Image forming apparatus

An image forming apparatus comprising:

• a pair of registration rollers that
• can be moved in a width direction orthogonal to a sheet conveyance direction,
• are rotatably supported,
• are pressed against each other in a registration position,
• are moved in the width direction to reach a predetermined home position before a sheet reaches the registration position and
• nip the sheet which has reached the registration position and rotate to covey the sheet;
• an image formation unit that
• performs scanning exposure on a member to be exposed to form an electrostatic latent image on the member to be exposed,
• thereafter develops the electrostatic latent image into a toner image and
• transfers the toner image to the sheet in a transfer position on a downstream side in the sheet conveyance direction relative to the registration position;
• a roller movement mechanism that moves the pair of registration rollers in the width direction;
• a detection unit that detects a position of the sheet in the width direction in a detection position between the registration position and the transfer position in the sheet conveyance direction;
• and
• a control unit that individually performs a displacement correction on the sheet, the displacement correction being performed by
• determining, before a target sheet which is the sheet nipped by the pair of registration rollers reaches the transfer position, based on position data of the target sheet obtained by the detection performed by the detection unit, a displacement direction and a displacement amount relative to a target position of the target sheet in the width direction as displacement information, and
• moving, from the home position, the pair of registration rollers in a direction opposite to the displacement direction indicated by the displacement information only by the displacement amount indicated by the displacement information,
• wherein the control unit
• determines, based on pieces of the displacement information of a predetermined number of the sheets that have been passed through the registration position, tendency information indicating a tendency of the displacement direction and the displacement amount relative to the target position of the sheet in the width direction, and
• performs at least one of first processing and second processing based on the tendency information,
• the control unit displaces, as the first processing, the home position from a position before the performance of the first processing in a direction opposite to the displacement direction indicated by the tendency information only by the displacement amount indicated by the tendency information and
• the control unit displaces, as the second processing, a writing start position of the electrostatic latent image in a main scanning direction from a position before the performance of the second processing in the displacement direction indicated by the tendency information only by the displacement amount indicated by the tendency information.