| 摘要 |
PURPOSE:To increase the sampling period simply, by performing a plurality of samplings as to one blade of the sector mirror. CONSTITUTION:To the shaft 23 of the sector motor 4, the sector mirror 1 consisting of the mirror reflection part 11, transparent section 12, and non-reflection section 13, three parts, and the gate disc 20 having 6 notch holes 21 corresponding to the parts 11 to 13 of the sector mirror by two each, are fitted. When the sector motor 4 starts, the sector mirror 1 and the gate disc 20 are turned, the incident light to the sector mirror 1 is incident to the detector as the signal for reflection light, test piece light and non-signal light per one revolution of the sector motor 4. Since the two notch holes 21 are set to the gate disc 20 corresponding to each signal, the sampling frequency is detected as double, as if the number of revolutions or the number of blades of the sector mirror 1 were doubled. |
