Abstract: A sheet processing apparatus includes a puncher, a first sensor positioned upstream of the puncher in the conveyance direction, a second sensor positioned upstream of the first detection position in the conveyance direction, a drive source configured to drive the puncher, a controller configured to control the drive source. The controller executes a control mode including a first process of controlling a rotation speed of the puncher on a basis of a detection result of the second sensor and a second process of controlling the rotation speed of the puncher on a basis of a detection result of the first sensor. In the control mode, the controller does not stop rotation of the puncher in a period between the punching process on the preceding sheet and a punching process on the succeeding sheet.

Abstract: A pressing structure for a hole-punching unit includes an axle, two wrenching pieces, a pole and two pressing pieces, wherein the axle is axially attached to a case of the hole-punching unit, with one end of the axle axially connecting to a control knob, each wrenching piece connecting to the axle near its end, the pressing piece having a spring coil disposed at its middle and pivotally connected to the pole, and the pressing piece having a pair of lapping portions extending from a first side of the spring coil, and a pair of suppressing portions extending from a second side of the spring coil, the lapping portions leaning against an upper edge of the wrenching piece for the control knob to drive the wrenching piece to move synchronously, so as to let the suppressing portions to press the hole-punching assembly and to fasten the hole-punching assembly.

Abstract: There is provided a punching device including: a die member having a plurality of die holes formed therein; a plurality of punch members which are caused to advance into the die holes to punch holes in a member to be punched; an operating member having cam portions formed along a direction intersecting the direction of advancement of the punch members, the operating member being moved along the direction intersecting the direction of advancement of the punch members to cause by a conversion function of the cam portions the punch members to advance into the die holes; and a drive unit for selectively causing advancement of the plurality of punch members by changing the direction of movement of the operating member.