Abstract: An apparatus for the scanning of objects by means of ultrasound echography, comprising a mosaic (10) of ultrasound transducers which is connected to a transmitter stage (20) and a receiver stage (30) for the reception and processing of the ultrasound echos corresponding to the obstacles encountered by the transmitted signals in their direction of propagation, and also comprising a display stage (40). The transducers of the mosaic (10) are grouped in 2.sup.n subwindows in which a non-corrected echogram of an area of the objects scanned is formed. The receiver stage (30) comprises a device for determining correction delays to be applied to delay devices (61 . . . 68), said device comprising 2.sup.n -1 intercorrelation circuits (101,102, etc.) which operate on the basis of n successive divide-by-two operations of the aperture of the mosaic (10).

Abstract: A device for the calibration of an ultrasonic transducer includes a container (4) in which are immersed a calibration transducer (1), a rigid flat body (2) which contacts the front of the transducer (1) by way of a bevelled edge so that the distribution of the ultrasonic velocities is not disturbed in any way, a rigid hemisphere (3) which projects from a first principal surface (8) of the body, and the transducer (5) to be calibrated. The transducer (5) is displaceable so that a beam of ultrasonic energy to be emitted or received by this transducer can pass through any point situated within or near the hemisphere (3).

Abstract: A processing circuit is connected to the output of a mosaic which consists of n first electrodes on a first principal surface of a TGS plate and 2p second electrodes on the second principal surface thereof. The circuit is constructed so that the output connections of the second electrodes are grouped in p resultant groups which are connected, via p paths which each comprise an amplifier and a variable delay line, to the inputs of a first adder. The output of the first adder is connected, via a network of (q-1) delay lines having a fixed delay time, to the inputs of q parallel variable delay lines which are connected in parallel and which are connected to the inputs of a second adder. The delay times thus realized are controlled so that a first ultrasonic lens and a second ultrasonic lens are successively formed.

Abstract: A device for scanning and display by means of ultrasonic waves, comprising an electro-acoustic converter including a rectangular matrix of transducers. A number of switching members are adapted to select a rectangular scanning zone in the matrix, to group the transducers in the scanning zone in annular concentric configurations, and to displace the scanning zone in the longitudinal direction of the matrix.