Abstract: A quota management apparatus includes a management section. The management section manages a value of a printing quota indicating a usable amount of an image forming apparatus by a user according to an image forming instruction by the user. If the image forming apparatus forms an image on a sheet on which an image is erased, the management section performs either a control of subtracting a value smaller than that in a case in which the image forming apparatus forms the image on a sheet on which the erasing of an image is not executed from the value of the printing quota, or a control of not subtracting the value of the printing quota.

Abstract: Certain embodiments provide a fuser including a cylindrical fixing belt, a heating unit configured to heat the fixing belt, a pressurized section, a first nip forming section, a second nip forming section, and a moving mechanism. The pressurized section is arranged in contact with the fixing belt. The first nip forming section is fixed in a position where the first nip forming section presses the fixing belt against the pressurized section. The second nip forming section is configured to be movable between a position where the second nip forming section can press the fixing belt against the pressurized section and a position where the second nip forming section is separated from the fixing belt. The moving mechanism moves the second nip forming section.

Abstract: A sheet skew correcting device includes a first sheet conveyance unit which a conveyance force at a center side is less 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 less 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: Certain embodiments provide a fuser including a cylindrical fixing belt, a heating unit configured to heat the fixing belt, a pressurized section, a first nip forming section, a second nip forming section, and a moving mechanism. The pressurized section is arranged in contact with the fixing belt. The first nip forming section is fixed in a position where the first nip forming section presses the fixing belt against the pressurized section. The second nip forming section is configured to be movable between a position where the second nip forming section can press the fixing belt against the pressurized section and a position where the second nip forming section is separated from the fixing belt. The moving mechanism moves the second nip forming section.

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: 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: 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 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. In a copy mode, the temperature of the heat roller and the press roller is finely controlled. In a copy standby mode, only the power required for maintaining a set temperature is supplied.

Abstract: A fixing device includes a heat roller having a degaussing alloy material, an induction heating member for exciting the heat roller, an inverter circuit for giving power at a predetermined frequency to the induction heating member, and a control unit, and when driving at a first drive frequency and fixing small size sheets by continuous passing, a local temperature rise occurs at an end part of the heat roller, and the end part approaches the Curie temperature, and when impedance of the inverter circuit reduces and an excessive current flows in the circuit, the fixing device drives at a higher second drive frequency, thereby increases a resistance of the heat roller by an epidermal effect of magnetic flux, increases an apparent resistance of the inverter circuit, makes it possible to use a flowing current within a normal range, heating a central part of the heat roller, and continues the fixing.

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 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 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: 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: 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 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 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: 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: 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.