Abstract: An acoustic actuator includes a support layer, in which a self-supporting structure is defined and connected to the support layer by at least two suspensions, at least one magnetostrictive layer which has been disposed on the support layer and is provided at least in part on the self-supporting structure, and a device for generating a magnetic field in the magnetostrictive layer. The way in which the loudspeaker works is based on the magnetostrictive effect, which results in a change in the dimensions of the self-supporting structure in an alternating magnetic field. This causes the self-supporting structure to oscillate. A method for producing an acoustic actuator is also provided.

Abstract: In hearing devices, more particularly in hearing aids, it is desirable to be able to design an earpiece for generating sound in the audible range which is as small as possible. Such an earpiece can then be worn comfortably on an ear or in an auditory canal. A sound transducer for the hearing device disclosed here may be formed as a micro-electromechanical system and the transducer enables generation of an acoustic signal with little distortion. Provision is made for a hearing device with a sound transducer, which has a field generation apparatus for generating an electric or magnetic field and an emission apparatus for generating sound. Here, the emission apparatus has a multiplicity of fingers that are penetrated by the field of the field generation apparatus, wherein the shape of the fingers can be changed by means of the field of the field generation apparatus in order to generate the sound.

Abstract: An acoustic actuator comprises a support layer (3), in which a self-supporting structure (1) is defined which is connected to the support layer (3) by means of at least two suspensions (7), at least one magnetostrictive layer (4) which has been put on the support layer (3) and is provided at least in part on the self-supporting structure (1), and means (2; 5) for generating a magnetic field in the magnetostrictive layer (4). The way in which the loudspeaker works is based on the magnetostrictive effect, which results in a change in the dimensions of the self-supporting structure in an alternating magnetic field. This causes the self-supporting structure to oscillate.

Abstract: In hearing devices, more particularly in hearing aids, it is desirable to be able to design an earpiece for generating sound in the audible range which is as small as possible. Such an earpiece can then be worn comfortably on an ear or in an auditory canal. A sound transducer for the hearing device disclosed here may be formed as a micro-electromechanical system and the transducer enables generation of an acoustic signal with little distortion. Provision is made for a hearing device with a sound transducer, which has a field generation apparatus for generating an electric or magnetic field and an emission apparatus for generating sound. Here, the emission apparatus has a multiplicity of fingers that are penetrated by the field of the field generation apparatus, wherein the shape of the fingers can be changed by means of the field of the field generation apparatus in order to generate the sound.

Abstract: An ultrasound transducer for diagnostic and therapeutic generates ultrasound waves of different wavelengths in diagnostics mode or therapy mode. The ultrasound transducer has an n.times..lambda./4 matching layer for a propagation medium adjoining the ultrasound transducer, and a piezoelectric ultrasound transducer element with a first electrode located between the matching layer and the ultrasound transducer element, a second electrode attached at the opposite side of the ultrasound transducer element, and a third electrode that divides the ultrasound transducer element into two regions. Ultrasound waves can be generated for the diagnostics mode and for the therapy mode dependent on the division of the ultrasound transducer element. The n.times..lambda./4 matching layer is effective for the wavelength of the ultrasound waves in diagnostics mode as well as in therapy mode.

Abstract: An ultrasound array has a number of oscillator elements arranged side-by-side, each oscillator element having a trapezoidal cross-section. The oscillator elements are separated from each other by incisions having non-parallel walls, which are co-planar with surfaces of the piezoelectric material comprising the oscillator element. The incisions terminate in a damping member, to which all of the oscillator elements are attached. The incisions are produced with an excimer laser whose laser beam is focused onto a prepared layered material, with the incisions proceeding along a line.

Abstract: An ultrasonic transducer comprises a support body, a piezoelectric layer of a material with a relatively high dielectric constant and high acoustic impedance, a first impedance matching layer and a second impedance matching layer (10). The first matching layer consists of silicon.

Abstract: An ultrasonic transducer system is disclosed consisting of a support body (2), a radiating layer (8,9), a first .lambda./4 matching layer (10,11) and a second .lambda./4 matching layer (12,13). According to the invention, at least two ultrasonic transducers (4,6) with different and predetermined mid-frequencies are attached to a common support body (2) and have natural foci which overlap if the ultrasonic transducers (4,6) are mechanically separated. The ultrasonic transducer (4), having the higher mid-frequency, is provided with a larger radiating surface (4). This configuration, through the appropriate selection of the mid-frequencies, allows compensation for the frequency dependent damping of the transmission medium by frequency related weighting during radiation. In this manner, substantial improvements with respect to bandwidth of the total transmission path, from transmitting transducer through transmission media to receiving transducer, and the image quality can be realized.

Abstract: In the disclosed transducer, a frame supports the edges of a piezopolymer sheet coated on both faces with electrodes, while a holding structure supports an area but leaves a larger area of the central portion of the sheet unsupported. According to preferred embodiments, the frame stretches the sheet, in the form of a membrane, across one or more contact areas on the holding structure, and the contact area approximates a point located near the center of the sheet or a number of concentric annuli. Preferably, the structure forms one terminal contacting one electrode and the frame forms another terminal contacting the other electrode.

Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse. Always only one group of the transducer elements on the linear array is active and is connected via transmit switches to the transmitting system, and via receiver switches in series with a wiring arrangement to the receiving system. This facilitates the implementation of an ultrasonic imaging system for high ultrasonic frequencies, particularly in the order of at least 30 MHz, in which the use of a switching matrix in the radiation and receiving system is avoided.

Abstract: Ultrasonic imaging system with a linear array having several transducer elements of which a respective group of commonly controlled transducer elements forms one beam aperture and to which one transmitting system and one receiving system is allocated. A delay time is digitally set for each transducer element of the beam aperture and triggered by means of a starting pulse, and the echo signals of the transducer elements of the beam aperture are added and phase delayed by the software. In this manner, an ultrasonic imaging system for high ultrasonic frequencies, particularly at least in the order of 30 MHz is achieved in which transmitting and receiving lens can be created independently of one another in the computer by changing the software, while the hardware remains unchanged.

Abstract: An ultrasonic sensor for determining objects in air or other gaseous media is disclosed. The sensor comprises a first ultrasonic transducer having a piezoelectric transmitter. A reflector is provided having a concave surface facing the first ultrasonic transducer which forms a segment of an ellipsoid. The reflector has two focal points, the first of which is closer to the reflector and the second of which is near the object to be detected. Between the first ultrasonic transducer and the reflector, a second ultrasonic transducer is provided which is arranged at the first focal point of the reflector. Preferably, the surface of the second ultrasonic transducer facing the reflector forms a spherical segment. By this arrangement, an increase of the receiving aperture is achieved, and objects can be determined which have a normal to the reflection surface inclined with respect to the axis of the sound lobe by an object position angle which is substantially larger than .+-.3.degree..

Abstract: An ultrasound array has a number of oscillator elements arranged side-by-side, each oscillator element having a trapezoidal cross-section. The oscillator elements are separated from each other by incisions having non-parallel walls, which are co-planar with surfaces of the piezoelectric material comprising the oscillator element. The incisions terminate in a damping member, to which all of the oscillator elements are attached. The incisions are produced with an excimer laser whose laser beam is focused onto a prepared layered material, with the incisions proceeding along a line.