1. Field of the Invention
The present invention relates to a sheet processing apparatus, a method for controlling the sheet processing apparatus, a storage medium, and a program.
2. Description of the Related Art
In general, known sheet processing apparatuses include a sheet processing apparatus which performs a saddle-stitching binding process (refer to Japanese Patent Laid-Open No. 2008-013275). In the saddle-stitching binding process, after center portions of a plurality of sheets are bound, the bound sheets are folded into two so as to form a book shape and output.
When such a sheet processing apparatus performs the saddle-stitching binding process, a plurality of sheets are folded, and the plurality of folded sheets are conveyed by conveying rollers so as to be output. Note that since the plurality of sheets which are to be conveyed have been bound, the sheets are not considerably shifted from one another while the sheets are conveyed.
Furthermore, a center-folding binding process may be executed using a system the same as that used in the saddle-stitching binding process. In the center-folding binding process, a plurality of sheets which are not bound but folded can be conveyed.
However, when the center-folding binding process is performed, since the plurality of sheets to be conveyed are not bound, only a smaller number of sheets can be conveyed in a stable state when compared with a case of the saddle-stitching binding process. This is because a large number of sheets are not stably conveyed in a state in which the sheets are folded since the conveying rollers does not have sufficient force to sandwich and hold the sheets.
Therefore, when a number of sheets which can be reliably subjected to the saddle-stitching binding process are subjected to the center-folding binding process, the sheets to be output may be shifted from one another while the sheets are conveyed after the center-folding binding process is performed.