Patent ID: 7599639

Claim:
A sheet post-processing apparatus connected to an image forming apparatus, comprising: a sheet conveying portion which receives a sheet discharged from an apparatus on an upstream side, conveys and discharges the sheet to an apparatus on a downstream side or a discharge tray; a sheet post-processing portion which carries out post-processing on the sheet; and a power saving control portion which renders said sheet post-processing apparatus into a power saving state, wherein said power saving control portion maintains electric power supply to said sheet conveying portion, and interrupts electric power supply to said sheet post-processing portion, and wherein when there is no instructions for a post-processing operation from the image forming apparatus, said sheet post-processing apparatus, even in said power saving state, conveys a sheet which is discharged, from said apparatus on the upstream side to the apparatus on the downstream side or the discharge tray with use of said sheet conveying portion to which the electric power is maintained by said power saving control portion.