A binding device includes a first pushing member that includes protrusions along one direction and that pushes a recording-material bundle as a result of pushing the protrusions against one of surfaces of the recording-material bundle, the protrusions disposed side by side in a direction that intersects the one direction; and a second pushing member that includes protrusions along the one direction and that pushes the recording-material bundle as a result of pushing the protrusions against the other surface of the recording-material bundle, the protrusions disposed side by side in the direction that intersects the one direction, wherein, in at least one end portion in the one direction of each protrusion of at least one of the first pushing member and the second pushing member, a hollow is disposed in a top portion of each protrusion.

A sheet processing apparatus includes a binding portion binding a plurality of sheets stacked on a sheet stacking portion as a bundle by deforming the sheets without a staple. The sheet processing apparatus further includes a moving member moving the sheet bundle bound at a binding position by the binding portion from the binding position and a restricting member restricting the move of the sheet bundle such that a distance between the sheet bundle and the moving member is kept to be less than a predetermined distance in moving the sheet bundle by the moving member.

The present invention is to provide a sheet processing device including: a receiving tray capable of accommodating therein a sheet having, at a part thereof, a protruding portion and a sheet not having the protruding portion in a mixed state; a first binding member that binds the accommodated sheet bundle at a substantially center thereof in a sheet conveying direction; a folding section that folds the sheet bundle bound by the first binding member in two; and a second binding member that binds protruding portions of the sheet bundle folded by the folding section on a fore edge side of the sheet bundle. With this configuration, the fore edge side of the folded and saddle-stitched sheet bundle can be bound by temporary binding. Thus, a sheet processing device capable of ensuring the security of a saddle-stitched sheet bundle can be provided.

A sheet processing device includes: a stacking unit configured to stack a plurality of sheets to obtain a sheet bundle; a stitched-sheet number acquiring unit configured to acquire a number of sheets in the sheet bundle, which is a target to be stitched; a permanent stitching unit configured to permanently stitch the sheet bundle; a temporary stitching unit configured to be capable of temporarily stitching a plurality of areas of the sheet bundle; a selecting unit configured to select any one of the permanent stitching unit and the temporary stitching unit to be used; and a stitching-process control unit configured to, when the temporary stitching unit is selected by the selecting unit, control the temporary stitching unit so as to change a number of areas that are stitched by the temporary stitching unit.

A recording-medium binding device includes a first tooth row that includes teeth arranged in a tooth arrangement direction and a second tooth row that includes teeth, that is to be engaged with the first tooth row, and that cooperates with the first tooth row to bind recording media by pinching a batch of the recording media. In the tooth arrangement direction, the first and the second tooth rows have first and second ranges. In the first range, an engaging height is a first engaging height, and a width of an effective tooth top is a first effective tooth top width. In the second range, the engaging height is a second engaging height that is smaller than the first engaging height, and a width of an effective tooth top is a second effective tooth top width that is larger than the first effective tooth top width.

A recording-medium binding device includes a first tooth row and a second tooth row. The first tooth row and the second tooth row to be engaged with the first tooth row cooperate with each other to pinch a recording medium batch. The first tooth row and the second tooth row include at least one first region and at least one second region adjacent to the at least one first region. When the first tooth row and the second tooth row are engaged with each other, teeth of the first tooth row and teeth of the second tooth row overlap one another in a tooth height direction by a first engagement overlapping amount in the at least one first region and by a second engagement overlapping amount in the at least one second region. The second engagement overlapping amount is larger than the first engagement overlapping amount.

A recording-medium binding device includes a first tooth row including plural teeth and a second tooth row including plural teeth. The first and second tooth rows include a central region and end regions. The plural teeth of each of the first and second tooth rows include at least one tooth disposed in the central region and at least one tooth dispose in each of the end regions. In a process of pinching the recording medium batch, the at least one tooth of the first tooth row in the end region and the at least one tooth of the second tooth row in the end region pinch the recording medium batch earlier than the at least one tooth of the first tooth row in the central region and the at least one tooth of the second tooth row in the central region.

A binding device includes a first pressing member that presses a recording-medium stack from one surface side of the recording-medium stack, a second pressing member disposed at a position opposed to the first pressing member to press the recording-medium stack from the other surface side of the recording-medium stack, and a reduction part provided in at least one pressing member of the first pressing member and the second pressing member to reduce creases in recording media of the recording-medium stack in a binding operation when a number of the recording media in the recording-medium stack is smaller than a maximum number of recording media to be bound by the first pressing member and the second pressing member.

A binding apparatus includes a first pressing member including a base part and multiple projections projecting from the base part, the first pressing member presses a recording media stack from one side; and a second pressing member including a base part and multiple projections projecting from the base part, the second pressing member facing the first pressing member and pressing the recording media stack from the other side. At least one of the first and second pressing members has at least one lower projection whose apex in a projecting direction closer to the base part than the apexes of the other projections are, and the lower projection is provided in the first or second pressing member that has more projections than the other, or more lower projections are provided in the first or second pressing member that has more projections than the other.

A sheet processing apparatus includes a binding portion binding a plurality of sheets stacked on a sheet stacking portion as a bundle by deforming the sheets without a staple. The sheet processing apparatus further includes a moving member moving the sheet bundle bound at a binding position by the binding portion from the binding position and a restricting member restricting the move of the sheet bundle such that a distance between the sheet bundle and the moving member is kept to be less than a predetermined distance in moving the sheet bundle by the moving member.