| 摘要 |
1. Method for ultrasonic scanning of an object in which by means of an ultrasonic head consisting of a plurality of transducer elements (2) arranged next to each other, ultrasonic pulses are transmitted along different respective linear scanning lines (Z1, Zi, Zn) into the object ; the echo signals are measured as a function of the scanning depth in reception periods following a respective ultrasonic pulse ; during each reception period the aperture (A1, A2, A3) of the ultrasonic head is enlarged, as a function of the scanning depth gradually through activation of an increasing number of transducer elements starting from an initial value (A1) ; the directional characteristic (L1, L2, L3) of the ultrasonic head (A1, A2, A3) is adjusted by the choice of the time delays of the echo signals, characterised in that activated transducer elements for enlarging the aperture are chosen so that the centre of gravity of the aperture, except when scanning along the central scanning line, is displaced with increasing scanning depth, along the transducer elements ; the aperture is enlarged in each case to a terminal value, assigned to the maximum scanning depth and encompassing all transducer elements ; the directional characteristic (L1, L2, L3) is controlled in such a way that the receiving direction cuts, in each case, at an angle, the respective scanning line in the scanning depths corresponding to the different apertures, which angle is a function of the scanning line, whereby this angle becomes nil for the central scanning line, the evaluation of the echo signals is restricted in each case to the signal values (S1, S2, S3) which correspond to the cutting region of the respective receiving direction (L1, L2, L3) with the respective scanning line (Z1, Zi, Zn).
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