| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a means for detecting amount of remaining sheets with high precision and reducing failure and cost. <P>SOLUTION: A remaining amount detection device has one set of light emitting means 250, a light receiving means 251, and a pair of detection parts. The light receiving means receives the light emitted by the light emitting means and penetrating a bundle of recording papers 20 loaded on a paper feeding tray 21 and converts it into voltage Va corresponding to amount of receiving light to output it. Whether the detected voltage Va is in any of scopes of detected voltage (amount of penetrated light) divided in accordance with each remaining amount of recording papers 0, 1, 2, 3, etc. fixed in advance, namely, a scope corresponding to each remaining amount is determined to detect the number of sheets. When the number of detected sheets is below the predetermined number of sheets, it is used to display alarm and control stop of display image forming operation. When running-out of paper occurs during job, it is possible to avoid occurrence of defect in image forming operation (image formation becomes useless unless running-out of paper is predicted because the number of recording papers 20-1 to 20-3 held in a paper feeding passage is smaller than the number of sheets having image formed on a transfer belt 5). <P>COPYRIGHT: (C)2007,JPO&INPIT |
