Sheet finisher, sheet processing apparatus, image forming system and methods for the same

A sheet finisher comprising:

• a conveyance member for conveying a sheet to an ejection direction;
• a sheet ejection section having paired rollers, for ejecting the conveyed sheet by nipping the sheet by the paired rollers;
• and
• a control section for controlling the conveyance member and the sheet ejection section to make the paired rollers in a half-open state when conveying the sheet, and after a front end portion of the sheet in the ejection direction passes a nipping position of the paired rollers, temporarily stop conveying the sheet by the conveyance member, make the paired rollers press-contact with each other, nip and re-convey the sheet, and eject the sheet out of the finisher.

A sheet finishing method comprising:

• placing and adjusting a sheet to which a predetermined processing is carried out on a sheet placing member;
• stapling a predetermined number of the adjusted sheets;
• and
• blowing air to the sheet placing member from above of the sheet placing member,
• wherein each of the sheets is pressed against the sheet placing member by the blown air when each of the sheets to which the predetermined processing is carried out is placed on the sheet placing member, and the sheets are adjusted and stapled.

A sheet finishing method comprising:

• conveying a sheet to an ejection direction;
• and
• ejecting the conveyed sheet by nipping it by paired rollers,
• wherein the paired rollers are made in a half-open state when the sheet is conveyed, and after a front end portion of the sheet in the ejection direction passes a nipping position of the paired rollers, the sheet conveyance is temporarily stopped, and the paired rollers are press-contacted with each other, and the sheet is nipped to be re-conveyed and ejected.