| 摘要 |
PURPOSE:To enhance resolving power in scanning and slice directions, by performing weighting increasing the amplitude of a transmitting and/receiving signal toward an outside element to each element of an annular array vibrator. CONSTITUTION:Pulsers 3a-3d form high voltage pulses from a timing pulse generating circuit 1 to drive annular array vibrators 4. At this time, weighting is applied to the vibrators 4 by an amplitude control circuit 5 so that the amplitude of the high voltage pulse becomes higher toward the outside vibrator. At the time of reception, the receiving signals received by the annular array vibrators 4 are added by an adder circuit 8 through preamplifiers 6a-6d and delay circuits 7a-7d. An mu-factor control circuit 10 performs weighting so that sensitivity becomes higher toward the receiving signal of the outside vibrator. |
