Patent ID: 8002259

Claim:
An image forming apparatus, comprising: a plurality of paper sheet trays, each of the paper sheet trays accommodating a plurality of paper sheets therein, a formed image being transferred to each of the paper sheets; a plurality of detecting sections, each of which is provided in each of the paper sheet trays, for detecting a residual amount of the paper sheets accommodated in each of the paper sheet trays; and a paper sheet managing section for conducting consecutive operations including: acquiring the residual amount of the paper sheets accommodated in each of the paper sheet trays from each of the detecting sections; calculating a total sum of the residual amounts of paper sheets having same attributes; comparing the total sum of the residual amounts of the paper sheets having the same attributes with a maximum accommodating capacity of each of the paper sheet trays currently accommodating the paper sheets having the same attributes; and notifying an operator that a vacant tray can be made by collecting the residual amounts of the paper sheets having the same attributes into a specific paper sheet tray when a combination of the paper sheet trays currently accommodating the residual amounts of the paper sheets having the same attributes makes the total sum of the residual amounts of the paper sheets equal to or smaller than a maximum accommodating capacity of the specific paper sheet tray.