| 摘要 |
A deflection angle detecting device includes a light source, a path switching plane switching the optical path of part of light radiated from the light source, a detecting reflection surface placed on the optical path switched by the path switching plane and provided to the light-deflecting element, and a photodetector receiving light reflected by the detecting reflection surface to detect the deflection angle of the light-deflecting element in accordance with the position where the light is received. In this case, a transmission surface with positive power is interposed between the detecting reflection surface and the photodetector. |
