JP5463981B2

JP5463981B2 - Fixing apparatus and image forming apparatus

Info

Publication number: JP5463981B2
Application number: JP2010058695A
Authority: JP
Inventors: 浩松本
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2010-03-16
Filing date: 2010-03-16
Publication date: 2014-04-09
Anticipated expiration: 2030-03-16
Also published as: JP2011191585A

Description

本発明は、定着装置及び画像形成装置に関する。 The present invention relates to a fixing device and an image forming apparatus.

定着装置では、搬送されてきた用紙の定着面及び非定着面の両面から定着ローラを略同時に接触させ、用紙を加熱及び加圧する。これにより、定着面に形成されているトナー画像が用紙に定着する。「定着面」とは、用紙の両面のうち定着時にトナー画像が定着する面をいう。また、「非定着面」とは、用紙の両面のうち「定着面」とは反対の面をいう。
従来、定着ローラが用紙の定着面に接触すると、トナーの一部が定着ローラに融着して用紙が定着ローラに張り付く場合があり、このとき紙詰まりが発生する問題がある。 In the fixing device, the fixing roller is brought into contact with both the fixing surface and the non-fixing surface of the conveyed paper substantially simultaneously to heat and pressurize the paper. As a result, the toner image formed on the fixing surface is fixed on the sheet. “Fixing surface” refers to a surface of a sheet on which a toner image is fixed upon fixing. Further, the “non-fixing surface” refers to the surface opposite to the “fixing surface” of both sides of the sheet.
Conventionally, when the fixing roller comes into contact with the fixing surface of the paper, a part of the toner may be fused to the fixing roller and the paper may stick to the fixing roller. At this time, there is a problem that paper jam occurs.

そこで、用紙と定着ローラとが接触するニップ領域において、定着ローラを通過してきた用紙の定着面に風を吹き付けることにより、定着ローラに張り付いた用紙を定着ローラから分離して紙詰まりを防止し得る定着装置又は画像形成装置が存在する（特許文献１参照）。 Therefore, in the nip area where the paper and the fixing roller are in contact with each other, by blowing air to the fixing surface of the paper that has passed through the fixing roller, the paper stuck to the fixing roller is separated from the fixing roller to prevent paper jamming. There is a fixing device or an image forming apparatus that can be obtained (see Patent Document 1).

特開２００７−２１９４３０号公報JP 2007-219430 A

しかし、特許文献１に記載の定着装置又は画像形成装置では、用紙の定着面に吹き付けた風の影響で、用紙の非定着面に接触する定着ローラに用紙が巻き付いてしまう場合があり、このとき紙詰まりが発生する。 However, in the fixing device or the image forming apparatus described in Patent Document 1, the paper may be wound around the fixing roller that contacts the non-fixing surface of the paper due to the influence of the wind blown on the fixing surface of the paper. A paper jam occurs.

本発明の課題は、用紙の定着面に接触する定着ローラ又は非定着面に接触する定着ローラの何れにも用紙が張り付いたり巻き付いたりしないように用紙に風を吹き付けて、紙詰まりを確実に防止し得る定着装置及び画像形成装置を提供することである。 An object of the present invention is to blow paper on the paper so that the paper does not stick or wrap around either the fixing roller that contacts the fixing surface of the paper or the fixing roller that contacts the non-fixing surface. It is an object of the present invention to provide a fixing device and an image forming apparatus that can be prevented.

本発明によれば、用紙の表裏面のうち、定着時にトナー画像が定着する一方を定着面、他方を非定着面とした場合、定着面及び非定着面の両面を加熱及び加圧することでトナー画像を用紙の定着面に定着させる定着装置において、
前記用紙の定着面を加熱及び加圧する第１の定着ローラと、
前記用紙の非定着面を加熱及び加圧する第２の定着ローラと、
風を発生するとともに、発生した風を前記用紙と前記第１の定着ローラとの接触部近傍において前記第１の定着ローラを通過してきた前記用紙の定着面に吹き付ける第１の送風機構と、
風を発生するとともに、発生した風を前記用紙と前記第２の定着ローラとの接触部近傍において前記第２の定着ローラを通過してきた前記用紙の非定着面に吹き付ける第２の送風機構と、
前記第１の送風機構による前記用紙の定着面に風を吹き付ける制御と、前記第２の送風機構による前記用紙の非定着面に風を吹き付ける制御と、を風の吹付けを異ならせるように個別に制御可能な制御部と、
を備え、
前記第１の送風機構は、前記用紙の非定着面に風が吹き付けられる位置よりも前記用紙の搬送方向上流側で、前記用紙の定着面に風を吹き付け、
前記第２の送風機構は、前記用紙の定着面に風が吹き付けられる位置よりも前記用紙の搬送方向下流側で、前記用紙の非定着面に風を吹き付ける定着装置が提供される。 According to the present invention, when one of the front and back surfaces of the paper on which the toner image is fixed during fixing is a fixing surface and the other is a non-fixing surface, the toner is obtained by heating and pressurizing both the fixing surface and the non-fixing surface. In a fixing device for fixing an image on a fixing surface of a sheet,
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
Thereby generating the wind, the first blowing mechanism attaching can spray the generated wind to the fixing surface of the sheet that has passed through the first fixing roller in the contact vicinity of the said sheet first fixing roller ,
Thereby generating the wind, a second blowing mechanism attaching can spray the generated wind to the non-fixing surface of the sheet that has passed through the second fixing roller in the contact vicinity of the said sheet second fixing roller When,
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
Equipped with a,
The first air blowing mechanism blows air to the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown to the non-fixing surface of the paper.
The second blower mechanism is provided with a fixing device that blows air on the non-fixing surface of the paper at a position downstream of the position where the air is blown on the fixing surface of the paper in the conveyance direction of the paper .

また、本発明によれば、用紙の表裏面のうち、定着時にトナー画像が定着する一方を定着面、他方を非定着面とした場合、定着面及び非定着面の両面を加熱及び加圧することでトナー画像を用紙の定着面に定着させる定着装置を備えた画像形成装置において、
前記用紙の定着面を加熱及び加圧する第１の定着ローラと、
前記用紙の非定着面を加熱及び加圧する第２の定着ローラと、
風を発生するとともに、発生した風を前記用紙と前記第１の定着ローラとの接触部近傍において前記第１の定着ローラを通過してきた前記用紙の定着面に吹き付ける第１の送風部と、
風を発生するとともに、発生した風を前記用紙と前記第２の定着ローラとの接触部近傍において前記第２の定着ローラを通過してきた前記用紙の非定着面に吹き付ける第２の送風部と、
前記第１の送風機構による前記用紙の定着面に風を吹き付ける制御と、前記第２の送風機構による前記用紙の非定着面に風を吹き付ける制御と、を風の吹付けを異ならせるように個別に制御可能な制御部と、
を備え、
前記第１の送風機構は、前記用紙の非定着面に風が吹き付けられる位置よりも前記用紙の搬送方向上流側で、前記用紙の定着面に風を吹き付け、
前記第２の送風機構は、前記用紙の定着面に風が吹き付けられる位置よりも前記用紙の搬送方向下流側で、前記用紙の非定着面に風を吹き付ける画像形成装置が提供される。 Further, according to the present invention, when one of the front and back surfaces of the paper on which the toner image is fixed during fixing is a fixing surface and the other is a non-fixing surface, both the fixing surface and the non-fixing surface are heated and pressed. In the image forming apparatus having a fixing device for fixing the toner image on the fixing surface of the paper with
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
Thereby generating the wind, and a first blower attaching can spray the generated wind to the fixing surface of the sheet that has passed through the first fixing roller in the contact vicinity of the said sheet first fixing roller ,
Thereby generating the wind, a second blower attaching can spray the generated wind to the non-fixing surface of the sheet that has passed through the second fixing roller in the contact vicinity of the said sheet second fixing roller When,
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
Equipped with a,
The first air blowing mechanism blows air to the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown to the non-fixing surface of the paper.
An image forming apparatus is provided in which the second air blowing mechanism blows air to the non-fixing surface of the paper at a downstream side of the paper conveyance direction from a position where air is blown to the fixing surface of the paper .

本発明によれば、用紙の定着面に接触する第１の定着ローラ及び非定着面に接触する第２の定着ローラの何れにも用紙が張り付いたり巻き付いたりしないように用紙に風を吹き付けることができ、紙詰まりを確実に防止することができる。 According to the present invention, the wind is blown to the paper so that the paper does not stick or wrap around either the first fixing roller that contacts the fixing surface of the paper or the second fixing roller that contacts the non-fixing surface. It is possible to reliably prevent paper jams.

画像形成装置の概略構成図である。1 is a schematic configuration diagram of an image forming apparatus. 定着装置の概略構成図である。1 is a schematic configuration diagram of a fixing device. ニップ領域を示す図である。It is a figure which shows a nip area | region. 送風処理を示すフロー図である。It is a flowchart which shows a ventilation process. 実験結果を示す図である。It is a figure which shows an experimental result.

本実施形態における画像形成装置の構成及び動作について、図面を用いて詳細に説明する。なお、本実施形態は一例であり、本発明はこれに限定されるものではない。例えば、本実施形態ではモノクロの画像形成装置を例に挙げて説明しているが、カラーの画像形成装置によっても本発明を実施することは可能である。 The configuration and operation of the image forming apparatus in this embodiment will be described in detail with reference to the drawings. In addition, this embodiment is an example and this invention is not limited to this. For example, in the present embodiment, a monochrome image forming apparatus has been described as an example. However, the present invention can also be implemented by a color image forming apparatus.

図１に、画像形成装置１０の概略構成を示す。
画像形成装置１０は、自動原稿搬送部２０、スキャナ部３０、画像形成部４０、給紙部５０等を備えて構成される。 FIG. 1 shows a schematic configuration of the image forming apparatus 10.
The image forming apparatus 10 includes an automatic document feeder 20, a scanner unit 30, an image forming unit 40, a paper feeding unit 50, and the like.

自動原稿搬送部２０は、原稿載置トレイに置かれた原稿Ｄを一枚ずつ所定の搬送路に搬送する。
スキャナ部３０は、搬送される原稿Ｄに光源を照射し、原稿Ｄから反射される反射光を受光する。スキャナ部３０は、受光した光信号を電気信号（画像データ）に変換し、変換された画像データを画像形成部４０に出力する。 The automatic document conveyance unit 20 conveys the document D placed on the document placement tray one by one to a predetermined conveyance path.
The scanner unit 30 irradiates the conveyed document D with a light source and receives reflected light reflected from the document D. The scanner unit 30 converts the received optical signal into an electrical signal (image data), and outputs the converted image data to the image forming unit 40.

画像形成部４０は、画像データに基づいて感光体ドラム４１にトナー画像を形成し、形成されたトナー画像を用紙Ｐに転写して定着するまでの一連の画像形成動作を行う。 The image forming unit 40 forms a toner image on the photosensitive drum 41 based on the image data, and performs a series of image forming operations until the formed toner image is transferred to the paper P and fixed.

感光体ドラム４１周辺の構成及び動作について、簡潔に説明する。
帯電装置４２は、感光体ドラム４１の表面を均一に帯電する。
露光装置４３は、感光体ドラム４１の非画像領域を露光し、露光した部分の電荷を除去することで画像領域に静電潜像を形成する。
現像装置４４は、静電潜像にトナーを付着させてトナー画像を現像する。
転写装置４５は、用紙Ｐの裏面からトナーとは逆極性の電荷を付加し、静電力により感光体ドラム４１に付着しているトナー画像を用紙Ｐの表面に転写する。 The configuration and operation around the photosensitive drum 41 will be briefly described.
The charging device 42 uniformly charges the surface of the photosensitive drum 41.
The exposure device 43 exposes a non-image area of the photosensitive drum 41 and forms an electrostatic latent image in the image area by removing the charge in the exposed portion.
The developing device 44 develops the toner image by attaching toner to the electrostatic latent image.
The transfer device 45 applies a charge having a polarity opposite to that of the toner from the back surface of the paper P, and transfers the toner image attached to the photosensitive drum 41 to the surface of the paper P by electrostatic force.

分離装置４６は、用紙Ｐの裏面から転写時とは逆極性の電荷を付加し、用紙Ｐと感光体ドラム４１とを分離する。
分離爪４７は、分離装置４６による分離処理後も用紙Ｐと感光体ドラム４１とが分離されない場合、感光体ドラム４１の表面に当接して用紙Ｐと感光体ドラム４１とを分離する。クリーニング装置４８は、用紙Ｐに転写されずに感光体ドラム４１に付着している残留トナーをブラシやブレード等で除去する。 The separation device 46 adds a charge having a polarity opposite to that at the time of transfer from the back surface of the paper P, and separates the paper P and the photosensitive drum 41.
The separation claw 47 contacts the surface of the photosensitive drum 41 to separate the paper P and the photosensitive drum 41 when the paper P and the photosensitive drum 41 are not separated even after the separation processing by the separation device 46. The cleaning device 48 removes residual toner adhering to the photosensitive drum 41 without being transferred to the paper P with a brush or a blade.

定着装置４９は、搬送されてきた用紙Ｐを両面から加熱及び加圧し、用紙Ｐの表面に形成されたトナー画像を定着させる。 The fixing device 49 heats and presses the conveyed paper P from both sides to fix the toner image formed on the surface of the paper P.

これより以下の説明では、トナー画像が定着する用紙Ｐの表面を「定着面」といい、トナー画像が定着しない用紙Ｐの裏面を「非定着面」という。なお、両面印刷の場合は用紙Ｐの両面の何れもトナー画像が定着するが、この場合は定着時を基準として判断する。すなわち、両面印刷又は片面印刷の何れであっても、定着時にトナー画像が定着する面を定着面、定着時にトナー画像が定着しない面を非定着面とする。 In the following description, the surface of the paper P on which the toner image is fixed is referred to as “fixing surface”, and the back surface of the paper P on which the toner image is not fixed is referred to as “non-fixing surface”. In the case of double-sided printing, the toner image is fixed on both sides of the paper P. In this case, the determination is based on the fixing time. In other words, in both duplex printing and simplex printing, a surface on which a toner image is fixed at the time of fixing is a fixing surface, and a surface on which the toner image is not fixed at the time of fixing is a non-fixing surface.

給紙部５０は、トレイに複数種類の用紙Ｐを収容しており、所定の搬送路を介して画像形成部４０に用紙Ｐを給紙する。 The paper feeding unit 50 stores a plurality of types of paper P in a tray, and feeds the paper P to the image forming unit 40 via a predetermined conveyance path.

制御部１は、ＣＰＵ、ＲＡＭ、ＲＯＭ等を備えて構成される。ＣＰＵは、ＲＯＭに記憶されている各種プログラムをＲＡＭに展開し、展開された各種プログラムとの協働により画像形成装置１０の動作を統括的に制御する。本実施形態では特に、定着装置４９の制御について説明する。 The control unit 1 includes a CPU, a RAM, a ROM, and the like. The CPU expands various programs stored in the ROM to the RAM, and comprehensively controls the operation of the image forming apparatus 10 in cooperation with the expanded various programs. In the present embodiment, the control of the fixing device 49 will be described in particular.

図２に、定着装置４９の概略構成を示す。
定着装置４９は、加熱ローラ４９１、第１の定着ローラ４９２、第２の定着ローラ４９３、定着ベルト４９４、第１のファン４９５、第２のファン４９６等を備えて構成される。 FIG. 2 shows a schematic configuration of the fixing device 49.
The fixing device 49 includes a heating roller 491, a first fixing roller 492, a second fixing roller 493, a fixing belt 494, a first fan 495, a second fan 496, and the like.

加熱ローラ４９１は、径＝５２ｍｍ、芯金材質＝アルミニウム、芯金厚み＝３．０ｍｍ、表面材質＝ＰＴＦＥのローラであり、内部に高出力ヒータを備えて構成される。加熱ローラ４９１は、用紙Ｐの搬送向に対して順方向に回転し、定着ベルト４９４を介して第１の定着ローラ４９２を加熱する。 The heating roller 491 is a roller having a diameter = 52 mm, a core metal material = aluminum, a core metal thickness = 3.0 mm, and a surface material = PTFE, and includes a high output heater therein. The heating roller 491 rotates in the forward direction with respect to the conveyance direction of the paper P and heats the first fixing roller 492 via the fixing belt 494.

第１の定着ローラ４９２は、径＝４０ｍｍ、芯金材質＝ＳＵＳ、芯金径＝２５ｍｍ、芯金厚み＝中実、ゴム層厚み＝７．５ｍｍ、ゴム層硬度＝ＪＩＳ−Ａ１０°のローラである。第１の定着ローラ４９２は、用紙Ｐの搬送方向に対して順方向に回転し、搬送されてきた用紙Ｐの定着面を加熱又は加圧する。 The first fixing roller 492 is a roller having a diameter = 40 mm, a core metal material = SUS, a core metal diameter = 25 mm, a core metal thickness = solid, a rubber layer thickness = 7.5 mm, and a rubber layer hardness = JIS-A 10 °. is there. The first fixing roller 492 rotates in the forward direction with respect to the transport direction of the paper P, and heats or presses the fixing surface of the transported paper P.

第２の定着ローラ４９３は、径＝５０ｍｍ、芯金材質＝アルミニウム、芯金厚み＝３．０ｍｍ、ゴム層厚み＝２．０ｍｍ、ゴム層硬度＝ＪＩＳ−Ａ１０°、表層材質＝ＰＦＡのローラであり、内部に高出力ヒータを備えて構成される。第２の定着ローラ４９３は、用紙Ｐの搬送方向に対して順方向に回転し、搬送されてきた用紙Ｐの非定着面を加熱又は加圧する。 The second fixing roller 493 is a roller having a diameter = 50 mm, a core metal material = aluminum, a core metal thickness = 3.0 mm, a rubber layer thickness = 2.0 mm, a rubber layer hardness = JIS-A 10 °, and a surface layer material = PFA. Yes, with a high-power heater inside. The second fixing roller 493 rotates in the forward direction with respect to the transport direction of the paper P, and heats or presses the non-fixing surface of the transported paper P.

定着ベルト４９４は、径＝８０ｍｍ、基材材質＝ＰＩ、基材厚み＝７０μｍ、中間層厚み＝２２０μｍ、中間層強度＝ＪＩＳ−Ａ３０°、表層材質＝ＰＦＡ、表層厚み＝３０μｍのベルトである。定着ベルト４９４は、加熱ローラ４９１及び第１の定着ローラ４９２を連動させて用紙Ｐの搬送方向に対して順方向に回転する。 The fixing belt 494 is a belt having a diameter = 80 mm, a base material = PI, a base material thickness = 70 μm, an intermediate layer thickness = 220 μm, an intermediate layer strength = JIS-A 30 °, a surface layer material = PFA, and a surface layer thickness = 30 μm. The fixing belt 494 rotates in the forward direction with respect to the conveyance direction of the paper P by interlocking the heating roller 491 and the first fixing roller 492.

第１のファン４９５は、径＝６０ｍｍのプロペラ及びモータ等を備えた軸流ファンである。第１のファン４９５は、風の吹き付け位置を正確に定めるダクトＤ１に接続され、用紙Ｐの定着面に風を吹き付ける。風の吹き付け位置、角度、風速及びタイミングが適切な場合、第１のファン４９５は、第１の定着ローラ４９２に張り付いた用紙Ｐを第１の定着ローラ４９２から分離することができる。なお、第１のファン４９５は、軸流ファン以外に送風機構を備えるコンプレッサー等でもよい。 The first fan 495 is an axial fan including a propeller having a diameter = 60 mm, a motor, and the like. The first fan 495 is connected to the duct D1 that accurately determines the wind blowing position, and blows the wind onto the fixing surface of the paper P. When the wind blowing position, angle, wind speed, and timing are appropriate, the first fan 495 can separate the paper P stuck to the first fixing roller 492 from the first fixing roller 492. The first fan 495 may be a compressor provided with a blower mechanism in addition to the axial fan.

第２のファン４９６は、径＝４０ｍｍのプロペラ及びモータ等を備えた軸流ファンである。第２のファン４９６は、風の吹き付け位置を正確に定めるダクトＤ２に接続され、用紙Ｐの非定着面に風を吹き付ける。風の吹き付け位置、角度、風速及びタイミングが適切な場合、第２のファン４９６は、第２の定着ローラ４９３に用紙Ｐが巻き付かないようにすることができる。なお、第２のファン４９６は、軸流ファン以外に送風機構を備えるコンプレッサー等でもよい。 The second fan 496 is an axial fan including a propeller having a diameter = 40 mm, a motor, and the like. The second fan 496 is connected to the duct D <b> 2 that accurately determines the wind blowing position, and blows the wind onto the non-fixing surface of the paper P. When the wind blowing position, angle, wind speed, and timing are appropriate, the second fan 496 can prevent the sheet P from being wound around the second fixing roller 493. The second fan 496 may be a compressor provided with a blower mechanism in addition to the axial fan.

図３に、ニップ領域を示す。
「ニップ領域」とは、用紙Ｐと第１の定着ローラ４９２又は第２の定着ローラ４９３とが接触する領域をいう。
用紙Ｐは、ニップ領域に進入して第１の定着ローラ４９２及び第２の定着ローラ４９３と接触し、接触により加熱及び加圧される。加熱及び加圧されることにより、用紙Ｐの定着面に形成されたトナー画像が用紙Ｐに定着する。 FIG. 3 shows the nip region.
The “nip area” refers to an area where the paper P and the first fixing roller 492 or the second fixing roller 493 are in contact with each other.
The sheet P enters the nip region and comes into contact with the first fixing roller 492 and the second fixing roller 493, and is heated and pressed by the contact. The toner image formed on the fixing surface of the paper P is fixed on the paper P by being heated and pressurized.

ここで、トナー画像が用紙Ｐに定着する際、トナーの一部が第１の定着ローラ４９２に融着する場合がある。このとき、用紙Ｐが第１の定着ローラ４９２に張り付く現象が確認される。第１の定着ローラ４９２に張り付いた用紙Ｐを第１の定着ローラ４９２から分離するため、第１のファン４９５は用紙Ｐの定着面に風を吹き付ける。一方、第１のファン４９５から吹き付けられた風の影響で、用紙Ｐが第２の定着ローラ４９３に巻き付く場合がある。第２の定着ローラ４９３に用紙Ｐが巻き付く現象を回避するため、第２のファン４９６は用紙Ｐの非定着面に風を吹き付ける。
第１のファン４９５又は第２のファン４９６によって吹き付ける風の（１）位置、（２）角度、（３）風速、（４）ＯＮタイミング、については後述する条件を満たすことが必要となる。 Here, when the toner image is fixed on the paper P, a part of the toner may be fused to the first fixing roller 492. At this time, a phenomenon in which the paper P sticks to the first fixing roller 492 is confirmed. The first fan 495 blows air on the fixing surface of the paper P in order to separate the paper P stuck to the first fixing roller 492 from the first fixing roller 492. On the other hand, the paper P may be wound around the second fixing roller 493 due to the influence of the wind blown from the first fan 495. In order to avoid the phenomenon in which the paper P is wound around the second fixing roller 493, the second fan 496 blows air on the non-fixing surface of the paper P.
The (1) position, (2) angle, (3) wind speed, and (4) ON timing of the wind blown by the first fan 495 or the second fan 496 must satisfy the conditions described later.

すなわち、第１のファン４９５によって吹き付ける風の（１）位置ｘ１、（２）角度α、（３）風速Ｗ１、（４）ＯＮタイミングＴ１と、第２のファン４９６によって吹き付ける風の（１）位置ｘ２、（２）角度β、（３）風速Ｗ２、（４）ＯＮタイミングＴ２との関係は、下記式１〜４を満たすことを要する。
ｘ１＜ｘ２・・・（１）
α＜β・・・・・（２）
Ｗ１≧Ｗ２・・・（３）
Ｔ１＜Ｔ２・・・（４） That is, (1) position x1 of wind blown by the first fan 495, (2) angle α, (3) wind speed W1, (4) ON timing T1, and (1) position of wind blown by the second fan 496 The relationship between x2, (2) angle β, (3) wind speed W2, and (4) ON timing T2 needs to satisfy the following expressions 1-4.
x1 <x2 (1)
α <β (2)
W1 ≧ W2 (3)
T1 <T2 (4)

式（１）の位置ｘ１及び位置ｘ２は、風を吹き付ける方向と仮想搬送路とが交差する位置であり、ここでは用紙Ｐの搬送方向を正方向とする。すなわち、式（１）によれば、用紙Ｐの搬送方向において、第１のファン４９５は第２のファン４９６よりも上流側で用紙Ｐの定着面に風を吹き付け、その後に第２のファン４９６が用紙Ｐの非定着面に風を吹き付ける。式（１）を満たさない場合、第１のファン４９５よりも先に第２のファン４９６が用紙Ｐの非定着面に風を吹き付けることになり、用紙Ｐが第１の定着ローラ４９２に張り付いて分離することができなくなる。よって、式（１）を満たす必要がある。
なお、式（１）を満たす場合でも、位置ｘ１又はｘ２が第１の定着ローラ４９２又は第２の定着ローラ４９３に極端に近づきすぎず、離れすぎないことを要する。極端に近づきすぎると、吹き付けた風の影響で第１の定着ローラ４９２又は第２の定着ローラ４９３の温度が低下し、定着性能が低下するためである。また、極端に離れすぎると、吹き付ける風の影響が少なくなり分離性能が低下するためである。 The position x1 and the position x2 in the expression (1) are positions where the wind blowing direction and the virtual transport path intersect, and here, the transport direction of the paper P is a positive direction. That is, according to Expression (1), in the conveyance direction of the sheet P, the first fan 495 blows air on the fixing surface of the sheet P upstream from the second fan 496, and then the second fan 496. Blows wind on the non-fixing surface of the paper P. If the expression (1) is not satisfied, the second fan 496 blows wind on the non-fixing surface of the paper P before the first fan 495, and the paper P sticks to the first fixing roller 492. Cannot be separated. Therefore, it is necessary to satisfy Expression (1).
Even when Expression (1) is satisfied, it is necessary that the position x1 or x2 is not too close to the first fixing roller 492 or the second fixing roller 493 and is not too far away. This is because if the temperature is too close, the temperature of the first fixing roller 492 or the second fixing roller 493 decreases due to the influence of the blown wind, and the fixing performance decreases. Moreover, if it is too far away, the influence of the blowing wind is reduced and the separation performance is lowered.

式（２）の角度α及び角度βは、風を吹き付ける方向と仮想搬送路とのなす角である。すなわち、式（２）によれば、第１のファン４９５は第２のファン４９６よりも鋭角に風を吹き付ける。式（２）は、式（１）を満たすことを前提として、角度について規定したものである。式（２）を満たさない場合、第１のファン４９５よりも先に第２のファン４９６が用紙Ｐの非定着面に風を吹き付けることになり、用紙Ｐが第１の定着ローラ４９２に張り付いて分離することができなくなる。よって、式（２）を満たす必要がある。 The angle α and the angle β in Expression (2) are angles formed by the direction of blowing wind and the virtual transport path. That is, according to Equation (2), the first fan 495 blows wind at an acute angle than the second fan 496. Equation (2) defines the angle on the assumption that equation (1) is satisfied. When the expression (2) is not satisfied, the second fan 496 blows wind on the non-fixing surface of the paper P before the first fan 495, and the paper P sticks to the first fixing roller 492. Cannot be separated. Therefore, it is necessary to satisfy Expression (2).

式（３）の風速Ｗ１及び風速Ｗ２は、第１のファン４９５からの風速をＷ１、第２のファン４９６からの風速をＷ２とし、単位を[ｍ／ｓ]としたものである。式（３）によれば、第１のファン４９５は第２のファン４９６よりも風速を大きくして風を吹き付ける。式（３）を満たさない場合、第１のファン４９５よりも強い力で第２のファン４９６が用紙Ｐの非定着面に風を吹き付けることになり、用紙Ｐが第１の定着ローラ４９２に張り付いて分離することができなくなる。よって、式（３）を満たす必要がある。
なお、風速Ｗ１及びＷ２はプロペラの回転数を上げ下げすることで切り替え可能としてもよいし、ダクトＤ１及びＤ２を伸縮可能な構造にして、ダクトＤ１及びＤ２の先端位置を用紙Ｐに接近させる又は離すことで切り替え可能としてもよい。 The wind speed W1 and the wind speed W2 in the formula (3) are set such that the wind speed from the first fan 495 is W1, the wind speed from the second fan 496 is W2, and the unit is [m / s]. According to Expression (3), the first fan 495 blows wind at a higher wind speed than the second fan 496. If the expression (3) is not satisfied, the second fan 496 blows wind on the non-fixing surface of the paper P with a stronger force than the first fan 495, and the paper P is stretched on the first fixing roller 492. It becomes impossible to separate. Therefore, it is necessary to satisfy Expression (3).
The wind speeds W1 and W2 may be switched by increasing or decreasing the rotation speed of the propeller, or the ducts D1 and D2 are configured to be extendable and the leading ends of the ducts D1 and D2 are brought close to or separated from the paper P. It may be possible to switch.

式（４）のＯＮタイミングＴ１及びＴ２は、第１のファン４９５から風の吹き付けを開始するタイミングをＴ１、第２のファン４９６から風の吹き付けを開始するタイミングをＴ２としたものである。式（４）によれば、第１のファン４９５は第２のファン４９６よりも早いタイミングで用紙Ｐに風を吹き付ける。式（４）を満たさない場合、第１のファン４９５よりも早く第２のファン４９６が用紙Ｐの非定着面に風を吹き付けることになり、用紙Ｐが第１の定着ローラ４９２に張り付いて分離することができなくなる。よって、式（４）を満たす必要がある。
なお、ＯＮタイミングＴとＯＮタイミングＴ２とが略同一であると、定着面及び非定着面から吹き付ける風の影響で用紙Ｐの姿勢が不安定になり画質劣化が発生する場合がある。よって、これを回避するため、式（４）を満たした上で更に、ＯＮタイミングＴ２は用紙Ｐの先端が位置Ｘ２に到達したタイミングであることが好ましい。 In the ON timings T1 and T2 in Expression (4), the timing at which the blowing of wind from the first fan 495 is started is T1, and the timing at which the blowing of wind from the second fan 496 is started is T2. According to Equation (4), the first fan 495 blows wind on the paper P at a timing earlier than that of the second fan 496. When the expression (4) is not satisfied, the second fan 496 blows wind on the non-fixing surface of the paper P earlier than the first fan 495, and the paper P sticks to the first fixing roller 492. It becomes impossible to separate. Therefore, it is necessary to satisfy Expression (4).
If the ON timing T and the ON timing T2 are substantially the same, the posture of the paper P may become unstable due to the wind blown from the fixing surface and the non-fixing surface, and image quality degradation may occur. Therefore, in order to avoid this, it is preferable that the ON timing T2 is a timing at which the leading edge of the paper P reaches the position X2 after satisfying the expression (4).

図４を参照して、送風処理について説明する。
送風処理により、用紙Ｐが第１の定着ローラ４９２に張り付いたり、又は用紙Ｐが第２の定着ローラ４９３に巻き付いたりすることを回避することができる。
なお、本処理開始の前提として、プリントジョブ実行を指示する指示信号が制御部１に出力されたものとする。プリントジョブ実行を指示する指示信号は、例えば図示しない操作部のプリント実行ボタンが押下された場合、或いは外部端末からプリント実行ボタンが押下された場合に制御部１に出力される。 With reference to FIG. 4, the air blowing process will be described.
By the blowing process, it is possible to avoid the sheet P from sticking to the first fixing roller 492 or the sheet P from being wound around the second fixing roller 493.
It is assumed that an instruction signal for instructing execution of a print job is output to the control unit 1 as a premise for starting this processing. An instruction signal instructing execution of a print job is output to the control unit 1 when, for example, a print execution button of an operation unit (not shown) is pressed or when a print execution button is pressed from an external terminal.

制御部１は、プリントジョブ実行を指示する指示信号を入力すると、用紙Ｐを定着装置４９に通紙する際の通紙条件を決定する（ステップＳ１）。
「通紙条件」とは、紙情報、環境情報、画像情報を含むものである。 When an instruction signal for instructing execution of a print job is input, the control unit 1 determines a sheet passing condition for passing the sheet P to the fixing device 49 (step S1).
“Paper passing conditions” include paper information, environmental information, and image information.

「紙情報」とは、紙質や種類に関する情報であって、例えば厚紙／薄紙、コート紙／一般紙等の情報である。なお、薄紙の方が厚紙よりも剛度が低いため第１の定着ローラ４９２に張り付き易い。よって、例えば用紙Ｐが薄紙の場合、制御部１は第１のファン４９５を動作して用紙Ｐの定着面に風を吹き付け、用紙Ｐが第１の定着ローラ４９２に張り付くことを防止する制御を行うことになる。 “Paper information” is information relating to paper quality and type, for example, information on thick paper / thin paper, coated paper / general paper, and the like. Note that the thin paper has a lower rigidity than the thick paper, and thus is more likely to stick to the first fixing roller 492. Therefore, for example, when the paper P is thin paper, the control unit 1 operates the first fan 495 to blow air on the fixing surface of the paper P, and performs control to prevent the paper P from sticking to the first fixing roller 492. Will do.

「環境情報」とは、画像形成装置１０の設置場所周辺の温度又は湿度に関する情報である。なお、低温低湿の場合、用紙Ｐの内部に含まれる水分は枯渇しており用紙Ｐは乾燥する。乾燥した用紙Ｐの剛度は高いため、第１の定着ローラ４９２に張り付き難い。一方、高温多湿の場合は用紙Ｐの内部に含まれる水分が多い。水分が多くて湿気た用紙Ｐの剛度は低いため、用紙Ｐが第１の定着ローラ４９２に張り付き易い。よって、例えば低温多湿の場合、制御部１は第１のファン４９５を動作して用紙Ｐの定着面に風を吹き付け、用紙Ｐが第１の定着ローラ４９２に張り付くことを防止する制御を行うことになる。 “Environmental information” is information relating to the temperature or humidity around the installation location of the image forming apparatus 10. In the case of low temperature and low humidity, the water contained in the paper P is depleted and the paper P is dried. Since the rigidity of the dried paper P is high, it is difficult to stick to the first fixing roller 492. On the other hand, in the case of high temperature and humidity, the moisture contained in the paper P is large. Since the moisture and moisture of the paper P is low in rigidity, the paper P tends to stick to the first fixing roller 492. Therefore, for example, in the case of low temperature and high humidity, the control unit 1 operates the first fan 495 to blow air on the fixing surface of the paper P, and performs control to prevent the paper P from sticking to the first fixing roller 492. become.

「画像情報」とは、画像パターン、トナー付着量、先端余白量に関する情報である。
例えば「画像パターン」がいわゆるベタ画像である場合、第１の定着ローラ４９２に融着するトナー量が多いため、用紙Ｐは第１の定着ローラ４９２に張り付き易い。
また、「トナー付着量」が多い場合、第１の定着ローラ４９２に融着するトナー量が多いため、用紙Ｐは第１の定着ローラ４９２に張り付き易い。なお、モノクロの画像形成装置１０よりもカラーの画像形成装置の場合に、複数色（ＹＭＣＫ色）のトナー画像が何層にも渡って形成されるため、「トナー付着量」が多くなる。
また、「先端余白量」が少ない場合、用紙Ｐの先端には一定量のトナーが存在することを意味し、第１の定着ローラ４９２に張り付いた用紙Ｐを分離し難い。
よって、例えばベタ画像の場合であり、トナー付着量が多い場合であり、更には先端余白量が少ない場合、制御部１は第１のファン４９５を動作して用紙Ｐの定着面に風を吹き付け、用紙Ｐが第１の定着ローラ４９２に張り付くことを防止する制御を行うことになる。 “Image information” is information relating to the image pattern, the toner adhesion amount, and the leading edge margin amount.
For example, when the “image pattern” is a so-called solid image, the amount of toner fused to the first fixing roller 492 is large, and thus the paper P is likely to stick to the first fixing roller 492.
Further, when the “toner adhesion amount” is large, the amount of toner fused to the first fixing roller 492 is large, and thus the sheet P is likely to stick to the first fixing roller 492. In the case of a color image forming apparatus as compared with the monochrome image forming apparatus 10, the toner image of a plurality of colors (YMCK colors) is formed in multiple layers, and thus the “toner adhesion amount” increases.
Further, when the “leading margin amount” is small, it means that a certain amount of toner is present at the leading edge of the paper P, and it is difficult to separate the paper P stuck to the first fixing roller 492.
Therefore, for example, in the case of a solid image, when the toner adhesion amount is large, and when the leading edge margin amount is small, the control unit 1 operates the first fan 495 to blow air on the fixing surface of the paper P. Then, control is performed to prevent the paper P from sticking to the first fixing roller 492.

制御部１は、決定された通紙条件に基づいて、エア分離が必要か否か判断する（ステップＳ２）。
「エア分離」とは、定着ローラに用紙が張り付いたり巻き付いたりすることを回避するため、或いは張り付いたり巻き付いたりした用紙を定着ローラから分離するために、用紙に風を吹き付けることをいう。本実施形態では、第１のファン４９５から用紙Ｐの定着面に風を吹き付けることをいい、これに伴い第２のファン４９６から用紙Ｐの非定着面に風を吹き付けることをいう。なお、エア分離が行われる際の第１のファン４９５及び第２のファン４９６の設置関係、及び、第１のファン４９５及び第２のファン４９６に対する制御部１の制御は、上記式（１）〜（４）を満たすものとする。 The control unit 1 determines whether air separation is necessary based on the determined sheet passing condition (step S2).
“Air separation” refers to blowing air on a sheet in order to prevent the sheet from sticking or wrapping around the fixing roller, or to separate the sheet stuck or wound from the fixing roller. In this embodiment, it means that air is blown from the first fan 495 to the fixing surface of the paper P, and accordingly, air is blown from the second fan 496 to the non-fixing surface of the paper P. The installation relationship of the first fan 495 and the second fan 496 when air separation is performed, and the control of the control unit 1 with respect to the first fan 495 and the second fan 496 are expressed by the above equation (1). It shall satisfy (4).

エア分離が必要ない場合（ステップＳ２；Ｎ）、制御部１は、第１のファン４９５又は第２のファン４９６を動作させず、送風処理を終了する。
「エア分離が必要ない場合」とは、例えば通紙条件において用紙Ｐが厚紙であり、環境が低温低湿であり、定着面に形成されたトナー画像がいわゆるベタ画像でもない場合である。 When air separation is not necessary (step S2; N), the control unit 1 does not operate the first fan 495 or the second fan 496 and ends the blowing process.
The “case where air separation is not required” is, for example, the case where the paper P is thick paper under the paper passing condition, the environment is low temperature and low humidity, and the toner image formed on the fixing surface is not a so-called solid image.

エア分離が必要な場合（ステップＳ２；Ｙ）、制御部１は、決定された通紙条件に基づいて、エア分離を行う（ステップＳ３）。
「エア分離が必要な場合」とは、例えば通紙条件において用紙Ｐが薄紙であり、環境が高温高湿であり、定着面に形成されたトナー画像がいわゆるベタ画像の場合である。 When air separation is required (step S2; Y), the control unit 1 performs air separation based on the determined sheet passing condition (step S3).
The “case where air separation is required” is, for example, the case where the paper P is thin paper under the paper passing condition, the environment is high temperature and high humidity, and the toner image formed on the fixing surface is a so-called solid image.

エア分離が必要な場合において、例えば通紙条件が薄紙、高温高湿、ベタ画像の全てを満たす場合、用紙Ｐが第１の定着ローラ４９２に特に張り付き易く用紙Ｐを第１の定着ローラ４９２から特に分離し難いため、エア分離の必要性が大きい。この場合、エア分離における風速Ｗ１を大きくし、例えば風速Ｗ１＝１５ｍ／ｓとする。一方、通紙条件が薄紙、高温高湿、ベタ画像のうち、薄紙のみを満たす場合、エア分離は必要であるが分離はし易い。よって、この場合、エア分離における風速Ｗ１を最小限にし、例えば風速Ｗ１＝５ｍ／ｓとする。不要な量の風を吹き付けないようにすることで、第１の定着ローラ４９２又は第２の定着ローラ４９３の温度を高温のまま維持することができ、定着性能の低下を回避することができる。 When air separation is necessary, for example, when the sheet passing condition satisfies all of thin paper, high temperature and high humidity, and a solid image, the paper P is particularly easily stuck to the first fixing roller 492, and the paper P is removed from the first fixing roller 492. Since separation is particularly difficult, there is a great need for air separation. In this case, the wind speed W1 in the air separation is increased, for example, the wind speed W1 = 15 m / s. On the other hand, when the paper passing condition satisfies only thin paper among thin paper, high temperature and high humidity, and solid images, air separation is necessary, but separation is easy. Therefore, in this case, the wind speed W1 in the air separation is minimized, for example, the wind speed W1 = 5 m / s. By preventing an unnecessary amount of wind from being blown, the temperature of the first fixing roller 492 or the second fixing roller 493 can be maintained at a high temperature, and a decrease in fixing performance can be avoided.

制御部１は、一定時間経過後、或いは画像形成終了時に、第１のファン４９５及び第２のファン４９６を停止して（ステップＳ４）、送風処理を終了する。 The control unit 1 stops the first fan 495 and the second fan 496 after a predetermined time has elapsed or at the end of image formation (step S4), and ends the blowing process.

図５に、実験結果を示す。
実験は、複数種類の用紙を用いて画像形成を行い、画像形成中において第１の定着ローラ４９２又は第２の定着ローラ４９３に用紙が張り付いたり巻き付いたりしないか否かを画像形成に用いた用紙の種類ごとに目視確認することで行った（実施例１）。本実験により、第１のファン４９５又は第２のファン４９６の分離性能を確認することができる。用紙の種類には、８５ｇｓｍのコート紙、１０５ｇｓｍのコート紙、１２６ｇｓｍのコート紙、６４ｇｓｍの一般紙を用いた。なお、「ｇｓｍ」とは、グラムパースクエアメートルの略であり、坪量を意味する。 FIG. 5 shows the experimental results.
In the experiment, image formation was performed using a plurality of types of paper, and whether or not the paper was stuck or wound around the first fixing roller 492 or the second fixing roller 493 during image formation was used for image formation. This was done by visually checking each type of paper (Example 1). By this experiment, the separation performance of the first fan 495 or the second fan 496 can be confirmed. As the paper type, 85 gsm coated paper, 105 gsm coated paper, 126 gsm coated paper, and 64 gsm general paper were used. Note that “gsm” is an abbreviation for Gram per Square Meter and means basis weight.

また、比較のため、第１のファン４９５及び第２のファン４９６のうち、第１のファン４９５のみを備えた定着装置（比較例１）及び第２のファン４９６のみを備えた定着装置（比較例２）を構成要素とする画像形成装置についても同様の実験を行った。比較例１においては、風速Ｗ１をＷ１＝１５ｍ／ｓ又は１０ｍ／ｓと切り替えて実験を行った。
まず、実施例１について説明する。
〔実施例１〕 For comparison, of the first fan 495 and the second fan 496, the fixing device including only the first fan 495 (Comparative Example 1) and the fixing device including only the second fan 496 (Comparison) A similar experiment was conducted on an image forming apparatus having Example 2) as a constituent element. In Comparative Example 1, the experiment was performed by switching the wind speed W1 to W1 = 15 m / s or 10 m / s.
First, Example 1 will be described.
[Example 1]

実施例１では、本実施形態に係る定着装置４９を備えた画像形成装置１０を用いて実験を行った。すなわち、実施例１では、第１のファン４９５及び第２のファン４９６の両方で用紙に風を吹き付けた。
実施例１によれば、第１の定着ローラ４９２又は第２の定着ローラ４９３の何れのローラにも用紙は張り付かず、巻き付かないことが確認された（評価：〇）。
〔比較例１〕 In Example 1, an experiment was performed using the image forming apparatus 10 including the fixing device 49 according to the present embodiment. That is, in Example 1, wind was blown to the paper by both the first fan 495 and the second fan 496.
According to Example 1, it was confirmed that the paper did not stick to any of the first fixing roller 492 or the second fixing roller 493 and was not wound (evaluation: ◯).
[Comparative Example 1]

比較例１では、第１のファン４９５及び第２のファン４９６のうち、第１のファン４９５のみを備えた定着装置を構成要素とする画像形成装置を用いて実験を行った。
比較例１によれば、ある程度剛度の高い１０５ｇｓｍのコート紙や１２６ｇｓｍのコート紙を用いて画像形成を行った場合、第１の定着ローラ４９２又は第２の定着ローラ４９３の何れのローラにも用紙は張り付かず、巻き付かないことが確認された（評価：〇）。 In Comparative Example 1, an experiment was performed using an image forming apparatus including a fixing device including only the first fan 495 as a component, out of the first fan 495 and the second fan 496.
According to the first comparative example, when image formation is performed using 105 gsm coated paper or 126 gsm coated paper having a certain degree of rigidity, the paper is placed on either the first fixing roller 492 or the second fixing roller 493. It was confirmed that no sticking and no winding (evaluation: ○).

しかし、剛度の低い８５ｇｓｍのコート紙や６４ｇｓｍの一般紙を用いて画像形成を行った場合、第１の定着ローラ４９２又は第２の定着ローラ４９３の何れかに用紙が張り付いたり巻き付いたりした（評価：×）。
具体的には、風速Ｗ１＝１５ｍ／ｓの場合、８５ｇｓｍのコート紙や６４ｇｓｍの一般紙を第１の定着ローラ４９２から分離することはできるが（評価：〇）、吹き付けた風の影響で第２の定着ローラ４９３に巻き付いた（評価：×）。
一方、風速Ｗ１＝１０ｍ／ｓの場合、８５ｇｓｍのコート紙や６４ｇｓｍの一般紙を第１の定着ローラ４９２から分離することができず張り付いた（評価：×）。
〔比較例２〕 However, when image formation was performed using a low-stiffness 85 gsm coated paper or 64 gsm ordinary paper, the paper stuck or wrapped around either the first fixing roller 492 or the second fixing roller 493 ( Evaluation: x).
Specifically, when the wind speed W1 = 15 m / s, it is possible to separate 85 gsm coated paper or 64 gsm general paper from the first fixing roller 492 (evaluation: ◯), but the effect of the blown wind No. 2 was wound around the fixing roller 493 (evaluation: x).
On the other hand, when the wind speed W1 = 10 m / s, the 85 gsm coated paper or the 64 gsm general paper could not be separated from the first fixing roller 492 (evaluation: x).
[Comparative Example 2]

比較例２では、第１のファン４９５及び第２のファン４９６のうち、第２のファン４９６のみを備えた定着装置を構成要素とする画像形成装置を用いて実験を行った。
比較例２によれば、剛度の高い１２６ｇｓｍのコート紙を用いて画像形成を行った場合、第１の定着ローラ４９２又は第２の定着ローラ４９３の何れのローラにも用紙は張り付かず、巻き付かないことが確認された（評価：〇）。
しかし、剛度の低い８５ｇｓｍのコート紙や６４ｇｓｍの一般紙、ある程度剛度の高い１０５ｇｓｍのコート紙を用いて画像形成を行った場合、第１の定着ローラ４９２に用紙が張り付いた（評価：×）。 In Comparative Example 2, an experiment was performed using an image forming apparatus including a fixing device including only the second fan 496 among the first fan 495 and the second fan 496.
According to Comparative Example 2, when image formation is performed using 126 gsm coated paper having high rigidity, the sheet does not stick to either the first fixing roller 492 or the second fixing roller 493, and is wound. It was confirmed that it was not attached (evaluation: ○).
However, when image formation was performed using 85 gsm coated paper having low rigidity, 64 gsm general paper, or 105 gsm coated paper having a certain degree of rigidity, the paper stuck to the first fixing roller 492 (evaluation: x). .

以上のように、本実施形態によれば、ニップ領域において用紙Ｐの定着面及び非定着面の両面から風を吹き付けることができる。よって、第１の定着ローラ４９２に用紙Ｐが張り付いたり、又は第２の定着ローラ４９３に用紙Ｐが巻き付いたりすることを回避することができ、紙詰まりを確実に防止することができる。 As described above, according to the present embodiment, wind can be blown from both the fixing surface and the non-fixing surface of the paper P in the nip region. Therefore, it is possible to avoid the sheet P from sticking to the first fixing roller 492 or the sheet P from being wound around the second fixing roller 493, and it is possible to reliably prevent a paper jam.

また、第１のファン４９５は、第２のファン４９６よりも用紙搬送方向上流側で用紙Ｐの定着面に風を吹き付けることができる（式１参照）。よって、第１の定着ローラ４９２に用紙Ｐが張り付くことを回避しつつ、第２の定着ローラ４９３に用紙Ｐが巻き付くことを回避することができ、紙詰まりの発生を確実に防止することができる。 Further, the first fan 495 can blow air on the fixing surface of the paper P on the upstream side of the second fan 496 in the paper transport direction (see Formula 1). Therefore, it is possible to avoid the paper P from being wrapped around the second fixing roller 493 while avoiding the paper P from sticking to the first fixing roller 492, and to reliably prevent the occurrence of a paper jam. it can.

また、第１のファン４９５は、第２のファン４９６よりも鋭角に用紙Ｐの定着面に風を吹き付けることができる（式２参照）。よって、第１の定着ローラ４９２に用紙Ｐが張り付くことを回避しつつ、第２の定着ローラ４９３に用紙Ｐが巻き付くことを回避することができ、紙詰まりの発生を確実に防止することができる。 Further, the first fan 495 can blow air toward the fixing surface of the paper P at an acute angle than the second fan 496 (see Formula 2). Therefore, it is possible to avoid the paper P from being wrapped around the second fixing roller 493 while avoiding the paper P from sticking to the first fixing roller 492, and to reliably prevent the occurrence of a paper jam. it can.

また、第１のファン４９５は、第２のファン４９６よりも風速を大きくして用紙Ｐの定着面に風を吹き付けることができる（式３参照）。よって、第１の定着ローラ４９２に用紙Ｐが張り付くことを回避しつつ、第２の定着ローラ４９３に用紙Ｐが巻き付くことを回避することができ、紙詰まりの発生を確実に防止することができる。 In addition, the first fan 495 can blow wind toward the fixing surface of the paper P at a higher wind speed than the second fan 496 (see Formula 3). Therefore, it is possible to avoid the paper P from being wrapped around the second fixing roller 493 while avoiding the paper P from sticking to the first fixing roller 492, and to reliably prevent the occurrence of a paper jam. it can.

また、第１のファン４９５は、第２のファン４９６よりも先に用紙Ｐの定着面に風を吹き付けることができる（式４参照）。よって、第１の定着ローラ４９２に用紙Ｐが張り付くことを回避しつつ、第２の定着ローラ４９３に用紙Ｐが巻き付くことを回避することができ、紙詰まりの発生を確実に防止することができる。 Further, the first fan 495 can blow wind on the fixing surface of the paper P prior to the second fan 496 (see Formula 4). Therefore, it is possible to avoid the paper P from being wrapped around the second fixing roller 493 while avoiding the paper P from sticking to the first fixing roller 492, and to reliably prevent the occurrence of a paper jam. it can.

また、通紙条件に基づいて、用紙Ｐの定着面又は非定着面に吹き付ける風の風速を切り替えることができる。不要な量の風を吹き付けないため、定着装置４９の温度を高温のまま維持し、定着性能を維持することができる。 Further, the wind speed of the wind blown on the fixing surface or the non-fixing surface of the paper P can be switched based on the sheet passing condition. Since an unnecessary amount of wind is not blown, it is possible to maintain the fixing device 49 at a high temperature and maintain the fixing performance.

１０画像形成装置
２０自動原稿搬送部
３０スキャナ部
４０画像形成部
４９定着装置
４９１加熱ローラ
４９２第１の定着ローラ
４９３第２の定着ローラ
４９４定着ベルト
４９５第１のファン
４９６第２のファン
５０給紙部
１制御部 DESCRIPTION OF SYMBOLS 10 Image forming apparatus 20 Automatic document conveyance part 30 Scanner part 40 Image forming part 49 Fixing apparatus 491 Heating roller 492 First fixing roller 493 Second fixing roller 494 Fixing belt 495 First fan 496 Second fan 50 Paper feeding Part 1 Control part

Claims

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
Thereby generating the wind, the first blowing mechanism attaching can spray the generated wind to the fixing surface of the sheet that has passed through the first fixing roller in the contact vicinity of the said sheet first fixing roller ,
Thereby generating the wind, a second blowing mechanism attaching can spray the generated wind to the non-fixing surface of the sheet that has passed through the second fixing roller in the contact vicinity of the said sheet second fixing roller When,
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
Equipped with a,
The first air blowing mechanism blows air to the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown to the non-fixing surface of the paper.
The second blower mechanism is a fixing device that blows air to the non-fixing surface of the paper at a downstream side of the paper conveyance direction from a position where the air is blown to the fixing surface of the paper.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first blowing mechanism that generates wind and blows the generated wind on the fixing surface of the sheet that has passed through the first fixing roller in the vicinity of a contact portion between the sheet and the first fixing roller;
A second air blowing mechanism that generates wind and blows the generated wind on a non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of a contact portion between the paper and the second fixing roller;
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
With
The first blowing mechanism includes a direction in which wind is blown to the fixing surface of the paper and a conveyance direction of the paper, compared to an angle formed by a direction in which wind is blown on the non-fixing surface of the paper and a conveyance direction of the paper. Blow the wind on the fixing surface of the paper so that the angle formed by
The second air blowing mechanism includes a direction in which wind is blown to the non-fixing surface of the paper and a conveyance direction of the paper from an angle formed by a direction in which wind is blown on the fixing surface of the paper and a conveyance direction of the paper. A fixing device that blows wind on the non-fixing surface of the paper so that the angle formed by the paper becomes larger.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first blowing mechanism that generates wind and blows the generated wind on the fixing surface of the sheet that has passed through the first fixing roller in the vicinity of a contact portion between the sheet and the first fixing roller;
A second air blowing mechanism that generates wind and blows the generated wind on a non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of a contact portion between the paper and the second fixing roller;
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
With
The control unit controls the first air blowing mechanism or the second air blowing mechanism so that the wind speed blown to the fixing surface of the paper is larger than the wind speed blown to the non-fixing surface of the paper. Fixing device to perform.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first blowing mechanism that generates wind and blows the generated wind on the fixing surface of the sheet that has passed through the first fixing roller in the vicinity of a contact portion between the sheet and the first fixing roller;
A second air blowing mechanism that generates wind and blows the generated wind on a non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of a contact portion between the paper and the second fixing roller;
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
With
The control unit is configured so that the timing at which the wind is blown to the fixing surface of the paper is earlier than the timing at which the wind is blown to the non-fixing surface of the paper. A fixing device that controls the air blowing mechanism.

The controller controls the air blown by the first blower mechanism or the second blower mechanism based on any or all of the information on the paper stiffness, environment, image pattern, toner adhesion amount, or leading edge margin amount. The fixing device according to any one of claims 1 to 4, which controls the wind speed.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In an image forming apparatus provided with a fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing section that generates wind and blows the generated wind on the fixing surface of the sheet that has passed through the first fixing roller in the vicinity of the contact portion between the sheet and the first fixing roller;
A second air blowing section for generating wind and blowing the generated wind on the non-fixing surface of the sheet that has passed through the second fixing roller in the vicinity of the contact portion between the sheet and the second fixing roller;
The control of blowing air to the fixing surface of the paper by the first air blowing mechanism and the control of blowing air to the non-fixing surface of the paper by the second air blowing mechanism are individually performed so that the wind blowing is different. A controllable control unit,
With
The first air blowing mechanism blows air to the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown to the non-fixing surface of the paper.
The image forming apparatus in which the second air blowing mechanism blows air to the non-fixing surface of the paper at a downstream side of the paper conveyance direction from a position where the air is blown to the fixing surface of the paper.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing unit that blows air on a fixing surface of the paper that has passed through the first fixing roller in the vicinity of a contact portion between the paper and the first fixing roller;
A second air blower that blows air on the non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of the contact portion between the paper and the second fixing roller;
A control unit that performs control to blow air on the fixing surface of the paper by the first air blowing unit, and performs control to blow air on the non-fixing surface of the paper by the second air blowing unit;
With
The first air blowing unit blows air on the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown on the non-fixing surface of the paper.
The second air blower is a fixing device that blows air to the non-fixing surface of the paper at a downstream side of the paper conveyance direction from a position where air is blown to the fixing surface of the paper.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing unit that blows air on a fixing surface of the paper that has passed through the first fixing roller in the vicinity of a contact portion between the paper and the first fixing roller;
A second air blower that blows air on the non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of the contact portion between the paper and the second fixing roller;
A control unit that performs control to blow air on the fixing surface of the paper by the first air blowing unit, and performs control to blow air on the non-fixing surface of the paper by the second air blowing unit;
With
The first air blower includes a direction in which wind is blown to the fixing surface of the paper and a direction in which the paper is transported than an angle formed by a direction in which wind is blown on the non-fixing surface of the paper and a transport direction of the paper. Blow the wind on the fixing surface of the paper so that the angle formed by
The second air blowing unit includes a direction in which wind is blown to the non-fixing surface of the paper and a conveyance direction of the paper, with respect to an angle between a direction in which wind is blown on the fixing surface of the paper and a conveyance direction of the paper. A fixing device that blows wind on the non-fixing surface of the paper so that the angle formed by the paper becomes larger.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing unit that blows air on a fixing surface of the paper that has passed through the first fixing roller in the vicinity of a contact portion between the paper and the first fixing roller;
A second air blower that blows air on the non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of the contact portion between the paper and the second fixing roller;
A control unit that performs control to blow air on the fixing surface of the paper by the first air blowing unit, and performs control to blow air on the non-fixing surface of the paper by the second air blowing unit;
With
The control unit controls the first air blowing unit or the second air blowing unit so that the wind speed blown to the fixing surface of the paper is higher than the wind speed blown to the non-fixing surface of the paper. Fixing device to perform.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In the fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing unit that blows air on a fixing surface of the paper that has passed through the first fixing roller in the vicinity of a contact portion between the paper and the first fixing roller;
A second air blower that blows air on the non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of the contact portion between the paper and the second fixing roller;
A control unit that performs control to blow air on the fixing surface of the paper by the first air blowing unit, and performs control to blow air on the non-fixing surface of the paper by the second air blowing unit;
With
The control unit is configured so that the timing at which wind is blown to the fixing surface of the paper is earlier than the timing at which wind is blown to the non-fixing surface of the paper. Fixing device that controls the unit.

The controller controls the air blown by the first blower mechanism or the second blower mechanism based on any or all of the information on the paper stiffness, environment, image pattern, toner adhesion amount, or leading edge margin amount. The fixing device according to any one of claims 7 to 10, which controls a wind speed of the air.

Of the front and back sides of the paper, if one of the front and back surfaces of the paper to which the toner image is fixed is the fixing surface and the other is the non-fixing surface, the toner image is fixed to the paper by heating and pressing both the fixing surface and the non-fixing surface. In an image forming apparatus provided with a fixing device for fixing to
A first fixing roller for heating and pressing the fixing surface of the paper;
A second fixing roller for heating and pressing the non-fixing surface of the paper;
A first air blowing unit that blows air on a fixing surface of the paper that has passed through the first fixing roller in the vicinity of a contact portion between the paper and the first fixing roller;
A second air blower that blows air on the non-fixing surface of the paper that has passed through the second fixing roller in the vicinity of the contact portion between the paper and the second fixing roller;
A control unit that performs control to blow air on the fixing surface of the paper by the first air blowing unit, and performs control to blow air on the non-fixing surface of the paper by the second air blowing unit;
With
The first air blowing unit blows air on the fixing surface of the paper on the upstream side in the transport direction of the paper from a position where air is blown on the non-fixing surface of the paper.
The second air blower is an image forming apparatus that blows wind on the non-fixing surface of the paper at a position downstream of the position where the wind is blown on the fixing surface of the paper in the conveyance direction of the paper.