| 摘要 |
PURPOSE:To make the circuit scale small, and also, to enhance the accuracy of a delay time by providing a comparing means for selecting a desired signal from plural phase shift signals based on delay time data, and outputting a delay pulse signal for driving a transducer, when its pulse counting value coincides with the delay time data. CONSTITUTION:When a reference clock generating means 21 generates a reference clock A, a frequency dividing means 22 generates its frequency dividing pulse signal B, supplies it to a phase shifting means 23, plural phase shift signals are generated, and these are supplied to a selecting means 26 of each channel CH1, CH2,.... On the other hand, a delay time data supply means 24 supplies delay time data related to each transducer to a latch circuit 25 of each channel and allows this circuit to hold it, and this delay time data is supplied to the selecting means 26. In such a state, a desired signal is selected from in plural phase shift signals, and a pulse is counted by a counting means 27, and supplied to a comparing means 28. When a coincidence of this delay time data and the counting value is confirmed, a delay pulse signal is outputted to a pulse generating circuit 30. |
