Abstract: An image forming apparatus including: an image former that forms an image on a recording material; includes a fixer that has a first fixing member having an elastic layer, a second fixing member that forms a fixing nip with the first fixing member, and an external heater that heats the first fixing member from outside, and fixes the image on the recording material by heating and pressing the conveyed recording material at the fixing nip; and a hardware processor that executes a thermal expansion mode, in which in the thermal expansion mode, the hardware processor causes the external heater to heat the first fixing member to a temperature higher than a temperature during normal printing.

Abstract: An image forming apparatus including: an image former that forms an image on a recording material; includes a fixer that has a first fixing member having an elastic layer, a second fixing member that forms a fixing nip with the first fixing member, and an external heater that heats the first fixing member from outside, and fixes the image on the recording material by heating and pressing the conveyed recording material at the fixing nip; and a hardware processor that executes a thermal expansion mode, in which in the thermal expansion mode, the hardware processor causes the external heater to heat the first fixing member to a temperature higher than a temperature during normal printing.

Abstract: An image forming apparatus includes: a fusing device having a pad member and a pressure member that works to form a nip region in the interface with the pad member; a contact condition changing mechanism that optimizes the distribution of interfacial pressure in the nip region by changing the contact condition between the pad member and the pressure member, and that changes the contact condition between the pad member and the pressure member by moving either or both of the pad member and the pressure member; an image information sensor that senses image information from a sheet of paper having passed through the nip region; and a processor that makes the contact condition changing mechanism optimize the distribution of interfacial pressure in the nip region with reference to a sensing result obtained by the image information sensor.

Abstract: An image forming apparatus includes an image fixing unit to pass a sheet carrying an unfixed toner image on a first side. The image fixing unit includes: a first fixing section adjacent to the first side of the sheet; a first heating section to heat the first fixing section; a second fixing section adjacent to a second side opposite to the first side of the sheet; and a second heating section to heat the second fixing section. The image forming apparatus further includes: sheet feeding trays holding sheets; a storage unit storing fixing temperatures of the fixing sections preset for each type of the sheets in the sheet feeding trays; and a controller to select standby temperatures from the fixing temperatures, based on temperature profiles of the fixing sections, and to instruct the heating sections to respectively maintain the fixing sections at the selected standby temperatures during a standby mode.

Abstract: An image forming apparatus includes an image fixing unit to pass a sheet carrying an unfixed toner image on a first side. The image fixing unit includes: a first fixing section adjacent to the first side of the sheet; a first heating section to heat the first fixing section; a second fixing section adjacent to a second side opposite to the first side of the sheet; and a second heating section to heat the second fixing section. The image forming apparatus further includes: sheet feeding trays holding sheets; a storage unit storing fixing temperatures of the fixing sections preset for each type of the sheets in the sheet feeding trays; and a controller to select standby temperatures from the fixing temperatures, based on temperature profiles of the fixing sections, and to instruct the heating sections to respectively maintain the fixing sections at the selected standby temperatures during a standby mode.

Abstract: An image forming apparatus includes: a first conveyance section disposed on an upstream side of the image formation position in a sheet conveyance direction of the long sheet, and configured to convey the long sheet to the image formation position; a second conveyance section disposed on a downstream side of the image formation position in the sheet conveyance direction, and configured to convey the long sheet on which the toner image is formed; a displacement detection section configured to detect displacement of the long sheet in a sheet width direction; and a control section configured to move the first conveyance section in the sheet width direction to orient the long sheet in the sheet width direction, and move the second conveyance section in a direction identical to a direction along which the first conveyance section is moved based on a detection result of the displacement detection section.

Abstract: An image forming apparatus has an image forming unit that forms an image on a sheet, a fixing unit that performs fixing of the sheet on which the image is formed, a first conveyance route that has a reverse conveyance route and a second conveyance route that does not pass the reverse conveyance route, and a control unit that performs first control for conveying a previously printed sheet which is printed previously via the first conveyance route and second control for conveying a subsequently printed sheet which is printed subsequently via the second conveyance route, and exerts control to feed the previously printed sheet and the subsequently printed sheet in an overlapped manner after the first conveyance route and the second conveyance route merge together.

Abstract: An image forming apparatus includes: a first conveyance section disposed on an upstream side of the image formation position in a sheet conveyance direction of the long sheet, and configured to convey the long sheet to the image formation position; a second conveyance section disposed on a downstream side of the image formation position in the sheet conveyance direction, and configured to convey the long sheet on which the toner image is formed; a displacement detection section configured to detect displacement of the long sheet in a sheet width direction; and a control section configured to move the first conveyance section in the sheet width direction to orient the long sheet in the sheet width direction, and move the second conveyance section in a direction identical to a direction along which the first conveyance section is moved based on a detection result of the displacement detection section.

Abstract: an image forming apparatus including; a non-inversion conveyance unit that conveys a sheet to a downstream without inverting through the image forming unit; an inversion conveyance unit that inverts the sheet with printing on one side and that conveys the sheet to an upstream; a first sheet inversion unit that is arranged on the inversion conveyance unit and inverts the front and back of the sheet conveyed by the inversion conveyance unit; a control unit that controls the image forming unit and the conveyance unit, wherein the control unit includes a single-sided print mode and a double-sided print mode, and at a breakpoint of jobs, the control unit discharges the sheet so as to provide charge polarity that does not electrostatically attract a sheet discharged just before the breakpoint and a sheet discharged just after the breakpoint at least in the double-sided print mode.

Abstract: An image forming apparatus includes a fixing side member disposed at a position on a fixing surface side of a sheet on which a toner image is formed; a back side supporting member that forms a fixing nip for conveying the sheet in a tightly sandwiching manner when the back side supporting member is in pressure contact with the fixing side member; and a voltage applying section that applies to both sides of the sheet passed through the fixing nip voltages opposite in polarity to surface potentials of the both sides.

Abstract: An image forming apparatus includes: a fixing unit that heats and presses a recording sheet having a toner image formed thereon, by means of a fixing nip portion to thereby fix the toner image to the recording sheet; a translation section that translates the fixing unit in a direction that is orthogonal to a conveying direction of the recording sheet; and a controlling section that controls the translation section so that the fixing unit is translated by a translation amount that is one-half of a value obtained by subtracting an image width of the toner image from a sheet width of the recording sheet.

Abstract: An image forming apparatus includes a fixing side member disposed at a position on a fixing surface side of a sheet on which a toner image is formed; a back side supporting member that forms a fixing nip for conveying the sheet in a tightly sandwiching manner when the back side supporting member is in pressure contact with the fixing side member; and a voltage applying section that applies to both sides of the sheet passed through the fixing nip voltages opposite in polarity to surface potentials of the both sides.

Abstract: An image forming apparatus includes: a fixing member; a moving section that moves the fixing member in a sheet width direction; a temperature detection section disposed at a position corresponding to an end portion of the fixing member, the temperature detection section moving together with the fixing member to detect a temperature of the end portion; and a control section that performs a first movement control and a second movement control on the basis of a result of a detection by the temperature detection section, the first movement control being intended to move the fixing member in the sheet width direction in a reciprocating manner with a predetermined cycle, the second movement control being intended to move the fixing member in the sheet width direction so that the temperature of the fixing member falls within a predetermined temperature range.

Abstract: An image forming apparatus including; a non-inversion conveyance unit that conveys a sheet to a downstream without inverting through the image forming unit; an inversion conveyance unit that inverts the sheet with printing on one side and that conveys the sheet to an upstream; a first sheet inversion unit that is arranged on the inversion conveyance unit and inverts the front and back of the sheet conveyed by the inversion conveyance unit; a control unit that controls the image forming unit and the conveyance unit, wherein the control unit includes a single-sided print mode and a double-sided print mode, and at a breakpoint of jobs, the control unit discharges the sheet so as to provide charge polarity that does not electrostatically attract a sheet discharged just before the breakpoint and a sheet discharged just after the breakpoint at least in the double-sided print mode.

Abstract: An image forming apparatus has an image forming unit that forms an image on a sheet, a fixing unit that performs fixing of the sheet on which the image is formed, a first conveyance route that has a reverse conveyance route and a second conveyance route that does not pass the reverse conveyance route, and a control unit that performs first control for conveying a previously printed sheet which is printed previously via the first conveyance route and second control for conveying a subsequently printed sheet which is printed subsequently via the second conveyance route, and exerts control to feed the previously printed sheet and the subsequently printed sheet in an overlapped manner after the first conveyance route and the second conveyance route merge together.

Abstract: An image forming apparatus includes: a fixing member; a moving section that moves the fixing member in a sheet width direction; a temperature detection section disposed at a position corresponding to an end portion of the fixing member, the temperature detection section moving together with the fixing member to detect a temperature of the end portion; and a control section that performs a first movement control and a second movement control on the basis of a result of a detection by the temperature detection section, the first movement control being intended to move the fixing member in the sheet width direction in a reciprocating manner with a predetermined cycle, the second movement control being intended to move the fixing member in the sheet width direction so that the temperature of the fixing member falls within a predetermined temperature range.

Abstract: An image forming apparatus includes: a fixing unit that heats and presses a recording sheet having a toner image formed thereon, by means of a fixing nip portion to thereby fix the toner image to the recording sheet; a translation section that translates the fixing unit in a direction that is orthogonal to a conveying direction of the recording sheet; and a controlling section that controls the translation section so that the fixing unit is translated by a translation amount that is one-half of a value obtained by subtracting an image width of the toner image from a sheet width of the recording sheet.

Abstract: Fixing belt is brought into pressure-contact with the surface of fixing roller such that fixing belt rotates according to rotation of fixing roller, thereby forming, between fixing belt and fixing roller, fixing nip portion through which recording sheets pass. A pressing area of an opposing surface of pressing member contacting the surface of fixing roller via fixing belt is smaller in each end portion of the opposing surface in the axis direction of fixing roller than in a central portion of the opposing surface in the axis direction of fixing roller. This makes speed of conveying recording sheets faster in each edge portion in the width direction perpendicular to a recording sheet conveyance direction than in a central portion in the width direction. Thus, creases of recording sheets can be prevented while a recording sheet passes through fixing nip portion between fixing roller and fixing belt mutually brought into pressure-contact.

Abstract: A first pad has a first nip forming surface which extends in a direction X. An angle formed between an end portion of the first nip forming surface and an XZ plane is smaller than an angle formed between a central portion of the first nip forming surface and the XZ plane, where the XZ plane is formed on a downstream side of the first nip forming surface. Thereby, a fixing device is provided which suppresses generation of wrinkles on a recording material when the fixing device fixes toner on the recording material and conveys it.

Abstract: A fixing device includes: a heating section which heats a recording material; an induction heating heater which heats the heating section by an electromagnetic induction action; a pressing section facing the heating section, which presses the recording material against the heating section; an auxiliary heating member in contact with heating section, provided downstream of the induction heating heater, and upstream of a nip area fanned between heating section and the pressing section, which heats the heating section; an auxiliary heating member temperature sensor which measures a temperature of the auxiliary heating member; and a heating section temperature sensor provided downstream of the induction heating heater and upstream of the auxiliary heating member, which measures a temperature of the heating section.