| 摘要 |
PROBLEM TO BE SOLVED: To provide an excellent ultrasonic diagnosis apparatus with a light and handy probe which can be opened and controlled in the minor axial direction or in the direction of a lens. SOLUTION: The main frequency of the vibrator at the center of opening among vibrators P1-P3 of a probe 1 is high. Therefore, the sensitivity of a high frequency component is high at the center of opening. As for a low frequency component, the sensitivity is corrected by addition resistances RS-1 to RS-3 to be at the same level at the center and the rim of the opening. The received signal is amplified by a receiving circuit 3. The sensitivity of the received signal of the high frequency component is high in the short distance; and in the long distance, the received signal is processed by a dynamic filter 4 with a high sensitivity of received signals of the low frequency component. Therefore, a thin beam with a narrow opening can be obtained in the short distance, while a highly directive beam with a wide opening can be obtained in the long distance. |
