Abstract: In an induction heating fixing device according to the invention, a first induction heating coil that generates an induced current across the total length of a heat roller is provided on the outer circumference of the heat roller having a metal conductive layer. A second induction heating coil that generates an induced current at a central part of the heat roller is provided, which crosses the first induction heating coil and is arranged on the outer side than the first induction heating coil. With the first induction heating coil, the heat roller is heated across the total length without generating any uneven temperature. On-off control of the first induction heating coil and the second induction heating coil is carried out, and the temperature distribution in the longitudinal direction of the heat roller is kept constant irrespective of the size of a sheet paper P.

Abstract: A fixing device of the invention detects a temperature of plural positions of a heat roller by a multiple non-contact temperature sensor at the same time and controls the temperature of plural heat source members The non-contact temperature sensor and a contact temperature sensor detect the temperature of the same position. According to the detection result, maintenance is performed or a temperature conversion table is corrected, the non-contact temperature sensor is maintained with high precision, and the heat roller is controlled the temperature with high precision.

Abstract: A fixing apparatus includes a mold (holding member) formed by injection molding to hold a coil so that the coil maintains a predetermined positional relation with respect to a heating roller, and capable of holding a temperature sensor which detects a temperature of the heating roller and a thermostat which detects an abnormal temperature of the heating roller in predetermined positions facing the heating roller.

Abstract: In a fixing device of an image forming apparatus of the present invention, inner surfaces of upper and lower frames for respectively supporting a heat roller and a pressure roller are formed as a mirror surface. Between the heat roller and an infrared temperature sensor, an infrared transmission filter for cutting infrared rays beyond a wave length zone equivalent to a heatable area of the heat roller is installed. Detection results of a surface temperature of the heat roller by the infrared temperature sensor are prevented from exceeding the error tolerance due to infrared rays radiated from other than the heat roller. Temperature control for the heat roller is improved and a fixed image of high image quality is obtained.

Abstract: In an aspect of this invention, a fixing device includes a heating member including a first area and a second area formed of conductive members (e.g., aluminum and iron) having different magnetic permeability ratios, and an induction heating unit which generates a magnetic field from a coil to induction-heat this heating member, and the fixing device changes a frequency of a high-frequency current to be supplied to the coil to thereby control a heating area of the heating member.

Abstract: In a fixing device for an image forming apparatus of the invention, circumferences of both side parts of an elastic layer are made larger than a circumference of a central part, and the expansion of a foamed rubber layer is absorbed by space between the elastic layer and a metal conductive layer. Thereby, the hardness of a heat roller at the time of fixing is made nearly uniform across the entire length in the shaft direction. The contact area of a core member and the elastic layer in the both side parts of the heat roller is made larger, and the stress per unit area generated in the elastic layer due to contact with the pressure roller is reduced.

Abstract: A fixing apparatus according to one aspect of the present invention includes a non-contact temperature detecting element 81 allocated in non-contact with a heat roller, the sensing element detecting a temperature of the heat roller. The non-contact temperature sensing section 81 includes a thermopile P which detects a target temperature Pt of a heat roller 2, a temperature element CPU 100 which estimates an ambient temperature at the periphery of the thermopile P and computes an estimated ambient temperature SQt, and a thermister Q which detects an ambient temperature Qt at the periphery of the thermopile and outputs the ambient temperature Qt at an output voltage of a predetermined rate with respect to a total output voltage value corresponding to the estimated ambient temperature SQt.

Abstract: In an aspect of this invention, a fixing device includes a heating member including a first area and a second area formed of conductive members (e.g., aluminum and iron) having different magnetic permeability ratios, and an induction heating unit which generates a magnetic field from a coil to induction-heat this heating member, and the fixing device changes a frequency of a high-frequency current to be supplied to the coil to thereby control a heating area of the heating member.

Abstract: In a drive detection device for a fixing device according to an embodiment of the present invention, a non-paper passing area of a heat roller is formed by a surface where a metal conductive layer is exposed and a surface where a silicon rubber layer is exposed. The drive detection device has an infrared temperature sensor that detects the temperature of the non-paper passing area. When a detection result of the infrared temperature sensor is fluctuated a fixed amount or more in a predetermined time, the drive detection device determines that the heat roller is rotating. Otherwise, the drive detection device determines that the heat roller is not rotating.

Abstract: A heat roller of a fixing apparatus according to an embodiment of the invention has a slidable metal belt on an outer side of an elastic roller. The width of the metal belt is made larger than that of the elastic roller. Flanges, each of which regulates a sliding movement of the metal belt by being in contact with an edge of the metal belt, are provided on both sides of a press roller opposite the metal belt.

Abstract: A fixing apparatus according to the present invention comprises a heat roller 2 which comprises an elastic member 2b having an outer diameter which is different from another one in an axial direction, and an conductive layer 2c provided outside of the elastic member 2b, wherein a maximum outer diameter and a minimum outer diameter of the elastic member 2b has a difference therebetween ranging from 0.2 mm to 3.0 mm.

Abstract: There is provided a technique in which in a roller apparatus including a roller constructed by inserting a core member in a cylindrical elastic body, the occurrence of disadvantages due to the reduction in bonding strength between the elastic body and the core member is suppressed by a simple structure. In the roller apparatus including a core member that rotates around a rotation axis, and a cylindrical elastic body in which the core member is inserted, at least a boundary portion between the elastic body at an end position in a direction of the rotation axis P and the core member is coated with a coating part.

Abstract: In a heat roller of a fixing apparatus according to an embodiment of the present invention, a sleeve is slidable with respect to a supporting roller. Flanges that regulate the sleeve have smooth surfaces, are arranged at gaps apart from a foamed rubber layer of the supporting roller, and freely rotate with respect to the supporting roller. Edges at both ends of the foamed rubber layer of the supporting roller are formed in an R shape and set shorter than the length of a body of the press roller. The sleeve has markings for detecting a state of the heat roller.

Abstract: In a fixing apparatus of an embodiment of the invention, a heat roller forwardly and reversely rotated by a drive motor capable of forwardly and reversely rotating is heated by an induction heating coil also when it is reversely rotated. Further, the roller control temperature of the heat roller by a control system is adjusted according to a time of forward rotation of the heat roller and a time of reverse rotation, or a time when the heat roller and a press roller are separated from each other and a time when they are in contact with each other. Besides, after a specified time has passed since an instruction of reverse rotation or forward rotation by a drive signal, output of the induction heating coil is tuned on.

Abstract: An image formation apparatus is provided for supporting adjustment of the distance between a heat roller and a heating unit for heating the heat roller, thereby supporting adjustment of supplied power to the heating unit. The image formation apparatus includes a heat roller for clamping paper with a toner image formed thereon with a pressurization roller; a heating unit being placed facing the heat roller for heating the heat roller; a power supply unit for supplying power to the heating unit; an acquisition unit for acquiring a power value based on the power supplied from the power supply unit; a comparison unit for making a comparison between the power value acquired by the acquisition unit and a predetermined power value; and a display unit for displaying information concerning adjustment of a distance from the heat roller to the heating unit based on the comparison result of the comparison unit.

Abstract: A fixing device according to an embodiment of the present invention includes a microcomputer that exclusively performs temperature control for the fixing device. The microcomputer periodically calculates electric power that can be supplied to the fixing device. The microcomputer detects the temperature of the fixing device and the temperature in a printer unit and feedback-controls electric power supplied to the fixing device.

Abstract: A heat roller of a fixing apparatus according to an embodiment of the invention has a slidable metal belt on an outer side of an elastic roller. At the room temperature, the outer diameter of the elastic roller is smaller than the inner diameter of the metal belt. On the other hand, when the elastic roller is thermally expanded, the metal belt and the elastic roller fit onto each other in a state in which the metal belt fastens the elastic roller.

Abstract: A fixing apparatus according to an embodiment of the present invention controls, using a CPU and a temperature comparator, an inverter circuit that supplies electric power to an induction heating coil and performs temperature control for a heat roller. The CPU adjusts and controls a power value supplied by the inverter circuit. When the adjustment and control of the power value by the CPU is late, the inverter circuit is ON-OFF controlled by the temperature comparator.

Abstract: A fixing device according to an embodiment of the present invention heats a metal conductive layer of a heat roller using an induction current generating coil. In order to supplement a heat capacity of the heat roller, a press roller having a large heat capacity is heated by a halogen lamp. During a start of activation of an image forming apparatus, when a printer control circuit is started, the supply of electric power to the halogen lamp is started before warming-up is started.

Abstract: A fixing apparatus of an image forming apparatus of the present invention, in arrival timing of a temperature falling area of a heat roller passing a nip at opposite position ? of an induction heating coil from temperature detection position ? by an infrared temperature sensor around the heat roller, according to detection results by the infrared temperature sensor, controls an output value of the induction heating coil under control of an inverter circuit, heats and returns the heat roller in real time to a fixable temperature, and realizes energy conversation. At the time of arrival at the nip, the heat controller is always set to a fixed fixable temperature, thus in a fixed image, a high image quality free of ripple marks can be obtained.