JP5530749B2

JP5530749B2 - Fixing apparatus and image forming apparatus

Info

Publication number: JP5530749B2
Application number: JP2010033012A
Authority: JP
Inventors: 輝昭黒田
Original assignee: 株式会社沖データ
Priority date: 2010-02-17
Filing date: 2010-02-17
Publication date: 2014-06-25
Anticipated expiration: 2030-02-17
Also published as: JP2011170051A

Description

本発明は、電子写真プリンタ、複写機、ファクシミリなどの画像形成装置における定着装置に関する。 The present invention relates to a fixing device in an image forming apparatus such as an electrophotographic printer, a copying machine, and a facsimile.

従来の白黒またはカラー画像を形成するプリンタ、複写機、ファクシミリ等の画像形成装置における定着装置は、定着ベルトの内側に設けられ、その定着ベルトを通して加圧する定着ローラと、この定着ローラに対向して定着ベルトの外周面に接触する加圧ローラとによりニップ部（当接領域）を形成するとともに、支持部材に支持された面状ヒータによって定着ベルトを加熱し、その熱および圧力により現像剤を用紙に定着するようにしている（例えば、特許文献１参照）。 A conventional fixing device in an image forming apparatus such as a printer, a copying machine, or a facsimile that forms a monochrome image or a color image is provided inside a fixing belt, and a fixing roller that presses the fixing belt is opposed to the fixing roller. A nip portion (contact area) is formed by a pressure roller that contacts the outer peripheral surface of the fixing belt, and the fixing belt is heated by a sheet heater supported by a support member. (See, for example, Patent Document 1).

特開２００７−３２２８８８号公報（段落「００１５」〜段落「００２６」、図２）JP 2007-322888 (paragraph “0015” to “0026”, FIG. 2)

しかしながら、上述した従来の技術においては、定着ベルトとの接触面積が小さい面状加熱部材で定着ベルトを加熱しているため、定着ベルトヘの熱伝達効率が低く、定着ローラと加圧ローラとのニップ部が定着温度に到達するまでに長い時間を必要とするという問題がある。 However, in the above-described conventional technology, the fixing belt is heated by the planar heating member having a small contact area with the fixing belt, so that the heat transfer efficiency to the fixing belt is low, and the nip between the fixing roller and the pressure roller is low. There is a problem that it takes a long time for the portion to reach the fixing temperature.

本発明は、このような問題を解決することを課題とし、定着ローラと加圧ローラとのニップ部が定着温度に到達するまでの時間を短縮することを目的とする。 An object of the present invention is to solve such a problem, and an object of the present invention is to shorten the time until the nip portion between the fixing roller and the pressure roller reaches the fixing temperature.

そのため、本発明は、現像剤を加熱して媒体上に定着させる定着装置において、前記現像剤と前記媒体へ熱を供給する定着部材と、前記定着部材を加熱する発熱体と、前記発熱体を支持する支持部材と、前記定着部材を前記発熱体に押圧する押圧部材と、前記定着部材と当接する第１の加圧部材と、前記定着部材と当接する第２の加圧部材とを有し、前記発熱体は、前記定着部材の移動方向における前記支持部材の上流側に配置され、少なくとも前記第１の加圧部材と前記第２の加圧部材のうち一つが回転体であり、前記回転体が前記定着部材に接触し、回転することで、前記定着部材を移動させ、前記定着部材は、前記媒体とともに移動し、前記現像剤と前記媒体へ熱を供給する定着ベルトであり、前記押圧部材は、前記発熱体を前記支持部材に前記定着ベルトを介して押圧し、前記第１の加圧部材は、前記定着ベルトの移動方向における前記押圧部材の下流で前記定着ベルトの一面に接触し、前記第２の加圧部材は、前記定着ベルトを挟んで前記第１の加圧部材と対向して配置され、前記定着ベルトに前記媒体を押圧する加圧ローラであり、前記支持部材は、前記押圧部材と前記加圧ローラとの間で前記定着ベルトと接触し、前記定着ベルトの移動方向における前記定着ベルトとの接触部の長さが前記移動方向に直交する方向の中央部と端部で異なることを特徴とする。 Therefore, the present invention provides a fixing device that heats a developer and fixes it on a medium, a fixing member that supplies heat to the developer and the medium, a heating element that heats the fixing member, and the heating element. A supporting member that supports the pressing member; a pressing member that presses the fixing member against the heating element; a first pressing member that contacts the fixing member; and a second pressing member that contacts the fixing member. The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member, and at least one of the first pressure member and the second pressure member is a rotating body, and the rotation The fixing member is moved by contacting and rotating the fixing member, and the fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium. The member supports the heating element. The first pressure member is in contact with one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt, and the second pressure member is A pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt, and the support member includes the pressure member and the pressure roller. The length of the contact portion with the fixing belt in the moving direction of the fixing belt is different between the center portion and the end portion in the direction orthogonal to the moving direction .

このようにした本発明は、定着ローラと加圧ローラとのニップ部が定着温度に到達するまでの時間を短縮することができるという効果が得られる。 According to the present invention as described above, it is possible to shorten the time until the nip portion between the fixing roller and the pressure roller reaches the fixing temperature.

第１の実施例における定着装置の構成を示す断面図Sectional drawing which shows the structure of the fixing device in a 1st Example. 第１の実施例における画像形成装置の構成を示す説明図Explanatory drawing which shows the structure of the image forming apparatus in 1st Example. 第１の実施例における定着ローラおよび加圧ローラの断面説明図Sectional explanatory drawing of the fixing roller and the pressure roller in the first embodiment 第１の実施例における加圧部材の断面説明図Cross-sectional explanatory drawing of the pressure member in the first embodiment 第１の実施例における定着ベルトの断面説明図Sectional explanatory drawing of the fixing belt in the first embodiment 第１の実施例における面状発熱体の断面説明図Cross-sectional explanatory drawing of the planar heating element in the first embodiment 第１の実施例における面状発熱体の分解斜視図Exploded perspective view of a planar heating element in the first embodiment 第１の実施例における面状発熱体および支持体の斜視図The perspective view of the planar heat generating body and support body in 1st Example 第１の実施例における定着装置の構成を示す断面図Sectional drawing which shows the structure of the fixing device in a 1st Example. 第２の実施例における定着装置の構成を示す断面図Sectional drawing which shows the structure of the fixing device in 2nd Example. 第２の実施例における面状発熱体および支持体の斜視図Perspective view of planar heating element and support in the second embodiment 第２の実施例における面状発熱体および支持体の斜視図（変形例）Perspective view of a sheet heating element and a support in the second embodiment (modified example) 第３の実施例における定着装置の構成を示す断面図Sectional drawing which shows the structure of the fixing device in 3rd Example. 第３の実施例における定着装置の構成を示す斜視図The perspective view which shows the structure of the fixing device in a 3rd Example. 第３の実施例における定着パッドの断面図Sectional drawing of the fixing pad in 3rd Example 第３の実施例における面状発熱体の分解斜視図Exploded perspective view of a planar heating element in the third embodiment 第３の実施例における支持部材の側面図および斜視図Side view and perspective view of support member in third embodiment 第３の実施例における定着ベルトの説明図Explanatory drawing of the fixing belt in the third embodiment 第３の実施例における定着装置の側面図Side view of the fixing device according to the third embodiment. 第４の実施例における定着装置の構成を示す断面図Sectional drawing which shows the structure of the fixing device in a 4th Example. 第４の実施例における定着装置の構成を示す要部断面図Sectional drawing of the principal part showing the configuration of the fixing device in the fourth embodiment

以下、図面を参照して本発明による定着装置および画像形成装置の実施例を説明する。 Hereinafter, embodiments of a fixing device and an image forming apparatus according to the present invention will be described with reference to the drawings.

図２は第１の実施例における画像形成装置の構成を示す説明図である。 FIG. 2 is an explanatory diagram showing the configuration of the image forming apparatus in the first embodiment.

図２において、画像形成装置としてのプリンタ２０は、用紙（記録媒体）を搬送する用紙搬送部２４、記録光露光部材としてのＬＥＤ（ＬｉｇｈｔＥｍｉｔｔｉｎｇＤｉｏｄｅ）ヘッド２３、記録光に応じたトナー像を形成する現像装置であるトナー像形成部２５、トナー像（現像剤像）が形成された用紙を搬送するとともにその用紙およびトナーを加熱して用紙上にトナー像を定着させる定着装置２６からなる。 In FIG. 2, a printer 20 as an image forming apparatus forms a toner image corresponding to a recording light, a paper conveying unit 24 that conveys a paper (recording medium), an LED (Light Emitting Diode) head 23 as a recording light exposure member, and the recording light. And a fixing device 26 that conveys a sheet on which a toner image (developer image) is formed and heats the sheet and toner to fix the toner image on the sheet.

用紙搬送部２４により用紙が搬送される順にトナー像形成部２５、定着装置２６と配置されている。また、ＬＥＤヘッド２３はトナー像形成部２５に隣接して配置されている。 The toner image forming unit 25 and the fixing device 26 are arranged in the order in which the sheets are conveyed by the sheet conveying unit 24. The LED head 23 is disposed adjacent to the toner image forming unit 25.

図示しない制御部が印刷指示を受けると、用紙搬送部２４は画像形成のタイミングに合わせて用紙をトナー像形成部２５へ搬送する。 When a control unit (not shown) receives a print instruction, the paper transport unit 24 transports the paper to the toner image forming unit 25 in accordance with the timing of image formation.

ＬＥＤヘッド２３は、印刷指示による印刷情報に応じた記録光をトナー像形成部２５へ照射し、トナー像形成部２５は照射された記録光に応じたトナー像を用紙搬送部２４によって搬送された用紙上に形成する。 The LED head 23 irradiates the toner image forming unit 25 with recording light corresponding to the printing information based on the printing instruction, and the toner image forming unit 25 conveys the toner image corresponding to the irradiated recording light by the paper conveying unit 24. Form on paper.

その後、用紙搬送部２４によって定着装置２６へ用紙が搬送されると、その用紙は定着装置２６の熱と圧力によって用紙上のトナー像が定着されたのちに装置外へ排出される。 Thereafter, when the paper is transported to the fixing device 26 by the paper transport unit 24, the paper is discharged out of the device after the toner image on the paper is fixed by the heat and pressure of the fixing device 26.

なお、画像形成装置の各動作は、図示しないＣＰＵ（ＣｅｎｔｒａｌＰｒｏｃｅｓｓｉｎｇＵｎｉｔ）等の制御手段および演算手段としての制御部により、メモリ等の記憶手段に記憶された制御プログラム（ソフトウェア）に基づいて制御される。 Each operation of the image forming apparatus is controlled based on a control program (software) stored in a storage unit such as a memory by a control unit such as a CPU (Central Processing Unit) (not shown) and a control unit as a calculation unit. The

図１は第１の実施例における定着装置の構成を示す断面図である。 FIG. 1 is a cross-sectional view showing the configuration of the fixing device in the first embodiment.

図１において、定着装置２６は、用紙を搬送するために用紙とともに移動し、その用紙および現像剤としてのトナーに熱を供給する定着部材としての無端状の定着ベルト２、接触する定着ベルト２を加熱する加熱手段としての面状発熱体４、面状発熱体４を支持する支持部材としての支持体３、定着ベルト２と面状発熱体４の接触を安定させる安定化手段および定着ベルト２を介して面状発熱体４を支持体３に押圧する押圧手段（押圧部材）としての補助ローラ８、定着ベルト２の移動方向における補助ローラ８の下流に配置され、定着ベルト２の一面に接触する第３の加圧部材としての加圧部材（加圧パッド）９および第１の加圧部材としての定着ローラ１、定着ベルト２を挟んで加圧部材９および定着ローラ１と対向配置され、定着ベルト２に用紙を押圧する第２の加圧部材としての加圧ローラ５からなり、図１における矢印が示す媒体搬送方向に搬送される用紙７に未定着トナー６を定着させる。 In FIG. 1, a fixing device 26 moves with a sheet to convey the sheet, and includes an endless fixing belt 2 as a fixing member that supplies heat to the sheet and toner as a developer, and a fixing belt 2 that contacts the fixing belt 2. A sheet heating element 4 as a heating means for heating, a support 3 as a support member for supporting the sheet heating element 4, a stabilizing means for stabilizing the contact between the fixing belt 2 and the sheet heating element 4, and the fixing belt 2 are provided. An auxiliary roller 8 as a pressing means (pressing member) that presses the sheet heating element 4 against the support 3 via the auxiliary roller 8 is arranged downstream of the auxiliary roller 8 in the moving direction of the fixing belt 2 and contacts one surface of the fixing belt 2. the third pressure member (pressure pad) of the pressing member 9 and the fixing roller 1 as a first pressing member, which sandwich the fixing belt 2 is arranged a pressure member 9 and the fixing roller 1 and the counter, fixing bell 2 to consist pressure roller 5 as a second pressing member for pressing the sheet to fix the unfixed toner 6 on the paper 7 being conveyed in the medium conveyance direction indicated by an arrow in FIG.

定着ベルト２の温度は、図示しない温度検知手段により検出され、図示しない制御部により、所定の温度に保たれている。図示しない温度検知手段は、定着ベルト２の外側面または内側面に当接したもの、あるいは微小なギャップを設けた非接触のものであってもよい。 The temperature of the fixing belt 2 is detected by a temperature detection unit (not shown), and is maintained at a predetermined temperature by a control unit (not shown). The temperature detecting means (not shown) may be in contact with the outer or inner surface of the fixing belt 2 or non-contact with a minute gap.

定着ベルト２は面状発熱体４、加圧部材９、定着ローラ１、支持体３に張架されており、加圧ローラ５は定着ベルト２を介して加圧部材９及び定着ローラ１と接触している。なお、定着ベルト２は、面状発熱体４、加圧部材９、定着ローラ１、支持体３に密着することなく撓んでいてもよい。 The fixing belt 2 is stretched around the sheet heating element 4, the pressure member 9, the fixing roller 1, and the support 3, and the pressure roller 5 is in contact with the pressure member 9 and the fixing roller 1 through the fixing belt 2. doing. The fixing belt 2 may be bent without being in close contact with the sheet heating element 4, the pressure member 9, the fixing roller 1, and the support 3.

定着ローラ１、加圧ローラ５は、図３（ａ）に示すように弾性層３２と芯金３１にて構成される。また、定着ローラ１、加圧ローラ５は図３（ｂ）に示すように離型層３３を弾性層３２の上に形成したものでもよい。 The fixing roller 1 and the pressure roller 5 are composed of an elastic layer 32 and a cored bar 31 as shown in FIG. Further, the fixing roller 1 and the pressure roller 5 may be formed by forming a release layer 33 on the elastic layer 32 as shown in FIG.

弾性層３２は、通常シリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。芯金３１は、一定の剛性を保つためにアルミニウム、鉄、ステンレスなどの金属製パイプまたはシャフトが用いられる。 The elastic layer 32 is usually made of a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber. The cored bar 31 is made of a metal pipe or shaft such as aluminum, iron or stainless steel in order to maintain a certain rigidity.

加圧部材９は、図４に示すように表層４１と、弾性層４２と、基材４３とにより構成される。定着ベルト２と接触する表層４１は、通常シリコン系樹脂、またはフッ素系樹脂などの耐熱性が高く表面摩擦抵抗が低い樹脂材料が用いられる。弾性層４２は、通常シリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。基材４３は、一定の剛性を保つためにアルミニウム、鉄、ステンレスなどの金属材料が用いられる。 As shown in FIG. 4, the pressing member 9 includes a surface layer 41, an elastic layer 42, and a base material 43. For the surface layer 41 in contact with the fixing belt 2, a resin material having a high heat resistance and a low surface friction resistance is usually used, such as a silicon resin or a fluorine resin. The elastic layer 42 is usually made of a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber. The base material 43 is made of a metal material such as aluminum, iron or stainless steel in order to maintain a certain rigidity.

加圧ローラ５は、図示しないフレームにベアリングを介して回転自在に保持されており、図示しないギアを有している。このギアが用紙搬送部２４から回転駆動されることにより加圧ローラ５は図１の矢印Ａが示す方向に回転し、定着ベルト２は加圧ローラ５との摩擦力によって従動し、定着ローラ１は定着ベルト２との摩擦力によって従動することで図１の矢印Ｂが示す方向に回転駆動される。 The pressure roller 5 is rotatably held by a frame (not shown) via a bearing, and has a gear (not shown). When this gear is driven to rotate from the paper transport unit 24, the pressure roller 5 rotates in the direction indicated by the arrow A in FIG. 1, and the fixing belt 2 is driven by the frictional force with the pressure roller 5, so that the fixing roller 1 1 is driven to rotate in the direction indicated by arrow B in FIG.

なお、用紙搬送部２４から回転駆動されるのは定着ローラ１でも良い。または、用紙搬送部２４から回転駆動されるのは定着ローラ１と加圧ローラ５の両方であっても良い。 Note that the fixing roller 1 may be driven to rotate from the paper transport unit 24. Alternatively, both the fixing roller 1 and the pressure roller 5 may be rotationally driven from the paper transport unit 24.

定着ローラ１と加圧部材９は、ばね等の図示しない弾性体により、加圧ローラ５に圧接する向きに押し付けられている。加圧ローラ５は、定着ベルト２を介して定着ローラ１に対向する位置において定着ローラ１に当接している。また、加圧ローラ５は、定着ベルト２を介して加圧部材９に対向する位置において加圧部材９に当接している。これらにより、加圧ローラ５が定着ベルト２を介して定着ローラ１に当接するニップ部と、加圧ローラ５が定着ベルト２を介して加圧部材９に当接するニップ部とが形成されている。 The fixing roller 1 and the pressure member 9 are pressed in a direction to come into pressure contact with the pressure roller 5 by an elastic body (not shown) such as a spring. The pressure roller 5 is in contact with the fixing roller 1 at a position facing the fixing roller 1 through the fixing belt 2. Further, the pressure roller 5 is in contact with the pressure member 9 at a position facing the pressure member 9 through the fixing belt 2. Thus, a nip portion where the pressure roller 5 contacts the fixing roller 1 via the fixing belt 2 and a nip portion where the pressure roller 5 contacts the pressure member 9 via the fixing belt 2 are formed. .

定着ベルト２は、図５（ａ）に示すように薄い基体５１（ニッケル、ポリイミド、ステンレスなどからなる基体の場合は強度、可撓性を両立するため厚さが好ましくは３０〜１５０μｍ位が適当）上に、弾性層５２としてシリコンゴム（低硬度と高熱伝導性を両立するため厚さが好ましくは５０〜３００μｍ）又はフッソ樹脂（磨耗による減肉と高熱伝導性を両立するため厚さが好ましくは１０〜５０μｍ）を薄く形成し、離型層５３を弾性層５２の上に設けてもよく、また図５（ｂ）に示すように基体５１上に離型層５３を設けたものでもよく、定着ローラ１、支持体３、加圧体９に対して離型層５３を外側にして張架される。 As shown in FIG. 5A, the fixing belt 2 has a thin base 51 (in the case of a base made of nickel, polyimide, stainless steel, etc.), and preferably has a thickness of about 30 to 150 μm in order to achieve both strength and flexibility. In addition, silicon rubber (thickness is preferably 50 to 300 μm to achieve both low hardness and high thermal conductivity) or fluorine resin (thickness is preferred to achieve both thinning due to wear and high thermal conductivity) as the elastic layer 52. 10 to 50 μm) may be thinly formed, and the release layer 53 may be provided on the elastic layer 52, or the release layer 53 may be provided on the base 51 as shown in FIG. The fixing roller 1, the support 3, and the pressure member 9 are stretched with the release layer 53 outside.

離型層５３は、定着ローラ１または加圧ローラ５の離型層３３と同様に耐熱性が高く、また成型後の表面自由エネルギーが低い樹脂、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（パーフルオロアルコキシアルカン）、ＦＥＰ（パーフルオロエチレン−プロペンコポリマー）などの代表的なフッ素系樹脂（厚さが好ましくは１０〜５０μｍ）を用いることができる。 The release layer 53 is a resin having high heat resistance and low surface free energy after molding, such as PTFE (polytetrafluoroethylene), PFA (partite), like the release layer 33 of the fixing roller 1 or the pressure roller 5. Typical fluorine-based resins (thickness is preferably 10 to 50 μm) such as fluoroalkoxyalkane) and FEP (perfluoroethylene-propene copolymer) can be used.

支持体３は、アルミニウム、銅など熱伝導性、加工性の高い金属、またはこれらを主成分とする合金、あるいは耐熱性、剛性の高い鉄、鉄系の合金類、ステンレスなどで構成されている。 The support 3 is made of a metal having high thermal conductivity and workability such as aluminum or copper, or an alloy containing these as a main component, or iron, iron-based alloys, stainless steel, etc. having high heat resistance and rigidity. .

図６（ａ）または図６（ｂ）に示すように定着ベルトの回転方向における支持体３の上流側の端部には、面状発熱体４が接着されることなく支持体３に載置され、面状発熱体４は支持体３に形成された図示しない係止部材で側面が係止され、ずれないようになっている。また、面状発熱体４より下流側（補助ローラ８と加圧ローラ５との間）の支持体３には定着ベルトと接触する摺動面（曲面）が形成されている。したがって、この摺動面は定着ベルトの回転方向における面状発熱体４の下流側に設けられている。なお、支持体３の端部とは、図６（ｃ）に示すように、面状発熱体４が支持体３の中央部に配置されていないことを意味している。 As shown in FIG. 6A or 6B, the sheet heating element 4 is placed on the support 3 without being bonded to the upstream end of the support 3 in the rotation direction of the fixing belt. The side surface of the planar heating element 4 is locked by a locking member (not shown) formed on the support 3 so that it does not shift. Further, a sliding surface (curved surface) that comes into contact with the fixing belt is formed on the support body 3 on the downstream side (between the auxiliary roller 8 and the pressure roller 5) from the planar heating element 4. Therefore, this sliding surface is provided on the downstream side of the planar heating element 4 in the rotation direction of the fixing belt. In addition, the edge part of the support body 3 means that the planar heating element 4 is not arrange | positioned in the center part of the support body 3, as shown in FIG.6 (c).

また、支持体３と面状発熱体４は、補助ローラ８で定着ベルト２を介して面状発熱体４を支持体３に押圧することで一体化し、面状発熱体４の熱を支持体３に伝達するようになっている。 Further, the support 3 and the planar heating element 4 are integrated by pressing the planar heating element 4 against the support 3 via the fixing belt 2 by the auxiliary roller 8, and the heat of the planar heating element 4 is supported by the support. 3 is transmitted.

面状発熱体４は、定着ベルト２の内側面と接触する面は平面、あるいは円弧状であり、セラミックヒータ、ステンレスヒータなどが用いられる。図７（ａ）は面状発熱体４が平板状の場合における分解斜視図であり、面状発熱体４は、例えばステンレス鋼（ＳＵＳ４３０）などの基板７０上に電気絶縁層７１として薄くガラス膜を形成し、その上にニッケル−クロム合金あるいは銀−パラジウム合金の粉末をスクリーン印刷によってペースト状に抵抗発熱体７３を形成し、また端部に銀など化学的に安定で電気抵抗の低い金属や、タングステンなどの高融点金属によって電極７４を形成し、その上にガラス、あるいはＰＴＦＥ(ポリテトラフルオロエチレン)、ＰＦＡ(パーフルオロアルコキシアルカン)、ＦＥＰ(パーフルオロエチレン−プロペンコポリマー)などの代表的なフッ素系樹脂による保護層７５で保護したものが用いられる。この場合、定着ベルト２の内側面に接触する面は、抵抗発熱体７３側かあるいは反対側の面であってもどちらでもよい。図７（ｂ）は面状発熱体４の１面が円弧状の場合における分解斜視図であり、基板７６の片側の面が凸状に湾曲しており、この面が定着ベルト２の内側面と接触する。 The surface heating element 4 has a flat surface or a circular arc surface in contact with the inner surface of the fixing belt 2, and a ceramic heater, a stainless steel heater, or the like is used. FIG. 7A is an exploded perspective view in the case where the planar heating element 4 has a flat plate shape. The planar heating element 4 is a thin glass film as an electrical insulating layer 71 on a substrate 70 such as stainless steel (SUS430). A resistance heating element 73 is formed in a paste form by screen printing with a powder of nickel-chromium alloy or silver-palladium alloy, and a chemically stable metal having a low electrical resistance, such as silver. The electrode 74 is formed of a refractory metal such as tungsten, and glass or a typical material such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene-propene copolymer) is formed thereon. Those protected by a protective layer 75 made of fluorine resin are used. In this case, the surface contacting the inner surface of the fixing belt 2 may be either the resistance heating element 73 side or the opposite surface. FIG. 7B is an exploded perspective view in the case where one surface of the sheet heating element 4 has an arc shape, and one surface of the substrate 76 is curved in a convex shape, and this surface is the inner surface of the fixing belt 2. Contact with.

補助ローラ８の表面は、定着ローラ１あるいは加圧ローラ５と同様に弾性層を備え、例えばシリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。芯金も同様に一定の剛性を保つためにアルミニウム、鉄、ステンレスなどの金属製パイプまたはシャフトが用いられる。また弾性層の上に離型層として、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（パーフルオロアルコキシアルカン）、ＦＥＰ（パーフルオロエチレン−プロペンコポリマー）などの代表的なフッ素系樹脂（厚さが好ましくは１０〜５０μｍ）を形成してもよい。あるいは弾性層の代わりにシリコンオイル、フッ素オイルなどの離型剤を塗布するためのスポンジ材やフェルトであってもよい。 The surface of the auxiliary roller 8 is provided with an elastic layer like the fixing roller 1 or the pressure roller 5, and a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber is used. Similarly, a metal pipe such as aluminum, iron, or stainless steel or a shaft is used for the metal core in order to maintain a certain rigidity. Further, as a release layer on the elastic layer, for example, a typical fluorine resin (thickness is preferable) such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene-propene copolymer), etc. 10 to 50 μm) may be formed. Alternatively, a sponge material or felt for applying a release agent such as silicon oil or fluorine oil instead of the elastic layer may be used.

図８は第１の実施例における面状発熱体および支持体の斜視図であり、支持体３と面状発熱体４を一体化した状態を示している。ここで、支持体３の面状発熱体４との接触長さＬ１（ｍｍ）と、面状発熱体４の発熱領域の長さＬ２（ｍｍ）は、Ｌ１≦Ｌ２の関係となっている。 FIG. 8 is a perspective view of the sheet heating element and the support in the first embodiment, and shows a state in which the support 3 and the sheet heating element 4 are integrated. Here, the contact length L1 (mm) of the support 3 with the planar heating element 4 and the length L2 (mm) of the heating region of the planar heating element 4 have a relationship of L1 ≦ L2.

上述した構成の作用について説明する。 The operation of the above configuration will be described.

図１において、定着ベルト２は、支持体３、面状発熱体４に対して摺動しながら加圧ローラ５によって矢印Ｂが示す方向に回転駆動され、面状発熱体４に電力が供給されることで面状発熱体４との接触部が加熱される。図示しない温度検知手段によって定着ベルト２の表面温度を検知し、これをもとに図示しない制御部によって面状発熱体４への供給電力が制御され、定着ベルト２の表面が適正温度に維持される。 In FIG. 1, the fixing belt 2 is rotationally driven in the direction indicated by the arrow B by the pressure roller 5 while sliding with respect to the support 3 and the sheet heating element 4, and electric power is supplied to the sheet heating element 4. Thus, the contact portion with the planar heating element 4 is heated. The surface temperature of the fixing belt 2 is detected by a temperature detection means (not shown), and the power supplied to the planar heating element 4 is controlled by a control unit (not shown) based on this, so that the surface of the fixing belt 2 is maintained at an appropriate temperature. The

トナー６が転写された記録媒体７は、定着ベルト２に形成されたニップ部を通して搬送され、記録媒体７上のトナー６が定着ベルト２及び加圧ローラ５による加熱及び加圧により記録媒体７に定着される。 The recording medium 7 onto which the toner 6 has been transferred is conveyed through a nip formed on the fixing belt 2, and the toner 6 on the recording medium 7 is heated and pressed by the fixing belt 2 and the pressure roller 5 onto the recording medium 7. It is fixed.

図１および図９は、それぞれ面状発熱体４が定着ベルト２の回転方向に対して支持体３、９に形成された摺動面の上流側（図１）、または下流側（図９）に配置されている場合を示している。この２種類の構成におけるＡ４サイズの印刷媒体を縦送りする定着装置において、Ａ４サイズの印刷媒体の搬送方向における中央部のトナーを定着させる定着ベルト２の中央部の温度と、Ａ４サイズの印刷媒体の搬送方向における側端部のトナーを定着させる定着ベルト２の端部の温度を計測したところ、その中央部と端部との温度差は、面状発熱体４を支持体３における上流側の端部に配置した図１の場合、１０℃以下となり、面状発熱体４を支持体３における下流側の端部に配置した図９の場合、２０〜３０℃となった。 1 and FIG. 9 respectively show the upstream side (FIG. 1) or the downstream side (FIG. 9) of the sliding surface on which the planar heating element 4 is formed on the supports 3 and 9 with respect to the rotation direction of the fixing belt 2. The case where it is arrange | positioned is shown. In the fixing device that vertically feeds the A4 size print medium in the two types of configurations, the temperature at the center of the fixing belt 2 that fixes the toner at the center in the transport direction of the A4 size print medium, and the A4 size print medium When the temperature of the end portion of the fixing belt 2 for fixing the toner at the side end portion in the conveyance direction of the toner is measured, the temperature difference between the center portion and the end portion indicates that the sheet heating element 4 is located upstream of the support 3. In the case of FIG. 1 arranged at the end, the temperature is 10 ° C. or lower, and in the case of FIG. 9 where the planar heating element 4 is arranged at the downstream end of the support 3, the temperature is 20-30 ° C.

以下に、その計測条件を示す。 The measurement conditions are shown below.

定着ベルト２は、内径４０ｍｍ、基体をポリイミド（厚さ８０μｍ）、弾性層をシリコンゴム（厚さ１５０μｍ）、離型層をＰＦＡ（厚さ３０μｍ）、
定着ローラ１は、φ１６弾性層をシリコンスポンジ（厚さ１ｍｍ）ＡＳＫＥＲＣ硬度８０度、
加圧ローラ５は、φ３６弾性層をシリコンゴム（厚さ１ｍｍ）ＡＳＫＥＲＣ硬度８０度、
加圧部材９は、弾性層をシリコンゴム１ｍｍＪＩＳ−Ａ硬度２０度、
加圧部材９の加圧力は、２０ｋｇ・ｆ、
面状発熱体４は、ステンレスヒータ幅１２ｍｍ出力１２００Ｗ、
補助ローラ８は、φ１４弾性層をシリコンスポンジ（厚さ４ｍｍ）ＡＳＫＥＲＣ硬度３５度押圧荷重１．５ｋｇ・ｆ、
支持体３は、アルミニウムで厚さ１．５ｍｍであり、定着ベルト２との摺動部の長さは、１８ｍｍ、２種とも体積、熱容量は等しい、
定着ベルト２の目標温度は、１６０℃（２０℃から１６０℃に加熱）、
印刷媒体の搬送方向におけるニップ部の幅は、１３ｍｍ、
定着ベルト２の周速度は、７５ｍｍ／ｓとした。 The fixing belt 2 has an inner diameter of 40 mm, the base is polyimide (thickness 80 μm), the elastic layer is silicon rubber (thickness 150 μm), the release layer is PFA (thickness 30 μm),
The fixing roller 1 has a φ16 elastic layer made of silicon sponge (thickness 1 mm), ASKER C hardness 80 degrees,
The pressure roller 5 has a φ36 elastic layer made of silicon rubber (thickness 1 mm), ASKER C hardness 80 degrees,
The pressure member 9 has an elastic layer made of silicon rubber 1 mm JIS-A hardness 20 degrees,
The pressing force of the pressure member 9 is 20 kg · f,
The planar heating element 4 is a stainless steel heater with a width of 12 mm and an output of 1200 W.
The auxiliary roller 8 has a φ14 elastic layer made of silicon sponge (thickness 4 mm) ASKER C hardness 35 degrees, pressing load 1.5 kg · f,
The support 3 is made of aluminum and has a thickness of 1.5 mm. The length of the sliding portion with the fixing belt 2 is 18 mm, both of which have the same volume and heat capacity.
The target temperature of the fixing belt 2 is 160 ° C. (heated from 20 ° C. to 160 ° C.),
The width of the nip portion in the conveyance direction of the print medium is 13 mm,
The peripheral speed of the fixing belt 2 was 75 mm / s.

このように定着ベルトの中央部と端部との温度差が異なる理由を以下に説明する。 The reason why the temperature difference between the central portion and the end portion of the fixing belt is different will be described below.

図９に示すように面状発熱体４を定着ベルト２の回転方向に対して支持体９１に形成された摺動面の下流側に配置した構成において、補助ローラ８で定着ベルト２を介して面状発熱体４を支持体９１に押圧している部分と、定着ローラ１および加圧部材９が定着ベルト２を介して加圧ローラ５に押圧され形成されるニップ部とは、定着ベルト２が図９の矢印Ｂが示す方向に回転するとき、定着ベルト２は撓む位置関係にあるため、定着ベルト２は支持体９１の摺動面から離間し、支持体９１から定着ベルト２へ熱が伝達されない。 As shown in FIG. 9, in the configuration in which the sheet heating element 4 is arranged on the downstream side of the sliding surface formed on the support 91 with respect to the rotation direction of the fixing belt 2, the auxiliary roller 8 passes through the fixing belt 2. The portion where the sheet heating element 4 is pressed against the support 91 and the nip portion formed by pressing the fixing roller 1 and the pressure member 9 against the pressure roller 5 via the fixing belt 2 are the fixing belt 2. 9 rotates in the direction indicated by the arrow B in FIG. 9, the fixing belt 2 is in a positional relationship of bending, so that the fixing belt 2 is separated from the sliding surface of the support 91 and heat is transferred from the support 91 to the fixing belt 2. Is not transmitted.

一方、図１に示すように面状発熱体４を定着ベルト２の回転方向に対して支持体３に形成された摺動面の上流側の端部に配置した構成においては、補助ローラ８で定着ベルト２を介して面状発熱体４を支持体３に押圧している部分と、定着ローラ１および加圧部材９が定着ベルト２を介して加圧ローラ５に押圧され形成されるニップ部とは、定着ベルト２が図１の矢印Ｂが示す方向に回転するとき、定着ベルト２は張る位置関係にあるため、定着ベルト２は支持体３の摺動面（曲面）に接触し、支持体３から定着ベルト２へ熱が効率良く伝達される。 On the other hand, as shown in FIG. 1, in the configuration in which the planar heating element 4 is arranged at the upstream end of the sliding surface formed on the support 3 with respect to the rotation direction of the fixing belt 2, the auxiliary roller 8 A portion where the sheet heating element 4 is pressed against the support 3 via the fixing belt 2, and a nip portion formed by pressing the fixing roller 1 and the pressure member 9 against the pressure roller 5 via the fixing belt 2. Means that when the fixing belt 2 rotates in the direction indicated by the arrow B in FIG. 1, the fixing belt 2 is in a tensioned positional relationship, so that the fixing belt 2 comes into contact with the sliding surface (curved surface) of the support 3 and is supported. Heat is efficiently transferred from the body 3 to the fixing belt 2.

支持体３の定着ベルト２が摺動する部分の長さが同じで面状発熱体４の幅も同じであるにもかかわらず定着装置の立ち上がり時間に関係するＡ４サイズの印刷媒体の中央部に当接する定着ベルト２の中央部の温度と、Ａ４サイズの印刷媒体の端部に当接する定着ベルト２の端部との温度に違いが現れたのは、図１に示す構成においては、定着ベルト２の張りが定着ベルト２の支持体３への接触を促し、定着ベルト２と支持体３との接触面積が広くなり、支持体３から定着ベルト２への熱伝達効率が高くなるためである。 Even though the length of the portion of the support 3 on which the fixing belt 2 slides is the same and the width of the sheet heating element 4 is the same, the center of the A4 size print medium related to the rise time of the fixing device is provided. The difference between the temperature at the center portion of the fixing belt 2 that contacts the end portion of the fixing belt 2 that contacts the end portion of the A4 size printing medium appears in the configuration shown in FIG. This is because the tension of 2 promotes the contact of the fixing belt 2 with the support 3, the contact area between the fixing belt 2 and the support 3 is increased, and the heat transfer efficiency from the support 3 to the fixing belt 2 is increased. .

以上説明したように、第１の実施例では、面状発熱体を定着ベルトの回転方向における支持体に形成された摺動部としての摺動面の上流側に配置したことにより、定着ベルトに対する熱伝達効率を高くすることができ、定着ローラと加圧ローラのニップ部が定着温度に到達するまでの時間を短縮することができるという効果が得られる。 As described above, in the first embodiment, the planar heating element is arranged on the upstream side of the sliding surface as the sliding portion formed on the support in the rotation direction of the fixing belt, so that The heat transfer efficiency can be increased, and the time until the nip portion between the fixing roller and the pressure roller reaches the fixing temperature can be shortened.

第２の実施例の構成は、支持体の構成が第１の実施例と異なるものである。 The configuration of the second embodiment is different from the first embodiment in the configuration of the support.

図１０は第２の実施例における定着装置の構成を示す断面図、図１１は第２の実施例における面状発熱体および支持体の斜視図である。なお、上述した第１の実施例と同様の部分は、同一の符号を付してその説明を省略する。 FIG. 10 is a cross-sectional view showing the configuration of the fixing device in the second embodiment, and FIG. 11 is a perspective view of the sheet heating element and the support in the second embodiment. Note that parts similar to those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

図１０および図１１において、支持体９２は、定着部材としての定着ベルト２が摺動する中央部の距離と両端部の距離とが異なるように形成されている。その支持体９２の定着ベルト２が摺動する中央部の距離Ｌｃと、両端部の距離Ｌｆ（図中左）および距離Ｌｒ（図中右）との関係は、Ｌｃ≧Ｌｆ、かつＬｃ≧Ｌｒとなっている。そのほかの構成は、第１の実施例における支持体３と同様である。 10 and 11, the support 92 is formed such that the distance between the central portion where the fixing belt 2 as the fixing member slides and the distance between both ends are different. The relationship between the distance Lc at the center of the support 92 on which the fixing belt 2 slides, the distance Lf (left in the figure) and the distance Lr (right in the figure) at both ends is Lc ≧ Lf and Lc ≧ Lr It has become. Other configurations are the same as those of the support 3 in the first embodiment.

なお、図１２に示すように支持体９３の定着ベルト２が摺動する中央部の距離Ｌｃと、両端部の距離Ｌｆ（図中左）および距離Ｌｒ（図中右）との関係を、Ｌｃ≦Ｌｆ、かつＬｃ≦Ｌｒの関係としてもよい。 As shown in FIG. 12, the relationship between the distance Lc of the central portion where the fixing belt 2 of the support 93 slides, the distance Lf (left in the figure) and the distance Lr (right in the figure) of both ends is expressed as Lc. ≦ Lf and Lc ≦ Lr may be satisfied.

支持体９２には熱伝導性、加工性の高いアルミニウムを主成分とする合金を用いる場合、その合金で曲面が形成された固有の押出し材を用い、曲面以外の部位をプレス加工し成形する。また、アルミニウムを主成分とする合金の板材をプレス加工し、全体を成形するようにしても良い。 When an alloy mainly composed of aluminum having high thermal conductivity and workability is used for the support 92, a unique extruded material having a curved surface formed of the alloy is used, and parts other than the curved surface are pressed and molded. Alternatively, an alloy plate material mainly composed of aluminum may be pressed to form the whole.

支持体の定着ベルト２が摺動する中央部の距離をＬｃ、両端部の距離をＬｆ（図中左）およびＬｒ（図中右）とした場合、図１１に示す本実施例の支持体９２は、Ｌｃ≧Ｌｆ、かつＬｃ≧Ｌｒの関係となっており、Ｌｆ＝Ｌｃ＝Ｌｒの関係となっている図１に示す第１の実施例の支持体３とは異なっている。 When the distance of the central portion of the support where the fixing belt 2 slides is Lc, and the distance between both ends is Lf (left in the figure) and Lr (right in the figure), the support 92 of this embodiment shown in FIG. Is different from the support 3 of the first embodiment shown in FIG. 1 in which Lc ≧ Lf and Lc ≧ Lr, and Lf = Lc = Lr.

図１に示す支持体３と図１１に示す支持体９２の体積、熱容量は同じであり、支持体と定着ベルト２が摺動する距離（Ｌｃ、Ｌｆ、Ｌｒ）が異なっている。 The volume and heat capacity of the support 3 shown in FIG. 1 and the support 92 shown in FIG. 11 are the same, and the distance (Lc, Lf, Lr) that the support and the fixing belt 2 slide is different.

この２種類の構成におけるＡ４サイズの印刷媒体を縦送りする定着装置において、Ａ４サイズの印刷媒体の搬送方向における中央部のトナーを定着させる定着ベルト２の中央部の温度と、Ａ４サイズの印刷媒体の搬送方向における側端部のトナーを定着させる定着ベルト２の端部の温度を計測したところ、Ａ４サイズの印刷媒体の中央部のトナーを定着させる定着ベルト２の中央部の温度と、Ａ４サイズの印刷媒体の端部のトナーを定着させる定着ベルト２の両端部との温度差は、本実施例の支持体９２を備えた場合、５℃以下となり、第１の実施例の支持体３を備えた場合、１０℃以下となった。 In the fixing device that vertically feeds the A4 size print medium in the two types of configurations, the temperature at the center of the fixing belt 2 that fixes the toner at the center in the transport direction of the A4 size print medium, and the A4 size print medium When the temperature at the end of the fixing belt 2 for fixing the toner at the side end in the conveying direction of the toner is measured, the temperature at the center of the fixing belt 2 for fixing the toner at the center of the A4 size printing medium and the A4 size are measured. The temperature difference between both ends of the fixing belt 2 for fixing the toner at the end of the print medium is 5 ° C. or less when the support 92 of this embodiment is provided, and the support 3 of the first embodiment is When provided, the temperature was 10 ° C. or lower.

定着ベルト２は、内径４０ｍｍ、基体をポリイミド（厚さ８０μｍ）、弾性層をシリコンゴム（厚さ１５０μｍ）、離型層をＰＦＡ（厚さ３０μｍ）、
定着ローラ１は、φ１６弾性層をシリコンスポンジ（厚さ１ｍｍ）ＡＳＫＥＲＣ硬度８０度、
加圧ローラ５は、φ３６弾性層をシリコンゴム（厚さ１ｍｍ）ＡＳＫＥＲＣ硬度８０度、
加圧部材９は、弾性層をシリコンゴム（厚さ１ｍｍ）ＪＩＳ−Ａ硬度２０度、
加圧部材９の加圧力は、２０ｋｇ・ｆ、
面状発熱体４は、ステンレスヒータ幅１２ｍｍ出力１２００Ｗ、
補助ローラ８は、φ１４弾性層をシリコンスポンジ（厚さ４ｍｍ）ＡＳＫＥＲＣ硬度３５度押圧荷重１．５ｋｇ・ｆ、
支持体３は、アルミニウムで厚さ１．５ｍｍであり、定着ベルト２との摺動部の面積は、４，０００ｍｍ^２、２種とも体積、熱容量は等しい、
定着ベルト２の目標温度は、１６０℃（２０℃から１６０℃に加熱）、
印刷媒体の搬送方向におけるニップ部の幅は、１３ｍｍ、
定着ベルト２の周速度は、７５ｍｍ／ｓとした。 The fixing belt 2 has an inner diameter of 40 mm, the base is polyimide (thickness 80 μm), the elastic layer is silicon rubber (thickness 150 μm), the release layer is PFA (thickness 30 μm),
The fixing roller 1 has a φ16 elastic layer made of silicon sponge (thickness 1 mm), ASKER C hardness 80 degrees,
The pressure roller 5 has a φ36 elastic layer made of silicon rubber (thickness 1 mm), ASKER C hardness 80 degrees,
The pressure member 9 has an elastic layer made of silicon rubber (thickness 1 mm) JIS-A hardness 20 degrees,
The pressing force of the pressure member 9 is 20 kg · f,
The planar heating element 4 is a stainless steel heater with a width of 12 mm and an output of 1200 W.
The auxiliary roller 8 has a φ14 elastic layer made of silicon sponge (thickness 4 mm) ASKER C hardness 35 degrees, pressing load 1.5 kg · f,
The support 3 is made of aluminum and has a thickness of 1.5 mm. The area of the sliding portion with the fixing belt 2 is 4,000 mm ² , both of which have the same volume and heat capacity.
The target temperature of the fixing belt 2 is 160 ° C. (heated from 20 ° C. to 160 ° C.),
The width of the nip portion in the conveyance direction of the print medium is 13 mm,
The peripheral speed of the fixing belt 2 was 75 mm / s.

以上のことから本実施例によれば、図１０および図１１に示す構成において支持体９２の定着ベルト２が摺動する距離を印刷媒体の搬送方向における幅方向の位置で調整することにより、Ａ４サイズの印刷媒体の搬送方向における中央部のトナーを定着させる定着ベルト２の中央部とＡ４サイズの印刷媒体の搬送方向における側端部のトナーを定着させる定着ベルト２の両端部との温度差を制御することが可能である。 From the above, according to the present embodiment, by adjusting the distance in which the fixing belt 2 of the support 92 slides in the configuration shown in FIGS. 10 and 11 at the position in the width direction in the conveyance direction of the print medium, A4 The temperature difference between the central portion of the fixing belt 2 for fixing the toner at the central portion in the conveyance direction of the size printing medium and the both ends of the fixing belt 2 for fixing the toner at the side edge in the conveyance direction of the A4 size printing medium. It is possible to control.

なお、画像形成装置内の定着装置２６周辺の空気の流れ等の周辺環境により定着ベルト２の中央部と端部の放熱量は変化するため、図１２に示す構成の支持体９３で定着ベルト２の両端部との温度差を制御するようにしてもよい。 Note that the amount of heat radiation at the center and end of the fixing belt 2 varies depending on the surrounding environment such as the air flow around the fixing device 26 in the image forming apparatus. You may make it control the temperature difference with both ends.

以上説明したように、第２の実施例では、第１の実施例の効果に加え、定着ベルトが摺動する支持体の中央部および端部の距離を調整することで、定着ベルトの媒体幅方向の温度を制御することができるという効果が得られる。 As described above, in the second embodiment, in addition to the effects of the first embodiment, by adjusting the distance between the center portion and the end portion of the support on which the fixing belt slides, the medium width of the fixing belt is adjusted. The effect that the temperature in the direction can be controlled is obtained.

第３の実施例の構成は、定着装置の構成が第１の実施例と異なるものであり、その他の構成は第１の実施例と同様である。なお、上述した第１の実施例と同様の部分は、同一の符号を付してその説明を省略する。 The configuration of the third embodiment is different from that of the first embodiment in the configuration of the fixing device, and the other configurations are the same as those of the first embodiment. Note that parts similar to those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

図１３は第３の実施例における定着装置の構成を示す断面図、図１４は第３の実施例における定着装置の構成を示す斜視図である。 FIG. 13 is a cross-sectional view showing the configuration of the fixing device in the third embodiment, and FIG. 14 is a perspective view showing the configuration of the fixing device in the third embodiment.

図１３および図１４において、定着装置２６は、定着ローラ１と、複数の部材に巻き掛けられ、用紙を搬送するために用紙とともに移動し、その用紙およびトナーに熱を供給する無端状の定着ベルト２と、定着ベルト２を加熱する熱源としての面状ヒータ（面状発熱体）１０４と、面状ヒータ１０４を支持する支持部材（支持体）１０３と、支持部材１０３に支持された面状ヒータ１０４をその支持部材１０３に定着ベルト２を介して押圧する押圧部材としての押圧ローラ１０８と、支持部材１０３の端部に固定されて定着ベルト２の移動方向における押圧ローラ１０８の下流に配置され、定着ベルト２の一面に接触する加圧部材（ニップ形成部材）としての定着パッド１０９と、定着ベルト２の移動方向における押圧ローラ１０８の下流に、定着パッド１０９および定着ローラ１に対向して配置され、定着ベルト２を定着パッド１０９および定着ローラ１に圧接する第２の加圧部材としての加圧ローラ５とを備え、図１３における矢印が示す媒体搬送方向に搬送される用紙７に未定着トナー６を定着させる。 13 and 14, the fixing device 26 is an endless fixing belt that is wound around the fixing roller 1 and a plurality of members, moves with the sheet to convey the sheet, and supplies heat to the sheet and toner. 2, a planar heater (planar heating element) 104 as a heat source for heating the fixing belt 2, a supporting member (supporting body) 103 that supports the planar heater 104, and a planar heater supported by the supporting member 103. A pressing roller 108 as a pressing member that presses 104 to the support member 103 via the fixing belt 2, and is fixed to an end of the supporting member 103 and is arranged downstream of the pressing roller 108 in the moving direction of the fixing belt 2, A fixing pad 109 as a pressure member (nip forming member) that contacts one surface of the fixing belt 2 and downstream of the pressing roller 108 in the moving direction of the fixing belt 2. Disposed opposite the fixing pad 109 and the fixing roller 1, and a pressure roller 5 as a second pressing member that presses the fixing belt 2 to the fixing pads 109 and the fixing roller 1, represented by an arrow in FIG. 13 Unfixed toner 6 is fixed on the sheet 7 conveyed in the medium conveying direction.

なお、加圧ローラ５の内部にはローラ表面の温度上昇を加速させるために図示しないハロゲンヒータを有していてもよい。 The pressure roller 5 may have a halogen heater (not shown) in order to accelerate the temperature rise on the roller surface.

支持部材１０３は、レバー１２０に保持されており、ばね等の図示しない弾性体により、レバー１２０の支点１２０ａを支点として、支持部材１０３に固定された定着パッド１０９が、加圧ローラ５に圧接する図１３における矢印Ｇが示す方向に押し付けられている。 The support member 103 is held by the lever 120, and the fixing pad 109 fixed to the support member 103 is pressed against the pressure roller 5 by using an elastic body (not shown) such as a spring with the fulcrum 120 a of the lever 120 as a fulcrum. It is pressed in the direction indicated by the arrow G in FIG.

定着ローラ１は、レバー１２０と同じ支点１２０ａを有するレバー１２１に図示しないベアリングを介して回転自在に保持されており、ばね等の図示しない弾性体により、支点１２０ａを支点として加圧ローラ５に圧接する図１３における矢印Ｈが示す方向に押し付けられている。 The fixing roller 1 is rotatably held by a lever 121 having the same fulcrum 120a as that of the lever 120 via a bearing (not shown), and is pressed against the pressure roller 5 by an elastic body (not shown) such as a spring with the fulcrum 120a as a fulcrum. It is pressed in the direction indicated by the arrow H in FIG.

押圧ローラ１０８は、定着ローラ１を保持しているレバー１２１に図示しないベアリングを介して回転自在に保持されており、ばね等の図示しない弾性体により、定着ベルト２を介して面状ヒータ１０４に圧接する図１３における矢印Ｊが示す方向に押し付けられている。 The pressure roller 108 is rotatably held by a lever 121 that holds the fixing roller 1 via a bearing (not shown), and is attached to the sheet heater 104 via the fixing belt 2 by an elastic body (not shown) such as a spring. It is pressed in the direction indicated by the arrow J in FIG.

なお、押圧ローラ１０８の製品硬度はＡＳＫＥＲ-Ｃ硬度で３５度±５度、押圧荷重は１．５ｋｇ・ｆ±０．５ｋｇ・ｆとなっている。 The product hardness of the pressing roller 108 is 35 ° ± 5 ° in terms of ASKER-C hardness, and the pressing load is 1.5 kg · f ± 0.5 kg · f.

また、図１４に示すように押圧ローラ１０８の幅方向の長さＬ１８と面状ヒータ１０４の幅方向の長さＬ１４、支持部材１０３の幅方向の長さＬ１３、及び定着ベルト２の幅方向の長さＬ１２の関係は、安定的に定着ベルト２を加熱するために、Ｌ１４≧Ｌ１８≧Ｌ１２≧Ｌ１３の関係となっている。 Further, as shown in FIG. 14, the width L 18 in the width direction of the pressure roller 108, the length L 14 in the width direction of the sheet heater 104, the length L 13 in the width direction of the support member 103, and the width direction of the fixing belt 2. The relationship of the length L12 is L14 ≧ L18 ≧ L12 ≧ L13 in order to stably heat the fixing belt 2.

さらに、押圧ローラ１０８は、定着ベルト２を介して面状ヒータ１０４に圧接され、この圧接力で面状ヒータ１０４は支持部材１０３に押圧されて一体化されているので、面状ヒータ１０４の一方の面で定着ベルト２を加熱し、もう一方の面で支持部材１０３を加熱している。 Further, the pressing roller 108 is pressed against the sheet heater 104 via the fixing belt 2, and the sheet heater 104 is pressed against and integrated with the support member 103 by this pressing force, so that one of the sheet heaters 104 is integrated. The fixing belt 2 is heated on this surface, and the support member 103 is heated on the other surface.

加圧ローラ５は、定着ベルト２を介して、定着パッド１０９および定着ローラ１に対向する位置で、それぞれに当接している。 The pressure roller 5 is in contact with the fixing pad 109 and the fixing roller 1 through the fixing belt 2 at positions facing each other.

これらにより、加圧ローラ５が定着ベルト２を介して定着パッド１０９に当接する当接範囲である第１のニップ部と、加圧ローラ５が定着ベルト２を介して定着ローラ１に当接する当接範囲である第２のニップ部とが形成されている。 As a result, the first nip portion where the pressure roller 5 is in contact with the fixing pad 109 via the fixing belt 2 and the contact between the pressure roller 5 and the fixing roller 1 via the fixing belt 2 are contacted. A second nip portion that is a contact area is formed.

なお、定着ローラ１および加圧ローラ５の構成は、第１の実施例と同様である。 The configurations of the fixing roller 1 and the pressure roller 5 are the same as those in the first embodiment.

定着パッド１０９は、図１５に示すように表層１０９ａと弾性層１０９ｂにて構成され、例えば接着材で支持部材１０３に固定されている。定着ベルト２と接触する表層１０９ａは、通常シリコン系樹脂、またはフッ素系樹脂などの耐熱性が高く表面摩擦抵抗が低い樹脂材料が用いられる。弾性層１０９ｂは、通常シリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。 As shown in FIG. 15, the fixing pad 109 includes a surface layer 109a and an elastic layer 109b, and is fixed to the support member 103 with an adhesive, for example. For the surface layer 109a in contact with the fixing belt 2, a resin material having high heat resistance and low surface friction resistance, such as silicon resin or fluorine resin, is usually used. For the elastic layer 109b, a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber is usually used.

定着ベルト２は、図５（ａ）に示すように薄い基体５１（ニッケル、ポリイミド、ステンレスなどからなる基体の場合は強度と可撓性を両立するため、厚さが好ましくは３０〜１５０μｍ位が適当）上に、弾性層５２としてシリコンゴム（低硬度と高熱伝導性を両立するため、厚さが好ましくは５０〜３００μｍ）又はフッソ樹脂（磨耗による減肉と高熱伝導性を両立するため、厚さが好ましくは１０〜５０μｍ）を薄く形成し、その弾性層５２の上に離型層５３を形成している。また図５（ｂ）に示すように基体５１上に離型層５３を設けたものでもよく、定着ローラ１、支持部材１０３、定着パッド１０９に対して離型層５３を外側にして配置されている。 As shown in FIG. 5A, the fixing belt 2 is a thin base 51 (in the case of a base made of nickel, polyimide, stainless steel, etc.), and the thickness is preferably about 30 to 150 μm in order to achieve both strength and flexibility. In addition, as the elastic layer 52, silicon rubber (thickness is preferably 50 to 300 μm in order to achieve both low hardness and high thermal conductivity) or fluorine resin (in order to achieve both thinning due to wear and high thermal conductivity) Is preferably 10 to 50 μm, and a release layer 53 is formed on the elastic layer 52. Further, as shown in FIG. 5B, a release layer 53 may be provided on the base 51, and the release layer 53 is disposed outside the fixing roller 1, the support member 103, and the fixing pad 109. Yes.

離型層５３は、離型層３３と同様に耐熱性が高く、また成型後の表面自由エネルギーが低い樹脂、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（パーフルオロアルコキシアルカン）、ＦＥＰ（パーフルオロエチレン−プロペンコポリマー）などの代表的なフッ素系樹脂（厚さが好ましくは１０〜５０μｍ）を用いることができる。 Like the release layer 33, the release layer 53 is a resin having high heat resistance and low surface free energy after molding, such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluorocarbon). Typical fluorine-based resins (thickness is preferably 10 to 50 μm) such as ethylene-propene copolymer) can be used.

なお、外側の表面粗さはＲａ：０.６（μｍ）以下で、内側の表面粗さはＲａ：５．０（μｍ）以下である。 The outer surface roughness is Ra: 0.6 (μm) or less, and the inner surface roughness is Ra: 5.0 (μm) or less.

また、定着ベルト２の幅方向の寸法は３２０ｍｍで、厚さは２６０μｍとなり、定着ベルト２は周速２００ｍｍ／ｓで回転し、カラー画像を１分間にＡ４サイズの用紙を横送りで４０枚に定着する。 The fixing belt 2 has a width direction dimension of 320 mm and a thickness of 260 μm. The fixing belt 2 rotates at a peripheral speed of 200 mm / s, and a color image is 40 sheets of A4 size paper laterally fed per minute. To settle.

支持部材１０３は、アルミニウム、銅など熱伝導性、加工性の高い金属、またはこれらを主成分とする合金、あるいは耐熱性、剛性の高い鉄、鉄系の合金類、ステンレスなどで構成されている。 The support member 103 is made of a metal having high thermal conductivity and workability such as aluminum or copper, or an alloy containing these as a main component, or iron, iron-based alloys, stainless steel, or the like having high heat resistance and rigidity. .

定着ベルト２の回転方向に対して支持部材１０３の上流側の端部には、面状ヒータ１０４が接着されることなく支持部材１０３に載置され、面状ヒータ１０４は支持部材１０３に形成された図示しない係止部材で側面が係止され、ずれないようになっている。 The sheet heater 104 is placed on the support member 103 without being bonded to the upstream end of the support member 103 with respect to the rotation direction of the fixing belt 2, and the sheet heater 104 is formed on the support member 103. The side surfaces are locked by a locking member (not shown) so as not to be displaced.

また、支持部材１０３と面状ヒータ１０４は、押圧ローラ１０８で定着ベルト２を介して面状ヒータ１０４を支持部材１０３に押圧することで一体化し、面状ヒータ１０４の熱を支持部材１０３に伝達するようになっている。 Further, the support member 103 and the planar heater 104 are integrated by pressing the planar heater 104 against the support member 103 via the fixing belt 2 by the pressing roller 108, and the heat of the planar heater 104 is transmitted to the support member 103. It is supposed to be.

また、支持部材１０３は、押圧ローラ１０８と加圧ローラ５との間において定着ベルト２と接触する湾曲部（曲面）が形成されており、その定着ベルト２との接触面には、摺動性を高めるためにフッ素系の樹脂を形成していてもよい。なお、支持部材１０３の幅方向の長さは３１５ｍｍで、湾曲部の半径が２２．５ｍｍ±１．０ｍｍとなり定着ベルト２の初期状態の内径とほぼ等しい。 The support member 103 is formed with a curved portion (curved surface) that contacts the fixing belt 2 between the pressing roller 108 and the pressure roller 5, and the contact surface with the fixing belt 2 has a sliding property. Fluorine resin may be formed in order to increase the resistance. The length of the support member 103 in the width direction is 315 mm, and the radius of the curved portion is 22.5 mm ± 1.0 mm, which is substantially equal to the inner diameter of the fixing belt 2 in the initial state.

さらに、支持部材１０３の定着ベルト２との接触面は、摺動性及び伝熱性を考慮して平滑であり、表面粗さをＲａ：６．３（μｍ）以下にする。面状ヒータ１０４を支持する部分は凹形状、またはＬ字形状になっている。 Further, the contact surface of the support member 103 with the fixing belt 2 is smooth in consideration of slidability and heat transfer, and the surface roughness is Ra: 6.3 (μm) or less. The portion that supports the planar heater 104 is concave or L-shaped.

面状ヒータ１０４は、電流を流すことで発熱する発熱体であり、定着ベルト２の内側面と接触する面は平面であり、セラミックヒータ、ステンレスヒータなどが用いられる。図１６は、面状ヒータ１０４の分解斜視図であり、面状ヒータ１０４は、例えばステンレス鋼（ＳＵＳ４３０）などの基板１６０上に電気絶縁層１６１として薄くガラス膜を形成し、その上にニッケル−クロム合金あるいは銀−パラジウム合金の粉末をスクリーン印刷によってペースト状に抵抗発熱体１６３を形成し、また端部に銀など化学的に安定で電気抵抗の低い金属や、タングステンなどの高融点金属によって電極１６４を形成し、その上にガラス、あるいはＰＴＦＥ(ポリテトラフルオロエチレン)、ＰＦＡ(パーフルオロアルコキシアルカン)、ＦＥＰ(パーフルオロエチレン−プロペンコポリマー)などの代表的なフッ素系樹脂による保護層１６５で保護したものが用いられる。 The planar heater 104 is a heating element that generates heat when an electric current flows. The surface that contacts the inner surface of the fixing belt 2 is a flat surface, and a ceramic heater, a stainless steel heater, or the like is used. FIG. 16 is an exploded perspective view of the planar heater 104. In the planar heater 104, a thin glass film is formed as an electrical insulating layer 161 on a substrate 160 such as stainless steel (SUS430), and nickel- A resistance heating element 163 is formed in a paste form by screen printing of a chromium alloy or silver-palladium alloy powder, and an electrode is formed of a chemically stable and low electrical resistance metal such as silver or a high melting point metal such as tungsten at the end. 164 is formed thereon, and is protected with a protective layer 165 made of glass or a typical fluorine resin such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), and FEP (perfluoroethylene-propene copolymer). Used.

この場合、定着ベルト２の内側面に接触する面は、抵抗発熱体１６３側の面かあるいはその反対側の保護層１６５で保護された面のどちらでもよい。なお、面状ヒータ１０４は効率よく定着ベルト２を加熱するために、定着ベルト２と支持部材１０３を加熱している。また、幅方向の長さは３７５ｍｍで発熱部の長さが３３０ｍｍとなり、３５０℃の時に出力１２００Ｗである。 In this case, the surface in contact with the inner surface of the fixing belt 2 may be either the surface on the resistance heating element 163 side or the surface protected by the protective layer 165 on the opposite side. The planar heater 104 heats the fixing belt 2 and the support member 103 in order to efficiently heat the fixing belt 2. The length in the width direction is 375 mm, the length of the heat generating part is 330 mm, and the output is 1200 W at 350 ° C.

押圧ローラ１０８の表面は、定着ローラ１あるいは加圧ローラ５と同様に弾性層を備え、例えばシリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。 The surface of the pressure roller 108 is provided with an elastic layer like the fixing roller 1 or the pressure roller 5, and a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber is used.

押圧ローラ１０８の芯金も、定着ローラ１あるいは加圧ローラ５と同様に一定の剛性を保つためにアルミニウム、鉄、ステンレスなどの金属製パイプまたはシャフトが用いられる。 The metal core of the pressure roller 108 is also made of a metal pipe or shaft such as aluminum, iron or stainless steel in order to maintain a certain rigidity like the fixing roller 1 or the pressure roller 5.

また、弾性層の上に離型層として、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（パーフルオロアルコキシアルカン）、ＦＥＰ（パーフルオロエチレン−プロペンコポリマー）などの代表的なフッ素系樹脂（厚さが好ましくは１０〜５０μｍ）を形成してもよい。あるいは弾性層の代わりにシリコンオイル、フッ素オイルなどの離型剤を塗布するためのスポンジ材やフェルトであってもよい。 Moreover, as a release layer on the elastic layer, for example, a typical fluorine resin (thickness) such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene-propene copolymer), etc. Preferably, 10 to 50 μm) may be formed. Alternatively, a sponge material or felt for applying a release agent such as silicon oil or fluorine oil instead of the elastic layer may be used.

加圧ローラ５は、図示しないフレームにベアリングを介して回転自在に保持されており、図示しないギアを有している。このギアが用紙搬送部２４から回転駆動されることにより加圧ローラ５は図１３の矢印Ｃが示す方向に回転し、定着ベルト２は加圧ローラ５と、定着ローラ１は定着ベルト２との摩擦力によって従動することで図１３の矢印Ｄが示す方向に回転駆動される。 The pressure roller 5 is rotatably held by a frame (not shown) via a bearing, and has a gear (not shown). When this gear is rotationally driven from the paper transport unit 24, the pressure roller 5 rotates in the direction indicated by the arrow C in FIG. 13, and the fixing belt 2 is connected to the pressure roller 5 and the fixing roller 1 is connected to the fixing belt 2. By being driven by the frictional force, it is rotationally driven in the direction indicated by the arrow D in FIG.

また、定着ベルト２の一部には、駆動のためのトルクを低減するために、テンションが加わっていない部分がある。 Further, a part of the fixing belt 2 includes a portion where no tension is applied in order to reduce driving torque.

さらに、加圧ローラ５が図１３の矢印Ｃが示す方向へ回転すると、定着ベルト２はニップ部に向けて矢印Ｄが示す方向に引っ張られる。また、定着ベルト２は押圧ローラ１０８と面状ヒータ１０４で圧接されているので矢印Ｅが示す方向に引っ張られ、定着ベルト２には矢印Ｆが示す方向に力が加わり、支持部材１０３の湾曲部と接触する。 Further, when the pressure roller 5 rotates in the direction indicated by the arrow C in FIG. 13, the fixing belt 2 is pulled in the direction indicated by the arrow D toward the nip portion. Further, since the fixing belt 2 is in pressure contact with the pressing roller 108 and the sheet heater 104, the fixing belt 2 is pulled in the direction indicated by the arrow E, and a force is applied to the fixing belt 2 in the direction indicated by the arrow F, so Contact with.

図１７は第３の実施例における支持部材の側面図および斜視図であり、図１７（ａ）は側面図、図１７（ｂ）は斜視図である。 FIGS. 17A and 17B are a side view and a perspective view of a support member according to the third embodiment, in which FIG. 17A is a side view and FIG. 17B is a perspective view.

図１７において、支持部材１０３の形状の一部は、円弧状の形状ｒ１をなし、定着ベルト２と接触するベルト摺動部（湾曲部）、すなわち略半円筒状の曲面を形成している。形状ｒ１の半径は、定着ベルト２と支持部材１０３の接触を安定させるために、図１８に示す定着ベルト２の初期の円筒形状の内径Ｒの半径とほぼ等しいことが望ましい。 In FIG. 17, a part of the shape of the support member 103 has an arcuate shape r <b> 1 and forms a belt sliding portion (curved portion) in contact with the fixing belt 2, that is, a substantially semi-cylindrical curved surface. The radius of the shape r1 is desirably substantially equal to the radius of the inner diameter R of the initial cylindrical shape of the fixing belt 2 shown in FIG. 18 in order to stabilize the contact between the fixing belt 2 and the support member 103.

本実施例では、定着ベルト２の半径を２２．５ｍｍにしたので、支持部材１０３の円弧形状のベルト摺動部の半径も２２．５ｍｍである。ただし、定着ベルト２へ安定的な伝熱を考慮すると、支持部材１０３のベルト摺動部の半径は１５〜３０ｍｍまで許容できる。なお、上記の寸法は常温時に管理されている寸法である。 In this embodiment, since the radius of the fixing belt 2 is 22.5 mm, the radius of the arc-shaped belt sliding portion of the support member 103 is also 22.5 mm. However, in consideration of stable heat transfer to the fixing belt 2, the radius of the belt sliding portion of the support member 103 can be allowed to be 15 to 30 mm. In addition, said dimension is a dimension managed at normal temperature.

また、支持部材１０３の円弧形状は、図１９に示す支持部材１９３のように、定着ベルト２又は記録媒体７の波打ちや弛みによって、記録媒体７上の未定着のトナー６が第１のニップ部の手前において定着ベルト２に接触し、画像の乱れが発生しないよう角度θ１を確保し、定着ベルト２を自然な形状に近づけるために、定着ベルト２の回転方向の上流側の形状ｒ２の半径よりも下流側の第１のニップ部入り口近くの形状ｒ３の半径を小さくすることが望ましい。 Further, the arc shape of the support member 103 is such that, as in the support member 193 shown in FIG. 19, the unfixed toner 6 on the recording medium 7 is moved to the first nip portion by the wavy or slack of the fixing belt 2 or the recording medium 7. In order to secure the angle θ1 so that the image is not disturbed by contact with the fixing belt 2 in front of the fixing belt 2 and to bring the fixing belt 2 closer to a natural shape, the radius of the shape r2 on the upstream side in the rotation direction of the fixing belt 2 is larger. It is also desirable to reduce the radius of the shape r3 near the first nip entrance on the downstream side.

図１３において、印刷動作時、つまり定着ベルト２が、加圧ローラ５によって矢印Ｄが示す方向に回転駆動されると、定着ベルト２は、加圧部材としての定着パッド１０９と加圧ローラ５との第１のニップ部と、押圧ローラ１０８と面状ヒータ１０４の圧接部との間で張架され、支持部材１０３の湾曲部に接触し、面状ヒータ１０４と支持部材１０３とに対して摺動しながら回転する。 In FIG. 13, during the printing operation, that is, when the fixing belt 2 is rotationally driven by the pressure roller 5 in the direction indicated by the arrow D, the fixing belt 2 includes the fixing pad 109 as the pressure member and the pressure roller 5. The first nip portion is stretched between the pressing roller 108 and the pressure contact portion of the planar heater 104, contacts the curved portion of the support member 103, and slides relative to the planar heater 104 and the support member 103. Rotates while moving.

電力が供給され、発熱している状態の面状ヒータ１０４によって、押圧ローラ１０８で面状ヒータ１０４に圧接された定着ベルト２と、面状ヒータ１０４と接触している支持部材１０３が加熱される。 The sheet heater 104 that is supplied with power and generates heat heats the fixing belt 2 that is pressed against the sheet heater 104 by the pressure roller 108 and the support member 103 that is in contact with the sheet heater 104. .

この加熱された支持部材１０３は、回転駆動によって接触する定着ベルト２を加熱する。図示しない温度検知手段によって定着ベルト２の表面温度を検知し、これをもとに図示しない制御部によって面状ヒータ１０４への供給電力が制御され、定着ベルト２の表面を適正温度に維持する。 The heated support member 103 heats the fixing belt 2 that is in contact with the rotating support member 103. The surface temperature of the fixing belt 2 is detected by a temperature detection unit (not shown), and the power supplied to the planar heater 104 is controlled by a control unit (not shown) based on this temperature to maintain the surface of the fixing belt 2 at an appropriate temperature.

定着ベルト２が、押圧ローラ１０８と面状ヒータ１０４との第３のニップ部と、定着パッド１０９と加圧ローラ５との第１のニップ部の両方で挟持され、加圧ローラ５側の接触面により定着ベルト２が従動回転し始めると、第１のニップ部が回転駆動されてから、定着ベルト２を通じて第３のニップ部が従動するため、第１と第３のニップ部間で定着ベルト２が引っ張られ、支持部材１０３の湾曲部の摺動面に定着ベルト２が巻き付けられる。 The fixing belt 2 is sandwiched by both the third nip portion between the pressing roller 108 and the planar heater 104 and the first nip portion between the fixing pad 109 and the pressure roller 5, and contacts the pressure roller 5 side. When the fixing belt 2 starts to be driven to rotate by the surface, the third nip portion is driven through the fixing belt 2 after the first nip portion is rotationally driven, so that the fixing belt is interposed between the first and third nip portions. 2 is pulled, and the fixing belt 2 is wound around the sliding surface of the curved portion of the support member 103.

なお、定着ベルト２を支持部材１０３に効果的に巻き付かせるためには、第１と第３のニップ部は、定着ベルト２の回転を中心とすると、９０度以上の位置関係にあるものとする。 In order to effectively wind the fixing belt 2 around the support member 103, the first and third nip portions have a positional relationship of 90 degrees or more with the rotation of the fixing belt 2 as the center. To do.

トナー６が転写された記録媒体７は定着ベルト２に形成されたニップ部を通過して搬送され、記録媒体７上のトナー６が定着ベルト２及び加圧ローラ５による加熱及び加圧により記録媒体７に定着される。 The recording medium 7 onto which the toner 6 has been transferred is conveyed through a nip formed on the fixing belt 2, and the toner 6 on the recording medium 7 is heated and pressed by the fixing belt 2 and the pressure roller 5 to record the recording medium. 7 is fixed.

ニップ部内において、定着ベルト２の弾性層５２と、定着パッド１０９の弾性層１０９ｂと、定着ローラ１の弾性層３２とは、記録媒体７の表面の凹凸による段差と、カラー画像で有ればトナー６が多層のために生じる段差に対して、弾性変形することで追従し、定着ムラのない良好な定着を行う。 In the nip portion, the elastic layer 52 of the fixing belt 2, the elastic layer 109b of the fixing pad 109, and the elastic layer 32 of the fixing roller 1 are stepped due to unevenness on the surface of the recording medium 7, and toner if it is a color image. 6 follows the step generated due to the multilayer by elastically deforming, and performs good fixing without uneven fixing.

このように、押圧ローラ１０８で定着ベルト２を支持部材１０３に押圧し、その支持部材１０３と面状ヒータ１０４とを一体化することにより、定着ベルト２および支持部材１０３を面状ヒータ１０４で安定的に加熱することが可能となった。 In this way, the fixing belt 2 is pressed against the support member 103 by the pressing roller 108, and the support member 103 and the planar heater 104 are integrated to stabilize the fixing belt 2 and the support member 103 with the planar heater 104. Heating was possible.

また、定着ベルト２が回転するときに、定着ベルト２を加圧部材としての定着パッド１０９と加圧ローラ５のニップ部と、面状ヒータ１０４と押圧ローラ１０８の圧接部との間で張架し、支持部材１０３の湾曲部の摺動面に接触させるようにしたことにより、面状ヒータ１０４で加熱された支持部材１０３から定着ベルト２へ伝熱することが可能となり、定着ベルト２を加熱する時間を長くすることが可能となった。 Further, when the fixing belt 2 rotates, the fixing belt 2 is stretched between the fixing pad 109 as a pressure member and the nip portion of the pressure roller 5, and the pressure contact portion of the sheet heater 104 and the pressure roller 108. In addition, by making contact with the sliding surface of the curved portion of the support member 103, heat can be transferred from the support member 103 heated by the planar heater 104 to the fixing belt 2, and the fixing belt 2 is heated. It became possible to lengthen the time to do.

このように押圧ローラ１０８を設けたことにより、定着ベルト２を安定的に面状ヒータ１０４に接触させるとともに、面状ヒータ１０４を支持部材１０３に押圧して一体化することが可能となり、また定着ベルト２を定着パッド１０９と加圧ローラ５のニップ部と、面状ヒータ１０４と押圧ローラ１０８の圧接部との間で張架することにより、回転する定着ベルト２を支持部材１０３の湾曲部に接触させることが可能になったので、熱伝達効率が高くなり、定着ベルト２の加熱時間を短縮することが可能となった。 By providing the pressure roller 108 in this manner, the fixing belt 2 can be stably brought into contact with the planar heater 104, and the planar heater 104 can be pressed and integrated with the support member 103, and the fixing can be performed. The belt 2 is stretched between the nip portion between the fixing pad 109 and the pressure roller 5 and the pressure contact portion between the sheet heater 104 and the pressure roller 108, so that the rotating fixing belt 2 is attached to the curved portion of the support member 103. Since the contact can be achieved, the heat transfer efficiency is increased, and the heating time of the fixing belt 2 can be shortened.

なお、本実施例では、定着ベルト２を安定的に面状ヒータ１０４に接触させる押圧部材として、押圧ローラを用いたが、定着ベルト２を面状ヒータ１０４に押付けることができるものであれば、スプリングなどの付勢手段によって定着ベルトを押圧するパッドを用いても良い。 In this embodiment, a pressing roller is used as a pressing member for stably bringing the fixing belt 2 into contact with the planar heater 104, but any member that can press the fixing belt 2 against the planar heater 104 is used. Alternatively, a pad that presses the fixing belt by a biasing means such as a spring may be used.

以上説明したように、第３の実施例では、定着ベルトを介して面状ヒータを支持部材に押圧する押圧ローラを設け、面状ヒータの熱を支持部材に伝達し、その支持部材に回転する定着ベルトを接触させることにより、熱伝達効率が高くなり、定着ベルトの加熱時間を短縮することができるという効果が得られる。 As described above, in the third embodiment, the pressing roller that presses the planar heater against the support member via the fixing belt is provided, the heat of the planar heater is transmitted to the support member, and the support member rotates. By bringing the fixing belt into contact with each other, it is possible to increase the heat transfer efficiency and to shorten the heating time of the fixing belt.

図２０は第４の実施例における定着装置の構成を示す断面図である。なお、上述した第１および第３の実施例と同様の部分は、同一の符号を付してその説明を省略する。 FIG. 20 is a cross-sectional view showing the structure of the fixing device in the fourth embodiment. The same parts as those in the first and third embodiments described above are denoted by the same reference numerals, and the description thereof is omitted.

図２０において、定着装置２６は、定着ベルト２を張架するとともに、その定着ベルト２を内側から付勢する付勢手段としての張架ローラ２０１を備えている。 In FIG. 20, the fixing device 26 includes a tension roller 201 as a biasing unit that stretches the fixing belt 2 and biases the fixing belt 2 from the inside.

張架ローラ２０１は、図示しないレバーにベアリングを介して回転自在に保持されており、ばね等の図示しない弾性体により、定着ベルト２が支持部材１０３に接触する方向で、且つ定着ベルト２が面状ヒータ１０４と離れない方向、つまり図２１に示す面状ヒータ１０４と定着ベルト２との接触面と、定着ベルト２とのなす角度θ２が、矢印Ｍの方向に０度より大きくなるように、図２０における矢印Ｋが示す方向に付勢されている。 The tension roller 201 is rotatably supported by a lever (not shown) via a bearing, and the fixing belt 2 is in a direction in which the fixing belt 2 comes into contact with the support member 103 by an elastic body (not shown) such as a spring. 21, that is, the angle θ2 formed by the fixing belt 2 and the contact surface between the planar heater 104 and the fixing belt 2 shown in FIG. It is biased in the direction indicated by the arrow K in FIG.

張架ローラ２０１の表面は、定着ローラ１あるいは加圧ローラ５と同様に弾性層を備え、例えばシリコンゴム、またはスポンジ状シリコンゴム、フッ素ゴムなど耐熱性の高いゴム材料が用いられる。芯金も同様に一定の剛性を保つためにアルミニウム、鉄、ステンレスなどの金属製パイプまたはシャフトが用いられる。また弾性層の上に離型層として、例えばＰＴＦＥ（ポリテトラフルオロエチレン）、ＰＦＡ（パーフルオロアルコキシアルカン）、ＦＥＰ（パーフルオロエチレン−プロペンコポリマー）などの代表的なフッ素系樹脂（厚さが好ましくは１０〜５０μｍ）を形成してもよい。 The surface of the tension roller 201 is provided with an elastic layer like the fixing roller 1 or the pressure roller 5, and a rubber material having high heat resistance such as silicon rubber, sponge-like silicon rubber, or fluorine rubber is used. Similarly, a metal pipe such as aluminum, iron, or stainless steel or a shaft is used for the metal core in order to maintain a certain rigidity. Further, as a release layer on the elastic layer, for example, a typical fluorine resin (thickness is preferable) such as PTFE (polytetrafluoroethylene), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylene-propene copolymer), etc. 10 to 50 μm) may be formed.

図２０において、印刷動作時、張架ローラ２０１で支持部材１０３に接触し、且つ面状ヒータ１０４から離れない方向に張架された定着ベルト２は、支持部材１０３と面状ヒータ１０４に対して摺動しながら加圧ローラ５によって矢印Ｄが示す方向に回転駆動される。 In FIG. 20, during the printing operation, the fixing belt 2 that is in contact with the support member 103 by the stretching roller 201 and is not separated from the planar heater 104 is fixed to the support member 103 and the planar heater 104. While being slid, the pressure roller 5 is rotationally driven in the direction indicated by the arrow D.

面状ヒータ１０４に電力が供給されることで付勢された押圧ローラ１０８で面状ヒータ１０４に圧接された定着ベルト２と、面状ヒータ１０４に一体化された支持部材１０３とが加熱される。この加熱された支持部材１０３は摺動回転する定着ベルト２を加熱する。 The fixing belt 2 pressed against the planar heater 104 by the pressing roller 108 energized by supplying electric power to the planar heater 104 and the support member 103 integrated with the planar heater 104 are heated. . The heated support member 103 heats the fixing belt 2 that slides and rotates.

このように張架ローラ２０１を設けたことにより、定着ベルト２を安定的に支持部材１０３に接触させることが可能になったので、第３の実施例よりも熱伝達効率が高くなり、定着ベルト２の加熱時間をさらに短縮することが可能となった。 Since the tension roller 201 is provided in this manner, the fixing belt 2 can be stably brought into contact with the support member 103. Therefore, the heat transfer efficiency is higher than that in the third embodiment, and the fixing belt It became possible to further shorten the heating time of 2.

以上説明したように、第４の実施例では、張架ローラを設けたことにより、定着ベルトを安定的に支持部材に接触させることができ、熱伝達効率をさらに高め、定着ベルトの加熱時間をさらに短縮することができるという効果が得られる。 As described above, in the fourth embodiment, by providing the stretching roller, the fixing belt can be stably brought into contact with the support member, further improving the heat transfer efficiency and reducing the heating time of the fixing belt. Furthermore, the effect that it can shorten is acquired.

なお、第１の実施例から第４の実施例において、画像形成装置をプリンタとして説明したが、これに限られることなく、複合機（ＭＦＰ：ＭｕｌｔｉＦｕｎｃｔｉｏｎＰｅｒｉｐｈｅｒａｌｓ）、ファクシミリ、または複写装置としてもよい。 In the first to fourth embodiments, the image forming apparatus has been described as a printer. However, the image forming apparatus is not limited to this, and may be a multi function peripheral (MFP), a facsimile, or a copying apparatus. .

また、定着ベルトは、無端状のベルトとして説明したが、終端を有するものであってもよい。 Further, although the fixing belt has been described as an endless belt, it may have an end.

さらに、第１の実施例から第４の実施例の構成を組み合わせることによって、より効率良く定着ベルトを加熱することができる。 Further, the fixing belt can be heated more efficiently by combining the configurations of the first to fourth embodiments.

１定着ローラ
２定着ベルト
３、１０３支持体（支持部材）
４、１０４面状発熱体（面状ヒータ）
５加圧ローラ
６トナー
７用紙（記録媒体）
８補助ローラ
９、１０９加圧部材（定着パッド）
２０プリンタ（画像形成装置）
２３ＬＥＤヘッド
２４用紙搬送部
２５トナー像形成部
２６定着装置
１０８押圧ローラ
１２０、１２１レバー
２０１張架ローラ DESCRIPTION OF SYMBOLS 1 Fixing roller 2 Fixing belt 3, 103 Support body (support member)
4, 104 Planar heating element (planar heater)
5 Pressure roller 6 Toner 7 Paper (recording medium)
8 Auxiliary roller 9, 109 Pressure member (fixing pad)
20 Printer (image forming device)
23 LED head 24 Paper transport unit 25 Toner image forming unit 26 Fixing device 108 Pressure roller 120, 121 Lever 201 Tension roller

Claims

In a fixing device that heats and fixes a developer on a medium,
A fixing member for supplying heat to the developer and the medium;
A heating element for heating the fixing member;
A support member for supporting the heating element;
A pressing member that presses the fixing member against the heating element;
A first pressure member in contact with the fixing member;
A second pressure member in contact with the fixing member;
The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member,
At least one of the first pressure member and the second pressure member is a rotator, and the rotator contacts and rotates the fixing member to move the fixing member .
The fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium;
The pressing member presses the heating element to the support member via the fixing belt,
The first pressure member contacts one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt;
The second pressure member is a pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt.
The support member is in contact with the fixing belt between the pressing member and the pressure roller, and a length of a contact portion with the fixing belt in a moving direction of the fixing belt is perpendicular to the moving direction. A fixing device characterized by being different between a central portion and an end portion .

The fixing device according to claim 1.
The support member is
On the upstream side in the moving direction of the fixing member with respect to the heating element, it is not in contact with the fixing member,
A fixing device, wherein the fixing member is in contact with the fixing member on the downstream side in the moving direction of the fixing member with respect to the heat generating element.

The fixing device according to claim 1 .
The fixing device, wherein the fixing belt is an endless belt.

The fixing device according to claim 3 .
The fixing device, wherein the fixing belt is stretched between the pressing member and the pressure roller when rotating, and contacts the support member.

The fixing device according to any one of claims 1 to 4 ,
The fixing device, wherein the first pressure member is a fixing roller.

The fixing device according to any one of claims 1 to 5 ,
The fixing device is characterized in that the support member is molded by an extrusion process.

The fixing device according to any one of claims 1 to 5 ,
The fixing device is characterized in that the support member is molded from a plate material by press working.

In a fixing device that heats and fixes a developer on a medium,
A fixing member that supplies heat to the developer and the medium and moves in a predetermined direction;
A heating element for heating the fixing member;
A support member that supports the heating element and has a sliding portion that slides on the fixing member;
A pressing member that presses the fixing member against the heating element;
A first pressure member in contact with the fixing member;
A second pressure member in contact with the fixing member;
The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member,
The sliding portion is disposed on the downstream side of the heating element in the moving direction of the fixing member,
At least one of the first pressure member and the second pressure member is a rotator, and the rotator contacts and rotates the fixing member to move the fixing member .
The fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium;
The pressing member presses the heating element to the support member via the fixing belt,
The first pressure member contacts one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt;
The second pressure member is a pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt.
The support member has a substantially semi-cylindrical curved surface, and the curved surface is in contact with the fixing belt between the pressing member and the first pressure member,
The fixing device, wherein the first pressure member is formed on the support member .

The fixing device according to claim 8 .
The support member is
On the upstream side in the moving direction of the fixing member with respect to the heating element, it is not in contact with the fixing member,
A fixing device, wherein the fixing member is in contact with the fixing member on the downstream side in the moving direction of the fixing member with respect to the heat generating element.

The fixing device according to claim 8 or 9 ,
The fixing belt is an endless belt,
A fixing device, wherein a radius of the curved surface is substantially equal to a radius of the fixing belt.

The fixing device according to claim 8 or 9 ,
The fixing belt is an endless belt,
A fixing device, wherein a radius of the curved surface on the downstream side in the moving direction of the fixing belt is smaller than a radius of the curved surface on the upstream side.

The fixing device according to claim 10 or 11 ,
The fixing device, wherein the fixing belt is stretched between the pressing member and the pressure roller when rotating, and contacts the curved surface.

The fixing device according to any one of claims 10 to 12 ,
A tension roller is provided to stretch the fixing belt;
The fixing device, wherein the fixing belt is in contact with the curved surface.

The fixing device according to claim 13 .
The fixing device, wherein the tension roller is urged in a direction in which the fixing belt is brought into contact with the curved surface and in a direction in which the belt is brought into contact with the heating element.

Image forming apparatus characterized by claim 1 having a fixing apparatus according to any one of claims 14.

In a fixing device that heats and fixes a developer on a medium,
A fixing member for supplying heat to the developer and the medium;
A heating element for heating the fixing member;
A support member for supporting the heating element;
A pressing member that presses the fixing member against the heating element;
A first pressure member in contact with the fixing member;
A second pressure member in contact with the fixing member;
The fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium;
The pressing member presses the heating element to the support member via the fixing belt,
The first pressure member contacts one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt;
The second pressure member is a pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt.
The support member is in contact with the fixing belt between the pressing member and the pressure roller, and a length of a contact portion with the fixing belt in a moving direction of the fixing belt is perpendicular to the moving direction. A fixing device characterized by being different between a central portion and an end portion.

The fixing device according to claim 16 .
The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member,
At least one of the first pressure member and the second pressure member is a rotating body, and the rotating body contacts the fixing member and rotates to move the fixing member. A fixing device.

The fixing device according to claim 17 .
The support member is
On the upstream side in the moving direction of the fixing member with respect to the heating element, it is not in contact with the fixing member,
A fixing device, wherein the fixing member is in contact with the fixing member on the downstream side in the moving direction of the fixing member with respect to the heat generating element.

In a fixing device that heats and fixes a developer on a medium,
A fixing member that supplies heat to the developer and the medium and moves in a predetermined direction;
A heating element for heating the fixing member;
A support member that supports the heating element and has a sliding portion that slides on the fixing member;
A pressing member that presses the fixing member against the heating element;
A first pressure member in contact with the fixing member;
A second pressure member in contact with the fixing member;
The sliding portion is disposed on the downstream side of the heating element in the moving direction of the fixing member,
The fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium;
The pressing member presses the heating element to the support member via the fixing belt,
The first pressure member contacts one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt;
The second pressure member is a pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt.
The support member has a substantially semi-cylindrical curved surface, and the curved surface is in contact with the fixing belt between the pressing member and the first pressure member,
The fixing device, wherein the first pressure member is formed on the support member.

The fixing device according to claim 19 .
The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member,
At least one of the first pressure member and the second pressure member is a rotating body, and the rotating body contacts the fixing member and rotates to move the fixing member. A fixing device.

The fixing device according to claim 20 , wherein
The support member is
On the upstream side in the moving direction of the fixing member with respect to the heating element, it is not in contact with the fixing member,
A fixing device, wherein the fixing member is in contact with the fixing member on the downstream side in the moving direction of the fixing member with respect to the heat generating element.

In a fixing device that heats and fixes a developer on a medium,
A fixing member that supplies heat to the developer and the medium and moves in a predetermined direction;
A heating element for heating the fixing member;
A support member that supports the heating element and has a sliding portion that slides on the fixing member;
A pressing member that presses the fixing member against the heating element;
A first pressure member in contact with the fixing member;
A second pressure member in contact with the fixing member;
The sliding portion is disposed on the downstream side of the heating element in the moving direction of the fixing member,
The fixing member is a fixing belt that moves together with the medium and supplies heat to the developer and the medium;
The pressing member presses the heating element to the support member via the fixing belt,
The first pressure member contacts one surface of the fixing belt downstream of the pressing member in the moving direction of the fixing belt;
The second pressure member is a pressure roller that is disposed to face the first pressure member across the fixing belt and presses the medium against the fixing belt.
The support member has a substantially semi-cylindrical curved surface, and the curved surface is in contact with the fixing belt between the pressing member and the first pressure member,
The first pressure member is formed on the support member,
The fixing belt is an endless belt,
A fixing device, wherein a radius of the curved surface on the downstream side in the moving direction of the fixing belt is smaller than a radius of the curved surface on the upstream side.

The fixing device according to claim 22 , wherein
The heating element is disposed on the upstream side of the support member in the moving direction of the fixing member,
At least one of the first pressure member and the second pressure member is a rotating body, and the rotating body contacts the fixing member and rotates to move the fixing member. A fixing device.

24. The fixing device according to claim 23 .
The support member is
On the upstream side in the moving direction of the fixing member with respect to the heating element, it is not in contact with the fixing member,
A fixing device, wherein the fixing member is in contact with the fixing member on the downstream side in the moving direction of the fixing member with respect to the heat generating element.