A sheet post-processing device includes a conveying section that conveys a paper sheet; a punch section that punches punch holes in the paper sheet conveyed by the conveying section; a stacker section that stores the paper sheet in which the punch holes are punched by the punch section; a binding section that binds a paper sheet bundle stored in the stacker section with a binding member; and a controller that controls the above sections. The controller selectively performs a ring binding mode and a direct binding mode. The ring binding mode is a mode in which punch holes are punched in the paper sheet by the punch section and then the binding member is made to penetrate the punch holes for binding. The direct binding mode is a mode in which the binding member is directly driven into the paper sheet bundle without punching the punch holes in the sheet.

A sheet post-processing device includes a conveying section that conveys a paper sheet; a punch section that punches punch holes in the paper sheet conveyed by the conveying section; a stacker section that stores the paper sheet in which the punch holes are punched by the punch section; a binding section that binds a paper sheet bundle stored in the stacker section with a binding member; and a controller that controls the above sections. The controller selectively performs a ring binding mode and a direct binding mode. The ring binding mode is a mode in which punch holes are punched in the paper sheet by the punch section and then the binding member is made to penetrate the punch holes for binding. The direct binding mode is a mode in which the binding member is directly driven into the paper sheet bundle without punching the punch holes in the sheet.

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 when an end portion of the at least one pressing member is pressed against the recording-medium stack.

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 when an end portion of the at least one pressing member is pressed against the recording-medium stack.

A sheet processing apparatus includes a conveying portion, a stack portion on which sheets conveyed by the conveying portion are stacked, a first regulating portion regulating a position of a sheet bundle stacked on the stack portion in a crossing direction, a second regulating portion regulating a position of a sheet bundle on the stack portion in a conveying direction, a first binding device moved in the crossing direction and binding a corner portion of a sheet bundle by a staple, a second binding device binding a corner portion of a sheet bundle without a staple, and a controller positioning the first binding device and binding a corner portion of a sheet bundle by the first binding device. The controller also moves the second binding device and binds a corner portion of a sheet bundle without a staple by the second binding device.

A sheet processing apparatus includes a conveying portion, a stack portion on which sheets conveyed by the conveying portion are stacked, a first regulating portion regulating a position of a sheet bundle stacked on the stack portion in a crossing direction, a second regulating portion regulating a position of a sheet bundle on the stack portion in a conveying direction, a first binding device moved in the crossing direction and binding a corner portion of a sheet bundle by a staple, a second binding device binding a corner portion of a sheet bundle without a staple, and a controller positioning the first binding device and binding a corner portion of a sheet bundle by the first binding device. The controller also moves the second binding device and binds a corner portion of a sheet bundle without a staple by the second binding device.

A sheet binding device includes a first tooth-shaped member that has plural arranged teeth, and a second tooth-shaped member that has plural arranged teeth, bites the first tooth-shaped member to clamp and bind sheets in cooperation with the first tooth-shaped member, and is tilted relative to the first tooth-shaped member from a beginning of biting to a completion of biting.

A binding apparatus includes: a first pressing member that presses a recording-medium stack from one side of the recording-medium stack; a second pressing member that faces the first pressing member and presses the recording-medium stack from the other side of the recording-medium stack; and a suppressing part provided in at least one of the first pressing member and the second pressing member, the suppressing part suppressing damage to recording media that may be caused when a recording-medium stack including a smaller number of sheets than the maximum number of sheets that can be bound is bound with the first pressing member and the second pressing member.

A binding apparatus includes: a first pressing member that presses a recording-medium stack from one side of the recording-medium stack; a second pressing member that faces the first pressing member and presses the recording-medium stack from the other side of the recording-medium stack; and a suppressing part provided in at least one of the first pressing member and the second pressing member, the suppressing part suppressing damage to recording media that may be caused when a recording-medium stack including a smaller number of sheets than the maximum number of sheets that can be bound is bound with the first pressing member and the second pressing member.

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 when an end portion of the at least one pressing member is pressed against the recording-medium stack.