DE102015015901B3 - Oscillating element for an ultrasonic transducer with a translation lattice-based multiple resonance - Google Patents

Abstract

Oscillation system comprising a mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) as oscillating body and at least one piezoelectric oscillating element (2) driving the oscillation of said oscillating body per mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) for use in an ultrasonic transducer (TR), the piezoelectric vibrating element (2) of the vibrating system being mechanically connected to the mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) and wherein the mechanical connection between the piezoelectric oscillating element (2) of the oscillating system and the mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) is effected by gluing by means of an adhesive and / or soldering and / or welding , and wherein the oscillating system, consisting of the mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) and the piezoelectric oscillating element (2), is provided with a housing (1) mechanically by means of an elastic adhesive (3) , 1a, 1c) of an ultrasonic transducer (TR) with the shortest connecting line from the center of gravity of the piezoelectric oscillating element (2) to the housing (1, 1a, 1c) intersecting the elastic adhesive (3), characterized in that the oscillating system of the ultrasonic transducer consisting of mounting element (6, 6b , 6c, 6d, 6e, 6i, 6j, 6k) and piezoelectric vibrating element (2) upon driving the piezoelectric vibrating element (2) by a driving circuit (US) at least two or more mechanical resonance frequencies, a first resonant frequency and a second resonant frequency of each other are different, and that at least one of these resonant frequencies of the natural frequencies of the piezoelectric vibrating element (2) without anmontiertes mounting member is different and that the mounting member (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) at least one pattern of Openings (10) on a surface of the mounting element (6, 6b, 6c, 6d, 6e, 6i, 6j, 6k) and / or recesses on a surface of the ...

Description

introduction

Various ultrasonic transducers are known in the prior art. These play, for example, in connection with the distance detection when parking vehicles an important role. In this process, an ultrasonic wave is emitted by an ultrasonic transducer, reflected by an object in the path of the vehicle and typically recovered by the same ultrasonic transducer. From the running time and the amplitude can be closed on the one hand on the presence of an obstacle in the track and on the other hand on the distance to the ultrasonic transducer. The ultrasound transducer thus operates at least temporarily as an ultrasound transmitter and at times as an ultrasound receiver.

The prior art is based on the 1 to 4 explained.

1 shows a typical circuit of the prior art. At this point, the importance of all components of the circuit is not discussed. Instead, there is a restriction to the most important parts of the circuit. The components are so far named in the list of reference numbers that a person skilled in the art can rework the circuit. In this circuit, the transducer (TR) is driven by the drive circuit (US _ctr ) via the first line (DRV1) and the second line (DRV2) for the differential drive of its piezoelectric oscillating element (FIG. 2 . 2 ) to send. In this case, in the transmitter (UE), the output signal of the drive _circuit (US _ctr ) is _clamped high in order to optimally adapt the output (DRV1, DRV2) of the drive _circuit to (US _ctr ) to the resonance _{impedance of} the piezoelectric oscillating element (FIG. 2 . 2 ) of the ultrasonic transducer (TR). Is the piezoelectric vibrating element ( 2 . 2 ) of the ultrasonic transducer (TR) is not activated, it is possible, via a substantially capacitive network (C _TD1 , C _AIN1 , C _AIN2 , R _AIN ), in cooperation with the inductance of the transformer (UE), to pass through the piezoelectric oscillating element ( _FIG . 2 . 2 ) received electrical signal of the ultrasonic transducer (TR) by the drive circuit via a first input signal (AING) and a second input signal (AINS) are received and processed. The result of the evaluation is then typically reported via a data bus, for example a LIN bus, to a higher-level entity.

2 shows a typical ultrasonic transducer in cross section.

The ultrasound transducers are typically not rotationally symmetrical. On the housing typically exist two opposite flats to ensure a defined assembly. The emission characteristic is modulated in the prior art by a varying thickness of the housing wall. Typical prior art ultrasonic transducers exhibit this varying case thickness to adjust the aperture angles in the x and y directions. This method of forming the radiation angle is relatively complicated because it requires complex three-dimensional shapes.

The housing diameter varies in the prior art between 14 and 18 mm, but this is not exactly n · λ _L , where n is an integer and λ _{L is} the wavelength of the sound in the air, but the different frequencies in the same sensor module housing through a broadband cabinet resonance can be emitted and received. The wavelength λ _L is at a typical oscillation frequency of 58 kHz at 5.9 mm in air at room temperature, and at 108 mm in aluminum. The wavelength in aluminum, from which the housing of the ultrasonic transducer is made, is therefore typically a factor of 18.3 greater than the wavelength in air.

In principle, an ultrasonic transducer with two or more resonance frequencies and different emission characteristics is advantageous in order to be able to use these different emission characteristics for different measurement tasks. Exemplary properties of the ultrasound transducer at these resonance frequencies would be a broad opening angle of the sound lobe at short range and, alternatively, a small opening angle of the sound lobe at long range (eg 6 to 8 m). This would allow, for example, a Nahfeldkennung for ultrasound-based parking aids in a motor vehicle bumper.

Against this background, a simple method for adjusting these resonant frequencies and the bandwidth and the quality at these resonant frequencies in the manufacture of the ultrasonic transducer would be desirable in order to be able to set different frequency configurations quickly and easily.

Typically, the ultrasound transducer is symmetrical to a 2-fold axis ( 13 ). In this example he has a housing ( 1 ) with a housing bottom ( 1b ) and housing walls ( 1c ). Typically, it is an at least approximately cylindrical housing wall ( 1c ). The housing ( 1 ) is at least partially, preferably as a whole, electrically conductive, for example made of aluminum and, for example produced in a thermoforming process. A piezoelectric oscillating element ( 2 ) is by means of an electrically conductive adhesive ( 8th ) in the housing ( 1 ) on the housing bottom ( 1b ) glued. The piezoelectric vibrating element ( 2 ) has a second electrical contact ( 2 B ), which on the side of the piezoelectric vibrating element ( 2 ) attached to the electrically conductive adhesive ( 8th ) is facing. The second electrical contact of the piezoelectric oscillating element ( 2 ) is thus typically electrically conductive with the electrically conductive adhesive ( 8th ) connected. The other first contact ( 2a ) is typically located on the other surface of the piezoelectric vibrating element ( 2 ), the surface with the second contact ( 2 B ) of the piezoelectric oscillating element ( 2 ) is opposite. The first contact ( 2a ) of the piezoelectric vibrating element ( 2 ) is thus largely electrically from the second contact ( 2 B ) of the piezoelectric vibrating element ( 2 ) - apart from the capacitive coupling between the two - isolated. The electrically conductive adhesive ( 8th ) touches up to an outer adhesive edge ( 3c ) the piezoelectric vibrating element ( 2 ). This typically has an outer edge ( 2c ), which is typically larger in diameter than the said adhesive edge ( 3c ) having. The first electrical contact ( 2a ) of the piezoelectric vibrating element ( 2 ) is typically by means of a first electrical lead ( 4 ) connected. The housing ( 1 ) and thus also the second electrical contact ( 2 B ) of the piezoelectric vibrating element ( 2 ) are connected via a second supply line ( 5 ) connected. Is between the first and second supply line ( 4 . 5 ) applied a voltage, it is due to the piezoelectric properties of the piezoelectric vibrating element ( 2 ) to a contraction or expansion thereof depending on the polarity of the applied voltage. If this happens with a suitable transmission frequency, then in particular the housing bottom ( 1b ) and the housing wall ( 1c ) into mechanical resonance and a sound wave is transmitted through the housing bottom ( 1b ) radiated downwards into the air. The diameter of the housing bottom is typically an integer (n-fold) multiple of the wavelength (λ _L ) of the sound in the air at transmission frequency. In the past, it has proven to be useful if the diameter of the housing bottom was 6 times the sound wavelength (λ _L ) in air.

3 shows a simplified cross section through the ultrasonic module (SM). A printed circuit _board (PCB) typically carries the drive circuit (US _ctr , 1 ) and the peripheral components (see 1 ). This printed circuit board (PCB) can be connected to the outside world via a plug (Con). The ultrasonic transducer (TR) is located to the left of the printed circuit rotated 90 ° with the housing bottom ( 1c . 2 ) pointing to the left. Typically, the ultrasonic transducers are mounted directly in the bumper of a vehicle. If necessary, a coating prevents direct contact with electrically charged objects. In the case of an electrostatic discharge - commonly referred to as ESD event (ESD) - prevents the capacitive network (C _TD1 , C _AIN1 , C _AIN2 , R _AIN ) in cooperation with the inductance of the transmitter (UE) that this ESD pulse the _{Drive circuit} (US _ctr ) reach undamped and thus damage.

The in 1 used transformer is relatively expensive. Therefore, there is a need to be able to dispense with this. 4 shows a prior art circuit without the transmitter (UE) with another drive circuit (US), which is suitable for such a direct drive.

The ultrasonic transducer (TR) is in the example of the 4 operated and controlled directly by means of the first line (DRV1) and the second line (DRV2).

The first line (DRV1) and the second line (DRV2) of the driver (DRV) are outputs. This makes effective ESD protection difficult because these two lines (DRV1, DRV2) require the transmission energy to be introduced into the converter and any ESD protection element in the supply line would lower the drive efficiency.

About two capacitances, the received signal by means of a first input signal (AING) for coupling the received signal of the transducer (TR) in the drive _circuit (US _ctr ), which plays the role of a signal _ground , and by means of a second input signal (AINS) for the coupling of the Receiving signal of the transducer (TR) in the drive _circuit (US _ctr ), which plays the role of the signal, tapped and fed to the processing. Without limiting the generality, we assume here by way of example that the second supply line ( 5 . 2 ) is connected to the second line (DRV2) and capacitively connected to the second input signal (AING). Analogously, we assume that the first supply line ( 4 . 2 ) is connected to the first line (DRV1) and capacitively connected to the first input signal (AINS).

From the JP S61-29 596 U an ultrasonic transmitting device is known in which a piezoelectric vibrating element (reference numeral 12 of the JP S61-29 596 U ) on a mounting element (reference numeral 11 of the JP S61-29 596 U ) is mounted. The assembly is done on a punched or etched free mounting island (reference numeral 11-2 of the JP S61-29 596 U ), which via four cross-shaped symmetrically arranged webs (reference numeral 11-1 of the JP S61-29 596 U9 the mechanical connection to a remaining frame, the part of the mounting element (reference numeral 11 of the JP S61-29 596 U ). This arrangement of mounting element (reference numeral 11 of the JP S61-29 596 U ) and piezoelectric vibrating element (reference numeral 12 of the JP S61-29 596 U ) is in a housing (reference numeral 13 of the JP S61-29 596 U ) built-in. The webs (reference numeral 11-1 of the JP S61-29 596 U ) represent mechanical springs that upon excitation of the piezoelectric vibrating element (reference numeral 12 of the JP S61-29 596 U ) with the mass of the oscillating system consisting of mounting element (reference numeral 11 of the JP S61-29 596 U ) and piezoelectric vibrating element (reference numeral 12 of the JP S61-29 596 U ) form a resonant vibration system. The system we through a perforated cover plate with sound passage openings (reference numeral 10 of the JP S61-29 596 U ) mechanically protected against the ingress of foreign bodies. This system has the advantage that by means of a larger piezoelectric oscillating body (reference numerals 12 of the JP S61-29 596 U ) very high sound power levels can be radiated. In addition to the disadvantage of material fatigue of the springs (reference numeral 11-1 of the JP S61-29 596 U However, this system has only one main resonant frequency and is therefore not suitable for the purpose of the invention alone.

A similar system is from the JP S60-111 199 U known. Here, the mounting element (reference numeral 3-2 of the JP S60-111 199 U ) but no breakthroughs. The mounting element here forms a homogeneous rotationally symmetric surface and has as in the case of JP S61-29 596 U only one resonance frequency.

From the US 2010/060 111 A1 is a MEMS oscillator is known, which can have several resonant frequencies by means of breakthroughs. ( 4 and section [0064] US 2010/060 111 A1 It is known that such MEMS oscillators currently do not achieve sufficient Schallabstrahlleistung, for example, to build an ultrasonic measuring device for use in a parking aid for a car with it. Moreover, such MEMS devices are too expensive over the two previous Japanese designs.

From this cost aspect, it is also necessary transformer between the piezoelectric vibrating element and the drive circuit, such as from JP H03-182 200 A known to avoid. However, such direct drive leads to unsuitable design to ESD problems.

It is known from the literature (for example, John R. Vig, "Dual-mode oscillators for clocks and sensors", 1999 IEEE Ultrasonics Symposium, pages 859 to 868) that piezoelectric oscillating elements at three different resonance fundamental frequencies, in a quasi-longitudinal Fashion and in a fast quasi-Scheer mode and in a slow quasi-Scheer mode, and whose harmonics can be excited. (See John R. Vig, "Dual-mode Oscillators for Clocks and Sensors," 1999 IEEE Ultrasonics Symposium, 1 These resonant frequencies are referred to below and in the claims as natural frequencies of the piezoelectric vibrating element.

From the EP 0 707 898 A2 , of the US 4 434 827 A and the US 5 423 319 A For example, a method for producing a transducer component and precisely this transducer component itself is known, in which a piezoelectric base body (reference symbol 98 of the EP 0 707 898 A2 ) a structure for impedance matching (reference numerals 24 of the EP 0 707 898 A2 ) is introduced into the electrical base body. This is done by means of regularly arranged trenches (reference numerals 30 of the EP 0 707 898 A2 ), which in this area in the piezoelectric body (reference numeral 98 of the EP 0 707 898 A2 ) are manufactured. After electrical contacting, the component produced in this way can be used. The in the EP 0 707 898 A2 disclosed technical teaching does not solve the problem of setting a further resonant frequency.

From the US 2004/0 114 467 A1 is a high-density pixel array known.

From the US 2002/0156373 A1 For example, an ultrasonic transducer array having a plurality of piezoelectric elements that can be operated independently is known. The piezoelectric elements are arranged at regular intervals and form in this way a one-dimensional grid. In a further development of the technical teaching of US 2002/0156373 A1 ( 12 of the US 2002/0156373 A1 ) These are arranged in a cylinder segment to each other and can thus form a two-dimensional grid of vibrating bodies.

From the JP S62-098 394 U an ultrasonic transducer is known whose cover (reference numeral 3 of the JP S62-098 394 U ) is pierced by sound passage openings arranged in a two-dimensional hexagonal lattice.

All these devices have in common that they suggest no possibility for generating further resonance frequencies.

Object of the invention

It is the object of the invention to provide a device as a vibration system of mounting element and piezoelectric vibrating body for use in an ultrasonic transducer, which is intended for use with ultrasonic-based distance measuring devices for parking aids in the motor vehicle, which can radiate sound at a plurality of resonant frequencies, which are different from the natural frequencies of the piezoelectric vibrating body.

This object is achieved by a vibration system consisting of a mounting element and a piezoelectric vibrating element according to claim 1. Further embodiments according to the invention form the subclaims.

Description of the invention

The invention relates to an ultrasound transducer (TR) having at least one piezoelectric oscillating element (FIG. 2 ). The special feature of this ultrasound transducer is that it has a housing ( 1 ), which is at least partially electrically conductive, and that the housing ( 1 ) via an electrically conductive, in particular metallic, housing bottom ( 1a ) and at least one at least partially electrically conductive, in particular metallic, housing wall ( 1c ). The decisive difference with the prior art is that the housing ( 1 ) relative to the at least one piezoelectric oscillating element ( 2 ) is electrically isolated. This allows the housing ( 1 ) are earthed separately and in the case of an ESD event the energy of the ESD pulse can no longer be 2 ) to the inputs and outputs (DRV1, DRV2, AING, AINS) of the drive circuit.

A typical feature of the ultrasonic transducer is characterized in that the housing ( 1 ) of the ultrasonic transducer with at least one electrically insulating and acoustically suitable damping casting compound or filling compound ( 12 ), in particular poured, is. This is particularly advantageous in order to ensure the mechanical integrity of the ultrasonic transducer (TR) over its lifetime and to allow a rapid swinging of the housing. It has proven to be particularly advantageous if the housing ( 1 ) with an electrically insulating and acoustically damping encapsulant or filler mass ( 12 ) is filled, in particular poured, is that the oscillation amplitude of the piezoelectric vibrating element ( 2 ) of the ultrasound transducer per oscillation period by more than 0.05% or more than 0.1% or more than 0.2% or more than 0.5% or more than 1% or more than 2% or more than 5% or more than 10%.

For the purposes of this disclosure, "acoustically damping" means that this material dampens the vibrations in such a way that, after the passage of the acoustic wave through the relevant acoustically damping material, the amplitude is lower. The potting compound is therefore designed usually dampening, so that the radiation is minimized in the sensor housing itself. On the other hand, the adhesive should have a low level of acoustic damping so that the sound power and acoustic sensitivity of a device according to the invention are as equal as possible to those of the prior art.

Typically, the at least one piezoelectric oscillating element ( 2 ) by means of at least one electrically insulating adhesive ( 3 ) in the electrically conductive housing ( 1 ) mechanically on the housing bottom ( 1b ) attached. Of course, other attachment methods are conceivable. However, it has been shown that this method of attachment is the most advantageous. The resulting advantage, unlike the prior art, is that the at least one piezoelectric oscillating element ( 2 ) electrically from this housing ( 1 ) and thus the said ESD events can no longer reach the connections (DRV1, DRV2, AING, AINS) of the drive _circuit (US _ctr ).

Thus, it is preferably such that the at least one piezoelectric oscillating element ( 2 ) of the ultrasound transducer (TR) at least one first electrical contact ( 2a ) and at least one second electrical contact ( 2 B ), wherein at least these two contacts ( 2a . 2 B ) of the at least one piezoelectric oscillating element ( 2 ) of the housing ( 1 ) and / or from an electrical connection ( 7 ) of the housing ( 1 ) are electrically isolated. If there are further contacts, they should not reduce the isolation of the control _circuit (US _ctr ) from ESD events.

Typically, at least one first contact ( 2a ) on a first surface of the vibrating element ( 2 ) and / or at least one second contact ( 2 B ) on one of the first surface of the vibrating element ( 2 ) opposite, the second surface of the vibrating element ( 2 ).

By the isolation of the at least one piezoelectric oscillating element ( 2 ) from the housing ( 1 ) arises now the problem of electrical contacting of the at least one piezoelectric vibrating element ( 2 ), which hitherto in the prior art from the back by means of an electrically conductive adhesive ( 8th ) took place and now is no longer possible. Namely, an object of the invention is also not to change the components of the prior art. This contacting problem is caused by at least one electrically conductive mounting element, for example a mounting ring ( 6 ) on which the at least one piezoelectric oscillating element ( 2 ) electrically conductive with at least one second contact ( 2 B ) is mechanically fastened. This second contact ( 2 B ) of the at least one piezoelectric oscillating element ( 2 ) is thus with at least one electrically conductive and / or semiconducting mounting element ( 6 . 6 . 6c . 6d . 6e ), in particular an electrically conductive mounting ring ( 6 ), electrically and mechanically connected, wherein the electrical connection, for example, by at least one electrically conductive adhesive and / or soldering and / or welding takes place or can take place.

Theoretically possible, but not appropriate, is a purely mechanical connection, for example, with electrically insulating Kelber, since then the electrical contact would have to be made separately.

Due to the shape and type of mechanical connection of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), the vibration characteristics and the sound radiation and the reception properties can be modified. This is the core of the invention.

The oscillating system according to the invention consists primarily of a mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) as a vibrating body and at least one of the vibration of this vibrating body driving piezoelectric vibrating element ( 2 ) per mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ). It is typically intended for use in an ultrasonic transducer (TR) for use in a motor vehicle. The piezoelectric vibrating element ( 2 ) of the oscillating system is connected to the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) mechanically connected. Typically, the mechanical connection between piezoelectric oscillating element ( 2 ) of the vibration system and the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) by gluing with an adhesive and / or soldering and / or welding. The oscillating system is typically made by means of an elastic adhesive ( 3 ) mechanically with a housing ( 1 . 1a . 1c ) of an ultrasonic transducer (TR). Other mounting methods such as welding, soldering and pressing and other known connection forms are conceivable. In contrast to the prior art, the mechanical connection between the oscillating system, consisting of the oscillating element ( 2 ) and the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) in the region of the vibrating element ( 2 ) so that the shortest connecting line from the center of gravity of the piezoelectric vibrating element ( 2 ) to the housing ( 1 . 1a . 1c ), in which the vibration system is to be mounted, the elastic adhesive ( 3 ) cuts. Without this elasticity of the adhesive, the system would not be able to oscillate. The adhesive has losses in the form of a sound attenuation, which are preferably designed so that the vibration system such as sound radiation and adhesive damping oscillates asymptotically quickly when the vibrating element is no longer operated. The adhesive and its positioning below the vibrating element are therefore critical for a good reception performance in order to be able to detect sound reflection well even at short distances. The inventive oscillation system of the ultrasonic transducer consisting of mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and piezoelectric vibrating element ( 2 ) is characterized in contrast to the prior art in that when driving the piezoelectric vibrating element ( 2 ) by a drive _circuit (US _ctr ) at least two or more mechanical resonance frequencies, a first resonant frequency and a second resonant frequency and possibly other resonant frequencies can be excited, which are different from each other. In particular, at least one of these resonant frequencies is of the three natural frequencies of the piezoelectric oscillating element ( 2 ) and the frequencies of the corresponding harmonics. Here, these frequencies relate to the natural frequencies of the piezoelectric vibrating element without anmontiertes mounting element. The basic idea of the invention is therefore to excite natural oscillations of a mounting element with a discrete larger vibrating element. In order to enable several natural frequencies of the mounting element, or better of the vibration system consisting of mounting element and piezoelectric vibrating element, the structure of the mounting element is suitably modified. For this purpose, the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) typically via at least one opening ( 9 . 9b . 9c . 9d ) and / or recess and / or recess, which allows several eigenmodes of the mounting element. Such a recess may also be a recess or indentation of the edge of the mounting element. The frequency ratio of the amount of the second resonant frequency divided by the amount of the first resonant frequency then depends on a diameter and / or the position of this opening (FIG. 9 . 9b . 9c . 9d ) and / or recess and / or recess and / or recess and / or recess on the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ).

A refined embodiment of a device according to the invention is characterized in that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) at least one pattern of openings ( 10 ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and / or depressions on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and / or increases ( 10b ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), which translational displacement along a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) by at least a first distance n ₁ · a1 and / or a second distance m ₁ · a ₂ , where n ₁ and m ₁ are integers, at least partially imaged onto themselves, ie in particular a one- or two-dimensional grating on a surface of the mounting element (FIG. 6 . 6b . 6c . 6d . 6e . 6i . 6y ). In this case, the frequency ratio of the magnitude of the second resonant frequency divided by the magnitude of the first resonant frequency depends on the first distance a ₁ and typically on the first distance a ₂ and the angle between the associated directions of these distances (a ₁ , a ₂ ).

Analogously, the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) at least one pattern of openings ( 10 ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and / or depressions on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and / or increases ( 10b ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) which, when rotationally displaced about an axis of symmetry along a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) by at least a first angle n ₃ · θ ₁ where n _{3 is} an integer, at least partially mapped back on itself. It also typically forms a one- or two-dimensional rotary grid on a surface of the mounting element (FIG. 6 . 6b . 6c . 6d . 6e . 6i . 6y ). In this case, the frequency ratio of the magnitude of the second resonance frequency divided by the magnitude of the first resonance frequency now depends on the first angle θ ₁ .

The ultrasonic transducer transducer system, and thus the ultrasonic transducer itself, typically has at least two distinct grades or resonant bandwidths, a first grade or first resonant bandwidth at the first resonant frequency on one side, and a second grade or second resonant bandwidth at the second resonant frequency the other side. This can be achieved for example by suitable arrangement of splices between the mounting element and the housing.

Similarly, the ultrasonic transducer may have two or more distinct radiation characteristics, a first radiation characteristic at the first resonance frequency and a second radiation characteristics at the second resonance frequency. In this case, radiation characteristic is to be understood such that the sound amplitude radiated by the vibration system per steradian into the space from the angle between the connection axis from the point at which the sound amplitude is detected to a point of reference to the surface normal ( 14 ) to the surface ( 2a ) on the one side and the corresponding surface normal ( 14 ) to the surface ( 2a ) of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) depends on the other side.

As already mentioned, the area of the mounting element can be varied to produce the appropriate acoustic properties. In particular, a first plane cross-sectional area of a mounting element (FIG. 6b . 6c . 6d . 6e . 6i . 6y ), in particular the mounting ring ( 6 ) perpendicular to the surface normal of a surface of the mounting element ( 6b . 6c . 6d . 6e . 6i . 6y ), in particular the mounting ring ( 6 ), have a different shape than a second plane cross-sectional area of the piezoelectric vibrating element (FIG. 2 ), which are also perpendicular to the surface normal of a first or second surface of the piezoelectric vibrating element ( 2 ). In this case, it is particularly useful if the mounting element is provided with acoustic stub lines, which preferably each individually represents a resonator for the desired resonant frequency. In special embodiments of the invention, the centroid of the surface of the mounting element ( 6b . 6c . 6d . 6e . 6i . 6y ) with respect to the centroid of a first or second surface of the piezoelectric vibrating element ( 2 ) arranged offset.

With a suitable combination of such acoustic lines and damping elements in the form of a suitable, only locally applied adhesive 10 can be achieved that the Schallabstrahlachse ( 11 ) Vibrational system of the ultrasound transducer (TR) not parallel to the surface normal ( 14 . 15 ) of the first or second surface of the piezoelectric vibrating element ( 2 ). This from the literature (eg US 4413629 ) only known when using multiple vibrating systems.

It is most preferred that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) with at least one opening ( 9 . 9b . 9c . 9d ) and / or recess and / or recess below the vibrating element ( 2 ) to adjust the flexural rigidity of the mounting member. This has the purpose of adjusting the acoustic impedance of the mounting element as an acoustic sound conductor in the region of the vibrating element to the acoustic impedance of the vibrating element and is thus not known in this function from the literature. It is thus the function of this opening to improve the energy input from the piezoelectric vibrating element into the mounting element.

Very preferably, this indicates Mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) the said grid on. Preferably, the grid structure is hexagonal or square. The lattice symmetry thus preferably four or sechzählig.

Preferably, the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) or a part thereof, z. B. an acoustic stub, at least a measure of length, which is an integer (k-fold) multiple of the average sound wavelength (λ) in the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) divided by four is (k · λ / 4).

An essential element of such an acoustic mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) may be that there is an acoustic branch line, z. B. as acoustic stub, having. Such a stub can end freely in the room or be fixed by a suitable adhesive at the end. This acoustic finish can be suitably adjusted by the choice of adhesive and the processing of the gluing process. As a result, for example λ / 2 and λ / 4 resonators can be generated.

In addition to the mounting element itself and the housing can be structured appropriately. For example, the ultrasound transducer (TR) may have at least one further structure in the housing bottom, which has a pattern of depressions (FIG. 17 ) and / or increases ( 17 ) and / or openings, the translational displacement along a surface of the housing bottom ( 1b ) by at least a first distance n ₂ · a ₃ and / or a second distance m ₂ · a ₄ , where n ₂ and m ₂ are integers, is at least partially imaged on itself, ie in particular a one- or two- or forming a three-dimensional grid.

Of particular importance is a circuit for controlling a vibrating system according to the invention which has a drive circuit (USctr) at least as a subcircuit, the drive _circuit (US _ctr ) via a first electrical line (DRV1) and a second electrical line (DRV2) directly and above all transformerless with the piezoelectric oscillating element ( 2 ) of the vibrating system is electrically connected. The drive _circuit (US _ctr ) can be an electrical voltage- _modulated transmit signal with a transmission frequency via the first line (DRV1) and the second line (DRV2) to the piezoelectric vibrating element ( 2 ) of the vibration system. The control _circuit (US _ctr ) comprises at least one first inverter consisting of at least one first transistor (T1), which is driven by a first transmit signal (Φ _1a ), and at least one second transistor (T3), which with a complementary first transmit signal ( Φ _1b ) is driven. In this case, the first inverter drives the second line (DRV2) for direct transferless differential activation of the piezoelectric oscillating element (FIG. 2 ). The drive _circuit (US _ctr ) comprises at least one second inverter consisting of at least one second transistor (T2), which is driven with a second transmit signal (Φ _2a ), which may be in particular opposite to the first transmit signal (Φ _1a ), and at least one fourth transistor (T4), which is driven with a complementary second transmission signal (Φ _2b ), which may in particular be opposite to the complementary first transmission signal (Φ _1b ). The second inverter drives the first line (DRV1) for direct transferless differential activation of the piezoelectric oscillating element (FIG. 2 ). The drive _circuit (US _ctr ) typically switches off the transmit signals (φ _1a , φ _1b , φ _2a , φ _2b ) during reception and thus at least temporarily the transistors (T1, T2, T3, T4). Preferably, the drive _circuit (US _ctr ) can generate at least a first transmission frequency, with which the voltage difference between the first line (DRV1) and the second line (DRV2) is modulated and which excites the first resonant frequency of the oscillating system. In addition, the control _circuit (US _ctr ) may preferably _generate at least one second transmission frequency possibly also simultaneously with the first transmission frequency with which the voltage difference between the first line (DRV1) and the second line (DRV2) is modulated and which the second resonant frequency of the oscillating system stimulates.

The ultrasonic transducer according to the invention can thus by a suitable choice and design of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) not only one, but two or three or even more resonant frequencies, in particular a first resonant frequency and a second resonant frequency and optionally a third resonant frequency and possibly further resonant frequencies which are different from each other. The mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and the construction technique with bonds ( 3 , b) designed so that the quality of each resonant oscillation at each resonant frequency satisfies its own frequency-specific requirements. The ultrasonic transducer according to the invention therefore has at least two mutually different goodness or resonance bandwidths, a first quality or first resonance bandwidth at a first resonance frequency on the one side and a second quality or second resonance bandwidth at a second resonance frequency on the other side. These provide a means to be able to switch the emission characteristics by means of frequency-specific excitations by a drive circuit (US) in operation depending on the resulting measurement task without design change by simple frequency switching. The ultrasound transducer (TR) according to the invention therefore has at least two mutually different emission characteristics, a first emission characteristic at a first resonance frequency and a second emission characteristic at a second resonance frequency. These, in turn, are a means of being able to switch between at least two measurement tasks, such as near-range distance measurement when parking with a car and far-range distance measurement when looking for a parking space, which is the ultimate goal.

It is therefore possible that, depending on the application, it makes sense if at least one first plane cross-sectional area of at least one mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the mounting ring ( 6 ) perpendicular to the surface normal of a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular a mounting ring ( 6 ), has a different shape than at least one second plane cross-sectional area of at least one piezoelectric oscillating element (FIG. 2 ), which are also perpendicular to the surface normal of a first or second surface of the piezoelectric vibrating element ( 2 ). Or to put it briefly: it makes sense if the shape of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) of the piezoelectric vibrating element ( 2 ) deviates. This shape, in particular the outer edge of at least one mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can be selected relatively freely, but always has an influence on the acoustic properties of the ultrasonic transducer (TR). This is particularly advantageous in the manufacture of small numbers of ultrasonic transducers (TR), since the mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can be produced quickly and inexpensively, for example, by photolithographic etching and / or laser cutting in small quantities. In this way, a simple and cost-effective adaptation of the properties of the ultrasonic transducer to specific tasks is possible. This flexibility of the acoustic properties of the ultrasonic transducers (TR) in their production is thus a byproduct of the ESD robustness outlined above.

Through these modifications and / or, for example, the tilted installation of at least one package of piezoelectric oscillating element ( 2 ) and mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can be achieved that the Schallabstrahlachse ( 11 ) of the ultrasound transducer (TR) not parallel to a surface normal (TR) 14 . 15 ) of a first or second surface of the respective piezoelectric vibrating element ( 2 ). In this case, the surface as the first surface of the respective piezoelectric vibrating element ( 2 ), which is the first contact ( 2a ) of the relevant piezoelectric vibrating element ( 2 ) wearing. Alternatively, the sound emission axis ( 11 ) of the ultrasonic transducer (TR) also not parallel to a housing axis ( 13 ) and / or an axis of symmetry of the housing ( 1c ) and / or the housing walls ( 1c ) and / or to a surface normal of an inner or outer surface of the housing bottom ( 1b ) of the housing ( 1 ) be.

What for the Schallabstrahlachse ( 11 ), can also be used for the surface normal ( 14 . 15 ) a surface of the piezoelectric vibrating element ( 2 ) can be achieved. Again, this can not parallel to a housing axis ( 13 ) and / or an axis of symmetry of the housing ( 1c ) and / or the housing walls ( 1c ) and / or to a surface normal of an inner or outer surface of the housing bottom ( 1b ) of the housing ( 1 ) to be ordered.

Typically, the housing ( 1 ) of the ultrasonic transducer cup-shaped. The construction height (h) of adhesive ( 3 ) and optional mounting element or optional mounting ring ( 6 ) and vibrating element ( 2 ) smaller than the height (h _G ) of the housing ( 1 ).

At the same time, the distance (d) between the first surface of the oscillating element is typically ( 2 ) and the upper edge of the cup-shaped housing ( 1 ) greater than the construction height (h).

The mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can be designed relatively freely. A particularly simple and experience preferably form is that of an electrically conductive sheet metal ring. In this case, the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) for the ultrasonic transducer (TR) according to the invention with a vibration system according to the invention at least one opening ( 9 . 9b . 9c . 9d ) and / or recess and / or recess, the mechanical properties of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) at a position of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ). As a result, for example, locally that mean modulus of elasticity can be changed. Here, the averaging over the opening takes place. A mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can be single or multiple openings ( 9 . 9b . 9c . 9d . 10 . 20 ) and / or single or multiple recesses and / or single or multiple wells have. Single or multiple openings ( 9 . 9b . 9c . 9d . 10 . 20 ) can completely or only partially under the piezoelectric vibrating element ( 2 ) can be arranged. Single or multiple openings ( 9 . 9b . 9c . 9d . 10 . 20 ) can be completely over or even partially over the electrically insulating adhesive ( 3 ) can be arranged. Single or multiple openings ( 9 . 9b . 9c . 9d . 10 . 20 ) can be completely over or even partially in an area of an overhang ( 6g , L) of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), which will be explained later, may be arranged.

Single or multiple openings ( 9 . 9b . 9c . 9d . 10 . 20 ) can, for example, cylindrical openings or slots or openings of other shape in the respective mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) be. However, it may also be only individual or several blind holes, single or multiple notches or individual or several other depressions from the upper or lower surface (side) of the respective mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) act.

It is conceivable that a mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) instead of the individual or also has a plurality of openings or individual or even several recesses and / or individual or even a plurality of recesses or at the same time with these, in the reverse manner, single or multiple increases. These individual or even a plurality of elevations may be, for example, single or multiple projecting cylinders or individual or multiple grooves or single or multiple protuberances of another form on the respective mounting member on the upper or lower surface (side) of the respective mounting element.

For example, some of these single or multiple apertures may be arranged in a two- or one-dimensional grid with a unit cell. This repeats the arrangement of the structures -. B. openings and elevations - the unit cell when moving along a surface of the respective mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) by at least one grating vector in at least one grating direction. A particular embodiment of a mounting element according to the invention ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) therefore has at least one pattern - the said unit cell - of openings ( 10 ) and / or increases ( 10b ) which translates translationally along a surface of said mounting member by at least a first distance n _1. a ₁ and / or a second distance m ₁ .a ₂ , where n ₁ and m ₁ are integers, at least partially on top of each other itself is formed, so in particular forms a one- or two- or three-dimensional grid.

Particularly suitable patterns can be generated by means of the arrangement in a square hexagonal grid. In this case, the lattice structure of the two-dimensional lattice is hexagonal or square. The lattice symmetry is then four or sixteen. Of course, rectangular and / or rhombic grids are conceivable.

These structures can basically also in the housing bottom ( 1b ) are introduced. One embodiment of the ultrasound transducer according to the invention is therefore characterized, inter alia, by the fact that the ultrasound transducer has at least one further structure in the housing bottom, which in a similar manner to the mounting element has a pattern of recesses (FIG. 17 ) and / or increases ( 17 ) and / or openings - the said unit cell - which, when translationally displaced by at least a first distance n ₂ · a ₃ and / or a second distance m ₂ · a ₄ , where n ₂ and m ₂ are integers, at least partially is again imaged on itself, so in particular forms a one- or two- or three-dimensional grid.

In this case, the three-dimensionality can be achieved in that at least the housing bottom is laminated together from several layers with a respective two-dimensional grid.

In principle, this methodology also makes possible an optimization in terms of the fact that the transducer (TR) can have more than one resonance frequency and can have a different quality. If a control _circuit (US _ctr ) is no longer so frequency-selective, a user can use the structures of the mounting element ( _FIG. 6 . 6b . 6c . 6d . 6e . 6i . 6y ) or in the housing bottom ( 1b ) realize the intention to achieve at a first frequency, a resonance of lower quality of the resonance and thus a larger frequency bandwidth of the sensor, in particular the settling time after the transmission of the transmit pulse and thus the "dead" area in which a on the ultrasonic transducer based distance sensor, for example, a parking sensor of a car, due to this own decay still can not perceive obstacles to minimize and at another, second frequency, in contrast, to achieve a resonance better quality of resonance, in order to achieve a better range by the longer transmission pulse ,

Accordingly, the control _circuit (US _ctr ) can be designed such that, depending on the currently desired measurement task, for example for a first measurement task, for example a proximity measurement with a short settling time, a transmission signal on the first line (DRV1) and the second line (DRV2). which has a first transmission signal frequency which leads to a resonance of the ultrasonic transducer (TR) in a first resonance frequency of the ultrasonic transducer (TR) with a first quality and a first radiation characteristic, and for a second measurement task, for example a distance measurement in Long settling time far-end, using a transmit signal on the first line (DRV1) and the second line (DRV2) having a second transmit signal frequency resulting in resonance of the ultrasonic transducer (TR) at a second resonant frequency of the ultrasonic transducer (TR ) with a second quality and a second emission characteristic. Of course, it is conceivable to provide more than two measurement tasks with possibly more than two transmission frequencies and, if appropriate, more than two resonance frequencies and possibly more than two grades and possibly more than two emission characteristics.

With the help of a thus electrically opposite the housing ( 1 ) isolated piezoelectric vibrating element ( 2 ) can now be built an electrical circuit. This circuit for controlling an ultrasonic transducer (TR) with a vibrating element according to the invention comprises at least one piezoelectric vibrating element (FIG. 2 ) of the ultrasonic transducer (TR) and the Control circuit (DRV) This in turn comprises, as part of the circuit, at least one first inverter consisting of at least one first transistor (T1) and at least one second transistor (T3). The first transistor (T1) is driven by a first transmission signal (Φ _1a ). The second transistor (T3) is driven with a complementary first transmission signal (Φ _1b ). These transistors (T1, T3) drive a second line (DRV2) for direct differential activation of the piezoelectric oscillating element (FIG. 2 ). Furthermore, the circuit comprises at least one second inverter consisting of at least one second transistor (T2) which is driven by a second transmit signal (φ _2a ), which may in particular be opposite to the first transmit signal (φ _1a ). In addition, the circuit comprises at least one fourth transistor (T4), which is driven with a complementary second transmit signal (Φ _2b ), which may in particular be opposite to the complementary first transmit signal (Φ _1ab ). The two transistors (T2, T4) drive a first line (DRV1) for direct differential activation of the piezoelectric oscillating element (FIG. 2 ). Since the transmission signals would interfere with the reception, the transmission signals (φ _1a , φ _1b , φ _2a , φ _2b ) switch off the transistors (T1, T2, T3, T4) at least temporarily during reception. For this to work, at least one piezoelectric oscillating element ( 2 ) preferably in an at least cup-shaped Faraday cage, a housing ( 1 ), assembled. This housing ( 1 ) is preferably of the first line (DRV1) and the second line (DRV2) and the piezoelectric oscillating element ( 2 ) and isolated by a connection (ESD_GND) to a potential defined with respect to the other parts of the circuit, preferably an ESD ground.

To the influence of the housing ( 1 ) by capacitive coupling and the like to minimize the rest of the circuit, it is advantageous if the housing ( 1 ) of the ultrasonic transducer (TR) is connected to a low-impedance voltage source or to a capacitance, for example, against signal ground or to the connection to a supply voltage line or a ground line as ESD grounding.

So that a piezoelectric oscillating element ( 2 ), it is advantageous if the relevant piezoelectric oscillating element ( 2 ) can be driven isolated from the ESD ground via two lines (DRV1, DRV2) and a suitable drive signal is applied as a voltage between these two lines (DRV2, DRV1), which has at least one edge and / or polarity change, preferably in digital form. In that case, such a piezoelectric vibrating element ( 2 ) are excited with a digital signal.

In addition to the ultrasonic transducer (TR), the mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and the associated drive circuit, the invention also includes a method for producing such an ultrasonic transducer (TR).

• • Bereitstellen eines Gehäuses (1),
• • Einbringen mindestens einer elektrisch isolierenden Klebemasse (3) in das Gehäuse (1),
• • mechanisches Verbinden mindestens eines elektrisch leitenden Montageelements (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere eines Montagerings (6), mit der mindestens einen elektrisch isolierenden Klebemasse (3)
• • Einbringen mindestens eines piezoelektrischen Schwingelementes (2) in das Gehäuse (1),
• • mechanisches Verbinden des mindestens einen piezoelektrischen Schwingelementes (2), das mindestens einen ersten elektrischen Kontakt (2a) und mindestens einen zweiten Kontakt (2b) aufweist, mit der mindestens elektrisch isolierenden Klebemasse (3),
• • mechanisches und elektrisches Verbinden des mindestens einen Schwingelementes (2) mittels mindestens eines zweiten Kontakts (2b) mit dem mindestens einen elektrisch leitenden Montageelement (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere dem Montagering (6),
• • elektrisches Verbinden mindestens einer ersten elektrischen Zuleitung (4) mit dem mindestens einen ersten elektrischen Kontakt (2a) des mindestens einen piezoelektrischen Schwingelements (2),
• • elektrisches Verbinden mindestens einer zweiten elektrischen Zuleitung (5) mit dem mindestens einen zweiten elektrischen Kontakt (2b) des mindestens einen piezoelektrischen Schwingelements (2) und/oder mit dem mindestens einen elektrisch leitenden Montageelement (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere dem elektrisch leitenden Montagering (6),
• • ggf. elektrisches Verbinden mindestens einer dritten elektrischen Zuleitung (7) mit dem Gehäuse (1).

This includes in a first form the steps:

• • providing a housing ( 1 )
• Introducing at least one electrically insulating adhesive ( 3 ) in the housing ( 1 )
• Mechanically connecting at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular a mounting ring ( 6 ), with the at least one electrically insulating adhesive ( 3 )
• Introducing at least one piezoelectric oscillating element ( 2 ) in the housing ( 1 )
• Mechanical connection of the at least one piezoelectric oscillating element ( 2 ), which has at least one first electrical contact ( 2a ) and at least one second contact ( 2 B ), with the at least electrically insulating adhesive ( 3 )
• Mechanical and electrical connection of the at least one vibrating element ( 2 ) by means of at least one second contact ( 2 B ) with the at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the mounting ring ( 6 )
• Electrically connecting at least one first electrical supply line ( 4 ) with the at least one first electrical contact ( 2a ) of the at least one piezoelectric oscillating element ( 2 )
• Electrically connecting at least one second electrical supply line ( 5 ) with the at least one second electrical contact ( 2 B ) of the at least one piezoelectric oscillating element ( 2 ) and / or with the at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the electrically conductive mounting ring ( 6 )
• If necessary electrical connection of at least one third electrical supply line ( 7 ) with the housing ( 1 ).

In this case, the steps are preferably carried out in the order indicated above.

• • Bereitstellen eines Gehäuses (1),
• • Einbringen mindestens einer elektrisch isolierenden Klebemasse (3, 3b) in das Gehäuse (1),
• • mechanisches und elektrisches Verbinden mindestens eines Schwingelementes (2), das mindestens einen ersten elektrischen Kontakt (2a) und mindestens einen zweiten Kontakt (2b) aufweist, mittels mindestens eines zweiten Kontakts (2b) mit mindestens einem elektrisch leitenden Montageelement (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere dem Montagering (6),
• • Einbringen des mindestens einen piezoelektrischen Schwingelementes (2) und des mindestens einen Montageelementes (6, 6b, 6c, 6d, 6e) in das Gehäuse (1),
• • mechanisches Verbinden des mindestens einen elektrisch leitenden Montageelements (6, 6b, 6c, 6d, 6e), insbesondere eines Montagerings (6), mit der mindestens einen elektrisch isolierenden Klebemasse (3, 3b) und mechanisches Verbinden des mindestens einen piezoelektrischen Schwingelementes (2) mit der mindestens einen elektrisch isolierenden Klebemasse (3, 3b),
• • elektrisches Verbinden mindesten einer ersten elektrischen Zuleitung (4) mit dem mindestens einen ersten Kontakt (2a) des mindestens einen piezoelektrischen Schwingelements (2),
• • elektrisches Verbinden mindestens einer zweiten elektrischen Zuleitung (5) mit dem mindestens einen zweiten Kontakt (2b) des mindestens einen piezoelektrischen Schwingelements (2) und/oder mit dem mindestens einen elektrisch leitenden Montageelement (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere dem elektrisch leitenden Montagering (6),
• • ggf. elektrisches Verbinden mindestens einer dritten elektrischen Zuleitung (7) mit dem Gehäuse (1)

However, at least one piezoelectric oscillating element ( 2 ) with at least one mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) first and then into the housing ( 1 ) are used. The associated method then comprises the steps:

• • providing a housing ( 1 )
• Introducing at least one electrically insulating adhesive ( 3 . 3b ) in the housing ( 1 )
• Mechanical and electrical connection of at least one vibrating element ( 2 ), which has at least one first electrical contact ( 2a ) and at least one second contact ( 2 B ), by means of at least one second contact ( 2 B ) with at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the mounting ring ( 6 )
• Introducing the at least one piezoelectric oscillating element ( 2 ) and the at least one mounting element ( 6 . 6b . 6c . 6d . 6e ) in the housing ( 1 )
• Mechanically connecting the at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e ), in particular a mounting ring ( 6 ), with the at least one electrically insulating adhesive ( 3 . 3b ) and mechanically connecting the at least one piezoelectric oscillating element ( 2 ) with the at least one electrically insulating adhesive ( 3 . 3b )
• Electrically connecting at least a first electrical supply line ( 4 ) with the at least one first contact ( 2a ) of the at least one piezoelectric oscillating element ( 2 )
• Electrically connecting at least one second electrical supply line ( 5 ) with the at least one second contact ( 2 B ) of the at least one piezoelectric oscillating element ( 2 ) and / or with the at least one electrically conductive mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the electrically conductive mounting ring ( 6 )
• If necessary electrical connection of at least one third electrical supply line ( 7 ) with the housing ( 1 )

Again, the process of preparation preferably follows the sequence given above.

In addition, at least one space between at least one overhang ( 6g ) at least one mounting element ( 6e ) and the housing bottom ( 1b ) still with at least one special mass ( 18 ) are filled. This is usually done before the introduction of the relevant mounting element ( 6e ) in the housing ( 1 ). However, the mass may also after this introduction, if necessary, through openings ( 17 . 10 ) are injected into the space in question. Both basic variants of the process described above can therefore be around the step
"Introducing at least one mass ( 18 ) or at least one medium ( 18 ), which finally between at least one mounting element ( 6e ) and caseback ( 1b ), "
be supplemented. Whereby this step can be carried out at different points of the respective process.

• • „Ausfüllen des Gehäuses (1) mit mindestens einer Vergussmasse oder mindestens einer Füllmasse (12)”

ergänzt werden. Wobei dieser Schritt typischerweise als letzter Schritt des Prozesses durchgeführt wird.In addition, the housing ( 1 ) even with at least one potting compound ( 12 ) are shed. Alternatively, other fillers can be introduced. Both basic variants of the process described above can therefore be around the step

• • "Filling the housing ( 1 ) with at least one potting compound or at least one filling compound ( 12 ) "

be supplemented. This step is typically done as the last step of the process.

Description of the figures

The invention will be described in more detail below with reference to the figures.

1 shows a drive circuit with a transmitter for an ultrasonic transducer according to the prior art.

2 shows a simplified cross section through an ultrasonic transducer according to the prior art.

3 shows a simplified cross section through a sensor module according to the prior art.

4 shows a drive circuit without a transmitter for an ultrasonic transducer according to the prior art.

5 shows a driver stage of the drive circuit.

6 shows a simplified cross-section through an ultrasonic transducer with inventive oscillating system.

7 shows a simplified cross section through an ultrasonic transducer transducer with inventive vibration system, which is potted.

8th shows a drive circuit according to the invention without a transformer for an ultrasonic transducer with inventive oscillating system.

9 shows a simplified cross section through an ultrasonic transducer with inventive oscillating system with housing axis of symmetry.

10 shows a simplified cross-section through an ultrasonic transducer with inventive vibration system and housing axis of symmetry, which is potted.

11 shows a simplified cross-section through an ultrasonic transducer with inventive vibration system and housing axis of symmetry, wherein the piezoelectric vibrating element is tilted.

12 shows a simplified cross section through a potted, ultrasonic transducer with inventive vibration system and housing axis of symmetry, wherein the piezoelectric vibrating element is tilted.

13 shows a simplified cross section through an ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the opening in the mounting member is asymmetrical and reduced.

14 shows a simplified cross section through a molded ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the opening in the mounting member is asymmetrical and reduced.

15 shows a simplified cross-section through an ultrasonic transducer with inventive oscillation system, wherein the mounting member protrudes on one side and the opening in the mounting member is asymmetrical and reduced and wherein the piezoelectric vibrating element is tilted.

16 shows a simplified cross section through a potted, ultrasonic transducer with inventive vibration system, wherein the mounting member protrudes on one side and the opening in the mounting member is asymmetric and reduced and wherein the piezoelectric vibrating element is tilted.

17a shows an exemplary mounting element of 7 . 9 . 10 . 11 . 12 in the supervision.

17b shows an exemplary mounting element of 13 . 14 . 15 . 16 in the supervision.

18a shows an exemplary mounting element in which only the opening is reduced in size and asymmetrical in plan view.

18b shows an exemplary elliptical mounting element with reduced asymmetrically placed opening and an overhang with a two-dimensional hole grid (two-dimensional crystal) in the plan.

19 shows an exemplary round mounting element with a double-sided overhang and two exemplary areas with an exemplary two-dimensional perforated grid in the plan.

20 shows an exemplary round mounting element with a double-sided overhang and four exemplary openings ( 20 ) in the area of this overhang in supervision.

21 shows a simplified cross section through an ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the overhang rests on both sides of adhesive and wherein there is a perforated grid in the region of the overhang.

22 shows a simplified cross section through a potted, ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the overhang rests on both sides of adhesive and wherein there is a perforated grid in the region of the overhang.

23 shows a simplified cross section through an ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the overhang rests on both sides of adhesive and wherein there is a perforated grid in the region of the overhang and below the overhang in the housing bottom is an insert element.

24 shows a simplified cross section through a potted, ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the overhang on both sides rests on adhesive and wherein in the overhang is a perforated grid and below the overhang in the housing base structural elements (in this case blind holes) is ,

25 shows a simplified cross-section through an ultrasonic transducer with inventive oscillating system, wherein the mounting member protrudes on one side and the overhang rests on both sides of adhesive and wherein there is a grid of elevations in the region of the overhang.

26 shows an extension of 19 by two acoustic stub lines (SL1 and SL2) for generating at least two further resonance frequencies.

The further description of the invention in its various concrete forms takes place now on hand of 5 to 25 , The claimed scope results from the claims.

5 shows a typical driver circuit (DRV) for driving the first line (DRV1) and the second line (DRV2). The driver circuit (DRV) is supplied with electrical power by a supply voltage (VDRV) which is typically supplied within the drive _circuit (US _ctr ) from the external supply (VSUP_LINE, 4 ) is produced. A first transistor (T1), which is typically a p-channel MOS transistor is driven with a first signal (Φ _1a) and pulling the first line (DRV1) typically (with the first contact 2a ) of the piezoelectric vibrating element ( 2 ) to a positive potential when the first transistor (T1) turns on. A third transistor (T3), which is typically an n-channel MOS transistor, is driven with a first complementary signal (φ _1b ) and pulls the first line (DRV1) to a ground potential when the third transistor (T3) turns. An unshown blocking circuit prevents simultaneous switching on of the first and third transistors (T1, T3). During reception, the first and third transistors (T1, T3) are turned off.

A second transistor (T2), which is typically a p-channel MOS transistor, is driven with a second signal (Φ ₂₎ and pulls the second conduit (DRV2), typically (with the second contact 2 B ) of the piezoelectric vibrating element ( 2 ) is connected to a positive potential when the second transistor (T2) turns on. A fourth transistor (T4), which is typically an n-channel MOS transistor, is driven with a second complementary signal (φ _2b ) and pulls the second line (DRV2) to a ground potential when the fourth transistor (T4) turns. An unshown blocking circuit prevents the simultaneous switching on of the second and fourth transistor (T2, T3). During reception, the second and fourth transistors (T2, T4) are also off. Typically, the first and second signals are complementary to one another such that the level of the AC voltage between the first and second lines is approximately twice the level of the supply voltage (VDRV).

During reception, all four transistors (T1, T2, T3, T4) are typically off. The circuit (DRV) then has a high resistance output at its outputs (DRV1, DRV2).

In order to solve the problem of ESD, the device with the oscillating system according to the invention provides an electrical insulation of the piezoelectric oscillating element ( 2 ) opposite the housing ( 1 ) in front. This is in 6 shown. An electrical contacting of the second contact ( 2 B ) of the piezoelectric vibrating element ( 2 ) but must still be possible. 6 shows the corresponding solution schematically. For this purpose, a mounting element ( 6 ) are introduced into the ultrasound transducer (TR). This is preferably at least partially electrically conductive, so that the piezoelectric vibrating element ( 2 ) can be mechanically connected to this electrically conductive. The electrical connection takes place via the second contact ( 2 B ) of the piezoelectric vibrating element ( 2 ) instead of. The electrically conductive mechanical connection between second contact ( 2 B ) of the piezoelectric vibrating element ( 2 ) and the mounting element ( 6 ) can be produced for example by electrically conductive bonding and / or by soldering and / or welding. The mounting element ( 6 ) is connected to the second electrical supply line ( 5 ) electrically conductively connected, which now instead of the housing ( 1 ) can be electrically connected to the second line (DRV2).

The piezoelectric vibrating element ( 2 ) and the mounting element ( 6 ) are protected by an electrically insulating adhesive ( 3 ) in the housing ( 1 ) typically on the housing bottom ( 1b ) attached. That housing ( 1 ) itself is connected via a special electrical connection ( 7 ) of the housing ( 1 ) connected to a special ESD ground (ESD_GND). In the case of an ESD event, the energy of the ESD pulse is thus not conducted into the drive _circuit (US _ctr ) but into an ESD ground connection (ESD-GND). In practice, it is recommended to develop the design with suitable EMC simulation tools, because despite this derivation capacitive and inductive couplings can still lead to disturbances, which are massively weakened compared to the state of the art.

As already mentioned above, it has proved to be favorable if the diameter (L _G ) of the typically round housing (FIG. 1 ) is an integer multiple (n-times) of the wavelength of the sound in air (λ _L ). This results in a certain directivity of the radiated sound of the ultrasonic transducer (TR). The sound emission direction ( 11 ) is here by the reference numeral 11 indicated.

In the example of 6 owns the mounting element ( 6 ) a symmetrical opening ( 9 ), here by way of example of the electrically insulating adhesive ( 3 ) is filled. It is at the mounting element ( 6 ) more like a mounting ring ( 6 ). Its outer edge in this example has a radius which is greater than the radius of the outer edge ( 2c ) of the piezoelectric vibrating element ( 2 ). Likewise, the radius of the outer edge of the mounting element is greater than the radius of the circle of the adhesive edge ( 3c ). This means that the Mounting ring ( 6 ) in this example a little over the piezoelectric vibrating element ( 2 ) and the adhesive edge ( 3c ) stands out.

The mounting ring or the mounting element ( 6 ) of course changes the rocking properties of the piezoelectric vibrating element ( 2 ). An important claimed side effect of the construction according to the invention is therefore that by suitable shaping of the mounting element ( 6 ) and suitable attachment of the Pact of piezoelectric vibrating element ( 2 ) and mounting element ( 6 ), so the vibration system, the vibration and radiation properties of the ultrasonic transducer (TR) can be selectively modified. This is particularly advantageous because only the shape of the mounting element ( 6 ), while leaving all other components of the ultrasonic transducer (TR) in their construction. Is the mounting element ( 6 ), for example, produced by photolithographic etching and / or laser cutting, it is possible to produce even the smallest quantities of special ultrasonic transducers (TR) cost, without the housing ( 1 ) or the outer crystal form of the piezoelectric vibration element ( 2 ) must be changed.

The housing ( 1 ) is then clamped with the indicated notches in a holder. The brackets are then typically used as a fixed bearing, which allow a rotational degree of freedom you thus the torsional vibration of the housing ( 1 ) to allow this typically annular axis.

In many cases, it makes sense if the housing ( 1 ) with a potting compound ( 12 ) or another suitable substance. This casting compound ( 12 ) is in 10 drawn by way of example. Selection and consistency of this potting compound should be based on the requirements of the respective task. For this purpose, FEM simulations of the ultrasonic transducer should be performed during the design phase.

9 and 10 also show a housing axis ( 13 ). Instead of the housing axis ( 13 ) can also be a surface normal of the housing bottom ( 1b ) with regard to the uses of this housing axis ( 13 ), if this is even.

By tilting the package from the piezoelectric vibrating element ( 2 ) and the mounting element ( 6 ) opposite the housing bottom ( 1b ) by a tilt angle β, the Schallabstrahlrichtung ( 11 ) opposite the housing axis ( 13 ) are tilted by a radiation angle α. 11 shows this case. Here, in this example, the tilt angle β refers in one expression to the angle between a parallel ( 16 ) to the housing axis ( 13 ) and a normal ( 14 ) to a first surface of the piezoelectric vibrating element ( 2 ). The first surface of the piezoelectric vibrating element ( 2 ) should be the surface of the same, the first electrical contact ( 2a ) wearing. Instead of the normal ( 14 ) to a first surface of the piezoelectric vibrating element ( 2 ) can also be the normal to a second surface of the piezoelectric vibrating element ( 2 ) be used. The second surface of the piezoelectric vibrating element ( 2 ) should be the surface of the same, the second electrical contact ( 2 B ) wearing.

Instead of the normal ( 14 ) to a first surface of the piezoelectric vibrating element ( 2 ) can also be the normal to a surface of the mounting element ( 6 ) be used.

Instead of parallels ( 16 ) to the housing axis ( 13 ) can also be a parallel ( 16 ) are used to a normal of a surface of the case bottom for the definition of the tilt angle β or the radiation angle α.

12 shows the device 11 with a filling compound ( 12 ).

13 turns off the ultrasonic transducer (TR) 9 with a modified mounting element ( 6b ) This has a non-centric opening ( 9b ), which is smaller than the opening ( 9 ) of the 9 is. At the same time, the shape of the mounting element ( 6b ) to a one-sided overhang ( 6g ), which over the Klebekannte ( 3c ) further than in the case of 9 protrudes. The asymmetry of the position of the opening ( 9b ), their size and the one-sided overhang ( 6g ) lead to a change in the vibration characteristics of the ultrasonic transducer (TR) and to a distortion of the sound field that is generated by this when transmitting. In particular, there is an altered interaction between the mounting element ( 6b ), the housing bottom ( 1b ) and the housing wall ( 1c ) in the area and environment of the one-sided overhang ( 6g ). Typically, this will determine the direction and magnitude of the sound radiation direction (FIG. 11 ) and the shape of the Schallabstrahlkeule influenced.

Also, if necessary, change the resonance frequencies and the damping behavior. All of this will be optimized by the skilled artisan in the design typically with FEM simulation during the design phase. 14 shows again 13 with a suitable filling ( 12 ).

This asymmetry of 12 and 13 Of course, with the tilting of the 10 and 11 be combined. 15 shows the combination of tilting with the asymmetry of the mounting element ( 6b ) and 16 these with a filling ( 12 ).

The 17 to 20 show some exemplary mounting elements ( 6 . 6b . 6c . 6d . 6i . 6y ) in the plan view of a rotationally symmetrical piezoelectric oscillating element ( 2 ).

17a shows the mounting element ( 6 ) of the 9 . 10 . 11 . 12 in the supervision. The later position of the adhesive ( 3c ) as well as the later position of the outer edges of the piezoelectric oscillating element are marked by way of example. The mounting element ( 6 ) indicates the opening already described ( 9 ) on. It is therefore a mounting ring.

17b shows the mounting element ( 6b ) of the 13 . 14 . 15 . 16 in the supervision. The later position of the adhesive ( 3c ) as well as the later position of the outer edges of the piezoelectric oscillating element are marked by way of example. The mounting element ( 6b ) has the already described, reduced and asymmetrically located circular opening ( 9b ) on. An example is the asymmetric mounting of the piezoelectric oscillating element ( 2 ), the location of which is determined by its external characteristics ( 2c ) is indicated. Also the glue known ( 3c ) should be asymmetrical. In this example, the glue is known ( 3c ) symmetrical to the outside ( 2c ) of the piezoelectric vibrating element ( 2 ) arranged. This is advantageous, but not mandatory. There may be applications in which a further asymmetry makes sense. It is therefore an asymmetric mounting ring.

17a shows an exemplary mounting ring ( 6c ), which without overhang ( 6g ), or whose overhang is only very small. The adhesive ( 3c ) and the outside ( 2c ) of the piezoelectric vibrating element ( 2 ) are in this example symmetrical to the outer edge of the mounting element ( 6c ) to be ordered. Only the opening ( 9c ) is arranged asymmetrically.

17b shows another exemplary mounting element ( 6d ) with an elliptical outer edge. The opening ( 9d ) is reduced in size and arranged acentrically. The intended layers of the adhesive ( 3c ) and the outside ( 2c ) of the piezoelectric oscillating element ( 2 ) are also acentric and asymmetric to the opening ( 9d ) arranged. The area of the one-sided overhang ( 6g ) is additionally equipped with a grid of openings ( 10 ) Mistake. In this example, these form a two-dimensional grid (a two-dimensional crystal), which determines the average mechanical properties of the mounting element (FIG. 6d ), such as the mean modulus of elasticity changes in this area. As a result, the areal distribution of properties of the mounting element determining the propagation of sound and / or vibration ( 6d ) are modified locally by simple mechanical structuring. In the example, the two-dimensional grid on a first lattice constant a1 and a second lattice constant a _2. Of course, it is conceivable to use other unit cells for the two- or one-dimensional grid consisting of more than just one opening ( 10 ) to use. It is also conceivable to different areas of the surfaces of the mounting elements ( 6d ) with different two-dimensional lattices, which differed by the alignment of the lattices, lattice constants, unit cells and elements (openings, elevations, depressions) of the unit cells. In the example of 18b is the unit cell for simplicity a single opening ( 10 ). The openings ( 10 ) can, for example, cylindrical openings or slots or openings of other shape in the respective mounting element ( 6d ) be. But it may also just blind holes, notches or other depressions from the upper or lower surface (side) of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) act. Instead of such bulges but also the reverse case is conceivable. It may take place instead of the openings ( 10 ) thus also to increase a one- or two-dimensional grid act. The elevations of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) can, for example projecting cylinders or grooves or protuberances of other shape on the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) on the upper or lower surface (side) of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) be.

In the example of 18b the grid lines are straight. Instead, it is also conceivable that the grid lines lie on curved lines. In this case, however, at least one lattice constant is typically not constant, which makes it difficult to calculate the mechanical properties.

19 shows an example of a mounting element ( 6i ), which after mounting in the housing ( 1 ) should have a two-sided overhang (L). For simplicity, the opening of the opening ( 9 ) of the 9 . 10 . 11 and 12 , The outer edge of the mounting element ( 6i ) is circular. The intended placement of the adhesive ( 3c ), the outsider ( 2c ) of the piezoelectric vibrating element ( 2 ) and the opening ( 9 ) are symmetrical and centric with respect to the outer edge of the mounting element ( 6i ). In contrast to the previously discussed mounting elements, it is provided here, the mounting element ( 6i ) when mounted in the housing ( 1 ) also stick to the outside edge. This creates a second adhesive ( 3d ), which is also shown in dashed lines with regard to its planned location. In the area of the overhang (L) clamped on both sides, there are two two-dimensional lattices, which are here through openings ( 10 ) be generated. The mounting element ( 6i ) has a first axis of symmetry (Sym ₁ ) and a second axis of symmetry (Sym ₂ ), which in this example is perpendicular to the first axis of symmetry (Sym ₁ ). As a result of this structuring, the ultrasound transducer at least partially emits a multipole sound field.

20 show another example of a conceivable mounting element ( 6y ) with four more openings 20 , Also such openings ( 20 ) can be a local modification of the mechanical and acoustic properties of a mounting element ( 6y ). A symmetry is often useful, but not mandatory. Also, the shape and size of the openings ( 20 ) do not match.

The openings ( 20 ) may be, for example, openings or slots or openings of other shape in the respective mounting element. But it may also just blind holes, notches or other depressions from the upper or lower surface (side) of the mounting element ( 6y ) act. Instead of such bulges but here the reverse case is conceivable. It may take place instead of the openings ( 20 ) thus also to increase a one- or two-dimensional grid act.

The elevations of the mounting element ( 6y ) can, for example projecting cylinders or grooves or protuberances of other shape on the mounting element ( 6y ) on the upper or lower surface (side) of the mounting element ( 6y ) be. All forms can be mounted on a mounting element ( 6y ) are mixed. However, this increases the cost of production, which is why this will only come to fruition in special cases.

21 shows an ultrasonic transducer with a mounting element ( 6e ) in cross-section, which has a two-sided overhang (L). The mounting element ( 6e ) with a first electrically insulating adhesive ( 3 ) on the housing ( 1 ) attached. A second set of electrically insulating adhesive ( 3b ) fastens the mounting element ( 6e ) on the other side of the double-sided overhang (L). This results in a further adhesive edge ( 3d ). In the example, the mounting member has a first thickness (d1). The space between the mounting element ( 6e ) and caseback ( 1b ) has a second thickness (d2). The mounting element is in this area with a two-dimensional grid of holes (openings 10 ) Mistake. Is the housing ( 1 ) filled with air, the volume of air between the mounting element ( 6e ) and caseback ( 1b ) with the air. By suitable selection of the dimensions of the lattice spacings (a ₁ , a ₂ , a) and / or the size of the openings ( 10 ) and / or the second distance (d2) and / or the thickness (d1) of the mounting element ( 6e ) etc. the interaction can be set.

In particular, a temporal phase shift between a deflection of the housing bottom ( 1b ) in the region of the piezoelectric oscillating element ( 2 ) and a deflection in the region of the second splice ( 3b ) be achieved. It is particularly advantageous if the additional splice ( 3b ) not, as in 19 drawn, the entire mounting element ( 6e ), but for example remains limited to the area of the second axis of symmetry (Sym2).

It should be mentioned at this point that it is conceivable that the openings ( 9 . 20 ) completely under the piezoelectric oscillating element ( 2 ), as well as completely in the area of an overhang ( 6g , L) and partly under the piezoelectric oscillating element ( 2 ) and / or partially and in particular at the same time partly in the area of an overhang ( 6g , L) can be located. Also, it is not mandatory that the outer shape of the mounting element ( 6 . 6b . 6c . 6d . 6e ) is always round or elliptical. In principle, any shapes are conceivable, wherein the outer edge also under the piezoelectric vibrating element and within the adhesive known ( 3c ) can run.

22 shows again 21 with a potting compound ( 12 ). In this case, the gap between mounting element ( 6e ) and caseback ( 1b ) with the potting compound ( 12 ), another mass or with a gas, in particular air, be filled.

23 show the 21 , wherein under the overhang (L) a structured form element ( 6f ) is inserted and fixed, the properties of the space between the mounting element ( 6e ) and caseback ( 1b ) and the mechanical properties of the housing bottom ( 1b ) changed. The form element ( 6f ) can, for example, in the housing bottom ( 1b ) glued. In the example, the form element ( 6f ) Wells ( 17 ), which change its mechanical and acoustic properties. In these wells ( 17 ) and / or elevations of the housing bottom ( 1b ) or this in the housing bottom ( 1b ) insert element ( 6f ), which in particular can form a one- or two-dimensional grid, are modifications of the mechanical properties of the housing bottom ( 1b ). As recesses, these can be, for example, cylindrical blind holes or slots or depressions of a different shape in the molded element ( 6f ) or in the housing bottom ( 1b ) from the top or bottom of the Caseback ( 1b ) ago. As elevations, these, for example, protruding cylinders or grooves or protuberances of other shape in the form of element ( 6f ) or in the housing bottom ( 1b ) from the top or bottom of the case bottom.

24 shows the ultrasonic transducer (TR) of 23 with the difference that this with a potting compound ( 12 ) is filled. Between the overhanging overhang (L) of the mounting element ( 6e ) and the housing bottom ( 1b ) is a mass or a medium ( 18 ) for modifying the mechanical and / or acoustic properties. The openings ( 10 ) in the mounting element ( 6e ) are in this example with the mass ( 18 ) filled. Openings ( 17 ) in the housing bottom ( 1b ) of its bottom and top modify locally the mechanical and / or acoustic properties. These too are with the mass ( 18 ) filled by way of example.

25 shows an ultrasonic transducer (TR) 21 again with a mounting element ( 6e ) in cross-section, which has a two-sided overhang (L). The mounting element ( 6e ) is again with a first electrically insulating adhesive ( 3 ) on the housing ( 1 ) attached. A second set of electrically insulating adhesive ( 3b ) fastens the mounting element ( 6e ) on the other side of the double-sided overhang (L). This results in a further adhesive edge ( 3d ). In the example, the mounting member has a first thickness (d1). The space between the mounting element ( 6e ) and caseback ( 1b ) has a second thickness (d2). The mounting element is in this area with a two-dimensional grid of bulges (elevations 10b ) Mistake. Is the housing ( 1 ) filled with air, the volume of air between the mounting element ( 6e ) and caseback ( 1b ) with the air. By suitable selection of the dimensions of the lattice spacings (a ₁ , a ₂ , a) and / or the size of the elevations ( 10b ) and / or the second distance (d2) and / or the thickness (d1) of the mounting element ( 6e ) etc., the interaction and the mechanical properties of the overhang (L) can be adjusted.

In particular, again a temporal phase shift between a deflection of the housing bottom ( 1b ) in the region of the piezoelectric oscillating element ( 2 ) and a deflection in the region of the second splice ( 3b ) be achieved. It is particularly advantageous if the additional splice ( 3b ) not, as in 19 drawn, the entire mounting element ( 6e ), but for example remains limited to the area of the second axis of symmetry (Sym2).

It should be mentioned at this point that it is conceivable that the surveys ( 10b ) completely under the piezoelectric oscillating element ( 2 ), as well as completely in the area of an overhang ( 6g , L) and partly under the piezoelectric oscillating element ( 2 ) and / or partially and in particular at the same time partly in the area of an overhang ( 6g , L) can be located. Also, it is not mandatory that the outer shape of the mounting element ( 6 . 6b . 6c . 6d . 6e ) is always round or elliptical. In principle, any shapes are conceivable, wherein the outer edge again under the piezoelectric vibrating element and within the adhesive known ( 3c ) can run.

• i. eine Änderung der Güte und/oder Bandbreite
• ii. eine Änderung der Richtcharakteristik (akustisches Abstrahlverhalten)
• iii. eine Änderung des Frequenzverhaltens (weitere Resonanzen auf unterschiedlichen Frequenzen)

erreicht werden. Weitere Mittel zum modifizieren dieser drei Punkte i bis iii sind die Anzahl, Größe, Form und Positionierung von weiteren Öffnungen (9, 9b, 9c, 9d) in dem Montageelement (6, 6b, 6c, 6d, 6e, 6i, 6j), die Anzahl, Größe, Form und Positionierung des Montageelements (6, 6b, 6c, 6d, 6e, 6i, 6j) und/oder weiterer Montageelemente (6, 6b, 6c, 6d, 6e, 6i, 6j), insbesondere die Form der Außenkannte der Montageelemente (6, 6b, 6c, 6d, 6e, 6i, 6j) in der Aufsicht, und deren jeweilige Dicke (d1) des jeweiligen Montageelements (6, 6b, 6c, 6d, 6e, 6i, 6j), der Abstand (d2) zwischen den jeweiligen Montageelementen (6e) und der jeweiligen Innenseite des Gehäusebodens (1b) im Bereich eines einseitig aufliegenden Überhangs (6g) des jeweiligen Montageelements (6e) oder im Bereich eines beidseitig aufliegender Überhangs (L) des jeweiligen Montageelements (6e), sowie die Anordnung der Montageelemente (6, 6b, 6c, 6d, 6e, 6i, 6j) zueinander, sowie die Anzahl, Größe, Position und mechanischen und akustischen Eigenschaften der jeweiligen Kleber Stützpunkte (3, 3b), die Form der jeweiligen Klebekannte (3c, 3d) sowie die Anordnung dieser zueinander und die geometrischen, mechanischen und akustischen Eigenschaften von Füllmaterialien (12, 18) und Massen oder Medien zwischen dem jeweiligen Montageelement (6e) und dem Gehäuseboden (1b).With such grid structures of openings ( 10 ) and / or depressions in general or increases ( 10b ), as described in this disclosure, may in particular

• i. a change in quality and / or bandwidth
• ii. a change in the directional characteristic (acoustic radiation behavior)
• iii. a change of the frequency behavior (further resonances on different frequencies)

be achieved. Further means for modifying these three points i to iii are the number, size, shape and positioning of further openings (FIG. 9 . 9b . 9c . 9d ) in the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), the number, size, shape and positioning of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) and / or other mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), in particular the shape of the outer edge of the mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ) in the plan view, and their respective thickness (d1) of the respective mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), the distance (d2) between the respective mounting elements ( 6e ) and the respective inner side of the housing bottom ( 1b ) in the area of a one-sided overhang ( 6g ) of the respective mounting element ( 6e ) or in the region of a double-sided overhang (L) of the respective mounting element ( 6e ), as well as the arrangement of the mounting elements ( 6 . 6b . 6c . 6d . 6e . 6i . 6y ), as well as the number, size, position and mechanical and acoustic properties of the respective adhesive bases ( 3 . 3b ), the shape of the respective adhesive ( 3c . 3d ) and the arrangement of these to each other and the geometric, mechanical and acoustic properties of filling materials ( 12 . 18 ) and masses or media between the respective mounting element ( 6e ) and the housing bottom ( 1b ).

26 shows an example based on the example of 19 for a mounting element ( 6k ), which after mounting in the housing ( 1 ) should now have a one-sided overhang (L). For simplicity, the opening of the opening ( 9 ) of the 9 . 10 . 11 and 12 , The outer edge of the mounting element ( 6k ) is only still largely circular. The intended placement of the adhesive ( 3c ), the outsider ( 2c ) of the piezoelectric vibrating element ( 2 ) and the opening ( 9 ) are symmetrical and centric with respect to the outer edge of the mounting element ( 6k ). In contrast to the previously discussed mounting elements, it is provided here, the mounting element ( 6k ) when mounted in the housing ( 1 ) also stick to the outside edge on the left side. This creates a second adhesive known ( 3d ), which is also shown in dashed lines with regard to its planned location. The second glue ( 3d ) but now includes only a part of the mounting element ( 6k ) In the area of the cantilevered overhang (L) there are two two-dimensional lattices, which here through openings ( 10 ) be generated. The mounting element ( 6k ) has with respect to the main body a first axis of symmetry (Sym ₁ ) and a second axis of symmetry (Sym ₂ ), which in this example is perpendicular to the first axis of symmetry (Sym ₁ ). As a result of this structuring, the ultrasound transducer at least partially emits a multipole sound field. In addition, the exemplary mounting element ( 6k ) with two acoustic stub lines (SL1 and SL2), which at the end of a third bond ( 3e ) exhibit. This third bond leads back to a sound node in this area and to the sound reflection to the main body of the mounting element. Together with this result then different resonance frequencies. The connection of the first acoustic stub (SL1) through the perforation of the mounting element in the area of the connection is different than for the second acoustic stub. This leads to a modification of resonance frequency and resonance quality.

LIST OF REFERENCE NUMBERS

1

electrically conductive cup-shaped housing;

1a

Bottom of the case ( 1 ). The floor ( 1a ) of the housing typically represents the sound membrane and radiates downwards from the ultrasound;

1c

Housing wall;

2

piezoelectric vibrating element;

2a

first electrical contact of the piezoelectric oscillating element ( 2 );

2 B

second electrical contact of the piezoelectric oscillating element ( 2 );

2c

Außenkannte the piezoelectric vibrating element ( 2 );

3

electrically insulating adhesive or first interpolation point of an electrically insulating adhesive which is used to transmit the vibrations of the piezoelectric oscillating element ( 2 ) is capable of and possibly has sufficient elasticity to the vibrations of the piezoelectric vibrating element ( 2 ) while allowing a reliable mechanical connection to the housing bottom ( 1a ) and ensure sufficient electrical isolation over the life of the ultrasonic transducer (TR).

3b

second interpolation point of the electrically insulating adhesive ( 3 ). This forms the abutment or a support point for the overhanging overhang (L) of the mounting element ( 6e ) between the adhesive edges ( 3c . 3d ) of the electrically insulating adhesive ( 3 . 3b ).

3c

Adhesive edge of the electrically insulating adhesive ( 3 ) or the first interpolation point of the electrically insulating adhesive ( 3 );

3d

Adhesive edge of the second base of the electrically insulating adhesive ( 3b );

3e

third support point for the support of the acoustic stub lines by an adhesive, which is preferably also electrically insulating. The position, size, thickness and type of adhesive affect the resonant frequency and the resonant quality of the respective acoustic stub (SL1, SL2);

4

first electrical lead, electrical connection of the first contact ( 2a );

5

second electrical lead, electrical connection of the piezoelectric oscillating element ( 2 ) via the second electrical contact ( 2 B ) of the piezoelectric vibrating element ( 2 );

6

electrically conductive, exemplary circular mounting ring with a symmetrically arranged opening ( 9 ) below the piezoelectric vibrating element ( 2 ).

6b

electrically conductive, exemplary circular mounting ring, which opposite the Außenkannte ( 2c ) of the piezoelectric oscillating element ( 2 ) and the kind is enlarged, that after the Mounting the overhang ( 6g ). He has an exemplary, non-centric and reduced opening ( 9b ) below the piezoelectric vibrating element ( 2 ) on.

6c

electrically conductive, exemplary circular mounting ring, which opposite the Außenkannte ( 2c ) of the piezoelectric oscillating element ( 2 ) is arranged symmetrically. He has an exemplary, non-centric and reduced opening ( 9c ) below the piezoelectric vibrating element ( 6 ) on.

6d

electrically conductive, exemplary circular mounting ring, which opposite the Außenkannte ( 2c ) of the piezoelectric oscillating element ( 2 ) and the type is increased, that after assembly, an overhang ( 6g ). He has an exemplary, non-centric and reduced opening ( 9d ) below the piezoelectric vibrating element ( 2 ) on. It also has a two-dimensional grid of openings ( 10 ) having a first grid spacing (a ₁ ) in a first direction parallel to the surface of the mounting element and a second grid spacing (a ₂ ) in a second direction parallel to the surface of the mounting element, the first and second directions being non-parallel.

6e

electrically conductive, exemplary mounting ring, opposite the Außenkannte ( 2c ) of the piezoelectric oscillating element ( 2 ) is offset and the type is increased, that results after mounting a two-sided overhang (L). He has an exemplary, non-centric and reduced opening ( 9b ) below the piezoelectric vibrating element ( 2 ) on. It also has a one- or two-dimensional grid of openings ( 10 ) with a grid spacing (a) in a first direction parallel to the surface of the mounting element.

6f

Insertion element in the housing bottom ( 1b ) with depressions ( 17 ) or corresponding elevations, which in particular can also form a one- or two-dimensional grid.

6g

Area of the one-sided overhang ( 6g ) of the mounting element ( 6b ) over the top edge ( 3c ) of the electrically insulating adhesive ( 3 ).

6i

electrically conductive, exemplary symmetrical mounting ring, which in terms of its radius relative to the mounting ring ( 6 ) ( 17a ) of the type is increased, that after assembly results in an all-round equally wide, bilaterally overhanging (L). He has an exemplary, centric opening ( 9 ) below the piezoelectric vibrating element ( 2 ) on. In addition, it has two areas, each with an exemplary two-dimensional grid of openings ( 10 ) with a grid spacing (a) in a first direction parallel to the surface of the mounting element. The mounting ring has a first axis of symmetry (Sym ₁ ) and a second axis of symmetry (Sym ₂ ).

6y

electrically conductive, exemplary symmetrical mounting ring, which in terms of its radius relative to the mounting ring ( 6 ) ( 17a ) of the type is increased, that after assembly results in an all-round equally wide, bilaterally overhanging (L). He has an exemplary, centric opening ( 9 ) below the piezoelectric vibrating element ( 2 ) on. In addition, it has, for example, four openings ( 20 ) in the area of the overhang (L). The mounting ring has a first axis of symmetry (Sym ₁ ) and a second axis of symmetry (Sym ₂ ).

6k

electrically conductive, exemplary symmetrical mounting ring with two acoustic stub lines (SL1 and SL2), which in terms of its radius relative to the mounting ring ( 6 ) ( 17a ) of the type is increased, that after assembly results in an all-round equally wide, bilaterally overhanging (L). He has an exemplary, centric opening ( 9 ) below the piezoelectric vibrating element ( 2 ) on. In addition, it has two areas, each with an exemplary two-dimensional grid of openings ( 10 ) with a grid spacing (a) in a first direction parallel to the surface of the mounting element. Without the acoustic stub lines (SL1 and SL2), the mounting ring has a first symmetry axis (Sym ₁ ) and a second symmetry axis (Sym ₂ ).

7

electrical connection of the housing ( 1 ) isolated from the piezoelectric vibrating element ( 2 ).

8th

electrically conductive adhesive used to transmit the vibrations of the piezoelectric vibrating element ( 2 ) is capable of and possibly has sufficient elasticity to the vibrations of the piezoelectric vibrating element ( 2 ) while allowing a reliable mechanical and electrical connection to the housing bottom ( 1a ) over the life of the ultrasonic transducer (TR).

9

Opening in the electrically conductive mounting ring ( 6 ) below the piezoelectric vibrating element ( 6 ). Typically, the opening after assembly with the electrically insulating adhesive ( 3 ) filled.

9b

exemplary, non-centric and reduced opening in the electrically conductive mounting ring ( 6 ) below the piezoelectric vibrating element ( 6 ). Typically, the opening after assembly with the electrically insulating adhesive ( 3 ) filled.

9c

exemplary, non-centric and reduced opening in the electrically conductive mounting ring ( 6 ) below the piezoelectric vibrating element ( 6 ). Typically, the opening after assembly with the electrically insulating adhesive ( 3 ) filled.

9d

exemplary, non-centric and reduced opening in the electrically conductive mounting ring ( 6 ) below the piezoelectric vibrating element ( 6 ). Typically, the opening after assembly with the electrically insulating adhesive ( 3 ) filled.

10

Opening a one- or two-dimensional grid. The openings may be, for example, cylindrical openings or slots or openings of another shape in the mounting element. But it can also be just blind holes, notches or other depressions from the upper or lower surface (side) of the mounting element ago.

10b

Elevations of a one- or two-dimensional grid. The ridges may, for example, act on protruding cylinders or grooves or protuberances of other shape in the mounting member from the upper or lower surface (side) of the mounting member.

11

sound radiation

12

Potting compound or filler

13

Housing axis (symmetry axis) of the housing / housing walls ( 1c ) or surface normal of the housing bottom ( 1b )

14

Surface normal of the first surface of the piezoelectric oscillating element ( 2 ) (carries the first electrical contact ( 2a ) of the piezoelectric vibrating element ( 2 ))

15

Surface normal of the second surface of the piezoelectric vibrating element ( 2 ) (carries the second electrical contact ( 2 B ) of the piezoelectric vibrating element ( 2 ))

16

parallel displaced housing axis ( 13 ) (Symmetry axis) of the housing (s) ( 1c ) or parallel displaced surface normal of the housing bottom ( 1b )

17

recesses and / or elevations of the housing bottom ( 1b ) or an insert element located in the housing bottom ( 6f ), which can in particular form a one- or two-dimensional grid. As recesses, these can be, for example, cylindrical blind holes or slots or depressions of a different shape in the housing bottom ( 1b ) from the top or bottom of the case bottom be. As elevations, these, for example, projecting cylinders or grooves or protuberances of other shape in the housing bottom ( 1b ) from the top or bottom of the case bottom. It may also be such structures in or on an insert element ( 6f ) in the housing bottom ( 1b ) act.

18

Mass or medium between mounting element ( 6e ) and caseback ( 1b ).

19

third electrical lead, electrical connection of the housing ( 1 ) and the piezoelectric vibrating element ( 2 ) over the electrically conductive adhesive ( 3 ) and the second electrical contact ( 2 B ) of the piezoelectric vibrating element ( 2 )

20

Opening in the area of the overhang (L) in the round mounting ring ( 6y )

α

Beam angle of the sound waves with respect to the surface normal of the housing bottom ( 1a ) or with respect to the housing axis ( 13 )

β

Tilt angle of the surface normal ( 14 . 15 ) of a first or second surface or a cross-sectional area of the piezoelectric vibrating element ( 2 ) or tilt angle of an axis of symmetry of the piezoelectric vibrating element ( 2 ) on one side in relation to the surface normal ( 13 ) of the housing bottom ( 1a ) or with respect to the housing axis ( 13 ) on the other hand

λ _L

Wavelength of the radiated sound waves in air

a

exemplary grid spacing for the repetition of the arrangement of openings ( 10 ) in an exemplary direction parallel to the surface of the mounting element (FIG. 6 . 6b . 6c . 6d . 6f ) for forming the pattern of a one- or two-dimensional lattice in the mounting element ( 6 . 6b . 6c . 6d . 6f ). For example, the first and second grid pitches (a ₁ , a ₂ ) may be equal to the root of a and the first and second directions may be perpendicular to each other. This is in 18 shown.

a ₁

first grid spacing for the repetition of the arrangement of openings ( 10 ) and / or depressions ( 10 ) and / or increases ( 10b ) in a first direction parallel to the surface of the mounting element ( 6 . 6b . 6c . 6d . 6f ) for forming the pattern of a two-dimensional lattice in the mounting element ( 6 . 6b . 6c . 6d . 6f ). The first and the second direction are not parallel to each other.

a ₂

second grid spacing for the repetition of the arrangement of openings ( 10 ) and / or depressions ( 10 ) and / or increases ( 10b ) in a second direction parallel to the surface of the mounting element ( 6 . 6b . 6c . 6d . 6f ) for forming the pattern of a two-dimensional lattice in the mounting element ( 6 . 6b . 6c . 6d . 6f ). The first and the second direction are not parallel to each other.

a ₃

third grid spacing for the repetition of the arrangement of depressions ( 17 ) and / or increases ( 17 ) and / or openings in a first direction parallel to a surface of the housing bottom ( 1b ) for forming the pattern of a two-dimensional lattice in the surface of the housing bottom ( 1b ). The third and the fourth direction are not parallel to each other.

a ₄

fourth grid spacing for repetition of the repetition of the array of wells ( 17 ) and / or increases ( 17 ) and / or openings in a fourth direction parallel to a surface of the housing bottom ( 1b ) for forming the pattern of a two-dimensional lattice in the surface of the housing bottom ( 1b ). The third and the fourth direction are not parallel to each other.

AING

first input signal for the coupling of the received signal of the transducer (TR) in the drive _circuit (US _ctr ). (Signal ground)

AINS

second input signal for the coupling of the received signal of the transducer (TR) in the drive _circuit (US _ctr ). (Signal)

BUS_M

Connection of the bus ground (LIN_M) to the control _circuit (US _ctr )

BUS_S

Connection of the bus signal (LIN_S) to the control _circuit (US _ctr )

C _AIN1

first decoupling capacitor for the transducer according to the prior art

C _AIN2

second decoupling capacitor for the transducer according to the prior art

C _BUS

Filter capacitor for the mass of the data bus (LIN_M, LIN_S)

C _VDDA

Filter capacitor of the internal analog supply voltage (VDDA) of the drive _circuit (US _ctr ).

C _VDDD

Screening capacitor of the internal digital supply voltage (VDDD) of the drive _circuit (US _ctr ).

C _SUP1

first filter capacitor in the supply

C _SUP2

second filter capacitor in the supply

C _{SUP_TD}

Capacity in the screening of the reference node of the transmitter (UE)

C _TD1

Coupling capacitor and adjustment for the transducer according to the prior art

d

Distance between the surface of the vibrating element ( 2 ) and the upper edge of the cup-shaped housing ( 1 )

d1

Thickness of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y )

d2

Distance between mounting element ( 6e ) and the inside of the housing bottom ( 1b ) in the area of the one-sided overhang ( 6g ) of the mounting element ( 6e ) or in the area of the overhang (L) of the mounting element resting on both sides ( 6e )

DATA

Data pin on plug (Con) of the ultrasonic module (SM)

DRV

Driver circuit for direct control of the transducer (TR)

DRV 1

first line for the differential control of the piezoelectric oscillating element ( 2 )

DRV2

second line for the differential control of the piezoelectric oscillating element ( 2 )

D _SUP

Diode as reverse polarity protection

ESD

exemplary point of attack of an ESD event on the ultrasound module (SM)

ESD_GND

ESD ground connection of the housing ( 1 )

GND

Ground pin on plug (Con)

GNDA

internal analog supply of the drive _circuit (US _ctr ).

GND B

Connection of the system _ground to the control _circuit (US _ctr )

GNDD

internal digital power supply of the drive _circuit (US _ctr ).

GNDP

Supply _{ground of} the control _circuit (US _ctr ) after screening and _reverse polarity protection

H

Construction height of adhesive ( 3 . 3b . 8th ) and mounting element or mounting ring ( 6 ) and vibrating element ( 2 )

h _G

Height of housing

L

Area of the overhang of the mounting element ( 6e ) over the top edge ( 3c ) of the electrically insulating adhesive ( 3 . 3b ).

L _G

Diameter of the typically round housing (other housing forms are of course possible.)

LIN_M

Ground line of the data bus

LIN_S

Signal line of the data bus

n

Preferably integer, positive factor between the wavelength λ _{L of} the radiated sound waves in air and the diameter L _{G of} the typically round housing ( 1 ) or housing bottom ( 1a ).

PCB

Board inside the ultrasound module (SM). This typically carries the evaluation circuit (US _ctr ) and its external components (see 1 ). It is in the housing of the ultrasonic module with the transducer (TR) and the plug (Con) electrically and mechanically connected.

R _AIN

Decoupling resistor for the ultrasonic transducer (TR) according to the prior art

R _SUP

Series resistor in the supply line, which serves the low-pass filtering of the supply

R _{SUP_TD}

Series resistor in the screening of the reference node of the transformer (UE)

R _TD1

Damping resistance and adjustment for the ultrasonic transducer (TR) according to the prior art

SL1

first acoustic stub or branch line

SL2

second acoustic stub or branch line

SM

Ultrasound module. The ultrasound _module typically includes the PCB with the evaluation circuit (US _ctr ) and its periphery, the plug (Con) for connection of the ultrasound _module , and the ultrasound transducer (TR). The caseback ( 1a ), the housing ( 1 ) shows in 3 to the left. This sound emission is therefore in the example to the left.

Sym ₁

first symmetry axis of the exemplary round mounting ring ( 6i . 6y ). A reflection on this symmetry axis forms the left part of the geometry of the mounting ring ( 6i ) on the right part.

Sym ₂

second axis of symmetry of the exemplary round mounting ring ( 6i . 6y ). A reflection on this symmetry axis forms the upper part of the geometry of the mounting ring ( 6i ) on the lower part.

T1

first transistor of the driver circuit (DRV) for the direct control of the ultrasonic transducer (TR)

T2

second transistor of the driver circuit (DRV) for the direct control of the ultrasonic transducer (TR)

T3

third transistor of the driver circuit (DRV) for direct activation of the ultrasonic transducer (TR)

T4

fourth transistor of the driver circuit (DRV) for the direct control of the ultrasonic transducer (TR)

TR

transducer

UE

Transformer according to the prior art

US _ctr

Drive Circuit of Ultrasonic Transducer (TR)

V _BAT

unfiltered supply voltage, preferably the DC supply voltage of a motor vehicle. This is typically loaded with interfering signals.

V _DDA

internal analog supply voltage of the control _circuit (US _ctr ).

VDDD

internal digital supply voltage of the control _circuit (US _ctr ).

VDRV

Operating voltage of the driver circuit (DRV) or connection for a filter capacitor for stabilizing the operating voltage of the driver circuit (DRV).

V _SUP

Supply voltage of the drive circuit (US _ctr) after screening and reverse polarity protection

VSUP

Supply voltage of the control _circuit (US _ctr ) after screening and _reverse polarity protection

VSUP_LINE

Supply voltage pin on plug (Con) of the ultrasonic module (SM)

Claims (12)

Oscillation system consisting of a mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) as a vibrating body and at least one of the vibration of this vibrating body driving piezoelectric vibrating element ( 2 ) per mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) for use in an ultrasound transducer (TR), wherein the piezoelectric vibrating element ( 2 ) of the vibration system with the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) is mechanically connected and wherein the mechanical connection between piezoelectric oscillating element ( 2 ) of the vibration system and the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) by gluing by means of an adhesive and / or soldering and / or welding, and wherein the vibration system consisting of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) and the piezoelectric vibrating element ( 2 ) is provided by means of an elastic adhesive ( 3 ) mechanically with a housing ( 1 . 1a . 1c ) of an ultrasonic transducer (TR), wherein the shortest connecting line from the center of gravity of the piezoelectric vibrating element (FIG. 2 ) to the housing ( 1 . 1a . 1c ) the elastic adhesive ( 3 ), characterized in that the vibration system of the ultrasonic transducer consisting of mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) and piezoelectric oscillating element ( 2 ) when driving the piezoelectric vibrating element ( 2 ) by a drive circuit (US) at least two or more mechanical resonance frequencies, a first resonance frequency and a second resonance frequency, which are different from each other, and in that at least one of these resonant frequencies is dependent on the natural frequencies of the piezoelectric oscillating element ( 2 ) is different without anmontiertes mounting element and that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) at least one pattern of openings ( 10 ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) and / or depressions on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) and / or increases ( 10b ) on a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ), which translational displacement along a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) by at least a first distance n ₁ · a ₁ and / or a second distance m ₁ · a ₂ , where n ₁ and m ₁ are integers, at least partially imaged onto itself, ie a one- or two-dimensional grating a surface of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) and that the frequency ratio of the magnitude of the second resonant frequency divided by the magnitude of the first resonant frequency depends on the first distance a1. The ultrasonic transducer (TR) vibration system according to claim 1, characterized in that the ultrasonic transducer includes at least two distinct grades or resonance bandwidths, a first quality or first resonance bandwidth at the first resonant frequency on the one side and a second quality or second resonant bandwidth the second resonant frequency on the other side. Oscillation system for an ultrasonic transducer (TR) according to claim 1, characterized in that the ultrasonic transducer has at least two mutually different radiation characteristics, a first radiation characteristic at the first resonant frequency and a second radiation characteristics at the second resonant frequency, wherein radiation characteristic means that by the sound system radiated sound amplitude per steradian from the angle between the connecting axis from the point at which the sound amplitude is detected to a point of reference to the surface normal ( 14 ) to the surface ( 2a ) on the one side and the corresponding surface normal ( 14 ) to the surface ( 2a ) of the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) depends on the other side. Oscillation system for an ultrasonic transducer (TR) according to claim 1, characterized in that a first plane cross-sectional area of a mounting element (FIG. 6b . 6c . 6d . 6e . 6i . 6y . 6k ) perpendicular to the surface normal of a surface of the mounting element ( 6b . 6c . 6d . 6e . 6i . 6y . 6k ) has a different shape than a second plane cross-sectional area of the piezoelectric vibrating element (FIG. 2 ), which are also perpendicular to the surface normal of a first or second surface of the piezoelectric vibrating element ( 2 ) and that the centroid of the surface of the mounting element ( 6b . 6c . 6d . 6e . 6i . 6y . 6k ) with respect to the centroid of a first or second surface of the piezoelectric vibrating element ( 2 ) is offset. Oscillation system for an ultrasonic transducer according to claim 1, characterized in that the Schallabstrahlachse ( 11 ) Vibrational system of the ultrasound transducer (TR) not parallel to the surface normal ( 14 . 15 ) of the first or second surface of the piezoelectric vibrating element ( 2 ). Mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) for a vibration system according to claim 1, characterized in that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) at least one opening ( 9 . 9b . 9c . 9d ) and / or recess and / or recess below the vibrating element ( 2 ) having. Mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) for a vibration system according to claim 1, characterized in that the lattice structure is hexagonal or square, the lattice symmetry is thus four or sechzählig. Mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) for a vibration system according to claim 1, characterized in that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) has at least one length dimension which is an integer (k-fold) multiple of the mean sound wave length (λ) in the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) divided by four is (k · λ / 4). Mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) for a vibration system according to claim 1, characterized in that the mounting element ( 6 . 6b . 6c . 6d . 6e . 6i . 6y . 6k ) has at least one acoustic branch line and / or an acoustic stub (SL1, SL2). Ultrasonic transducer with a vibration system according to claim 1, characterized in that the ultrasound transducer (TR) has at least one further structure in the housing bottom, which has a pattern of depressions ( 17 ) and / or increases ( 17 ) and / or openings, the translational displacement along a surface of the housing bottom ( 1b ) by at least a first distance n ₂ · a ₃ and / or a second distance m ₂ · a ₄ , where n ₂ and m ₂ are integers, at least partially imaged on itself again, that forms a one- or two- or three-dimensional grid. Ultrasonic transducer with a vibration system according to claim 1, characterized in that the ultrasound transducer (TR) has at least one further structure in the housing bottom, which has a pattern of depressions ( 17 ) and / or increases ( 17 ) and / or openings which, when rotationally displaced along a surface of the housing bottom ( 1b ) by at least a first angle n ₃ · θ ₃ where n _{3 is} an integer, is at least partially imaged on itself again, that forms a one- or two- or three-dimensional grid. Circuit for driving a vibration system according to claim 1, characterized in that the circuit has a drive circuit (US _ctr ) at least as a subcircuit and that the drive _circuit (US _ctr ) via a first electrical line (DRV1) and a second electrical line (DRV2) directly and transformerless with the piezoelectric oscillating element ( 2 ) of the vibration system is electrically connected and that the drive _circuit (US _ctr ) an electrical voltage- _modulated transmit signal having a transmission frequency via the first line (DRV1) and the second line (DRV2) to the piezoelectric vibrating element ( 2 ) of the oscillatory system and that the drive _circuit (US _ctr ) _comprises at least one first inverter consisting of at least one first transistor (T1) which is driven by a first transmit signal (Φ _1a ) and at least one second transistor (T3), which is driven by a complementary first transmission signal (Φ _1b ), wherein the first inverter controls the second line (DRV2) for direct transformerless differential activation of the piezoelectric vibration element (FIG. 2 ), and that the drive _circuit (US _ctr ) _comprises at least one second inverter consisting of at least one second transistor (T2), which is driven by a second transmit signal (Φ _2a ), and at least one fourth transistor (T4), which with a second complementary transmission signal (Φ _2b ) is driven, wherein the second inverter, the first line (DRV1) for the direct transformerless differential control of the piezoelectric vibrating element ( 2 ) drives, and that the drive _circuit (US _ctr ) the transmit signals (Φ _1a , Φ _1b , Φ _2a , Φ _2b ) during reception, the transistors (T1, T2, T3, T4) at least temporarily _turns off and that the drive _circuit (US _ctr ) can generate at least a first transmission frequency, with which the voltage difference between the first line (DRV1) and the second line (DRV2) is modulated and which excites the first resonant frequency of the oscillating system, and that the drive _circuit (US _ctr ) generate at least a second transmission frequency can with which the voltage difference between the first line (DRV1) and the second line (DRV2) is modulated and which excites the second resonant frequency of the oscillating system.

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