| 摘要 |
PROBLEM TO BE SOLVED: To efficiently sort sheets P sequentially discharged from an image forming apparatus at a high speed.SOLUTION: When performing sheet sorting by alternately offsetting a sheet loading position on a paper receiving base 21 forward and backward with respect to a conveyance direction of sheets P, although the paper receiving base 21 is lifted and lowered in accordance with a sheet loading amount so that a sheet drop height H may be substantially constant on the basis of a detection result from a sheet height position detection optical sensor 29, the heavy paper receiving base 21 is not lifted or lowered during the sheet sorting, and an offset guide plate 52 and a first sheet abutment member 53 are moved by predetermined offset amounts for each sheet sorting. Furthermore, when moving an end fence plate 82 and a second sheet abutment member 97 by predetermined offset amounts for each sheet sorting, the second sheet abutment member 97 is moved upward by using an upward movement driving means 93. |
