Abstract: In a saddle-stitching apparatus, when a sheet is transported to a center-folding unit, a folding blade moves from a retrieved position to a nip position between a pair of folding rollers. A forward end of the folding blade comes into contact with a fold of the sheet, so that the sheet is folded along the fold. When the sheet is attached to the nip position between the folding rollers, the folding rollers start rotating and then, the folding blade inserts the center-folded sheet between the folding rollers. After the center-fold finishing is completed, the rotations of the folding rollers stop in timing at which the folding blade is pulled out of the nip position between the folding rollers. When pulling the folding blade out of the nip position between the folding rollers, the rotations of the folding rollers restart.

Abstract: A post-processing device includes a sheet transporting section that transports one or more sheets, a cutting section that cuts the sheet along a transporting direction of the sheet being transported by the sheet transporting section and a paper piece transporting section that transports a paper piece cut by the cutting section, and a transporting speed of the paper piece transporting section is set lower than a transporting speed of the sheet transporting section.

Abstract: When changing the turn-on/off patterns, a controller of a fixing device sets a control interval of the turn-on/off pattern so as to be longer than a first period of time that does not exert any influence to a flicker value and to be shorter than a second period of time that does not exert any influence to a response to temperature control. The controller of the fixing device selects a third turn-on/off pattern in which power difference between power of a first turn-on/off pattern before the change in the turn-on/off pattern and power of a second turn-on/off pattern after the change in the turn-on/off pattern is smaller than a set reference power difference.

Abstract: The image forming system contains an image forming apparatus and a post-processing apparatus. The post-processing apparatus includes a flattening unit that flattens a back portion of a booklet, an elevating mechanism that moves the flattening unit operating together with a conveyance of the booklet and a post-processing control portion that controls the flattening unit to perform flattening processing which flattens the back portion of the booklet during the conveyance of the booklet by the elevating mechanism. The elevating mechanism elevates a booklet-holding mechanism including the flattening unit operating together with a conveyance of the booklet. The booklet-holding mechanism and the flattening unit moves up and down between cut-off processing portion and discharging portion operating together with the conveyance of the booklet. A square back roller reciprocatively moves along the back portion of the booklet together with the movement of roller moving mechanism.

Abstract: When changing the turn-on/off patterns, a controller of a fixing device sets a control interval of the turn-on/off pattern so as to be longer than a first period of time that does not exert any influence to a flicker value and to be shorter than a second period of time that does not exert any influence to a response to temperature control. The controller of the fixing device selects a third turn-on/off pattern in which power difference between power of a first turn-on/off pattern before the change in the turn-on/off pattern and power of a second turn-on/off pattern after the change in the turn-on/off pattern is smaller than a set reference power difference.

Abstract: In a saddle-stitching apparatus, when a sheet is transported to a center-folding unit, a folding blade moves from a retrieved position to a nip position between a pair of folding rollers. A forward end of the folding blade comes into contact with a fold of the sheet, so that the sheet is folded along the fold. When the sheet is attached to the nip position between the folding rollers, the folding rollers start rotating and then, the folding blade inserts the center-folded sheet between the folding rollers. After the center-fold finishing is completed, the rotations of the folding rollers stop in timing at which the folding blade is pulled out of the nip position between the folding rollers. When pulling the folding blade out of the nip position between the folding rollers, the rotations of the folding rollers restart.

Abstract: An image forming apparatus is provided with a fixing unit in which flickers can be effectively reduced while inhibiting electric current imbalance. The fixing unit comprises a fixing heater, a switching unit for switching the fixing heater on/off with an AC power source, and a control unit which controls the switching unit to switch in units of the half wave period of the AC power source AC, and a storing unit for storing a plurality of energization patterns which define the ways of performing the switch control. Each energization pattern corresponds to a control cycle which contains a three or more odd number of the half wave periods each of which is either an OFF period and an ON period, and all the half wave periods of the smaller in number of the ON periods and the OFF periods are not successively arranged.

Abstract: A post-processing device includes a sheet transporting section that transports one or more sheets, a cutting section that cuts the sheet along a transporting direction of the sheet being transported by the sheet transporting section and a paper piece transporting section that transports a paper piece cut by the cutting section, and a transporting speed of the paper piece transporting section is set lower than a transporting speed of the sheet transporting section.

Abstract: An image forming apparatus is provided with a fixing unit in which flickers can be effectively reduced while inhibiting electric current imbalance. The fixing unit comprises a fixing heater, a switching unit for switching the fixing heater on/off with an AC power source, and a control unit which controls the switching unit to switch in units of the half wave period of the AC power source AC, and a storing unit for storing a plurality of energization patterns which define the ways of performing the switch control. Each energization pattern corresponds to a control cycle which contains a three or more odd number of the half wave periods each of which is either an OFF period and an ON period, and all the half wave periods of the smaller in number of the ON periods and the OFF periods are not successively arranged.

Abstract: The image forming system contains an image forming apparatus and a post-processing apparatus. The post-processing apparatus includes a flattening unit that flattens a back portion of a booklet, an elevating mechanism that moves the flattening unit operating together with a conveyance of the booklet and a post-processing control portion that controls the flattening unit to perform flattening processing which flattens the back portion of the booklet during the conveyance of the booklet by the elevating mechanism. The elevating mechanism elevates a booklet-holding mechanism including the flattening unit operating together with a conveyance of the booklet. The booklet-holding mechanism and the flattening unit moves up and down between cut-off processing portion and discharging portion operating together with the conveyance of the booklet. A square back roller reciprocatively moves along the back portion of the booklet together with the movement of roller moving mechanism.