| 摘要 |
PURPOSE:To evaluate the plane inclining accuracy of a polyhedron mirror surface precisely and efficiently, by measuring the up and down fluctuation of a laser beam on the light receiving surface of a position detector based on the electric signal, which is outputted from the position detector. CONSTITUTION:A polyhedron mirror 1 is rotated by a motor. The laser beam from a laser light source 5 is reflected by every reflecting surface 1a. A light receiving surface 7a of a position sensor 7 is scanned in the direction of an arrow at a scanning angle theta'. At every scanning laser beam from each reflecting surface 1a, the Y coordinate at the specified X coordinate of the position sensor 7 is obtained. Then the coordinate is converted into a digital value by an A/D converter 14 and stored in an operation control part 15. After the sampling of (n) rotations of the polyhedron mirror 1, the plane inclining accuracy at every reflecting surface 1a is computed based on the stored data by the operation control part 15. |
