JP5842390B2

JP5842390B2 - Fixing apparatus and image forming apparatus

Info

Publication number: JP5842390B2
Application number: JP2011123710A
Authority: JP
Inventors: 明子伊藤
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2011-06-01
Filing date: 2011-06-01
Publication date: 2016-01-13
Anticipated expiration: 2031-06-01
Also published as: JP2012252105A

Description

本発明は、記録媒体の分離手段を備えた定着装置およびそれを備えた画像形成装置に関する。 The present invention relates to a fixing device including a recording medium separating unit and an image forming apparatus including the fixing device.

画像形成装置では、記録媒体に転写されたトナーを記録媒体に定着するための定着装置を備えている。定着装置としては、定着回転体と加圧回転体と発熱部材を備え、定着回転体と加圧回転体とを接触状態とすることで定着ニップを形成し、発熱部材で定着回転体または加圧回転体の少なくとも一方を加熱し、トナーが転写された記録媒体を定着ニップに通過させることで、記録媒体とトナーに熱と圧力を与えてトナーを記録媒体に定着している。
定着装置では、記録媒体が定着ニップ通過時に、定着回転体あるいは加圧回転体の表面に付着することがあるため、定着回転体あるいは加圧回転体の表面に剥離層をコーティングするとともに、定着ニップの下流側に分離部材を配置している。この分離部材としては、記録媒体が付着する回転体の表面に先端を接触状態とした分離爪や爪状剥離部材が一般に用いられることが多い。 The image forming apparatus includes a fixing device for fixing the toner transferred to the recording medium to the recording medium. The fixing device includes a fixing rotator, a pressure rotator, and a heat generating member. A fixing nip is formed by bringing the fixing rotator and the pressure rotator into contact with each other. By heating at least one of the rotating bodies and passing the recording medium onto which the toner has been transferred through the fixing nip, heat and pressure are applied to the recording medium and the toner to fix the toner to the recording medium.
In the fixing device, since the recording medium may adhere to the surface of the fixing rotator or the pressure rotator when passing through the fixing nip, the surface of the fixing rotator or the pressure rotator is coated with a release layer and the fixing nip. A separating member is disposed on the downstream side of the first member. As the separation member, a separation claw or a claw-like peeling member whose tip is in contact with the surface of the rotating body to which the recording medium adheres is often used.

このように分離爪や爪状剥離部材が常時、定着回転体あるいは加圧回転体の表面に接触していると、接触部分の剥離層が磨耗し、その部分だけ記録媒体が回転体から離型せずに、記録媒体上のトナーが欠けることで、画像に悪影響を生じることが知られている。
そこで、特許文献１では、ソレノイド等により分離爪を回動可能に支持し、分離爪の先端を定着回転体に対して接触／離間可能としている。
特許文献２では、爪状剥離部材の先端部を弾性変形可能にして定着回転体の表面に接触させたものが開示されている。 As described above, when the separation claw or the claw-like peeling member is always in contact with the surface of the fixing rotator or the pressure rotator, the peeling layer at the contact portion is worn, and the recording medium is released from the rotator only at that portion. In addition, it is known that the toner on the recording medium is lacking, thereby causing an adverse effect on the image.
Therefore, in Patent Document 1, the separation claw is rotatably supported by a solenoid or the like, and the tip of the separation claw can be contacted / separated from the fixing rotating body.
Patent Document 2 discloses a claw-like peeling member whose tip is elastically deformable and brought into contact with the surface of a fixing rotator.

特許文献１では、記録媒体の分離時に分離爪の先端が定着回転体の表面に接触するので、常に分離爪が定着回転体に接触する場合に比べれば、接触時間が短くなり、結果定着回転体の剥離層に傷が生じるまでの時間は長くなるが、分離爪のとがった先端が定着回転体の表面に接触するので、定着回転体の表面に分離爪によって傷が生じるのを完全に防ぐことは難しい。
特許文献２では、爪状剥離部材の先端部が弾性変形することで、定着回転体の離型層に傷が生じる可能性が減ることが考えられるが、それに伴い、記録媒体が爪状剥離部材と定着回転体との間に入り込み易くなる、すなわち、剥離機能が低下する可能性を否定できない。
本発明は、記録媒体が付着する定着回転体または加圧回転体の表面に傷が生じる可能性を低減しながら、分離性能を維持することが可能な定着装置および画像形成装置を提供することを、その目的とする。 In Patent Document 1, since the tip of the separation claw contacts the surface of the fixing rotator when the recording medium is separated, the contact time is shortened compared to the case where the separation claw always contacts the fixing rotator, and as a result, the fixing rotator is obtained. Although it takes longer to scratch the release layer, the pointed tip of the separation claw contacts the surface of the fixing rotator, so that the surface of the fixing rotator is completely prevented from being scratched by the separation nail. Is difficult.
In Patent Document 2, it is considered that the possibility that the release layer of the fixing rotator is damaged is reduced by elastically deforming the tip of the nail-shaped peeling member. It is difficult to deny that there is a possibility that the peeling function is deteriorated.
The present invention provides a fixing device and an image forming apparatus capable of maintaining separation performance while reducing the possibility of scratches on the surface of a fixing rotator or a pressure rotator to which a recording medium adheres. And its purpose.

本発明に係る、互いに回転可能な定着回転体および加圧回転体と、少なくとも定着回転体を加熱する発熱手段を備え、定着回転体および加圧回転体で形成される定着ニップにトナー像が転写された記録媒体を通過させ、熱と圧力の作用により前記トナー像を記録媒体に定着させる定着装置は、定着ニップを通過した記録媒体を定着回転体または加圧回転体の表面から分離する可撓性分離部材を有し、この可撓性分離部材は、定着回転体または加圧回転体の回転軸の軸線方向と直交する長手方向に形成された板状の保持部材と、長手方向に延びた薄い板状またはフィルム状であって、定着回転体または加圧回転体の表面に向かって保持部材から突出するように略半円筒状に変形させて保持部材にその両端が固定された可撓性部材とを有し、可撓性分離部材は、定着回転体または加圧回転体の表面に可撓性部材が接触して保持部材に向かって変位するように配置されていることを特徴としている。 A toner image is transferred to a fixing nip formed by the fixing rotator and the pressure rotator according to the present invention, the fixing rotator and the pressure rotator rotatable relative to each other, and at least heat generating means for heating the fixing rotator. The fixing device that passes the recorded recording medium and fixes the toner image to the recording medium by the action of heat and pressure is a flexible device that separates the recording medium that has passed through the fixing nip from the surface of the fixing rotator or the pressure rotator. The flexible separation member has a plate-like holding member formed in a longitudinal direction perpendicular to the axial direction of the rotation shaft of the fixing rotator or the pressure rotator , and extends in the longitudinal direction. A thin plate or film that is deformed into a substantially semi-cylindrical shape so that it protrudes from the holding member toward the surface of the fixing rotator or pressure rotator, and both ends are fixed to the holding member. And flexible Separating member is characterized in that the flexible member is arranged so as to be displaced toward the holding member in contact with the surface of the fixing rotator or pressure rotating body.

本発明によれば、定着ニップを通過した記録媒体を定着回転体または加圧回転体の表面から分離する可撓性分離部材が、定着回転体または加圧回転体の回転軸の軸線方向と直交する長手方向に形成された板状の保持部材と、長手方向に延びた薄い板状またはフィルム状であって、定着回転体または加圧回転体の表面に向かって保持部材から突出するように略半円筒状に変形させて保持部材にその両端が固定された可撓性部材とを有し、定着回転体または加圧回転体の表面に可撓性部材が接触して保持部材に向かって変位するように可撓性分離部材を配置したので、定着回転体または加圧回転体に付着した記録媒体の分離性能を維持しつつも、定着回転体または加圧回転体の表面との接触が面接触となるため、定着回転体または加圧回転体の表面に傷が生じる可能性を低減することができる。 According to the present invention, the flexible separation member that separates the recording medium that has passed through the fixing nip from the surface of the fixing rotator or the pressure rotator is orthogonal to the axial direction of the rotation axis of the fixing rotator or the pressure rotator. A plate-like holding member formed in the longitudinal direction, and a thin plate-like or film-like shape extending in the longitudinal direction, and projecting from the holding member toward the surface of the fixing rotator or the pressure rotator. A flexible member which is deformed into a semi-cylindrical shape and fixed at both ends of the holding member. The flexible member contacts the surface of the fixing rotating body or the pressure rotating body and is displaced toward the holding member. Since the flexible separating member is arranged so as to maintain the separation performance of the recording medium attached to the fixing rotator or the pressure rotator, the contact with the surface of the fixing rotator or the pressure rotator is surface. Because of contact, the surface of the fixing rotator or pressure rotator It is possible to reduce the possibility of scratches occur.

本発明の一実施形態である複写機の概略構成を示す全体図。1 is an overall view showing a schematic configuration of a copying machine according to an embodiment of the present invention. 本発明の一実施形態である定着装置の構成を示す拡大図。FIG. 2 is an enlarged view showing a configuration of a fixing device according to an embodiment of the present invention. （ａ）は本発明の主要部となる可撓性分離部材の構成を示す斜視図、（ｂ）は可撓性分離部材を構成する保持部材の構成を示す斜視図、（ｃ）は可撓性分離部材を構成する可撓性部材の構成を示す斜視図。(A) is a perspective view which shows the structure of the flexible separation member used as the principal part of this invention, (b) is a perspective view which shows the structure of the holding member which comprises a flexible separation member, (c) is flexible The perspective view which shows the structure of the flexible member which comprises a sex separation member. 可撓性分離部材と定着回転体との配置関係を示す斜視図。The perspective view which shows the arrangement | positioning relationship between a flexible separation member and a fixing rotary body. （ａ）は可撓性部材の材質の状態を示す図、（ｂ）は可撓性部材を円弧形状にした状態を示す図、（ｃ）は円弧形状部を変形させた状態を示す図、（ｄ）は可撓性部材の変形特性を説明する斜視図。(A) is a figure which shows the state of the material of a flexible member, (b) is a figure which shows the state which made the flexible member the circular arc shape, (c) is a figure which shows the state which deform | transformed the circular arc-shaped part, (D) is a perspective view explaining the deformation | transformation characteristic of a flexible member. （ａ）は可撓性分離部材と定着回転体の接触状態を可撓性分離部材の長手方向から見た図、（ｂ）は可撓性分離部材により記録媒体の分離前の状態を定着回転体の軸線方向から見た部分図、（ｃ）は可撓性分離部材により記録媒体が良好に分離された状態を定着回転体の軸線方向から見た図、（ｄ）は可撓性分離部材を備えていない場合も不具合を示す図。(A) is a view of the contact state between the flexible separation member and the fixing rotator as viewed from the longitudinal direction of the flexible separation member, and (b) is a state in which the recording medium is separated by the flexible separation member. FIG. 4C is a partial view as seen from the axial direction of the body, FIG. 8C is a view when the recording medium is satisfactorily separated by the flexible separating member as seen from the axial direction of the fixing rotating body, and FIG. The figure which shows a malfunction also when not provided. 定着回転体の軸線方向に複数の可撓性分離部材を備えた状態を示す図。The figure which shows the state provided with the some flexible separation member in the axial direction of the fixing rotary body. 定着回転体の軸線方向に複数の可撓性分離部材を連続して備えた状態を示す図。The figure which shows the state which provided the some flexible separation member continuously in the axial direction of the fixing rotary body. （ａ）は可撓性分離部材の変形前の状態を示す図、（ｂ）は可撓性分離部材全体が変形した状態を示す図、（ｃ）は可撓性分離部材の下端側が変形した状態を示す図、（ｄ）は可撓性分離部材の上端側が変形した状態を示す図。(A) is a figure which shows the state before a deformation | transformation of a flexible separation member, (b) is a figure which shows the state which the whole flexible separation member deform | transformed, (c) is the lower end side of a flexible separation member deform | transformed. The figure which shows a state, (d) is a figure which shows the state which the upper end side of the flexible separation member deform | transformed. （ａ）は下端側が定着回転体と接触した可撓性分離部材と記録媒体の分離前の状態を示す図、（ｂ）は記録媒体の分離不良状態を示す図、（ｃ）は上端側が定着回転体と接触した可撓性分離部材と記録媒体の分離前の状態を示す図、（ｄ）は記録媒体の分離良好状態を示す図。(A) is a diagram showing a state before separation of the flexible separation member whose lower end side is in contact with the fixing rotator and the recording medium, (b) is a diagram showing a poor separation state of the recording medium, and (c) is a state where the upper end side is fixed. The figure which shows the state before isolation | separation of the flexible separation member and recording medium which contacted the rotary body, (d) is a figure which shows the separation favorable state of a recording medium. （ａ）は可撓性分離部材における記録媒体との接触部を示す斜視図、（ｂ）は可撓性分離部材における可撓性部材の変形量を示す拡大図。(A) is a perspective view which shows the contact part with the recording medium in a flexible separation member, (b) is an enlarged view which shows the deformation amount of the flexible member in a flexible separation member. （ａ）はフッ素コーティングのコーティング領域が可撓性分離部材全体の場合を説明した斜視図、（ｂ）はフッ素コーティングのコーティング領域が可撓性分離部材における定着回転体との接触領域の場合を説明した斜視図。(A) is a perspective view explaining the case where the coating region of the fluorine coating is the entire flexible separation member, and (b) is the case where the coating region of the fluorine coating is a contact region with the fixing rotating body in the flexible separation member. FIG.

以下、本発明の実施形態について図面を用いて説明する。最初に画像形成装置の全体構成を説明し、その後に特徴部分の構成を説明する。図１は、画像形成装置の一形態である複写機１を示す。複写機１は、プリンタ部２と、プリンタ部２の上部に取付けられた画像読取装置３とを備えている。画像読取装置３を省いた場合、プリンタ部２自体が画像形成装置となる。画像形成装置の形態としては、複写機１やプリンタ部２に限るものではなく、ファクシミリ単体あるいは複写機１、プリンタ部２、ファクシミリの内の少なくとも２つ以上が組み合わされた複合機器も含まれる。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the overall configuration of the image forming apparatus will be described, and then the configuration of the characteristic portion will be described. FIG. 1 shows a copying machine 1 which is an embodiment of an image forming apparatus. The copying machine 1 includes a printer unit 2 and an image reading device 3 attached to the upper part of the printer unit 2. When the image reading device 3 is omitted, the printer unit 2 itself is an image forming device. The form of the image forming apparatus is not limited to the copying machine 1 or the printer unit 2, but also includes a facsimile machine alone or a composite device in which at least two of the copying machine 1, the printer unit 2, and the facsimile machine are combined.

プリンタ部２内の略中央部には画像形成部４が配置されている。画像形成部４は、像担持体であるドラム状の感光体５、この感光体５のまわりに配置された帯電装置６、現像装置７、転写装置８、クリーニング装置９等により構成されている。現像装置７にはトナー補給装置１０が接続されている。この画像形成部４では、感光体５の外周面が帯電装置６により所定の電位に帯電され、帯電された感光体５の外周面が光書込装置１１によって露光されることにより感光体５の外周面に静電潜像が形成される。そしてこの静電潜像に対して現像装置７からトナーが供給されることにより静電潜像がトナー像として顕像化され、顕像化されたトナー像が転写装置８により記録媒体Ｓ上に転写される。この転写時に記録媒体Ｓ上に転写されずに感光体５の外周面に残留したトナーは、クリーニング装置９により除去される。現像装置７では、重合法で製造された重合トナーが用いられている。 An image forming unit 4 is disposed at a substantially central portion in the printer unit 2. The image forming unit 4 includes a drum-shaped photoconductor 5 as an image carrier, a charging device 6 arranged around the photoconductor 5, a developing device 7, a transfer device 8, a cleaning device 9, and the like. A toner replenishing device 10 is connected to the developing device 7. In this image forming unit 4, the outer peripheral surface of the photoconductor 5 is charged to a predetermined potential by the charging device 6, and the outer peripheral surface of the charged photoconductor 5 is exposed by the optical writing device 11. An electrostatic latent image is formed on the outer peripheral surface. The electrostatic latent image is visualized as a toner image by supplying toner from the developing device 7 to the electrostatic latent image, and the visualized toner image is transferred onto the recording medium S by the transfer device 8. Transcribed. The toner remaining on the outer peripheral surface of the photosensitive member 5 without being transferred onto the recording medium S during the transfer is removed by the cleaning device 9. In the developing device 7, polymerized toner manufactured by a polymerization method is used.

プリンタ部２における画像形成部４の下方には、記録媒体Ｓを収納する上下二段の給紙カセット１２、記録媒体Ｓを手差し給紙可能な手差しトレイ１３等が設けられている。プリンタ部２内には、給紙カセット１２や手差しトレイ１３から給紙された記録媒体Ｓがプリンタ部２と画像読取装置３との間の空隙部に形成された排紙トレイ１４に向けて搬送される搬送経路１５が形成され、この搬送経路１５に沿って、搬送ローラ１６、レジストローラ１７、画像形成部４、定着装置１８、排紙ローラ１９等が配置されている。さらに、記録媒体Ｓの搬送方向に沿った定着装置１８よりも下流側には、搬送経路１５から分岐された反転搬送経路２０が設けられている。この複写機１では、定着装置１８を通過した記録媒体Ｓを反転搬送経路２０へ送り込み、この反転搬送経路２０を経由して記録媒体Ｓを画像形成部４の上流側へ表裏逆向きにして送り出すことにより、記録媒体Ｓの両面へ画像形成を可能としている。画像形成装置としては、反転搬送経路２０を持たない片面印刷ものに対応した複写機であってもよい。 Below the image forming unit 4 in the printer unit 2, an upper and lower two-stage sheet feeding cassette 12 that stores the recording medium S, a manual feed tray 13 that can manually feed the recording medium S, and the like are provided. In the printer unit 2, the recording medium S fed from the paper feed cassette 12 or the manual feed tray 13 is conveyed toward a paper discharge tray 14 formed in a gap between the printer unit 2 and the image reading device 3. A transport path 15 is formed, and along the transport path 15, a transport roller 16, a registration roller 17, an image forming unit 4, a fixing device 18, a paper discharge roller 19, and the like are arranged. Further, a reverse conveyance path 20 branched from the conveyance path 15 is provided on the downstream side of the fixing device 18 along the conveyance direction of the recording medium S. In the copying machine 1, the recording medium S that has passed through the fixing device 18 is sent to the reverse conveyance path 20, and the recording medium S is sent to the upstream side of the image forming unit 4 in the reverse direction via the reverse conveyance path 20. Thus, it is possible to form an image on both sides of the recording medium S. The image forming apparatus may be a copying machine that supports single-sided printing that does not have the reverse conveyance path 20.

画像読取装置３には、読取対象となる原稿を自動送りするＡＤＦ（自動原稿搬送装置）２１、コンタクトガラス２２、原稿の読取面を照明する光源２３、原稿の読取面からの反射光を順次反射させる複数のミラー２４、結像用光学レンズ２５、ＣＣＤ等のイメージセンサ２６などが設けられている。 The image reading device 3 sequentially reflects an ADF (automatic document feeder) 21 that automatically feeds a document to be read, a contact glass 22, a light source 23 that illuminates the document reading surface, and reflected light from the document reading surface. A plurality of mirrors 24, an imaging optical lens 25, an image sensor 26 such as a CCD, and the like are provided.

図２に示すように、定着装置１８は、それぞれ軸心周りに回転自在な定着回転体である定着ローラ２７と、加圧回転体である加圧ローラ２８と、発熱手段となる熱源３０を有し、画像形成部４でトナー像が転写された記録媒体Ｓがこれらの定着ローラ２７の表面２７ａと加圧ローラ２８の表面２８ａとが接触することで形成された定着ニップ部２９を通過し、その通過過程で熱と圧力とを加えられ、記録媒体Ｓ上のトナー像が記録媒体Ｓに定着される。 As shown in FIG. 2, the fixing device 18 includes a fixing roller 27 that is a fixing rotator that is rotatable around an axis, a pressure roller 28 that is a pressure rotator, and a heat source 30 that serves as a heating unit. Then, the recording medium S on which the toner image is transferred by the image forming unit 4 passes through the fixing nip 29 formed by the contact between the surface 27a of the fixing roller 27 and the surface 28a of the pressure roller 28, Heat and pressure are applied during the passage process, and the toner image on the recording medium S is fixed to the recording medium S.

定着ローラ２７は、例えば肉厚１ｍｍ以下のローラを用いて温度応答性を向上させ、定着温度までの昇温時間を１０秒程度にまで短縮するようにしてもよい。定着ローラ２７の外周面には、フッ素コート処理を施し離型層２７ｂを設けている。本形態において、離型層２７ｂの表面を定着ローラ２７の表面２７ａとする。定着ローラ２７の内部には、ヒータなどから構成された熱源３０が配置されていて、定着ローラ２７をその内部から加熱している。熱源３０は、図示例では２つであるが、１つでもよいし、３つ以上であってもよい。 For example, the fixing roller 27 may be a roller having a wall thickness of 1 mm or less to improve the temperature responsiveness, and the temperature raising time to the fixing temperature may be shortened to about 10 seconds. The outer peripheral surface of the fixing roller 27 is subjected to a fluorine coating process to provide a release layer 27b. In this embodiment, the surface of the release layer 27 b is the surface 27 a of the fixing roller 27. Inside the fixing roller 27, a heat source 30 constituted by a heater or the like is disposed, and the fixing roller 27 is heated from the inside. The number of heat sources 30 is two in the illustrated example, but may be one, or may be three or more.

定着ローラ２７の周りには、その周面に接触させたサーミスタ（温度検知手段）３１およびサーモスタット３２が設けられている。本形態では、サーミスタ３１で定着ローラ２７の表面温度を検知し、その検知結果に基づきサーモスタット３２で熱源３０をオンオフすることにより定着ローラ２７を所定温度に保持する。 Around the fixing roller 27, a thermistor (temperature detecting means) 31 and a thermostat 32 are provided in contact with the peripheral surface. In this embodiment, the thermistor 31 detects the surface temperature of the fixing roller 27, and the heat source 30 is turned on / off by the thermostat 32 based on the detection result, thereby holding the fixing roller 27 at a predetermined temperature.

加圧ローラ２８の周りには、加圧スプリング３３により支点３４を中心として反時計まわりに回動するように付勢された加圧アーム３５が設けられている。加圧アーム３５で加圧ローラ２８を付勢して定着ローラ２７に押し当てることにより、定着ローラ２７と加圧ローラ２８との間に定着ニップ部２９を形成する。 Around the pressure roller 28, there is provided a pressure arm 35 urged by the pressure spring 33 so as to rotate counterclockwise about the fulcrum 34. By pressing the pressure roller 28 with the pressure arm 35 and pressing it against the fixing roller 27, a fixing nip portion 29 is formed between the fixing roller 27 and the pressure roller 28.

記録媒体Ｓの搬送方向に沿った定着ニップ部２９の下流側には、本発明の特徴部分となる可撓性分離部材３６が配置されている。可撓性分離部材３６は、図３に示すように、保持部材３６０と可撓性部材３６１とを備えている。可撓性分離部材３６は、定着ローラ２７の軸線方向ａと直交する長手方向ｂに長く形成された薄い板状またはフィルム状の可撓性部材３６１を略半円筒状に変形させて、同じく長手方向ｂに長く形成された板状の保持部材３６０の両側３６０ａ、３６０ｂに、可撓性部材３６１の両側３６１ａ，３６１ｂを接着などにより固定することで構成されている。可撓性分離部材３６は、図４に示すように、定着ローラ２７の表面２７ａに、その長手方向ｂが定着ローラ２７の軸線方向ａと直交するように配置されて、湾曲させた可撓性部材３６１を軸線方向ａと直交する方向から接触させて配置されている。可撓性部材３６１を軸線方向ａと直交する方向から接触させるとは、可撓性部材３６１を保持部材３６０に向かって変位させるように、可撓性部材３６１を定着ローラ２７の表面２７ａに接触好ましくは圧接させることである。本形態において、記録媒体Ｓは、定着ローラ２７の表面２７ａに付着するものとする。 On the downstream side of the fixing nip portion 29 along the conveyance direction of the recording medium S, a flexible separation member 36 serving as a characteristic portion of the present invention is disposed. As illustrated in FIG. 3, the flexible separation member 36 includes a holding member 360 and a flexible member 361. The flexible separating member 36 is formed by deforming a thin plate-like or film-like flexible member 361 formed long in a longitudinal direction b orthogonal to the axial direction a of the fixing roller 27 into a substantially semi-cylindrical shape, and is The two sides 361a and 361b of the flexible member 361 are fixed to both sides 360a and 360b of a plate-like holding member 360 formed long in the direction b by bonding or the like. As shown in FIG. 4, the flexible separation member 36 is arranged on the surface 27 a of the fixing roller 27 so that its longitudinal direction b is orthogonal to the axial direction “a” of the fixing roller 27 and is curved. The member 361 is disposed in contact with the member from a direction orthogonal to the axial direction a. The contact of the flexible member 361 from the direction orthogonal to the axial direction “a” means that the flexible member 361 is brought into contact with the surface 27 a of the fixing roller 27 so as to displace the flexible member 361 toward the holding member 360. Preferably it is press-contacting. In this embodiment, the recording medium S is attached to the surface 27a of the fixing roller 27.

図５（ａ）〜図５（ｃ）は、可撓性部材３６１を長手方向ｂから見たときの図である。本形態において、可撓性部材３６１は、図５（ａ）に示すように、厚さ数十または数百μｍの薄い金属製あるいは樹脂製の板材を、図５（ｂ）に示すように、両側３６１ａ，３６１ｂを近づけて略半円筒状に撓ませて、図５（ｃ）に示すように保持部材３６０に固定する。そして、この半円筒形状部３６１ｃに、別の厚い平板３２０を押し付けることで、保持部材３６０に向かって円筒の半径が縮まる方向にさらに変形する。ここではわかりやすいように、平板３２０を押し付けて変形した場合を図示したが、定着装置１８に用いる場合は、図４に示すように曲面を有する定着ローラ２７の表面２７ａに半円筒形状部３６１ｃを押し付けて配置する。図５（ｄ）に示すように、可撓性分離部材３６は、可撓性部材３６１が保持部材３６０に固定されることで、可撓性部材３６１と保持部材３６０の間に、長手方向ｂに位置する両端３６ｃ、３６ｄが開放された空間部が形成される。つまり、可撓性部材３６１は、半円筒形状部３６１ｃをつぶす方向には容易に変形し易く、長手方向ｂには容易に変形し難く構成されている。 FIG. 5A to FIG. 5C are diagrams when the flexible member 361 is viewed from the longitudinal direction b. In this embodiment, the flexible member 361 is made of a thin metal or resin plate having a thickness of several tens or several hundreds of μm, as shown in FIG. 5A, as shown in FIG. Both sides 361a and 361b are brought close to each other and bent into a substantially semi-cylindrical shape, and fixed to the holding member 360 as shown in FIG. Then, by pressing another thick flat plate 320 against the semi-cylindrical portion 361c, the semi-cylindrical portion 361c is further deformed in a direction in which the radius of the cylinder is reduced toward the holding member 360. Here, for the sake of clarity, the case where the flat plate 320 is pressed and deformed is illustrated, but when used in the fixing device 18, the semi-cylindrical portion 361c is pressed against the surface 27a of the fixing roller 27 having a curved surface as shown in FIG. Arrange. As shown in FIG. 5D, the flexible separation member 36 is fixed in the longitudinal direction b between the flexible member 361 and the holding member 360 by fixing the flexible member 361 to the holding member 360. A space portion is formed in which both ends 36c and 36d positioned at are opened. That is, the flexible member 361 is configured to be easily deformed in the direction in which the semi-cylindrical portion 361c is crushed and not easily deformed in the longitudinal direction b.

図６（ａ）は、定着ローラ２７と可撓性分離部材３６を長手方向ｂ（紙面垂直方向）から見た図である。図中、一転点線は定着ローラ２７の回転軸を示し、可撓性分離部材３６は、この回転軸（軸線方向ａ）と直交する紙面垂直方向に長手方向ｂが位置するように配置されている。図６（ｂ）、図６（ｃ）は、図６（ａ）のＡ−Ａ断面線で切った場合の概略図であり、具体的には定着ローラ２７の軸線方向から見た図である。なお、図６（ｂ）、図６（ｃ）では、保持部材３６０を省略している。可撓性部材３６１が定着ローラ２７の表面２７ａと接触しているので、定着ニップを通過して定着ローラ２７の表面２７ａに付着した記録媒体Ｓは、可撓性分離部材３６によって、定着ローラ２７の表面２７ａから分離される。これに対して、可撓性分離部材３６が存在しない場合、図６（ｄ）に示すように、記録媒体Ｓは定着ローラ２７の表面２７ａから分離されない。 FIG. 6A is a view of the fixing roller 27 and the flexible separation member 36 as seen from the longitudinal direction b (the direction perpendicular to the paper surface). In the figure, the one-turn dotted line indicates the rotation axis of the fixing roller 27, and the flexible separation member 36 is arranged so that the longitudinal direction b is positioned in the direction perpendicular to the rotation plane (axial direction a). . FIGS. 6B and 6C are schematic views taken along the line AA in FIG. 6A, and specifically are views seen from the axial direction of the fixing roller 27. FIG. . In FIG. 6B and FIG. 6C, the holding member 360 is omitted. Since the flexible member 361 is in contact with the surface 27 a of the fixing roller 27, the recording medium S that has passed through the fixing nip and adhered to the surface 27 a of the fixing roller 27 is fixed by the flexible separation member 36. Separated from the surface 27a. On the other hand, when the flexible separation member 36 is not present, the recording medium S is not separated from the surface 27a of the fixing roller 27 as shown in FIG.

従来技術で説明した先端が尖った分離爪は、定着ローラ２７の表面２７ａと点接触に近く、その材質には金属が使用されることが多いため、定着ローラ２７の外周面にコーティングされた離型層２７ｂよりも硬い。分離爪に圧をかけて分離爪と定着ローラ２７が互いに接触状態にあるとき、分離爪が削れるよりも定着ローラ２７の離型層２７ｂが削れる方が容易であるため、定着ローラ２７の外周面の離型層２７ｂ（フッ素コーティング）が磨耗し易い。 The separation claw having a sharp tip described in the prior art is close to a point contact with the surface 27a of the fixing roller 27, and a metal is often used as the material thereof. Therefore, the separation claw coated on the outer peripheral surface of the fixing roller 27 is used. Harder than mold layer 27b. When the separation claw and the fixing roller 27 are in contact with each other by applying pressure to the separation claw, it is easier to scrape the release layer 27b of the fixing roller 27 than to scrape the separation claw. The mold release layer 27b (fluorine coating) is subject to wear.

これに対し、本形態のように、分離爪に代えて、可撓性分離部材３６を、定着ローラ２７と記録媒体Ｓの分離に用いると、可撓性分離部材３６の可撓性部材３６１が定着ローラ２７の表面３７ａと変形した状態で接触しているので、面接触となり、半円筒形状部３６１ａが保持部材３６０側に向かってつぶれる方向に変形し易くなり、分離爪を用いた場合に比べると、定着ローラ２７の離型層２７ｂ（フッ素コーティング）が磨耗し難くなる。 On the other hand, when the flexible separation member 36 is used for separating the fixing roller 27 and the recording medium S instead of the separation claw as in this embodiment, the flexible member 361 of the flexible separation member 36 is Since it is in contact with the surface 37a of the fixing roller 27 in a deformed state, it comes into surface contact, and the semi-cylindrical portion 361a is easily deformed in the direction of collapsing toward the holding member 360, which is compared with the case where a separation claw is used. Then, the release layer 27b (fluorine coating) of the fixing roller 27 is hardly worn.

また、図示しないが、定着ローラ２７に、薄い板金（または樹脂など）を近接させて記録媒体Ｓを分離することは公知であり、「分離板」方式と呼ばれるものがある。このような「分離板」方式としては例えば特開２００６−０１１１９３号公報が挙げられる。このような分離板を定着ローラ２７に近づけ過ぎると、記録媒体Ｓ上のトナーが分離板に固着してしまい、画像不良の原因となるおそれや分離板と定着ローラ２７のギャップが増えて分離できなくなるおそれがある。一方、分離板を定着ローラ２７から離しすぎると、トナー固着は減らせたとしても定着ローラ２７とのギャップが広がることで、分離できなくなるおそれがある。すなわち、分離板を分離部材として用いる場合、定着ローラ２７とのギャップ管理が非常に重要である。しかし、ギャップを細かく管理できる構成を設けるのは、コストアップの原因となりかねない。 Although not shown, it is known that a thin sheet metal (or resin or the like) is brought close to the fixing roller 27 to separate the recording medium S, and there is a so-called “separating plate” method. An example of such a “separation plate” method is disclosed in JP-A-2006-011193. If such a separation plate is too close to the fixing roller 27, the toner on the recording medium S is fixed to the separation plate, which may cause an image defect and increase the gap between the separation plate and the fixing roller 27 to allow separation. There is a risk of disappearing. On the other hand, if the separation plate is too far from the fixing roller 27, even if the toner fixation is reduced, the gap with the fixing roller 27 may be widened, and separation may not be possible. That is, when using the separation plate as a separation member, management of the gap with the fixing roller 27 is very important. However, providing a configuration capable of finely managing the gap may cause an increase in cost.

これに対して、本形態で説明した可撓性分離部材３６は、もともと定着ローラ２７の表面２７ａと接触させていて、両者のギャップはゼロであり、ギャップゼロを保って接触していればよい。すなわち、分離板のように僅かなギャップ変動に分離性能が左右されることはない。一般的に、２つの部材のギャップをゼロに近い一定の値に保つよりもゼロのままにする、すなわち、互いに接触させ続ける方が、容易に実現できるのは言うまでもない。本形態では既存の分離板方式のような、細かいギャップ管理が不要となるというメリットもある。 On the other hand, the flexible separation member 36 described in this embodiment is originally in contact with the surface 27a of the fixing roller 27, and the gap between the two is zero, and it is sufficient that the gap is kept in contact with the gap zero. . That is, the separation performance is not affected by a slight gap variation unlike the separation plate. In general, it goes without saying that it is easier to keep the gap between the two members at zero than to maintain a constant value close to zero, that is, to keep them in contact with each other. In this embodiment, there is also an advantage that fine gap management is not required as in the existing separator plate system.

図２から図６においては、可撓性分離部材３６の基本構成と作用を説明するために、定着ローラ２７に対して１つの可撓性分離部材３６を配置した構成として説明した。このため、比較的幅の狭い記録媒体Ｓの分離には有効である。 2 to 6, in order to explain the basic configuration and operation of the flexible separation member 36, the configuration in which one flexible separation member 36 is disposed with respect to the fixing roller 27 has been described. Therefore, it is effective for separating the recording medium S having a relatively narrow width.

複写機１のユーザには、ユーザが自由なサイズの記録媒体Ｓを使用したいというニーズがあるが、従来のように予め分離爪の位置が決まっている場合、通紙可能な記録媒体Ｓのサイズは限られており、それ以外のサイズの記録媒体Ｓを通紙すると、分離できずに、耳折れ、ジャム等が発生するおそれがあった。このため、決まったサイズの記録媒体Ｓしか使えないのは、画像形成装置の使い勝手が十分であるとは言えない。 The user of the copying machine 1 has a need for the user to use a recording medium S of any size, but when the position of the separation claw is determined in advance as in the prior art, the size of the recording medium S that can be passed. However, when a recording medium S having a size other than that is passed, there is a possibility that the ear may be folded or jammed without being separated. For this reason, the fact that only the recording medium S of a predetermined size can be used cannot be said to be sufficient in usability of the image forming apparatus.

そこで、図７、図８に示す形態では、可撓性分離部材３６を、定着ローラ２７の軸線方向ａに複数配置してユニット化したのである。図７では、軸線方向ａに対して間隔を開けて可撓性分離部材３６を複数個配置して可撓性分離ユニット３６Ａとしている。このように、定着ローラ２７の軸線方向ａに対して複数の可撓性分離部材３６を、可撓性部材３６１をつぶした状態で定着ローラ２７の表面２７ａに接触した状態で配置すると、複写機１でよく使われる記録媒体Ｓのサイズに対応することができ、様々なサイズの記録媒体Ｓを分離できるので好ましい。 7 and 8, a plurality of flexible separation members 36 are arranged in the axial direction a of the fixing roller 27 to form a unit. In FIG. 7, a plurality of flexible separation members 36 are arranged at intervals with respect to the axial direction a to form a flexible separation unit 36A. As described above, when the plurality of flexible separation members 36 are arranged in contact with the surface 27a of the fixing roller 27 in a state where the flexible member 361 is crushed with respect to the axial direction a of the fixing roller 27, the copying machine is provided. This is preferable because it can correspond to the size of the recording medium S often used in No. 1, and the recording medium S of various sizes can be separated.

図８に示す形態での場合、定着ローラ２７の軸線方向ａに対して間隔を開けずに可撓性分離部材３６を配置して可撓性分離ユニット３６Ｂとしている。この場合には、不定形サイズの記録媒体Ｓの分離も可能となり、好みのサイズの記録媒体Ｓを利用したいというユーザの要望に応えることができるので好ましい構成となる。 In the case of the form shown in FIG. 8, the flexible separation unit 36B is formed by disposing the flexible separation member 36 without a gap with respect to the axial direction a of the fixing roller 27. In this case, it is possible to separate the recording medium S having an irregular size, and it is possible to meet the user's desire to use the recording medium S having a desired size, which is a preferable configuration.

図９は、可撓性分離部材３６の変形の形態を説明する図である。図９（ａ）は、可撓性分離部材３６を定着ローラ２７の軸線方向から見た時の変形前の状態を示す。可撓性分離部材３６の全体に、例えば平板（不図示）を押し当てると、図９（ｂ）に示すように可撓性部材３６１の全体が保持部材３６０に向かって変形する。これに対し、図９（ｃ）は、可撓性分離部材３６の下方側３６ｄに、図９（ｄ）は可撓性分離部材３６の上方側３６ｃに、図示しない平板を押し当てて変形した状態を示す。 FIG. 9 is a diagram for explaining a deformation mode of the flexible separation member 36. FIG. 9A shows a state before deformation when the flexible separation member 36 is viewed from the axial direction of the fixing roller 27. When, for example, a flat plate (not shown) is pressed against the entire flexible separation member 36, the entire flexible member 361 is deformed toward the holding member 360 as shown in FIG. 9B. On the other hand, FIG. 9C is deformed by pressing a flat plate (not shown) against the lower side 36d of the flexible separating member 36 and FIG. 9D is pressed against the upper side 36c of the flexible separating member 36. Indicates the state.

このような可撓性分離部材３６の変形状態の違いと、記録媒体Ｓの分離性について図１０、図１１を用いて説明する。 The difference in the deformation state of the flexible separation member 36 and the separation property of the recording medium S will be described with reference to FIGS.

図１０（ａ）〜図１０（ｄ）は、定着ニップ通過後の、定着ローラ２７の表面２７ａに貼りついた記録媒体Ｓの状態を示す。図１０（ａ）、図１０（ｂ）は、可撓性分離部材３６の、定着ローラ２７の回転方向下流側に位置する部分（ここでは下方側３６ｄとする）が定着ローラ２７の表面２７ａに接触した場合を示し、図１０（ｃ）、図１０（ｄ）は、可撓性分離部材３６の、定着ローラ２７の回転方向上流側に位置する部分（ここでは上方側３６ｃとする）が定着ローラ２７の表面２７ａに接触した場合を示す。 FIGS. 10A to 10D show the state of the recording medium S adhered to the surface 27a of the fixing roller 27 after passing through the fixing nip. 10 (a) and 10 (b), the portion of the flexible separation member 36 located downstream in the rotation direction of the fixing roller 27 (here, the lower side 36d) is on the surface 27a of the fixing roller 27. 10 (c) and 10 (d) show a case where the flexible separation member 36 is positioned on the upstream side in the rotation direction of the fixing roller 27 (here, the upper side 36c) is fixed. The case where it contacts the surface 27a of the roller 27 is shown.

記録媒体Ｓが定着ローラ２７の回転に伴い、可撓性分離部材３６に近づくと、図１０（ａ）に示すように、可撓性分離部材３６の下方側３６ｄを定着ローラ２７の表面２７ａに接触させた場合、図５（ｄ）で示したように、可撓性分離部材３６は、可撓性部材３６１の半円筒状部３６１ｃをつぶす方向に変形し易い。したがって、記録媒体Ｓが分離するよりも、可撓性分離部材３６が変形する方が容易であるため、図１０（ｂ）に示すように、記録媒体Ｓが定着ローラ２７と可撓性分離部材３６の間に入り込んでしまい分離されない。 When the recording medium S approaches the flexible separation member 36 as the fixing roller 27 rotates, the lower side 36d of the flexible separation member 36 is placed on the surface 27a of the fixing roller 27 as shown in FIG. When contacted, the flexible separation member 36 is easily deformed in the direction of crushing the semi-cylindrical portion 361c of the flexible member 361, as shown in FIG. Therefore, since the flexible separating member 36 is easier to deform than the recording medium S is separated, the recording medium S is fixed to the fixing roller 27 and the flexible separating member as shown in FIG. 36 is not separated.

一方、記録媒体Ｓが定着ローラ２７の回転に伴い、可撓性分離部材３６に近づくと、図１０（ｃ）に示すように、可撓性分離部材３６の上方側３６ｃを定着ローラ２７の表面２７ａに接触させた場合、図５（ｄ）で示したように、可撓性分離部材３６は、その長手方向ｂに変形しにくい構成であるため、可撓性部材３６が変形するよりも、記録媒体Ｓが分離する方が容易である。このため、図１０（ｄ）に示すように記録媒体Ｓが可撓性分離部材３６の上方側３６ｃによって定着ローラ２７の表面２７ａから分離される。 On the other hand, when the recording medium S approaches the flexible separation member 36 as the fixing roller 27 rotates, the upper side 36c of the flexible separation member 36 is placed on the surface of the fixing roller 27 as shown in FIG. When contacted with 27a, as shown in FIG. 5D, the flexible separation member 36 is configured to be difficult to deform in the longitudinal direction b, so that the flexible member 36 is deformed rather than deformed. It is easier to separate the recording medium S. Therefore, the recording medium S is separated from the surface 27a of the fixing roller 27 by the upper side 36c of the flexible separation member 36 as shown in FIG.

より詳しく説明すると、図１１（ａ）において太線で囲った部分、すなわち、可撓性分離部材３６の上方側３６ｃに位置する可撓性部材３６１の端面３６１Ａが、定着ローラ２７の表面２７ａと接触していてギャップはゼロであり、記録媒体Ｓが、この端面３６１Ａに当たり、記録媒体Ｓが定着ローラ２７の表面２７ａから分離される。このように定着ローラ２７の形状に沿って可撓性分離部材３６が、略半円筒形状に変形可能であると、定着ローラ２７との接触が面接触となり、従来の分離爪のように、定着ローラ２７の外周面の離型層２７ｂ（フッ素コーティング）を磨耗させることが極めて少なくなる。 More specifically, a portion surrounded by a thick line in FIG. 11A, that is, an end surface 361 A of the flexible member 361 located on the upper side 36 c of the flexible separation member 36 is in contact with the surface 27 a of the fixing roller 27. Thus, the gap is zero, the recording medium S hits the end surface 361A, and the recording medium S is separated from the surface 27a of the fixing roller 27. When the flexible separating member 36 can be deformed into a substantially semi-cylindrical shape along the shape of the fixing roller 27 as described above, the contact with the fixing roller 27 becomes a surface contact, and the fixing is performed like a conventional separation claw. The wear of the release layer 27b (fluorine coating) on the outer peripheral surface of the roller 27 is extremely reduced.

定着ローラ２７に押し付けて変形させた状態における、可撓性分離部材３６の可撓性部材３６１の変形方向への厚さｔは、図１１（ｂ）に示すように、５ｍｍ以内が好ましい。これは、これ以上大きいと、可撓性部材３６１の開口部３６ｃまたは開口部３６ｄに記録媒体Ｓが引っかかって、分離できなくなるおそれがあるためである。このように、可撓性分離部材３６における定着ローラ２７の回転方向の上流側に位置する部分を定着ローラ２７の表面２７ａに押し付けることで、分離性能を向上させることができる。 The thickness t of the flexible separation member 36 in the deformation direction in the state of being pressed against the fixing roller 27 and deformed is preferably within 5 mm as shown in FIG. This is because if it is larger than this, the recording medium S may be caught in the opening 36c or 36d of the flexible member 361 and cannot be separated. In this way, the separation performance can be improved by pressing the portion of the flexible separation member 36 located on the upstream side in the rotation direction of the fixing roller 27 against the surface 27 a of the fixing roller 27.

可撓性分離部材３６が記録媒体Ｓや定着ローラ２７と接触すると、記録媒体Ｓや定着ローラ２７に存在するトナーが可撓性分離部材３６に固着する可能性がある。固着したトナーは、分離不良や画像不良（再び記録媒体Ｓに移って画像が乱れる）の原因となることがある。これを防ぐための１つの形態として、可撓性部材３６１の表面に摩擦係数が少ないフッ素コーティングなどのコーティングを行い、離型層３７０を形成するのが好ましい。このような離型層３７０を形成するにより、トナー固着がしにくくなり、前述の不具合がでる可能性を減らすことができる。図１２（ａ）、図１２（ｂ）は離型層３７０のコーティング領域を示すものである。コーティング領域としては、図１２（ａ）に示すように、可撓性分離部材３６の可撓性部材３６１全面をコーティングして離型層３７０を形成してもよいし、あるいは図１２（ｂ）に示すように、可撓性分離部材３６の一部を、例えば、主として定着ローラ２７の表面２７ａと接触する（トナー固着が起こりやすい）可撓性部材３６１の部分のみをコーティングして、部分的に離型層３７０を形成する形態でもよい。 When the flexible separation member 36 comes into contact with the recording medium S or the fixing roller 27, there is a possibility that the toner present on the recording medium S or the fixing roller 27 is fixed to the flexible separation member 36. The fixed toner may cause separation failure or image failure (transfer to the recording medium S again to disturb the image). As one form for preventing this, it is preferable to form the release layer 370 by coating the surface of the flexible member 361 with fluorine coating or the like having a low friction coefficient. By forming such a release layer 370, it is difficult to fix the toner, and the possibility of the above-described problems occurring can be reduced. 12A and 12B show the coating region of the release layer 370. FIG. As the coating region, as shown in FIG. 12 (a), the entire surface of the flexible member 361 of the flexible separation member 36 may be coated to form the release layer 370, or FIG. 12 (b). As shown in FIG. 4, a part of the flexible separating member 36 is coated, for example, only on the part of the flexible member 361 that is mainly in contact with the surface 27a of the fixing roller 27 (where toner fixation is likely to occur). Alternatively, the release layer 370 may be formed.

本形態では、トナー固着抑止のために可撓性分離部材３６にフッ素コーティングなどを施したが、コーティング処理ではなく、トナー固着がしにくい摩擦係数が少ない材質で、少なくとも可撓性部材３６１を構成するようにしてよい。この場合、可撓性部材３６１に使用する材質は制限されるが、コーティング処理の必要がなくなる。 In this embodiment, the flexible separation member 36 is coated with fluorine to prevent toner sticking. However, at least the flexible member 361 is made of a material having a low coefficient of friction that is difficult to fix the toner, rather than a coating process. You may do it. In this case, the material used for the flexible member 361 is limited, but the coating process is not necessary.

上述の形態において、可撓性分離部材３６は、定着回転体となる定着ローラ２７の表面２７ａに接触させる形態として説明したが、可撓性分離部材３６の接触対象としては定着ローラ２７に限定されるものではなく、記録媒体Ｓが加圧回転体である加圧ローラ２８の場合、加圧ローラ２８の表面に接触させた形態としてもよい。あるいは、特開２００７−３３４２０５号公報に記載の、表層の定着スリーブだけが摺動により回転し、内部に固定のパッドや熱源を有する方式の定着回転体の場合、定着スリーブの表面に可撓性分離部材３６を接触させる形態としてもよい。 In the above embodiment, the flexible separation member 36 has been described as being in contact with the surface 27a of the fixing roller 27 serving as a fixing rotating body. However, the contact target of the flexible separation member 36 is limited to the fixing roller 27. In the case where the recording medium S is the pressure roller 28 that is a pressure rotator, the recording medium S may be in contact with the surface of the pressure roller 28. Alternatively, in the case of a fixing rotating body of the type described in Japanese Patent Application Laid-Open No. 2007-334205, in which only the surface fixing sleeve rotates by sliding and has a fixed pad or heat source inside, the surface of the fixing sleeve is flexible. It is good also as a form which makes the separation member 36 contact.

上述の形態において、定着装置１８は、定着ローラ２７と加熱ローラ２８を用いたローラ方式のものを例示したが、定着回転体として、複数ローラ間に巻きかけられた無端ベルトを用いたベルト方式のものであってもよい。この場合、ベルト表面に可撓性分離部材３６を接触させて配置することで、ローラ表面に接触させて場合と同様の効果を得ることができる。 In the above embodiment, the fixing device 18 is exemplified by a roller type using the fixing roller 27 and the heating roller 28. However, the fixing device 18 is a belt type using an endless belt wound around a plurality of rollers as the fixing rotating body. It may be a thing. In this case, by arranging the flexible separation member 36 in contact with the belt surface, it is possible to obtain the same effect as in the case of contacting the roller surface.

つまり、可撓性分離部材３６を用いることで、従来の分離爪方式とは異なり、可撓性分離部材３６が、定着回転体や加圧回転体に対して点接触ではなく面接触となるので、定着回転体や加圧回転体の表面に傷が生じる可能性を低減しながら、分離性能を維持することが可能となる。 That is, by using the flexible separation member 36, unlike the conventional separation claw method, the flexible separation member 36 is not in point contact but in surface contact with the fixing rotator or the pressure rotator. The separation performance can be maintained while reducing the possibility of scratches on the surfaces of the fixing rotator and the pressure rotator.

可撓性分離部材３６を接触対象となる定着回転体（定着ローラ２７）または加圧回転体（加圧ローラ２８）の軸線方向に複数設けることで、各種サイズの記録媒体Ｓの分離を良好に行えるようになる。 By providing a plurality of flexible separation members 36 in the axial direction of the fixing rotator (fixing roller 27) or pressure rotator (pressure roller 28) to be contacted, the recording medium S of various sizes can be separated satisfactorily. You can do it.

可撓性分離部材３６を接触対象となる定着回転体（定着ローラ２７）または加圧回転体（加圧ローラ２８）の軸線方向の全域に設けることで、不定形サイズを含む、各種サイズの記録媒体Ｓの分離を良好に行えるようになる。 By providing the flexible separation member 36 over the entire area in the axial direction of the fixing rotator (fixing roller 27) or the pressure rotator (pressure roller 28) to be contacted, recording of various sizes including irregular sizes is possible. The medium S can be separated satisfactorily.

可撓性分離部材３６における回転方向上流側に位置する部分を、定着回転体（定着ローラ２７）または加圧回転体（加圧ローラ２８）に押しつけて配置したので、記録媒体Ｓが、可撓性分離部材３６の端面３６１Ａに当たって分離し易くなり、さらに分離性能を向上させることができる。 Since the portion of the flexible separating member 36 located upstream in the rotation direction is pressed against the fixing rotator (fixing roller 27) or the pressure rotator (pressure roller 28), the recording medium S is flexible. It becomes easy to separate by hitting the end surface 361A of the sex separation member 36, and the separation performance can be further improved.

可撓性分離部材３６の全部または一部に、フッ素コーティングなどの離型層を設けることで、トナー固着による画像不良・分離不良の可能性を低減することができる。 Providing a release layer such as a fluorine coating on all or part of the flexible separation member 36 can reduce the possibility of image failure and separation failure due to toner adhesion.

１８定着装置
２７定着回転体
２７ａ定着回転体の表面
２８加圧回転体
２８ａ加圧回転体の表面
２９定着ニップ
３０発熱手段
３６可撓性分離部材
３６ｃ回転方向上流側に位置する部分
３６０保持部材
３６１可撓性部材
３７０離型層
ａ軸線方向
ｂ長手方向
Ｓ記録媒体 DESCRIPTION OF SYMBOLS 18 Fixing device 27 Fixing rotator 27a Surface of fixing rotator 28 Pressurizing rotator 28a Surface of pressurizing rotator 29 Fixing nip 30 Heating means 36 Flexible separation member 36c Portion located upstream in rotational direction
360 holding member
361 Flexible member 370 Release layer a Axial direction
b Longitudinal direction S Recording medium

特開２００５−０９９４２６号公報Japanese Patent Laying-Open No. 2005-099426 特開２０１０−２３０９２８号公報JP 2010-230928 A

Claims

互いに回転可能な定着回転体および加圧回転体と、少なくとも定着回転体を加熱する発熱手段を備え、前記定着回転体および加圧回転体で形成される定着ニップにトナー像が転写された記録媒体を通過させ、熱と圧力の作用により前記トナー像を前記記録媒体に定着させる定着装置において、
前記定着ニップを通過した記録媒体を、前記定着回転体または前記加圧回転体の表面から分離する可撓性分離部材を有し、
前記可撓性分離部材は、前記定着回転体または前記加圧回転体の回転軸の軸線方向と直交する長手方向に形成された板状の保持部材と、前記長手方向に延びた薄い板状またはフィルム状であって、前記定着回転体または前記加圧回転体の表面に向かって前記保持部材から突出するように略半円筒状に変形させて前記保持部材にその両端が固定された可撓性部材とを有し、
前記可撓性分離部材は、前記定着回転体または前記加圧回転体の表面に前記可撓性部材が接触して前記保持部材に向かって変位するように配置されていることを特徴とする定着装置。 A recording medium having a fixing rotator and a pressure rotator that are rotatable relative to each other, and heat generation means for heating at least the fixing rotator, and having a toner image transferred to a fixing nip formed by the fixing rotator and the pressure rotator. In the fixing device for fixing the toner image to the recording medium by the action of heat and pressure,
A flexible separation member that separates the recording medium that has passed through the fixing nip from the surface of the fixing rotator or the pressure rotator;
The flexible separating member includes a plate-like holding member formed in a longitudinal direction orthogonal to the axial direction of the rotation shaft of the fixing rotator or the pressure rotator, and a thin plate-like member extending in the longitudinal direction or A flexible film that is deformed into a substantially semi-cylindrical shape so as to protrude from the holding member toward the surface of the fixing rotator or the pressure rotator, and both ends thereof are fixed to the holding member. And having a member
The fixing is characterized in that the flexible separating member is arranged so that the flexible member contacts a surface of the fixing rotating body or the pressure rotating body and is displaced toward the holding member. apparatus.

前記可撓性分離部材は、前記軸線方向に複数配置されていることを特徴とする請求項１記載の定着装置。 The fixing device according to claim 1, wherein a plurality of the flexible separation members are arranged in the axial direction.

前記可撓性分離部材は、前記軸線方向の全域に複数配置されていることを特徴とする請求項１記載の定着装置。 The fixing device according to claim 1, wherein a plurality of the flexible separation members are arranged in the entire area in the axial direction.

前記可撓性部材は、前記定着回転体または前記加圧回転体の回転方向上流側に位置する部分が、前記定着回転体または前記加圧回転体の表面に接触するように配置されていることを特徴とする請求項１ないし３の何れか１項に記載の定着装置。 The flexible member is disposed such that a portion located on the upstream side in the rotation direction of the fixing rotator or the pressure rotator is in contact with the surface of the fixing rotator or the pressure rotator. The fixing device according to claim 1, wherein the fixing device is a fixing device.

前記可撓性部材は、少なくとも前記定着回転体または前記加圧回転体との接触部位に離型層を有することを特徴とする請求項１ないし４の何れか１項に記載の定着装置。 5. The fixing device according to claim 1, wherein the flexible member has a release layer at least at a contact portion with the fixing rotator or the pressure rotator. 6.

請求項１ないし５の何れか１項に記載の定着装置を備えたことを特徴とする画像形成装置。 An image forming apparatus comprising the fixing device according to claim 1.