A sheet stacking apparatus includes a discharging portion including a nip portion nipping and conveying a sheet, a stacking portion on which the sheet discharged by the discharging portion is stacked, an air blowing unit configured to blow air toward a lower face of the sheet being discharged by the discharging portion, and an air volume control portion configured to control the air blowing unit such that a volume of the air blown by the air blowing unit is switched from a first air volume to a second air volume which is smaller than the first air volume while the nip portion of the discharging portion is nipping and conveying the sheet to set the volume of the air to the second air volume in a case where a trailing end of the sheet discharged by the discharging portion passes through the nip portion.

An image forming apparatus includes an image forming device, a transport route, a purge transport route, an image forming transport route, a transport roller, and a blowing machine. The image forming device forms an image on a sheet. The transport route extends to a predetermined position. The purge transport route extends to a downstream side in a sheet transport direction, from the predetermined position. The image forming transport route is branched from the purge transport route at the predetermined position, and extends toward the image forming device. The transport roller transports the sheet along the transport route, and along one of the purge transport route and the image forming transport route. The blowing machine delivers the sheet to one of the purge transport route and the image forming transport route, by blowing air to the sheet being transported along the transport route.

A sheet stacking apparatus includes a discharging portion including a nip portion nipping and conveying a sheet, a stacking portion on which the sheet discharged by the discharging portion is stacked, an air blowing unit configured to blow air toward a lower face of the sheet being discharged by the discharging portion, and an air volume control portion configured to control the air blowing unit such that a volume of the air blown by the air blowing unit is switched from a first air volume to a second air volume which is smaller than the first air volume while the nip portion of the discharging portion is nipping and conveying the sheet to set the volume of the air to the second air volume in a case where a trailing end of the sheet discharged by the discharging portion passes through the nip portion.

An aspect of the present invention includes: a sheet storage unit configured to store sheets; an air blowing unit configured to blow air; a duct configured as a flow passage to an air blowing outlet for blowing air sent from the air blowing unit toward the front end of an upper part of a sheet bundle stored in the sheet storage unit; a suction transport unit configured to suck a sheet floating from the sheet bundle upward and transport the sheet; a shutter member configured to block the flow passage in the duct; and an openable/closeable member configured to open an opening part of the duct, such that air staying in the duct by blocking the flow passage by the shutter member is discharged from the opening part.

An image forming apparatus includes an image forming portion; a discharge portion configured to discharge a recording material on which an image is formed by the image forming portion, wherein a delivery conveyance portion having a power source circuit is mountable in a space adjacent to the image forming portion and configured to convey the recording material to a post-processing apparatus; a detection unit configured to detect a temperature; a cooling unit configured to cool the image forming portion; and a control unit configured to control, in a case where the delivery conveyance portion is mounted, rotation of the cooling unit based on the temperature detected by the detection unit in a standby state in which an image forming operation is not performed.

An image forming apparatus includes an image forming portion; a discharge portion configured to discharge a recording material on which an image is formed by the image forming portion, wherein a delivery conveyance portion having a power source circuit is mountable in a space adjacent to the image forming portion and configured to convey the recording material to a post-processing apparatus; a detection unit configured to detect a temperature; a cooling unit configured to cool the image forming portion; and a control unit configured to control, in a case where the delivery conveyance portion is mounted, rotation of the cooling unit based on the temperature detected by the detection unit in a standby state in which an image forming operation is not performed.

An image forming apparatus, including: an image forming portion; a discharge portion configured to discharge a recording material on which an image is formed by the image forming portion, wherein a delivery conveyance portion having a power source circuit is mountable in a space adjacent to the image forming portion and configured to convey the recording material to a post-processing apparatus; a detection unit configured to detect a temperature; a cooling unit configured to cool the image forming portion; and a control unit configured to control, in a case where the delivery conveyance portion is mounted, rotation and stop of the cooling unit based on the temperature detected by the detection unit in a second state in which start of an operation of forming the image is waited for after a first state in which the image is formed on the recording material by the image forming portion.

An image forming apparatus, including: an image forming portion; a discharge portion configured to discharge a recording material on which an image is formed by the image forming portion, wherein a delivery conveyance portion having a power source circuit is mountable in a space adjacent to the image forming portion and configured to convey the recording material to a post-processing apparatus; a detection unit configured to detect a temperature; a cooling unit configured to cool the image forming portion; and a control unit configured to control, in a case where the delivery conveyance portion is mounted, rotation and stop of the cooling unit based on the temperature detected by the detection unit in a second state in which start of an operation of forming the image is waited for after a first state in which the image is formed on the recording material by the image forming portion.

A sheet stacking apparatus includes a discharging portion including a nip portion nipping and conveying a sheet, a stacking portion on which the sheet discharged by the discharging portion is stacked, an air blowing unit configured to blow air toward a lower face of the sheet being discharged by the discharging portion, and an air volume control portion configured to control the air blowing unit such that a volume of the air blown by the air blowing unit is switched from a first air volume to a second air volume which is smaller than the first air volume while the nip portion of the discharging portion is nipping and conveying the sheet to set the volume of the air to the second air volume in a case where a trailing end of the sheet discharged by the discharging portion passes through the nip portion.

A sheet discharging device includes a shift tray 202 on which a sheet P1 is stacked, a discharging roller 6 that discharges a sheet P2 onto the shift tray 202, a blowing device 230 that sends air to a lower surface of the sheet P2 discharged by the discharging roller 6, a blocking member 231 that blocks air sent to the lower surface of the sheet P2 from a blowing port 230-2 of the blowing device 230, and a control unit that controls the blocking amount of the blocking member 231. The blocking amount is determined based upon sheet information including sheet-type information, sheet-size information, and sheet-thickness information, for example.