| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent increase in cost and decrease in image formation speed, by detecting the presence or the absence of a sheet of paper at an early stage, while correctly deciding whether the sheet of paper has been properly placed. <P>SOLUTION: A manual insertion paper feed tray 17, on which sheets of paper of two or more different sizes, which are to be conveyed in the direction of arrow Y representing a paper conveyance direction are freely placed, is provided with first to third size group detectors 31 to 33 for detecting the size group to which the placed paper belongs, and a paper presence/absence detector 35 for detecting the presence or absence of a sheet of paper. When images are formed consecutively using sheets of paper placed on the manual insertion tray 17, the presence or the absence of each sheet of paper is detected by using the first to third size group detectors. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
