| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a small rotating position detector of a deflection mirror capable of detecting the rotating position with high accuracy by simple constitution. SOLUTION: In this device, a mirror holder 21 holding a deflection mirror 22 on the front surface is made rotatable around a rotary shaft, a pair of reflection planes 37a, 37b is arranged on the back surface of the mirror holder 21 at an interval bordering the rotary shaft and a pair of photosensors 40, 41 composed of light emitting elements 40a, 41a and light receiving elements 40b, 41b as a set is oppositely arranged at an interval apart respectively from a pair of reflection planes 37a, 37b. Here, this device detects the rotating position of the deflection mirror 22 based on the differential output between the light receiving output outputted from the light receiving element of one photosensor receiving a light beam reflected by the reflection plane opposed to one photosensor emitted from the light emitting element of one photosensor and the light receiving output outputted from the light receiving element of the other photosensor receiving a light beam reflected by the reflection plane opposed to the other photosensor emitted from the light emitting element of the other photosensor.</p> |
