Patent ID: 7433645

Claim:
An image forming apparatus comprising: a generating unit adapted to generate an image forming job including image data corresponding to a plurality of pages; an image forming unit adapted to form an image on paper; a plurality of paper feeding units, each capable of feeding a paper used for image formation with the image forming unit; a storing unit adapted to store multiple pieces of paper characteristic information, each of the multiple pieces of paper characteristic information indicating characteristics of a paper stacked on each of the plurality of paper feeding units; a designating unit adapted to designate at least one paper feeding unit corresponding to paper characteristic information included in the image forming job among the plurality of paper feeding units based on the multiple pieces of paper characteristic information stored by the storing unit; a paper characteristic detecting unit adapted to detect the characteristics of paper conveyed on a paper feed path fed from any one of the plurality of paper feeding units; a first determining unit adapted to determine whether or not the characteristics of paper fed from the paper feeding unit designated by the designating unit correspond to the paper characteristic information included in the image forming job based on the detection result of the paper characteristic detecting unit; and a control unit adapted to control, in a case where two or more paper feeding units are designated by the designating unit, each of the two or more designated paper feeding units adapted to feed at least one paper sheet on the paper feed path so as to perform detection by the paper characteristic detection unit and then determination by the first determining unit for paper fed from the two or more designated paper feeding units before execution of the image forming job, wherein the image forming unit forms the image on paper based on the image data included in the image forming job in a case where the first determining unit determines that the characteristics of paper fed from one of the two or more designated paper feeding units correspond to the paper characteristic information included in the image forming job.