Image forming apparatus with accurate sheet conveyance

An image forming apparatus configured to form an image on a sheet by a sheet conveyance operation in which the sheet is conveyed and an image forming operation in which the image is formed on the sheet that is at rest, the sheet conveyance operation and the image forming operation being repeated alternately a plurality times, comprising:

• a conveyor mechanism having a motor and configured to convey the sheet by a driving force of the motor;
• a motor driver configured to drive the motor;
• and
• a controller configured to implement a control relating to the sheet conveyance operation by execution of motor control processing in which a control input with respect to the motor is calculated and a signal corresponding to the control input is inputted to the motor driver,
• wherein the controller implements the motor control processing in each sheet conveyance operation such that the control input is repeatedly calculated for permitting the sheet to be conveyed to a target stop position correspond to a current sheet conveyance operation and for keeping the sheet located at the target stop position and such that the signal corresponding to the calculated control input is repeatedly inputted to the motor driver, and
• wherein, in the motor control processing, the controller calculates the control input such that, after the sheet has reached the target stop position, the control input is equal to a hold control input required for permitting the sheet to be kept located at the target stop position and such that, at a start point of the motor control processing, the control input is not smaller than the hold control input in the motor control processing in a previous sheet conveyance operation.