JP6021758B2

JP6021758B2 - Fixing apparatus and image forming apparatus having the same

Info

Publication number: JP6021758B2
Application number: JP2013163363A
Authority: JP
Inventors: 鐘浩権; 良平 ▲徳▼永
Original assignee: Kyocera Document Solutions Inc
Current assignee: Kyocera Document Solutions Inc
Priority date: 2013-08-06
Filing date: 2013-08-06
Publication date: 2016-11-09
Anticipated expiration: 2033-08-06
Also published as: JP2015031918A

Description

本発明は、定着装置及びそれを備えた画像形成装置に関し、特にベルト部材がローラーの軸方向に片寄るのを規制する定着装置及びそれを備えた画像形成装置に関するものである。 The present invention relates to a fixing device and an image forming apparatus including the fixing device, and more particularly to a fixing device that restricts a belt member from shifting in the axial direction of a roller and an image forming apparatus including the fixing device.

画像形成装置は、感光体ドラム等の像担持体に形成されたトナー像を記録媒体に転写し、トナー像を担持する記録媒体を定着装置に向けて搬送し、定着装置において、熱及び圧力を加えることにより記録媒体上の未定着トナー像を記録媒体に定着させている。定着装置には、定着ローラーとヒートローラーとの間で回転可能に張架されたベルト部材と、ベルト部材に圧接される加圧ローラーとを備え、記録媒体がベルト部材と加圧ローラーとの間の定着ニップ部を通過する間にトナー像を記録媒体に定着させるベルト定着方式がある。 The image forming apparatus transfers a toner image formed on an image carrier such as a photosensitive drum to a recording medium, conveys the recording medium carrying the toner image toward a fixing device, and heat and pressure are applied to the fixing device. In addition, the unfixed toner image on the recording medium is fixed on the recording medium. The fixing device includes a belt member that is rotatably stretched between a fixing roller and a heat roller, and a pressure roller that is pressed against the belt member, and the recording medium is disposed between the belt member and the pressure roller. There is a belt fixing method in which a toner image is fixed on a recording medium while passing through the fixing nip portion.

ベルト定着方式の定着装置では、ベルト部材がローラーの軸方向に移動して片寄る（蛇行する）場合がある。ベルト部材の片寄り（蛇行）は、ベルト部材に負荷がかかる定着ニップ部を通過したときに最も発生しやすい他、ベルト部材に内接する複数のベルト内ローラー間の平行度が低いときなどにも発生する。ベルト部材の片寄りが発生すると、記録媒体上のトナー像の位置ずれが生じる等の定着不良の要因となり、またベルト部材の片寄りが継続すると、ベルト部材の幅方向の端部が破損するおそれがあった。 In a belt fixing type fixing device, the belt member may move in the axial direction of the roller and shift (meander). The deviation (meandering) of the belt member is most likely to occur when the belt member passes through the fixing nip portion where the load is applied to the belt member, and also when the parallelism between the plurality of rollers in the belt inscribed in the belt member is low. Occur. If the deviation of the belt member occurs, it may cause a fixing failure such as a displacement of the toner image on the recording medium. If the deviation of the belt member continues, the end of the belt member in the width direction may be damaged. was there.

そこで、ベルト部材の片寄りを抑制する技術が従来から知られている。例えば、従来の定着装置は、ベルト部材と、ベルト部材の内周面に接する定着ローラーおよびヒートローラーと、ベルト部材を介して定着ローラーに圧接される加圧ローラーと、を備え、ヒートローラーの軸方向の両端部に、ベルト部材がヒートローラーの軸方向に片寄るのを規制する一対の規制部材が設けられる。この定着装置は、ベルト部材がヒートローラーの軸方向に片寄ると、規制部材によってベルト部材をヒートローラーの軸方向内側に戻す（移動させる）ように構成されている。 Therefore, a technique for suppressing the deviation of the belt member has been conventionally known. For example, a conventional fixing device includes a belt member, a fixing roller and a heat roller that are in contact with the inner peripheral surface of the belt member, and a pressure roller that is pressed against the fixing roller via the belt member. A pair of restricting members that restrict the belt member from shifting in the axial direction of the heat roller are provided at both ends of the direction. This fixing device is configured to return (move) the belt member to the inner side in the axial direction of the heat roller by the regulating member when the belt member is shifted in the axial direction of the heat roller.

なお、複数のベルト内ローラーの外周面にガイド溝を設け、ガイド溝に係合する被ガイド部をベルト部材の内周面に設けることによって、ベルト部材の片寄りを抑制する定着装置が、例えば特許文献１および２に開示されている。 A fixing device that suppresses the deviation of the belt member by providing a guide groove on the outer peripheral surface of the plurality of belt inner rollers and providing a guided portion that engages with the guide groove on the inner peripheral surface of the belt member. It is disclosed in Patent Documents 1 and 2.

特開２０００−００１２３７号公報JP 2000-001237 A 特開２００２−１４５４２９号公報JP 2002-145429 A

しかしながら、従来の定着装置では、ベルト部材が片寄りした場合、ベルト部材の片寄りを解消するために、ベルト部材を１つの規制部材により所定位置まで一度に移動させる。このため、規制部材とベルト部材との接触部分においてベルト部材にかかる負荷が大きくなるので、ベルト部材が破損する場合があるという問題点があった。 However, in the conventional fixing device, when the belt member is displaced, the belt member is moved to a predetermined position by one restriction member at a time in order to eliminate the displacement of the belt member. For this reason, since the load applied to the belt member becomes large at the contact portion between the regulating member and the belt member, the belt member may be damaged.

本発明は、上記のような課題を解決するためになされたものであり、本発明の目的は、ベルト部材の破損および片寄りを抑制することが可能な定着装置及びそれを備えた画像形成装置を提供することである。 The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fixing device capable of suppressing breakage and deviation of the belt member and an image forming apparatus including the same. Is to provide.

上記目的を達成するために、本発明の定着装置は、加熱部材により加熱される無端状のベルト部材と、ベルト部材の内周面に接する回転可能な２つ以上のベルト内ローラーと、ベルト部材の外周面に対向配置され、ベルト部材を介してベルト内ローラーの１つに圧接される回転可能な加圧ローラーと、を備え、ベルト部材と加圧ローラーとにより形成された定着ニップ部に記録媒体を挿通して、記録媒体上の未定着トナー像を定着する定着装置であって、２つのベルト内ローラーの軸方向の両端部には、ベルト部材がベルト内ローラーの軸方向に片寄るのを規制する一対の第１規制部材および一対の第２規制部材がそれぞれ設けられており、第１規制部材および第２規制部材の各々は、ベルト部材をベルト内ローラーの軸方向内側に移動させる規制面を含み、規制面は、ベルト内ローラーの軸方向内寄りに位置する第１位置と、ベルト内ローラーの軸方向外寄りに位置し第１位置よりも大径の第２位置と、を有し、一対の第１規制部材の第１位置同士の間の距離をｘ１、一対の第１規制部材の第２位置同士の間の距離をｘ１ｍａｘ、一対の第２規制部材の第１位置同士の間の距離をｘ２、とした場合、第１規制部材および第２規制部材は、ｘ１＜ｘ２＜ｘ１ｍａｘの関係を満たすように配置されている。 In order to achieve the above object, a fixing device of the present invention includes an endless belt member heated by a heating member, two or more in-belt rollers that are in contact with the inner peripheral surface of the belt member, and a belt member. And a rotatable pressure roller that is disposed opposite to the outer peripheral surface of the belt and pressed against one of the inner rollers of the belt via the belt member, and records on a fixing nip formed by the belt member and the pressure roller. A fixing device that inserts a medium and fixes an unfixed toner image on a recording medium. The belt member is offset in the axial direction of the belt inner roller at both ends in the axial direction of the two belt inner rollers. A pair of first restricting members and a pair of second restricting members are provided, respectively, and each of the first restricting member and the second restricting member moves the belt member inward of the belt inner roller in the axial direction. The regulation surface includes a first position located on the inner side in the axial direction of the inner roller of the belt, and a second position located on the outer side in the axial direction of the inner roller and larger in diameter than the first position. The distance between the first positions of the pair of first restricting members is x1, the distance between the second positions of the pair of first restricting members is x1max, and the first positions of the pair of second restricting members are When the distance between the first restriction member and the second restriction member is x2, the first restriction member and the second restriction member are disposed so as to satisfy the relationship of x1 <x2 <x1max.

本発明によれば、２つのベルト内ローラーの軸方向の両端部には、ベルト部材がベルト内ローラーの軸方向に片寄るのを規制する一対の第１規制部材および一対の第２規制部材がそれぞれ設けられており、一対の第１規制部材の第１位置同士の間の距離をｘ１、一対の第１規制部材の第２位置同士の間の距離をｘ１ｍａｘ、一対の第２規制部材の第１位置同士の間の距離をｘ２、とした場合、第１規制部材および第２規制部材は、ｘ１＜ｘ２＜ｘ１ｍａｘの関係を満たすように配置されている。これにより、ベルト部材が片寄りした場合、ベルト部材の側端部を第２規制部材によって第２規制部材の第１位置まで戻した（移動させた）後、第１規制部材によって第１規制部材の第１位置まで戻す（移動させる）ことになる。すなわち、ベルト部材を所定位置まで徐々に戻す（移動させる）ことができる。このため、規制部材とベルト部材との接触部分においてベルト部材にかかる負荷が大きくなるのを抑制することができるので、ベルト部材が破損するのを抑制することができる。 According to the present invention, the pair of first restricting members and the pair of second restricting members for restricting the belt members from being offset in the axial direction of the in-belt rollers are respectively provided at both axial ends of the two in-belt rollers. The distance between the first positions of the pair of first restricting members is x1, the distance between the second positions of the pair of first restricting members is x1max, and the first of the pair of second restricting members is provided. When the distance between the positions is x2, the first restricting member and the second restricting member are arranged so as to satisfy the relationship x1 <x2 <x1max. As a result, when the belt member is displaced, the side end portion of the belt member is returned (moved) to the first position of the second restriction member by the second restriction member, and then the first restriction member is moved by the first restriction member. Is returned (moved) to the first position. That is, the belt member can be gradually returned (moved) to a predetermined position. For this reason, since it can suppress that the load concerning a belt member becomes large in the contact part of a control member and a belt member, it can suppress that a belt member is damaged.

本発明の第１実施形態の定着装置を備えた画像形成装置の全体構造を概略的に示した断面図である。1 is a cross-sectional view schematically illustrating an overall structure of an image forming apparatus including a fixing device according to a first embodiment of the present invention. 本発明の第１実施形態の定着装置の構造を示した断面図である。1 is a cross-sectional view illustrating a structure of a fixing device according to a first embodiment of the present invention. 本発明の第１実施形態の定着装置の第１規制部材および第２規制部材周辺の構造を示した平面図である。FIG. 3 is a plan view showing a structure around a first restriction member and a second restriction member of the fixing device according to the first embodiment of the present invention. 本発明の第２実施形態の定着装置の構造を示した断面図である。It is sectional drawing which showed the structure of the fixing device of 2nd Embodiment of this invention.

以下、本発明の実施形態について図面を参照して説明する。 Embodiments of the present invention will be described below with reference to the drawings.

（第１実施形態）
図１〜図３を参照して、本発明の第１実施形態による定着装置５を備えた画像形成装置１について説明する。画像形成装置１は、タンデム型カラープリンターであって、記録媒体である用紙Ｐを収容する給紙部１０と、給紙部１０の上方に配される４つの画像形成部２９ａ〜２９ｄと、画像形成部２９ａ〜２９ｄの上方に配設される露光器３３ａ〜３３ｄと、画像形成部２９ａ〜２９ｄの左方に配設される定着装置５と、給紙部１０の右方に配設される用紙搬送路２０と、画像形成装置１の上部に用紙Ｐを排出する排出部５０とを備えている。 (First embodiment)
An image forming apparatus 1 including a fixing device 5 according to a first embodiment of the present invention will be described with reference to FIGS. The image forming apparatus 1 is a tandem type color printer, and includes a paper feeding unit 10 that stores paper P as a recording medium, four image forming units 29a to 29d arranged above the paper feeding unit 10, and an image. Exposed units 33a to 33d disposed above the forming units 29a to 29d, the fixing device 5 disposed to the left of the image forming units 29a to 29d, and the right side of the paper feeding unit 10. A sheet conveyance path 20 and a discharge unit 50 that discharges the sheet P at the top of the image forming apparatus 1 are provided.

給紙部１０は画像形成装置１内の下方に配設され、給紙部１０には、用紙Ｐを収納し挿脱可能に画像形成装置１に装着された給紙カセット１３が設けられる。給紙部１０の右方には、用紙搬送路２０が配設され、フィードローラー２１によって給紙カセット１３内に載置された用紙Ｐが１枚ずつ用紙搬送路２０に送り出される。手差しトレイ２３は、給紙部１０に載置されていないサイズの用紙Ｐ等を供給するもので、フィードローラー２２を備え、フィードローラー２２によって用紙Ｐが１枚ずつ用紙搬送路２０に送り出され、送り出された用紙Ｐは、画像形成部２９ａ〜２９ｄに向けて搬送される。 The paper feeding unit 10 is disposed below the image forming apparatus 1, and the paper feeding unit 10 is provided with a paper feeding cassette 13 that accommodates the paper P and is detachably attached to the image forming apparatus 1. A paper transport path 20 is disposed on the right side of the paper feed unit 10, and the paper P placed in the paper feed cassette 13 is sent out to the paper transport path 20 one by one by the feed roller 21. The manual feed tray 23 supplies paper P or the like of a size that is not placed on the paper supply unit 10, and includes a feed roller 22. The paper P is fed one by one to the paper transport path 20 by the feed roller 22, The fed paper P is conveyed toward the image forming units 29a to 29d.

画像形成部２９ａ〜２９ｄは、用紙搬送方向の上流側（図１の右側）から順にシアン、マゼンタ、イエロー、ブラックの色ごとに用紙搬送ベルト３８に対向して配設される。各画像形成部２９ａ〜２９ｄは、感光体３１ａ〜３１ｄを有し、感光体３１ａ〜３１ｄの周囲には、帯電器３２ａ〜３２ｄと、現像装置３４ａ〜３４ｄと、転写ローラー３５ａ〜３５ｄと、クリーナー３６ａ〜３６ｄとが配設されている。 The image forming units 29a to 29d are arranged so as to face the sheet conveying belt 38 for each color of cyan, magenta, yellow, and black in order from the upstream side in the sheet conveying direction (the right side in FIG. 1). Each of the image forming units 29a to 29d includes photoreceptors 31a to 31d, and around the photoreceptors 31a to 31d, chargers 32a to 32d, developing devices 34a to 34d, transfer rollers 35a to 35d, and cleaners. 36a to 36d are disposed.

感光体３１ａ〜３１ｄは、感光層を形成する感光材料として、アモルファスシリコン感光体が用いられ、シアン、マゼンタ、イエロー、ブラックの各色に対応して配設される。感光層は有機感光体（ＯＰＣ感光体）でもよい。現像装置３４ａ〜３４ｄは、感光体３１ａ〜３１ｄの右方に配設され、現像ローラー等を有し、感光体３１ａ〜３１ｄにトナーを供給する。帯電器３２ａ〜３２ｄは、現像装置３４ａ〜３４ｄに対して感光体３１ａ〜３１ｄの回転方向の上流側に配設され、感光体３１ａ〜３１ｄの表面を一様に帯電させる。 The photoconductors 31a to 31d are amorphous silicon photoconductors as photosensitive materials for forming the photosensitive layer, and are arranged corresponding to each color of cyan, magenta, yellow, and black. The photosensitive layer may be an organic photoreceptor (OPC photoreceptor). The developing devices 34a to 34d are disposed on the right side of the photoconductors 31a to 31d, have a developing roller, and supply toner to the photoconductors 31a to 31d. The chargers 32a to 32d are disposed upstream of the developing devices 34a to 34d in the rotation direction of the photoconductors 31a to 31d, and uniformly charge the surfaces of the photoconductors 31a to 31d.

露光器３３ａ〜３３ｄは、パーソナルコンピューター等から画像入力部（図略）に入力された画像データに基づいて、帯電器３２ａ〜３２ｄと現像装置３４ａ〜３４ｄの間から感光体３１ａ〜３１ｄの表面にレーザー光を照射する。照射されたレーザー光により感光体３１ａ〜３１ｄの表面には静電潜像が形成され、この静電潜像が現像装置３４ａ〜３４ｄにより現像される。 The exposure units 33a to 33d are arranged on the surfaces of the photoreceptors 31a to 31d from between the chargers 32a to 32d and the developing devices 34a to 34d based on image data input to an image input unit (not shown) from a personal computer or the like. Irradiate with laser light. Electrostatic latent images are formed on the surfaces of the photoreceptors 31a to 31d by the irradiated laser light, and the electrostatic latent images are developed by the developing devices 34a to 34d.

用紙搬送ベルト３８は、駆動ローラー４０及び従動ローラー４１間に張架される無端状のベルトからなり、感光体３１ａ〜３１ｄと転写ローラー３５ａ〜３５ｄとの間に用紙Ｐを担持して搬送するベルト走行路を形成する。転写ローラー３５ａ〜３５ｄが用紙搬送ベルト３８を挟んで感光体３１ａ〜３１ｄに圧接することで、転写ニップ部が形成される。用紙搬送路２０から搬送される用紙Ｐが用紙搬送ベルト３８に担持され、用紙搬送ベルト３８の回転によって感光体３１ａ〜３１ｄのトナー像が各転写ニップ部において用紙Ｐに順次転写され、用紙Ｐにはシアン、マゼンタ、イエロー、ブラックの４色のトナー像が重ね合わされる。 The sheet transport belt 38 is an endless belt stretched between the driving roller 40 and the driven roller 41, and is a belt that carries and transports the sheet P between the photoreceptors 31a to 31d and the transfer rollers 35a to 35d. Form a travel path. The transfer rollers 35a to 35d are brought into pressure contact with the photoreceptors 31a to 31d with the paper transport belt 38 interposed therebetween, thereby forming a transfer nip portion. The paper P transported from the paper transport path 20 is carried on the paper transport belt 38, and the toner images of the photoconductors 31 a to 31 d are sequentially transferred onto the paper P in each transfer nip portion by the rotation of the paper transport belt 38, and are transferred to the paper P. Is superimposed with toner images of four colors of cyan, magenta, yellow and black.

トナータンク３９ａ〜３９ｄは、現像装置３４ａ〜３４ｄにトナーを補給するものであり、画像形成部２９ａ〜２９ｄの上方に配設され、シアン、マゼンタ、イエロー、ブラックの各色のトナーを収容する。 The toner tanks 39a to 39d supply toner to the developing devices 34a to 34d, and are disposed above the image forming units 29a to 29d, and store toners of cyan, magenta, yellow, and black.

定着装置５は、用紙搬送ベルト３８の下流側に配設され、画像形成部２９ａ〜２９ｄにおいてトナー像が転写された用紙Ｐを加熱及び加圧して用紙Ｐにトナー像を溶融定着させる。定着装置５を通過した用紙Ｐは、用紙搬送路１５から排出部５０へ排出される。 The fixing device 5 is disposed on the downstream side of the paper conveyance belt 38, and heats and presses the paper P on which the toner image is transferred in the image forming units 29a to 29d to melt and fix the toner image on the paper P. The paper P that has passed through the fixing device 5 is discharged from the paper transport path 15 to the discharge unit 50.

定着装置５は図２に示すように、電磁誘導により加熱される定着方式を採用しており、ベルト部材６１と、ベルト部材６１の内周面に接する回転可能な２つのベルト内ローラー６２と、ベルト部材６１の外周面に対向配置され、ベルト部材６１を介してベルト内ローラー６２に圧接される回転可能な加圧ローラー６３と、ベルト部材６１を加熱する加熱部材である誘導加熱部６４と、ベルト部材６１の表面の温度を検知する温度検知部（図示せず）と、温度検知部及び誘導加熱部６４に接続される制御部（図示せず）と、誘導加熱部６４のコイルに高周波電流を供給する電源（図示せず）と、を含んでいる。 As shown in FIG. 2, the fixing device 5 employs a fixing method that is heated by electromagnetic induction, and includes a belt member 61, two rotatable belt inner rollers 62 that are in contact with the inner peripheral surface of the belt member 61, and A rotatable pressure roller 63 disposed opposite to the outer peripheral surface of the belt member 61 and pressed against the in-belt roller 62 via the belt member 61; an induction heating unit 64 that is a heating member for heating the belt member 61; A temperature detection unit (not shown) for detecting the temperature of the surface of the belt member 61, a control unit (not shown) connected to the temperature detection unit and the induction heating unit 64, and a high-frequency current in the coil of the induction heating unit 64 And a power source (not shown).

ベルト部材６１は、無端状の耐熱ベルトであり、内周側から順に、例えば厚み３０〜５０μｍ程度の電鋳ニッケルからなる誘導発熱層６１ａと、例えば厚み２００〜５００μｍ程度のシリコーンゴム等からなる弾性層６１ｂと、例えば厚み３０μｍのフッ素樹脂（例えば、ＦＰＡ）等からなり定着ニップ部Ｎで未定着トナー像を溶融定着する際の離型性を向上させる離型層６１ｃと、が積層されて構成される。 The belt member 61 is an endless heat-resistant belt, and in order from the inner peripheral side, for example, an induction heating layer 61a made of electroformed nickel having a thickness of about 30 to 50 μm, and an elastic made of silicone rubber or the like having a thickness of about 200 to 500 μm. A layer 61b and a release layer 61c made of, for example, a fluororesin (for example, FPA) having a thickness of 30 μm and the like, which improve releasability when an unfixed toner image is melted and fixed at the fixing nip portion N, are laminated. Is done.

ベルト内ローラー６２は、ベルト部材６１を介して加圧ローラー６３に圧接される定着ローラー６５と、定着ローラー６５に対向配置されるヒートローラー６６と、を含んでいる。例えば、定着ローラー６５は、外径４０ｍｍに設定され、ステンレス鋼やアルミニウム等の円筒型の芯金６５ａの外周面上に厚み５〜１０ｍｍのシリコーンゴム製の弾性層６５ｂを有し、弾性層６５ｂはベルト部材６１の内周面に対向している。例えば、ヒートローラー６６は、外径３０ｍｍに設定され、厚み０．３〜０．５ｍｍの鉄基材６６ａの外周面上に厚み０．２〜１．０ｍｍの離型層（例えば、ＰＦＡ層）６６ｂを有する。強磁性部材である鉄を用いてヒートローラー６６を構成することによって、発熱効率を向上させることが可能である。 The in-belt roller 62 includes a fixing roller 65 that is pressed against the pressure roller 63 via the belt member 61, and a heat roller 66 that is disposed to face the fixing roller 65. For example, the fixing roller 65 has an outer diameter of 40 mm, and has an elastic layer 65b made of silicone rubber having a thickness of 5 to 10 mm on the outer peripheral surface of a cylindrical cored bar 65a such as stainless steel or aluminum. Is opposed to the inner peripheral surface of the belt member 61. For example, the heat roller 66 is set to an outer diameter of 30 mm, and a release layer (for example, a PFA layer) having a thickness of 0.2 to 1.0 mm on the outer peripheral surface of an iron base material 66a having a thickness of 0.3 to 0.5 mm. 66b. By forming the heat roller 66 using iron which is a ferromagnetic member, it is possible to improve the heat generation efficiency.

加圧ローラー６３は、円筒型の芯金６３ａと、芯金６３ａの外周面上に形成される弾性層６３ｂと、弾性層６３ｂの表面を覆う離型層６３ｃと、を備える。例えば、加圧ローラー６３は、外径３５ｍｍに設定され、ステンレス鋼やアルミニウム等の芯金６３ａの外周面上に厚み２〜５ｍｍのシリコーンゴム製の弾性層６３ｂを有し、弾性層６３ｂの外周面上に厚み５０μｍのフッ素樹脂（例えば、ＦＰＡ）等からなる離型層６３ｃを有する。また、加圧ローラー６３は図示しないモーター等の駆動源によって回転駆動させられ、加圧ローラー６３の回転によってベルト部材６１、定着ローラー６５およびヒートローラー６６は従動回転する。加圧ローラー６３とベルト部材６１との圧接する部分に定着ニップ部Ｎが形成され、定着ニップ部Ｎでは、用紙搬送ベルト３８から送られた用紙Ｐ上の未定着トナー像が加熱及び加圧され用紙Ｐ上にトナー像が定着される。 The pressure roller 63 includes a cylindrical cored bar 63a, an elastic layer 63b formed on the outer peripheral surface of the cored bar 63a, and a release layer 63c that covers the surface of the elastic layer 63b. For example, the pressure roller 63 is set to an outer diameter of 35 mm, has an elastic layer 63b made of silicone rubber having a thickness of 2 to 5 mm on the outer peripheral surface of a core metal 63a such as stainless steel or aluminum, and the outer periphery of the elastic layer 63b. On the surface, there is a release layer 63c made of fluororesin (for example, FPA) having a thickness of 50 μm. The pressure roller 63 is rotated by a driving source such as a motor (not shown), and the belt member 61, the fixing roller 65, and the heat roller 66 are driven to rotate by the rotation of the pressure roller 63. A fixing nip portion N is formed at a portion where the pressure roller 63 and the belt member 61 are pressed against each other. In the fixing nip portion N, an unfixed toner image on the paper P sent from the paper transport belt 38 is heated and pressed. The toner image is fixed on the paper P.

誘導加熱部６４は、コイル６４ａと、ボビン６４ｂと、磁性体コア６４ｃとを備え、電磁誘導によりベルト部材６１を発熱させるものである。誘導加熱部６４は、長手方向（図２の紙面の表裏方向）に延びて、ヒートローラー６６の外周の略半分を囲うようにベルト部材６１に対向して配設される。 The induction heating unit 64 includes a coil 64a, a bobbin 64b, and a magnetic core 64c, and causes the belt member 61 to generate heat by electromagnetic induction. The induction heating unit 64 extends in the longitudinal direction (the front and back direction of the paper surface of FIG. 2) and is disposed so as to face the belt member 61 so as to surround substantially half of the outer periphery of the heat roller 66.

コイル６４ａは、ベルト部材６１の幅方向（図２の紙面の表裏方向）に沿ってループ状に複数回（例えば９ターン）巻回してボビン６４ｂに取り付けられる。またコイル６４ａは、電源（図示せず）に接続され、電源から供給される高周波電流により交流磁束を発生させる。コイル６４ａからの磁束は磁性体コア６４ｃを通過し、図２の紙面に平行な方向に導かれ、ベルト部材６１の誘導発熱層６１ａに沿って通過する。誘導発熱層６１ａを通過する磁束の交流的な強さの変化によって誘導発熱層６１ａには渦電流が生じる。誘導発熱層６１ａに渦電流が流れると、誘導発熱層６１ａの電気抵抗によってジュール熱が発生して、ベルト部材６１が発熱（自己発熱）することになる。 The coil 64a is attached to the bobbin 64b by being wound a plurality of times (for example, 9 turns) in a loop shape along the width direction of the belt member 61 (the front and back direction in FIG. 2). The coil 64a is connected to a power source (not shown) and generates an alternating magnetic flux by a high-frequency current supplied from the power source. The magnetic flux from the coil 64 a passes through the magnetic core 64 c, is guided in a direction parallel to the paper surface of FIG. 2, and passes along the induction heating layer 61 a of the belt member 61. An eddy current is generated in the induction heating layer 61a due to a change in the alternating strength of the magnetic flux passing through the induction heating layer 61a. When an eddy current flows through the induction heating layer 61a, Joule heat is generated by the electrical resistance of the induction heating layer 61a, and the belt member 61 generates heat (self-heating).

制御部（図示せず）は、マイクロコンピューターとＲＡＭ及びＲＯＭ等の記憶素子等で構成され、温度検知部（図示せず）によって検知されたベルト部材６１の表面温度に基づいて、電源（図示せず）からコイル６４ａに供給される高周波電流を制御することで、定着ニップ部Ｎに送られた用紙Ｐを適切に定着処理する。 The control unit (not shown) includes a microcomputer, a storage element such as a RAM and a ROM, and the like, and based on the surface temperature of the belt member 61 detected by the temperature detection unit (not shown), a power source (not shown). The sheet P sent to the fixing nip portion N is appropriately fixed by controlling the high-frequency current supplied to the coil 64a.

ベルト部材６１が加熱され定着可能温度に昇温すると、定着ニップ部Ｎで挟持された用紙Ｐが加熱されるとともに、加圧ローラー６３によって加圧されることにより、用紙Ｐ上の粉体状態のトナーが用紙Ｐに溶融定着される。定着処理された用紙Ｐはベルト部材６１の外周面から分離される。このように、ベルト部材６１は薄肉の熱伝導性の良好な材質からなり熱容量が小さいため、短時間で定着装置５のウォーミングアップを行なうことができ、画像形成が迅速に開始される。 When the belt member 61 is heated and heated to a fixable temperature, the paper P sandwiched by the fixing nip portion N is heated and pressed by the pressure roller 63, so that the powder state on the paper P is changed. The toner is melted and fixed on the paper P. The fixed sheet P is separated from the outer peripheral surface of the belt member 61. Thus, since the belt member 61 is made of a thin material having good thermal conductivity and has a small heat capacity, the fixing device 5 can be warmed up in a short time, and image formation is started quickly.

ベルト定着方式の定着装置５では、負荷のかかる定着ニップ部Ｎをベルト部材６１が通過したときや、ベルト内ローラー６２（定着ローラー６５およびヒートローラー６６）間の平行度が低いときなどに、ベルト部材６１が定着ローラー６５の軸方向に片寄る（蛇行する）ので、本実施形態では、ベルト部材６１の軸方向への片寄り（蛇行）を規制する規制部材（第１規制部材６７および第２規制部材６８）が設けられている。 In the belt fixing type fixing device 5, when the belt member 61 passes through the fixing nip portion N where load is applied, or when the parallelism between the belt inner rollers 62 (the fixing roller 65 and the heat roller 66) is low, the belt Since the member 61 is offset (meanders) in the axial direction of the fixing roller 65, in the present embodiment, the regulating member (the first regulating member 67 and the second regulation) that regulates the deviation (meandering) of the belt member 61 in the axial direction. A member 68) is provided.

図３に示すように、定着ローラー６５の軸方向の両端部に一対の第１規制部材６７が設けられ、ヒートローラー６６の軸方向の両端部に一対の第２規制部材６８が設けられる。すなわち、定着ローラー６５をベルト部材６１の回転方向（図２の時計回り方向）の最下流とした場合、第２規制部材６８は、第１規制部材６７に比べて、ベルト部材６１の回転方向上流側に配置される。 As shown in FIG. 3, a pair of first restriction members 67 are provided at both axial ends of the fixing roller 65, and a pair of second restriction members 68 are provided at both axial ends of the heat roller 66. That is, when the fixing roller 65 is the most downstream in the rotation direction of the belt member 61 (clockwise direction in FIG. 2), the second restriction member 68 is upstream of the rotation direction of the belt member 61 compared to the first restriction member 67. Placed on the side.

第１規制部材６７は、略円盤状に形成されており、定着ローラー６５の芯金６５ａの両端部に固定されている。第１規制部材６７は、ベルト部材６１を定着ローラー６５の軸方向内側に移動させる規制面６７ａを含んでいる。規制面６７ａは、断面的に見て、定着ローラー６５の軸方向に対して傾斜する傾斜面（テーパー状）に形成されている。なお、規制面６７ａは、断面的に見て、Ｒ形状を有するように形成されていてもよい。 The first restricting member 67 is formed in a substantially disc shape and is fixed to both ends of the core metal 65 a of the fixing roller 65. The first regulating member 67 includes a regulating surface 67 a that moves the belt member 61 inward in the axial direction of the fixing roller 65. The restriction surface 67a is formed in an inclined surface (tapered shape) that is inclined with respect to the axial direction of the fixing roller 65 when viewed in cross section. The restriction surface 67a may be formed to have an R shape when viewed in cross section.

また、規制面６７ａは、定着ローラー６５の軸方向内寄りに位置する第１位置Ｐ６７ａと、定着ローラー６５の軸方向外寄りに位置し第１位置Ｐ６７ａよりも大径の第２位置Ｐ６７ｂと、を有する。 The restricting surface 67a includes a first position P67a that is located on the inner side in the axial direction of the fixing roller 65, a second position P67b that is located on the outer side in the axial direction of the fixing roller 65, and has a larger diameter than the first position P67a. Have

第２規制部材６８も第１規制部材６７と同様に、略円盤状に形成されており、ヒートローラー６６の鉄基材６６ａの両端部に固定されている。第２規制部材６８は、ベルト部材６１をヒートローラー６６の軸方向内側に移動させる規制面６８ａを含んでいる。規制面６８ａは、断面的に見て、ヒートローラー６６の軸方向に対して傾斜する傾斜面（テーパー状）に形成されている。なお、規制面６８ａは、断面的に見て、Ｒ形状を有するように形成されていてもよい。 Similarly to the first restriction member 67, the second restriction member 68 is formed in a substantially disk shape, and is fixed to both ends of the iron base material 66a of the heat roller 66. The second restriction member 68 includes a restriction surface 68 a that moves the belt member 61 inward of the heat roller 66 in the axial direction. The restriction surface 68a is formed in an inclined surface (tapered shape) that is inclined with respect to the axial direction of the heat roller 66 when viewed in cross section. The restricting surface 68a may be formed to have an R shape when viewed in cross section.

また、規制面６８ａは、ヒートローラー６６の軸方向内寄りに位置する第１位置Ｐ６８ａと、ヒートローラー６６の軸方向外寄りに位置し第１位置Ｐ６８ａよりも大径の第２位置Ｐ６８ｂと、を有する。 Further, the regulation surface 68a includes a first position P68a located on the inner side in the axial direction of the heat roller 66, a second position P68b located on the outer side in the axial direction of the heat roller 66 and having a larger diameter than the first position P68a, Have

そして、一対の第１規制部材６７の第１位置Ｐ６７ａ同士の間の距離をｘ１、一対の第１規制部材６７の第２位置Ｐ６７ｂ同士の間の距離をｘ１ｍａｘ、一対の第２規制部材６８の第１位置Ｐ６８ａ同士の間の距離をｘ２、一対の第２規制部材６８の第２位置Ｐ６８ｂ同士の間の距離をｘ２ｍａｘ、とした場合、第１規制部材６７および第２規制部材６８は、ｘ１＜ｘ２＜ｘ１ｍａｘ＜ｘ２ｍａｘの関係を満たすように配置されている。 The distance between the first positions P67a of the pair of first restricting members 67 is x1, the distance between the second positions P67b of the pair of first restricting members 67 is x1max, and the distance between the pair of second restricting members 68. When the distance between the first positions P68a is x2, and the distance between the second positions P68b of the pair of second restriction members 68 is x2max, the first restriction member 67 and the second restriction member 68 are x1. They are arranged so as to satisfy the relationship of <x2 <x1max <x2max.

上記構成により、ベルト部材６１が軸方向へ片寄ると、ベルト部材６１の側端部は、第２規制部材６８によって第１位置Ｐ６８ａまで戻され（移動され）、その後、第１規制部材６７によって第１位置Ｐ６７ａまで戻される（移動される）。このようにして、ベルト部材６１の片寄りが解消される。 With the above configuration, when the belt member 61 is offset in the axial direction, the side end portion of the belt member 61 is returned (moved) to the first position P68a by the second restriction member 68, and then the first restriction member 67 It is returned (moved) to the 1 position P67a. In this way, the deviation of the belt member 61 is eliminated.

本実施形態では、上記のように、２つのベルト内ローラー６２の軸方向の両端部には、一対の第１規制部材６７および一対の第２規制部材６８がそれぞれ設けられており、一対の第１規制部材６７の第１位置Ｐ６７ａ同士の間の距離をｘ１、一対の第１規制部材６７の第２位置Ｐ６７ｂ同士の間の距離をｘ１ｍａｘ、一対の第２規制部材６８の第１位置Ｐ６８ａ同士の間の距離をｘ２、とした場合、第１規制部材６７および第２規制部材６８は、ｘ１＜ｘ２＜ｘ１ｍａｘの関係を満たすように配置されている。これにより、ベルト部材６１が片寄りした場合、ベルト部材６１の側端部を第２規制部材６８によって第２規制部材６８の第１位置Ｐ６８ａまで戻した（移動させた）後、第１規制部材６７によって第１規制部材６７の第１位置Ｐ６７ａまで戻す（移動させる）ことになる。すなわち、ベルト部材６１を所定位置まで徐々に戻す（移動させる）ことができる。このため、規制部材（第１規制部材６７および第２規制部材６８）とベルト部材６１との接触部分においてベルト部材６１にかかる負荷が大きくなるのを抑制することができるので、ベルト部材６１が破損するのを抑制することができる。 In the present embodiment, as described above, the pair of first restricting members 67 and the pair of second restricting members 68 are respectively provided at both ends in the axial direction of the two in-belt rollers 62. The distance between the first positions P67a of the first restricting member 67 is x1, the distance between the second positions P67b of the pair of first restricting members 67 is x1max, and the first positions P68a of the pair of second restricting members 68 are the same. When the distance between the first restriction member 67 and the second restriction member 68 is x2, the first restriction member 67 and the second restriction member 68 are disposed so as to satisfy the relationship of x1 <x2 <x1max. As a result, when the belt member 61 is offset, the first regulating member is moved after the side end of the belt member 61 is returned (moved) to the first position P68a of the second regulating member 68 by the second regulating member 68. 67, the first restricting member 67 is returned (moved) to the first position P67a. That is, the belt member 61 can be gradually returned (moved) to a predetermined position. For this reason, since it can suppress that the load concerning the belt member 61 becomes large in the contact part of the regulating member (the 1st regulating member 67 and the 2nd regulating member 68) and the belt member 61, the belt member 61 is damaged. Can be suppressed.

また、上記のように、定着ローラー６５をベルト部材６１の回転方向の最下流とした場合、第２規制部材６８は、第１規制部材６７に比べて、ベルト部材６１の回転方向上流側に配置されている。これにより、ベルト部材６１の片寄りを第２規制部材６８および第１規制部材６７によって定着ニップ部Ｎに向けて徐々に解消することができる。このため、定着ニップ部Ｎにおいてベルト部材６１の片寄りに起因する定着不良が発生するのを抑制することができる。 Further, as described above, when the fixing roller 65 is located at the most downstream side in the rotation direction of the belt member 61, the second restriction member 68 is disposed on the upstream side in the rotation direction of the belt member 61 compared to the first restriction member 67. Has been. Accordingly, the deviation of the belt member 61 can be gradually eliminated toward the fixing nip portion N by the second restriction member 68 and the first restriction member 67. For this reason, it is possible to suppress the occurrence of fixing failure due to the deviation of the belt member 61 in the fixing nip portion N.

また、上記のように、第１規制部材６７は、定着ローラー６５に設けられている。これにより、ベルト部材６１の片寄りを定着ニップ部Ｎにおいて最も少なくすることができるので、より効果的である。また、定着ローラー６５はローラー径が比較的大きくベルト部材６１とのかかり量（接触面積）も比較的大きいので、定着ローラー６５に第１規制部材６７を設けて定着ローラー６５の部分でベルト部材６１の片寄りを解消させるのは、特に有効である。 Further, as described above, the first regulating member 67 is provided on the fixing roller 65. Thereby, the deviation of the belt member 61 can be minimized in the fixing nip portion N, which is more effective. Further, since the fixing roller 65 has a relatively large roller diameter and a relatively large amount (contact area) with the belt member 61, the fixing roller 65 is provided with a first regulating member 67, and the belt member 61 is provided at the fixing roller 65 portion. It is particularly effective to eliminate the deviation of the.

また、上記のように、一対の第２規制部材６８の第２位置Ｐ６８ｂ同士の間の距離をｘ２ｍａｘとした場合、第１規制部材６７および第２規制部材６８は、ｘ１＜ｘ２＜ｘ１ｍａｘ＜ｘ２ｍａｘの関係を満たすように配置されている。これにより、第２規制部材６８の規制面６８ａは、第１規制部材６７の規制面６７ａよりも軸方向の外側まで配置されるので、ベルト部材６１の片寄りが大きい場合であっても、ベルト部材６１の片寄りを容易に解消することができる。 As described above, when the distance between the second positions P68b of the pair of second restricting members 68 is x2max, the first restricting member 67 and the second restricting member 68 have x1 <x2 <x1max <x2max. It is arranged to satisfy the relationship. Thereby, since the regulating surface 68a of the second regulating member 68 is arranged to the outside in the axial direction than the regulating surface 67a of the first regulating member 67, even if the deviation of the belt member 61 is large, the belt The deviation of the member 61 can be easily eliminated.

（第２実施形態）
次に、図４を参照して、本発明の第２実施形態の定着装置５について説明する。 (Second Embodiment)
Next, the fixing device 5 according to the second embodiment of the present invention will be described with reference to FIG.

本発明の第２実施形態の定着装置５では図４に示すように、ベルト内ローラー６２は、定着ローラー６５およびヒートローラー６６の他、ベルト部材６１に張力を付与するテンションローラー６９を含んでいる。 In the fixing device 5 according to the second embodiment of the present invention, as shown in FIG. 4, the in-belt roller 62 includes a tension roller 69 that applies tension to the belt member 61 in addition to the fixing roller 65 and the heat roller 66. .

テンションローラー６９は、定着ローラー６５からヒートローラー６６に向かうベルト部材６１の内面に接触している。また、テンションローラー６９は、図示しない付勢部材により付勢されることによって、ベルト部材６１を外周面側に押圧している。これにより、ベルト部材６１の撓みを防止することが可能である。特に、電磁誘導式の誘導加熱部６４を用いる場合、誘導加熱部６４とヒートローラー６６との間の距離を一定に保持するために、誘導加熱部６４をヒートローラー６６の軸受部等にバネ力により押圧させる構成がよく用いられる。この場合、ヒートローラー６６と定着ローラー６５との間の距離が狭くなり、ベルト部材６１に撓みが生じやすくなるが、テンションローラー６９を設けることによって、ベルト部材６１の撓みを容易に防止することが可能であり、ベルト部材６１の張力を安定させることが可能である。 The tension roller 69 is in contact with the inner surface of the belt member 61 from the fixing roller 65 toward the heat roller 66. The tension roller 69 presses the belt member 61 toward the outer peripheral surface side by being biased by a biasing member (not shown). Thereby, it is possible to prevent the belt member 61 from being bent. In particular, when the electromagnetic induction type induction heating unit 64 is used, in order to keep the distance between the induction heating unit 64 and the heat roller 66 constant, the induction heating unit 64 is applied to the bearing portion of the heat roller 66 with a spring force. A configuration in which the pressure is pressed is often used. In this case, the distance between the heat roller 66 and the fixing roller 65 is reduced, and the belt member 61 is likely to bend. However, by providing the tension roller 69, the belt member 61 can be easily prevented from being bent. This is possible, and the tension of the belt member 61 can be stabilized.

また、テンションローラー６９は、アルミニウムなどの熱伝導率の高い材料により形成されている。これにより、ベルト部材６１の軸方向の温度分布を均一化することが可能であるので、小サイズの用紙に連続で印字する場合であっても、ベルト部材６１の軸方向の温度分布を均一化することができ、定着不良が発生するのを抑制することができる。 The tension roller 69 is made of a material having high thermal conductivity such as aluminum. As a result, the temperature distribution in the axial direction of the belt member 61 can be made uniform, so that the temperature distribution in the axial direction of the belt member 61 can be made uniform even when continuously printing on a small size sheet. It is possible to suppress the occurrence of fixing failure.

なお、テンションローラー６９は、ローラー径が定着ローラー６５やヒートローラー６６と比べて小さく、ベルト部材６１とのかかり量（接触面積）も小さい。このため、ベルト部材６１の片寄りを規制する規制部材（第１規制部材６７および第２規制部材６８）は、テンションローラー６９には設けられておらず、上記第１実施形態と同様、定着ローラー６５に第１規制部材６７が設けられ、ヒートローラー６６に第２規制部材６８が設けられている。 The tension roller 69 has a smaller roller diameter than the fixing roller 65 and the heat roller 66, and the amount of contact (contact area) with the belt member 61 is also small. For this reason, the restricting members (the first restricting member 67 and the second restricting member 68) that restrict the deviation of the belt member 61 are not provided in the tension roller 69, and as in the first embodiment, the fixing roller. A first restriction member 67 is provided at 65, and a second restriction member 68 is provided at the heat roller 66.

第２実施形態のその他の構造は、上記第１実施形態と同様である。 Other structures of the second embodiment are the same as those of the first embodiment.

本実施形態では、上記のように、ヒートローラー６６はテンションローラー６９に比べてローラー径が大きくベルト部材６１とのかかり量（接触面積）も大きいので、テンションローラー６９を設ける場合であっても、ヒートローラー６６に第２規制部材６８を設けるのは、特に有効である。 In the present embodiment, as described above, the heat roller 66 has a larger roller diameter than the tension roller 69 and a large amount (contact area) with the belt member 61, so even when the tension roller 69 is provided, It is particularly effective to provide the second regulating member 68 on the heat roller 66.

第２実施形態のその他の効果は、上記第１実施形態と同様である。 Other effects of the second embodiment are the same as those of the first embodiment.

なお、今回開示された実施形態は、すべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した実施形態の説明ではなく特許請求の範囲によって示され、さらに特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれる。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

例えば、上記実施形態では、ヒートローラー６６の周辺に誘導加熱部６４を設け、電磁誘導によりベルト部材６１を加熱した例について示したが、本発明はこれに限らず、ヒートローラー６６の内部にハロゲンヒーター等を設けることによってベルト部材６１を加熱してもよい。 For example, in the above-described embodiment, an example in which the induction heating unit 64 is provided around the heat roller 66 and the belt member 61 is heated by electromagnetic induction has been described. However, the present invention is not limited thereto, and a halogen is provided inside the heat roller 66. The belt member 61 may be heated by providing a heater or the like.

また、上記実施形態では、加圧ローラー６３を加熱しない例について示したが、本発明はこれに限らず、加圧ローラー６３の内部にハロゲンヒーター等を設け、ベルト部材６１だけでなく加圧ローラー６３も加熱してもよい。 Moreover, although the example which does not heat the pressure roller 63 was shown in the said embodiment, this invention is not limited to this, A halogen heater etc. are provided in the inside of the pressure roller 63, and not only the belt member 61 but a pressure roller. 63 may also be heated.

また、上記実施形態では、温度検知部を、ベルト部材の温度を検知するように構成した例について示したが、本発明はこれに限らず、温度検知部を、各ローラーの温度を検知するように構成してもよい。 Moreover, in the said embodiment, although the temperature detection part was shown about the example comprised so that the temperature of a belt member might be detected, this invention is not limited to this, A temperature detection part seems to detect the temperature of each roller. You may comprise.

また、上記実施形態では、第２規制部材６８を第１規制部材６７に比べてベルト部材６１の回転方向上流側に配置した例について示したが、本発明はこれに限らず、第２規制部材６８を第１規制部材６７に比べてベルト部材６１の回転方向下流側に配置してもよい。 In the above-described embodiment, the example in which the second restricting member 68 is arranged on the upstream side in the rotation direction of the belt member 61 as compared with the first restricting member 67 is shown, but the present invention is not limited to this, and the second restricting member. 68 may be arranged on the downstream side in the rotation direction of the belt member 61 as compared with the first regulating member 67.

また、上記第２実施形態では、ベルト内ローラー６２が定着ローラー６５、ヒートローラー６６およびテンションローラー６９を含む場合に、規制部材（第１規制部材６７および第２規制部材６８）をテンションローラー６９には設けず、定着ローラー６５およびヒートローラー６６に設けた例について示したが、本発明はこれに限らない。規制部材（第１規制部材６７および第２規制部材６８）の一方をテンションローラー６９に設けてもよい。ただし、テンションローラー６９はベルト部材６１とのかかり量（接触面積）が比較的小さいので、テンションローラー６９には第２規制部材６８を設けることが好ましい。 In the second embodiment, when the in-belt roller 62 includes the fixing roller 65, the heat roller 66, and the tension roller 69, the restriction member (the first restriction member 67 and the second restriction member 68) is used as the tension roller 69. However, the present invention is not limited to this example. One of the regulating members (the first regulating member 67 and the second regulating member 68) may be provided on the tension roller 69. However, since the tension roller 69 has a relatively small amount of contact (contact area) with the belt member 61, the tension roller 69 is preferably provided with a second regulating member 68.

また、上記実施形態では、第２規制部材６８の第２位置Ｐ６８ｂが第１規制部材６７の第２位置Ｐ６７ｂよりも軸方向の外側まで配置されている場合（ｘ１ｍａｘ＜ｘ２ｍａｘの場合）について示したが、本発明はこれに限らない。第１規制部材６７の第２位置Ｐ６７ｂが第２規制部材６８の第２位置Ｐ６８ｂよりも軸方向の外側まで配置されていてもよい。 Moreover, in the said embodiment, it showed about the case where the 2nd position P68b of the 2nd control member 68 is arrange | positioned to the outer side of the axial direction rather than the 2nd position P67b of the 1st control member 67 (when x1max <x2max). However, the present invention is not limited to this. The second position P67b of the first restricting member 67 may be disposed to the outside in the axial direction from the second position P68b of the second restricting member 68.

また、上述した実施形態および変形例の構成を適宜組み合わせて得られる構成についても、本発明の技術的範囲に含まれる。 Further, a configuration obtained by appropriately combining the configurations of the above-described embodiment and modification examples is also included in the technical scope of the present invention.

１画像形成装置
５定着装置
６１ベルト部材
６２ベルト内ローラー
６３加圧ローラー
６４誘導加熱部（加熱部材）
６５定着ローラー
６６ヒートローラー
６７第１規制部材
６７ａ規制面
６８第２規制部材
６８ａ規制面
６９テンションローラー
Ｎ定着ニップ部
Ｐ用紙（記録媒体）
Ｐ６７ａ、Ｐ６８ａ第１位置
Ｐ６７ｂ、Ｐ６８ｂ第２位置
ｘ１、ｘ１ｍａｘ、ｘ２、ｘ２ｍａｘ距離 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 5 Fixing apparatus 61 Belt member 62 In-belt roller 63 Pressure roller 64 Induction heating part (heating member)
65 fixing roller 66 heat roller 67 first regulating member 67a regulating surface 68 second regulating member 68a regulating surface 69 tension roller N fixing nip P paper (recording medium)
P67a, P68a First position P67b, P68b Second position x1, x1max, x2, x2max Distance

Claims

加熱部材により加熱される無端状のベルト部材と、
前記ベルト部材の内周面に接する回転可能な２つ以上のベルト内ローラーと、
前記ベルト部材の外周面に対向配置され、前記ベルト部材を介して前記ベルト内ローラーの１つに圧接される回転可能な加圧ローラーと、
を備え、前記ベルト部材と前記加圧ローラーとにより形成された定着ニップ部に記録媒体を挿通して、前記記録媒体上の未定着トナー像を定着する定着装置であって、
２つの前記ベルト内ローラーの軸方向の両端部には、前記ベルト部材が前記ベルト内ローラーの軸方向に片寄るのを規制する一対の第１規制部材および一対の第２規制部材がそれぞれ設けられており、
前記第１規制部材および前記第２規制部材の各々は、前記ベルト部材を前記ベルト内ローラーの軸方向内側に移動させる規制面を含み、
前記規制面は、前記ベルト内ローラーの軸方向内寄りに位置する第１位置と、前記ベルト内ローラーの軸方向外寄りに位置し前記第１位置よりも大径の第２位置と、を有し、
前記一対の第１規制部材の第１位置同士の間の距離をｘ１、前記一対の第１規制部材の第２位置同士の間の距離をｘ１ｍａｘ、前記一対の第２規制部材の第１位置同士の間の距離をｘ２、とした場合、前記第１規制部材および前記第２規制部材は、ｘ１＜ｘ２＜ｘ１ｍａｘの関係を満たすように配置され、
前記ベルト内ローラーは、前記ベルト部材を介して前記加圧ローラーに圧接される定着ローラーと、前記定着ローラーに対向配置されるヒートローラーと、を含み、
前記定着ローラーを前記ベルト部材の回転方向の最下流とした場合、前記第２規制部材は、前記第１規制部材に比べて、前記ベルト部材の回転方向上流側の前記ベルト内ローラーに配置されていることを特徴とする定着装置。 An endless belt member heated by a heating member;
Two or more in-belt rollers that are rotatable and in contact with the inner peripheral surface of the belt member;
A rotatable pressure roller disposed opposite to the outer circumferential surface of the belt member and pressed against one of the rollers in the belt via the belt member;
A fixing device that fixes a non-fixed toner image on the recording medium by inserting a recording medium through a fixing nip formed by the belt member and the pressure roller,
A pair of first restricting members and a pair of second restricting members that restrict the belt members from shifting in the axial direction of the in-belt rollers are respectively provided at both axial ends of the two in-belt rollers. And
Each of the first restriction member and the second restriction member includes a restriction surface that moves the belt member inward in the axial direction of the in-belt roller,
The restriction surface has a first position located on the inner side in the axial direction of the inner roller of the belt and a second position located on the outer side in the axial direction of the inner roller and larger in diameter than the first position. And
The distance between the first positions of the pair of first restricting members is x1, the distance between the second positions of the pair of first restricting members is x1max, and the first positions of the pair of second restricting members are When the distance between the first restriction member and the second restriction member is x2, the first restriction member and the second restriction member are arranged so as to satisfy a relationship of x1 <x2 <x1max .
The in-belt roller includes a fixing roller pressed against the pressure roller via the belt member, and a heat roller disposed to face the fixing roller,
When the fixing roller is at the most downstream side in the rotation direction of the belt member, the second restriction member is disposed on the inner belt roller on the upstream side in the rotation direction of the belt member as compared with the first restriction member. A fixing device.

前記規制面は、断面的に見て、前記ベルト内ローラーの軸方向に傾斜する傾斜面（テーパー状）に形成されているか、Ｒ形状を有するように形成されていることを特徴とする請求項１に記載の定着装置。 The said regulation surface is formed in the inclined surface (taper shape) which inclines in the axial direction of the said roller in a belt seeing in cross section, or it is formed so that it may have a R shape. The fixing device according to 1.

前記第１規制部材は、前記定着ローラーに設けられていることを特徴とする請求項１または２に記載の定着装置。 The first regulating member, a fixing device according to claim 1 or 2, characterized in that provided on the fixing roller.

前記ベルト内ローラーは、前記ベルト部材に張力を付与するテンションローラーを含み、
前記第２規制部材は、前記ヒートローラーに設けられていることを特徴とする請求項３に記載の定着装置。 The in-belt roller includes a tension roller that applies tension to the belt member,
The fixing device according to claim 3, wherein the second regulating member is provided on the heat roller.

前記一対の第２規制部材の第２位置同士の間の距離をｘ２ｍａｘとした場合、前記第１規制部材および前記第２規制部材は、ｘ１＜ｘ２＜ｘ１ｍａｘ＜ｘ２ｍａｘの関係を満たすように配置されていることを特徴とする請求項１〜４のいずれか１項に記載の定着装置。 When the distance between the second positions of the pair of second restricting members is x2max, the first restricting member and the second restricting member are arranged so as to satisfy the relationship of x1 <x2 <x1max <x2max. The fixing device according to claim 1, wherein the fixing device is a fixing device.

請求項１〜５のいずれか１項に記載の定着装置を備えることを特徴とする画像形成装置。 An image forming apparatus comprising the fixing device according to claim 1.