| 摘要 |
PROBLEM TO BE SOLVED: To reduce the weight and a dimension of a rotary polygonal body assembly by providing a rotary shaft and at least a single surface, and constituting the surface so as to have a diffraction grating element folded back in a reflecting mode on it. SOLUTION: The double rebound surface tracking polygonal body 10 having a diffraction grating element 12 folded back in a reflecting mode on a standard flat surface 14, has a rotary shaft 8. The diffraction grating element 12 folded back in a reflecting mode travels in parallel to the edge of the flat surface 14 almost crossing the rotary shaft 8. This diffraction grating element 12 folded back in a reflecting mode can remove the necessity for an excess polygonal body having a projecting surface. The diffraction grating element 12 folded back in a reflecting mode is a reflective diffraction grating, and can be an UV-cured epoxy film which is adhered to an aluminum diamond finishing surface of a conventional technology and is folded back from a master. |
