Ultrasonic detection system

An ultrasonic detection system, comprising means for emitting an ultrasonic wave signal in all peripheral directions, a plurality of ultrasonic transducers arranged circularly at equal intervals for receiving said ultrasonic wave signals reflected back from said directions, a plurality of composite output circuits for combining the outputs of k (k>1) transducers which are successively adjoining in a predetermined circumferential direction to produce a plurality of directive composite outputs, and means for deriving said composite outputs sequentially in time division fashion for indications;

• said ultrasonic transducers being classified into m groups each consisting of n transducers which are successively adjoining in said circumferential direction, the number of said composite output circuits being designated as n, where m and n are integers greater than one and n is equal to or greater than k, n switching circuits each having m inputs connected respectively to the outputs of the j-th (j = 1, 2, . . . n) transducers of said m groups of transducers, said switching circuits being connected to said composite output circuits such that n sequential combinations of switching circuits each consisting of k switching circuits which are circulatingly adjoining in said circumferential direction are coupled sequentially to said composite output circuits, and control means for deriving n outputs at a time from said switching circuits which are circulatingly adjoining in said circumferential direction and, at the same time, shifting said n outputs one by one in said circumferential direction.