| 摘要 |
PURPOSE: To enable visualization of a remote object and to obtain an image of high resolution. CONSTITUTION: The shape of a piezoelectric vibrator 2 transmitting and receiving an ultrasonic wave is made convex and the center of curvature of this convex piezoelectric vibrator 2a is made a virtual position of transmission of the ultrasonic wave, that is, a virtual sound source 11. The central part of the convex piezoelectric vibrator 2a is cut 2d in the shape of a concentric circle and separated and the center of this separated piezoelectric vibrator 2c is made a position 11b of reception of the ultrasonic wave. Thus, an ultrasonic sensor part wherein a large aperture of the whole of the convex piezoelectric vibrator 2a is used at the time of transmission of the ultrasonic wave and a small aperture of the separated piezoelectric vibrator 2c is used at the time of reception of the ultrasonic wave is prepared. By this ultrasonic sensor part, the position of a reflecting source of the ultrasonic wave is visualized by using the virtual position of reception of the ultrasonic wave and a time required from transmission of the ultrasonic wave to reception thereof. |
