Abstract: A fixing unit (14) of an image forming apparatus (1) includes a heating member (48) having a first area where a sheet does not come into contact with the heating member (48) and a second area where the sheet comes into contact with the heating member (48). The fixing unit (14) further includes a coil (52) forming a magnetic field, cores (54,56) forming a magnetic path near the coil (52), a nonmagnetic magnetism adjusting member (90) arranged on the magnetic path and having a closed frame, and a switcher (58,60) capable of switching the magnetism adjusting member (90) between a first state where the magnetism adjusting member (90) generates an induction current resulting from the magnetic field to shield the magnetism in the first area, and a second state where the magnetism adjusting member (90) generates no induction current and the magnetism is not shielded in the first area.

Abstract: A fixing device (30) has a fixing member (30) adapted to be heated by induction heating based on a magnetic field from an induction coil (34). A pressing member (40) is disposed in contact with the fixing member (30) to define therebetween a nip zone (N) for passing a sheet (P) therethrough. The fixing member includes a heating layer (32). The heating layer (32) has a temperature-sensitive metal layer (321) and formed on the side of the induction coil (34), and a nonmagnetic metal layer (322) laminated onto the temperature-sensitive metal layer (321). The nonmagnetic metal layer is made of aluminum as a metal having a low specific resistance, and formed to have a thickness (50 ?m) allowing the nonmagnetic metal layer to be substantially free from a temperature rise due to the induction heating.

Abstract: A fixing apparatus used in an image forming apparatus has a fixing member for fixing toner on paper and a pressure member making contact therewith to form in between a nip through which paper is passed. The fixing member has a support member formed of a ferromagnetic material and a heating layer formed adjacent thereto in the form of a thin layer of a non-magnetic, electrically conductive material. When a high-frequency electric current is passed through an exciting coil that is combined with the fixing member, the fixing member produces a high-frequency magnetic field, thereby produces induced eddy currents in the heating layer of the fixing member, thereby produces Joule's heat in the heating layer, and thereby heats the fixing member. A leaking magnetic flux is absorbed by the support member of the ferromagnetic member, and thus has reduced influence on metal parts located around the fixing apparatus.

Abstract: A fixing device is provided with a fixing member for thermally fixing a transferred toner image to a transfer material, and a pressing member held in contact with the fixing member to form a nip portion where the transfer material is caused to pass through, wherein the fixing member includes a nonmagnetic metal layer made of nonmagnetic metal, a temperature-sensitive metal layer made of temperature-sensitive metal, and an induction coil for induction heating by supplying magnetism toward the nonmagnetic metal layer and the temperature-sensitive metal layer. The thickness of the nonmagnetic metal layer is set such that an amount of heat produced by the fixing member is larger than an amount of heat evolved singly by the temperature-sensitive metal layer.

Abstract: An image forming unit of a copier is provided with an image fixing unit (fixing device) adopting an induction heating method. A heating roller of this image fixing unit includes a heat producing layer made of a temperature-sensitive magnetic material whose permeability changes with temperature, and a supporting layer disposed adjacent to the heat producing layer and made of a nonmagnetic and electrically conductive material. The heat producing layer has a width substantially equal to a passing area (about 294 mm) for sheets along a direction of an axis of rotation of the heating roller and smaller than a width (about 310 mm) of an induction heating coil.

Abstract: A fixing apparatus used in an image forming apparatus has a fixing member for fixing toner on paper and a pressure member making contact therewith to form in between a nip through which paper is passed. The fixing member has a support member formed of a ferromagnetic material and a heating layer formed adjacent thereto in the form of a thin layer of a non-magnetic, electrically conductive material. When a high-frequency electric current is passed through an exciting coil that is combined with the fixing member, the fixing member produces a high-frequency magnetic field, thereby produces induced eddy currents in the heating layer of the fixing member, thereby produces Joule's heat in the heating layer, and thereby heats the fixing member. A leaking magnetic flux is absorbed by the support member of the ferromagnetic member, and thus has reduced influence on metal parts located around the fixing apparatus.

Abstract: A fixing device includes a heated body of a hollow cylindrical shape that is made of a conductive material and driven to rotate about an axis center, and a coil that heats the heated body by means of induction heating. The coil is formed of plural coil elements divided in an axial direction of the coil parallel to a rotational axis direction of the heated body, and the coil elements are aligned in such a manner that directions of magnetic fields of adjacent coil elements are opposite to each other. The heated body is set stationary in the rotational axis direction and the coil is reciprocally driven in the axial direction.

Abstract: A fixing device has a heating roller with a heat source therein. A power supply operates the heat source for heating a transfer material and fixing a toner image thereon. A pressure roller is spaced from the heating roller and a facing member faces the heating roller. An endless fixing belt is mounted on the facing member and the heating roller and contacts the pressure roller to form a nip. A temperature detector faces the outer surface of the fixing belt for detecting the surface temperature thereof. An excessive temperature preventer faces part of the outer surface of the heating roller where the fixing belt is not mounted for detecting the surface temperature of the heating roller and cutting off the power supply to the heat source when the surface temperature rises above a preset temperature.

Abstract: A fixing apparatus used in an image forming apparatus has a fixing member for fixing toner on paper and a pressure member making contact therewith to form in between a nip through which paper is passed. The fixing member has a support member formed of a ferromagnetic material and a heating layer formed adjacent thereto in the form of a thin layer of a non-magnetic, electrically conductive material. When a high-frequency electric current is passed through an exciting coil that is combined with the fixing member, the fixing member produces a high-frequency magnetic field, thereby produces induced eddy currents in the heating layer of the fixing member, thereby produces Joule's heat in the heating layer, and thereby heats the fixing member. A leaking magnetic flux is absorbed by the support member of the ferromagnetic member, and thus has reduced influence on metal parts located around the fixing apparatus.

Abstract: A fixing device (30) has a fixing member (30) adapted to be heated by induction heating based on a magnetic field from an induction coil (34). A pressing member (40) is disposed in contact with the fixing member (30) to define therebetween a nip zone (N) for passing a sheet (P) therethrough. The fixing member includes a heating layer (32). The heating layer (32) has a temperature-sensitive metal layer (321) formed on the side of the induction coil (34), and a nonmagnetic-metal layer (322) laminated onto the temperature-sensitive metal layer (321). The nonmagnetic metal layer (321) is made of a metal (copper (Cu)) having a specific resistance less than that of aluminum, and formed to have a thickness (30 ?m) allowing the nonmagnetic metal layer to be substantially free from a temperature rise due to the induction heating.

Abstract: An image forming unit (40) of a copier (1) is provided with an image fixing unit (fixing device) (47) adopting an induction heating method. A heating roller (47a) of this image fixing unit (47) includes a heat producing layer (47d) made of a temperature-sensitive magnetic material whose permeability changes with temperature, and a supporting layer (47e) disposed adjacent to the heat producing layer (47d) and made of a nonmagnetic and electrically conductive material. The heat producing layer (47d) has a width substantially equal to a passing area (L1) (about 294 mm) for (A3) sheets along a direction of an axis of rotation of the heating roller (47a) and smaller than a width (L3) (about 310 mm) of an induction heating coil (47c).

Abstract: A fixing device is provided with a fixing member for thermally fixing a transferred toner image to a transfer material, and a pressing member held in contact with the fixing member to form a nip portion where the transfer material is caused to pass through, wherein the fixing member includes a nonmagnetic metal layer made of nonmagnetic metal, a temperature-sensitive metal layer made of temperature-sensitive metal, and an induction coil for induction heating by supplying magnetism toward the nonmagnetic metal layer and the temperature-sensitive metal layer. The thickness of the nonmagnetic metal layer is set such that an amount of heat produced by the fixing member is larger than an amount of heat evolved singly by the temperature-sensitive metal layer.

Abstract: A fixing device (30) has a fixing member (30) adapted to be heated by induction heating based on a magnetic field from an induction coil (34). A pressing member (40) is disposed in contact with the fixing member (30) to define therebetween a nip zone (N) for passing a sheet (P) therethrough. The fixing member includes a heating layer (32). The heating layer (32) has a temperature-sensitive metal layer (321) and formed on the side of the induction coil (34), and a nonmagnetic metal layer (322) laminated onto the temperature-sensitive metal layer (321). The nonmagnetic metal layer is made of aluminum as a metal having a low specific resistance, and formed to have a thickness (50 ?m) allowing the nonmagnetic metal layer to be substantially free from a temperature rise due to the induction heating.

Abstract: A fixing apparatus used in an image forming apparatus has a fixing member for fixing toner on paper and a pressure member making contact therewith to form in between a nip through which paper is passed. The fixing member has a support member formed of a ferromagnetic material and a heating layer formed adjacent thereto in the form of a thin layer of a non-magnetic, electrically conductive material. When a high-frequency electric current is passed through an exciting coil that is combined with the fixing member, the fixing member produces a high-frequency magnetic field, thereby produces induced eddy currents in the heating layer of the fixing member, thereby produces Joule's heat in the heating layer, and thereby heats the fixing member. A leaking magnetic flux is absorbed by the support member of the ferromagnetic member, and thus has reduced influence on metal parts located around the fixing apparatus.

Abstract: An image forming apparatus which includes a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: An image forming apparatus comprising: a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: A device for cleaning a transfer belt of an image-forming machine in which the transfer belt is wound around a drive roller and a driven roller that are disposed at a predetermined distance, in parallel with each other and is positioned opposite a photosensitive material drum in a transfer zone. A fur brush which has an electrically conducting property is rotated in contact with the surface of the transfer belt. A bias voltage is applied to the fur brush, the bias voltage having a polarity the same as the polarity for electrically charging the toner of a toner image formed on the photosensitive material drum. An opposed electrode is disposed opposite the fur brush and in contact with the back surface of the transfer belt.

Abstract: This invention relates to an image forming apparatus with a transfer unit for transferring toner electrically to an electrostatic latent image formed on a photoreceptor onto a copy sheet. The image forming apparatus has a transfer electrode charge supply means for supplying electric charges to a transfer electrode provided in the transfer unit to electrically attract the toner onto the copy sheet and control means for controlling the quantity of electric charges to be supplied to the photoreceptor via the transfer electrode from the transfer electrode charge supply means based on a photoreceptor inflow current flowing to the photoreceptor through the charge send/receive means and on a photoreceptor outflow current flowing out from the photoreceptor through a ground wire connecting the photoreceptor and the ground. The charge send/receive means, other than the transfer unit, sends and receives electric charges to and from the photoreceptor.

Abstract: A multi-directional driving mechanism includes a moving plate supported rotatably on a supporting shaft and having an input portion and a plurality of output portions, a solenoid coupled to the input portion of the moving plate for causing the moving plate to pivot through a predetermined angle, and a plurality of coupling members each having one end coupled to the plurality of output portions provided on the moving plate. A transfer device for an image forming machine has contacting/separating mechanisms for moving a transfer belt unit, a moving mechanism for moving a cleaning blade, and the multi-directional driving mechanism, the other end each of the plurality of coupling members of the multi-directional driving mechanism being coupled to the contacting/separating mechanisms or the moving mechanism.

Abstract: A transfer device for an image forming machine has a belt unit including a driving roller, a driven roller disposed at a distance from the driving roller, a transfer belt looped between the driving roller and the driven roller, and a transfer roller disposed opposite an image bearing member with the transfer belt interposed therebetween; a contacting/separating device for moving the belt unit between a transfer position and a non-transfer position; and a voltage source for applying a predetermined voltage onto the transfer roller. The transfer roller is disposed apart from the transfer belt, and when the belt unit is brought to the transfer position by the contacting/separating device, the transfer roller presses the transfer belt against the image bearing member. Another embodiment includes a cleaning blade disposed apart from the transfer belt, and which in the transfer position contacts the transfer belt.