JPH06332331A - Thermal fixing device - Google Patents

Thermal fixing device

Info

Publication number
JPH06332331A
JPH06332331A JP13919193A JP13919193A JPH06332331A JP H06332331 A JPH06332331 A JP H06332331A JP 13919193 A JP13919193 A JP 13919193A JP 13919193 A JP13919193 A JP 13919193A JP H06332331 A JPH06332331 A JP H06332331A
Authority
JP
Japan
Prior art keywords
roller
heating roller
resistance
heating
pattern
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
JP13919193A
Other languages
Japanese (ja)
Inventor
Hiroto Sato
弘人 佐藤
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.)
Ushio Denki KK
Ushio Inc
Original Assignee
Ushio Denki KK
Ushio Inc
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 Ushio Denki KK, Ushio Inc filed Critical Ushio Denki KK
Priority to JP13919193A priority Critical patent/JPH06332331A/en
Publication of JPH06332331A publication Critical patent/JPH06332331A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To shorten time required for raising the temperature of a heating roller to a prescribed temperature, to simplify and miniaturize a device and to control heat generating distribution by providing the heating roller with a specified resistance pattern and providing the resistance pattern with electrodes for making a current flow. CONSTITUTION:The ring-like electrodes 4 and 4a of the heating roller 1 are provided so as to be respectively electrically conducted to the resistance pattern 3 consisting of a resistance heating substance at one place. Then, power feeding brushes 5 and 5a are brought into contact with the outside surfaces of the electrodes 4 and 4a and connected to an outside power source. By impressing a prescribed voltage on the electrodes 4 and 4a through the brushes 5 and 5a, the current is made to flow to the pattern 3 and the roller 1 is heated. By changing the shape of the pattern 3, the heat generating distribution in the longitudinal direction of the roller 1 can be optionally controlled to be varied. Besides, since the pattern 3 is formed out of the resistance heating substance whose coefficient of resistance change to temperature is positive, the overheating of the roller 1 at an initial pre-heating time is prevented from occurring.

Description

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

【0001】[0001]

【産業上の利用分野】本発明は、例えば電子写真方式な
どで形成した未定着トナー像を持つ紙などの記録材を加
熱ローラーと加圧ローラーとの間を通過させてトナーを
加熱、溶融することにより記録材にトナ−を定着させる
加熱定着装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention heats and melts a toner by passing a recording material such as paper having an unfixed toner image formed by an electrophotographic method between a heating roller and a pressure roller. The present invention relates to a heat fixing device for fixing a toner on a recording material.

【0002】[0002]

【従来の技術】以下、従来の定着装置を説明する。加熱
ローラーの内部の空間にハロゲンランプなどの熱源をも
ち、その熱源から発せられる輻射熱によって間接的にロ
ーラー本体を加熱する装置がある(以下、従来例1と称
する)。これは、例えば、特開昭59ー116775号
に開示されているように、アルミニウムなどの中空金属
パイプの外表面にフッ素樹脂などから成る離型性皮膜を
設け、該パイプの内部空間にハロゲンランプなどの放射
熱源を配した構造の加熱ローラーを用い、使用時には放
射熱源から発する輻射熱によって内部空気層を介してロ
ーラー本体を所定の温度まで昇温させるものである。
2. Description of the Related Art A conventional fixing device will be described below. There is a device that has a heat source such as a halogen lamp in the space inside the heating roller and indirectly heats the roller body by radiant heat emitted from the heat source (hereinafter referred to as Conventional Example 1). This is because, for example, as disclosed in JP-A-59-116775, a release coating made of a fluororesin or the like is provided on the outer surface of a hollow metal pipe such as aluminum, and a halogen lamp is provided in the inner space of the pipe. A heating roller having a structure in which a radiant heat source such as is arranged is used, and the roller body is heated to a predetermined temperature by the radiant heat emitted from the radiant heat source through the internal air layer during use.

【0003】これに対して、抵抗体膜に電流を流して発
生するジュール熱によって加熱ローラーを直接加熱する
装置もある(以下、従来例2と称する)。これは、例え
ば、特開昭59ー155872号に開示されているよう
に、金属製パイプの外面にプラズマ溶射して形成されT
iO2 系セラミックの抵抗体膜を有する構造の加熱ロー
ラーを用い、使用時にこの抵抗体膜に電流を流して発生
するジュール熱によって該加熱ローラーの本体を直接加
熱するものである。
On the other hand, there is also an apparatus for directly heating the heating roller by Joule heat generated by passing an electric current through the resistor film (hereinafter referred to as Conventional Example 2). This is formed by plasma spraying on the outer surface of a metal pipe, as disclosed in, for example, Japanese Patent Application Laid-Open No. 59-155872.
A heating roller having a structure having an iO 2 -based ceramic resistor film is used, and the body of the heating roller is directly heated by Joule heat generated by passing an electric current through the resistor film during use.

【0004】[0004]

【発明が解決しようとする課題】しかしながら、このよ
うな加熱装置においては、以下のような問題点がある。 〔従来例1における問題点〕 記録材を加熱ローラーと加圧ローラーの間を通過させ
加熱させる際に、加熱ローラーはトナー粒子と記録材に
熱を奪われる。従って、加熱ローラーの熱容量が小さい
時には、短時間に大量の定着動作を行うと加熱ローラー
の温度が降下して、良好な定着性能が得られない場合が
ある。これを防ぐためには、加熱ローラーの熱容量を大
きくする必要があり、しかもローラー本体はハロゲンラ
ンプなどの放射熱源によって内部空気層を介して間接的
に加熱されるためローラーを所定の温度まで昇温させる
時間(以下、予熱時間と呼ぶ)が長くなる。この予熱時
間を短縮させるためには、大電力の放射熱源を必要と
し、装置の省電力化の妨げになる。 加熱ローラーの内部の熱源に用いるハロゲンランプに
は、通電開始時に一時的に過大な電流(以下、突入電流
と呼ぶ)が流れる。そのため、電力を供給する回路の部
品にはこの突入電流に耐えうるものを使用するか、又
は、突入電流を抑えるための機構を別に設けることが必
要になる。いずれにしても、装置の小型化及び簡略化の
妨げになる。 加熱ローラーの内部の空間に熱源であるハロゲンラン
プを有する構造のため、ローラーの径を小さくするには
限界があり、装置の小型化の妨げになる。
However, such a heating device has the following problems. [Problems in Conventional Example 1] When the recording material is heated by passing between the heating roller and the pressure roller, the heating roller draws heat from the toner particles and the recording material. Therefore, when the heat capacity of the heating roller is small, if a large amount of fixing operation is performed in a short time, the temperature of the heating roller may drop, and good fixing performance may not be obtained. In order to prevent this, it is necessary to increase the heat capacity of the heating roller, and since the roller body is indirectly heated by the radiant heat source such as a halogen lamp via the internal air layer, the temperature of the roller is raised to a predetermined temperature. The time (hereinafter referred to as the preheating time) becomes long. In order to shorten the preheating time, a radiant heat source of high power is required, which hinders power saving of the device. In the halogen lamp used as the heat source inside the heating roller, an excessively large current (hereinafter referred to as inrush current) flows at the start of energization. Therefore, it is necessary to use a component that can withstand this inrush current as a component of a circuit that supplies power, or to separately provide a mechanism for suppressing the inrush current. In any case, this hinders downsizing and simplification of the device. Since the structure has a halogen lamp as a heat source in the space inside the heating roller, there is a limit in reducing the diameter of the roller, which hinders downsizing of the device.

【0005】〔従来例2における問題点〕 抵抗体膜として用いられるTiO2 系セラミックは、
温度が上昇するに従って電気抵抗値が減少するという負
の抵抗温度係数を有しているので、定められた電圧印加
の場合に流れる電流は大きくなる。その結果、抵抗体は
更に温度が上昇する性質をもつので加熱昇温時の温度制
御が極めて困難になり、加熱ローラーを予熱する際に、
所定の温度よりも過昇温してしまう現象(オーバーシュ
ート)が起こり易い。このような抵抗体の温度−相対電
気抵抗率の関係を図7のグラフG1 に示す。この内容は
Kingery,Bowen,Uhlmann著の「セ
ラミックス材料科学入門−応用編(1981)」文献中
の835ペ−ジから引用している。図7における横軸は
抵抗体の温度を示し、縦軸は温度20℃での相対電気抵
抗率を1とした場合の相対値で示してある。グラフG1
はTiO2 系セラミック抵抗体、例えばTi2 3 の特
性を示す。グラフG1が右下がりの傾向を示す故にTi
2 3 セラミックは負の抵抗温度係数を有することを示
している。前記のような過昇温を防ぐには、抵抗体膜と
入力電源との間に、所定温度に達すると抵抗体膜への通
電を停止させる制御回路を組み込むことが必要になる。
これは装置の小型化、コストダウンの妨げになる。 加熱ローラーを具備する方式では、ローラー長手方向
の両端部はローラーを支持するための軸受けに熱を奪わ
れるので、通常は端部付近の配熱を中央部付近よりもや
や大きくすることが行われる。従来例2でこれを行うた
めには、発熱層である抵抗体膜の膜厚を端部付近と中央
部付近では変える必要があるが、製作可能な膜厚の範囲
に限界がある上に、膜厚そのものを正確に制御すること
が容易でないために、希望する配熱分布を得られない場
合がある。 以上、従来の技術には種々の問題点を有している。
[Problems in Conventional Example 2] The TiO 2 -based ceramic used as the resistor film is
Since it has a negative temperature coefficient of resistance in which the electric resistance value decreases as the temperature rises, the current flowing when a prescribed voltage is applied becomes large. As a result, since the resistor has the property of further increasing the temperature, it becomes extremely difficult to control the temperature when heating and raising the temperature, and when preheating the heating roller,
A phenomenon (overshoot) in which the temperature rises above a predetermined temperature easily occurs. The temperature-relative electrical resistivity relationship of such a resistor is shown in graph G1 of FIG. This content is quoted from page 835 of "Introduction to Ceramics Materials Science-Applications (1981)" by Kingery, Bowen, and Uhlmann. The horizontal axis in FIG. 7 represents the temperature of the resistor, and the vertical axis represents the relative value when the relative electrical resistivity at a temperature of 20 ° C. is 1. Graph G1
Indicates the characteristics of a TiO 2 -based ceramic resistor such as Ti 2 O 3 . Since the graph G1 shows a downward sloping tendency, Ti
The 2 O 3 ceramic is shown to have a negative temperature coefficient of resistance. In order to prevent the above-mentioned excessive temperature rise, it is necessary to incorporate a control circuit between the resistor film and the input power source to stop the energization of the resistor film when a predetermined temperature is reached.
This hinders downsizing of the device and cost reduction. In the system equipped with a heating roller, heat is taken by the bearings for supporting the roller at both ends in the roller longitudinal direction, so heat distribution in the vicinity of the end is usually made slightly larger than in the vicinity of the center. . In order to do this in Conventional Example 2, it is necessary to change the film thickness of the resistor film, which is the heat generating layer, in the vicinity of the end portion and in the vicinity of the central portion, but there is a limit to the range of film thickness that can be manufactured, and Since it is not easy to accurately control the film thickness itself, a desired heat distribution may not be obtained. As described above, the conventional technique has various problems.

【0006】[0006]

【発明の目的】本発明は、以上のような問題点を解決す
るためになされたもので、その目的は 、加熱ローラーを所定の温度まで加熱するための予熱
時間を短縮し、且つ省電力化を図る。 加熱開始時に過大な電流が流れることがなく、装置の
小型化と簡略化を図る 加熱ローラーの径を小さくすることにより装置の小型
化を図る。 予熱初期の加熱ローラーの過昇温(オーバーシュー
ト)を小さく抑える。 加熱ローラーの長手方向の配熱に容易に分布をもたす
ことが出来る。 以上のことを可能とする加熱定着装置を提供することに
ある。
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to shorten the preheating time for heating a heating roller to a predetermined temperature and to save power. Plan. An excessive current does not flow at the start of heating, and the device is downsized and simplified. The device is downsized by reducing the diameter of the heating roller. Minimize excessive temperature rise (overshoot) of the heating roller in the initial stage of preheating. The heat distribution in the longitudinal direction of the heating roller can be easily distributed. It is an object of the present invention to provide a heat fixing device that enables the above.

【0007】[0007]

【課題を解決するための手段】前記目的を達成するため
に、本発明における加熱ローラーは、ロ−ラ−部を形成
している円筒状基材の表面に抵抗温度係数が正である抵
抗発熱物質により略帯状に形成される抵抗パターンを設
け、なおかつ、該抵抗パターンに電流を流すための電極
を有する。本発明は、以上の構成よりなる加熱定着装置
である。
In order to achieve the above object, the heating roller in the present invention has a resistance heating coefficient in which the temperature coefficient of resistance is positive on the surface of a cylindrical substrate forming a roller portion. A resistance pattern formed of a material in a substantially band shape is provided, and an electrode for passing a current through the resistance pattern is provided. The present invention is a heat fixing device having the above-mentioned configuration.

【0008】[0008]

【作用】加熱ローラーに配設された各電極間に電圧を印
加して、抵抗発熱物質からなる抵抗パターンに電流を流
し、この時発生するジュール熱によってローラー本体で
ある円筒状基材を所定の温度に昇温させる。抵抗パタ−
ンの形状を変えることにより、加熱ロ−ラ−の長手方向
の配熱分布は任意に可変制御出来る。更に、抵抗パター
ンは抵抗温度係数が正である抵抗発熱物質により形成さ
れるので、温度の上昇につれて抵抗率が大きくなり、予
熱初期の加熱ローラーの過昇温(オーバーシュート)を
抑える。所定の温度に昇温された加熱ローラーと、該加
熱ローラーに圧接された加圧ローラーを互いの母線方向
が一致するように回転させ、未定着トナー像をもつ記録
材を前記二つのローラー間を通過させる。この時記録材
はトナーの付着した面が加熱ローラー側になるように通
過させることにより、トナーを加熱、溶融させて記録材
に定着せしめる。
Function: A voltage is applied between the electrodes arranged on the heating roller to cause an electric current to flow in a resistance pattern made of a resistance heating material, and the Joule heat generated at this time causes the cylindrical base material, which is the roller body, to move to a predetermined position. Raise to temperature. Resistance pattern
By changing the shape of the heating roller, the heat distribution in the longitudinal direction of the heating roller can be variably controlled. Further, since the resistance pattern is formed of a resistance heating material having a positive resistance temperature coefficient, the resistivity increases as the temperature rises, and an excessive temperature rise (overshoot) of the heating roller at the initial stage of preheating is suppressed. The heating roller heated to a predetermined temperature and the pressure roller pressed against the heating roller are rotated so that their generatrix directions are aligned with each other, and a recording material having an unfixed toner image is transferred between the two rollers. Let it pass. At this time, the recording material is passed so that the surface on which the toner adheres is on the heating roller side, so that the toner is heated and melted to be fixed on the recording material.

【0009】[0009]

【実施例】以下、図面を用いて本発明を詳細に説明す
る。図1は本発明に係わる加熱定着装置の概略正面図、
図2は同装置の側面図を示す。同図において1は加熱ロ
ーラー、2は加圧ローラー、3は抵抗発熱物質からなる
略帯状の抵抗パターン、4、4aは導電体からなるリン
グ状の電極、5、5aは給電ブラシ、6、6aは軸受
け、7は駆動ギアで、加熱ローラー1の片側は軸受け6
を介して駆動ギアに接続され、加熱ローラー1の反対側
は軸受け6aを介して側板(図示せず)に回転自在に保
持されている。8は加圧ローラーの芯金、9は記録材、
10は記録材に付着する未定着トナ−粒子である。リン
グ状の電極4、4aは抵抗発熱物質からなる抵抗パター
ン3とそれぞれ1ケ所ずつ電気的導通をもつように設け
られ、給電ブラシ5、5aは電極4、4aの外表面と接
触している。給電ブラシ5、5aは外部電源(図示せ
ず)と電気的に接続されており、この給電ブラシ5、5
aを介して電極4、4aに所定の電圧を印加することに
より、抵抗パターン3に電流を流して加熱ローラー1を
加熱する構成になっている。所定の温度まで加熱された
加熱ローラー1は駆動ギア7によって回転し、該加熱ロ
ーラー1と圧接して回転する加圧ローラー2との間を記
録材9を通過させることにより、未定着トナー粒子10
を加熱、溶融させて記録材に定着せしめる。
The present invention will be described in detail below with reference to the drawings. 1 is a schematic front view of a heat fixing device according to the present invention,
FIG. 2 shows a side view of the device. In the figure, 1 is a heating roller, 2 is a pressure roller, 3 is a substantially strip-shaped resistance pattern made of a resistance heating material, 4 and 4a are ring electrodes made of a conductor, 5 and 5a are power supply brushes, and 6 and 6a. Is a bearing, 7 is a drive gear, and one side of the heating roller 1 is a bearing 6
Is connected to a drive gear via a bearing, and the opposite side of the heating roller 1 is rotatably held by a side plate (not shown) via a bearing 6a. 8 is a pressure roller core metal, 9 is a recording material,
Reference numeral 10 denotes unfixed toner particles attached to the recording material. The ring-shaped electrodes 4, 4a are provided so as to be electrically connected to the resistance pattern 3 made of a resistance heating material at one place, and the power supply brushes 5, 5a are in contact with the outer surfaces of the electrodes 4, 4a. The power feeding brushes 5, 5a are electrically connected to an external power source (not shown).
By applying a predetermined voltage to the electrodes 4 and 4a via a, a current is passed through the resistance pattern 3 to heat the heating roller 1. The heating roller 1 heated to a predetermined temperature is rotated by the drive gear 7, and the recording material 9 is passed between the heating roller 1 and the pressure roller 2 which rotates in pressure contact with the unfixed toner particles 10.
Is heated and melted and fixed on the recording material.

【0010】加熱ローラー1の構成については図3、図
4、図5で詳細に説明する。図3はこの発明にかかる加
熱ローラーの一部を切り欠いた正面図、図4は図3のA
ーA断面図、図5は加熱ローラーに設けられた抵抗パタ
ーン3の形状展開図である。同図において、11は加熱
ローラー1の本体である円筒状基材、12、12aは導
電性を持つ導電層、13はガラスを主成分にした保護
層、14は加熱ローラー1の最外表面を覆う離型層であ
る。加熱ローラー1の本体である円筒状基材11は内径
15mm、肉厚1.5mmのアルミナパイプであり、そ
の外表面上にAgーPd合金を主成分とした略帯状の抵
抗パターン3を設ける。電極4、4aは内径約18m
m、肉厚2mm、幅7mmのCu系の導電性のリングで
あり、抵抗パターン3と電気的に導通を保つように設け
られた導電層12、12aにそれぞれ固定して取り付け
られている。抵抗パターン3の厚みは一定にして幅1.
5mm、全長は電極4、4a間の電気抵抗値が所定の値
になるようにし、図5のようなパターン形状に決められ
る。更に、図4に示すように、抵抗パターン3の保護と
電気的絶縁性を確保するために、抵抗パターン3を設け
たあと、導電層12、12a以外の円筒状基材11の外
表面にガラスを主成分とした保護層13を設け、更にそ
の外表面上に記録材9が通過する部分にはフッ素樹脂な
どの離型層14を設ける。尚、図5に示すように、加熱
ローラー1の両端部付近に配設する抵抗パターン3のパ
ターン密度は中央部に比べて大きくする事により、定着
動作時に加熱ローラー1の両端部付近の温度が降下する
ことを防止する。定着動作時には、電極4、4a間に電
圧を印加して、抵抗パターン3に電流を流して発生する
ジュール熱によって加熱ローラー1を所定の温度まで昇
温させるが、円筒状基材11を直接加熱する方式のた
め、熱源をローラー内にもつ間接加熱方式に比べ少ない
電力でしかも短時間に昇温させることが出来る。また、
間接加熱方式にみられる予熱初期に内部熱源に過大な電
流(突入電流)が流れることもなく、円筒状基材11の
内部に熱源を配設しないので加熱ローラー1の小径化も
可能になる。また、抵抗パターン3のパターン形状を変
えることによって円筒状基材11の長手方向即ち、加熱
ローラー1の長手方向の配熱の分布も容易に可変制御が
できる。更に、抵抗パターン3を構成するAgーPd合
金は、温度が高くなるに従い電流が流れにくくなるとい
う正の抵抗温度係数を有するので、予熱初期にみられる
加熱ローラー1の過昇温(オーバーシュート)を小さく
制御できる。このような抵抗パタ−ンの温度−相対電気
抵抗率の関係を図7のグラフG2 に示す。図7における
横軸は抵抗体の温度を示し、縦軸は温度20℃での相対
電気抵抗率を1とした場合の相対値で示してある。グラ
フG2は発明者の実測によるものであり、Ag−Pd合
金抵抗体の特性を示す。グラフG2 が右上がり故に、A
g−Pd合金は正の抵抗温度係数を有することを示して
いる。
The structure of the heating roller 1 will be described in detail with reference to FIGS. 3, 4 and 5. 3 is a front view in which a part of the heating roller according to the present invention is cut away, and FIG. 4 is A in FIG.
5A is a sectional view, and FIG. 5 is a shape development view of the resistance pattern 3 provided on the heating roller. In the figure, 11 is a cylindrical base material which is the main body of the heating roller 1, 12 and 12a are conductive layers having conductivity, 13 is a protective layer containing glass as a main component, and 14 is the outermost surface of the heating roller 1. It is a release layer that covers. The cylindrical base material 11 which is the main body of the heating roller 1 is an alumina pipe having an inner diameter of 15 mm and a wall thickness of 1.5 mm, and a substantially strip-shaped resistance pattern 3 containing Ag-Pd alloy as a main component is provided on the outer surface thereof. Electrodes 4, 4a have an inner diameter of about 18m
m is a Cu-based conductive ring having a thickness of 2 mm and a width of 7 mm, and is fixedly attached to the conductive layers 12 and 12 a provided so as to be electrically connected to the resistance pattern 3. The resistance pattern 3 has a constant thickness and a width of 1.
The total length is 5 mm, and the electrical resistance value between the electrodes 4 and 4a is set to a predetermined value, and the pattern shape is determined as shown in FIG. Further, as shown in FIG. 4, after the resistance pattern 3 is provided in order to protect the resistance pattern 3 and ensure electrical insulation, a glass is formed on the outer surface of the cylindrical substrate 11 other than the conductive layers 12 and 12a. Is provided as a main component, and a release layer 14 such as a fluororesin is provided on the outer surface of the protective layer 13 where the recording material 9 passes. As shown in FIG. 5, the pattern density of the resistance pattern 3 disposed near both ends of the heating roller 1 is made larger than that at the central portion, so that the temperature near both ends of the heating roller 1 during the fixing operation is increased. Prevent it from falling. During the fixing operation, a voltage is applied between the electrodes 4 and 4a, and the heating roller 1 is heated to a predetermined temperature by Joule heat generated by passing a current through the resistance pattern 3, but the cylindrical substrate 11 is directly heated. Because of this method, it is possible to raise the temperature in a short time with less electric power as compared with the indirect heating method having a heat source in the roller. Also,
An excessive current (rush current) does not flow through the internal heat source at the initial stage of preheating as seen in the indirect heating method, and since the heat source is not provided inside the cylindrical base material 11, the heating roller 1 can be downsized. Further, by changing the pattern shape of the resistance pattern 3, the distribution of heat distribution in the longitudinal direction of the cylindrical substrate 11, that is, the longitudinal direction of the heating roller 1 can be easily variably controlled. Furthermore, since the Ag-Pd alloy forming the resistance pattern 3 has a positive temperature coefficient of resistance in which the current becomes more difficult to flow as the temperature rises, overheating (overshoot) of the heating roller 1 observed in the early stage of preheating. Can be controlled small. The relationship between the temperature and the relative electrical resistivity of such a resistance pattern is shown in the graph G2 of FIG. The horizontal axis in FIG. 7 represents the temperature of the resistor, and the vertical axis represents the relative value when the relative electrical resistivity at a temperature of 20 ° C. is 1. A graph G2 is based on actual measurement by the inventor and shows characteristics of the Ag-Pd alloy resistor. Graph G2 goes up to the right, so A
The g-Pd alloy is shown to have a positive temperature coefficient of resistance.

【0011】抵抗パターン3のパターン形状は図5に示
すような形状に限定されるものでなく、目的とする加熱
ローラー1の長手方向の配熱分布に応じて任意に変えて
も良い。例えば、抵抗パターン3は複数本の帯状パター
ンであっても良いし、パターンの幅も部分的に大きくし
たり、又は小さくしたりしても良い。また、加熱ローラ
ー1の円筒状基材11の形状は中空である限定はなく、
中実であっても良い。円筒状基材11の材質はアルミナ
に限定する必要はないが、導電性のものを用いる場合は
抵抗パターン3と円筒状基材11の間に絶縁層を設ける
必要がある。
The pattern shape of the resistance pattern 3 is not limited to the shape as shown in FIG. 5, and may be arbitrarily changed according to the heat distribution in the longitudinal direction of the heating roller 1 as desired. For example, the resistance pattern 3 may be a plurality of strip-shaped patterns, and the width of the pattern may be partially increased or decreased. Further, the shape of the cylindrical substrate 11 of the heating roller 1 is not limited to be hollow,
It may be solid. The material of the cylindrical base material 11 need not be limited to alumina, but when a conductive material is used, it is necessary to provide an insulating layer between the resistance pattern 3 and the cylindrical base material 11.

【0012】他の実施例として、図6を用いて説明す
る。基本的な装置の構成は、図1に示す本発明の実施例
と同じであるが、電力を供給するための電極4、4aを
加熱ローラー1の片側部付近にやや間隔をおいて並べて
取り付ける点が異なる。抵抗パターン3はこれらの電極
4、4aより中央部の円筒状基材11の表面に配設され
る。この実施例では前述の効果に加えて、給電のための
機構を加熱ローラー1の片側に集中できるので、給電ブ
ラシ5、5aの保持器(図示せず)を一体化できる利点
がある。また、給電ブラシ5、5aに接続される結線
(図示せず)の配設が容易になるなどの利点もある。
Another embodiment will be described with reference to FIG. The structure of the basic device is the same as that of the embodiment of the present invention shown in FIG. 1, but the electrodes 4 and 4a for supplying electric power are mounted side by side with a little space near one side of the heating roller 1. Is different. The resistance pattern 3 is arranged on the surface of the cylindrical base material 11 in the central portion of the electrodes 4 and 4a. In this embodiment, in addition to the effects described above, the mechanism for power feeding can be concentrated on one side of the heating roller 1, so that there is an advantage that a holder (not shown) for the power feeding brushes 5 and 5a can be integrated. Further, there is an advantage that the connection (not shown) connected to the power feeding brushes 5 and 5a can be easily arranged.

【0013】[0013]

【発明の効果】以上詳細に説明したように、本発明の効
果を整理すると下記のようになる。 抵抗発熱物質である抵抗パターンで発生するジュール
熱により加熱ローラーの円筒基材を直接加熱するので、
加熱ローラーを所定の温度まで昇温させる予熱時間が短
くなり、省電力化も可能である。 ハロゲンランプのような熱源を使わないので、加熱の
ための初期通電時に過大な電流(突入電流)が流れない
ので、そのための特段の機構を不要とし、加熱定着装置
の小型化及び簡略化が可能である。 ローラーの内部に熱源を配設しない構造のため、ロー
ラーの小径化が可能になり、その結果、加熱定着装置の
小型化が可能である。 抵抗パターンの材質に抵抗温度係数が正である例えば
AgーPd合金を用いることにより、加熱ローラーの予
熱初期の過昇温(オーバーシュート)を小さく抑えるこ
とが容易となる。 抵抗パターンのパターン形状を任意に変えることによ
り、加熱ローラーの配熱分布を簡単にしかも大きく変え
ることが可能である。
As described in detail above, the effects of the present invention can be summarized as follows. Since the cylindrical base material of the heating roller is directly heated by the Joule heat generated by the resistance pattern which is a resistance heating substance,
Preheating time for heating the heating roller to a predetermined temperature is shortened, and power saving is possible. Since a heat source such as a halogen lamp is not used, an excessive current (rush current) does not flow at the time of initial energization for heating, so no special mechanism for this is required, and the heating and fixing device can be downsized and simplified. Is. Since the heat source is not provided inside the roller, the diameter of the roller can be reduced, and as a result, the heat fixing device can be downsized. By using, for example, an Ag-Pd alloy having a positive temperature coefficient of resistance as the material of the resistance pattern, it becomes easy to suppress an excessive temperature rise (overshoot) in the initial stage of preheating of the heating roller. By arbitrarily changing the pattern shape of the resistance pattern, the heat distribution of the heating roller can be changed easily and largely.

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

【図1】この発明にかかる加熱定着装置の概略正面図を
示す。
FIG. 1 is a schematic front view of a heat fixing device according to the present invention.

【図2】この発明にかかる加熱定着装置の側面図を示
す。
FIG. 2 is a side view of the heat fixing device according to the present invention.

【図3】この発明にかかる加熱ローラーの一部を切り欠
いた正面図を示す。
FIG. 3 is a front view in which a part of a heating roller according to the present invention is cut away.

【図4】図3のAーA断面図を示す。FIG. 4 is a sectional view taken along line AA of FIG.

【図5】この発明にかかる抵抗パターンの形状展開図を
示す。
FIG. 5 shows a shape development view of a resistance pattern according to the present invention.

【図6】この発明にかかる他の実施例の概略正面図を示
す。
FIG. 6 shows a schematic front view of another embodiment according to the present invention.

【図7】抵抗発熱体(Ti 2 3 セラミック及びAg-P
d合金)の温度と相対電気抵抗率の関係を示す。
FIG. 7: Resistance heating element (Ti 2 O 3 ceramic and Ag-P
The relationship between the temperature of (d alloy) and relative electrical resistivity is shown.

【符号の説明】[Explanation of symbols]

1 加熱ローラー 9
記録材 2 加圧ローラー 10
未定着トナー 3 抵抗パターン 11
円筒状基材 4、4a 電極 12、12
a 導電層 5、5a 給電ブラシ 13
保護層 6、6a 軸受け 14
離型層 7 駆動ギア 8 加圧ローラーの芯金
1 heating roller 9
Recording material 2 Pressure roller 10
Unfixed toner 3 Resistance pattern 11
Cylindrical substrate 4, 4a Electrode 12, 12
a conductive layer 5, 5a power supply brush 13
Protective layer 6, 6a Bearing 14
Release layer 7 Drive gear 8 Core bar of pressure roller

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 加熱ローラーと該加熱ローラーに圧接さ
れた加圧ローラーとの間に未定着トナ−像をもつ記録材
を通過させるように構成した定着装置において、 前記加熱ローラーは、ロ−ラ−部を形成している円筒状
基材の表面に抵抗温度係数が正である抵抗発熱物質によ
り略帯状に形成される抵抗パタ−ンを設け、 なおかつ、該抵抗パタ−ンに電流を流すための電極を有
することを特徴とする加熱定着装置。
1. A fixing device configured to pass a recording material having an unfixed toner image between a heating roller and a pressure roller pressed against the heating roller, wherein the heating roller is a roller. To provide a resistance pattern formed in a substantially band shape by a resistance heating substance having a positive resistance temperature coefficient on the surface of the cylindrical base material forming the − portion, and for supplying an electric current to the resistance pattern. A heat-fixing device having the electrode of
JP13919193A 1993-05-19 1993-05-19 Thermal fixing device Pending JPH06332331A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13919193A JPH06332331A (en) 1993-05-19 1993-05-19 Thermal fixing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13919193A JPH06332331A (en) 1993-05-19 1993-05-19 Thermal fixing device

Publications (1)

Publication Number Publication Date
JPH06332331A true JPH06332331A (en) 1994-12-02

Family

ID=15239678

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13919193A Pending JPH06332331A (en) 1993-05-19 1993-05-19 Thermal fixing device

Country Status (1)

Country Link
JP (1) JPH06332331A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6607864B2 (en) 2001-06-20 2003-08-19 Fuji Xerox Co., Ltd. Image forming method
KR100782801B1 (en) * 2001-05-04 2007-12-06 삼성전자주식회사 The fixing roller Power-source supply apparatus of electrophotographic image forming apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100782801B1 (en) * 2001-05-04 2007-12-06 삼성전자주식회사 The fixing roller Power-source supply apparatus of electrophotographic image forming apparatus
US6607864B2 (en) 2001-06-20 2003-08-19 Fuji Xerox Co., Ltd. Image forming method

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