Abstract: The invention relates to an impulse sound traducer for the ultrasonic range. Transducers in prior art require complicated and expensive technology in order to really generate good impulses. The invention aims at providing a sound transducer for the ultrasonic range, which transmits strong and short impulses, has high senstivity and ensures repeatability of parameters. This is achieved by a sound transducer for the ultrasonic range that is used both as a transmitter and as a receiver and is comprised of an elementary block made of piezoelectric material, wherein the height of the elementary blocks consisting of piezoelectric material is bigger than its width and the block on the output end of the impulse has a formed edge so that the elementary block has a T-shape in the longitudinal section, wherein one electrode is provided on the outlet surface while the other electrode extends above the edge on the block.

Abstract: A method and an apparatus for analyzing a structure, for example, a fingerprint or a hand print, in which the finger or hand is placed upon a plate which forms an ultrasonic wave waveguide and ultrasonic radiation, launched into the waveguide parallel to the surface against which the object is placed. The reflected and backscattered waves are analyzed utilizing horizontally polarized ultrasonic shear waves propagated in the body from at least one transducer at a side of the body. The pickup transducer can also be provided on the side of the body.

Abstract: A generator for spherical ultrasonic waves can replace a point source transducer and has a large-area transducer whose output ultrasonic waves are condensed in a funnel and fed to a monomodal waveguide, e.g. a tube at the output end of which phase-correct perfectly spherical waves are emitted.

Abstract: The number of transducers in the scanning of an ultrasonic field from an object is reduced by providing ultrasonic collectors at spaced apart locations in the medium and transmitting the ultrasonic waves which are collected to a transducer through waveguides or paths having different transit times. The waveguides can be individually of different lengths or can be of equal length and terminate at different distances along a common collecting waveguide.

Abstract: For determination of surface and special surface characteristics of an object, e.g. a fingerprint, the finger tip is placed on a convex surface of a support which is irradiated through a liquid or solid medium with spherical ultrasonic waves from a point source provided as a hole in a carrier for a ring of receiving transducers.