JPH08286534A - Heating device and image forming device - Google Patents

Abstract

PURPOSE: To enable the improvement of fixing performance and the prevention of the occurrence of tailing, a peeling offset, a high-temperature offset, etc., for instance, in an image heating/fixing device of a device which is excellent in heating performance and durability and capable of reduction in the cost, etc., without various kinds of problems created in a conventional device using a ceramic heater as a heating member, in a film heating system heating device. CONSTITUTION: Members 12 and 20 for forming a nip part N with a film 11 are provided, at least one side member 12 of the nip forming members 12 and 20 is used as an electromagnetic induction heater member and a magnetic field generating means 13 for exerting a magnetic field on the member 12, to obtain electromagnetic induction heating is provided as well. Then, a heated material P is introduced between the film 11 in the nip part N and the other side member 20, to hold/carry the nip part N together with the film 11, so that the heated material P is heated by the electromagnetic induction heating of the heater member 12 with the film 11.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、例えば、電子写真方式
・静電記録方式等の作像プロセスを採用した画像形成装
置において、作像プロセス部で記録材（転写材・印字用
紙・感光紙・静電記録紙等）に転写方式或は直接方式で
形成担持させた目的の画像情報の未定着トナー像を固着
像として熱定着処理する加熱定着装置等として使用する
加熱装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording material (transfer material, printing paper, photosensitive paper, etc.) in an image forming process section in an image forming apparatus adopting an image forming process such as an electrophotographic method and an electrostatic recording method. The present invention relates to a heating device used as a heat fixing device for performing a heat fixing process of an unfixed toner image of intended image information formed and carried on an electrostatic recording paper or the like) by a transfer method or a direct method as a fixed image.

【０００２】[0002]

【従来の技術】以下便宜上、画像形成装置に具備される
加熱定着装置を例にして説明する。2. Description of the Related Art For the sake of convenience, a heat fixing device provided in an image forming apparatus will be described as an example.

【０００３】従来、加熱定着装置としては、熱ローラ方
式やフィルム加熱方式の装置が広く用いられている。Conventionally, as a heat fixing device, a device of a heat roller system or a film heating system has been widely used.

【０００４】ａ）熱ローラ方式の装置 熱ローラ方式の加熱定着装置は、所定の温度に加熱・温
調した熱ローラ（以下、定着ローラと記す）と、これに
圧接させた弾性加圧ローラを有し、該両ローラで形成さ
れる圧接ニップ部（以下、定着ニップ部と記す）に未定
着トナー像を形成担持させた被加熱材としての記録材を
導入して挟持搬送させることで、記録材の定着ニップ部
通過過程において定着ローラの熱で未定着トナー像を記
録材上に永久画像として固着定着させるものである。A) Heat roller type device The heat roller type heat fixing device comprises a heat roller (hereinafter referred to as a fixing roller) which is heated and adjusted to a predetermined temperature, and an elastic pressure roller brought into pressure contact with the heat roller. A recording material as a heated material having an unfixed toner image formed thereon is introduced into a pressure contact nip portion (hereinafter, referred to as a fixing nip portion) formed by the both rollers, and is nipped and conveyed to perform recording. The unfixed toner image is fixed and fixed as a permanent image on the recording material by the heat of the fixing roller in the process of the material passing through the fixing nip portion.

【０００５】図１３に該熱ローラ方式の加熱定着装置の
要部の構成模型図を示した。４０は定着ローラであり、
アルミニューム製の中空芯金（金属製中空ローラ）４２
と、その内部に挿入配設した加熱手段としてのハロゲン
ランプ４１と、中空芯金４２の外周面を被覆させた離型
性層４３等よりなる。中空芯金４２はハロゲンランプ４
１の通電発熱で内部から加熱される。離型性層４３は定
着ローラ表面に対するトナーオフセットを防止する層で
あり、トナー離型性に優れた性能を示すポリテトラフル
オロエチレン（ＰＴＦＥ）、パーフルオロアルコキシテ
トラフルオロエチレン共重合体（ＰＦＡ）などの層であ
る。４４は定着ローラ４０の表面に接触させて設けたサ
ーミスタであり、定着ローラ４０の表面温度を検知して
不図示の通電制御部へフィードする。通電制御部はサー
ミスタ４４で検知される定着ローラ表面温度が所定のほ
ぼ一定温度（定着温度、未定着トナー像を熱融解させて
記録材上に適切に定着させる温度）に維持されるように
ハロゲンランプ４４に対する給電をｏｎ／ｏｆｆ制御す
る。即ち定着ローラ４０は所定の定着温度に加熱・温調
される。FIG. 13 shows a schematic diagram of the essential parts of the heat roller type heat fixing device. 40 is a fixing roller,
Aluminum hollow core (hollow metal roller) 42
And a halogen lamp 41 as a heating means inserted and arranged therein, a release layer 43 and the like covering the outer peripheral surface of the hollow cored bar 42. Hollow core 42 is halogen lamp 4
It is heated from the inside by the energization heat generation of 1. The releasable layer 43 is a layer for preventing toner offset to the surface of the fixing roller, and polytetrafluoroethylene (PTFE), perfluoroalkoxytetrafluoroethylene copolymer (PFA), etc. exhibiting excellent toner releasability. Layers. Reference numeral 44 denotes a thermistor provided in contact with the surface of the fixing roller 40, which detects the surface temperature of the fixing roller 40 and feeds it to an energization controller (not shown). The energization control unit controls the halogen so that the surface temperature of the fixing roller detected by the thermistor 44 is maintained at a predetermined substantially constant temperature (fixing temperature, temperature at which the unfixed toner image is thermally melted and appropriately fixed on the recording material). The power supply to the lamp 44 is on / off controlled. That is, the fixing roller 40 is heated / controlled to a predetermined fixing temperature.

【０００６】５０は弾性加圧ローラであり、その両端部
側に不図示の加圧バネを配設して所定の圧接力をもって
上記定着ローラ４０の下面に圧接させて定着ローラ５０
との間に所定幅の定着ニップ部Ｎを形成する。この加圧
ローラ５０は、芯金５１と、その外側に同心一体にロー
ラ状に形成したシリコンゴム弾性層あるいはシリコンゴ
ムを発泡して成るスポンジ弾性層５２と、さらにその外
周面を被覆させた、定着ローラ外層と同様のＰＴＦＥあ
るいはＰＦＡの離型性層５３より成る。よってこの弾性
加圧ローラ５０を定着ローラに弾性に抗して圧接させる
ことで両ローラ４０・５０間に所定の十分なニップ幅の
定着ニップ部Ｎを形成させることがきる。Reference numeral 50 denotes an elastic pressure roller, and pressure springs (not shown) are provided on both ends of the elastic pressure roller, and they are pressed against the lower surface of the fixing roller 40 with a predetermined pressing force to fix the fixing roller 50.
A fixing nip portion N having a predetermined width is formed between the and. The pressure roller 50 includes a cored bar 51, a silicon rubber elastic layer concentrically formed on the outside thereof in a roller shape or a sponge elastic layer 52 formed by foaming silicon rubber, and the outer peripheral surface thereof. It comprises a release layer 53 of PTFE or PFA similar to the outer layer of the fixing roller. Therefore, by fixing the elastic pressure roller 50 against the fixing roller against the elasticity, a fixing nip portion N having a predetermined sufficient nip width can be formed between the rollers 40 and 50.

【０００７】そして上記の互いに圧接させた定着ローラ
４０と加圧ローラ５０を矢示のように回転駆動させ、定
着ニップ部Ｎに未定着トナー像ｔを形成担持させた被加
熱材としての記録材Ｐを導入して挟持搬送させること
で、記録材Ｐの定着ニップ部通過過程において定着ロー
ラ４０の熱で未定着トナー像ｔを記録材Ｐ上に永久画像
として定着させるものである。The above-mentioned fixing roller 40 and pressure roller 50, which are in pressure contact with each other, are rotationally driven as indicated by an arrow to form an unfixed toner image t in the fixing nip portion N, and a recording material as a heated material. By introducing P and nipping and conveying it, the unfixed toner image t is fixed as a permanent image on the recording material P by the heat of the fixing roller 40 while the recording material P passes through the fixing nip portion.

【０００８】このような熱ローラ方式の加熱定着装置に
おいては、被加熱材としての記録材Ｐに熱が奪われても
急激に定着ニップ部Ｎ中の温度が下がらないようにする
ために、定着ローラ４０にある程度の熱容量を持たせて
いる。このため、プリント信号が画像形成装置本体に送
られたときに、即座にプリント動作を開始できるよう
に、スタンバイ時も定着ローラ４０を所定温度に暖めた
状態にしている。すなわちプリント動作のないスタンバ
イ時に定着ローラ４０を所定温度に加熱しておき、プリ
ント信号を受信すると、記録材Ｐが定着ニップ部Ｎに到
達するまでに定着ローラ４０が定着に必要な温度になる
まで加熱を行って、記録材Ｐ上のトナー像ｔを加熱定着
していた。In such a heat roller type heat fixing device, in order to prevent the temperature in the fixing nip portion N from rapidly lowering even if heat is absorbed by the recording material P as a material to be heated, the fixing is performed. The roller 40 has a certain heat capacity. For this reason, when the print signal is sent to the main body of the image forming apparatus, the fixing roller 40 is kept warm to a predetermined temperature even during standby so that the printing operation can be started immediately. That is, when the fixing roller 40 is heated to a predetermined temperature during the standby without a printing operation and the print signal is received, the fixing roller 40 reaches the temperature required for fixing before the recording material P reaches the fixing nip portion N. The toner image t on the recording material P was heated and fixed by heating.

【０００９】ｂ）フィルム加熱方式の装置 この装置は、特開昭63 -313182号公報・特開平2-157878
号公報・特開平4- 44075号公報・特開平4-204980号公報
等に提案されいる。図１４の（ａ）に該装置の要部の概
略構成を示した。即ち、支持体６２に固定支持させた加
熱部材（加熱体、以下ヒータと記す）６１と、該ヒータ
６１に耐熱性の薄肉フィルム（以下、定着フィルムと記
す）６３を挟んで所定のニップ幅のニップ部（定着ニッ
プ部）Ｎを形成させて圧接させた弾性加圧ローラ５０を
有する。ヒータ６１は通電により所定の温度に加熱・温
調される。定着フィルム６３は不図示の駆動手段或は加
圧ローラ５０の回転力により、定着ニップ部Ｎにおいて
ヒータ６１面に密着・摺動しつつ矢示ａの方向に搬送移
動される、円筒状或はエンドレスベルト状、もしくはロ
ール巻きの有端ウエブ状の部材である。B) Film heating type device This device is disclosed in JP-A-63-313182 and JP-A-2-157878.
It is proposed in Japanese Patent Laid-Open No. 4-44075, Japanese Patent Laid-Open No. 4-204980, and the like. FIG. 14A shows a schematic configuration of the main part of the device. That is, a heating member (heating body, hereinafter referred to as a heater) 61 fixedly supported by a support body 62 and a heat-resistant thin film (hereinafter referred to as a fixing film) 63 are sandwiched between the heaters 61 to provide a predetermined nip width. The nip portion (fixing nip portion) N is formed and the elastic pressure roller 50 is brought into pressure contact. The heater 61 is heated / controlled to a predetermined temperature by being energized. The fixing film 63 is conveyed in the direction of arrow a while being in close contact with and sliding on the surface of the heater 61 in the fixing nip portion N by the rotational force of the driving means (not shown) or the pressure roller 50. It is an endless belt-shaped member or a roll-wound end-shaped web-shaped member.

【００１０】ヒータ６１を所定の温度に加熱・温調さ
せ、定着フィルム６３を搬送移動ａさせた状態におい
て、定着ニップ部Ｎの定着フィルム６３と加圧ローラ５
０との間に被加熱材としての未定着トナー像ｔを形成担
持させた記録材Ｐを導入すると、記録材Ｐは定着フィル
ム６３の面に密着して該定着フィルム６３と一緒に定着
ニップ部Ｎを挟持搬送される。この定着ニップ部Ｎにお
いて、記録材Ｐ・トナー像ｔがヒータ６１により定着フ
ィルム６３を介して加熱されて記録材Ｐ上のトナー像ｔ
が加熱定着される。定着ニップ部Ｎを通った記録材部分
は定着フィルム６３の面から剥離して搬送される。In a state where the heater 61 is heated / controlled to a predetermined temperature and the fixing film 63 is conveyed and moved a, the fixing film 63 in the fixing nip portion N and the pressure roller 5 are.
When the recording material P on which the unfixed toner image t as a material to be heated is formed and carried between the recording material P and 0, the recording material P comes into close contact with the surface of the fixing film 63 and the fixing nip portion together with the fixing film 63. N is nipped and conveyed. In the fixing nip portion N, the recording material P / toner image t is heated by the heater 61 through the fixing film 63, and the toner image t on the recording material P is heated.
Is heated and fixed. The recording material portion passing through the fixing nip portion N is separated from the surface of the fixing film 63 and conveyed.

【００１１】加熱部材としてのヒータ６１には一般にセ
ラミックヒータが使用される。例えば、アルミナ等の電
気絶縁性・良熱伝導性・低熱容量のセラミック基板６１
ａの面（定着フィルム６３と対面する側の面）に基板長
手（図面に垂直の方向）に沿って銀パラジューム（Ａｇ
／Ｐｂ）・Ｔａ₂ Ｎ等の通電発熱抵抗層６１ｂを形成具
備させ、さらに該発熱抵抗層形成面を薄肉のガラス保護
層６１ｃで覆ってなるものである。このセラミックヒー
タ６１は通電発熱抵抗層６１ｂに通電がなされることに
より該通電発熱抵抗層６１ｂが発熱してセラミック基板
６１ａ・ガラス保護層６１ｃを含むヒータ全体が急速昇
温する。このヒータ６１の昇温が不図示の温度検知手段
により検知されて不図示の通電制御部へフィードされ
る。通電制御部は温度検知手段で検知されるヒータ温度
が所定のほぼ一定温度（定着温度）に維持されるように
通電発熱抵抗層６１ｂに対する給電を制御する。即ちヒ
ータ６１は所定の定着温度に加熱・温調される。A ceramic heater is generally used as the heater 61 as a heating member. For example, a ceramic substrate 61 made of alumina or the like, which has electric insulation, good thermal conductivity, and low heat capacity.
On the surface of a (the surface facing the fixing film 63) along the length of the substrate (direction perpendicular to the drawing), the silver palladium (Ag
/Pb).Ta ₂ N and the like, and a conductive heating resistance layer 61b is formed and provided, and the heating resistance layer forming surface is covered with a thin glass protective layer 61c. In the ceramic heater 61, when the energization heating resistance layer 61b is energized, the energization heating resistance layer 61b generates heat, and the entire heater including the ceramic substrate 61a and the glass protective layer 61c is rapidly heated. The temperature rise of the heater 61 is detected by a temperature detecting means (not shown) and is fed to an energization controller (not shown). The energization control unit controls the power supply to the energization heating resistance layer 61b so that the heater temperature detected by the temperature detection unit is maintained at a predetermined substantially constant temperature (fixing temperature). That is, the heater 61 is heated / controlled to a predetermined fixing temperature.

【００１２】定着フィルム６３は、定着ニップ部Ｎにお
いてヒータ６１の熱を効率よく被加熱材としての記録材
Ｐに与えるため、厚みは２０〜７０μｍとかなり薄くし
ている。図１４の（ｂ）に定着フィルム６３の層構成例
の模型図を示した。この定着フィルム６３は、フィルム
基層６３ａ、導電性プライマー層６３ｂ、離型性層６３
ｃの３層構成である。フィルム基層６３ａ側がヒータ側
であり、離型性層６３ｃ側が加圧ローラ側である。フィ
ルム基層６３ａはヒータ６１のガラス保護層６１ｃより
絶縁性の高いポリイミド、ポリアミドイミド、ＰＥＥＫ
等であり、耐熱性、高弾性を有している。また、このフ
ィルム基層６３ａにより定着フィルム６３全体の引裂強
度等の機械的強度を保っている。導電性プライマー層６
３ｂは厚み２〜６μｍ程度の薄い層で形成されている。
離型性層６３ｃは定着フィルム６３に対するトナーオフ
セット防止層であり、ＰＦＡ、ＰＴＦＥ、ＦＥＰ等のフ
ッ素樹脂を厚み１０μｍ程度に被覆して形成してある。The fixing film 63 has a considerably small thickness of 20 to 70 μm in order to efficiently apply the heat of the heater 61 to the recording material P as a material to be heated in the fixing nip portion N. FIG. 14B shows a model diagram of an example of the layer structure of the fixing film 63. The fixing film 63 includes a film base layer 63a, a conductive primer layer 63b, and a release layer 63.
It has a three-layer structure of c. The film base layer 63a side is the heater side, and the releasable layer 63c side is the pressure roller side. The film base layer 63a is made of polyimide, polyamideimide, or PEEK, which has higher insulation than the glass protective layer 61c of the heater 61.
Etc., and has heat resistance and high elasticity. Further, the film base layer 63a maintains mechanical strength such as tear strength of the entire fixing film 63. Conductive primer layer 6
3b is formed of a thin layer having a thickness of about 2 to 6 μm.
The releasable layer 63c is a toner offset prevention layer for the fixing film 63, and is formed by coating a fluororesin such as PFA, PTFE or FEP to a thickness of about 10 μm.

【００１３】定着フィルム６３を全体に絶縁性のものに
した場合には、画像形成装置の転写部で電荷が与えられ
た記録材（転写材）が定着ニップ部Ｎを通過することに
より定着フィルム６３と加圧ローラ５０の表面電位が上
昇し、チャージアップを引き起こす。このため定着フィ
ルム６３と加圧ローラ５０の間に電界が発生して定着フ
ィルムにトナーオフセットが発生することがある。これ
を避けるために上記のように定着フィルム６３の中間層
であるプライマー層６３ｂにカーボンブラックを混入す
る等により該プライマー層の導電化を行っている。さら
にこの導電性プライマー層６３ｂを電気的にアースに落
としている。これにより定着フィルム６３のチャージア
ップを防ぎ、トナーオフセットの発生を防止している。When the fixing film 63 is entirely insulative, the recording material (transfer material) to which electric charges have been applied in the transfer portion of the image forming apparatus passes through the fixing nip portion N so that the fixing film 63 is formed. Then, the surface potential of the pressure roller 50 rises, causing charge-up. Therefore, an electric field may be generated between the fixing film 63 and the pressure roller 50 to cause toner offset on the fixing film. In order to avoid this, the primer layer is made conductive by mixing carbon black into the primer layer 63b which is the intermediate layer of the fixing film 63 as described above. Further, the conductive primer layer 63b is electrically grounded. This prevents the fixing film 63 from being charged up and prevents toner offset.

【００１４】このようなフィルム加熱方式の装置には加
熱部材としてのヒータ６１や定着フィルム６３に低熱容
量のものを使用でき、また定着ニップ部Ｎのみを加熱す
ることで、クイックスタートの加熱定着を実現でき、ス
タンバイ時においてもヒータ６１を暖めておく必要はな
く、消費電力を低く抑えられる。In such a film heating type apparatus, a heater 61 as a heating member and a fixing film 63 having a low heat capacity can be used, and by heating only the fixing nip portion N, quick start heat fixing can be performed. This can be realized, and it is not necessary to warm the heater 61 even during standby, and power consumption can be suppressed to a low level.

【００１５】[0015]

【発明が解決しようとする課題】しかしながら、上述
ａ）の熱ローラ方式の加熱定着装置（図１３）では、ス
タンバイ時にも定着ローラ４０を所定温度に暖めておく
ために、常時電力を供給しなくてはならず、消費電力が
多い。また、画像形成装置本体の電源をオンしてから所
定温度に達するまでに定着ローラ４０の熱容量に応じて
時間がかかり、例えば最近の薄肉の定着ローラであって
も、最低３０秒位はウエイト状態となる（以後ウエイト
タイムという）。このため、スタンバイ時の消費電力を
極力減らすために、非プリント時に電源をオフしておい
てもプリントする度に定着ローラ４０が所定温度に暖ま
るまで待たなくてはならなくなる。However, in the heat roller type heat fixing device (FIG. 13) of the above a), the fixing roller 40 is warmed to a predetermined temperature even in the standby state, so that power is not always supplied. Power consumption. Further, it takes time depending on the heat capacity of the fixing roller 40 after the power of the image forming apparatus main body is turned on until the temperature reaches a predetermined temperature. For example, even a recent thin fixing roller has a waiting state for at least 30 seconds. (Hereinafter referred to as wait time). For this reason, in order to reduce the power consumption during standby as much as possible, it is necessary to wait until the fixing roller 40 warms up to a predetermined temperature each time printing is performed, even if the power is turned off during non-printing.

【００１６】上述ｂ）のフィルム加熱方式の加熱定着装
置は、熱容量の小さな加熱部材としてのヒータ６１等で
ウエイトタイムのない定着を実施できて、スタンバイ状
態が必要ではなくなるが、以下のような問題がある。In the film heating type heat fixing device of the above b), the heater 61 or the like having a small heat capacity can perform the fixing without the wait time, and the standby state is not necessary, but the following problems occur. There is.

【００１７】即ち、低熱容量のヒータ６１により定着フ
ィルム６３を介して被加熱材としての記録材Ｐに熱を与
えるため、ヒータ６１のガラス保護層６１ｃや定着フィ
ルム６３の厚みは極力抑えなければならない。すなわち
定着ニップ部Ｎへの熱の伝わりを良好に保つためには、
それぞれの厚みを抑える必要があり、これにより初めて
ウエイトタイムのない加熱定着が可能となる。That is, since the heater 61 having a low heat capacity applies heat to the recording material P as a material to be heated through the fixing film 63, the thickness of the glass protective layer 61c of the heater 61 and the fixing film 63 must be suppressed as much as possible. . That is, in order to maintain good heat transfer to the fixing nip portion N,
It is necessary to reduce the thickness of each, and this makes it possible to perform heat fixing without a wait time for the first time.

【００１８】ガラス保護層６１ｃや定着フィルム６３の
厚みを極力抑えた場合、絶縁破壊を起こさぬために、ヒ
ータ６１の導通部分と定着フィルム中間層の導電性プラ
イマー層６３ｂの間の耐電圧を保たなければならないた
め、ガラス保護層６１ｃやフィルム基層６３ａのポリイ
ミド等は抵抗値の高い絶縁性となっている。When the thicknesses of the glass protective layer 61c and the fixing film 63 are suppressed as much as possible, the withstand voltage between the conductive portion of the heater 61 and the conductive primer layer 63b of the fixing film intermediate layer is maintained in order to prevent dielectric breakdown. Therefore, the polyimide or the like of the glass protective layer 61c and the film base layer 63a has an insulating property with a high resistance value.

【００１９】ガラス保護層６１ｃの厚みを厚くすること
で耐電圧は満たすことはできるが、この場合は、熱伝導
性が悪くなり、定着不良を引き起こしてしまう。Although the withstand voltage can be satisfied by increasing the thickness of the glass protective layer 61c, in this case, the thermal conductivity is deteriorated and fixing failure is caused.

【００２０】このため絶縁耐圧を持たせ、かつウエイト
タイムのない加熱定着を可能とするためには、ガラス保
護層６１ｃを薄くして、かつガラス保護層６１ｃより耐
電圧性の強いフィルム基層６３ａの厚みを極力抑える必
要があり、フィルム基層６３ａの厚みは１５〜６５μｍ
とフィルム全体の７５％以上の厚みを持たせることで、
絶縁性、および機械的強度を確保している。Therefore, in order to have a withstand voltage and enable heat fixing without a wait time, the glass protective layer 61c is made thin and the film base layer 63a having a higher withstand voltage than the glass protective layer 61c is formed. It is necessary to suppress the thickness as much as possible, and the thickness of the film base layer 63a is 15 to 65 μm.
By having a thickness of 75% or more of the whole film,
Insulation and mechanical strength are secured.

【００２１】フィルム中間層のプライマー層６３ｂは前
述したように定着フィルム６３がチャージアップしてト
ナーオフセットを引き起こすことを防止するために、導
電性を付与する必要があり、定着フィルムの構成を複雑
にしている。また薄い定着フィルム中に満遍なくごく薄
い層で導電性プライマー層６３ｂを形成する必要があ
り、コストアップの要因となってしまう。The primer layer 63b, which is an intermediate layer of the film, is required to have conductivity in order to prevent the fixing film 63 from being charged up and causing toner offset as described above, which complicates the structure of the fixing film. ing. Further, it is necessary to form the conductive primer layer 63b as a thin layer evenly in the thin fixing film, which causes a cost increase.

【００２２】定着フィルムの表面を絶縁性とし、さらに
加圧ローラ表層の表面抵抗を高くした場合には、記録材
Ｐが定着ニップ部Ｎから排出される際に定着フィルム表
面が剥離帯電される。この結果、剥離帯電した定着フィ
ルムが再度定着ニップ部Ｎに達したとき、記録材上のト
ナー像を剥ぎ取ってしまう（以後、剥離オフセットとい
う）。When the surface of the fixing film is made insulating and the surface resistance of the surface layer of the pressure roller is made high, the surface of the fixing film is peeled and charged when the recording material P is discharged from the fixing nip portion N. As a result, when the peeling-charged fixing film reaches the fixing nip portion N again, the toner image on the recording material is peeled off (hereinafter referred to as peeling offset).

【００２３】さらに定着フィルム表層の離型層６３ｃと
してのフッ素樹脂層は熱伝導性の悪化を防ぐために、１
０μｍ程度のごく薄い層で形成されているため、定着フ
ィルム表面にムラ無く塗布することが困難となる。特に
ピンホールやごく薄く離型層が塗布されている部位が存
在すると、記録材Ｐが定着ニップ部Ｎに搬送されてきた
際に、記録材上の転写保持電荷がこの部位を通じて定着
フィルム６３の導電性プライマー層６３ｂにリークして
しまうことがある。また、耐久により定着フィルム表面
が摩耗されると、定着フィルムの表層の高抵抗離型性層
６３ｃが薄くなり、同様に転写保持電荷が導電性プライ
マー層６３ｂにリークしてしまう。この場合、記録材Ｐ
上のトナー像ｔはもはや記録材上に吸着された状態にな
いため、定着フィルム上に転移してオフセットを引き起
こしてしまう。Further, the fluororesin layer as the release layer 63c on the surface of the fixing film has a thickness of 1 in order to prevent deterioration of thermal conductivity.
Since it is formed of a very thin layer of about 0 μm, it becomes difficult to apply it evenly on the surface of the fixing film. In particular, if there is a pinhole or a portion where the release layer is applied very thinly, when the recording material P is conveyed to the fixing nip portion N, the transfer holding charge on the recording material of the fixing film 63 passes through this portion. It may leak to the conductive primer layer 63b. Further, when the surface of the fixing film is abraded due to durability, the high resistance release layer 63c on the surface layer of the fixing film becomes thin, and similarly, the transfer holding charge leaks to the conductive primer layer 63b. In this case, the recording material P
The upper toner image t is no longer in a state of being adsorbed on the recording material, so that it is transferred to the fixing film and causes an offset.

【００２４】また、この従来のフィルム加熱方式の装置
構成では、定着ニップ部Ｎにおいてヒータ６１から定着
フィルム６３を介して加圧ローラ５０の方向への熱伝達
に主眼をおいているので、加熱定着装置のヒータ長手方
向の熱の伝達を良好とすることは構成上困難である。こ
のためヒータ長手方向の幅サイズが小さい記録材を通紙
した場合、ヒータ長手方向の通紙部領域のヒータ部分の
熱は記録材上のトナー像の熱定着に使用されるが、ヒー
タ長手方向の非通紙部領域のヒータ部分の熱は直接加圧
ローラを加熱することになる。よって加圧ローラ５０の
長手方向の通紙部領域と非通紙部領域に温度差が生じ
（非通紙部昇温）、加圧ローラ５０を駆動して定着フィ
ルム６３・記録材Ｐを搬送する系では部分的に搬送力が
異なる。この結果、従動回転する薄い定着フィルム６３
にねじれが生じ、最悪の場合挫屈により定着フィルム６
３が破損してしまう。また、昇温部位の耐熱性も十分に
考慮しなくてはならない等、部材のコストアップをも招
いてしまう。さらにヒータ長手方向の熱の流れが少ない
ため、ヒータ６１の発熱抵抗層６１ｂの長手に沿う抵抗
値分布がそのまま記録材の定着性に影響を与えることか
ら、ヒータ６１の発熱抵抗層６１ｂの長手に沿う抵抗値
分布にシビアな均一性が求められてしまう。Further, in this conventional film heating type apparatus configuration, the heat is transferred from the heater 61 to the pressure roller 50 through the fixing film 63 in the fixing nip portion N, so that heat fixing is performed. It is difficult to improve the heat transfer in the longitudinal direction of the heater of the device because of the structure. Therefore, when a recording material having a small width in the longitudinal direction of the heater is passed through, the heat of the heater portion in the paper passing area in the longitudinal direction of the heater is used for heat fixing the toner image on the recording material. The heat of the heater portion in the non-sheet passing portion area directly heats the pressure roller. Therefore, a temperature difference occurs between the paper passing portion area and the non-paper passing portion area in the longitudinal direction of the pressure roller 50 (temperature rise of the non-paper passing portion), and the pressure roller 50 is driven to convey the fixing film 63 and the recording material P. In the system, the transporting force is partially different. As a result, the thin fixing film 63 that is driven to rotate
Twist occurs, and in the worst case buckling causes the fixing film 6
3 will be damaged. In addition, the heat resistance of the temperature rising portion must be fully taken into consideration, leading to an increase in the cost of the member. Furthermore, since the heat flow in the longitudinal direction of the heater is small, the resistance value distribution along the length of the heating resistance layer 61b of the heater 61 directly affects the fixing property of the recording material. Severe uniformity is required for the resistance value distribution along the line.

【００２５】さらに定着ニップ部Ｎにおいて熱容量の小
さな定着フィルム６３が急激に加熱され、その伝熱によ
って定着ニップ部Ｎに導入した記録材Ｐ上のトナー像ｔ
を加熱定着しているため、記録材は定着ニップ部Ｎに進
入する直前まで加熱されず、定着ニップ部Ｎに入った途
端に急激に加熱されることになる。このとき定着ニップ
部Ｎに突入した記録材からは加熱により水蒸気が放出さ
れるが、この水蒸気は定着ニップ部Ｎ内へ突入すること
ができず、定着ニップ部Ｎの記録材搬送方向上流側外部
へ流される。この結果、記録材より発生した水蒸気は、
また定着ニップ部Ｎに達していない転写材部分上の未定
着トナー像を記録材搬送方向上流側へ吹き飛ばし画質を
劣化させる（以後、尾引きという）。Further, the fixing film 63 having a small heat capacity is rapidly heated in the fixing nip portion N, and the toner image t on the recording material P introduced into the fixing nip portion N by the heat transfer.
Since the recording material is heated and fixed, the recording material is not heated until just before entering the fixing nip portion N, and is heated rapidly as soon as it enters the fixing nip portion N. At this time, water vapor is released from the recording material that has entered the fixing nip portion N by heating, but this water vapor cannot penetrate into the fixing nip portion N and the outside of the fixing nip portion N on the upstream side in the recording material conveyance direction. Shed to. As a result, the water vapor generated from the recording material is
Further, the unfixed toner image on the transfer material portion that has not reached the fixing nip portion N is blown to the upstream side in the recording material conveyance direction to deteriorate the image quality (hereinafter referred to as tailing).

【００２６】さらに記録材は定着ニップ部Ｎ内の記録材
搬送方向下流側まで加熱され、定着ニップ部Ｎを出て、
その時点では未だトナーが十分に溶融された状態のまま
定着フィルム６３から分離させられるため、高温オフセ
ットの発生を引き起こしてしまう。Further, the recording material is heated to the downstream side in the fixing nip portion N in the recording material conveying direction, exits the fixing nip portion N, and
At that time, since the toner is still separated from the fixing film 63 in a sufficiently melted state, high temperature offset occurs.

【００２７】本発明は上記後者のフィルム加熱方式の加
熱装置に属するものであるが、従来装置における上述の
ような各種問題点のない加熱装置、及び該加熱装置を像
加熱装置として備える画像形成装置を提供することを目
的とする。The present invention belongs to the latter film heating type heating device, but a heating device which does not have the above-mentioned various problems in the conventional device, and an image forming apparatus having the heating device as an image heating device. The purpose is to provide.

【００２８】[0028]

【課題を解決するための手段】本発明は下記の構成を特
徴とする加熱装置及び画像形成装置である。The present invention is a heating device and an image forming apparatus characterized by the following configurations.

【００２９】（１）フィルムを挟んでニップ部を形成す
る部材と、そのニップ形成部材の少なくとも一方側部材
は電磁誘導発熱性部材にし該部材に磁界を作用させて電
磁誘導発熱させる磁界発生手段を具備させ、ニップ部の
フィルムと他方側部材の間に被加熱材を導入してフィル
ムと共にニップ部を挟持搬送させ、ニップ部において被
加熱材をフィルムを介して電磁誘導発熱性部材の電磁誘
導発熱の熱で加熱するようにしたことを特徴とする加熱
装置。(1) A member forming a nip portion with a film sandwiched between it and at least one member of the nip forming member is an electromagnetic induction heat-generating member, and a magnetic field generating means for applying a magnetic field to the member to generate electromagnetic induction heat is provided. The heated material is introduced between the film in the nip portion and the member on the other side, and the nip portion is nipped and conveyed together with the film. In the nip portion, the heated material is electromagnetically induced heat generation of the electromagnetic induction heating member through the film. A heating device characterized by being heated by the heat of.

【００３０】（２）フィルムに導電性を付与したことを
特徴とする前記（１）記載の加熱装置。(2) The heating device as described in (1) above, wherein the film is provided with conductivity.

【００３１】（３）フィルムは、電磁誘導発熱性部材側
のフィルム内面の表面抵抗値が、その反対側のフィルム
外面の表面抵抗値よりも低い抵抗値であることを特徴と
する前記（２）記載の加熱装置。(3) The film is characterized in that the surface resistance value of the inner surface of the film on the electromagnetic induction heating member side is lower than the surface resistance value of the outer surface of the film on the opposite side. The heating device described.

【００３２】（４）他方側部材の表層に導電性を付与し
たことを特徴とする前記（１）乃至（３）の何れかに記
載の加熱装置。(4) The heating device according to any one of the above (1) to (3), wherein the surface layer of the other member is provided with conductivity.

【００３３】（５）電磁誘導発熱性部材に、フィルム搬
送方向に直交する方向である長手方向における熱容量に
分布を持たせ、長手中央部に比べ両端部の方が熱容量が
大きいことを特徴とする前記（１）記載の加熱装置。(5) The electromagnetic induction heat-generating member is characterized in that the heat capacity in the longitudinal direction, which is the direction orthogonal to the film transport direction, is distributed, and that the heat capacity at both ends is greater than at the longitudinal center. The heating device according to (1) above.

【００３４】（６）電磁誘導発熱性部材と、該部材を電
磁誘導加熱させる磁界発生手段としての励磁コイルとの
間に間隙が存在し、その隙間が電磁誘導発熱性部材のフ
ィルム搬送方向に直交する方向である長手方向において
長手中央部に比べ両端部の方が広くなっていることを特
徴とする前記（１）記載の加熱装置。(6) There is a gap between the electromagnetic induction heat-generating member and the exciting coil as the magnetic field generating means for heating the member by electromagnetic induction, and the gap is orthogonal to the film conveying direction of the electromagnetic induction heat-generating member. The heating device according to (1) above is characterized in that both end portions are wider than a longitudinal center portion in a longitudinal direction which is a direction of the heating.

【００３５】（７）電磁誘導発熱性部材はフィルム搬送
方向に直交する方向である長手方向において材質を異に
する複数の部材で構成され、長手中央部の透磁率に比べ
両端部の透磁率を低く形成したことを特徴とする前記
（１）記載の加熱装置。(7) The electromagnetic induction heating member is composed of a plurality of members made of different materials in the longitudinal direction which is the direction orthogonal to the film transport direction, and has a magnetic permeability at both ends that is higher than the magnetic permeability at the longitudinal center. The heating device according to (1) above, which is formed low.

【００３６】（８）電磁誘導発熱性部材はニップ部の被
加熱材入口直前部において被加熱材搬送方向に関して他
方側部材から離間する方向に傾斜、あるいは湾曲した形
状をなしていることを特徴とする前記（１）記載の加熱
装置。(8) The electromagnetic induction heat-generating member is inclined or curved in a direction away from the other member in the conveying direction of the material to be heated in the portion just before the material to be heated inlet of the nip portion. The heating device according to (1) above.

【００３７】（９）電磁誘導発熱性部材はニップ部にお
いてフィルム搬送方向に複数の部材から構成され、フィ
ルム搬送方向上流側の部材の透磁率が下流側の部材の透
磁率に比べ大きいことを特徴とする前記（１）記載の加
熱装置。(9) The electromagnetic induction heating member is composed of a plurality of members in the film transport direction at the nip portion, and the magnetic permeability of the upstream member in the film transport direction is higher than that of the downstream member. The heating device according to (1) above.

【００３８】（１０）被加熱材が加熱処理すべき画像を
担持させた記録材であり、装置が該被記録材に画像を加
熱処理する像加熱装置であることを特徴とする前記
（１）乃至（９）の何れかに記載の加熱装置。(10) The heating material is a recording material carrying an image to be heat-treated, and the apparatus is an image heating device for heating the image on the recording material. The heating device according to any one of (1) to (9).

【００３９】（１１）前記（１）乃至（９）の何れかに
記載の加熱装置を像加熱装置として備えていることを特
徴とする画像形成装置。(11) An image forming apparatus comprising the heating device according to any one of (1) to (9) as an image heating device.

【００４０】[0040]

【作用】即ち本発明は、加熱部材を、従来のセラミック
ヒータではなく、電磁誘導発熱性部材（磁気誘導発熱性
部材）にし、これを磁界発生手段の磁界により電磁誘導
発熱させ、その熱をフィルムを介して被加熱材に与える
ようにしたことに特徴を有するフィルム加熱方式・電磁
誘導加熱方式の加熱装置である。That is, in the present invention, the heating member is not a conventional ceramic heater but an electromagnetic induction heat generating member (magnetic induction heat generating member), and the heat is generated by electromagnetic induction by the magnetic field of the magnetic field generating means, and the heat is formed into a film. It is a film heating type / electromagnetic induction heating type heating device characterized in that it is applied to the material to be heated via.

【００４１】．加熱部材としての電磁誘導発熱性部材
は具体的には強磁性導電材であるＦｅ・Ｃｏ・Ｎｉ・Ｃ
ｕ・Ｃｒ等の金属、それらの合金を使用することがで
き、これにより装置の加熱部材はそれ自体低熱容量で高
熱伝導性の部材にすることができる。そしてこれに磁界
を作用させて電磁誘導発熱させることで、従来の低熱容
量のセラミックヒータと同様に、あるいはこれよりもさ
らに効率的に、急速に所定の温度へ昇温・加熱状態にさ
せることができる。.. The electromagnetic induction heating member as a heating member is specifically Fe / Co / Ni / C which is a ferromagnetic conductive material.
Metals such as u.Cr and alloys thereof can be used, whereby the heating member of the device can itself be a member having low heat capacity and high thermal conductivity. By applying a magnetic field to this to generate electromagnetic induction heat, the temperature can be rapidly raised to a predetermined temperature and brought into a heating state in the same manner as in a conventional low heat capacity ceramic heater or more efficiently. it can.

【００４２】したがって、ニップ部を高速で加熱するこ
とが可能となり、加熱部材としてセラミックヒータを用
いたものと同様にスタンバイ中に予備加熱する必要がな
いため、ウエイトタイムをなくすことができる。Therefore, it is possible to heat the nip portion at high speed, and it is not necessary to preheat during standby as in the case of using a ceramic heater as a heating member, so that the wait time can be eliminated.

【００４３】．また加熱部材が電磁誘導性部材である
ことで、セラミックヒータである場合には必要とする該
セラミックヒータとフィルムとの間の絶縁破壊防止対策
処置の必要性がなくなり、したがってフィルムの絶縁耐
圧性は必要なく、フィルムのチャージアップを防止する
ために、フィルムの基層に容易に導電性を付与すること
が可能となる。また、フィルムの７５％以上を占める基
層に導電性を付与することができるため、導電部材の分
散性も向上し、フィルムの長手方向、周方向に満遍なく
導電性を付与できる。これによりフィルムの生産性を向
上することができ、コストダウンを容易にする。.. Further, since the heating member is an electromagnetic induction member, it is not necessary to take measures for preventing dielectric breakdown between the ceramic heater and the film, which is necessary when the heating member is a ceramic heater. It is possible to easily impart conductivity to the base layer of the film in order to prevent charge-up of the film without need. In addition, since conductivity can be imparted to the base layer that occupies 75% or more of the film, the dispersibility of the conductive member is also improved, and the conductivity can be imparted evenly in the longitudinal direction and the circumferential direction of the film. Thereby, the productivity of the film can be improved and the cost can be easily reduced.

【００４４】．加熱部材は上述のように強磁性金属部
材であり熱伝導性に優れているため、セラミックヒータ
とは異なり、長手方向への熱の流れを生み、小サイズの
被加熱材が通紙された場合であっても非通紙部領域の熱
を通紙部領域へ流す働きが良好であり、非通紙部昇温現
象の緩和がなされる。よって非通紙部昇温に起因するフ
ィルム挫屈等の問題を引き起こすことなく、装置構成部
材に高い耐熱性も要求されない。[0044] Since the heating member is a ferromagnetic metal member and has excellent thermal conductivity as described above, unlike the ceramic heater, it produces heat flow in the longitudinal direction, and when a small-sized material to be heated is passed through. Even in this case, the function of allowing the heat of the non-sheet passing portion area to flow to the sheet passing portion area is good, and the temperature rise phenomenon of the non-sheet passing portion is alleviated. Therefore, a problem such as film buckling due to a temperature rise in the non-sheet passing portion is not caused, and high heat resistance is not required for the apparatus constituent members.

【００４５】．加熱部材がセラミックヒータである場
合には発熱抵抗層の長手に沿う抵抗値分布が該セラミッ
クヒータの長手に沿う温度分布、画像加熱定着装置にあ
っては定着性にシビアに効いてくるのに対して、本発明
のように加熱部材が電磁誘導発熱性部材である場合には
長手方向の発熱分布に寄与する特性も緩和され、画像加
熱定着装置にあっては転写材の定着性を均一にする働き
がある。[0045] When the heating member is a ceramic heater, the resistance value distribution along the length of the heating resistance layer has a temperature distribution along the length of the ceramic heater, whereas in the image heating and fixing device, the fixing property is severely affected. Therefore, when the heating member is an electromagnetic induction heat-generating member as in the present invention, the characteristics contributing to the heat generation distribution in the longitudinal direction are alleviated, and in the image heating and fixing device, the fixing property of the transfer material is made uniform. It has a function.

【００４６】また、加熱部材の長手方向の形状や材料は
容易に変更が可能であるので、これらを変えるだけで容
易に任意の温度分布を持たせることができる。Further, since the shape and material of the heating member in the longitudinal direction can be easily changed, it is possible to easily give an arbitrary temperature distribution only by changing these.

【００４７】．フィルムの基層を複数層構成とし、加
熱部材に接触する側の層を導電性にしニップ部側の層を
高抵抗層とすることにより、フィルム表面の絶縁性を高
めることが可能となる。この結果、画像加熱定着装置に
あっては被加熱材としての記録材上の転写保持電荷がフ
ィルムの導電性層にリークする可能性が無くなり、トナ
ー像が記録材上に静電気的に吸着された状態が維持され
るため、オフセット等の画像劣化を引き起こすことがな
い。.. By forming the base layer of the film into a plurality of layers, making the layer in contact with the heating member conductive and making the layer on the nip side a high resistance layer, it becomes possible to enhance the insulating property of the film surface. As a result, in the image heating and fixing device, there is no possibility that the transfer holding charge on the recording material as the material to be heated leaks to the conductive layer of the film, and the toner image is electrostatically adsorbed on the recording material. Since the state is maintained, image deterioration such as offset does not occur.

【００４８】．加熱部材の少なくとも上流側を、ニッ
プ部を形成する他方側部材から離間する方向へ傾斜させ
る等することにより、ニップ部直前の雰囲気の温度を高
め、ニップ部直前とニップ部内上流との急激な温度差を
無くすことができる。.. The temperature of the atmosphere immediately before the nip portion is increased by inclining at least the upstream side of the heating member in the direction away from the other side member forming the nip portion, thereby increasing the temperature immediately before the nip portion and the abrupt temperature between the inside of the nip portion and the upstream side. The difference can be eliminated.

【００４９】これによりニップ部直前に搬送されてきた
被記録材は、ニップ部直前の加熱部材からの放射熱をフ
ィルムを介して与えられることになる（プレ加熱）。As a result, the recording material conveyed immediately before the nip portion is given radiant heat from the heating member immediately before the nip portion through the film (pre-heating).

【００５０】したがって画像加熱定着装置にあっては、
記録材上のトナー像は上記のプレ加熱で若干溶融される
ため、ニップ部において記録材から発生した水蒸気がニ
ップ部直前のトナー像を吹き飛ばす尾引きの発生を防止
できる。Therefore, in the image heating and fixing device,
Since the toner image on the recording material is slightly melted by the above-mentioned preheating, it is possible to prevent the occurrence of tailing in which the water vapor generated from the recording material in the nip portion blows off the toner image immediately before the nip portion.

【００５１】．ニップ部内において加熱部材の上流側
と下流側を異なった部材で構成することにより、ニップ
部内の搬送方向に温度分布を持たせることが可能とな
り、特に上流側に比べて下流側を低い温度設定となるよ
うに構成すれば、画像加熱装置にあっては高温オフセッ
トを容易に防止することが可能となる。.. By configuring the upstream side and the downstream side of the heating member with different members in the nip portion, it is possible to have a temperature distribution in the conveyance direction inside the nip portion, and in particular, the downstream side has a lower temperature setting than the upstream side. With this configuration, it is possible to easily prevent high temperature offset in the image heating apparatus.

【００５２】[0052]

【実施例】【Example】

〈第１の実施例〉（図１〜図３） （１）画像形成装置例（図１） 図１に本発明に従う加熱装置を記録材画像の加熱定着装
置（像加熱装置）として具備させた画像形成装置の一例
の概略構成を示した。本例の画像形成装置は転写式電子
写真プロセス利用のレーザビームプリンタである。<First Embodiment> (FIGS. 1 to 3) (1) Example of image forming apparatus (FIG. 1) FIG. 1 is equipped with a heating device according to the present invention as a heating and fixing device (image heating device) for a recording material image. The schematic configuration of an example of the image forming apparatus is shown. The image forming apparatus of this example is a laser beam printer using a transfer type electrophotographic process.

【００５３】１は感光ドラムであり、ＯＰＣ、アモルフ
ァスＳｅ、アモルファスＳｉ等の感光材料層がアルミニ
ウムやニッケルなどのシリンダ状の基体上に形成されて
いる。この感光ドラム１は矢印の時計方向に所定の周速
度（プロセススピード）をもって回転駆動され、その回
転過程で帯電ローラ２によってその表面が所定の極性・
電位に一様帯電される。２ａは帯電ローラ２に対する帯
電バイアス印加電源である。Reference numeral 1 is a photosensitive drum, and a photosensitive material layer of OPC, amorphous Se, amorphous Si or the like is formed on a cylindrical substrate such as aluminum or nickel. The photosensitive drum 1 is rotationally driven in a clockwise direction indicated by an arrow at a predetermined peripheral speed (process speed), and the surface of the photosensitive drum 1 has a predetermined polarity by a charging roller 2 during the rotation process.
It is uniformly charged to the electric potential. Reference numeral 2a is a charging bias application power source for the charging roller 2.

【００５４】次に、その帯電処理面に、不図示のレーザ
ビームスキャナから目的の画像情報の時系列電気デジタ
ル画素信号に応じてＯＮ／ＯＦＦ制御（変調制御）され
て出力されるレーザビーム３による走査露光を受ける。
これにより回転感光ドラム１の面に目的の画像情報に対
応した静電潜像が形成される。Next, a laser beam 3 is outputted from the laser beam scanner (not shown) on / off controlled (modulation controlled) according to the time-series electric digital pixel signal of the target image information on the charging surface. Receive scanning exposure.
As a result, an electrostatic latent image corresponding to the target image information is formed on the surface of the rotary photosensitive drum 1.

【００５５】この静電潜像は現像装置４でトナー像とし
て現像・可視化される。現像方法としては、ジャンピン
グ現像法、２成分現像法、ＦＥＥＤ現像法などが用いら
れ、イメージ露光と反転現像とを組み合わせて用いられ
ることが多い。４ａは現像ローラに対する現像バイアス
印加電源である。This electrostatic latent image is developed and visualized as a toner image by the developing device 4. As a developing method, a jumping developing method, a two-component developing method, an FEED developing method, or the like is used, and image exposure and reversal developing are often used in combination. Reference numeral 4a denotes a developing bias application power source for the developing roller.

【００５６】そのトナー像は、感光ドラム１とこれに接
触させた転写装置としての転写ローラ５とのニップ部
（転写部）Ｔに対して不図示の給紙部から所定のタイミ
ングで搬送された記録材Ｐの面に感光ドラム１側から順
次に転写される。記録材Ｐは感光ドラム１と転写ローラ
５に一定の加圧力で挟持されて転写部Ｔを搬送される。
５ａは転写ローラに対する転写バイアス印加電源であ
る。The toner image is conveyed to the nip portion (transfer portion) T between the photosensitive drum 1 and the transfer roller 5 as a transfer device brought into contact with the photosensitive drum 1 from a paper feeding portion (not shown) at a predetermined timing. The images are sequentially transferred onto the surface of the recording material P from the photosensitive drum 1 side. The recording material P is nipped by the photosensitive drum 1 and the transfer roller 5 with a constant pressure, and is conveyed in the transfer portion T.
Reference numeral 5a denotes a transfer bias application power source for the transfer roller.

【００５７】転写部Ｔを通ってトナー像の転写を受けた
記録材Ｐは回転感光ドラム１面から分離されて、次に説
明する加熱定着装置６へ搬送導入され、トナー像の加熱
定着処理を受け、プリントアウトされる。The recording material P which has received the transfer of the toner image through the transfer portion T is separated from the surface of the rotary photosensitive drum 1 and is conveyed and introduced into the heat fixing device 6 which will be described below, and the heat fixing processing of the toner image is performed. Received and printed out.

【００５８】一方、記録材Ｐに対するトナー像転写後の
回転感光ドラム１の面はクリーニング装置７により転写
残りトナー等の残存付着物の除去を受けて清掃され、繰
り返して作像に供される。On the other hand, the surface of the rotary photosensitive drum 1 after the transfer of the toner image onto the recording material P is cleaned by the cleaning device 7 after removal of residual adhered substances such as transfer residual toner, and is repeatedly used for image formation.

【００５９】（２）加熱定着装置６（図２） 図２は加熱定着装置６部分の拡大模型図である。(2) Heat Fixing Device 6 (FIG. 2) FIG. 2 is an enlarged schematic view of the heat fixing device 6 portion.

【００６０】この加熱定着装置６は、定着フィルム１１
を挟んで定着ニップ部Ｎを形成する部材１２・２０と、
そのニップ形成部材１２・２０の一方側部材１２は電磁
誘導発熱性部材（金属部材、導電部材、誘導磁性材、磁
性金属材、磁界吸収金属材などとも称される）にし該部
材１２に磁界を作用させて電磁誘導発熱させる磁界発生
手段１３を具備させ、定着ニップ部Ｎの定着フィルム１
１と他方側部材２０の間に被加熱材としての記録材Ｐを
導入して定着フィルム１１と共に定着ニップ部Ｎを挟持
搬送させ、定着ニップ部Ｎにおいて記録材Ｐを定着フィ
ルム１１を介して電磁誘導発熱性部材１２の電磁誘導発
熱の熱で加熱するようにしたものである。This heating and fixing device 6 includes a fixing film 11
Members 12 and 20 that form the fixing nip portion N by sandwiching
The one-side member 12 of the nip forming members 12 and 20 is an electromagnetic induction heat generating member (also referred to as a metal member, a conductive member, an induction magnetic material, a magnetic metal material, a magnetic field absorbing metal material, etc.), and a magnetic field is applied to the member 12. The fixing film 1 in the fixing nip portion N is provided with the magnetic field generating means 13 for causing the electromagnetic induction to generate heat.
A recording material P as a material to be heated is introduced between the first and second side members 20 to sandwich and convey the fixing nip portion N together with the fixing film 11, and the recording material P is electromagnetically conveyed through the fixing film 11 at the fixing nip portion N. The induction heating member 12 is heated by the heat of electromagnetic induction heating.

【００６１】本実施例において、定着フィルム１１は熱
容量の小さな円筒状のシームレスフィルムである。図３
は本実施例における定着フィルム１１の層構成模型図で
あり、クイックスタートを可能にするために１００μｍ
以下の厚みで、耐熱性・高弾性を有するポリイミド、ポ
リアミドイミド、ＰＥＥＫ、ＰＥＳ、ＰＰＳ、ＰＦＡ、
ＰＴＦＥ、ＦＥＰ等にカーボンブラック、金属フィラー
等の導電性部材を混入して導電性を付与した円筒状フィ
ルム基層１１ａの外周面に、離型性層１１ｂとしてＰＦ
Ａ、ＰＴＦＥ、ＦＥＰ等のフッ素樹脂層を塗布したもの
である。この円筒状の定着フィルム１１の内面の表面抵
抗Ｒ０と外面の表面抵抗Ｒ１の間にはＲ０＜Ｒ１の関係
がある。また、長寿命の装置を構成するために充分な強
度を持ち、耐久性に優れた定着フィルム１１としては２
０μｍ以上の厚みが必要である。よって定着フィルム１
１の厚みとしては２０μｍ以上１００μｍ以下が最適で
ある。ここで導電性を付与したフィルム基層１１ａの厚
みは定着フィルム１１の全体的な機械的強度を保持する
ために、定着フィルム１１の７０％以上を占めている。In this embodiment, the fixing film 11 is a cylindrical seamless film having a small heat capacity. FIG.
Is a model diagram of the layer structure of the fixing film 11 in the present embodiment, and is 100 μm in order to enable quick start.
Polyimide, polyamide imide, PEEK, PES, PPS, PFA having heat resistance and high elasticity with the following thickness,
PF is used as a releasable layer 11b on the outer peripheral surface of the cylindrical film base layer 11a which is made conductive by mixing a conductive member such as carbon black or metal filler into PTFE, FEP or the like.
It is a coating of a fluororesin layer such as A, PTFE or FEP. The surface resistance R0 of the inner surface and the surface resistance R1 of the outer surface of the cylindrical fixing film 11 have a relationship of R0 <R1. In addition, the fixing film 11 has sufficient strength to form a long-life device and has excellent durability.
A thickness of 0 μm or more is required. Therefore, fixing film 1
The optimum thickness of 1 is 20 μm or more and 100 μm or less. Here, the thickness of the film base layer 11a having conductivity is 70% or more of that of the fixing film 11 in order to maintain the overall mechanical strength of the fixing film 11.

【００６２】定着フィルム１１を挟んで定着ニップ部Ｎ
を形成させた部材１２・２０の一方側部材１２は本実施
例では電磁誘導発熱して加熱部材（ヒータ）として機能
する高熱伝導性の金属板であり、強磁性導電部材である
Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｃｒ等の金属、あるいはこれ
からなる合金で形成されていることが望ましい。以下、
この電磁誘導発熱性部材１２を加熱部材と記す。この加
熱部材１２は定着ニップ部Ｎにおいて定着フィルム１１
の搬送方向に直交する方向（図面に垂直の方向）を長手
とする横長部材である。この加熱部材１２は熱容量を抑
え、かつ機械的強度を満足し、加工性の良好な０．２ｍ
ｍ以上４ｍｍ以下の厚みで形成されることが望ましい。A fixing nip portion N with the fixing film 11 interposed therebetween.
The one side member 12 of the members 12 and 20 formed with is a metal plate of high thermal conductivity that functions as a heating member (heater) by generating heat by electromagnetic induction in the present embodiment, and is a ferromagnetic conductive member such as Fe, Co, It is desirable to be formed of a metal such as Ni, Cu or Cr, or an alloy thereof. Less than,
This electromagnetic induction heat generating member 12 is referred to as a heating member. In the fixing nip portion N, the heating member 12 is fixed to the fixing film 11.
Is a laterally long member having a longitudinal direction in a direction (perpendicular to the drawing) orthogonal to the conveyance direction of. This heating member 12 has a heat capacity of 0.2 m, which suppresses heat capacity, satisfies mechanical strength, and has good workability.
It is desirable to be formed with a thickness of m or more and 4 mm or less.

【００６３】この加熱部材１２に磁界を作用させて電磁
誘導発熱させる磁界発生手段１３は本実施例はフェライ
ト等の強磁性体よりなるコア１３ａと、これに巻いた導
線コイル（巻線）１３ｂからなる励磁コイルであり、加
熱部材１２の定着フィルム挟み込み面側とは反対面側に
配設してある。In this embodiment, the magnetic field generating means 13 for applying a magnetic field to the heating member 12 to generate electromagnetic induction heat is composed of a core 13a made of a ferromagnetic material such as ferrite and a conductive wire coil (winding) 13b wound around the core 13a. The exciting coil is provided on the side of the heating member 12 opposite to the side where the fixing film is sandwiched.

【００６４】定着フィルム１１を挟んで定着ニップ部Ｎ
を形成させた部材１２・２０の他方側部材２０は本実施
例では弾性加圧ローラであり、芯金２１と、該芯金２１
の外側に同心一体にローラ状に形成した、シリコンゴム
やフッ素ゴム等の耐熱ゴムあるいはシリコンゴムを発泡
して形成された弾性層２２からなり、この上にＰＦＡ、
ＰＴＦＥ、ＦＥＰ等の離型性層２３を形成してあっても
よい。A fixing nip portion N with the fixing film 11 interposed therebetween.
The other member 20 on the other side of the members 12 and 20 on which the cores are formed is an elastic pressure roller in this embodiment, and includes a cored bar 21 and the cored bar 21.
A heat-resistant rubber such as silicone rubber or fluororubber or an elastic layer 22 formed by foaming silicone rubber, which is concentrically and integrally formed on the outer side of the PFA,
The release layer 23 such as PTFE or FEP may be formed.

【００６５】そして、加熱部材１２と励磁コイル１３の
アセンブリに円筒状の定着フィルム１１をルーズに外嵌
し、加熱部材１２に対して定着フィルム１１を挟ませて
加圧ローラ２０を弾性に抗して所定の押圧力で圧接させ
て、所定幅の定着ニップ部Ｎを形成させてある。加熱部
材１２はその両端部を、あるいは不図示の支持部材に保
持させて該支持部材の両端部を不図示の装置側板間に支
持させてあり、加圧ローラ２０はその両端側に配設した
加圧ばね等の加圧手段で加熱部材１２に対して定着フィ
ルム１１を挟ませて所定の定着ニップ部Ｎが形成される
ように十分に加圧されている。Then, the cylindrical fixing film 11 is loosely fitted on the assembly of the heating member 12 and the exciting coil 13, and the fixing film 11 is sandwiched between the heating member 12 and the pressure roller 20 against the elasticity. Then, the fixing nip portion N having a predetermined width is formed by pressing them with a predetermined pressing force. The heating member 12 has both ends thereof held by supporting members (not shown) so that both ends of the supporting member are supported between device side plates (not shown), and the pressure roller 20 is arranged at both ends thereof. Sufficient pressure is applied such that a predetermined fixing nip portion N is formed by sandwiching the fixing film 11 against the heating member 12 by a pressing means such as a pressing spring.

【００６６】加圧ローラ２０は駆動系Ｍにより矢示の反
時計方向に所定の周速度で回転駆動され、この加圧ロー
ラ２０の回転駆動による、定着ニップ部Ｎにおける該ロ
ーラ２０と定着フィルム１１の外面との摩擦力で定着フ
ィルム１１に直接的に回転力が作用し（記録材Ｐが定着
ニップ部Ｎに導入されたときは該記録材Ｐを介して定着
フィルム１１に回転力が間接的に作用）、該円筒状の定
着フィルム１１が定着ニップ部Ｎにおいて加熱部材１２
の下面に圧接摺動しつつ加熱部材１２と励磁コイル１３
とのアセンブリの外回りを矢示の時計方向ａに回転駆動
される。定着ニップ部Ｎの定着フィルム内面と加熱部材
１２の摺擦部には耐熱性グリース等の潤滑剤を少量介在
させてある。これにより定着フィルム１１がスムーズに
回転可能となる。The pressure roller 20 is rotationally driven in the counterclockwise direction indicated by an arrow at a predetermined peripheral speed by the drive system M, and the rotational driving of the pressure roller 20 causes the roller 20 and the fixing film 11 in the fixing nip portion N to rotate. The rotational force acts directly on the fixing film 11 by the frictional force with the outer surface of the fixing film 11 (when the recording material P is introduced into the fixing nip portion N, the rotational force is indirectly applied to the fixing film 11 via the recording material P). Of the heating member 12 in the fixing nip portion N.
The heating member 12 and the exciting coil 13 while sliding in pressure contact with the lower surface of the
Is driven to rotate in the clockwise direction a as indicated by an arrow, around the outer periphery of the assembly. A small amount of a lubricant such as heat resistant grease is interposed between the inner surface of the fixing film of the fixing nip portion N and the sliding portion of the heating member 12. This allows the fixing film 11 to rotate smoothly.

【００６７】上記において、加熱部材１２・励磁コイル
１３・定着フィルム１１が定着部材１０を構成する。In the above, the heating member 12, the exciting coil 13 and the fixing film 11 constitute the fixing member 10.

【００６８】加熱部材１２を磁気誘導発熱させる磁界発
生手段としての励磁コイル１３は加熱部材１２の長手方
向の寸法とほぼ同じ長さの横長部材であり、長手方向端
部より不図示の電源によりコア１３ａに巻かれた導線コ
イル１３ｂに通電される。ここでコア１３ａは一般にス
イッチング電源用として用いられているもので、本実施
例の励磁コイル１３のコア１３ａは横断面Ｉ型コアであ
る。コア１３ａの形状はＥ型、Ｕ型、その他、任意の形
状・形態のものにすることができる。The exciting coil 13 as a magnetic field generating means for magnetically heating the heating member 12 is a horizontally long member having substantially the same length as the lengthwise dimension of the heating member 12, and a core is supplied from a power source (not shown) from an end portion in the longitudinal direction. The conductor coil 13b wound around 13a is energized. Here, the core 13a is generally used for a switching power supply, and the core 13a of the exciting coil 13 of the present embodiment is an I-shaped cross section core. The shape of the core 13a can be E-shaped, U-shaped, or any other shape and form.

【００６９】励磁コイル１３と加熱部材１２の間には断
熱効果の高いガラス層やポリイミド、ポリアミドイミ
ド、ＰＦＡ、ＰＦＴＥ等の層を設けてもよい。この層を
設けることで励磁コイル１３のフェライトコア１３ａが
伝熱によって加熱され、磁束が減少するのを防ぎ、加熱
部材１２のより効率の高い誘導加熱が可能となる。Between the exciting coil 13 and the heating member 12, a glass layer having a high heat insulating effect or a layer of polyimide, polyamide imide, PFA, PFTE or the like may be provided. By providing this layer, it is possible to prevent the ferrite core 13a of the exciting coil 13 from being heated by heat transfer and to reduce the magnetic flux, and it is possible to perform induction heating of the heating member 12 with higher efficiency.

【００７０】また、フェライトコア１３ａに巻かれる導
線コイル１３ｂは、絶縁耐電圧性に優れた塩化ビニル等
の樹脂またはエラストマーのチューブで覆われている導
線を使用することにより絶縁耐電圧を懸念する必要がな
くなる。このため、励磁コイル１３の下に導電性の加熱
部材１２を配置することは何ら問題がなく、該加熱部材
１２の外側に導電性の定着フィルム１１を接触摺動させ
ても絶縁破壊を引き起こす等の問題は全くない。The conductor coil 13b wound around the ferrite core 13a needs to be concerned about the insulation withstand voltage by using a conductor covered with a tube of resin such as vinyl chloride or an elastomer excellent in insulation withstand voltage or an elastomer tube. Disappears. Therefore, there is no problem in disposing the conductive heating member 12 under the exciting coil 13, and even if the conductive fixing film 11 is slid on the outside of the heating member 12, dielectric breakdown is caused. There is no problem with.

【００７１】以上の構成で、磁界発生手段としての励磁
コイル１３の導線コイル１３ｂに高周波電流を印加する
と、印加電流に応じた交番磁界が発生して、強磁性導電
部材である加熱部材１２には上記の磁界の変化を妨げる
かのように渦電流が流れる。この渦電流が加熱部材１２
の表皮抵抗に比例した電力でジュール熱を発生させ、加
熱部材１２が電磁誘導発熱して急速昇温し、ヒータとし
て機能する。加熱部材１２はその温度が不図示の温度検
知手段で検知され、その温度検知情報により加熱部材１
２の温度が所定の一定温度に維持されるように励磁コイ
ル１３の導線コイル１３ｂに印加される高周波電流が制
御されて、温調される。When a high frequency current is applied to the wire coil 13b of the exciting coil 13 as the magnetic field generating means with the above structure, an alternating magnetic field is generated in accordance with the applied current, and the heating member 12 which is a ferromagnetic conductive member. Eddy currents flow as if to hinder the change in the magnetic field. This eddy current is applied to the heating member 12
The Joule heat is generated by electric power proportional to the skin resistance of the heating member 12, and the heating member 12 generates heat by electromagnetic induction to rapidly raise the temperature, and functions as a heater. The temperature of the heating member 12 is detected by a temperature detecting means (not shown), and the heating member 1 is detected by the temperature detection information.
The high frequency current applied to the conductor coil 13b of the exciting coil 13 is controlled and temperature-controlled so that the temperature of 2 is maintained at a predetermined constant temperature.

【００７２】定着フィルム１１を回転駆動させ、加熱部
材１２を上記のように励磁コイル１３により電磁誘導発
熱させて所定の温度に加熱・温調させた状態において、
定着ニップ部Ｎの定着フィルム１１と加圧ローラ２０と
の間に被加熱材としての未定着トナー像ｔを形成担持さ
せた記録材Ｐを導入すると、記録材Ｐは定着フィルム１
１の面に密着して該定着フィルム１１と一緒に定着ニッ
プ部Ｎを挟持搬送される。この定着ニップ部Ｎにおい
て、記録材Ｐ・トナー像ｔが、電磁誘導発熱させて所定
の温度に加熱・温調させた状態の加熱部材１２により定
着フィルム１１を介して加熱されて記録材Ｐ上のトナー
像ｔが加熱定着される。定着ニップ部Ｎを通った記録材
部分は定着フィルム１１の面から剥離して搬送される。In a state in which the fixing film 11 is rotationally driven and the heating member 12 is heated by the exciting coil 13 by electromagnetic induction to heat and regulate the temperature to a predetermined temperature.
When a recording material P on which an unfixed toner image t as a material to be heated is formed and carried is introduced between the fixing film 11 in the fixing nip portion N and the pressure roller 20, the recording material P becomes the fixing film 1.
The fixing nip portion N is conveyed while being in close contact with the surface 1 of the fixing film 11. In the fixing nip portion N, the recording material P and the toner image t are heated on the recording material P via the fixing film 11 by the heating member 12 in a state where the recording material P and the toner image t are heated and adjusted to a predetermined temperature by electromagnetic induction heat generation. The toner image t of is fixed by heating. The recording material portion that has passed through the fixing nip portion N is separated from the surface of the fixing film 11 and conveyed.

【００７３】（３）装置６の評価 定着フィルム１１のフィルム基層１１ａをポリイミドに
カーボンブラックを混入して５０μｍの厚みで形成し、
そのカーボンブラックの配合量を振って、定着フィルム
１１のフィルム基層１１ａの体積抵抗率の変化と、画像
加熱定着実行時の定着フィルム１１の帯電量と静電オフ
セットの評価を行った。(3) Evaluation of Device 6 The film base layer 11a of the fixing film 11 is formed to have a thickness of 50 μm by mixing carbon black into polyimide.
By changing the blending amount of the carbon black, the change in the volume resistivity of the film base layer 11a of the fixing film 11, and the charge amount and electrostatic offset of the fixing film 11 during the image heating and fixing were evaluated.

【００７４】また、フィルム基層１１ａにカーボンブラ
ックを大量に配合した場合には定着フィルム１１の引裂
強度等の機械的強度が懸念されるため、定着フィルム１
１の耐久性能についても検討した。When a large amount of carbon black is mixed in the film base layer 11a, the mechanical strength such as tear strength of the fixing film 11 may be concerned, so that the fixing film 1
The durability performance of No. 1 was also examined.

【００７５】定着フィルム１１はその外表面に高抵抗の
ＰＦＡを１０μｍの厚みでコーティングして離型性層１
１ｂを形成し、外表面の表面抵抗率は１０¹⁵Ω以上とし
た。The outer surface of the fixing film 11 is coated with high resistance PFA to a thickness of 10 μm to form the releasable layer 1.
1b was formed, and the surface resistivity of the outer surface was 10 ¹⁵ Ω or more.

【００７６】加熱部材１２はニッケル（Ｎｉ）板とし、
２ｍｍの厚みで長手方向に渡って均一に形成されてい
る。The heating member 12 is a nickel (Ni) plate,
It has a thickness of 2 mm and is formed uniformly in the longitudinal direction.

【００７７】加圧ローラ２０は外径１７ｍｍの芯金２１
に、４ｍｍ厚の導電性シリコンゴムローラ層２２を形成
し、その外側に離型性層２３として５０μｍ厚の高抵抗
のＰＦＡチューブを被せたものを使用した。The pressure roller 20 is a core metal 21 having an outer diameter of 17 mm.
The conductive silicon rubber roller layer 22 having a thickness of 4 mm was formed thereon, and the release layer 23 was covered with a high resistance PFA tube having a thickness of 50 μm.

【００７８】定着フィルム１１の帯電量は高抵抗の記録
材（転写材）Ｐを１００枚連続して通紙した直後の電位
を測定した。通紙する記録材が高抵抗になるほど転写部
Ｔで記録材Ｐの背面にのる転写電荷が多くなり、その
分、定着フィルム１１の帯電量も多くなると考えられ
る。The charge amount of the fixing film 11 was measured by measuring the potential immediately after 100 sheets of high-resistance recording material (transfer material) P were continuously passed. It is considered that the higher the resistance of the recording material passing through, the greater the transfer charge on the back surface of the recording material P at the transfer portion T, and the larger the charge amount of the fixing film 11 correspondingly.

【００７９】結果を表１に示す。表中の○は問題ないレ
ベル、△は許容レベル、×は劣悪を示す（これは他の表
においても同じ）。The results are shown in Table 1. In the table, ◯ indicates a level with no problem, Δ indicates an acceptable level, and x indicates poor (this is the same in other tables).

【００８０】[0080]

【表１】 以上の結果から、定着フィルム１１のフィルム基層１１
ａの体積抵抗率が１０¹¹Ωｃｍ以下、好ましくは１０¹⁰
Ωｃｍ以下であれば帯電量をある程度抑えることがで
き、オフセットのレベルも改善されることがわかる。[Table 1] From the above results, the film base layer 11 of the fixing film 11
The volume resistivity of a is 10 ¹¹ Ωcm or less, preferably 10 ¹⁰
It can be seen that if it is Ωcm or less, the charge amount can be suppressed to some extent, and the offset level is also improved.

【００８１】また、定着フィルム１１のフィルム基層１
１ａに配合するカーボンブラックの配合量を増やして体
積抵抗率を１０³ Ωｃｍ以下にした場合は、定着フィル
ム１１の耐久性能が若干悪化するが、問題の無いレベル
であることから、上記の構成の定着フィルム１１のフィ
ルム基層１１ａの体積抵抗率を１０¹¹Ωｃｍ以下、好ま
しくは１０¹⁰Ωｃｍ以下にすることで、定着フィルム１
１のチャージアップによるオフセットの発生のない加熱
定着が可能となる。Further, the film base layer 1 of the fixing film 11
If the volume resistivity is reduced to 10 ³ Ωcm or less by increasing the amount of carbon black compounded in 1a, the durability of the fixing film 11 is slightly deteriorated, but since it is at a level without a problem, By fixing the volume resistivity of the film base layer 11a of the fixing film 11 to 10 ¹¹ Ωcm or less, preferably 10 ¹⁰ Ωcm or less, the fixing film 1
It is possible to perform heat fixing without the occurrence of offset due to the charge-up of 1.

【００８２】ところで上記実験によれば、使用した加圧
ローラ２０の表層２３のＰＦＡチューブの体積抵抗率は
１０¹⁵Ωｃｍ以上の高抵抗であり、この場合、定着フィ
ルム１１および加圧ローラ２０の表面の抵抗値が大きく
なるため、剥離オフセットの発生が懸念されるため、加
圧ローラ表層２３のＰＦＡチューブの体積抵抗率を振っ
て剥離オフセットレベルの比較を行った。なお、加圧ロ
ーラ表層２３のＰＦＡチューブの抵抗値は定着フィルム
１１のフィルム基層１１ａと同様にカーボンブラックの
配合量を変えることで変更した。また、上記構成におい
て定着フィルム１１のフィルム基層１１ａの体積抵抗率
は１０⁵ Ωｃｍ〜１０⁶ Ωｃｍのものを使用し、定着フ
ィルム表面の表面抵抗率は１０¹⁵Ω以上とした。According to the above experiment, the volume resistivity of the PFA tube of the surface layer 23 of the pressure roller 20 used was as high as 10 ¹⁵ Ωcm or more. In this case, the surface of the fixing film 11 and the pressure roller 20 was Since there is a concern that peeling offset may occur due to the increase in the resistance value of No. 2, the peeling offset level was compared by shaking the volume resistivity of the PFA tube of the pressure roller surface layer 23. The resistance value of the PFA tube of the pressure roller surface layer 23 was changed by changing the compounding amount of carbon black as in the film base layer 11a of the fixing film 11. Further, in the above constitution, the volume resistivity of the film base layer 11a of the fixing film 11 is 10 ⁵ Ωcm to 10 ⁶ Ωcm, and the surface resistivity of the fixing film surface is 10 ¹⁵ Ω or more.

【００８３】評価結果を表２に示す。The evaluation results are shown in Table 2.

【００８４】[0084]

【表２】 以上の結果より、定着フィルム１１のチャージアップを
防ぐために定着フィルム１１のフィルム基層１１ａを導
電化し、定着フィルム表面に高抵抗のフッ素樹脂層１１
ｂを塗布した場合、加圧ローラ２０の表面の抵抗値は低
い方が剥離オフセットのレベルが良いことがわかる。特
に加圧ローラ表層２３は導電性を付与してその体積抵抗
率を１０¹²Ωｃｍ以下、好ましくは１０¹¹Ωｃｍ以下に
することで、剥離オフセットの発生のない加熱定着が可
能となる。[Table 2] From the above results, in order to prevent the fixing film 11 from being charged up, the film base layer 11a of the fixing film 11 is made conductive, and the high resistance fluororesin layer 11 is formed on the surface of the fixing film.
It can be seen that when b is applied, the lower the resistance value of the surface of the pressure roller 20, the better the level of peeling offset. In particular, the pressure roller surface layer 23 is provided with conductivity so that its volume resistivity is 10 ¹² Ωcm or less, preferably 10 ¹¹ Ωcm or less, so that heat fixing without peeling offset is possible.

【００８５】以上から定着フィルム１１のフィルム基層
１１ａの体積抵抗率を１０¹¹Ωｃｍ以下、加圧ローラ２
０の表層２３の体積抵抗率を１０¹²Ωｃｍ以下にするこ
とで、定着フィルム１１のチャージアップによるオフセ
ットを防止し、かつ剥離オフセットの発生の無い良好な
加熱定着が達成される。From the above, the volume resistivity of the film base layer 11a of the fixing film 11 is 10 ¹¹ Ωcm or less, the pressure roller 2
By setting the volume resistivity of the surface layer 23 of 0 to 10 ¹² Ωcm or less, offset due to charge up of the fixing film 11 is prevented, and good heat fixing without peeling offset is achieved.

【００８６】また、本実施例の装置６のように、電磁誘
導発熱性部材を加熱部材（ヒータ）とするフィルム加熱
方式・電磁誘導加熱方式の加熱定着装置は、加熱部材１
２が熱伝導性の高い金属であることから、定着ニップ部
Ｎの長手方向の熱の分布を緩和する方向への熱の流れが
生じるため、前述従来例のセラミックヒータ６１を加熱
部材とするフィルム加熱方式の加熱定着装置（図１４）
の場合にはセラミックヒータ６１の発熱抵抗層６１ｂの
長手に沿う抵抗値分布がシビアであるのに対して、簡単
な構成で定着ニップ部Ｎの温度の均一化が図れる。さら
に長手方向の熱の流れがあるため、小サイズの記録材を
通紙したときの通紙部領域と非通紙部領域の温度差を緩
める効果（非通紙部昇温の緩和）があり、、定着フィル
ム１１のねじれを防止することができる。Further, like the apparatus 6 of this embodiment, the heating fixing device of the film heating system / electromagnetic induction heating system using the electromagnetic induction heating member as the heating member (heater) is the heating member 1
Since 2 is a metal having a high thermal conductivity, a heat flow occurs in a direction that alleviates the heat distribution in the longitudinal direction of the fixing nip portion N. Therefore, the film using the ceramic heater 61 of the conventional example as a heating member. Heating type heat fixing device (Fig. 14)
In this case, the resistance value distribution along the length of the heating resistance layer 61b of the ceramic heater 61 is severe, but the temperature of the fixing nip portion N can be made uniform with a simple configuration. Furthermore, since there is a heat flow in the longitudinal direction, it has the effect of relaxing the temperature difference between the paper passing area and the non-paper passing area when a small-sized recording material is passed (relaxation of temperature rise in the non-paper passing area). The twist of the fixing film 11 can be prevented.

【００８７】〈第２の実施例〉（図２・図４） 本実施例は上記第１の実施例において、使用する定着フ
ィルム１１として下記の層構成のものを使用した。ま
た、加熱部材１２はその端部において不図示の接点によ
りダイオード１４（図２）を介して接地した。ダイオー
ド１４の接続はトナーの帯電電位と反対の極性を中和す
る方向にしている。例えば、トナーがマイナスに帯電さ
れる場合であれば、加熱部材１２はプラスに振れること
のない様に図２に示した方向で接続されている。加圧ロ
ーラ２０の表層にはＰＦＡ、ＰＴＦＥ、ＦＥＴ等の離型
性能に優れた離型性層２３を設けており、記録材Ｐとの
離型性を保っている。その他の加熱定着装置・画像形成
装置の構成は第１の実施例の装置と同様であるので再度
の説明を省略する。<Second Embodiment> (FIGS. 2 and 4) In this embodiment, the fixing film 11 used in the first embodiment has the following layer structure. The heating member 12 was grounded at its end through a diode 14 (FIG. 2) by a contact (not shown). The connection of the diode 14 is directed to neutralize the polarity opposite to the charging potential of the toner. For example, when the toner is negatively charged, the heating member 12 is connected in the direction shown in FIG. 2 so as not to swing positively. The surface layer of the pressure roller 20 is provided with a releasable layer 23 such as PFA, PTFE, FET, etc., which has excellent releasability, and keeps releasability from the recording material P. The other configurations of the heat fixing device and the image forming device are the same as those of the device according to the first embodiment, and thus the repetitive description will be omitted.

【００８８】本実施例において用いる定着フィルム１１
はフィルム基層を２重あるいは多重構造とする。図４の
層構成模型図の定着フィルム１１はフィルム基層１１ａ
を内外２重層１１ａ₁ ・１１ａ₂ にしたものである。Fixing film 11 used in this embodiment
The film base layer has a double or multiple structure. The fixing film 11 in the layer structure model diagram of FIG. 4 is a film base layer 11a.
To form the inner and outer double layers 11a ₁ and 11a ₂ .

【００８９】加熱部材１２に接触する最も内側の第１基
層１１ａ₁ は、前記第１の実施例のフィルム基層と同様
に、耐熱性・熱可塑性を有するポリイミド、ポリアミド
イミド、ＰＥＥＫ、ＰＥＳ、ＰＰＳ、ＰＦＡ、ＰＴＦ
Ｅ、ＦＥＰ等にカーボンブラック、金属フィラ等の導電
性部材を混入して導電性を付与した層（以下、導電性基
層と記す）としてあり、表面抵抗、および体積抵抗が低
くなっている。The innermost first base layer 11a ₁ contacting the heating member 12 is made of polyimide, polyamideimide, PEEK, PES, PPS, which has heat resistance and thermoplasticity, like the film base layer of the first embodiment. PFA, PTF
It is a layer (hereinafter, referred to as a conductive base layer) in which a conductive member such as carbon black or a metal filler is mixed into E, FEP or the like to impart conductivity, and has a low surface resistance and a low volume resistance.

【００９０】その外側の第２基層１１ａ₂ は、ポリイミ
ド、ポリアミドイミド、ＰＥＥＫ、ＰＥＳ、ＰＰＳ、Ｐ
ＦＡ、ＰＴＦＥ、ＦＥＰ等の層であるが、導電性部材の
混入はない層（以下、高抵抗基層と記す）としてある。The second base layer 11a _{2 on} the outer side is made of polyimide, polyamide-imide, PEEK, PES, PPS, P.
Although it is a layer of FA, PTFE, FEP, or the like, it is a layer in which a conductive member is not mixed (hereinafter referred to as a high resistance base layer).

【００９１】また、定着フィルム１１の表層には記録材
Ｐ上のトナーの離型性や記録材の分離性を確保するため
のＰＦＡ、ＰＴＦＥ、ＦＥＰ、シリコーン樹脂等の離型
性の良好な耐熱樹脂を混合ないし単独で塗布して、離型
性層１１ｂを設けてもよい。この離型性層１１ｂも高抵
抗の層である。The surface of the fixing film 11 is made of heat-resistant material such as PFA, PTFE, FEP, and silicone resin, which has good releasability for ensuring releasability of the toner on the recording material P and releasability of the recording material. The releasable layer 11b may be provided by mixing or applying the resins alone. This releasable layer 11b is also a high resistance layer.

【００９２】よって、定着フィルム１１の表面は表面抵
抗、体積抵抗ともに高くなっている。すなわち本実施例
では定着フィルム１１の内面側（加熱部材１２に接触す
る側の面）を導電性基層層１１ａ₁ とし、外面（加圧ロ
ーラ２０側）を高抵抗層１１ａ₂ ・１１ｂとし、かつ外
面側の高抵抗層の厚みを機械的強度の保てる基層にも付
加している。また、定着フィルム１１の総厚において、
内側の導電性基層１１ａ₁ は満遍なく導電性が得られる
ように１０μｍ以上の厚みで形成されており、その外側
の高抵抗基層１１ａ₂ が１０μｍ以上、およびさらにそ
の外側の高抵抗層であるの離型性層１１ｂが１０μｍ程
度の厚みで形成されている。すなわち定着フィルム外面
側の高抵抗層１１ａ₂ ＋１１ｂは合計２０μｍ以上の厚
みがある。Therefore, the surface of the fixing film 11 has high surface resistance and high volume resistance. Namely the inner surface of the fixing film 11 (the surface on the side in contact with the heating member 12) and the conductive base layer 11a ₁ in the present embodiment, the outer surface (the pressure roller 20 side) to the high resistance layer 11a ₂ · 11b, and The thickness of the high resistance layer on the outer surface side is also added to the base layer that can maintain mechanical strength. In addition, in the total thickness of the fixing film 11,
The inner conductive base layer 11a ₁ is formed with a thickness of 10 μm or more so as to obtain conductivity evenly, the high resistance base layer 11a _{2 on the} outer side is 10 μm or more, and the outer high resistance layer is separated from the high resistance layer 11a _2. The moldable layer 11b is formed with a thickness of about 10 μm. That is, the high resistance layer 11a ₂ + 11b on the outer surface side of the fixing film has a total thickness of 20 μm or more.

【００９３】以上の構成で定着フィルム１１のフィルム
基層１１ａの導電性基層１１ａ₁ と高抵抗基層１１ａ₂
の定着フィルム総厚に占める厚みの割合をいろいろと振
ってオフセットの程度を比較した。特に耐久時に定着フ
ィルム１１の表層の離型性層１１ｂが摩耗により削れ
て、記録材Ｐの転写保持電荷がリークすることによるオ
フセット（耐久オフセット）と、剥離オフセットについ
て評価を行った。With the above structure, the conductive base layer 11a ₁ and the high resistance base layer 11a ₂ of the film base layer 11a of the fixing film 11 are formed.
The degree of offset was compared by varying the ratio of the thickness to the total thickness of the fixing film. In particular, the offset (durability offset) due to the transfer holding charge of the recording material P leaking due to abrasion of the releasable layer 11b on the surface of the fixing film 11 during durability and the peeling offset were evaluated.

【００９４】耐久は記録材Ｐを２０万枚搬送した後にオ
フセットの発生を評価した。For durability, occurrence of offset was evaluated after 200,000 recording materials P were conveyed.

【００９５】定着フィルム１１の総厚は６０μｍとし、
そのうちＰＦＡコーティングの離型性層１１ｂは１０μ
ｍとし、フィルム基層１１ａの導電性基層１１ａ₁ はポ
リイミドにカーボンブラックを入れて抵抗値を下げ、体
積抵抗率を約１０⁵ Ωｃｍ以上とした。また、高抵抗基
層１１ａ₂ はポリイミド単体で形成し、体積抵抗率は１
０¹⁵Ωｃｍ以上とした。The total thickness of the fixing film 11 is 60 μm,
Among them, the release layer 11b of PFA coating is 10μ
m, and the conductive base layer 11a ₁ of the film base layer 11a was prepared by adding carbon black to polyimide to reduce the resistance value, and the volume resistivity was about 10 ⁵ Ωcm or more. Also, the high-resistance base layer 11a ₂ is formed of polyimide alone, and has a volume resistivity of 1
It was set to 0 ¹⁵ Ωcm or more.

【００９６】加圧ローラ２０は、前記第１の実施例と同
様に、外径１７ｍｍの芯金２１に４ｍｍ厚の導電シリコ
ンゴムローラ層２２を形成し、その外層に離型性層２３
として、体積抵抗率が約１０¹¹Ωｃｍ、５０μｍ厚のＰ
ＦＡチューブを被せたものを使用した。In the pressure roller 20, as in the first embodiment, a conductive silicon rubber roller layer 22 having a thickness of 4 mm is formed on a core metal 21 having an outer diameter of 17 mm, and a releasing layer 23 is formed on the outer layer thereof.
As a P having a volume resistivity of about 10 ¹¹ Ωcm and a thickness of 50 μm.
The one covered with the FA tube was used.

【００９７】結果を表３に示す。The results are shown in Table 3.

【００９８】[0098]

【表３】 以上の結果より、高抵抗基層１１ａ₂ の厚みが４５μｍ
以下、好ましくは４０μｍ以下とすることにより、剥離
オフセットの発生のない良好な定着が可能となることが
わかる。また、耐久オフセットの発生を防ぐためには、
高抵抗基層１１ａ₂ の厚みが５μｍ以上、好ましくは１
０μｍ以上必要である。ここで高抵抗基層１１ａ₂ の厚
みが４５μｍ以上のときに耐久オフセットが発生してい
るが、これは定着フィルム全体の高抵抗化によりチャー
ジアップし易くなっているために、静電気的に起こるオ
フセットである。[Table 3] From the above results, the thickness of the high resistance base layer 11a ₂ is 45 μm.
It will be understood that, when the thickness is preferably 40 μm or less, good fixing can be performed without causing peeling offset. Also, to prevent the occurrence of durability offset,
The high resistance base layer 11a _{2 has} a thickness of 5 μm or more, preferably 1
0 μm or more is required. Here, when the thickness of the high resistance base layer 11a ₂ is 45 μm or more, a durable offset occurs, but this is an offset that occurs electrostatically because the high resistance of the entire fixing film makes it easy to charge up. is there.

【００９９】以上本実施例では、定着フィルム１１に容
易に導電性を付与でき、かつ定着フィルム外面側に高抵
抗基層基層１１ａ₂ を設けることで、耐久により定着フ
ィルム表層が摩耗した際であっても、リークによるオフ
セット等の画像劣化を起こすことなく、加熱定着するこ
とが可能となる。さらに定着フィルム１１の外面側の基
層１１ａ₂ はカーボンブラック等のフィラを混入しない
ので、引裂強度等の機械的強度にも優れ、よって耐久性
能が飛躍的に改善される。これにより、画像形成装置そ
のものの高速化にも対応が可能となる。あるいは定着フ
ィルム１１の総厚を薄くすることも可能となるので、こ
の場合伝熱性が向上し、定着性にも有利となる。As described above, in the present embodiment, when the fixing film 11 can be easily provided with conductivity and the high resistance base layer base layer 11a ₂ is provided on the outer surface of the fixing film, the surface layer of the fixing film is worn due to durability. Also, it is possible to perform heat fixing without causing image deterioration such as offset due to leak. Further, since the base layer 11a ₂ on the outer surface side of the fixing film 11 does not contain a filler such as carbon black, it has excellent mechanical strength such as tear strength, and thus durability performance is dramatically improved. As a result, it becomes possible to cope with the speedup of the image forming apparatus itself. Alternatively, since it is possible to reduce the total thickness of the fixing film 11, the heat transfer property is improved in this case, which is advantageous for the fixing property.

【０１００】〈第３の実施例〉（図５・図６） 本実施例は前記第１の実施例において、加熱部材１２
に、定着フィルム搬送方向ａに直交する方向である長手
方向の熱容量に分布をもたせ、長手中央部に比べ両端部
の方を熱容量−大にしたものである。<Third Embodiment> (FIGS. 5 and 6) This embodiment is the same as the first embodiment except that the heating member 12 is used.
In addition, the heat capacity in the longitudinal direction, which is the direction orthogonal to the fixing film transport direction a, has a distribution, and the heat capacity at both end portions is larger than that at the longitudinal center portion.

【０１０１】即ち、本実施例では図５の（ａ）と（ｂ）
に示した加熱部材１２と励磁コイル１３のアセンブリの
側面図と平面図のように、加熱部材１２の長手方向にお
ける厚みと幅を、長手中央部よりも両端部の方を何れも
大きくした形状（断面積−大）に加熱部材１２を構成す
ることで、加熱部材１２に長手方向の熱容量に分布をも
たせ、長手中央部に比べ両端部の方を熱容量−大にして
ある。これにより加熱部材１２は長手中央部に比べ、両
端部の方が暖まり難くなる。That is, in this embodiment, (a) and (b) of FIG.
As shown in the side view and the plan view of the assembly of the heating member 12 and the exciting coil 13 shown in FIG. 2, the heating member 12 has a shape in which the thickness and width in the longitudinal direction are larger at both end portions than at the longitudinal central portion ( By configuring the heating member 12 to have a large cross-sectional area, the heating member 12 is provided with a distribution in the heat capacity in the longitudinal direction, and the heat capacity at both ends is larger than that at the longitudinal center. As a result, the heating member 12 is less likely to be warmed at both end portions than in the longitudinal center portion.

【０１０２】一般に、磁界発生手段として図示例のよう
な、加熱部材１２とほぼ同長の横長の励磁コイル１３を
用いた場合、磁束密度は中央部のＡに比べ両端部のＢの
方が高くなる。これは励磁コイル１３の端部の巻線の折
り返し部の影響であり、このために加熱部材１２の電磁
誘導発熱による長手方向に沿う温度分布は不均一となっ
てしまう可能性がある。In general, when a horizontally long exciting coil 13 having substantially the same length as the heating member 12 is used as the magnetic field generating means, the magnetic flux density is higher in B at both end portions than in A at the central portion. Become. This is due to the folded portion of the winding at the end of the exciting coil 13, and therefore the temperature distribution along the longitudinal direction due to the electromagnetic induction heat generation of the heating member 12 may become uneven.

【０１０３】そこで本実施例においては加熱部材１２の
形状を上記のようにして、加熱部材１２の長手方向の熱
容量に分布をもたせ、長手中央部に比べ両端部の方を熱
容量−大にすることで、上記磁束密度の違いにかかわら
ず加熱部材１２の長手方向に沿う温度分布の均一化を図
ったものである。Therefore, in this embodiment, the shape of the heating member 12 is set as described above so that the heat capacity of the heating member 12 in the longitudinal direction is distributed, and the heat capacity at both end portions is larger than that at the longitudinal center portion. Thus, the temperature distribution along the longitudinal direction of the heating member 12 is made uniform regardless of the difference in the magnetic flux density.

【０１０４】また、加熱部材１２について、同一部材で
加熱されやすい両端部の熱容量を大きくした場合、加熱
部材の断面積は大きくなる。よって加熱部材１２の中央
部に比べ、両端部の方が長手方向への熱の流れが容易に
なる。これにより、小サイズの記録材Ｐを搬送したとき
に非通紙部上昇を緩和する効果がより顕著に得られる。
さらに、加熱部材１２の長手方向の熱の流れが多くなる
ことから、長手方向の温度分布のムラを解消する働きも
ある。When the heat capacity of both end portions of the heating member 12 which are easily heated by the same member is increased, the sectional area of the heating member is increased. Therefore, compared to the central part of the heating member 12, the heat flow in the longitudinal direction becomes easier at both ends. As a result, the effect of alleviating the rise of the non-sheet passing portion when the small-sized recording material P is conveyed can be more remarkably obtained.
Further, since the heat flow in the longitudinal direction of the heating member 12 increases, it also has the function of eliminating the uneven temperature distribution in the longitudinal direction.

【０１０５】以上を確認するために、加熱部材１２の表
面の温度分布を測定した。比較として長手方向に均一の
材質で、均一の熱容量の分布を持つ加熱部材を用いた場
合についても温度分布を測定した。In order to confirm the above, the temperature distribution on the surface of the heating member 12 was measured. As a comparison, the temperature distribution was measured also when a heating member having a uniform material in the longitudinal direction and having a uniform heat capacity distribution was used.

【０１０６】確認のために用いた加熱部材１２は、本実
施例に相当するものとして、Ｎｉの板を用いて図５のよ
うな形状にして長手方向の熱容量に分布をもたせ、長手
中央部に比べ両端部の方を熱容量−大にした。比較例の
加熱部材は同じくＮｉの板であるが、長手方向に渡って
均一の体積で形成した部材、即ち長手方向の熱容量分布
が均一な部材である。また、励磁コイル１３の巻線には
１００ｋＨｚの高周波の交流を印加した。The heating member 12 used for confirmation corresponds to this embodiment, and is made of a Ni plate to have a shape as shown in FIG. In comparison, the heat capacity at both ends was larger. The heating member of the comparative example is also a Ni plate, but is a member formed with a uniform volume in the longitudinal direction, that is, a member having a uniform heat capacity distribution in the longitudinal direction. Further, a high-frequency alternating current of 100 kHz was applied to the winding of the exciting coil 13.

【０１０７】測定結果を図６に示す。図６より、加熱部
材を長手方向で均一熱容量の部材とした比較例において
は、長手中央部に比べて両端部の温度が高くなっている
ことがわかる。これに比べ本実施例の加熱部材１２のよ
うに長手方向に熱容量の分布を持たせ、中央部に比べ両
端部の方が熱容量が大きくなるように形成した場合に
は、温度分布は長手方向左端から右端まで略均一な温度
分布となっている。The measurement results are shown in FIG. From FIG. 6, it can be seen that in the comparative example in which the heating member has a uniform heat capacity in the longitudinal direction, the temperature at both end portions is higher than that at the longitudinal center portion. On the other hand, in the case where the heating member 12 of this embodiment has a heat capacity distribution in the longitudinal direction and is formed such that both end portions have a larger heat capacity than the central portion, the temperature distribution is left end in the longitudinal direction. The temperature distribution is almost uniform from to the right end.

【０１０８】以上から、加熱部材長手方向において加熱
部材１２の熱容量に適切な分布を持たせることにより、
前述従来例のセラミックヒータ６１を加熱部材とするフ
ィルム加熱方式の加熱定着装置（図１４）の場合にはセ
ラミックヒータ６１の発熱抵抗層６１ｂの長手に沿う抵
抗値分布がシビアであるのに対して、簡単な構成で定着
ニップ部Ｎの温度の均一化が図れる。この結果、記録材
Ｐ上のトナー像ｔの定着性の均一化も図れる。From the above, by providing an appropriate distribution in the heat capacity of the heating member 12 in the longitudinal direction of the heating member,
In the case of the film heating type heat fixing device (FIG. 14) in which the ceramic heater 61 of the conventional example is used as a heating member, the resistance value distribution along the length of the heating resistance layer 61b of the ceramic heater 61 is severe. The temperature of the fixing nip portion N can be made uniform with a simple configuration. As a result, the fixing property of the toner image t on the recording material P can be made uniform.

【０１０９】また、同一部材で加熱部材１２の両端部の
熱容量を大きくした場合、加熱部材１２の両端断面の面
積は中央部に比べ大きくなるため、両端部での長手方向
への熱の流れが中央部に比べて大きくなる。この結果、
小サイズの記録材を搬送したときの搬送域と非搬送域の
温度差を暖める効果があり、定着フィルム１１のねじれ
を防止することができ、定着部材１０（１１〜１３）お
よび加圧部材２０の耐熱性能を暖めることができ、コス
トダウンとなる。When the heat capacity of both ends of the heating member 12 is increased by the same member, the area of the cross section of both ends of the heating member 12 becomes larger than that of the central part, so that the heat flow in the longitudinal direction at both ends. Larger than the central part. As a result,
This has the effect of warming the temperature difference between the transport area and the non-transport area when a small-sized recording material is transported, can prevent the fixing film 11 from twisting, and can fix the fixing member 10 (11 to 13) and the pressing member 20. The heat resistance performance of can be warmed up, resulting in cost reduction.

【０１１０】〈第４の実施例〉（図７） 本実施例は前記第１の実施例において、加熱部材１２
と、磁界発生手段としての励磁コイル１３との間に隙間
をもたせ、その隙間を、フィルム搬送方向に直交する方
向である長手方向において長手中央部に比べて両端部の
方を広くしたものである。<Fourth Embodiment> (FIG. 7) This embodiment is the same as the first embodiment except that the heating member 12 is used.
And an exciting coil 13 serving as a magnetic field generating means, and a gap is made wider at both ends in the longitudinal direction, which is a direction orthogonal to the film transport direction, than at the longitudinal center. .

【０１１１】即ち図７のように、加熱部材１２と励磁コ
イル１３は長手方向に渡って若干離間している。このと
きその間隙αは、加熱部材１２の上面を長手中央部から
両端部に向かって緩く下る傾斜面の形状にすることで、
長手方向中央部に対して両端部の方が広い隙間となるよ
うにしている。あるいは加熱部材１２の長手中央部のみ
励磁コイル１３と接触させ、両端部に向かうにつれ励磁
コイル１３から離間する方向に傾斜を有している。加熱
部材１２の定着ニップ部Ｎ側の面はストレートのニップ
部を形成するため、フラットな面になっている。よって
加熱部材１２の肉厚は長手方向中央部に比べ両端部に向
かうにつれ徐々に薄くなっている。That is, as shown in FIG. 7, the heating member 12 and the exciting coil 13 are slightly separated in the longitudinal direction. At this time, the gap α is formed by forming the upper surface of the heating member 12 into the shape of an inclined surface that gently descends from the longitudinal center to both ends.
Both ends are wider than the central part in the longitudinal direction. Alternatively, only the longitudinal center portion of the heating member 12 is brought into contact with the exciting coil 13, and the heating member 12 has an inclination in a direction away from the exciting coil 13 toward both ends. The surface of the heating member 12 on the side of the fixing nip portion N is a flat surface because it forms a straight nip portion. Therefore, the wall thickness of the heating member 12 gradually becomes smaller toward both end portions than in the central portion in the longitudinal direction.

【０１１２】以上の場合、加熱部材１２は、励磁コイル
１３からの間隙が小さい長手中央部の方が間隙の大きい
両端部に比べ、励磁コイル１３による磁束が有効に渦電
流発生に寄与するため発熱効率が高い。この結果、磁束
密度が高い両端部の発熱が抑えられ、長手方向に渡って
均一な温度分布にすることが可能となる。In the above case, the heating member 12 generates heat because the magnetic flux from the exciting coil 13 effectively contributes to the generation of the eddy current in the longitudinal center portion where the gap from the exciting coil 13 is smaller than in the both end portions where the gap is large. High efficiency. As a result, heat generation at both ends having high magnetic flux density is suppressed, and it becomes possible to obtain a uniform temperature distribution in the longitudinal direction.

【０１１３】また、本実施例では加熱部材１２の大きさ
を小さく抑えて温度分布を均一にすることが可能とな
り、小型の定着部材１０を構成することができる。Further, in this embodiment, the size of the heating member 12 can be suppressed to be small and the temperature distribution can be made uniform, so that a small fixing member 10 can be constructed.

【０１１４】〈第５の実施例〉（図８） 本実施例は前記第１の実施例において、加熱部材１２
を、フィルム搬送方向に直交する方向である長手方向に
おいて材質を異にする複数の部材で構成して長手中央部
の透磁率に両端部の透磁率を低くしたものである。<Fifth Embodiment> (FIG. 8) This embodiment is the same as the first embodiment except that the heating member 12 is used.
Is composed of a plurality of members made of different materials in the longitudinal direction, which is the direction orthogonal to the film transport direction, and the magnetic permeability at both ends is made lower than the magnetic permeability at the longitudinal center.

【０１１５】図８のものは、加熱部材１２は２つの材質
部材１２ａ・１２ｂにより構成されており、長手中央部
は透磁率μａの材質部材１２ａで構成し、両端部は透磁
率μｂの材質部材１２ｂで構成し、μａ＞μｂの関係が
ある。In FIG. 8, the heating member 12 is composed of two material members 12a and 12b. The longitudinal center portion is composed of the material member 12a having the magnetic permeability μa, and the both ends are made of the material member having the magnetic permeability μb. 12b, and there is a relation of μa> μb.

【０１１６】すなわちこの加熱部材１２は長手方向の中
央部に比べ、両端部の方が透磁率が低く、例えば中央部
の部材１２ａを鉄で構成し、両端部の部材１２ｂをアル
ミやＮｉで構成している。加熱部材の透磁率は温度上昇
と深い関わりがあり、特に透磁率の高い部材の方が温度
が上昇しやすい。このため、前述第３の実施例で述べた
ように加熱部材１２の両端部の温度上昇を抑えるため
に、本実施例のごとく加熱部材１２の両端部の透磁率を
中央部に比べ低くすることで、加熱部材１２の長手方向
の温度分布のムラを小さく抑えることが可能となる。That is, the heating member 12 has lower magnetic permeability at both end portions than the central portion in the longitudinal direction. For example, the central member 12a is made of iron, and the end portions 12b are made of aluminum or Ni. are doing. The magnetic permeability of the heating member is closely related to the temperature rise, and the temperature of the member having a high magnetic permeability is likely to rise. Therefore, as described in the third embodiment, in order to suppress the temperature rise at both ends of the heating member 12, the magnetic permeability at both ends of the heating member 12 is made lower than that at the central portion as in the present embodiment. Therefore, it becomes possible to suppress the unevenness of the temperature distribution in the longitudinal direction of the heating member 12 to be small.

【０１１７】また、本実施例では加熱部材１２の長手中
央部と両端部とでの材質を異なるものにしたが、さらに
複数の異なった部材を長手方向に並べることにより、任
意の発熱分布を持たせることができる。この方法によれ
ば加熱部材１２の形状を複雑にする必要はなく、材質に
よって任意の温度分布を得ることが可能となる。よって
生産性の悪化を招くことなく、容易に構成することがで
きる。Further, in the present embodiment, the materials of the longitudinal center portion and both end portions of the heating member 12 are made different, but by arranging a plurality of different members in the longitudinal direction, an arbitrary heat generation distribution can be obtained. Can be made. According to this method, it is not necessary to make the shape of the heating member 12 complicated, and it is possible to obtain an arbitrary temperature distribution depending on the material. Therefore, the structure can be easily configured without deteriorating the productivity.

【０１１８】〈第６の実施例〉（図９・図１０） 本実施例は前記第１の実施例において、加熱部材１２に
ついて、図９のように、定着ニップ部Ｎの記録材入口直
前部においてフィルム搬送方向ａに関して加圧ローラ２
０から離間する方向に傾斜、あるいは湾曲した形状部１
２ｃを設けたものである。<Sixth Embodiment> (FIGS. 9 and 10) In this embodiment, in the heating member 12 in the first embodiment, as shown in FIG. 9, the portion immediately before the recording material entrance of the fixing nip portion N is shown. In the film transport direction a at the pressure roller 2
Shaped portion 1 that is inclined or curved in a direction away from 0
2c is provided.

【０１１９】即ち、加熱部材のフィルム搬送方向ａの少
なくとも上流側は、記録材Ｐが定着ニップ部Ｎへ突入す
る直前、すなわち定着ニップ部Ｎより若干上流側におい
てニップ部Ｎと反対方向、加圧ローラ２０から離間する
方向に傾斜部１２ｃを持っており、この傾斜部１２ｃに
沿って定着フィルム１１が摺動搬送される。なお、定着
ニップ部Ｎでは加熱部材１２に対して定着フィルム１１
を挟ませて加圧ローラ２０を該加圧ローラの長手両端部
より不図示の加圧手段により加圧しているため、定着ニ
ップ部Ｎ内に加熱部材１２の傾斜部１２ｃの始点ｄがあ
ると、その部分ｄで定着フィルム１１を強くしごくこと
になり、定着フィルムが破損する恐れが生じる。このた
め、加熱部材１２が加圧ローラ２０から離間する方向に
傾斜する始点ｄは定着ニップ部Ｎより若干上流側の方が
望ましい。That is, at least on the upstream side of the heating member in the film transport direction a, the pressure is applied immediately before the recording material P enters the fixing nip portion N, that is, slightly upstream of the fixing nip portion N, in the direction opposite to the nip portion N. It has an inclined portion 12c in a direction away from the roller 20, and the fixing film 11 is slid and conveyed along the inclined portion 12c. In the fixing nip portion N, the fixing film 11 is
Since the pressure roller 20 is pressed by the pressure means (not shown) from both longitudinal ends of the pressure roller while sandwiching the sheet, there is a start point d of the inclined portion 12c of the heating member 12 in the fixing nip portion N. Since the fixing film 11 is strongly squeezed at the portion d, the fixing film may be damaged. For this reason, it is desirable that the starting point d at which the heating member 12 is inclined in the direction away from the pressure roller 20 is slightly upstream of the fixing nip portion N.

【０１２０】加熱部材１２は高熱伝導性の部材より形成
されているため、加熱部材１２の上記傾斜部１２ｃのフ
ィルム搬送方向上流側先端まで容易に加熱することがで
きる。このため、本実施例では、前述従来例の熱ローラ
方式の加熱定着装置（図１３）と同様に、定着ニップ部
Ｎの直前の雰囲気もこの傾斜部１１ｃから定着フィルム
１１を介して十分に暖められる（プレ加熱部）。よっ
て、記録材Ｐが搬送されてきたときに、定着ニップ部Ｎ
の直前の雰囲気の温度が高められているため、記録材Ｐ
上のトナー像Ｔが若干溶融気味となり、トナー自体に粘
性が生まれる。この結果、定着ニップ部Ｎにて記録材Ｐ
が加熱されることにより発生する水蒸気が、定着ニップ
部直前で定着ニップ部Ｎより上流側のトナーを吹き飛ば
すごとく流れたとしても、記録材Ｐ上のトナー像ｔはト
ナー間の結びつきにより上流側に飛ばされることなく、
尾引き等の画像劣化を引き起こさない。Since the heating member 12 is formed of a member having high thermal conductivity, the tip of the inclined portion 12c of the heating member 12 on the upstream side in the film transport direction can be easily heated. Therefore, in the present embodiment, the atmosphere immediately before the fixing nip portion N is sufficiently warmed from this inclined portion 11c through the fixing film 11 as in the above-described conventional heat roller type heat fixing device (FIG. 13). (Pre-heating section). Therefore, when the recording material P is conveyed, the fixing nip portion N
Since the temperature of the atmosphere immediately before is increased, the recording material P
The upper toner image T becomes slightly melted, and the toner itself becomes viscous. As a result, at the fixing nip portion N, the recording material P
Even if the water vapor generated by heating the toner flows just like the toner on the upstream side of the fixing nip portion N immediately before the fixing nip portion, the toner image t on the recording material P moves to the upstream side due to the connection between the toner particles. Without being skipped
Does not cause image deterioration such as tailing.

【０１２１】また、本実施例における加熱部材１２の形
状は、図１０のもののように、ニップ側に湾曲した形状
を付加してあっても良い。この場合には、加熱部材１２
の定着ニップ部Ｎ側に特に定着フィルム１１をしごく様
な屈曲した部位が無いため、定着フィルム１１はスムー
ズに加熱部材１２の湾曲部にしたがって摺接しながら搬
送される。このため、定着フィルム１１の機械的強度の
緩和にも優位であり、生産性も向上する。Further, the shape of the heating member 12 in this embodiment may be a curved shape on the nip side as shown in FIG. In this case, the heating member 12
Since the fixing film 11 does not have a squeeze-like bent portion on the side of the fixing nip portion N, the fixing film 11 is conveyed while smoothly sliding along the curved portion of the heating member 12. For this reason, the fixing film 11 is superior in the mechanical strength relaxation, and the productivity is also improved.

【０１２２】〈第７の実施例〉（図１１） 本実施例は上記第６の実施例の図９の装置の加熱部材１
２を、図１１のように、定着ニップ部Ｎにおいてフィル
ム搬送方向ａに、透磁率μｄ・μｅを異にする複数の部
材１２ｄ・１２ｅで構成したものである。<Seventh Embodiment> (FIG. 11) This embodiment is the heating member 1 of the apparatus shown in FIG. 9 of the sixth embodiment.
As shown in FIG. 11, 2 is composed of a plurality of members 12d and 12e having different magnetic permeabilities μd and μe in the fixing nip portion N in the film transport direction a.

【０１２３】フィルム搬送方向上流側の部材１２ｄの透
磁率μｄと下流側の部材１２ｅの透磁率μｅとではμｄ
＞μｅの関係がある。すなわち加熱部材１２のフィルム
搬送方向上流側の部材１２ｄは下流側の部材１２ｅに比
べて透磁率が大きく発熱量が多い。例えば、上流側の部
材１２ｄが強磁性のＦｅやＣｏ、Ｎｉ、ジンコート鋼板
で等で形成され、下流側の部材１２ｅがアルミや非磁性
のステンレス、ジンコート鋼板で形成されている。The magnetic permeability μd of the member 12d on the upstream side in the film transport direction and the magnetic permeability μe of the member 12e on the downstream side are μd.
There is a relation of> μe. That is, the member 12d on the upstream side of the heating member 12 in the film transport direction has a larger magnetic permeability and a larger amount of heat generation than the member 12e on the downstream side. For example, the member 12d on the upstream side is formed of ferromagnetic Fe, Co, Ni, a zinc coated steel plate, or the like, and the member 12e on the downstream side is formed of aluminum, nonmagnetic stainless steel, or a zinc coated steel plate.

【０１２４】この結果、定着ニップ部Ｎにおいて、この
定着ニップ部Ｎ内のフィルム搬送方向上流側領域部で記
録材Ｐ上のトナー像ｔが加熱溶融され、下流側領域部で
は若干低い温度で加熱される。あるいは下流側領域部で
はほとんど発熱がない。そのため、トナー像ｔが加熱さ
れ過ぎたまま定着ニップ部Ｎの下流側へ搬出されること
はなくなり、加熱溶融後に若干冷やされて、トナー像ｔ
が記録材Ｐ上にしっかりと固定されてから、定着ニップ
部Ｎの下流側へ搬出される。よって高温オフセット等の
画像劣化を防止することができる。As a result, in the fixing nip portion N, the toner image t on the recording material P is heated and melted in the upstream area in the film conveying direction in the fixing nip portion N, and is heated at a slightly lower temperature in the downstream area portion. To be done. Alternatively, there is almost no heat generation in the downstream region. Therefore, the toner image t will not be carried out to the downstream side of the fixing nip portion N while being overheated, and will be cooled slightly after being heated and melted, and the toner image t will be cooled.
Is firmly fixed on the recording material P, and then is conveyed to the downstream side of the fixing nip portion N. Therefore, image deterioration such as high temperature offset can be prevented.

【０１２５】〈第８の実施例〉（図１２） 図１２の（ａ）乃至（ｃ）はそれぞれ本発明に従うフィ
ルム加熱方式・電磁誘導加熱方式の加熱装置の他の構成
形態例を示したものである。<Eighth Embodiment> (FIG. 12) FIGS. 12 (a) to 12 (c) show other structural examples of the film heating type / electromagnetic induction heating type heating device according to the present invention. Is.

【０１２６】（ａ）のものは、加熱部材１２と磁界発生
手段としての励磁コイル１３のアセンブリの加熱部材１
２の下面と、駆動ローラ３１と、従動ローラ（テンショ
ンローラ）３２との３部材間にエンドレスベルト状のフ
ィルム１１を懸回張設して駆動ローラ３１によりフィル
ム１１を回転駆動する構成のものである。２０はフィル
ム１１を挟んで加熱部材１２の下面圧接させてニップ部
Ｎを形成させた加圧ローラである。(A) is the heating member 1 of the assembly of the heating member 12 and the exciting coil 13 as the magnetic field generating means.
The endless belt-shaped film 11 is suspended and stretched between the three members of the lower surface of 2, the driving roller 31, and the driven roller (tension roller) 32, and the film 11 is rotationally driven by the driving roller 31. is there. Reference numeral 20 denotes a pressure roller having a nip portion N formed by pressing the lower surface of the heating member 12 with the film 11 interposed therebetween.

【０１２７】（ｂ）のものは、加熱部材１２と磁界発生
手段としての励磁コイル１３のアセンブリの加熱部材１
２の下面と、駆動ローラ３１の２部材間にエンドレスベ
ルト状のフィルム１１を懸回張設して駆動ローラ３１に
より回転駆動する構成のものである。２０は加圧ローラ
である。(B) is the heating member 1 of the assembly of the heating member 12 and the exciting coil 13 as the magnetic field generating means.
The endless belt-shaped film 11 is suspended and stretched between the lower surface of 2 and the two members of the driving roller 31, and the driving roller 31 rotates and drives the film 11. Reference numeral 20 is a pressure roller.

【０１２８】（ｃ）のものは、フィルム１１として、エ
ンドレスベルト状のものではなく、ロール巻きにした長
尺の有端フィルムを用い、これを繰り出し軸３４側か
ら、加熱部材１２と磁界発生手段としての励磁コイル１
３のアセンブリの加熱部材１２の下面を経由させて巻き
取り軸３５側へ所定の速度で走行させるように構成した
ものである。２０は加圧ローラである。In the case of (c), the film 11 is not an endless belt-shaped one, but a long end film wound in a roll is used, and the heating member 12 and the magnetic field generating means are fed from the feeding shaft 34 side. Excitation coil 1 as
The assembly of No. 3 is configured to run at a predetermined speed to the winding shaft 35 side via the lower surface of the heating member 12. Reference numeral 20 is a pressure roller.

【０１２９】以上の第１〜第８の実施例の加熱装置は、
画像の加熱定着装置としてばかりではなく、例えば画像
を担持した記録材を加熱して表面性（つや出しなど）を
改質する装置、仮定着処理する装置、シート上の材料を
搬送しつつ加熱や乾燥、ラミネート処理する装置など広
く被加熱材の加熱装置として利用できる。The heating devices of the above first to eighth embodiments are
Not only as an image heating and fixing device, but also for example, a device that modifies the surface properties (such as polishing) by heating a recording material carrying an image, a hypothetical fixing device, and heating and drying while conveying the material on the sheet. It can be widely used as a heating device for materials to be heated such as a device for laminating.

【０１３０】またフィルム１１を挟んでニップ部を形成
する他方側部材としての加圧ローラ２０についても電磁
誘導発熱性部材にして所望の温度に加熱状態にさせるこ
ともできる。Further, the pressure roller 20 as the other side member forming the nip portion with the film 11 sandwiched therebetween can also be made into an electromagnetic induction heat generating member and heated to a desired temperature.

【０１３１】[0131]

【発明の効果】以上のように本発明によれば、フィルム
加熱方式の加熱装置について、加熱部材としてセラミッ
クヒータを用いた従来装置の前述のような諸問題、即ち
セラミックヒータとフィルムとの間の絶縁破壊防止対策
処置の必要性、フィルムの絶縁耐圧性の必要性、非通紙
部昇温現象に起因するフィルム挫屈等の問題、加熱部材
の長手に沿う温度分布等の問題のない、加熱性能・耐久
性に優れ、低コスト化等が可能な装置にすることがで
き、画像加熱定着装置にあっては定着性能の向上、尾引
き・剥離オフセット・高温オフセット等の発生防止等が
可能となる。As described above, according to the present invention, in the film heating type heating device, the above-mentioned problems of the conventional device using the ceramic heater as the heating member, that is, between the ceramic heater and the film There is no need for insulation breakdown prevention measures, film withstand voltage, film buckling, etc. due to the phenomenon of temperature rise in the non-sheet passing area, heating without problems such as temperature distribution along the length of the heating member. It can be a device that has excellent performance and durability and can be manufactured at low cost. In the image heating and fixing device, it is possible to improve the fixing performance and prevent the occurrence of tailing, peeling offset, high temperature offset, etc. Become.

【図面の簡単な説明】[Brief description of drawings]

【図１】画像形成装置例の概略構成図FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus.

【図２】画像加熱定着装置部分の拡大図FIG. 2 is an enlarged view of an image heating and fixing device portion.

【図３】定着フィルムの層構成模型図[Fig. 3] Model diagram of layer structure of fixing film

【図４】第２の実施例における定着フィルムの層構成模
型図FIG. 4 is a schematic diagram of the layer structure of a fixing film in the second embodiment.

【図５】（ａ）及び（ｂ）はそれぞれ第３の実施例にお
ける、加熱部材と励磁コイルのアセンブリの側面模型図
と平面模型図5A and 5B are a side model view and a plan model view of an assembly of a heating member and an exciting coil in a third embodiment, respectively.

【図６】第３の実施例における加熱部材と比較例の加熱
部材の長手方向に沿う表面温度分布図FIG. 6 is a surface temperature distribution diagram along the longitudinal direction of the heating member of the third embodiment and the heating member of the comparative example.

【図７】第４の実施例における、加熱部材と励磁コイル
のアセンブリの側面模型図FIG. 7 is a side model view of the assembly of the heating member and the exciting coil in the fourth embodiment.

【図８】第５の実施例における、加熱部材と励磁コイル
のアセンブリの側面模型図FIG. 8 is a side model view of the assembly of the heating member and the exciting coil in the fifth embodiment.

【図９】第６の実施例装置の要部の模型図FIG. 9 is a model diagram of a main part of a sixth embodiment device.

【図１０】他の構成形態の要部の模型図FIG. 10 is a model diagram of a main part of another configuration mode.

【図１１】第７の実施例装置の要部の模型図FIG. 11 is a model diagram of a main part of the seventh embodiment device.

【図１２】（ａ）・（ｂ）・（ｃ）はそれぞれ他の装置
構成形態例の概略図12 (a), (b), and (c) are schematic views of other device configuration examples.

【図１３】熱ローラ方式の加熱定着装置の概略図FIG. 13 is a schematic view of a heat roller type heat fixing device.

【図１４】（ａ）はフィルム加熱方式の加熱定着装置の
要部の概略図、（ｂ）はフィルムの層構成模型図FIG. 14A is a schematic view of a main part of a film heating type heat fixing device, and FIG. 14B is a schematic diagram of a film layer structure.

【符号の説明】[Explanation of symbols]

６ 画像加熱定着装置（加熱装置） １０ 定着部材 １１ 定着フィルム １２ 加熱部材（電磁誘導発熱性部材、金属板） １３ 励磁コイル（磁界発生手段） ２０ 加圧ローラ Ｎ 定着ニップ部 Ｐ 記録材（被加熱材） ｔ トナー像 6 image heating fixing device (heating device) 10 fixing member 11 fixing film 12 heating member (electromagnetic induction heating member, metal plate) 13 exciting coil (magnetic field generating means) 20 pressure roller N fixing nip portion P recording material (heated) Material) t Toner image

Claims (11)

【特許請求の範囲】[Claims] 【請求項１】 フィルムを挟んでニップ部を形成する部
材と、そのニップ形成部材の少なくとも一方側部材は電
磁誘導発熱性部材にし該部材に磁界を作用させて電磁誘
導発熱させる磁界発生手段を具備させ、ニップ部のフィ
ルムと他方側部材の間に被加熱材を導入してフィルムと
共にニップ部を挟持搬送させ、ニップ部において被加熱
材をフィルムを介して電磁誘導発熱性部材の電磁誘導発
熱の熱で加熱するようにしたことを特徴とする加熱装
置。1. A member for forming a nip portion with a film interposed therebetween, and at least one member of the nip forming member is an electromagnetic induction heat-generating member, and magnetic field generating means for applying a magnetic field to the member to generate electromagnetic induction heat is provided. Then, the material to be heated is introduced between the film in the nip portion and the member on the other side, and the nip portion is nipped and conveyed together with the film. A heating device characterized by being heated by heat. 【請求項２】 フィルムに導電性を付与したことを特徴
とする前記請求項１記載の加熱装置。2. The heating device according to claim 1, wherein the film is provided with conductivity. 【請求項３】 フィルムは、電磁誘導発熱性部材側のフ
ィルム内面の表面抵抗値が、その反対側のフィルム外面
の表面抵抗値よりも低い抵抗値であることを特徴とする
前記請求項２記載の加熱装置。3. The film according to claim 2, wherein a surface resistance value of an inner surface of the film on the electromagnetic induction heating member side is lower than a surface resistance value of an outer surface of the film on the opposite side. Heating device. 【請求項４】 他方側部材の表層に導電性を付与したこ
とを特徴とする前記請求項１乃至請求項３の何れかに記
載の加熱装置。4. The heating device according to claim 1, wherein the surface layer of the other member has conductivity. 【請求項５】 電磁誘導発熱性部材に、フィルム搬送方
向に直交する方向である長手方向における熱容量に分布
を持たせ、長手中央部に比べ両端部の方が熱容量が大き
いことを特徴とする前記請求項１記載の加熱装置。5. The electromagnetic induction heat-generating member is provided with a distribution of heat capacity in the longitudinal direction, which is a direction orthogonal to the film transport direction, and both end portions have a larger heat capacity than the longitudinal central portion. The heating device according to claim 1. 【請求項６】 電磁誘導発熱性部材と、該部材を電磁誘
導加熱させる磁界発生手段としての励磁コイルとの間に
間隙が存在し、その隙間が電磁誘導発熱性部材のフィル
ム搬送方向に直交する方向である長手方向において長手
中央部に比べ両端部の方が広くなっていることを特徴と
する前記請求項１記載の加熱装置。6. A gap exists between the electromagnetic induction heating member and an exciting coil as a magnetic field generating means for heating the member by electromagnetic induction, and the gap is orthogonal to the film transport direction of the electromagnetic induction heating member. The heating device according to claim 1, wherein both end portions are wider than a longitudinal center portion in a longitudinal direction which is a direction. 【請求項７】 電磁誘導発熱性部材はフィルム搬送方向
に直交する方向である長手方向において材質を異にする
複数の部材で構成され、長手中央部の透磁率に比べ両端
部の透磁率を低く形成したことを特徴とする前記請求項
１記載の加熱装置。7. The electromagnetic induction heat-generating member is composed of a plurality of members made of different materials in a longitudinal direction which is a direction orthogonal to a film conveying direction, and has a lower magnetic permeability at both end portions than a magnetic permeability at a longitudinal central portion. The heating device according to claim 1, wherein the heating device is formed. 【請求項８】 電磁誘導発熱性部材はニップ部の被加熱
材入口直前部において被加熱材搬送方向に関して他方側
部材から離間する方向に傾斜、あるいは湾曲した形状を
なしていることを特徴とする前記請求項１記載の加熱装
置。8. The electromagnetic induction heat-generating member has a shape inclined or curved in a direction away from the other member in the conveying direction of the material to be heated in the portion immediately before the material to be heated inlet of the nip portion. The heating device according to claim 1. 【請求項９】 電磁誘導発熱性部材はニップ部において
フィルム搬送方向に複数の部材から構成され、フィルム
搬送方向上流側の部材の透磁率が下流側の部材の透磁率
に比べ大きいことを特徴とする前記請求項１記載の加熱
装置。9. The electromagnetic induction heating member is composed of a plurality of members in the film transport direction at the nip portion, and the magnetic permeability of the upstream member in the film transport direction is greater than the magnetic permeability of the downstream member. The heating device according to claim 1, wherein 【請求項１０】 被加熱材が加熱処理すべき画像を担持
させた記録材であり、装置が該被記録材に画像を加熱処
理する像加熱装置であることを特徴とする前記請求項１
乃至請求項９の何れかに記載の加熱装置。10. The heating material is a recording material carrying an image to be heat-treated, and the apparatus is an image heating device for heating the image on the recording material.
The heating device according to claim 9. 【請求項１１】 前記請求項１乃至請求項９の何れかに
記載の加熱装置を像加熱装置として備えていることを特
徴とする画像形成装置。11. An image forming apparatus comprising the heating device according to any one of claims 1 to 9 as an image heating device.