To provide a post-processing device, capable of preventing generation of post-processing defective caused by thickness of a paper bundle in a case where paper of different thickness is mixed in the single paper bundle.
In a case where a post-processing mode (for stapling, bookbinding, punching, etc.) at an operation part 153 in an image forming device, a bundle thickness determining process is executed. In the bundle thickness determining process, paper thickness data Xn obtained based on output of a paper thickness detecting sensor 909 is integrated to determine paper thickness data integrated value Sum as total of thickness of all the paper passing the paper thickness detecting sensor 909 up to now (step S104). As the paper thickness data integrated value Sum reaches a prescribed value (step S105), an overflow flat is put on (step S106), and a dividing and stapling process is executed (step S107).
MIYAKE NORIFUMI
FUJII TAKAYUKI
FUKATSU YASUO
HANADA TAKAKO
