| 摘要 |
PURPOSE:To detect whether the controller is operated exactly or not at the time of especially controlling the beam diameter of the printer, and also, whether the prescribed light quantity is outputted to the plate making surface or not, when this beam diameter is changed. CONSTITUTION:In the printer for reflecting light emitted from a light source by the surface of a polygon mirror rotated by a motor and executing exposure and write to a sensitized material through a lens, a light quantity sensor 6 set to the outside of a printing area, a beam switching unit 11 having plural apertures, a driving circuit 8 for executing rotation control to this beam switching unit 11 are provided, and constituted so that light outputted through the aperture of the beam switching unit 11 with respect to light emitted from the light source is detected by the light quantity sensor 6. |
