A transducer assembly operable to transmit ultrasonic energy in a desired direction towards a zone adapted to be acoustically coupled to an object or area of interest is disclosed which has a transducer layer, a backing material disposed behind the transducer layer with respect to the desired direction, and a back-matching layer disposed between the transducer layer and the backing material to reflect towards the transducer layer part of the ultrasonic energy directed from the transducer layer to the backing material. The backing layer has an acoustic impedance higher than the acoustic impedance of the back-matching layer. The back-matching material has an impedance less than the impedance of the transducer layer and the transducer layer has a thickness greater than a ¼ of the wavelength of the ultrasound waves the assembly is configured to generate. A process for manufacturing a transducer assembly is also disclosed.

A transducer device may include an active layer having a proximal surface and a backing layer having a distal side and a proximal side, the distal side being adjacent to the proximal surface. The proximal side may include (1) at least one first reflective surface approximately parallel to the proximal surface and positioned a first distance from the proximal surface, and (2) at least one second reflective surface approximately parallel to the proximal surface and positioned a second distance from the proximal surface, the second distance being different than the first distance.

An ultrasonic probe according to one embodiment comprises: a plurality of sound absorbing bodies that form a sound absorbing layer; at least one ground connection part that is joined between the sound absorbing bodies; at least one center connection part that is joined between the sound absorbing bodies and has an electrode; a plurality of side connection parts that are joined between the sound absorbing bodies and disposed outside the center connection part and have an electrode; and a plurality of piezoelectric bodies that are disposed in front of the sound absorbing layer to be electrically connected to the ground connection part, the center connection part, and the side connection parts.

An ultrasonic transducer is described, including a piezoelectric element, a fluid medium contact layer, a matching layer between the piezoelectric element and the fluid medium contact layer, and a backing layer. Ultrasound sensor devices utilising the ultrasonic transducer are also described, for use in systems for analysing a fluid such as milk.

An ultrasonic transducer (200) includes: a piezoelectric vibrator assembly (10), an acoustic matching layer (20), a heat sink (30), and an acoustic absorption layer (40). The heat sink (30) comprises a body (31), and a head portion (32) and a tail portion (33). The body (31) has a central axis extending in a direction from the head portion (32) to the tail portion (33). A surface of the tail portion (33) of the heat sink (30) disposed away from the head portion (32) is a first surface (331). The first surface (331) is an oblique surface or a tapered surface. The angle between the first surface (331) and the central axis is an acute angle. The acoustic absorption layer (40) at least covers the first surface (331).

The ultrasound probe includes a piezoelectric element including a piezoelectric composition and an electrode that applies a voltage to the piezoelectric composition. The piezoelectric composition has piezoelectric characteristics expressed by any coordinates included in a region formed by a polyhedron having a plurality of predetermined points as vertexes in Cartesian coordinates (k.sub.eff, ε.sub.33.sup.S, E.sub.c) including variables k.sub.eff, ε.sub.33.sup.S and E.sub.c.

Disclosed is an ultrasonic transducer including: at least one piezoelectric wafer having two parallel planar main faces: a front face and a posterior face; at least one posterior plate having two parallel planar main faces: an anterior face and a rear face, the anterior face of the posterior plate extending facing, and in contact with, the posterior face of the piezoelectric wafer. The posterior plate has a thickness between three and seven times the thickness of the piezoelectric wafer. The posterior plate has an acoustic impedance between 10 MPa.Math.s.Math.m−1 and 35 MPa.Math.s.Math.m−1. Also disclosed is a method for assembling such a transducer as well as a flowmeter including at least one such transducer.

Disclosed are methods, devices, apparatuses, and systems for an under-display ultrasonic fingerprint sensor. A display device may include a platen, a display underlying the platen, and an ultrasonic fingerprint sensor underlying the display, where the ultrasonic fingerprint sensor is configured to transmit and receive ultrasonic waves via an acoustic path through the platen and the display. A light-blocking layer and/or an electrical shielding layer may be provided between the ultrasonic fingerprint sensor and the display, where the light-blocking layer and/or the electrical shielding layer are in the acoustic path. A mechanical stress isolation layer may be provided between the ultrasonic fingerprint sensor and the display, where the mechanical stress isolation layer is in the acoustic path.

An ultrasonic transducer having a flexible printed circuit board with a thick metal layer and a manufacturing method thereof are disclosed. The ultrasonic transducer, according to an embodiment of the present invention, comprises: an active element that generates an ultrasonic signal, wherein the active element has a thickness of ¼λ or less at the center frequency of the generated ultrasonic signal; and a flexible printed circuit board that includes a metal layer with a predetermined thickness, which is formed on one surface of the active element and is electrically connected to the active element, wherein the metal layer blocks ultrasonic waves that propagate in an opposite direction to a predetermined travel path of the ultrasonic waves.

A method is provided for measuring a flow rate of a fluid. The method incudes emitting a periodic signal from a first ultrasonic transductor, where the periodic signal is emitted by the piezoelectric wafer and passes through a liquid media. Unwanted reflections of the periodic signal are delayed so that the first periods of the periodic signal are representatives of the passage measurement. The first periods of the periodic signal are received at a second ultrasonic transductor having a piezoelectric wafer that receives the periodic signal. The flow rate of the fluid is determined by using the first periods of the periodic signal.