Sheet processing device

A sheet processing device comprising:

• a processing tray on which a sheet is stacked;
• a processing unit which performs a predetermined processing on the sheet on the processing tray;
• a discharge port through which the processed sheet is discharged;
• a discharge rollers pair having a lower roller provided in the discharge port and an upper roller facing the lower roller, the discharge rollers pair conveying the sheet on the processing tray;
• a supporting arm which supports the upper roller and is provided to be turnable between a first position where the upper roller comes into contact with the lower roller to hold the sheet on the processing tray and a second position where the upper roller separates from the lower roller to open the discharge port;
• an interlock mechanism which stops a performing of the processing by the processing unit when a turning of the supporting arm to the second position is detected;
• and
• a controller which controls the processing unit, the supporting arm and the interlock mechanism,
• wherein the interlock mechanism includes:
• a switch which detects the turning of the supporting arm to the second position;
• and
• a switch moving mechanism which moves the switch to an actuator non-detective position and an actuator detective position,
• wherein the controller controls the supporting arm so as to perform a pre-processing where the supporting arm is turned to the second position to receive the sheet between the upper roller and the lower roller every time when the sheet is conveyed, and then turned to the first position to convey and stack the received sheet on a predetermined position on the processing tray,
• controls the processing unit to perform the processing on the stacked sheet after the pre-processing, and
• controls the switch moving mechanism to move the switch to the non-detective position during the pre-processing and to move the switch to the detective position when the processing is performed.