Abstract: A fixing device includes a belt that has an endless shape, a roller that forms a nip with the belt, a support member that supports the belt interposed between the support member and the roller, a coil that generates a magnetic field for inducing current in the belt, an auxiliary heat generation member that generates heat with the current induced by the magnetic field in the loop of the belt, and a temperature sensor that is opposed to the auxiliary heat generation member with the belt interposed between the element and the auxiliary heat generation member and detects the temperature of an outer peripheral surface of the belt.

Abstract: To provide a technique for preventing a temperature rise in a non-sheet passing areas in a fixing device. The fixing device includes: a heating rotational member that includes at least one roller and heats a toner transferred on a sheet; a pressing roller that nips and carries the sheet in cooperation with the heating rotational member; a heating device that heats the heating rotational member; and heat pipes arranged, on the inside of at least one of the roller of the heating rotational member and the pressing roller, in ranges on both the sides in an axial direction of the roller from positions closer to the center in the axial direction than both the ends of a minimum sheet passing range in the axial direction of the roller of the nipped and carried sheet to positions further on the outer sides in the axial direction than both the ends of a maximum sheet passing range.

Abstract: A temperature equalizing roller includes a metal pipe, a heat pipe that is located inside the metal pipe and has a thermal expansion coefficient higher than that of the metal pipe, and a joining layer. The joining layer lies between an outer peripheral surface of the heat pipe and an inner peripheral surface of the metal pipe, joins the outer peripheral surface of the heat pipe and the inner peripheral surface of the metal pipe, and has a higher thermal conductivity than a thermal conductivity of air.

Abstract: The fixing device of the image forming apparatus of the present invention is provided with a heat transfer probe which contacts the heat roller and a surface temperature of the heat roller is transferred thereto. The erroneous detection of the surface temperature of the heat roller caused from materials adhered to the heat roller is prevented, induction heating coils is regulated at a high level of accuracy using the highly precious detection result obtained from the heat transfer probe, the temperature control of the heat roller is promoted and a fixed image of high quality is obtained.

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 fuser includes: a rotational member configured to rotate; a press member configured to form a nip between the press member and the rotational member; an induction-current generator configured to generate an induction current in the rotational member; and a controller configured to reduce a nip temperature of the nip when a leading end of a recording medium reaches the nip to be lower than a nip temperature when an image on the recording medium is fixed.

Abstract: A fixing apparatus of the present invention includes a heating roller 2 that is a cylindrical member having a center axis, a pressurizing roller 3 that exerts pressure on the heating roller 2, and a temperature detecting element 6 that detects the temperature of the heating roller 2. The outer peripheral surface of the heating roller 2 is induction heated on the basis of the temperature information detected by the temperature detecting element 6. The fixing apparatus thus utilizes induction heating. The present invention is characterized in that the temperature detecting element 6 is placed in an area located vertically below the center axis of the heating member 2 and vertically below the outer peripheral surface of the heating member. The temperature detecting element 6 is thus provided at a position where it is unlikely to suffer thermal convection from the heating roller 2.

Abstract: A fuser includes: a belt member; plural rotational members configured to support the belt member; a press member configured to form a nip between the press member and the belt member; an induction-current generator configured to generate induction current in the belt member; and a controller configured to increase the induction current while a recording medium passes through the nip.

Abstract: A fuser includes: a rotational member configured to rotate; a press member configured to press a recording medium at a nip between the rotational member; an induction-current generator configured to generate induction current in the rotational member; and a controller configured to increase rotating speed of the rotational member after a trailing end of a preceding recording medium passes through the nip until a leading end of a following recording medium reaches the nip.

Abstract: A fuser includes: a rotational member configured to rotate; a press member configured to press the rotational member; an induction-current generator configured to generate induction current in the rotational member; and a separator configured to separate a leading end of a recording medium that passes through a nip from the rotational member, when a distal end is in a separating position, and move to an open position.

Abstract: A fuser includes: a rotational member configured to rotate; a press member configured to press a recording medium at a nip between the rotational member; an induction-current generator configured to generate induction current in the rotational member; a heat insulator partially transparent to an infrared ray; an insulator driver configured to move the heat insulator to cover the press member; and a thermometer configured to receive the infrared ray emitted from the press member.

Abstract: Certain embodiments provide a fuser including: a heat roller; a press roller; a coil; an inverter; a driver; a mechanism configured to change a clearance of a gap between a coil and an outer circumferential surface of the heat roller; and a controller. The controller sends information indicating a first power level to the driver. The mechanism changes the clearance to a first distance. The controller sends information indicating a second power level larger than the first power level to the driver. The mechanism changes the clearance to a second distance larger than the first distance.

Abstract: An induction heating device of the invention is made to have a two-layer structure in which at an end of a magnetic core of an induction current generating coil, a litz wire of outside three turns is stacked on a litz wire of inside three turns. The width of a joint portion between plural induction current generating coils is made narrow, and a mutual induction current generated at the joint portion is reduced. Further, the whole length of the litz wire is shortened without changing the length of the magnetic core of the inductor current generating coil.

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 of paper P.

Abstract: A transferring and fixing device includes an image carrier member to hold an unfixed toner image, a heat member to heat the unfixed toner image on the image carrier member, a pressure member which comes in press contact with the image carrier member, nips a recording medium with the image carrier member, and presses and conveys the recording medium, and a vibrating member to transmit vibrations to the recording medium passing through between the image carrier member and the pressure member.

Abstract: A heating fuser includes: a rotating member configured to heat a toner transferred onto a sheet; a first coil body configured to generate a first magnetic field for inducing eddy-current in a first area including the center in a rotation axis direction of the rotating member; second coil bodies configured to generate second magnetic fields for inducing eddy-current in second areas of the rotating member adjacent to the first area in the rotation axis direction; third coil bodies located to extend over the first and second coil bodies when viewed in a direction orthogonal to the rotation axis direction; and a driving circuit configured to drive the third coil bodies between a first state in which the third coil bodies generate magnetic fields for weakening the first magnetic field and a second state in which the third coil bodies generate magnetic fields for strengthening the second magnetic fields.

Abstract: Plural main cores and plural sub-cores are arranged spaced apart from each other along a direction orthogonal to a rotating direction of a heat belt. The plural main cores are opposed to a first area where a sheet having first width in the heat belt passes. The plural sub-cores are opposed to second areas that are areas excluding the first area in an area where the sheet having second width larger than the first width in the heat belt passes. The plural sub-cores have thickness in the direction orthogonal to the rotating direction of the heat belt smaller than the thickness of the plural main cores.

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 fixing device of this invention enables variable control of power to be supplied to a heat roller side or a press roller side in accordance with the temperature of the heat roller and the press roller while each mode is carried out. A secondary battery is used in addition to a commercial power source, thus enabling supply of power to the heat roller side or the press roller side. The secondary battery is used when necessary, thus increasing the power supply. In a copy mode, the temperature of the heat roller and the press roller is controlled in detail. In a non-copy state, the power supply to the fixing device is stopped.

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.