| 摘要 |
PURPOSE:To manufacture and assemble easily a polygon mirror, and also to improve its accuracy by attaching a plane mirror to a base material through an electrostrictive element, and correcting an error of the plane mirror by varying an applied voltage to the electrostrictive element in accordance with a rotational angle of the base material. CONSTITUTION:On each surface of a polygon 1 of a base material, a plane mirror 2 is stuck and installed to three electrostrictive elements 3 which expand and contract up and down. An applied voltage to the three electrostrictive elements 3 is supplied from the respective power sources 5 through a slip ring 4. Each surface of the plane mirror 2 is adjusted finely, the applied voltage to the electrostrictive element 3 of three points, which is required for correcting an error is grasped, this data is set to controller 7 for switching the voltage, a surface for scanning a laser beam, etc. is detected by a rotational angle sensor 6, the applied voltage to each electrostrictive element 3 is varied in accordance with its surface, and each mirror surface is adjusted finely so that an error of an angle of reflection, etc. of the laser beam is not generated. |
