JP2008139779A

JP2008139779A - Heating means, fixing device, and image forming apparatus provided with the same

Info

Publication number: JP2008139779A
Application number: JP2006328381A
Authority: JP
Inventors: Susumu Tsukada; 将塚田; Satoru Izawa; 悟伊澤; Yasunari Obara; 泰成小原; Koji Nihonyanagi; 亘児二本柳
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2006-12-05
Filing date: 2006-12-05
Publication date: 2008-06-19

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface heating type fixing device in which the thermal deterioration of a fixing roller and hot offset are eliminated by changing the area irradiated with radiation heat in a fixing roller in its longitudinal direction according to the paper width of a recording material passing therethrough, so as not to irradiate the non-paper passing portion of the fixing roller with the radiation heat, thereby the deterioration by heat of the fixing roller and the hot offset are eliminated and simultaneously the destabilization of paper conveyance and the damage of the fixing roller are eliminated by changing the amount of the radiation heat between the paper passing portion and non-paper passing portion of the fixing roller, to uniform the temperature distribution of the fixing roller in its longitudinal direction. <P>SOLUTION: In the surface heating type fixing device, a shield member can be introduced in the irradiation path of the radiation heat transmitted toward the fixing roller from a heat source. The surface heating type fixing device is configured not to irradiate the non-paper passing portion of the fixing roller with the radiation heat by changing the irradiation area of the radiation heat in the fixing roller in its longitudinal direction, according to the paper width of the recording material passing therethrough. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は電子写真方式、静電記録方式などの作像プロセスを経て画像を形成する画像形成装置、および該画像形成装置に具備される加熱手段、定着装置に関する。 The present invention relates to an image forming apparatus that forms an image through an image forming process such as an electrophotographic system or an electrostatic recording system, and a heating unit and a fixing device provided in the image forming apparatus.

従来、画像形成プロセス手段（電子写真プロセス・静電記録プロセス・磁気記録プロセスなど）で記録材（転写材シート・エレクトロファックスシート・静電記録紙・ＯＨＰシート・印刷用紙・フォーマット紙など）に転写方式あるいは直接方式にて形成担持させた画像情報の未定着トナー像を加熱・加圧によって該記録材面に永久固着させる定着装置として、熱ローラ方式あるいはフィルム加熱方式の定着装置が広く用いられている。 Conventionally, transfer to recording material (transfer material sheet, electrofax sheet, electrostatic recording paper, OHP sheet, printing paper, format paper, etc.) by image forming process means (electrophotographic process, electrostatic recording process, magnetic recording process, etc.) As a fixing device for permanently fixing an unfixed toner image of image information formed and supported by a method or a direct method to the recording material surface by heating and pressing, a fixing device of a heat roller method or a film heating method is widely used. Yes.

フィルム加熱方式の定着装置は、特開昭６３−３１３１８２号、特開平２−１５７８７８号、特開平４−４４０７５号、特開平４−２０４９８０号公報などに提案されている。フィルム加熱方式の定着装置は、ヒータ及びフィルムとして低熱容量の部材を用いることができるため、熱ローラ方式の定着装置と比較して、ニップ部Ｎの温度を良好な定着性が得られる温度まで到達させる時間が短く（クイックスタート性）、スタンバイ時の消費電力も大幅に小さくできる（省電力）などの利点がある。しかし、フィルム加圧方式の定着装置のフィルムは弾性を有さないため、トナー像をつぶすことによる画像の劣化がおこりやすい。 A film heating type fixing device has been proposed in JP-A-63-313182, JP-A-2-157878, JP-A-4-44075, JP-A-4-204980, and the like. Since the film heating type fixing device can use a low heat capacity member as a heater and a film, the temperature of the nip portion N reaches a temperature at which good fixing property can be obtained as compared with the heat roller type fixing device. There are advantages such as a short time (quick start) and a significant reduction in power consumption during standby (power saving). However, since the film of the film pressure type fixing device does not have elasticity, the image is liable to be deteriorated by crushing the toner image.

そこで、表面加熱方式の定着装置が特開平７−１５２２７１号、特開平８−１２９３１３号公報などに提案されている。図１２に従来の表面加熱方式の定着装置の断面概略図を示す。１１は表面に弾性層を有する定着ローラ、１２は表面に弾性層を有する加圧ローラ、１３は輻射熱を発生する熱源としてのハロゲンヒータ、１４はハロゲンヒータの輻射熱を反射して定着ローラを効率的に加熱する反射部材である。 Therefore, surface heating type fixing devices have been proposed in JP-A-7-152271, JP-A-8-129313, and the like. FIG. 12 is a schematic sectional view of a conventional surface heating type fixing device. 11 is a fixing roller having an elastic layer on the surface, 12 is a pressure roller having an elastic layer on the surface, 13 is a halogen heater as a heat source for generating radiant heat, and 14 is an effective heater for reflecting the radiant heat of the halogen heater to make the fixing roller efficient. It is the reflecting member which heats.

定着ローラ１１は、円柱状のアルミもしくは鉄の芯金１１１の上に、シリコンゴムあるいは発泡シリコンゴムを形成した弾性層１１２と、高い熱伝導を有する鉄・ＳＵＳ・ニッケル等からなる１０〜１００μｍの薄層金属スリーブ１１３と、ＰＴＦＥあるいはＰＦＡ等の離型性層１１４とを、順次形成して構成される。 The fixing roller 11 has a cylindrical aluminum or iron core bar 111 and an elastic layer 112 in which silicon rubber or foamed silicon rubber is formed, and iron, SUS, nickel or the like having a high thermal conductivity and a thickness of 10 to 100 μm. A thin metal sleeve 113 and a release layer 114 such as PTFE or PFA are sequentially formed.

加圧ローラ１２は、円柱状のアルミもしくは鉄の芯金１２１の上に、シリコンゴムあるいは発泡シリコンゴムによる弾性層１２２と、ＰＴＦＥあるいはＰＦＡなどによる離型性層１２３とを、順次層形成して構成される。加圧ローラ１２は、不図示の加圧手段によって定着ローラ１１に圧接され、ニップ部Ｎを形成するとともに、不図示の駆動手段によって回転駆動される。 The pressure roller 12 is formed by sequentially forming an elastic layer 122 made of silicon rubber or foamed silicon rubber and a releasable layer 123 made of PTFE or PFA on a cylindrical aluminum or iron core 121. Composed. The pressure roller 12 is pressed against the fixing roller 11 by a pressure unit (not shown) to form a nip portion N and is rotationally driven by a drive unit (not shown).

定着ローラ１１は不図示のギア列によって加圧ローラ１２の駆動を受けることで回転する。未定着トナー像を有する記録材Ｐはニップ部Ｎ導入され、定着ローラ１１と加圧ローラ１２とで挟持搬送される。記録材Pはハロゲンヒータ１３の輻射熱によって表面を加熱された定着ローラ１１から熱を与えられ、この熱と加圧によって記録材P上の未定着トナー像は記録材Pに定着される。 The fixing roller 11 rotates by being driven by the pressure roller 12 by a gear train (not shown). The recording material P having an unfixed toner image is introduced into the nip portion N and is nipped and conveyed between the fixing roller 11 and the pressure roller 12. The recording material P receives heat from the fixing roller 11 whose surface is heated by the radiant heat of the halogen heater 13, and the unfixed toner image on the recording material P is fixed to the recording material P by this heat and pressure.

このような表面加熱方式の定着装置は、記録材と接触する定着ローラの表層を選択的に加熱して定着することにより、ニップ部Ｎの温度を良好な定着性が得られる温度まで到達させる時間が短く（クイックスタート性）、スタンバイ時の消費電力も大幅に低減できる（省電力）とともに、トナー像に接触する定着ローラの表層が弾性を有するため、高画質な定着画像を得ることができる。
特開昭６３−３１３１８２号公報特開平２−１５７８７８号公報開平４−４４０７５号公報特開平４−２０４９８０号公報特開平７−１５２２７１号公報特開平８−１２９３１３号公報 Such a surface heating type fixing device selectively heats and fixes the surface layer of the fixing roller in contact with the recording material, thereby allowing the temperature of the nip portion N to reach a temperature at which good fixability can be obtained. Is short (quick start), power consumption during standby can be greatly reduced (power saving), and the fixing roller in contact with the toner image has elasticity, so that a high-quality fixed image can be obtained.
JP-A-63-313182 Japanese Patent Laid-Open No. 2-157878 Kaihei 4-44075 JP-A-4-204980 Japanese Patent Laid-Open No. 7-152271 JP-A-8-129313

このような定着装置では、数種類のサイズの異なる記録材を使用することが一般的である。しかしながら、例えば、最大Ａ4サイズ（紙幅２１０ｍｍ）の縦送りが可能な装置において、Ｂ5（紙幅１８２ｍｍ）やハガキ（紙幅１００ｍｍ）などの幅の狭い記録材（以下、小サイズ紙と称する）を通紙すると、いわゆる非通紙部昇温と呼ばれる現象が発生した。 In such a fixing device, it is common to use several kinds of recording materials having different sizes. However, for example, in a device capable of vertical feeding of maximum A4 size (paper width 210 mm), a narrow recording material (hereinafter referred to as small size paper) such as B5 (paper width 182 mm) or postcard (paper width 100 mm) is passed. Then, a phenomenon called so-called non-sheet passing portion temperature rise occurred.

非通紙部昇温とは、通紙部は良好な定着性を得るために所定温度で保持されるように温度制御されるのに対して、非通紙部では、通紙されないために定着ローラあるいは加熱ローラの熱が奪われず、昇温する現象である。 Non-sheet-passing part temperature rise means that the temperature of the sheet-passing part is controlled so as to be held at a predetermined temperature in order to obtain good fixability, whereas the non-sheet-passing part is fixed because no sheet is passed. This is a phenomenon in which the heat of the roller or the heating roller is not removed and the temperature rises.

非通紙部昇温が発生すると、定着ローラの非通紙部において熱劣化が発生する恐れがある。また、小サイズ紙連続通紙の後に、より大きなサイズの記録材を通すと、非通紙部であったところでトナーが過溶融となってホットオフセットが発生する恐れがある。 When the temperature rise of the non-sheet passing portion occurs, there is a possibility that thermal deterioration occurs in the non-sheet passing portion of the fixing roller. Further, if a recording material having a larger size is passed after the continuous passage of small size paper, the toner may be overmelted at the non-sheet passing portion and hot offset may occur.

そこで本発明では、表面加熱方式の定着装置において、通紙される記録材の紙幅に応じて定着ローラ長手方向における輻射熱の照射領域を変えることで、定着ローラの熱劣化やホットオフセットのない定着装置を提案する。 Therefore, according to the present invention, in the surface heating type fixing device, by changing the irradiation area of the radiant heat in the longitudinal direction of the fixing roller in accordance with the paper width of the recording material to be passed, the fixing device without thermal deterioration or hot offset of the fixing roller. Propose.

また、非通紙部昇温によって、定着ローラの通紙部と非通紙部とでの温度差が大きくなったときは、熱膨張の格差が大きくなってクラウン形状となり、紙搬送性が不安定になる恐れがある。さらに、定着ローラの薄層金属スリーブに凹みが発生して破損にいたる恐れがある。 In addition, when the temperature difference between the sheet passing portion and the non-sheet passing portion of the fixing roller increases due to the temperature rise in the non-sheet passing portion, the thermal expansion difference becomes large and a crown shape is formed, resulting in poor paper transportability. There is a risk of becoming stable. Further, the thin metal sleeve of the fixing roller may be dented and damaged.

そこで、表面加熱方式の定着装置において、定着ローラの通紙部と非通紙部とで輻射熱の照射量を変えて定着ローラ長手方向の温度分布を均一にすることで、定着ローラの熱劣化やホットオフセットをなくすとともに、紙搬送の不安定化や定着ローラ破損のない定着装置を提案する。 Therefore, in a surface heating type fixing device, the temperature distribution in the longitudinal direction of the fixing roller is made uniform by changing the irradiation amount of the radiant heat between the paper passing portion and the non-paper passing portion of the fixing roller. We propose a fixing device that eliminates hot offset and does not destabilize paper conveyance or damage the fixing roller.

本発明の請求項１によれば、少なくとも、定着ローラと、輻射熱を発して前記定着ローラの表面を外部より加熱する熱源を具備する加熱手段と、を有する定着装置において、前記加熱手段は遮蔽部材を有し、該遮蔽部材は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に導入可能であり、該導入部における輻射熱を遮蔽することで定着ローラに対する輻射熱の照射領域を変えることが可能であることを特徴とする加熱手段および定着装置である。 According to a first aspect of the present invention, there is provided a fixing device including at least a fixing roller and a heating unit that generates a radiant heat and heats the surface of the fixing roller from the outside, wherein the heating unit is a shielding member. The shielding member can be introduced into a radiant heat irradiation path from the heat source direction toward the fixing roller, and the radiant heat irradiation region to the fixing roller can be changed by shielding the radiant heat at the introduction portion. A heating means and a fixing device.

本発明の請求項２によれば、請求項１に記載の加熱手段および定着装置において、該加熱手段は駆動手段を有し、該駆動手段は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に前記遮蔽部材を導入したり、あるいは照射経路内から除去したりすることが可能であることを特徴とする加熱手段および定着装置である。 According to a second aspect of the present invention, in the heating means and the fixing device according to the first aspect, the heating means has a driving means, and the driving means has a radiation heat irradiation path from the heat source direction toward the fixing roller. The heating means and the fixing device are characterized in that the shielding member can be introduced into or removed from the irradiation path.

本発明の請求項３によれば、請求項１、２に記載の加熱手段および定着装置と、紙幅検知手段と、を有する画像形成装置において、
該紙幅検知手段は定着装置に通紙される記録材の紙幅を検知し、検知された記録材の紙幅に応じて前記遮蔽部材の照射経路に対する導入量を決定することを特徴とする加熱手段および定着装置である。 According to a third aspect of the present invention, in the image forming apparatus comprising the heating unit and the fixing device according to the first and second aspects, and a paper width detecting unit,
The paper width detecting means detects the paper width of the recording material passed through the fixing device, and determines the introduction amount of the shielding member with respect to the irradiation path in accordance with the detected paper width of the recording material. It is a fixing device.

本発明の請求項４によれば、請求項１〜３に記載の加熱手段および定着装置において、前記遮蔽部材は、定着ローラの非通紙部に向かう輻射熱の照射経路内に導入されることを特徴とする加熱手段および定着装置である。 According to a fourth aspect of the present invention, in the heating means and the fixing device according to the first to third aspects, the shielding member is introduced into an irradiation path of radiant heat toward a non-sheet passing portion of the fixing roller. The heating means and the fixing device are characterized.

本発明の請求項５によれば、請求項４に記載の加熱手段および定着装置において、前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位に開口部を有し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする加熱手段および定着装置である。 According to a fifth aspect of the present invention, in the heating unit and the fixing device according to the fourth aspect, the opening is provided in a portion of the shielding member that is introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller. The heating unit and the fixing device are characterized in that the irradiation amount of radiant heat can be changed between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller.

本発明の請求項６によれば、請求項４、５に記載の加熱手段および定着装置において、前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位は輻射熱の一部を透過し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする加熱手段および定着装置である。 According to a sixth aspect of the present invention, in the heating means and the fixing device according to the fourth and fifth aspects, the portion of the shielding member introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller is radiant heat. The heating means and the fixing device are characterized in that the irradiation amount of the radiant heat can be changed between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller.

本発明の請求項７によれば、記録材に未定着のトナー像を形成する画像形成手段を有する画像形成装置において、１〜６に記載の加熱手段および定着装置を有することを特徴とする画像形成装置である。 According to claim 7 of the present invention, an image forming apparatus having an image forming means for forming an unfixed toner image on a recording material, comprising the heating means and the fixing device according to any one of claims 1 to 6. Forming device.

（作用）
表面加熱方式の定着装置において、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に遮蔽部材を導入可能とし、通紙される記録材の紙幅に応じて定着ローラ長手方向における輻射熱の照射領域を変えて、定着ローラ非通紙部への輻射熱の照射をおこなわないことで、非通紙部昇温を抑制し、定着ローラの熱劣化やホットオフセットをなくすことができる。 (Function)
In a surface heating type fixing device, it is possible to introduce a shielding member into the irradiation path of radiant heat from the heat source direction toward the fixing roller, and the irradiation area of the radiant heat in the longitudinal direction of the fixing roller according to the paper width of the recording material to be passed. In other words, by not irradiating the fixing roller non-sheet passing portion with radiant heat, it is possible to suppress the temperature increase of the non-sheet passing portion and eliminate the heat deterioration and hot offset of the fixing roller.

あるいは、表面加熱方式の定着装置において、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に遮蔽部材を導入可能とし、該遮蔽部材によって定着ローラの通紙部と非通紙部とで輻射熱の照射量を変えて定着ローラ長手方向の温度分布を均一にすることで、定着ローラの熱劣化やホットオフセットをなくすとともに、紙搬送の不安定化や定着ローラ破損をなくすことができる。 Alternatively, in the surface heating type fixing device, a shielding member can be introduced into the irradiation path of the radiant heat from the heat source direction toward the fixing roller, and the radiant heat is transmitted between the sheet passing portion and the non-sheet passing portion of the fixing roller by the shielding member. By changing the irradiation amount to make the temperature distribution in the longitudinal direction of the fixing roller uniform, it is possible to eliminate thermal deterioration and hot offset of the fixing roller, as well as instability of paper conveyance and damage to the fixing roller.

表面加熱方式の定着装置において、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に遮蔽部材を導入可能とし、通紙される記録材の紙幅に応じて定着ローラ長手方向における輻射熱の照射領域を変えて、定着ローラ非通紙部への輻射熱の照射をおこなわないことで、非通紙部昇温を抑制し、定着ローラの熱劣化やホットオフセットをなくすことができる。 In the surface heating type fixing device, a shielding member can be introduced into the radiation path of the radiant heat from the heat source direction toward the fixing roller, and the radiant heat irradiation area in the fixing roller longitudinal direction is set according to the paper width of the recording material to be passed. In other words, by not irradiating the fixing roller non-sheet passing portion with radiant heat, it is possible to suppress the temperature increase of the non-sheet passing portion and eliminate the heat deterioration and hot offset of the fixing roller.

以下に本発明の実施の形態を添付図面に基づいて説明する。 Embodiments of the present invention will be described below with reference to the accompanying drawings.

図２に本発明に係る画像形成装置要部の構成図を示す。感光ドラム１は、アルミニウムやニッケル等から成るシリンダ状の基板上にＯＰＣ等の感光材料を塗布して構成されている。この感光ドラム１は図示矢印方向に回転駆動される。感光ドラム１の表面は、回転駆動されることによって帯電部位、潜像部位、現像部位、転写部位を巡回する。 FIG. 2 shows a configuration diagram of a main part of the image forming apparatus according to the present invention. The photosensitive drum 1 is configured by applying a photosensitive material such as OPC on a cylindrical substrate made of aluminum, nickel, or the like. The photosensitive drum 1 is driven to rotate in the direction of the arrow shown in the figure. The surface of the photosensitive drum 1 circulates around a charged portion, a latent image portion, a developing portion, and a transfer portion by being rotationally driven.

帯電手段としての帯電ローラ２は感光ドラム１の表面を一様に帯電する。潜像手段としてのスキャナー３は画像情報に応じてＯＮ／ＯＦＦ制御され、かつ走査されるレーザービーム3aを発光し、感光ドラム１上に静電潜像を形成する。この静電潜像は、現像手段４において現像され、トナー像として可視化される。尚、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。 A charging roller 2 as a charging unit uniformly charges the surface of the photosensitive drum 1. A scanner 3 as a latent image means is controlled to be turned on / off according to image information and emits a scanned laser beam 3 a to form an electrostatic latent image on the photosensitive drum 1. This electrostatic latent image is developed by the developing means 4 and visualized as a toner image. As a development method, a jumping development method, a two-component development method, an FEED development method, or the like is used, and image exposure and reversal development are often used in combination.

記録材Pは所定のタイミングで矢印方向に給紙・搬送される。可視化されたトナー像は、転写手段としての転写ローラ５により、感光ドラム１の表面から記録材Ｐ上に転写される。記録材Ｐは感光ドラム１と転写ローラ５によって狭持搬送され、定着装置６に導入される。尚、転写ローラ５によって記録材Ｐに転写されずに感光ドラム１上に残存した転写残トナーは、クリーニング装置７により感光ドラム１表面より除去される。 The recording material P is fed and conveyed in the direction of the arrow at a predetermined timing. The visualized toner image is transferred onto the recording material P from the surface of the photosensitive drum 1 by a transfer roller 5 as transfer means. The recording material P is nipped and conveyed by the photosensitive drum 1 and the transfer roller 5 and introduced into the fixing device 6. Incidentally, the transfer residual toner remaining on the photosensitive drum 1 without being transferred to the recording material P by the transfer roller 5 is removed from the surface of the photosensitive drum 1 by the cleaning device 7.

図１に本発明に係る加熱手段および定着装置の第一実施形態を示す。（ａ）は定着装置の断面概略図、（ｂ）は上方から見た定着装置の長手方向平面概略図、（ｃ）は定着ローラ方向から見た加熱手段の長手方向平面概略図である。ここで、前述した従来の定着装置と同じ部材の符号は図１２と統一する。 FIG. 1 shows a first embodiment of a heating means and a fixing device according to the present invention. (A) is a schematic sectional view of the fixing device, (b) is a schematic plan view in the longitudinal direction of the fixing device as viewed from above, and (c) is a schematic plan view in the longitudinal direction of the heating means as viewed from the fixing roller direction. Here, the same reference numerals as those of the conventional fixing device described above are used in FIG.

１１は弾性層を有する定着ローラ、１２は弾性層を有し定着ローラ１１に圧接される加圧ローラ、１３は定着ローラ１１の外部に設けられ、輻射熱を発生する熱源としてのハロゲンヒータ、１４は内面に熱反射性を有する反射部材、１５a１、１５ａ２は定着ローラ１１とハロゲンヒータ１３および反射部材１４との間に導入可能な遮蔽部材、１６ａ１、１６ａ２は遮蔽部材１５ａ１、１５ａ２をそれぞれ移動することが可能な駆動手段である。 11 is a fixing roller having an elastic layer, 12 is a pressure roller having an elastic layer and pressed against the fixing roller 11, 13 is a halogen heater provided outside the fixing roller 11 as a heat source for generating radiant heat, and 14 Reflective members having heat reflectivity on the inner surface, 15a1 and 15a2 are shielding members that can be introduced between the fixing roller 11, the halogen heater 13 and the reflective member 14, and 16a1 and 16a2 can move the shielding members 15a1 and 15a2, respectively. Possible drive means.

定着ローラ１１は少なくとも弾性層を有する層構造をなす円柱状のローラである。円柱状のアルミもしくは鉄の芯金１１１の上に、シリコンゴムあるいは発泡シリコンゴムによる弾性層１１２と、高熱伝導性を有する鉄・ＳＵＳ・ニッケルなどによる１０〜１００μｍの薄層金属スリーブ１１３と、ＰＴＦＥあるいはＰＦＡなどによる離型性層１１４とを、順次層形成させて構成する。離型性層１１４には、熱吸収性を高めるために、カーボンブラック等の耐熱黒色顔料を混ぜている。 The fixing roller 11 is a cylindrical roller having a layer structure having at least an elastic layer. On a cylindrical aluminum or iron core 111, an elastic layer 112 made of silicon rubber or foamed silicon rubber, a 10-100 μm thin metal sleeve 113 made of iron, SUS, nickel, etc. having high thermal conductivity, PTFE Alternatively, a release layer 114 made of PFA or the like is formed by sequentially forming layers. The releasable layer 114 is mixed with a heat-resistant black pigment such as carbon black in order to increase heat absorption.

加圧ローラ１２は少なくとも弾性層を有する層構造をなす円柱状のローラである。円柱状のアルミもしくは鉄の芯金１２１の上に、シリコンゴムあるいは発泡シリコンゴムによる弾性層１２２と、ＰＴＦＥあるいはＰＦＡなどによる離型性層１２３とを、順次層形成して構成する。加圧ローラ１２は不図示の加圧手段によって定着ローラ１１に圧接され、ニップ部Ｎを形成する。 The pressure roller 12 is a cylindrical roller having a layer structure having at least an elastic layer. An elastic layer 122 made of silicon rubber or foamed silicon rubber and a releasable layer 123 made of PTFE or PFA are sequentially formed on a cylindrical aluminum or iron core 121. The pressure roller 12 is pressed against the fixing roller 11 by a pressing means (not shown) to form a nip portion N.

ハロゲンヒータ１３は通電によって輻射熱を発生する熱源である。ハロゲンヒータ１３は記録材の搬送方向に対して垂直な方向に長手寸法を有するように配置される。また、ハロゲンヒータ１３は定着ローラ１１の外部に位置し、ニップ部Ｎの紙搬送方向上流側に、定着ローラ１１の長手に平行に対向させて配設させる。 The halogen heater 13 is a heat source that generates radiant heat when energized. The halogen heater 13 is arranged to have a longitudinal dimension in a direction perpendicular to the recording material conveyance direction. The halogen heater 13 is positioned outside the fixing roller 11, and is disposed on the upstream side of the nip portion N in the paper conveyance direction so as to face the longitudinal direction of the fixing roller 11.

反射部材１４は開口部を有した楕円柱状で、内面に熱反射性を有する構成をもつ。反射部材１４はハロゲンヒータ１３を内包する。開口部は定着ローラ１１に向けられる。定着ローラ１１表面の一部に輻射熱の焦点が合うように、反射部材１４の内径形状、開口部を構成し、かつ、ハロゲンヒータ１、反射部材１４を配置することで、効率的に定着ローラ１１表面を加熱する。 The reflecting member 14 has an elliptical column shape having an opening, and has a configuration having heat reflectivity on the inner surface. The reflection member 14 includes the halogen heater 13. The opening is directed to the fixing roller 11. By forming the inner diameter shape and opening of the reflecting member 14 so that the radiant heat is focused on a part of the surface of the fixing roller 11 and arranging the halogen heater 1 and the reflecting member 14, the fixing roller 11 is efficiently arranged. Heat the surface.

定着ローラ１１は不図示の駆動手段によって矢印方向に駆動回転される。加圧ローラ１２は、不図示のギア列によって定着ローラ１１の駆動回転を受け、矢印方向に従動回転される。 The fixing roller 11 is driven and rotated in the direction of the arrow by a driving unit (not shown). The pressure roller 12 receives driving rotation of the fixing roller 11 by a gear train (not shown) and is driven to rotate in the direction of the arrow.

未定着トナー像を有した記録材Ｐは、ニップ部Ｎに導入される。未定着トナー像はハロゲンヒータ１３の輻射熱によって加熱した定着ローラ１１から加熱され、かつ定着ローラ１１と加圧ローラ１２にから加圧されることで、記録材Ｐに定着される。なお、定着ローラ１１の通紙部の温度は、不図示の温度検知手段や制御手段によってハロゲンヒータ１３の照射量を制御することで、良好な定着画像が得られるように所定温度に制御される。 The recording material P having an unfixed toner image is introduced into the nip portion N. The unfixed toner image is fixed on the recording material P by being heated from the fixing roller 11 heated by the radiant heat of the halogen heater 13 and being pressed by the fixing roller 11 and the pressure roller 12. Note that the temperature of the sheet passing portion of the fixing roller 11 is controlled to a predetermined temperature so that a good fixed image can be obtained by controlling the irradiation amount of the halogen heater 13 by a temperature detection unit or a control unit (not shown). .

次に、本実施例の特徴である遮蔽部材１５ａ１、１５ａ２と、駆動手段１６ａ１、１６ａ１、および、紙幅検知手段８について説明する。ここで本実施形態の定着装置の通紙位置は中央基準とする。 Next, the shielding members 15a1 and 15a2, the driving means 16a1 and 16a1, and the paper width detecting means 8 which are the features of this embodiment will be described. Here, the sheet passing position of the fixing device of the present embodiment is assumed to be the center reference.

平板状の遮蔽部材１５ａ1、１５ａ２と、駆動部材１６ａ１、１６ａ２は、それぞれ紙幅両端方面に対を成して１組ずつ配置される。遮蔽部材１５ａ１、１５ａ２は、紙幅検知手段によって検知される記録材Ｐの紙幅に応じて、駆動手段１６ａ１、１６ａ２によって、ハロゲンヒータ１３および反射部材１４から定着ローラ１１の非通紙部へと向かう輻射熱の照射経路内に導入されたり、あるいは、該位置から除去されたりすることで、定着ローラ１１における輻射熱の照射領域を変える。本実施形態における遮蔽部材１５ａ１、１５ａ２の移動方向は、紙幅方向（図中、通紙端部方向−通紙中央方向）である。 The flat shield members 15a1 and 15a2 and the drive members 16a1 and 16a2 are arranged in pairs in pairs on both ends of the paper width. The shielding members 15a1 and 15a2 radiate heat from the halogen heater 13 and the reflecting member 14 toward the non-sheet passing portion of the fixing roller 11 by the driving units 16a1 and 16a2 according to the paper width of the recording material P detected by the paper width detecting unit. The irradiation area of the radiant heat in the fixing roller 11 is changed by being introduced into or removed from the irradiation path. The moving direction of the shielding members 15a1 and 15a2 in the present embodiment is the paper width direction (in the drawing, the paper passing edge direction-the paper passing center direction).

なお、通紙位置を片側基準とするときは、小サイズ紙通紙時の非通紙側となる定着ローラ１１の片端部方面にのみ遮蔽部材と駆動手段を1組、具備させても良い。 Note that when the sheet passing position is used as a one-side reference, a set of a shielding member and a driving unit may be provided only on one side of the fixing roller 11 on the non-sheet passing side when small-size sheets are passed.

紙幅検知手段８は、記録材Ｐがニップ部Ｎに導入される以前に記録材Ｐの紙幅を検知することが好ましい。本実施形態では、紙幅検知手段８として画像形成装置の給紙口に配置される紙幅規制部材を用いている（図２）。その他の紙幅検知手段として、記録材の搬送経路に配置されるフォトインタラプタなどを用いてもよい。 It is preferable that the paper width detecting unit 8 detects the paper width of the recording material P before the recording material P is introduced into the nip portion N. In the present embodiment, a paper width regulating member disposed at the paper feed port of the image forming apparatus is used as the paper width detecting means 8 (FIG. 2). As other paper width detection means, a photo interrupter arranged in the conveyance path of the recording material may be used.

駆動手段１６ａ１、１６ａ２は、本実施形態においては、不図示のモータによって回転駆動するローラを有し、該ローラが遮蔽部材１５ａ１、１５ａ２に圧接された状態で回転駆動することで、遮蔽部材１５ａ１、１５ａ２をそれぞれ駆動する構成としたが、遮蔽部材１５ａ１、１５ａ２を所定の範囲に移動することが可能であれば、その他の構成でもよい。 In the present embodiment, the driving means 16a1 and 16a2 have rollers that are rotationally driven by a motor (not shown), and the rollers are rotationally driven in a state of being pressed against the shielding members 15a1 and 15a2, so that the shielding members 15a1 and 16a2 are rotated. Although 15a2 is configured to be driven, other configurations may be used as long as the shielding members 15a1 and 15a2 can be moved to a predetermined range.

紙幅検知手段８によって検知された記録材Ｐの紙幅は、不図示の制御手段にフィードバックされる。制御手段は、紙幅検知手段８によって検知された記録材Ｐの紙幅に応じて、定着ローラ１１における輻射熱の照射領域を決定し、目的の照射領域が得られるように遮蔽部材１５ａ１、１５ａ２を駆動手段１６ａ１、１６ａ２によって移動する。 The paper width of the recording material P detected by the paper width detection unit 8 is fed back to a control unit (not shown). The control means determines the irradiation area of the radiant heat in the fixing roller 11 according to the paper width of the recording material P detected by the paper width detection means 8, and drives the shielding members 15a1 and 15a2 so as to obtain the target irradiation area. It moves by 16a1, 16a2.

通紙される記録材の紙幅によって決定される定着ローラ１１における輻射熱の照射領域について説明する。定着ローラ１１における輻射熱の照射領域は、紙幅方向における定着均一性を確保され、かつ、非通紙部昇温が可能な限り抑制されるように、記録材Ｐの紙幅に応じて予め設定されている。本実施形態において、通紙可能な記録材Ｐの最大紙幅であるＡ４サイズ縦送り（紙幅２１０ｍｍ）、最小紙幅でハガキサイズ縦送り（紙幅１００ｍｍ）とし、それぞれの照射領域はＡ４サイズで２１６ｍｍ、ハガキサイズで１０６ｍｍとした。 The radiant heat irradiation area in the fixing roller 11 determined by the paper width of the recording material to be passed will be described. The irradiation area of the radiant heat in the fixing roller 11 is set in advance according to the paper width of the recording material P so that the fixing uniformity in the paper width direction is ensured and the temperature rise of the non-sheet passing portion is suppressed as much as possible. Yes. In the present embodiment, A4 size vertical feed (paper width 210 mm), which is the maximum paper width of the recording material P that can be passed, and postcard size vertical feed (paper width 100 mm) at the minimum paper width, each irradiation area is 216 mm, postcard A4 size. The size was 106 mm.

表１に、本実施形態の定着装置と従来の定着装置とでの、小サイズ連続通紙による定着ローラ熱劣化の発生比較を示す。ここで、本実施形態の定着装置はこれまで述べてきたものであるが、従来の定着装置とは先述の遮蔽部材１５ａ１、１５ａ２、駆動手段１６ａ１、１６ａ２を具備しないものである。 Table 1 shows a comparison of occurrence of heat deterioration of the fixing roller due to small-size continuous sheet passing between the fixing device of the present embodiment and the conventional fixing device. Here, the fixing device of the present embodiment has been described so far, but the conventional fixing device does not include the above-described shielding members 15a1 and 15a2 and driving means 16a1 and 16a2.

表１の定着ローラ熱劣化の評価条件は、定着ローラの通紙部の制御温度をそれぞれ１６０℃、１８０℃、２００℃として、記録材をハガキ（１００ｍｍ×１４８ｍｍ）を用い、通紙幅：１００ｍｍ、記録材の搬送速度：１５０ｍｍ／ｓｅｃ、１分あたりの通紙枚数：１０枚、連続通紙枚数：１０００枚とした。 The evaluation conditions for fixing roller thermal degradation in Table 1 are as follows: the control temperature of the sheet passing portion of the fixing roller is set to 160 ° C., 180 ° C., and 200 ° C., and the recording material is postcard (100 mm × 148 mm). The conveyance speed of the recording material was 150 mm / sec, the number of sheets passed per minute: 10 sheets, and the number of continuous sheets passed: 1000 sheets.

ここで、１６０℃制御においても定着性は十分に確保されており、１８０℃制御、２００℃制御はより定着ローラに熱劣化が発生しやすい状況を作るためにおこなった加速試験である。 Here, the fixing property is sufficiently secured even at 160 ° C. control, and the 180 ° C. control and the 200 ° C. control are acceleration tests conducted in order to create a situation in which heat deterioration is more likely to occur in the fixing roller.

表１に示すように、従来例では１８０℃制御以上で定着ローラの熱劣化が発生したが、本実施形態では２００℃制御をおこなっても定着ローラの熱劣化は発生しなかった。 As shown in Table 1, in the conventional example, thermal degradation of the fixing roller occurred at 180 ° C. or higher, but in this embodiment, thermal degradation of the fixing roller did not occur even when 200 ° C. control was performed.

表２に、本実施形態の定着装置と従来の定着装置とでの、小サイズ紙通紙の後のより大きな記録材におけるホットオフセットの発生比較を示す。ここで、本実施形態および従来の定着装置とは、表1で熱劣化を比較したものである。 Table 2 shows a comparison of occurrence of hot offset in a larger recording material after passing through small-size paper between the fixing device of this embodiment and the conventional fixing device. Here, the present embodiment and the conventional fixing device are those in which thermal degradation is compared in Table 1.

表２の小サイズ紙通紙の後のより大きな記録材におけるホットオフセットの評価条件は、表１に示した試験を行った１０ｓｅｃ後に、坪量６４ｇ／ｍのＡ４サイズ紙に文字画像を印字することとした。 The evaluation conditions for hot offset in a larger recording material after passing through the small-size paper in Table 2 are as follows. 10 seconds after performing the test shown in Table 1, a character image is printed on A4 size paper having a basis weight of 64 g / m. It was decided.

ここで、表１のときと同様に、１６０℃制御においても定着性は十分に確保されており、１８０℃制御、２００℃制御はよりホットオフセットが発生しやすい状況を作るためにおこなった加速試験である。 Here, as in the case of Table 1, the fixing property is sufficiently secured even at 160 ° C. control, and the acceleration test conducted to create a situation where hot offset is more likely to occur at 180 ° C. control and 200 ° C. control. It is.

このように、表面加熱方式の定着装置において、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に遮蔽部材を導入可能とし、通紙される記録材の紙幅に応じて定着ローラ長手方向における輻射熱の照射領域を変えて、定着ローラ非通紙部への輻射熱の照射をおこなわないことで、非通紙部昇温を抑制し、定着ローラの熱劣化やホットオフセットをなくすことができる。 As described above, in the surface heating type fixing device, the shielding member can be introduced into the irradiation path of the radiant heat from the heat source direction toward the fixing roller, and the radiant heat in the longitudinal direction of the fixing roller according to the paper width of the recording material to be passed. By not changing the irradiation area to irradiate the fixing roller non-sheet passing portion with radiant heat, it is possible to suppress the temperature increase of the non-sheet passing portion and to eliminate the heat deterioration and hot offset of the fixing roller.

第一実施形態では遮蔽部材の移動方向を紙幅方向としたが、定着ローラ長手方向に対して垂直方向、すなわち、定着装置の上下方向に移動するようにしてもよい。 In the first embodiment, the moving direction of the shielding member is the paper width direction, but it may be moved in a direction perpendicular to the longitudinal direction of the fixing roller, that is, in the vertical direction of the fixing device.

図３に本発明に係る加熱手段および定着装置の第二実施形態を示す。（ａ）は定着装置の断面概略図、（ｂ）は上方から見た定着装置の長手方向平面概略図、（ｃ）は定着ローラ方向から見た加熱装置の長手方向平面概略図である。ここで、第一実施形態と同じ部材の符号は統一する。 FIG. 3 shows a second embodiment of the heating means and the fixing device according to the present invention. (A) is a schematic cross-sectional view of the fixing device, (b) is a schematic plan view in the longitudinal direction of the fixing device viewed from above, and (c) is a schematic plan view in the longitudinal direction of the heating device viewed from the fixing roller direction. Here, the code | symbol of the same member as 1st embodiment is unified.

遮蔽部材１５ｂ１、１５ｂ２は、定着装置の上下方向に移動する。 The shielding members 15b1 and 15b2 move in the vertical direction of the fixing device.

遮蔽部材１５ｂ１、１５ｂ２の輻射熱の照射経路に対向する辺の形状は、遮蔽部材１５ｂ１、１５ｂ２の移動に伴って輻射熱の照射経路を通紙両端側から輻射熱を遮蔽し、かつ、定着ローラに対する輻射熱の照射領域は、通紙可能な記録材のサイズに適応して紙幅方向における定着均一性を確保するように構成する。本実施例では、図３（ｃ）のように、輻射熱の走者経路に対して交差する角度をなす線状としている。その他の形状として、図４の遮蔽部材１５ｃ１、１５ｃ２のように階段状とし、よく使用される代表的な記録材のサイズに合わせて輻射熱の照射領域を不連続に変わるようにしてもよい。ただし、不定形の記録材を通紙したときに対応して輻射熱の照射領域を連続に変えられるように、図３（ｃ）のようにする方が好ましい。 The shape of the side of the shielding members 15b1 and 15b2 facing the irradiation path of the radiant heat shields the radiant heat from both ends of the paper through the irradiation path of the radiant heat as the shielding members 15b1 and 15b2 move, and the radiant heat of the fixing roller The irradiation area is configured to ensure fixing uniformity in the paper width direction in accordance with the size of the recording material that can be passed. In this embodiment, as shown in FIG. 3 (c), a linear shape is formed that intersects the radiant heat runner path. As other shapes, it may be stepped like the shielding members 15c1 and 15c2 of FIG. 4, and the irradiation area of the radiant heat may be changed discontinuously according to the size of a typical recording material often used. However, it is preferable to use the configuration shown in FIG. 3C so that the irradiation region of the radiant heat can be changed continuously corresponding to the passage of the irregular recording material.

このように、遮蔽部材の移動方向を定着装置の上下方向にすることで、加熱手段および定着装置の長手寸法の肥大化を避けることができると共に、第一実施形態と同様の効果を得る。 Thus, by making the moving direction of the shielding member the vertical direction of the fixing device, enlargement of the longitudinal dimension of the heating means and the fixing device can be avoided, and the same effect as in the first embodiment can be obtained.

第一実施形態、第二実施形態では、加熱手段において通紙両端部に対を成す遮蔽部材と駆動手段をそれぞれ１組ずつ配置したが、第三実施形態の加熱手段は1組の遮蔽部材と駆動手段とを有する例である。 In the first embodiment and the second embodiment, a pair of shielding members and driving means that are paired at both ends of the paper passing in the heating means are arranged, but the heating means of the third embodiment is a set of shielding members. It is an example which has a drive means.

図５に本発明に係る加熱手段および定着装置の第三実施形態を示す。（ａ）は定着装置の断面概略図、（ｂ）は上方から見た定着装置の長手方向平面概略図、（ｃ）は定着ローラ方向から見た加熱装置の長手方向平面概略図である。ここで、第一実施形態と同じ部材の符号は統一する。 FIG. 5 shows a third embodiment of the heating means and the fixing device according to the present invention. (A) is a schematic cross-sectional view of the fixing device, (b) is a schematic plan view in the longitudinal direction of the fixing device viewed from above, and (c) is a schematic plan view in the longitudinal direction of the heating device viewed from the fixing roller direction. Here, the code | symbol of the same member as 1st embodiment is unified.

加熱手段は遮蔽部材１５ｄと駆動手段１６ｄを１組のみ有する。遮蔽部材１５ｄの輻射熱の照射経路に対向する辺は、通紙端部より通紙中央に行くに従がって深く切れ込んだ略Ｖ字の形状をもつ。この形状を有することで、駆動手段１６ｄを用いて遮蔽部材１５ｄを輻射熱の照射経路に導入したり、あるいは除去したりすることで、定着ローラ１１における輻射熱の照射領域を変えることができ、第２実施形態と同様の効果を得る。 The heating means has only one set of shielding member 15d and driving means 16d. The side of the shielding member 15d facing the irradiation path of the radiant heat has a substantially V shape that is deeply cut from the end of the sheet passing toward the center of the sheet. By having this shape, the irradiation area of the radiant heat in the fixing roller 11 can be changed by introducing or removing the shielding member 15d into the radiant heat irradiation path using the driving unit 16d. The same effect as the embodiment is obtained.

本実施形態において、遮蔽部材１５ｄの輻射熱の照射経路に対向する辺の形状は略Ｖ字形状としたが、その他の形状として、よく使用される代表的な記録材のサイズに合わせて輻射熱の照射領域を不連続に変える階段状のようにしてもよい。ただし、不定形の記録材を通紙したときに対応して輻射熱の照射領域を連続に変えられるように、略Ｖ字形状にする方が好ましい。 In this embodiment, the shape of the side of the shielding member 15d that faces the irradiation path of the radiant heat is substantially V-shaped, but as other shapes, the radiant heat is irradiated in accordance with the size of a typical recording material that is often used. You may make it like the step shape which changes an area | region discontinuously. However, it is preferable to make it substantially V-shaped so that the irradiation region of the radiant heat can be changed continuously corresponding to the passage of the irregular recording material.

第四実施形態では、加熱手段および定着装置の長手寸法および高さ寸法を極力大きくしない構成を提案する。 In the fourth embodiment, a configuration is proposed in which the longitudinal dimension and the height dimension of the heating means and the fixing device are not increased as much as possible.

図６に本発明に係る加熱手段の第四実施形態を示す。ここで、第一実施形態と同じ部材の符号は統一する。 FIG. 6 shows a fourth embodiment of the heating means according to the present invention. Here, the code | symbol of the same member as 1st embodiment is unified.

本実施形態において、遮蔽部材１５ｅは開口部を有する円筒形状である。開口部の長手寸法は図５のように、遮蔽部材１５ｅの円周位置によって異なり、最大寸法で定着ローラに対する輻射熱の最大照射領域を、最小寸法で最小照射領域を得る。遮蔽部材１５ｅは内部にハロゲンヒータ１３および反射部材１４を具備する。遮蔽部材１５ｅは駆動手段１６ｅによって回転駆動される。 In the present embodiment, the shielding member 15e has a cylindrical shape having an opening. As shown in FIG. 5, the longitudinal dimension of the opening varies depending on the circumferential position of the shielding member 15e, and the maximum irradiation area of the radiant heat to the fixing roller is obtained with the maximum dimension, and the minimum irradiation area is obtained with the minimum dimension. The shielding member 15e includes a halogen heater 13 and a reflecting member 14 inside. The shielding member 15e is rotationally driven by the driving means 16e.

遮蔽部材１５ｅは、紙幅検知手段８によって検知された記録材の紙幅に従がって、駆動手段１６ｅで回転駆動され、定着ローラに対する目的の輻射熱の照射領域を得る。 The shielding member 15e is rotationally driven by the driving unit 16e in accordance with the paper width of the recording material detected by the paper width detecting unit 8, and obtains a target radiant heat irradiation region for the fixing roller.

図６では加熱手段に1組の遮蔽部材１５ｅと駆動手段１６ｅとを具備させているが、図７のように、通紙両端方面にそれぞれ遮蔽部材１５ｆ１、１５ｆ２と駆動手段１６ｆ１、１６ｆ２とを１組ずつ具備させても良い。遮蔽部材１５ｆ１、１５ｆ２は図７のように円柱を斜めに切った形状をしており、遮蔽部材１５ｆ１、１５ｆ２が同じ角度、同方向に回転し、定着ローラに対する輻射熱の最小照射領域と最大照射領域が目的の寸法となるように構成する。 In FIG. 6, the heating means is provided with a pair of shielding members 15e and driving means 16e. However, as shown in FIG. 7, shielding members 15f1 and 15f2 and driving means 16f1 and 16f2 are respectively provided on both sides of the sheet passing. One set may be provided. The shielding members 15f1 and 15f2 have a shape obtained by obliquely cutting a cylinder as shown in FIG. 7. The shielding members 15f1 and 15f2 rotate in the same angle and in the same direction, and the minimum irradiation area and the maximum irradiation area of the radiant heat to the fixing roller. Is configured to have a target dimension.

第一実施形態から第四実施形態までは、遮蔽部材のハロゲンヒータに対する向きを平行とした。第五実施形態では、遮蔽部材のハロゲンヒータに対向する面が、輻射熱の照射方向に対して交差する角度をなし、輻射熱のハロゲンヒータの長手中心側に傾ける構成とする。また、遮蔽部材のハロゲンヒータに対向する面は熱反射性を有する。 From 1st embodiment to 4th embodiment, the direction with respect to the halogen heater of the shielding member was made parallel. In the fifth embodiment, the surface of the shielding member that faces the halogen heater forms an angle that intersects with the irradiation direction of the radiant heat, and is inclined to the longitudinal center side of the radiant heat halogen heater. Further, the surface of the shielding member that faces the halogen heater has heat reflectivity.

図８に本発明に係る加熱手段および定着装置の第五実施形態を示す。ここで、第一実施形態と同じ部材の符号は統一する。本実施形態において、加熱手段は通紙両端方面に対を成す遮蔽部材１５ｇ１、１５ｇ２と、駆動手段１６ｇ１、１６ｇ２をそれぞれ１組ずつ有し、遮蔽部材１５ｇ１、１５ｇ２は輻射熱の照射方向に対して交差する角度をなし、輻射熱のハロゲンヒータの長手中心側に傾ける構成とする。また、遮蔽部材１５ｇ１、１５ｇ２は駆動手段１６ｇ１、１６ｇ２によって通紙中央方向−通紙端部方向に移動可能とする。さらに、遮蔽部材のハロゲンヒータに対向する面は熱反射性を有する。 FIG. 8 shows a fifth embodiment of the heating means and the fixing device according to the present invention. Here, the code | symbol of the same member as 1st embodiment is unified. In the present embodiment, the heating means has a pair of shielding members 15g1 and 15g2 and driving means 16g1 and 16g2 each paired on both sides of the sheet passing, and the shielding members 15g1 and 15g2 intersect with the irradiation direction of the radiant heat. The angle is set to be inclined toward the longitudinal center of the radiant heat halogen heater. Further, the shielding members 15g1 and 15g2 can be moved by the driving means 16g1 and 16g2 in the sheet passing center direction to the sheet passing end portion direction. Furthermore, the surface of the shielding member facing the halogen heater has heat reflectivity.

遮蔽部材１５ｇ１、１５ｇ２は、紙幅検知手段８によって検知された記録材の紙幅に従がって、駆動手段１６ｇ１、１６ｇ２によって移動され、定着ローラに対する目的の輻射熱の照射領域を得る。 The shielding members 15g1 and 15g2 are moved by the driving means 16g1 and 16g2 in accordance with the paper width of the recording material detected by the paper width detecting means 8, and obtain a target radiation heat irradiation area for the fixing roller.

このような構成とすることで、遮蔽部材１５ｇ１、１５ｇ２が輻射熱の照射経路に導入されたときは、ハロゲンヒータ１３および反射部材１４から定着ローラ１１長手の非通紙部方向に放射された輻射熱は、遮蔽部材１５ｇ１、１５ｇ２によって、ハロゲンヒータ１３および反射部材１４の長手中央方向に反射され、反射部材１４によって定着ローラ１１の長手中央方向に反射されるのため、定着ローラ１１の通紙部に輻射熱を集中することができ、熱効率の向上が図れる。 With such a configuration, when the shielding members 15g1 and 15g2 are introduced into the irradiation path of the radiant heat, the radiant heat radiated from the halogen heater 13 and the reflecting member 14 toward the non-sheet passing portion of the fixing roller 11 is as follows. The shielding members 15g1 and 15g2 reflect the halogen heater 13 and the reflecting member 14 in the longitudinal center direction, and the reflecting member 14 reflects the fixing roller 11 in the longitudinal center direction. The heat efficiency can be improved.

本実施形態では、加熱手段は通紙両端方向に対をなす遮蔽部材と駆動手段を１組ずつ有し、遮蔽部材は駆動手段によって通紙中央方向−通紙端部方向に移動可能とする構成としたが、加熱手段が有する遮蔽部材と駆動手段は１組であっても良い。また、遮蔽手段の移動する方向は定着ローラの上下方向でも良い（図９参照）。さらに、遮蔽部材は開口部を有する円筒形状であってもよい。 In the present embodiment, the heating means has a pair of a shielding member and a driving means that make a pair in the both-end direction of the sheet, and the shielding member can be moved by the driving means in the direction from the sheet passing center to the sheet passing end. However, the shielding member and the driving unit included in the heating unit may be one set. Further, the moving direction of the shielding means may be the vertical direction of the fixing roller (see FIG. 9). Furthermore, the shielding member may have a cylindrical shape having an opening.

第六実施形態では、遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位に開口部を設け、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする。 In the sixth embodiment, an opening is provided in a portion of the shielding member that is introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller, and the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller are provided. It is possible to change the irradiation amount of radiant heat.

図１０に本発明に係る加熱手段および定着装置の第六実施形態を示す。ここで、第一実施形態と同じ部材の符号は統一する。加熱手段は、通紙両端方面に対を成す遮蔽部材１５ｉ１、１５ｉ２と、駆動手段１６ｉ１、１６ｉ２をそれぞれ１組ずつ有する。また、遮蔽部材１５ｉ１と１５ｉ２はそれぞれ複数の平板状の遮蔽板１５ｊ1〜４と、１５ｊ５〜８で構成される。複数の平板状の遮蔽板１５ｊ１〜８は輻射熱の照射方向に対して交差する角度をなし、その交差する角度は輻射熱のハロゲンヒータの長手中心側に傾けた方向であり、かつ、遮蔽板１５ｊ1〜４のそれぞれおよび遮蔽板１５ｊ５〜８のそれぞれはある間隔で並列に構成する。この構成によって遮蔽部材１５ｉ１と１５ｉ２は開口部を有する。 FIG. 10 shows a sixth embodiment of the heating means and the fixing device according to the present invention. Here, the code | symbol of the same member as 1st embodiment is unified. The heating unit includes a pair of shielding members 15i1 and 15i2 and a pair of driving units 16i1 and 16i2 that are paired on both sides of the sheet. Further, the shielding members 15i1 and 15i2 are constituted by a plurality of flat shielding plates 15j1 to 15j4 and 15j5 to 8, respectively. The plurality of flat shield plates 15j1 to 8 form an angle that intersects the irradiation direction of the radiant heat, the intersecting angle is a direction inclined toward the longitudinal center side of the radiant heat halogen heater, and the shield plates 15j1 to 15j1 Each of 4 and the shielding plates 15j5 to 8 are configured in parallel at a certain interval. With this configuration, the shielding members 15i1 and 15i2 have openings.

遮蔽部材１５ｉ１、１５ｉ２は、紙幅検知手段８によって検知された記録材の紙幅に従がって、駆動手段１６ｉ１、１６ｉ２によって、定着ローラの非通紙部に導入される。定着ローラの通紙部は、遮蔽部材１５ｉ１と１５ｉ２とによって輻射熱を遮蔽されることがなく、記録材の紙幅方向において均一な定着性を得る。一方、定着ローラの非通紙部は遮蔽部材１５ｉ１、１５ｉ２の開口部を通過した輻射熱を照射される。 The shielding members 15 i 1 and 15 i 2 are introduced into the non-sheet passing portion of the fixing roller by the driving units 16 i 1 and 16 i 2 according to the paper width of the recording material detected by the paper width detecting unit 8. The sheet passing portion of the fixing roller is not shielded from the radiant heat by the shielding members 15i1 and 15i2, and obtains a uniform fixing property in the paper width direction of the recording material. On the other hand, the non-sheet passing portion of the fixing roller is irradiated with radiant heat that has passed through the openings of the shielding members 15i1 and 15i2.

遮蔽板１５ｊ1〜８の寸法、遮蔽板１５ｊ１〜８の輻射熱の照射方向に対して交差する角度、遮蔽板１５ｊ1〜４のそれぞれおよび遮蔽板１５ｊ５〜８のぞれぞれの間隔は、定着ローラ１１の通紙部と非通紙部の温度が同じになるように構成する。本実施形態では、遮蔽板１５ｊ1〜８の寸法を高さ２０ｍｍ×幅３０ｍｍ、輻射熱の照射方向に対して交差する角度を２０°、遮蔽板１５ｊ1〜４のそれぞれの間隔および遮蔽板１５ｊ５〜８のぞれぞれの間隔を７ｍｍ、とした。 The dimensions of the shielding plates 15j1 to 8, the angle intersecting the radiation direction of the shielding plates 15j1 to 8, the intervals between the shielding plates 15j1 to 4 and the shielding plates 15j5 to 8 are determined by the fixing roller 11. The temperature of the sheet passing portion and the non-sheet passing portion are configured to be the same. In the present embodiment, the dimensions of the shielding plates 15j1-8 are 20 mm high × 30 mm wide, the angle intersecting the irradiation direction of the radiant heat is 20 °, the spacing between the shielding plates 15j1-4, and the shielding plates 15j5-8. The interval between each was 7 mm.

このように、遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位に開口部を設け、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変え、定着ローラ長手方向における温度分布を均一にすることで、定着ローラの熱劣化やホットオフセットをなくすとともに、紙搬送の不安定化や定着ローラ破損をなくすことができる。 As described above, an opening is provided in a portion of the shielding member that is introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller, and radiant heat is transmitted between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. By changing the irradiation amount and making the temperature distribution in the longitudinal direction of the fixing roller uniform, it is possible to eliminate thermal deterioration and hot offset of the fixing roller, as well as to eliminate paper conveyance instability and fixing roller damage.

なお、遮蔽部材に開口部を設ける構成としては、定着ローラ長手方向における温度分布を均一にできれば、例えば、第一実施形態から第五実施形態で示した遮蔽部材に開口部を具備させるなど、その他の構成としても良い。 In addition, as a configuration in which the opening portion is provided in the shielding member, if the temperature distribution in the longitudinal direction of the fixing roller can be made uniform, for example, the opening portion is provided in the shielding member shown in the first to fifth embodiments. It is good also as a structure of.

第七実施形態では、遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位は輻射熱の一部を透過し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする。 In the seventh embodiment, the portion of the shielding member introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller transmits a part of the radiant heat, and the sheet passing portion and the non-sheet passing in the longitudinal direction of the fixing roller. It is possible to change the irradiation amount of radiant heat between the portions.

図１１に本発明に係る加熱手段および定着装置の第七実施形態を示す。ここで、第一実施形態と同じ部材の符号は統一する。遮蔽部材１５ｋ１、１５ｋ２は光透過性を有し、紙幅検知手段８によって検知された記録材の紙幅に従がって、それぞれ駆動手段１６ｋ１、１６ｋ２に移動され、定着ローラに対する目的の輻射熱の照射領域を得る。 FIG. 11 shows a seventh embodiment of the heating means and the fixing device according to the present invention. Here, the code | symbol of the same member as 1st embodiment is unified. The shielding members 15k1 and 15k2 are light transmissive, and are moved to the driving means 16k1 and 16k2, respectively, according to the paper width of the recording material detected by the paper width detecting means 8, and are irradiated with the target radiant heat on the fixing roller. Get.

遮蔽部材１５ｋ１、１５ｋ２の光透過性は、定着ローラ１１の通紙部と非通紙部の温度が略同等となるものとする。本実施形態では、透過率５０％の減光フィルタを用いた。 The light transmittance of the shielding members 15k1 and 15k2 is such that the temperatures of the paper passing portion and the non-paper passing portion of the fixing roller 11 are substantially equal. In the present embodiment, a neutral density filter having a transmittance of 50% is used.

このように、遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位は輻射熱の一部を透過し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えて、定着ローラ長手方向における温度分布を均一にすることで、定着ローラの熱劣化やホットオフセットをなくすとともに、紙搬送の不安定化や定着ローラ破損をなくすことができる。 As described above, the portion of the shielding member introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller transmits a part of the radiant heat, and the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. By changing the irradiation amount of radiant heat and making the temperature distribution in the longitudinal direction of the fixing roller uniform, it is possible to eliminate thermal deterioration and hot offset of the fixing roller, as well as destabilization of paper conveyance and damage to the fixing roller. .

本発明に係る加熱手段および定着装置の第一実施形態（ａ）定着装置の断面概略図（ｂ）上方から見た定着装置の長手方向平面概略図（ｃ）定着ローラ方向から見た加熱手段の長手方向平面概略図First Embodiment of Heating Means and Fixing Device According to the Present Invention (a) Schematic sectional view of fixing device (b) Schematic plan view in longitudinal direction of fixing device as viewed from above (c) Heating means as viewed from fixing roller direction Longitudinal plan view 発明に係る画像形成装置要部の構成図Configuration diagram of main part of image forming apparatus according to invention 本発明に係る加熱手段および定着装置の第二実施形態（ａ）定着装置の断面概略図（ｂ）上方から見た定着装置の長手方向平面概略図（ｃ）定着ローラ方向から見た加熱手段の長手方向平面概略図Second Embodiment of Heating Means and Fixing Device According to the Present Invention (a) Schematic sectional view of fixing device (b) Schematic plan view in longitudinal direction of fixing device as viewed from above (c) Heating means as viewed from fixing roller direction Longitudinal plan view 第二実施形態に係るその他の加熱手段の概略図Schematic of other heating means according to the second embodiment 本発明に係る加熱手段および定着装置の第三実施形態（ａ）定着装置の断面概略図（ｂ）上方から見た定着装置の長手方向平面概略図（ｃ）定着ローラ方向から見た加熱手段の長手方向平面概略図Third Embodiment of Heating Unit and Fixing Device According to the Present Invention (a) Schematic sectional view of fixing device (b) Schematic plan view in longitudinal direction of fixing device viewed from above (c) Heating unit viewed from fixing roller direction Longitudinal plan view 本発明に係る加熱手段および定着装置の第四実施形態Fourth embodiment of heating means and fixing device according to the present invention 第四実施形態に係るその他の加熱手段の概略図Schematic of other heating means according to the fourth embodiment 本発明に係る加熱手段および定着装置の第五実施形態Fifth embodiment of heating means and fixing device according to the present invention 第五実施形態に係るその他の加熱手段および定着装置の概略図Schematic of other heating means and fixing device according to the fifth embodiment 本発明に係る加熱手段および定着装置の第六実施形態Sixth embodiment of heating means and fixing device according to the present invention 本発明に係る加熱手段および定着装置の第七実施形態Seventh embodiment of heating means and fixing device according to the present invention 従来の表面加熱方式の定着装置の断面概略図Cross-sectional schematic diagram of a conventional surface heating type fixing device

符号の説明Explanation of symbols

１感光ドラム
２帯電ローラ
３スキャナー
３a レーザービーム
４現像手段
５転写ローラ
６定着装置
７クリーニング装置
８紙幅検知手段
１１定着ローラ
１１１芯金
１１２弾性層
１１３薄層金属スリーブ
１１４離型性層
１２加圧ローラ
１２１芯金
１２２弾性層
１２３離型性層
１３ハロゲンヒータ
１４反射部材
１５ａ１、１５ａ２本発明の第一実施形態に係る遮蔽部材
１５ｂ１、１５ｂ２、１５ｃ１、１５ｃ２本発明の第二実施形態に係る遮蔽部材
１５ｄ本発明の第三実施形態に係る遮蔽部材
１５ｅ、１５ｆ１、１５ｆ２本発明の第四実施形態に係る遮蔽部材
１５ｇ１、１５ｇ２、１５ｈ本発明の第五実施形態に係る遮蔽部材
１５ｉ1、１５ｉ２本発明の第六実施形態に係る遮蔽部材
１５ｊ１〜８本発明の第六実施形態に係る遮蔽部材に具備される遮蔽板
１５ｋ１、１５ｋ２本発明の第七実施形態に係る遮蔽部材
１６ａ１、１５ａ２本発明の第一実施形態に係る駆動手段
１６ｂ１、１６ｂ２、１６ｃ１、１６ｃ２本発明の第二実施形態に係る駆動手段
１６ｄ本発明の第三実施形態に係る駆動手段
１６ｅ、１６ｆ１、１６ｆ２本発明の第四実施形態に係る駆動手段
１６ｇ１、１６ｇ２、１６ｈ本発明の第五実施形態に係る駆動手段
１６ｉ1、１６ｉ２本発明の第六実施形態に係る駆動手段
１６ｋ１、１６ｋ２本発明の第七実施形態に係る駆動手段
Ｎニップ部
Ｐ記録材
Ｔトナー像 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Scanner 3a Laser beam 4 Developing means 5 Transfer roller 6 Fixing device 7 Cleaning device 8 Paper width detection means 11 Fixing roller 111 Core metal 112 Elastic layer 113 Thin layer metal sleeve 114 Releasable layer 12 Pressure roller 121 Metal core 122 Elastic layer 123 Release layer 13 Halogen heater 14 Reflective member 15a1, 15a2 Shield member 15b1, 15b2, 15c1, 15c2 according to the first embodiment of the present invention Shield member 15d according to the second embodiment of the present invention Shielding members 15e, 15f1, 15f2 according to the third embodiment of the present invention Shielding members 15g1, 15g2, 15h according to the fourth embodiment of the present invention Shielding members 15i1, 15i2 according to the fifth embodiment of the present invention Shielding member 15j1-8 according to sixth embodiment Sixth embodiment of the present invention Shielding plate provided in shielding member according to embodiment 15k1, 15k2 Shielding member according to seventh embodiment of present invention 16a1, 15a2 Driving means 16b1, 16b2, 16c1, 16c2 according to first embodiment of the present invention Driving means 16d according to the second embodiment Driving means 16e, 16f1, 16f2 according to the third embodiment of the present invention Driving means 16g1, 16g2, 16h according to the fourth embodiment of the present invention Driving according to the fifth embodiment of the present invention Means 16i1, 16i2 Driving means according to the sixth embodiment of the present invention 16k1, 16k2 Driving means according to the seventh embodiment of the present invention N Nip portion P Recording material T Toner image

Claims

少なくとも、定着ローラと、輻射熱を発して前記定着ローラの表面を外部より加熱する熱源を具備する加熱手段において、
前記加熱手段は遮蔽部材を有し、該遮蔽部材は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に導入可能であり、該導入部における輻射熱を遮蔽することで定着ローラに対する輻射熱の照射領域を変えることが可能であることを特徴とする加熱手段。 At least in a heating means comprising a fixing roller and a heat source that emits radiant heat and heats the surface of the fixing roller from the outside,
The heating means includes a shielding member, and the shielding member can be introduced into a radiation heat radiation path from the heat source direction toward the fixing roller, and the radiation heat is irradiated to the fixing roller by shielding the radiation heat at the introduction portion. A heating means characterized in that the region can be changed.

請求項１に記載の加熱手段において、
該加熱手段は駆動手段を有し、該駆動手段は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に前記遮蔽部材を導入したり、あるいは照射経路内から除去したりすることが可能であることを特徴とする加熱手段。 The heating means according to claim 1,
The heating unit has a driving unit, and the driving unit can introduce or remove the shielding member into the irradiation path of the radiant heat from the heat source direction toward the fixing roller. Heating means characterized by being.

請求項１、２に記載の加熱手段と、紙幅検知手段と、を有する画像形成装置において、
該紙幅検知手段は定着装置に通紙される記録材の紙幅を検知し、検知された記録材の紙幅に応じて前記遮蔽部材の照射経路に対する導入量を決定することを特徴とする加熱手段。 An image forming apparatus comprising: the heating unit according to claim 1; and a paper width detection unit.
The heating means characterized in that the paper width detecting means detects the paper width of the recording material passed through the fixing device, and determines the introduction amount of the shielding member to the irradiation path in accordance with the detected paper width of the recording material.

請求項１〜３に記載の加熱手段において、
前記遮蔽部材は、定着ローラの非通紙部に向かう輻射熱の照射経路内に導入されることを特徴とする加熱手段。 The heating means according to claims 1 to 3,
The heating means, wherein the shielding member is introduced into an irradiation path of radiant heat toward the non-sheet passing portion of the fixing roller.

請求項４に記載の加熱手段において、
前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位に開口部を有し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする加熱手段。 The heating means according to claim 4,
The shielding member has an opening at a portion to be introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller, and the radiation amount of the radiant heat at the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. It is possible to change the heating means.

請求項４、５に記載の加熱手段において、
前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位は輻射熱の一部を透過し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする加熱手段。 The heating means according to claims 4 and 5,
The portion of the shielding member introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller transmits a part of the radiant heat, and radiant heat is transmitted between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. A heating means characterized in that the irradiation amount can be changed.

少なくとも、定着ローラと、輻射熱を発して前記定着ローラの表面を外部より加熱する熱源を具備する加熱手段と、を有する定着装置において、
前記加熱手段は遮蔽部材を有し、該遮蔽部材は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に導入可能であり、該導入部における輻射熱を遮蔽することで定着ローラに対する輻射熱の照射領域を変えることが可能であることを特徴とする定着装置。 In a fixing device having at least a fixing roller, and a heating unit including a heat source that emits radiant heat and heats the surface of the fixing roller from the outside.
The heating means includes a shielding member, and the shielding member can be introduced into a radiation heat radiation path from the heat source direction toward the fixing roller, and the radiation heat is irradiated to the fixing roller by shielding the radiation heat at the introduction portion. A fixing device capable of changing an area.

請求項７に記載の定着装置において、
該加熱手段は駆動手段を有し、該駆動手段は、熱源方面から定着ローラ方面に向かう輻射熱の照射経路内に前記遮蔽部材を導入したり、あるいは照射経路内から除去したりすることが可能であることを特徴とする定着装置。 The fixing device according to claim 7,
The heating unit has a driving unit, and the driving unit can introduce or remove the shielding member into the irradiation path of the radiant heat from the heat source direction toward the fixing roller. There is a fixing device.

請求項７、８に記載の定着装置と、紙幅検知手段と、を有する画像形成装置において、
該紙幅検知手段は定着装置に通紙される記録材の紙幅を検知し、検知された記録材の紙幅に応じて前記遮蔽部材の照射経路に対する導入量を決定することを特徴とする定着装置。 An image forming apparatus comprising: the fixing device according to claim 7; and a paper width detecting unit.
The paper width detecting means detects the paper width of the recording material passed through the fixing device, and determines the introduction amount of the shielding member to the irradiation path in accordance with the detected paper width of the recording material.

請求項７〜９に記載の定着装置において、
前記遮蔽部材は、定着ローラの非通紙部に向かう輻射熱の照射経路内に導入されることを特徴とする定着装置。 The fixing device according to claim 7, wherein:
The fixing device, wherein the shielding member is introduced into an irradiation path of radiant heat toward a non-sheet passing portion of the fixing roller.

請求項１０に記載の定着装置において、
前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位に開口部を有し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする定着装置。 The fixing device according to claim 10.
The shielding member has an opening at a portion introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller, and the amount of radiant heat irradiated between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. It is possible to change the fixing device.

請求項１０、１１に記載の定着装置において、
前記遮蔽部材における定着ローラの非通紙部に向かう輻射熱の照射経路内に導入される部位は輻射熱の一部を透過し、定着ローラの長手方向における通紙部と非通紙部とで輻射熱の照射量を変えることが可能であることを特徴とする定着装置。 The fixing device according to claim 10 or 11,
The portion of the shielding member introduced into the irradiation path of the radiant heat toward the non-sheet passing portion of the fixing roller transmits a part of the radiant heat, and radiant heat is transmitted between the sheet passing portion and the non-sheet passing portion in the longitudinal direction of the fixing roller. A fixing device capable of changing an irradiation amount.

記録材に未定着のトナー像を形成する画像形成手段を有する画像形成装置において、
請求項１〜１２に記載の加熱手段または定着装置を有することを特徴とする画像形成装置。 In an image forming apparatus having image forming means for forming an unfixed toner image on a recording material,
An image forming apparatus comprising the heating unit or the fixing device according to claim 1.