JP3478251B2 - Fixing device - Google Patents
Fixing deviceInfo
- Publication number
- JP3478251B2 JP3478251B2 JP2000194184A JP2000194184A JP3478251B2 JP 3478251 B2 JP3478251 B2 JP 3478251B2 JP 2000194184 A JP2000194184 A JP 2000194184A JP 2000194184 A JP2000194184 A JP 2000194184A JP 3478251 B2 JP3478251 B2 JP 3478251B2
- Authority
- JP
- Japan
- Prior art keywords
- heating
- roller
- temperature
- fixing
- toner
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Fixing For Electrophotography (AREA)
- General Induction Heating (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、複写機やファクシ
ミリ、プリンタなどの静電記録式画像形成装置に使用さ
れる定着装置に関し、より具体的には電磁誘導加熱方式
の定着装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an electrostatic recording type image forming apparatus such as a copying machine, a facsimile or a printer, and more specifically to an electromagnetic induction heating type fixing device. .
【０００２】[0002]
【従来の技術】プリンタ、複写機、ファクシミリなどの
画像形成装置に対し、近年、省エネルギー化および高速
化についての市場要求が強くなってきている。そして、
これらの要求性能を達成するためには、画像形成装置に
用いられる定着装置の熱効率の改善が重要である。2. Description of the Related Art In recent years, market demands for energy saving and high speed have been strong for image forming apparatuses such as printers, copying machines and facsimiles. And
In order to achieve these required performances, it is important to improve the thermal efficiency of the fixing device used in the image forming apparatus.
【０００３】ここで、電子写真記録、静電記録、磁気記
録等の適宜の画像形成プロセス手段により転写（間接）
方式もしくは直接方式により形成された未定着トナー画
像を記録材シート、印刷紙、感光紙、静電記録紙などの
記録材に定着させるための定着装置として、熱ローラ方
式、フィルム加熱方式、電磁誘導加熱方式等の接触加熱
方式の定着装置が広く採用されている。Here, transfer (indirect) by an appropriate image forming process means such as electrophotographic recording, electrostatic recording and magnetic recording.
As a fixing device for fixing an unfixed toner image formed by a direct method or a direct method to a recording material such as recording material sheet, printing paper, photosensitive paper, electrostatic recording paper, a heat roller method, a film heating method, an electromagnetic induction A contact heating type fixing device such as a heating type has been widely adopted.
【０００４】熱ローラ方式の定着装置は、内部にハロゲ
ンランプ等の熱源を有し、所定の温度に温調される定着
ローラと、これに圧接させた加圧ローラとの回転ローラ
対を基本構成としており、これらの回転ローラ対の接触
部いわゆる定着ニップ部に記録材を導入して挟持搬送さ
せ、定着ローラおよび加圧ローラからの熱および圧力に
より未定着トナー画像を溶融させて定着させるものであ
る。The heat roller type fixing device has a heat roller such as a halogen lamp inside and a rotary roller pair consisting of a fixing roller which is temperature-controlled to a predetermined temperature and a pressure roller pressed against the fixing roller. The recording material is introduced into the contact portion of these rotating roller pairs, the so-called fixing nip portion, and is nipped and conveyed, and the unfixed toner image is fused and fixed by heat and pressure from the fixing roller and the pressure roller. is there.
【０００５】また、フィルム加熱方式の定着装置は、た
とえば特開昭６３−３１３１８２号公報や特開平１−２
６３６７９号公報等に提案されている。Further, a film heating type fixing device is disclosed in, for example, JP-A-63-313182 and JP-A-1-2.
It is proposed in Japanese Patent No. 63679.
【０００６】この装置は、支持部材に固定支持させた加
熱体に耐熱性を有した薄肉の定着フィルムを介して記録
材を密着させ、定着フィルムを加熱体に対して摺動移動
させながら加熱体の有する熱をフィルム材を介して記録
材に供給するものである。この定着装置においては、加
熱体として、例えば、耐熱性、絶縁性、良熱伝導性等の
特性を有するアルミナ（Ａｌ2Ｏ3）や窒化アルミニウム
（ＡｌＮ）等のセラミック基板と、通電により発熱する
抵抗層をこの基板上に備えた構成を基本とするセラミッ
クヒータを、定着フィルムとして薄膜で低熱容量のもの
を用いることができるために、熱ローラ方式の定着装置
よりも伝熱効率が高く、ウォームアップ時間の短縮が図
れ、クイックスタート化や省エネルギー化が可能にな
る。In this apparatus, a recording material is brought into close contact with a heating member fixedly supported by a supporting member through a thin heat-resistant fixing film, and the fixing film is slidably moved with respect to the heating member. The heat of the above is supplied to the recording material through the film material. In this fixing device, as a heating body, for example, a ceramic substrate such as alumina (Al 2 O 3 ) or aluminum nitride (AlN), which has characteristics such as heat resistance, insulation, and good thermal conductivity, generates heat when energized. Since a ceramic heater based on the structure in which a resistance layer is provided on this substrate can be used as a fixing film having a thin film and a low heat capacity, the heat transfer efficiency is higher than that of a heat roller type fixing device, and warm-up is possible. The time can be shortened, and quick start and energy saving can be achieved.
【０００７】電磁誘導加熱方式の定着装置として、特公
平８−２２２０６号公報では、交番磁界により磁性金属
部材に渦電流を発生させジュール熱を生じさせ、このジ
ュール熱により金属部材を含む加熱体を磁気誘導発熱さ
せることが提案されている。As a fixing device of an electromagnetic induction heating system, in Japanese Patent Publication No. 8-22206, an alternating magnetic field generates an eddy current in a magnetic metal member to generate Joule heat, and the Joule heat causes a heating body including the metal member. It has been proposed to generate magnetically induced heat.
【０００８】以下に磁気誘導加熱方式の定着装置の構成
について説明する。ここで、図８は従来の電磁誘導加熱
方式による定着装置を示す模式図である。The structure of the magnetic induction heating type fixing device will be described below. Here, FIG. 8 is a schematic view showing a fixing device by a conventional electromagnetic induction heating method.
【０００９】図８に示すように、定着装置は、コイルが
巻き回された励磁コイルユニット１８と加熱部である磁
性金属部材１９とからなる電磁誘導加熱構造体である加
熱体２０が装着されたフィルム内面ガイド２１と、磁性
金属部材１９を内壁に臨ませた状態でフィルム内面ガイ
ド２１を包囲する耐熱性を備えた円筒状のフィルム１７
と、磁性金属部材１９の位置でフィルム１７に圧接して
このフィルム１７との間に定着ニップ部Ｎを形成すると
ともに当該フィルム１７を従動回転させる加圧ローラ２
２とから構成されている。As shown in FIG. 8, the fixing device is equipped with a heating body 20 which is an electromagnetic induction heating structure composed of an exciting coil unit 18 around which a coil is wound and a magnetic metal member 19 which is a heating portion. Heat-resistant cylindrical film 17 surrounding the film inner surface guide 21 and the film inner surface guide 21 with the magnetic metal member 19 facing the inner wall.
And a pressure roller 2 that presses the film 17 at the position of the magnetic metal member 19 to form a fixing nip portion N between the film 17 and the film 17 and rotates the film 17 accordingly.
2 and.
【００１０】ここで、フィルム１７は、膜厚が１００μ
ｍ以下、好ましくは５０μｍ以下２０μｍ以上の耐熱性
を有するＰＴＦＥ、ＰＦＡ、ＦＥＰの等の単層フィル
ム、あるいはポリイミド、ポリアミドイミド、ＰＥＥ
Ｋ、ＰＥＳ、ＰＰＳ等のフィルムの外周表面にＰＴＦ
Ｅ、ＰＦＡ、ＦＥＰ等をコーティングした複合層フィル
ムが使用されている。The film 17 has a thickness of 100 μm.
Single layer film such as PTFE, PFA, FEP or the like having heat resistance of m or less, preferably 50 μm or less and 20 μm or more, or polyimide, polyamide imide, PEE
PTF on the outer surface of K, PES, PPS, etc. films
Composite layer films coated with E, PFA, FEP, etc. are used.
【００１１】また、フィルム内面ガイド２１は熱硬化性
のあるＰＥＥＫ、ＰＰＳ等の樹脂より形成された剛性、
耐熱性を有する部材からなり、加熱体２０はこのような
フィルム内面ガイド２１の下面の略中央部に嵌め込まれ
ている。The inner film guide 21 is made of a thermosetting resin such as PEEK or PPS.
The heating element 20 is made of a heat-resistant member, and is fitted into the lower surface of the film inner surface guide 21 at a substantially central portion thereof.
【００１２】加圧ローラ２２は、芯金２２ａと、この芯
金２２ａの周囲に設けられたシリコンゴム等の離型性の
良い耐熱ゴム層２２ｂからなり、軸受手段および付勢手
段（何れも図示せず）により所定の押圧力を持ってフィ
ルム１７を挟んで加熱体２０の磁性金属部材１９に圧接
するように配設されている。そして駆動手段（図示せ
ず）により反時計回りに回転駆動される。The pressure roller 22 is composed of a cored bar 22a and a heat-resistant rubber layer 22b provided around the cored bar 22a and having good releasability such as silicon rubber. It is arranged so as to be pressed against the magnetic metal member 19 of the heating body 20 with the film 17 sandwiched by a predetermined pressing force (not shown). Then, it is rotationally driven counterclockwise by a driving means (not shown).
【００１３】この加圧ローラ２２の回転駆動により、加
圧ローラ２２とフィルム１７との間に摩擦力が発生して
フィルム１７に回転力が作用することで、フィルム１７
は加熱体２０の磁性金属部材１９に密着しながら摺動回
転する。By the rotational driving of the pressure roller 22, a frictional force is generated between the pressure roller 22 and the film 17, and the rotational force acts on the film 17, whereby the film 17
Slides and rotates while being in close contact with the magnetic metal member 19 of the heating body 20.
【００１４】加熱体２０が所定の温度に立ち上がった状
態において、フィルム１７を介して加熱体２０と加圧ロ
ーラ２２とで形成される定着ニップ部Ｎのフィルム１７
と加圧ローラ２２との間に、画像形成部（図示せず）で
形成された未定着トナー画像Ｔを有した記録材１１を導
入する。すると、この記録材１１は加圧ローラ２２とフ
ィルム１７とに挟まれて定着ニップ部Ｎを搬送されるこ
とにより加熱体２０の磁性金属部材１９の保有する熱が
フィルム１７を介して記録材１１に付与され、記録材１
１上の未定着トナー像Ｔが記録材１１上に溶融定着され
る。なお、定着ニップ部Ｎの出口においては、通過した
記録材１１はフィルム１７の表面から分離されて排紙ト
レイ（図示せず）に搬送される。In a state where the heating body 20 has risen to a predetermined temperature, the film 17 in the fixing nip portion N formed by the heating body 20 and the pressure roller 22 with the film 17 interposed therebetween.
The recording material 11 having the unfixed toner image T formed by the image forming unit (not shown) is introduced between the pressure roller 22 and the pressure roller 22. Then, the recording material 11 is sandwiched between the pressure roller 22 and the film 17 and conveyed through the fixing nip portion N, so that the heat held by the magnetic metal member 19 of the heating body 20 is transferred to the recording material 11 via the film 17. Recording material 1
The unfixed toner image T on No. 1 is fused and fixed on the recording material 11. At the exit of the fixing nip portion N, the recording material 11 that has passed is separated from the surface of the film 17 and conveyed to a discharge tray (not shown).
【００１５】また、特開平７−２９５４１４号公報に
は、円筒状回転発熱部材の外側に電磁誘導加熱部材を設
けるとともに電磁誘導加熱部材によって加熱される領域
の外側に温度センサを設ける構成が開示されている。Further, Japanese Patent Laid-Open No. 7-295414 discloses a structure in which an electromagnetic induction heating member is provided outside a cylindrical rotary heating member and a temperature sensor is provided outside a region heated by the electromagnetic induction heating member. ing.
【００１６】さらに、特開平７−３１９３１２号公報に
は、円筒状回転発熱部材の内側に電磁誘導加熱部材を設
けるとともに円筒状回転発熱部材の外側の電磁誘導加熱
部材との対向位置に温度検知素子を設ける構成が開示さ
れている。Further, in Japanese Unexamined Patent Publication No. 7-19312, an electromagnetic induction heating member is provided inside the cylindrical rotary heating member and a temperature detecting element is provided outside the cylindrical rotary heating member so as to face the electromagnetic induction heating member. Is disclosed.
【００１７】[0017]
【発明が解決しようとする課題】ここで、特開平７−２
９５４１４号公報に開示されている電磁誘導加熱方式の
定着装置においては、電磁誘導加熱部材によって加熱さ
れる領域の外側に回転発熱部材の表面温度を検出する温
度センサが設けられているため、回転発熱部材が何らか
の原因で回転しなくなったときに加熱部での温度の異常
上昇を検知できないといった不具合が生じ、装置の破損
等を招く恐れがある。[Patent Document 1] Japanese Patent Application Laid-Open No. 7-2
In the electromagnetic induction heating type fixing device disclosed in Japanese Patent Publication No. 95414, a temperature sensor for detecting the surface temperature of the rotary heat generating member is provided outside the region heated by the electromagnetic induction heating member, and therefore the rotary heat generation is performed. When the member does not rotate for some reason, an abnormal rise in temperature in the heating unit cannot be detected, which may lead to damage to the device.
【００１８】また、特開平７−３１９３１２号公報に開
示されている電磁誘導加熱方式の定着装置においては、
電磁誘導加熱部材との対向位置にサーモスタット等の安
全装置を設けて温度制御等の暴走による発熱部での温度
の異常上昇を防止する方策がとられている。しかし、電
磁誘導発熱部材の外周面には一般にゴム層や離型層など
が形成されており、特にフルカラー画像形成装置におけ
る定着装置では、４層以上に積層されたトナー粒子から
なる厚みのある層を十分に包み込んで均一に加熱溶融す
るために、フィルムの表面に２００μｍ程度のゴム層が
設けられる。Further, in the fixing device of the electromagnetic induction heating system disclosed in Japanese Patent Laid-Open No. 7-19312,
A safety device such as a thermostat is provided at a position facing the electromagnetic induction heating member to prevent an abnormal rise in temperature at the heat generating portion due to runaway such as temperature control. However, a rubber layer or a release layer is generally formed on the outer peripheral surface of the electromagnetic induction heating member, and particularly in a fixing device in a full-color image forming apparatus, a thick layer composed of toner particles laminated in four or more layers. In order to sufficiently wrap the resin and uniformly heat and melt it, a rubber layer of about 200 μm is provided on the surface of the film.
【００１９】このような構成をとった場合には、ゴム層
の低い熱伝導性のために熱応答性が悪くなり、電磁誘導
加熱部材によって加熱される回転発熱部材の内面とトナ
ーに接する外面とでは温度差が非常に大きくなる。この
ため、トナーの定着性能を大きく左右するトナー加熱媒
体であるフィルム表面の温度制御が難しくなってしま
う。また、回転発熱部材と安全装置との間に空気層とゴ
ム層とが存在するため、発熱部材の昇温速度に対して安
全装置の応答速度が遅くなり、回転発熱部材が急速に温
度上昇して回転発熱部材自体が熱変形などの破損を引き
起こす場合がある。With such a construction, the low thermal conductivity of the rubber layer deteriorates the thermal responsiveness, and the inner surface of the rotary heat generating member heated by the electromagnetic induction heating member and the outer surface of the rotary heating member are in contact with the toner. Then, the temperature difference becomes very large. For this reason, it becomes difficult to control the temperature of the film surface, which is a toner heating medium, which greatly affects the fixing performance of the toner. Further, since the air layer and the rubber layer are present between the rotary heat generating member and the safety device, the response speed of the safety device becomes slower than the heating rate of the heat generating member, and the temperature of the rotary heat generating member rises rapidly. As a result, the rotating heat generating member itself may cause damage such as thermal deformation.
【００２０】そこで、本発明は、誘導加熱手段の電磁誘
導により加熱されるトナー加熱媒体の異常な温度上昇を
防止することのできる電磁誘導加熱方式の定着装置を提
供することを目的とする。Therefore, an object of the present invention is to provide an electromagnetic induction heating type fixing device capable of preventing an abnormal temperature rise of a toner heating medium heated by electromagnetic induction of an induction heating means.
【００２１】[0021]
【課題を解決するための手段】この課題を解決するため
に、本発明の定着装置は、磁性金属部材から構成されて
誘導加熱手段の電磁誘導により加熱される加熱ローラ
と、加熱ローラと平行に配置された定着ローラと、加熱
ローラと定着ローラとに張架されて加熱ローラにより加
熱されるとともにこれらのローラによって回転される無
端帯状のトナー加熱媒体と、トナー加熱媒体を介して定
着ローラに圧接されるとともにトナー加熱媒体に対して
順方向に回転して定着ニップ部を形成する加圧ローラ
と、定着ニップ部の入口近傍に配設されてトナー加熱媒
体の温度を検出する第１の温度検出手段と、前記加熱ロ
ーラの円筒内中空部に配置され前記加熱ローラの温度を
検出する第２の温度検出手段と、これらの温度検出手段
により検出される温度情報に基づいてトナー加熱媒体が
回転状態か否かを判定する判定手段とを有し、判定手段
によりトナー加熱媒体が停止状態と判定された場合に誘
導加熱手段の電磁誘導による加熱を停止させるものであ
る。In order to solve this problem, a fixing device of the present invention comprises a heating roller which is made of a magnetic metal member and is heated by electromagnetic induction of an induction heating means, and in parallel with the heating roller. An endless belt-shaped toner heating medium that is stretched between the fixing roller and the heating roller and the fixing roller, is heated by the heating roller, and is rotated by these rollers, and is pressed against the fixing roller through the toner heating medium. A pressure roller that rotates in the forward direction with respect to the toner heating medium to form the fixing nip portion, and a first temperature detection that is disposed near the entrance of the fixing nip portion and detects the temperature of the toner heating medium. Means and the heating
Second temperature detecting means arranged in the hollow portion of the roller inside the cylinder for detecting the temperature of the heating roller, and whether or not the toner heating medium is rotating based on the temperature information detected by these temperature detecting means. And a heating means for stopping the heating of the induction heating means by electromagnetic induction when the toner heating medium is determined to be in the stopped state.
【００２２】このように、トナー加熱媒体の回転および
停止状態を定着ニップ部の入口近傍に配設されてトナー
加熱媒体の温度を検出する第１の温度検出手段と加熱ロ
ーラの温度を検出する第２の温度検出手段とによって判
定しているので、誘導加熱手段の電磁誘導により加熱さ
れるトナー加熱媒体の異常な温度上昇を防止することが
可能になる。In this way, the first temperature detecting means for detecting the temperature of the toner heating medium and the first temperature detecting means for detecting the temperature of the toner heating medium are provided near the entrance of the fixing nip for the rotation and stop state of the toner heating medium. It is possible to prevent an abnormal temperature rise of the toner heating medium heated by the electromagnetic induction of the induction heating means because the determination is made by the second temperature detecting means.
【００２３】[0023]
【発明の実施の形態】本発明の請求項１に記載の発明
は、磁性金属部材から構成されて誘導加熱手段の電磁誘
導により加熱される加熱ローラと、加熱ローラと平行に
配置された定着ローラと、加熱ローラと定着ローラとに
張架されて加熱ローラにより加熱されるとともにこれら
のローラによって回転される無端帯状のトナー加熱媒体
と、トナー加熱媒体を介して定着ローラに圧接されると
ともにトナー加熱媒体に対して順方向に回転して定着ニ
ップ部を形成する加圧ローラと、定着ニップ部の入口近
傍に配設されてトナー加熱媒体の温度を検出する第１の
温度検出手段と、前記加熱ローラの円筒内中空部に配置
され前記加熱ローラの温度を検出する第２の温度検出手
段と、これらの温度検出手段により検出される温度情報
に基づいてトナー加熱媒体が回転状態か否かを判定する
判定手段とを有する定着装置であり、トナー加熱媒体の
回転および停止状態を第１の温度検出手段と第２の温度
検出手段とによって判定しているので、誘導加熱手段の
電磁誘導により加熱されるトナー加熱媒体の異常な温度
上昇を防止することが可能になるという作用を有する。DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a heating roller which is composed of a magnetic metal member and is heated by electromagnetic induction of induction heating means, and a fixing roller which is arranged in parallel with the heating roller. An endless belt-shaped toner heating medium that is stretched between a heating roller and a fixing roller and is heated by the heating roller, and is rotated by these rollers, and is pressed against the fixing roller through the toner heating medium and heats the toner. a first temperature detecting means for detecting the temperature of the toner heating medium is arranged a pressure roller for forming a fixing nip portion rotates in the forward direction, near the entrance of the fixing nip portion with respect to the medium, the heating Located in the hollow part of the roller cylinder
A second temperature detecting means for detecting the temperature of the heating roller is a fixing device having the toner heating medium based on the temperature information detected by these temperature detection means and a determining means for determining whether the rotational state Since the rotation and stop state of the toner heating medium is determined by the first temperature detecting means and the second temperature detecting means, the abnormal temperature of the toner heating medium heated by the electromagnetic induction of the induction heating means is determined. It has the effect of making it possible to prevent the rise.
【００２４】本発明の請求項２に記載の発明は、請求項
１記載の発明において、判定手段によりトナー加熱媒体
が停止状態と判定された場合には、誘導加熱手段の電磁
誘導による加熱を停止させる定着装置であり、トナー加
熱媒体の温度上昇をより速い応答速度で精度高く検出す
ることができるので、トナー加熱媒体の熱変形などによ
る破損を未然に防止することが可能になるという作用を
有する。According to a second aspect of the present invention, in the invention according to the first aspect, the heating by the electromagnetic induction of the induction heating means is stopped when the toner heating medium is judged to be in the stopped state by the judgment means. Since it is a fixing device that can detect the temperature rise of the toner heating medium with high response speed and high accuracy, it is possible to prevent damage due to thermal deformation of the toner heating medium. .
【００２５】以下、本発明の実施の形態１について、図
１から図８を用いて説明する。なお、これらの図面にお
いて同一の部材には同一の符号を付しており、また、重
複した説明は省略されている。The first embodiment of the present invention will be described below with reference to FIGS. 1 to 8. In addition, in these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.
【００２６】図１は本発明の一実施の形態である定着装
置を示す説明図、図２（ａ）は図１の定着装置における
誘導加熱手段の励磁コイルを示す断面図、図２（ｂ）は
図１の定着装置における誘導加熱手段の励磁コイルを示
す側面図、図３は図１の定着装置における誘導加熱手段
による交番磁界と渦電流の発生を示す説明図、図４は図
１の定着装置の動作を示すフローチャート、図５は図１
の定着装置において電磁誘導加熱されたときの通常状態
の耐熱性ベルトの内面温度と加熱ローラの加熱部の内面
温度との関係を示すグラフ、図６は図１の定着装置にお
いて耐熱性ベルトが加熱初期から回転していない状態で
電磁誘導加熱されたときの耐熱性ベルトの内面温度と加
熱ローラの加熱部の内面温度との関係を示すグラフ、図
７は図１の定着装置において耐熱性ベルトが加熱開始か
ら所定時間後に回転しなくなった状態で電磁誘導加熱さ
れたときの耐熱性ベルトの内面温度と加熱ローラの加熱
部の内面温度との関係を示すグラフである。FIG. 1 is an explanatory view showing a fixing device according to an embodiment of the present invention, FIG. 2 (a) is a sectional view showing an exciting coil of induction heating means in the fixing device of FIG. 1, and FIG. 2 (b). 1 is a side view showing an exciting coil of induction heating means in the fixing device of FIG. 1, FIG. 3 is an explanatory view showing generation of an alternating magnetic field and an eddy current by the induction heating means in the fixing device of FIG. 1, and FIG. 4 is fixing of FIG. FIG. 5 is a flow chart showing the operation of the apparatus.
6 is a graph showing the relationship between the inner surface temperature of the heat resistant belt and the inner surface temperature of the heating portion of the heating roller when being heated by electromagnetic induction in the fixing device of FIG. FIG. 7 is a graph showing the relationship between the inner surface temperature of the heat resistant belt and the inner surface temperature of the heating portion of the heating roller when electromagnetically heated in the state where it does not rotate from the initial stage. 7 is a graph showing the relationship between the inner surface temperature of the heat resistant belt and the inner surface temperature of the heating portion of the heating roller when electromagnetic induction heating is performed in a state in which the heating roller does not rotate after a predetermined time from the start of heating.
【００２７】図１に示す定着装置は画像形成装置に用い
られる電磁誘導加熱方式の定着装置であり、誘導加熱手
段６の電磁誘導により加熱される加熱ローラ１と、加熱
ローラ１と平行に配置された定着ローラ２と、加熱ロー
ラ１と定着ローラ２とに張架されて加熱ローラ１により
加熱されるとともに定着ローラ２の回転により矢印Ａ方
向に回転する無端帯状の耐熱性ベルト（トナー加熱媒
体）３と、耐熱性ベルト３を介して定着ローラ２に圧接
されるともに耐熱性ベルト３に対して順方向に回転する
加圧ローラとから構成されている。The fixing device shown in FIG. 1 is an electromagnetic induction heating type fixing device used in an image forming apparatus, and is arranged in parallel with the heating roller 1 heated by the electromagnetic induction of the induction heating means 6. Endless belt-shaped heat-resistant belt (toner heating medium) that is stretched between the heating roller 1 and the fixing roller 2 and is heated by the heating roller 1 and that rotates in the direction of arrow A when the fixing roller 2 rotates. 3 and a pressure roller which is pressed against the fixing roller 2 via the heat resistant belt 3 and rotates in the forward direction with respect to the heat resistant belt 3.
【００２８】図示するように、定着装置にはサーミスタ
などの熱応答性の高い感温素子である温度検出手段５が
２箇所に設けられている。すなわち、温度検出手段５
は、定着ニップ部Ｎの入口側近傍において耐熱性ベルト
３の内面側に当接して配置されてこの耐熱性ベルト３の
温度を検出する第１の温度検出手段５ａと、加熱ローラ
１の表面に当接して配置されてこの加熱ローラ１の温度
を検出する第２の温度検出手段５ｂである。As shown in the figure, the fixing device is provided with two temperature detecting means 5 which are temperature sensitive elements such as thermistors having a high thermal response. That is, the temperature detecting means 5
Is provided on the surface of the heating roller 1 and the first temperature detecting means 5a which is arranged in contact with the inner surface side of the heat resistant belt 3 near the entrance side of the fixing nip portion N to detect the temperature of the heat resistant belt 3. It is a second temperature detecting means 5b which is arranged in contact with the heating roller 1 and detects the temperature of the heating roller 1.
【００２９】ここで、加熱ローラ１はたとえばＳＵＳ等
の中空円筒状の磁性金属部材からなり、外径がたとえば
２０ｍｍ、肉厚がたとえば０．３ｍｍとされて、低熱容
量で昇温の速い構成となっている。Here, the heating roller 1 is made of a hollow cylindrical magnetic metal member such as SUS, has an outer diameter of 20 mm and a wall thickness of 0.3 mm, for example, and has a low heat capacity and a rapid temperature rise. Has become.
【００３０】定着ローラ２は、たとえばＳＵＳ等の金属
製の芯金２ａと、耐熱性を有するシリコーンゴムをソリ
ッド状または発泡状にして芯金２ａを被覆した弾性部材
２ｂとからなる。そして、加圧ローラ４からの押圧力で
この加圧ローラ４との間に所定幅の接触部を形成するた
めに外径を３０ｍｍ程度として加熱ローラ１より大きく
しており、弾性部材２ｂの肉厚を３〜８ｍｍ程度、硬度
を１５〜５０°（Ａｓｋｅｒ Ｃ）程度としている。The fixing roller 2 comprises a cored bar 2a made of metal such as SUS, and an elastic member 2b coated with a cored bar 2a made of heat-resistant silicone rubber in a solid or foamed state. The outer diameter of the elastic member 2b is about 30 mm, which is larger than that of the heating roller 1 in order to form a contact portion having a predetermined width with the pressing roller 4 by the pressing force from the pressing roller 4. The thickness is about 3 to 8 mm and the hardness is about 15 to 50 ° (Asker C).
【００３１】このような構成により、加圧ローラ１の熱
容量が定着ローラ２の熱容量より小さくなるので、加熱
ローラ１が急速に加熱されてウォームアップ時間が短縮
される。With this structure, the heat capacity of the pressure roller 1 is smaller than that of the fixing roller 2, so that the heating roller 1 is rapidly heated and the warm-up time is shortened.
【００３２】加熱ローラ１と定着ローラ２の間に張架さ
れた耐熱性ベルト３は、誘導加熱手段６によって加熱さ
れる加熱ローラ１との接触部位Ｗで加熱される。そし
て、駆動手段（図示せず）による定着ローラ２の回転に
伴う耐熱性ベルト３の回転によって耐熱性ベルト３の内
面が連続的に加熱され、結果としてベルト全体に亘って
加熱される。The heat resistant belt 3 stretched between the heating roller 1 and the fixing roller 2 is heated at the contact portion W with the heating roller 1 heated by the induction heating means 6. Then, the inner surface of the heat resistant belt 3 is continuously heated by the rotation of the heat resistant belt 3 accompanying the rotation of the fixing roller 2 by the driving means (not shown), and as a result, the entire belt is heated.
【００３３】ここで、耐熱性ベルト３は、Ｎｉ、Ｃｕ、
Ｃｒ等の磁性を有する金属部材を基材とした発熱層３ａ
と、その表面を被覆するようにして設けられたシリコー
ンゴム、フッ素ゴム等の弾性部材からなる離型層３ｂと
から構成される複合層ベルトである。The heat resistant belt 3 is made of Ni, Cu,
Heat generating layer 3a based on a metal member having magnetism such as Cr
And a release layer 3b made of an elastic material such as silicone rubber or fluororubber so as to cover the surface thereof.
【００３４】これによれば、仮に何らかの原因で、たと
えば耐熱性ベルト３と加熱ローラ１との間に異物が混入
してギャップが生じたとしても、耐熱性ベルト３の発熱
層３ａの電磁誘導による発熱で耐熱性ベルト３自体が発
熱するので、温度ムラが少なく信頼性が高くなる。According to this, even if for some reason, for example, a foreign substance is mixed between the heat resistant belt 3 and the heating roller 1 to cause a gap, it is caused by the electromagnetic induction of the heat generating layer 3a of the heat resistant belt 3. Since the heat-resistant belt 3 itself generates heat due to heat generation, temperature unevenness is small and reliability is high.
【００３５】なお、発熱層３ａの厚さとしては、２０μ
ｍから５０μｍ程度が望ましく、特に３０μｍ程度が望
ましい。The thickness of the heat generating layer 3a is 20 μm.
It is preferably about m to 50 μm, particularly about 30 μm.
【００３６】発熱層３ａの厚さが５０μｍより大きい場
合には、ベルト回転時に発生する歪み応力が大きくな
り、剪断力によるクラックの発生や機械的強度の極端な
低下を引き起こす。また、発熱層３ａの厚さが２０μｍ
より小さい場合には、ベルト回転時の蛇行が原因で発生
するベルト端部へのスラスト負荷によりクラックや割れ
等の破損が発生する。When the thickness of the heat generating layer 3a is larger than 50 μm, the strain stress generated when the belt is rotated becomes large, which causes cracks due to shearing force and extremely reduces mechanical strength. The thickness of the heat generating layer 3a is 20 μm.
If it is smaller than the above range, a crack load such as a crack or a break occurs due to a thrust load applied to the belt end portion caused by meandering when the belt rotates.
【００３７】一方、離型層３ｂの厚さとしては、１００
μｍから３００μｍ程度が望ましく、特に２００μｍ程
度が望ましい。このようにすれば、記録材１１上に形成
されたトナー像Ｔを耐熱性ベルト３の表層部が十分に包
み込むため、トナー像Ｔを均一に加熱溶融することが可
能になる。On the other hand, the thickness of the release layer 3b is 100
The thickness is preferably about 300 μm, more preferably about 200 μm. By doing so, the toner image T formed on the recording material 11 is sufficiently covered by the surface layer portion of the heat resistant belt 3, so that the toner image T can be uniformly heated and melted.
【００３８】離型層３ｂの厚さが１００μｍよりも小さ
い場合には、耐熱性ベルト３の熱容量が小さくなってト
ナー定着工程においてベルト表面温度が急速に低下し、
定着性能を十分に確保することができない。また、離型
層３ｂの厚さが３００μｍよりも大きい場合には、耐熱
性ベルト３の熱容量が大きくなってウォームアップにか
かる時間が長くなるのに加え、トナー定着工程において
ベルト表面温度が低下しにくくなって、定着部出口にお
ける融解したトナーの凝集効果が得られず、離型性が低
下してトナーがベルトに付着する、いわゆるホットオフ
セットが発生する。When the thickness of the release layer 3b is less than 100 μm, the heat capacity of the heat resistant belt 3 becomes small and the belt surface temperature rapidly decreases in the toner fixing step.
The fixing performance cannot be sufficiently secured. Further, when the thickness of the release layer 3b is larger than 300 μm, the heat capacity of the heat resistant belt 3 becomes large, the time required for warming up becomes long, and the belt surface temperature is lowered in the toner fixing step. It becomes difficult to obtain the effect of aggregating the melted toner at the outlet of the fixing unit, the releasability is lowered, and the toner adheres to the belt, so-called hot offset occurs.
【００３９】なお、耐熱性ベルト３の基材として、Ｎ
ｉ、Ｃｕ、Ｃｒ等の金属部材からなる発熱層３ａの代わ
りに、フッ素系樹脂、ポリイミド樹脂、ポリアミド樹
脂、ポリアミドイミド樹脂、ＰＥＥＫ樹脂、ＰＥＳ樹
脂、ＰＰＳ樹脂などの耐熱性を有する樹脂層を用いても
よい。As the base material of the heat resistant belt 3, N
Instead of the heat generating layer 3a made of a metal member such as i, Cu, or Cr, a resin layer having heat resistance such as a fluorine resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin, or a PPS resin is used. May be.
【００４０】基材が耐熱性の高い樹脂部材である樹脂層
から構成されれば、耐熱性ベルト３が加熱ローラ１の曲
率に応じて密着しやすくなるため、加熱体の保有する熱
がベルト３に効率良く伝達される。If the base material is composed of a resin layer which is a resin member having a high heat resistance, the heat resistant belt 3 easily adheres to the heating roller 1 in accordance with the curvature of the heating roller 1. Be efficiently transmitted to.
【００４１】この場合、樹脂層の厚さとしては、２０μ
ｍから１５０μｍ程度が望ましく、特に７５μｍ程度が
望ましい。樹脂層の厚さが２０μｍよりも小さい場合に
は、ベルト回転時の蛇行に対する機械的強度が得られな
い。また、樹脂層の厚さが１５０μｍより大きい場合に
は、熱遮蔽効果が高くなって加熱ローラ１から耐熱性ベ
ルト３の離型層３ｂへの熱伝播効率が低下するため、定
着性能の低下が発生する。In this case, the thickness of the resin layer is 20 μm.
The thickness is preferably about m to 150 μm, and more preferably about 75 μm. If the thickness of the resin layer is less than 20 μm, mechanical strength against meandering during belt rotation cannot be obtained. Further, when the thickness of the resin layer is larger than 150 μm, the heat shielding effect is enhanced and the heat transfer efficiency from the heating roller 1 to the release layer 3b of the heat resistant belt 3 is reduced, so that the fixing performance is deteriorated. Occur.
【００４２】加圧ローラ４は、たとえばＳＵＳまたはア
ルミ等の熱伝導の高い金属製の円筒部材からなる芯金４
ａと、この芯金４ａの表面に設けられた耐熱性およびト
ナー離型性の高い弾性部材４ｂとから構成されている。The pressure roller 4 is made of a metal such as SUS or aluminum having a high heat conductivity, and is made of a metal cylindrical member.
a and an elastic member 4b provided on the surface of the cored bar 4a and having high heat resistance and high toner releasability.
【００４３】このような加圧ローラ４は耐熱性ベルト３
を介して定着ローラ２を押圧して定着ニップ部Ｎを形成
しているが、本実施の形態では、定着ニップ部Ｎの出口
部でトナーの剥離作用が大きくなるように、外径は定着
ローラ２と同じ３０ｍｍ程度であるが、肉厚は２〜５ｍ
ｍ程度で定着ローラ２より薄く、また硬度は２０〜６０
°（Ａｓｋｅｒ Ｃ）程度で定着ローラ２より硬くされ
ている。Such a pressure roller 4 is a heat resistant belt 3.
Although the fixing nip portion N is formed by pressing the fixing roller 2 via the fixing roller 2 in this embodiment, the outer diameter of the fixing roller is set so that the toner peeling action is increased at the exit portion of the fixing nip portion N. It is about 30 mm, which is the same as No. 2, but the wall thickness is 2 to 5 m.
m is thinner than the fixing roller 2 and has a hardness of 20 to 60
It is made harder than the fixing roller 2 at about ° (Asker C).
【００４４】電磁誘導により加熱ローラ１を加熱する誘
導加熱手段６は、図２に示すように、磁界発生手段であ
る励磁コイル７と、この励磁コイル７が巻き回されたコ
イルガイド板８とを有している。ここで、コイルガイド
板８は加熱ローラ１の外周面に近接配置された半円弧形
状をしており、励磁コイル７は長い一本の励磁コイル線
材をこのコイルガイド板８に沿って加熱ローラ１の軸方
向に交互に巻き付けたものからなり、その巻き付け長さ
は耐熱性ベルト３と加熱ローラ１とが接する領域と同じ
にされている。The induction heating means 6 for heating the heating roller 1 by electromagnetic induction includes, as shown in FIG. 2, an exciting coil 7 which is a magnetic field generating means and a coil guide plate 8 around which the exciting coil 7 is wound. Have Here, the coil guide plate 8 is in the shape of a semi-circular arc disposed in the vicinity of the outer peripheral surface of the heating roller 1, and the exciting coil 7 includes one long exciting coil wire along the coil guide plate 8. Are alternately wound in the axial direction, and the winding length is the same as the region where the heat resistant belt 3 and the heating roller 1 are in contact with each other.
【００４５】これによれば、当該誘導加熱手段６により
電磁誘導加熱される加熱ローラ１の領域が最大となり、
発熱している加熱ローラ１表面と耐熱性ベルト３とが接
する時間も最大となるので、伝熱効率が高くなる。According to this, the area of the heating roller 1 which is electromagnetically induction-heated by the induction heating means 6 becomes maximum,
Since the time during which the surface of the heat roller 1 that is generating heat and the heat resistant belt 3 are in contact with each other is maximized, the heat transfer efficiency is increased.
【００４６】なお、励磁コイル７は、発振回路が周波数
可変とされた駆動電源（図示せず）に接続されている。The exciting coil 7 is connected to a driving power source (not shown) whose frequency is variable in the oscillation circuit.
【００４７】励磁コイル７のさらに外側には、フェライ
ト等の強磁性体よりなる半円弧形状部材である励磁コイ
ルコア９が、励磁コイルコア支持部材１０に固定されて
励磁コイル７に近接配設されている。なお、本実施の形
態において、励磁コイルコア９は比透磁率が２５００の
ものを使用している。An exciting coil core 9, which is a semi-arcuate member made of a ferromagnetic material such as ferrite, is fixed to the exciting coil core supporting member 10 and is arranged close to the exciting coil 7 outside the exciting coil 7. . In this embodiment, the exciting coil core 9 has a relative magnetic permeability of 2500.
【００４８】励磁コイル７には駆動電源から１０ｋＨｚ
〜１ＭＨｚの高周波交流電流、好ましくは２０ｋＨｚ〜
８００ｋＨｚの高周波交流電流が給電され、これにより
交番磁界を発生する。そして、加熱ローラ１と耐熱性ベ
ルト３との接触領域Ｗおよびその近傍部においてこの交
番磁界が加熱ローラ１および耐熱性ベルト３の発熱層３
ａに作用し、これらの内部では上記の磁界の変化を妨げ
る方向Ｂに渦電流Ｉが流れる。The excitation coil 7 has a drive power source of 10 kHz.
~ 1 MHz high frequency alternating current, preferably 20 kHz ~
A high-frequency alternating current of 800 kHz is supplied to generate an alternating magnetic field. Then, in the contact area W between the heating roller 1 and the heat resistant belt 3 and in the vicinity thereof, this alternating magnetic field causes the heat generation layer 3 of the heating roller 1 and the heat resistant belt 3.
An eddy current I flows in the direction B which acts on a and prevents the change of the magnetic field.
【００４９】この渦電流Ｉが加熱ローラ１および発熱層
３ａの抵抗に応じたジュール熱を発生させ、主として加
熱ローラ１と耐熱性ベルト３との接触領域およびその近
傍部において加熱ローラ１および発熱層３ｂを有する耐
熱性ベルト３が電磁誘導発熱して加熱される。This eddy current I generates Joule heat corresponding to the resistance of the heating roller 1 and the heat generating layer 3a, and mainly in the contact area between the heating roller 1 and the heat resistant belt 3 and in the vicinity thereof, the heating roller 1 and the heat generating layer 3a. The heat resistant belt 3 having 3b is heated by electromagnetic induction heat generation.
【００５０】このようにして加熱された耐熱性ベルト３
は第１の温度検出手段５ａにより内面の温度が検知され
る。また、第２の温度検出手段５ｂにより加熱ローラ１
の加熱部内面の温度が検知される。そして、これらの温
度検出手段５ａ，５ｂによる検出温度は判定手段（図示
せず）に送られ、判定手段において、温度検出手段５
ａ，５ｂで検出された温度情報に基づいて耐熱性ベルト
３が回転状態か否かが判定される。The heat-resistant belt 3 thus heated
The temperature of the inner surface is detected by the first temperature detecting means 5a. In addition, the heating roller 1 is heated by the second temperature detecting means 5b.
The temperature of the inner surface of the heating part of is detected. Then, the temperatures detected by these temperature detecting means 5a, 5b are sent to a judging means (not shown), and the temperature detecting means 5 is detected in the judging means.
Based on the temperature information detected at a and 5b, it is determined whether the heat resistant belt 3 is in the rotating state.
【００５１】次に、このような構成の電磁誘導加熱方式
の定着装置の動作を、図４、図５、図６および図７を用
いて説明する。Next, the operation of the fixing device of the electromagnetic induction heating system having such a configuration will be described with reference to FIGS. 4, 5, 6 and 7.
【００５２】図４において、先ず、駆動手段（図示せ
ず）により定着ローラ２を回転させ（ステップＳ１）、
電磁誘導による加熱を開始する（ステップＳ２）。電磁
誘導加熱が開始されると、第１の温度検出手段５ａによ
り検出される定着ニップ部Ｎの入口側近傍での耐熱性ベ
ルト３の内面温度θａが所定温度、たとえば１８０℃に
なるように温度制御を行う（ステップＳ３）。なお、本
実施の形態では、比例積分制御により温度制御を行う。In FIG. 4, first, the fixing roller 2 is rotated by driving means (not shown) (step S1),
Heating by electromagnetic induction is started (step S2). When the electromagnetic induction heating is started, the inner surface temperature θa of the heat resistant belt 3 in the vicinity of the inlet side of the fixing nip portion N detected by the first temperature detecting means 5a is set to a predetermined temperature, for example 180 ° C. Control is performed (step S3). In this embodiment, temperature control is performed by proportional-plus-integral control.
【００５３】ここで、温度制御した際、通常状態の耐熱
性ベルト３の内面温度θａおよび加熱ローラ１の加熱部
の内面温度θｂの状態は、図５に示すようになる。図５
において、加熱ローラ１の内面温度θｂと耐熱性ベルト
３の内面温度θａは所定の温度差θｂ−ａを保って推移
する。加熱ローラ１との接触部位Ｗでは内面温度θａお
よび内面温度θｂは同温度であるが、接触部位Ｗ以降で
は耐熱性ベルト３は加熱されないので、放熱される分だ
け温度が低下するためである。Here, when the temperature is controlled, the state of the inner surface temperature θa of the heat resistant belt 3 and the inner surface temperature θb of the heating portion of the heating roller 1 in the normal state are as shown in FIG. Figure 5
In, the inner surface temperature θb of the heating roller 1 and the inner surface temperature θa of the heat resistant belt 3 change while maintaining a predetermined temperature difference θb-a. This is because the inner surface temperature θa and the inner surface temperature θb are the same at the contact portion W with the heating roller 1, but since the heat resistant belt 3 is not heated after the contact portion W, the temperature is reduced by the amount of heat released.
【００５４】ステップＳ３において温度制御を行い、加
熱ローラ１の加熱部内面温度θｂと耐熱性ベルト３内面
温度θａの差を演算し、この差と所定の温度差θｃとを
比較判定する（ステップＳ４）。ここで、温度差θｃは
通常状態の温度差θｂ−ａに環境等による変動分を加味
した値で、ここでは３０℃とされている。In step S3, the temperature is controlled to calculate the difference between the inner surface temperature θb of the heating portion of the heating roller 1 and the inner surface temperature θa of the heat resistant belt 3, and the difference is compared with a predetermined temperature difference θc (step S4). ). Here, the temperature difference θc is a value obtained by adding a variation due to the environment or the like to the temperature difference θb-a in the normal state, and is set to 30 ° C. here.
【００５５】このステップＳ４における比較判定した結
果がθｂ−θａ＜θｃの場合は、通常状態と判定されて
ステップＳ５へ移行する。また、比較判定した結果がθ
ｂ−θａ≧θｃの場合は、図６および図７に示すように
耐熱性ベルト３は停止状態と判定されてステップＳ６へ
移行する。When the result of the comparison and determination in step S4 is θb-θa <θc, it is determined that the normal state and the process proceeds to step S5. In addition, the result of comparison judgment is θ
If b−θa ≧ θc, as shown in FIGS. 6 and 7, the heat resistant belt 3 is determined to be in a stopped state, and the process proceeds to step S6.
【００５６】すなわち、ステップＳ４における比較判定
した結果がθｂ−θａ＜θｃの場合は、印字終了かどう
かの判定を行い（ステップＳ５）、印字終了でなければ
前述したステップＳ３へ移行して温度制御を継続する。
また、印字終了であれば電磁誘導加熱をオフし（ステッ
プＳ７）、定着駆動ローラの駆動をオフして（ステップ
Ｓ８）定着動作を完了する。That is, if the result of the comparison determination in step S4 is θb-θa <θc, it is determined whether or not the printing is completed (step S5). If the printing is not completed, the process proceeds to step S3 described above to control the temperature. To continue.
When the printing is completed, the electromagnetic induction heating is turned off (step S7), the driving of the fixing driving roller is turned off (step S8), and the fixing operation is completed.
【００５７】また、ステップＳ４における比較判定した
結果がθｂ−θａ≧θｃの場合は、耐熱性ベルト３が停
止状態であるとのエラーメッセージをユーザへ報知手段
（図示せず）により報知し（ステップＳ６）、電磁誘導
加熱をオフし（ステップＳ７）、定着駆動ローラの駆動
をオフして（ステップＳ８）定着動作を完了する。If the result of the comparison judgment in step S4 is θb-θa ≧ θc, an error message that the heat resistant belt 3 is in a stopped state is notified to the user by the notification means (not shown) (step). S6), the electromagnetic induction heating is turned off (step S7), the driving of the fixing driving roller is turned off (step S8), and the fixing operation is completed.
【００５８】これにより、耐熱性ベルト３が何らかの原
因で回転しなくなったときにおける加熱ローラ１との接
触部での温度の異常上昇を未然に防止することが可能に
なる。This makes it possible to prevent an abnormal rise in temperature at the contact portion with the heating roller 1 when the heat resistant belt 3 stops rotating for some reason.
【００５９】このように、本実施の形態によれば、耐熱
性ベルト３の回転または停止状態を定着ニップ部Ｎの入
口近傍に配設された温度検出手段５の温度情報によって
判定しているので、定着装置が小型になって部品コスト
を削減することが可能になるとともに、温度上昇をより
速い応答速度で精度高く検出することが可能になるの
で、トナー加熱媒体の熱変形などによる破損を未然に防
止することができる。As described above, according to the present embodiment, the rotation or stop state of the heat resistant belt 3 is determined by the temperature information of the temperature detecting means 5 arranged near the entrance of the fixing nip portion N. Since the fixing device can be downsized and the cost of parts can be reduced and the temperature rise can be detected with high response speed and high accuracy, damage due to thermal deformation of the toner heating medium can be prevented. Can be prevented.
【００６０】このように、本実施の形態によれば、耐熱
性ベルト３の回転または停止状態を定着ニップ部Ｎの入
口近傍に配設された第１の温度検出手段５ａと加熱ロー
ラ１の加熱部内面に配置された第２の温度検出手段５ｂ
によって判定しているので、定着装置が小型になって部
品コストを削減することが可能になるとともに、温度上
昇をより速い応答速度で精度高く検出することが可能に
なるので、トナー加熱媒体の熱変形などによる破損を未
然に防止することができる。As described above, according to the present embodiment, when the heat-resistant belt 3 is rotated or stopped, the first temperature detecting means 5a arranged near the entrance of the fixing nip portion N and the heating roller 1 are heated. Second temperature detecting means 5b arranged on the inner surface of the section
Since the fixing device is downsized, the cost of parts can be reduced, and the temperature rise can be detected accurately with a faster response speed. It is possible to prevent damage due to deformation or the like.
【００６１】[0061]
【発明の効果】以上のように、本発明によれば、トナー
加熱媒体の回転または停止状態を定着ニップ部の入口近
傍に配設された第１の温度検出手段と加熱ローラの加熱
部内面に配置された第２の温度検出手段の温度情報によ
って判定しているので、誘導加熱手段の電磁誘導により
加熱されるトナー加熱媒体の異常な温度上昇を防止する
ことが可能になるという有効な効果が得られる。As described above, according to the present invention, the rotation or stop state of the toner heating medium is detected by the first temperature detecting means arranged near the inlet of the fixing nip portion and the inner surface of the heating portion of the heating roller. Since the judgment is made based on the temperature information of the second temperature detecting means arranged, it is possible to prevent an abnormal temperature rise of the toner heating medium heated by the electromagnetic induction of the induction heating means. can get.
【００６２】また、判定手段によりトナー加熱媒体が停
止状態と判定された場合には誘導加熱手段の電磁誘導に
よる加熱を停止させることにより、トナー加熱媒体の熱
変形などによる破損を未然に防止することが可能になる
という有効な効果が得られる。When the determination means determines that the toner heating medium is in a stopped state, the induction heating means stops the heating by electromagnetic induction to prevent the toner heating medium from being damaged due to thermal deformation. There is an effective effect that it becomes possible.
【図１】本発明の一実施の形態である定着装置を示す説
明図FIG. 1 is an explanatory diagram showing a fixing device according to an embodiment of the present invention.
【図２】（ａ）図１の定着装置における誘導加熱手段の
励磁コイルを示す断面図
（ｂ）その側面図2A is a sectional view showing an exciting coil of an induction heating unit in the fixing device of FIG. 1, and FIG.
【図３】図１の定着装置における誘導加熱手段による交
番磁界と渦電流の発生を示す説明図FIG. 3 is an explanatory view showing the generation of an alternating magnetic field and an eddy current by the induction heating means in the fixing device of FIG.
【図４】図１の定着装置の動作を示すフローチャートFIG. 4 is a flowchart showing the operation of the fixing device of FIG.
【図５】図１の定着装置において電磁誘導加熱されたと
きの通常状態の耐熱性ベルトの内面温度と加熱ローラの
加熱部の内面温度との関係を示すグラフ5 is a graph showing the relationship between the inner surface temperature of the heat resistant belt and the inner surface temperature of the heating portion of the heating roller in the normal state when electromagnetically heated in the fixing device of FIG.
【図６】図１の定着装置において耐熱性ベルトが加熱初
期から回転していない状態で電磁誘導加熱されたときの
耐熱性ベルトの内面温度と加熱ローラの加熱部の内面温
度との関係を示すグラフFIG. 6 shows the relationship between the inner surface temperature of the heat resistant belt and the inner surface temperature of the heating portion of the heating roller when the heat resistant belt is electromagnetically heated in the fixing device of FIG. Graph
【図７】図１の定着装置において耐熱性ベルトが加熱開
始から所定時間後に回転しなくなった状態で電磁誘導加
熱されたときの耐熱性ベルトの内面温度と加熱ローラの
加熱部の内面温度との関係を示すグラフ7 is a diagram showing a relationship between an inner surface temperature of the heat resistant belt and an inner surface temperature of a heating portion of the heating roller when the heat resistant belt is electromagnetically heated in a state where the heat resistant belt does not rotate after a predetermined time from the start of heating in the fixing device of FIG. Graph showing the relationship
【図８】従来の電磁誘導加熱方式による定着装置を示す
摸式図FIG. 8 is a schematic diagram showing a fixing device using a conventional electromagnetic induction heating method.
１ 加熱ローラ ２ 定着ローラ ３ 耐熱性ベルト（トナー加熱媒体） ４ 加圧ローラ ５ 温度検出手段 ５ａ 第１の温度検出手段 ５ｂ 第２の温度検出手段 ６ 誘導加熱手段 ７ 励磁コイル ９ 励磁コイルコア １２ 誘導加熱手段 １５ 励磁コイルコア Ｎ 定着ニップ部 Ｔ トナー像 1 heating roller 2 fixing roller 3 Heat resistant belt (toner heating medium) 4 pressure roller 5 Temperature detection means 5a First temperature detecting means 5b Second temperature detecting means 6 induction heating means 7 Excitation coil 9 Excitation coil core 12 Induction heating means 15 Excitation coil core N fixing nip T toner image
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平11−45028（ＪＰ，Ａ) 特開 平４−352185（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) G03G 13/20 G03G 15/20 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-45028 (JP, A) JP-A-4-352185 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) G03G 13/20 G03G 15/20
Claims (2)
の電磁誘導により加熱される加熱ローラと、 前記加熱ローラと平行に配置された定着ローラと、 前記加熱ローラと前記定着ローラとに張架されて前記加
熱ローラにより加熱されるとともにこれらのローラによ
って回転される無端帯状のトナー加熱媒体と、 前記トナー加熱媒体を介して前記定着ローラに圧接され
るとともに前記トナー加熱媒体に対して順方向に回転し
て定着ニップ部を形成する加圧ローラと、 前記定着ニップ部の入口近傍に配設されて前記トナー加
熱媒体の温度を検出する第１の温度検出手段と、前記加熱ローラの円筒内中空部に配置され 前記加熱ロー
ラの温度を検出する第２の温度検出手段と、 前記第１の温度検出手段と前記第２の温度検出手段とに
より検出される温度情報に基づいて前記トナー加熱媒体
が回転状態か否かを判定する判定手段とを有することを
特徴とする定着装置。1. A heating roller which is made of a magnetic metal member and is heated by electromagnetic induction of induction heating means, a fixing roller which is arranged in parallel with the heating roller, and a tension roller which is stretched between the heating roller and the fixing roller. And an endless belt-shaped toner heating medium that is heated by the heating roller and is rotated by these rollers, and is pressed against the fixing roller via the toner heating medium and in a forward direction with respect to the toner heating medium. A pressure roller that rotates to form a fixing nip portion, a first temperature detecting unit that is disposed near the entrance of the fixing nip portion and that detects the temperature of the toner heating medium, and a hollow inside of the heating roller cylinder. a second temperature detecting means for detecting a disposed part temperature of the heating roller is detected with the first temperature sensing means by said second temperature detecting means Fixing apparatus wherein the toner heating medium based on the temperature information and having a determining means for determining whether the rotational state.
停止状態と判定された場合に前記誘導加熱手段の電磁誘
導による加熱を停止させることを特徴とする請求項１記
載の定着装置。2. The fixing device according to claim 1, wherein heating by the electromagnetic induction of the induction heating means is stopped when the toner heating medium is judged to be in a stopped state by the judging means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000194184A JP3478251B2 (en) | 2000-06-28 | 2000-06-28 | Fixing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000194184A JP3478251B2 (en) | 2000-06-28 | 2000-06-28 | Fixing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2002014566A JP2002014566A (en) | 2002-01-18 |
| JP3478251B2 true JP3478251B2 (en) | 2003-12-15 |
Family
ID=18693052
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000194184A Expired - Fee Related JP3478251B2 (en) | 2000-06-28 | 2000-06-28 | Fixing device |
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| Country | Link |
|---|---|
| JP (1) | JP3478251B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006058502A (en) * | 2004-08-19 | 2006-03-02 | Ricoh Co Ltd | Toner and developer for electrostatic image development, image forming apparatus, process cartridge using the same and image forming method |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005091890A (en) * | 2003-09-18 | 2005-04-07 | Ricoh Co Ltd | Fixing control device, image forming apparatus, and fixing control method |
| JP2005241470A (en) | 2004-02-26 | 2005-09-08 | Denso Corp | Detector and method for detecting force acting on tire |
| JP5041716B2 (en) * | 2005-03-18 | 2012-10-03 | 株式会社リコー | Fixing method and image forming method |
| JP2007017768A (en) * | 2005-07-08 | 2007-01-25 | Hitachi Displays Ltd | Display device |
| JP4592783B2 (en) * | 2008-05-20 | 2010-12-08 | シャープ株式会社 | Fixing device and image forming apparatus having the fixing device |
| JP5558696B2 (en) * | 2008-11-19 | 2014-07-23 | キヤノン株式会社 | Fixing apparatus and image forming apparatus |
| US8890771B2 (en) | 2010-01-06 | 2014-11-18 | Apple Inc. | Transparent electronic device |
| JP2014010319A (en) * | 2012-06-29 | 2014-01-20 | Canon Inc | Fixing device and image forming apparatus |
-
2000
- 2000-06-28 JP JP2000194184A patent/JP3478251B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006058502A (en) * | 2004-08-19 | 2006-03-02 | Ricoh Co Ltd | Toner and developer for electrostatic image development, image forming apparatus, process cartridge using the same and image forming method |
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|---|---|
| JP2002014566A (en) | 2002-01-18 |
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