Trimming device, post-processing device, and image forming apparatus with post-processing device

A trimming device comprising:

• a moving unit including
• a roller that transports a booklet which includes one or more sheets and which is folded in half at a center portion of the booklet, with a folded portion of the booklet at a front,
• a skew correction gate that corrects a posture of the booklet in response to a leading end of the booklet transported by the roller abutting against the skew correction gate, the skew correction gate being capable of advancing to an abutting position on a path of the booklet and retracting from the path, and
• an upper guide that extends at least between the roller and the skew correction gate, the upper guide guides an upper surface of the booklet, the moving unit being movable in a transport direction between (i) a predetermined upstream position and (ii) a downstream position downstream of the upstream position in the transport direction;
• a lower guide that guides a lower surface of the booklet transported by the roller;
• and
• a cutter that cuts a downstream fore edge portion of the booklet in the transport direction, the cutter being capable of advancing to the path of the booklet and retracting from the path of the booklet, wherein
• the upper guide is configured such that a gap between the upper guide and the lower guide widens in accordance with a thickness of the booklet to allow the booklet to pass through the gap,
• the roller includes
• a lower roller that comes into contact with the lower surface of the booklet, and
• an upper roller that comes into contact with the upper surface of the booklet, the upper roller being capable of moving up and down, and
• an upstream portion of the upper guide at the upstream position is supported by the upper roller and moves up and down as the upper roller moves up and down, and
• the upper roller includes
• a rotation shaft, and
• a bearing including an elongating slot into which the rotation shaft is inserted, and
• the upstream portion is supported by the bearing.

A trimming device comprising:

• a moving unit including
• a roller that transports a booklet which includes one or more sheets and which is folded in half at a center portion of the booklet, with a folded portion of the booklet at a front,
• a skew correction gate that corrects a posture of the booklet in response to a leading end of the booklet transported by the roller abutting against the skew correction gate, the skew correction gate being capable of advancing to an abutting position on a path of the booklet and retracting from the path, and
• an upper guide that extends at least between the roller and the skew correction gate, the upper guide guides an upper surface of the booklet, the moving unit being movable in a transport direction between (i) a predetermined upstream position and (ii) a downstream position downstream of the upstream position in the transport direction;
• a lower guide that guides a lower surface of the booklet transported by the roller;
• and
• a cutter that cuts a downstream fore edge portion of the booklet in the transport direction, the cutter being capable of advancing to the path of the booklet and retracting from the path of the booklet, wherein
• the upper guide is configured such that a gap between the upper guide and the lower guide widens in accordance with a thickness of the booklet to allow the booklet to pass through the gap,
• the upper guide or the lower guide includes a boss that defines a minimum interval between the lower guide and the upper guide,
• the skew correction gate moves upward to retract from the path, and
• in moving upward, the skew correction gate hooks the upper guide to lift a downstream portion of the upper guide.