Abstract: An image forming apparatus configured to form a toner image on a sheet, including: a transfer belt configured to bear and transfer the toner image to the sheet conveyed at given conveying speed; a drive roller configured to drive the transfer belt; a speed detection roller held in contact with the transfer belt and configured to output roller information on rotational speed of the speed detection roller when the speed detection roller rotates as the transfer belt runs; a motor configured to drive the drive roller; a motor speed output portion configured to output motor information on rotational speed of the motor; and a control element configured to control the rotational speed of the motor.

Abstract: An image forming apparatus has an intermediate transfer belt stretched lightly across rollers to move endlessly in a sub-scanning direction upon image formation and has an outer surface to which a toner image formed by a development unit is transferred. A secondary transfer opposing roller is one of the rollers across which the intermediate transfer belt is stretched. A secondary transfer roller contacts the outer surface of the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to recording paper. A movement mechanism moves at least one of the rollers or the secondary transfer roller and changes a pressed state of the intermediate transfer belt by the secondary transfer roller at a nip of the secondary transfer opposing roller and the secondary transfer roller. A movement mechanism control unit controls a travel distance of the roller to be moved by the movement mechanism.

Abstract: A control unit is provided with an excitation current output section for outputting an excitation current to a stepping motor, a first level judging section for judging a drive stop time level indicating the duration of a time during which the stepping motor is not driven, a storage storing a plurality of starting torque values required to start driving the stepping motor and a plurality of drive stop time levels while relating them to each other, and a controller for obtaining the starting torque value corresponding to the drive stop time level judged by the first level judging section by referring to the storage, calculating an excitation current value which gives the obtained starting torque value and outputting an excitation current having the calculated excitation current value.

Abstract: An image forming apparatus has an intermediate transfer belt stretched lightly across rollers to move endlessly in a sub-scanning direction upon image formation and has an outer surface to which a toner image formed by a development unit is transferred. A secondary transfer opposing roller is one of the rollers across which the intermediate transfer belt is stretched. A secondary transfer roller contacts the outer surface of the intermediate transfer belt and transfers the toner image on the intermediate transfer belt to recording paper. A movement mechanism moves at least one of the rollers or the secondary transfer roller and changes a pressed state of the intermediate transfer belt by the secondary transfer roller at a nip of the secondary transfer opposing roller and the secondary transfer roller. A movement mechanism control unit controls a travel distance of the roller to be moved by the movement mechanism.

Abstract: A motor drive control device for controlling a rotational speed of a motor includes: a motor driver for rotationally driving a motor; a correction amount calculating section for detecting a rotational speed of an output of the motor in accordance with an alternate current signal outputted from an FG sensor and detecting a rotational position of a photoconductive drum, which is rotated by a rotational drive force of the motor, in accordance with a pulse outputted from an encoder; a speed controller for generating a speed control signal corresponding to a total correction amount, which is a sum of a correction amount calculated in the correction amount calculating section based on a rotational speed of the motor and a correction amount calculated based on a rotational position of the photoconductive drum, and outputting the generated speed control signal to the motor driver.

Abstract: An image forming apparatus configured to form a toner image on a sheet, including: a transfer belt configured to bear and transfer the toner image to the sheet conveyed at given conveying speed; a drive roller configured to drive the transfer belt; a speed detection roller held in contact with the transfer belt and configured to output roller information on rotational speed of the speed detection roller when the speed detection roller rotates as the transfer belt runs; a motor configured to drive the drive roller; a motor speed output portion configured to output motor information on rotational speed of the motor; and a control element configured to control the rotational speed of the motor.

Abstract: A control unit is provided with an excitation current output section for outputting an excitation current to a stepping motor, a first level judging section for judging a drive stop time level indicating the duration of a time during which the stepping motor is not driven, a storage storing a plurality of starting torque values required to start driving the stepping motor and a plurality of drive stop time levels while relating them to each other, and a controller for obtaining the starting torque value corresponding to the drive stop time level judged by the first level judging section by referring to the storage, calculating an excitation current value which gives the obtained starting torque value and outputting an excitation current having the calculated excitation current value.

Abstract: A motor drive control device for controlling a rotational speed of a motor includes: a motor driver for rotationally driving a motor; a correction amount calculating section for detecting a rotational speed of an output of the motor in accordance with an alternate current signal outputted from an FG sensor and detecting a rotational position of a photoconductive drum, which is rotated by a rotational drive force of the motor, in accordance with a pulse outputted from an encoder; a speed controller for generating a speed control signal corresponding to a total correction amount, which is a sum of a correction amount calculated in the correction amount calculating section based on a rotational speed of the motor and a correction amount calculated based on a rotational position of the photoconductive drum, and outputting the generated speed control signal to the motor driver.