| 摘要 |
PURPOSE:To adjust a scan length by varying a deflection angle of a light beam by a rotary polygon mirror, in accordance with expansion and contraction of a scan distance required for the light beam by a size variation of a recording medium, by providing plural rotary polygon mirrors whose number of faces is different from each other. CONSTITUTION:The titled scanner contains a light source optical system 1 for emitting a light beam, at least two pieces of rotary polygon mirrors 10, 12 having each different number of faces, an incident optical path switching optical system 6 for making an incident light beam incident selectively on one of the rotary polygon mirrors 10, 12, a reflecting optical path switching optical system 30 for setting the reflecting optical beams which have been reflected and deflected by the rotary polygon mirrors 10, 12, into a prescribed plane, respectively, and a scanning lens system 32 which has been placed in an optical path of the reflected light beams which have been set in the prescribed plane by this optical system 30. It can be applied suitably to a device for reading a radiation image which has been recorded in a cumulative phosphor for showing an accelerated phosphorescence property. In this way, even if a size of a body to be scanned is varied, an effective scan time rate is held high, and a light beam scan can be executed efficiently. |
