JP2006284649A - Fixing device - Google Patents
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- JP2006284649A JP2006284649A JP2005100994A JP2005100994A JP2006284649A JP 2006284649 A JP2006284649 A JP 2006284649A JP 2005100994 A JP2005100994 A JP 2005100994A JP 2005100994 A JP2005100994 A JP 2005100994A JP 2006284649 A JP2006284649 A JP 2006284649A
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Abstract
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本発明は、複写機やプリンタ等の画像形成装置において、記録材上に形成された未定着トナー像を加熱溶融して該記録材に定着させる定着装置に関し、特に、熱源として誘導発熱方式の熱源を利用した定着装置に関する。 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device that heats and melts an unfixed toner image formed on a recording material in an image forming apparatus such as a copying machine or a printer and fixes the image to the recording material. The present invention relates to a fixing device using the.
画像形成装置において採用される定着装置は、通常、回転可能の定着ローラと、該定着ローラに圧接される、回転可能の加圧ローラと、該定着ローラを加熱する熱源とを備えており、該熱源で定着ローラを加熱し、該定着ローラ及び前記加圧ローラ間のニップ部に、トナー像を保持する記録材を通過させることで、該トナー像を該記録材に溶融定着させる。 A fixing device employed in an image forming apparatus usually includes a rotatable fixing roller, a rotatable pressure roller that is pressed against the fixing roller, and a heat source that heats the fixing roller. The fixing roller is heated by a heat source, and a recording material holding a toner image is passed through a nip portion between the fixing roller and the pressure roller, so that the toner image is melt-fixed on the recording material.
かかる熱源としては、旧来、代表的には、定着ローラに内蔵されたハロゲンランプヒータが採用されてきたが、今日の省エネルギーの要請から、高い熱変換効率が得られる電磁誘導発熱方式の熱源が注目されている。例えば、特許第２６１６４３３号公報は、絶縁支持体上に渦巻きパターンに形成したコイルに通電して磁束を発生させ、該発生磁束で金属製の、定着ローラとして使用するヒートローラを電磁誘導発熱させる定着装置を開示している。 As such a heat source, a halogen lamp heater built in a fixing roller has been typically used in the past. However, due to today's demand for energy saving, a heat source of an electromagnetic induction heat generation method that can obtain high heat conversion efficiency has attracted attention. Has been. For example, Japanese Patent No. 2616433 discloses a fixing in which a coil formed in a spiral pattern on an insulating support is energized to generate a magnetic flux, and a heat roller made of metal and used as a fixing roller is electromagnetically heated by the generated magnetic flux. An apparatus is disclosed.
さらに、最近では、旧来のハロゲンランプヒータを用いた熱ローラ方式の定着装置と同等或いはそれ以上の熱変換効率が得られ、定着温度への立ち上がりが迅速で、さらに、定着装置のコンパクト化が可能な定着装置として、コイルへの通電により発生する磁束をフェライトコアなどのコア材で、定着ローラに設けた電磁誘導発熱層に導くような構成の定着装置も提案されるようになってきている。 Furthermore, recently, heat conversion efficiency equivalent to or higher than that of heat roller type fixing devices using conventional halogen lamp heaters can be obtained, the rise to the fixing temperature is rapid, and the fixing device can be made more compact. As such a fixing device, a fixing device having a configuration in which a magnetic flux generated by energizing a coil is guided to an electromagnetic induction heat generating layer provided on a fixing roller by a core material such as a ferrite core has been proposed.
その一つに、電磁誘導発熱層を有する、回転可能の定着ローラと、該定着ローラに圧接される、回転可能の加圧ローラと、前記定着ローラの電磁誘導発熱層を電磁誘導発熱させるための磁束発生装置（磁性体コアと励磁コイルを有するもの）とを備え、前記磁束発生装置の発生磁束によって前記定着ローラの電磁誘導発熱層を発熱させることで定着ローラを加熱する定着装置がある。 For example, a rotatable fixing roller having an electromagnetic induction heat generating layer, a rotatable pressure roller pressed against the fixing roller, and an electromagnetic induction heat generating layer for heating the electromagnetic induction heat generating layer of the fixing roller. There is a fixing device that includes a magnetic flux generation device (having a magnetic core and an excitation coil), and heats the fixing roller by causing the electromagnetic induction heating layer of the fixing roller to generate heat by the magnetic flux generated by the magnetic flux generation device.
かかる定着装置の定着ローラとしては、内側から外側へ順に、支持層、スポンジ層、電磁誘導発熱性層、弾性層及び離型層の少なくとも５層を一体的に積層した構成のものが知られているが、誘導発熱用ベルト（外側のローラ部）内にスポンジローラを挿入し、該スポンジローラと誘導発熱用ベルトは接着せず、誘導発熱用ベルトの蛇行を規制する規制部材を定着ローラ端部に対して設けた定着ローラも提案されている。 As a fixing roller of such a fixing device, one having a structure in which at least five layers of a support layer, a sponge layer, an electromagnetic induction heat generating layer, an elastic layer, and a release layer are integrally laminated in order from the inside to the outside is known. However, a sponge roller is inserted into the induction heat generating belt (outer roller portion), the sponge roller and the induction heat generating belt are not bonded, and a regulating member for restricting the meandering of the induction heat generating belt is used as the fixing roller end portion. Also, a fixing roller provided for the above has been proposed.
このように誘導発熱用ベルトにスポンジローラを内挿し、両者を接着しない構成の定着ローラは、両者の接着を省略しているので、定着装置コストを接着コスト分低減することができるとともに、誘導発熱用ベルトとスポンジローラ間の界面の接着性低下の問題が発生する余地がなく、それだけ寿命が長い、という利点がある。 The fixing roller having the structure in which the sponge roller is inserted in the induction heating belt and does not adhere to both of them omits the adhesion of the both, so that the fixing device cost can be reduced by the adhesion cost and the induction heating is performed. There is an advantage that there is no room for the problem of lowering the adhesiveness at the interface between the belt for use and the sponge roller, and that the life is long.
しかしながら、誘導発熱用ベルト（外側のローラ部）にスポンジローラを内挿し、両者を接着せず、誘導発熱用ベルトの蛇行を規制部材で規制する定着ローラは、定着ローラと加圧ローラ間の圧接ニップ部で誘導発熱用ベルトが撓みながら蛇行し、それにより誘導発熱用ベルトと前記規制部材が当接して、そのストレスにより誘導発熱用ベルトが端部で割れて破損しやすいという問題がある。 However, the fixing roller that inserts a sponge roller into the induction heating belt (outer roller portion) and does not bond them together and restricts the meandering of the induction heating belt with a regulating member is a pressure contact between the fixing roller and the pressure roller. There is a problem that the induction heating belt meanders while being bent at the nip portion, whereby the induction heating belt and the regulating member come into contact with each other, and the induction heating belt is easily broken and damaged by the stress.
また、前記のように磁性体コアと励磁コイルを有する磁束発生装置では、励磁コイルは、記録材の搬送方向と直交する方向に長く延びる形状に巻回形成されるが、かかる励磁コイル両端の屈曲部付近では、発生する磁束の密度が不均一になり、それによる不安定な磁界の影響を受けて、定着ローラの電磁誘導発熱層を定着ローラの回転中心軸線方向（記録材の搬送方向と直交する方向）に均一に発熱させることが困難であり、そのため、定着ローラ全体としても、ローラの回転中心軸線方向（記録材の搬送方向と直交する方向）に均一に加熱することが困難となり、ひいては、トナー像の定着不良を招く。 Further, in the magnetic flux generator having the magnetic core and the exciting coil as described above, the exciting coil is wound in a shape extending long in a direction perpendicular to the recording material conveyance direction. Near the area, the density of the generated magnetic flux becomes non-uniform, and due to the influence of an unstable magnetic field, the electromagnetic induction heating layer of the fixing roller is placed in the direction of the rotation center axis of the fixing roller (perpendicular to the recording material conveyance direction). Therefore, it is difficult to uniformly heat the fixing roller as a whole in the rotation center axis direction of the roller (direction perpendicular to the recording material conveyance direction). This leads to poor fixing of the toner image.
そこで本発明は、電磁誘導発熱層を有する、回転可能の定着ローラと、該定着ローラに圧接される、回転可能の加圧ローラと、前記定着ローラの電磁誘導発熱層を電磁誘導発熱させるための磁束発生装置とを備えており、前記磁束発生装置の発生磁束によって前記定着ローラの電磁誘導発熱層を発熱させ、該定着ローラ及び前記加圧ローラ間のニップ部に、トナー像を保持する記録材を通過させることで、該トナー像を該記録材に溶融定着させることができ、前記定着ローラは、前記電磁誘導発熱層を有する外側ローラ部と、該外側ローラ部内に挿入された、スポンジ層を有する内側ローラ部とを含んでおり、前記外側ローラ部の前記内側ローラ部に対するローラ回転中心軸線方向への移動を抑制する移動抑制部が、該外側ローラ部の少なくとも片側端部に対して設けられている定着装置であって、定着ローラの電磁誘導発熱層をローラ回転中心軸線方向に均一に発熱させることができ、それにより定着ローラをローラ回転中心軸線方向に均一に加熱して、それだけ良好なトナー像定着を達成することができる定着装置を提供することを課題とする。 Accordingly, the present invention provides a rotatable fixing roller having an electromagnetic induction heat generating layer, a rotatable pressure roller pressed against the fixing roller, and an electromagnetic induction heat generating layer for the electromagnetic induction heat generating layer of the fixing roller. A recording material that heats an electromagnetic induction heating layer of the fixing roller by the magnetic flux generated by the magnetic flux generation device and holds a toner image at a nip portion between the fixing roller and the pressure roller. The toner image can be melt-fixed on the recording material, and the fixing roller includes an outer roller portion having the electromagnetic induction heat generating layer and a sponge layer inserted into the outer roller portion. A movement restraining portion that restrains movement of the outer roller portion in the axial direction of the roller rotation axis with respect to the inner roller portion. Also, the fixing device is provided at one end of the fixing roller, and can heat the electromagnetic induction heat generating layer of the fixing roller uniformly in the roller rotation center axis direction, thereby causing the fixing roller to move in the roller rotation center axis direction. It is an object of the present invention to provide a fixing device that can uniformly heat and achieve a satisfactory toner image fixing.
また、本発明は、かかる定着装置であって、耐久性に富む定着装置を提供することを課題とする。
また、本発明は、各部を、全体のコンパクト化、省スペース化が可能に配置できる定着装置を提供することを課題とする。
Another object of the present invention is to provide such a fixing device having a high durability.
Another object of the present invention is to provide a fixing device in which each unit can be arranged so as to be compact and space-saving as a whole.
本発明は、電磁誘導発熱層を有する、回転可能の定着ローラと、該定着ローラに圧接される、回転可能の加圧ローラと、前記定着ローラの電磁誘導発熱層を電磁誘導発熱させるための磁束発生装置とを備えており、前記磁束発生装置の発生磁束によって前記定着ローラの電磁誘導発熱層を発熱させ、該定着ローラ及び前記加圧ローラ間のニップ部に、トナー像を保持する記録材を通過させることで、該トナー像を該記録材に溶融定着させることができ、前記定着ローラは、前記電磁誘導発熱層を有する外側ローラ部と、該外側ローラ部内に挿入された、スポンジ層を有する内側ローラ部とを含んでおり、前記外側ローラ部の前記内側ローラ部に対するローラ回転中心軸線方向への移動を抑制する移動抑制部が、該外側ローラ部の少なくとも片側端部に対して設けられている定着装置であって、
前記磁束発生装置は磁性体コア及び励磁コイルを有しており、
該励磁コイルは、前記記録材の搬送方向と直交する方向に長く延びる形状に巻回形成されており、
該励磁コイルの、前記記録材搬送方向と直交する方向における両端屈曲部の内側部間の距離Ｌｃ１と、前記定着ローラの回転中心軸線方向の全長Ｌ１（ローラ幅Ｌ１）と、前記加圧ローラの回転中心軸線方向の全長Ｌ２（ローラ幅Ｌ２）と、トナー像定着処理可能の記録材サイズのうち最大サイズの記録材の、搬送方向と直交する方向の搬送幅Ｌｐとが、 Ｌｃ１≧Ｌ１＞Ｌ２＞Ｌｐの関係を満たす定着装置を提供する。
The present invention relates to a rotatable fixing roller having an electromagnetic induction heat generating layer, a rotatable pressure roller pressed against the fixing roller, and a magnetic flux for causing electromagnetic induction heat generation of the electromagnetic induction heat generating layer of the fixing roller. A recording material that heats the electromagnetic induction heat generating layer of the fixing roller by the magnetic flux generated by the magnetic flux generating device, and holds a toner image at a nip portion between the fixing roller and the pressure roller. By passing the toner image, the toner image can be melt-fixed on the recording material, and the fixing roller has an outer roller portion having the electromagnetic induction heat generating layer and a sponge layer inserted into the outer roller portion. An inner roller portion, and a movement suppressing portion that suppresses movement of the outer roller portion relative to the inner roller portion in the roller rotation center axis direction is at least one of the outer roller portions. A fixing device is provided for an end portion,
The magnetic flux generator has a magnetic core and an exciting coil,
The exciting coil is wound and formed in a shape extending long in a direction orthogonal to the conveying direction of the recording material,
A distance Lc1 between the inner portions of the bent portions in the direction orthogonal to the recording material conveyance direction of the excitation coil, a total length L1 (roller width L1) in the rotation center axis direction of the fixing roller, and the pressure roller The total length L2 (roller width L2) in the rotation center axis direction and the conveyance width Lp in the direction orthogonal to the conveyance direction of the largest recording material among the recording material sizes that can be subjected to toner image fixing processing are Lc1 ≧ L1> L2. A fixing device satisfying a relationship of> Lp is provided.
本発明に係るこの定着装置によると、磁束発生装置における励磁コイルの、記録材搬送方向と直交する方向における両端屈曲部の内側部間の距離Ｌｃ１と、定着ローラの回転中心軸線方向の全長Ｌ１（ローラ幅Ｌ１）とがＬｃ１≧Ｌ１の関係に設定されるので、定着ローラ（特にその電磁誘導発熱層）が励磁コイルの屈曲端部に生じる不安定な磁界の影響を受け難くなり、定着ローラを全域にわたって均一に加熱することができ、ひいては、それだけ良好なトナー像定着を行える。 According to the fixing device of the present invention, the distance Lc1 between the inner portions of the bent portions in the direction orthogonal to the recording material conveyance direction of the exciting coil in the magnetic flux generator and the total length L1 (in the rotation center axis direction of the fixing roller) Since the roller width L1) and Lc1 ≧ L1 are set, the fixing roller (especially the electromagnetic induction heat generation layer) is not easily affected by the unstable magnetic field generated at the bent end of the exciting coil. Heating can be performed uniformly over the entire area, and as a result, good toner image fixing can be performed.
前記移動抑制部としては、前記外側ローラ部の回転中心軸線方向において該外側ローラ部の外側に配置されて該外側ローラ部の端に臨み、該外側ローラ部の回転中心軸線方向の動きを規制する規制部材を例示できる。また、前記外側ローラ部の回転中心軸線方向における端部と、前記内側ローラ部との間に配置されて該外側ローラ部及び内側ローラ部を該外側ローラ部の端部の接着領域で接着する接着剤も例示できる。 The movement restraining portion is disposed outside the outer roller portion in the direction of the rotation center axis of the outer roller portion, faces the end of the outer roller portion, and restricts the movement of the outer roller portion in the rotation center axis direction. A restriction member can be illustrated. Also, an adhesion that is arranged between the end portion of the outer roller portion in the direction of the rotation center axis and the inner roller portion and bonds the outer roller portion and the inner roller portion at the bonding region of the end portion of the outer roller portion. An agent can also be illustrated.
移動抑制部としてかかる規制部材を採用する場合についてみると、本発明に係る定着装置では定着ローラ全長Ｌ１＞加圧ローラ全長Ｌ２の関係が設定されるので、定着ローラと加圧ローラ間の圧接ニップ部では、定着ローラ（さらに言えば、特に、その外側ローラ部）の撓み変形が発生する。しかし、定着ローラの加圧ローラと接触しない領域では定着ローラの撓みが小さく抑制され、定着ローラの外側ローラ部が蛇行しようとするとき、前記規制部材には該外側ローラ部端部が略円形の形状で当接し、それにより外側ローラ部の端部の各部が規制部材から受けるストレスを軽減でき、外側ローラ部の端部での割れを抑制し、ひいては、定着ローラ、さらには定着装置全体の寿命を長びかせることができる。 In the case where such a restricting member is employed as the movement restraining portion, the relationship of the fixing roller total length L1> the pressure roller total length L2 is set in the fixing device according to the present invention. In the portion, the deformation of the fixing roller (more specifically, the outer roller portion thereof) is deformed. However, in the region where the fixing roller does not come into contact with the pressure roller, the bending of the fixing roller is suppressed to be small, and when the outer roller portion of the fixing roller tries to meander, the end portion of the outer roller portion of the regulating member is substantially circular. Contact with the shape, which can reduce the stress that each part at the end of the outer roller part receives from the regulating member, suppresses cracking at the end of the outer roller part, and consequently the life of the fixing roller and the entire fixing device Can be prolonged.
また、移動抑制部として前記接着剤を採用する場合についてみると、外側ローラ部の、内側ローラ部に接着される最も内側の層（例えば前記電磁誘導発熱層）及び内側ローラ部の、外側ローラ部に接着される最も外側の層（例えばスポンジ層）は、通常、熱膨張率が異なるため、定着装置使用時の熱により、外側ローラ部が内側ローラ部から剥がれたり、外側ローラ部が変形したりする恐れがあるところ、前記のとおり、接着領域を外側ローラ部の端部のみとすることで、外側ローラ部の剥がれや変形が抑制され、ひいては、定着ローラ、さらには定着装置全体の寿命をそれだけ長びかせることができる。 In the case where the adhesive is used as the movement suppressing portion, the innermost layer (for example, the electromagnetic induction heat generating layer) bonded to the inner roller portion of the outer roller portion and the outer roller portion of the inner roller portion. Since the outermost layer (for example, sponge layer) bonded to the sheet usually has a different coefficient of thermal expansion, the outer roller part may be peeled off from the inner roller part or the outer roller part may be deformed due to heat when the fixing device is used. However, as described above, the adhesive region is limited to the end of the outer roller portion, so that peeling and deformation of the outer roller portion can be suppressed, and as a result, the life of the fixing roller and the entire fixing device can be reduced accordingly. Can be long.
移動抑制部として規制部材を採用する場合であれ、接着剤を採用する場合であれ、本発明に係る定着装置では、移動抑制部は外側ローラ部の端部に対して設けられ、且つ、定着ローラ全長Ｌ１＞加圧ローラ全長Ｌ２の関係が設定さるので、外側ローラ部の損傷が抑制され、ひいては、定着装置の耐久性が向上する。 In the fixing device according to the present invention, whether the restricting member is used as the movement suppressing unit or the adhesive, the movement suppressing unit is provided to the end of the outer roller unit, and the fixing roller Since the relationship of total length L1> pressure roller total length L2 is set, damage to the outer roller portion is suppressed, and as a result, durability of the fixing device is improved.
接着剤を採用する場合、接着領域は、定着ローラの外側ローラ部の端部のうち、さらに、記録材を通過させる領域（一般に通紙領域と称されている領域）、さらに言えば、より好ましくは、トナー像定着処理可能の記録材サイズのうち最大サイズの記録材の、搬送方向と直交する方向の搬送幅Ｌｐの領域より外側に限定してもよく、そうすることで、接着剤層による画質への影響が抑制される状態で外側ローラ部の接着剥がれを起きにくくして、定着装置の耐久性を向上させることができる。 In the case where an adhesive is used, the bonding area is more preferably an area through which the recording material passes (an area generally referred to as a paper passing area) among the ends of the outer roller portion of the fixing roller. May be limited to the outside of the region of the conveyance width Lp in the direction orthogonal to the conveyance direction of the maximum size of the recording material size that can be subjected to toner image fixing processing. It is possible to improve the durability of the fixing device by making it difficult for the outer roller portion to peel off when the influence on the image quality is suppressed.
また、接着剤を採用する場合、定着ローラと加圧ローラ間の圧接ニップ部（ニップ形成領域）で定着ローラ（特にその外側ローラ部）が、ローラ回転により、繰り返し撓み変形して接着剥がれが発生する場合があることに備えて、定着ローラの外側ローラ部における、加圧ローラと接触しない、撓み変形が無いか又は小さい、加圧ローラから開放されている領域（外側ローラ部開放領域）に接着領域を設定してもよい。 Also, when an adhesive is used, the fixing roller (especially the outer roller) is repeatedly bent and deformed due to the rotation of the roller at the pressure nip (nip forming area) between the fixing roller and the pressure roller. In order to be prepared, the outer roller portion of the fixing roller is not in contact with the pressure roller, is not deformed or is small, and is bonded to a region released from the pressure roller (outer roller portion opening region). An area may be set.
定着ローラ及び加圧ローラのローラ回転中心軸線方向の熱分布を均一化させる均熱ローラを前記加圧ローラに回転可能に接触させてもよい。かかる均熱ローラの採用により、小サイズの記録材を連続的に両ローラニップ部に通過させる場合の、両ローラの、記録材が通過しない領域の過昇温を抑制することができる。均熱ローラの回転中心軸線方向の長さＬ３は、均熱ローラの端部エッジによる加圧ローラの損傷を抑制するために、加圧ローラ全長Ｌ２以上（Ｌ３≧Ｌ２）であることが望ましい。定着ローラ及び加圧ローラの熱分布均一化を積極的に行えるように、均熱ローラを加熱する熱源を設けてもよい。 A heat equalizing roller for making the heat distribution in the axial direction of the rotation axis of the fixing roller and the pressure roller uniform may be brought into contact with the pressure roller so as to be rotatable. By adopting such a soaking roller, it is possible to suppress an excessive temperature rise in a region where the recording material does not pass through both rollers when a small size recording material is continuously passed through the both roller nips. The length L3 of the heat equalizing roller in the rotation center axis direction is desirably equal to or greater than the pressure roller full length L2 (L3 ≧ L2) in order to suppress damage to the pressure roller due to the edge of the heat equalizing roller. A heat source for heating the soaking roller may be provided so that the heat distribution of the fixing roller and the pressure roller can be positively made uniform.
ところで、前記ように、定着ローラ全長Ｌ１＞加圧ローラ全長Ｌ２の関係が設定される場合、加圧ローラと接触しない定着ローラの両端部は加圧ローラにより熱が奪われない分、加圧ローラとの接触領域より高温になる傾向がある。さらにこの定着ローラ両端部は記録材が通らない領域であり、記録材への熱移動がない領域でもあるので、両ローラ間に記録材をある程度連続して通すと、さらに高温になり、定着ローラの劣化や破損を引き起こす温度（過昇温）となる可能性がある。 By the way, when the relationship of the fixing roller total length L1> the pressure roller total length L2 is set as described above, both ends of the fixing roller not in contact with the pressure roller are not deprived of heat by the pressure roller. It tends to be hotter than the contact area. Further, both ends of the fixing roller are regions through which the recording material does not pass and there is also no heat transfer to the recording material. Therefore, if the recording material is passed between the rollers to some extent, the temperature becomes even higher. There is a possibility that the temperature (excessive temperature rise) will cause deterioration or breakage.
電磁誘導加熱方式では、磁性体コアの設置幅Ｌcoreとほぼ等価な発熱域が得られるので、Ｌ２≧Ｌcore≧Ｌｐとして、定着ローラ両端部の過昇温を抑え、記録材搬送幅範囲の熱分布を均一化するようにしてもよい。 In the electromagnetic induction heating method, a heat generation area substantially equivalent to the installation width Lcore of the magnetic core is obtained, so that overheating at both ends of the fixing roller is suppressed as L2 ≧ Lcore ≧ Lp, and the heat distribution in the recording material conveyance width range is achieved. May be made uniform.
本発明に係る定着装置では、前記のとおり、Ｌｃ１≧Ｌ１＞Ｌ２＞Ｌｐの関係が満たされることで、定着ローラをローラ回転中心軸線方向に均一に加熱でき、定着装置の耐久性を向上させつつ、装置各部を全体のコンパクト化、省スペース化が可能に配置できる。 In the fixing device according to the present invention, as described above, when the relationship of Lc1 ≧ L1> L2> Lp is satisfied, the fixing roller can be heated uniformly in the roller rotation center axis direction, and the durability of the fixing device is improved. The various parts of the apparatus can be arranged so that the overall size and space can be saved.
以上説明したように本発明によると、電磁誘導発熱層を有する、回転可能の定着ローラと、該定着ローラに圧接される、回転可能の加圧ローラと、前記定着ローラの電磁誘導発熱層を電磁誘導発熱させるための磁束発生装置とを備えており、前記磁束発生装置の発生磁束によって前記定着ローラの電磁誘導発熱層を発熱させ、該定着ローラ及び前記加圧ローラ間のニップ部に、トナー像を保持する記録材を通過させることで、該トナー像を該記録材に溶融定着させることができ、前記定着ローラは、前記電磁誘導発熱層を有する外側ローラ部と、該外側ローラ部内に挿入された、スポンジ層を有する内側ローラ部とを含んでおり、前記外側ローラ部の前記内側ローラ部に対するローラ回転中心軸線方向への移動を抑制する移動抑制部が、該外側ローラ部の少なくとも片側端部に対して設けられている定着装置であって、定着ローラの電磁誘導発熱層をローラ回転中心軸線方向に均一に発熱させることができ、それにより定着ローラをローラ回転中心軸線方向に均一に加熱して、それだけ良好なトナー像定着を達成することができる定着装置を提供することができる。 As described above, according to the present invention, a rotatable fixing roller having an electromagnetic induction heat generating layer, a rotatable pressure roller pressed against the fixing roller, and the electromagnetic induction heat generating layer of the fixing roller are electromagnetically connected. A magnetic flux generation device for inductively generating heat, the electromagnetic induction heat generation layer of the fixing roller is heated by the magnetic flux generated by the magnetic flux generation device, and a toner image is formed at a nip portion between the fixing roller and the pressure roller. The toner image can be melt-fixed on the recording material by passing the recording material holding the recording material, and the fixing roller is inserted into the outer roller portion having the electromagnetic induction heat generating layer and the outer roller portion. An inner roller portion having a sponge layer, and a movement suppressing portion for suppressing movement of the outer roller portion with respect to the inner roller portion in the roller rotation center axis direction. A fixing device provided for at least one end of a roller unit, wherein the electromagnetic induction heat generating layer of the fixing roller can uniformly generate heat in the axial direction of the roller rotation center, whereby the fixing roller is It is possible to provide a fixing device capable of achieving uniform toner image fixing by heating uniformly in the axial direction.
また、本発明によると、かかる定着装置であって、耐久性に富む定着装置を提供することができる。
また、本発明によると、装置各部を、全体のコンパクト化、省スペース化が可能に配置できる定着装置を提供することができる。
Further, according to the present invention, it is possible to provide such a fixing device, which has high durability.
In addition, according to the present invention, it is possible to provide a fixing device in which each part of the apparatus can be arranged so as to be compact and space-saving as a whole.
本発明に係る定着装置の例を図面を参照して説明する。
図１は定着装置の１例の断面図である。
図１に示す定着装置は、誘導加熱型のものであり、電磁誘導発熱式の定着ローラ１と、定着ローラ１と接触してニップＮを形成する加圧ローラ２と、定着ローラ１の外側に配置されて磁束を発生する磁束発生装置３とを備えている。
An example of a fixing device according to the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of an example of a fixing device.
The fixing device shown in FIG. 1 is of an induction heating type, and includes an electromagnetic induction heating type fixing roller 1, a pressure roller 2 that contacts the fixing roller 1 to form a nip N, and an outer side of the fixing roller 1. And a magnetic flux generator 3 that is arranged to generate magnetic flux.
磁束発生装置３の磁束によって定着ローラ１を発熱させてから、未定着トナー像ｔを担持した記線材Ｐを定着ローラ１と加圧ローラ２との間を通過させ、ニップＮによって記録材Ｐを挟持搬送しながら未定着像ｔを記録材Ｐに溶融定着（加熱定着）させる。 After the fixing roller 1 is heated by the magnetic flux of the magnetic flux generator 3, the recording material P carrying the unfixed toner image t is passed between the fixing roller 1 and the pressure roller 2, and the recording material P is fed by the nip N. The unfixed image t is melt-fixed (heat-fixed) on the recording material P while being nipped and conveyed.
この定着装置は、記線材Ｐに未定着像ｔを形成する（図示しない）作像手段と共に、複写機、レーザプリンタ又はファクシミリ機等の画像形成装置を構成することができる。
記録材Ｐとは、例えば、記録紙、ＯＨＰ用シート等の記録材であり、未定着像ｔは、例えば、樹脂や、磁性材や、着色料等からなる加熱溶融性のトナーからなる未定着トナー像である。
This fixing device can constitute an image forming apparatus such as a copying machine, a laser printer, or a facsimile machine together with an image forming means (not shown) for forming an unfixed image t on the recording material P.
The recording material P is, for example, a recording material such as recording paper or an OHP sheet, and the unfixed image t is an unfixed material made of a heat-meltable toner made of, for example, a resin, a magnetic material, or a colorant. It is a toner image.
定着ローラ１と加圧ローラ２とは、平行に対向して配置され、それぞれの両端側が、図示しない軸受部材に回転自在に支持されている。定着ローラ１は、図示しないバネ等の加圧機構によって、加圧ローラ２側へ付勢され、加圧ローラ２の外面に所定圧力で圧接されて、前記ニップＮを形成する。
この定着装置においては、定着ローラ１の回転中心軸線方向（軸方向）の全長（ローラ幅）Ｌ１と加圧ローラ２の回転中心軸線方向（軸方向）の全長（ローラ幅）Ｌ２とは、Ｌ１＞Ｌ２の関係にあり（図３参照）、Ｌ２と記録材サイズのうち最大サイズの記録材Ｐの、搬送方向と直交する方向の搬送幅Ｌｐとは、Ｌ２＞Ｌｐの関係にある（図６参照）。
The fixing roller 1 and the pressure roller 2 are arranged to face each other in parallel, and both end sides thereof are rotatably supported by a bearing member (not shown). The fixing roller 1 is urged toward the pressure roller 2 by a pressure mechanism such as a spring (not shown), and is pressed against the outer surface of the pressure roller 2 with a predetermined pressure to form the nip N.
In this fixing device, the total length (roller width) L1 in the rotation center axis direction (axial direction) of the fixing roller 1 and the total length (roller width) L2 in the rotation center axis direction (axial direction) of the pressure roller 2 are L1. > L2 (see FIG. 3), and L2> Lp is the relationship between L2 and the conveyance width Lp in the direction perpendicular to the conveyance direction of the largest recording material P among the recording material sizes (FIG. 6). reference).
加圧ローラ２は、モータ等の駆動手段９によって、図中時計回り方向に、所定の周速度で回転駆動される。定着ローラ１は、ニップＮでの加圧ローラ２との圧接摩擦力によって、加圧ローラ２の回転に従勤して回転する。 The pressure roller 2 is rotationally driven at a predetermined peripheral speed in the clockwise direction in the figure by a driving means 9 such as a motor. The fixing roller 1 rotates in accordance with the rotation of the pressure roller 2 by the frictional force of contact with the pressure roller 2 at the nip N.
定着ローラ１は、図１及び図２に示すように、外側ローラ部１５と、この外側ローラ部１５の内側に接着しないで挿入されている内側ローラ部１０とを備えている。
内側ローラ部１０は、径方向の内側から外側に順に配置された支持層１１、スポンジ層１２及び保護層１３を有する。
外側ローラ部１５は、径方向の内側から外側に順に配置された電磁誘導発熱層１６、弾性層１７及び離型層１８を有する。
As shown in FIGS. 1 and 2, the fixing roller 1 includes an outer roller portion 15 and an inner roller portion 10 that is inserted without being bonded inside the outer roller portion 15.
The inner roller unit 10 includes a support layer 11, a sponge layer 12, and a protective layer 13 that are arranged in order from the inner side to the outer side in the radial direction.
The outer roller portion 15 includes an electromagnetic induction heat generating layer 16, an elastic layer 17, and a release layer 18 that are sequentially arranged from the inner side to the outer side in the radial direction.
内側ローラ部１０の支持層１１は、例えば、外径が４０ｍｍで厚さが３ｍｍのアルミニュウム製の芯金シリンダを用いる。なお、支持層１１としては、材質の強度が確保できれば、例えば、鉄、ＰＰＳ（ポリフェニレンサルファイド）のような耐熱性材のモールドパイプを使用することも可能であるが、いずれにしても、芯金が発熱するのを防ぐために、電磁誘導加熱の影響が少ない非磁性材料を用いるのが望ましい。 The support layer 11 of the inner roller unit 10 uses, for example, an aluminum core bar cylinder having an outer diameter of 40 mm and a thickness of 3 mm. As the support layer 11, for example, a mold pipe made of a heat resistant material such as iron or PPS (polyphenylene sulfide) can be used as long as the strength of the material can be ensured. In order to prevent heat generation, it is desirable to use a non-magnetic material that is less affected by electromagnetic induction heating.
スポンジ層１２は、電磁誘導発熱層１６で発生した熱を断熱保持するためのものであり、耐熱性及び弾性を有するゴム材や樹脂材のスポンジ体（断熱構造体）が用いられる。このように、スポンジ層１２に、耐熱性及び弾性を有するゴム材や樹脂材のスポンジ体（断熱構造体）を用いることにより、電磁誘導発熱層１６を確実に断熱保持するとともに、電磁誘導発熱層１６の撓みを許容してニップＮの幅寸法を増やし、さらに、定着ローラ１のローラ硬度を加圧ローラ２よりも小さくして、記録材排出性及び記録材分離性能を向上させることができる。 The sponge layer 12 is for insulating and holding the heat generated in the electromagnetic induction heat generating layer 16, and a sponge material (heat insulation structure) made of a rubber material or a resin material having heat resistance and elasticity is used. As described above, the sponge layer 12 is made of a heat-resistant and elastic rubber or resin sponge (heat insulating structure), so that the electromagnetic induction heating layer 16 can be reliably insulated and the electromagnetic induction heating layer. The width of the nip N can be increased by allowing 16 deflections, and the roller hardness of the fixing roller 1 can be made smaller than that of the pressure roller 2 to improve the recording material discharge performance and the recording material separation performance.
例えば、スポンジ層１２に、シリコンスポンジ材を用いる場合、厚さが２ｍｍ〜１０ｍｍ、望ましくは３ｍｍ〜７ｍｍであって、硬度がアスカーゴム硬度計で２０〜６０度、望ましくは３０〜５０度に設定される。 For example, when a silicon sponge material is used for the sponge layer 12, the thickness is set to 2 to 10 mm, preferably 3 to 7 mm, and the hardness is set to 20 to 60 degrees, preferably 30 to 50 degrees with an Asker rubber hardness meter. The
保護層１３は、電磁誘導発熱層１６の内面との摩擦力を軽減し、外側ローラ部１５の軸方向の動き（蛇行力）を抑制するためのもので、例えば、ＰＦＡ（テトラフルオロエチレン−パーフルオロアルキルビニルエーテル共重合体）、ＰＴＦＥ（ポリテトラフルオロエチレン）、ＦＥＰ（６ふっ化プロピレン・４ふっ化エチレンコポリマー）、ＰＦＥＰ（テトラフルオロエチレン−ヘキサフルオロプロピレン共重合体）等のフッ素樹脂が好ましく用いられる。この保護層１３の厚さは、５μｍ〜１００μｍが好ましく、１０μｍ〜１５μｍがより好ましい。 The protective layer 13 is for reducing the frictional force with the inner surface of the electromagnetic induction heat generating layer 16 and suppressing the axial movement (meandering force) of the outer roller portion 15. For example, PFA (tetrafluoroethylene-par Fluororesin such as fluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (hexafluoropropylene / tetrafluoroethylene copolymer), PFEP (tetrafluoroethylene-hexafluoropropylene copolymer) is preferably used. It is done. The thickness of the protective layer 13 is preferably 5 μm to 100 μm, and more preferably 10 μm to 15 μm.
電磁誘導発熱層１６は、例えば、厚さが１０μｍ〜１００μｍ、、望ましくは２０μｍ〜５０μｍの無端状のニッケル電鋳ベルト層である。なお、電磁誘導発熱層１６の他の材料としては、例えば、磁性ステンレスのような磁性材料（磁性金属）といった、比較的透磁率が高く、適当な抵抗率ρを有するものを用いてもよい。また、非磁性材料でも、金属などの導電性のある材料は、例えば、材料を薄膜にすることにより使用できる。
また、電磁誘導発熱層１６は、樹脂に発熱粒子を分散させたものを用いてもよく、電磁誘導発熱層１６に、樹脂ベースのものを用いることによって、記録材Ｐの分離性を一層よくすることができる。
The electromagnetic induction heat generating layer 16 is, for example, an endless nickel electroformed belt layer having a thickness of 10 μm to 100 μm, preferably 20 μm to 50 μm. In addition, as another material of the electromagnetic induction heat generating layer 16, for example, a material having a relatively high magnetic permeability and an appropriate resistivity ρ such as a magnetic material (magnetic metal) such as magnetic stainless steel may be used. Moreover, even if it is a nonmagnetic material, electroconductive materials, such as a metal, can be used by making a material into a thin film, for example.
The electromagnetic induction heat generating layer 16 may be made of a resin in which heat generating particles are dispersed. By using a resin-based material for the electromagnetic induction heat generating layer 16, the separation property of the recording material P is further improved. be able to.
そして、電磁誘導発熱層１６では、磁束発生装置３の磁束によって、渦電流が発生してジュール熱により発熱し、この発熱により定着ローラ１が加熱される。この加熱を、電磁誘導加熱という。 In the electromagnetic induction heat generating layer 16, an eddy current is generated by the magnetic flux of the magnetic flux generator 3, and heat is generated by Joule heat, and the fixing roller 1 is heated by this heat generation. This heating is called electromagnetic induction heating.
弾性層１７は、耐熱性及び弾性を有するゴム材や樹脂材からなり、記録材Ｐと定着ローラ１の表面との密着性を高める。弾性層１７としては、例えば、定着温度での使用に耐えられるシリコンゴムやフッ素ゴム等の耐熱性エラストマーを用いる。弾性層１７には、熱伝導性や補強等を目的として各種充填剤を混入してもよく、大理石、ガラス等があり、実用的には、シリカ、アルミナ、酸化マグネシウム、窒化ホウ素、酸化ベリリウム等がある。 The elastic layer 17 is made of a heat-resistant and elastic rubber material or resin material, and improves the adhesion between the recording material P and the surface of the fixing roller 1. As the elastic layer 17, for example, a heat-resistant elastomer such as silicon rubber or fluorine rubber that can withstand use at a fixing temperature is used. Various kinds of fillers may be mixed in the elastic layer 17 for the purpose of thermal conductivity, reinforcement, etc., and there are marble, glass, etc., and practically silica, alumina, magnesium oxide, boron nitride, beryllium oxide, etc. There is.
弾性層１７の厚みは、例えば、１０μｍ〜８００μｍが好ましく、１００μｍ〜３００μｍがより好ましい。弾性層１７の厚みが１０μｍ未満であると、厚み方向の弾性力を得ることが難しくなる一方、弾性層１７の厚みが８００μｍを超えると、電磁誘導発熱層１６で発生した熱が、定着ローラ１の外周面に達し難くなり、熱効率が悪化する傾向がある。 For example, the thickness of the elastic layer 17 is preferably 10 μm to 800 μm, and more preferably 100 μm to 300 μm. When the thickness of the elastic layer 17 is less than 10 μm, it is difficult to obtain an elastic force in the thickness direction. On the other hand, when the thickness of the elastic layer 17 exceeds 800 μm, the heat generated in the electromagnetic induction heat generating layer 16 is generated by the fixing roller 1. It tends to be difficult to reach the outer peripheral surface, and the thermal efficiency tends to deteriorate.
弾性層１７の硬度は、ＪＩＳ硬度で１〜８０度が好ましく、５〜３０度がより好ましく、弾性層１７における強度の低下及び密着性の不良を防止しつつ、未定着像（トナー）ｔの定着性の不良を防止できる。この場合、弾性層１７は、シリコンゴムからなることが好ましく、このシリコンゴムとしては、具体的に述べると、１成分系、２成分系又は３成分系以上のシリコンゴム（ＬＴＶ型（低温加硫型））等を使用できる。なお、この実施形態においては、弾性層１７は、ＪＩＳ硬度１０度、厚さ２００μｍのシリコンゴムである。 The hardness of the elastic layer 17 is preferably 1 to 80 degrees and more preferably 5 to 30 degrees in terms of JIS hardness, while preventing a decrease in strength and poor adhesion in the elastic layer 17 while preventing unfixed image (toner) t. Fixing failure can be prevented. In this case, the elastic layer 17 is preferably made of silicone rubber. Specifically, the silicone rubber can be specifically described as one-component, two-component or three-component or more silicone rubber (LTV type (low temperature vulcanization). Type)) etc. can be used. In this embodiment, the elastic layer 17 is silicon rubber having a JIS hardness of 10 degrees and a thickness of 200 μm.
離型層１８は、定着ローラ１の表面の離型性を高めるものであり、定着温度での使用に耐えられるとともに、トナー離型性を有する。離型層１８としては、例えば、シリコンゴム、フッ素ゴムや、ＰＦＡ、ＰＴＦＥ、ＦＥＰ、ＰＦＥＰ等のフッ素樹脂が用いられる。 離型層１８の厚さは、５μｍ〜１００μｍが好ましく、１０μｍ〜５０μｍがより好ましい。なお、柄径層１８の中に、導電材、耐磨耗材、良熱伝導材をフィラーとして添加してもよい。また、層間接着力を向上させるために、プライマ等による接着処理を行ってもよい。 The release layer 18 enhances the release property of the surface of the fixing roller 1, can withstand use at the fixing temperature, and has toner release properties. As the release layer 18, for example, silicon rubber, fluororubber, or fluororesin such as PFA, PTFE, FEP, and PFEP is used. The thickness of the release layer 18 is preferably 5 μm to 100 μm, and more preferably 10 μm to 50 μm. In the handle diameter layer 18, a conductive material, an abrasion resistant material, and a good heat conductive material may be added as a filler. Further, in order to improve the interlayer adhesion, an adhesion treatment with a primer or the like may be performed.
図１に示すように、加圧ローラ２は、径方向の内側から外側に順に配置された支持層２１、スポンジ層２２及び離型層２３を有する。加圧ローラ２の支持層２１、スポンジ層２２及び離型層２３は、それぞれ、定着ローラ１の支持層１１、スポンジ層１２及び離型層１８と同様である。 As shown in FIG. 1, the pressure roller 2 includes a support layer 21, a sponge layer 22, and a release layer 23 that are sequentially arranged from the inner side to the outer side in the radial direction. The support layer 21, the sponge layer 22 and the release layer 23 of the pressure roller 2 are the same as the support layer 11, the sponge layer 12 and the release layer 18 of the fixing roller 1, respectively.
例えば、支持層２１は、外径２０ｍｍで厚さ３ｍｍのアルミニゥム芯金である。スポンジ層２２は、厚さ７ｍｍのシリコンスポンジゴムである。離型層２３は、厚さ１０μｍ〜５０μｍのＰＴＦＥやＰＦＡ等のフッ素樹脂である。 For example, the support layer 21 is an aluminum core bar having an outer diameter of 20 mm and a thickness of 3 mm. The sponge layer 22 is a silicon sponge rubber having a thickness of 7 mm. The release layer 23 is a fluororesin such as PTFE or PFA having a thickness of 10 μm to 50 μm.
支持層２１の材質は、強度が確保できれば、例えば、鉄、ＰＰＳ（ポリフェニレンサルファイド）のような耐熱性材のモールドパイプを使用することも可能であるが、芯金が発熱するのを防ぐために、電磁誘導加熱の影響が少ない非磁性材を用いるのが望ましい。なお、スポンジ層２２として、シリコンスポンジゴムの代わりに、ソリッドゴムを用いて、さらなる離型性の向上を図るようにしてもよい。 As long as the material of the support layer 21 can secure the strength, for example, a mold pipe made of a heat-resistant material such as iron or PPS (polyphenylene sulfide) can be used, but in order to prevent the cored bar from generating heat, It is desirable to use a non-magnetic material that is less affected by electromagnetic induction heating. In addition, as the sponge layer 22, solid rubber may be used instead of silicon sponge rubber to further improve the releasability.
加圧ローラ２は、定着ローラ１に対して、３００Ｎ〜５００Ｎの荷重で圧接されており、この場合、ニップＮの幅寸法（記録材Ｐの搬送方向の寸法）は、約５ｍｍ〜１０ｍｍになる。もちろん、荷重を変化させて、ニップＮの幅寸法を変えてもよい。 The pressure roller 2 is pressed against the fixing roller 1 with a load of 300 N to 500 N. In this case, the width dimension of the nip N (the dimension in the conveyance direction of the recording material P) is about 5 mm to 10 mm. . Of course, the width of the nip N may be changed by changing the load.
図１に示すように、磁束発生装置３は、励磁コイル３１と磁性体コア３２とを備え、定着ローラ１の外側で、定着ローラ１に対向させて、定着ローラ１の長手方向に沿わせて配置している。 As shown in FIG. 1, the magnetic flux generator 3 includes an exciting coil 31 and a magnetic core 32, and faces the fixing roller 1 on the outside of the fixing roller 1 along the longitudinal direction of the fixing roller 1. It is arranged.
磁性体コア３２は、横断面が下方開口のコップ状（台形）に形成されたコイルボビン３３と、このコイルボビン３３を所定の隙間を介して覆うカバー部材３４とを備えている。磁性体コア３２は、定着ローラ１の軸方向に沿った長尺部材であり、コイルボビン３３の内部にて、定着ローラ１の横断面略半分を覆う。 The magnetic core 32 includes a coil bobbin 33 that is formed in a cup shape (trapezoidal shape) whose cross section is a downward opening, and a cover member 34 that covers the coil bobbin 33 with a predetermined gap therebetween. The magnetic core 32 is a long member along the axial direction of the fixing roller 1, and covers approximately half of the cross section of the fixing roller 1 inside the coil bobbin 33.
磁性体コア３２は、中央部に定着ローラ１側に突出した突出部３２ａを有しており、定着ローラ１の発熱効率を高めている。磁性体コア３２としては、高透磁率かつ低損失のものを用い、例えば、パーマロイのような合金を用いた場合、磁性体コア３２の内部の渦電流損失が高周波で大きくなるため、積層構造にしてもよい。 The magnetic core 32 has a protruding portion 32 a protruding toward the fixing roller 1 at the center, and increases the heat generation efficiency of the fixing roller 1. As the magnetic core 32, one having a high magnetic permeability and low loss is used. For example, when an alloy such as permalloy is used, the eddy current loss inside the magnetic core 32 increases at a high frequency. May be.
磁性体コア３２は、磁気回路の効率の向上と磁気遮蔽のために用いられる。励磁コイル３１と磁性体コア３２の磁気回路部分は、磁気遮蔽が十分にできる手段がある場合、前記突出部３２ａを省いてもよい。また、樹脂部に磁性粉を分散させた材料からなるコアを用いた場合、透磁率は比較的低いが、形状を自由に設定することができる。 The magnetic core 32 is used for improving the efficiency of the magnetic circuit and for magnetic shielding. The magnetic circuit portions of the exciting coil 31 and the magnetic core 32 may omit the protruding portion 32a if there is a means that can sufficiently shield the magnetic field. Further, when a core made of a material in which magnetic powder is dispersed in the resin portion is used, the magnetic permeability is relatively low, but the shape can be freely set.
励磁コイル３１は、コイルボビン３３とカバー部材３４との間の隙間に存在し、長尺のコイルボビン３３に沿って長手方向にわたって導線を巻回した構造であり、横断面が台形形状となる。 The exciting coil 31 is present in the gap between the coil bobbin 33 and the cover member 34, and has a structure in which a conducting wire is wound along the long coil bobbin 33 in the longitudinal direction, and has a trapezoidal cross section.
この励磁コイル３１には、高周波コンバータ４が接続されて、１００Ｗ〜２０００Ｗの高周波電力が供給される。このため、励磁コイル３１としては、細い線を数十から数百本を束ねてリッツ線にしたものを用いており、巻き線に伝熱した場合を考慮して、耐熱性の樹脂で被覆したものを用いる。 The exciting coil 31 is connected to the high frequency converter 4 and supplied with high frequency power of 100 W to 2000 W. For this reason, the exciting coil 31 is a litz wire in which dozens or hundreds of thin wires are bundled, and is coated with a heat-resistant resin in consideration of heat transfer to the winding. Use things.
そして、励磁コイル３１には、高周波コンバータ４により、１０ｋＨｚ〜１００ｋＨｚの交流電圧が印加される。この交流電流によって誘導された磁束は、磁性体コア３２の内部を外部に漏れることなく通り、磁性体コア３２の突出部３２ａで初めて磁性体コア３２の外部に漏れて、定着ローラ１の電磁誘導発熱層１６を貫き、これにより電磁誘導発熱層１６に渦電流が流れて、電磁誘導発熱層１６自体がジュール発熱する。電磁誘導発熱層１６の発熱で定着ローラ１が加熱状態となる。 An AC voltage of 10 kHz to 100 kHz is applied to the excitation coil 31 by the high frequency converter 4. The magnetic flux induced by the alternating current passes through the magnetic core 32 without leaking to the outside, leaks to the outside of the magnetic core 32 for the first time at the protruding portion 32a of the magnetic core 32, and electromagnetic induction of the fixing roller 1 occurs. Through the heat generation layer 16, an eddy current flows through the electromagnetic induction heat generation layer 16, and the electromagnetic induction heat generation layer 16 itself generates Joule heat. The fixing roller 1 is heated by the heat generated by the electromagnetic induction heat generating layer 16.
定着ローラ１の表面に当接するように、温度センサ６が配置される。この温度センサ６は、例えば、サーミスタであり、定着ローラ１の表面温度を検出する。
温度センサ６には制御回路５が接続され、制御回路５は、温度センサ６から入力される定着ローラ１の表面温度検出信号に基づいて、定着ローラ１の加熱と温調制御を行う。
具体的に述べると、制御回路５は、温度センサ６からの信号に基づいて、高周波コンバータ４を制御し、高周波コンバータ４にて励磁コイル３１への電力供給を増減させることで、定着ローラ１の表面温度が定着に要求される所定の一定温度になるように自動制御する。
A temperature sensor 6 is disposed so as to contact the surface of the fixing roller 1. The temperature sensor 6 is a thermistor, for example, and detects the surface temperature of the fixing roller 1.
A control circuit 5 is connected to the temperature sensor 6, and the control circuit 5 performs heating and temperature control of the fixing roller 1 based on a surface temperature detection signal of the fixing roller 1 input from the temperature sensor 6.
More specifically, the control circuit 5 controls the high frequency converter 4 based on a signal from the temperature sensor 6, and increases or decreases the power supply to the exciting coil 31 by the high frequency converter 4, thereby Automatic control is performed so that the surface temperature becomes a predetermined constant temperature required for fixing.
次に、この定着装置の作用を説明する。加圧ローラ２が回転駆動され、これに伴って、定着ローラ１が従動回転する。また、定着ローラ１の電磁誘導発熱層１６が、磁束発生装置３の発生磁束の作用により、電磁誘導発熱すると共に、定着ローラ１の表面温度が、所定の一定温度になるように、自動制御される。そして、定着ローラ１と加圧ローラ２とのニップＮに、図示しない作像手段から搬送された未定着（トナー）像ｔを形成担持した記録材（代表的には記録紙）Ｐが導入される。この場合、記録材Ｐにおける未定着像ｔを形成した担持面側が、定着ローラ１に対面する。 Next, the operation of this fixing device will be described. The pressure roller 2 is rotationally driven, and accordingly, the fixing roller 1 is driven to rotate. Further, the electromagnetic induction heat generating layer 16 of the fixing roller 1 is automatically controlled so as to generate electromagnetic induction heat by the action of the magnetic flux generated by the magnetic flux generator 3 and the surface temperature of the fixing roller 1 becomes a predetermined constant temperature. The A recording material (typically recording paper) P that forms and carries an unfixed (toner) image t conveyed from an image forming means (not shown) is introduced into a nip N between the fixing roller 1 and the pressure roller 2. The In this case, the carrying surface side on which the unfixed image t is formed on the recording material P faces the fixing roller 1.
ニップＮに導入された記録材Ｐは、ニップＮにて扶持搬送され、定着ローラ１で加熱されて、未定着像ｔが記録材Ｐに溶融定着される。
ニップＮを通過した記録材Ｐは、定着ローラ１から分離して排出搬送される。
定着ローラ１の表面に当接するように、分離爪８が配置される。この分離爪８は、記録材Ｐが、ニップＮを通過後に、定着ローラ１の表面に張り付いてしまった場合に、この記録材Ｐを定着ローラ１の表面から強制的に分離させて、紙詰まりによる故障（ジャム）発生を防止する。
The recording material P introduced into the nip N is nipped and conveyed at the nip N and heated by the fixing roller 1, and the unfixed image t is melted and fixed on the recording material P.
The recording material P that has passed through the nip N is separated from the fixing roller 1 and discharged and conveyed.
A separation claw 8 is disposed so as to contact the surface of the fixing roller 1. The separation claw 8 forcibly separates the recording material P from the surface of the fixing roller 1 when the recording material P sticks to the surface of the fixing roller 1 after passing through the nip N, and Prevents jamming due to clogging.
このとき、定着ローラ１では、発熱に寄与すると共に渦電流を発生させる電磁誘導発熱層１６の熱容量は、小さくて、かつ、電磁誘導発熱層１６は、スポンジ層１２により断熱保持されているため、弾性層１７及び離型層１８は迅速に加熱される。このため、定着ローラ１の表面が定着に必要な温度に迅速に到達すると共に、記録材Ｐに熱が奪われても熱の供給が追いつく。 At this time, in the fixing roller 1, the heat capacity of the electromagnetic induction heat generating layer 16 that contributes to heat generation and generates eddy current is small, and the electromagnetic induction heat generating layer 16 is insulated and held by the sponge layer 12. The elastic layer 17 and the release layer 18 are rapidly heated. For this reason, the surface of the fixing roller 1 quickly reaches the temperature required for fixing, and the supply of heat catches up even if the recording material P is deprived of heat.
また、スポンジ層１２により断熱保持させた電磁誘導発熱層１６自体の撓みを利用して、定着ローラ１と加圧ローラ２とのニップＮの形成に対して、弾性層１７を２００μｍと薄くしても、十分な幅寸法のニップＮが形成でき、マイクログロス（微小な光沢むら）の発生がなく、ＯＨＰ用シートのような、定着ローラ１に巻き付きやすい記録材に対しても、十分な分離性能を確保できる。 Further, the elastic layer 17 is made as thin as 200 μm with respect to the formation of the nip N between the fixing roller 1 and the pressure roller 2 by utilizing the bending of the electromagnetic induction heat generating layer 16 itself heat-insulated by the sponge layer 12. However, it is possible to form a nip N having a sufficient width dimension, no microgloss (fine gloss unevenness), and sufficient separation performance even for a recording material such as an OHP sheet that is easily wound around the fixing roller 1. Can be secured.
図３に示すように、定着ローラ１は、外側ローラ部１５の両端部の軸方向の外側に配置されて、外側ローラ部１５の内側ローラ部１０に対するローラ回転中心軸線方向（軸方向）の動きを規制する（移動抑制部の一例としての）一対の規制部材４０を備えている。 As shown in FIG. 3, the fixing roller 1 is disposed outside in the axial direction at both ends of the outer roller portion 15, and moves in the axial direction (axial direction) of the roller rotation center with respect to the inner roller portion 10 of the outer roller portion 15. Is provided with a pair of restricting members 40 (as an example of a movement restraining portion).
さらに言えば、規制部材４０は、円環状であり、この規制部材４０の中央孔の内面は、支持層１１を構成する芯部材４１の軸部４１ａに嵌めこまれて固定されている。
そして、一対の規制部材４０は、外側ローラ部１５の両端を外側から挟んで、外側ローラ部１５の軸方向の動きを規制する。
Furthermore, the regulating member 40 has an annular shape, and the inner surface of the central hole of the regulating member 40 is fitted and fixed to the shaft portion 41 a of the core member 41 constituting the support layer 11.
The pair of restricting members 40 restrict the movement of the outer roller portion 15 in the axial direction with both ends of the outer roller portion 15 sandwiched from the outside.
また、定着ローラ１の外側ローラ部１５の軸方向の中央寄りに接触する加圧ローラ２の接触面２５の、加圧ローラ回転中心軸線方向（軸方向）長さ（ここではローラ２の幅Ｌ２と一致する長さ）は、定着ローラ１の外側ローラ部１５の軸方向の長さ（ここではローラ１の幅Ｌ１と同じ長さ）よりも小さい。内側ローラ部１０の軸方向の長さと外側ローラ部１５の軸方向の長さとは、略同一である。 Further, the pressure roller rotation center axial direction (axial direction) length (here, the width L2 of the roller 2) of the contact surface 25 of the pressure roller 2 that contacts the axial center of the outer roller portion 15 of the fixing roller 1 Is equal to the axial length of the outer roller portion 15 of the fixing roller 1 (here, the same length as the width L1 of the roller 1). The axial length of the inner roller portion 10 and the axial length of the outer roller portion 15 are substantially the same.
ここで、加圧ローラ２の接触面２５とは、加圧ローラ２が定着ローラ１に接触しつつ少なくとも一回転するときに、加圧ローラ２の外周面に形成される定着ローラ１に接触した軌跡をいう。 Here, the contact surface 25 of the pressure roller 2 is in contact with the fixing roller 1 formed on the outer peripheral surface of the pressure roller 2 when the pressure roller 2 makes at least one rotation while being in contact with the fixing roller 1. A trajectory.
換言すれば、定着ローラ１の外周面は、定着ローラ１の軸方向の一端から他端へ順次、外側ローラ部開放領域、ニップ形成領域及び外側ローラ部開放領域を有する。
外側ローラ部開放領域とは、加圧ローラ２と定着ローラ１の外側ローラ部１５とが接触しない領域をいう。ニップ形成領域とは、加圧ローラ２と定着ローラ１の外側ローラ部１５とが接触する領域をいう。
In other words, the outer peripheral surface of the fixing roller 1 has an outer roller portion opening region, a nip forming region, and an outer roller portion opening region sequentially from one end to the other end in the axial direction of the fixing roller 1.
The outer roller part open area refers to an area where the pressure roller 2 and the outer roller part 15 of the fixing roller 1 do not contact each other. The nip forming region is a region where the pressure roller 2 and the outer roller portion 15 of the fixing roller 1 are in contact with each other.
このように、内側ローラ部１０と外側ローラ部１５とは接着されておらず、外部ローラ部１５の両端部の軸方向の外側に一対の規制部材４０が配置されているので、加圧ローラ２が定着ローラ１に接触しつつ、定着ローラ１及び加圧ローラ２が回転するときに、規制部材４０によって、外側ローラ部１５の軸方向への動き（蛇行）を規制する。 As described above, the inner roller portion 10 and the outer roller portion 15 are not bonded to each other, and the pair of regulating members 40 are disposed outside the both ends of the outer roller portion 15 in the axial direction. When the fixing roller 1 and the pressure roller 2 rotate while contacting the fixing roller 1, the movement (meandering) of the outer roller portion 15 in the axial direction is restricted by the restriction member 40.
このとき、加圧ローラ２の接触面２５の軸方向の長さは、定着ローラ１の外側ローラ部１５の軸方向の長さよりも小さいので、外側ローラ部１５の両端部（外側ローラ部開放領域）は、加圧ローラ２の押圧による撓み変形（弾性変形）を殆ど受けない。 At this time, since the axial length of the contact surface 25 of the pressure roller 2 is smaller than the axial length of the outer roller portion 15 of the fixing roller 1, both end portions of the outer roller portion 15 (outer roller portion opening region). ) Hardly undergoes bending deformation (elastic deformation) due to the pressing of the pressure roller 2.
したがって、外側ローラ部１５の両端部は、外側ローラ部１５の両端部が軸方向から見て略円形の形状で、規制部材４０に接触することになり、外側ローラ部１５の両端部が受けるストレス（規制部材からの押圧力によるストレス）を軽減でき、外側ローラ部１５の両端部での割れを防止し、定着ローラ１の寿命を向上させることができる。 Therefore, both end portions of the outer roller portion 15 are substantially circular in shape when viewed from the axial direction, and come into contact with the restricting member 40, so that both end portions of the outer roller portion 15 receive stress. (Stress due to pressing force from the regulating member) can be reduced, cracking at both ends of the outer roller portion 15 can be prevented, and the life of the fixing roller 1 can be improved.
また、規制部材４０は、定着ローラ１を回転させるとき、外側ローラ部１５の軸方向への動き（蛇行）を防止するので、定着ローラ１を通過する記録材Ｐの画質が一層良好になる。 Further, since the regulating member 40 prevents the outer roller portion 15 from moving in the axial direction (meandering) when the fixing roller 1 is rotated, the image quality of the recording material P passing through the fixing roller 1 is further improved.
また、規制部材４０は、芯部材４１に固定されているので、規制部材４０が、内側ローラ部１０及び外側ローラ部１５と共に回転することで、外側ローラ部１５の端部にかかるストレスを小さくでき、この外側ローラ部１５の端部の破損を防止することが可能になる。 Further, since the regulating member 40 is fixed to the core member 41, the stress applied to the end portion of the outer roller portion 15 can be reduced by rotating the regulating member 40 together with the inner roller portion 10 and the outer roller portion 15. It becomes possible to prevent the end portion of the outer roller portion 15 from being damaged.
また、内側ローラ部１０と外側ローラ部１５との間に接着剤を用いていないので、内側ローラ部１０と外側ローラ部１５との接着剥がれの問題がなく、それだけ耐久性の向上が期待できるととともに、接着剤コストの低減が可能になる。 In addition, since no adhesive is used between the inner roller portion 10 and the outer roller portion 15, there is no problem of adhesion peeling between the inner roller portion 10 and the outer roller portion 15, and an improvement in durability can be expected accordingly. At the same time, the adhesive cost can be reduced.
定着ローラとしては、以上説明した定着ローラ１のほか、図４及び図５に例示する定着ローラ５１を採用することもできる。
図４は、定着ローラ５１の一部の断面を示しており、図５は定着ローラ５１における、後述する接着領域Ｚ１を、加圧ローラとともに示している。
As the fixing roller, in addition to the fixing roller 1 described above, a fixing roller 51 illustrated in FIGS. 4 and 5 may be employed.
FIG. 4 shows a partial cross section of the fixing roller 51, and FIG. 5 shows an adhesive region Z1 (to be described later) in the fixing roller 51 together with the pressure roller.
定着ローラ５１は、外側ローラ部１５とそれに挿入された内側ローラ部１０を含んでいる。
外側ローラ部１５は、図１の定着ローラ１の外側ローラ部１５と同様に、径方向の内側から外側に順に配置された電磁誘導発熱層１６、弾性層１７及び離型層１８を有している。
内側ローラ部１０は、径方向の内側から外側に順に配置された支持層１１及びスポンジ層１２を有する。これらは、図１に示す定着ローラ１の内側ローラ部１０の支持層１１及びスポンジ層１２と実質上同じものである。ここでの内側ローラ部１０は図１の定着ローラ１の内側ローラ部１０における保護層１３を有していない。
The fixing roller 51 includes an outer roller portion 15 and an inner roller portion 10 inserted therein.
The outer roller portion 15 has an electromagnetic induction heat generating layer 16, an elastic layer 17 and a release layer 18 arranged in order from the inner side to the outer side in the radial direction, like the outer roller portion 15 of the fixing roller 1 of FIG. Yes.
The inner roller unit 10 includes a support layer 11 and a sponge layer 12 that are sequentially arranged from the inner side to the outer side in the radial direction. These are substantially the same as the support layer 11 and the sponge layer 12 of the inner roller portion 10 of the fixing roller 1 shown in FIG. The inner roller portion 10 here does not have the protective layer 13 in the inner roller portion 10 of the fixing roller 1 of FIG.
そして、定着ローラ５１は、前記の規制部材４０に代えて、図５に示すように、外側ローラ部１５の両端部と内側ローラ部１０の間にのみ配置されて、外側ローラ部１５の電磁誘導発熱層１６の端部と内側ローラ部１０のスポンジ層１２とを互いに接着する（移動抑制部の一例としての）接着剤１４を備えている。この接着剤１４によって、外側ローラ部１５の内側ローラ部１０に対する軸方向及び周方向への移動が抑制される。 The fixing roller 51 is disposed only between both end portions of the outer roller portion 15 and the inner roller portion 10 as shown in FIG. 5 in place of the regulating member 40, and electromagnetic induction of the outer roller portion 15 is performed. An adhesive 14 (as an example of a movement restraining portion) is provided to bond the end portion of the heat generating layer 16 and the sponge layer 12 of the inner roller portion 10 to each other. The adhesive 14 suppresses movement of the outer roller portion 15 in the axial direction and the circumferential direction with respect to the inner roller portion 10.
このように、接着剤１４のある接着領域Ｚ１は、外側ローラ部１５の両端部と内側ローラ部１０との間にのみ配置されており、且つ、前記のとおり、加圧ローラ２の接触面２５の軸方向の長さは、定着ローラ５１の外側ローラ部１５の軸方向の長さよりも小さいので、加圧ローラ２が定着ローラ５１に接触しつつ、定着ローラ５１及び加圧ローラ２が回転するときに、外側ローラ部１５の両端部は、加圧ローラ２の押庄による撓み変形を殆ど受けていないので、外側ローラ部１５の両端部と内側ローラ部１０との間の接着剤１４の接着剥がれを防止して、定着ローラ５１の耐久性を維持することができる。 As described above, the adhesive region Z1 where the adhesive 14 is present is disposed only between the both end portions of the outer roller portion 15 and the inner roller portion 10, and, as described above, the contact surface 25 of the pressure roller 2. Is smaller than the axial length of the outer roller portion 15 of the fixing roller 51, so that the fixing roller 51 and the pressure roller 2 rotate while the pressure roller 2 is in contact with the fixing roller 51. Sometimes, both end portions of the outer roller portion 15 are hardly subjected to bending deformation due to the pressing of the pressure roller 2, so that the adhesive 14 is bonded between the both end portions of the outer roller portion 15 and the inner roller portion 10. The durability of the fixing roller 51 can be maintained by preventing peeling.
なお、接着領域Ｚ１は、定着ローラ５１の外側ローラ部１５の端部のうち、さらに、記録材Ｐを通過させる領域、より好ましくは、トナー像定着処理可能の記録材サイズのうち最大サイズの記録材の、搬送方向と直交する方向の搬送幅Ｌｐ（図６参照）の領域より外側に限定してもよく、そうすることで、接着剤層による画質への影響が抑制される状態で外側ローラ部１５の接着剥がれを起きにくくして、定着ローラ５１、ひいては定着装置の耐久性を向上させることができる。 Note that the adhesion region Z1 is a region where the recording material P further passes through the end of the outer roller portion 15 of the fixing roller 51. More preferably, the maximum size of the recording material size that can be subjected to toner image fixing processing is recorded. The outer roller may be limited to the outside of the region of the conveyance width Lp (see FIG. 6) in the direction orthogonal to the conveyance direction of the material, so that the influence on the image quality by the adhesive layer is suppressed. It is possible to improve the durability of the fixing roller 51 and, consequently, the fixing device by making it difficult for the peeling of the portion 15 to occur.
また、定着ローラ５１と加圧ローラ２間の圧接ニップ部Ｎで定着ローラ５１（特にその外側ローラ部１５）が、ローラ回転により、繰り返し撓み変形して接着剥がれが発生する場合があることに備えて、外側ローラ部１５における、加圧ローラ２と接触しない、撓み変形が無いか又は小さい、加圧ローラから開放されている領域（外側ローラ部開放領域）（図３参照）に接着領域を設定してもよい。 In addition, the fixing roller 51 (particularly the outer roller portion 15) at the pressure nip portion N between the fixing roller 51 and the pressure roller 2 may be repeatedly bent and deformed due to the rotation of the roller to cause adhesion peeling. In the outer roller portion 15, the adhesive region is set in a region (outer roller portion opening region) (see FIG. 3) that is not in contact with the pressure roller 2, is not deformed or is small, and is released from the pressure roller. May be.
以上説明してきた定着装置のさらに説明すべき重要な特徴として、加圧ローラ２の軸方向の長さＬ２が定着ローラ１の軸方向の長さＬ１よりも短い定着装置構成において、磁束発生装置３の励磁コイル３１のローラ回転中心軸線方向（軸方向）の幅が規定されていることを挙げることができる。 As an important feature to be further described of the fixing device described above, in the fixing device configuration in which the axial length L2 of the pressure roller 2 is shorter than the axial length L1 of the fixing roller 1, the magnetic flux generator 3 It can be mentioned that the width of the exciting coil 31 in the roller rotation center axis direction (axial direction) is defined.
この点について図６を参照して説明する。
磁束発生装置３は磁性体コア３２及び励磁コイル３１を有し、励磁コイル３１は記録材Ｐの搬送方向と直交する幅方向に長く伸びた形状に巻回された構成であり、励磁コイル３１両端の屈曲部の内側部間距離Ｌｃ１を定着ローラ１の全長Ｌ１より長く設定している。
This point will be described with reference to FIG.
The magnetic flux generator 3 has a magnetic core 32 and an excitation coil 31, and the excitation coil 31 is wound in a shape extending long in the width direction orthogonal to the conveyance direction of the recording material P. The distance Lc1 between the inner portions of the bent portions is set to be longer than the total length L1 of the fixing roller 1.
図７に、このときの定着ローラ１の温度分布と最大サイズ記録材幅Ｌｐの関係を示す。 励磁コイル３１両端の屈曲部では、磁束分布が急激に変化するが、ここでは、励磁コイル３１両端の屈曲部の内側部間距離Ｌｃ１を定着ローラ１の全長Ｌ１より長く設定することで、励磁コイル３１両端の屈曲部からの不安定な磁束の影響を受け難くしてあり、これにより、定着ローラ１の軸方向端部においても中央部と同様に磁束密度が均一になり、定着ローラ１を記録材を通過させる領域の全域にわたって均一に加熱することができる。 FIG. 7 shows the relationship between the temperature distribution of the fixing roller 1 and the maximum size recording material width Lp at this time. The magnetic flux distribution changes abruptly at the bent portions at both ends of the exciting coil 31. Here, the distance Lc1 between the inner portions of the bent portions at both ends of the exciting coil 31 is set longer than the total length L1 of the fixing roller 1, thereby Thus, the magnetic flux density is uniform at the axial end portion of the fixing roller 1 as in the central portion, and the fixing roller 1 is recorded. It is possible to uniformly heat the entire region through which the material passes.
すなわち、本例では、励磁コイル３１両端の屈曲部の内側部間距離Ｌｃ１と定着ローラ１の全長Ｌ１と、加圧ローラ２の全長Ｌ２と、通紙可能な最大幅サイズの記録材Ｐmax の搬送幅Ｌｐとの関係を、
Ｌｃ１≧Ｌ１＞Ｌ２＞Ｌｐとすることにより、耐久性を維持しながら、記録材Ｐの幅方向にわたり均一なトナー 像加熱処理が可能になり、また、省スペースを考えた場合の励磁コイル３１、定着ローラ１、加圧ローラ２、記録材Ｐの配置関係が最適化される。
したがって、装置のコンパクト化、省スペース化を可能とした定着装置及び画像形成装置を提供することができようになる。
但し、定着ローラ１のみに着目すれば、定着ローラ１の長手方向（軸方向）では、中央部と比べて端部で放熱面積が大きく、放熱量が大きくなってしまうので、図７における定着ローラ１の全長Ｌ１の端部付近では、中央部より若干温度が下がる傾向にある。
That is, in this example, the distance Lc1 between the bent portions at both ends of the exciting coil 31, the total length L1 of the fixing roller 1, the total length L2 of the pressure roller 2, and the conveyance of the recording material Pmax having the maximum width size capable of passing paper. The relationship with the width Lp is
By satisfying Lc1 ≧ L1>L2> Lp, it is possible to perform a uniform toner image heating process in the width direction of the recording material P while maintaining the durability, and the exciting coil 31 when space saving is considered. The arrangement relationship between the fixing roller 1, the pressure roller 2, and the recording material P is optimized.
Accordingly, it is possible to provide a fixing device and an image forming apparatus that can be made compact and space-saving.
However, if attention is paid only to the fixing roller 1, in the longitudinal direction (axial direction) of the fixing roller 1, the heat radiation area is larger and the heat radiation amount is larger at the end portion than in the center portion. In the vicinity of the end of the entire length L1 of 1, the temperature tends to be slightly lower than the central portion.
本発明に係る定着装置においては、図８に示すように、均熱ローラ５０を加圧ローラ２に回転可能に圧接させてもよい。
均熱ローラ５０は、本例では低熱容量のもので、定着ローラ１及び加圧ローラ２の軸方向の熱分布を均一にならすために圧接させるためのもので、特に小サイズ幅の記録材を連続的に通過させる場合における定着ローラ１及び加圧ローラ２の、記録材が通過しない領域（非通紙領域）の過昇温を抑制することができる。
In the fixing device according to the present invention, as shown in FIG. 8, the soaking roller 50 may be rotatably contacted to the pressure roller 2.
The heat equalizing roller 50 has a low heat capacity in this example, and is used to press the heat distribution in the axial direction of the fixing roller 1 and the pressure roller 2 uniformly. Particularly, a recording material having a small size width is used. Overheating of the fixing roller 1 and the pressure roller 2 in the region where the recording material does not pass (non-sheet passing region) when continuously passing can be suppressed.
均熱ローラ５０を採用する場合、均熱ローラ５０の全長Ｌ３と加圧ローラ２の全長Ｌ２の関係を、L3≧Ｌ２として、均熱ローラ５０のエッジで加圧ローラ２が破損することを防止することが望ましい。 When the soaking roller 50 is employed, the relationship between the overall length L3 of the soaking roller 50 and the overall length L2 of the pressure roller 2 is set to L3 ≧ L2, and the pressure roller 2 is prevented from being damaged at the edge of the soaking roller 50. It is desirable to do.
図９に、磁束発生装置３の磁性体コア３２の設置幅Ｌcoreと、加圧ローラ２の全長Ｌ２と、通紙可能な最大幅サイズの記録材Ｐmax の搬送幅Ｌｐとの関係を示す。図９に示すように、電磁誘導加熱方式では、磁性体コア３２の設置幅Ｌcoreとほぼ等価な発熱域が得られる。 FIG. 9 shows the relationship between the installation width Lcore of the magnetic core 32 of the magnetic flux generation device 3, the total length L2 of the pressure roller 2, and the conveyance width Lp of the recording material Pmax having the maximum width size capable of passing paper. As shown in FIG. 9, in the electromagnetic induction heating method, a heat generation area substantially equivalent to the installation width Lcore of the magnetic core 32 can be obtained.
一方、定着ローラ１の全長Ｌ１と加圧ローラ２の全長Ｌ２がＬ１＞Ｌ２の構成の場合、加圧ローラ２と当接しない定着ローラ１の両端部は加圧ローラ２により熱が奪われない分、加圧ローラ２との当接領域より高温になる傾向にある。さらに、この定着ローラ１の両端部は記録材Ｐの非通紙領域にも相当するので、記録材Ｐをある程度連続で通すと、記録材Ｐへの熱移動がないので、さらに高温になり、定着ローラ１の劣化や破損を引き起こす温度（過昇温）となる可能性がある。 On the other hand, when the total length L1 of the fixing roller 1 and the total length L2 of the pressure roller 2 are L1> L2, both ends of the fixing roller 1 not in contact with the pressure roller 2 are not deprived of heat by the pressure roller 2. Therefore, the temperature tends to be higher than the contact area with the pressure roller 2. Further, since both end portions of the fixing roller 1 also correspond to non-sheet passing regions of the recording material P, if the recording material P is continuously passed to some extent, there is no heat transfer to the recording material P, so that the temperature becomes even higher. There is a possibility that the temperature (excessive temperature rise) may cause deterioration or breakage of the fixing roller 1.
そこで、磁性体コア３２の設置幅Ｌcoreと、加圧ローラ２の全長Ｌ２と、通紙可能な最大幅サイズの記録材Ｐmax の搬送幅Ｌｐとの関係を、Ｌ２≧Ｌcore≧Ｌｐに設定することで、定着ローラ１の両端部の過昇温を抑えて、記録材Ｐの搬送幅範囲を均一に加熱可能とすることができる。 Therefore, the relationship between the installation width Lcore of the magnetic core 32, the total length L2 of the pressure roller 2, and the conveyance width Lp of the recording material Pmax having the maximum width that can be passed is set to L2 ≧ Lcore ≧ Lp. Thus, it is possible to uniformly heat the conveyance width range of the recording material P while suppressing an excessive temperature rise at both ends of the fixing roller 1.
本発明は、均一加熱により良好な定着トナー画像を得ることができ、各種画像形成装置に利用できる定着装置の提供に利用できる。 The present invention can be used to provide a fixing device that can obtain a good fixing toner image by uniform heating and can be used in various image forming apparatuses.
１、５１：定着ローラ
１０：内側ローラ部
１１：支持層
１２：スポンジ層
１３：保護層
１４：接着剤（移動抑制部の例）
１５：外側ローラ部
１６：電磁誘導発熱層
１７：弾性層
１８：離型層
２：加圧ローラ
２１：支持層
２２：スポンジ層
２３：離型層
２５：接触面
３：磁束発生装置
３１：励磁コイル
３２：磁性体コア
９：駆動手段
４０：規制部材（移動抑制部の例）
Ｚ１：接着領域
Ｐ：記録材
ｔ：未定着像
Ｌ１：定着ローラ全長
Ｌ２：加圧ローラ全長
Ｌｃ１：コイル３１の両端屈曲部の内側部間の距離
Ｌｐ：最大幅サイズ記録材の搬送幅
Ｌcore：励磁コア設置幅
DESCRIPTION OF SYMBOLS 1, 51: Fixing roller 10: Inner roller part 11: Support layer 12: Sponge layer 13: Protective layer 14: Adhesive (Example of a movement suppression part)
15: Outer roller section 16: Electromagnetic induction heating layer 17: Elastic layer 18: Release layer 2: Pressure roller 21: Support layer 22: Sponge layer 23: Release layer 25: Contact surface 3: Magnetic flux generator 31: Excitation Coil 32: Magnetic core 9: Driving means 40: Restricting member (example of movement restraining portion)
Z1: adhesion area P: recording material t: unfixed image L1: fixing roller full length L2: pressure roller full length Lc1: distance Lp between the inner side portions of both ends of the coil 31 Lp: transport width Lcore of the maximum width size recording material: Excitation core installation width
Claims (6)
前記磁束発生装置は磁性体コア及び励磁コイルを有しており、
該励磁コイルは、前記記録材の搬送方向と直交する方向に長く延びる形状に巻回形成されており、
該励磁コイルの、前記記録材搬送方向と直交する方向における両端屈曲部の内側部間の距離Ｌｃ１と、前記定着ローラの回転中心軸線方向の全長Ｌ１と、前記加圧ローラの回転中心軸線方向の全長Ｌ２と、トナー像定着処理可能の記録材サイズのうち最大サイズの記録材の、搬送方向と直交する方向の搬送幅Ｌｐとが、
Ｌｃ１≧Ｌ１＞Ｌ２＞Ｌｐの関係を満たすことを特徴とする定着装置。 A rotatable fixing roller having an electromagnetic induction heat generating layer, a rotatable pressure roller pressed against the fixing roller, and a magnetic flux generator for generating electromagnetic induction heat in the electromagnetic induction heat generating layer of the fixing roller. The electromagnetic induction heat generating layer of the fixing roller is heated by the magnetic flux generated by the magnetic flux generator, and a recording material holding a toner image is passed through a nip portion between the fixing roller and the pressure roller. The toner image can be melt-fixed on the recording material, and the fixing roller includes an outer roller portion having the electromagnetic induction heating layer and an inner roller having a sponge layer inserted into the outer roller portion. A movement restraining portion that restrains movement of the outer roller portion with respect to the inner roller portion in the roller rotation center axis direction, at least of the outer roller portion. A fixing device is provided for the side end portions,
The magnetic flux generator has a magnetic core and an exciting coil,
The exciting coil is wound and formed in a shape extending long in a direction orthogonal to the conveying direction of the recording material,
A distance Lc1 between the inner portions of the bent portions at both ends in a direction orthogonal to the recording material conveyance direction of the excitation coil, a total length L1 in the rotation center axis direction of the fixing roller, and a rotation center axis direction of the pressure roller. The total length L2 and the conveyance width Lp in the direction orthogonal to the conveyance direction of the largest recording material among the recording material sizes that can be subjected to the toner image fixing process,
A fixing device satisfying a relationship of Lc1 ≧ L1>L2> Lp.
The fixing device according to claim 1, wherein an installation width Lcore of the magnetic core in the magnetic flux generation device satisfies L2 ≧ Lcore ≧ Lp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005100994A JP4539407B2 (en) | 2005-03-31 | 2005-03-31 | Fixing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005100994A JP4539407B2 (en) | 2005-03-31 | 2005-03-31 | Fixing device |
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| JP2006284649A true JP2006284649A (en) | 2006-10-19 |
| JP4539407B2 JP4539407B2 (en) | 2010-09-08 |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010122489A (en) * | 2008-11-20 | 2010-06-03 | Canon Inc | Image heating device |
| JP2010145958A (en) * | 2008-12-22 | 2010-07-01 | Konica Minolta Business Technologies Inc | Fixing device and image forming apparatus with the same |
| JP2010169737A (en) * | 2009-01-20 | 2010-08-05 | Konica Minolta Business Technologies Inc | Fixing device and image forming apparatus including the same |
| JP2011022263A (en) * | 2009-07-14 | 2011-02-03 | Konica Minolta Business Technologies Inc | Fixing device |
| JP2012008403A (en) * | 2010-06-25 | 2012-01-12 | Kyocera Mita Corp | Fixing device and image forming apparatus |
| US8849169B2 (en) | 2011-01-11 | 2014-09-30 | Ricoh Company, Ltd. | Fixing device and image forming apparatus including same |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09305043A (en) * | 1996-05-10 | 1997-11-28 | Canon Inc | Heating device and image forming device |
| JP2003098877A (en) * | 2001-09-20 | 2003-04-04 | Konica Corp | Fixing device and image forming device |
| JP2003223980A (en) * | 2002-01-31 | 2003-08-08 | Canon Inc | Heating device and image forming device |
| JP2004029564A (en) * | 2002-06-27 | 2004-01-29 | Sharp Corp | Fixing device |
| JP2004210538A (en) * | 2003-01-08 | 2004-07-29 | Canon Inc | Carrier roller and image forming device equipped with it |
| JP2005049812A (en) * | 2003-07-16 | 2005-02-24 | Toshiba Corp | Fixing device and heating roller |
-
2005
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09305043A (en) * | 1996-05-10 | 1997-11-28 | Canon Inc | Heating device and image forming device |
| JP2003098877A (en) * | 2001-09-20 | 2003-04-04 | Konica Corp | Fixing device and image forming device |
| JP2003223980A (en) * | 2002-01-31 | 2003-08-08 | Canon Inc | Heating device and image forming device |
| JP2004029564A (en) * | 2002-06-27 | 2004-01-29 | Sharp Corp | Fixing device |
| JP2004210538A (en) * | 2003-01-08 | 2004-07-29 | Canon Inc | Carrier roller and image forming device equipped with it |
| JP2005049812A (en) * | 2003-07-16 | 2005-02-24 | Toshiba Corp | Fixing device and heating roller |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010122489A (en) * | 2008-11-20 | 2010-06-03 | Canon Inc | Image heating device |
| JP2010145958A (en) * | 2008-12-22 | 2010-07-01 | Konica Minolta Business Technologies Inc | Fixing device and image forming apparatus with the same |
| JP2010169737A (en) * | 2009-01-20 | 2010-08-05 | Konica Minolta Business Technologies Inc | Fixing device and image forming apparatus including the same |
| JP2011022263A (en) * | 2009-07-14 | 2011-02-03 | Konica Minolta Business Technologies Inc | Fixing device |
| JP2012008403A (en) * | 2010-06-25 | 2012-01-12 | Kyocera Mita Corp | Fixing device and image forming apparatus |
| US8849169B2 (en) | 2011-01-11 | 2014-09-30 | Ricoh Company, Ltd. | Fixing device and image forming apparatus including same |
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| Publication number | Publication date |
|---|---|
| JP4539407B2 (en) | 2010-09-08 |
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