Rksumk. -La rCtine est constituke d'une matrice de transducteurs Blectrostatiques rkalis6s a partir de deux circuits imprim6s comportant l'un 256 Clectrodes 1inCaires horizontales, l'autre 256 Blectrodes verticales. Ces deux circuits enserrent une feuille diklectrique a haute rigidit6. Les points de transduction correspondent aux croisements des lignes et des colonnes, le circuit avant Btant transparent la radiation ultrasonore. La polarisation exclusive d'une ligne assure le fonctionnement des

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... seuls transducteurs associ6s A cette ligne dont le signal est trait6 simultanbment par 256 circuits de rkception. Des hologrammes ainsi obtenus en 50 ms avec la simulation Blectronique d'une onde de ref& rence a incidence normale et oblique seront prCsentBs ainsi que l'image reconstruite correspondante. Abstract. -The acoustical hologram is given by a 256 x 256 matrix of electrostatic transducers obtained with two printed circuits : n lines are metallized on the first and n columns on the second and a thin sheet of dielectric material is set between them. Each transducer is located at the crossing of one line and one column. The lines are polarized one after the other so that the matrix is operated line by line. The information given by the 256 transducers corresponding to the polarized line is delivered by the columns to 256 signal processing circuits. Holograms obtained in 50 ms with the electronic simulation of a normal or inclined reference beam are presented with the corresponding optical reconstructions.