EP0121772B1 - Roll fusing unit - Google Patents

Roll fusing unit Download PDF

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Publication number
EP0121772B1
EP0121772B1 EP84102432A EP84102432A EP0121772B1 EP 0121772 B1 EP0121772 B1 EP 0121772B1 EP 84102432 A EP84102432 A EP 84102432A EP 84102432 A EP84102432 A EP 84102432A EP 0121772 B1 EP0121772 B1 EP 0121772B1
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EP
European Patent Office
Prior art keywords
heating
roller
fixing device
temperature
roll
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.)
Expired
Application number
EP84102432A
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German (de)
French (fr)
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EP0121772A1 (en
Inventor
Reinhold Euler
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.)
Hoechst AG
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Hoechst AG
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Filing date
Publication date
Application filed by Hoechst AG filed Critical Hoechst AG
Priority to AT84102432T priority Critical patent/ATE23229T1/en
Publication of EP0121772A1 publication Critical patent/EP0121772A1/en
Application granted granted Critical
Publication of EP0121772B1 publication Critical patent/EP0121772B1/en
Expired legal-status Critical Current

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
    • G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat
    • G03G15/2039—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat with means for controlling the fixing temperature
    • G03G15/2042—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat with means for controlling the fixing temperature specially for the axial heat partition

Definitions

  • the invention relates to a fixing device for fixing a toner image on copying material, with a heating device arranged transversely to the direction of passage of the copying material and suitable for different copying material formats, which has a central heating element in the central zone and a divided heating element in both peripheral zones, each with one central and one divided Heating element assigned temperature sensors which are connected to a control for the power supply to the heating elements.
  • Such a fixing device is known from the document DE-A-2634002, which has a heating device divided into heating sections, which is arranged in a frame.
  • a first heating section consists of a heat-insulated electrical heating wire which is arranged in a zigzag shape in a central zone of the frame, the width of the heating section corresponding to the width of the narrowest recording sheet to be developed.
  • a second heating section which consists of two electrical, heat-insulated zigzag heating wires, is arranged outside the first heating section. The width of the two heating wires corresponds to the width of a wider recording sheet to be fixed.
  • the central zone of the fixing device is adjoined by temperature sensors which detect the heat generated by the first and second heating sections.
  • the fixing device comprises an upper and a lower frame with the heating sections described above, and a recording plate to be fixed is heated both from above and from below.
  • the temperature distribution along the individual frame is kept constant over the frame length by a controller that receives its signals from the temperature sensors.
  • a heating roller fixing device in which the heating element has a non-uniform radiation density in the axial direction in the switched-on state, such that there is a temperature distribution on the surface of the fixing roller in the axial direction, which is in the middle and on the two axial ends has a minimum and in between each has a maximum.
  • the only temperature sensor of this heating roller fixing device is arranged close to its surface at the level of the maxima of the surface temperature of the fixing roller.
  • An infrared radiator is provided as the heating element, which has a higher radiation density in the axial direction at its two ends than in the middle.
  • this heating roller fixing device With this heating roller fixing device, the most uniform possible temperature distribution on the surface of the fixing roller is to be achieved in order to improve the fixing of a toner image on copy paper and to achieve good adhesion of the toner to the paper.
  • a fixing temperature that is too low results in insufficient fixing, so that the toner image can easily be wiped off the copy paper.
  • an excessively high fixing temperature leads to the so-called offset effect, in which a part of the toner image is removed from the copy paper and adheres to the fixing roller and is then transferred to other areas of the copy paper.
  • DE-A-3224239 discloses a roller arrangement comprising a heating and a printing roller for thermal fixing, between which a copy paper with a toner image thereon is transported forward.
  • a heating roller In the heating roller there is a heating element with which the surface temperature of the heating roller is kept at a predetermined temperature.
  • the heating roller and the printing roller are rotated before the surface temperature of the heating roller reaches the predetermined temperature.
  • the motor that rotates the heating and the printing roller is switched off.
  • the heating element in the heating roller is controlled by a temperature sensor which is arranged at one point in such a way that it determines the surface temperature of the heating roller.
  • a toner image fixing device comprising a heating and printing roller
  • a temperature sensor measures the surface temperature of the heating roller and the size of the pressure force of the printing roller on the heating roller is regulated as a function of the measured surface temperature.
  • This is intended to achieve a uniform fixing quality of the toner image on a copy sheet which is transported through between the two rollers, since the fixing process is influenced both by the temperature and by the contact pressure between the two rollers in such a way that, for example, the surface temperature increases as the Contact pressure is reduced and the contact pressure increases as the surface temperature drops becomes.
  • the relationship between these two variables is regulated on the basis of a predetermined surface temperature / contact pressure relationship.
  • the roller fixing station according to European patent application 80101465 (EP-A-0017092) is equipped with a pair of rotatable rollers, one of which has end portions that taper outwards.
  • the role includes an outer sleeve, which is attached centrally on an axis.
  • the main parts of the inner surface of the sleeve have stepped sections with increasing diameter at each tapered end of the sleeve.
  • Screw-in plugs are fastened to parts of the axle in the tapered end sections of the sleeve.
  • the main body of each plug has a smaller diameter than the surface part of the inner sleeve.
  • the plugs are rotatable on the axis and move linearly from a retracted position, in which there is play between the plugs and the sleeve of the roller, in an engagement position, in which end flanges of the plugs are engaged with the stepped parts of the sleeve.
  • the end portions of the sleeve are not mechanically supported by the flanges of the plugs, so that the pressure of the counter roller presses the tapered end portions of the sleeve against the stopper.
  • the degree of taper and the size of the gap between the plugs and the sleeve are coordinated so that the behavior of the role of a substantially flat, i.e.. H. does not correspond to a rejuvenating role.
  • the tapered formation of the roll is maintained when the end plugs are screwed inward in the axial direction, and this prevents wrinkling of the copy paper, which usually occurs in the fusing station at high humidity.
  • the roller works like an essentially flat cylindrical roller which has no taper. Due to the pressure of the counter roller, the tapered configuration of the roller is flattened. Using this roll under this condition prevents the so-called smear effect on the copy in dry conditions, i.e. very low humidity in the fuser.
  • the plugs can be adjusted manually when the two rollers are separated from one another or by means of a motor controlled by a moisture sensor.
  • the taper achieves a higher peripheral speed near the edge of the roll, so that copy paper that passes through the nip between two rolls experiences a higher peripheral speed along the edges compared to the speed in the middle. As a result, the copy paper stretches and does not wrinkle even at high relative humidity in the fuser.
  • the copy paper tends to curl or form small waves, so that when the copy paper enters the fixing device, it comes into premature contact with the fixing roller, causing the image to be smeared.
  • the aim is to achieve a temperature distribution that is as uniform as possible over the length of the fixing roller while compensating for the temperature drop near the roller ends in order to maintain a constant copy quality, or the contact pressure between the fixing roller and the pressure roller is regulated in accordance with the respective measured temperature so that a predetermined pressure / Temperature relationship is maintained, or a roller tapering outwards in the end sections is used, which flattens under the pressure of another roller, in order to obtain a uniform pressure over the length of the roller to avoid wrinkles.
  • the object of the invention is to improve a fixing device of the type described in the introduction in such a way that both conventional copies such as A4 and A3 and large-format copies such as A2 or A1 develop wrinkles or waves or pinch folds with impairment of the copy image and that different copy materials such as opaque or transparent papers or foils can be used.
  • the heating device is a heating roller, in the interior of which a central coil is arranged as a heating element in the central zone and in each of which peripheral zones adjoining the central zone on the left and right are arranged a coil of a divided heating element such that the central one Coil overlaps with each of the two coils in each edge zone so that the current supply to the heating elements is regulated in such a way that a temperature distribution with an extremum in the central zone and maxima near the two end faces of the heating roller occurs on the surface of the heating roller in the axial direction, and that a Temperature sensor the location of the extremum of the temperature distribution in the middle of the roll and the other temperature sensor opposite the center of one of the edge zones of the heating roll.
  • the advantages of the invention are that large-format copies can be made without wrinkles and waves, regardless of the nature of the copying material, and that the shape of the fixing roller at the time of contact with the pressure roller can be compared with little effort due to the temperature curve that can be set via the fixing roller length to the conical design of the known fixing roller with screwable plugs, which are adjustable in the axial direction of the roller, is achieved.
  • a fixing device 1 shown in FIG. 1 comprises a heating roller 10 and a pressure roller 2.
  • the upper heating roller 10 or fixing roller is mounted in bearings 5 and 6, for example ball bearings, and the bottom pressure roller 2 is mounted in bearings 23, 24, each inside the rollers are arranged.
  • the storage within the rollers takes place approximately at a distance of 20 mm from the respective end faces of the rollers.
  • the upper heating roller 10 has a length of about 670 mm and usually consists of an aluminum tube with a wall thickness of 7 to 9 mm and a silicone rubber coating 25 with a thickness of about 1 to 1.2 mm.
  • the coating with silicone rubber ends about 30 to 32 mm in front of the end faces 17, 18 of the heating roller 10.
  • the pressure roller 2 also consists of an aluminum cylinder with a wall thickness of about 6 mm and a coating of silicone rubber and a tube made of a shrink film, the thickness the silicone rubber coating and the hose are approximately 3 mm. This coating extends from face to face.
  • the pressure roller 2 interacts with the heating roller 10 in order to grasp the copying material and to transport it through the gap between the two rollers.
  • the shaft section projecting from the end face 17 of the roller 10 carries a clutch 3 with a gearwheel 26, which is driven by a toothed belt 4 or a roller chain.
  • a temperature sensor 19 for example a thermistor or a thermocouple, is arranged near the surface of the heating roller 10 opposite the center of the roller, the two connecting wires of which are connected to a controller 21, shown schematically in FIG. 1, which controls the copying program sequence.
  • a further temperature sensor 20 Near the surface and the one end face 17 of the heating roller 10 there is a further temperature sensor 20, namely a thermistor or a thermocouple, which is connected to the controller 21 with its two connecting wires.
  • the two temperature sensors ensure that the energy supply to heating elements, which are arranged inside the heating roller, is interrupted when predetermined temperatures are reached at the measuring points.
  • Connection wires 7, 8, and 7 ', 8' lead from the inside of the heating roller 10 to the controller 21, which has a control circuit for actuating relays which remove the connection to the mains supply of the heating elements when predetermined temperature setpoints are reached.
  • the two electric heating elements 11 and 13 run parallel to a roller axis 12.
  • the heating element 11 is enclosed by a glass cylinder 9 in which a coil 14 extends, which extends over a central zone b of the heating roller 10.
  • the length of this central zone b is approximately 310 mm.
  • the connecting wires 7, 7 ′ lead out of the glass cylinder 9 from the two ends of the helix 14.
  • the other heating element 13 has two coils 15 and 16, which are located in the edge zones a, c of the heating roller 10 adjoining the central zone b on the left and right.
  • the two coils 15 and 16 are connected to one another in the middle by a heating wire and melted into a glass cylinder 22, through the end walls of which the two connecting wires 8, 8 'of the heating element 13 are passed.
  • the individual helix 15, 16 has a length of approximately 150 mm.
  • the length of the helix 14 in the central zone b corresponds at least to the width of the DIN A3 format and is generally 300 to 305 mm.
  • the helix 14 in the central zone b overlaps in an area g with each of the two helices 15, 16 in each of the peripheral zones a, c.
  • the current supply to the heating elements 11, 13 is controlled in such a way that a temperature distribution shown in FIG. 3 results on the surface of the heating roller 10 in the axial direction, which is a minimum in the central zone b and near the two end faces 17, 18 of the heating roller 10 maxima has e and f.
  • the temperature sensor 19 is located at the level of the minimum d of the surface temperature in the middle of the roller and the other temperature sensor 20 is at the level of the maximum of the surface temperature of the heating roller 10 near one of the end faces 17 and 18, respectively. Due to the overlap of the coils 14, 15, 16, a uniform temperature profile is achieved at the transition points from the central zone to the peripheral zones.
  • the heating elements 11, 13 are controlled by the temperature sensors 19, 20 in such a way that a temperature difference .DELTA.u of 2 to 10 ° C. occurs between the center of the heating roller 10 and the edge zones a and c of the heating roller. This temperature difference arises as soon as the two heating elements 11 and 13 are heated.
  • the size of the temperature difference A ⁇ J- is determined as a function of the copying material, a smaller temperature difference being generally chosen for opaque paper than for transparent paper.
  • the heating of the two heating elements takes place in such a way that in the case of formats of the copying material of A4 and A3, only the heating element 11 with the coil 14 in the central zone b of the heating roller 10 is initially switched on. As soon as the measured temperature difference A ⁇ J- is greater than 2 to 10 ° C. between the central zone b and the peripheral zones a and c, the heating element 13 with the two coils 15 and 16 is automatically switched on by the controller 21. This is supposed to miss that the temperature difference will be greater than 10 ° C, otherwise the waiting times will be too long, if after longer operation of the fuser for fixing DIN A3 and A4 formats to larger formats such as DIN A2 and DIN A1 is switched.
  • both heating elements 11 and 13 are switched on at the same time.
  • Narrow web papers are to be understood as papers that are cut to formats along the direction of the paper tape. Due to the production of these papers, they shrink only in the transverse direction when moisture is removed, but hardly in the longitudinal direction.
  • the mass, nature of the copying materials and the environmental parameters such as temperature, air humidity and length of stay in the climatic chamber are listed in the table below.
  • the narrow web papers whether opaque or transparent papers, show great dimensional stability in the longitudinal direction, the maximum shrinkage when the relative humidity is reduced by 57% and the temperature drops from 30 ° C to 20 ° C, 2.8 mm with an average length of 500 mm, while in the transverse direction the maximum shrinkage can be up to 15 mm with an average width of 500 mm.
  • the table shows that tracing paper shrinks more than opaque paper or expands when the relative humidity increases, while plastic film as copying material, such as Hostaphan @, is largely dimensionally stable in both the transverse and longitudinal directions.
  • the temperature difference ⁇ between the individual edge zone and the center of the roller arrangement should not exceed 10 ° C, otherwise the roller pressure in the edge zones will be greater than in the middle, so that the throughput speed of the copy paper at the edges will be higher than in the middle.
  • the copy image is then duplicated, the cause of which is the accumulation of the slower paper zones in the middle of the bow wave mentioned above.
  • the temperature is at least d 180 ° C., in the maxima e to 193 ° C. and in the peripheral zones of the heating roller over the entire peripheral zone region 186 ° C. .
  • the constant temperature which arises in the peripheral zones is the highest temperature within the temperature zones of the heating roller which are effective for fixing, while the temperature maxima e and f lie outside the silicone coating and thus the roller area which is effective for fixing.
  • Fig. 4 shows a temperature curve over the heating roller length, which is set after long operation of the fuser by appropriate control of the power supply to the heating elements 11 and 13. It can be seen that the central zone b of the heating roller is subjected to greater stress than the edge zones a, c during longer operation, with the result that the diameter in the center of the heating roller is increased by approximately 0.1 mm per 10,000 copies compared to the Diameters of the edge zones a and c decreases. A conceivable explanation for this could be a stronger mechanical abrasion and / or a greater discharge of silicone oil from the silicone rubber coating in the middle of the heating roller. This process requires an adjustment of the temperature profile in such a way that the temperature of the central zone is raised compared to that of the peripheral zones in order to continue to ensure a uniform mutual pressure of the rollers over their entire length.
  • the characteristic temperature in the maximum d 'in the central zone is, for example, 182 ° C, in the maxima e' and f 'approximately 181 ° C and in the peripheral zones on average 175 ° C for the temperature profile according to FIG. 4.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Fixing For Electrophotography (AREA)
  • Massaging Devices (AREA)
  • Control And Other Processes For Unpacking Of Materials (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • General Induction Heating (AREA)

Abstract

A fixing roller device having a pressure roller and a heating roller as the fixing roller. Heating elements sealed into glass cylinders are located inside the heating roller, parallel to a roller axis. One heating element consists of a coil in a middle zone of the heating roller, while the other heating element has two coils in edge zones of the heating roll. Two temperature sensors are arranged respectively in the middle of the heating roller and near one of the end faces of the heating roller, at a small distance from the heating roller surface, and are connected to a control system which controls the current supply to the heating elements and cuts this supply as soon as the temperatures measured by the temperature sensors reach predetermined intended values.

Description

Die Erfindung betrifft eine Fixiervorrichtung zum Fixieren eines Tonerbildes auf Kopiermaterial, mit einer quer zur Durchlaufrichtung des Kopiermaterials angeordneten, für verschiedene Kopiermaterialformate geeigneten Heizeinrichtung, die in der Mittelzone ein zentrales und in beiden Randzonen ein unterteiltes Heizelement aufweist, mit je einem dem zentralen und dem unterteilten Heizelement zugeordneten Temperaturfühler, die an eine Steuerung für die Stromzufuhr zu den Heizelementen angeschlossen sind.The invention relates to a fixing device for fixing a toner image on copying material, with a heating device arranged transversely to the direction of passage of the copying material and suitable for different copying material formats, which has a central heating element in the central zone and a divided heating element in both peripheral zones, each with one central and one divided Heating element assigned temperature sensors which are connected to a control for the power supply to the heating elements.

Eine derartige Fixiervorrichtung ist aus der Druckschrift DE-A-2634002 bekannt, die eine in Heizabschnitte unterteilte Heizeinrichtung aufweist, die in einem Rahmen angeordnet ist. Ein erster Heizabschnitt besteht aus einem wärmeisolierten elektrischen Heizdraht, der in Zickzackform in einer zentralen Zone des Rahmens angeordnet ist, wobei die Breite des Heizabschnittes der Breite des schmalsten, zu entwickelnden Aufzeichnungsblattes entspricht. Ein zweiter Heizabschnitt, der aus zwei elektrischen, wärmeisolierten Heizdrähten in Zickzackform besteht, ist ausserhalb des ersten Heizabschnittes angeordnet. Die Breite der zwei Heizdrähte entspricht der Breite eines breiteren, zu fixierenden Aufzeichnungsblattes. Der zentralen Zone der Fixiervorrichtung sind Temperaturfühler benachbart, welche die von den ersten und zweiten Heizabschnitten erzeugte Wärme erfassen. Die Fixiervorrichtung umfasst einen oberen und einen unteren Rahmen mit den voranstehend beschriebenen Heizabschnitten, und ein zu fixierendes Aufzeichnungsplatte wird sowohl von oben als auch von unten her erwärmt. Die Temperaturverteilung längs des einzelnen Rahmens wird durch eine Steuerung, die von den Temperaturfühlern ihre Signale erhält, über die Rahmenlänge konstant gehalten.Such a fixing device is known from the document DE-A-2634002, which has a heating device divided into heating sections, which is arranged in a frame. A first heating section consists of a heat-insulated electrical heating wire which is arranged in a zigzag shape in a central zone of the frame, the width of the heating section corresponding to the width of the narrowest recording sheet to be developed. A second heating section, which consists of two electrical, heat-insulated zigzag heating wires, is arranged outside the first heating section. The width of the two heating wires corresponds to the width of a wider recording sheet to be fixed. The central zone of the fixing device is adjoined by temperature sensors which detect the heat generated by the first and second heating sections. The fixing device comprises an upper and a lower frame with the heating sections described above, and a recording plate to be fixed is heated both from above and from below. The temperature distribution along the individual frame is kept constant over the frame length by a controller that receives its signals from the temperature sensors.

Aus der DE-B-2949996 ist eine Heizwalzenfixiervorrichtung bekannt, bei der das Heizelement im eingeschalteten Zustand in axialer Richtung eine ungleichmässige Strahlungsdichte aufweist, derart, dass sich auf der Oberfläche der Fixierwalze in Axialrichtung eine Temperaturverteilung ergibt, die in der Mitte und an den beiden axialen Enden ein Minimum und dazwischen jeweils ein Maximum aufweist. Der einzige Temperaturfühler dieser Heizwalzenfixiervorrichtung ist auf der Höhe der Maxima der Oberflächentemperatur der Fixierwalze dicht an ihrer Oberfläche angeordnet. Als Heizelement ist ein Infrarotstrahler vorgesehen, der in axialer Richtung an seinen beiden Enden eine höhere Strahlungsdichte aufweist als in der Mitte.From DE-B-2949996 a heating roller fixing device is known, in which the heating element has a non-uniform radiation density in the axial direction in the switched-on state, such that there is a temperature distribution on the surface of the fixing roller in the axial direction, which is in the middle and on the two axial ends has a minimum and in between each has a maximum. The only temperature sensor of this heating roller fixing device is arranged close to its surface at the level of the maxima of the surface temperature of the fixing roller. An infrared radiator is provided as the heating element, which has a higher radiation density in the axial direction at its two ends than in the middle.

Mit dieser Heizwalzenfixiervorrichtung soll eine möglichst gleichmässige Temperaturverteilung auf der Oberfläche der Fixierwalze erreicht werden, um das Fixieren eines Tonerbildes auf Kopierpapier zu verbessern und eine gute Haftung des Toners auf dem Papier zu erzielen. Ganz allgemein hat eine zu niedrige Fixiertemperatur ein ungenügendes Fixieren zur Folge, so dass sich das Tonerbild leicht vom Kopierpapier abwischen lässt. Andererseits führt eine zu hohe Fixiertemperatur zu dem sogenannten Offset-Effekt, bei dem ein Teil des Tonerbildes vom Kopierpapier abgenommen wird und auf der Fixierwalze haftet und dann auf andere Bereiche des Kopierpapiers übertragen wird.With this heating roller fixing device, the most uniform possible temperature distribution on the surface of the fixing roller is to be achieved in order to improve the fixing of a toner image on copy paper and to achieve good adhesion of the toner to the paper. In general, a fixing temperature that is too low results in insufficient fixing, so that the toner image can easily be wiped off the copy paper. On the other hand, an excessively high fixing temperature leads to the so-called offset effect, in which a part of the toner image is removed from the copy paper and adheres to the fixing roller and is then transferred to other areas of the copy paper.

Bei der bekannten Heizwalzenfixiervorrichtung wird erreicht, dass in axialer Richtung der Fixierwalze in der Mitte gerade kein Maximum der Temperaturverteilung vorliegt, vielmehr sind derartige Maxima zwischen den beiden Enden und der Mitte der Fixierwalze vorhanden. Zwar wird auch bei einer derartigen Anordnung ein an und für sich nicht erwünschtes Überschwingen der Temperaturwerte über den Sollwert an den Stellen stattfinden, an denen sich die Maxima der Temperaturverteilung befinden, jedoch wird dieser Effekt dadurch kompensiert, dass in axialer Richtung der Fixierwalze in der Mitte und an den beiden Enden Bereiche geringerer Temperaturen vorliegen, so dass sich zwangsläufig ein Temperaturausgleich an der Oberfläche der Fixierwalze über ihre Länge ergibt. Zu dem Überschwingen der Temperaturwerte kommt es dadurch, dass der Temperaturfühler bei Erreichen des Sollwertes einer gewünschten Temperatur die Stromzufuhr zum Heizelement abschaltet, die Fixierwalze jedoch zu diesem Zeitpunkt eine erhebliche Wärmemenge gespeichert hat und infolge der Trägheit des Systems diese zu Temperaturen über dem Sollwert fü h rt.In the known heating roller fixing device it is achieved that there is just no maximum of the temperature distribution in the middle in the axial direction of the fixing roller, rather such maxima are present between the two ends and the center of the fixing roller. Even with such an arrangement, an undesirable overshoot of the temperature values above the setpoint will take place at the points where the maxima of the temperature distribution are located, but this effect is compensated for by the fact that in the axial direction of the fixing roller in the middle and regions of lower temperatures are present at both ends, so that there is an inevitable temperature compensation on the surface of the fixing roller over its length. The temperature values overshoot due to the fact that the temperature sensor switches off the power supply to the heating element when the target value of a desired temperature is reached, but at this point the fixing roller has stored a considerable amount of heat and, due to the inertia of the system, the temperature at the temperature exceeds the target value rt.

Aus der DE-A-3224239 ist eine Walzenanordnung aus einer Heiz- und einer Druckwalze zum thermischen Fixieren bekannt, zwischen denen ein Kopierpapier mit einem darauf befindlichen Tonerbild vorwärtstransportiert wird. In der Heizwalze befindet sich ein Heizelement, mit dem die Oberflächentemperatur der Heizwalze auf einer vorgegebenen Temperatur gehalten wird. Beim Einschalten des Kopiergeräts werden die Heizwalze und die Druckwalze in Drehung versetzt, bevor die Oberflächentemperatur der Heizwalze die vorgegebene Temperatur erreicht. Sobald diese Temperatur erreicht ist, wird der Motor, der die Heiz-und die Druckwalze in Drehung versetzt, ausgeschaltet. Die Steuerung des Heizelements in der Heizwalze erfolgt über einen Temperaturfühler, der an einer Stelle so angeordnet ist, dass er die Oberflächentemperatur der Heizwalze ermittelt.DE-A-3224239 discloses a roller arrangement comprising a heating and a printing roller for thermal fixing, between which a copy paper with a toner image thereon is transported forward. In the heating roller there is a heating element with which the surface temperature of the heating roller is kept at a predetermined temperature. When the copier is switched on, the heating roller and the printing roller are rotated before the surface temperature of the heating roller reaches the predetermined temperature. As soon as this temperature has been reached, the motor that rotates the heating and the printing roller is switched off. The heating element in the heating roller is controlled by a temperature sensor which is arranged at one point in such a way that it determines the surface temperature of the heating roller.

Aus der US-A-4232959 ist eine Tonerbild-Fixiervorrichtung aus Heiz- und Druckwalze bekannt, bei der ein Temperaturfühler die Oberflächentemperatur der Heizwalze misst und in Abhängigkeit von der gemessenen Oberflächentemperatur die Grösse der Andruckkraft der Druckwalze an die Heizwalze geregelt wird. Dadurch soll eine gleichmässige Fixierqualität des Tonerbilds auf einem Kopierblatt, das zwischen den beiden Walzen hindurchtransportiert wird, erreicht werden, da der Fixiervorgang sowohl über die Temperatur als auch über den Anpressdruck zwischen den beiden Walzen in der Weise beeinflusst wird, dass beispielsweise bei steigender Oberflächentemperatur der Anpressdruck verringert und bei sinkender Oberflächentemperatur der Anpressdruck erhöht wird. Der Zusammenhang zwischen diesen beiden Grössen wird dabei aufgrund einer vorgegebenen Oberflächentemperatur/Anpressdruck-Beziehung geregelt.From US-A-4232959 a toner image fixing device comprising a heating and printing roller is known, in which a temperature sensor measures the surface temperature of the heating roller and the size of the pressure force of the printing roller on the heating roller is regulated as a function of the measured surface temperature. This is intended to achieve a uniform fixing quality of the toner image on a copy sheet which is transported through between the two rollers, since the fixing process is influenced both by the temperature and by the contact pressure between the two rollers in such a way that, for example, the surface temperature increases as the Contact pressure is reduced and the contact pressure increases as the surface temperature drops becomes. The relationship between these two variables is regulated on the basis of a predetermined surface temperature / contact pressure relationship.

Die Rollen-Fixierstation nach der Europäischen Patentanmeldung 80101465 (EP-A-0017092) ist mit einem Paar drehbarer Rollen ausgerüstet, von denen eine nach aussen sich verjüngende Endabschnitte aufweist. Die Rolle umfasst eine äussere Hülse, die zentral auf einer Achse befestigt ist. Die Hauptteile der Innenfläche der Hülse besitzen abgestufte Abschnitte mit ansteigendem Durchmesser an jedem sich verjüngenden Ende der Hülse. In den verjüngenden Endabschnitten der Hülse sind verschraubbare Stopfen auf Teilen der Achse befestigt. Der Hauptkörper jedes Stopfens besitzt einen kleineren Durchmesser als der Flächenteil der inneren Hülse. Die Stopfen sind auf der Achse drehbar und bewegen sich linear von einer zurückgezogenen Position, in der ein Spiel zwischen den Stopfen und der Hülse der Rolle besteht, in einer Eingriffsposition, in der Endflansche der Stopfen mit den abgestuften Teilen der Hülse im Eingriff sind. In der zurückgezogenen Position erfolgt keine mechanische Abstützung der Endabschnitte der Hülse durch die Flansche der Stopfen, so dass der Druck der Gegenrolle die sich verjüngenden Endabschnitte der Hülse gegen den Stopfen anpresst. Der Grad der Verjüngung und die Grösse des Spalts zwischen den Stopfen und der Hülse sind so aufeinander abgestimmt, dass das Verhalten der Rolle einer im wesentlichen ebenen, d. h. sich nicht verjüngenden Rolle entspricht.The roller fixing station according to European patent application 80101465 (EP-A-0017092) is equipped with a pair of rotatable rollers, one of which has end portions that taper outwards. The role includes an outer sleeve, which is attached centrally on an axis. The main parts of the inner surface of the sleeve have stepped sections with increasing diameter at each tapered end of the sleeve. Screw-in plugs are fastened to parts of the axle in the tapered end sections of the sleeve. The main body of each plug has a smaller diameter than the surface part of the inner sleeve. The plugs are rotatable on the axis and move linearly from a retracted position, in which there is play between the plugs and the sleeve of the roller, in an engagement position, in which end flanges of the plugs are engaged with the stepped parts of the sleeve. In the retracted position, the end portions of the sleeve are not mechanically supported by the flanges of the plugs, so that the pressure of the counter roller presses the tapered end portions of the sleeve against the stopper. The degree of taper and the size of the gap between the plugs and the sleeve are coordinated so that the behavior of the role of a substantially flat, i.e.. H. does not correspond to a rejuvenating role.

Die sich verjüngende Ausbildung der Rolle wird beibehalten, wenn die Endstopfen in axialer Richtung nach innen geschraubt werden und dadurch wird eine Faltenbildung des Kopierpapiers, die üblicherweise bei hoher Feuchtigkeit in der Fixierstation auftritt, verhindert.The tapered formation of the roll is maintained when the end plugs are screwed inward in the axial direction, and this prevents wrinkling of the copy paper, which usually occurs in the fusing station at high humidity.

Werden die Endstopfen in axialer Richtung nach aussen geschraubt, so arbeitet die Rolle wie eine im wesentlichen ebene zylindrische Rolle, die keine Verjüngung besitzt. Infolge des Anpressdrukkes der Gegenrolle wird die sich verjüngende Konfiguration der Rolle abgeflacht. Der Einsatz dieser Rolle unter dieser Bedingung verhindert den sogenannten Verschmierungseffekt auf der Kopie bei trockenen Bedingungen, d.h. sehr geringer Luftfeuchtigkeit in der Fixierstation. Die Einstellung der Stopfen kann manuell vorgenommen werden, wenn die beiden Rollen voneinander getrennt sind oder mittels eines Motors, der über einen Feuchtigkeitsfühler gesteuert wird.If the end plugs are screwed outwards in the axial direction, the roller works like an essentially flat cylindrical roller which has no taper. Due to the pressure of the counter roller, the tapered configuration of the roller is flattened. Using this roll under this condition prevents the so-called smear effect on the copy in dry conditions, i.e. very low humidity in the fuser. The plugs can be adjusted manually when the two rollers are separated from one another or by means of a motor controlled by a moisture sensor.

Durch die Verjüngung wird eine höhere Umfangsgeschwindigkeit nahe der Kante der Rolle erzielt, so dass ein Kopierpapier, das den Spalt zwischen zwei Rollen durchläuft, eine höhere periphere Geschwindigkeit längs den Kanten im Vergleich zu der Geschwindigkeit in der Mitte erfährt. Daraus resultiert, dass das Kopierpapier sich streckt und keine Falten selbst bei hoher relativer Feuchtigkeit in der Fixierstation bildet.The taper achieves a higher peripheral speed near the edge of the roll, so that copy paper that passes through the nip between two rolls experiences a higher peripheral speed along the edges compared to the speed in the middle. As a result, the copy paper stretches and does not wrinkle even at high relative humidity in the fuser.

Bei sehr trockenen Bedingungen neigt das Kopierpapier dazu, sich zu kräuseln oder kleine Wellen zu bilden, so dass es, sobald das Kopierpapier in die Fixiervorrichtung eintritt, zu einem vorzeitigen Kontakt mit der Fixierrolle kommt, wodurch eine Verschmierung des Bildes verursacht wird.In very dry conditions, the copy paper tends to curl or form small waves, so that when the copy paper enters the fixing device, it comes into premature contact with the fixing roller, causing the image to be smeared.

Bei den bekannten Fixiervorrichtungen wird eine möglichst gleichmässige Temperaturverteilung über die Länge der Fixierwalze unter Kompensation des Temperaturabfalls nahe der Walzenenden angestrebt, um gleichbleibende Kopienqualität zu erhalten, oder der Anpressdruck zwischen Fixier- und Druckwalze entsprechend der jeweiligen gemessenen Temperatur so geregelt, dass eine vorgegebene Druck/Temperatur-Beziehung eingehalten wird, oder eine sich in den Endabschnitten nach aussen verjüngende Rolle eingesetzt, die sich unter dem Anpressdruck einer weiteren Rolle abflacht, um so einen gleichmässigen Andruck über die Rollenlänge zur Vermeidung von Faltenbildung zu erhalten.In the known fixing devices, the aim is to achieve a temperature distribution that is as uniform as possible over the length of the fixing roller while compensating for the temperature drop near the roller ends in order to maintain a constant copy quality, or the contact pressure between the fixing roller and the pressure roller is regulated in accordance with the respective measured temperature so that a predetermined pressure / Temperature relationship is maintained, or a roller tapering outwards in the end sections is used, which flattens under the pressure of another roller, in order to obtain a uniform pressure over the length of the roller to avoid wrinkles.

Aufgabe der Erfindung ist es, eine Fixiervorrichtung der eingangs beschriebenen Art so zu verbessern, dass sowohl bei den üblichen Kopien wie DIN-A4 und DIN-A3 als auch bei grossformatigen Kopien wie DIN-A2 oder DIN-A1 eine Falten- oder Wellenbildung oder Quetschfalten mit Beeinträchtigung des Kopierbildes ausgeschlossen werden und dass unterschiedliche Kopiermaterialien wie opake oder transparente Papiere oder Folien verwendet werden können.The object of the invention is to improve a fixing device of the type described in the introduction in such a way that both conventional copies such as A4 and A3 and large-format copies such as A2 or A1 develop wrinkles or waves or pinch folds with impairment of the copy image and that different copy materials such as opaque or transparent papers or foils can be used.

Diese Aufgabe wird erfindungsgemäss dadurch gelöst, dass die Heizeinrichtung eine Heizwalze ist, in deren Innerem in der Mittelzone eine zentrale Wendel als Heizelement und in deren, an die Mittelzone links und rechts anschliessenden Randzonen je eine Wendel eines unterteilten Heizelements angeordnet sind, dass sich die zentrale Wendel mit jeder der beiden Wendeln in jeder Randzone überlappt, dass die Stromzufuhr zu den Heizelementen so geregelt ist, dass auf der Oberfläche der Heizwalze in Axialrichtung eine Temperaturverteilung mit einem Extremum in der Mittelzone und Maxima nahe den beiden Stirnflächen der Heizwalze auftritt, und dass ein Temperaturfühler dem Ort des Extremums der Temperaturverteilung in der Walzenmitte und der andere Temperaturfühler der Mitte einer der Randzonen der Heizwalze gegenüberliegt.This object is achieved according to the invention in that the heating device is a heating roller, in the interior of which a central coil is arranged as a heating element in the central zone and in each of which peripheral zones adjoining the central zone on the left and right are arranged a coil of a divided heating element such that the central one Coil overlaps with each of the two coils in each edge zone so that the current supply to the heating elements is regulated in such a way that a temperature distribution with an extremum in the central zone and maxima near the two end faces of the heating roller occurs on the surface of the heating roller in the axial direction, and that a Temperature sensor the location of the extremum of the temperature distribution in the middle of the roll and the other temperature sensor opposite the center of one of the edge zones of the heating roll.

Die weitere Ausgestaltung der Erfindung ergibt sich aus den Merkmalen der Ansprüche 2 bis 12.The further embodiment of the invention results from the features of claims 2 to 12.

Mit der Erfindung werden die Vorteile erzielt, dass grossformatige Kopien falten- und wellenfrei erstellt werden können, unabhängig von der Beschaffenheit des Kopiermaterials und dass die Formgebung der Fixierwalze zum Zeitpunkt des Kontaktes mit der Andruckwalze durch den über die Fixierwalzenlänge einstellbaren Temperaturverlauf mit geringem Aufwand im Vergleich zu der konischen Ausbildung der bekannten Fixierwalze mit verschraubbaren Pfropfen, die in axialer Richtung der Walze verstellbar sind, erreicht wird.The advantages of the invention are that large-format copies can be made without wrinkles and waves, regardless of the nature of the copying material, and that the shape of the fixing roller at the time of contact with the pressure roller can be compared with little effort due to the temperature curve that can be set via the fixing roller length to the conical design of the known fixing roller with screwable plugs, which are adjustable in the axial direction of the roller, is achieved.

Die Erfindung wird im folgenden anhand eines zeichnerisch dargestellten Ausführungbeispiels näher erläutert.The invention is explained in more detail below with reference to an exemplary embodiment shown in the drawing.

Es zeigen:

  • Fig. 1 eine schematische, perspektivische Darstellung einer Fixiervorrichtung nach der Erfindung;
  • Fig. 2 eine Schnittansicht durch die Heizwalze der in Fig. 1 dargestellten Fixiervorrichtung;
  • Fig. 3 eine grafische Darstellung des Temperaturverlaufs über die Länge der Fixierwalze, und
  • Fig. 4 einen gegenüber Fig. 3 unterschiedlichen Temperaturverlauf über die Länge der Fixierwalze.
Show it:
  • Figure 1 is a schematic, perspective view of a fixing device according to the invention.
  • Fig. 2 is a sectional view through the heating roller of the fixing device shown in Fig. 1;
  • Fig. 3 is a graphical representation of the temperature profile over the length of the fixing roller, and
  • FIG. 4 shows a temperature profile that differs from FIG. 3 over the length of the fixing roller.

Eine in Fig. 1 dargestellte Fixiervorrichtung 1 umfasst eine Heizwalze 10 und eine Andruckwalze 2. Die obere Heizwalze 10 bzw. Fixierwalze ist in Lagern 5 und 6, beispielsweise Kugellagern, und die untere Andruckwalze 2 in Lagern 23, 24 gelagert, die jeweils im Inneren der Walzen angeordnet sind. Die Lagerung innerhalb der Walzen erfolgt dabei etwa in einem Abstand von 20 mm von den jeweiligen Stirnflächen der Walzen. Die obere Heizwalze 10 besitzt etwa eine Länge von 670 mm und besteht üblicherweise aus einem Aluminiumrohr mit einer Wandstärke von 7 bis 9 mm sowie einer Silikongummibeschichtung 25 mit einer Dikke von etwa 1 bis 1,2 mm. Die Beschichtung mit Silikongummi endet etwa 30 bis 32 mm vor den Stirnflächen 17, 18 der Heizwalze 10. Die Andruckwalze 2 besteht gleichfalls aus einem Aluminiumzylinder mit einer Wandstärke von etwa 6 mm und einer Beschichtung aus Silikongummi und einem Schlauch aus einer Schrumpffolie, wobei die Dikken der Silikongummibeschichtung und des Schlauches ungefähr 3 mm betragen. Diese Beschichtung erstreckt sich von Stirnfläche zu Stirnfläche.A fixing device 1 shown in FIG. 1 comprises a heating roller 10 and a pressure roller 2. The upper heating roller 10 or fixing roller is mounted in bearings 5 and 6, for example ball bearings, and the bottom pressure roller 2 is mounted in bearings 23, 24, each inside the rollers are arranged. The storage within the rollers takes place approximately at a distance of 20 mm from the respective end faces of the rollers. The upper heating roller 10 has a length of about 670 mm and usually consists of an aluminum tube with a wall thickness of 7 to 9 mm and a silicone rubber coating 25 with a thickness of about 1 to 1.2 mm. The coating with silicone rubber ends about 30 to 32 mm in front of the end faces 17, 18 of the heating roller 10. The pressure roller 2 also consists of an aluminum cylinder with a wall thickness of about 6 mm and a coating of silicone rubber and a tube made of a shrink film, the thickness the silicone rubber coating and the hose are approximately 3 mm. This coating extends from face to face.

Die Andruckwalze 2 wirkt mit der Heizwalze 10 zusammen, um das Kopiermaterial zu erfassen und durch den Spalt zwischen den beiden Walzen hindurchzutransportieren.The pressure roller 2 interacts with the heating roller 10 in order to grasp the copying material and to transport it through the gap between the two rollers.

Der von der Stirnfläche 17 der Walze 10 vorspringende Wellenabschnitt trägt eine Kupplung 3 mit einem Zahnrad 26, das von einem Zahnriemen 4 bzw. einer Rollenkette, angetrieben wird.The shaft section projecting from the end face 17 of the roller 10 carries a clutch 3 with a gearwheel 26, which is driven by a toothed belt 4 or a roller chain.

Nahe der Oberfläche der Heizwalze 10 ist gegenüber der Mitte der Walze ein Temperaturfühler 19, beispielsweise ein Thermistor oder ein Thermoelement angeordnet, dessen beide Anschlussdrähte mit einer in Fig. 1 schematisch angedeuteten Steuerung 21, die den Kopierprogrammablauf steuert, verbunden sind. Nahe der Oberfläche und der einen Stirnfläche 17 der Heizwalze 10 befindet sich ein weiterer Temperaturfühler 20, nämlich ein Thermistor oder ein Thermoelement, das mit seinen beiden Anschlussdrähten mit der Steuerung 21 in Verbindung steht. Die beiden Temperaturfühler stellen sicher, dass die Energiezufuhr zu Heizelementen, die im Inneren der Heizwalze angeordnet sind, bei Erreichen von vorgegebenen Temperaturen an den Messstellen unterbrochen wird. Anschlussdrähte 7, 8, bzw. 7', 8' führen aus dem Inneren der Heizwalze 10 zu der Steuerung 21, die eine Steuerschaltung zur Betätigung von Relais aufweist, welche die Verbindung zur der Netzversorgung der Heizelemente bei Erreichen von vorgegebenen Sollwerten der Temperatur aufheben.A temperature sensor 19, for example a thermistor or a thermocouple, is arranged near the surface of the heating roller 10 opposite the center of the roller, the two connecting wires of which are connected to a controller 21, shown schematically in FIG. 1, which controls the copying program sequence. Near the surface and the one end face 17 of the heating roller 10 there is a further temperature sensor 20, namely a thermistor or a thermocouple, which is connected to the controller 21 with its two connecting wires. The two temperature sensors ensure that the energy supply to heating elements, which are arranged inside the heating roller, is interrupted when predetermined temperatures are reached at the measuring points. Connection wires 7, 8, and 7 ', 8' lead from the inside of the heating roller 10 to the controller 21, which has a control circuit for actuating relays which remove the connection to the mains supply of the heating elements when predetermined temperature setpoints are reached.

Aus Fig. 2 sind Einzelheiten des Aufbaus der Heizwalze 10 ersichtlich. Im Inneren der Heizwalze 10 verlaufen die beiden elektrischen Heizelemente 11 und 13 parallel zu einer Walzenachse 12. Das Heizelement 11 wird von einem Glaszylinder 9 eingeschlossen, in dem eine Wendel 14 verläuft, die sich über eine Mittelzone b der Heizwalze 10 erstreckt. Die Länge dieser Mittelzone b ist etwa 310 mm. Von den beiden Enden der Wendel 14 führen die Anschlussdrähte 7, 7' aus dem Glaszylinder 9 heraus. Das andere Heizelement 13 weist zwei Wendeln 15 und 16 auf, die sich in den an die Mittelzone b links und rechts anschliessenden Randzonen a, c der Heizwalze 10 befinden. Die beiden Wendeln 15 und 16 sind in der Mitte durch einen Heizdraht miteinander verbunden und in einen Glaszylinder 22 eingeschmolzen, durch dessen Stirnwände die beiden Anschlussdrähte 8, 8' des Heizelements 13 hindurchgeführt sind. Die einzelne Wendel 15, 16 besitzt eine Länge von ungefähr 150 mm. Die Länge der Wendel 14 in der Mittelzone b entspricht zumindest gleich der Breite des DIN-A3-Formats und beträgt im allgemeinen 300 bis 305 mm.2 details of the structure of the heating roller 10 can be seen. In the interior of the heating roller 10, the two electric heating elements 11 and 13 run parallel to a roller axis 12. The heating element 11 is enclosed by a glass cylinder 9 in which a coil 14 extends, which extends over a central zone b of the heating roller 10. The length of this central zone b is approximately 310 mm. The connecting wires 7, 7 ′ lead out of the glass cylinder 9 from the two ends of the helix 14. The other heating element 13 has two coils 15 and 16, which are located in the edge zones a, c of the heating roller 10 adjoining the central zone b on the left and right. The two coils 15 and 16 are connected to one another in the middle by a heating wire and melted into a glass cylinder 22, through the end walls of which the two connecting wires 8, 8 'of the heating element 13 are passed. The individual helix 15, 16 has a length of approximately 150 mm. The length of the helix 14 in the central zone b corresponds at least to the width of the DIN A3 format and is generally 300 to 305 mm.

Die Wendel 14 in der Mittelzone b überlappt sich in einem Bereich g mit jeder der beiden Wendeln 15, 16 in jeder der Randzonen a, c. Die Stromzufuhr zu den Heizelementen 11, 13 wird derart gesteuert, dass sich auf der Oberfläche der Heizwalze 10 in Axialrichtung eine in Fig. 3 dargestellte Temperaturverteilung ergibt, die in der Mittelzone b ein Minimum und nahe den beiden Stirnflächen 17, 18 der Heizwalze 10 Maxima e und f aufweist. Zur genauen Steuerung der Temperaturverteilung befindet sich der Temperaturfühler 19 auf der Höhe des Minimums d der Oberflächentemperatur in der Walzenmitte und der andere Temperaturfühler 20 auf der Höhe des Maximums der Oberflächentemperatur der Heizwalze 10 nahe einer der Stirnflächen 17 bzw. 18. Durch die Überlappung der Wendeln 14, 15, 16 wird an den Übergangsstellen von der Mittelzone zu den Randzonen ein gleichmässiger Temperaturverlauf erreicht.The helix 14 in the central zone b overlaps in an area g with each of the two helices 15, 16 in each of the peripheral zones a, c. The current supply to the heating elements 11, 13 is controlled in such a way that a temperature distribution shown in FIG. 3 results on the surface of the heating roller 10 in the axial direction, which is a minimum in the central zone b and near the two end faces 17, 18 of the heating roller 10 maxima has e and f. For precise control of the temperature distribution, the temperature sensor 19 is located at the level of the minimum d of the surface temperature in the middle of the roller and the other temperature sensor 20 is at the level of the maximum of the surface temperature of the heating roller 10 near one of the end faces 17 and 18, respectively. Due to the overlap of the coils 14, 15, 16, a uniform temperature profile is achieved at the transition points from the central zone to the peripheral zones.

Die Steuerung der Heizelemente 11, 13 durch die Temperaturfühler 19, 20 erfolgt in der Weise, dass sich eine Temperaturdifferenz Δü von 2 bis 10 °C zwischen der Mitte der Heizwalze 10 und den Randzonen a und c der Heizwalze einstellt. Diese Temperaturdifferenz stellt sich ein, sobald die beiden Heizelemente 11 und 13 beheizt werden.The heating elements 11, 13 are controlled by the temperature sensors 19, 20 in such a way that a temperature difference .DELTA.u of 2 to 10 ° C. occurs between the center of the heating roller 10 and the edge zones a and c of the heating roller. This temperature difference arises as soon as the two heating elements 11 and 13 are heated.

Die Grösse der Temperaturdifferenz A{J- wird in Abhängigkeit von dem Kopiermaterial festgelegt, wobei für Opakpapier im allgemeinen eine kleinere Temperaturdifferenz als für Transparentpapier gewählt wird.The size of the temperature difference A {J- is determined as a function of the copying material, a smaller temperature difference being generally chosen for opaque paper than for transparent paper.

Die Beheizung der beiden Heizelemente erfolgt derart, dass bei Formaten des Kopiermaterials von DIN-A4 und DIN-A3 zunächst nur das Heizelement 11 mit der Wendel 14 in der Mittelzone b der Heizwalze 10 eingeschaltet ist. Sobald die gemessene Temperaturdifferenz A{J- grösser als 2 bis 10 °C zwischen der Mittelzone b und den Randzonen a und c ist, wird durch die Steuerung 21 das Heizelement 13 mit den beiden Wendeln 15 und 16 automatisch zugeschaltet. Dadurch soll vermieden werden, dass die Temperaturdifferenz grösser als 10°C wird, da ansonsten die Wartezeiten zu gross werden, falls nach längerem Betrieb der Fixierstation zum Fixieren von DIN-A3- und DIN-A4-Formaten auf grössere Formate wie DIN-A2 und DIN-A1 umgeschaltet wird.The heating of the two heating elements takes place in such a way that in the case of formats of the copying material of A4 and A3, only the heating element 11 with the coil 14 in the central zone b of the heating roller 10 is initially switched on. As soon as the measured temperature difference A {J- is greater than 2 to 10 ° C. between the central zone b and the peripheral zones a and c, the heating element 13 with the two coils 15 and 16 is automatically switched on by the controller 21. This is supposed to miss that the temperature difference will be greater than 10 ° C, otherwise the waiting times will be too long, if after longer operation of the fuser for fixing DIN A3 and A4 formats to larger formats such as DIN A2 and DIN A1 is switched.

Werden von Anfang an grosse Formate wie DIN-A1 und DIN-A2 entwickelt, so werden beide Heizelemente 11 und 13 zur gleichen Zeit eingeschaltet.If large formats such as DIN-A1 and DIN-A2 are developed from the start, both heating elements 11 and 13 are switched on at the same time.

Mit der Steuerung der Oberflächentemperatur der Heizwalze 10 innerhalb von Temperaturzonen lassen sich die Probleme im Zusammenhang mit der Falten- und Wellenbildung, die vor allem bei grossformatigen DIN-A2- und DIN-A1-Kopien bei Verwendung von bekannten Fixiervorrichtungen mit herkömmlicher Temperaturregelung auftreten, lösen. Wird bei den bekannten Fixiervorrichtungen eine möglichst gleichförmige Temperatur über die Länge der Fixierwalze eingestellt, so kommt es zu unerwünschter Faltenbildung in der Mitte der Kopie, die, wie genaue Untersuchungen ergaben, dadurch entsteht, dass die Durchtrittsgeschwindigkeit im Walzenspalt in der Mitte der Walzenanordnung grösser als an den Rändern ist. Es werden dann die Randzonen zur Mitte des Kopiermaterials zusammengeschoben, und es bildet sich eine Längswelle aus, die beim Durchtritt durch den Walzenspalt zu einer Quetschfalte zusammengepresst wird. Die Faltenbildung tritt überwiegend im mittleren Bereich der zweiten Hälfte einer DIN-A1- bzw. DIN-A2-Kopie aus Transparentpapier auf. Ein weiteres Problem bei den herkömmlichen Fixiervorrichtungen, mit denen grossformatige Kopien erstellt werden sollen, ergibt sich aus der Duplizierung des Kopienbildes durch einen Doppelabdruck, bei dem ein zweites Bild nur wenige Zehntel Millimeter gegenüber dem ersten Bild versetzt, in der zweiten Hälfte einer DIN-A1- bzw. DIN-A2-Kopie, vorwiegend bei Opakpapier, auftritt. Eine mögliche Erklärung für diese Erscheinung ist darin zu sehen, dass sich in der Mitte des Kopiermaterials eine sogenannte Bugwelle ausbildet, wobei es zu einer vorzeitigen Berührung des Tonerbildes auf der Bugwelle mit der Heizwalze kommt, wodurch es zu einem Kaltoffset-Effekt kommt, der das zweite, gegenüber dem ersten Bild versetzte Bild, verursacht.By controlling the surface temperature of the heating roller 10 within temperature zones, the problems associated with the formation of wrinkles and waves, which occur especially with large-format DIN A2 and DIN A1 copies when using known fixing devices with conventional temperature control, can be solved . If, in the known fixing devices, a temperature that is as uniform as possible is set over the length of the fixing roller, undesirable wrinkles occur in the center of the copy, which, as detailed investigations have shown, result from the fact that the passage speed in the roller gap in the center of the roller arrangement is greater than is on the edges. The edge zones are then pushed together towards the center of the copying material, and a longitudinal shaft is formed, which is compressed into a pinch fold as it passes through the nip. The formation of wrinkles mainly occurs in the middle area of the second half of a DIN A1 or DIN A2 copy made of transparent paper. Another problem with the conventional fixing devices with which large-format copies are to be produced arises from the duplication of the copy image by means of a double impression, in which a second image is offset by only a few tenths of a millimeter compared to the first image, in the second half of a DIN A1 - or DIN A2 copy, mainly with opaque paper. A possible explanation for this phenomenon can be seen in the fact that a so-called bow wave forms in the middle of the copying material, whereby the toner image on the bow wave comes into premature contact with the heating roller, which leads to a cold offset effect, which causes this second image offset from the first image.

Um die Faltenbildung und die Duplizierung des Originalbildes zu ergründen, wurden zunächst sogenannte Schmalbahnpapiere in einer Klimakammer untersucht. Unter Schmalbahnpapieren sind solche Papiere zu verstehen, die längs zur Laufrichtung des Papierbandes auf Formate zugeschnitten sind. Aufgrund der Herstellung dieser Papiere schrumpfen diese bei Feuchtigkeitsentzug im wesentlichen nur in Querrichtung, jedoch kaum in Längsrichtung.To investigate the formation of wrinkles and the duplication of the original image, so-called narrow web papers were first examined in a climatic chamber. Narrow web papers are to be understood as papers that are cut to formats along the direction of the paper tape. Due to the production of these papers, they shrink only in the transverse direction when moisture is removed, but hardly in the longitudinal direction.

Die Masse, Beschaffenheit der Kopiermaterialien und die Umgebungsgrössen wie Temperatur, Luftfeuchtigkeit, Verweildauer in der Klimakammer sind nachstehend tabellarisch angeführt.

Figure imgb0001
The mass, nature of the copying materials and the environmental parameters such as temperature, air humidity and length of stay in the climatic chamber are listed in the table below.
Figure imgb0001

Wie die Tabellenwerte erkennen lassen, zeigen die Schmalbahnpapiere, ob nun Opak- oder Transparentpapiere, in Längsrichtung grosse Formstabilität, die maximale Schrumpfung bei Verminderung der relativen Luftfeuchtigkeit um 57% und bei einer Temperaturabnahme von 30 °C auf 20 °C beträgt, 2,8 mm bei einer mittleren Länge von 500 mm, während in Querrichtung die maximale Schrumpfung bis zu 15 mm bei einer mittleren Breite von 500 mm betragen kann.As can be seen from the table values, the narrow web papers, whether opaque or transparent papers, show great dimensional stability in the longitudinal direction, the maximum shrinkage when the relative humidity is reduced by 57% and the temperature drops from 30 ° C to 20 ° C, 2.8 mm with an average length of 500 mm, while in the transverse direction the maximum shrinkage can be up to 15 mm with an average width of 500 mm.

Bei Erhöhung der relativen Luftfeuchtigkeit tritt der umgekehrte Effekt auf, nämlich eine Ausdehnung bzw. eine Quellung in Querrichtung.When the relative humidity increases, the opposite effect occurs, namely an expansion or swelling in the transverse direction.

Der Tabelle ist zu entnehmen, dass Transparentpapier stärker als Opakpapier schrumpft bzw. bei einer Erhöhung der relativen Luftfeuchtigkeit sich ausdehnt, während Kunststoff-Folie als Kopiermaterial, wie beispielsweise Hostaphan@ sowohl in Quer- als auch in Längsrichtung weitgehend massstabil ist.The table shows that tracing paper shrinks more than opaque paper or expands when the relative humidity increases, while plastic film as copying material, such as Hostaphan @, is largely dimensionally stable in both the transverse and longitudinal directions.

Werden nun beispielsweise Opak- bzw. Transparentpapiere, die auf der Oberfläche das zu entwickelnde Tonerbild tragen, durch die Fixierstation transportiert, so wird in dieser den Papieren durch die Wärmeentwicklung der Heizelemente Feuchtigkeit entzogen, d.h. es kommt zu einer Schrumpfung der Papiere, vor allem in Querrichtung. Dadurch werden die Randzonen des Kopierpapiers in Richtung Mitte des Kopierblattes geschoben, und in der Mitte bildet sich daraufhin eine Längswelle im Kopierpapier aus. Durch den in der Mitte der Walzenanordnung auftretenden Papierstau ergibt sich eine Pressung der Walzen. Es muss eine grössere Menge Material im Vergleich zu den Rändern der Walzen durch die Pressstelle hindurchtransportiert werden, was nur möglich ist, wenn die Durchlaufgeschwindigkeit des Kopierpapiers in der Mitte im Vergleich zu den Rändern ansteigt, was jedoch andererseits zu der unerwünschten Faltenbildung, wie voranstehend erörtert wurde, führt. Um dieser zu begegnen, ist es erforderlich, die Durchlaufgeschwindigkeit an den Rändern der Walzenanordnung zu vergrössern, d.h. an die durch das Papierschrumpfen erhöhte Durchlaufgeschwindigkeit in der Walzenmitte anzugleichen. Dies geschieht durch die Ausbildung der Heizwalze 10, wie sie anhand der Zeichnungen erläutert wurde. Durch die Zonenregelung der Temperatur der Heizwalze besitzt diese in den Randzonen einen geringfügig grösseren Durchmesser, so dass die Walzenpressungen in den Randzonen und in der Mitte aneinander angeglichen sind und somit die Durchlaufgeschwindigkeit des Kopierpapiers über die gesamte Walzenbreite annähernd gleich gross ist.If, for example, opaque or transparent papers carrying the toner image to be developed are transported through the fusing station, moisture is removed from the papers in the fusing station, i.e. the papers shrink, especially in the transverse direction. As a result, the edge zones of the copy paper are pushed towards the center of the copy sheet, and a longitudinal wave then forms in the copy paper in the middle. The paper jam occurring in the middle of the roller arrangement results in the rollers being pressed. A larger amount of material has to be transported through the press site compared to the edges of the rollers, which is only possible if the throughput speed of the copy paper increases in the middle compared to the edges, but on the other hand leads to the undesirable wrinkling, as discussed above was leads. In order to counteract this, it is necessary to increase the throughput speed at the edges of the roller arrangement, i.e. to adapt to the throughput speed increased by the paper shrinking in the middle of the roll. This is done by the formation of the heating roller 10, as was explained with reference to the drawings. Due to the zone control of the temperature of the heating roller, it has a slightly larger diameter in the edge zones, so that the roller pressures in the edge zones and in the middle are aligned with each other and the throughput speed of the copy paper is approximately the same across the entire roller width.

Die Temperaturdifferenz Δδ zwischen der einzelnen Randzone und der Mitte der Walzenanordnung soll 10 °C nicht überschreiten, da anderenfalls die Walzenpressung in den Randzonen grösser als in der Mitte wird, so dass die Durchlaufgeschwindigkeit des Kopierpapiers an den Rändern höher als in der Mitte wird. Es kommt dann zu einer Duplizierung des Kopierbildes, deren Ursache die Anhäufung der langsamer transportierten Papierzonen in der Mitte zu der voranstehend erwähnten Bugwelle ist.The temperature difference Δδ between the individual edge zone and the center of the roller arrangement should not exceed 10 ° C, otherwise the roller pressure in the edge zones will be greater than in the middle, so that the throughput speed of the copy paper at the edges will be higher than in the middle. The copy image is then duplicated, the cause of which is the accumulation of the slower paper zones in the middle of the bow wave mentioned above.

Bei dem in Fig. 3 schematisch dargestellten, jedoch charakteristischen Temperaturverlauf über die Länge der Heizwalze 10 beträgt die Temperatur im Minimum d 180 °C, in den Maxima e auf f 193 °C und in den Randzonen der Heizwalze über den gesamten Randzonenbereich 186 °C. Die sich in den Randzonen einstellende konstante Temperatur ist die höchste Temperatur innerhalb der für die Fixierung wirksamen Temperaturzonen der Heizwalze, während die Temperaturmaxima e und f ausserhalb der Silikonbeschichtung und somit des für die Fixierung wirksamen Walzenbereichs liegen.In the case of the characteristic temperature profile shown schematically in FIG. 3 over the length of the heating roller 10, the temperature is at least d 180 ° C., in the maxima e to 193 ° C. and in the peripheral zones of the heating roller over the entire peripheral zone region 186 ° C. . The constant temperature which arises in the peripheral zones is the highest temperature within the temperature zones of the heating roller which are effective for fixing, while the temperature maxima e and f lie outside the silicone coating and thus the roller area which is effective for fixing.

Fig. 4 gibt einen Temperaturverlauf über die Heizwalzenlänge wieder, der nach längerem Betrieb der Fixierstation durch entsprechende Steuerung der Stromzufuhr zu den Heizelementen 11 und 13 eingestellt wird. Es zeigt sich nämlich, dass die Mittelzone b der Heizwalze bei längerem Betrieb stärker als die Randzonen a, c beansprucht wird, was zur Folge hat, dass der Durchmesser in der Mitte der Heizwalze um etwa 0,1 mm pro 10000 Kopien im Vergleich zu den Durchmessern der Randzonen a und c abnimmt. Eine denkbare Erklärung hierfür könnte ein stärkerer mechanischer Abrieb und/oder ein stärkerer Austrag von Silikonöl aus der Silikongummibeschichtung in der Mitte der Heizwalze sein. Dieser Vorgang erfordert eine Anpassung des Temperaturprofils in der Weise, dass die Temperatur der Mittelzone gegenüber derjenigen der Randzonen angehoben wird, um weiterhin einen gleichmässigen gegenseitigen Andruck der Walzen über ihre Gesamtlänge zu gewährleisten.Fig. 4 shows a temperature curve over the heating roller length, which is set after long operation of the fuser by appropriate control of the power supply to the heating elements 11 and 13. It can be seen that the central zone b of the heating roller is subjected to greater stress than the edge zones a, c during longer operation, with the result that the diameter in the center of the heating roller is increased by approximately 0.1 mm per 10,000 copies compared to the Diameters of the edge zones a and c decreases. A conceivable explanation for this could be a stronger mechanical abrasion and / or a greater discharge of silicone oil from the silicone rubber coating in the middle of the heating roller. This process requires an adjustment of the temperature profile in such a way that the temperature of the central zone is raised compared to that of the peripheral zones in order to continue to ensure a uniform mutual pressure of the rollers over their entire length.

Die charakteristische Temperatur im Maximum d' in der Mittelzone beträgt beispielsweise 182 °C, in den Maxima e' und f' etwa 181 °C und in den Randzonen im Mittel 175 °C bei dem Temperaturprofil nach Fig. 4.The characteristic temperature in the maximum d 'in the central zone is, for example, 182 ° C, in the maxima e' and f 'approximately 181 ° C and in the peripheral zones on average 175 ° C for the temperature profile according to FIG. 4.

Claims (13)

1. A fixing device for fixing a toner image on copying material, comprising a heating unit arranged transversely to the direction of the copying material passage and being suitable for different copying material formats, which heating unit has, in its middle zone, a central heating element, and, in both its edge zones, a subdivided heating element with one temperature sensor, each, adjoined to the central and the subdivided heating elements, the temperature sensors being connected to a control system for the supply of current to the heating element, characterized in that the heating unit is a heating roll (10), in the interior of which a central coil (14) as heating element (11) is located in the middle zone (b), and one coil (15,16), each, of a subdivided heating element (13) is located in the edge zones (a, c) respectively adjoining the left and right of the middle zone, that the central coil overlaps with each of the two coils (15,16) in each edge zone (a, c), that the current supply to the heating elements (11, 13) is so controlled that on the surface of the heating roll (10) there results a temperature distribution in the axial direction which exhibits an extreme value (d; d') in the middle zone and maxima (e, f; e', f') near the two end faces (17, 18) of the heating roll (10) and that one temperature sensor (19) is located opposite to the extreme value (d; d') of the temperature distribution in the middle of the roll and the other temperature sensor (20) is located opposite to the middle of one of the edge zones (a, c) of the heating roll (10).
2. A fixing device as claimed in claim 1, characterized in that the extreme value in the middle zone is a minimum (d).
3. A fixing device as claimed in claim 1, characterized in that the extreme value in the middle zone is a maximum (d').
4. A fixing device as claimed in claim 1, characterized in that the length of the coil (14) in the middle zone (b) is at least equal to the width of DIN-A3 format.
5. A fixing device as claimed in claim 1, characterized in that each coil (15, 16) in the edge zones (a, c) has a length of at least 150 mm.
6. A fixing device as claimed in claim 1, characterized in that the overlap between the coil (14) in the middle zone (b) and the coils (15, 16) in the edge zones (a, c) is up to 5 mm.
7. A fixing device as claimed in claim 1, characterized in that the control of the heating elements (11, 13) by the temperature sensors (19, 20) is effected in such a manner that a temperature difference Δϑ of 2 to 10 °C between the middle of the heating roll (10) and the edge zones (a, c) of the heating roll is set up as soon as both heating elements (11,13) are heated.
8. A fixing device as claimed in claim 5, characterized in that the magnitude of the temperature difference Δϑ is chosen in accordance with the particular copying material.
9. A fixing device as claimed in claim 1, characterized in that, in the case of DIN-A4 and DIN-A3 formats of the copying material, only the heating element (11) with the coil (14) in the middle zone (b) of the heating roll (10) is switched on.
10. A fixing device as claimed in claim 9, characterized in that the heating element (13) with the two coils (15, 16) in the edge zones (a, c) is also switched on as soon as the measured temperature difference Δû is greater than 2 to 10 °C.
11. A fixing device as claimed in claim 1, characterized in that, for DIN-A2 and DIN-A1 formats of the copying material, both heating elements (11, 13) are switched on.
12. A fixing device as claimed in claim 8, characterized in that a silicone rubber coating (25) of the heating roll (10) terminat es at a distance of 30 to 33 mm each of the end faces (17,18) of the heating roll (10) and that the maxima (e and f) of the temperature occur beyond the silicone rubber coating (25) of the heating roll (10).
EP84102432A 1983-03-16 1984-03-07 Roll fusing unit Expired EP0121772B1 (en)

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AT84102432T ATE23229T1 (en) 1983-03-16 1984-03-07 ROLLER FIXING DEVICE.

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DE19833309398 DE3309398A1 (en) 1983-03-16 1983-03-16 ROLLER FIXING DEVICE
DE3309398 1983-03-16

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Families Citing this family (67)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4693179A (en) * 1984-12-10 1987-09-15 Lockwood Technical, Inc. Temperature controlled rotary screen printing apparatus
JPH0652674B2 (en) * 1985-02-05 1994-07-06 ミノルタカメラ株式会社 Halogen heating element for heating device
US4684784A (en) * 1986-04-24 1987-08-04 Eastman Kodak Company Fuser temperature control
JPH079163Y2 (en) * 1986-12-16 1995-03-06 富士ゼロックス株式会社 Fixer controller for copier
JPH0727477Y2 (en) * 1987-07-03 1995-06-21 株式会社リコー Fixing temperature controller for heat roller fixing device in copier
US4994852A (en) * 1987-08-18 1991-02-19 Minolta Camera Kabushiki Kaisha Image forming apparatus having a malfunction detection device and power shutdown therefor
JPH0727471Y2 (en) * 1987-08-20 1995-06-21 キヤノン株式会社 Image forming device
US5035546A (en) * 1987-10-01 1991-07-30 Gte Valenite Corporation Radiused on-edge indexable cutting insert
US5329342A (en) * 1988-02-29 1994-07-12 Canon Kabushiki Kaisha Image fixing apparatus
US4825242A (en) * 1988-03-28 1989-04-25 Xerox Corporation Fusing apparatus control system
NL8802202A (en) * 1988-09-07 1990-04-02 Oce Nederland Bv METHOD AND APPARATUS FOR HEAT-FIXING A POWDER IMAGE ON A RECEIVER.
DE3941193A1 (en) * 1989-12-13 1991-07-04 Siemens Ag Heat radiator exchange appts. for heating rollers of fixing unit - uses central opening in bearing for insertion and removal of radiating module for electrophotographic copier or printer
JPH043454U (en) * 1990-04-20 1992-01-13
DE4244905C2 (en) * 1991-06-07 1998-01-08 Ricoh Kk Fixing unit for fixing image on recording sheet for image prodn. unit e.g. copier
US5300996A (en) * 1991-06-07 1994-04-05 Ricoh Company, Ltd. Fixing apparatus
DE69217436T2 (en) * 1991-09-24 1997-07-10 Canon Kk Image heater with multiple temperature detectors
US5189480A (en) * 1992-01-31 1993-02-23 Eastman Kodak Company Apparatus for fixing a toner image including eccentrically mounted pressure relieving means
US5241159A (en) * 1992-03-11 1993-08-31 Eastman Kodak Company Multi-zone heating for a fuser roller
DE69332233T2 (en) * 1992-03-31 2003-04-17 Canon Kk Image heater with control of the actuation of several heating elements
US5350896A (en) * 1993-11-22 1994-09-27 Xerox Corporation Dual lamp fuser
JPH07160137A (en) * 1993-12-01 1995-06-23 Hitachi Ltd Fixing device, fixing method and recording device
US5580478A (en) * 1994-05-09 1996-12-03 Minnesota Mining And Manufacturing Company Apparatus for controlling the temperature of and a moveable, electrically heated object using two way on axis optical communication
US5497218A (en) * 1994-08-24 1996-03-05 Xerox Corporation Three point thermistor temperature set up
US5750961A (en) * 1994-10-19 1998-05-12 Imation Corp. Method for controlling the actual temperature of an intermittently operated heating means, particularly of an electric heating means
JPH08137306A (en) * 1994-11-10 1996-05-31 Minolta Co Ltd Electromagnetic induction heating system fixing device
JPH09197875A (en) * 1996-01-16 1997-07-31 Minolta Co Ltd Fixing device and image forming device
US5787321A (en) * 1996-02-09 1998-07-28 Asahi Kogaku Kogyo Kabushiki Kaisha Temperature controlling device for fixing unit
US5760375A (en) * 1996-10-08 1998-06-02 Hall; Timothy G. Heated rollers
JP3743543B2 (en) * 1996-10-25 2006-02-08 リコープリンティングシステムズ株式会社 Fixing device for electrophotographic apparatus
JP3372803B2 (en) * 1996-12-20 2003-02-04 キヤノン株式会社 Image forming device
JPH10198248A (en) * 1997-01-08 1998-07-31 Fujitsu Ltd Image forming device
US5754917A (en) * 1997-04-11 1998-05-19 Xerox Corporation High temperature safety system for a fusing subsystem module for an electrophotographic printer
JPH1124462A (en) * 1997-05-09 1999-01-29 Hitachi Koki Co Ltd Toner image heating device
US6011939A (en) * 1998-07-30 2000-01-04 Hewlett-Packard Company Sensing print media size to temperature control a multi-heating element fixing device
FR2784759B1 (en) * 1998-10-16 2002-08-02 Sagem PRINTING POWDER FIXING OVEN
US6188854B1 (en) * 1999-11-09 2001-02-13 Tommy C. Coleman Non-contact thermal temperature controller
JP3647290B2 (en) * 1998-11-30 2005-05-11 キヤノン株式会社 Image heating apparatus and image forming apparatus
JP2000250340A (en) * 1999-02-26 2000-09-14 Canon Inc Fixing device and image forming device
US6118969A (en) * 1999-09-10 2000-09-12 Lexmark International, Inc. Electrophotographic fuser roll having distributed thermal mass
JP2002055423A (en) * 2000-06-02 2002-02-20 Fuji Photo Film Co Ltd Temperature control method and device
JP2002062758A (en) 2000-08-22 2002-02-28 Canon Inc Heating device and image forming apparatus provided with the same
US6643476B1 (en) * 2000-10-31 2003-11-04 Kabushiki Kaisha Toshiba Image forming apparatus with accurate temperature control for various media having different thickness
US6353718B1 (en) 2000-11-17 2002-03-05 Xerox Corporation Xerographic fusing apparatus with multiple heating elements
JP4659204B2 (en) * 2000-11-24 2011-03-30 キヤノン株式会社 Fixing apparatus and image forming apparatus provided with the fixing apparatus
JP4781523B2 (en) * 2000-12-06 2011-09-28 株式会社東芝 Fixing control method and apparatus therefor
JP3720725B2 (en) * 2001-04-17 2005-11-30 キヤノン株式会社 Image forming apparatus
JP2002351240A (en) * 2001-05-28 2002-12-06 Toshiba Tec Corp Fixing device
JP3826008B2 (en) 2001-10-15 2006-09-27 キヤノン株式会社 Image heating device
US6816688B2 (en) * 2002-01-02 2004-11-09 Kabushiki Kaisha Toshiba Image forming apparatus
JP3800118B2 (en) * 2002-03-27 2006-07-26 ブラザー工業株式会社 Thermal fixing device and image forming apparatus
US6763206B2 (en) * 2002-05-14 2004-07-13 Kabushiki Kaisha Toshiba Image forming apparatus with an induction heating fixing unit for shortening warm up time
JP2004012804A (en) * 2002-06-06 2004-01-15 Toshiba Tec Corp Heating device using induction heating, and fixing device
JP2004013016A (en) * 2002-06-10 2004-01-15 Toshiba Tec Corp Fixing device and image forming apparatus
DE10227953B4 (en) * 2002-06-22 2005-04-07 Schott Glas print Setup
US7406286B2 (en) * 2003-02-14 2008-07-29 Seiko Epson Corporation Fixing device and image forming apparatus including a heating roller with multiple heaters
US7031626B1 (en) * 2003-03-28 2006-04-18 Eastman Kodak Company Fixing roller system and method
US6882804B2 (en) * 2003-05-13 2005-04-19 Hewlett-Packard Development Company, Lp. Fuser and fusing roller useable in a printing process, laser printer, and method of printing
KR100619011B1 (en) * 2003-12-15 2006-08-31 삼성전자주식회사 Fusing roller and electro-photographic image forming apparatus having the same
US20050175367A1 (en) * 2004-02-11 2005-08-11 Kabushiki Kaisha Toshiba Fixing device, image forming apparatus, and fixing method
KR100659270B1 (en) * 2005-11-07 2006-12-20 삼성전자주식회사 Heating roller assembly for image forming apparatus
US8172738B2 (en) * 2006-01-18 2012-05-08 3M Innovative Properties Company Dead-shaft roller with aerostatic rotary union
JP2007212579A (en) * 2006-02-07 2007-08-23 Kyocera Mita Corp Fixing device
US7228082B1 (en) * 2006-08-24 2007-06-05 Xerox Corporation Belt fuser having a multi-tap heating element
US7738806B2 (en) * 2008-06-25 2010-06-15 Xerox Corporation Fuser assemblies, xerographic apparatuses and methods of fusing toner on media
JP2012189722A (en) 2011-03-09 2012-10-04 Ricoh Co Ltd Fixing device, image forming device and image forming method
US20140050497A1 (en) * 2012-08-15 2014-02-20 Xerox Corporation Independent control of pressure roller heating elements to provide gloss uniformity
JP6311226B2 (en) * 2013-06-25 2018-04-18 株式会社リコー Fixing apparatus and image forming apparatus

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1187569A (en) * 1966-04-28 1970-04-08 Arlside Ltd Reprographic Apparatus
FR1492748A (en) * 1966-09-16 1967-08-18 Unilever Nv Improved device for heat fixing images formed by powdered ink on a support
JPS4923215B1 (en) * 1968-05-24 1974-06-14
US3498596A (en) * 1968-05-24 1970-03-03 Xerox Corp Heat fixing apparatus for fusible material
US3539161A (en) * 1968-05-24 1970-11-10 Xerox Corp Heat fixing apparatus for fusible material
JPS5350444Y2 (en) * 1972-08-23 1978-12-02
JPS50160042A (en) * 1974-06-15 1975-12-25
JPS5217028A (en) * 1975-07-30 1977-02-08 Konishiroku Photo Ind Co Ltd Fixing device for the copying machine
US4232959A (en) * 1978-09-05 1980-11-11 Eastman Kodak Company Toner image fusing apparatus
JPS5581378A (en) * 1978-12-15 1980-06-19 Konishiroku Photo Ind Co Ltd Heat roller fixing device
JPS59829B2 (en) * 1979-02-24 1984-01-09 コニカ株式会社 Heat roller type fixing device for electrophotographic copying equipment
US4253392A (en) * 1979-04-09 1981-03-03 International Business Machines Corporation Hollow fuser roll with variable taper
JPS56119160A (en) * 1980-02-25 1981-09-18 Fuji Xerox Co Ltd Heating fixation roll
JPS5753773A (en) * 1980-09-16 1982-03-30 Ricoh Co Ltd Heat-roller fixing device
JPS5763570A (en) * 1980-10-03 1982-04-17 Canon Inc Fixing device
JPS57158866A (en) * 1981-03-27 1982-09-30 Canon Inc Thermal fixing device for toner image
JPS57211180A (en) * 1981-06-22 1982-12-24 Minolta Camera Co Ltd Temperature controlling method for heat roller fixing device
JPS584167A (en) * 1981-06-30 1983-01-11 Sharp Corp Heat fixing roller

Also Published As

Publication number Publication date
ATE23229T1 (en) 1986-11-15
JPS59177581A (en) 1984-10-08
EP0121772A1 (en) 1984-10-17
CA1220509A (en) 1987-04-14
DE3461123D1 (en) 1986-12-04
DE3309398A1 (en) 1984-09-20
US4585325A (en) 1986-04-29

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