| 摘要 |
PURPOSE: To obtain optimum wave fidelity and noise performance. CONSTITUTION: A ultrasonic converter 10 used for an ultrasonic image forming system provided with signal transmission and reception circuits connected to a converter via a cable 12 has a converter 16 for converting a ultrasonic energy into an electronic signal and an input connected to that converter 16, and an output connected to the cable 12 and is made of variable gain amplifying means for amplifying the electronic signal by means of a gain determined by means of the gain control signal from the image forming system. This converter is typically portable, and those variable gain amplifying circuits 18 an 20 are preferably mounted on the portable unit in very proximity to a converter element. The variable gain amplifying circuits 16 are preferably a converter array provided with plural converter elements, and those converter elements are each provided with a preamplifier and a variable gain amplifier related therewith. |
