JP2006091448A - Thermal fixing apparatus and image forming apparatus - Google Patents

Thermal fixing apparatus and image forming apparatus Download PDF

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JP2006091448A
JP2006091448A JP2004277204A JP2004277204A JP2006091448A JP 2006091448 A JP2006091448 A JP 2006091448A JP 2004277204 A JP2004277204 A JP 2004277204A JP 2004277204 A JP2004277204 A JP 2004277204A JP 2006091448 A JP2006091448 A JP 2006091448A
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recording material
entrance guide
contact portion
fixing
fixing entrance
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Takahiro Uchiyama
高広 内山
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Canon Inc
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Canon Inc
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Abstract

<P>PROBLEM TO BE SOLVED: To stably carry a recording material to a thermal fixing apparatus, then, to suppress the occurrence of wrinkles on the recording material, a defective image at automatically printing on both sides, and a defective image such as transfer blurring in a cardboard of a small passing width. <P>SOLUTION: The shape of a guiding member for guiding the recording material to the thermal fixing apparatus is formed so that the longitudinal center part may be lower than the longitudinal end part on the side close to the thermal fixing apparatus, and also, the longitudinal center part may be as high as the longitudinal end part on the side away from the thermal fixing apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は記録材上に形成された画像を記録材に定着する加熱定着装置、およびこの加熱定着装置を用いた複写機やプリンター等の画像形成装置に関するものである。   The present invention relates to a heat fixing device for fixing an image formed on a recording material to the recording material, and an image forming apparatus such as a copying machine or a printer using the heat fixing device.

従来、被加熱体である記録材上に形成された画像を定着する加熱定着装置には熱ローラー方式が一般的であった。しかしながら、大きな熱容量を要し、電源投入から画像出力までの装置の立ち上りに時間を要した。   Conventionally, a heat roller system is generally used for a heat fixing apparatus for fixing an image formed on a recording material which is a heated object. However, a large heat capacity is required, and it takes time to start up the apparatus from power-on to image output.

そこで、最近では省電力化、および電源投入から画像出力までの時間短縮を実現するために、例えば特開昭６３−３１３１８２号公報、特開平２−１５７８７８号公報に記載されているようなフィルム加熱定着方式、つまり薄膜フィルムを介して記録材を加熱する加熱体と、この記録材を前記フィルムを介して前記加熱体に加圧する加圧体とを有する加熱装置を定着装置として適用することが提案されている。   Therefore, recently, in order to realize power saving and shortening the time from power-on to image output, film heating as described in, for example, Japanese Patent Application Laid-Open Nos. 63-313182 and 2-157878 It is proposed that a fixing device, that is, a heating device having a heating body for heating a recording material through a thin film and a pressure body for pressing the recording material to the heating body through the film is applied as a fixing device. Has been.

図１３はフィルム加熱定着方式による従来の加熱装置を示す概略構成図である。   FIG. 13 is a schematic configuration diagram showing a conventional heating apparatus using a film heat fixing system.

１０１はヒーターステーであり、このフィルムステー１０１は加熱体１０３を露呈させて支持した横断面Ｕ字状のフィルム支持部材としてのフィルムガイド部材である。   Reference numeral 101 denotes a heater stay, and the film stay 101 is a film guide member as a film support member having a U-shaped cross section that supports the heating body 103 by exposing it.

１０２はフィルムステー２１に外嵌させてある横断面円形の耐熱性フィルム（以下、フィルムと略称する）である。   Reference numeral 102 denotes a heat-resistant film (hereinafter abbreviated as a film) having a circular cross section that is externally fitted to the film stay 21.

１０３は加熱体としてのヒータであり、このヒータ１０３はフィルム１０２もしくは被加熱体としての記録材Ｐの搬送方向ａに対して直角方向を長手とする細長の耐熱性・絶縁性・良熱伝導性の基板と、この基板の表面側の短手方向中央部に基板長手に沿って形成具備させた抵抗発熱体と、この抵抗発熱体を形成した加熱体表面を保護させた耐熱性オーバーコート層と、抵抗発熱体の長手両端部の給電用電極とともに、基板裏面側に具備させた加熱体温度を検知するサーミスタ等の検温素子１０５等からなる全体に低熱容量の線状加熱体を基板構成体とする。上記ヒータ１０３の基板は、例えば、アルミナや窒化アルミニウム等の厚み１mm・幅１０ｍｍのものである。また、抵抗発熱体は例えば、Ａｇ／Ｐｄ（銀パラジウム）、ＲｕＯ2、Ｔａ2Ｎ等の電気抵抗材料をスクリーン印刷等により、厚み約１０μｍ、幅１〜３ｍｍの線状もしくは細帯状に塗工して形成したものである。給電用電極は例えばＡｇ等のスクリーン印刷パターン層、オーバーコート層は例えば約１０μｍ厚の耐熱体ガラス層である。 Reference numeral 103 denotes a heater as a heating body, and the heater 103 is an elongated heat resistance, insulating property, and good thermal conductivity with the direction perpendicular to the conveyance direction a of the film 102 or the recording material P as a heated body. A resistance heating element formed along the length of the substrate at the center in the lateral direction on the surface side of the substrate, and a heat-resistant overcoat layer protecting the heating element surface on which the resistance heating element is formed, A linear heating element having a low heat capacity as a whole is composed of a power supply electrode at both longitudinal ends of the resistance heating element and a temperature detecting element 105 such as a thermistor for detecting the temperature of the heating element provided on the back side of the substrate. To do. The substrate of the heater 103 is, for example, one having a thickness of 1 mm and a width of 10 mm, such as alumina or aluminum nitride. For example, the resistance heating element is coated with an electric resistance material such as Ag / Pd (silver palladium), RuO 2 , Ta 2 N or the like by screen printing or the like in a linear or narrow strip shape having a thickness of about 10 μm and a width of 1 to 3 mm. Formed. The power supply electrode is a screen printing pattern layer such as Ag, and the overcoat layer is a heat-resistant body glass layer having a thickness of about 10 μm, for example.

上記加圧ローラ１０４とヒータ２３との間にフィルム１０２を挟んで圧接ニップ部（定着ニップ部）Ｎを形成し、且つフィルム１０２を回転駆動させるフィルム外面接触駆動手段として作用する。このフィルム駆動ローラ兼加圧ローラ１０４は芯金１０４aとシリコンゴム等よりなる弾性体層１０４ｂと最外層の離形層１０４ｃよりなり、不図示の軸受け手段・付勢手段により所定の押圧力をもってフィルム１０２を挟ませてヒーター１０３の表面に圧接させて配設してある。この加圧ローラ１０４は不図示のモータＭによる回転駆動により、この加圧ローラ１０４とフィルム１０２の外面との摩擦力で該フィルムに搬送力を付与する。   A pressure nip portion (fixing nip portion) N is formed by sandwiching the film 102 between the pressure roller 104 and the heater 23, and acts as a film outer surface contact driving means for driving the film 102 to rotate. The film driving roller / pressure roller 104 includes a cored bar 104a, an elastic body layer 104b made of silicon rubber and the like, and an outermost release layer 104c. The film driving roller / pressing roller 104 has a predetermined pressing force by a bearing means and a biasing means (not shown). 102 is placed in pressure contact with the surface of the heater 103. The pressure roller 104 is rotationally driven by a motor M (not shown) to apply a conveying force to the film by a frictional force between the pressure roller 104 and the outer surface of the film 102.

１１１は定着入り口ガイドであり、記録材を圧接ニップ部に案内するガイド部材である。   Reference numeral 111 denotes a fixing entrance guide, which is a guide member for guiding the recording material to the pressure nip portion.

上記加熱体１０３は、抵抗発熱体の長手両端部の給電用電極に対する給電により該抵抗発熱体が長手全長にわたって発熱することで昇温し、その昇温が検温素子１０５で検知される。その検温素子１０５の出力をＡ／Ｄ変換し制御装置１０８に取り込み、その情報をもとにトライアック１０９により抵抗発熱体に通電するＡＣ電源１１０のＡＣ電圧を位相、波数制御等により、加熱体通電電力を制御することで、加熱体１０３の温度制御を行う。即ち、検温素子１０５の検知温度が所定の設定温度より低いと加熱体１０３が昇温するように、また、高い場合は加熱体１０３が降温するように通電を制御することで加熱体１０３は定着時、一定の温度に調整される。而して、加熱体１０３の温度が所定に立ち上り、かつ加圧ローラ１０４の回転によるフィルム１０２の回転周速度が定常化した状態において、画像定着すべき記録材Ｐが加熱体１０３と加圧ローラ１０４とで形成される圧接ニップ部Ｎを挟持搬送されることにより、加熱体１０３の熱がフィルム１０２を介して記録材Ｐに付与され、記録材Ｐ上の未定着顕画像（トナー画像）Ｔが記録材Ｐ面に加熱定着される。そして、圧接ニップ部Ｎを通った記録材Ｐはフィルム１０２の面から分離されて搬送される。   The heating element 103 is heated when the resistance heating element generates heat over the entire length by supplying power to the power supply electrodes at both ends of the resistance heating element, and the temperature rise is detected by the temperature measuring element 105. The output of the temperature measuring element 105 is A / D converted and taken into the control device 108. Based on the information, the AC voltage of the AC power source 110 energized by the triac 109 to the resistance heating element is controlled by the phase and wave number control. The temperature of the heating body 103 is controlled by controlling the electric power. That is, the heating body 103 is fixed by controlling energization so that the heating body 103 is heated when the temperature detected by the temperature measuring element 105 is lower than a predetermined set temperature, and when it is higher, the heating body 103 is cooled. When adjusted to a certain temperature. Thus, in a state where the temperature of the heating body 103 rises to a predetermined level and the rotational peripheral speed of the film 102 is stabilized by the rotation of the pressure roller 104, the recording material P to be image-fixed becomes the heating body 103 and the pressure roller. 104, the heat of the heating body 103 is applied to the recording material P through the film 102, and an unfixed visible image (toner image) T on the recording material P is transferred. Is fixed to the surface of the recording material P by heating. The recording material P that has passed through the pressure nip N is separated from the surface of the film 102 and conveyed.

上記フィルム方式の加熱定着装置において、圧接ニップ部に記録材を案内する定着入り口ガイド１１１の形状としては、記録材搬送方向と直行する長手方向の形状は端部と中央部の高さが同じく、同一面上に形成された定着入り口ガイドが一般的に用いられている。
特開昭６３−３１３１８２号公報 特開平２−１５７８７８号公報 In the film-type heat fixing device, as the shape of the fixing entrance guide 111 for guiding the recording material to the pressure nip portion, the shape in the longitudinal direction perpendicular to the recording material conveyance direction has the same height at the end portion and the central portion. A fixing entrance guide formed on the same surface is generally used.
JP-A-63-313182 Japanese Patent Laid-Open No. 2-157878

しかしながら近年、画像形成装置や加熱定着装置の高速化が進み、それに伴い加熱定着装置の加熱体制御温度が高温になると共に、加圧体を加熱体を圧接する圧力が高圧化している。   However, in recent years, the speed of image forming apparatuses and heat-fixing apparatuses has been increased, and accordingly, the heating element control temperature of the heat-fixing apparatus has become high, and the pressure for pressing the pressure body against the heating body has increased.

そのような状況の中、記録材の搬送速度が高速化するに従い、記録材が加熱定着装置の圧接ニップに突入する際や、記録材が定着入り口ガイドへ接触する際の搬送不良や画像不良の発生頻度が高くなっている。   Under such circumstances, as the recording material conveyance speed increases, the conveyance failure or image failure occurs when the recording material enters the pressure nip of the heat fixing device or when the recording material contacts the fixing entrance guide. The frequency of occurrence is high.

しかしながら、上記の従来のフィルム加熱方式を用いた画像形成装置において圧接ニップ部に記録材を案内する定着入り口ガイドの形状としては、記録材搬送方向と直行する長手方向の形状は端部と中央部の高さが同じく、同一面上に形成された定着入り口ガイドが一般的に用いられているため、以下のような欠点があった。   However, in the image forming apparatus using the conventional film heating method, the shape of the fixing entrance guide for guiding the recording material to the pressure nip portion is the shape of the longitudinal direction perpendicular to the recording material conveyance direction is the end portion and the central portion. Since the fixing entrance guide formed on the same surface is generally used with the same height, there are the following drawbacks.

まず第1に高温高湿環境下で水分を吸収した薄い記録材を使用した場合、記録材のシワが発生してしまう場合があった。   First, when a thin recording material that has absorbed moisture in a high temperature and high humidity environment is used, wrinkles of the recording material may occur.

また、第２に記録材の両面に印字を行なう場合、１面目の画像形成時に生じるカールの影響により、２面目印字時に記録材の搬送が乱れることにより画像飛び散りが発生する場合があった。   Secondly, when printing is performed on both sides of the recording material, there is a case where image scattering occurs due to disturbance of the conveyance of the recording material at the time of printing on the second side due to the influence of curl generated when the image on the first side is formed.

また、第３に通紙幅が狭い（小サイズ）の厚紙を使用した場合に、定着入り口ガイドに接触する際の衝撃により、転写部の画像が乱れる転写ブレが発生する場合があった。   Thirdly, when thick paper having a narrow sheet passing width (small size) is used, there is a case where transfer blur occurs in which an image on the transfer portion is disturbed by an impact when contacting the fixing entrance guide.

従来の定着入り口ガイドの形状においては、高速化した画像形成装置のフィルム加熱定着装置において、上記問題を全て満足するような安定した記録材の搬送を得ることができなかった。   With the conventional fixing entrance guide shape, the film heating and fixing apparatus of the image forming apparatus, which has been increased in speed, cannot stably convey the recording material that satisfies all the above problems.

本出願にかかわる第1の発明の目的は、記録材を安定して搬送し、記録材のシワ、自動両面時の画像不良、通紙幅が狭い厚紙における転写ブレ等の画像不良が発生しない加熱定着装置を提供することである。   The object of the first invention related to the present application is to heat and fix the recording material stably so as not to cause image defects such as wrinkles of the recording material, image defects at the time of automatic double-sided printing, and transfer blur on thick paper having a narrow sheet passing width. Is to provide a device.

本出願にかかわる第２の発明の目的は、記録材を安定して搬送し、記録材のシワ、自動両面時の画像不良、通紙幅が狭い厚紙における転写ブレ等の画像不良が発生しない画像形成装置を提供することである。   The object of the second invention related to the present application is to form an image in which the recording material is conveyed stably and no image defects such as wrinkles of the recording material, image failure at the time of automatic double-sided printing, and transfer blur on a thick paper having a narrow sheet passing width occur. Is to provide a device.

本出願にかかわる第３の発明の目的は、記録材を安定して搬送し、記録材のシワ、自動両面時の画像不良、通紙幅が狭い厚紙における転写ブレ等の画像不良が発生しない最大通紙幅がA4サイズの画像形成装置を提供することである。   The object of the third invention related to the present application is to convey the recording material stably, and to prevent the occurrence of image defects such as wrinkles of the recording material, image defects at the time of automatic double-sided printing, and transfer blur on thick paper having a narrow sheet passing width. An image forming apparatus having a paper width of A4 size is provided.

本出願にかかわる第４の発明の目的は、画像形成装置の最大通紙サイズに関わらず、記録材を安定して搬送し、記録材のシワ、自動両面時の画像不良、通紙幅が狭い厚紙における転写ブレ等の画像不良が発生しない画像形成装置を提供することである。   The object of the fourth invention related to the present application is to convey the recording material stably regardless of the maximum sheet passing size of the image forming apparatus, to make the recording material wrinkled, to have an image defect at the time of automatic duplexing, and to be a thick paper having a narrow sheet passing width. It is an object of the present invention to provide an image forming apparatus that does not cause image defects such as transfer blur.

上記目的を達成するために、本出願に係わる第1の発明は、加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置において、定着入り口ガイドの記録材搬送方向と直行する長手方向の形状は、加熱体と加圧体の圧接部に近接する側においては長手方向中央部が長手方向端部よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部と長手方向端部が同じ高さの形状であることを特徴とする。   In order to achieve the above object, a first invention according to the present application includes a heating body, a pressure member that is pressed against the heating body, and a fixing inlet that is disposed to face the pressure contact portion between the heating body and the pressure body. A fixing entrance guide in a heating and fixing apparatus, which includes a guide, guides a recording material carrying an unfixed image to a press contact portion by a fixing entrance guide, and applies thermal energy of a heating body to the recording material by passing the recording material through the press contact portion. The shape in the longitudinal direction perpendicular to the recording material conveyance direction is such that the central portion in the longitudinal direction is lower than the end portion in the longitudinal direction on the side close to the press contact portion between the heating body and the pressure body, On the side opposite to the side close to the pressure contact portion of the pressure body, the central portion in the longitudinal direction and the end portion in the longitudinal direction have the same height.

本出願に係わる第２の発明は、像担持体上に形成した現像剤像を記録材上に転写する転写部と、加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する画像形成装置において、定着入り口ガイドの記録材搬送方向と直行する長手方向の形状は、加熱体と加圧体の圧接部に近接する側においては長手方向中央部が長手方向端部よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部と長手方向端部が同じ高さの形状であることを特徴とする。   According to a second aspect of the present application, there is provided a transfer unit that transfers a developer image formed on an image carrier onto a recording material, a heating body, a pressure member that is in pressure contact with the heating body, a heating body, and pressurization. A fixing entrance guide arranged opposite to the pressure contact portion of the body, and the recording material carrying the unfixed image is guided to the pressure contact portion by the fixing entrance guide and is passed through the pressure contact portion so that the recording material is heated. In an image forming apparatus having a heat fixing device that applies thermal energy and a conveyance guide that is disposed upstream of the fixing inlet guide in the recording material conveyance direction and guides the recording material to the fixing inlet guide, the recording material conveyance direction of the fixing inlet guide The shape in the longitudinal direction that is orthogonal to the pressure body is a shape in which the central portion in the longitudinal direction is lower than the end portion in the longitudinal direction on the side close to the pressure contact portion between the heating body and the pressure body, and the pressure contact portion between the heating body and the pressure body Near side and opposite side Oite is characterized in that the longitudinal center portion and the longitudinal end portion is in the form of the same height.

本出願に係わる第３の発明は、像担持体上に形成した現像剤像を記録材上に転写する転写部と、加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する記録材の最大通紙可能サイズがＡ４サイズである画像形成装置において、定着入り口ガイドは記録材搬送方向と直行する長手方向に対し長手中央領域と長手端部領域で形成され、その形状が加熱体と加圧体の圧接部に近接する側においては長手方向中央部領域が長手方向端部領域よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部領域と長手方向端部領域が同じ高さの形状であり、その定着入り口ガイド長手方向中央部領域の幅は７０ｍｍ以上であることを特徴とする。   According to a third aspect of the present application, there is provided a transfer unit that transfers a developer image formed on an image carrier onto a recording material, a heating body, a pressure member that is in pressure contact with the heating body, a heating body, and a pressure A fixing entrance guide arranged opposite to the pressure contact portion of the body, and the recording material carrying the unfixed image is guided to the pressure contact portion by the fixing entrance guide and is passed through the pressure contact portion so that the recording material is heated. The maximum sheet passing size of a recording material having a heat fixing device that applies thermal energy and a conveyance guide that is arranged upstream of the fixing entrance guide in the recording material conveyance direction and guides the recording material to the fixing entrance guide is A4 size. In the image forming apparatus, the fixing entrance guide is formed in a longitudinal central region and a longitudinal end region with respect to the longitudinal direction perpendicular to the recording material conveyance direction, and the shape thereof is close to the pressure contact portion of the heating body and the pressure body. In the longitudinal direction The part area has a lower shape than the end part in the longitudinal direction, and the center part in the longitudinal direction and the end part in the longitudinal direction have the same height on the side opposite to the side close to the press contact part of the heating body and the pressurizing body. The width of the central region of the fixing entrance guide in the longitudinal direction is 70 mm or more.

本出願に係わる第４の発明は、像担持体上に形成した現像剤像を記録材上に転写する転写部と、加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する画像形成装置において、定着入り口ガイドは記録材搬送方向と直行する長手方向に対し長手中央領域と長手端部領域で形成され、その形状が加熱体と加圧体の圧接部に近接する側においては長手方向中央部領域が長手方向端部領域よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部領域と長手方向端部領域が同じ高さの形状であり、その定着入り口ガイド長手方向中央部領域の幅は画像形成装置の最大通紙サイズ幅の３３％以上であることを特徴とする。   According to a fourth aspect of the present application, there is provided a transfer unit that transfers a developer image formed on an image carrier onto a recording material, a heating body, a pressure member that is in pressure contact with the heating body, a heating body, and a pressure A fixing entrance guide arranged opposite to the pressure contact portion of the body, and the recording material carrying the unfixed image is guided to the pressure contact portion by the fixing entrance guide and is passed through the pressure contact portion so that the recording material is heated. In an image forming apparatus having a heat fixing device that applies thermal energy and a conveyance guide that is disposed upstream of the fixing entrance guide in the recording material conveyance direction and guides the recording material to the fixing inlet guide, the fixing inlet guide is in the recording material conveyance direction. The longitudinal central region and the longitudinal end region are formed with respect to the longitudinal direction perpendicular to the longitudinal direction, and the longitudinal central portion region is more than the longitudinal end region on the side close to the press contact portion of the heating body and the pressure body. Low shape In addition, on the side opposite to the side close to the press contact portion of the heating body and the pressure body, the longitudinal center region and the longitudinal end region have the same height, and the fixing entrance guide longitudinal center region The width is 33% or more of the maximum sheet passing width of the image forming apparatus.

以上説明したように、本発明に係わる第1と第２の発明によれば、定着入り口ガイドの記録材搬送方向と直行する長手方向の形状は、加熱体と加圧体の圧接部に近接する側においては長手方向中央部が長手方向端部よりも低い形状とすることで、記録材が加熱定着装置の圧接ニップ部へ突入する際に記録材の搬送形状を凹形状とし、記録材の端部から圧接ニップ部に突入させることができる。   As described above, according to the first and second aspects of the present invention, the shape of the fixing entrance guide in the longitudinal direction perpendicular to the recording material conveyance direction is close to the pressure contact portion between the heating body and the pressure body. On the side, the central part in the longitudinal direction is lower than the end part in the longitudinal direction, so that when the recording material enters the press-contact nip part of the heat fixing device, the conveying shape of the recording material is concave, and the end of the recording material It can be made to rush into the pressure nip part from the part.

よって、記録材の端部側から徐々に端部方向に伸ばすように搬送させる事ができ、記録材の中央部に記録材が重なるような歪みを発生させないようにすることができる。   Therefore, the recording material can be transported so as to gradually extend from the end side toward the end portion, and distortion that overlaps the recording material at the central portion of the recording material can be prevented.

また、両面印字時の1面目において記録材先端にカールが発生し、記録材先端が搬送方向と直行する方向で中央が凸状態で転写部から搬送された状態においても、定着入り口ガイド形状が凹形状で構成されているために凸状態を緩和することができる。すなわち圧接部に突入した際の記録材の凸状態からの急激に反り返りを防止し、記録材上のトナー像を乱すような衝撃を緩和することができる。   In addition, curling occurs at the leading edge of the recording material on the first side during duplex printing, and the shape of the fixing entrance guide is concave even when the leading edge of the recording material is conveyed from the transfer section with the center protruding in the direction perpendicular to the conveying direction. Since it is configured in a shape, the convex state can be relaxed. That is, it is possible to prevent the recording material from abruptly warping from the convex state when entering the press contact portion, and to mitigate the impact that disturbs the toner image on the recording material.

また、幅狭（小サイズ）の厚紙を搬送した際に搬送される定着入り口ガイド長手中央部Ｃ位置における搬送ガイド接続部と搬送ガイドは同一の高さにあり段差がないため、記録材が搬送ガイドから定着入り口ガイドに搬送された際に記録材先端が急激に定着入り口ガイドに接触することなく、転写部に影響を及ぼすような衝撃を防止できる。   Further, since the conveyance guide connecting portion and the conveyance guide at the fixing entrance guide longitudinal central portion C position conveyed when conveying narrow (small size) thick paper are at the same height and there is no step, the recording material is conveyed. When the recording material is transported from the guide to the fixing entrance guide, the leading edge of the recording material does not abruptly contact the fixing entrance guide, and an impact that affects the transfer portion can be prevented.

本発明に係わる第３の発明によれば、最大通紙サイズがＡ4サイズの画像形成装置において、上記第1と第２の発明の効果を得る事ができる。   According to the third aspect of the present invention, the effects of the first and second aspects can be obtained in an image forming apparatus having a maximum sheet passing size of A4.

本発明に係わる第４の発明によれば、画像形成装置の最大通紙サイズに係わらず、上記第1と第２の発明の効果を得る事ができる。   According to the fourth aspect of the present invention, the effects of the first and second aspects can be obtained regardless of the maximum sheet passing size of the image forming apparatus.

（実施例１）
以下、本実施例の形態を添付図面に基づいて説明する。 Example 1
Hereinafter, the form of a present Example is demonstrated based on an accompanying drawing.

図２は本発明の実施例1における画像形成装置の概略構成図である。   FIG. 2 is a schematic configuration diagram of the image forming apparatus in Embodiment 1 of the present invention.

画像形成装置は、像担持体としての感光ドラム1を備え、感光ドラム1は駆動手段である本体駆動モータ１２によって矢印の方向に所定のプロセススピード（ＰＳ＝２００ｍｍ/ｓ）で回転駆動される。   The image forming apparatus includes a photosensitive drum 1 as an image bearing member, and the photosensitive drum 1 is rotationally driven in a direction of an arrow at a predetermined process speed (PS = 200 mm / s) by a main body driving motor 12 as a driving unit.

感光ドラム1の周囲には、その回転方向に沿って順に、帯電装置としての帯電ローラ２、露光装置３、現像装置４、転写装置としての転写ローラ５、クリーニング装置としてのクリーニングブレード６が配置されている。   Around the photosensitive drum 1, a charging roller 2 as a charging device, an exposure device 3, a developing device 4, a transfer roller 5 as a transfer device, and a cleaning blade 6 as a cleaning device are arranged in order along the rotation direction. ing.

また、装置本体下部には、紙等の記録材Ｐを収納した給紙カセット７が配置されており、記録材Ｐの搬送経路に沿って順に、給紙ローラ１５、搬送ローラ８、トップセンサ９、感光ドラム1と転写ローラ５、搬送ガイド１０、定着装置１１、排紙ローラ１３、排紙トレイ１４が配置されている。   In addition, a paper feed cassette 7 that stores a recording material P such as paper is disposed at the lower part of the apparatus main body. A paper feed roller 15, a transport roller 8, and a top sensor 9 are sequentially arranged along the transport path of the recording material P. A photosensitive drum 1, a transfer roller 5, a conveyance guide 10, a fixing device 11, a paper discharge roller 13, and a paper discharge tray 14 are disposed.

次に、上述した構成の画像形成装置の動作を説明する。   Next, the operation of the image forming apparatus having the above-described configuration will be described.

本体駆動モータ１２によって矢印方向に回転駆動された感光ドラム1は、帯電ローラ２によって所定の極性、所定の電位に一様に帯電される。帯電後の感光ドラム1は、その表面に対しレーザー光学系の露光装置３によって画像情報に基づいた露光Ｌがなされ、露光部分の電荷が除去されて静電潜像が形成される。静電潜像は、現像装置４によって現像される。現像装置４は、現像ローラを有し、この現像ローラに現像バイアスを印加して感光ドラム１上の静電潜像にトナーを付着させトナー像として現像（顕像化）する。   The photosensitive drum 1 rotated and driven in the direction of the arrow by the main body drive motor 12 is uniformly charged to a predetermined polarity and a predetermined potential by the charging roller 2. The surface of the charged photosensitive drum 1 is subjected to exposure L based on the image information by the exposure device 3 of the laser optical system on the surface thereof, and the charge of the exposed portion is removed to form an electrostatic latent image. The electrostatic latent image is developed by the developing device 4. The developing device 4 has a developing roller, and a developing bias is applied to the developing roller to attach toner to the electrostatic latent image on the photosensitive drum 1 and develop (develop) it as a toner image.

トナー像は、転写ローラ５によって紙等の記録材Ｐに転写される。記録材Ｐは、給紙カセット７に収納され、給紙ローラ１５によって給紙され、搬送ローラ８によって搬送され、トップセンサ９を通過し、感光ドラム１と転写ローラ５間の転写ニップ部に搬送される。このとき記録材Ｐは、トップセンサ９によって先端が検知され、感光ドラム１上のトナー像と同期がとられる。転写ローラ５には、転写バイアスが印加され、これにより、感光ドラム１上のトナー像が記録材Ｐ上の所定の位置に転写される。   The toner image is transferred to the recording material P such as paper by the transfer roller 5. The recording material P is stored in the paper feed cassette 7, fed by the paper feed roller 15, transported by the transport roller 8, passes through the top sensor 9, and is transported to the transfer nip portion between the photosensitive drum 1 and the transfer roller 5. Is done. At this time, the leading edge of the recording material P is detected by the top sensor 9 and is synchronized with the toner image on the photosensitive drum 1. A transfer bias is applied to the transfer roller 5, whereby the toner image on the photosensitive drum 1 is transferred to a predetermined position on the recording material P.

転写によって表面に未定着トナー像を担持した記録材Ｐは、搬送ガイド１０に沿って定着装置１１に搬送され、ここで未定着トナーが加熱、加圧されて記録材Ｐ上に定着される。   The recording material P carrying the unfixed toner image on the surface by transfer is transported along the transport guide 10 to the fixing device 11 where the unfixed toner is heated and pressurized to be fixed on the recording material P.

このトナー像定着後の記録材Ｐは、排紙ローラ１３によって装置本体上面の排紙トレイ１４上に排出される。   The recording material P after the toner image is fixed is discharged onto a paper discharge tray 14 on the upper surface of the apparatus main body by a paper discharge roller 13.

一方、トナー像転写後の感光ドラム１は、記録材Ｐに転写されないで表面に残ったトナーがクリーニング装置６のクリーニングブレードによって除去され、次の画像形成が行われる。   On the other hand, after the toner image is transferred, the toner remaining on the surface without being transferred to the recording material P is removed by the cleaning blade of the cleaning device 6, and the next image formation is performed.

以上の動作を繰り返すことで、次々に画像形成を行うことができる。   By repeating the above operation, image formation can be performed one after another.

図３は本発明の実施例1における定着装置１１の概略構成を示す断面図である。   FIG. 3 is a cross-sectional view illustrating a schematic configuration of the fixing device 11 according to the first exemplary embodiment of the present invention.

本実施例における加熱定着装置は、加熱体としてセラミックヒータを用いたフィルム加熱方式の加熱装置である。   The heat fixing device in this embodiment is a film heating type heating device using a ceramic heater as a heating body.

図３において、３１は加熱材支持体としての耐熱性樹脂性である横長のヒーターステーであり、下記のエンドレスフィルム３２（以下フィルム）の内面のガイド部材となる。   In FIG. 3, reference numeral 31 denotes a horizontally long heater stay that is a heat-resistant resin as a heating material support, and serves as a guide member on the inner surface of the following endless film 32 (hereinafter referred to as a film).

３２は耐熱性のエンドレスフィルムであり、加熱体であるヒータ３３を含む上記ヒーターステー３１に外嵌させてある。このフィルム３３の内周長とヒータ3を含むヒーターステー３１の外周長はフィルムの方を例えば３mm程大きくしてあり、従ってフィルム３２は、ヒータ３３を含むステー３１に対して周長が余裕をもってルーズに外嵌している。   Reference numeral 32 denotes a heat-resistant endless film which is externally fitted to the heater stay 31 including the heater 33 which is a heating body. The inner peripheral length of the film 33 and the outer peripheral length of the heater stay 31 including the heater 3 are about 3 mm larger than that of the film. Therefore, the film 32 has a sufficient peripheral length with respect to the stay 31 including the heater 33. It fits loosely.

加熱体であるヒータ３３は、アルミナ等でできた基板の略中央に沿って、例えばAg/Pd（銀パラジウム）等の電気抵抗材料（発熱体）を厚み１０μｍ、幅約１〜5mmにスクリーン印刷等により塗工し、その上に保護層としてガラスやフッ素樹脂等をコートしている。   The heater 33, which is a heating element, is screen-printed with an electric resistance material (heating element) such as Ag / Pd (silver palladium) with a thickness of 10 μm and a width of about 1 to 5 mm along substantially the center of the substrate made of alumina or the like. Etc., and coated with glass or fluororesin as a protective layer.

３４はヒータ３３との間でフィルム2を挟んで圧接ニップ部Ｎを形成し、フィルム３２を駆動する回転体としての加圧ローラであり、アルミの加圧ローラ芯金３４aとこの軸に外装したシリコーンゴムを用いた加圧ローラ弾性体部３４bとからなり、加圧ローラ芯金３４aの端部が不図示の駆動手段であるモータにより駆動されることで矢印の方向に回転駆動される。加圧ローラ３４が回転駆動されることでフィルム３２も回転駆動される。   A pressure roller 34 is a pressure roller as a rotating body that drives the film 32 by forming a pressure nip portion N by sandwiching the film 2 with the heater 33. The pressure roller core metal 34a is externally mounted on the shaft. It consists of a pressure roller elastic body portion 34b using silicone rubber, and is driven to rotate in the direction of the arrow by driving the end of the pressure roller mandrel 34a by a motor which is a driving means (not shown). When the pressure roller 34 is driven to rotate, the film 32 is also driven to rotate.

１１２は定着入り口ガイドであり、搬送ガイド１０により搬送された記録材Ｐを定着装置の圧接ニップ部Ｎに案内するガイド部材である。定着入り口ガイド１１２は、定着装置１１の記録材搬送方向の上流側の搬送ガイド１０との間に配置されている。   Reference numeral 112 denotes a fixing entrance guide, which is a guide member that guides the recording material P conveyed by the conveyance guide 10 to the press nip N of the fixing device. The fixing entrance guide 112 is disposed between the fixing guide 11 and the conveyance guide 10 on the upstream side in the recording material conveyance direction.

フィルム３２は非駆動時においてはヒータ３３と加圧ローラ３４との圧接ニップ部Ｎに挟まれている部分を除く残余の大部分は略全周長部分がテンションフリーである。   When the film 32 is not driven, the remaining part of the film 32 except for the part sandwiched between the pressure nip N between the heater 33 and the pressure roller 34 is substantially tension free.

加圧ローラ３４が回転駆動されると圧接ニップ部Ｎにおいてフィルム３２に加圧ローラ３４の回転周速と略同速度をもってフィルム裏面がヒータ３３の面を摺動しつつ矢印方向に回転駆動される。   When the pressure roller 34 is driven to rotate, the film 32 is driven to rotate in the direction of the arrow at the pressure nip N while the film back surface slides on the surface of the heater 33 at substantially the same rotational speed as the pressure roller 34. .

フィルム駆動とヒータ３３の発熱体への通電を行わせた状態において、未定着画像を担持した記録材が圧接ニップ部Ｎのフィルム３２と加圧ロー３４との間に像担持体面上向きで導入されると、記録材はフィルム３２と一緒に定着ニップ部Ｎを通過していき、定着ニップ部Ｎにおいてフィルム裏面に接しているヒータ３３の熱エネルギーがフィルム2を介して記録材に付与されてトナー像Ｔの熱定着がなされ、加熱定着装置外へ排出する。   In a state where the film drive and the heater 33 are energized, the recording material carrying the unfixed image is introduced between the film 32 and the pressure row 34 in the press nip N so as to face the image carrier surface upward. Then, the recording material passes through the fixing nip portion N together with the film 32, and the heat energy of the heater 33 in contact with the back surface of the film in the fixing nip portion N is applied to the recording material through the film 2 and the toner. The image T is heat-fixed and discharged out of the heat-fixing device.

次に本実施例1の特徴である定着入り口ガイドの構成を説明する。   Next, the structure of the fixing entrance guide, which is a feature of the first embodiment, will be described.

図１は本実施例１における定着入り口ガイド１１２の斜視図、図４は定着入り口ガイドの長手方向中央部と長手方向端部の位置関係を表わす概略断面図である。   FIG. 1 is a perspective view of a fixing entrance guide 112 according to the first exemplary embodiment, and FIG. 4 is a schematic cross-sectional view showing a positional relationship between a longitudinal center portion and a longitudinal end portion of the fixing entrance guide.

図1において図中の上側は定着装置１１側の面であり定着装置側Ａ面であり、図中の下側は転写側の面を転写側Ｂ面である。図３が示すように定着入り口ガイドの転写側Ｂ面は搬送ガイド１０と近接設置されている。   In FIG. 1, the upper side in the figure is the surface on the fixing device 11 side and is the fixing device side A surface, and the lower side in the drawing is the transfer side surface is the transfer side B surface. As shown in FIG. 3, the transfer side B surface of the fixing entrance guide is installed close to the conveyance guide 10.

上記構成により、記録材Ｐは転写部から搬送ガイド１０を経由し、定着入り口ガイド１１２のＢ面側からＡ面側に搬送され、定着装置１１の定着ニップ部Ｎに案内搬送される。   With the above configuration, the recording material P is transported from the transfer portion via the transport guide 10 to the A surface side from the B surface side of the fixing entrance guide 112 and is guided and transported to the fixing nip portion N of the fixing device 11.

定着入り口ガイド１１２の形状について更に詳しく説明する。本実施例の画像形成装置の最大通紙幅はＬＴＲサイズ（幅２１６ｍｍ）であり、定着入り口ガイド１１２の記録材搬送方向と直行する長手方向の幅は２３０ｍｍである。記録材は定着入り口ガイド１１２の長手中央位置が記録材の中央位置と一致するように中央基準で搬送される。   The shape of the fixing entrance guide 112 will be described in more detail. The maximum sheet passing width of the image forming apparatus of this embodiment is LTR size (width 216 mm), and the width in the longitudinal direction perpendicular to the recording material conveyance direction of the fixing entrance guide 112 is 230 mm. The recording material is conveyed on the basis of the center so that the longitudinal center position of the fixing entrance guide 112 coincides with the center position of the recording material.

図1に示すように定着入り口ガイドは長手方向中央部における幅１２６ｍｍの中央領域Ｃと長手方向両端部における幅５２ｍｍの端部領域Ｄとで形状が異なっている。   As shown in FIG. 1, the shape of the fixing entrance guide is different between a central region C having a width of 126 mm at the central portion in the longitudinal direction and an end region D having a width of 52 mm at both ends in the longitudinal direction.

図４は定着入り口ガイド１１２を画像形成装置の横方向から見た断面図であり、図中の左側は長手方向端部領域Ｄの形状、中央は長手方向中央領域Ｃの形状、右側が搬送ガイド１０を示し、それぞれの高さ方向を比較した図である。定着入り口ガイドの転写側Ｂ面の高さは端部領域Ｄと中央領域Ｃは同じであり、搬送ガイド１０と同じ高さになっている。定着入り口ガイドの定着装置側Ａ面の高さは端部領域Ｄに比べ中央領域Ｃは1ｍｍ低く定着ニップ部から離れたい形状をしている。   4 is a cross-sectional view of the fixing entrance guide 112 as viewed from the lateral direction of the image forming apparatus. In the drawing, the left side is the shape of the longitudinal end region D, the center is the shape of the longitudinal center region C, and the right side is the conveyance guide. FIG. 10 is a diagram comparing the height directions. The height of the transfer entrance B surface of the fixing entrance guide is the same in the end region D and the central region C and is the same as that of the conveyance guide 10. The height of the fixing device side A surface of the fixing entrance guide is lower than the end region D by 1 mm in the central region C, and is shaped to be separated from the fixing nip portion.

次に比較例としての定着入り口ガイドの形状を図５から図８に示し、形状を説明する。   Next, the shape of a fixing entrance guide as a comparative example is shown in FIGS.

図５、図６は比較例１としての従来の画像形成装置において用いられている定着入り口ガイド１１３の形状であり、図５は斜視図、図６は定着入り口ガイドの長手方向中央部と長手方向端部の位置関係を表わす概略断面図である。   5 and 6 show the shape of the fixing entrance guide 113 used in the conventional image forming apparatus as Comparative Example 1, FIG. 5 is a perspective view, and FIG. 6 shows the longitudinal center and longitudinal direction of the fixing entrance guide. It is a schematic sectional drawing showing the positional relationship of an edge part.

図５に示すように定着入り口ガイド１１３は長手方向全域に渡って同一の平面で形成されている。   As shown in FIG. 5, the fixing entrance guide 113 is formed in the same plane over the entire longitudinal direction.

図６の左側は長手方向端部領域Ｄの形状、右側は長手方向中央領域Ｃの形状である。転写側Ｂ面、及び定着側Ａ面の高さは長手方向の全領域で同じである。   The left side of FIG. 6 is the shape of the end region D in the longitudinal direction, and the right side is the shape of the central region C in the longitudinal direction. The heights of the transfer side B surface and the fixing side A surface are the same in all regions in the longitudinal direction.

図７、図８は比較例２としての定着入り口ガイド１１４の形状であり、図５は斜視図、図６は定着入り口ガイドの長手方向中央部と長手方向端部の位置関係を表わす概略断面図である。   7 and 8 show the shape of the fixing entrance guide 114 as Comparative Example 2, FIG. 5 is a perspective view, and FIG. 6 is a schematic sectional view showing the positional relationship between the longitudinal center and the longitudinal end of the fixing entrance guide. It is.

定着入り口ガイドは長手方向中央部における幅１２６ｍｍの中央領域Ｃと長手方向両端部における幅５２ｍｍの端部領域Ｄとで形状が異なり、中央領域Ｃの高さが端部領域Ｄに比べ全体的に１ｍｍ低い形状をしている。   The fixing entrance guide has a different shape in the central region C having a width of 126 mm in the central portion in the longitudinal direction and the end region D having a width of 52 mm in both ends in the longitudinal direction, and the height of the central region C is generally larger than that in the end region D. The shape is 1 mm lower.

図８は定着入り口ガイド１１４を画像形成装置の横方向から見た断面図であり、図中の左側は長手方向端部領域Ｄの形状、中央は長手方向中央領域Ｃの形状、右側が搬送ガイド１０を示し、それぞれの高さ方向を比較した図である。   FIG. 8 is a cross-sectional view of the fixing entrance guide 114 as viewed from the lateral direction of the image forming apparatus. In the drawing, the left side is the shape of the longitudinal end region D, the center is the shape of the longitudinal center region C, and the right side is the conveyance guide. FIG. 10 is a diagram comparing the height directions.

定着入り口ガイド１１４における転写側Ｂ面側の中央領域Ｃの高さは、端部領域Ｄと搬送ガイドに比べ1ｍｍ低い形状をしている。また、定着装置側Ａ面の高さは端部領域Ｄに比べ中央領域Ｃは1ｍｍ低く定着ニップ部から離れたい形状をしている。   The height of the central region C on the transfer side B surface side of the fixing entrance guide 114 is 1 mm lower than the end region D and the conveyance guide. Also, the height of the fixing device side A surface is 1 mm lower than the end region D in the central region C, and the shape is desired to be separated from the fixing nip.

本実施例の定着入り口ガイド１１２と比較例の定着入り口ガイド１１３と定着入り口ガイド１１４を用いて、記録材のシワと両面印字時の飛び散りと幅狭紙（小サイズ）厚紙の転写ブレの比較を行なった。実験条件を以下に示す。   Using the fixing entrance guide 112 of this embodiment, the fixing entrance guide 113 of the comparative example, and the fixing entrance guide 114, the wrinkles of the recording material, the scattering during double-sided printing, and the transfer blur of narrow paper (small size) thick paper are compared. I did it. Experimental conditions are shown below.

記録材シワの評価としては、高温高湿環境Ｈ/Ｈ（３２.５℃／８５％）において放置した記録材（６０ｇ/ｍ2紙、ＬＴＲサイズ）を１０００枚通紙し、記録材に発するシワの発生枚数と発生率を比較した。両面印字時の画像飛び散りとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）に放置した記録材（７５ｇ/ｍ2紙、ＬＴＲサイズ）にハーフトーン（２ドット３スペース横線）を両面印字し、ハーフトーン画像上のトナーの飛び散りを比較した。 As an evaluation of recording material wrinkles, 1000 sheets of recording material (60 g / m 2 paper, LTR size) left in a high-temperature and high-humidity environment H / H (32.5 ° C./85%) was passed and emitted to the recording material. The number of wrinkles and the rate of wrinkles were compared. Image scattering during double-sided printing is half-tone (2-dot, 3-space horizontal) printing on a recording material (75 g / m 2 paper, LTR size) left in a low-temperature, low-humidity environment L / L (15 ° C / 10%). Then, the scattering of toner on the halftone image was compared.

幅狭紙（小サイズ）厚紙の転写ブレとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）で記録材（１２８ｇ/ｍ2紙、３インチ幅×５インチ長さサイズ）にハーフトーン（２ドット３スペース横線）を印字し、ハーフトーン画像上の転写ブレを比較した。 As for the transfer blur of narrow paper (small size) and thick paper, the recording material (128 g / m 2 paper, 3 inch width x 5 inch length size) is halftone in a low temperature and low humidity environment L / L (15 ° C / 10%). (2-dot 3-space horizontal line) was printed, and the transfer blur on the halftone image was compared.

比較結果を以下の表1に示す。   The comparison results are shown in Table 1 below.

Figure 2006091448
以上のように、記録材シワに関しては、比較例1としての定着入り口ガイド１１３では１.２％の記録材でシワが発生した。それに対して、本実施例の定着入り口ガイド１１２では記録材のシワは発生しなかった。
Figure 2006091448
 As described above, with respect to the recording material wrinkles, wrinkles were generated with 1.2% of the recording material in the fixing entrance guide 113 as Comparative Example 1. In contrast, the fixing entrance guide 112 of this embodiment did not cause wrinkles of the recording material.

また、両面２面目の飛び散りに関しては、比較例1としての定着入り口ガイド１１３では２４％の記録材でハーフトーン画像の飛び散りが発生した。それに対して、本実施例の定着入り口ガイド１１２ではハーフトーン画像の飛び散りは発生しなかった。   Further, regarding the scattering on the second surface of both surfaces, the halftone image was scattered with 24% recording material in the fixing entrance guide 113 as Comparative Example 1. On the other hand, in the fixing entrance guide 112 of this embodiment, the halftone image was not scattered.

また、小サイズ紙厚紙の転写ブレに関しては、比較例２としての定着入り口ガイド１１４ではハーフトーン画像で転写ブレが発生した。それに対して、本実施例の定着入り口ガイド１１２では転写ブレの発生はなかった。   Further, regarding the transfer blur of the small-size cardboard, transfer blur occurred in the halftone image in the fixing entrance guide 114 as Comparative Example 2. On the other hand, no transfer blur occurred in the fixing entrance guide 112 of this embodiment.

以上のように本実施例における定着入り口ガイド１１２の構成により、記録材のシワ、両面２面目の飛び散り、小サイズ厚紙の転写ブレの発生を防止することができる。
（実施例２） As described above, with the configuration of the fixing entrance guide 112 in this embodiment, it is possible to prevent the recording material from wrinkling, the scattering of the second surface on both sides, and the occurrence of transfer blur on small-size thick paper.
(Example 2)

次に、本発明の第２の実施形態について図９と図１０を用いて説明する。なお、第1の実施形態との共通個所には同一符号を付して説明を省略する。   Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to a common part with 1st Embodiment, and description is abbreviate | omitted.

図９は本実施例２における定着入り口ガイド１１２の斜視図、図１０は定着入り口ガイドの長手方向中央部と長手方向端部の位置関係を表わす概略断面図である。   FIG. 9 is a perspective view of the fixing entrance guide 112 according to the second embodiment, and FIG. 10 is a schematic cross-sectional view showing the positional relationship between the longitudinal center and the longitudinal end of the fixing entrance guide.

図９において図中の上側は定着装置１１側の面であり定着装置側Ａ面であり、図中の下側は転写側の面を転写側Ｂ面である。図３が示すように定着入り口ガイドの転写側Ｂ面は搬送ガイド１０と近接設置されている。   In FIG. 9, the upper side in the figure is the surface on the fixing device 11 side and is the fixing device side A surface, and the lower side in the drawing is the transfer side surface is the transfer side B surface. As shown in FIG. 3, the transfer side B surface of the fixing entrance guide is installed close to the conveyance guide 10.

上記構成により、記録材Ｐは転写部から搬送ガイド１０を経由し、定着入り口ガイド１１５のＢ面側からＡ面側に搬送され、定着装置１１の定着ニップ部Ｎに案内搬送される。   With the above configuration, the recording material P is transported from the transfer portion via the transport guide 10 to the A surface side from the B surface side of the fixing entrance guide 115 and is guided and transported to the fixing nip portion N of the fixing device 11.

定着入り口ガイド１１５の形状について更に詳しく説明する。本実施例の画像形成装置の最大通紙幅はＬＴＲサイズ（幅２１６ｍｍ）であり、定着入り口ガイド１１５の記録材搬送方向と直行する長手方向の幅は２３０ｍｍである。記録材は定着入り口ガイド１１５の長手中央位置が記録材の中央位置と一致するように中央基準で搬送される。   The shape of the fixing entrance guide 115 will be described in more detail. The maximum sheet passing width of the image forming apparatus of this embodiment is LTR size (width 216 mm), and the width in the longitudinal direction perpendicular to the recording material conveyance direction of the fixing entrance guide 115 is 230 mm. The recording material is conveyed on the basis of the center so that the longitudinal center position of the fixing entrance guide 115 coincides with the center position of the recording material.

図９に示すように定着入り口ガイドは長手方向中央部における幅７０ｍｍの中央領域Ｃと長手方向両端部における幅８０ｍｍの端部領域Ｄとで形状が異なっている。   As shown in FIG. 9, the shape of the fixing entrance guide is different between a central region C having a width of 70 mm at the central portion in the longitudinal direction and an end region D having a width of 80 mm at both longitudinal ends.

図１０は定着入り口ガイド１１５を画像形成装置の横方向から見た断面図であり、図中の左側は長手方向端部領域Ｄの形状、中央は長手方向中央領域Ｃの形状、右側が搬送ガイド１０を示し、それぞれの高さ方向を比較した図である。定着入り口ガイドの転写側Ｂ面の高さは端部領域Ｄと中央領域Ｃは同じであり、搬送ガイド１０と同じ高さになっている。定着入り口ガイドの定着装置側Ａ面の高さは端部領域Ｄに比べ中央領域Ｃは1ｍｍ低く定着ニップ部から離れたい形状をしている。   FIG. 10 is a cross-sectional view of the fixing entrance guide 115 as viewed from the lateral direction of the image forming apparatus. In the drawing, the left side is the shape of the longitudinal end region D, the center is the shape of the longitudinal central region C, and the right side is the conveyance guide. FIG. 10 is a diagram comparing the height directions. The height of the transfer entrance B surface of the fixing entrance guide is the same in the end region D and the central region C and is the same as that of the conveyance guide 10. The height of the fixing device side A surface of the fixing entrance guide is lower than the end region D by 1 mm in the central region C, and is shaped to be separated from the fixing nip portion.

以上に説明した本実施例２の定着入り口ガイド１１５を含め、定着入り口ガイド長手方向の中央領域Ｃの幅と、長手方向の端部領域Ｄの幅を変えて、記録材のシワと両面印字時の飛び散りと幅狭紙（小サイズ）厚紙の転写ブレの比較を行なった。実験条件を以下に示す。   The width of the central region C in the longitudinal direction of the fixing entrance guide and the width of the end region D in the longitudinal direction, including the fixing entrance guide 115 of the second embodiment described above, are changed, and the recording material is wrinkled and double-sided printed. Was compared with the transfer blur of narrow paper (small size) thick paper. Experimental conditions are shown below.

記録材シワの評価としては、高温高湿環境Ｈ/Ｈ（３２.５℃／８５％）において放置した記録材（６０ｇ/ｍ2紙、ＬＴＲサイズ）を１０００枚通紙し、記録材に発するシワの発生枚数と発生率を比較した。両面印字時の画像飛び散りとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）に放置した記録材（７５ｇ/ｍ2紙、ＬＴＲサイズ）にハーフトーン（２ドット３スペース横線）を両面印字し、ハーフトーン画像上のトナーの飛び散りを比較した。 As an evaluation of recording material wrinkles, 1000 sheets of recording material (60 g / m 2 paper, LTR size) left in a high-temperature and high-humidity environment H / H (32.5 ° C./85%) was passed and emitted to the recording material. The number of wrinkles and the rate of wrinkles were compared. Image scattering during double-sided printing is half-tone (2-dot, 3-space horizontal) printing on a recording material (75 g / m 2 paper, LTR size) left in a low-temperature, low-humidity environment L / L (15 ° C / 10%). Then, the scattering of toner on the halftone image was compared.

幅狭紙（小サイズ）厚紙の転写ブレとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）で記録材（１２８ｇ/ｍ2紙、３インチ幅×５インチ長さサイズ）にハーフトーン（２ドット３スペース横線）を印字し、ハーフトーン画像上の転写ブレを比較した。 As for the transfer blur of narrow paper (small size) and thick paper, the recording material (128 g / m 2 paper, 3 inch width x 5 inch length size) is halftone in a low temperature and low humidity environment L / L (15 ° C / 10%). (2-dot 3-space horizontal line) was printed, and the transfer blur on the halftone image was compared.

比較結果を以下の表２に示す。   The comparison results are shown in Table 2 below.

Figure 2006091448
以上のように、記録材シワに関しては、中央領域Ｃの幅が５０ｍｍと６０ｍｍの定着入り口ガイドにおいては記録材でシワが発生した。それに対して、本実施例の定着入り口ガイド１０４である中央領域Ｃの幅が７０ｍｍと８０ｍｍでは記録材のシワは発生しなかった。
Figure 2006091448
 As described above, with respect to the recording material wrinkles, wrinkles were generated in the recording material in the fixing entrance guide having the width of the central region C of 50 mm and 60 mm. On the other hand, when the width of the central region C which is the fixing entrance guide 104 of this embodiment is 70 mm and 80 mm, no wrinkles of the recording material occurred.

以上のように中央領域Ｃの幅が７０ｍｍ以上で記録材のシワの発生を防止する事ができる。   As described above, the wrinkles of the recording material can be prevented when the width of the central region C is 70 mm or more.

また、両面２面目の飛び散りに関しては、中央領域Ｃの幅が５０ｍｍと６０ｍｍの定着入り口ガイドにおいては飛び散りが発生した。それに対して、本実施例の定着入り口ガイド１０４である中央領域Ｃの幅が７０ｍｍと８０ｍｍでは飛び散りは発生しなかった。   As for the scattering on the second surface of both surfaces, the scattering occurred in the fixing entrance guide with the central region C having a width of 50 mm and 60 mm. In contrast, no scattering occurred when the width of the central region C, which is the fixing entrance guide 104 of this embodiment, was 70 mm and 80 mm.

以上のように中央領域Ｃの幅が７０ｍｍ以上で記録材の飛び散りを防止する事ができる。   As described above, it is possible to prevent the recording material from being scattered when the width of the central region C is 70 mm or more.

また、小サイズ紙厚紙の転写ブレに関しては、全ての定着入り口ガイドで転写ブレの発生はなかった。以上のように本実施例における定着入り口ガイド１１５の構成を含め中央領域Ｃの幅が７０ｍｍ以上で構成により、記録材のシワ、両面２面目の飛び散り、小サイズ厚紙の転写ブレの発生を防止することができる。
（実施例３） Further, regarding the transfer blur of the small size cardboard, no transfer blur occurred in all the fixing entrance guides. As described above, the width of the central area C including the configuration of the fixing entrance guide 115 in this embodiment is 70 mm or more, thereby preventing the wrinkles of the recording material, the scattering of the second surface of both sides, and the occurrence of transfer blur of small size thick paper. be able to.
(Example 3)

次に、本発明の第２の実施形態について図１１と１２を用いて説明する。なお、第1の実施形態との共通個所には同一符号を付して説明を省略する。   Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to a common part with 1st Embodiment, and description is abbreviate | omitted.

図１１は本実施例３における定着入り口ガイド１１６の斜視図、図１１は定着入り口ガイドの長手方向中央部と長手方向端部の位置関係を表わす概略断面図である。   FIG. 11 is a perspective view of the fixing entrance guide 116 according to the third embodiment, and FIG. 11 is a schematic cross-sectional view showing the positional relationship between the longitudinal center and the longitudinal end of the fixing entrance guide.

図１１において図中の上側は定着装置１１側の面であり定着装置側Ａ面であり、図中の下側は転写側の面を転写側Ｂ面である。図３が示すように定着入り口ガイドの転写側Ｂ面は搬送ガイド１０と近接設置されている。   In FIG. 11, the upper side in FIG. 11 is the surface on the fixing device 11 side and is the fixing device side A surface, and the lower side in the drawing is the transfer side surface is the transfer side B surface. As shown in FIG. 3, the transfer side B surface of the fixing entrance guide is installed close to the conveyance guide 10.

上記構成により、記録材Ｐは転写部から搬送ガイド１０を経由し、定着入り口ガイド１１６のＢ面側からＡ面側に搬送され、定着装置１１の定着ニップ部Ｎに案内搬送される。   With the above configuration, the recording material P is transported from the transfer portion via the transport guide 10 to the A surface side from the B surface side of the fixing entrance guide 116 and is guided and transported to the fixing nip portion N of the fixing device 11.

定着入り口ガイド１１６の形状について更に詳しく説明する。本実施例の画像形成装置の最大通紙幅はＡ３サイズ（幅２９７ｍｍ）であり、定着入り口ガイド１１６の記録材搬送方向と直行する長手方向の幅は３１０ｍｍである。記録材は定着入り口ガイド１１６の長手中央位置が記録材の中央位置と一致するように中央基準で搬送される。   The shape of the fixing entrance guide 116 will be described in more detail. The maximum sheet passing width of the image forming apparatus of this embodiment is A3 size (width 297 mm), and the width of the fixing entrance guide 116 in the longitudinal direction perpendicular to the recording material conveyance direction is 310 mm. The recording material is conveyed on the basis of the center so that the longitudinal center position of the fixing entrance guide 116 coincides with the center position of the recording material.

図１１に示すように定着入り口ガイドは長手方向中央部における幅９５ｍｍの中央領域Ｃと長手方向両端部における幅１０７.５ｍｍの端部領域Ｄとで形状が異なっている。   As shown in FIG. 11, the shape of the fixing entrance guide is different between a central region C having a width of 95 mm in the central portion in the longitudinal direction and an end region D having a width of 107.5 mm at both ends in the longitudinal direction.

図１２は定着入り口ガイド１１６を画像形成装置の横方向から見た断面図であり、図中の左側は長手方向端部領域Ｄの形状、中央は長手方向中央領域Ｃの形状、右側が搬送ガイド１０を示し、それぞれの高さ方向を比較した図である。定着入り口ガイドの転写側Ｂ面の高さは端部領域Ｄと中央領域Ｃは同じであり、搬送ガイド１０と同じ高さになっている。定着入り口ガイドの定着装置側Ａ面の高さは端部領域Ｄに比べ中央領域Ｃは1ｍｍ低く定着ニップ部から離れたい形状をしている。   12 is a cross-sectional view of the fixing entrance guide 116 as viewed from the lateral direction of the image forming apparatus. In the drawing, the left side is the shape of the longitudinal end region D, the center is the shape of the longitudinal center region C, and the right side is the conveyance guide. FIG. 10 is a diagram comparing the height directions. The height of the transfer entrance B surface of the fixing entrance guide is the same in the end region D and the central region C and is the same as that of the conveyance guide 10. The height of the fixing device side A surface of the fixing entrance guide is lower than the end region D by 1 mm in the central region C, and is shaped to be separated from the fixing nip portion.

以上に説明した本実施例２の定着入り口ガイド１１６を含め、定着入り口ガイド長手方向の中央領域Ｃの幅と、長手方向の端部領域Ｄの幅を変えて、記録材のシワと両面印字時の飛び散りと幅狭紙（小サイズ）厚紙の転写ブレの比較を行なった。実験条件を以下に示す。   Including the fixing entrance guide 116 of the second embodiment described above, the width of the central region C in the longitudinal direction of the fixing entrance guide and the width of the end region D in the longitudinal direction are changed, and the recording material is wrinkled and double-sided printing is performed. Was compared with the transfer blur of narrow paper (small size) thick paper. Experimental conditions are shown below.

記録材シワの評価としては、高温高湿環境Ｈ/Ｈ（３２.５℃／８５％）において放置した記録材（６０ｇ/ｍ2紙、Ａ3サイズ）を１０００枚通紙し、記録材に発するシワの発生枚数と発生率を比較した。両面印字時の画像飛び散りとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）に放置した記録材（７５ｇ/ｍ2紙、ＬＤＲサイズ）にハーフトーン（２ドット３スペース横線）を両面印字し、ハーフトーン画像上のトナーの飛び散りを比較した。 As an evaluation of recording material wrinkles, 1000 sheets of recording material (60 g / m 2 paper, A3 size) left in a high-temperature and high-humidity environment H / H (32.5 ° C./85%) was passed and emitted to the recording material. The number of wrinkles and the rate of wrinkles were compared. Image scattering during double-sided printing is half-tone (2-dot, 3-space horizontal) printing on a recording material (75 g / m 2 paper, LDR size) left in a low-temperature, low-humidity environment L / L (15 ° C / 10%). Then, the scattering of toner on the halftone image was compared.

幅狭紙（小サイズ）厚紙の転写ブレとしては、低温低湿環境Ｌ/Ｌ（１５℃／１０％）で記録材（１２８ｇ/ｍ2紙、３インチ幅×５インチ長さサイズ）にハーフトーン（２ドット３スペース横線）を印字し、ハーフトーン画像上の転写ブレを比較した。 As for the transfer blur of narrow paper (small size) and thick paper, the recording material (128 g / m 2 paper, 3 inch width x 5 inch length size) is halftone in a low temperature and low humidity environment L / L (15 ° C / 10%). (2-dot 3-space horizontal line) was printed, and the transfer blur on the halftone image was compared.

比較結果を以下の表３に示す。   The comparison results are shown in Table 3 below.

Figure 2006091448
以上のように、記録材シワに関しては、中央領域Ｃの幅が７５ｍｍと８５ｍｍの定着入り口ガイドにおいては記録材でシワが発生した。それに対して、本実施例の定着入り口ガイド１１６である中央領域Ｃの幅が９５ｍｍと１０５ｍｍでは記録材のシワは発生しなかった。
Figure 2006091448
 As described above, with respect to the recording material wrinkles, wrinkles were generated in the recording material in the fixing entrance guide having the width of the central region C of 75 mm and 85 mm. On the other hand, when the width of the central area C which is the fixing entrance guide 116 of this embodiment is 95 mm and 105 mm, no wrinkles of the recording material occurred.

以上のように中央領域Ｃの幅が９５ｍｍ以上で記録材のシワの発生を防止する事ができる。   As described above, the wrinkles of the recording material can be prevented when the width of the central region C is 95 mm or more.

また、両面２面目の飛び散りに関しては、中央領域Ｃの幅が７５ｍｍと８５ｍｍの定着入り口ガイドにおいては飛び散りが発生した。それに対して、本実施例の定着入り口ガイド１１６である中央領域Ｃの幅が９５ｍｍと１０５ｍｍでは飛び散りは発生しなかった。   As for the scattering on the second surface of both surfaces, the scattering occurred in the fixing entrance guide with the central region C having a width of 75 mm and 85 mm. On the other hand, no scattering occurred when the width of the central region C, which is the fixing entrance guide 116 of this embodiment, was 95 mm and 105 mm.

以上のように中央領域Ｃの幅が９５ｍｍ以上で記録材の飛び散りを防止する事ができる。   As described above, when the width of the central region C is 95 mm or more, scattering of the recording material can be prevented.

また、小サイズ紙厚紙の転写ブレに関しては、全ての定着入り口ガイドで転写ブレの発生はなかった。以上のように本実施例における定着入り口ガイド１１５の構成を含め中央領域Ｃの幅が９５ｍｍ以上で構成により、記録材のシワ、両面２面目の飛び散り、小サイズ厚紙の転写ブレの発生を防止することができる。   Further, regarding the transfer blur of the small size cardboard, no transfer blur occurred in all the fixing entrance guides. As described above, the width of the central region C including the configuration of the fixing entrance guide 115 in this embodiment is 95 mm or more, thereby preventing the wrinkles of the recording material, the scattering of the second surface of both sides, and the occurrence of transfer blur of small size thick paper. be able to.

本実施例においては、最大通紙幅２９７ｍｍに対し中央領域Ｃの幅が９５ｍｍ以上で良好な記録材の搬送を行なうことができ、その中央領域Ｃの幅は最大通紙幅に対する中央領域の幅は３１.９９％以上である。   In this embodiment, it is possible to carry a good recording material when the width of the central area C is 95 mm or more with respect to the maximum paper passing width of 297 mm, and the width of the central area C is 31 with respect to the maximum paper passing width. It is more than .99%.

また、実施例２においては、最大通紙幅２１６ｍｍに対し中央領域Ｃの幅が７０ｍｍ以上で良好な記録材の搬送を行うことができ、その中央領域Ｃの幅は最大通紙幅に対する中央領域の幅は３２.４１％以上である。   In the second embodiment, the central area C is 70 mm or more in width with respect to the maximum sheet passing width of 216 mm, and a good recording material can be conveyed. The width of the center area C is the width of the center area with respect to the maximum sheet passing width. Is 32.41% or more.

以上の結果より、他の最大通紙幅を有する画像形成装置においても、最大通紙幅に対し中央領域Ｃの幅が３３％以上で低い定着入り口ガイドの構成において、記録材のシワ、両面２面目の飛び散り、小サイズ厚紙の転写ブレの発生を防止し、同様の効果を得ることができる。   From the above results, even in the image forming apparatus having other maximum sheet passing widths, the wrinkles of the recording material and the second surface on both sides of the fixing sheet are formed in the structure of the fixing entrance guide with the width of the central area C being 33% or more with respect to the maximum sheet passing width. The same effect can be obtained by preventing the occurrence of scattering and transfer blurring of small-size thick paper.

本発明の実施例1に係る定着入り口ガイドの概略構成を示す斜視図1 is a perspective view showing a schematic configuration of a fixing entrance guide according to Embodiment 1 of the present invention. FIG. 本発明に係る画像形成装置の概略構成を示す断面図。1 is a cross-sectional view showing a schematic configuration of an image forming apparatus according to the present invention. 本発明に係る加熱定着装置の概略構成を示す断面図。1 is a cross-sectional view showing a schematic configuration of a heat fixing apparatus according to the present invention. 本発明の実施例1に係る定着入り口ガイドの構成を示す断面図。FIG. 3 is a cross-sectional view showing a configuration of a fixing entrance guide according to Embodiment 1 of the present invention. 比較例1に係る定着入り口ガイドの概略構成を示す斜視図。FIG. 5 is a perspective view showing a schematic configuration of a fixing entrance guide according to Comparative Example 1. 比較例1に係る定着入り口ガイドの構成を示す断面図。FIG. 6 is a cross-sectional view showing a configuration of a fixing entrance guide according to Comparative Example 1. 比較例２に係る定着入り口ガイドの概略構成を示す斜視図。FIG. 9 is a perspective view illustrating a schematic configuration of a fixing entrance guide according to Comparative Example 2. 比較例２に係る定着入り口ガイドの構成を示す断面図。FIG. 6 is a cross-sectional view illustrating a configuration of a fixing entrance guide according to Comparative Example 2. 本発明の実施例２に係る定着入り口ガイドの概略構成を示す斜視図。FIG. 6 is a perspective view illustrating a schematic configuration of a fixing entrance guide according to a second embodiment of the invention. 本発明の実施例２に係る定着入り口ガイドの構成を示す断面図。Sectional drawing which shows the structure of the fixing entrance guide which concerns on Example 2 of this invention. 本発明の実施例３に係る定着入り口ガイドの概略構成を示す斜視図。FIG. 9 is a perspective view illustrating a schematic configuration of a fixing entrance guide according to a third embodiment of the invention. 本発明の実施例３に係る定着入り口ガイドの構成を示す断面図。Sectional drawing which shows the structure of the fixing entrance guide which concerns on Example 3 of this invention. 従来例に係る加熱定着装置の概略構成を示す断面図。Sectional drawing which shows schematic structure of the heat fixing apparatus which concerns on a prior art example.

符号の説明Explanation of symbols

10 搬送ガイド
111、112、113、114、115、116 定着入り口ガイド
Ｎ 定着加熱装置の圧接ニップ部 10 Transport guide
111, 112, 113, 114, 115, 116 Fixing entrance guide N Pressure nip part of fixing heating device

Claims (4)

加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置において、
定着入り口ガイドの記録材搬送方向と直行する長手方向の形状は、加熱体と加圧体の圧接部に近接する側においては長手方向中央部が長手方向端部よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部と長手方向端部が同じ高さの形状であることを特徴とする加熱定着装置。 A heating member, a pressure member pressed against the heating member, and a fixing entrance guide disposed to face the pressure contact portion between the heating body and the pressure member, and a recording material carrying an unfixed image by the fixing entrance guide In the heating and fixing device that applies the thermal energy of the heating body to the recording material by guiding the pressure contact portion and passing the pressure contact portion,
The shape of the fixing entrance guide in the longitudinal direction perpendicular to the recording material conveyance direction is such that the central portion in the longitudinal direction is lower than the end portion in the longitudinal direction on the side close to the press contact portion of the heating body and the pressurizing body. A heating and fixing apparatus, wherein a longitudinal center portion and a longitudinal end portion have the same height on a side opposite to a side close to a pressure contact portion between a body and a pressure body. 像担持体上に形成した現像剤像を記録材上に転写する転写部と、
加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、
定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する画像形成装置において、
定着入り口ガイドの記録材搬送方向と直行する長手方向の形状は、加熱体と加圧体の圧接部に近接する側においては長手方向中央部が長手方向端部よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部と長手方向端部が同じ高さの形状であることを特徴とする画像形成装置。 A transfer unit for transferring the developer image formed on the image carrier onto a recording material;
A heating member, a pressure member pressed against the heating member, and a fixing entrance guide disposed to face the pressure contact portion of the heating body and the pressure member, and a recording material carrying an unfixed image by the fixing entrance guide A heating and fixing device that guides the pressure contact portion and passes the heat contact portion through the pressure contact portion to impart thermal energy of the heating body to the recording material;
In an image forming apparatus having a conveyance guide that is arranged upstream of the fixing entrance guide in the recording material conveyance direction and guides the recording material to the fixing entrance guide.
The shape of the fixing entrance guide in the longitudinal direction perpendicular to the recording material conveyance direction is such that the central portion in the longitudinal direction is lower than the end portion in the longitudinal direction on the side close to the press contact portion of the heating body and the pressurizing body. An image forming apparatus characterized in that a longitudinal center portion and a longitudinal end portion have the same height on a side opposite to a side close to a pressure contact portion between a body and a pressure body. 像担持体上に形成した現像剤像を記録材上に転写する転写部と、
加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、
定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する記録材の最大通紙可能サイズがＡ４サイズである画像形成装置において、
定着入り口ガイドは記録材搬送方向と直行する長手方向に対し長手中央領域と長手端部領域で形成され、その形状が加熱体と加圧体の圧接部に近接する側においては長手方向中央部領域が長手方向端部領域よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部領域と長手方向端部領域が同じ高さの形状であり、その定着入り口ガイド長手方向中央部領域の幅は７０ｍｍ以上であることを特徴とする画像形成装置。 A transfer unit for transferring the developer image formed on the image carrier onto a recording material;
A heating member, a pressure member pressed against the heating member, and a fixing entrance guide disposed to face the pressure contact portion between the heating body and the pressure member, and a recording material carrying an unfixed image by the fixing entrance guide A heating and fixing device that guides the pressure contact portion and passes the heat contact portion through the pressure contact portion to impart thermal energy of the heating body to the recording material;
In an image forming apparatus in which the maximum sheet passing size of a recording material that is disposed upstream of the fixing entrance guide in the recording material conveyance direction and has a conveyance guide for guiding the recording material to the fixing entrance guide is A4 size,
The fixing entrance guide is formed of a longitudinal central region and a longitudinal end region with respect to the longitudinal direction orthogonal to the recording material conveyance direction, and the longitudinal direction central region on the side close to the press contact portion of the heating body and the pressing body. Is a shape lower than the longitudinal end region, and the longitudinal central portion region and the longitudinal end region have the same height on the side opposite to the side close to the press contact portion of the heating body and the pressurizing body. An image forming apparatus, wherein the width of the fixing entrance guide longitudinal center region is 70 mm or more. 像担持体上に形成した現像剤像を記録材上に転写する転写部と、
加熱体と、加熱体に圧接する加圧部材と、加熱体と加圧体の圧接部に対向して配置された定着入り口ガイドとを備え、未定着画像を担持した記録材を定着入り口ガイドにより圧接部に案内し、圧接部に通過させることにより記録材に加熱体の熱エネルギーを付与する加熱定着装置と、
定着入り口ガイドの記録材搬送方向上流部に配置され、記録材を定着入り口ガイドに案内する搬送ガイドを有する画像形成装置において、
定着入り口ガイドは記録材搬送方向と直行する長手方向に対し長手中央領域と長手端部領域で形成され、その形状が加熱体と加圧体の圧接部に近接する側においては長手方向中央部領域が長手方向端部領域よりも低い形状であると共に、加熱体と加圧体の圧接部に近接する側と反対側においては長手方向中央部領域と長手方向端部領域が同じ高さの形状であり、その定着入り口ガイド長手方向中央部領域の幅は画像形成装置の最大通紙サイズ幅の３３％以上であることを特徴とする画像形成装置。 A transfer unit for transferring the developer image formed on the image carrier onto a recording material;
A heating member, a pressure member pressed against the heating member, and a fixing entrance guide disposed to face the pressure contact portion of the heating body and the pressure member, and a recording material carrying an unfixed image by the fixing entrance guide A heating and fixing device that guides the pressure contact portion and passes the pressure contact portion to impart thermal energy of the heating body to the recording material;
In an image forming apparatus having a conveyance guide that is arranged upstream of the fixing entrance guide in the recording material conveyance direction and guides the recording material to the fixing entrance guide.
The fixing entrance guide is formed of a longitudinal central region and a longitudinal end region with respect to the longitudinal direction orthogonal to the recording material conveyance direction, and the longitudinal direction central region on the side close to the press contact portion of the heating body and the pressing body. Is a shape lower than the longitudinal end region, and the longitudinal central region and the longitudinal end region have the same height on the side opposite to the side close to the press contact portion of the heating body and the pressurizing body. An image forming apparatus, wherein the width of the fixing entrance guide longitudinal center region is 33% or more of the maximum sheet passing width of the image forming apparatus.
JP2004277204A 2004-09-24 2004-09-24 Thermal fixing apparatus and image forming apparatus Withdrawn JP2006091448A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009175460A (en) * 2008-01-25 2009-08-06 Ricoh Co Ltd Image forming apparatus
JP2009175458A (en) * 2008-01-25 2009-08-06 Ricoh Co Ltd Image forming apparatus
US8041277B2 (en) 2008-01-25 2011-10-18 Ricoh Company, Ltd. Image forming apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009175460A (en) * 2008-01-25 2009-08-06 Ricoh Co Ltd Image forming apparatus
JP2009175458A (en) * 2008-01-25 2009-08-06 Ricoh Co Ltd Image forming apparatus
US8041277B2 (en) 2008-01-25 2011-10-18 Ricoh Company, Ltd. Image forming apparatus

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