| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmission circuit capable of omitting a high voltage switch. SOLUTION: An ultrasonic diagnostic apparatus is equipped with a transmission circuit for supplying a drive signal to respective vibrators, a first stage amplifying circuit 1 for amplifying an inputted ultrasonic signal and a second stage amplifying circuit having a semiconductor element for amplifying the ultrasonic signal outputted from the first stage amplifying circuit and supplying the output of the semiconductor element to the vibrators. A plurality of the first stage amplifying circuits are provided correspondingly to predetermined transmission/reception calibers and a plurality of the second stage amplifying circuits are provided to the respective vibrators. The outputs of the respective first stage amplifying circuits are inputted to a plurality of the predetermined stage amplifying circuits. The each of the second stage amplifying circuits has a control circuit for controlling the semiconductor element so as to turn the same on and off on the basis of an inputted vibrator selection signal Tcnt and the semiconductor element being the amplifying element of the second stage amplifying circuit is turned on and off to select the vibrator to omit a high voltage switch. COPYRIGHT: (C)2004,JPO
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