| 摘要 |
PURPOSE:To perform clear image display and to measure the distance to and direction, shape of an object by storing reflected waves by two ultrasonic wave receivers, setting evaluation parts in a video range successively, and deciding on whether a reflector is present or not within the range. CONSTITUTION:An ultrasonic wave transmitter 1 and two ultrasonic wave receivers 6 and 7 arranged in a V shape are rotated in one body to transmit an ultrasonic wave and receive reflected waves at rotating angles theta1-theta8 respectively. Detection signals are AD-converted and stored in a memory 14. Evaluation parts 18 are set successively within the desired video range 15, and a signal in a gate period corresponding to the evaluation part of each receive signal is extracted and added. If a reflector is present at the evaluation part 18, both receives receive reflected waves in the gate period, so the signal level rises. When no reflector is present, the signal level drops and the difference between both cases is large. Therefore, whether the reflector is present or not, and position, size, etc., of the reflector are recognized more clearly than before, and an image displayed on a display device 19 is clear. |
