Sheet processing apparatus, image forming system and sheet processing method

An image forming system, comprising:

• a sheet processing apparatus including:
• a fold roller pair to fold a sheet being pushed into a nip thereof;
• a reinforce roller to reinforce a fold of the sheet folded by the fold roller pair;
• a support portion to move the reinforce roller in a direction perpendicular to a sheet conveying direction;
• a sensor to sense a position of the support portion;
• a distance sensing portion to sense a distance to a first position and a distance to a second position from a stop position of the support portion, when the sensor senses an abnormal stop of the support portion;
• and
• a control unit to compare the distance to the first position and the distance to the second position sensed by the distance sensing portion and to control the support portion to move in a direction where a moving distance is shorter;
• and
• an image forming apparatus including:
• an image forming unit to form an image on the sheet based on inputted image information;
• and
• a sheet feeding unit to feed the sheet to the image forming unit.

A sheet processing method, comprising:

• folding a sheet being pushed into a nip of a fold roller pair;
• reinforcing a fold of the sheet folded by the fold roller pair by a reinforce roller;
• supporting the reinforce roller with a support portion;
• sensing a position of the support portion with a sensor;
• sensing a distance to a first position and a distance to a second position from a stop position of the support portion with a distance sensing portion, when the sensor senses an abnormal stop of the support portion;
• and
• comparing the distance to the first position and the distance to the second position sensed by the distance sensing portion and controlling the support portion to move in a direction where a moving distance is shorter.