Abstract: The system comprises a high resolution camera (1) mounted above a conveyor plane (4) along which objects are displaced, thereby enabling the top face of each object to be observed. The camera (1) is fitted with an objective lens system (5) having a motor-driven focusing system that operates in association with a pickup (8) that produces a signal (S) representative of the vertical profile of the top face of each object relative to the conveyor plane. The profile signal serves to produce positioning references (C) for the focusing mechanism in order to take account of variations in the height of the top face of each object while that object is moving beneath the objective lens system of the camera. Such an image acquisition system is employed to read addresses automatically from postal packets for the purpose of performing automatic sorting.

Abstract: The apparatus of the invention for discriminating mail in a paper envelope from mail in a plastics envelope makes use of a pneumatic technique. In particular, the apparatus comprises a pneumatic system suitable for deforming the envelope to be inspected by applying suction and for measuring variation in pressure associated with said deformation, whereby the inspected envelope is detected as being a paper envelope or as being a plastics envelope. This pneumatic detector may be associated with a detector operating by means of an optical effect for the purpose of controlling a labelling device in equipment for processing flat articles.

Abstract: A process of utilizing ultrasound for acquiring data representative of the internal portions of a structure and the display of the data thus obtained. This process includes the emitting of sequences of ultrasound to the structure under consideration and receiving therefrom corresponding echoes. For each sequence two groups of transducer elements are selected for generating ultrasound beams of possible N different focal characteristics sequentially. The ultrasound beams alternate from one group to the other except when a given beam corresponds to the most distant focal zone. In that case, the succeeding emission is carried out without alternating, i.e., the emission is generated from the same group.