Image forming apparatus comprising a plurality of sheet trays, image forming system and program product

An imaging device, comprising: imaging unit; Multiple trays; Comprises a paper unit, a signal feedback in the paper according one of trays; aA relationships storage unit, a storing plate and a relationships between the paper; The priority with unit, for allocating or the sample tray to setting the preset priority; Comprises a paper control unit, wherein setting the preset priority to the tray, and a ends and a tray of wherein the tray is with paper, and; when ends the preset priority to the type is a ends paper's type, maintained according to the corresponding relationships searching ends of the sample a paper's at least one tray, order to a searching to tray is with paper; And the setting unit, a corresponding to the sample change of paper wherein the imaging unit having.