| 摘要 |
PURPOSE:To enable the control of correct delay time and a beam focusing without deterioration a combined performance of the circuit by a constitution wherein an appropriate delay time is added to each of multiultrasonic receiving signals by means of a change-over switch, an adder, a fixed delay circuit and a variable delay circuit. CONSTITUTION:Receiving signals of ultrasonic vibrators 1-1-1-N arranged in an array type pass through a change-over switch 8, adders 3-0, 3-(N-1) and a switch 5 and are delivered to fixed delay lines 6-1-6-N and variable delay lines 7-1-7-N. Further, the output signal of a delay circuit 7 enters the adder 3 where a delay time is added and a connection is made so as to repeat siad procedures sequentially. When deflection angle theta is amall, the receiving signal passes only through the delay line 7 by means of the switch 5, and when the theta is large, it passes through also the fixed delay line 7 by means of the switch 5. A change-over switch 8 is selectively connected by a command from ROM etc. Thus, without deteriorating the combined performance of the circuit, a correct control of the delay time and a beam forcusing becomes feasible. |
