An image forming apparatus according to the present invention includes: a conveyor that conveys continuous paper; an image former that forms an image on the continuous paper being conveyed; a fixer that pressurizes and heats the continuous paper passing through a fixing nip by bringing rotor into pressure contact with each other to form the fixing nip and rotating the rotors, to fix an image on the continuous paper; and a hardware processor that releases the fixing nip and stop rotation of the rotors and conveyance of the continuous paper by the conveyor when a lastly formed image in accordance with a print job passes through the fixing nip, the hardware processor then performing re-conveyance in which the continuous paper is conveyed by the conveyor with the fixing nip being left released and without rotation of the rotors, before performing warm-up of the fixer.

A fixing device includes: a fixing element; a heat source heating the fixing element; a press roller pressed against the fixing element, to form with the fixing element a nip region where a recording sheet passes; a driver device rotating the press roller; and a controller controlling the heat source to set a temperature of the fixing element to a predetermined target temperature, and controlling the driver device to set a rotation speed of the press roller to a predetermined target rotation speed. The controller determines the target rotation speed by adding a correction value to a normal rotation speed, based on the temperature of the fixing element at start of job, a type of the recording sheet, ambient temperature, and elapsed time from start of paper feed, and sets the rotation speed of the press roller to the target rotation speed.

A conveyance control device includes a fixing device including a first rotary body, a cooling device including a second rotary body, and control circuitry. The circuitry records a first drive amount for the second body when the first and second bodies are driven at a speed, a second drive amount for the second body when the second body is driven without the first body being driven, a third drive amount for the second body when the second body is driven to rotate faster than a rotating speed and the first body is driven, and a fourth drive amount for the second body when the second body is driven to rotate slower than the rotating speed and the first body is driven. The circuitry performs correction based on the drive amounts in such a manner that a drive amount of the second body becomes equivalent to the second drive amount.

Provided is an image forming apparatus capable of preventing or suppressing occurrence of density unevenness even when a shearing force is applied between an image face on paper and a fixing belt. The image forming apparatus includes an image former, a fixer, and a controller. The image former forms a toner image constituted by a plurality of dots each containing a toner on paper. The fixer includes a fixing member moving at a first velocity and a pressure member forming a fixing nip portion with the fixing member and moving at a second velocity, and fixes the toner image on the paper at the fixing nip portion. When the first velocity and the second velocity at the fixing nip portion are different, the controller determines a toner amount to be attached to paper so as to make a toner amount distribution different in each of the dots before fixing.

A fixing device according to an embodiment includes an endless belt, a pressure element, a heating member, an adjustment mechanism, and a controller. The pressure element conveys and presses a sheet to the endless belt. The heating member is on the inner side of the belt and has a heat generating element for heating the belt. The adjustment mechanism moves the heating member or the pressure element to adjust the nip width between the heating member and the pressure element. The controller controls the adjustment mechanism so that A>BN is satisfied, where A is the nip width during a fixing process in which a colored material is fixed to the sheet, B is the nip width during a heating process conducted before the fixing process, and N is the length of the heat generating element in the sheet conveyance direction.

A fixing device includes: a first pressing unit that rotates; a second pressing unit that comes into press-contact with the first pressing unit to form a nip portion at which a toner image is fixed on a recording medium; a heating unit that heats at least one of the first and second pressing units; and a first cleaning unit that comes into contact with a surface of at least one of the first and second pressing units to perform cleaning, the fixing device being configured to perform a high-temperature rotating operation that includes rotating the first or second pressing unit and heating a surface of the first or second pressing unit coming into contact with the first cleaning unit to a temperature higher than a temperature during fixing; and then to perform a cleaning operation that includes causing a cleaning material to pass through the nip portion.

An image forming apparatus including: a fixer that fixes a toner image formed on a recording medium by pressing and heating the recording medium nipped in a nip portion formed by causing two rotating bodies to pressedly abut on each other, and conveying the recording medium by rotating the rotating bodies; a motor that drives the rotating bodies by transmitting a torque to at least one of the rotating bodies; a torque detector that detects the torque transmitted to the rotating body by the motor; a temperature detector that detects temperature of the rotating body; a speed detector that detects a conveyance speed for conveying the recording medium by the fixer; and a controller that corrects the detected torque based on at least any one of the detected temperature and the detected conveyance speed and predicts a life of the fixer based on the corrected torque.

A fixing device according to an embodiment includes an endless belt, a pressure element, a heating member, an adjustment mechanism, and a controller. The pressure element conveys and presses a sheet to the endless belt. The heating member is on the inner side of the belt and has a heat generating element for heating the belt. The adjustment mechanism moves the heating member or the pressure element to adjust the nip width between the heating member and the pressure element. The controller controls the adjustment mechanism so that A>BN is satisfied, where A is the nip width during a fixing process in which a colored material is fixed to the sheet, B is the nip width during a heating process conducted before the fixing process, and N is the length of the heat generating element in the sheet conveyance direction.

Provided is an image forming apparatus capable of preventing or suppressing occurrence of density unevenness even when a shearing force is applied between an image face on paper and a fixing belt. The image forming apparatus includes an image former, a fixer, and a controller. The image former forms a toner image constituted by a plurality of dots each containing a toner on paper. The fixer includes a fixing member moving at a first velocity and a pressure member forming a fixing nip portion with the fixing member and moving at a second velocity, and fixes the toner image on the paper at the fixing nip portion. When the first velocity and the second velocity at the fixing nip portion are different, the controller determines a toner amount to be attached to paper so as to make a toner amount distribution different in each of the dots before fixing.

A control unit of the invention compares printing setting suitable for a determined type of a recording material and printing setting of the recording material input by a user, and in a case where a difference between the printing setting suitable for the determined type of the recording material and the printing setting of the recording material input by the user falls in a predetermined range, the control unit performs a printing operation in accordance with the printing setting of the recording material input by the user, and in a case where the difference is greater than the predetermined range, the control unit performs the printing operation by changing the printing setting of the recording material input by the user, which is used when the difference is smaller than the predetermined range.