JP2005003028A

JP2005003028A - Rotor device, heating device, fixing device and image forming device

Info

Publication number: JP2005003028A
Application number: JP2003164702A
Authority: JP
Inventors: Takatoshi Chiba; 敬要千葉
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2003-06-10
Filing date: 2003-06-10
Publication date: 2005-01-06

Abstract

PROBLEM TO BE SOLVED: To elongate the service life of a rotor itself by slowing the progress of sliding damages on the surface of the rotor due to an abutting member. SOLUTION: This rotor device comprises at least two rotors 1, 3 to be rotated while pressing one against the other and the abutting members 7b, 9b arranged abutting on the surfaces of the rotors, respectively. The abutting members are so arranged as to be dislocated from each other by their widths or greater in the axial direction of the rotors. COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、回転体装置、加熱装置、定着装置及び画像形成装置に関する。
【０００２】
より詳しくは、互いに圧接しながら回転する少なくとも２つ以上の回転体それぞれの表面に当接配置される当接部材を備える回転体装置に関する。
【０００３】
また、第１及び第２の回転体間に被加熱材を導入して、該被加熱材に熱エネルギーを付与する加熱装置に関する。
【０００４】
また、第１及び第２の定着回転体間に被加熱材としての記録材を導入し、該記録材に熱エネルギーと加圧力を付与して未定着画像の定着を行う定着装置に関する。
【０００５】
また、転写材・感光紙・静電記録紙などの被記録材上に、電子写真方式・インクンジェット方式あるいは静電記録方式などの適宜の作像形成手段によって形成担持させた画像を加熱して、像定着や、艶等の表面性の改質、仮定着等を行う像加熱装置を備える複写機、レーザプリンタなどの画像形成装置に関する。
【０００６】
【従来の技術】
一般に、電子写真方式を採用した複写機等の画像情報記録装置（画像形成装置）では、記録シート上に転写したトナー像を定着させるために、通常は加熱・加圧式定着装置が設けられている。
【０００７】
この種の定着装置は、互いに圧接しながら回転する表面に弾性層を設けた定着ローラとこれと圧接する加圧ローラとを備え、未定着トナー像が形成された記録シートをこれらローラ間の圧接部（定着ニップ部）に挿通させて未定着トナー像の加熱・定着を行うようにしたものである。
【０００８】
従来、熱加圧方式の定着装置として、定着ローラ及び加圧ローラ内部にそれぞれヒータ（加熱源）を設け、該各ローラ表面にサーミスタなどの温度検知センサをそれぞれ当該配置させ、該各センサの検出温度に基づいて対応するローラ内部のヒータへの給電を制御することによって、該各ローラ表面の温調制御を正確に行えるものが知られている（例えば、特許文献１参照）。
【０００９】
一方、外部加熱式の定着装置としては、定着ローラ表面に外部加熱体を接触させて該ローラを表面から加熱することによって、定着ローラ表面温度の上昇時間を短縮し、大量の記録画像を高速出力する際の定着ローラの温度低下を防ぐものが知られている（例えば、特許文献２参照）。
【００１０】
外部加熱方式を採用する主な理由について説明する。通常、定着装置においては、定着ローラがその表面に熱伝導性の低い弾性層を有しており、前記定着ローラ内部にある加熱源からの熱供給のみで前記ローラ表面温度を設定温度まで到達させるためには多くの時間を必要とする。
【００１１】
また、高速で大量の記録画像を出力する場合に、前述の通り、前記定着ローラ内部にある加熱源からの熱供給のみでは、定着ローラは定着ニップ部を通過する記録媒体に熱を奪われてしまい、定着ローラ表面温度がトナー像を定着できないまでに低下してしまう。
【００１２】
そこで、上述のような問題を回避する手段として、定着ローラ表面に外部加熱体を配設して、温度上昇時間を短縮し、高速出力する際の定着ローラの温度低下を防ぐ外部加熱方式の定着装置が実用化されている。
【００１３】
図８に外部加熱方式を用いた定着装置の一例を示す。
【００１４】
図８における定着装置は外部加熱体にローラ（以下外部加熱ローラ２と記す）を用いている。外部加熱ローラ２はローラ内部に熱源であるヒータ５を有し、加熱定着部材（図８では定着ローラ１）表面に回転自在に直接接触し、定着ローラ１を加熱する。
【００１５】
定着ローラ１は、ローラ内部に熱源であるヒータ４を有する。前記定着ローラ１は加圧部材（図８では加圧ローラ３）に圧接している。加圧ローラ３はローラ内部に熱源であるヒータ６を有している。
【００１６】
外部加熱ローラ２により表面を加熱された定着ローラ１と加圧ローラ３とによって、未定着トナー像ｔがシート面上に形成担持された記録シートＰをローラ間の定着ニップ部Ｎに挟持搬送させて未定着トナー像を該シート面上に加熱・加圧して定着する。
【００１７】
外部加熱方式に限らず、熱加圧方式の定着装置において、熱源を有するローラの表面温度を制御するため、熱源を有するローラ各々の温度を検出する少なくとも１つ以上の温度検知手段７・８・９が各々のローラに配置される。
【００１８】
前記温度検知手段としては検出精度を上げつつ、コストも安価であるローラ表面に当接するタイプの温度検知センサ（例えば、サーミスタ）が多く使用されている。
【００１９】
図９に、外部加熱方式を用いた定着装置において温度検知手段７ａ・７ｂ・８ａ・８ｂ・９ａ・９ｂをローラ１・２・３表面の同一位置に当接配置させた一例を示す。図９は図８の定着装置を矢印Ａ方向から見た図である。
【００２０】
各ローラ１・２・３に対応する第１の温度検知手段７ｂ・８ｂ・９ｂは本従来例では、最小紙サイズ幅内に配置される。
【００２１】
また、各ローラ１・２・３に対応する第２の温度検知手段７ａ・８ａ・９ａは前述の温度検知手段７ｂ・８ｂ・９ｂとローラ軸方向で異なる位置に配置され、本従来例では最大紙サイズ幅外に配置されている。
【００２２】
従来の定着装置において、外部加熱ローラ２に当接する第１の温度検知手段８ｂと、定着ローラ１に当接する第１の温度検知手段７ｂがローラ軸方向（ローラ長手方向）で同じ位置にあって、対応するローラ表面温度の検出を行う。
【００２３】
このように温度検知手段をローラ軸方向で同一位置に配置することで、記録材のサイズが変更した場合に、一の温度検知体は非通紙部の温度を検知し、また他の温度検知体は通紙部の温度を検知するような不具合を防止するようにしている。
【特許文献１】
特開２００２−３２３８２８号公報
【特許文献２】
特開２００３−２９５６３号公報
【００２４】
【発明が解決しようとする課題】
図８に示す定着ローラ１及び外部加熱ローラ２は装置稼働時、図８の矢印方向（定着ローラ１にあっては時計方向、外部加熱ローラ５あっては反時計方向）に回転している。
【００２５】
温度検知手段７・８・９はそれぞれ対応するローラに対しローラ表面に当接している。そのため、ローラの回転数の増加と共に温度検知手段の当接面で各々のローラ表面に摺動キズが発生してくる場合がある。
【００２６】
図９における温度検知手段の配置において、定着ローラ１に当接する第１の温度検知手段７ｂと、外部加熱ローラ２に当接する第１の温度検知手段８ｂが同じ位置にあることにより、前述した摺動キズの発生位置は定着ローラ１及び外部加熱ローラ２共に同じ位置になる。
【００２７】
仮に、定着ローラ１及び外部加熱ローラ２においてローラ表面の同じ位置に摺動キズが発生した場合、定着ローラ１に付着したトナーや記録紙の紙粉などの異物が摺動キズ又はその周囲に留まってローラ表面の同一部分に付着しやすくなる。この場合、装置稼働時に定着ニップ部において該異物が被記録材面でローラ表面に擦られるので、該ローラの使用頻度の増加に伴い摺動キズの進行が加速度的に速くなり、各ローラの所望寿命（画像不良が発生しない）を達成するための阻害要素となることが懸念される。
【００２８】
また、外部加熱ローラ２は定着ローラ１表面を加熱することを目的としている。そのため外部加熱ローラ２表面は、熱伝導性の低い弾性層を持たずに表面は金属表面及び微少のフッ素層を持つ程度である。
【００２９】
さらに定着ローラ１は、表面に熱伝導性の低い弾性層を持っている。
【００３０】
上記にふまえて、同じ位置に温度検知手段７ｂ・８ｂがあると同じ位置に温度検知手段による摺動キズが発生する場合がある。
【００３１】
この場合、外部加熱ローラ２側の摺動キズは当該ローラ表面において金属面等で鋭利なエッジになることがあるため、定着ローラ１表面に与えるダメージが大きくなる。
【００３２】
さらに定着ローラ１は定着ローラ１自身が持っている温度検知手段７ｂによる摺動キズが発生しているため、外部加熱ローラ２表面の上記エッジ状の摺動キズとの摺擦によって該摺動キズの進行が加速されてしまい、前述と同様に、各ローラの所望寿命（画像不良が発生しない）を達成するための阻害要素になることが懸念される。
【００３３】
前述の構成においては、定着ローラ１に当接する第１の温度検知手段７ｂと、外部加熱ローラ２に当接する第１の温度検知手段８ｂにおける摺動キズの関係を述べたが、上述した項目が最も画像に影響する摺動キズであり、同様のことが、各ローラにおける第２の温度検知手段７ａ・８ａ・９ａでも発生し、同様に定着ローラ１と加圧ローラ３の関係でも発生する可能性がある。
【００３４】
上述のような温度検知手段による定着ローラ及び加圧ローラ表面の摺動キズの進行は外部加熱式の定着装置のみならず、熱加圧方式の定着装置においても同様に起り得る。
【００３５】
例えば、熱加圧方式の定着装置において、定着ローラ及び加圧ローラ表面のローラ軸方向の同一位置にそれぞれ温度検知手段を当接配置した場合、各ローラ表面の同じ位置に温度検知手段による摺動キズが発生する可能性がある。各ローラ表面に摺動キズが発生した場合、その摺動キズはローラの回転数の増加に伴って摺進行し、各ローラの所望寿命を達成するための阻害要素となる。
【００３６】
また、定着ローラ表面のローラ軸方向の同一位置にローラ周方向で一定角度離隔させてそれぞれ温度検知手段を当接配置した場合にも、該ローラ表面の同じ位置に温度検知手段による摺動キズが発生する可能性がある。定着ローラ表面に摺動キズが発生した場合、その摺動キズはローラの回転数の増加に伴って進行し、定着ローラの所望寿命を達成するための阻害要素となる。
【００３７】
そのため、外部加熱式若しくは熱加圧方式の定着装置において、回転体としての各ローラについて摺動キズの進行を防止するため、単一のローラに当接配置される少なくとも２つ以上の温度検知手段の配置態様を工夫する必要がある。
【００３８】
そこで、本発明の目的は、回転体の当接部材による回転体表面の摺動キズの進行を遅らせ、回転体それ自体の使用寿命を延ばすことのできる回転体装置を提供することにある。
【００３９】
また、第１及び第２の回転体の温度検知手段による回転体表面の摺動キズの進行を遅らせ、各回転体それ自体の使用寿命を延ばすことのできる加熱装置を提供することにある。
【００４０】
また、第１及び第２の定着回転体と外部回転体の温度検知手段による回転体表面の摺動キズの進行を遅らせ、各々の回転体それ自体の使用寿命を延ばすことのできる定着装置を提供することにある。
【００４１】
また、像形成手段により被加熱材としての記録材上に形成された画像を加熱する像加熱手段として前記定着装置を備える画像形成装置を提供することにある。
【００４２】
【課題を解決するための手段】
本発明に係る回転体装置、加熱装置、定着装置及び画像形成装置は下記の構成を特徴とする。
【００４３】
１）互いに圧接しながら回転する少なくとも２つ以上の回転体と、前記回転体それぞれの表面に当接配置される当接部材を備える回転体装置において、前記各当接部材はそれぞれ回転体軸方向において該当接部材の幅以上ずれて配置される回転体装置。
【００４４】
２）当接部材は回転体の温度を検知する温度検知体であることを特徴とする上記１に記載の回転体装置。
【００４５】
３）互いに圧接しながら回転する第１及び第２の回転体と、前記第１及び第２の回転体それぞれの内部に配設される熱源と、前記各々の回転体表面に当接配置される少なくとも１個以上の温度検知手段をもち、前記第１の回転体及び第２の回転体の圧接部に被加熱材を挟持搬送して加熱する加熱装置において、前記第１の回転体表面に当接する温度検知手段の回転体軸方向の位置が、前記第２の回転体表面に当接する温度検知手段の回転体軸方向の位置と、前記温度検知手段の幅以上ずれて配置されていることを特徴とする加熱装置。
【００４６】
４）互いに圧接しながら回転する第１及び第２の回転体と、前記第１又は第２、若しくは第１及び第２の回転体の表面に当接して回転する１本以上の外部回転体と、前記第１、第２及び外部回転体それぞれの内部に配設される熱源と、前記各々の回転体表面に当接配置される少なくとも１個以上の温度検知手段をもち、前記第１の回転体及び第２の回転体の圧接部に被加熱材を挟持搬送して加熱する加熱装置において、前記外部回転体表面に当接する温度検知手段の回転体軸方向の位置が、前記第１又は第２の回転体表面に当接する温度検知手段の回転体軸方向の位置と、前記温度検知手段の幅以上ずれて配置されていることを特徴とする加熱装置。
【００４７】
５）前記第１の回転体表面に当接する温度検知手段の回転体軸方向の位置が、前記第２の回転体表面に当接する温度検知手段の回転体軸方向の位置と、前記温度検知手段の幅以上ずれて配置されていることを特徴とする上記５に記載の加熱装置。
【００４８】
６）互いに圧接しながら回転する第１及び第２の定着回転体に、前記第１及び第２の定着回転体表面に当接して回転する１本以上の外部回転体と、前記第１、第２及び外部回転体内部に配設される熱源と、前記各々の回転体表面に当接配置される少なくとも１個以上の温度検知手段をもち、前記第１の定着回転体及び第２の定着回転体の圧接部に未定着トナーを保持した記録材を挟持搬送して定着を行う定着装置において、前記外部回転体に当接する温度検知手段の回転体軸方向の位置が、前記第１又は第２の定着回転体に当接する温度検知手段の回転体軸方向の位置と、前記温度検知手段の幅以上ずれて配置されていることを特徴とする定着装置。
【００４９】
７）前記第１及び第２の定着回転体と外部回転体に当接する少なくとも１つの前記温度検知手段の回転体軸方向位置が、圧接部における記録材の最小通紙幅内に配置されていることを特徴とする上記６に記載の定着装置。
【００５０】
８）前記第１及び第２の定着回転体と外部回転体に当接する少なくとも１つの前記温度検知手段の回転体軸方向位置が、圧接部における記録材の最大通紙幅外に配置されていることを特徴とする上記６に記載の定着装置。
【００５１】
９）前記第１及び第２の定着回転体と外部回転体に当接する前記温度検知手段の回転体軸方向位置が、該各々の回転体で前記温度検知手段の幅以上ずれて配置されていることを特徴とする上記６に記載の定着装置。
【００５２】
１０）前記外部回転体の軸方向長さがこれに当接する第１及び第２の定着回転体のいずれかの軸方向長さより長く、前記外部回転体の温度検知手段の当接位置を、前記外部回転体と相対する定着回転体が当接しない当該外部回転体の軸方向長さの位置に配置し、第１及び第２の定着回転体の温度検知手段の位置と、前記外部回転体の温度検知手段の位置が、温度検知手段の幅以上ずれて配置されていることを特徴とする上記６に記載の定着装置。
【００５３】
１１）前記第２の定着回転体の軸方向長さがこれに当接する第１の定着回転体の軸方向長さより長く、前記第２の定着回転体の温度検知手段の当接位置を、前記第２の定着回転体と相対する第１の定着回転体が当接しない当該第２の定着回転体軸方向長さの位置に配置し、第１の定着回転体の温度検知手段位置と、第２の定着回転体の温度検知手段位置が、温度検知手段の幅以上ずれて配置されていることを特徴とする上記６に記載の定着装置。
【００５４】
１２）被加熱材としての記録材上に画像を形成する像形成手段と、該記録材上の画像を加熱する像加熱手段とを備える画像形成装置において、前記像加熱手段が上記３ないし５のいずれかに記載の加熱装置であることを特徴とする画像形成装置。
【００５５】
１３）記録材上に画像を形成する像形成手段と、該記録材上の画像を加熱して定着させる像定着手段とを備える画像形成装置において、前記像定着手段が上記６ないし１１のいずれかに記載の定着装置であることを特徴とする画像形成装置。
【００５６】
【発明の実施の形態】
以下、図面を参照して、本発明の実施形態を具体的に説明する。
【００５７】
なお、前述した図８及び図９に示す定着装置の構成部材と同一機能を有する部材には同符号を付し、説明は省略する。
【００５８】
（実施例１）
図１は、外部加熱方式の定着装置を図８のＡ側から見た図であり、特に、定着ローラ及び外部加熱ローラそれぞれに個々に当接する第１の温度検知手段の一配置例を示す説明図である。
【００５９】
図１における定着装置では、定着ローラ１と加圧ローラ３間の定着ニップ部Ｎに挟持搬送される被加熱材としての記録材（記録シート）の最小紙サイズ幅内において、外部加熱ローラ２に当接する第１の温度検知手段８ｂを、定着ローラ１に当接する第１の温度検知手段７ｂに対し、温度検知手段の幅分ローラ軸方向にずらして配置してある。
【００６０】
上述のように温度検知手段を定着ローラ１と外部加熱ローラ２でずらして配置することにより、外部加熱ローラ２に当接する第１の温度検知手段８ｂによる外部加熱ローラ表面の摺動キズと、定着ローラ１に当接する第１の温度検知手段７ｂによる定着ローラ１表面の摺動キズがローラ軸方向で同じ箇所に発生しない。つまり摺動キズは定着ローラ１及び外部加熱ローラ２表面において温度検知手段７ｂ・８ｂのずらし量に応じた異なる位置に発生することになる。
【００６１】
この場合、定着ローラ１及び外部加熱ローラ２表面において、摺動キズのずれ位置に応じた異なる位置にトナーや紙粉などの異物が留まることになる。このため、装置稼働時には異物は定着ニップ部においてローラ表面の摺動キズのずれ位置に応じた異なる位置に被記録材によって擦られることとなり、定着ローラ及び外部加熱ローラの回転数の増加に伴う摺動キズの進行を遅らせることができる。
【００６２】
また、定着ローラ１及び外部加熱ローラ２表面に発生する摺動キズの位置は温度検知手段７ｂ・８ｂのずらし量に応じて異なっているので、外部加熱ローラ２側の摺動キズが鋭利なエッジになることを防止できて定着ローラ１表面に与えるダメージを小さくできると共に、定着ローラ表面に発生する摺動キズの進行を防止できる。
【００６３】
これによって、各ローラそれ自体の使用寿命を延ばすことができ、各ローラの所望寿命を達成することが可能になる。
【００６４】
（実施例２）
図２は、実施例１の定着装置において定着ローラの温度検知手段と一定の関係をもって加圧ローラに当接する第１の温度検知手段の一配置例を示す説明図である。
【００６５】
本例では、実施例１における構成をとりながら、加圧ローラ３に当接する第１の温度検知手段９ｂを、定着ローラ１に当接する第１の温度検知手段７ｂに対し、温度検知手段の幅分ローラ軸方向にずらして配置したものである。
【００６６】
この構成をとることにより、定着ローラ１に当接する第１の温度検知手段７ｂによる定着ローラ表面の摺動キズと、加圧ローラ３に当接する第１の温度検知手段９ｂによる加圧ローラ表面の摺動キズがローラ軸方向で同じ箇所に発生しないため、定着ローラ表面の摺動キズと加圧ローラ表面の摺動キズの関係についても、上述した外部加熱ローラ表面の摺動キズと定着ローラ表面の摺動キズの場合と同様な理由で、定着ローラ表面及び加圧ローラ表面の摺動キズの進行を遅らせることができ、よって、該各ローラの所望寿命を達成することが可能になる。
【００６７】
（実施例３）
図３は、実施例２の定着装置において定着ローラ、外部加熱ローラ及び加圧ローラそれぞれに個々に当接する第２の温度検知手段の一配置例を示す説明図である。
【００６８】
図３における定着装置では、定着ローラ１と加圧ローラ３間の定着ニップ部Ｎに挟持搬送される被加熱材としての記録材（記録シート）の最大紙サイズ幅外の非通紙部において、定着ローラ１、外部加熱ローラ２及び加圧ローラ３それぞれに当接する第２の温度検知手段７ａ・８ａ・９ａを、第１の温度検知手段７ｂ・８ｂ・９ｂと同様に、温度検知手段の幅分ローラ軸方向にずらして配置したものである。
【００６９】
この構成をとることにより、定着ローラ１に当接する第２の温度検知手段７ａによる定着ローラ表面の摺動キズと、外部加熱ローラ２に当接する第２の温度検知手段８ａによる外部加熱ローラ表面の摺動キズと、加圧ローラ３に当接する第２の温度検知手段９ａによる加圧ローラ表面の摺動キズがローラ軸方向で同じ箇所に発生しないため、定着ローラ表面の摺動キズと外部加熱ローラ表面の摺動キズと定着ローラ表面の摺動キズ、及び定着ローラ表面の摺動キズと加圧ローラ表面の摺動キズの関係についても、上述した場合と同様な理由で、定着ローラ表面、外部加熱ローラ表面及び加圧ローラ表面の摺動キズの進行を遅らせることができ、よって、該各ローラの所望寿命を達成することが可能になる。
【００７０】
（実施例４）
図４は、実施例２の定着装置において外部加熱ローラに当接する第２の温度検知手段の一配置例を示す説明図である。
【００７１】
図４における定着装置では、外部加熱ローラ２は端部に軸方向に延ばした延長部２ａを有している。延長部２ａを持たせる理由は、外部加熱ローラ２が図示しない定着ローラとの接離機構を持つためである。接離機構が必要な理由については後述する。
【００７２】
接離機構により定着装置待機時、外部加熱ローラ２は定着ローラ１に接しない位置で停止している。定着装置動作開始と同時に、外部加熱ローラ２は定着ローラ１に当接し、定着ローラ１表面を加熱する。この動作を定着装置待機時→定着装置動作ごとに繰り返す。この繰り返しの離間動作において、定着ローラ１と外部加熱ローラ２の軸方向長さが同じであると、表層が金属または、微少なフッ素コート層である外部加熱ローラ２のローラ軸端部により定着ローラ１の表面にダメージを与えてしまう。そのため延長部２ａを設けることにより、定着ローラ１に対するダメージを軽減する配慮をしている。
【００７３】
本例では、前述した延長部２ａに外部加熱ローラ２に当接する第２の温度検知手段８ａを配置することにより、該温度検知手段を定着ローラ１に当接する第２の温度検知手段７ａに対し温度検知手段の幅分ローラ軸方向に位置をずらして配置している。
【００７４】
これにより、定着ローラ１に当接する第２の温度検知手段７ａによる定着ローラ表面の摺動キズと、外部加熱ローラ２に当接する第２の温度検知手段８ａによる外部加熱ローラ表面の摺動キズがローラ軸方向で同じ箇所に発生しないため、定着ローラ表面の摺動キズと外部加熱ローラ表面の摺動キズの関係について、上述した実施例１の場合と同様な理由で、定着ローラ表面及び外部加熱ローラ表面の摺動キズの進行を遅らせることができ、よって、該各ローラの所望寿命を達成することが可能になる。
【００７５】
（外部加熱ローラ２の接離機構の必要性の説明）
外部加熱ローラ２は、定着ローラ１に温度を受け渡すため表面温度が高い。
【００７６】
定着ローラ１に用紙が巻き付いた場合に定着ローラ１と外部加熱ローラ２の当接部に用紙Ｐが突入したままの状態で、用紙Ｐに外部加熱ローラ２が接触し、定着ローラ１との間で圧力をかけ続けると発煙等の問題を引き起こす可能性があり、これを防止するため接離機構を設けることが１つめの理由である。
【００７７】
次に定着装置スタンバイ時において、外部加熱ローラ２が定着ローラ１に当接していることによる定着ローラ１の外周方向の温度分布が当接部だけ高温になる温度ムラをさけるために接離機構を設けている。外周方向の温度分布ムラにより、定着時に定着ムラが出来てしまうことがある。
【００７８】
以上が接離機構を設ける理由である。
【００７９】
（実施例５）
図５は、実施例４の定着装置において加圧ローラに当接する第２の温度検知手段の一配置例を示す説明図である。
【００８０】
図５における定着装置では、加圧ローラ３は端部に軸方向に延ばした延長部３ａを有している。延長部３ａを有する理由は、最も記録材としての用紙及びトナーによるダメージを受け、最もローラ寿命において条件が厳しい定着ローラ１の加圧ローラ３の端部によるダメージを無くすために設けている。
【００８１】
本例では、前述した延長部３ａに加圧ローラ３に当接する第２の温度検知手段９ａを配置することにより、該温度検知手段を定着ローラ１に当接する第２の温度検知手段７ａに対し温度検知手段の幅分ローラ軸方向に位置をずらして配置している。
【００８２】
これにより、定着ローラ１に当接する第２の温度検知手段７ａによる定着ローラ表面の摺動キズと、加圧ローラ３に当接する第２の温度検知手段９ａによる加圧ローラ表面の摺動キズがローラ軸方向で同じ箇所に発生しないため、定着ローラ表面の摺動キズと加圧ローラ表面の摺動キズの関係について、上述した実施例２の場合と同様な理由で、定着ローラ表面及び加圧ローラ表面の摺動キズの進行を遅らせることができ、よって、該各ローラの所望寿命を達成することが可能になる。
【００８３】
（実施例６）
図６は、熱加圧方式の定着装置を図８のＡ側から見た図であり、特に、定着ローラ及び加圧ローラそれぞれに個々に当接する第１の温度検知手段の一配置例を示す説明図である。
【００８４】
図６における定着装置では、例えば、定着ローラ１と加圧ローラ３間の定着ニップ部Ｎに挟持搬送される記録材の最小紙サイズ幅内において、加圧ローラ３に当接する第１の温度検知手段９ｂを、定着ローラ１に当接する第１の温度検知手段７ｂに対し、温度検知手段の幅分ローラ軸方向にずらして配置してある。
【００８５】
これにより、定着ローラ１に当接する第１の温度検知手段７ｂによる定着ローラ表面の摺動キズと、加圧ローラ３に当接する第１の温度検知手段９ｂによる加圧ローラ表面の摺動キズがローラ軸方向で同じ箇所に発生しないため、定着ローラ表面の摺動キズと加圧ローラ表面の摺動キズの関係についても、実施例２の場合と同様な理由で、定着ローラ表面及び加圧ローラ表面の摺動キズの進行を遅らせることができ、よって、該各ローラの所望寿命を達成することが可能になる。
【００８６】
（実施例７）
図７は本発明に係る画像形成装置の一例を示す概略構成図であり、加熱装置として上記第１〜４の実施例のいずれかの定着装置を適用したものである。
【００８７】
図７において、符号１００は画像形成装置としてのレーザプリンタである。
【００８８】
レーザプリンタ１００において、パーソナルコンピュータやワードプロセッサ等の外部情報機器から送信された画像情報を基にビデオコントローラボード（画像信号作成手段）１０４が画像信号を作成する。なお、ここではビデオコントローラボード１０４上に設置されている各種の電子部品は図示を省略している。
【００８９】
そしてこのビデオコントローラボード１０４で作成された画像信号に応じたレーザ光Ｌをレーザスキャナ１０５が所定方向（図では時計方向）に回転している感光ドラム１０６Ａ上に照射して、感光ドラム１０６Ａ上に順次静電潜像を形成する。
【００９０】
そして、感光ドラム１０６Ａ上に形成された静電潜像は、プロセスユニット６内の現像器（不図示）から供給されるトナーによって順次顕画化されて転写ローラ１０７との間の転写部位へ搬送される。
【００９１】
一方、給紙カセット１０８内に積載収納されている記録材Ｓが所定方向（図では反時計方向）に１回転する半月状の給紙ローラ１０９によって最上位の記録材Ｓから１枚ずつ順次給紙パス１１０Ａへ送り出され、その記録材Ｓは搬送ローラ対１１１によって給紙パス１１０を通じて回転停止中のレジストローラ対１１２に搬送される。
【００９２】
レジストローラ対１１２に到達した記録材Ｓは、記録材先端レジストローラ対１１２のニップに突き当たった後、所定のループを形成するまで搬送が続けられて斜行状態の矯正がなされる。
【００９３】
斜行状態の矯正を終えた記録材Ｓは、感光ドラム６Ａ上のトナー像と位置を合わせるタイミングをとって回転を開始するレジストローラ対１１２によって転写部へ搬送され、ここで、転写ローラ１０７により感光ドラム１０６Ａ上のトナー像が記録材面上に転写される。
【００９４】
トナー像の転写を終えた記録材Ｓは搬送ガイド１１３上を通って定着装置１４へ搬送され、ここで、転写されたトナー像が記録材面に定着される。
【００９５】
トナー像の定着処理を終えた記録材Ｓは、印字面を下向きに積載する場合には、搬送面１１６とそれに対向する揺動ガイド１２４によって作られる搬送路を通って、不図示の駆動源をそなえたフェイスダウン排紙ローラ１１９とそれと圧接して従動するコロ１２５によってプリンタ本体１００の上部のフェイスダウン排紙トレイ１１７上へ排紙される。
【００９６】
また、印字面を上向きに積載（フェイスダウン積載）する場合は、フェイスアップトレイ１２２の回転中心１２３を支点に矢印Ａのように開き、不図示の駆動源を備えたフェイスアップローラ１１８とそれに圧接されて従動するコロ１１５によって、フェイスアップトレイ１２２Ａ上の搬送部１２４Ａ上に記録材の印字面を上向きに排出する。
【００９７】
（その他）
１）前述した実施形態では、各ローラに当接する温度検知手段の位置を温度検知手段の幅分ずらした定着装置を例示したが、本発明はこれに限定されるものではなく、摺動キズが重ならない位置であれば、同様の効果を得ることができる。
【００９８】
２）前述した実施形態では、各ローラにおける第１の温度検知手段が最小紙サイズ幅内に配置される定着装置を例示したが、本発明はこれに限定されるものではなく、所望の温度が検知できる位置であり、摺動キズが重ならない位置であれば、同様の効果を得ることができる。
【００９９】
３）前述した実施形態では、各ローラにおける第２の温度検知手段が最大紙サイズ幅外に配置される定着装置を例示したが、本発明はこれに限定されるものではなく、所望の温度が検知できる位置であり、摺動キズが重ならない位置であれば、同様の効果を得ることができる。
【０１００】
４）前述した実施形態では、１本の外部加熱ローラが定着ローラに当接する定着装置を例示したが、本発明はこれに限定されるものではなく、例えば定着ローラに外部加熱ローラが複数当接する構成の定着装置であってもよく、該定着装置に本発明を適用することにより、同様の効果を得ることができる。
【０１０１】
５）前述した実施形態では、外部加熱ローラが定着ローラのみに当接する定着装置を例示したが、本発明はこれに限定されるものではなく、例えば加圧ローラに外部加熱ローラが当接する構成の定着装置であってもよく、該定着装置に本発明を適用することにより、同様の効果を得ることができる。
【０１０２】
６）温度検知手段（温度検知体）に代えて、ローラ表面に一定の機能を作用させる例えば除電部材や其の他任意の部材を当接部材として適宜用いることができる。
【０１０３】
７）本発明の定着装置は外部加熱方式や熱加圧方式の定着装置に限らず、フィルム加熱定着方式の定着装置にも適用できる。この場合、定着ローラに代えて、加熱体（熱源）を有するステーに外嵌され、該ステーの外形に沿って回転されるエンドレス状の耐熱性フィルムが用いられる。その場合、フィルム表面に当接する部材として、該フィルム表面に一定の機能を作用させる例えば除電部材や其の他任意の部材を適宜用いることができる。
【０１０４】
８）本発明の加熱装置は実施形態例の画像加熱定着装置に限らず、画像を担持した記録材を加熱してつや等の表面性を改質する像加熱装置、仮定着する像加熱装置、その他、被加熱材の加熱乾燥装置、加熱ラミネート装置など、広く被加熱材を加熱処理する手段・装置として使用できる。
【０１０５】
【発明の効果】
以上説明したとおり、本発明に係る回転体装置によれば、回転体、または第１及び第２の回転体において、これらの回転体表面に回転体軸方向で当接部材それぞれが該当接部材の幅以上ずれて配置されるので、回転体表面に当接部材によって発生する摺動キズの進行を遅らせることができ、回転体それ自体の使用寿命を延ばすことができる、という効果を奏する。
【０１０６】
本発明に係る加熱装置によれば、第１及び第２の回転体、または第１、第２及び外部回転体において、これらの回転体表面に回転体軸方向で温度検知手段それぞれが該温度検知手段の幅以上ずれて配置されるので、回転体表面に温度検知手段によって発生する摺動キズの進行を遅らせることができ、回転体それ自体の使用寿命を延ばすことができる、という効果を奏する。
【０１０７】
本発明に係る定着装置によれば、第１及び第２の定着回転体と外部回転体において、これらの回転体表面に回転体軸方向で温度検知手段それぞれが該温度検知手段の幅以上ずれて配置されるので、回転体表面に温度検知手段によって発生する摺動キズの進行を遅らせることができ、回転体それ自体の使用寿命を延ばすことができる、という効果を奏する。
【図面の簡単な説明】
【図１】外部加熱方式の実施例１の定着装置の概略構成を示し、定着ローラ及び外部加熱ローラ表面に当接する第１の温度検知手段の一配置例を示す説明図。
【図２】同方式の実施例２の定着装置の概略構成を示し、定着ローラ及び加圧ローラ表面に当接する第１の温度検知手段の一配置例を示す説明図。
【図３】同方式の実施例３の定着装置の概略構成を示し、定着ローラ、外部加熱ローラ及び加圧ローラ表面に当接する第２の温度検知手段の一配置例を示す説明図。
【図４】同方式の実施例４の定着装置の概略構成を示し、定着ローラ及び外部加熱ローラ表面に当接する第２の温度検知手段の一配置例を示す説明図。
【図５】同方式の実施例５の定着装置の概略構成を示し、定着ローラ及び加圧ローラに当接する第２の温度検知手段の一配置例を示す説明図。
【図６】熱加圧方式の定着装置を示し、定着ローラ及び加圧ローラ表面に当接する第１の温度検知手段の一配置例を示す説明図。
【図７】図１ないし図６に示す定着装置のいずれかを備える画像形成装置としてのレーザプリンタの概略構成図。
【図８】外部加熱方式の定着装置の概略構成を示す正面図。
【図９】図８に示す定着装置をＡ方向から見た側面図。
【符号の説明】
１…定着ローラ
２…外部加熱ローラ
２ａ…外部加熱ローラの端部延長部
３…加圧ローラ
３ａ…加圧ローラの端部延長部
４…定着ローラヒータ
５…外部加熱ローラヒータ
６…加圧ローラヒータ
７…定着ローラに当接する温度検知手段
７ａ…定着ローラに当接する第２の温度検知手段
７ｂ…定着ローラに当接する第１の温度検知手段
７ｃ…定着ローラに当接する他の温度検知手段
８…外部加熱ローラに当接する温度検知手段
８ａ…外部加熱ローラに当接する第２の温度検知手段
８ｂ…外部加熱ローラに当接する第１の温度検知手段
９…加圧ローラに当接する温度検知手段
９ａ…加圧ローラに当接する第２の温度検知手段
９ｂ…加圧ローラに当接する第１の温度検知手段[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotating body device, a heating device, a fixing device, and an image forming apparatus.
[0002]
More specifically, the present invention relates to a rotating body device including a contact member that is disposed in contact with the surfaces of at least two or more rotating bodies that rotate while being pressed against each other.
[0003]
The present invention also relates to a heating device that introduces a material to be heated between the first and second rotating bodies and applies thermal energy to the material to be heated.
[0004]
The present invention also relates to a fixing device that introduces a recording material as a material to be heated between first and second fixing rotators and applies thermal energy and pressure to the recording material to fix an unfixed image.
[0005]
In addition, an image formed and supported on a recording material such as a transfer material, photosensitive paper, or electrostatic recording paper by an appropriate image forming unit such as an electrophotographic system, an ink jet system, or an electrostatic recording system is heated. In particular, the present invention relates to an image forming apparatus such as a copying machine or a laser printer provided with an image heating apparatus that performs image fixing, surface property modification such as glossiness, and assumed wearing.
[0006]
[Prior art]
In general, in an image information recording apparatus (image forming apparatus) such as a copying machine adopting an electrophotographic method, a heating / pressure type fixing device is usually provided in order to fix a toner image transferred onto a recording sheet. .
[0007]
This type of fixing device includes a fixing roller provided with an elastic layer on a surface that rotates while being pressed against each other, and a pressure roller that is pressed against the fixing roller, and a recording sheet on which an unfixed toner image is formed is pressed against the rollers. In this case, the unfixed toner image is heated and fixed by being inserted into a portion (fixing nip portion).
[0008]
Conventionally, as a heat-pressure type fixing device, a heater (heating source) is provided inside the fixing roller and the pressure roller, respectively, and a temperature detection sensor such as a thermistor is arranged on the surface of each roller, and the detection of each sensor. It is known that the temperature control of the surface of each roller can be accurately controlled by controlling the power supply to the corresponding heater inside the roller based on the temperature (see, for example, Patent Document 1).
[0009]
On the other hand, as an external heating type fixing device, an external heating body is brought into contact with the surface of the fixing roller, and the roller is heated from the surface, thereby shortening the rise time of the surface temperature of the fixing roller and outputting a large amount of recorded images at high speed. There is known one that prevents the temperature of the fixing roller from being lowered during the process (for example, see Patent Document 2).
[0010]
The main reason for adopting the external heating method will be described. Usually, in the fixing device, the fixing roller has an elastic layer with low heat conductivity on the surface thereof, and the surface temperature of the roller reaches a set temperature only by supplying heat from a heating source inside the fixing roller. It takes a lot of time.
[0011]
Further, when outputting a large amount of recorded images at high speed, as described above, the fixing roller is deprived of heat by the recording medium passing through the fixing nip portion only by supplying heat from the heating source inside the fixing roller. As a result, the surface temperature of the fixing roller is lowered until the toner image cannot be fixed.
[0012]
Therefore, as a means for avoiding the above-mentioned problems, an external heating body is provided on the surface of the fixing roller to shorten the temperature rising time and prevent the fixing roller from lowering the temperature when outputting at high speed. The device has been put into practical use.
[0013]
FIG. 8 shows an example of a fixing device using an external heating method.
[0014]
The fixing device in FIG. 8 uses a roller (hereinafter referred to as an external heating roller 2) as an external heating body. The external heating roller 2 has a heater 5 as a heat source inside the roller, and directly contacts the surface of the heat fixing member (the fixing roller 1 in FIG. 8) in a freely rotatable manner to heat the fixing roller 1.
[0015]
The fixing roller 1 has a heater 4 as a heat source inside the roller. The fixing roller 1 is in pressure contact with a pressure member (the pressure roller 3 in FIG. 8). The pressure roller 3 has a heater 6 as a heat source inside the roller.
[0016]
The fixing sheet 1 whose surface is heated by the external heating roller 2 and the pressure roller 3 cause the recording sheet P on which the unfixed toner image t is formed and supported on the sheet surface to be nipped and conveyed to the fixing nip portion N between the rollers. The unfixed toner image is fixed on the sheet surface by heating and pressing.
[0017]
In a heat-pressure type fixing device, not only an external heating method, in order to control the surface temperature of the roller having the heat source, at least one temperature detecting means 7, 8, for detecting the temperature of each roller having the heat source. 9 is arranged on each roller.
[0018]
As the temperature detecting means, a temperature detecting sensor (for example, a thermistor) of a type that comes in contact with the roller surface, which is improved in detection accuracy and low in cost, is often used.
[0019]
FIG. 9 shows an example in which the temperature detecting means 7a, 7b, 8a, 8b, 9a, and 9b are disposed in contact with the same positions on the surfaces of the rollers 1, 2, and 3 in the fixing device using the external heating method. FIG. 9 is a view of the fixing device of FIG.
[0020]
In this conventional example, the first temperature detecting means 7b, 8b, 9b corresponding to the rollers 1, 2, 3 are arranged within the minimum paper size width.
[0021]
The second temperature detecting means 7a, 8a, 9a corresponding to the rollers 1, 2, 3 are arranged at different positions in the roller axial direction from the temperature detecting means 7b, 8b, 9b described above. Arranged outside the paper size width.
[0022]
In the conventional fixing device, the first temperature detecting means 8b contacting the external heating roller 2 and the first temperature detecting means 7b contacting the fixing roller 1 are at the same position in the roller axial direction (roller longitudinal direction). The corresponding roller surface temperature is detected.
[0023]
By arranging the temperature detection means at the same position in the roller axis direction in this way, when the size of the recording material is changed, one temperature detection body detects the temperature of the non-sheet passing portion and the other temperature detection. The body is designed to prevent problems such as detecting the temperature of the paper passing portion.
[Patent Document 1]
JP 2002-323828 A
[Patent Document 2]
JP 2003-29563 A
[0024]
[Problems to be solved by the invention]
The fixing roller 1 and the external heating roller 2 shown in FIG. 8 rotate in the direction of the arrow in FIG. 8 (clockwise for the fixing roller 1 and counterclockwise for the external heating roller 5) when the apparatus is in operation.
[0025]
The temperature detecting means 7, 8 and 9 are in contact with the roller surfaces of the corresponding rollers. For this reason, sliding scratches may occur on the surface of each roller at the contact surface of the temperature detecting means as the number of rotations of the roller increases.
[0026]
In the arrangement of the temperature detection means in FIG. 9, the first temperature detection means 7b that contacts the fixing roller 1 and the first temperature detection means 8b that contacts the external heating roller 2 are at the same position. The occurrence position of the moving scratch is the same for both the fixing roller 1 and the external heating roller 2.
[0027]
If sliding flaws occur at the same position on the roller surface of the fixing roller 1 and the external heating roller 2, foreign matters such as toner adhering to the fixing roller 1 and paper dust of the recording paper remain on the sliding flaw or the periphery thereof. It tends to adhere to the same part of the roller surface. In this case, since the foreign matter is rubbed against the roller surface by the surface of the recording material at the fixing nip portion when the apparatus is in operation, the progress of sliding scratches is accelerated at an accelerated rate as the use frequency of the roller increases. There is a concern that this may be an impediment to achieving the lifetime (no image failure occurs).
[0028]
The external heating roller 2 is intended to heat the surface of the fixing roller 1. Therefore, the surface of the external heating roller 2 does not have an elastic layer with low thermal conductivity, and the surface has a metal surface and a minute fluorine layer.
[0029]
Further, the fixing roller 1 has an elastic layer with low thermal conductivity on the surface.
[0030]
In view of the above, if the temperature detection means 7b and 8b are at the same position, there may be a case where a sliding scratch is generated by the temperature detection means at the same position.
[0031]
In this case, sliding scratches on the external heating roller 2 side may be sharp edges on the surface of the roller, such as a metal surface, so that damage to the surface of the fixing roller 1 is increased.
[0032]
Furthermore, since the fixing roller 1 has a sliding scratch due to the temperature detecting means 7b of the fixing roller 1 itself, the sliding scratch is caused by the sliding with the edge-shaped sliding scratch on the surface of the external heating roller 2. As described above, there is a concern that it may become an impediment factor for achieving the desired life of each roller (no image defect occurs).
[0033]
In the above-described configuration, the relationship between the sliding scratches in the first temperature detecting means 7b contacting the fixing roller 1 and the first temperature detecting means 8b contacting the external heating roller 2 has been described. This is a sliding scratch that most affects the image, and the same thing occurs in the second temperature detection means 7a, 8a, and 9a in each roller, and can also occur in the relationship between the fixing roller 1 and the pressure roller 3 as well. There is sex.
[0034]
The progress of sliding scratches on the surfaces of the fixing roller and the pressure roller by the temperature detecting means as described above can occur not only in the external heating type fixing device but also in the heat pressure type fixing device.
[0035]
For example, in a heat-pressure type fixing device, when the temperature detection means is in contact with the fixing roller and the pressure roller surface at the same position in the roller axial direction, the temperature detection means slides at the same position on each roller surface. Scratches may occur. When sliding scratches are generated on the surface of each roller, the sliding scratches slide as the number of rotations of the rollers increases, which becomes an impediment to achieving the desired life of each roller.
[0036]
In addition, even when the temperature detection means is disposed at the same position in the roller axial direction on the surface of the fixing roller and spaced apart by a certain angle in the circumferential direction of the roller, sliding scratches by the temperature detection means are caused at the same position on the roller surface. May occur. When a sliding scratch occurs on the surface of the fixing roller, the sliding scratch progresses as the number of rotations of the roller increases, and becomes an impediment factor for achieving a desired life of the fixing roller.
[0037]
Therefore, in the external heating type or thermal pressure type fixing device, at least two temperature detection means arranged in contact with a single roller in order to prevent the progress of sliding scratches on each roller as a rotating body It is necessary to devise the arrangement mode.
[0038]
SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating body device capable of delaying the progress of sliding scratches on the surface of a rotating body by a contact member of the rotating body and extending the service life of the rotating body itself.
[0039]
It is another object of the present invention to provide a heating device that can delay the progress of sliding scratches on the surface of the rotating body by the temperature detecting means of the first and second rotating bodies and extend the service life of each rotating body itself.
[0040]
Also provided is a fixing device capable of delaying the progress of sliding scratches on the surface of the rotating body by the temperature detecting means of the first and second fixing rotating bodies and the external rotating body and extending the service life of each rotating body itself. There is to do.
[0041]
Another object of the present invention is to provide an image forming apparatus provided with the fixing device as an image heating means for heating an image formed on a recording material as a heated material by an image forming means.
[0042]
[Means for Solving the Problems]
The rotating body device, the heating device, the fixing device, and the image forming apparatus according to the present invention are characterized by the following configurations.
[0043]
1) A rotating body device including at least two or more rotating bodies that rotate while being pressed against each other, and an abutting member that is disposed in contact with a surface of each of the rotating bodies. The rotating body device is arranged so as to deviate by more than the width of the corresponding contact member.
[0044]
2) The rotating body device according to 1 above, wherein the contact member is a temperature detecting body that detects the temperature of the rotating body.
[0045]
3) First and second rotating bodies that rotate while being pressed against each other, a heat source disposed inside each of the first and second rotating bodies, and a surface of each of the rotating bodies. In a heating apparatus that has at least one temperature detecting means and sandwiches and conveys a material to be heated to the pressure contact portions of the first rotating body and the second rotating body, the surface of the first rotating body is contacted. The position of the temperature detecting means in contact with the rotating body axis direction is arranged so as to be shifted from the position of the temperature detecting means in contact with the second rotating body surface in the rotating body axis direction by more than the width of the temperature detecting means. Heating device characterized.
[0046]
4) First and second rotating bodies that rotate while being pressed against each other, and one or more external rotating bodies that rotate in contact with the surface of the first or second, or first and second rotating bodies, The first rotation includes a heat source disposed inside each of the first, second, and external rotating bodies, and at least one temperature detecting means disposed in contact with the surface of each rotating body. In the heating apparatus that sandwiches and conveys the material to be heated between the pressure contact portions of the body and the second rotating body, the position of the temperature detecting means in contact with the surface of the external rotating body in the rotating body axial direction is the first or first position. A heating device, wherein the temperature detecting means contacting the surface of the rotating body is disposed so as to be shifted from the position of the temperature detecting means by at least the width of the temperature detecting means.
[0047]
5) The position of the temperature detecting means in contact with the first rotating body surface in the rotating body axis direction is the position of the temperature detecting means in contact with the second rotating body surface in the rotating body axis direction, and the temperature detecting means. 6. The heating device as described in 5 above, wherein the heating device is arranged so as to deviate by more than the width of the above.
[0048]
6) First and second fixing rotators rotating while being pressed against each other, one or more external rotators rotating in contact with the surfaces of the first and second fixing rotators, and the first and second 2 and a heat source disposed inside the external rotator and at least one temperature detecting means disposed in contact with the surface of each rotator, the first fixing rotator and the second fixing rotation. In a fixing device that performs fixing by sandwiching and transporting a recording material holding unfixed toner in the pressure contact portion of the body, the position of the temperature detecting means in contact with the external rotating body in the rotating body axial direction is the first or second position. The fixing device is characterized in that the position of the temperature detecting means in contact with the fixing rotating body is shifted from the position of the axis of the rotating body by more than the width of the temperature detecting means.
[0049]
7) The position of the at least one temperature detecting unit in contact with the first and second fixing rotators and the external rotator in the axial direction of the rotator is disposed within the minimum sheet passing width of the recording material at the press contact portion. 7. The fixing device as described in 6 above.
[0050]
8) The position of the at least one temperature detecting means in contact with the first and second fixing rotators and the external rotator in the axial direction of the rotator is disposed outside the maximum sheet passing width of the recording material at the press contact portion. 7. The fixing device as described in 6 above.
[0051]
9) The position of the temperature detection means in contact with the first and second fixing rotators and the external rotator in the axial direction of the rotator is shifted by more than the width of the temperature detection means in each of the rotators. 7. The fixing device as described in 6 above.
[0052]
10) The axial length of the external rotating body is longer than the axial length of any of the first and second fixing rotating bodies in contact with the external rotating body, and the contact position of the temperature detecting means of the external rotating body is It is arranged at the position of the axial length of the external rotator where the fixing rotator facing the external rotator does not come into contact, the position of the temperature detecting means of the first and second fixing rotators, and the position of the external rotator 7. The fixing device as described in 6 above, wherein the position of the temperature detecting means is arranged so as to deviate by more than the width of the temperature detecting means.
[0053]
11) The axial length of the second fixing rotator is longer than the axial length of the first fixing rotator contacting the second fixing rotator, and the contact position of the temperature detecting means of the second fixing rotator is The first fixing rotator is disposed at a position of the axial length of the second fixing rotator where the first fixing rotator opposed to the second fixing rotator does not come into contact, and the temperature detecting means position of the first fixing rotator, 7. The fixing device as described in 6 above, wherein the temperature detecting means position of the fixing rotator of No. 2 is shifted by more than the width of the temperature detecting means.
[0054]
12) An image forming apparatus comprising an image forming unit for forming an image on a recording material as a heated material, and an image heating unit for heating an image on the recording material. An image forming apparatus comprising the heating apparatus according to any one of the above.
[0055]
13) In an image forming apparatus including an image forming unit that forms an image on a recording material and an image fixing unit that heats and fixes the image on the recording material, the image fixing unit is any one of 6 to 11 above. An image forming apparatus comprising the fixing device according to claim 1.
[0056]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
[0057]
Members having the same functions as those of the fixing device shown in FIGS. 8 and 9 described above are denoted by the same reference numerals and description thereof is omitted.
[0058]
(Example 1)
FIG. 1 is a diagram of an external heating type fixing device as viewed from the side A in FIG. 8, and in particular, an explanation showing an arrangement example of first temperature detection means that individually contact the fixing roller and the external heating roller, respectively. FIG.
[0059]
In the fixing device in FIG. 1, the external heating roller 2 is placed within the minimum paper size width of a recording material (recording sheet) as a heated material that is nipped and conveyed by a fixing nip N between the fixing roller 1 and the pressure roller 3. The first temperature detecting means 8b that is in contact with the fixing roller 1 is shifted from the first temperature detecting means 7b that is in contact with the fixing roller 1 in the roller axial direction by the width of the temperature detecting means.
[0060]
As described above, the temperature detection means is displaced between the fixing roller 1 and the external heating roller 2, so that the first temperature detection means 8b in contact with the external heating roller 2 has a sliding scratch on the surface of the external heating roller and the fixing. Sliding scratches on the surface of the fixing roller 1 due to the first temperature detecting means 7b contacting the roller 1 do not occur at the same location in the roller axial direction. That is, sliding scratches are generated at different positions on the surfaces of the fixing roller 1 and the external heating roller 2 according to the shift amounts of the temperature detecting means 7b and 8b.
[0061]
In this case, on the surfaces of the fixing roller 1 and the external heating roller 2, foreign matters such as toner and paper dust remain at different positions corresponding to the positions of sliding scratches. For this reason, when the apparatus is in operation, the foreign matter is rubbed by the recording material at different positions according to the displacement position of the sliding scratches on the roller surface in the fixing nip portion, and the sliding accompanying the increase in the rotation speed of the fixing roller and the external heating roller. The progression of motion scratches can be delayed.
[0062]
Further, since the position of the sliding scratches generated on the surfaces of the fixing roller 1 and the external heating roller 2 differs depending on the shift amount of the temperature detecting means 7b and 8b, the sliding scratches on the external heating roller 2 side are sharp edges. Can be prevented, damage to the surface of the fixing roller 1 can be reduced, and progress of sliding scratches generated on the surface of the fixing roller can be prevented.
[0063]
This can extend the service life of each roller itself and achieve the desired life of each roller.
[0064]
(Example 2)
FIG. 2 is an explanatory diagram showing an arrangement example of the first temperature detection unit that contacts the pressure roller with a fixed relationship with the temperature detection unit of the fixing roller in the fixing device of the first embodiment.
[0065]
In this example, the width of the temperature detecting means is larger than that of the first temperature detecting means 7b contacting the fixing roller 1 with the first temperature detecting means 9b contacting the pressure roller 3 while adopting the configuration in the first embodiment. The minute roller is displaced in the axial direction.
[0066]
By adopting this configuration, the flaw on the surface of the fixing roller due to the first temperature detecting means 7b abutting on the fixing roller 1 and the surface of the pressure roller due to the first temperature detecting means 9b abutting on the pressure roller 3 are obtained. Since sliding scratches do not occur at the same place in the roller axial direction, the relationship between the sliding scratches on the surface of the fixing roller and the sliding scratches on the surface of the pressure roller is the same as that described above. For the same reason as in the case of sliding scratches, it is possible to delay the progress of the sliding scratches on the surface of the fixing roller and the pressure roller, thereby achieving the desired life of each roller.
[0067]
Example 3
FIG. 3 is an explanatory diagram showing an example of the arrangement of the second temperature detection means that individually contacts the fixing roller, the external heating roller, and the pressure roller in the fixing device according to the second embodiment.
[0068]
In the fixing device in FIG. 3, in a non-sheet passing portion outside the maximum paper size width of a recording material (recording sheet) as a heated material that is nipped and conveyed by a fixing nip portion N between the fixing roller 1 and the pressure roller 3. Similarly to the first temperature detection means 7b, 8b, and 9b, the second temperature detection means 7a, 8a, and 9a that are in contact with the fixing roller 1, the external heating roller 2, and the pressure roller 3, respectively, The minute roller is displaced in the axial direction.
[0069]
By adopting this configuration, the flaw on the surface of the fixing roller due to the second temperature detecting means 7a contacting the fixing roller 1 and the surface of the external heating roller due to the second temperature detecting means 8a contacting the external heating roller 2 are obtained. Since the sliding flaw and the sliding flaw on the pressure roller surface by the second temperature detecting means 9a contacting the pressure roller 3 do not occur at the same place in the roller axial direction, the flaw on the fixing roller surface and the external heating Regarding the relationship between the sliding scratches on the roller surface and the fixing roller surface, and the relationship between the sliding scratches on the fixing roller surface and the pressing roller surface, for the same reason as described above, The progress of sliding scratches on the surface of the external heating roller and the pressure roller can be delayed, so that the desired life of each roller can be achieved.
[0070]
(Example 4)
FIG. 4 is an explanatory diagram showing an example of the arrangement of the second temperature detection means that comes into contact with the external heating roller in the fixing device according to the second embodiment.
[0071]
In the fixing device shown in FIG. 4, the external heating roller 2 has an extension 2a extending in the axial direction at the end. The reason why the extension 2a is provided is that the external heating roller 2 has a contact / separation mechanism with a fixing roller (not shown). The reason why the contact / separation mechanism is necessary will be described later.
[0072]
When the fixing device is on standby by the contact / separation mechanism, the external heating roller 2 stops at a position where it does not contact the fixing roller 1. Simultaneously with the start of the fixing device operation, the external heating roller 2 contacts the fixing roller 1 and heats the surface of the fixing roller 1. This operation is repeated for each fixing device operation when the fixing device is on standby. In this repeated separation operation, if the axial lengths of the fixing roller 1 and the external heating roller 2 are the same, the fixing roller is formed by the roller shaft end portion of the external heating roller 2 whose surface layer is a metal or a minute fluorine coat layer. Damage to the surface of 1. Therefore, consideration is given to reducing damage to the fixing roller 1 by providing the extension 2a.
[0073]
In this example, the second temperature detecting means 8a that contacts the external heating roller 2 is disposed in the extension portion 2a described above, so that the temperature detecting means is in contact with the second temperature detecting means 7a that contacts the fixing roller 1. The position is shifted in the roller axis direction by the width of the temperature detecting means.
[0074]
As a result, there are sliding scratches on the surface of the fixing roller due to the second temperature detection means 7a contacting the fixing roller 1, and sliding scratches on the surface of the external heating roller due to the second temperature detection means 8a contacting the external heating roller 2. Since it does not occur at the same location in the roller axial direction, the relationship between the sliding scratches on the surface of the fixing roller and the sliding scratches on the surface of the external heating roller is the same as in the case of the above-described first embodiment. The progress of the sliding scratches on the roller surface can be delayed, so that the desired life of each roller can be achieved.
[0075]
(Description of necessity of contact / separation mechanism of external heating roller 2)
Since the external heating roller 2 delivers the temperature to the fixing roller 1, the surface temperature is high.
[0076]
When the paper is wound around the fixing roller 1, the external heating roller 2 comes into contact with the fixing roller 1 while the paper P is still in the contact portion between the fixing roller 1 and the external heating roller 2. If pressure is continuously applied, problems such as smoke generation may occur, and the first reason is to provide a contact / separation mechanism to prevent this.
[0077]
Next, in standby mode of the fixing device, a contact / separation mechanism is provided to avoid temperature unevenness in which the temperature distribution in the outer circumferential direction of the fixing roller 1 due to the external heating roller 2 being in contact with the fixing roller 1 is high only in the contact portion. Provided. Due to temperature distribution unevenness in the outer peripheral direction, fixing unevenness may occur during fixing.
[0078]
The above is the reason for providing the contact / separation mechanism.
[0079]
(Example 5)
FIG. 5 is an explanatory diagram showing an example of the arrangement of the second temperature detection means that contacts the pressure roller in the fixing device according to the fourth embodiment.
[0080]
In the fixing device shown in FIG. 5, the pressure roller 3 has an extension 3a extending in the axial direction at the end. The reason for having the extension portion 3a is to eliminate the damage caused by the end of the pressure roller 3 of the fixing roller 1 that is most damaged by the paper and toner as the recording material and has the most severe conditions in the roller life.
[0081]
In this example, the second temperature detection means 9a that contacts the pressure roller 3 is disposed in the extension portion 3a described above, so that the temperature detection means is in contact with the second temperature detection means 7a that contacts the fixing roller 1. The position is shifted in the roller axis direction by the width of the temperature detecting means.
[0082]
As a result, there are sliding scratches on the surface of the fixing roller due to the second temperature detection means 7a that contacts the fixing roller 1, and sliding scratches on the surface of the pressure roller due to the second temperature detection means 9a that contacts the pressure roller 3. Since it does not occur at the same location in the roller axial direction, the relationship between the sliding scratch on the surface of the fixing roller and the sliding scratch on the surface of the pressure roller is the same as in the case of the above-described second embodiment, and the pressure on the surface of the fixing roller. The progress of the sliding scratches on the roller surface can be delayed, so that the desired life of each roller can be achieved.
[0083]
(Example 6)
FIG. 6 is a view of the heat-pressure type fixing device as viewed from the side A in FIG. 8, and in particular, shows an arrangement example of the first temperature detection means that individually contacts the fixing roller and the pressure roller. It is explanatory drawing.
[0084]
In the fixing device in FIG. 6, for example, the first temperature detection that contacts the pressure roller 3 within the minimum paper size width of the recording material nipped and conveyed by the fixing nip portion N between the fixing roller 1 and the pressure roller 3. The means 9b is shifted from the first temperature detecting means 7b in contact with the fixing roller 1 in the roller axis direction by the width of the temperature detecting means.
[0085]
As a result, there are sliding scratches on the surface of the fixing roller due to the first temperature detecting means 7b contacting the fixing roller 1, and sliding scratches on the surface of the pressure roller due to the first temperature detecting means 9b contacting the pressure roller 3. Since it does not occur at the same location in the roller axial direction, the relationship between the sliding scratches on the surface of the fixing roller and the sliding scratches on the surface of the pressure roller is the same as in the case of the second embodiment. The progress of sliding scratches on the surface can be delayed, so that the desired life of each roller can be achieved.
[0086]
(Example 7)
FIG. 7 is a schematic configuration diagram showing an example of an image forming apparatus according to the present invention, in which any one of the fixing devices of the first to fourth embodiments is applied as a heating device.
[0087]
In FIG. 7, reference numeral 100 denotes a laser printer as an image forming apparatus.
[0088]
In the laser printer 100, a video controller board (image signal creating means) 104 creates an image signal based on image information transmitted from an external information device such as a personal computer or a word processor. Here, various electronic components installed on the video controller board 104 are not shown.
[0089]
The laser scanner 105 irradiates the photosensitive drum 106A rotating in a predetermined direction (clockwise in the figure) with the laser light L corresponding to the image signal generated by the video controller board 104, and then onto the photosensitive drum 106A. Sequentially, an electrostatic latent image is formed.
[0090]
The electrostatic latent image formed on the photosensitive drum 106 A is successively visualized by toner supplied from a developing device (not shown) in the process unit 6 and conveyed to a transfer portion between the transfer roller 107. Is done.
[0091]
On the other hand, the recording materials S loaded and stored in the paper feeding cassette 108 are sequentially fed one by one from the uppermost recording material S by a half-moon shaped paper feeding roller 109 that rotates once in a predetermined direction (counterclockwise in the figure). The recording material S is sent out to the paper path 110A, and is conveyed by the conveyance roller pair 111 to the registration roller pair 112 whose rotation is stopped through the paper supply path 110.
[0092]
The recording material S that has reached the registration roller pair 112 abuts against the nip of the recording material front end registration roller pair 112 and then continues to be conveyed until a predetermined loop is formed, thereby correcting the skew state.
[0093]
The recording material S that has been corrected in the skew state is conveyed to the transfer section by the registration roller pair 112 that starts rotating at the timing of aligning the position with the toner image on the photosensitive drum 6 A. The toner image on the photosensitive drum 106A is transferred onto the recording material surface.
[0094]
After the transfer of the toner image, the recording material S passes through the conveyance guide 113 and is conveyed to the fixing device 14, where the transferred toner image is fixed on the recording material surface.
[0095]
When the recording material S that has completed the fixing process of the toner image is stacked with the printing surface facing downward, the recording material S passes through the conveyance path formed by the conveyance surface 116 and the swing guide 124 opposed thereto, and a drive source (not shown) is provided. The paper is discharged onto the face-down paper discharge tray 117 at the top of the printer main body 100 by the face-down paper discharge roller 119 and the roller 125 that is driven in pressure contact therewith.
[0096]
When the printing surface is loaded upward (face-down loading), the face-up roller 118 having a driving source (not shown) and a pressure contact with the rotation center 123 of the face-up tray 122 are opened as indicated by an arrow A. Then, the driven roller 115 discharges the printing surface of the recording material upward onto the conveyance unit 124A on the face-up tray 122A.
[0097]
(Other)
1) In the above-described embodiment, the fixing device in which the position of the temperature detection unit that contacts each roller is shifted by the width of the temperature detection unit is exemplified. However, the present invention is not limited to this, and a sliding scratch is generated. If the positions do not overlap, the same effect can be obtained.
[0098]
2) In the above-described embodiment, the fixing device in which the first temperature detecting unit in each roller is disposed within the minimum paper size width is exemplified, but the present invention is not limited to this, and a desired temperature is set. The same effect can be obtained if it is a position that can be detected and does not overlap with sliding scratches.
[0099]
3) In the above-described embodiment, the fixing device in which the second temperature detecting unit in each roller is disposed outside the maximum paper size width is exemplified, but the present invention is not limited to this, and a desired temperature is set. The same effect can be obtained if it is a position that can be detected and does not overlap with sliding scratches.
[0100]
4) In the above-described embodiment, the fixing device in which one external heating roller is in contact with the fixing roller is illustrated. However, the present invention is not limited to this, and for example, a plurality of external heating rollers are in contact with the fixing roller. The fixing device may be configured, and the same effect can be obtained by applying the present invention to the fixing device.
[0101]
5) In the above-described embodiment, the fixing device in which the external heating roller is in contact with only the fixing roller is exemplified. However, the present invention is not limited to this, and for example, the external heating roller is in contact with the pressure roller. A fixing device may be used, and the same effect can be obtained by applying the present invention to the fixing device.
[0102]
6) In place of the temperature detection means (temperature detection body), for example, a static elimination member or any other member that causes a certain function to act on the roller surface can be used as the contact member.
[0103]
7) The fixing device of the present invention is not limited to a fixing device of an external heating method or a heat and pressure method, but can be applied to a fixing device of a film heating fixing method. In this case, instead of the fixing roller, an endless heat-resistant film that is externally fitted to a stay having a heating body (heat source) and rotated along the outer shape of the stay is used. In that case, as a member that contacts the film surface, for example, a static elimination member or any other member that causes a certain function to act on the film surface can be used as appropriate.
[0104]
8) The heating device of the present invention is not limited to the image heating and fixing device of the embodiment, but an image heating device that heats a recording material carrying an image to improve surface properties such as gloss, an image heating device that is supposed to be worn, and the like It can be widely used as a means / device for heat-treating a material to be heated, such as a heating / drying device or a heating laminating device.
[0105]
【The invention's effect】
As described above, according to the rotating body device according to the present invention, in the rotating body or the first and second rotating bodies, each of the contact members on the surface of the rotating body in the axial direction of the rotating body is the corresponding contact member. Since they are arranged so as to deviate by more than the width, it is possible to delay the progress of the sliding scratches generated by the contact member on the surface of the rotating body and to prolong the service life of the rotating body itself.
[0106]
According to the heating device of the present invention, in the first and second rotating bodies, or the first, second, and external rotating bodies, the temperature detecting means on the surfaces of these rotating bodies in the axial direction of the rotating body respectively. Since the arrangement is shifted by more than the width of the means, the progress of the sliding scratches generated by the temperature detecting means on the surface of the rotating body can be delayed, and the service life of the rotating body itself can be extended.
[0107]
According to the fixing device of the present invention, in each of the first and second fixing rotators and the external rotator, the temperature detectors are shifted by more than the width of the temperature detectors in the axial direction of the rotator. Since it is arranged, the progress of sliding scratches generated by the temperature detecting means on the surface of the rotating body can be delayed, and the service life of the rotating body itself can be extended.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a schematic configuration of a fixing device according to a first embodiment of an external heating method, and illustrating an arrangement example of a first temperature detection unit that comes into contact with a surface of a fixing roller and an external heating roller.
FIG. 2 is an explanatory diagram illustrating a schematic configuration of a fixing device according to a second embodiment of the same system, and an example of an arrangement of first temperature detection means that abuts against the surfaces of the fixing roller and the pressure roller.
FIG. 3 is an explanatory diagram illustrating a schematic configuration of a fixing device according to a third embodiment of the same system, and illustrating an example of arrangement of second temperature detection means that abuts on the surfaces of the fixing roller, the external heating roller, and the pressure roller.
FIG. 4 is an explanatory diagram showing a schematic configuration of a fixing device according to a fourth embodiment of the same system, and showing an example of arrangement of second temperature detection means that abuts against the surfaces of the fixing roller and the external heating roller.
FIG. 5 is an explanatory diagram illustrating a schematic configuration of a fixing device according to a fifth embodiment of the same system and illustrating an arrangement example of a second temperature detection unit that contacts the fixing roller and the pressure roller.
FIG. 6 is an explanatory diagram showing an arrangement example of a first temperature detection unit that is in contact with the surface of the fixing roller and the pressure roller, showing the fixing device of the heat and pressure type.
7 is a schematic configuration diagram of a laser printer as an image forming apparatus including any one of the fixing devices shown in FIGS. 1 to 6. FIG.
FIG. 8 is a front view illustrating a schematic configuration of an external heating type fixing device.
9 is a side view of the fixing device shown in FIG. 8 as viewed from the direction A. FIG.
[Explanation of symbols]
1. Fixing roller
2 ... External heating roller
2a: External heating roller end extension
3 ... Pressure roller
3a: End extension of pressure roller
4. Fixing roller heater
5 ... External heating roller heater
6 ... Pressure roller heater
7. Temperature detecting means that contacts the fixing roller
7a ... Second temperature detecting means in contact with the fixing roller
7b. First temperature detecting means that contacts the fixing roller.
7c: Other temperature detecting means that contacts the fixing roller
8 ... Temperature detection means that contacts the external heating roller
8a: second temperature detecting means in contact with the external heating roller
8b. First temperature detecting means that contacts the external heating roller.
9 ... Temperature detection means that contacts the pressure roller
9a: second temperature detecting means in contact with the pressure roller
9b ... 1st temperature detection means contact | abutted to a pressure roller

Claims

In a rotating body device comprising at least two or more rotating bodies that rotate while being pressed against each other, and a contact member that is disposed in contact with the surface of each of the rotating bodies,
Each of the contact members is a rotating body device arranged so as to be shifted by a width of the corresponding contacting member or more in the rotating body axial direction.

The rotating body device according to claim 1, wherein the contact member is a temperature detecting body that detects a temperature of the rotating body.

First and second rotating bodies that rotate while being pressed against each other, a heat source that is disposed inside each of the first and second rotating bodies, and at least one that is disposed in contact with the surface of each rotating body In a heating apparatus having at least one piece of temperature detection means and sandwiching and conveying a material to be heated to the pressure contact portion of the first rotating body and the second rotating body,
The position of the temperature detecting means in contact with the first rotating body surface in the rotating body axis direction is the position of the temperature detecting means in contact with the second rotating body surface in the rotating body axis direction and the width of the temperature detecting means. A heating device characterized by being displaced as described above.

First and second rotating bodies that rotate while being pressed against each other; one or more external rotating bodies that rotate in contact with the surface of the first or second or first and second rotating bodies; and A heat source disposed in each of the first, second and external rotating bodies; and at least one temperature detecting means disposed in contact with the surface of each of the rotating bodies; In the heating apparatus that sandwiches and conveys the material to be heated to the pressure contact portion of the second rotating body, and heats it,
The position of the temperature detecting means in contact with the external rotating body surface in the rotating body axis direction is the position of the temperature detecting means in contact with the first or second rotating body surface in the rotating body axis direction, and the position of the temperature detecting means. A heating device, wherein the heating device is arranged so as to be shifted by a width or more.

The position of the temperature detecting means in contact with the first rotating body surface in the rotating body axis direction is the position of the temperature detecting means in contact with the second rotating body surface in the rotating body axis direction and the width of the temperature detecting means. The heating device according to claim 4, wherein the heating device is arranged so as to be shifted as described above.

The first and second fixing rotators rotating while being pressed against each other, one or more external rotators rotating in contact with the surfaces of the first and second fixing rotators, and the first, second and A heat source disposed inside the external rotator, and at least one temperature detecting means disposed in contact with the surface of each rotator, the first fixing rotator and the second fixing rotator. In a fixing device that performs fixing by sandwiching and transporting a recording material holding unfixed toner in a pressure contact portion,
The position of the temperature detecting means in contact with the external rotating body in the direction of the rotating body axis is the position of the temperature detecting means in contact with the first or second fixing rotating body in the direction of the rotating body axis and the width of the temperature detecting means. A fixing device characterized by being displaced as described above.

The position of the at least one temperature detecting means in contact with the first and second fixing rotators and the external rotator in the axial direction of the rotator is disposed within the minimum sheet passing width of the recording material at the press contact portion. The fixing device according to claim 6.

The position of the at least one temperature detecting means in contact with the first and second fixing rotators and the external rotator is disposed outside the maximum sheet passing width of the recording material at the press contact portion. The fixing device according to claim 6.

The position of the temperature detecting means in contact with the first and second fixing rotators and the external rotator in the axial direction of the rotator is shifted by more than the width of the temperature detecting means. The fixing device according to claim 6.

The axial length of the external rotating body is longer than the axial length of one of the first and second fixing rotating bodies in contact with the external rotating body, and the contact position of the temperature detecting means of the external rotating body is set to the external rotation The position of the temperature detecting means of the first and second fixing rotators and the temperature detection of the external rotator are arranged at the position of the axial length of the external rotator where the fixing rotator facing the body does not contact. The fixing device according to claim 6, wherein the position of the unit is arranged so as to be shifted by a width greater than the width of the temperature detection unit.

The axial length of the second fixing rotator is longer than the axial length of the first fixing rotator contacting the second fixing rotator, and the contact position of the temperature detecting means of the second fixing rotator is set to the second fixing rotator. The first fixing rotator opposed to the first fixing rotator is disposed at a position in the axial length of the second fixing rotator, the temperature detecting means position of the first fixing rotator, and the second fixing rotator The fixing device according to claim 6, wherein the position of the temperature detecting unit of the fixing rotator is arranged so as to deviate by more than the width of the temperature detecting unit.

In an image forming apparatus comprising: an image forming unit that forms an image on a recording material as a material to be heated; and an image heating unit that heats an image on the recording material.
6. An image forming apparatus, wherein the image heating unit is the heating apparatus according to claim 3.

In an image forming apparatus comprising: an image forming unit that forms an image on a recording material; and an image fixing unit that heats and fixes the image on the recording material.
12. The image forming apparatus according to claim 6, wherein the image fixing unit is the fixing device according to claim 6.