JP5553224B2

JP5553224B2 - Fixing device and image forming apparatus using the same

Info

Publication number: JP5553224B2
Application number: JP2010163213A
Authority: JP
Inventors: 祥宏原田
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2010-07-20
Filing date: 2010-07-20
Publication date: 2014-07-16
Anticipated expiration: 2030-07-20
Also published as: JP2012027095A

Description

本発明は、記録媒体上の未定着画像を定着せしめる定着装置及びこれを用いた画像形成装置に関するものである。 The present invention relates to a fixing device for fixing an unfixed image on a recording medium and an image forming apparatus using the same.

電子写真方式を利用した画像形成装置では、記録紙に転写された未定着トナー像を定着させるための定着装置が搭載されている。定着装置は、例えば駆動源により回転駆動される定着ローラと該定着ローラ圧接して回転する加圧ローラとの間に形成された定着ニップにトナー像が転写された記録紙を通過させることで記録紙上にトナー像を定着させる。 In an image forming apparatus using an electrophotographic system, a fixing device for fixing an unfixed toner image transferred onto a recording sheet is mounted. For example, the fixing device performs recording by passing a recording sheet on which a toner image is transferred to a fixing nip formed between a fixing roller that is rotationally driven by a driving source and a pressure roller that rotates by pressing the fixing roller. Fix the toner image on the paper.

この種の定着装置においては、定着工程時に記録紙がうねりにより平面形状から局所的に面外変形する所謂紙しわが生じてしまうことがあった。そのため、例えば、特許文献１には、図９に示すように、定着ローラ１００の弾性層１０１の両端部の厚みを中央部よりも厚くして、定着ローラ１００の形状を両端部よりも中央部が小径の所謂「逆クラウン形状」とした定着装置が記載されている。定着ローラ１００の形状を逆クラウン形状にすることで、外径の大きい端部の紙搬送速度が中央部に比べて速くなり、定着ニップの記録紙に搬送方向と直交する方向（以下、紙幅方向という）の外側に引っ張る力が働く。定着ニップを通過する記録紙が、このような紙幅方向外側に引っ張る力を受けることで、紙しわの発生を抑制することができる。 In this type of fixing device, there is a case where a so-called paper wrinkle is generated in which the recording paper is locally deformed out of the plane due to waviness during the fixing process. Therefore, for example, in Patent Document 1, as shown in FIG. 9, the thickness of both ends of the elastic layer 101 of the fixing roller 100 is made thicker than the center, and the shape of the fixing roller 100 is set to the center than the both ends. Describes a fixing device having a so-called “reverse crown shape” with a small diameter. By making the shape of the fixing roller 100 into an inverted crown shape, the paper conveyance speed at the end portion having a large outer diameter becomes faster than that at the central portion, and the direction perpendicular to the conveyance direction of the recording paper in the fixing nip (hereinafter referred to as the paper width direction). The pulling force works outside. Since the recording paper passing through the fixing nip receives such a force pulling outward in the paper width direction, generation of paper wrinkles can be suppressed.

しかしながら、図８に示すように、定着ローラ１００を逆クラウン形状にした場合、中央部のニップ圧が低下してしまい、中央部の定着性能が両端部に比べて低下してしまう。特に、記録紙として厚紙を用いた場合、中央部に定着不良が生じる虞があった。そこで、定着ローラ１００の両端部の外径と中央部の外径との差を小さくし、中央部のニップ圧の低下を抑制し、中央部の定着性能の低下を抑制することも考えられる。しかし、この場合、長時間の使用により弾性層が劣化し、定着ニップから定着ローラ１００の回転中心までの距離が定着ローラ２８の両端部と中央部とでほぼ同じになり、記録紙の紙しわを経時で抑制できなくなってしまうという問題があった。さらに、薄紙等の紙しわが生じやすい記録紙の場合は、十分に紙しわを抑制できないという問題もあった。 However, as shown in FIG. 8, when the fixing roller 100 is formed in an inverted crown shape, the nip pressure at the central portion is lowered, and the fixing performance at the central portion is lowered as compared with both end portions. In particular, when thick paper is used as the recording paper, there is a risk that fixing failure may occur in the central portion. Therefore, it is also conceivable to reduce the difference between the outer diameter of both ends of the fixing roller 100 and the outer diameter of the central portion, suppress the decrease in the nip pressure in the central portion, and suppress the decrease in the fixing performance in the central portion. However, in this case, the elastic layer deteriorates due to use for a long time, and the distance from the fixing nip to the rotation center of the fixing roller 100 becomes substantially the same at both ends and the center of the fixing roller 28, and the paper wrinkles of the recording paper. There is a problem that it becomes impossible to suppress the aging over time. Further, in the case of recording paper such as thin paper that is likely to cause paper wrinkles, there is a problem that paper wrinkles cannot be sufficiently suppressed.

本発明は以上の問題点に鑑みなされたものであり、その目的は、幅広い紙種の記録紙に対して良好な定着性を保ちつつ紙しわの発生を経時にわたり抑制することができる定着装置及びこれを用いた画像形成装置を提供することである。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a fixing device capable of suppressing the occurrence of paper wrinkles over time while maintaining good fixability for recording paper of a wide variety of paper types. An image forming apparatus using the same is provided.

請求項１乃至６の発明は、記録媒体を搬送しながら該記録媒体上の未定着トナー像を該記録媒体上に定着する定着ニップを形成し、無端移動するように構成された２つの定着ニップ形成部材と、該定着ニップを通過する該記録媒体に熱を加える加熱手段とを備える定着装置において、該２つの定着ニップ形成部材の少なくとも何れか一方を、該記録媒体の面方向に対して直交する方向と、該記録媒体の面方向に沿った方向との２方向へ加圧可能な加圧手段と、該定着ニップを通過する該記録媒体の面方向から外れた面外変形量を検知する面外変形量検知手段と、該面外変形量検知手段の検知結果に基づいて、該加圧手段が２つの定着ニップ形成部材の少なくとも何れか一方を加圧する加圧量を制御する制御手段とを備えている。
また、上記記録媒体の面外変形量を記憶する記憶手段を備え、上記制御手段は、該記憶手段に記憶された面外変形量と上記面外変形量検知手段で検知された面外変形量とに基づいて上記加圧手段を制御する。
以上の基本構成を備えている。
そして、請求項１の発明は、上記基本構成において、上記制御手段は、上記面外変形量検知手段の検知結果が、上記記憶手段で予め記憶された限界面外変形量に達しているか否かを判定し、達していると判定した場合に紙しわが発生している虞がある旨を報知するための報知処理を行うことを特徴とするものである。
また、請求項２の発明は、上記基本構成において、上記記憶手段は、上記面外変形量検知手段が検知した検知結果を時系列に記憶しており、上記制御手段は、該記録手段に時系列で記憶された面外変形量に基づいて定着装置の寿命を予測し、寿命であると予測した場合に上記定着ニップ形成部材を交換する必要がある旨を報知するための報知処理を行うことを特徴とするものである。
また、請求項３の発明は、上記基本構成において、上記記憶手段は、上記記録媒体の種類毎に上記面外変形量検知手段が検知した検知結果を時系列に記憶しており、上記制御手段は、該記録手段に時系列で記憶された面外変形量に基づいて、該記録媒体の種類毎に紙しわの発生率が高くなる面外変形量の閾値を算出し、該閾値を超える記録紙が使用される場合に紙しわが発生する確率が高い旨を報知するための報知処理を行うことを特徴とするものである。
また、請求項４の発明は、上記基本構成において、上記面外変形量検知手段は、定着ニップ通過後の上記記録媒体の面外変形量を検知し、上記制御手段は、該面外変形量検知手段の検知結果が上記記憶手段で予め記憶された限界面外変形量に達しているか否かを判定し、達していると判定した場合に紙しわが発生した旨を報知するための報知処理を行うことを特徴とするものである。
更に、請求項５の発明は、請求項１乃至４の何れか一の定着装置において、上記定着ニップ形成部材は、回転軸を中心として回転する回転体であり、上記加圧手段は、上記記録媒体の面方向に沿った方向に加圧することにより、該回転体の軸方向中央部を該記録媒体の搬送方向に向かって撓ませることを特徴とするものである。
請求項６の発明は、像担持体上に形成された静電潜像をトナー像として可視像化する現像装置と、該トナー像を転写材に転写する転写装置と、該転写材上の未定着画像を熱定着させる定着装置を備えた画像形成装置において、上記定着装置が請求項１乃至５の何れかか一の定着装置であることを特徴とするものである。
請求項１乃至５の定着装置は、２つの定着ニップ形成部材の間に定着ニップを形成する。加圧手段は、定着ニップ形成部材の少なくとも何れか一方に、記録媒体の面方向に対して直交する方向へ加圧して所定のニップ圧をかけ、さらに記録媒体の面方向に沿った方向に加圧して、定着ニップ部材を記録媒体の面方向に沿って撓ませることができる。例えば、定着ニップを通過する記録媒体が面外変形していても、定着ニップ形成部材を面方向に撓ませることにより、定着ニップで記録媒体搬送方向と直交する方向（紙幅方向）に働く力が外側を向き、すなわち記録媒体を該方向に引っ張ることになり、紙しわの発生を抑制することができる。定着ニップ形成部材を撓ませても、実用上の撓み量においてはニップ幅の均一性が保たれることが確認されている。よって、逆クラウン形状のローラ使用時に見られるような局所的なニップ圧の低下は生じず、記録媒体搬送方向と直交する方向（ローラ軸方向）で一様な定着性能を持たせることができる。また、記録媒体の面外変形量と、記録媒体の紙しわの発生確率とには相関関係があることが確認されているので、制御手段は面外変形量検知手段の検知結果に基づいて記録媒体に紙しわが発生するか否かを把握することができる。よって、制御手段は、面外変形量検知手段が検知した記録媒体の面外変形量に応じて定着ニップ形成部材の撓み量を制御することによって、記録媒体に紙しわが発生しない必要最小限の撓み量にすることができる。すなわち、経時に亘って紙幅方向での均一な定着性を保ちながら記録媒体への紙しわの発生を抑制することができる。 According to the first to sixth aspects of the present invention, two fixing nips configured to endlessly move while forming a fixing nip for fixing an unfixed toner image on the recording medium onto the recording medium while conveying the recording medium. In a fixing device including a forming member and a heating unit that applies heat to the recording medium passing through the fixing nip, at least one of the two fixing nip forming members is orthogonal to the surface direction of the recording medium And a pressing means capable of pressing in two directions, a direction along the surface direction of the recording medium, and an out-of-plane deformation amount deviating from the surface direction of the recording medium passing through the fixing nip. An out-of-plane deformation detection means, and a control means for controlling the pressurization amount by which the pressing means presses at least one of the two fixing nip forming members based on the detection result of the out-of-plane deformation detection means. It has .
In addition, the storage unit stores the out-of-plane deformation amount of the recording medium, and the control unit stores the out-of-plane deformation amount stored in the storage unit and the out-of-plane deformation amount detected by the out-of-plane deformation detection unit. Based on the above, the pressurizing means is controlled .
The above basic configuration is provided.
In the first aspect of the present invention, in the basic configuration , the control means determines whether or not the detection result of the out-of-plane deformation detection means reaches a limit out-of-plane deformation amount stored in advance in the storage means. And a notification process for notifying that there is a possibility that paper wrinkles are generated when it is determined that the sheet has reached.
According to a second aspect of the present invention, in the basic configuration , the storage unit stores the detection results detected by the out-of-plane deformation amount detection unit in time series, and the control unit stores time in the recording unit. Performing a notification process for predicting the life of the fixing device based on the out-of-plane deformation amount stored in series and notifying that the fixing nip forming member needs to be replaced when the life is predicted. It is characterized by.
According to a third aspect of the present invention, in the basic configuration , the storage unit stores, in time series, detection results detected by the out-of-plane deformation detection unit for each type of the recording medium. Calculates a threshold of the out-of-plane deformation amount at which the occurrence rate of paper wrinkles increases for each type of the recording medium based on the out-of-plane deformation amount stored in time series in the recording means, and records exceeding the threshold A notification process is performed to notify that there is a high probability that paper wrinkles will occur when paper is used.
According to a fourth aspect of the present invention, in the basic configuration , the out-of-plane deformation amount detecting unit detects an out-of-plane deformation amount of the recording medium after passing through the fixing nip, and the control unit includes the out-of-plane deformation amount. A notification process for determining whether or not the detection result of the detection means has reached the limit out-of-plane deformation amount stored in advance in the storage means, and notifying that a paper wrinkle has occurred when it is determined that the detection result has been reached. It is characterized by performing.
Further, the invention of claim 5 is the fixing device according to any one of claims 1 to 4, wherein the fixing nip forming member is a rotating body that rotates about a rotation axis, and the pressing means is the recording device. By pressurizing in the direction along the surface direction of the medium, the central portion in the axial direction of the rotating body is bent toward the conveyance direction of the recording medium.
According to a sixth aspect of the present invention, there is provided a developing device that visualizes an electrostatic latent image formed on an image carrier as a toner image, a transfer device that transfers the toner image to a transfer material, and a transfer device on the transfer material. An image forming apparatus including a fixing device for thermally fixing an unfixed image is characterized in that the fixing device is the fixing device according to any one of claims 1 to 5 .
The fixing device of claims 1 to 5, to form a fixing nip between the two fixing nip forming member. The pressurizing unit applies a predetermined nip pressure by applying pressure to at least one of the fixing nip forming members in a direction perpendicular to the surface direction of the recording medium, and further applies the pressure in the direction along the surface direction of the recording medium. By pressing, the fixing nip member can be bent along the surface direction of the recording medium. For example, even when the recording medium passing through the fixing nip is deformed out of plane, the force acting in the direction perpendicular to the recording medium conveyance direction (paper width direction) is caused by bending the fixing nip forming member in the surface direction. Since the recording medium is pulled outward, that is, the recording medium is pulled in this direction, generation of paper wrinkles can be suppressed. It has been confirmed that even when the fixing nip forming member is bent, the uniformity of the nip width is maintained in the practical amount of bending. Accordingly, the local nip pressure is not lowered as seen when the reverse crown-shaped roller is used, and uniform fixing performance can be provided in the direction perpendicular to the recording medium conveyance direction (roller axial direction). In addition, since it has been confirmed that there is a correlation between the out-of-plane deformation amount of the recording medium and the occurrence probability of paper wrinkles on the recording medium, the control unit performs recording based on the detection result of the out-of-plane deformation amount detecting unit. Whether or not paper wrinkles are generated on the medium can be grasped. Therefore, the control means controls the amount of bending of the fixing nip forming member according to the amount of out-of-plane deformation of the recording medium detected by the out-of-plane deformation detection means, thereby minimizing paper wrinkles on the recording medium. The amount of deflection can be made. That is, it is possible to suppress the occurrence of paper wrinkles on the recording medium while maintaining a uniform fixing property in the paper width direction over time.

本発明は、広い紙種の記録紙に対して良好な定着性を保ちつつ紙しわの発生を経時にわたり抑制することができる定着装置及びこれを用いた画像形成装置を提供できるという優れた効果がある。 INDUSTRIAL APPLICABILITY The present invention has an excellent effect that it can provide a fixing device capable of suppressing the occurrence of paper wrinkles over time while maintaining good fixing properties for recording paper of a wide variety of paper types, and an image forming apparatus using the same. is there.

本実施形態に係るプリンタの概略構成図。1 is a schematic configuration diagram of a printer according to an embodiment. 同プリンタに採用される定着装置の制御ブロック図を含む概略構成図。FIG. 2 is a schematic configuration diagram including a control block diagram of a fixing device employed in the printer. 同定着装置の要部構成を説明する断面図。FIG. 3 is a cross-sectional view illustrating a main configuration of the fixing device. 同定着装置の定着ニップ周辺を紙搬送方向から見た構成を示す概略構成図。FIG. 2 is a schematic configuration diagram illustrating a configuration in which the periphery of a fixing nip of the fixing device is viewed from a paper conveyance direction. 定着装置の定着ニップ周辺を上部から見た構成を示す概略構成図。FIG. 3 is a schematic configuration diagram illustrating a configuration in which the periphery of a fixing nip of the fixing device is viewed from above. （ａ）は、加熱ローラの撓み状態を説明する模式図、（ｂ）は定着ニップで記録紙に対して記録紙幅方向へ働く力の向きを示した模式図、（ｃ）は定着ニップの幅を示した模式図。(A) is a schematic diagram illustrating the bending state of the heating roller, (b) is a schematic diagram illustrating the direction of a force acting in the recording paper width direction on the recording paper at the fixing nip, and (c) is the width of the fixing nip. The schematic diagram which showed. （ａ）は、紙しわが発生する際のラインパタンＬＰの形状と面外変形量検知結果を示す模式図、（ｂ）は、紙しわが発生しない際のラインパタンＬＰの形状と面外変形量検知結果を示す模式図。(A) is a schematic diagram showing the shape of the line pattern LP when the paper wrinkle is generated and the detection result of the out-of-plane deformation, and (b) is the shape of the line pattern LP when the paper wrinkle is not generated and the out-of-plane deformation. The schematic diagram which shows quantity detection result. 撓み量調整の制御手順を説明する制御フロー図。The control flow figure explaining the control procedure of deflection amount adjustment. 従来の定着ローラの構成を示す断面図。Sectional drawing which shows the structure of the conventional fixing roller.

以下、本発明を電子写真方式の画像形成装置であるプリンタに適用した実施形態について説明する。図１は、本実施形態に係るプリンタの概略構成図である。図１に示すように、このプリンタは、潜像担持体としての感光体ドラム５１を有している。感光体ドラム５１は、図中矢印方向に回転駆動されながら、感光体ドラム５１に接触する一様帯電手段としての帯電ローラ５２により、その表面を一様に帯電される。その後、潜像形成手段としての光書込ユニット５３により画像情報に基づき走査露光されて、感光体ドラム５１の表面に静電潜像が形成される。感光体ドラム５１上に形成された静電潜像は、現像装置５４により現像され、感光体ドラム５１上にトナー像が形成される。感光体ドラム５１上に形成されたトナー像は、転写ローラ５５により、給紙トレイ５６から給紙ローラ５７及びレジストローラ対５８を経て搬送される記録紙Ｐ上に転写される。転写終了後の記録紙Ｐは、定着装置１によりトナー像が定着され、排紙ローラ対５９によって排紙トレイ６０上に排出積載される。なお、転写されずに感光体ドラム５１上に残留した転写残トナーは、クリーニング手段としてのクリーニングユニット６１により感光体ドラム５１の表面から除去される。また、感光体ドラム５１上の残留電荷は、除電手段としての除電ランプ６２で除去される。 Hereinafter, an embodiment in which the present invention is applied to a printer which is an electrophotographic image forming apparatus will be described. FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment. As shown in FIG. 1, this printer has a photosensitive drum 51 as a latent image carrier. The surface of the photosensitive drum 51 is uniformly charged by a charging roller 52 as uniform charging means that contacts the photosensitive drum 51 while being driven to rotate in the direction of the arrow in the drawing. Thereafter, scanning exposure is performed based on image information by an optical writing unit 53 as a latent image forming unit, and an electrostatic latent image is formed on the surface of the photosensitive drum 51. The electrostatic latent image formed on the photosensitive drum 51 is developed by the developing device 54, and a toner image is formed on the photosensitive drum 51. The toner image formed on the photosensitive drum 51 is transferred by the transfer roller 55 onto the recording paper P conveyed from the paper feed tray 56 through the paper feed roller 57 and the registration roller pair 58. After the transfer, the recording paper P is fixed with a toner image by the fixing device 1 and discharged onto the paper discharge tray 60 by the paper discharge roller pair 59. The transfer residual toner that is not transferred and remains on the photosensitive drum 51 is removed from the surface of the photosensitive drum 51 by a cleaning unit 61 as a cleaning unit. Further, the residual charge on the photosensitive drum 51 is removed by a static elimination lamp 62 as a static elimination means.

次に、本実施形態のプリンタの特徴部である定着装置１について詳しく説明する。図２は、本実施形態のプリンタに採用される定着装置の制御ブロック図を含む概略構成図である。図３は定着装置の要部構成を説明する断面図である。この定着装置１は、図２に示すように、ニップ形成部材としての加熱ローラ２と加圧ローラ３とを備えている。また、加圧ローラ３には、図示しない駆動源により回転駆動される駆動ローラ４が圧接している。 Next, the fixing device 1 that is a characteristic part of the printer of this embodiment will be described in detail. FIG. 2 is a schematic configuration diagram including a control block diagram of the fixing device employed in the printer of the present embodiment. FIG. 3 is a cross-sectional view for explaining the main configuration of the fixing device. As shown in FIG. 2, the fixing device 1 includes a heating roller 2 and a pressure roller 3 as nip forming members. A driving roller 4 that is rotationally driven by a driving source (not shown) is in pressure contact with the pressure roller 3.

上記加熱ローラ２は、図２及び図３に示すように記録紙Ｐに担持されているトナー像に接触する側に配置され、金属からなる芯金部２１とシリコンゴム等の弾性体２２からなる軸芯２０と、軸芯２０を囲んで設けられたシリコンゴム等からなる円筒状の弾性層２３とによって構成されている。加熱ローラ２の軸芯２０は、芯金部２１が弾性体２２で挟まれた構成となっており、軸芯２０全体としては円柱状の形状となっている。そして、加熱ローラ２の芯金部２１の両端は、固定の軸受を介して、装置本体の不図示の側壁に取り付けられている。上記軸芯２０の外周には、潤滑剤２４が塗布されており、円筒状の弾性層２３が回転自在に配置されている。加熱ローラ２の弾性層２３は、駆動ローラ４の回転駆動により、加圧ローラ３を介して従動回転することになる。また、加熱ローラ２は、定着ニップＮで挟持される記録紙Ｐを加熱する加熱手段としての機能も兼ね備える。例えば、本実施形態に係る加熱ローラ２は、弾性層２３の外側に薄い金属膜２５が巻かれ、不図示の電磁誘導加熱器により表面の金属層１９が加熱される。 The heating roller 2 is disposed on the side in contact with the toner image carried on the recording paper P as shown in FIGS. 2 and 3, and is composed of a metal core 21 made of metal and an elastic body 22 such as silicon rubber. The shaft core 20 is constituted by a cylindrical elastic layer 23 made of silicon rubber or the like provided so as to surround the shaft core 20. The shaft core 20 of the heating roller 2 has a configuration in which a cored bar portion 21 is sandwiched between elastic bodies 22, and the shaft core 20 as a whole has a cylindrical shape. Then, both ends of the cored bar portion 21 of the heating roller 2 are attached to side walls (not shown) of the apparatus main body via fixed bearings. A lubricant 24 is applied to the outer periphery of the shaft core 20, and a cylindrical elastic layer 23 is rotatably disposed. The elastic layer 23 of the heating roller 2 is driven to rotate via the pressure roller 3 by the rotational driving of the driving roller 4. The heating roller 2 also has a function as a heating unit for heating the recording paper P sandwiched by the fixing nip N. For example, in the heating roller 2 according to this embodiment, a thin metal film 25 is wound around the elastic layer 23, and the surface metal layer 19 is heated by an electromagnetic induction heater (not shown).

上記加圧ローラ３も同様に、金属からなる芯金部３１とシリコンゴム等の弾性体３２からなる軸芯３０と、軸芯３０を囲んで設けられたシリコンゴム等からなる円筒状の弾性層３３とによって構成されている。加圧ローラ３の軸芯３０は、芯金部３１が弾性体３２で挟まれた構成となっており、軸芯３０全体としては円柱状の形状となっている。そして、加圧ローラ３の芯金部３１の両端は、固定の軸受を介して、装置本体の不図示の側壁に取り付けられている。上記軸芯３０の外周には、潤滑剤３４が塗布されており、円筒状の弾性層３３が回転自在に配置されている。加圧ローラ３の弾性層３３は、駆動ローラ４の回転駆動により従動回転することになる。 Similarly, the pressure roller 3 has a metal core 31 and a shaft 30 formed of an elastic body 32 such as silicon rubber, and a cylindrical elastic layer formed of silicon rubber or the like provided around the shaft 30. 33. The shaft core 30 of the pressure roller 3 has a configuration in which a core 31 is sandwiched between elastic bodies 32, and the shaft core 30 as a whole has a cylindrical shape. Then, both ends of the cored bar 31 of the pressure roller 3 are attached to side walls (not shown) of the apparatus main body via fixed bearings. A lubricant 34 is applied to the outer periphery of the shaft core 30, and a cylindrical elastic layer 33 is rotatably disposed. The elastic layer 33 of the pressure roller 3 is driven to rotate by the rotational driving of the driving roller 4.

図４は定着装置の定着ニップ周辺を紙搬送方向から見た構成を示す概略構成図、図５は定着装置の定着ニップ周辺を上部から見た構成を示す概略構成図である。図４に示すように、上記加熱ローラ２の芯金部２１の両端に取り付けられた軸受２６ａ、２６ｂには、加圧手段たる加圧調整装置２７ａ、２７ｂが設けられている。この加圧調整装置２７は、図中矢印Ｗｖ方向で示すように、記録紙Ｐの面方向に沿った方向とは略直交する方向に、加熱ローラ２を加圧ローラ３に向かう方向に押し付けて圧接させ定着ニップＮを形成するための調整機構である。この加圧調整装置２７は、具体的には、装置内に組み込まれたプランジャ２８ａ、２８ｂを加圧ローラ３に向けて移動させることにより、加熱ローラ２を加圧ローラ３に向かう方向に押圧して定着ニップＮを形成する。 FIG. 4 is a schematic configuration diagram showing a configuration when the periphery of the fixing nip of the fixing device is viewed from the paper conveyance direction, and FIG. 5 is a schematic configuration diagram showing a configuration when the periphery of the fixing nip of the fixing device is viewed from above. As shown in FIG. 4, the bearings 26a and 26b attached to the both ends of the cored bar portion 21 of the heating roller 2 are provided with pressure adjusting devices 27a and 27b as pressure means. The pressure adjusting device 27 presses the heating roller 2 in a direction toward the pressure roller 3 in a direction substantially orthogonal to the direction along the surface direction of the recording paper P as indicated by an arrow Wv direction in the drawing. This is an adjusting mechanism for forming a fixing nip N by pressure contact. Specifically, the pressure adjusting device 27 moves the plungers 28 a and 28 b incorporated in the device toward the pressure roller 3 to press the heating roller 2 in the direction toward the pressure roller 3. Thus, the fixing nip N is formed.

また、図５に示すように上記加熱ローラ２の芯金部２１の両端には、加圧手段たる加圧調整装置４０ａ、４０ｂが設けられている。この加圧調整装置４０は、図中矢印Ｗｈ方向で示すように、加熱ローラ２の芯金部２１の両端を記録紙Ｐの面方向に沿った図中矢印Ａ方向で示す紙搬送方向Ａの逆方向に押圧し、加熱ローラ２の軸方向中央部を紙搬送方向に向かって撓ませるための力を加圧するための調整機構である。この加圧調整装置４０は、具体的には、装置内に組み込まれたプランジャ４１ａ、４１ｂを紙搬送方向Ａとは反対側へ移動させる。これにより、加熱ローラ２は軸受け２６ａ、２６ｂを支点として図中２点斜線Ｂに示すように軸方向中央部が紙搬送方向Ａへ撓む。加圧調整装置４０のプランジャ４１の移動量が増加すると、加熱ローラ２及び加圧ローラ３の撓み量が増加する。加圧調整装置４０のプランジャ４１の移動量を制御することにより、加熱ローラ２の撓み量を制御することができる。 Further, as shown in FIG. 5, pressure adjusting devices 40a and 40b as pressure means are provided at both ends of the cored bar portion 21 of the heating roller 2. As shown by the arrow Wh direction in the figure, the pressure adjusting device 40 has both ends of the cored bar 21 of the heating roller 2 in the paper transport direction A indicated by the arrow A direction in the figure along the surface direction of the recording paper P. It is an adjustment mechanism for pressing in the reverse direction and pressurizing a force for bending the central portion of the heating roller 2 in the axial direction. Specifically, the pressure adjusting device 40 moves the plungers 41 a and 41 b incorporated in the device to the side opposite to the paper transport direction A. As a result, the heating roller 2 has its bearings 26a and 26b as fulcrums and the central portion in the axial direction bends in the paper transport direction A as indicated by the two-dot oblique line B in the figure. When the movement amount of the plunger 41 of the pressure adjusting device 40 increases, the deflection amount of the heating roller 2 and the pressure roller 3 increases. The amount of deflection of the heating roller 2 can be controlled by controlling the amount of movement of the plunger 41 of the pressure adjusting device 40.

また、図示しないが、上記加圧ローラ３の芯金部３１の両端にも、加圧手段たる加圧調整装置が設けられている。この加圧調整装置は、上記加圧調整装置４０と同様に、加圧ローラ３の芯金部３１の両端を紙搬送方向Ａの逆方向に押圧し、加圧ローラ３の軸方向中央部を紙搬送方向Ａに向かって撓ませるための力を加圧するための調整機構である。この加圧調整装置３は、具体的には、上述したように、装置に組み込まれたプランジャを紙搬送方向Ａとは反対側へ移動させる。これにより、加圧ローラ３は軸受け３６ａ、３６ｂを支点として紙搬送方向Ａへ撓む。 Although not shown, pressure adjusting devices as pressure means are provided at both ends of the cored bar 31 of the pressure roller 3. Similar to the pressure adjusting device 40, this pressure adjusting device presses both ends of the cored bar 31 of the pressure roller 3 in the direction opposite to the paper conveying direction A, and the axial central portion of the pressure roller 3 is pressed. It is an adjustment mechanism for pressurizing a force for bending in the paper transport direction A. Specifically, as described above, the pressure adjusting device 3 moves the plunger incorporated in the device to the side opposite to the paper transport direction A. As a result, the pressure roller 3 bends in the paper transport direction A with the bearings 36a and 36b as fulcrums.

すなわち、本実施形態では、上記加熱ローラ２を矢印Ｗｖ方向に加圧する加圧調整装置２７、上記加熱ローラ２及び加圧ローラ３を矢印Ｗｈ方向に加圧するための加圧調整装置４０と図示しない加圧調整装置とによって、定着ニップ形成部材である加熱ローラ２及び加圧ローラ３を２方向Ｗｖ、Ｗｈへ加圧する加圧手段を構成している。なお、加圧手段の構成は、本実施形態の構成に限定されず、例えば、上記加熱ローラ２と加圧ローラ３のどちらか一方のローラのみに、軸方向中央部を紙搬送方向Ａに向かって撓ませるために、矢印Ｗｈ方向に加圧する加圧調整装置を設けてもよい。 That is, in the present embodiment, a pressure adjusting device 27 that pressurizes the heating roller 2 in the direction of the arrow Wv, a pressure adjusting device 40 that pressurizes the heating roller 2 and the pressure roller 3 in the direction of the arrow Wh, and not shown. The pressure adjusting device constitutes a pressure unit that pressurizes the heating roller 2 and the pressure roller 3 as fixing nip forming members in two directions Wv and Wh. Note that the configuration of the pressing means is not limited to the configuration of the present embodiment. For example, only one of the heating roller 2 and the pressing roller 3 has its center in the axial direction facing the paper conveyance direction A. Therefore, a pressure adjusting device that pressurizes in the arrow Wh direction may be provided.

図６（ａ）は、加熱ローラの撓み状態を説明する模式図、（ｂ）は定着ニップで記録紙に対して記録紙幅方向へ働く力の向きを示した模式図、（ｃ）は定着ニップの幅を示した模式図である。図６（ａ）に示すように、加熱ローラ２及び加圧ローラ３に撓みを持たせた場合、各ローラ２，３が定着ニップＮ内で記録紙Ｐを搬送しようとする力は、図６（ｂ）中矢印Ｃ方向で示すように、記録紙Ｐの幅方向の外向きに働く。そのため、定着ニップＮ内では、記録紙Ｐの幅方向両端部が外側へ引っ張られるため、紙しわは発生しにくくなる。 FIG. 6A is a schematic diagram for explaining the bending state of the heating roller, FIG. 6B is a schematic diagram showing the direction of the force acting in the recording paper width direction on the recording paper at the fixing nip, and FIG. 6C is the fixing nip. It is the schematic diagram which showed the width | variety. As shown in FIG. 6A, when the heating roller 2 and the pressure roller 3 are bent, the force with which the rollers 2 and 3 try to transport the recording paper P in the fixing nip N is as shown in FIG. (B) Acts outward in the width direction of the recording paper P as indicated by the direction of the middle arrow C. Therefore, in the fixing nip N, both ends in the width direction of the recording paper P are pulled outward, so that paper wrinkles are less likely to occur.

ここで、定着ニップＮの紙搬送方向の幅は図６（ｃ）に示すとおり、加熱ローラ２及び加圧ローラ３の撓み量が大きくなければ記録紙幅方向に対してほぼ均一となる。加熱ローラ２及び加圧ローラ３の撓み量を大きく過ぎると中央部での定着ニップＮの紙搬送方向の幅は端部での幅より狭くなり不均一となる。しかしながら、加熱ローラ２及び加圧ローラ３の実用上の撓み量においては、プランジャ４１による加圧の変化や記録紙Ｐの種類に依存せず、記録紙幅方向のニップ幅の均一性は保たれる。このため、逆クラウン形状のローラ使用時と比較して、記録紙幅方向について一様な定着性能を持たせることができる。 Here, as shown in FIG. 6C, the width of the fixing nip N in the paper conveyance direction is almost uniform in the recording paper width direction unless the deflection amount of the heating roller 2 and the pressure roller 3 is large. If the amount of deflection of the heating roller 2 and the pressure roller 3 is too large, the width of the fixing nip N in the center in the paper conveyance direction becomes narrower than the width at the end and becomes non-uniform. However, the practical deflection amount of the heating roller 2 and the pressure roller 3 does not depend on the pressure change by the plunger 41 or the type of the recording paper P, and the uniformity of the nip width in the recording paper width direction is maintained. . For this reason, it is possible to provide a uniform fixing performance in the recording paper width direction as compared with the case of using a reverse crown-shaped roller.

さらに、本実施形態に係る定着装置１においては、図２に示すように、定着ニップＮの出入口の上方に、パタン投影機５及びエリアセンサ６が設けられている。図２において、記録紙Ｐは加熱ローラ２と加圧ローラ３とによって形成される定着ニップＮを図中矢印Ａ方向に搬送される。パタン投影機５は定着ニップＮの入口側に、記録紙Ｐの記録面に対して所定の角度を設けて設置され、記録紙Ｐの定着ニップＮの入口側近傍の記録紙全幅にわたり、ラインパタンＬＰａを照射する。エリアセンサ６は、記録紙ＰのラインパタンＬＰａ形成側で記録紙Ｐの記録面に対してパタン投影機５とは異なる所定の角度を設けて配置され、記録紙Ｐ上に形成されているラインパタンＬＰａを撮影する。記録紙Ｐに撓みのない場合には、エリアセンサ６はラインパタンＬＰａを直線として捉えられる。一方、記録紙Ｐに撓みが発生すると、記録紙Ｐの高さが局所的に変化して、面方向から外れて変形する面外変形が生じるため、エリアセンサ５は、パタン投影機６から記録紙Ｐの記録面に対して斜めに照射されているラインパタンＬＰａを歪んだ曲線として捉え、これを面外変化量として検知する。記録紙Ｐの面外変形量が大きくなり所定の値を超えると、その近傍で紙しわが発生することがわかっているので、記録紙Ｐの面外変形量を検知することで紙しわが発生するかどうかを予測することができる。また、記録紙Ｐの高さとラインパタンＬＰａの位置関係を予め検知しておくことで、エリアセンサ６の出力から記録紙Ｐの面外変形量を求めることができる。 Further, in the fixing device 1 according to the present embodiment, as shown in FIG. 2, a pattern projector 5 and an area sensor 6 are provided above the entrance / exit of the fixing nip N. In FIG. 2, the recording paper P is conveyed in the direction of arrow A in the drawing through a fixing nip N formed by a heating roller 2 and a pressure roller 3. The pattern projector 5 is installed on the inlet side of the fixing nip N at a predetermined angle with respect to the recording surface of the recording paper P. The pattern projector 5 extends over the entire width of the recording paper near the inlet side of the fixing nip N of the recording paper P. Irradiate with LPa. The area sensor 6 is arranged on the line pattern LPa forming side of the recording paper P at a predetermined angle different from that of the pattern projector 5 with respect to the recording surface of the recording paper P, and is formed on the recording paper P. Photograph pattern LPa. When the recording paper P is not bent, the area sensor 6 can recognize the line pattern LPa as a straight line. On the other hand, if the recording paper P bends, the height of the recording paper P changes locally, and an out-of-plane deformation occurs that deviates from the surface direction. Therefore, the area sensor 5 performs recording from the pattern projector 6. The line pattern LPa irradiated obliquely to the recording surface of the paper P is regarded as a distorted curve, and this is detected as an out-of-plane change amount. Since it has been known that when the amount of out-of-plane deformation of the recording paper P increases and exceeds a predetermined value, paper wrinkles occur in the vicinity thereof. Therefore, paper wrinkles are generated by detecting the amount of out-of-plane deformation of the recording paper P. You can predict whether to do it. Further, by detecting in advance the positional relationship between the height of the recording paper P and the line pattern LPa, the out-of-plane deformation amount of the recording paper P can be obtained from the output of the area sensor 6.

図７は、１枚の記録紙が搬送される過程でエリアセンサにより測定されたラインパタンＬＰの形状を示す模式図であり、ラインパタンＬＰから求めた記録紙Ｐの面外変形量を時刻ｔ０から時刻ｔｎまで時系列的に記載している。図７（ａ）は、紙しわが発生する際のラインパタンＬＰの形状と面外変形量検知結果を示す模式図である。図７（ａ）では、微小すべりが発生するなどして記録紙Ｐの幅方向両端部に対して内側に移動する力が生じて撓みが発生し、検知される面外変形量が記録紙Ｐの搬送量に伴って次第に大きくなっている。本実施形態においては、最大高さと最小高さの差分を最大面外変形量δとして、後述する制御部による各種判断に用いている。図７（ｂ）は、紙しわが発生しない際のラインパタンＬＰの形状と面外変形量検知結果を示す模式図である。記録紙に記録紙幅方向外側向きに力が働く場合には、記録紙Ｐにうねりが生じず平坦のまま搬送されるため、測定されるラインパタンＬＰの形状は平坦となり、本実施形態において検知される面外変形量としては略ゼロとなる。 FIG. 7 is a schematic diagram showing the shape of the line pattern LP measured by the area sensor in the process of transporting one sheet of recording paper. The out-of-plane deformation amount of the recording paper P obtained from the line pattern LP is expressed as time t0. From time to time tn. FIG. 7A is a schematic diagram illustrating the shape of the line pattern LP and the detection result of the out-of-plane deformation when paper wrinkles are generated. In FIG. 7A, a force that moves inwardly with respect to both ends in the width direction of the recording paper P is generated due to the occurrence of a microslip or the like. The amount gradually increases with the transport amount. In the present embodiment, the difference between the maximum height and the minimum height is used as the maximum out-of-plane deformation amount δ for various determinations by the control unit described later. FIG. 7B is a schematic diagram illustrating the shape of the line pattern LP and the detection result of the out-of-plane deformation when no paper wrinkle is generated. When a force is applied to the recording paper outward in the width direction of the recording paper, the recording paper P is conveyed without being wavy, so that the shape of the line pattern LP to be measured becomes flat and is detected in this embodiment. The amount of out-of-plane deformation is almost zero.

また、本実施形態に係る定着装置１において、制御手段たる制御部１０は、ＣＰＵ、ＲＯＭ、ＲＡＭなどで構成され、所定のプログラムを実行することにより、各手段の機能を実現している。図１に示すように、制御部１０はエリアセンサ６の出力値から、定着ニップＮの入口及び出口の記録紙Ｐの幅方向の面外変形量を演算している。すなわち、本実施形態においては、パタン投影機５、エリアセンサ６及び制御部１０とで面外変形量検知手段を構成している。また、制御部１０には、記憶手段たる不揮発性メモリ１１が接続されており、不揮発性メモリ１１には、予め実験で求めた基準の面外変形量や後述する限界面外変形量等が格納されている。また、この不揮発性メモリ１１には検知した面外変形量を紙種毎に時系列で格納することができる。また、制御部１０は、加圧調整装置４０の加圧力を制御してニップ圧や加熱ローラ２及び加圧ローラ３の撓み量や、不図示の電磁誘導加熱器の電源１２を制御して定着熱量を制御している。さらに、制御部１０には、報知手段たるスピーカや表示器を備えた報知部１３が接続されており、報知部１３を制御して使用者に所定の情報を報知することができる。また、制御部１０には、ユーザーによる入力が可能な操作部１４が接続されている。 Further, in the fixing device 1 according to the present embodiment, the control unit 10 serving as a control unit includes a CPU, a ROM, a RAM, and the like, and realizes the functions of each unit by executing a predetermined program. As shown in FIG. 1, the control unit 10 calculates the out-of-plane deformation amount in the width direction of the recording sheet P at the entrance and exit of the fixing nip N from the output value of the area sensor 6. That is, in the present embodiment, the pattern projector 5, the area sensor 6, and the control unit 10 constitute an out-of-plane deformation detection means. The control unit 10 is connected to a nonvolatile memory 11 serving as a storage unit, and the nonvolatile memory 11 stores a reference out-of-plane deformation amount obtained in advance by experiments, a limit out-of-plane deformation amount described later, and the like. Has been. In addition, the detected out-of-plane deformation amount can be stored in the nonvolatile memory 11 in time series for each paper type. Further, the control unit 10 controls the pressing force of the pressure adjusting device 40 to control the nip pressure, the deflection amount of the heating roller 2 and the pressure roller 3, and the power source 12 of an electromagnetic induction heater (not shown) for fixing. The amount of heat is controlled. Furthermore, the control unit 10 is connected to a notification unit 13 including a speaker or a display as a notification unit, and can control the notification unit 13 to notify the user of predetermined information. The control unit 10 is connected to an operation unit 14 that can be input by a user.

上記加熱ローラ２及び加圧ローラ３の撓み量は、記録紙Ｐの性質に応じて紙しわの発生しない必要最低限の量にするのが好ましい。さらに、加熱ローラ２及び加圧ローラ３の経時劣化に起因する紙しわの発生を抑制する必要がある。そこで、本実施形態においては、エリアセンサ６で定着ニップＮの入口の記録紙Ｐの幅方向の面外変形量を検知し、その検知結果に基づいて、加熱ローラ２及び加圧ローラ３の撓み量を調整することで、紙しわの発生を経時で抑制し、紙種に応じた最適な撓み量にすることができる。 The amount of bending of the heating roller 2 and the pressure roller 3 is preferably set to a minimum amount that does not cause paper wrinkling according to the properties of the recording paper P. Furthermore, it is necessary to suppress the occurrence of paper wrinkles due to the deterioration with time of the heating roller 2 and the pressure roller 3. Therefore, in the present embodiment, the area sensor 6 detects the amount of out-of-plane deformation in the width direction of the recording paper P at the entrance of the fixing nip N, and the heating roller 2 and the pressure roller 3 are bent based on the detection result. By adjusting the amount, the generation of paper wrinkles can be suppressed over time, and the optimum amount of bending according to the paper type can be achieved.

以下、撓み量調整の制御について具体的に説明する。図８は撓み量調整の制御手順を説明する制御フロー図である。まず、制御部１０は面外変形量を計測する紙種を特定する（Ｓ１）。紙種は、例えばユーザーに操作部１４により記録紙型番を入力させる。また、制御部１０は、その型番に相当する厚さや種類等の過去の実験値の記憶情報を不揮発性メモリ１１から読み込む。次に、パタン投影機５でラインパタンＬＰａを記録紙Ｐ上に投射し（Ｓ２）、ラインセンサ６で記録紙Ｐの搬送中のラインパタンＬＰａの形状を測定して、定着ニップＮの入口及び出口での面外変形形状を測定する（Ｓ３）。 Hereinafter, the control of the deflection amount adjustment will be specifically described. FIG. 8 is a control flowchart for explaining the control procedure of the deflection amount adjustment. First, the control unit 10 specifies a paper type for measuring the amount of out-of-plane deformation (S1). For the paper type, for example, the user inputs the recording paper model number by the operation unit 14. In addition, the control unit 10 reads storage information of past experimental values such as thickness and type corresponding to the model number from the nonvolatile memory 11. Next, the line pattern LPa is projected onto the recording paper P by the pattern projector 5 (S2), the shape of the line pattern LPa during conveyance of the recording paper P is measured by the line sensor 6, and the entrance of the fixing nip N and The out-of-plane deformation shape at the exit is measured (S3).

記録紙Ｐの後端に浮きが生じ、面外変形量を持った状態で記録紙Ｐの後端が定着ニップＮへ搬送されるとき、記録紙Ｐの後端の浮きが僅かであれば、定着ニップＮ内で紙しわなどが生じることはない。しかし、記録紙Ｐの後端の浮きが大きい場合、定着ニップＮで紙しわが発生する確率が高くなる。 If the trailing edge of the recording paper P is lifted and the trailing edge of the recording paper P is transported to the fixing nip N in a state having an out-of-plane deformation, if the trailing edge of the recording paper P is slight, No paper wrinkles or the like occur in the fixing nip N. However, when the trailing edge of the recording paper P is large, the probability that paper wrinkles will occur at the fixing nip N increases.

不揮発性メモリ１１には、この記録紙Ｐの後端の浮きの閾値である、限界面外変形量が、記録紙Ｐの種類毎に記憶されており、制御部１０は、不図示の温湿度計により環境を検知し、検知した環境と紙種情報とに基づいて、対応する限界面外変形量を読み出す。また、制御部１０は、エリアセンサ６により検知した面外変形形状に基づいて、最大面外変形量δを算出し、算出した最大面外変形量δが限界面外変形量を超えているか否かを判断する（Ｓ４）。最大面外変形量δが限界面外変形量を上回っている場合（Ｓ４のＹＥＳ）は、定着装置１に大きな不具合が発生している可能性があり、その紙種を用いる場合は、紙しわが確実に発生してしまう。そのため、制御部１０は、最大面外変形量δが限界面外変形量を上回っている場合は、報知部１３によりスピーカからアラームを発信するとともに、定着装置１を交換する旨を表示器に表示する（Ｓ９）。 The non-volatile memory 11 stores a limit out-of-plane deformation amount, which is a floating threshold of the trailing edge of the recording paper P, for each type of the recording paper P, and the control unit 10 performs temperature and humidity (not shown). The environment is detected by a meter, and the corresponding out-of-limit deformation amount is read based on the detected environment and paper type information. Further, the control unit 10 calculates the maximum out-of-plane deformation amount δ based on the out-of-plane deformation shape detected by the area sensor 6, and whether or not the calculated maximum out-of-plane deformation amount δ exceeds the limit out-of-plane deformation amount. (S4). If the maximum out-of-plane deformation amount δ exceeds the limit out-of-plane deformation amount (YES in S4), there is a possibility that a major problem has occurred in the fixing device 1. It will surely occur. Therefore, when the maximum out-of-plane deformation amount δ exceeds the limit out-of-plane deformation amount, the control unit 10 issues an alarm from the speaker by the notification unit 13 and displays on the display that the fixing device 1 is to be replaced. (S9).

一方、制御部１０は、最大面外変形量δが限界面外変形量以下の場合（Ｓ４のＮＯ）、エリアセンサ６により検知した面外変形形状に基づいて、加圧制御機構４０による加圧量、すなわち撓み量を演算する（Ｓ５）。不揮発性メモリ１１には、最適な記録紙幅方向の面外変形量が記憶されており、この情報は記録紙の種類や環境によって異なる値を持つ。そして、制御部１０は、検知した面外変形量が不揮発性メモリ１１に記憶された面外変形量に近くなるよう撓み量を求める。そして、制御部１０は、撓み量を求めたら、加圧力調整機構４０を制御し、加熱ローラ２及び加圧ローラ３を求めた撓み量分だけ撓ませる（Ｓ６、Ｓ７のＮＯ、Ｓ８）。また、撓み量調整中に調整の限界（プランジャ４１の移動限界）になった場合（Ｓ７のＹＥＳ）、制御部１０は加熱ローラ２の寿命であると判定し、報知部１３によりアラームを発信するとともに、定着装置１を交換する旨を表示部に表示する（Ｓ９）。 On the other hand, when the maximum out-of-plane deformation amount δ is equal to or less than the limit out-of-plane deformation amount (NO in S4), the control unit 10 applies pressure by the pressurization control mechanism 40 based on the out-of-plane deformation shape detected by the area sensor 6. The amount, that is, the deflection amount is calculated (S5). The non-volatile memory 11 stores an optimal out-of-plane deformation amount in the recording paper width direction, and this information has a different value depending on the type and environment of the recording paper. Then, the control unit 10 obtains the deflection amount so that the detected out-of-plane deformation amount is close to the out-of-plane deformation amount stored in the nonvolatile memory 11. And the control part 10 will control the pressurization adjustment mechanism 40, if it calculates | requires the amount of bending, and will bend the heating roller 2 and the pressure roller 3 by the calculated amount of bending (NO of S6, S7, S8). Further, when the adjustment limit (movement limit of the plunger 41) is reached during the deflection amount adjustment (YES in S 7), the control unit 10 determines that the life of the heating roller 2 has been reached and issues an alarm by the notification unit 13. At the same time, a message to replace the fixing device 1 is displayed on the display unit (S9).

図１に示すプリンタにおいては、ひとつの給紙トレイ５６のみを図示しているが、互いに異なる種類の記録紙Ｐを収容可能な複数の給紙トレイを備えていてもよい。このように画像形成に使用される記録紙Ｐの種類が複数の場合は、各給紙トレイに収容されているそれぞれの記録紙Ｐに対して、面外変形形状を測定して、撓み量調整が必要か否かなどを判定する。具体的には、制御部１０は、面外変形形状を計測する紙種を特定する。紙種の特定は、例えば、給紙トレイに記録紙Ｐをセットする際に、ユーザーに給紙トレイにセットされる記録紙Ｐの厚さや種類の情報を操作部１４により入力させ、入力した情報を不揮発性メモリ１１に記憶しておく。制御部１０は、不揮発性メモリ１１に記憶されている給紙トレイにセットされている記録紙Ｐの紙種情報を読み出すことで、面外変形形状を計測する紙種を特定することができる。このように、面外変形形状を計測する紙種を特定したら、不揮発性メモリ１１に記憶されているその紙種に対応する撓み量を読み出し、撓み量を調整してから、上述同様、パタン投影機５によりラインパタンＬＰａを照射し、ラインパタンＬＰａの面外変形形状を測定する。そして、給紙トレイに収容されている記録紙Ｐについて、定着装置１の寿命と判定された場合、その給紙トレイを使用禁止にする。また、給紙トレイに収容されている記録紙Ｐについて撓み量調整が必要な場合、その記録紙Ｐについて、加熱ローラ２及び加圧ローラ３の撓み量を求める。そして、不揮発性メモリ１１に各記録紙Ｐの種類毎に記憶されている撓み量を、求めた撓み量に書き換える。画像形成動作時には、使用される給紙トレイを特定し、その給紙トレイに収容されている記録紙に対応した撓み量を、不揮発性メモリから読み出し、読み出した撓み量に調整してから画像形成動作を行う。 In the printer shown in FIG. 1, only one paper feed tray 56 is illustrated, but a plurality of paper feed trays that can store different types of recording paper P may be provided. When there are a plurality of types of recording paper P used for image formation in this way, the amount of deflection is adjusted by measuring the out-of-plane deformation shape of each recording paper P stored in each paper feed tray. Whether or not is necessary. Specifically, the control unit 10 specifies the paper type for measuring the out-of-plane deformation shape. For specifying the paper type, for example, when the recording paper P is set in the paper feeding tray, the user inputs information on the thickness and type of the recording paper P set in the paper feeding tray by the operation unit 14, and the input information Is stored in the nonvolatile memory 11. The control unit 10 can specify the paper type for measuring the out-of-plane deformation shape by reading the paper type information of the recording paper P set in the paper feed tray stored in the nonvolatile memory 11. Thus, when the paper type for measuring the out-of-plane deformed shape is specified, the deflection amount corresponding to the paper type stored in the non-volatile memory 11 is read out, and after adjusting the deflection amount, the pattern projection is performed as described above. The line pattern LPa is irradiated by the machine 5, and the out-of-plane deformation shape of the line pattern LPa is measured. When the recording paper P stored in the paper feed tray is determined to have reached the end of its life, the paper feed tray is disabled. Further, when the deflection amount of the recording paper P stored in the paper feed tray needs to be adjusted, the deflection amounts of the heating roller 2 and the pressure roller 3 are obtained for the recording paper P. Then, the deflection amount stored for each type of recording paper P in the nonvolatile memory 11 is rewritten to the calculated deflection amount. At the time of image forming operation, the paper feed tray to be used is specified, the deflection amount corresponding to the recording paper stored in the paper feed tray is read from the non-volatile memory, and adjusted to the read deflection amount before image formation. Perform the action.

また、紙種毎に検知した面外変形量を時系列で不揮発性メモリ１１に記憶しておき、ある給紙トレイに収納されている記録紙Ｐに対応する撓み量が、調整の限界（プランジャ４１の移動限界）になった場合、この記録紙Ｐに対応する時系列の面外変形量データから、上述と同様にして、この記録紙Ｐの面外変形量が、限界面外変形量に達するまでの時間若しくは印刷枚数を求める。このようにして求められた時間若しくは印刷枚数から、紙しわの発生確率が高くなる閾値を設定し、時間若しくは印刷枚数が閾値に達したら、この給紙トレイに収容されている記録紙Ｐを使用する場合、画像形成動作を開始する前に、この記録紙を使用すると、紙しわが発生する確率が高い旨をアラームとともに警告表示する。また、定着装置１の交換を促す表示を行う。そして、求められた時間若しくは印刷枚数に達したら、この記録紙が収容されている給紙トレイの使用を禁止する。これにより、紙しわが生じる定着装置が使用されることはないため、記録紙の無駄が防止できる。 Further, the out-of-plane deformation amount detected for each paper type is stored in the nonvolatile memory 11 in time series, and the deflection amount corresponding to the recording paper P stored in a certain paper feed tray is the adjustment limit (plunger 41), the out-of-plane deformation amount of the recording paper P becomes the limit out-of-plane deformation amount from the time-series out-of-plane deformation amount data corresponding to the recording paper P in the same manner as described above. Find the time to reach or the number of prints. Based on the time or the number of printed sheets obtained in this way, a threshold value that increases the probability of occurrence of paper wrinkles is set, and when the time or the number of printed sheets reaches the threshold value, the recording paper P stored in the paper feed tray is used. In this case, when this recording paper is used before the image forming operation is started, a warning is displayed together with an alarm that the probability of paper wrinkling is high. Further, a display prompting replacement of the fixing device 1 is performed. When the required time or the number of printed sheets is reached, use of the paper feed tray in which the recording paper is stored is prohibited. As a result, since the fixing device that generates paper wrinkles is not used, waste of recording paper can be prevented.

更に、本実施形態に係る定着装置１においては、上記のとおり記録紙の面外変形量を監視しても、紙しわ発生を防止できなかった場合に備え、エリアセンサは、ニップ出口付近のレーザパタンＬＰｂを常時監視する。ニップ入口のレーザパタンＬＰａの場合と同様で、紙しわが発生しない場合にパタンは直線であるが、紙しわが発生した場合にパタンに歪みが生じる。これにより、制御部１０は紙しわが発生したか否かを判定することができ、発生した場合は報知部８により、その旨を報知することができる。 Furthermore, in the fixing device 1 according to the present embodiment, the area sensor detects the laser pattern near the nip exit in preparation for the case where the occurrence of paper wrinkle cannot be prevented even if the amount of out-of-plane deformation of the recording paper is monitored as described above. LPb is constantly monitored. As in the case of the laser pattern LPa at the nip entrance, when the paper wrinkle does not occur, the pattern is a straight line, but when the paper wrinkle occurs, the pattern is distorted. Thereby, the control part 10 can determine whether the paper wrinkle generate | occur | produced, and when it generate | occur | produces, the notification part 8 can alert | report that.

以上、本実施形態の定着装置１は、定着ニップ形成部材且つ加熱手段を兼ねる加熱ローラ２と、定着ニップ形成部材たる加圧ローラ３との間に定着ニップＮを形成する。制御部１０は、面外変形量検知手段であるエリアセンサ６が検知した記録紙Ｐの面外変形量に応じて加熱ローラ２・加圧ローラ３の撓み量を制御することによって、記録紙Ｐに紙しわが発生しない必要最小限の撓み量にすることができる。すなわち、経時に亘って紙幅方向での均一な定着性を保ちながら記録紙Ｐへの紙しわの発生を抑制することができる。
また、本実施形態に係る定着装置１において、上記加圧調整装置４０は、上記加熱ローラ２（及び加圧ローラ３）の回転軸たる芯金部５の両端を記録紙Ｐの面方向に沿った方向に加圧して、加熱ローラ１の軸方向中央部を記録紙Ｐの搬送方向に向かって撓ませる。これにより、定着ニップＮで記録紙幅方向に働く力は外向きとなるため、記録紙Ｐは幅方向両端へ引っ張られる。これにより、記録紙Ｐの紙しわが抑制される。
また、本実施形態に係る定着装置１は、記憶手段たる不揮発性メモリ１１を備え、紙種や環境に応じた適正な面外変形量を記憶する。よって、記憶する適正な面外変形量と検知した面外変形量データとに基づいて、加熱ローラ２・加圧ローラ３の撓み量を制御することで、適正な面外変形量となるように両ローラの撓み量を調整することができる。
また、本実施形態に係る定着装置１において、制御部１０は、エリアセンサ６が検知した面外変形量が、不揮発性メモリ１１に記憶された限界面外変形量に達している場合には、紙しわが発生している虞がある旨を報知部８（スピーカ及び表示器）に報知するための報知処理を行い、定着動作を禁止する。これにより紙しわが発生する定着装置が使用されることがなくなり、記録紙Ｐの無駄を抑制することができる。
また、本実施形態に係る定着装置１において、不揮発性メモリ１１は、エリアセンサ６が検知した面外変形量を時系列に記憶している。そして、制御部１０は、時系列で記憶された面外変形量に基づいて、上記定着装置１の寿命を予測し、寿命であると予測した場合には、定着装置１を交換する必要がある旨を報知するための報知処理を行う。これにより、紙しわが発生する前に定着装置１の交換がなされ、装置のダウンタイムが生じるのを抑制することができる。
また、本実施形態に係る定着装置１において、不揮発性メモリ１１はエリアセンサ６で検知された面外変形量データを時系列で記憶している。そして、制御部１０は、この記憶された面外変形量データに基づいて、記録紙Ｐの種類毎に紙しわの発生確率が高くなる閾値を算出し、閾値を超える記録紙Ｐが使用される場合、紙しわが発生する確率が高い旨を報知するための報知処理を行う。これにより、使用する記録紙Ｐを他のものに切り替える等の動作が促され、紙しわの発生を抑制することがきる。
また、本実施形態に係る定着装置１において、エリアセンサ６により定着ニップＮ通過後の記録紙Ｐの面外変形量を検知する。これにより、紙しわの発生を防止できず紙しわが発生した場合でも、これを検知することができる。 As described above, the fixing device 1 of the present embodiment forms the fixing nip N between the heating roller 2 that also serves as a fixing nip forming member and a heating unit and the pressure roller 3 that is a fixing nip forming member. The control unit 10 controls the deflection amount of the heating roller 2 and the pressure roller 3 according to the out-of-plane deformation amount of the recording paper P detected by the area sensor 6 which is an out-of-plane deformation detection means, thereby recording the recording paper P. It is possible to make the necessary minimum amount of bending without causing paper wrinkles. That is, the generation of paper wrinkles on the recording paper P can be suppressed while maintaining a uniform fixing property in the paper width direction over time.
Further, in the fixing device 1 according to the present embodiment, the pressure adjusting device 40 is arranged along the surface direction of the recording paper P at both ends of the cored bar portion 5 which is the rotation axis of the heating roller 2 (and the pressure roller 3). The central portion in the axial direction of the heating roller 1 is bent toward the conveyance direction of the recording paper P. As a result, the force acting in the recording paper width direction at the fixing nip N is directed outward, so that the recording paper P is pulled to both ends in the width direction. Thereby, the paper wrinkles of the recording paper P are suppressed.
Further, the fixing device 1 according to the present embodiment includes a nonvolatile memory 11 serving as a storage unit, and stores an appropriate out-of-plane deformation amount according to the paper type and environment. Therefore, by controlling the amount of deflection of the heating roller 2 and the pressure roller 3 based on the stored out-of-plane deformation amount and the detected out-of-plane deformation amount data, an appropriate out-of-plane deformation amount is obtained. The amount of deflection of both rollers can be adjusted.
In the fixing device 1 according to the present embodiment, the control unit 10 determines that the out-of-plane deformation amount detected by the area sensor 6 has reached the limit out-of-plane deformation amount stored in the nonvolatile memory 11. A notification process is performed to notify the notification unit 8 (speaker and display) that paper wrinkles may occur, and the fixing operation is prohibited. As a result, a fixing device that generates paper wrinkles is not used, and waste of the recording paper P can be suppressed.
In the fixing device 1 according to the present embodiment, the nonvolatile memory 11 stores the out-of-plane deformation amount detected by the area sensor 6 in time series. Then, the control unit 10 predicts the lifetime of the fixing device 1 based on the out-of-plane deformation amount stored in time series, and if it is predicted that it is the lifetime, it is necessary to replace the fixing device 1. An informing process for informing the effect is performed. As a result, it is possible to prevent the fixing device 1 from being replaced before the paper wrinkle is generated, and to cause downtime of the device.
In the fixing device 1 according to the present embodiment, the non-volatile memory 11 stores out-of-plane deformation amount data detected by the area sensor 6 in time series. Based on the stored out-of-plane deformation amount data, the control unit 10 calculates a threshold value that increases the wrinkle generation probability for each type of the recording paper P, and the recording paper P that exceeds the threshold is used. In this case, a notification process is performed to notify that there is a high probability that paper wrinkles will occur. As a result, an operation such as switching the recording paper P to be used to another one is promoted, and the occurrence of paper wrinkles can be suppressed.
In the fixing device 1 according to the present embodiment, the area sensor 6 detects the amount of out-of-plane deformation of the recording paper P after passing through the fixing nip N. As a result, the occurrence of paper wrinkles cannot be prevented, and even when paper wrinkles occur, this can be detected.

１定着装置
２加熱ローラ
３加圧ローラ
４駆動ローラ
５パタン投影機
６エリアセンサ
１０制御部
２７、４０加圧調整機構 DESCRIPTION OF SYMBOLS 1 Fixing device 2 Heating roller 3 Pressure roller 4 Driving roller 5 Pattern projector 6 Area sensor 10 Control units 27 and 40 Pressure adjusting mechanism

特開平５−４０４２８号公報JP-A-5-40428

Claims

A fixing nip for fixing an unfixed toner image on the recording medium onto the recording medium while conveying the recording medium is formed, and two fixing nip forming members configured to move endlessly, and through the fixing nip A fixing device comprising heating means for applying heat to the recording medium.
Pressurizing means capable of pressurizing at least one of the two fixing nip forming members in two directions, a direction perpendicular to the surface direction of the recording medium and a direction along the surface direction of the recording medium When,
An out-of-plane deformation amount detecting means for detecting an out-of-plane deformation amount deviating from the surface direction of the recording medium passing through the fixing nip;
Storage means for storing an out-of-plane deformation amount of the recording medium;
Based on the detection result of the stored plane deformation amount and the out-of-plane deformation amount detecting means in the storage means, a pressurization volume to pressurize at least one of said pressurizing means has two fixing nip forming member Control means for controlling ,
The control means controls the pressurizing means based on the out-of-plane deformation amount stored in the storage means and the out-of-plane deformation amount detected by the out-of-plane deformation detection means, and the out-of-plane deformation amount. It is determined whether or not the detection result of the detection means has reached the limit out-of-plane deformation amount stored in advance in the storage means, and if it is determined that there is a risk that paper wrinkles may have occurred. A fixing device that performs notification processing for notification .

A fixing nip for fixing an unfixed toner image on the recording medium onto the recording medium while conveying the recording medium is formed, and two fixing nip forming members configured to move endlessly, and through the fixing nip A fixing device comprising heating means for applying heat to the recording medium.
Pressurizing means capable of pressurizing at least one of the two fixing nip forming members in two directions, a direction perpendicular to the surface direction of the recording medium and a direction along the surface direction of the recording medium When,
An out-of-plane deformation amount detecting means for detecting an out-of-plane deformation amount deviating from the surface direction of the recording medium passing through the fixing nip;
Storage means for storing an out-of-plane deformation amount of the recording medium;
Based on the out-of-plane deformation amount stored in the storage unit and the detection result of the out-of-plane deformation amount detection unit, the pressurizing unit pressurizes at least one of the two fixing nip forming members. Control means for controlling,
The storage means stores the detection results detected by the out-of-plane deformation detection means in time series,
The control means controls the pressurizing means on the basis of the out-of-plane deformation amount stored in the storage means and the out-of-plane deformation amount detected by the out-of-plane deformation detection means. Performing a notification process for predicting the life of the fixing device based on the out-of-plane deformation amount stored in series and notifying that the fixing nip forming member needs to be replaced when the life is predicted. A fixing device characterized by the above.

A fixing nip for fixing an unfixed toner image on the recording medium onto the recording medium while conveying the recording medium is formed, and two fixing nip forming members configured to move endlessly, and through the fixing nip A fixing device comprising heating means for applying heat to the recording medium.
Pressurizing means capable of pressurizing at least one of the two fixing nip forming members in two directions, a direction perpendicular to the surface direction of the recording medium and a direction along the surface direction of the recording medium When,
An out-of-plane deformation amount detecting means for detecting an out-of-plane deformation amount deviating from the surface direction of the recording medium passing through the fixing nip;
Storage means for storing an out-of-plane deformation amount of the recording medium;
Based on the out-of-plane deformation amount stored in the storage unit and the detection result of the out-of-plane deformation amount detection unit, the pressurizing unit pressurizes at least one of the two fixing nip forming members. Control means for controlling,
The storage means stores the detection results detected by the out-of-plane deformation detection means for each type of the recording medium in time series,
The control means controls the pressurizing means on the basis of the out-of-plane deformation amount stored in the storage means and the out-of-plane deformation amount detected by the out-of-plane deformation detection means. Based on the out-of-plane deformation amount stored in a series, a threshold for the out-of-plane deformation amount at which the occurrence rate of paper wrinkles increases for each type of the recording medium, and when recording paper exceeding the threshold is used A fixing device that performs a notification process for notifying that the probability of occurrence of paper wrinkles is high.

A fixing nip for fixing an unfixed toner image on the recording medium onto the recording medium while conveying the recording medium is formed, and two fixing nip forming members configured to move endlessly, and through the fixing nip A fixing device comprising heating means for applying heat to the recording medium.
Pressurizing means capable of pressurizing at least one of the two fixing nip forming members in two directions, a direction perpendicular to the surface direction of the recording medium and a direction along the surface direction of the recording medium When,
An out-of-plane deformation amount detecting means for detecting an out-of-plane deformation amount deviating from the surface direction of the recording medium passing through the fixing nip;
Storage means for storing an out-of-plane deformation amount of the recording medium;
The out-of-plane deformation detection means detects an out-of-plane deformation amount of the recording medium after passing through the fixing nip,
The control means controls the pressurizing means based on the out-of-plane deformation amount stored in the storage means and the out-of-plane deformation amount detected by the out-of-plane deformation detection means, and the out-of-plane deformation amount. A notification process for determining whether or not the detection result of the detection means has reached the limit out-of-plane deformation amount stored in advance in the storage means, and notifying that a paper wrinkle has occurred when it is determined that the detection result has been reached. A fixing device.

  In the fixing device according to any one of claims 1 to 4,
  The fixing nip forming member is a rotating body that rotates about a rotation axis,
  The fixing device, wherein the pressurizing unit pressurizes in a direction along a surface direction of the recording medium to bend the central portion in the axial direction of the rotating body toward the conveyance direction of the recording medium.

A developing device that visualizes the electrostatic latent image formed on the image carrier as a toner image, a transfer device that transfers the toner image to a transfer material, and an unfixed image on the transfer material is thermally fixed. In an image forming apparatus provided with a fixing device,
An image forming apparatus wherein the fixing device is any one of a fixing device according to claim 1 to 5.