| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic diagnostic apparatus with switching power supply capable of preventing noise to ultrasonic diagnostic images without using a large-scale filter and controlling a power supply voltage to be supplied to an optional voltage value. SOLUTION: The ultrasonic diagnostic apparatus has a continuous wave transmission part for outputting continuous wave (CW) transmission signals to a probe vibrator and the switching power supply for supplying a desired power supply voltage to the continuous wave transmission part in order to determine the voltage of the continuous wave transmission signals. The switching power supply comprises a constant voltage power supply and a step-down chopper type power supply circuit. By turning the frequency of a switching clock for turning a switching element inside the power supply circuit ON/OFF to the frequency higher than the frequency of the continuous wave transmission signals, the noise is prevented from being generated in the ultrasonic diagnostic images. Also, by controlling the duty ratio of the switching clock, the power supply voltage of the optional voltage value is supplied to the continuous wave transmission part. Thus, the power supply voltage to be supplied to the continuous wave transmission part is finely adjusted. COPYRIGHT: (C)2008,JPO&INPIT
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