| 摘要 |
<p>PROBLEM TO BE SOLVED: To precisely and automatically sense change of thickness of a sheet by sensing change of reflected light quantity by a reflecting surface to vary in accordance with thickness of the sheet by a reflection type optical sensor. SOLUTION: Reflected light quantity which an optical sensor 140 receives from a reflecting surface 138 is decided by an interval of the reflecting surface 138 and the optical sensor 140 and an inclination of the reflecting surface 138. When a sheet S is inserted between a feed roller 114 and a friction roller 128, one end side of a friction roller guide 130 to which the friction roller 128 is connected is pushed upward by the sheet S, while the reflecting surface 138 on the other end side connected to a spring 132 is pushed downward. As moving quantity at this time is corresponding to thickness of the sheet S, an interval between the reflecting surface 138 and the optical sensor 140 changes in accordance with thickness of the sheet S. Consequently, reflected light quantity which the optical sensor 140 receives also changes proportionally in accordance with thickness of the sheet S. In such a principle, it is possible to precisely sense change of thickness of the sheet S.</p> |
