| 摘要 |
PURPOSE:To ease a mirror shock by providing a photocoupler in a mirror box, detecting that the mirror has arrived at the upper dead point position, and applying the electrical brake to a motor by the detection signal thereof. CONSTITUTION:In order to detect the arrival of a mirror 8 at the upper dead point position, a photocoupler 13 provided with a light projecting part consisting of a light emitting diode 14 and a lens 15 and a photodetecting part consisting of a photodetector 16 and a lens 17 is provided in the mirror box, and a reflection plate 19 is provided at the end edge of the mirror 7. When a mirror 7 moves to near the upper dead point, the output signal of the photocoupler 13 is sent to a switching circuit 30, then its contact (c) changes over to the contact (b). Since the power supply to a motor 31 is stopped and the motor 31 is shortcircuited by this, the electrical brake is applied thereto, and consequently, the mirror shock is eased. |
