| 摘要 |
PURPOSE:To make scanning lines easily visible by making the number of reflecting surfaces of a polygon mirror for scanning larger than that of the reflecting mirror of a polygon mirror for light reception and, at the same time, by coaxially arranging both of the polygon mirrors so that part of the reflecting surfaces of one polygon mirror can be in the same plane or parallel with part of the reflecting surfaces of the other polygon mirror. CONSTITUTION:The number of the reflecting surfaces S1, S2... of a rotating polygon mirror 10 for scanning is made larger than that of the reflecting surfaces T1-T4 of a rotating polygon mirror 15 for light reception. The polygon mirrors 10 and 15 are arranged on the same axis so that at least part of the reflecting surfaces of the polygon mirror 10 can be in the same plane or parallel with part of the reflecting surfaces of the polygon mirror 15. Since the number of the reflecting surface of the rotating polygon mirror 10 for scanning is increased, the scanning number of times of the polygon mirror in the used range is increased by the increased number of the reflecting surfaces and scanning lines can be made more easily visible. On the other hand, since the polygon mirror 10 for scanning and polygon mirror 15 for light reception are separate provided in such way, the reflecting surfaces of the polygon mirror for light reception can be increased so as to improve the reading accuracy. |
