Patent ID: 7207559

Claim:
A sheet treating apparatus for subjecting a sheet transported from an image forming apparatus to treatment, comprising: a sheet stacking portion which is arranged to stack a sheet ejected from the image forming apparatus, said sheet stacking portion being without an independent transporting drive force for transporting said sheet; a sheet treating portion which is arranged to subject the sheet transported from the image forming apparatus to a post-treatment; a sheet guiding portion which is arranged to selectively guide the sheet transported from the image forming apparatus to one of said sheet stacking portion and said sheet treating portion, wherein said sheet guiding portion comprises: a displacement body which can be displaced between a first position for guiding the sheet to said sheet stacking portion and a second position for guiding the sheet to said sheet treating portion; a drive portion which displaces said displacement body from the first position for guiding the sheet to said sheet stacking portion to the second position for guiding the sheet to said sheet treating portion; and a power supply activated biasing portion which, when said displacement body is in the position for guiding the sheet to said sheet treating portion and a power supply is turned off, biases said displacement body to be in the position for guiding the sheet to said sheet stacking portion; and a sheet treatment control portion which controls the sheet treating apparatus; wherein said sheet treating control portion arranges said sheet guiding portion to be in the first position to guide the sheet to said sheet stacking portion in a state in which the power supply of said sheet treating apparatus is turned off.