PURPOSE: To compensate the dispersion of sensitivity among channels by sending out gain control signals for variable gain amplifiers based on the identifying signal of the ultrasonic frequency of a probe and the control signal of a delay time and compensating the inserting loss of a delay circuit.
CONSTITUTION: The ultrasonic frequency of a probe 2 is identified in accordance with the type of the probe 2 by means of a decoder 18 as an identifying means. Based on the identifying signal S4 of the ultrasonic frequency from the decoder 18 and the control signal S1 of a delay time from a phasing circuit 3, a control device 6 sends out the gain control signals S5, S5,... for variable gain amplifiers 19, 19,... connected to the oscillating elements 1aW1n of the probe 2 respectively, to control the gain of each variable gain amplifier 19, 19,... by means of this gain control signal S5. Thereby, the inserting loss of each delay circuit 14, 14,... in the phasing circuit 3 corresponding to every channel Ch1WChn of echo signals can be compensated. Hence, the signal levels of the channels Ch1WChn can be nearly equalized compensating the dispersion of sensitivity among channels.
KISHIMOTO SHINJI
KAMIYAMA AKIHIRO
