Medium processing apparatus and image forming system incorporating same

A medium processing apparatus, comprising:

• a conveyor to convey a medium in a conveyance direction;
• a tray to support a plurality of media conveyed by the conveyor;
• a binder to bind the plurality of media supported on the tray;
• a mover to move the binder in a main scanning direction orthogonal to the conveyance direction along a surface of the plurality of media supported on the tray;
• and
• a switcher to guide a guided portion of the binder to switch between an oblique binding posture in which a longitudinal direction of a binding region bound by the binder is inclined with respect to the main scanning direction and a parallel binding posture in which the longitudinal direction of the binding region is oriented in the main scanning direction,
• the switcher including:
• a first passage extending in the main scanning direction, the guided portion to enter the first passage when the binder is in the oblique binding posture;
• a second passage extending in the main scanning direction on an upstream side from the first passage in the conveyance direction, the guided portion to enter the second passage when the binder is in the parallel binding posture;
• a movable wall to move between a blocking posture in which each of the first passage and the second passage is blocked by the movable wall and the first passage and the second passage communicate with each other and an open posture in which at least one of the first passage or the second passage is open;
• and
• an urging member to urge the movable wall toward the blocking posture, the movable wall to:
• guide the guided portion to the second passage while maintaining the blocking posture, when the guided portion moving along the first passage from an end side to a center side in the main scanning direction comes into contact with the movable wall,
• move to the open posture and cause the guided portion to pass when the guided portion moving along the second passage from the end side to the center side in the main scanning direction comes into contact with the movable wall;
• guide the guided portion to the first passage while maintaining the blocking posture, when the guided portion moving along the second passage from the center side to the end side in the main scanning direction comes into contact with the movable wall;
• and
• move to the open posture and cause the guided portion to pass when the guided portion moving along the first passage from the center side to the end side in the main scanning direction comes into contact with the movable wall.