Sheet-processing apparatus that folds a sheet, and image-forming system using the same

A sheet-processing apparatus comprising:

• a pair of folding rollers that folds a sheet;
• a thrusting member that thrusts the sheet to a position between the pair of folding rollers;
• a driving member that drives the pair of folding rollers to rotate;
• and
• a control unit that controls the driving member,
• wherein the control unit determines whether or not to perform step-out prevention control based on an image-forming condition, the step-out prevention control comprising controlling the driving member to stop or decelerate rotation of the pair of folding rollers at a timing at which the thrusting member is pulled out of the position between the pair of folding rollers,
• wherein after the thrusting member thrusts the sheet to the position between the pair of folding rollers, the control unit controls the driving member to stop or decelerate the rotation of the pair of folding rollers, at the timing at which the thrusting member is pulled out of the position between the pair of folding rollers, in a case in which the control unit has determined to perform the step-out prevention control, and
• wherein after the thrusting member thrusts the sheet to the position between the pair of folding rollers, the control unit does not control the driving member to stop or decelerate the rotation of the pair of folding rollers, at the timing at which the thrusting member is pulled out of the position between the pair of folding rollers, in a case in which the control unit has determined not to perform the step-out prevention control.

An image-forming system comprising:

• an image-forming apparatus that forms an image on a sheet;
• and
• a sheet-processing apparatus that performs a sheet processing on the sheet on which the image is formed,
• wherein the sheet-processing apparatus comprises:
• a pair of folding rollers that folds the sheet;
• a thrusting member that thrusts the sheet to a position between the pair of folding rollers;
• a driving member that drives the pair of folding rollers to rotate;
• and
• a control unit that controls the driving member, wherein after the thrusting member thrusts the sheet to the position between the pair of folding rollers, the control unit controls the driving member to stop the rotation of the pair of folding rollers, at a timing at which the thrusting member is pulled out of the position between the pair of folding rollers.

An image-forming system comprising:

• an image-forming apparatus that forms an image on a sheet;
• and
• a sheet-processing apparatus that performs a sheet processing on the sheet on which the image is formed,
• wherein the sheet-processing apparatus contains:
• a pair of folding rollers that folds the sheet;
• a thrusting member that thrusts the sheet to a position between the pair of folding rollers;
• a driving member that drives the pair of folding rollers to rotate;
• and
• a control unit that controls the driving member,
• wherein the control unit determines whether or not to perform step-out prevention control based on an image-forming condition, the step-out prevention control comprising controlling the driving member to stop or decelerate rotation of the pair of folding rollers at a timing at which the thrusting member is pulled out of the position between the pair of folding rollers,
• wherein after the thrusting member thrusts the sheet to the position between the pair of folding rollers, the control unit controls the driving member to stop or decelerate the rotation of the pair of folding rollers, at the timing at which the thrusting member is pulled out of the position between the pair of folding rollers, in a case in which the control unit has determined to perform the step-out prevention control, and
• wherein after the thrusting member thrusts the sheet to the position between the pair of folding rollers, the control unit does not control the driving member to stop or decelerate the rotation of the pair of folding rollers, at the timing at which the thrusting member is pulled out of the position between the pair of folding rollers, in a case in which the control unit has determined not to perform the step-out prevention control.