Finisher for image forming apparatus

Claim 1

A sorter for sorting sheets for use in an image forming apparatus, which comprises: a sheet feeding mechanism feeding sheets from said image forming apparatus; a plurality of bins accepting said sheets fed from said sheet feeding mechanism, said bins being arranged in a vertical direction; a discharging mechanism discharging said sheets so as to be accepted into said bins; an aligning mechanism aligning a side of said sheets in the bins, wherein said aligning mechanism is arranged laterally of said bins; a bin moving mechanism moving said bins to predetermined positions in an upward or downward direction so as to sort said sheets, said bin moving mechanism having a mechanism varying spacing between the bins so as to increase spacing between a group of at least five bins which are directly adjacent one another such that the efficiency of stacking of said sheets in said bins and of aligning of said sheets in said bins is increased, wherein said bin moving mechanism moves said bins to establish positional relationships therebetween, wherein interval A comprises an interval between a first bin of said five bins for accepting said discharged sheets from said discharging mechanism and a third bin of said five bins located at a position immediately over said first bin, interval B comprises an interval between said first bin and a second bin of said five bins located at a position immediately under said first bin, interval D comprises an interval between said third bin located at a position immediately over said first bin and a fifth bin of said five bins located at a position immediately over said third bin and wherein said intervals A, B and D are broader than an interval E between other adjacent regular bins; and said aligning mechanism and said bin moving mechanism operate at the same time, wherein said interval A is broader than said interval E while said first and third bins which form the interval A are moved by said bin moving mechanism to predetermined positions in the upward or downward direction so as to sort said sheets.