| 摘要 |
PURPOSE:To improve safety when travelling, by controlling an image pickup tube driving motor by means of CPU on the basis of a signal from a speed sensor thereby enabling automatic setting of a subject at the rear of car in accordance to the car speed. CONSTITUTION:Under travelling of car, the car speed is detected by a speed sensor 1 and the detected signal is processed in CPU2 then the digital signal is converted by a converter 3 into analog signal. Under low car speed, the potential at the conjunction (a) is low while that at the conjunction (c) is high to produce an output signal from first operational amplifier but the second operational amplifier 5 will not produce an output signal. Consequently, the first transistor 9 is disabled while second transistor 10 is enabled to rotate the motor 13 to the right thus to direct the image pickup tube downward. As a result, under low car speed, a subject at the rear position near to the car can be set. |
