JP2003177625A - Fixing device - Google Patents

Fixing device

Info

Publication number
JP2003177625A
JP2003177625A JP2001375498A JP2001375498A JP2003177625A JP 2003177625 A JP2003177625 A JP 2003177625A JP 2001375498 A JP2001375498 A JP 2001375498A JP 2001375498 A JP2001375498 A JP 2001375498A JP 2003177625 A JP2003177625 A JP 2003177625A
Authority
JP
Japan
Prior art keywords
fixing device
pressure roller
elastic body
change characteristic
roller
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.)
Pending
Application number
JP2001375498A
Other languages
Japanese (ja)
Inventor
Toshihiro Maeda
智弘 前田
Toshiaki Kagawa
敏章 香川
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.)
Sharp Corp
Original Assignee
Sharp Corp
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 Sharp Corp filed Critical Sharp Corp
Priority to JP2001375498A priority Critical patent/JP2003177625A/en
Publication of JP2003177625A publication Critical patent/JP2003177625A/en
Pending legal-status Critical Current

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  • Fixing For Electrophotography (AREA)
  • Rolls And Other Rotary Bodies (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device that prevents a nip width from changing due to elasticity characteristic with time without providing an electrical or mechanical device in order to control energizing force. <P>SOLUTION: The fixing device A is provided with a heat roller 10 which has a heat generation source, and a pressure roller 20 which forms a nip by bringing its peripheral face into pressure contact with the heat roller 10. In the case the elastic layer 21 composing the pressure roller 20 has an elastic body change characteristic, in which the hardness of the elastic layer 21 changes with time, a spring 32 which generates urging force for pressing the pressure roller 20 to the heat roller 10 has an urging force change characteristic, in which the urging force changes with time according the elastic body change characteristic. <P>COPYRIGHT: (C)2003,JPO

Description

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

【0001】[0001]

【発明の属する技術分野】本発明は,シート材上のトナ
ー像をシート材に定着するための加熱ローラ及び加圧ロ
ーラを具備する定着装置において,加圧ローラを加熱ロ
ーラ側へ付勢するための付勢手段の付勢力の調整に関す
るものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device having a heating roller and a pressure roller for fixing a toner image on a sheet material to the sheet material, for urging the pressure roller toward the heating roller side. The present invention relates to the adjustment of the urging force of the urging means.

【0002】[0002]

【従来の技術】従来より,加熱ローラ及び加圧ローラを
具備し,シート材上のトナー像をシート材に定着するた
めの定着装置が知られている。このような定着装置は,
上記定着を確実に行うために,加熱ローラの外周面と加
圧ローラの外周面とで接触面(以下,「ニップ」と称す
る)を形成している。このニップは,一般的に加熱ロー
ラ側に加圧ローラを付勢することによって形成されるも
のである。定着装置が上述のように概略構成されている
ため,上記2つのローラが回転している状況において,
上記ニップに対してトナー像が載ったシート材を挿入す
ることで,トナー像はシート材に熱と圧力とによって定
着される。ところで,上記定着装置は,加熱ローラ及び
加圧ローラの外周面においてニップを形成するため,少
なくとも1つローラの外周面は上記ニップを形成するの
に必要な弾性特性を有する必要がある。一般的には,加
圧ローラの外周面が上記弾性特性を有する素材(以下,
「弾性体」と称する)で構成される場合が多い。しか
し,上記弾性体は,上記ニップにおいて加熱ローラに接
触するものであるので,加熱ローラの熱やニップ形成時
の応力等によってその弾性特性を経時的に変化してしま
うものである。この弾性特性の変化は,通常,時間と共
に弾性体の硬度が低下して柔らかくなる傾向があるの
で,上記付勢力を調整しなければニップ幅(即ち,加熱
ローラの外周面と加圧ローラの外周面とが接触する部分
の弦長)が時間と共に大きくなる不具合がある。本来,
上記ニップ幅は定着が最適に行われるように調整される
ことが望ましく,従来は上記ニップ幅を電気的或いは機
械的に予め定められた最適な状態に保つような制御が行
われていた。
2. Description of the Related Art Conventionally, a fixing device having a heating roller and a pressure roller for fixing a toner image on a sheet material to the sheet material is known. Such a fixing device is
In order to ensure the above-mentioned fixing, the outer peripheral surface of the heating roller and the outer peripheral surface of the pressure roller form a contact surface (hereinafter referred to as "nip"). This nip is generally formed by urging a pressure roller toward the heating roller. Since the fixing device is roughly configured as described above, in the situation where the two rollers are rotating,
By inserting the sheet material on which the toner image is placed into the nip, the toner image is fixed on the sheet material by heat and pressure. By the way, since the fixing device forms a nip on the outer peripheral surfaces of the heating roller and the pressure roller, it is necessary that at least one outer peripheral surface of the roller has an elastic characteristic necessary for forming the nip. Generally, the outer peripheral surface of the pressure roller has the above-mentioned elastic properties (hereinafter,
Often referred to as "elastic body". However, since the elastic body comes into contact with the heating roller in the nip, its elastic characteristics change with time due to the heat of the heating roller, the stress at the time of forming the nip, and the like. Since this change in elastic property tends to decrease the hardness of the elastic body and become softer with time, the nip width (that is, the outer peripheral surface of the heating roller and the outer peripheral surface of the pressure roller) must be adjusted unless the biasing force is adjusted. There is a problem that the chord length of the part that contacts the surface increases with time. Originally
It is desirable that the nip width is adjusted so that the fixing is optimally performed, and conventionally, the nip width is electrically or mechanically controlled to maintain a predetermined optimal state.

【0003】[0003]

【発明が解決しようとする課題】しかしながら,ニップ
幅を従来のように電気的或いは機械的に制御しようとす
ると,ニップ幅,弾性特性,付勢力等を検出する必要が
ある。そのため,本来の画像形成における定着処理とは
直接関係ない上記検出に係る機器等が増加し,構造の複
雑化や制御の複雑化の問題がある。そこで,本発明は上
記事情に鑑みてなされたものであり,その目的とすると
ころは,上記付勢力を制御するために新たに電気的若し
くは機械的機器を設けることなく,経時的な上記弾性特
性の変化によって上記ニップ幅を変化させないようにす
る定着装置を提供することである。
However, in order to control the nip width electrically or mechanically as in the conventional case, it is necessary to detect the nip width, elastic characteristics, biasing force and the like. Therefore, the number of devices related to the above detection that are not directly related to the fixing process in the original image formation is increased, and there is a problem of complicated structure and complicated control. Therefore, the present invention has been made in view of the above circumstances, and it is an object of the present invention to provide the above elastic characteristics over time without newly providing an electric or mechanical device for controlling the biasing force. It is an object of the present invention to provide a fixing device that does not change the nip width due to the change of.

【0004】[0004]

【課題を解決するための手段】上記目的を達成するため
に本発明は,発熱源を有する加熱ローラと,該加熱ロー
ラに対して外周面を圧接することによってニップを形成
する加圧ローラとを具備し,上記加圧ローラを構成する
弾性体が,その硬度を経時的に変化する弾性体変化特性
を有する定着装置において,上記加圧ローラを上記加熱
ローラに加圧するための付勢力を発生する付勢手段が,
上記弾性体変化特性に応じて上記付勢力を経時的に変化
する付勢変化特性を有することを特徴とする定着装置と
して構成されている。また,前記付勢変化特性は,前記
弾性体変化特性による前記弾性体の硬度の低下に対して
近似的に前記付勢力が低下することが望ましい。このよ
うに本発明が構成されているので,弾性体の弾性体変化
特性が経時的に変化した場合に,その変化に応じて近似
的に上記付勢手段の付勢力も変化するので,従来のよう
に,付勢力調整用の機器等を定着装置に設ける必要がな
くなる結果,従来の画像品質を保ちながら定着装置の構
造や制御を簡素化することが可能となる。また,上記機
器が省略できる分定着装置の小型化が可能となると共
に,定着装置の構造が単純化されるのでメンテナンス等
が容易になる。
In order to achieve the above object, the present invention comprises a heating roller having a heat source and a pressure roller forming a nip by pressing the outer peripheral surface against the heating roller. In the fixing device having the elastic body that constitutes the pressure roller and has an elastic body changing characteristic whose hardness changes with time, a biasing force for pressing the pressure roller against the heating roller is generated. The urging means is
The fixing device is configured to have an urging change characteristic that changes the urging force with time according to the elastic body change characteristic. In addition, it is desirable that the bias change characteristic is such that the bias force is approximately reduced with respect to the decrease in hardness of the elastic body due to the elastic change characteristic. Since the present invention is configured as described above, when the elastic body change characteristic of the elastic body changes with time, the urging force of the urging means changes approximately in accordance with the change. As described above, since it is not necessary to provide a device for adjusting the urging force in the fixing device, it is possible to simplify the structure and control of the fixing device while maintaining the conventional image quality. Further, since the above-mentioned equipment can be omitted, the fixing device can be downsized, and since the structure of the fixing device is simplified, maintenance and the like are facilitated.

【0005】[0005]

【発明の実施の形態】以下添付図面を参照しながら,本
発明の実施の形態について説明し,本発明の理解に供す
る。尚,以下の実施の形態は,本発明を具体化した一例
であって,本発明の技術的範囲を限定する性格のもので
はない。ここに,図1は本発明の実施の形態に係る定着
装置の概略構成図,図2は加熱ローラ,加圧ローラ,及
び付勢手段の概略構成を示した模式図,図3はバネ32
と加圧ローラ20の特性に関するデータのグラフであ
る。
BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. Here, FIG. 1 is a schematic configuration diagram of a fixing device according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing a schematic configuration of a heating roller, a pressure roller, and a biasing means, and FIG.
3 is a graph of data relating to characteristics of the pressure roller 20.

【0006】本発明の実施の形態に係る定着装置Aの概
略構成を図1を用いて説明する。定着装置Aの大略は,
熱をシート材50に加えるための加熱ローラ10と,該
加熱ローラ10の外周面に対して同じく外周面を圧接す
ることによってニップを形成する加圧ローラ20とを具
備して構成されるものである。更に,上記定着装置A
は,加圧ローラ20の外周面を加熱ローラ10の外周面
に加圧するための付勢力を発生するための付勢手段の一
例であるバネ32と,該バネ32の付勢力をテコの原理
で伝達するための支持バー31(詳細は図2を用いて説
明する。)を具備している。上記加熱ローラ10は,内
部に発熱源となるランプ12と,ランプ12より発せら
れた熱をシート材に伝達するための薄肉芯金11とを具
備しており,該薄肉芯金11の外周面にはフッ素樹脂等
の高離型性の材料よりなる薄い外皮層(不図示)を具備
している。また,加熱ローラ12の上部には該外皮層に
付着したトナー等の不要物を除去するためのクリーニン
グローラ30が設けられている上記加圧ローラ20は,
その外周面を加熱ローラ10の外周面に圧接することに
よってニップを形成するために,形状を変化できる弾性
体よりなる弾性層21と,該弾性層21の内部にあって
該弾性層を固定するための芯金22とを具備して構成さ
れているこのように概略構成されている定着装置Aにお
いて,加熱ローラ10の外周面に対して加圧ローラ20
の外周面(即ち,弾性層21)を加圧する構成の詳細に
ついて図2を用いて説明する。尚,図2の符号において
図1の符号と同一の符号のものは,図1の符号のものと
同一である。
A schematic structure of a fixing device A according to an embodiment of the present invention will be described with reference to FIG. The outline of the fixing device A is
It comprises a heating roller 10 for applying heat to the sheet material 50, and a pressure roller 20 for forming a nip by pressing the outer peripheral surface of the heating roller 10 to the outer peripheral surface. is there. Furthermore, the fixing device A
Is a spring 32, which is an example of a biasing means for generating a biasing force for pressing the outer peripheral surface of the pressure roller 20 against the outer peripheral surface of the heating roller 10, and the biasing force of the spring 32 based on the lever principle. It is provided with a support bar 31 (details will be described with reference to FIG. 2) for transmission. The heating roller 10 includes a lamp 12 serving as a heat source inside and a thin cored bar 11 for transmitting heat generated by the lamp 12 to a sheet material. Is provided with a thin outer skin layer (not shown) made of a highly releasable material such as fluororesin. The pressure roller 20 is provided with a cleaning roller 30 on the heating roller 12 for removing unnecessary substances such as toner adhering to the outer skin layer.
In order to form a nip by pressing its outer peripheral surface against the outer peripheral surface of the heating roller 10, an elastic layer 21 made of an elastic body whose shape can be changed, and the elastic layer inside the elastic layer 21 are fixed. In the fixing device A having the above-described general structure including the core metal 22 for holding the pressure roller 20 against the outer peripheral surface of the heating roller 10.
Details of the structure for pressing the outer peripheral surface (that is, the elastic layer 21) will be described with reference to FIG. 2 that are the same as those in FIG. 1 are the same as those in FIG.

【0007】既に図1を用いて述べたように,加圧ロー
ラ20はバネ32の付勢力を支持バー31を介して得る
ことによって加熱ローラ10側へ付勢されるが,その仕
組みについて図2の模式図を用いて説明する。上記支持
バー31は,その一端に上記バネ32が取り付けられ,
他端にピン33で揺動自在に定着装置Aの外箱(不図
示)等に固定されている。更に,上記支持バー31の中
間部において,加圧ローラ20の軸がピン34によって
回転自在に設けられている。このような構成においてバ
ネ32が伸張する方向に付勢力を発生する場合には,支
持バー31においてバネ32の接続端側が上方向(図2
中の付勢方向)に持ち上げられるため,支持バー31の
中間部で回転自在に設けられる加圧ローラ20も図にお
いては上方向へ持ち上げられる。したがって,加圧ロー
ラ20の外周面が加熱ローラ10の外周面に圧接される
状態となる。このような構成を有する定着装置Aにおい
て,加圧ローラ20の弾性層21の硬度は経時的に低下
する特性(弾性体変化特性)を有するので,バネ32が
同一の付勢力で付勢するとニップ幅が増加して定着が最
適に行われない等の問題がある。そのため,本発明の定
着装置Aでは,弾性層21の弾性体変化特性の硬度低下
に応じて,付勢力が近似的に経時的に低下する付勢変化
特性を具備するバネ32を用いている。このようなバネ
32を用いることによって,上記弾性層21の硬度低下
が発生しても,バネ32の付勢力も弱まるので必要以上
に加圧ローラ20が加熱ローラ10側へ付勢されること
が無くなる。一例としてバネ32の具体的な仕様を表1
に示しておく。
As already described with reference to FIG. 1, the pressure roller 20 is urged toward the heating roller 10 side by obtaining the urging force of the spring 32 through the support bar 31, and the mechanism is shown in FIG. This will be described with reference to the schematic diagram of. The support bar 31 has the spring 32 attached to one end thereof,
The other end is swingably fixed to the outer box (not shown) of the fixing device A by a pin 33. Further, the shaft of the pressure roller 20 is rotatably provided by a pin 34 in the middle portion of the support bar 31. In such a structure, when the biasing force is generated in the direction in which the spring 32 extends, the connection end side of the spring 32 in the support bar 31 moves upward (see FIG. 2).
Since it is lifted in the urging direction), the pressure roller 20 rotatably provided at the intermediate portion of the support bar 31 is also lifted upward in the drawing. Therefore, the outer peripheral surface of the pressure roller 20 is in pressure contact with the outer peripheral surface of the heating roller 10. In the fixing device A having such a configuration, the hardness of the elastic layer 21 of the pressure roller 20 has a characteristic of decreasing with time (elastic body changing characteristic). Therefore, when the spring 32 is urged by the same urging force, There is a problem that the width is increased and the fixing is not performed optimally. Therefore, in the fixing device A of the present invention, the spring 32 having the biasing change characteristic in which the biasing force approximately decreases with time according to the decrease in the hardness of the elastic body changing characteristic of the elastic layer 21 is used. By using such a spring 32, even if the hardness of the elastic layer 21 decreases, the urging force of the spring 32 also weakens, so that the pressure roller 20 may be urged toward the heating roller 10 side more than necessary. Lost. Table 1 shows specific specifications of the spring 32 as an example.
It shows in.

【表1】 [Table 1]

【0008】上記表1の仕様を有するバネ32を具備す
る定着装置Aにおいて,バネ32と加圧ローラ20の特
性について図3を用いて説明する。先ず,図3(a)
は加圧ローラの弾性層の硬度とバネ荷重,図3(b)
はニップ幅とバネ荷重,図3(c)はニップ圧とバネ
荷重の各々を比較したグラフである。 (加圧ローラの弾性層の硬度とバネ荷重の関係につい
て<図3(a)>)定着装置Aが稼動を開始する初期段
階では,バネ32のバネ荷重(即ち,バネ32の付勢
力)は図3(a)より約23.6kgfで加圧されてい
ることが分かる。更に,上記初期段階以降においては,
定着装置Aに対するシート材の通紙枚数が増加するに伴
って,加圧ローラ20の弾性層21の硬度が低下するの
に近似的に比例する形でバネ32のバネ荷重も低下して
いることが分かる。
The characteristics of the spring 32 and the pressure roller 20 in the fixing device A having the spring 32 having the specifications shown in Table 1 will be described with reference to FIG. First, FIG. 3 (a)
Is the hardness and spring load of the elastic layer of the pressure roller, FIG.
Is a graph comparing the nip width and the spring load, and FIG. 3C is a graph comparing the nip pressure and the spring load. (Relationship between hardness of elastic layer of pressure roller and spring load <Fig. 3 (a)>) At the initial stage when the fixing device A starts to operate, the spring load of the spring 32 (that is, the urging force of the spring 32) is It can be seen from FIG. 3 (a) that the pressure is about 23.6 kgf. Furthermore, after the initial stage,
As the number of sheets of sheet material passing through the fixing device A increases, the spring load of the spring 32 also decreases in a manner approximately proportional to the decrease in hardness of the elastic layer 21 of the pressure roller 20. I understand.

【0009】(ニップ幅とバネ荷重の関係について<
図3(b)>)定着装置Aが稼動を開始する初期段階で
は,ニップ幅は図3(b)より約7.5mmに設定され
ていることが分かる。更に,上記初期段階以降において
は,バネ32のバネ荷重が加圧ローラ20の弾性層21
の硬度低下に応じて低下するので,上記ニップ幅は当初
の7.5mmmをほぼ維持していることが分かる。した
がって,定着装置Aは上記初期段階と同様の定着品質を
上記初期段階以降においても保つことが可能となる。
(Relationship between nip width and spring load <
It can be seen from FIG. 3B that the nip width is set to about 7.5 mm at the initial stage when the fixing device A starts to operate. Further, after the initial stage, the spring load of the spring 32 causes the elastic layer 21 of the pressure roller 20 to move.
It can be seen that the nip width is maintained at the initial value of 7.5 mm because it decreases as the hardness decreases. Therefore, the fixing device A can maintain the same fixing quality as in the initial stage even after the initial stage.

【0010】(ニップ圧とバネ荷重の関係について<
図3(c)>)バネ32のバネ荷重は上述した通り初期
段階に比べて低下するので,図3(c)に示す通りニッ
プ圧も低下する。しかし,このようにニップ圧が低下し
てもバネ荷重は約20kgf付近に収束するので,ニッ
プ圧も所定の圧力(約0.85kgf/cm2)以下に
ならないことが分かる。もちろん,上記所定の圧力は定
着品質を損なわないレベルの圧力以上になるよう予め設
計されているので,定着品質は初期段階の定着品質が保
たれることになる。
(Relationship between nip pressure and spring load <
Since the spring load of the spring 32 in FIG. 3 (c)> decreases as compared with the initial stage as described above, the nip pressure also decreases as shown in FIG. 3 (c). However, even if the nip pressure is reduced in this way, the spring load converges to about 20 kgf, so it is understood that the nip pressure does not fall below the predetermined pressure (about 0.85 kgf / cm 2 ). Of course, the predetermined pressure is designed in advance so as to be equal to or higher than the pressure at which the fixing quality is not impaired, so that the fixing quality at the initial stage is maintained.

【0011】[0011]

【発明の効果】本発明は,発熱源を有する加熱ローラ
と,該加熱ローラに対して外周面を圧接することによっ
てニップを形成する加圧ローラとを具備し,上記加圧ロ
ーラを構成する弾性体が,その硬度を経時的に変化する
弾性体変化特性を有する定着装置において,上記加圧ロ
ーラを上記加熱ローラに加圧するための付勢力を発生す
る付勢手段が,上記弾性体変化特性に応じて上記付勢力
を経時的に変化する付勢変化特性を有することを特徴と
する定着装置として構成されている。また,前記付勢変
化特性は,前記弾性体変化特性による前記弾性体の硬度
の低下に対して近似的に前記付勢力が低下することが望
ましい。このように本発明が構成されているので,弾性
体の弾性体変化特性が経時的に変化した場合に,その変
化に応じて近似的に上記付勢手段の付勢力も変化するの
で,従来のように,付勢力調整用の機器等を定着装置に
設ける必要がなくなるので,定着装置の構造や制御を簡
素化することが可能となる。また,上記機器が省略でき
る分定着装置の小型化が可能となる。
The present invention comprises a heating roller having a heat source and a pressure roller for forming a nip by pressing the outer peripheral surface of the heating roller against each other. In a fixing device in which a body has an elastic body change characteristic in which its hardness changes with time, an urging unit that generates an urging force for pressing the pressure roller against the heating roller has the elastic body change characteristic. Accordingly, the fixing device is configured to have a bias change characteristic that changes the bias force with time. In addition, it is desirable that the bias change characteristic is such that the bias force is approximately reduced with respect to the decrease in hardness of the elastic body due to the elastic change characteristic. Since the present invention is configured as described above, when the elastic body change characteristic of the elastic body changes with time, the urging force of the urging means changes approximately in accordance with the change. As described above, since it is not necessary to provide a device for adjusting the biasing force in the fixing device, the structure and control of the fixing device can be simplified. Further, since the above equipment can be omitted, the fixing device can be downsized.

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

【図1】本発明の実施の形態に係る定着装置の概略構成
図。
FIG. 1 is a schematic configuration diagram of a fixing device according to an embodiment of the present invention.

【図2】加熱ローラ,加圧ローラ,及び付勢手段の概略
構成を示した模式図。
FIG. 2 is a schematic diagram showing a schematic configuration of a heating roller, a pressure roller, and a biasing unit.

【図3】バネ32と加圧ローラ20の特性に関するデー
タのグラフ。
FIG. 3 is a graph of data regarding characteristics of the spring 32 and the pressure roller 20.

【符号の説明】[Explanation of symbols]

A………定着装置 10………加熱ローラ 11………薄肉芯金 12………ランプ 20………加圧ローラ 21………弾性層 22………芯金 30………クリーニングローラ 31………支持バー 32………バネ 33………固定軸 34………支持軸 A: Fixing device 10 ... Heating roller 11 ...... Thin core bar 12 ………… Lamp 20 ... Pressure roller 21 ......... elastic layer 22 ………… Core bar 30 ... Cleaning roller 31 ……… Support bar 32 ......... Spring 33 ………… Fixed axis 34 ... Support shaft

───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 2H033 AA21 AA23 BB04 BB29 BB30 BB34 CA39 3J103 AA02 AA13 AA24 AA32 BA31 BA41 CA66 FA15 GA02 GA26 GA66 HA03 HA05 HA12 HA15   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H033 AA21 AA23 BB04 BB29 BB30                       BB34 CA39                 3J103 AA02 AA13 AA24 AA32 BA31                       BA41 CA66 FA15 GA02 GA26                       GA66 HA03 HA05 HA12 HA15

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 発熱源を有する加熱ローラと,該加熱ロ
ーラに対して外周面を圧接することによってニップを形
成する加圧ローラとを具備し,上記加圧ローラを構成す
る弾性体が,その硬度を経時的に変化する弾性体変化特
性を有する定着装置において,上記加圧ローラを上記加
熱ローラに加圧するための付勢力を発生する付勢手段
が,上記弾性体変化特性に応じて上記付勢力を経時的に
変化する付勢変化特性を有することを特徴とする定着装
置。
1. An elastic body that comprises a heating roller having a heat source and a pressure roller that forms a nip by pressing the outer peripheral surface of the heating roller against the heating roller. In a fixing device having an elastic body change characteristic in which hardness changes with time, an urging unit that generates an urging force for pressing the pressure roller against the heating roller is responsive to the elastic body change characteristic. A fixing device having an urging change characteristic that changes the power over time.
【請求項2】 前記付勢変化特性は,前記弾性体変化特
性による前記弾性体の硬度の低下に対して近似的に前記
付勢力が低下するものである請求項1記載の定着装置。
2. The fixing device according to claim 1, wherein the biasing change characteristic is such that the biasing force is approximately reduced with respect to a decrease in hardness of the elastic body due to the elastic body change characteristic.
JP2001375498A 2001-12-10 2001-12-10 Fixing device Pending JP2003177625A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001375498A JP2003177625A (en) 2001-12-10 2001-12-10 Fixing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001375498A JP2003177625A (en) 2001-12-10 2001-12-10 Fixing device

Publications (1)

Publication Number Publication Date
JP2003177625A true JP2003177625A (en) 2003-06-27

Family

ID=19183867

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001375498A Pending JP2003177625A (en) 2001-12-10 2001-12-10 Fixing device

Country Status (1)

Country Link
JP (1) JP2003177625A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9134666B2 (en) 2013-07-12 2015-09-15 Konica Minolta, Inc. Fixing device and image forming apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9134666B2 (en) 2013-07-12 2015-09-15 Konica Minolta, Inc. Fixing device and image forming apparatus

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