Abstract: An image heating apparatus includes magnetic flux generating means for generating a magnetic flux; an image heating member for generating heat by eddy current produced by the magnetic flux generated by the magnetic flux generating means and for heating an image on a recording material fed thereto; a diverting member for diverting the eddy current produced in the image heating member by contacting at least a part, with respect to a widthwise direction perpendicular to a feeding direction of the recording material, of the image heating member to establish electrical connection with the image heating member; and driving means for contacting and spacing the diverting member relative to the image heating member.

Abstract: A fusing device for fusing a predetermined toner image on paper, and which controls the heating range of a fusing unit by inputting an eddy current generated by a transformer to a terminal corresponding to the size of paper selected from a plurality of terminals of the fusing unit. The fusing device includes a power supply unit to which a predetermined alternating current is input and which generates an induced current in response to the input alternating current, a fusing unit being resistance-heated and induction-heated by the induced current and fusing the toner image on the paper using the generated heat, and a controller for controlling the induced current supplied to the fusing unit according to the size of the paper.

Abstract: An image heating apparatus includes a plurality of heater element groups each having a plurality of heater elements. The heater elements are arranged along a direction intersecting an advancing direction of a recording material, and generate heat upon energization to heat a toner image on the recording material. A detecting mechanism is provided for detecting an abnormal state of the heater groups.

Abstract: A fixing control section of a fixing apparatus according to the present invention includes an end section priority temperature control mode. In the end section priority temperature control mode, the fixing control section temporarily turns off a main heater heating a center section of a fixing roller among a plurarity of heaters disposed inside the fixing roller in a case where a surface temperature of the end section of the fixing roller has reached a preset upper-limit fixing temperature, even if the surface temperature of the center section of the fixing roller is lower than a preset fixing temperature. As a result, destruction of the fixing roller can be prevented by a simple arrangement in the fixing apparatus which includes a plurarity of the heaters disposed inside the fixing roller.

Abstract: Provided is a printing device comprising a hot roller having an inside surface and an outside surface. A heating element is present within the hot roller. The inside surface has a first region, wherein the first region is coated with a first type of material. The inside surface has a second region, wherein the second region is coated with the first type of material, and wherein second region is of a different dimension than the first region. The inside surface has a third region, wherein the third region is coated with a second type of material.

Abstract: The heating apparatus of a surface-heating type, includes a rotary member, an opposing member that forms a nip with respect to the rotary member, and a heating member for heating a portion of a rotary member surface other than the nip, in which temperature used for heating the rotary member by the heating member is controlled, and a heating material inserted in the nip to be nipped and conveyed therein is heated using heat of the rotary member. Accordingly, after insertion of the heating material in the nip starts, control temperature of the heating member is increased before the rotary member rotates by one revolution, thereby preventing an uneven heating phenomenon of the heating material in the first revolution and the second revolution or later, and preventing uneven gloss due to the uneven heating phenomenon in the fixing apparatus.

Abstract: An embodiment of a fixing apparatus according to the present invention is a fixing apparatus provided with a roller for fixing and a plurality of heat sources that heat a surface of the roller, in which a surface temperature of the roller is detected and controlled at a prescribed temperature while a sheet of recording paper is subjected to pressure and heat by the roller to fix a developer onto the sheet of recording paper, comprising: a plurality of temperature detection means for detecting the surface temperature of the roller, wherein at least one of the temperature detection means is arranged in a position of the roller that does not overlap any of the heat sources when viewed from a peripheral surface side of the roller, or is arranged in a position away from a region of the roller to be controlled at the prescribed temperature.

Abstract: A high precision-heat fusing device is provided for heating unfused toner images in an electrostatographic reproducing machine. The high precision-heating and fusing apparatus includes (a) an endless rotatable shell defining an interior and having an exterior surface, a first end, a second end, and an axis for rotation; (b) at least six heating elements each having an end-to-end length and being selectively activatable, and arranged end-to-end in series and parallel to the axis of rotation; (c) at least six temperature sensors for sensing a temperature of the exterior surface at axially spaced apart points; and (d) a controller connected to the at least six heating elements and to the at least six temperature sensors for precisely sensing and controlling the temperature of the exterior surface at each of the axially spaced apart points.

Abstract: A fixing member having an outer peripheral surface brought in pressure contact with a sheet, an induction coil along the member, and a high frequency power source section that heats the heat generating layer of the fixing member by supplying an alternating current to the induction coil. A magnetic flux regulating section that restricts the generation of heat in a specified region of the fixing member in the widthwise direction of the sheet is provided. Image regions occupied by the image to be fixed are detected in the widthwise direction of the sheet. Control of specifying the region in which the generation of heat should be restricted for the magnetic flux regulating section is executed so that only regions corresponding to the image regions of the fixing member are substantially heated in the widthwise direction of the sheet, sheet-by-sheet according to the result of detection.

Abstract: A fusing device (23) has heat reflectors (238) and (239) positioned in consideration of the fact that convective heat loss from respective outer surfaces of the heat reflectors (238) and (239) depends on orientation of the outer surfaces. More specifically, each of the heat reflectors (238) and (239) are positioned so as to have a convective heat transfer coefficient ? of up to 0.9. The convective heat transfer coefficient ? is given by the following expression: ?=(Su+0.77Sh+0.54Sd)/(Su+Sh+Sd), were Su is a projected area of an outer surface of each of the heat reflectors on an upper horizontal plane, Sh is a projected area of the same on a vertical plane, and Sd is a projected area of the same on a lower horizontal plane.

Abstract: An image heating apparatus has a coil for generating magnetic flux, a rotatable heat generation member which generates heat by magnetic flux, a temperature detecting member for detecting a temperature of the heat generation member, an energization controller portion for controlling energization to the coil on the basis of an output of the temperature detecting member, a first magnetic flux shielding portion for blocking, in a first magnetic flux adjustment position, the magnetic flux directed toward a central portion of heat generation member, while permitting the magnetic flux directed to an end portion, and a second magnetic flux shielding portion for blocking, in a second magnetic flux adjustment position, the magnetic flux directed toward an end portion of the heat generation member, a moving unit for moving the first magnetic flux shielding portion and the second magnetic flux shielding portion, and a recovery operation controller portion for retracting the second magnetic flux shielding portion from the

Abstract: The contact rate between a heater 1 and a heater holder 2 is made higher at both ends in the longitudinal direction of the heater than at the center. Alternatively, the per-unit-length volume of the heater holder 2 in the longitudinal direction is made larger at the both ends in the longitudinal direction of the heater. In this configuration, the heat generated by the heater can easily escape into the heater holder side at the both ends but cannot easily escape into the heater holder side at the center. Although the per-unit-length heat amount in the longitudinal direction of the heater may be even, it is also possible to set the heat amount distribution in such a way that the heat amount at the both ends is larger than that at the center.

Abstract: An image forming apparatus, wherein a heating member heats a toner image formed on a sheet by an image forming portion, including: a first detector detecting a temperature of a first area of a contact area, which is contactable with the sheet, of the heating member, when a set width of the sheet is a predetermined width; a controller for controlling the heating member based on the output of the first detector; a second detector detecting a temperature of a second area outside of the first area; a cooler cooling the second area based on the output of the second detector; a third detector detecting a temperature of a third area on an end side in the width direction within the contact area; and a stopper stopping the image heating operation based on the output of the third detector.

Abstract: In an image heating apparatus including a rotatable heating roller to heat an image on a recording material at a nip part, and a cooling unit to cool the rotatable heating roller, the cooling unit includes a pipe that forms a cooling loop for circulating cooling fluid, and a heat transmission member provided slidably and rotatably around the pipe.

Abstract: The image heating apparatus includes a flexible sleeve including a stainless base layer; a heater being in contact with an inner circumferential surface of the flexible sleeve; and an elastic roller being in contact with an outer circumferential surface of the flexible sleeve and forming a nip portion with the heater, in which: a recording material bearing an image is heated while being pinched and conveyed at the nip portion; and the stainless base layer has an outer diameter of 18 mm to 24 mm and a thickness of 25 ?m to 30 ?m, and includes an outer circumferential surface being subjected to a blasting process. Bu the present invention, an image heating apparatus is capable of ensuring durability and a flexible sleeve used for the image heating apparatus.

Abstract: In an image forming apparatus having a fixing rotor (22) that is driven to rotate and fixes an image by heating a recording paper while conveying the paper pressurized against the rotor, an excitation coil (24) that is provided extending in an axial direction along the fixing rotor (22) and causes induction heating by applying an alternating magnetic field to the fixing rotor (22), and a demagnetizing coil (25) that is provided superposed on an end of the excitation coil (24) and is able to partially diminish a magnetic flux generated by the excitation coil (24), by making the shape of the portion that belongs to the demagnetizing coil (25) and overlaps the excitation coil (24) has an asymmetrical shape have no axis of symmetry in the direction in which the recording paper is conveyed, a trouble due to overheating and defective fixing due to a shortage in the generation of heat can be reduced even when a plurality of kinds of recording papers of slightly different sizes are used.

Abstract: A fixing unit thermally fixes a toner on a recording medium by a fixing member having a plurality of internal heaters and an outer peripheral surface, and a temperature sensor detects a surface temperature of the fixing member at a temperature detecting position. At least one first heater, of the heaters, receives power from a first power supply, and remaining second heaters receive power from a second power supply. One of the second heaters closest to the temperature detecting position is the same distance from the temperature detecting position as or is closer to the temperature detecting position than a first heater which is closest to the temperature detecting position.

Abstract: A fixing device includes: a fixing roller; a center temperature detection unit including a protective member, the center temperature detection unit contacts the fixing roller in an axial center of the fixing roller and detects a temperature of the center section; an end temperature detection unit that contacts the fixing roller at an end portion of the fixing roller outside of a maximum print area of the recording medium and detects a temperature of the end section; and a control unit that controls heating of the fixing roller performed by the heating unit so that the heating is stopped when the value detected by the center temperature detection unit has exceeded a first upper limit value and when the value detected by the end temperature detection unit has exceeded a second upper limit value, the first upper limit value being lower than the second upper limit value.

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 device for fixing an image formed on a recording material includes first and second rotary members having a nip part therebetween, a heating part that heats the first rotary member, a center portion temperature detecting unit that detects a temperature of a center portion of the first rotary member, and an end portion temperature detecting unit that detects a temperature of an end portion of the first rotary member. When recording materials each having a relatively large width consecutively pass through the nip part, a control unit controls a heating amount of a full width heating member based on the temperature detected by the center portion temperature detecting unit, and when recording materials each having a relatively small width consecutively pass through the nip part, the control unit controls the heating amount of the full width heating member based on the temperature detected by the end portion temperature detecting unit.

Abstract: A fixing device including a magnetic field generating device to generate a magnetic field, a fixing member to heat a recording material by heat generated in a first recording material passing area having a first width on the fixing member by electromagnetic induction heat generation by the magnetic field formed by the magnetic field generating device, a pressing member to form a nip portion where the pressing member and the fixing member press against each other to fix an unfixed image on the recording material, and at least one radiation heating device configured to heat a second recording material passing area having a second width.

Abstract: In a fixing apparatus of the present invention, an end section fixing control temperature changing section selects an end section fixing control temperature in accordance with the number of paper sheets that have been processed in one continuous printing process. A sub-heater on/off determining section turns on or off a sub-heater in accordance with a temperature detected by an end section temperature sensor and the end section fixing control temperature selected by the end section fixing control temperature changing section. This prevents the occurrence of fixing failure even in continuous printing with respect to large-size paper sheets in an arrangement in which a temperature sensor is disposed outside a maximum-size sheet passing region at an end section of a fixing roller and controls energization of a heater which is disposed corresponding to the end section of the fixing roller in accordance with a temperature detected by the temperature sensor.

Abstract: A fixing control section of a fixing apparatus according to the present invention includes an end section priority temperature control mode. In the end section priority temperature control mode, the fixing control section temporarily turns off a main heater heating a center section of a fixing roller among a plurarity of heaters disposed inside the fixing roller in a case where a surface temperature of the end section of the fixing roller has reached a preset upper-limit fixing temperature, even if the surface temperature of the center section of the fixing roller is lower than a preset fixing temperature. As a result, destruction of the fixing roller can be prevented by a simple arrangement in the fixing apparatus which includes a plurarity of the heaters disposed inside the fixing roller.

Abstract: A fixing device includes a fixing section, a sheet-width detector, a heating-width changing mechanism, a mixed feeding detector, and a controller. The fixing section includes at least a fixing member that fixes a toner image on a recording medium upon application of heat thereto. The sheet-width detector detects a width of the recording medium and outputs a sheet-width signal. The heat-width changing mechanism changes a heating width of the fixing member. The mixed feeding detector detects whether or not mixed feeding of a plurality of sheets of the recording medium having different widths is performed during a successive sheet feeding, and outputs a mixed feeding signal. The controller controls the heating-width changing mechanism to control the heating width based on the sheet-width signal and the mixed feeding signal.

Abstract: A fusing assembly includes (a) a first member having a first edge, a second edge and an end-to-end axis; (b) a second member having a fusing surface forming a fusing nip with the first member, and the fusing nip being located between the first edge and the second edge of each of the first member and the second member; (c) a heating member extending along the end-to-end axis for heating at least one of the first member and the second member to an image marking material fusing temperature; and (d) a temperature equalizing device for equalizing a temperature of the at least one of the first member and the second member, the temperature equalizing device including plural heat conductors, each heat conductor of the plural heat conductors including a first end and a second end, a body portion between the first end and the second end, the body portion being spaced from and out of contact with the fusing surface of the second member with only the first end and the second end discretely contacting the fusing surface,

Abstract: An image forming apparatus provided with a fixing unit, the fixing unit comprising: a fixing member having a heating member therein; a pressing member that presses against the fixing member, wherein an image supporting material carrying a toner image is grasped and conveyed by a nipping portion formed between the fixing member and the pressing member and the toner image is fixed by applying heat and pressure at the nipping portion; an air blowing section provided downstream of the nipping portion on a conveying path of the image supporting material; and an air flow path switching section that switches an air blow of the air blowing section in accordance with a size of the image supporting material for both ends of the conveying path and for both ends of the fixing member.

Abstract: A fixing apparatus of one embodiment of the present invention has a heating member which is heated by induction heating, a pressing member which supplies a predetermined pressure to the heating member, and induction heating mechanisms which supply a predetermined magnetic field to the heating member. The induction heating mechanisms have a plurality of coils. By arranging the adjacent coils and adjacent coils to overlap, the temperature distribution in the length direction of the heating member can be made uniform.

Abstract: Image heating apparatus capable of preventing an excessive temperature increase in a sheet non-passing area and heater for use in the image heating apparatus including: a substrate, a heat generating resistor formed on the substrate, and first and second electrodes for supplying an electric power to the heat generating resistor. Each of the first and second electrodes has a first area to contact a power supplying connector and a second area provided at an end portion electrically opposite to the first area along a longitudinal direction of the substrate, and the heat generating resistor is provided to electrically connect the second area of the first and second electrode so that when the heater is at a set temperature for an image heating operation a resistance value Rc of the second area, and a resistance value Rt between a portion within the second area of the first and second electrode and electrically closest to the first area satisfy a relation Rc/Rt<=1/30.

Abstract: Within a fixing roller (231) are disposed a main heater lamp (234a) for heating a central portion of the fixing roller and a sub-heater lamp (235a) for heating opposite end portions of the fixing roller. MRnh, SRnh and ?Rnh satisfy the formula (1) or (2): ?Rnh?30.5·Ln(Ht)+382??formula (1) MRnh??21.9·Ln(Ht)?198,??formula (2) where MRnh is a mean value of heat distribution in a no-heat generating section of the main heater lamp; SRnh is a mean value of heat distribution in the a no-heat generating section of the sub-heater lamp; ?Rnh is the sum total of these mean values; and Ht=vp/(Mh·?) where vp is a fixing speed (m/s), Mh a heat capacity per unit length of the heating member (J/(° C.·m)) and ? a heat conductivity of a material forming the heating member (W/(m·° C.)).

Abstract: A heating apparatus of an electromagnetic inductive heat generating type has a coil for generating a magnetic flux, a roller member for generating heat by the magnetic flux from the coil, and heating a material to be heated, and a magnetic flux shield member for shielding the magnetic flux from the coil to the roller member to thereby vary the generated heat distribution of the roller member, wherein provision is made for a guide provided in non-contact with the roller member for guiding the movement of the magnetic flux shield member to a predetermined magnetic flux suppressing position, thereby realizing an improvement in the faulty operation of the magnetic flux shield member.

Abstract: An apparatus is provided for fixing toner to a substrate including a heated fusing roller having a fusing surface. A heater element is located inside the fusing roller. A nip forming member cooperates with the fusing roller to define a fusing nip. A passive temperature control structure including a pair of members is located adjacent opposing end sections of the fusing roller, the passive temperature control structure operating to retain heat in the end sections. The passive temperature control structure may include heat reflecting members located adjacent to peripheral end portions of the hot roller to reflect heat back to the peripheral surface. In addition, the passive temperature control structure may include an end reflector facing axially toward an interior area or the hot roller for reflecting heat back to the interior of the hot roller.

Abstract: The present invention relates to a temperature detection apparatus having a radiant temperature detection section including at least a ray emission portion which radiates at least rays and a ray detection portion which detects the rays, and capable of detecting temperature without contacting a detection object, a first atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section is not more than predetermined temperature, and a second atmospheric temperature detection section which outputs temperature information having a high temperature follow-up property in a case where the atmospheric temperature of the radiant temperature detection section exceeds the predetermined temperature.

Abstract: A fixing apparatus according to the invention is provided with a heating roller 2 including an elastic member 2b and a metal conductive layer 2c. The elastic member has a greater outer diameter at its end portions than at its central portion. At least one air hole 100 is formed through the metal conductive layer 2c at a predetermined position opposing the small-diameter central portion of the elastic member. The air hole connects the outside to a clearance formed between the elastic member 2b and the metal conductive layer 2c.

Abstract: A heater control circuit performs ON/OFF control of a switching converter for a FET so that an AC line current supplied from a DI terminal becomes approximate to a predetermined value. A current flowing to a heater is stabilized to a predetermined value, and, unless an AC line voltage fluctuates, electric power supplied to the heater is held to a predetermined value. With this contrivance, in an image forming apparatus including a fixing heater (heating heater), a printing speed of the image forming apparatus can be improved to the greatest possible degree under such a condition that a total amount of utilizable electric power is restricted.

Abstract: An apparatus for fusing print sheets, such as in xerographic printing, comprises a heating element, and a temperature-sensitive mounting for the heating element. The mounting changes a position of the heating element over the course of use of the apparatus, thereby enabling a more efficient use of the heating element and emitted heat within the fusing apparatus.

Abstract: An induction heating type of fixing device to fix a recording material having a toner image thereon, having a heating member, an induction coil divided into a plurality of parts, a temperature detector for detecting a temperature of the heating member, a signal generator for generating a switching signal that periodically controls permission and prohibition of energization of each of the divided induction coils, and a controller for controlling supply of a driving current to each of the divided induction coils to heat the heating member. The controller controls the energization by periodically switching the driving current to each of the divided induction coils on the basis of an energization signal that determines the permission and the inhibition of the driving currents according to a signal of temperature detected by the temperature detector, and the switching signal.

Abstract: A fixing unit thermally fixes a toner on a recording medium by a fixing member having a plurality of internal heaters and an outer peripheral surface, and a temperature sensor detects a surface temperature of the fixing member at a temperature detecting position. At least one first heater, of the heaters, receives power from a first power supply, and remaining second heaters receive power from a second power supply. One of the second heaters closest to the temperature detecting position is the same distance from the temperature detecting position as or is closer to the temperature detecting position than a first heater which is closest to the temperature detecting position.

Abstract: A heating apparatus of an electromagnetic inductive heat generating type using a magnetic flux shield member, the heating apparatus including a coil for generating a magnetic flux, a roller member for generating heat by the magnetic flux from the coil, and heating a material to be heated, the magnetic flux shield member for shielding the magnetic flux from the coil to the roller member to thereby vary the generated heat distribution of the roller member, and a guide member provided in non-contact with the roller member for guiding the movement of the magnetic flux shield member to a predetermined magnetic flux suppressing position, thereby realizing an improvement in the faulty operation of the magnetic flux shield member.

Abstract: An image forming apparatus is provided with a pressing roller for pressing a sheet at the time of a fixing operation; a fixing roller having a hollow portion, facing the pressing roller, rising in temperature by being heated, and fixing a developer to the sheet by sandwiching the sheet between the fixing roller and the pressing roller; and induction heating coils including a center-section coil and an end-section coil, and arranged inside the fixing roller in an axial direction so as to leave a space between the center-section coil and the end-section coil, the space being adjusted so that the temperature of one surface of the fixing roller, the one surface opposing the space, is not higher than the temperatures of the other surface of the fixing roller, the other surface opposing central portions of the coils.

Abstract: A fixing apparatus of one embodiment of the present invention has a heating member which is heated by induction heating, a pressing member which supplies a predetermined pressure to the heating member, and induction heating mechanisms which supply a predetermined magnetic field to the heating member. The induction heating mechanisms have a plurality of coils. By arranging the adjacent coils and adjacent coils to overlap, the temperature distribution in the length direction of the heating member can be made uniform.

Abstract: The present invention is in the field of electrophotographic printers and copiers. More specifically this invention relates to the fuser apparatus used to fuse an image on a receiving sheet. According to just one aspect of the invention, an apparatus and process for fixing toner images to a receiving sheet is provided. The apparatus may include a fuser having a run condition and an idle condition, the fuser having a fuser roller, a fuser roller heater, and a fuser temperature sensor which inputs to a logic and control system which controls the heating of the fuser roller heater. The fuser roller may be cooled during or after the idle condition, prior to the first receiving sheet entering the fuser. The fuser roller has end portions and a middle portion, and the middle portion may be cooled relative to said end portions. Additional aspects and representative embodiments are described herein.

Abstract: The invention relates to the use of roller fusing in printing. In particular, the invention relates to the use of heated rollers. According to one aspect of the invention, a fixing process and system for use with a printing apparatus is provided wherein a flow of heat exchange medium through a first heating zone within a fixing roller and a second heating zone within the fixing roller is controlled, and marking material is fixed to a receiver with the fixing roller. According to another aspect of the invention, a fixing process and system for use with a printing apparatus is provided wherein marking material is fixed to a receiver with a fixing roller and wherein a heat exchange medium is flowed through a first heating zone within the fixing roller, the first heating zone being biased toward the receiver.

Abstract: A heating apparatus has an excitation coil; magnetic flux generator having a magnetic member core, the magnetic member core having a first magnetic core supported with a holder for the excitation coil and a rotatable second magnetic member core; an induction heat generating element for electromagnetic induction heat generation using the magnetic flux generated by the magnetic flux generator; a heating portion for receiving a recording material and for heating the recording material by the heat generated by the induction heat generating element; and a rotator for rotating second magnetic core to a different angular position to change a heat generation distribution in a longitudinal direction of the induction heat generating element.

Abstract: A heat roller having a cylindrical sheet-like heating element having a resistance member embedded into an insulating member. The sheet-like heating element is arranged between an inner tube and an outer tube. The resistance member is formed such that a heating density of the sheet-like heating element is changed in an axial direction of the heat roller. The heating density of the sheet-like heating element at its edge section is greater than that at a center in the axial direction of the heat roller.

Abstract: A heating apparatus includes first and second coil members, a heat roller and an input control mechanism. The first and second coil members respectively are part of first and second excitation circuits. The heat roller generates an eddy current inside by a magnetic field generated by the first and second coil members. The input control mechanism drives the first and second excitation circuits. The input control mechanism starts driving only the first excitation circuit from a state where operations of the first and second excitation circuits are stopped. When the temperature detection mechanism detects a predetermined temperature, the input control mechanism stops supplying power to the first excitation circuit and supplies power only to the second excitation circuit, and the heat roller initiates rotating.

Abstract: A heating device for heating a recording sheet. The heating device has a first heater located within a heating roller. The first heater has a heat distribution effective to form a low temperature region in an axially central portion of the heating roller and a high temperature region in each of axially opposite end portions of the heating roller. There is a second heater located within the heating roller that has a heat distribution effective to form a high temperature region in the axially central portion of the heating roller, a low temperature region in each of the opposite end portions of the heating roller, and a second-level high temperature region in each of axially opposite end portions of the high temperature region, the second-level high temperature region being lower in temperature than the high temperature region.

Abstract: A thermal fixing device is equipped with a plurality of heaters for heating a fixing member at different axial positions thereof for proper temperature control. When the difference between the center temperature TA and the end temperature TB exceeds a proper temperature difference range (15° C.), of the center temperature TA and the end temperature TB, the one nearer to the average temperature Tm of the fixing upper limit temperature Th and the fixing lower limit temperature T1. is selected. The control value for the farther halogen lamp is changed so as to approach the selected temperature. When the temperature difference is 10° C. or less, the control value is further changed. With this process, it is possible to set both the temperatures and the portion near the center of the thermal roller to temperatures within the proper temperature range.

Abstract: A heating apparatus has an excitation coil; magnetic flux generator having a magnetic member core, the magnetic member core having a first magnetic core supported with a holder for the excitation coil and a rotatable second magnetic member core; an induction heat generating element for electromagnetic induction heat generation using the magnetic flux generated by the magnetic flux generator; a heating portion for receiving a recording material and for heating the recording material by the heat generated by the induction heat generating element; and a rotator for rotating second magnetic core to a different angular position to change a heat generation distribution in a longitudinal direction of the induction heat generating element.

Abstract: An image fanning apparatus is provided with a pressing roller for pressing a sheet at the time of a fixing operation; a fixing roller having a hollow portion, facing the pressing roller, rising in temperature by being heated, and fixing a developer to the sheet by sandwiching the sheet between the fixing roller and the pressing roller; and induction heating coils including a center-section coil and an end-section coil, and arranged inside the fixing roller in an axial direction so as to leave a space between the center-section coil and the end-section coil, the space being adjusted so that the temperature of one surface of the fixing roller, the one surface opposing the space, is not higher than the temperatures of the other surface of the fixing roller, the other surface opposing central portions of the coils.

Abstract: A printer fuser with a plurality of separately powerable heating zones along its length for permitting variably controllable heat application to a medium.