| 摘要 |
<p>PURPOSE:To prevent slip between a paper sheet and transport rollers of respective pairs by differentiating transport speeds of transport rollers of a plurality of pairs so as to be higher as the roller pair is positioned on the lower side in the lower stream direction of paper sheet transport, and interposing one-way clutches with which transport rollers are idly rotated at stretching the paper sheet in the transport direction on respective shaft parts of transport roller. CONSTITUTION:In the case of selecting a both faces mode, a paper sheet formed with image on one face at the image transcribing part of a printer main body 2 is transported to a both faces unit 3. The paper sheet 13a is at first pinchedly held with a pair of second transport rollers 26 and transported at higher transport speed than the speed up to this point. In this case, as the paper sheet is laid over a first transport roller pair 25 and the second transport roller pair 26, it is pulled in the transport direction by difference of transport speed between the roller pair 25, 26 with the second roller pair 26. But, as an one-way clutch 39 is interposed between a rotating shaft 34 and a gear pulley 40, the first transport roller pair 25 is idly rotated, and slip of the paper sheet is avoided.</p> |
