| 摘要 |
PURPOSE:To attain size reduction by using the AC waveform of a synchronous motor which rotates a rotary mirror as a time reference, and using sampling gate pulses to sample a sample side signal and a reference side signal. CONSTITUTION:A light emitting diode 11 and a phototransistor 12 are fitted over or under a mechanism part. Mirrors of the rotary mirror 3 is held horizontal in a reference side measurement state, so light from the light emitting diode 11 is reflected by one of mirrors of the rotary mirror 3. Its reflected light is photodetected by the phototransistor 12, which then turns on. Thus, whether the rotary mirror 3 is in the reference side measurement state or not is read through this phototransistor 12. |
