状態で感光体４に当接することになり、感光体４が現像ユニット１２の規制部材５４によって損傷を受けることがなくなるため、感光体４と現像ローラ１３との間の現像ギャップｄを長期間適正に保つことができ、長期にわたり高品質の画像形成を行うことができる。   Further, as described above, in the image forming apparatus 1 of the present embodiment, when the developing unit 12 is mounted at a predetermined position of the image forming apparatus main body 11, the regulating member 54 of the developing unit 12 contacts the photoconductor 4. From the front, the pressing block portion 41 of the second slider 32 comes into contact with the protrusion 30 of the developing unit 12, and shocks when the developing unit 12 is mounted at a predetermined position in the image forming apparatus main body 11 are buffered by deformation of the slider spring 34. Can do. As a result, the image forming apparatus 1 according to the present embodiment comes into contact with the photosensitive member 4 in a state where the regulating member 54 of the developing unit 12 is buffered, and the photosensitive member 4 is damaged by the regulating member 54 of the developing unit 12. Therefore, the developing gap d between the photosensitive member 4 and the developing roller 13 can be maintained properly for a long period of time, and high-quality image formation can be performed over a long period of time.

また、本実施の形態の画像形成装置１は、従来技術のような複雑なリンク機構を必要とせず、スライダ３３、スライダバネ３４及び転写体保持バネ２３を備えた簡単な構成の転写体移動手段２８によって、感光体４から転写ローラ５を離間させることができるため、全体構造を小型化・軽量化することができると共に、低廉化を図ることができる。   In addition, the image forming apparatus 1 according to the present embodiment does not require a complicated link mechanism as in the prior art, and the transfer body moving means 28 having a simple configuration including the slider 33, the slider spring 34, and the transfer body holding spring 23. As a result, the transfer roller 5 can be separated from the photoconductor 4, so that the overall structure can be reduced in size and weight, and the cost can be reduced.

なお、本実施の形態は、感光体としてドラム状の感光体４を例示したが、これに限られず、ベルト状の感光体にも適用することができる。   In this embodiment, the drum-shaped photoconductor 4 is exemplified as the photoconductor, but the present invention is not limited to this and can be applied to a belt-shaped photoconductor.

また、本実施の形態は、感光体４に転写ローラ５を押圧する態様を例示したが、これに限られず、感光体４と転写ローラ５との間に僅かな隙間を生じさせるような構成にも適用することができる。   In the present embodiment, the mode in which the transfer roller 5 is pressed against the photoconductor 4 is exemplified. However, the present invention is not limited to this. The configuration is such that a slight gap is generated between the photoconductor 4 and the transfer roller 5. Can also be applied.

本発明は、電子写真方式の複写機、プリンタ、ファクシミリ及びこれらの複合機としての画像形成装置に広く適用することができる。   The present invention can be widely applied to an electrophotographic copying machine, a printer, a facsimile, and an image forming apparatus as a composite machine of these.

本発明の実施の形態に係る画像形成装置の概略構成図である。1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. 図１に示した画像形成装置の現像ユニットを取り外す状態を示す図である。FIG. 2 is a diagram illustrating a state where a developing unit of the image forming apparatus illustrated in FIG. 1 is removed. 図１の画像形成装置の感光体と転写体を拡大して示す詳細図である。FIG. 2 is an enlarged detailed view showing a photoconductor and a transfer body of the image forming apparatus of FIG. 1. 図１の画像形成装置の現像ユニットが現像位置にある場合の転写体移動手段の構成図である。FIG. 2 is a configuration diagram of a transfer member moving unit when a developing unit of the image forming apparatus in FIG. 1 is in a developing position. 図１の画像形成装置の現像ユニットが現像位置から離間した位置にある場合の転写体移動手段の構成図である。FIG. 2 is a configuration diagram of a transfer member moving unit when the developing unit of the image forming apparatus in FIG. 1 is located at a position separated from a developing position. 画像形成装置の一部を省略して示す外観斜視図であり、現像ユニットが現像位置にある場合の転写体移動手段を示す外観斜視図である。FIG. 2 is an external perspective view in which a part of the image forming apparatus is omitted, and is an external perspective view showing a transfer body moving unit when a developing unit is in a developing position. 図６と見る方向を変えた場合の転写体移動手段の外観斜視図である。FIG. 7 is an external perspective view of a transfer body moving unit when the viewing direction is changed from FIG. 6. 一般的な画像形成装置の構成を説明するための外観斜視図であり、現像ユニットが現像位置にある場合の外観斜視図である。FIG. 2 is an external perspective view for explaining a configuration of a general image forming apparatus, and is an external perspective view when a developing unit is in a developing position. 一般的な画像形成装置の構成を説明するための外観斜視図であり、現像ユニットが現像位置から離間した位置にある場合の外観斜視図である。FIG. 2 is an external perspective view for explaining a configuration of a general image forming apparatus, and is an external perspective view when a developing unit is located at a position separated from a developing position. 現像ユニットを取り外して感光体と転写体を示す画像形成装置の一部外観斜視図である。FIG. 3 is a partial external perspective view of the image forming apparatus showing a photoconductor and a transfer body with the developing unit removed. 現像ユニットを取り外してジャム処理する状態を示す画像形成装置の概略構成図である。FIG. 2 is a schematic configuration diagram of an image forming apparatus showing a state in which a developing unit is removed and jammed. 従来のジャム処理時における不具合解消手段を示す画像形成装置の概略構成図である。It is a schematic block diagram of the image forming apparatus which shows the fault solution means at the time of the conventional jam processing. 感光体と現像ローラの関係を示す外観斜視図である。2 is an external perspective view showing a relationship between a photoconductor and a developing roller. FIG. 感光体と現像ローラの端部の構造を示す外観斜視図である。FIG. 2 is an external perspective view showing structures of end portions of a photoconductor and a developing roller.

符号の説明Explanation of symbols

１……画像形成装置、３……転写材、４……感光体、５……転写ローラ（転写体）、１２……現像ユニット、２３……転写体保持バネ、２８……転写体移動手段、３０……突起（転写体移動手段駆動部）、３３……スライダ、３４……スライダバネ（転写体退避バネ）、５１，５２……傾斜面   DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 3 ... Transfer material, 4 ... Photoconductor, 5 ... Transfer roller (transfer body), 12 ... Development unit, 23 ... Transfer body holding spring, 28 ... Transfer body moving means , 30... Protrusion (transfer body moving means driving unit) 33. Slider 34. Slider spring (transfer body retracting spring) 51 and 52.

Claims (2)

表面に静電潜像が形成された感光体と、この感光体の表面に現像剤を供給して前記静電潜像をトナー像として可視化する現像ユニットと、前記感光体の表面に形成された前記トナー像を転写材に転写する転写体とを備え、
前記現像ユニットを前記感光体に対峙する現像位置に着脱できると共に、前記転写体を前記感光体に対峙する転写位置と前記感光体から十分に離間した退避位置とに転写体移動手段で移動できるようになっている画像形成装置において、
前記転写体移動手段は、
前記転写体を前記転写位置に弾性力で保持する転写体保持バネと、
前記感光体と接触しない位置に配置されて、前記転写体の移動方向に沿って移動するスライダと、
このスライダを前記転写体が前記感光体から離間する方向に向けて付勢する転写体退避バネと、を備え、
前記転写体保持バネが前記転写体を前記感光体に押すバネ力よりも、前記転写体退避バネが前記転写体を前記感光体から離間させる方向に押すバネ力の方が大きくなるように、前記転写体保持バネと前記転写体退避バネのバネ力が設定され、
前記現像ユニットが前記現像位置に装着される際に、前記現像ユニットが前記現像位置に近づくと、前記スライダに接触し、前記スライダを前記転写体退避バネのバネ力に抗して移動させ、前記転写体保持バネのバネ力によって前記転写体を前記転写位置に保持させることを可能にする一方、前記現像ユニットが前記現像位置から取り外されると、前記スライダから離脱し、前記転写体退避バネのバネ力によるスライダの移動を可能にして、前記転写体が前記退避位置へ移動するのを可能にする、転写体移動手段駆動部を前記現像ユニットに備えた、
ことを特徴とする画像形成装置。 A photosensitive member having an electrostatic latent image formed on the surface, a developing unit for supplying a developer to the surface of the photosensitive member to visualize the electrostatic latent image as a toner image, and a surface formed on the surface of the photosensitive member. A transfer body for transferring the toner image to a transfer material,
The developing unit can be attached to and detached from a developing position facing the photoconductor, and the transfer body can be moved by a transfer body moving means between a transfer position facing the photoconductor and a retracted position sufficiently separated from the photoconductor. In the image forming apparatus which is
The transfer body moving means includes:
A transfer body holding spring for holding the transfer body at the transfer position with an elastic force;
A slider that is disposed at a position not in contact with the photosensitive member and moves along a moving direction of the transfer member;
A transfer member retracting spring that urges the slider toward a direction in which the transfer member separates from the photosensitive member,
The spring force by which the transfer body retracting spring pushes the transfer body away from the photoconductor is larger than the spring force by which the transfer body holding spring pushes the transfer body against the photoconductor. The spring force of the transfer body holding spring and the transfer body retracting spring is set,
When the developing unit is mounted at the developing position, when the developing unit approaches the developing position, the slider comes into contact with the slider, and the slider is moved against the spring force of the transfer member retracting spring, While it is possible to hold the transfer body at the transfer position by the spring force of the transfer body holding spring, when the developing unit is removed from the developing position, the transfer body is detached from the slider and the spring of the transfer body retracting spring is released. The development unit is provided with a transfer body moving means driving unit that enables the slider to move by force and enables the transfer body to move to the retracted position.
An image forming apparatus. 前記現像ユニットの前記転写体移動手段駆動部と前記スライダとの接触部分が傾斜面であり、前記転写体移動手段駆動部と前記スライダとの接触動作及び離脱動作が滑らかに行われるようになっていることを特徴とする請求項１に記載の画像形成装置。   A contact portion between the transfer member moving unit driving unit and the slider of the developing unit is an inclined surface, and a contact operation and a detaching operation between the transfer member moving unit driving unit and the slider are smoothly performed. The image forming apparatus according to claim 1, wherein:
JP2003398788A 2003-11-28 2003-11-28 Image forming apparatus Pending JP2005157187A (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007199440A (en) * 2006-01-27 2007-08-09 Kyocera Mita Corp Image forming apparatus
JP2007199526A (en) * 2006-01-27 2007-08-09 Kyocera Mita Corp Image forming apparatus
JP2007206187A (en) * 2006-01-31 2007-08-16 Kyocera Mita Corp Image forming apparatus
JP2013003191A (en) * 2011-06-13 2013-01-07 Konica Minolta Business Technologies Inc Image forming apparatus
JP2014026214A (en) * 2012-07-30 2014-02-06 Kyocera Document Solutions Inc Image forming apparatus

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007199440A (en) * 2006-01-27 2007-08-09 Kyocera Mita Corp Image forming apparatus
JP2007199526A (en) * 2006-01-27 2007-08-09 Kyocera Mita Corp Image forming apparatus
JP2007206187A (en) * 2006-01-31 2007-08-16 Kyocera Mita Corp Image forming apparatus
JP2013003191A (en) * 2011-06-13 2013-01-07 Konica Minolta Business Technologies Inc Image forming apparatus
JP2014026214A (en) * 2012-07-30 2014-02-06 Kyocera Document Solutions Inc Image forming apparatus
CN103576523A (en) * 2012-07-30 2014-02-12 京瓷办公信息***株式会社 Image forming apparatus
US9092005B2 (en) 2012-07-30 2015-07-28 Kyocera Document Solutions Inc. Image forming apparatus with a removable drum unit

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