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 sheet skew correcting device includes a first sheet conveyance unit which a conveyance force at a center side is smaller than a conveyance force at a first side, a second sheet conveyance unit which is adjacent to the first sheet conveyance unit across the center and a conveyance force at the center side is smaller than a conveyance force at a second side, a first drive unit to drive the first rotator, a second drive unit to drive the third rotator, a detection unit to detect an inclination of the sheet, and a control unit to control the first drive unit and the second drive unit based on a detection result of the detection unit.

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 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: 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 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 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: 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: A fixing apparatus according to the present invention ensures a nip width larger than a certain value by a heating roller which has a thin film metal conductive layer, and a foamed rubber layer which is bonded to the end part of the metal conductive layer, formed with a gap in a center part, and not bonded to the metal conductive layer.

Abstract: A fixing apparatus includes an endless heating member having a metallic conductive layer, and a pressure member pressed to the heating member to form a nip to hold and convey a medium to be fixed. The apparatus also includes an induction heating coil arranged on an outer periphery of the heating member to generate an induced current, and a position sensor to detect a front end of the medium conveyed. The apparatus further includes a controller for controlling so as to increase an output value of the induction heating coil.

Abstract: A sheet carrying device includes: a sheet carrying unit having a first sheet carrying unit and a second sheet carrying unit, at least one of which has a sheet carrying force changing along a direction orthogonal to a traveling direction of a sheet, the first sheet carrying unit carrying the sheet in the traveling direction, the second sheet carrying unit carrying the sheet in the traveling direction together with the first sheet carrying unit; and a control unit which controls the carrying by the first sheet carrying unit and the carrying by the second sheet carrying unit on the basis of a result of detection from a detection unit which detects an inclination of the sheet that is traveling.

Abstract: According to an embodiment, a heating device having a plurality of heating members which heat the heating roller, a first thermoelectric converting section having a plurality of thermoelectric converting elements, each of which has a heat-absorbing surface and a cooling surface and generates electromotive force by difference in temperature between the heat-absorbing surface and the cooling surface, and formed along a curved surface of the heating roller, in which the heat-absorbing surface is disposed with a predetermined space from an outer circumferential surface of the heating roller, an auxiliary power supply charged with electric power generated by the first thermoelectric converting section, and a switching section which switches the apparatus between a first state in which electric power is supplied from utility power to the heating members and a second state in which electric power is supplied from the auxiliary power supply to the heating members, based on a predetermined signal.

Abstract: A fixing apparatus according to the present invention includes a heat roller 2 which includes an elastic member 2b having an outer diameter which is different from another one in an axial direction, and a 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: The present invention provides a technique that can contribute to the improvement of fixing performance while maintaining appropriate nip width. A heating roller includes: a core configured to rotate around a predetermined rotation axis; plural elastic layers laminated on the outer circumference of the core; and a conductive layer formed on the outer circumference of the plural elastic layers. The plural elastic layers have, in a rotation radius direction, larger specific heat in the elastic layer on the outer side than in the elastic layer on the inner side and have lower thermal conductivity in the elastic layer on the inner side than in the elastic layer on the outer side.

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 ensures a nip width larger than a certain value by a heating roller which has a thin film metal conductive layer, and a foamed rubber layer which is bonded to the end part of the metal conductive layer, formed with a gap in a center part, and not bonded to the metal conductive layer.

Abstract: To provide a technique for reducing waste of thermal energy in a fixing device. The fixing device includes: a heating rotational unit configured to heat a sheet on which a toner image is formed; a pressing rotational unit configured to come into press contact with the heating rotational unit to form a nip between the heating rotational unit and the pressing rotational unit and nip and carry the sheet in cooperation with the heating rotational unit; a heating device configured to heat the heating rotational unit; and a heat accumulating unit configured to cover at least a range above at least one of the heating rotational unit and the pressing rotational unit.

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: In an induction heat fixing device of the invention, a metal conductive layer of a heat roller is supported by a foamed rubber (sponge). A sheet paper is curled in a direction of separating from the heat roller by a nip shape between the heat roller and a press roller. The press roller is formed to be longer than the heat roller to such a degree that even if the heat roller laterally shifts, an edge of the press roller does not come in contact with the heat roller.