JPH05313528A - Thermal fixing device - Google Patents

Thermal fixing device

Info

Publication number
JPH05313528A
JPH05313528A JP11716792A JP11716792A JPH05313528A JP H05313528 A JPH05313528 A JP H05313528A JP 11716792 A JP11716792 A JP 11716792A JP 11716792 A JP11716792 A JP 11716792A JP H05313528 A JPH05313528 A JP H05313528A
Authority
JP
Japan
Prior art keywords
heat
fixing device
heating element
holder
ptc heating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP11716792A
Other languages
Japanese (ja)
Inventor
Tsutomu Hiraoka
平岡　　力
Junichi Matsuno
順一 松野
Masao Mitani
正男 三谷
Masaru Oda
大 小田
Shunichi Tsumura
俊一 津村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koki Holdings Co Ltd
Hitachi Ltd
Ube Corp
Original Assignee
Hitachi Ltd
Ube Industries Ltd
Hitachi Koki Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd, Ube Industries Ltd, Hitachi Koki Co Ltd filed Critical Hitachi Ltd
Priority to JP11716792A priority Critical patent/JPH05313528A/en
Priority to US08/057,637 priority patent/US5499087A/en
Priority to DE19934315741 priority patent/DE4315741C2/en
Publication of JPH05313528A publication Critical patent/JPH05313528A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
    • G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat
    • G03G15/2064—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat combined with pressure
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
    • G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat
    • G03G15/2053—Structural details of heat elements, e.g. structure of roller or belt, eddy current, induction heating
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/20—Details of the fixing device or porcess
    • G03G2215/2003—Structural features of the fixing device
    • G03G2215/2016—Heating belt
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/20—Details of the fixing device or porcess
    • G03G2215/2003—Structural features of the fixing device
    • G03G2215/2016—Heating belt
    • G03G2215/2035—Heating belt the fixing nip having a stationary belt support member opposing a pressure member
    • G03G2215/2038—Heating belt the fixing nip having a stationary belt support member opposing a pressure member the belt further entrained around one or more rotating belt support members

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
  • Resistance Heating (AREA)

Abstract

PURPOSE:To realize the thermal fixing device and an electrophotographic device which are stable in electric and thermal performance, low in power consumption and high in reliability, in a belt type thermal fixing device using a PTC heating element, and an electrophotographic device using the belt type thermal fixing device. CONSTITUTION:The PTC heating element 21 is adhered to a heat slinger 22 with an electrical insulating adhesive 25 having excellent thermal conductivity, the circumference is surrounded by a heat insulator frame 23 to obtain a heating body 17, and the heating body 17 is fitted to the bottom part of a recessed part provided on a holder 18 by interposing an elastic body 19 such as a silicone rubber. Thus, even if a fixing belt 3, the heating body 17, and the holder 18 are thermally deformed, a stable contact state is maintained among an electric wire 20, the heating body 17, and the fixing belt 3 with the elastic force of the elastic body 19.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、熱定着装置及びこの熱
定着装置を備えた電子写真装置に係り、特に発熱体とし
て正の抵抗温度特性（Ｐｏｓｉｔｉｖｅ Ｔｅｍｐｅｒ
ａｔｕｒｅＣｏｅｆｆｉｃｉｅｎｔ ｏｆ ｒｅｓｉｓ
ｔｉｖｉｔｙ 特性）を有するＰＴＣ発熱体を用い、そ
の熱エネルギ−をベルトを介して記録材に付与する熱定
着装置及びこの熱定着装置を備えた電子写真装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device and an electrophotographic apparatus equipped with the heat fixing device, and more particularly, to a positive resistance temperature characteristic (Positive Temper) as a heating element.
atureCoefficient of resistance
The present invention relates to a thermal fixing device that uses a PTC heating element having a (tivity characteristic) and applies its thermal energy to a recording material via a belt, and an electrophotographic apparatus including the thermal fixing device.

【０００２】[0002]

【従来の技術】従来、複写機や光プリンタ等の電子写真
装置に用いられる定着装置としては、内部にヒ−タを有
して所定の温度に維持された加熱ロ−ラと、弾性層で被
覆され加熱ロ−ラに圧接する加圧ロ−ラで構成され、前
記両ロ−ラにより、未定着のトナ−画像が形成された記
録材を挟持搬送しながら加熱する熱ロ−ラ定着方式が広
く使用されている。2. Description of the Related Art Conventionally, as a fixing device used in an electrophotographic apparatus such as a copying machine or an optical printer, a heating roller having a heater inside and maintained at a predetermined temperature and an elastic layer are used. A heat roller fixing system which is composed of a pressure roller which is covered and pressure-contacts a heating roller, and which heats the recording material on which an unfixed toner image is formed while being nipped and conveyed by both rollers. Is widely used.

【０００３】しかしながら熱ロ−ラ定着方式では、加熱
ロ−ラの熱容量が大きいため、加熱ロ−ラが定着に必要
な温度に達するまでの時間（ウォ−ムアップタイム）が
長く、またその温度を維持するための消費電力が大き
い。更に加熱ロ−ラと記録材とが剥離する点の温度及び
角度を自由に設定することが難しいため、加熱ロ−ラへ
トナ−が付着する、いわゆるオフセットが生じたり、記
録材が巻きついたりする等の欠点があった。However, in the heat roller fixing system, since the heat capacity of the heating roller is large, the time required for the heating roller to reach the temperature required for fixing (warm-up time) is long, and the temperature is also high. Power consumption for maintaining Further, since it is difficult to freely set the temperature and angle of the point where the heating roller and the recording material are separated from each other, the toner adheres to the heating roller, so-called offset occurs, or the recording material winds up. There were drawbacks such as doing.

【０００４】そこでこれらの欠点が無いベルト定着方式
が種々提案されている。このベルト定着方式は、加熱体
にベルトを接触させて移動させ、ベルトの加熱体側とは
反対側の面に記録材を加圧部材で加圧密着させてベルト
とともに加熱***置を移動通過させ、加熱体からベルト
を介して記録材に熱エネルギ−を与える方式である。そ
のためベルト定着方式は、熱ロ−ラ定着方式に比べ熱効
率が良く、ウォ−ムアップタイムや消費電力を小さくで
きる。又、用紙上のトナ−を加熱して溶融させた後、十
分冷却して用紙に固着させてベルトと剥離させることが
できる。Therefore, various belt fixing methods which do not have these drawbacks have been proposed. In this belt fixing method, the heating member is brought into contact with the belt to move, and the recording material is pressed and adhered to the surface of the belt opposite to the heating member side with a pressing member to move and pass through the heating member position together with the belt. In this method, heat energy is applied to a recording material from a heating body via a belt. Therefore, the belt fixing method has higher thermal efficiency than the heat roller fixing method, and the warm-up time and power consumption can be reduced. Further, after the toner on the paper is heated and melted, it can be sufficiently cooled and fixed to the paper to be separated from the belt.

【０００５】このベルト定着方式における加熱体として
は、厚膜ヒ−タ、ハロゲンランプ、ＰＴＣ発熱体等が考
案されている。特開昭６３−３１３１８２号公報では、
アルミナ基材にＴａ2Ｎ等よりなる線状若しくは帯状の
電気抵抗材を塗工した低熱容量の厚膜ヒ−タを使用して
おり、加熱体表面にベルトとの摺動保護層としてＴａ2
Ｏ5を形成している。ハロゲンランプ等の輻射熱を利用
したものとしては、米国特許第３，８１１，８２８号公
報又は特開平３−２５４７５号公報に開示のものがあげ
られる。更に特開平２−１５８７８２号公報には、加熱
体にＰＴＣ発熱体を用いたものとしてＰＴＣ発熱体をア
ルミニウムや銅等の金属板又はアルミナ等のセラミック
ス板の線状加熱板に接着して一体化した加熱体を用いて
いるものが開示されている。Thick film heaters, halogen lamps, PTC heating elements, etc. have been devised as heating elements in this belt fixing system. In Japanese Patent Laid-Open No. 63-313182,
Atsumakuhi low heat capacity was coated with linear or strip-shaped electrical resistance material consisting of Ta 2 N or the like to the alumina substrate - we use data, Ta 2 as a sliding protective layer of the belt in the heating surface
It forms O 5 . Examples of those utilizing radiant heat from a halogen lamp and the like include those disclosed in US Pat. No. 3,811,828 or Japanese Patent Laid-Open No. 3-25475. Further, in Japanese Unexamined Patent Publication No. 2-158782, a PTC heating element is used as a heating element, and the PTC heating element is bonded to a linear heating plate of a metal plate such as aluminum or copper or a ceramic plate such as alumina to be integrated. What uses the above-mentioned heating body is disclosed.

【０００６】これら加熱体のなかで、ＰＴＣ発熱体は、
ＰＴＣ発熱体材料に応じた固有の温度（キュ−リ温度）
に達すると急激に抵抗値が増大して発熱が抑制される自
己温度制御性を持つため、厚膜ヒ−タ、ハロゲンランプ
のように加熱体の温度を検出し制御することが不要であ
り、更に他の加熱体よりも最大消費電力を低くすること
が容易である。Among these heating elements, the PTC heating element is
Peculiar temperature (Curie temperature) according to PTC heating element material
Since it has self-temperature controllability in which the resistance value suddenly increases and heat generation is suppressed when it reaches, it is not necessary to detect and control the temperature of the heating element like thick film heaters and halogen lamps. Furthermore, it is easier to reduce the maximum power consumption than other heating bodies.

【０００７】[0007]

【発明が解決しようとする課題】しかしながら、ＰＴＣ
発熱体をベルト式熱定着装置に用いる場合、ＰＴＣ発熱
体特有のピンチ効果（ＰＴＣ発熱体内部に温度分布が生
じると、電流が流れにくくなり発熱量が低下する現象）
があり、ＰＴＣ発熱体の発熱量を有効に活用できないと
いった問題が生じる。即ち、ＰＴＣ発熱体の放熱面の温
度がベルトに熱を奪われて低下しても、放熱面以外の温
度がキュ−リ温度になっていると抵抗値が増大したまま
電流値が減少し、その結果、放熱面の温度を上げること
ができないという問題である。[Problems to be Solved by the Invention] However, PTC
When the heating element is used in a belt-type heat fixing device, a pinch effect peculiar to the PTC heating element (when temperature distribution occurs inside the PTC heating element, current flow becomes difficult and the amount of heat generation decreases)
Therefore, there arises a problem that the calorific value of the PTC heating element cannot be effectively utilized. That is, even if the temperature of the heat radiating surface of the PTC heating element is reduced by heat taken by the belt, if the temperature other than the heat radiating surface is the Curie temperature, the current value decreases while the resistance value increases, As a result, there is a problem that the temperature of the heat radiation surface cannot be increased.

【０００８】又、ＰＴＣ発熱体の支持材が熱変形するこ
とによって、加熱体の放熱面とベルトとの間に空隙がで
き、ベルトに熱が有効に供給されなかったり、或いはＰ
ＴＣ発熱体と電極との接触不良が生じ、そこにア−クが
発生してＰＴＣ発熱体を破損したりするという問題が生
じる。Further, when the support material of the PTC heating element is thermally deformed, a gap is formed between the heat radiation surface of the heating element and the belt, so that heat is not effectively supplied to the belt, or P
There arises a problem that a contact failure between the TC heating element and the electrode occurs, an arc is generated there, and the PTC heating element is damaged.

【０００９】従って、ＰＴＣ発熱体を用いたベルト式熱
定着装置においては、ＰＴＣ発熱体の支持材が熱変形し
ても、ＰＴＣ発熱体と電極との電気的接触状態及び加熱
体の放熱面とベルトとの熱的接触状態が良好に維持でき
るようにし、更にＰＴＣ発熱体内部の温度分布を極力一
様にさせ、ＰＴＣ発熱体全体の温度をベルトの温度変化
に対して敏感に反応させることが必須である。Therefore, in the belt-type thermal fixing device using the PTC heating element, even if the supporting material of the PTC heating element is thermally deformed, the electrical contact state between the PTC heating element and the electrode and the heat radiation surface of the heating element It is possible to maintain good thermal contact with the belt, to make the temperature distribution inside the PTC heating element as uniform as possible, and to make the temperature of the entire PTC heating element sensitive to the temperature change of the belt. Required.

【００１０】特開平２−１５８７８２号公報では、薄く
したＰＴＣ発熱体をアルミニウムや銅等の金属板或いは
アルミナ等のセラミックス板の線状加熱板に接着して一
体化することでＰＴＣ発熱体内部の温度分布を一様にす
る構成になっているが、加熱体の支持材の熱変形による
ＰＴＣ発熱体と電極との電気的接触状態及び加熱体とベ
ルトとの熱的接触状態に対する考慮が十分でなく、その
ため前記のように問題が発生し、実用化するうえで大き
な障害となっていた。In Japanese Patent Laid-Open No. 2-158782, the thinned PTC heating element is adhered to and integrated with a linear heating plate made of a metal plate such as aluminum or copper or a ceramic plate such as alumina to form an internal PTC heating element. Although the temperature distribution is made uniform, sufficient consideration must be given to the electrical contact state between the PTC heating element and the electrode and the thermal contact state between the heating element and the belt due to thermal deformation of the support material of the heating element. As a result, the problems described above occur, which is a major obstacle to practical use.

【００１１】本発明は、ＰＴＣ発熱体を用いたベルト式
熱定着装置における電気的、熱的問題を解決し、信頼性
の高い電子写真装置を提供することを目的とする。An object of the present invention is to solve the electrical and thermal problems in a belt type thermal fixing device using a PTC heating element and to provide a highly reliable electrophotographic device.

【００１２】[0012]

【課題を解決するための手段】上記目的はＰＴＣ発熱体
を用いたベルト式熱定着装置において、ＰＴＣ発熱体の
放熱面と放熱板とを熱伝導性の良い接着剤で接着し、他
の面は断熱材で囲って加熱体とし、加熱体を弾性体を有
するホルダの凹部に断熱性の電気絶縁材料を介在させて
嵌合し、更に放熱面の表面を耐熱性の潤滑剤で被覆した
構成とすることにより達成される。The above object is to provide a belt-type thermal fixing device using a PTC heating element, in which the heat radiation surface of the PTC heating element and the heat radiation plate are bonded with an adhesive having good thermal conductivity, and the other surface is bonded. Is a heating body surrounded by a heat insulating material, and the heating body is fitted into the recess of a holder having an elastic body with a heat insulating electrically insulating material interposed, and the heat radiation surface is covered with a heat resistant lubricant. It is achieved by

【００１３】本発明の熱定着装置には、以下の態様があ
る。The heat fixing device of the present invention has the following modes.

【００１４】（１）無端状の耐熱ベルトと、この耐熱ベ
ルトを回動させる駆動ロ−ラと、耐熱ベルトに接触しＰ
ＴＣ発熱体を支持するホルダとを備えるものであって、
ＰＴＣ発熱体を断熱性の電気絶縁材料を介在させてホル
ダに設けた凹部に嵌合したものである。(1) An endless heat resistant belt, a driving roller for rotating the heat resistant belt, and a P
A holder for supporting the TC heating element,
The PTC heating element is fitted in a recess provided in the holder with a heat insulating electrical insulating material interposed.

【００１５】（２）無端状の耐熱ベルトと、この耐熱ベ
ルトを回動させる駆動ロ−ラと、耐熱ベルトに接触しＰ
ＴＣ発熱体を支持するホルダとを備えるものであって、
ＰＴＣ発熱体をホルダに設けた凹部に弾性体を介在させ
て配置したものである。(2) An endless heat resistant belt, a driving roller for rotating the heat resistant belt, and a P
A holder for supporting the TC heating element,
The PTC heating element is arranged with a resilient member interposed in a recess provided in the holder.

【００１６】（３）無端状の耐熱ベルトと、この耐熱ベ
ルトを回動させる駆動ロ−ラと、耐熱ベルトに接触しＰ
ＴＣ発熱体を支持するホルダとを備えるものであって、
ＰＴＣ発熱体を断熱性の電気絶縁材料を介在させてホル
ダに設けた凹部に嵌合するものであって、断熱性の電気
絶縁材料とホルダに設けた凹部との間に弾性体を配置し
たものである。(3) An endless heat resistant belt, a drive roller for rotating the heat resistant belt, and a P
A holder for supporting the TC heating element,
A PTC heating element is fitted into a recess provided in a holder with a heat insulating electrical insulating material interposed, and an elastic body is disposed between the heat insulating electrical insulating material and the recess provided in the holder. Is.

【００１７】（４）（１）乃至（３）のいずれかに記載
のものであって、ＰＴＣ発熱体の放熱面に熱伝導性の良
い接着剤により放熱板を配置したものである。(4) In any one of (1) to (3), a heat radiating plate is arranged on the heat radiating surface of the PTC heating element with an adhesive having good thermal conductivity.

【００１８】（５）（４）に記載のものであって、ＰＴ
Ｃ発熱体の放熱板の表面又はＰＴＣ発熱体を嵌合したホ
ルダの表面を潤滑性の良い電気絶縁材料で被覆したもの
である。（６）（５）に記載のものであって、潤滑性の
良い電気的絶縁材料としてフッ素樹脂を用いたものであ
る。(5) As described in (4), PT
The surface of the heat radiating plate of the C heating element or the surface of the holder in which the PTC heating element is fitted is coated with an electrically insulating material having good lubricity. (6) In (5), the fluororesin is used as the electrically insulating material having good lubricity.

【００１９】（７）（２）又は（３）に記載のものであ
って、弾性体はゴム硬度５０°〜７０°のものである。(7) In (2) or (3), the elastic body has a rubber hardness of 50 ° to 70 °.

【００２０】（８）（１）乃至（４）のいずれかに記載
のものであって、ホルダを電気絶縁材料としたものであ
る。(8) In any one of (1) to (4), the holder is made of an electrically insulating material.

【００２１】（９）（１）乃至（４）、又は（８）のい
ずれかに記載のものであって、ＰＴＣ発熱体は小片状か
らなり、その放熱面に配置する放熱板に列状に配列し、
ホルダに設けた凹部に嵌合したものである。[0021] (9) In any one of (1) to (4) or (8), the PTC heating element is in the form of a small piece, and the PTC heating element is arranged in rows on a radiation plate arranged on the radiation surface. Arrayed in
It is fitted in the recess provided in the holder.

【００２２】（１０）（９）に記載のものであって、Ｐ
ＴＣ発熱体を複列に配置したものである。(10) As described in (9), P
The TC heating elements are arranged in double rows.

【００２３】（１１）（４）に記載のものであって、放
熱板は耐熱ベルトに接する面が凸状であるものである。(11) In the structure described in (4), the heat dissipation plate has a convex surface in contact with the heat resistant belt.

【００２４】（１２）無端状の耐熱ベルトと、この耐熱
ベルトを回動させる駆動ロ−ラと、耐熱ベルトに接触し
ＰＴＣ発熱体を支持するホルダとを備えるものであっ
て、ＰＴＣ発熱体の放熱面に熱伝導性の良い接着剤によ
り放熱板を配置するとともに放熱板配置面を除く部分を
断熱性の電気絶縁材料をもって覆い、ホルダに設けた凹
部に弾性材を介して嵌合するものであって、ホルダの表
面を潤滑性の良い絶縁材料で被覆したものである。(12) An endless heat-resistant belt, a drive roller for rotating the heat-resistant belt, and a holder for supporting the PTC heat-generating body in contact with the heat-resistant belt. A heat dissipation plate is placed on the heat dissipation surface with an adhesive with good thermal conductivity, and the parts other than the heat dissipation plate placement surface are covered with a heat insulating electrical insulating material, and the heat sink is fitted into the recess provided in the holder via an elastic material. That is, the surface of the holder is covered with an insulating material having good lubricity.

【００２５】又、本発明の電子写真装置は、感光ドラム
と、感光ドラム面上に静電潜像を形成する手段と、感光
ドラム面上に形成した静電潜像を現像してトナ−像とす
る現像手段と、トナ−像を用紙に転写する転写手段と、
用紙に転写されたトナ−像を用紙に定着する熱定着手段
とを備えるものであって、熱定着手段が（１）乃至（１
２）のいずれかの熱定着装置を用いたものである。Further, the electrophotographic apparatus of the present invention comprises a photosensitive drum, a means for forming an electrostatic latent image on the surface of the photosensitive drum, and a toner image by developing the electrostatic latent image formed on the surface of the photosensitive drum. And a transfer means for transferring the toner image onto the sheet,
A heat fixing means for fixing the toner image transferred on the paper to the paper, wherein the heat fixing means is (1) to (1).
The heat fixing device according to any one of 2) is used.

【００２６】[0026]

【作用】ＰＴＣ発熱体と放熱板とを熱伝導性の良い接着
剤で接着し、他の部分を断熱材で囲って加熱体とするこ
とにより、ＰＴＣ発熱体全体の温度が放熱板の温度に大
きく依存することになり、ＰＴＣ発熱体のピンチ効果を
低減できる。又、加熱体を断熱性の電気絶縁材料で断熱
してホルダの凹部に嵌合することにより、加熱体とホル
ダとの熱膨張差による熱変形を緩和することができ、更
にホルダの凹部に配置した弾性体によって加熱体の放熱
面の位置決め及び電極とＰＴＣ発熱体の接触を良好にす
ることができる。[Function] By bonding the PTC heating element and the heat radiation plate with an adhesive having good thermal conductivity and surrounding the other part with a heat insulating material to form a heating element, the temperature of the entire PTC heating element becomes the temperature of the heat radiation plate. This greatly depends on the pinch effect of the PTC heating element. Also, by heat-insulating the heating element with a heat insulating electrical insulating material and fitting it in the recess of the holder, thermal deformation due to the difference in thermal expansion between the heating element and the holder can be mitigated, and the heating element is placed in the recess of the holder. The elastic body can improve the positioning of the heat radiation surface of the heating element and the contact between the electrode and the PTC heating element.

【００２７】放熱面の表面を耐熱性の潤滑剤で被覆する
ことにより、放熱面と耐熱ベルトとの摺動性を向上させ
ることができる。尚、弾性体は加圧ロ−ラの押付力によ
って、放熱面がホルダ表面とフラットになる程度の弾性
率を有するものであれば良い。この理由は弾性率が小さ
い場合にはホルダの耐熱ベルトへの押付け力により放熱
面がホルダの凹部に沈み込み耐熱ベルトと接触不良を生
じ、弾性率が大きい場合には放熱面と耐熱ベルトとの接
触抵抗が増大するためである。By covering the surface of the heat radiating surface with a heat resistant lubricant, the slidability between the heat radiating surface and the heat resistant belt can be improved. It should be noted that the elastic body may be one having an elastic modulus such that the heat radiation surface becomes flat with the holder surface by the pressing force of the pressure roller. The reason for this is that when the elastic modulus is small, the pressing force of the holder on the heat-resistant belt causes the heat-dissipating surface to sink into the recess of the holder, resulting in poor contact with the heat-resistant belt. This is because the contact resistance increases.

【００２８】[0028]

【実施例】以下、本発明の一実施例を図１〜７により説
明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

【００２９】第１図は本実施例を示す電子写真装置の断
面図である。本図において、１点鎖線は用紙の流れを示
す。まず、ホッパ内に堆積した用紙８を一枚ずつ分離給
送して、屈曲ガイドＡ１２へ搬送する。搬送ロ−ラＡ１
０により、用紙８は感光ドラム１５上のトナ−が転写さ
れる転写部へ搬送される。感光ドラム１５上のトナ−像
は現像機１６により可視化される。その後、用紙８は耐
熱性を有する無端状の定着ベルト３、駆動プ−リ４、ホ
ルダ１８の凹部にＰＴＣ発熱体を用いた加熱体１７を嵌
合させた発熱ヘッド２、加圧ロ−ラ５、剥離ロ−ラ６及
び補助ロ−ラ７を備えるベルト式熱定着装置１へ搬送さ
れ、トナ−像は用紙８へ定着される。定着後の用紙８
は、搬送ロ−ラＢ１４により屈曲ガイドＢ１３へ送ら
れ、搬出ロ−ラ１１によりアウトプットトレイ（図示せ
ず）へ搬出される。FIG. 1 is a sectional view of an electrophotographic apparatus showing this embodiment. In the figure, the alternate long and short dash line indicates the flow of paper. First, the sheets 8 accumulated in the hopper are separated and fed one by one, and are conveyed to the bending guide A12. Transport roller A1
When 0, the sheet 8 is conveyed to the transfer portion where the toner on the photosensitive drum 15 is transferred. The toner image on the photosensitive drum 15 is visualized by the developing machine 16. After that, the paper 8 has an endless fixing belt 3 having heat resistance, a driving pulley 4, a heating head 2 in which a heating body 17 using a PTC heating body is fitted in a concave portion of a holder 18, a pressure roller. 5, the separation roller 6 and the auxiliary roller 7 are conveyed to the belt-type heat fixing device 1, and the toner image is fixed on the sheet 8. Paper 8 after fixing
Is sent to the bending guide B13 by the carrying roller B14, and carried out to an output tray (not shown) by the carrying-out roller 11.

【００３０】図２はベルト式熱定着装置１の構成を示し
たものである。以下、その動作を説明する。FIG. 2 shows the structure of the belt-type heat fixing device 1. The operation will be described below.

【００３１】無端状の定着ベルト３は、駆動プ−リ４に
よって矢印Ａの方向へ回転し、未定着トナ−９をのせた
用紙８と共に加熱体１７と加圧ロ−ラ５に接するニップ
部Ｎに搬送される。そしてそこで加熱体１７の熱により
加熱され、次にホルダ１８及び空気によって十分に冷却
された後、剥離ロ−ラ６によって用紙８と分離される。
そのため用紙８上の未定着トナ−９は、ニップ部Ｎで加
熱されて溶融した後、冷却されて用紙８に固着し定着ベ
ルト３と分離されるため、溶融したトナ−が定着ベルト
表面に付着するいわゆる高温オフセットが生じない。The endless fixing belt 3 is rotated in the direction of arrow A by the drive pulley 4 and contacts the heating member 17 and the pressure roller 5 together with the paper 8 on which the unfixed toner 9 is placed. Transported to N. Then, after being heated there by the heat of the heating body 17, and then sufficiently cooled by the holder 18 and air, it is separated from the paper 8 by the peeling roller 6.
Therefore, the unfixed toner 9 on the sheet 8 is heated and melted in the nip portion N, then cooled and fixed to the sheet 8 and separated from the fixing belt 3, so that the melted toner adheres to the surface of the fixing belt. The so-called high temperature offset does not occur.

【００３２】定着ベルト３は、加熱体１７の熱が瞬時に
トナ−及び用紙８に伝わるように十分薄く、且つ用紙８
と接触する面にはトナ−との剥離を容易とするためフッ
素系樹脂層が施したものを用いた。本実施例では、厚さ
３０μｍのＮｉの基材の表面に導電材を添加したＰＴＦ
Ｅ（４フッ化エチレン樹脂）を２０μｍ厚さで被覆した
ものを用いた。尚、定着ベルト３として、ポリイミド、
ポリエ−テルイミド等の耐熱樹脂のフィルムを用いても
良い。The fixing belt 3 is thin enough so that the heat of the heating body 17 can be instantaneously transferred to the toner and the paper 8, and the paper 8 is
The surface contacting with was used with a fluororesin layer for easy peeling from the toner. In this example, PTF in which a conductive material was added to the surface of a Ni base material having a thickness of 30 μm
E (tetrafluoroethylene resin) coated with a thickness of 20 μm was used. As the fixing belt 3, polyimide,
You may use the film of heat resistant resins, such as a polyether imide.

【００３３】駆動プ−リ４と補助ロ−ラ７の表面には、
耐熱性の高摩擦係数を有するシリコ−ンゴムが被覆され
ており、駆動プ−リ４と定着ベルト３との滑りを防いで
いる。尚シリコ−ンゴムの他に、駆動プ−リ４の表面に
微小な凹凸を付けるロ−レット処理を施しても良い。加
圧ロ−ラ５の軸長手方向の形状は、用紙のしわを防止す
るため逆クラウン形状になっている。On the surfaces of the drive pulley 4 and the auxiliary roller 7,
A silicone rubber having a high heat resistance and a high friction coefficient is coated to prevent slipping between the drive pulley 4 and the fixing belt 3. Note that, in addition to the silicone rubber, a knurling process for making fine irregularities on the surface of the drive pulley 4 may be performed. The shape of the pressure roller 5 in the axial longitudinal direction is an inverted crown shape in order to prevent wrinkling of the paper.

【００３４】次に本実施例における発熱ヘッド２の構成
について、図３乃至５により説明する。Next, the structure of the heating head 2 in this embodiment will be described with reference to FIGS.

【００３５】図３は発熱ヘッド２の断面図である。発熱
ヘッド２は２つの構成即ち加熱体１７とホルダ１８とか
らなり、弾性を有する断熱性で電気絶縁性の接着剤Ａ２
４を用いて、加熱体１７をホルダ１８に設けた幅Ｄの凹
部にはめこむ構成となっている。これにより、加熱体１
７とホルダ１８との間に熱膨張差が生じても、接着剤Ａ
２４層がその熱膨張差を吸収し、加熱体１７が長手方向
にわん曲したり捩じれたりするのを防いでいる。接着剤
Ａ２４には、シリコ−ン系或いはポリイミド系の接着剤
を用いた。FIG. 3 is a sectional view of the heating head 2. The heating head 2 is composed of two components, that is, a heating body 17 and a holder 18, and has an elastic and heat insulating and electrically insulating adhesive A2.
4 is used, the heating element 17 is fitted into the concave portion of the width D provided in the holder 18. Thereby, the heating element 1
Even if a difference in thermal expansion occurs between the holder 7 and the holder 18, the adhesive A
The 24 layers absorb the difference in thermal expansion, and prevent the heating element 17 from bending or twisting in the longitudinal direction. As the adhesive A24, a silicone-based or polyimide-based adhesive was used.

【００３６】ホルダ１８は、加熱体１７の放熱面を加圧
ロ−ラ５の加圧によりしっかりと定着ベルト３に接触さ
せ、又ニップ部Ｎを通過した後の定着ベルト３の冷却効
果を大きくするため、本実施例ではホルダの材質として
アルミニウムを用いた。尚、ホルダの材質はアルミニウ
ムの他、ＰＰＳ（ポリフェニレンサルファイド）、ＰＡ
Ｉ（ポリアミドイミド）ＰＩ（ポリイミド）、ＰＥＥＫ
（ポリエ−テルエ−テルケトン）、液晶ポリマ−等の高
耐熱性樹脂や、これらの樹脂とセラミックス，金属又は
ガラス等の複合材であっても良い。The holder 18 firmly brings the heat radiating surface of the heating body 17 into contact with the fixing belt 3 by the pressure of the pressure roller 5, and enhances the cooling effect of the fixing belt 3 after passing through the nip portion N. Therefore, in this embodiment, aluminum is used as the material of the holder. The material of the holder is aluminum, PPS (polyphenylene sulfide), PA
I (polyamide imide) PI (polyimide), PEEK
High heat resistant resins such as (polyether ether ketone) and liquid crystal polymers, and composite materials of these resins and ceramics, metal or glass may be used.

【００３７】弾性体１９は、２４０ｍｍ（長さ）×１２
ｍｍ（幅）×１．５ｍｍ（厚さ）、ゴム硬度５０°Ｈｓ
のシリコ−ンゴムのシ−ト材であり、加熱体１７やホル
ダ１８が熱変形しても、加熱体１７の放熱面がホルダの
凹部に沈み放熱面と定着ベルト３との接触が不良になら
ないよう、又ＰＴＣ発熱体２１と通電用の電線２０が接
触するように、その弾性力で加熱体１７を均一に押圧し
ている。尚、本実施例ではシリコ−ンゴムのゴム硬度が
５０°Ｈｓのものを用いたが、ゴム硬度が７０°Ｈｓの
ものを用いても同様の効果が得られた。又、弾性体１９
としては、板バネ、コイルバネを用いても良い。The elastic body 19 has a length of 240 mm (length) × 12.
mm (width) x 1.5 mm (thickness), rubber hardness 50 ° Hs
This is a sheet material of silicone rubber, and even if the heating body 17 and the holder 18 are thermally deformed, the heat radiating surface of the heating body 17 sinks into the recess of the holder and the contact between the heat radiating surface and the fixing belt 3 does not become defective. Also, the heating element 17 is uniformly pressed by its elastic force so that the PTC heating element 21 and the electric wire 20 for energization come into contact with each other. Although the silicone rubber having a rubber hardness of 50 ° Hs was used in this example, the same effect was obtained even when the silicone rubber having a rubber hardness of 70 ° Hs was used. Also, the elastic body 19
Alternatively, a leaf spring or a coil spring may be used.

【００３８】加熱体１７の放熱面とホルダ１８の表面に
は、ポリイミドの基材にフッ素樹脂を付加した耐熱性，
耐摩耗性及び電気絶縁性の潤滑剤２６を焼成塗工してい
る。これにより、発熱ヘッド２と定着ベルト３との摺動
性を良好にしている。尚、耐熱性、耐摩耗性、電気絶縁
性の潤滑手段として、表面に二硫化モリブデンを焼成し
ても良いし、或いはポリイミド・ポリエ−テルイミド等
の耐熱性樹脂の表面にＰＴＦＥ等のフッ素樹脂層を有す
るフィルムを被覆しても良い。又潤滑剤２６で被覆する
面は、加熱体１７の放熱面のみであっても良い。The heat radiating surface of the heating body 17 and the surface of the holder 18 are heat-resistant by adding fluorocarbon resin to a polyimide base material.
A wear resistant and electrically insulating lubricant 26 is applied by baking. As a result, the slidability between the heating head 2 and the fixing belt 3 is improved. As a lubricating means for heat resistance, wear resistance, and electrical insulation, molybdenum disulfide may be baked on the surface, or a fluororesin layer such as PTFE may be formed on the surface of a heat-resistant resin such as polyimide / polyetherimide. You may coat the film which has. The surface covered with the lubricant 26 may be only the heat dissipation surface of the heating body 17.

【００３９】加熱体１７は、ＰＴＣ発熱体２１の加圧ロ
−ラ５側に熱伝導性及び電気絶縁性の優れた接着剤Ｂ２
５で放熱板２２を接着して放熱面を形成し、他の面は断
熱材フレ−ム２３で囲った構成になっている。ここで放
熱板２２を介して、定着ベルト３にＰＴＣ発熱体２１の
熱エネルギ−が供給されるので、放熱板２２は、熱伝導
性の良い材料で厚さを十分薄くする必要があり、本実施
例では例えば、２４０ｍｍ（長さ）×８ｍｍ（幅）×
０．３ｍｍ（厚さ）の外形寸法のアルミニウム材を用い
た。又接着剤Ｂ２５には、熱伝導性の良いアルミナフィ
ラ入シリコ−ン系の接着剤を使用し、断熱材フレ−ム２
３には、ＰＰＳを用いた。尚、断熱材フレ−ム２３はＰ
ＡＩ，ＰＩ，ＰＥＥＫ又は液晶ポリマ−等の高耐熱性樹
脂や、これらの樹脂とセラミックス，金属又はガラスな
どの複合材でも良い。又、ＰＴＣ発熱体２１はチタン酸
バリウムを焼成した２０ｍｍ（長さ）×８ｍｍ（幅）×
１．０ｍｍ（厚さ）の板状のチップを上記放熱板２２の
定着ベルト３に接する面の裏面にその長手方向に沿って
順次密に複数個配設したものである。この構成によれ
ば、キュ−リ温度の異なるＰＴＣ発熱体チップを組み合
わせることで、加熱体１７の長手方向の温度分布を任意
に設定することができる。The heating element 17 is an adhesive B2 having excellent thermal conductivity and electrical insulation on the pressure roller 5 side of the PTC heating element 21.
In FIG. 5, the heat dissipation plate 22 is adhered to form a heat dissipation surface, and the other surface is surrounded by the heat insulating material frame 23. Here, since the heat energy of the PTC heating element 21 is supplied to the fixing belt 3 via the heat dissipation plate 22, the heat dissipation plate 22 needs to be made sufficiently thin with a material having good thermal conductivity. In the embodiment, for example, 240 mm (length) x 8 mm (width) x
An aluminum material having an outer dimension of 0.3 mm (thickness) was used. Also, as the adhesive B25, an alumina filler-containing silicone adhesive having good thermal conductivity is used.
PPS was used for 3. The insulation frame 23 is P
High heat resistant resin such as AI, PI, PEEK or liquid crystal polymer, or composite material of these resins and ceramics, metal or glass may be used. The PTC heating element 21 is formed by firing barium titanate 20 mm (length) x 8 mm (width) x
A plurality of 1.0 mm (thickness) plate-shaped chips are densely arranged along the longitudinal direction on the back surface of the surface of the heat dissipation plate 22 in contact with the fixing belt 3. According to this structure, the temperature distribution in the longitudinal direction of the heating element 17 can be set arbitrarily by combining the PTC heating element chips having different Curie temperatures.

【００４０】図４にＰＴＣ発熱体チップ２１の電極面を
示す。ＰＴＣ発熱体チップ２１の板厚方向の２面に電極
を設け、片面を全面電極２７とし、その面と反対側の面
にはチップの長手方向に２つの分割電極２８ａ及び２８
ｂを形成している。そして、図５の発熱ヘッドの構成図
に示すように、全面電極２７の面を放熱板２２に接着し
て放熱面とし、分割電極２８ａ及び２８ｂの面には通電
用の電線２０を接着または断熱材フレ−ム２３によって
圧接している。ＰＴＣ発熱体チップ２１は、発熱ヘッド
の長手方向にその間隔を小さくし密に配置する。ＰＴＣ
発熱体の電極の取りだし方法については、他にも板厚方
向或いは幅方向の２面を全面電極として通電する方法も
ある。本実施例では、放熱面を大きくすることで放熱面
温度がＰＴＣ発熱体全体の温度を支配的にすることがで
き、更に通電電極２８ａ及び２８ｂ部分の温度差を低減
できるため、ＰＴＣ発熱体のピンチ効果を防ぐことがで
きる。FIG. 4 shows the electrode surface of the PTC heating element chip 21. Electrodes are provided on two surfaces of the PTC heating element chip 21 in the plate thickness direction, one surface is a full-scale electrode 27, and two split electrodes 28a and 28 are provided on the surface opposite to that surface in the longitudinal direction of the chip.
b is formed. Then, as shown in the configuration diagram of the heating head of FIG. 5, the surface of the whole surface electrode 27 is adhered to the heat dissipation plate 22 to form a heat dissipation surface, and the electric wire 20 for conduction is adhered or insulated to the surfaces of the divided electrodes 28a and 28b. It is pressed by the material frame 23. The PTC heating element chips 21 are densely arranged with a small interval in the longitudinal direction of the heating head. PTC
As for the method of taking out the electrodes of the heating element, there is also another method of energizing the two surfaces in the plate thickness direction or the width direction as the entire electrodes. In the present embodiment, by increasing the heat dissipation surface, the temperature of the heat dissipation surface can dominate the temperature of the entire PTC heating element, and further, the temperature difference between the energizing electrodes 28a and 28b can be reduced. The pinch effect can be prevented.

【００４１】更に図６及び図７により本実施例の効果に
ついて説明する。Further, the effect of this embodiment will be described with reference to FIGS. 6 and 7.

【００４２】図６は、ホルダ凹部の底部に弾性体が無い
場合の加熱体拡大図である。トナ−９を用紙８に定着さ
せるには、ニップ部Ｎにおける定着ベルト３の温度をト
ナ−が十分溶融する温度、例えば１４０℃乃至１８０℃
にする必要がある。しかし、放熱板２２及び定着ベルト
３は熱により面外変形を起こすため、ホルダ凹部の底部
に加熱体１７が沈み、放熱板２２と定着ベルト３との間
に微小な空隙ができ真実の接触部分が減少してしまう。
その結果、放熱板２２の熱を定着ベルト３に十分伝える
ことができず、トナ−９の定着状態が低下する現象が生
じる。FIG. 6 is an enlarged view of the heating body when there is no elastic body at the bottom of the holder recess. In order to fix the toner 9 on the sheet 8, the temperature of the fixing belt 3 in the nip portion N is a temperature at which the toner melts sufficiently, for example, 140 ° C. to 180 ° C.
Need to However, since the heat radiating plate 22 and the fixing belt 3 are out-of-plane deformed by heat, the heating body 17 sinks at the bottom of the holder recess, and a minute gap is formed between the heat radiating plate 22 and the fixing belt 3 to make a true contact portion. Will decrease.
As a result, the heat of the heat dissipation plate 22 cannot be sufficiently transmitted to the fixing belt 3, and the fixing state of the toner 9 deteriorates.

【００４３】本実施例ではこのような現象を防ぐため図
７に示すように、ホルダ凹部の底部の幅Ｄわたる弾性体
１９を配置した。この弾性体１９は、加熱体１７が沈む
ことを防ぎ、放熱板２２がしっかりと定着ベルト３に圧
接するよう、加熱体１７を均一に押しつけるものであ
る。尚、この弾性体１９を配置した状態で放熱板２２の
定着ベルト３に接する面がホルダ１８の表面からわずか
に突出するようにした。このような構成のホルダを定着
ベルト３を介して加圧ロ−ラ５に押付けることにより、
弾性体１９が圧縮し突出している放熱板２２の表面はへ
こみ、ホルダ１８の表面と略同一面となる。更に、図７
に示すように弾性体１９の圧縮により生ずる弾性力ｗで
放熱板２２と定着ベルト３との接触が良好になる。又、
弾性体１９は、ＰＴＣ発熱体２１と電線２０、ＰＴＣ発
熱体２１と放熱板２２との剥離を防止する効果も兼ねて
いる。In the present embodiment, in order to prevent such a phenomenon, as shown in FIG. 7, an elastic body 19 is arranged over the width D of the bottom of the holder recess. The elastic body 19 prevents the heating body 17 from sinking and uniformly presses the heating body 17 so that the heat dissipation plate 22 is firmly pressed against the fixing belt 3. The surface of the heat dissipation plate 22 in contact with the fixing belt 3 with the elastic body 19 arranged is slightly projected from the surface of the holder 18. By pressing the holder having such a structure to the pressure roller 5 via the fixing belt 3,
The surface of the heat radiating plate 22 from which the elastic body 19 is compressed and protrudes is dented and becomes substantially flush with the surface of the holder 18. Furthermore, FIG.
As shown in FIG. 5, the elastic force w generated by the compression of the elastic body 19 improves the contact between the heat dissipation plate 22 and the fixing belt 3. or,
The elastic body 19 also has an effect of preventing the PTC heating element 21 and the electric wire 20 from being separated from the PTC heating element 21 and the heat radiating plate 22.

【００４４】図８は、本発明の他の実施例を説明する図
である。本実施例においては、ホルダ１８の材料として
電気絶縁性と断熱性を有するＰＰＳ樹脂を用いた。又、
ＰＴＣ発熱体２１及び電線２０等を弾性を有する接着剤
Ａ２４でを固定した。FIG. 8 is a diagram for explaining another embodiment of the present invention. In this embodiment, the holder 18 is made of PPS resin having electric insulation and heat insulation. or,
The PTC heating element 21, the electric wire 20, etc. were fixed with an adhesive A24 having elasticity.

【００４５】本実施例の構成は図３に示す実施例におけ
る断熱材フレ−ム２３をホルダまで拡大して用いたもの
であり、その結果前記実施例においてホルダの凹部と加
熱体との間に配置した弾性体を排除できる。 尚、本実
施例ではホルダ材料としてＰＰＳ樹脂を用いたが、ＰＰ
Ｓ樹脂に変わりポリイミド樹脂或いはこれら樹脂とセラ
ミックス，金属又はガラス等の複合材を用いても良い。The structure of the present embodiment is such that the heat insulating material frame 23 in the embodiment shown in FIG. 3 is enlarged and used up to the holder. As a result, in the above-mentioned embodiment, a space between the concave portion of the holder and the heating body is used. The arranged elastic body can be eliminated. Although PPS resin was used as the holder material in this embodiment, PP
Instead of the S resin, a polyimide resin or a composite material of these resins and ceramics, metal or glass may be used.

【００４６】図９は、本発明の他の実施例を説明する図
である。放熱板２２を接着したＰＴＣ発熱体と電線２０
を断熱材フレ−ム２３で囲った加熱体１７を図９の
（ａ）に示すポリイミド・ポリエ−テルイミドなどの耐
熱性樹脂３０の表面にＰＴＦＥなどのフッ素樹脂３１を
配置したフィルム２９で囲み、（ｂ）に示すようにホル
ダの凹部に弾性体１９を介して嵌合したものである。こ
れにより、加熱体１７とホルダ１８との間の電気絶縁性
および断熱性を向上させることができる。FIG. 9 is a diagram for explaining another embodiment of the present invention. PTC heating element to which heat sink 22 is bonded and electric wire 20
The heating element 17 surrounded by a heat insulating material frame 23 is surrounded by a film 29 in which a fluororesin 31 such as PTFE is arranged on the surface of a heat resistant resin 30 such as polyimide / polyetherimide shown in FIG. As shown in (b), it is fitted in the recess of the holder through the elastic body 19. Thereby, the electrical insulation and heat insulation between the heating element 17 and the holder 18 can be improved.

【００４７】図１０は、本発明の他の実施例を説明する
図である。放熱板２２にＰＴＣ発熱体２１を２列に配列
したものである。この構成によれば、ＰＴＣ発熱体チッ
プ２１の幅を大きくすることなしに、ＰＴＣ発熱体チッ
プ２１を２列にすることでニップ幅Ｎを広げることがで
き、高速の定着が可能となる。又、キュ−リ温度の異な
るＰＴＣ発熱体チップを組合わせることで、例えばニッ
プ上流側の温度を高くして、ニップ下流側の温度を低く
するようにニップ内部の温度分布を任意に設定すること
ができる。本実施例ではＰＴＣ発熱体２１を２列設けた
例について説明したが列の数を多くすることにより更に
高速定着が可能となる。FIG. 10 is a diagram for explaining another embodiment of the present invention. The PTC heating elements 21 are arranged in two rows on the heat dissipation plate 22. According to this configuration, the nip width N can be widened by arranging the PTC heating element chips 21 in two rows without increasing the width of the PTC heating element chips 21, which enables high-speed fixing. Further, by combining PTC heating element chips having different Curie temperatures, for example, the temperature distribution inside the nip is arbitrarily set so that the temperature on the upstream side of the nip is increased and the temperature on the downstream side of the nip is decreased. You can In the present embodiment, the example in which the PTC heating elements 21 are provided in two rows has been described, but by increasing the number of rows, higher-speed fixing becomes possible.

【００４８】図１１は、本発明の他の実施例を説明する
図である。本実施例ではニップ部における放熱板２２と
定着ベルト３との接触状態を良くするために、放熱板２
２の長手方向の形状を凸型にした。これにより定着ベル
ト３の面外変形を低減させることができる。定着ベルト
３は、前述したようにニップ部で熱膨張して面外変形を
生ずるが、長手方向即ち定着ベルト３の幅方向に対して
凸型の形状をした放熱板２２に圧接されるため、定着ベ
ルト３の熱膨張はその凸型形状にそって生じ（矢印Ｂ方
向）、面外変形が低減される。尚、図１１の（ａ）に示
す放熱板２２の凸量δは、１．５ｍｍ以下の範囲が良
い。FIG. 11 is a diagram for explaining another embodiment of the present invention. In this embodiment, in order to improve the contact state between the heat dissipation plate 22 and the fixing belt 3 in the nip portion, the heat dissipation plate 2
The shape of 2 in the longitudinal direction was convex. Thereby, the out-of-plane deformation of the fixing belt 3 can be reduced. As described above, the fixing belt 3 thermally expands in the nip portion to cause out-of-plane deformation, but since the fixing belt 3 is pressed against the heat dissipation plate 22 having a convex shape in the longitudinal direction, that is, the width direction of the fixing belt 3, The thermal expansion of the fixing belt 3 occurs along the convex shape (direction of arrow B), and the out-of-plane deformation is reduced. In addition, the convex amount δ of the heat dissipation plate 22 shown in FIG. 11A is preferably in the range of 1.5 mm or less.

【００４９】図１２は、本発明の他の実施例を説明する
図である。本実施例では放熱板２２と定着ベルト３との
接触状態を良くするため、放熱板２２の形状を定着ベル
ト３の進行方向即ち記録材の搬送方向に凸型にした。熱
膨張により面外変形の生じた定着ベルト３は、放熱板２
２の凸部を通過することによりしごかれ、面外変形が低
減される。放熱板２２の凸量γは、０．５ｍｍ以上の範
囲で大きいほど定着ベルト３の面外変形を低減できる。
しかし、放熱板２２の凸量γをあまり大きくすると例え
ば封筒を通紙させた場合、封筒の定着ベルトに接する面
と加圧ロ−ラに接する面に速度差が生じ、封筒シワが発
生する。このような不具合が生じない放熱板２２の凸量
を明らかにするために実験を行った結果、γは０．５ｍ
ｍ〜１．０ｍｍが適正範囲であることが判明した。FIG. 12 is a diagram for explaining another embodiment of the present invention. In this embodiment, in order to improve the contact state between the heat radiating plate 22 and the fixing belt 3, the heat radiating plate 22 has a convex shape in the traveling direction of the fixing belt 3, that is, the recording material conveying direction. The fixing belt 3 that has undergone out-of-plane deformation due to thermal expansion is installed in the heat sink 2.
By passing through the protrusions of No. 2, it is squeezed and out-of-plane deformation is reduced. The larger the convex amount γ of the heat dissipation plate 22 is in the range of 0.5 mm or more, the more the out-of-plane deformation of the fixing belt 3 can be reduced.
However, if the convex amount γ of the heat radiating plate 22 is too large, for example, when an envelope is passed, a speed difference occurs between the surface of the envelope in contact with the fixing belt and the surface of the envelope in contact with the pressure roller, and an envelope wrinkle occurs. As a result of an experiment for clarifying the convex amount of the heat sink 22 which does not cause such a defect, γ is 0.5 m
It was found that the appropriate range is m to 1.0 mm.

【００５０】[0050]

【発明の効果】本発明によれば、ＰＴＣ発熱体を用いて
ベルト式熱定着を行なう熱定着装置において、ＰＴＣ発
熱体と放熱板とを熱伝導性の良い接着剤で接着し、その
周囲を断熱材で囲って加熱体とすることによりＰＴＣ発
熱体のピンチ効果を防止できる、又加熱体を断熱性の電
気絶縁材料で断熱し弾性体を介してホルダの凹部に嵌合
することによって、加熱体、ホルダ、定着ベルトの熱変
形に起因する熱接触不良及びＰＴＣ発熱体と電極との電
気接触不良を防止することができる。更に放熱面の表面
を耐熱性の潤滑剤で被覆することにより加熱体と定着ベ
ルトとの摺動性を向上させることができる。従って、Ｐ
ＴＣ発熱体を用いたベルト式熱定着装置の定着性、信頼
性が向上でき、更に熱定着装置の温度制御が不要で最大
消費電力の低い電子写真装置を提供できる。According to the present invention, in a thermal fixing device for carrying out belt-type thermal fixing using a PTC heating element, the PTC heating element and the heat radiation plate are bonded with an adhesive having good thermal conductivity, and the periphery thereof is adhered. It is possible to prevent the pinch effect of the PTC heating element by surrounding it with a heat insulating material to form a heating element. Also, heat the heating element with a heat insulating electrically insulating material and fit it into the recess of the holder via an elastic body to heat it. It is possible to prevent defective thermal contact due to thermal deformation of the body, holder, and fixing belt and defective electrical contact between the PTC heating element and the electrode. Further, by covering the surface of the heat radiation surface with a heat resistant lubricant, the slidability between the heating body and the fixing belt can be improved. Therefore, P
It is possible to provide an electrophotographic apparatus that can improve the fixing property and reliability of a belt-type heat fixing device using a TC heating element and that does not require temperature control of the heat fixing device and has a maximum power consumption.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の実施例の電子写真装置の断面図であ
る。FIG. 1 is a sectional view of an electrophotographic apparatus according to an embodiment of the present invention.

【図２】図１の実施例に用いた熱定着装置の断面図であ
る。FIG. 2 is a sectional view of a thermal fixing device used in the embodiment of FIG.

【図３】発熱ヘッドの拡大断面図である。FIG. 3 is an enlarged sectional view of a heating head.

【図４】ＰＴＣ発熱体チップの斜視図である。FIG. 4 is a perspective view of a PTC heating element chip.

【図５】発熱ヘッドの構成を示す斜視図である。FIG. 5 is a perspective view showing a configuration of a heating head.

【図６】加熱体の動きを示す断面図である。FIG. 6 is a cross-sectional view showing the movement of the heating element.

【図７】弾性体の作用を説明する断面図である。FIG. 7 is a cross-sectional view illustrating the action of the elastic body.

【図８】本発明の他の実施例を示す発熱ヘッドの断面図
である。FIG. 8 is a cross-sectional view of a heating head showing another embodiment of the present invention.

【図９】本発明の他の実施例を示す発熱ヘッドの断面図
である。FIG. 9 is a sectional view of a heating head showing another embodiment of the present invention.

【図１０】本発明の他の実施例を示す発熱ヘッドの断面
図である。FIG. 10 is a cross-sectional view of a heating head showing another embodiment of the present invention.

【図１１】本発明の他の実施例を示す熱定着装置の斜視
図である。FIG. 11 is a perspective view of a heat fixing device showing another embodiment of the present invention.

【図１２】本発明の他の実施例を示す加熱体断面図であ
る。FIG. 12 is a sectional view of a heating body showing another embodiment of the present invention.

【符号の説明】[Explanation of symbols]

１…ベルト式熱定着装置 ２…発熱ヘッド ３…定着ベ
ルト ４…駆動プ−リ ５…加圧ロ−ラ ６…剥離ロ−ラ ７…補助ロ−ラ ８
…用紙 ９…トナ− １０…搬送ロ−ラＡ １１…搬出ロ−ラ １２…屈曲ガ
イドＡ １３…屈曲ガイドＢ １４…搬送ロ−ラＢ １５…感光
ドラム １６…現像機 １７…加熱体 １８…ホルダ １９…弾性体 ２０…電
線 ２１…ＰＴＣ発熱体 ２２…放熱板 ２３…断熱材
フレ−ム ２４…接着剤Ａ ２５…接着剤Ｂ ２６…潤滑剤 ２７…電極 ２８ａ，２８ｂ…分割電極
２９…フィルム ３０…耐熱性樹脂 ３１…フッ素樹脂。DESCRIPTION OF SYMBOLS 1 ... Belt-type thermal fixing device 2 ... Heating head 3 ... Fixing belt 4 ... Driving pulley 5 ... Pressing roller 6 ... Peeling roller 7 ... Auxiliary roller 8
... Paper 9 ... Toner 10 ... Conveying Roller A 11 ... Carrying Roller 12 ... Bending Guide A 13 ... Bending Guide B 14 ... Conveying Roller B 15 ... Photosensitive Drum 16 ... Developing Machine 17 ... Heating Body 18 ... Holder 19 ... Elastic body 20 ... Electric wire 21 ... PTC heating element 22 ... Radiating plate 23 ... Insulating material frame 24 ... Adhesive A 25 ... Adhesive B 26 ... Lubricant 27 ... Electrodes 28a, 28b ... Split electrodes 29 ... Film 30 ... Heat resistant resin 31 ... Fluorine resin.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 松野 順一 茨城県土浦市神立町502番地 株式会社日 立製作所機械研究所内 (72)発明者 三谷 正男 茨城県勝田市武田1060番地 日立工機株式 会社勝田研究所内 (72)発明者 小田 大 山口県宇部市大字小串1978−５ 宇部興産 株式会社無機材料研究所内 (72)発明者 津村 俊一 広島県呉市宝町６番９号 バブコック日立 株式会社呉工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Matsuno 502 Jinritsucho, Tsuchiura-shi, Ibaraki Machinery Research Institute, Hiritsu Manufacturing Co., Ltd. (72) Masao Mitani 1060 Takeda, Katsuta-shi, Ibaraki Hitachi Koki Co., Ltd. Inside the research institute (72) Oda Odai Oguchi, Ube City, Yamaguchi Prefecture 1978-5 In the Institute for Inorganic Materials, Ube Industries Ltd. (72) Inventor Shunichi Tsumura 6-9 Takara-cho, Kure-shi, Hiroshima Babcock Hitachi Kure Factory

Claims (13)

【特許請求の範囲】[Claims] 【請求項１】無端状の耐熱ベルトと、該耐熱ベルトを回
動させる駆動ロ−ラと、前記耐熱ベルトに接触し正の抵
抗温度特性を有する発熱体（以下、ＰＴＣ発熱体と称す
る）を支持するホルダとを備える熱定着装置において、
前記ＰＴＣ発熱体を断熱性の電気絶縁材料を介在させて
前記ホルダに設けた凹部に嵌合したことを特徴とする熱
定着装置。1. An endless heat-resistant belt, a drive roller for rotating the heat-resistant belt, and a heating element that comes into contact with the heat-resistant belt and has a positive resistance temperature characteristic (hereinafter referred to as PTC heating element). In a heat fixing device having a supporting holder,
A heat fixing device, wherein the PTC heating element is fitted in a recess provided in the holder with an electrically insulating material having a heat insulating property interposed therebetween. 【請求項２】無端状の耐熱ベルトと、該耐熱ベルトを回
動させる駆動ロ−ラと、前記耐熱ベルトに接触しＰＴＣ
発熱体を支持するホルダとを備える熱定着装置におい
て、前記ＰＴＣ発熱体を前記ホルダに設けた凹部に弾性
体を介在させて配置したことを特徴とする熱定着装置。2. An endless heat-resistant belt, a drive roller for rotating the heat-resistant belt, and a PTC for contacting the heat-resistant belt.
A thermal fixing device comprising a holder for supporting a heating element, wherein the PTC heating element is arranged in a recess provided in the holder with an elastic body interposed. 【請求項３】無端状の耐熱ベルトと、該耐熱ベルトを回
動させる駆動ロ−ラと、前記耐熱ベルトに接触しＰＴＣ
発熱体を支持するホルダとを備える熱定着装置におい
て、前記ＰＴＣ発熱体を断熱性の電気絶縁材料を介在さ
せて前記ホルダに設けた凹部に嵌合するものであって、
前記断熱性の電気絶縁材料と前記ホルダに設けた凹部と
の間に弾性体を配置したことを特徴とする熱定着装置。3. An endless heat-resistant belt, a drive roller for rotating the heat-resistant belt, and a PTC which contacts the heat-resistant belt.
A thermal fixing device comprising a holder supporting a heating element, wherein the PTC heating element is fitted in a recess provided in the holder with a heat insulating electrically insulating material interposed.
A heat fixing device, wherein an elastic body is arranged between the heat insulating electrically insulating material and a recess provided in the holder. 【請求項４】請求項１乃至３のいずれかに記載の熱定着
装置において、前記ＰＴＣ発熱体の放熱面に熱伝導性の
良い接着剤により放熱板を配置したことを特徴とする熱
定着装置。4. The heat fixing device according to claim 1, wherein a heat radiating plate is arranged on the heat radiating surface of the PTC heating element with an adhesive having good thermal conductivity. . 【請求項５】請求項１乃至３のいずれかに記載の熱定着
装置において、前記ＰＴＣ発熱体の放熱板の表面又はＰ
ＴＣ発熱体を嵌合した前記ホルダの表面を潤滑性の良い
電気絶縁材料で被覆したことを特徴とする熱定着装置。5. The thermal fixing device according to claim 1, wherein the surface of the heat radiating plate of the PTC heating element or P
A thermal fixing device characterized in that the surface of the holder fitted with a TC heating element is coated with an electrically insulating material having a good lubricating property. 【請求項６】請求項５に記載の熱定着装置において、前
記潤滑性の良い電気的絶縁材料としてフッ素樹脂を用い
たことを特徴とする熱定着装置。6. The thermal fixing device according to claim 5, wherein a fluorine resin is used as the electrically insulating material having good lubricity. 【請求項７】請求項２又は３に記載の熱定着装置におい
て、前記弾性体はゴム硬度５０°〜７０°のものである
ことを特徴とする熱定着装置。7. The thermal fixing device according to claim 2, wherein the elastic body has a rubber hardness of 50 ° to 70 °. 【請求項８】請求項１乃至３のいずれかに記載の熱定着
装置において、ホルダを電気絶縁材料としたことを特徴
する熱定着装置。8. The heat fixing device according to claim 1, wherein the holder is made of an electrically insulating material. 【請求項９】請求項１乃至３、又は８のいずれかに記載
の熱定着装置において、前記ＰＴＣ発熱体は小片状から
なり、その放熱面に配置する放熱板に列状に配列し、前
記ホルダに設けた凹部に嵌合したことを特徴とする熱定
着装置。9. The heat fixing device according to claim 1, wherein the PTC heating element is in the form of a small piece, and the PTC heating elements are arranged in a row on a heat radiating plate arranged on the heat radiating surface thereof. A heat fixing device fitted in a recess provided in the holder. 【請求項１０】請求項９に記載の熱定着装置において、
前記ＰＴＣ発熱体を複列に配置したことを特徴とする熱
定着装置。10. The thermal fixing device according to claim 9,
A thermal fixing device in which the PTC heating elements are arranged in double rows. 【請求項１１】請求項４に記載の熱定着装置において、
前記放熱板は耐熱ベルトに接する面が凸状であることを
特徴とする熱定着装置。11. The thermal fixing device according to claim 4,
The heat fixing device, wherein the heat dissipation plate has a convex surface in contact with the heat resistant belt. 【請求項１２】無端状の耐熱ベルトと、該耐熱ベルトを
回動させる駆動ロ−ラと、前記耐熱ベルトに接触しＰＴ
Ｃ発熱体を支持するホルダとを備える熱定着装置におい
て、前記ＰＴＣ発熱体の放熱面に熱伝導性の良い接着剤
により放熱板を配置するとともに前記放熱板配置面を除
く部分を断熱性の電気絶縁材料をもって覆い、前記ホル
ダに設けた凹部に弾性体を介して嵌合するものであっ
て、前記ホルダの表面を潤滑性の良い絶縁材料で被覆し
たことを特徴とする熱定着装置。12. An endless heat-resistant belt, a drive roller for rotating the heat-resistant belt, and a PT which contacts the heat-resistant belt.
In a thermal fixing device including a holder supporting a C heat generating element, a heat radiating plate is arranged on the heat radiating surface of the PTC heat generating element with an adhesive having good thermal conductivity, and a portion other than the heat radiating plate arranging surface is electrically insulating. A heat fixing device, which is covered with an insulating material and fits into a recess provided in the holder through an elastic body, and the surface of the holder is covered with an insulating material having good lubricity. 【請求項１３】感光ドラムと、感光ドラム面上に静電潜
像を形成する手段と、感光ドラム面上に形成した静電潜
像を現像してトナ−像とする現像手段と、トナ−像を用
紙に転写する転写手段と、用紙に転写されたトナ−像を
用紙に定着する熱定着手段とを備える電子写真装置にお
いて、前記熱定着手段が請求項１乃至１２のいずれかに
記載の熱定着装置を用いたことを特徴とする電子写真装
置。13. A photosensitive drum, a means for forming an electrostatic latent image on the surface of the photosensitive drum, a developing means for developing the electrostatic latent image formed on the surface of the photosensitive drum into a toner image, and a toner. 13. An electrophotographic apparatus comprising: a transfer unit that transfers an image onto a sheet; and a thermal fixing unit that fixes the toner image transferred onto the sheet onto the sheet. The thermal fixing unit according to claim 1. An electrophotographic apparatus using a heat fixing device.
JP11716792A 1991-04-22 1992-05-11 Thermal fixing device Withdrawn JPH05313528A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP11716792A JPH05313528A (en) 1992-05-11 1992-05-11 Thermal fixing device
US08/057,637 US5499087A (en) 1991-04-22 1993-05-07 Heat fixing device and electrophotographic apparatus incorporating the same having a PTC heating element received in a recess of a holder
DE19934315741 DE4315741C2 (en) 1992-05-11 1993-05-11 Heat fixing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11716792A JPH05313528A (en) 1992-05-11 1992-05-11 Thermal fixing device

Publications (1)

Publication Number Publication Date
JPH05313528A true JPH05313528A (en) 1993-11-26

Family

ID=14705109

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11716792A Withdrawn JPH05313528A (en) 1991-04-22 1992-05-11 Thermal fixing device

Country Status (2)

Country Link
JP (1) JPH05313528A (en)
DE (1) DE4315741C2 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896154A (en) * 1993-04-16 1999-04-20 Hitachi Koki Co., Ltd. Ink jet printer
KR101154898B1 (en) * 2007-09-12 2012-06-13 삼성전자주식회사 Fusing unit and image forming apparatus including the same
JP2013182234A (en) * 2012-03-05 2013-09-12 Oki Data Corp Fixing device and printer
JP2016001300A (en) * 2014-05-20 2016-01-07 キヤノン株式会社 Image heating device
JP2016018160A (en) * 2014-07-10 2016-02-01 株式会社リコー Fixation device and image forming apparatus
JP2016145961A (en) * 2015-01-30 2016-08-12 株式会社リコー Fixing device and image forming apparatus
JP2017120390A (en) * 2015-12-25 2017-07-06 株式会社リコー Fixing device and image forming apparatus
JP2017161892A (en) * 2016-03-03 2017-09-14 株式会社リコー Fixation device and image forming apparatus
JP2018005101A (en) * 2016-07-07 2018-01-11 株式会社リコー Fixation device and image formation device

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0370519B1 (en) * 1988-11-25 1995-03-08 Canon Kabushiki Kaisha An image fixing apparatus
EP0437205B1 (en) * 1990-01-12 1996-04-03 Canon Kabushiki Kaisha An image fixing apparatus
JPH04284481A (en) * 1991-03-14 1992-10-09 Hitachi Koki Co Ltd Thermal fixing device

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896154A (en) * 1993-04-16 1999-04-20 Hitachi Koki Co., Ltd. Ink jet printer
KR101154898B1 (en) * 2007-09-12 2012-06-13 삼성전자주식회사 Fusing unit and image forming apparatus including the same
JP2013182234A (en) * 2012-03-05 2013-09-12 Oki Data Corp Fixing device and printer
JP2016001300A (en) * 2014-05-20 2016-01-07 キヤノン株式会社 Image heating device
US10303097B2 (en) 2014-05-20 2019-05-28 Canon Kabushiki Kaisha Image heating apparatus having a heater and a supporting member that are bonded together at lateral surfaces thereof using an adhesive
JP2016018160A (en) * 2014-07-10 2016-02-01 株式会社リコー Fixation device and image forming apparatus
JP2016145961A (en) * 2015-01-30 2016-08-12 株式会社リコー Fixing device and image forming apparatus
JP2017120390A (en) * 2015-12-25 2017-07-06 株式会社リコー Fixing device and image forming apparatus
JP2017161892A (en) * 2016-03-03 2017-09-14 株式会社リコー Fixation device and image forming apparatus
JP2018005101A (en) * 2016-07-07 2018-01-11 株式会社リコー Fixation device and image formation device

Also Published As

Publication number Publication date
DE4315741C2 (en) 1998-10-22
DE4315741A1 (en) 1994-01-27

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