Sheet processing device and image formation apparatus provided with the same

A sheet processing device comprising:

• a plurality of pressing roller units that press a folding loop of a folded sheet bundle;
• and
• a support unit that is moved along the folding loop while supporting the pressing roller units, wherein
• the pressing roller units each include, as one unit, a rotatable pressing roller that presses the folding loop, a frame that movably holds a roller bracket that holds the pressing roller, and an elastic spring that is disposed between the frame and the roller bracket so as to bias the pressing roller in a sheet pressing direction, and
• the support unit supports, as one unit, a plurality of rows of the pressing roller units such that each pressing roller unit is arranged in a pair opposed to each other and that an interval between the pair is reduced stepwise from a downstream side to an upstream side in a moving direction of the support unit and includes an adjustment member for adjusting a position of the pressing roller units.

A sheet processing device comprising:

• a plurality of rows of pressing rollers that press a folding loop of a folded sheet bundle in a thickness direction;
• and
• a support unit that moves the plurality of rows of pressing rollers along the folding loop with the pressing rollers of each row opposed to each other and supports the plurality of rows of pressing rollers such that an interval between the opposed pressing rollers is reduced stepwise from a downstream side to an upstream side in a moving direction of the support unit, wherein
• the support unit includes, between the pressing rollers of adjacent rows in the moving direction, a guide member that guides the folding loop.

A sheet processing device comprising:

• a plurality of rows of pressing members that press a folding loop of a folded sheet bundle in a thickness direction;
• and
• a support unit that is moved along the folding loop with the pressing members of each row opposed to each other and supports the plurality of rows of the pressing members such that an interval between the opposed pressing members is reduced stepwise from a downstream side to an upstream side in a moving direction of the support unit;
• and
• a guide plate disposed between the pressing members of adjacent rows in the moving direction of the support unit so as to guide the folding loop, wherein
• the guide plate is positioned by the pressing member therebefore or thereafter.