Sheet processing apparatus and sheet processing method

A sheet processing apparatus comprising:

• a processing apparatus;
• and
• a saddle unit means which (a) is supported to pull out the processing apparatus along a direction orthogonal to a sheet transport direction, (b) has a stapling means, a folding blade means, a pair of folding rollers means, a first sheet transport path, and a second sheet transport path, the stapling means configured to perform a staple process to a bundle of sheets, the folding blade means and the pair of folding rollers means configured to perform a folding process to the bundle of sheets, the first sheet transport path configured to have a first transport guiding means and a second transport guiding means, and transporting the sheet to the stapling means and the pair of folding roller means, the first transport guiding means forming an outside wall surface of the first sheet transport path, the second transport guiding means forming an inside wall surface of the first sheet transport path, the second sheet transport path configured to transport switchback for performing the staple process and the folding process to the sheet which is transported to the first transport path, (c) when the saddle unit means is pulled out to the outside of the processing apparatus, opens the first transport guiding means to expose the outside of the first sheet transport path, and opens the second transport guiding means to expose the inside of the first sheet transport path.