| 摘要 |
PURPOSE:To prevent external high frequency noise from being picked up at a photodetector by providing noise absorbing capacitor to a photodetector element fitted to a slip ring housing. CONSTITUTION:A photo transistor (TR) element 4 is fitted to a TR base 6 implanted on the slip ring housing 5 and a hybrid IC board 9 provided with two noise absorbing chip capacitors 7, 8 is bonded and fixed to the slip ring housing 5. The capacitors 7, 8 constitute respectively a high pass filter, and even if external noise comes to the collector and emitter side of the photo TR4, the external noise is driven immediately to a ground 12 through the capacitors 7, 8 and a lead wire 12. |
