| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect the conveying condition of many sizes of sheets by less sheet sensors by arranging a pair of sheet sensors at prescribed positions, converting the sheet conveying timing into those values corresponding to the size of sheets, and comparing the values obtained after conversion with reference values so as to detect the time lag and the lag of the movement aslant. SOLUTION: Sheets fed from sheet feed cassettes 9a and 9b by sheet feed rolls 7a and 7b, respectively, are stopped temporarily at a register gate 11, and started to move simultaneously when the gate is opened. After passing the register call 12, they pass through two sheet sensors 13 and 14 which are arranged near both ends of the minimum feedable size of sheets in the direction at the right angle to the conveying direction, and arrive at a transfer equipment 5 for the transfer of toner images. Also a time from the opening of the gate to the passing of sheets through the sheet sensors 13 and 14 is measured, these values are converted into those values at the central part or both end parts of the sheets, and the time lag caused by the delay or advancement of the sheets and the sheet feed aslant are judged. If any abnormality occurs, an abnormality display lamp will light up and the printing will be stopped.</p> |
