Abstract: The invention relates to a probe for a device forming images from ultrasounds, in particular for the internal examination of the human body. The probe comprises transducers distributed in a curved array providing the possibility of a sectorial angular scanning and of generating ultrasonic beams converging towards a localized area where is arranged either a screen opaque to ultrasounds and formed with one or two openings in the vicinity of the center of converging area, with one or two lenses for ultrasounds in said opening or openings, either one or two electronic lenses formed with means for converting in parallel ultrasounds into electric signals, apparatus for differentially delaying the electric signals and apparatus for converting in parallel the electric signals, after a delay, into ultrasounds.

Abstract: A device for forming acoustical images comprises an ultrasonic source, a linear array of first receiving transducers for receiving the echoes from a target illuminated by a source. The signals from the linear array of first receiving transducers are processed by a system comprising an oscillator at a frequency higher than that of the source, and, for each said receiving transducers, a mixer, a filter for separating the components of the beating frequency and a transmitting transducer.

Abstract: The invention relates to a device which forms the product of convolution of two signals available in electrical form. This device consists of a substrate of lead molybdate in which there are created, at the two ends, volume elastic waves, which are longitudinal and transverse respectively for each of the two applied signals. The non-linear interaction of these waves produces an elastic wave of transverse mode, representing the product of convolution of the two signals.