JP2008170478A

JP2008170478A - Belt detent structure and image forming apparatus

Info

Publication number: JP2008170478A
Application number: JP2007000842A
Authority: JP
Inventors: Katsuto Haruno; 克仁春野
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2007-01-05
Filing date: 2007-01-05
Publication date: 2008-07-24

Abstract

【課題】ローラに掛架された無端ベルトの幅方向の寄りに起因した振動発生を防止できるベルト寄り止め構造を提供すること。
【解決手段】無端ベルト１の裏面にその周方向に亘って凸部３を設け、その凸部３と遊嵌可能な凹部６０３をローラ４の外周面にその周方向に亘って設けると共に、そのローラ４の端部を径方向に張り出し形成する。このように構成した無端ベルト１とローラ４とを、端部の軸方向内方の側面が無端ベルトの縁に隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架して、無端ベルト１の幅方向の寄りを完全に抑止する。
【選択図】図１To provide a belt detent structure capable of preventing the occurrence of vibration caused by the shift in the width direction of an endless belt hung on a roller.
A convex portion 3 is provided on the back surface of the endless belt 1 in the circumferential direction, and a concave portion 603 that can be loosely fitted to the convex portion 3 is provided on the outer circumferential surface of the roller 4 in the circumferential direction. The end of the roller 4 is formed so as to project in the radial direction. The endless belt 1 and the roller 4 configured as described above are engaged so that the axially inner side surface of the end is adjacent to the edge of the endless belt, and the convex portion 3 and the concave portion 603 are engaged. The endless belt 1 is hung on the roller 4 to completely prevent the endless belt 1 from shifting in the width direction.
[Selection] Figure 1

Description

本発明は、ローラに掛架された無端ベルトの幅方向の寄りを抑止させるベルト寄り止め構造、及び、その構造を備えた画像形成装置に関する。 The present invention relates to a belt detent structure that suppresses a shift in the width direction of an endless belt that is hung on a roller, and an image forming apparatus including the structure.

従来、転写ベルトの裏面の縁部に周方向に亘って凸状の寄り規制部材を設け、その寄り規制部材をローラの端面に当接可能なように、転写ベルトをローラに掛架したベルト寄り止め構造を備えた転写装置がある。
この転写装置によれば、寄り規制部材がローラの端面に当接して、転写ベルトの幅方向の寄りを抑止するから、転写ずれや、色ずれのない極めて好適な転写装置になっている（例えば特許文献１参照）。
特開２００４−１８４６９７公報 Conventionally, a convex shift regulating member has been provided on the edge of the back surface of the transfer belt in the circumferential direction, and the transfer belt is hung on the roller so that the shift regulating member can be brought into contact with the end surface of the roller. There is a transfer device with a stop structure.
According to this transfer device, the shift regulating member abuts against the end surface of the roller and suppresses the shift in the width direction of the transfer belt. Therefore, the transfer device is a very suitable transfer device with no transfer shift or color shift (for example, Patent Document 1).
Japanese Patent Laid-Open No. 2004-184697

上記した従来のベルト寄り止め構造は、通常の使用状態では、寄り規制部材がローラの外周面に乗り上がる恐れはまずないが、何らかの予期せぬ原因で、ローラの外周面に寄り規制部材が一旦乗り上げてしまうと、転写ベルトの幅方向の寄りを抑止する手段がなく、更なる改良の余地があった。
また、この寄り規制部材は、ベルト幅方向に振れがある取り付けがされると、場合によっては、寄り規制部材がローラの端面に圧接して上昇と落下を繰り返して、転写ベルトがガタガタと上下に振動してしまう場合があった。当然のことながら、その振動によって、転写ずれや、色ずれ等の画像異常が生じてしまう。そこで従来は、その転写ベルトから振動が発生しないように、転写ベルトに対する寄り規制部材の真直度の精度を上げる（取り付け精度、部材の加工精度を向上）等していたが、その手間と労力、すなわちコストがかさみ、その改善が望まれていた。
そこで本発明は、このような状況に鑑みてなされたものであり、上記問題点を解決できるベルト寄り止め構造及び画像形成装置を提供することを目的とする。 The above-described conventional belt detent structure is unlikely to cause the shift regulating member to ride on the outer peripheral surface of the roller in a normal use state. However, for some unexpected reason, the shift regulating member temporarily stops on the outer peripheral surface of the roller. When it gets on, there is no means for suppressing the shift of the transfer belt in the width direction, and there is room for further improvement.
In addition, when the deviation regulating member is attached with a vibration in the belt width direction, the deviation regulating member presses against the end surface of the roller and repeats rising and falling depending on the case. There was a case where it vibrates. As a matter of course, the vibration causes image abnormality such as transfer deviation and color deviation. Therefore, conventionally, the straightness of the deviation regulating member relative to the transfer belt has been increased so as not to generate vibration from the transfer belt (improving mounting accuracy and member processing accuracy). That is, the cost is high, and the improvement has been desired.
Accordingly, the present invention has been made in view of such a situation, and an object thereof is to provide a belt detent structure and an image forming apparatus that can solve the above-described problems.

上記技術課題を達成するために、本発明にかかるベルト寄り止め構造及び画像形成装置は、下記の技術的手段を講じた。
すなわち、請求項１にかかるベルト寄り止め構造は、無端ベルトの裏面にその周方向に亘って凸部を設け、該凸部と遊嵌可能な凹部をローラの外周面にその周方向に亘って設けると共に該ローラの端部を径方向に張り出し形成してなり、該端部の軸方向内方の側面が前記無端ベルトの縁に隣接するように、かつ、前記凸部と前記凹部とが係合するように、前記無端ベルトが前記ローラに掛架してなることを特徴とする。
請求項２にかかるベルト寄り止め構造は、請求項１において、前記端部の軸方向内方の側面と前記凹部の軸方向外方の側面とが、連続した垂直状に形成してなることを特徴とする。 In order to achieve the above technical problem, the belt detent structure and the image forming apparatus according to the present invention employ the following technical means.
That is, in the belt detent structure according to claim 1, a convex portion is provided on the back surface of the endless belt in the circumferential direction, and a concave portion that can be loosely fitted with the convex portion is provided on the outer circumferential surface of the roller in the circumferential direction. And an end portion of the roller is formed so as to protrude in the radial direction, the inner side surface in the axial direction of the end portion is adjacent to the edge of the endless belt, and the convex portion and the concave portion are engaged. The endless belt is hung on the roller so as to match.
According to a second aspect of the present invention, in the belt detent structure according to the first aspect, the axially inner side surface of the end portion and the axially outer side surface of the recess are formed in a continuous vertical shape. Features.

請求項３にかかるベルト寄り止め構造は、請求項１において、前記凹部の軸方向外方の側面を、軸方向外方に向かって漸次拡径したテーパー状に形成してなると共に、前記端部の軸方向内方の側面に向かって延出したこと、または、前記端部の軸方向内方の側面と兼ねたことを特徴とする。
請求項４にかかるベルト寄り止め構造は、請求項１において、前記凹部の軸方向外方の側面は、前記凹部の底面から立設した垂直面と、軸方向外方に向かって漸次拡径したテーパー面とを備え、該テーパー面を、前記端部の軸方向内方の側面に向かって延出したこと、または、前記端部の軸方向内方の側面と兼ねたことを特徴とする。
請求項５にかかるベルト寄り止め構造は、請求項１乃至４の何れか一項において、前記ローラは、前記凹部と前記端部とを形成したガイド部材と、ローラ本体とを備えたことを特徴とする。 According to a third aspect of the present invention, there is provided the belt detent structure according to the first aspect, wherein the axially outer side surface of the concave portion is formed in a tapered shape having a diameter gradually increased outward in the axial direction. It extends toward the axially inner side surface, or doubles as the axially inner side surface of the end portion.
According to a fourth aspect of the present invention, in the belt detent structure according to the first aspect, the axially outer side surface of the concave portion is gradually expanded in diameter toward the vertical surface standing from the bottom surface of the concave portion and axially outward. And a taper surface extending toward the inner side surface in the axial direction of the end portion or serving as the inner side surface in the axial direction of the end portion.
According to a fifth aspect of the present invention, in the belt detent structure according to any one of the first to fourth aspects, the roller includes a guide member in which the concave portion and the end portion are formed, and a roller body. And

請求項６にかかるベルト寄り止め構造は、請求項５において、前記ガイド部材を、前記ローラ本体に回動可能に設けたことを特徴とする。
請求項７にかかるベルト寄り止め構造は、請求項５において、前記凹部の軸方向内方の側面を形成すると共に前記ローラ本体の外径でもって形成した内側部材と、前記凹部の軸方向外方の側面及び底面と前記端部とを形成した外側部材とで前記ガイド部材を構成し、前記内側部材と前記外側部材との夫々を、前記ローラ本体に回動可能に設けたことを特徴とする。
請求項８にかかる画像形成装置は、請求項１乃至７の何れか一項に記載のベルト寄り止め構造を備えたことを特徴とする。 According to a sixth aspect of the present invention, in the belt detent structure according to the fifth aspect, the guide member is rotatably provided on the roller body.
According to a seventh aspect of the present invention, there is provided the belt detent structure according to the fifth aspect, wherein an inner member formed with an outer diameter of the roller body and an outer side of the concave portion in the axial direction is formed. The guide member is constituted by an outer member formed with side and bottom surfaces and the end portion, and each of the inner member and the outer member is rotatably provided on the roller body. .
An image forming apparatus according to an eighth aspect is provided with the belt detent structure according to any one of the first to seventh aspects.

請求項９にかかる画像形成装置は、記録材を搬送するベルト搬送手段と、該ベルト搬送手段で搬送した前記記録材に感光体上のトナー像を転写する転写手段とを備えた画像形成装置であって、前記ベルト搬送手段は、請求項１乃至７の何れか一項に記載のベルト寄り止め構造を備えたことを特徴とする。
請求項１０にかかる画像形成装置は、トナー像を搬送するベルト搬送手段と、該ベルト搬送手段で搬送した前記トナー像を記録材に転写する転写手段とを備えた画像形成装置であって、前記トナー像搬送手段は、請求項１乃至７の何れか一項に記載のベルト寄り止め構造を備えたことを特徴とする。
請求項１１にかかる画像形成装置は、請求項９または１０において、フルカラー像を前記記録材に記録可能に構成したことを特徴とする。 According to a ninth aspect of the present invention, there is provided an image forming apparatus comprising: a belt conveying unit that conveys a recording material; and a transfer unit that transfers a toner image on a photosensitive member to the recording material conveyed by the belt conveying unit. The belt conveying means comprises the belt detent structure according to any one of claims 1 to 7.
An image forming apparatus according to a tenth aspect is an image forming apparatus comprising: a belt conveying unit that conveys a toner image; and a transfer unit that transfers the toner image conveyed by the belt conveying unit to a recording material. A toner image conveying unit includes the belt detent structure according to any one of claims 1 to 7.
An image forming apparatus according to an eleventh aspect is characterized in that, in the ninth or tenth aspect, a full-color image can be recorded on the recording material.

本発明によれば、無端ベルトの裏面にその周方向に亘って設けた凸部と、ローラの外周面にその周方向に亘って設けた凹部とが係合して、無端ベルトの幅方向の寄りを抑止するから、寄りのない高精度のベルト駆動ができる。しかも、何らかの予期せぬ原因で、凸部がローラの外周面に乗り上がろうとする力が作用しても、径方向に張り出し形成した（反対側の）ローラの端部の側面が、無端ベルトの幅方向の寄りを抑止するから、凸部がローラの外周面に乗り上がる恐れを完全に払拭できる。
また、凸部をベルト幅方向に振れがある取り付けがされても、径方向に張り出し形成したローラの端部の側面をテーパー状に形成したことで、凸部がテーパー状の側面を滑らかに上昇し下降するから、結果的に、無端ベルトに対する凸部の真直度の精度を下げても、無端ベルトからの振動発生を防止できる。 According to the present invention, the convex portion provided in the circumferential direction on the back surface of the endless belt and the concave portion provided in the circumferential direction on the outer peripheral surface of the roller are engaged with each other, so that the width direction of the endless belt is increased. Since the deviation is suppressed, the belt drive can be performed with high accuracy without deviation. In addition, even if a force that causes the convex portion to ride on the outer peripheral surface of the roller is applied due to some unexpected cause, the side surface of the end portion of the roller that protrudes in the radial direction (on the opposite side) is an endless belt. Therefore, it is possible to completely eliminate the fear that the convex portion rides on the outer peripheral surface of the roller.
In addition, even if the convex part is attached with a wobbling in the belt width direction, the convex part smoothly rises up the tapered side surface by forming the side surface of the end of the roller protruding in the radial direction into a tapered shape. As a result, even if the straightness accuracy of the convex portion with respect to the endless belt is lowered, the generation of vibration from the endless belt can be prevented.

次に、本発明に係るベルト寄り止め構造の実施の形態を、添付図面を参照しながら説明する。
（実施の形態１）
実施の形態１にかかるベルト寄り止め構造は、図１に示すように、無端ベルト１と、ローラ４とで構成される。
無端ベルト１は、所要幅の無端状のベルト本体２と、そのベルト本体２の裏面両縁部にその周方向に亘って環状に設けられた断面視ブロック状の凸部３とで構成される。
この環状の凸部３は、無端ベルト１との一体成形で形成しても良く、また、別部材構成にしてベルト本体２の裏面縁部に接着しても良いものである。 Next, an embodiment of the belt detent structure according to the present invention will be described with reference to the accompanying drawings.
(Embodiment 1)
The belt detent structure according to the first embodiment includes an endless belt 1 and a roller 4 as shown in FIG.
The endless belt 1 includes an endless belt main body 2 having a required width, and a convex portion 3 having a block shape in a cross-sectional view provided annularly at both edges of the back surface of the belt main body 2 in the circumferential direction. .
The annular convex portion 3 may be formed by integral molding with the endless belt 1, or may be formed as a separate member and adhered to the back surface edge of the belt main body 2.

また、この凸部３は、図１に示すように、ベルト本体２の縁と揃えるように配設されているが、その縁より内方へ配設したり、その逆にベルト本体２の縁より僅かに突出するように外方へ配設しても良い。 Further, as shown in FIG. 1, the convex portion 3 is arranged so as to be aligned with the edge of the belt main body 2. However, the convex portion 3 is arranged inward from the edge or vice versa. You may arrange | position outward so that it may protrude slightly.

ローラ４は、ローラ本体５と、ガイド部材６０１とで構成される。
ローラ本体５は、無端ベルト１が掛架される大径部５１と、その大径部５１の両端から延設され機枠等に設けられた軸受けに挿嵌される小径部５２とで、外観視、段付きの丸軸状に形成されている。
ガイド部材６０１は、小径部５２が挿嵌される連通孔６０２が設けられた中空軸体の両端がフランジ状に張り出し形成されて、その中間部に、凸部３と遊嵌可能な凹部６０３が周方向に亘って凹設されてなる。
また、このガイド部材６０１は、そのフランジ状に張り出し形成された一端部６０４が、大径部５１の径と同一径で形成され、他端部６０５が、大径部５１より大きい径となるように張り出し形成され、さらに、その他端部６０５の軸方向内方の側面と、凹部６０３の軸方向外方の側面とが、図１に示すように、連続した垂直状の共通の側面６０６に形成されている。
このように形成されたガイド部材６０１は、連通孔６０２を介してその一端部６０４側から小径部５２に挿通されて、ローラ本体５の両端側に嵌合されている。 The roller 4 includes a roller body 5 and a guide member 601.
The roller body 5 includes a large-diameter portion 51 on which the endless belt 1 is suspended, and a small-diameter portion 52 that extends from both ends of the large-diameter portion 51 and is fitted into a bearing provided in a machine frame or the like. It is formed in a round shaft with a step.
The guide member 601 is formed such that both ends of a hollow shaft body provided with a communication hole 602 into which the small diameter portion 52 is inserted are formed in a flange shape, and a concave portion 603 that can be loosely fitted with the convex portion 3 is formed at an intermediate portion thereof. It is recessed over the circumferential direction.
Further, the guide member 601 has an end portion 604 formed in a flange shape so as to have the same diameter as that of the large diameter portion 51, and the other end portion 605 has a diameter larger than that of the large diameter portion 51. Further, the axially inner side surface of the other end 605 and the axially outer side surface of the recess 603 are formed on a continuous vertical common side surface 606 as shown in FIG. Has been.
The guide member 601 formed in this way is inserted into the small diameter portion 52 from the one end portion 604 side through the communication hole 602 and is fitted to both end sides of the roller body 5.

以上のように構成された実施の形態１にかかるベルト寄り止め構造は、図１に示すように、張り出し形成した他端部６０５の軸方向内方の側面と無端ベルト１の縁とが隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架する。
なお、凸部３と凹部６０３との係合状態は、その両側面同士が摺接する係合状態になっている。もっとも、ベルト寄りの原因にもなる不必要な間隙（クリアランス）でなければ、これらの摺接部は、接しないような係合関係としても良い。
このように、無端ベルト１をローラ４に掛架することで、係合した凸部３と凹部６０３とが、無端ベルト１の幅方向の寄りを抑止して、寄りのない高精度のベルト駆動を実現する。加えて、何らかの予期せぬ原因で、例えば、一方の凸部３が、ローラ本体５方向へ移動する力（ガイド部材６０１の一端部６０４へ乗り上がろうとする力）が作用しても、径方向に張り出し形成した他方のガイド部材６０１の他端部６０５が、無端ベルト１の幅方向の寄りを抑止するから、結果的に、凸部３がローラ本体５の外周面に乗り上がる恐れを完全に払拭でき、長期に亘って、寄りのない高精度のベルト駆動を実現できる。 In the belt detent structure according to the first embodiment configured as described above, as shown in FIG. 1, the side surface in the axial direction of the other end 605 formed in a protruding manner and the edge of the endless belt 1 are adjacent to each other. Thus, the endless belt 1 is hung on the roller 4 so that the convex portion 3 and the concave portion 603 are engaged with each other.
In addition, the engaging state of the convex part 3 and the recessed part 603 is an engaging state in which both side surfaces are in sliding contact. Of course, if the gap is not an unnecessary gap (clearance) that also causes the belt, the sliding contact portions may be engaged so as not to contact each other.
In this way, by hanging the endless belt 1 on the roller 4, the engaged convex portion 3 and the concave portion 603 prevent the endless belt 1 from shifting in the width direction, and the belt drive is highly accurate without any shift. To realize. In addition, even if, for some unexpected cause, for example, a force that moves one convex portion 3 in the direction of the roller main body 5 (a force that tries to climb onto one end portion 604 of the guide member 601) acts, Since the other end portion 605 of the other guide member 601 that protrudes in the direction prevents the endless belt 1 from shifting in the width direction, it is possible to completely prevent the convex portion 3 from riding on the outer peripheral surface of the roller body 5 as a result. It is possible to achieve high-accuracy belt driving without deviation over a long period of time.

なお、実施の形態１にかかるガイド部材６０１は、凹部６０３の軸方向外方の側面とフランジ状に張り出し形成された他端部６０５の軸方向内方の側面とが、連続した垂直状の共通の側面６０６に形成されているが、図２に示すガイド部材６２７のように、ベルト本体２と凸部３との配設位置に応じて、これらと沿うように、凹部６０３の軸方向外方の側面６０７とフランジ状に張り出し形成された他端部６０５の軸方向内方の側面６０８とに個別に形成しても良い。
また、図３に示すように、ローラ本体５の側面５３を利用して凹部６０３が形成されるように、他端部６０５のみをフランジ状に形成させたガイド部材６０９でも良い。
また、本実施の形態にかかるローラ４は、ガイド部材とローラ本体５とを別部材で構成しているが、一体成形で構成しても良いものである。 Note that the guide member 601 according to the first embodiment has a common vertical shape in which the axially outer side surface of the recess 603 and the axially inner side surface of the other end 605 formed in a flange shape are continuous. 2, but the guide member 627 shown in FIG. 2, the axially outward direction of the concave portion 603 extends along the belt body 2 and the convex portion 3 according to the arrangement position of the belt main body 2 and the convex portion 3. May be formed separately on the side surface 607 and the side surface 608 on the inner side in the axial direction of the other end 605 formed in a flange shape.
Moreover, as shown in FIG. 3, the guide member 609 which formed only the other end part 605 in the flange shape so that the recessed part 603 may be formed using the side surface 53 of the roller main body 5 may be sufficient.
Further, in the roller 4 according to the present embodiment, the guide member and the roller body 5 are configured as separate members, but may be configured by integral molding.

（実施の形態２）
実施の形態２にかかるベルト寄り止め構造は、図４に示すように、実施の形態１で例示したガイド部材６０１…の形状の一部（凹部６０３）を異ならせたもので、実施の形態１と共通する構成部は、同一符号を付して説明を省略する。
実施の形態２にかかるガイド部材６１０は、小径部５２が挿嵌される連通孔６０２が設けられた中空軸体の両端がフランジ状に張り出し形成されて、その中間部に、凸部３と遊嵌可能な凹部６０３が周方向に亘って凹設されてなる。
また、このガイド部材６１０は、そのフランジ状に張り出し形成された一端部６０４が、大径部５１の径と同一径で形成され、他端部６０５が、大径部５１より大きい径となるように張り出し形成され、その他端部６０５の軸方向内方の側面６１１と連絡される凹部６０３の軸方向外方の側面６１２が、軸方向外方に向かって漸次拡径されたテーパー状に形成されている。
さらに、このテーパー状に形成された側面６１２の軸方向内方の傾斜基点Ｘ１は、図４に示すように、凸部３の軸方向外方の稜角部Ｃより軸方向内方となっており、テーパー状の側面６１２の中途部に、その凸部３の軸方向外方の稜角部Ｃが近接または接するような配置関係になっている。一方、軸方向外方の傾斜基点Ｘ２は、掛架された無端ベルト１の表面と略同じ高さに位置されるようになっている。なお、実施の形態２では、このテーパー状の側面６１２のテーパー角を概ね３０度としている。 (Embodiment 2)
As shown in FIG. 4, the belt stopper structure according to the second embodiment is obtained by changing a part of the shape of the guide member 601... Illustrated in the first embodiment (recess 603). Constituent parts that are common to those are denoted by the same reference numerals and description thereof is omitted.
In the guide member 610 according to the second embodiment, both ends of a hollow shaft body provided with a communication hole 602 into which the small-diameter portion 52 is inserted are formed in a flange shape, and the projecting portion 3 and the loose portion are formed in the middle portion thereof. The recessed part 603 which can be fitted is recessed over the circumferential direction.
Further, the guide member 610 has one end portion 604 that is formed in a flange-like shape so as to have the same diameter as that of the large diameter portion 51, and the other end portion 605 has a larger diameter than the large diameter portion 51. An axially outward side surface 612 of the recess 603 that is formed in a protruding manner and communicates with the axially inwardly lateral surface 611 of the other end portion 605 is formed in a tapered shape that is gradually expanded in the axially outward direction. ing.
Further, the inclined base point X1 in the axial direction of the side surface 612 formed in a tapered shape is inward in the axial direction from the ridge corner C in the axially outward direction of the convex portion 3, as shown in FIG. The arrangement is such that the axially outward ridge corner C of the convex portion 3 is close to or in contact with the middle portion of the tapered side surface 612. On the other hand, the axially outwardly inclined base point X2 is positioned at substantially the same height as the surface of the suspended endless belt 1. In the second embodiment, the taper angle of the tapered side surface 612 is approximately 30 degrees.

なお、テーパー状に形成された側面６１２の軸方向内方の傾斜基点Ｘ１に、凸部３の軸方向外方の稜角部Ｃが位置するようにしても良い。また、実施の形態２では、テーパー状に形成された凹部６０３の軸方向外方の側面６１２と、他端部６０５の軸方向内方の側面６１１とを分けて、この両者を接続させた形状になっているが、図５に示すガイド部材６１３のように、軸方向外方のテーパー状の側面６１２のみで構成しても良い（他端部６０５の軸方向内方の側面６１１を兼ねる）。
このように形成されたガイド部材６１０は、連通孔６０２を介してその一端部６０４側から小径部５２に挿通されて、ローラ本体５の両端に嵌合されている。 In addition, the axially outward ridge corner C of the convex portion 3 may be positioned at the axially inwardly inclined base point X1 of the side surface 612 formed in a tapered shape. In the second embodiment, the axially outer side surface 612 of the concave portion 603 formed in a tapered shape and the axially inner side surface 611 of the other end portion 605 are separated and connected to each other. However, like the guide member 613 shown in FIG. 5, it may be configured only by the axially outward tapered side surface 612 (also serves as the axially inward side surface 611 of the other end portion 605). .
The guide member 610 thus formed is inserted into the small diameter portion 52 from the one end portion 604 side through the communication hole 602 and is fitted to both ends of the roller body 5.

以上のように構成された実施の形態２にかかるベルト寄り止め構造は、図４に示すように、張り出し形成した他端部６０５の軸方向内方の側面６１１と無端ベルト１の縁とが隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架する。
なお、凸部３と凹部６０３との係合状態は、軸方向内方の側面同士が摺接し、凸部３の軸方向外方の稜角部Ｃとテーパー状の側面６１２の中途部とが摺接する係合状態になっている。もっとも、ベルト寄りの原因にもなる不必要な間隙（クリアランス）でなければ、これらの摺接部は、接しないような係合関係としても良い。
このように、無端ベルト１をローラ４に掛架することで、係合した凸部３と凹部６０３とが、無端ベルト１の幅方向の寄りを抑止して、寄りのない高精度のベルト駆動を実現する。加えて、何らかの予期せぬ原因で、例えば、一方の凸部３が、ローラ本体５方向へ移動する力（ガイド部材６１０の一端部６０４へ乗り上がろうとする力）が作用しても、他方のテーパー状に形成された凹部６０３の軸方向外方の側面６１２に、左方の凸部３の、軸方向外方の稜角部Ｃが当接して、無端ベルト１の幅方向の寄りを抑止するから、結果的に、凸部３がローラ本体５の外周面に乗り上がる恐れを完全に払拭でき、長期に亘って、寄りのない高精度のベルト駆動を実現する。 In the belt detent structure according to the second embodiment configured as described above, as shown in FIG. 4, the side surface 611 in the axial direction of the other end 605 formed in an overhang and the edge of the endless belt 1 are adjacent to each other. The endless belt 1 is hung on the roller 4 so that the convex portion 3 and the concave portion 603 are engaged with each other.
Note that the engagement between the convex portion 3 and the concave portion 603 is such that the axially inner side surfaces are in sliding contact with each other, and the axially outward ridge corner C of the convex portion 3 and the middle portion of the tapered side surface 612 are slid. The contact state is in contact. Of course, if the gap is not an unnecessary gap (clearance) that also causes the belt, the sliding contact portions may be engaged so as not to contact each other.
In this way, by hanging the endless belt 1 on the roller 4, the engaged convex portion 3 and the concave portion 603 prevent the endless belt 1 from shifting in the width direction, and the belt drive is highly accurate without any shift. To realize. In addition, even if, for some unexpected reason, for example, a force that moves one convex portion 3 toward the roller body 5 (a force that tries to climb onto one end 604 of the guide member 610) acts, An axially outward ridge corner C of the left convex portion 3 is in contact with the axially outer side surface 612 of the concave portion 603 formed in a taper shape, thereby preventing the endless belt 1 from shifting in the width direction. Therefore, as a result, it is possible to completely wipe out the fear that the convex portion 3 rides on the outer peripheral surface of the roller main body 5 and realizes high-precision belt driving without deviation over a long period of time.

また、仮に、一方の凸部３がローラ本体５方向へ移動する力（ガイド部材６１０の一端部６０４へ乗り上がろうとする力）が大きく作用して、他方の凸部３が上昇と落下を繰り返すような大きな力が作用しても、凹部６０３の軸方向外方の側面６１２をテーパー状に形成したことで、無端ベルト１を内方に押し返す力が作用し、落下することなく、テーパー状の側面６１２に沿って他方の凸部３が滑らかに下降するから、振動と騒音を抑制することができる。したがって、かかる構造を画像形成装置の転写ベルト装置等に用いた場合、仮に、一方の凸部３がローラ本体５方向へ移動する力が作用している状態時においても、転写ずれや、色ずれを抑えることができる。
また、無端ベルト１と凸部３との真直度の精度（取り付け精度、部材の加工精度）を多少落としても、凹部６０３の軸方向外方の側面６１２をテーパー状に形成したことで、凸部３が凹部６０３の軸方向外方の側面６１２を乗り上げる場合も落ちる場合も滑らかにテーパー状の側面６１２に沿って動作するから、無端ベルト１の振動を抑止することができる。したがって、かかる構造を画像形成装置の転写ベルト装置等に用いた場合、画像品質を維持しつつコストを低減することができる。
また、凹部６０３の軸方向外方の側面６１２をテーパー状に形成したことで、無端ベルト１の縁が、ガイド部材６１０と当たらないため、無端ベルト１の縁を傷める恐れがない。 Also, if one of the convex portions 3 moves in the direction of the roller body 5 (a force that tends to climb onto one end portion 604 of the guide member 610), the other convex portion 3 rises and falls. Even when a large force is applied repeatedly, the axially outer side surface 612 of the recess 603 is formed into a taper shape, so that a force that pushes the endless belt 1 inwardly acts, and the taper shape does not fall. Since the other convex part 3 falls smoothly along the side surface 612, vibration and noise can be suppressed. Therefore, when such a structure is used for a transfer belt device of an image forming apparatus, even if a force that moves one convex portion 3 toward the roller main body 5 is acting, Can be suppressed.
Further, even if the straightness accuracy (attachment accuracy, member processing accuracy) between the endless belt 1 and the convex portion 3 is slightly reduced, the axially outer side surface 612 of the concave portion 603 is formed into a tapered shape. Since the portion 3 moves smoothly along the tapered side surface 612 whether or not it rides on the axially outer side surface 612 of the recess 603, the vibration of the endless belt 1 can be suppressed. Therefore, when such a structure is used for a transfer belt device of an image forming apparatus, the cost can be reduced while maintaining the image quality.
Further, since the axially outer side surface 612 of the concave portion 603 is formed in a tapered shape, the edge of the endless belt 1 does not contact the guide member 610, so that the edge of the endless belt 1 is not damaged.

（実施の形態３）
実施の形態３にかかるベルト寄り止め構造は、図６に示すように、実施の形態２と同様に、ガイド部材の形状の一部（凹部６０３）を異ならせたもので、実施の形態１と共通する構成部は、同一符号を付して説明を省略する。
実施の形態の３にかかるガイド部材６１４は、小径部５２が挿嵌される連通孔６０２が設けられた中空軸体の両端がフランジ状に張り出し形成されて、その中間部に、凸部３と遊嵌可能な凹部６０３が周方向に亘って凹設されてなる。
また、このガイド部材６１４は、そのフランジ状に張り出し形成された一端部６０４が、大径部５１の径と同一径で形成され、他端部６０５が、大径部５１より大きい径となるように張り出し形成され、その他端部６０５の軸方向内方の側面６１１と連絡される凹部６０３の軸方向外方の側面が、凹部６０３の底面から立設した垂直面６１５と、軸方向外方に向かって漸次拡径したテーパー面６１６とを備えて略階段状に形成されている。なお、実施の形態３では、このテーパー面６１６のテーパー角を概ね３０度としている。
さらに、このガイド部材６１４は、軸中心から垂直面６１５とテーパー面６１６との交点までの距離（垂直面６１５の高さ）Ｌ１が、軸中心から凸部３の内周面までの距離Ｌ２より大きくなっている。実施の形態３では、図６に示すように、その交点が凸部３の内周面内に収まるようにしているが、図７に示すガイド部材６１７のように、垂直面６１５とテーパー面６１６との交点が無端ベルト１の表面より径方向外方となるようにしても良い。 (Embodiment 3)
As shown in FIG. 6, the belt stopper structure according to the third embodiment is different from the first embodiment in that a part of the shape of the guide member (recess 603) is different from that of the first embodiment. Common components are denoted by the same reference numerals and description thereof is omitted.
In the guide member 614 according to the third embodiment, both ends of a hollow shaft body provided with a communication hole 602 into which the small diameter portion 52 is inserted are formed in a flange shape, and the convex portion 3 and the intermediate portion thereof are formed. A loosely fitable recess 603 is provided in the circumferential direction.
Further, the guide member 614 has an end portion 604 formed in a flange shape so as to have the same diameter as that of the large diameter portion 51, and the other end portion 605 has a diameter larger than that of the large diameter portion 51. An axially outward side surface of the concave portion 603 that is formed to protrude from the other end portion 605 and communicates with an axially inner side surface 611 of the other end portion 605, and a vertical surface 615 erected from the bottom surface of the concave portion 603, A tapered surface 616 that gradually increases in diameter is formed in a substantially step shape. In the third embodiment, the taper angle of the tapered surface 616 is approximately 30 degrees.
Further, the guide member 614 has a distance L1 from the axis center to the intersection of the vertical surface 615 and the tapered surface 616 (height of the vertical surface 615) L1 from a distance L2 from the axis center to the inner peripheral surface of the convex portion 3. It is getting bigger. In the third embodiment, as shown in FIG. 6, the intersection is within the inner peripheral surface of the protrusion 3, but the vertical surface 615 and the tapered surface 616 are similar to the guide member 617 shown in FIG. 7. The crossing point may be radially outward from the surface of the endless belt 1.

また、実施の形態３では、垂直面６１５とテーパー面６１６とで構成された凹部６０３の軸方向外方の側面と、他端部６０５の軸方向内方の側面６１１とを分けて、この両者を接続させた形状になっているが、図８に示すガイド部材６１８のように、垂直面６１５とテーパー面６１６とで、他端部６０５の軸方向内方の側面を兼ねるように構成しても良い。
このように形成されたガイド部材６１４は、連通孔６０２を介してその一端部６０４側から小径部５２に挿通されて、ローラ本体５の両端に嵌合されている。
以上のように構成された実施の形態３にかかるベルト寄り止め構造は、図６に示すように、張り出し形成した他端部６０５の軸方向内方の側面６１１と無端ベルト１の縁とが隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架する。 In the third embodiment, the axially outward side surface of the recess 603 formed by the vertical surface 615 and the tapered surface 616 and the axially inward side surface 611 of the other end portion 605 are divided into the two. However, like the guide member 618 shown in FIG. 8, the vertical surface 615 and the tapered surface 616 are configured so as to serve as the axially inner side surface of the other end portion 605. Also good.
The guide member 614 formed in this way is inserted into the small diameter portion 52 from the one end portion 604 side through the communication hole 602 and is fitted to both ends of the roller body 5.
In the belt detent structure according to the third embodiment configured as described above, as shown in FIG. 6, the side surface 611 in the axial direction of the other end portion 605 formed in an overhang and the edge of the endless belt 1 are adjacent to each other. The endless belt 1 is hung on the roller 4 so that the convex portion 3 and the concave portion 603 are engaged with each other.

なお、凸部３と凹部６０３との係合状態は、その両側面同士が摺接する係合状態になっている。もっとも、ベルト寄りの原因にもなる不必要な間隙（クリアランス）でなければ、これらの摺接部は、接しないような係合関係としても良い。
このように、無端ベルト１をローラ４に掛架することで、係合した凸部３と凹部６０３とが、無端ベルト１の幅方向の寄りを抑止して、寄りのない高精度のベルト駆動を実現する。
また、図６に示すように、垂直面６１５とテーパー面６１６との交点が、凸部３の内周面内に収まるように構成した場合、無端ベルト１の縁が、ガイド部材６１４と当たらないため、無端ベルト１の縁を傷める恐れがない。
また、仮に、一方の凸部３がローラ本体５方向へ移動する力（ガイド部材６１４の一端部６０４へ乗り上がろうとする力）が大きく作用して、他方の凸部３が垂直面６１５を乗り上げても、その垂直面６１５と連続するテーパー面６１６を形成したことで、無端ベルト１を内方に押し返す力が作用して、正常な位置に戻すことができる。 In addition, the engaging state of the convex part 3 and the recessed part 603 is an engaging state in which both side surfaces are in sliding contact. Of course, if the gap is not an unnecessary gap (clearance) that also causes the belt, the sliding contact portions may be engaged so as not to contact each other.
In this way, by hanging the endless belt 1 on the roller 4, the engaged convex portion 3 and the concave portion 603 prevent the endless belt 1 from shifting in the width direction, and the belt drive is highly accurate without any shift. To realize.
Further, as shown in FIG. 6, when the intersection of the vertical surface 615 and the tapered surface 616 is configured to be within the inner peripheral surface of the convex portion 3, the edge of the endless belt 1 does not contact the guide member 614. Therefore, there is no fear of damaging the edge of the endless belt 1.
Also, if one convex portion 3 moves in the direction of the roller body 5 (a force that tends to climb onto one end portion 604 of the guide member 614), the other convex portion 3 moves on the vertical surface 615. Even when the vehicle rides on, the tapered surface 616 that is continuous with the vertical surface 615 is formed, so that a force that pushes the endless belt 1 inwardly acts and can be returned to a normal position.

（実施の形態４）
実施の形態４にかかるベルト寄り止め構造は、図９に示すように、実施の形態２で例示したガイド部材６１０を、ローラ本体５に回動可能に設けた例である。なお、実施の形態２と共通する構成部は、同一符号を付して説明を省略する。
すなわち、実施の形態４にかかるガイド部材６１９は、ガイド部材６１９の両端面を連通する段付の挿通孔が設けられており、その挿通孔の両端に、少径部５２と嵌合されたベアリング６２０が内嵌されている。
このように形成されたガイド部材６１９は、挿通孔を介してその一端部側から小径部５２に挿通され、ガイド部材６１９の両端中央に内嵌されたベアリング６２０と少径部５２とが嵌合されて、ローラ本体５に回動可能に設けられている。
以上のように構成された実施の形態４にかかるベルト寄り止め構造は、図９に示すように、張り出し形成した他端部の軸方向内方の側面と無端ベルト１の縁とが隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架する。 (Embodiment 4)
The belt detent structure according to the fourth exemplary embodiment is an example in which the guide member 610 illustrated in the second exemplary embodiment is rotatably provided on the roller body 5 as illustrated in FIG. 9. Note that components that are the same as those in the second embodiment are denoted by the same reference numerals and description thereof is omitted.
That is, the guide member 619 according to the fourth embodiment is provided with stepped insertion holes that communicate with both end surfaces of the guide member 619, and bearings that are fitted with the small diameter portion 52 at both ends of the insertion hole. 620 is fitted inside.
The guide member 619 formed in this way is inserted into the small diameter portion 52 from one end side thereof through the insertion hole, and the bearing 620 and the small diameter portion 52 fitted in the center of both ends of the guide member 619 are fitted. Thus, the roller body 5 is rotatably provided.
As shown in FIG. 9, the belt detent structure according to the fourth embodiment configured as described above is such that the axially inward side surface of the other end portion and the edge of the endless belt 1 are adjacent to each other. In addition, the endless belt 1 is hung on the roller 4 so that the convex portion 3 and the concave portion 603 are engaged.

このように、無端ベルト１をローラ４に掛架することで、実施の形態２にかかる効果に加え、以下の効果を奏する。
すなわち、テーパー状に形成された凹部６０３の軸方向外方の側面に、凸部３の軸方向外方の稜角部が圧接して凸部３が上昇と下降を繰り返す際、ローラ本体５と係合されている無端ベルト１の領域と、テーパー状に形成された凹部６０３近傍の無端ベルト１の領域との間に生じた無端ベルト１の周方向の捻りを、ガイド部材６１９をローラ本体５に回動可能に設けたことで、捻りを吸収することができる。
なお、上記した例は、ころがり軸受けを用いた例であるが、すべり軸受けを用いて構成しても良い。 In this way, the endless belt 1 is hung on the roller 4, and in addition to the effects according to the second embodiment, the following effects are achieved.
That is, when the axially outward ridge corner of the convex portion 3 is pressed against the axially outer side surface of the concave portion 603 formed in a taper shape and the convex portion 3 repeats rising and lowering, the roller body 5 is engaged. The circumferential twist of the endless belt 1 generated between the joined endless belt 1 region and the endless belt 1 region near the recessed portion 603 formed in a tapered shape causes the guide member 619 to move to the roller body 5. By being provided so as to be rotatable, twist can be absorbed.
In addition, although the above-mentioned example is an example using a rolling bearing, you may comprise using a sliding bearing.

（実施の形態５）
実施の形態５にかかるベルト寄り止め構造は、図１０に示すように、実施の形態２で例示したガイド部材６１０を２部材で構成し、その夫々をローラ本体５に回動可能に設けた例である。なお、実施の形態２と共通する構成部は、同一符号を付して説明を省略する。
すなわち、実施の形態５にかかるガイド部材６２２は、ローラ本体５の外径でもって所要幅の略リング状に形成された内側部材６２５と、凹部６０３を形成するテーパー状の側面６１２及び底面と他端部とを形成した中空の略円錐台状の外側部材６２６とで構成されている。
また、略リング状に形成されたこの内側部材６２５は、その両端面を連通する段付の挿通孔が設けられており、その挿通孔の一端に、少径部５２と嵌合されたベアリング６２３が内嵌されている。 (Embodiment 5)
In the belt detent structure according to the fifth embodiment, as shown in FIG. 10, the guide member 610 exemplified in the second embodiment is composed of two members, each of which is provided on the roller body 5 so as to be rotatable. It is. Note that components that are the same as those in the second embodiment are denoted by the same reference numerals and description thereof is omitted.
That is, the guide member 622 according to the fifth embodiment includes an inner member 625 formed in a substantially ring shape having a required width with the outer diameter of the roller body 5, a tapered side surface 612 and a bottom surface that form the recess 603, and the like. It is comprised with the hollow substantially frustoconical outer member 626 which formed the edge part.
Further, the inner member 625 formed in a substantially ring shape is provided with a stepped insertion hole communicating with both end faces, and a bearing 623 fitted to the small diameter portion 52 at one end of the insertion hole. Is fitted.

さらに、中空の略円錐台状に形成された外側部材６２６は、その両端面を連通する段付の挿通孔が設けられており、その挿通孔の両端に、少径部５２と嵌合されたベアリング６２４が内嵌されている。
さらに、このガイド部材６２２は、内側部材６２５と小径部５２とが、内側部材６２５のベアリング６２３側の端面がローラ本体５の側面５３に隣接するようにベアリング６２３を介して嵌合されて、内側部材６２５がローラ本体５に回動可能に設けられていると共に、外側部材６２６と小径部５２とが、外側部材６２６の底面側の端面が内側部材６２５のベアリング側と反対側の端面に隣接するようにベアリング６２４を介して嵌合されて回動可能に設けられている。このように、内側部材６２５と外側部材６２６とが、ローラ本体５に対し、夫々独立して回動可能に設けられており、その内側部材６２５と外側部材６２６とで凹部６０３が形成される。 Further, the outer member 626 formed in a hollow substantially truncated cone shape is provided with stepped insertion holes that communicate with both end surfaces, and the small diameter portion 52 is fitted to both ends of the insertion holes. A bearing 624 is fitted inside.
Further, the guide member 622 is configured such that the inner member 625 and the small diameter portion 52 are fitted via the bearing 623 so that the end surface of the inner member 625 on the bearing 623 side is adjacent to the side surface 53 of the roller body 5. The member 625 is rotatably provided on the roller body 5, and the outer member 626 and the small diameter portion 52 are such that the end surface on the bottom surface side of the outer member 626 is adjacent to the end surface opposite to the bearing side of the inner member 625. Thus, it is fitted through a bearing 624 so as to be rotatable. As described above, the inner member 625 and the outer member 626 are provided so as to be independently rotatable with respect to the roller body 5, and the inner member 625 and the outer member 626 form a recess 603.

以上のように構成された実施の形態５にかかるベルト寄り止め構造は、図１０に示すように、張り出し形成した他端部の軸方向内方の側面と無端ベルト１の縁とが隣接するように、かつ、凸部３と凹部６０３とが係合するように、無端ベルト１をローラ４に掛架する。
このように、無端ベルト１をローラ４に掛架することで、実施の形態４にかかる効果に加え、以下の効果を奏する。
すなわち、ローラ本体５と係合されている無端ベルト１の領域と、内側部材６２５と係合されている無端ベルト１の領域との間に生じた無端ベルト１の周方向の捻り（ローラ本体５と係合されている無端ベルト１の領域と、テーパー状に形成された凹部６０３近傍の無端ベルト１の領域との間に生じた無端ベルト１の周方向の捻りより、その捻り量が少ない）を、内側部材６２５をローラ本体５に回動可能に設けたことで、捻りを吸収することができる。つまり、内側部材６２５と外側部材６２６の夫々を、ローラ本体５に回動可能に設けて、捻り量が異なる部位に対応するから、効率よく捻りを吸収することができる。
次に、上記した、実施の形態１〜５にかかるベルト寄り止め構造を備えたフルカラーの画像形成装置について、図１１〜図１３を参照しながら説明する。 In the belt detent structure according to the fifth embodiment configured as described above, as shown in FIG. 10, the side surface in the axial direction of the other end portion that is overhanging and the edge of the endless belt 1 are adjacent to each other. In addition, the endless belt 1 is hung on the roller 4 so that the convex portion 3 and the concave portion 603 are engaged.
As described above, the endless belt 1 is hung on the roller 4 to provide the following effects in addition to the effects according to the fourth embodiment.
That is, the circumferential twist of the endless belt 1 generated between the region of the endless belt 1 engaged with the roller body 5 and the region of the endless belt 1 engaged with the inner member 625 (the roller body 5 The twist amount is less than the circumferential twist of the endless belt 1 generated between the region of the endless belt 1 engaged with the endless belt 1 and the region of the endless belt 1 in the vicinity of the tapered recess 603) Since the inner member 625 is rotatably provided on the roller body 5, twist can be absorbed. That is, since each of the inner member 625 and the outer member 626 is rotatably provided on the roller body 5 and corresponds to a portion having a different twist amount, the twist can be efficiently absorbed.
Next, the above-described full-color image forming apparatus including the belt detent structure according to the first to fifth embodiments will be described with reference to FIGS.

（実施の形態６）
実施の形態６にかかる画像形成装置７は、図１１に示すように、ベルト搬送手段７０１と、作像手段７０２と、転写手段７０３と、定着手段７０４とを備えてなる。
ベルト搬送手段７０１は、駆動ローラ７０６とその駆動ローラ７０６と所要の間隔をおいて配設された従動ローラ７０７とを備えたローラ部７０５と、そのローラ部７０５に掛架され、記録材を吸着させて保持可能な無端状の記録材搬送ベルト７０８とを備えて構成され、図示しない駆動機構と係合された駆動ローラ７０６の回動によって、その記録材搬送ベルト７０８が反時計方向へ回動されるようになっている。
このベルト搬送手段７０１は、上記した実施の形態１〜５の何れかのベルト寄り止め構造が用いられている。すなわち、ローラ部７０５を構成する各ローラは、ガイド部材６０１…を備えて構成され、記録材搬送ベルト７０８は、その裏面両縁部にガイド部材６０１…と係合する凸部３を備えてなる。 (Embodiment 6)
As shown in FIG. 11, the image forming apparatus 7 according to the sixth exemplary embodiment includes a belt conveyance unit 701, an image forming unit 702, a transfer unit 703, and a fixing unit 704.
The belt conveying unit 701 is hung on the roller unit 705 including a driving roller 706 and a driven roller 707 disposed at a predetermined interval from the driving roller 706, and is hanged on the roller unit 705 to adsorb the recording material. And an endless recording material conveyance belt 708 that can be held, and the recording material conveyance belt 708 rotates counterclockwise by the rotation of a driving roller 706 engaged with a drive mechanism (not shown). It has come to be.
This belt conveying means 701 uses the belt detent structure according to any of the first to fifth embodiments. That is, each roller constituting the roller portion 705 is configured to include guide members 601..., And the recording material conveyance belt 708 includes convex portions 3 that engage with the guide members 601. .

作像手段７０２は、回動可能に構成したドラム状の感光体７０９を備え、その感光体７０９を一様帯電し画像データに基づいて感光体７０９へ光照射して静電潜像を形成しその静電潜像をトナー像に現像するように構成されている。この作像手段７０２は、イエロートナー像、マゼンタトナー像、シアントナー像、ブラックトナー像を形成させるために、記録材搬送ベルト７０８に沿って横一列に４つ並設されている。
転写手段７０３は、記録材搬送ベルト７０８を挟んで４つの感光体７０９に対向するように、記録材搬送ベルト７０８の裏面側に配設され、ベルト搬送手段７０１で搬送された記録材に感光体７０９上に形成した各色のトナー像を静電転写させるように構成されている。 The image forming means 702 includes a drum-shaped photoconductor 709 configured to be rotatable, and uniformly charges the photoconductor 709 to irradiate the photoconductor 709 with light based on image data to form an electrostatic latent image. The electrostatic latent image is developed into a toner image. Four image forming units 702 are arranged in a line along the recording material conveyance belt 708 to form a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image.
The transfer unit 703 is disposed on the back side of the recording material conveyance belt 708 so as to face the four photoconductors 709 with the recording material conveyance belt 708 interposed therebetween, and the photosensitive material is transferred to the recording material conveyed by the belt conveyance unit 701. 709 is configured to electrostatically transfer toner images of the respective colors formed on 709.

定着手段７０４は、ヒータが内装されたローラ対を備え、ベルト搬送手段７０１の搬送方向下流に、ベルト搬送手段７０１に近接配置されてなる。この定着手段７０４は、そのローラ対の間にフルカラートナー像を担持させた記録材を通過させることで、フルカラートナー像と記録材とが加熱及び加圧されて、フルカラートナー像が記録材に定着されるようになっている。
以上のように構成された実施の形態６にかかる画像形成装置７は、ベルト搬送手段７０１の搬送方向上流にベルト搬送手段７０１に近接配置したレジストローラ対７１０を介して、所要のタイミングでもって記録材を搬送し、移動している記録材搬送ベルト７０８の表面に記録材を吸着保持する。 The fixing unit 704 includes a pair of rollers with a built-in heater, and is disposed in the vicinity of the belt conveyance unit 701 downstream of the belt conveyance unit 701 in the conveyance direction. The fixing unit 704 passes the recording material carrying the full-color toner image between the pair of rollers, whereby the full-color toner image and the recording material are heated and pressurized, and the full-color toner image is fixed on the recording material. It has come to be.
The image forming apparatus 7 according to the sixth embodiment configured as described above performs recording at a required timing via the registration roller pair 710 disposed in the vicinity of the belt conveyance unit 701 upstream in the conveyance direction of the belt conveyance unit 701. The recording material is conveyed and sucked and held on the surface of the moving recording material conveyance belt 708.

次いで、記録材搬送ベルト７０８の表面に吸着した記録材は、各色の作像手段７０２及びそれに対応した転写手段７０３に順に移動して、イエロートナー像、マゼンタトナー像、シアントナー像、ブラックトナー像が記録材上に転写・重畳して、フルカラートナー像を形成する。
次いで、フルカラートナー像を担持した記録材は、ベルト搬送手段７０１から離間して定着手段７０４へ移動し、その定着手段７０４の通過と同時にフルカラートナー像が記録材に定着し、その後、画像形成装置外にフルカラー画像を形成した記録材を排紙する。
この実施の形態６にかかる画像形成装置７によれば、実施の形態１〜５にかかるベルト寄り止め構造の効果を奏して、転写ずれや、色ずれのない極めて好適な画像形成装置を提供できる。 Next, the recording material adsorbed on the surface of the recording material conveying belt 708 is sequentially moved to the image forming means 702 for each color and the transfer means 703 corresponding thereto, and a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image. Are transferred and superimposed on the recording material to form a full-color toner image.
Next, the recording material carrying the full-color toner image moves away from the belt conveying unit 701 and moves to the fixing unit 704, and the full-color toner image is fixed to the recording material simultaneously with the passage of the fixing unit 704. A recording material on which a full-color image is formed is discharged.
According to the image forming apparatus 7 according to the sixth embodiment, the effect of the belt detent structure according to the first to fifth embodiments can be obtained, and an extremely suitable image forming apparatus free from transfer displacement and color misregistration can be provided. .

（実施の形態７）
実施の形態７にかかる画像形成装置８は、図１２に示すように、ベルト搬送手段８０１と、作像手段８０２と、転写手段８０３と、定着手段８０４とを備えてなる。
ベルト搬送手段８０１は、駆動ローラ８０７とその駆動ローラ８０７と所要の間隔をおいて配設された従動ローラ８０８と、駆動ローラ８０７の下方に近接配置された入口ローラ８０９と、従動ローラ８０８の下方に近接配置されたバックアップローラ８１０とで略矩形状に配置されたローラ部８０５と、そのローラ部８０５に掛架され、トナー像を吸着させて担持させる無端状の中間転写ベルト８０６とを備えて構成され、図示しない駆動機構と係合された駆動ローラ８０７の回動によって、その中間転写ベルト８０６が反時計方向へ回動されるようになっている。
なお、この中間転写ベルト８０６は、例えば基体の厚さが５０〜６００μｍの樹脂フィルムあるいはゴムを基体とするベルトであり、後述する感光体８１２からのトナー像を転写可能な抵抗値を有している。 (Embodiment 7)
As shown in FIG. 12, the image forming apparatus 8 according to the seventh embodiment includes a belt conveying unit 801, an image forming unit 802, a transfer unit 803, and a fixing unit 804.
The belt conveying unit 801 includes a driving roller 807, a driven roller 808 disposed at a predetermined interval from the driving roller 807, an entrance roller 809 disposed close to the lower side of the driving roller 807, and a lower side of the driven roller 808. A roller portion 805 disposed in a substantially rectangular shape with a backup roller 810 disposed in proximity to the roller, and an endless intermediate transfer belt 806 that is hung on the roller portion 805 and adsorbs and carries a toner image. The intermediate transfer belt 806 is rotated counterclockwise by rotation of a driving roller 807 configured and engaged with a driving mechanism (not shown).
The intermediate transfer belt 806 is a belt based on a resin film or rubber having a base thickness of 50 to 600 μm, for example, and has a resistance value capable of transferring a toner image from a photoreceptor 812 described later. Yes.

このベルト搬送手段８０１は、上記した実施の形態１〜５の何れかのベルト寄り止め構造が用いられている。すなわち、ローラ部８０５を構成する各ローラは、ガイド部材６０１…を備えて構成され、中間転写ベルト８０６は、その裏面両縁部にガイド部材６０１…と係合する凸部３を備えてなる。
また、中間転写ベルト８０６を挟んで、従動ローラ８０８に対向する位置に、中間転写ベルト８０６の表面に残留された不要なトナーを拭い去るクリーニング装置８１１が設けられている。
作像手段８０２は、回動可能に構成したドラム状の感光体８１２を備え、その感光体８１２を一様帯電し画像データに基づいて感光体８１２へ光照射して静電潜像を形成しその静電潜像をトナー像に現像するように構成されている。この作像手段８０２は、イエロートナー像、マゼンタトナー像、シアントナー像、ブラックトナー像を形成させるために、中間転写ベルト８０６に沿って横一列に４つ並設されている。なお、各感光体８１２は、現像工程後の一部が中間転写ベルト８０６に接触するように配設される。 This belt conveying means 801 uses the belt detent structure according to any of the first to fifth embodiments. That is, each roller constituting the roller portion 805 is configured to include guide members 601..., And the intermediate transfer belt 806 includes convex portions 3 that engage with the guide members 601.
A cleaning device 811 for wiping off unnecessary toner remaining on the surface of the intermediate transfer belt 806 is provided at a position facing the driven roller 808 with the intermediate transfer belt 806 interposed therebetween.
The image forming unit 802 includes a drum-shaped photoconductor 812 configured to be rotatable, and uniformly charges the photoconductor 812 to irradiate the photoconductor 812 with light based on image data to form an electrostatic latent image. The electrostatic latent image is developed into a toner image. Four image forming units 802 are arranged in a row along the intermediate transfer belt 806 to form a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image. Each photoconductor 812 is disposed such that a part after the developing process contacts the intermediate transfer belt 806.

転写手段８０３は、中間転写ベルト８０６を挟んで４つの感光体８１２に対向するように、中間転写ベルト８０６の裏面側に配設され、夫々の感光体８１２上に形成した各色のトナー像を中間転写ベルト８０６上に静電転写させる１次転写ローラ８１３と、中間転写ベルト８０６を挟んで駆動ローラ８０７と対向配置され、中間転写ベルト８０６に担持されたフルカラートナー像（各色のトナー像が重畳されて形成される）を、記録材搬送路を介して搬送された記録材上に静電転写させる２次転写ローラ８１４とを備えて構成されている。
定着手段８０４は、ヒータを内装したローラ対を備え、２次転写ローラ８１４上方に記録材搬送路を介して配設されてなる。この定着手段８０４は、そのローラ対の間にフルカラートナー像を担持させた記録材を通過させることで、フルカラートナー像と記録材とが加熱及び加圧されて、フルカラートナー像が記録材に定着されるようになっている。 The transfer unit 803 is disposed on the back side of the intermediate transfer belt 806 so as to face the four photoconductors 812 with the intermediate transfer belt 806 interposed therebetween, and each color toner image formed on each photoconductor 812 is intermediated. A primary transfer roller 813 for electrostatic transfer onto the transfer belt 806 and a drive roller 807 across the intermediate transfer belt 806, and a full-color toner image (toner images of each color superimposed on the intermediate transfer belt 806 are superposed. And a secondary transfer roller 814 for electrostatic transfer onto the recording material conveyed through the recording material conveyance path.
The fixing unit 804 includes a pair of rollers with a built-in heater, and is disposed above the secondary transfer roller 814 via a recording material conveyance path. The fixing unit 804 passes the recording material carrying the full color toner image between the pair of rollers, so that the full color toner image and the recording material are heated and pressurized, and the full color toner image is fixed to the recording material. It has come to be.

以上のように構成された実施の形態７にかかる画像形成装置８は、回動した中間転写ベルト８０６の所定位置が、各色の作像手段８０２及びそれに対応した転写手段８０３に順に移動することで、イエロートナー像、マゼンタトナー像、シアントナー像、ブラックトナー像がその所定位置に転写・重畳して、中間転写ベルト８０６上にフルカラートナー像を形成する。
このフルカラートナー像の形成と前後して、２次転写ローラ８１４下方に記録材搬送路を介して配設したレジストローラ対８１５を介して、所要のタイミングでもって記録材が移動を開始する。
中間転写ベルト８０６上のフルカラートナー像と記録材とが、駆動ローラ８０７と２次転写ローラ８１４との間で対峙し、２次転写ローラ８１４によって、フルカラートナー像が記録材に静電転写する。
次いで、フルカラートナー像を担持した記録材は、ベルト搬送手段８０１から離間して定着手段８０４へ移動し、その定着手段８０４を通過と同時にフルカラートナー像が記録材に定着し、その後、画像形成装置８外にフルカラー画像を形成した記録材を排紙する。
この実施の形態７にかかる画像形成装置によれば、実施の形態１〜５にかかるベルト寄り止め構造の効果を奏して、転写ずれや、色ずれのない極めて好適な画像形成装置を提供できる。 In the image forming apparatus 8 according to the seventh embodiment configured as described above, the predetermined position of the rotated intermediate transfer belt 806 is sequentially moved to the image forming unit 802 for each color and the transfer unit 803 corresponding thereto. Then, a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image are transferred and superimposed at predetermined positions to form a full color toner image on the intermediate transfer belt 806.
Before and after the formation of the full-color toner image, the recording material starts to move at a required timing via the registration roller pair 815 disposed below the secondary transfer roller 814 via the recording material conveyance path.
The full-color toner image on the intermediate transfer belt 806 and the recording material face each other between the driving roller 807 and the secondary transfer roller 814, and the full-color toner image is electrostatically transferred to the recording material by the secondary transfer roller 814.
Next, the recording material carrying the full-color toner image moves away from the belt conveying unit 801 and moves to the fixing unit 804. The full-color toner image is fixed to the recording material simultaneously with passing through the fixing unit 804, and then the image forming apparatus. 8, the recording material on which the full-color image is formed is discharged.
According to the image forming apparatus according to the seventh embodiment, it is possible to provide an extremely suitable image forming apparatus free from transfer displacement and color misregistration, with the effect of the belt detent structure according to the first to fifth embodiments.

なお、中間転写ベルト上にフルカラートナー像を形成させる画像形成装置として、複数の感光体８１２を備えるものを例示したが、図１３に示すように、１つの感光体８１６と、各色の現像部を備えその感光体８１６に各色の現像部が対峙可能な現像手段８１７と、感光体上のトナー像が静電転写される中間転写ベルト８１８とを備え、中間転写ベルト８１８上で単色のトナー像を順に重畳させてフルカラートナー像を形成させる所謂ロータリー現像式の画像形成装置８１９でも良い。 An image forming apparatus for forming a full-color toner image on the intermediate transfer belt has been exemplified by a device including a plurality of photoconductors 812. However, as shown in FIG. 13, one photoconductor 816 and a developing unit for each color are provided. The photosensitive member 816 includes a developing unit 817 capable of facing each color developing unit, and an intermediate transfer belt 818 to which a toner image on the photosensitive member is electrostatically transferred. A single color toner image is formed on the intermediate transfer belt 818. A so-called rotary developing type image forming apparatus 819 that forms a full color toner image by superimposing them in order may also be used.

以上、本実施の形態にかかるベルト寄り止め構造及び画像形成装置を説明したが、上述した実施の形態は、本発明の好適な実施の形態の一例を示すものであり、本発明はそれに限定されるものではなく、その要旨を逸脱しない範囲内において、種々変形実施が可能である。
例えば、本実施の形態では、ガイド部材６０１…とローラ本体５と別部材で構成したが、ガイド部材とローラ本体５とを一体成形しても良い。
また、本実施の形態では、ガイド部材６０１…をローラ本体５の両端側に設けたことを例示したが、ガイド部材６０１…をローラ本体５の一端側だけ設けても良い。
また、実施の形態６及び７では、ローラ部７０５…を構成する各ローラに夫々ガイド部材６０１…を備えたものを例示したが、少なくとも、駆動ローラ７０６…にガイド部材６０１…が備えていれば良い。 The belt detent structure and the image forming apparatus according to the present embodiment have been described above. However, the above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto. However, various modifications may be made without departing from the scope of the invention.
For example, in the present embodiment, the guide members 601... And the roller body 5 are separate members, but the guide members and the roller body 5 may be integrally formed.
Further, in the present embodiment, the guide members 601... Are provided on both end sides of the roller body 5. However, the guide members 601.
In the sixth and seventh embodiments, the rollers constituting the roller portions 705 are illustrated as having guide members 601..., But at least the drive rollers 706 are provided with the guide members 601. good.

実施の形態１にかかるベルト寄り止め構造を示した縦断正面図である。It is the vertical front view which showed the belt offset structure concerning Embodiment 1. FIG. 実施の形態１の変形例１を示した縦断正面図である。FIG. 6 is a longitudinal front view showing a first modification of the first embodiment. 実施の形態１の変形例２を示した縦断正面図である。FIG. 6 is a longitudinal front view showing a second modification of the first embodiment. 実施の形態２にかかるベルト寄り止め構造を示した縦断正面図である。FIG. 5 is a longitudinal front view showing a belt detent structure according to a second embodiment. 実施の形態２の変形例を示した縦断正面図である。FIG. 10 is a longitudinal front view showing a modification of the second embodiment. 実施の形態３にかかるベルト寄り止め構造を示した縦断正面図である。FIG. 6 is a longitudinal front view showing a belt detent structure according to a third embodiment. 実施の形態３の変形例１を示した縦断正面図である。FIG. 10 is a longitudinal front view showing a first modification of the third embodiment. 実施の形態３の変形例２を示した縦断正面図である。FIG. 10 is a longitudinal front view showing a second modification of the third embodiment. 実施の形態４にかかるベルト寄り止め構造を示した縦断正面図である。FIG. 6 is a longitudinal front view showing a belt detent structure according to a fourth embodiment. 実施の形態５にかかるベルト寄り止め構造を示した縦断正面図である。FIG. 10 is a longitudinal front view showing a belt detent structure according to a fifth embodiment. 実施の形態６にかかる画像形成装置の概略を示した正面図である。FIG. 10 is a front view schematically showing an image forming apparatus according to a sixth embodiment. 実施の形態７にかかる画像形成装置の概略を示した正面図である。FIG. 10 is a front view showing an outline of an image forming apparatus according to a seventh embodiment; 実施の形態７の他の画像形成装置の概略を示した正面図である。FIG. 20 is a front view illustrating an outline of another image forming apparatus according to a seventh embodiment.

Explanation of symbols

１…無端ベルト、２…ベルト本体、３…凸部、４…ローラ、５…ローラ本体、６０１…ガイド部材、６０３…凹部、６０６…側面、６１２…テーパー状の側面、６１５…垂直面、６１６…テーパー面、６２５…内側部材、６２６…外側部材、７、８…画像形成装置、７０１、８０２…ベルト搬送手段、７０３、８０３…転写手段、７０９、８１２…感光体 DESCRIPTION OF SYMBOLS 1 ... Endless belt, 2 ... Belt main body, 3 ... Convex part, 4 ... Roller, 5 ... Roller main body, 601 ... Guide member, 603 ... Recessed part, 606 ... Side surface, 612 ... Tapered side surface, 615 ... Vertical surface, 616 ... Tapered surface, 625 ... Inner member, 626 ... Outer member, 7, 8 ... Image forming apparatus, 701, 802 ... Belt conveying means, 703, 803 ... Transfer means, 709, 812 ... Photoconductor

Claims

A convex portion is provided on the back surface of the endless belt in the circumferential direction, and a concave portion that can be loosely fitted to the convex portion is provided in the circumferential direction on the outer peripheral surface of the roller, and the end portion of the roller is extended in the radial direction. The endless belt is hung on the roller so that the axially inner side surface of the end is adjacent to the edge of the endless belt and the convex and concave portions are engaged with each other. A belt detent structure characterized by being constructed.

2. The belt detent structure according to claim 1, wherein an axially inner side surface of the end portion and an axially outer side surface of the recess are formed in a continuous vertical shape.

The axially outward side surface of the recess is formed in a tapered shape that gradually increases in diameter outward in the axial direction, and extends toward the axially inward side surface of the end portion, or The belt detent structure according to claim 1, which also serves as an axially inner side surface of the end portion.

The side surface on the axially outer side of the concave portion includes a vertical surface standing from the bottom surface of the concave portion, and a tapered surface that gradually increases in diameter toward the outer side in the axial direction. The belt detent structure according to claim 1, wherein the belt detent structure extends toward an inner side surface in the direction or serves as an inner side surface in the axial direction of the end portion.

5. The belt detent structure according to claim 1, wherein the roller includes a guide member in which the concave portion and the end portion are formed, and a roller main body.

6. The belt detent structure according to claim 5, wherein the guide member is rotatably provided on the roller body.

An inner member formed with an outer diameter of the roller body and an outer member formed with an axially outer side surface and a bottom surface of the recess and the end portion; 6. The belt detent structure according to claim 5, wherein the guide member is configured, and each of the inner member and the outer member is rotatably provided on the roller body.

An image forming apparatus comprising the belt detent structure according to claim 1.

An image forming apparatus comprising: a belt conveying unit that conveys a recording material; and a transfer unit that transfers a toner image on a photosensitive member to the recording material conveyed by the belt conveying unit.
An image forming apparatus, wherein the belt conveying unit includes the belt detent structure according to claim 1.

An image forming apparatus comprising: a belt conveying unit that conveys a toner image; and a transfer unit that transfers the toner image conveyed by the belt conveying unit to a recording material.
8. An image forming apparatus, wherein the toner image conveying unit includes the belt offset structure according to any one of claims 1 to 7.

11. The image forming apparatus according to claim 9, wherein a full color image is recorded on the recording material.