Post-processing device and image forming system

An image forming system comprising:

• a casing having an opening;
• an image forming mechanism that forms an image on a recording medium;
• a processing mechanism that is provided within the casing and performs a process on the recording medium on which the image is formed by the image forming mechanism;
• an outputting unit comprising a moving member and a contacting member contacting the recording medium, the moving member moving between a contact position to contact the recording medium and a non-contact position not to contact the recording medium, the outputting unit outputs the recording medium via the opening when the moving member is in the contact position;
• and
• a covering member that moves between a covering position to cover the opening and an un-covering position to uncover the opening to allow the recording medium to pass through the opening,
• wherein, when the processing mechanism performs the process on the recording medium, the covering member moves to the covering position, and after the process is performed by the processing mechanism, the covering member moves to the un-covering position while the moving member moves to the contact position.