Image forming apparatus

An image forming apparatus comprising:

• an image forming unit configured to form an image;
• a belt unit comprising a belt and configured to convey a recording sheet;
• a discharge unit configured to discharge the recording sheet;
• a controller configured to:
• form a first mark for detecting at least one of positional deviation and density deviation with the image forming unit on the belt;
• acquire an amount of deviation by measuring the first mark formed on the belt, the amount of deviation corresponding to the at least one of positional deviation and density deviation;
• if the amount of deviation is within a predetermined permissible range:
• determine a correction value for adjusting the at least one of positional deviation and density deviation based on the amount of deviation, and
• adjust the at least one of positional deviation and density deviation based on the correction value;
• and
• if the amount of deviation is out of the predetermined permissible range:
• form a second mark for detecting the at least one of positional deviation and density deviation on the recording sheet;
• and
• discharge the recording sheet by the discharge unit;
• wherein the belt unit is configured to convey the recording sheet such that the recording sheet passes between the belt unit and the image forming unit,
• wherein, prior to conveying in the recording sheet, the controller forms the first mark,
• wherein, prior to conveying in the recording sheet, the controller determines the correction value based on the amount of deviation being within the predetermined permissible range,
• wherein the belt unit is configured to convey the recording sheet while the controller forms the second mark based on the amount of deviation being out of the predetermined permissible range.