Patent ID: 7613422

Claim:
An image forming apparatus comprising: an image forming apparatus body in which a sheet ejection linear speed is changeable; at least one post-processing apparatus; and an intermediate conveyance unit positioned between the image forming apparatus body and the at least one post-processing apparatus, to both of which the intermediate conveyance unit is connected, the intermediate conveyance unit including: (i) a sheet feed-in section which feeds sheets ejected from the image forming apparatus body into the intermediate conveyance unit one by one at a same speed as the sheet ejection linear speed of the image forming apparatus body; (ii) a sheet storing section which stores at least two sheets that have been fed in by the sheet feed-in section, the sheet storing section including a sheet conveyance path; and (iii) a longitudinal alignment mechanism which aligns a sheet stored in the sheet storing section in a sheet longitudinal direction parallel to a conveyance direction of the sheet, the longitudinal alignment mechanism comprising: a stop member which is hit by a leading edge in a feed-in direction of a sheet that has been fed into the sheet storing section, the stop member being movable along the sheet conveyance path; a longitudinal alignment member which is hit by a trailing edge in a feed-in direction of a sheet that has been fed into the sheet storing section, the longitudinal alignment member being able to retreat from the sheet conveyance path; and paired feed-out rollers separable from each other and located on the sheet conveyance path between the stop member and the longitudinal alignment member; wherein the intermediate conveyance unit further includes a sheet feed-out section which feeds the at least two sheets stored in the sheet storing section out of the intermediate conveyance unit with the sheets superimposed on each other at a same speed as a receiving linear speed of the at least one post-processing apparatus; and wherein the image forming apparatus further comprises a control section which controls the longitudinal alignment mechanism such that the stop member is moved toward the longitudinal alignment member with the paired feed-out rollers separated from each other after a plurality of sheets are stored in the sheet storing section so as to make trailing edges in the feed-in direction of the plurality of sheets stored in the sheet storing section hit the longitudinal alignment member, and so that the plurality of sheets are nipped by the paired feed-out rollers and fed out by a driving rotation of the paired feed-out rollers while being superimposed on each other after the longitudinal alignment member has been retreated from the sheet conveyance path.