EP3739904A1 - Acoustic bending converter system and acoustic device - Google Patents

Abstract

The invention relates to an acoustic bending transducer system (1, 2) with a plurality of bending transducers (3, 4, 5) which are designed in such a way that deformable elements (3 ₁, 3 _{2 </ sub>, 4 ₁; 32, 3 ₄, 4 ₂; 3 ₁, 3 ₂, 3 '₁, 3' ₂) the bending transducers (3, 4, 5) oscillate coplanar in a common flat layer (10), the bending transducers (3, 4, 5) different resonance frequencies and different dimensions of the deformable elements (3 ₁, 3 ₂, 4 ₁; 3 ₂, 3 ₄, 4 ₂; 3 ₁, 3 ₂, 3 '<sub > 1}, 3 '₂) along a common longitudinal axis that is transverse to a direction of oscillation of the deformable elements (3 ₁, 3 <sub> 2 </ sub>, 4 ₁; 3 ₂, 3 ₄, 4 ₂; 3 <sub> 1 </ sub>, 3 ₂, 3 '₁, 3' ₂). Furthermore, the invention relates to an acoustic surface device with such an acoustic bending transducer system (1, 2).

Description

Technical area

Embodiments according to the invention relate to a micromechanical sound transducer.

background

• WO 2012/095185 A1 / Bezeichnung: MIKROMECHANISCHES BAUELEMENT
• WO 2016/202790 A2 / Bezeichnung: MEMS TRANSDUCER FOR INTERACTING WITH A VOLUME FLOW OF A FLUID AND METHOD FOR PRODUCING SAME
• DE 10 2015 206 774 A1

The technical field of the present application can be traced back to the following three documents, which describe micromechanical components:

• WO 2012/095185 A1 / Description: MICROMECHANICAL COMPONENT
• WO 2016/202790 A2 / Designation: MEMS TRANSDUCER FOR INTERACTING WITH A VOLUME FLOW OF A FLUID AND METHOD FOR PRODUCING SAME
• DE 10 2015 206 774 A1

Basically, these documents reveal the construction of bending transducers and their specific possibilities and mechanisms to interact with the environment. In particular, the aforementioned documents relate to a novel MEMS (micro-electromechanical system) actuator principle based on the fact that a silicon beam moves laterally in a plane, for example a substrate plane, which is defined by a silicon wafer or a wafer. The silicon bar, which is connected to the substrate in a cavity, interacts with a volume flow. The novel MEMS described therein are defined as NED (Nanoscopic Electrostatic Drive), a nanoscopic electrostatic drive.

Due to their proportions, these NEDs are particularly suitable for the miniaturization - downsizing of components while retaining the full range of functions - of everyday objects that are subject to increased integration requirements. For example, ultra-mobile end devices such as smartwatches or hearables are subject to very narrow limits in terms of installation space. With the above-mentioned NED, among other things, sound transducers can be implemented that can meet these increased demands, with both sound quantity and Sound quality can be significantly improved compared to conventional sound transducers. The integration requirements relate both to the adaptation to the existing installation space in general and to the system design together with several components.

In the document DE 10 2017 114 008 A1 a hearing aid or headphones is disclosed which is designed such that its external dimensions of the housing correspond to the internal dimensions of the auditory canal. A MEMS-based sound transducer is arranged in the housing so that a front volume is formed in the direction of the eardrum and a back volume in the direction of the earpiece, which are separated from one another by the MEMS-based sound transducer. The geometric dimensions of this sound transducer are designed in such a way that it does not restrict the geometric dimensions of the resonance volume, but it is difficult to keep a frequency profile constant over a large frequency range. In addition, the sound transducer consists of flexural transducers that are elastically suspended on one side and that extend over a cavity and the edge area of which is spaced apart on a front side by a gap. The gap increases due to the curvature of the transducers. Furthermore, a sound shielding device is disclosed which is formed by the side walls, the so-called sound blocking walls of the cavity. These walls are arranged in such a way that they at least partially prevent the lateral passage of sound along the gap. Disadvantageously, it is disclosed that the sound transducers are piezoelectric and are therefore subject to a pre-curvature, so that the measures disclosed serve to minimize the inaccuracies that result from this pre-curvature.

In the document DE 10 2017 108 594 A1 discloses a loudspeaker unit for a portable device for generating sound waves in the audible range, which is characterized by a small size and high performance. In addition to the electrodynamic loudspeaker, the loudspeaker unit also includes a MEMS-based tweeter, with the frequency ranges of both loudspeakers overlapping. As a result, the electrodynamic loudspeaker is compact and optimized for low frequencies. However, the high space requirement and the high power consumption continue to be disadvantageous, since two different system technologies have to be operated.

From the document DE 196 124 81 A1 Furthermore, an arrangement of a sound transducer for hearing aids that is tilted with respect to a longitudinal axis is known. The sound-generating membrane is a conductive film that is arranged between two flat electrodes and whose vibrations generate sound in the audible wavelength spectrum. This film is not arranged parallel to the eardrum, which minimizes unwanted resonances in the ear canal. However, with this structure no further functional elements can be monolithically integrated, which means that additional space is required outside the auditory canal.

Known solutions dispense with a particularly dense packing of sound transducers, or use external assembly methods to supplement individual functions (e.g. electrical connection).

In view of this, there is a need for a concept which, compared with the prior art, enables an increased packing density of the components in order to effectively and efficiently realize a high sound pressure.

It is therefore an object of the invention to provide an acoustic bending transducer system with increased efficiency and an acoustic device for improving sound conversion in a corridor such as e.g. to create an ear canal.

This object is achieved by means of the subjects and teachings in the independent patent claims 1 and 11.

For example, a compact arrangement of a large number of bending transducers of a bending transducer system, which is designed as a sound transducer and which enables the integration of further system components in limited space, ensures a high reproduction quality in an environment around the bending transducer system. The frequency curve reproduced with the sound transducer, as it results from the combination of transducer and the surrounding installation space, can be kept constant over a large frequency range, for example via the inclined alignment of the volume flow in a corridor, such as an ear canal. A variation can be less than 6 dB, for example.

The application describes a further development with regard to an optimization of the arrangement of bending transducers with regard to space requirements, sound pressure level and Sound quality. That can be produced by the NED in a specific environment - for example in the auditory canal of a human ear.

An acoustic bending transducer system with a large number of bending transducers is proposed, which are designed in such a way that deformable elements of the bending transducers oscillate in a coplanar manner in a common flat layer, the bending transducers having different resonance frequencies and different dimensions of the deformable elements along a common longitudinal axis that is transverse to a direction of vibration of the deformable elements. The bending transducers can be, for. B. electrostatic bending actuators (NED actuators), piezoelectric actuators or thermomechanical actuators act. The plurality of bending transducers are designed to be deflected in an oscillation plane. The bending transducers are arranged next to one another along a first axis in the common flat layer or plane of vibration and extend along a second axis that is transverse to the first axis. In order to make full use of the spatial conditions within the same common flat layer, individual or multiple bending transducers can also be arranged at an angle to the majority of the bending transducers aligned parallel to one another.

Another aspect of the application relates to an acoustic device, e.g. a hearing aid with: an acoustic bending transducer system with at least one bending transducer which has at least one deformable element that is arranged in a cavity and an opening through which a fluidic volume flow interacting with a movement of the bending transducer in the cavity passes, and a housing, which is adapted to be inserted in a passage, the bending transducer system being held in the housing such that the fluidic volume flow can be directed obliquely to a longitudinal axis of the passage in a state in which the housing is inserted into the passage. The acoustic device can be miniaturized and is therefore particularly suitable for installation in in-the-ear hearing aids (ITE) and hearables, as well as smartwatches and other ultra-mobile devices.

Advantages and functionalities of the features of the acoustic bending transducer system, as described above and below, apply equally to an acoustic device provided therewith.

Further developments according to the invention are defined in the subclaims.

According to one exemplary embodiment, the bending transducer system has one or more cavities in which the bending transducers are arranged and one or more openings in the cavities through which a fluidic volume flow that interacts with a plurality of bending transducers can pass. The openings in the cavities can be common openings of two or more cavities, which communicate with one another via the fluidic volume flow. In addition, openings in the cavities of the bending transducer system allow communication between individual bending transducers or the bending transducer system with an enveloping environment.

According to one embodiment, the bending transducers are arranged in a space that is delimited by a first and a second substrate parallel to the common plane of vibration, and walls between the substrates that define the space along a longitudinal direction or in a direction transverse to the longitudinal direction in the common plane of vibration Subdivide cavities that are arranged between adjacent bending transducers. A cavity is thus delimited, for example, by the first substrate, the second substrate and two opposing walls of adjacent bending transducers. Since the plurality of bending transducers is designed to be deflected via their deformable elements in the common plane of oscillation of a layer, the bending transducers can each be at a distance from the first substrate and the second substrate, through which adjacent cavities can be fluidically coupled to one another. Due to the fluidic coupling of adjacent cavities, a common force can be exerted by the plurality of bending transducers on a fluid located in the cavities, as a result of which a high sound level can be achieved with the micromechanical sound transducer.

Depending on the embodiment, each bending transducer of the acoustic bending transducer system can comprise a deformable element that is electrostatically, piezoelectrically or thermomechanically deformable. This provides a multitude of options for flexibly adapting the bending transducer system to desired requirements.

Furthermore, it is particularly advantageous if, in the acoustic bending transducer system, at least a first subset of at least one first bending transducer each has a deformable element clamped on one side, and additionally or alternatively at least a second subset of at least one second bending transducer each has a deformable element clamped on both sides. A grouping of individual subsets of specific bending transducers enables, on the one hand, an expedient use of the installation space and, at the same time, a targeted location of similar bending transducers to generate the desired frequencies or sound pressures. Because the deformable element of each bending transducer can be clamped on one or both sides, bending transducers with deformable elements of different mechanical properties and dimensions can be implemented, which in turn are responsible for generating different frequencies and sound pressures. Furthermore, an installation space that is present in the same layer of the bending transducer system can be used particularly advantageously.

This advantageously results in a greater oscillation amplitude at higher frequencies in the case of bending transducers clamped on one side, since the bending transducers clamped in on one side are characterized by an advantageous ratio of mass to length of the deformable element of the bending transducer.

In order to reproduce different frequencies and / or generate different sound pressures, according to a particularly advantageous embodiment, the at least first subset of at least one first bending transducer has on average a higher resonance frequency than the at least second subset of at least one second bending transducer, or vice versa. Due to certain requirements on the installation space and with regard to the various frequencies and their sound pressures, the rigidity, mass, length and cross-sectional geometry of the deformable elements of the respective bending transducers can be adapted.

In order to be able to reproduce different frequencies in a particularly simple and dedicated manner and / or to be able to generate different sound pressures, the first subset of at least one first bending transducer has a shorter length on average than the second subset of at least one second bending transducer.

According to a particularly preferred embodiment, each bending transducer delimits two opposing cavities, each cavity being accessible via at least one opening for the fluidic volume flow to pass through. It is thus possible to fluidically couple the individual cavities and thus to control the properties of the volume flow conveyed by the individual bending transducers in a targeted manner in particular with regard to a buildable pressure or sound pressure of the volume flow can be desired.

To generate sound pressures in a frequency spectrum by means of the acoustic bending transducer system that are accessible to the human ear, it is advisable to provide deformable elements in the bending transducers that are longer than 100 μm. In order to enable a particularly compact design of miniaturized sound transducers, the deformable element of each bending transducer should have a length that is less than 4000 μm. For the space-saving installation of the bending transducer system in an elongated shell, an outer dimension of the bending transducer system along the common longitudinal axis is a maximum lateral to the common flat layer and greater than an outer dimension of the bending transducer system transversely thereto.

In a particularly preferred embodiment, the outer dimension of the bending transducer system along the common longitudinal axis is between 750 μm and 2000 μm. In a still preferred exemplary embodiment, the outer dimension of the bending transducer system along the common longitudinal axis is between 800 μm and 1200 μm. Bending transducer systems with the dimensions mentioned above can be built into in-the-ear hearing aids in a space-saving manner, whereby sufficient hearing quality can be guaranteed for the user.

In particularly advantageous embodiments, a describes. The outer surface of the bending transducer system is coplanar to the common flat layer, an oval elongated along the common longitudinal axis, a rectangle elongated along the common longitudinal axis, or a polygon elongated along the common longitudinal axis. Such elongated shapes allow the installation space in an elongated envelope with a cylindrical or rectangular cross-section to be used particularly well. In addition, through a suitable choice of the outer surface or an outer contour of the bending transducer system, an inner cross section of an elongated sleeve can be essentially completely taken up, for example an auditory canal can be sealed.

According to an expedient embodiment, the bending transducers are subdivided into groups of one or more bending transducers, the several bending transducers along the common longitudinal axis in groups with several bending transducers are arranged one behind the other. In such an arrangement, the individual pressures of the volume flow caused by the respective deformable elements of the bending transducers would add up. Consequently, by staggering or grouping the bending transducers and their selective activation, not only a desired pressure or sound pressure of the volume flow emitted into the environment could be controlled in a targeted manner, but different sound frequencies could also be generated. For example, short bending transducers can be arranged in the area of the openings, since they are characterized by a comparatively high rigidity - relative to long bending transducers - which enables high resonance frequencies. If such bending transducers are arranged in the area of the openings, which connect the cavities with the environment, resonances can be avoided and thus a sound quality or a hearing quality can be improved. Additionally or alternatively, according to a further expedient embodiment, the bending transducers are divided into groups of one or more bending transducers, the several bending transducers being arranged next to one another in the common plane transversely to the common longitudinal axis in groups with several bending transducers. Analogous to the arrangement of several bending transducers one behind the other along the common longitudinal axis, a desired sound pressure and a location of the sound can also be controlled with an arrangement transverse to the common longitudinal axis next to one another.

The fluidic volume flow advantageously runs - in the bending transducer system - of the acoustic device in the plane of the common flat layer of the bending transducer system. Due to the arbitrary design and orientation of the cavities and deformable elements of the individual bending transducers of the bending transducer system, a targeted course of the fluidic volume flow in the bending transducer system can be provided and thus controlled. In this way, the volume flow can be directed specifically to the point where its effect on its environment is optimal.

In order to achieve a particularly advantageous interaction with the surroundings of the acoustic device, the bending transducer system is held in the housing in such a way that the fluidic volume flow of the acoustic device is at an angle between 5 ° and 80 °, between 10 ° and 40 °, or between 15 ° and 30 ° inclined to the longitudinal axis of the passage through the openings of the bending transducer system. By arranging the bending transducer relative to the longitudinal axis of the aisle, the deformable elements are related to their orientation, for example in the direction of the The eardrum of a human ear is positioned in an anti-parallel manner so that resonances in the ear canal are minimized. In addition, a higher packing density of the bending transducers can be achieved and higher sound pressures - based on a cross-sectional area of the corridor - can be achieved, a larger acoustically active surface of the acoustic device being generated.

In order to be able to use the acoustic device particularly efficiently, the acoustic bending transducer system can record and / or emit an acoustic signal via the fluidic volume flow passing through the openings. As a result, the acoustic bending transducer system is able to work simultaneously as a receiver and / or transmitter of acoustic signals, which in turn increases the flexibility when using the acoustic device considerably. The transmission or reception of acoustic signals can take place alternately or continuously.

According to an advantageous embodiment, the acoustic device further comprises: a control unit for controlling the individual bending transducers of the bending transducer system and an energy supply source for operating the acoustic device. Due to the diverse possibilities of miniaturizing the acoustic bending transducer system, additional components can be accommodated in it in a space-saving manner despite the small dimensions of the acoustic device. This contributes significantly to increasing the wearing comfort and user-friendliness of the acoustic device.

In order to achieve a particularly high level of flexibility when using the acoustic device, two or more acoustic bending transducer systems can be held in the housing, the common flat layer of the same being aligned parallel to one another. In this way, for example, acoustic devices can be arranged or manufactured in the form of a substrate stack, as a result of which highly complex structures can be implemented with relatively low manufacturing costs. In addition, acoustic devices can easily be individually adapted in this way. Finally, by stacking several acoustic bending transducer systems, a higher sound pressure can be generated and / or a larger representable frequency range can be covered.

The acoustic device can advantageously be built up monolithically consisting of several layers, or from substrates of different materials, which over a common layer are connected to one another or bonded. This can take place, for example, in the form of an arrangement of a cover wafer above or a handling wafer below a common device wafer.

In order to provide a particularly space-saving and compact form of the acoustic device, the control unit and / or the energy supply source are arranged in the common flat layer of a bending transducer system. The control unit is of course set up: for fluid dynamic damping, for signal processing, for wireless communication, for voltage transformation. It can contain sensors, software, for storing data, etc., which are arranged individually or jointly in the same acoustic device, or alternatively are provided separately from the acoustic device.

Brief description of the figure

Fig. 1

zeigt in einer perspektivischen Darstellung ein Biegewandlersystem gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 2

zeigt in einer perspektivischen Darstellung das Ausführungsbeispiel aus Fig. 1 mit Substratebenen;

Fig. 3

zeigt in einer perspektivischen Darstellung ein Biegewandlersystem gemäß einem weiteren Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 4

zeigt in einer perspektivischen Darstellung das Ausführungsbeispiel aus Fig. 3 mit Substratebenen;

Fig. 5

zeigt in einer Schnittdarstellung den Gehörgang, das Trommelfell und die Ohrmuschel eines menschlichen Ohres;

Fig. 6a

zeigt in einer perspektivischen Darstellung Elemente eines Biegewandlers gemäß einem Ausführungsbeispiel der vorliegenden Erfindung bei einem Anregungszustand;

Fig. 6b

zeigt in einer perspektivischen Darstellung Elemente des Biegewandlers aus Fig. 6a gemäß einem Ausführungsbeispiel der vorliegenden Erfindung bei einem weiteren Anregungszustand;

Fig. 7

zeigt eine Querschnittsansicht des Biegewandlers gemäß der Ausführungsform aus Fig. 6a entlang der Schnittebene A;

Fig. 8

zeigt in einer perspektivischen Darstellung ein Biegewandlersystem gemäß einem weiteren vorteilhaften Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 9

zeigt eine Querschnittsansicht eines Biegewandlers gemäß einem weiteren vorteilhaften Ausführungsbeispiel der vorliegenden Erfindung.

Exemplary embodiments according to the present invention are explained in more detail below with reference to the accompanying figures. With regard to the schematic figures shown, it is pointed out that the function blocks shown are to be understood both as elements or features of the device according to the invention and as corresponding method steps of the method according to the invention, and corresponding method steps of the method according to the invention can also be derived therefrom. Show it:

Fig. 1

shows in a perspective illustration a bending transducer system according to an embodiment of the present invention;

Fig. 2

shows the exemplary embodiment from FIG Fig. 1 with substrate levels;

Fig. 3

shows a perspective illustration of a bending transducer system according to a further exemplary embodiment of the present invention;

Fig. 4

shows the exemplary embodiment from FIG Fig. 3 with substrate levels;

Fig. 5

shows in a sectional view the auditory canal, the eardrum and the auricle of a human ear;

Figure 6a

shows, in a perspective illustration, elements of a bending transducer according to an exemplary embodiment of the present invention in an excited state;

Figure 6b

shows elements of the bending transducer in a perspective illustration Figure 6a according to an exemplary embodiment of the present invention in a further excited state;

Fig. 7

FIG. 13 shows a cross-sectional view of the bending transducer according to the embodiment of FIG Figure 6a along the cutting plane A;

Fig. 8

shows in a perspective illustration a bending transducer system according to a further advantageous embodiment of the present invention;

Fig. 9

shows a cross-sectional view of a bending transducer according to a further advantageous embodiment of the present invention.

Detailed description of the exemplary embodiments according to the figures

Before exemplary embodiments of the present invention are explained in more detail below with reference to the drawings, it is pointed out that identical, functionally identical or identically acting elements, objects and / or structures in the different figures are provided with the same or similar reference symbols, so that those in different Embodiments shown description of these elements is interchangeable or can be applied to one another.

Fig. 1 shows a perspective illustration of a bending transducer system according to an exemplary embodiment of the present invention in the form of a layered component 100 comprising a first bending transducer system 1 and a second bending transducer system 2, which are stacked on top of one another. The component 100 may comprise further bending transducer systems which are arranged in layers, for example, on the bending transducer system 1 and / or on the bending transducer system 2. A bending transducer system 1 or a bending transducer system 2 comprises several bending transducers 3, 4 which have the same or different predefined lengths. On the surface of the bending transducer system 1, an arrangement of the bending transducers 3, 4 of different lengths is shown as an example. The bending transducer 3 - identified by means of a continuous line - is longer than the bending transducer 4 - identified by means of a short dashed line. In the present exemplary embodiment, both the bending transducer system 1 and the bending transducer system 2 are L-shaped, so that the two bending transducer systems 1 and / or 2 stacked on top of one another to form an L-shaped component 100. The individual legs of the L-shaped component 100 have different lengths. In a region of a shorter leg of the L-shaped component 100, further bending transducers 4 and bending transducers 5 - indicated by means of a dot-dash line - are arranged, which have a third length. The lengths of the individual bending transducers 3, 4 and 5 are, for example: bending transducers 3 from 1000 μm to 4000 μm; Bending transducer 4 from 500 µm to 2000 µm; Bending transducer 5 from 100 µm to 1000 µm.

According to a preferred embodiment, the individual length ratios can be selected, for example: bending transducer 3 to bending transducer 4 between 1: 1.5 to 1: 3; Bending transducer 3 to bending transducer 5 between 1: 1.5 to 1: 3; or the length ratio of the bending transducer 4 to the bending transducer 5 between 1: 1.5 to 1: 3.

In the present embodiment, the individual bending transducers 1 or 2 are composed of bending transducers 3, 4 and 5, which are arranged parallel to one another in a plane of the bending transducer system 1 or the bending transducer system 2, the individual bending transducers 3, 4 and 5 along the longer leg of the L-shaped component 100 are aligned. On the star side in the longitudinal direction of the component 100, openings 13 are provided which enable the cavities contained in the bending transducer system 1 or bending transducer system 2 - not shown here - to be connected to the surroundings. Due to the L-shape of the component 100, the individual bending transducers 3, 4 and 5 are arranged such that short bending transducers 4, 5 are arranged in the shorter leg of the L-shaped component 100, the longer bending transducers 3 in the longer leg of the L-shaped Component are arranged

In this exemplary embodiment, the bending transducers 3, 4 and 5 are aligned along the longest side of the component. In a departure from this, however, exemplary embodiments can also contain a bending transducer alignment along the shortest side of the bending transducer system 1 and / or 2 or component 100. The openings 13 are then accordingly not arranged in the area 13, but always in the area of the clamps of the bending transducers 3, 4 clamped on both sides or in the area of the clamp 14 and the freely movable end of a bending transducer 5 clamped on one side.

The bending transducers 3, 4 and 5 are arranged in such a way that short bending transducers 5 are arranged in the vicinity of the openings 13. On the one hand, this results in the advantage that a higher packing density can be achieved within the bending transducer system 1 and / or 2 and this results in higher sound pressures. On the other hand, resonances can be avoided, which has a positive effect on the sound quality.

In the present exemplary embodiment, a control unit 21 is arranged adjacent to the layered component 100 in such a way that it complements the component 100 to form a rectangular structure, complementary to the L-shape of the component 100. As a result, an existing installation space that is available between the legs of the L-shaped component 100 is expediently used, with a particularly compact structure being created.

Exemplary embodiments are not limited to the L-shaped configuration of the external dimensions of the component. Further exemplary embodiments are not limited to the illustrated arrangement of the bending transducers 3, 4 and 5; rather, the arrangement can differ for each bending transducer system 1 or 2 (cf. Fig. 9 ).

Fig. 2 shows the exemplary embodiment from FIG Fig. 1 . In addition, a substrate plane 9 of a substrate layer is shown, which runs parallel to the substrate layer. It is also shown that a common plane of movement 10 is formed from the directions of movement 6, 7 and 8 of the respective bending transducers, the deformable elements of the bending transducers 3, 4 and 5 oscillating in a coplanar manner in a common flat substrate layer or plane of movement 10. The movement plane 10 and the substrate plane 9 are arranged parallel to one another.

Fig. 3 shows in a perspective illustration an embodiment of a component 100 with two stacked bending transducer systems 1 and 2, which have an oval outer shape. The openings 13 are preferably arranged in the area of the clamps 14 of the bending transducers 3, 4 clamped on both sides or in the area of the clamp 14 and the freely movable end of a bending transducer 5 clamped on one side. An oval outer geometry or shape of the component 100 has the advantage that it can be arranged tilted in a cylindrical or approximately cylindrical housing of an ultramobile terminal.

This exemplary embodiment shows an arrangement of the bending transducers 3, 4 and 5 along the longest alignment of the oval component geometry. However, embodiments of the bending transducers 3, 4 and 5 may equally contain different orientations. In addition, exemplary embodiments can contain different orientations of the bending transducers 3, 4 and 5 for each layer-like bending transducer system 1 or 2, 2 + n.

Further preferred exemplary embodiments are not restricted to this oval shape and are adapted or adaptable to the opposite spatial conditions and acoustic boundary conditions in order to achieve a maximum sound pressure.

Fig. 4 shows the exemplary embodiment from FIG Figure 3 . In addition, a substrate plane 9 is shown, which runs parallel to the substrate layer, the deformable elements of the bending transducers 3, 4 and 5 oscillating in a coplanar manner in a common flat substrate layer or movement plane 10. It is also shown that a movement plane 10 is formed from the movement directions 6, 7 and 8 of the respective bending transducers. The movement plane 10 and the common planar substrate layer or substrate plane 9 are arranged parallel to one another.

The Fig. 5 shows in a sectional illustration the auditory canal 31, the eardrum 32 and the auricle 30. It can be seen that the auditory canal has a cylindrical geometry or shape. With 101 the outer dimensions of an ultra-mobile terminal device, for example the outer shell of its housing, are shown, which are adapted to the auditory canal 31 and essentially seal it off from the environment. Such housings 101 can be adapted to the respective user, but must be manufactured individually in complex, mostly additive and slow processes. However, they enable an ultra-mobile terminal to be optimally seated in the auditory canal 31. Embodiments can also have an individually adapted geometry differing, simplified geometry, which are produced in cost-effective processes, for example injection molding processes. These geometries do not have an optimal fit of the ultra-mobile terminal device or its housing 101 in the auditory canal, which is why high sound pressures with high sound quality are necessary to compensate for these inaccuracies. The tilted arrangement of the component 100 or the bending transducer system 1 or 2 with respect to the longitudinal axis 11 of the housing 101 makes it possible to enlarge the acoustically active surface of the component 100 or the bending transducer system 1 or 2 by, on the one hand, a higher number of bending transducers 3, 4 and 5 to be arranged in the bending transducer system 1 or 2 and / or, on the other hand, to integrate longer bending transducers 3, 4 and 5 in the bending transducer system 1 or 2. The component 100 or the bending transducer system 1 or 2 is tilted about a transverse axis 105 of the ultramobile terminal in relation to the longitudinal axis 106, the angle of inclination α between the plane of movement 10 and the longitudinal axis 106 in a range between 90 ° and 180 °, preferably 150 ° and 170 °, particularly preferably 160 °.

By arranging the actuators relative to the housing axis, the deformable elements are positioned in an anti-parallel manner in relation to the orientation of the eardrum. This minimizes the resonances in the ear canal.

Embodiments are not limited to the illustrated tilting about the transverse axis of the housing 101. It is of course also possible to tilt the component 100 about the longitudinal and vertical axes 106 and 107 of the housing 101.

Figure 6a shows, in a perspective illustration, elements of a component 100 ′ according to an exemplary embodiment of the present invention in an excited state.

In particular, the Figure 6a in a perspective and greatly simplified illustration, a section of a component 100 ′ from a substrate, without showing a cover wafer 18 and handling wafer 19.

The acoustic device can advantageously be built up monolithically consisting of a plurality of layers, or from substrates of different materials which are connected or bonded to one another via a common layer. This can take place, for example, in the form of an arrangement of a cover wafer 18 above or a handling wafer 19 below a common device wafer 20. A cavity 11 is formed from a device wafer 20 by partially removing the material, which is formed by an edge 17 and the respective movable elements or electrodes of the bending transducers 3 ₂ , 3 ₄ and 4 ₂ , as well as by the substrate in the area of the clamping 14 is defined. Embodiments include alternative borders 17 of the cavity 11. On the one hand, the border 17 can be firmly connected to the substrate; on the other hand, the border 17 can consist of adjacent electrodes of a further bending transducer system 100 ′, formed from further bending transducers 3, 4 and 5. The illustrated bending transducers 3 ₂ , 3 ₄ , 4 ₂ and 3 ₁ , 3 ₂ , 4 ₁ are clamped on both sides in this exemplary embodiment and connected to the substrate via the respective clamp 14. Embodiments also include a one-sided clamping, which has the advantage of a large deflection of the freely movable end compared to a bilateral clamping.

The bending transducers 3, 4 and 5 can be clamped in a bending transducer system 1 and / or 2 both on one side and on both sides. It makes sense to clamp the shorter bending transducers 4, 5, which are arranged in the region of the openings 13, on one side and to clamp longer bending transducers 3, which are arranged towards the middle of the component, on both sides. This advantageously results in a greater oscillation amplitude at higher frequencies of the shorter, cantilevered bending transducers 5, since these are characterized by an advantageous ratio of mass to bending transducer length.

Furthermore, the basic functional principle for interaction with a volume flow, for example for generating sound or for pumping a fluid, is shown in such a bending transducer system 1 and / or 2. In a first time interval the bending transducers 3 ₁ , 3 ₂ , 4 ₁ and 3 ₂ , 3 ₄ and 4 ₂ move in the direction of the opposite edge 17 of the cavity 11 and thus reduce the volume within this cavity 11. A volume flow resulting from this volume reduction 16 conveys the fluid contained in the cavity 11 out of the cavity 11 through the openings 13.

The Figure 6b also shows the basic functional principle for interacting with a volume flow, for example to generate sound or to pump a fluid in such a bending transducer system 1 and / or 2. In a second time interval, the bending transducers 3 ₁ , 3 ₂ , 4 ₁ and 3 ₂ , 3 move ₄ and 4 ₂ away from the opposite edge 17 of the cavity 11 and thus increase the volume of the cavity 11. The volume flow 16 resulting from this increase in volume conveys the fluid through the openings 13 into the cavity 11.

Alternative exemplary embodiments do not contain an edge 17 firmly connected to the substrate, but rather further bending transducers, not shown here, which can be clamped in on one and / or both sides. In this case, in the first time interval, the adjacent bending transducer systems 1 and 2 would move away from one another in order to increase the volume of the cavity 11 and move towards one another in order to reduce the volume of the cavity. Further developing exemplary embodiments can include a combination of edges 17 that are firmly connected to the substrate and / or no edges 17 that are firmly connected to the substrate.

Fig. 7 FIG. 11 shows a cross-sectional view of a detail from a component 100 ′ along the cutting plane A of FIG Figure 6a . The illustration shows the handling wafer 19 and cover wafer 18, which form the vertical delimitation of the cavity 11, which is delimited by the bending transducers 3 ₁ and 3 ₂ and the border 17 in the area of the device wafer 20. The structure is a stack of layers, the individual layers being mechanically firmly connected to one another, in particular in a materially bonded manner. These layers are not shown in the figure. The layer-by-layer arrangement of electrically conductive layers enables a simple configuration, since the cavity 11 can be obtained by selective extraction from the layer 20 and bending transducer structures can remain through suitable adjustment of the manufacturing processes. Alternatively, it is also possible to arrange the bending transducer structures in whole or in part by other measures or processes in the cavity 11, for example by creating and / or positioning them in the cavity 11. In this case, the bending transducer structures can be compared to the parts of the layer remaining in the substrate 20 be formed differently, ie have different materials.

The Figure 8 shows in a perspective illustration an alternative embodiment of a layered component 100 with an upper bending transducer system 1 that has vertically arranged openings 13 ₁ in a cover wafer 18 ₁ for connecting the cavities 11 to the environment. A second bending transducer system 2 is arranged below the upper, first bending transducer system 1 and has laterally arranged openings 13 in a device wafer 20. Embodiments are not limited to the illustrated system of two bending transducer systems 1 and 2, rather only one bending transducer system 1 or 2 or a plurality of bending transducer systems 1, 2,..., N can be arranged. In the immediate vicinity, a control unit 21 is arranged that a Is part of the component 100 and which leads to the restriction of the available installation space of the bending transducer system 1 and which is connected to the bending transducer systems (not shown). Further openings in the handling wafer 19 of the upper bending transducer system 1 can be arranged in such a way that they are connected to openings in the cover wafer 18 of the second bending transducer system 2. Embodiments include that a handling wafer 19 of the first bending transducer system 1 can be dispensed with if - with anticipation of Fig. 9 - The device wafer 20 'of the second bending transducer system 2 can take over this function.

The Figure 9 shows in a cross-sectional representation an embodiment of an alternative component 100 ″ with an upper bending transducer system 1 that has vertically arranged openings 131 in the cover wafer 18. In this embodiment, the device wafers 20 and 20 'are on a common substrate layer 22, which also have a Lid wafers as well as handling wafers represent mechanically connected to one another, in particular materially connected. This exemplary embodiment shows by way of example how openings 13 ₁ , 13 ′ ₁ , 13 ″ ₁ can be arranged in the cover, handling or device wafer in order to be opposite to the Sound direction to be optimally arranged. The direction of sound can accordingly be determined by the volume flow interacting with the environment, which is determined by the movement of the deformable elements or the bending transducer 3 ₁ , 3 ₂ , 3 ' ₁ and 3' _{2 of} the component 100 ″.

1. 1. Biegewandlersystem
   • ∘ mit äußeren Abmessungen, die einer umgebenden Geometrie angepasst sind und die umgebende Geometrie eine Längsachse aufweist, die in etwa der Schallrichtung entspricht
   • ∘ enthält Biegewandler unterschiedlicher Länge, bestehend aus verformbaren Elementen die in Kavitäten angeordnet sind und mit einem Substrat verbunden sind
   • ∘ die Verformung des verformbaren Elements erfolgt quer zur lateralen Richtung in einer Substratebene (in plane)
   • ∘ enthält eine Vielzahl an verformbaren Elementen, deren jeweilige Bewegungsrichtungen eine gemeinsame Bewegungsebene in der Substratebene bilden
   • ∘ die verformbaren Elemente unterschiedliche Längen aufweisen und damit voneinander abweichende maximale Auslenkungen realisieren.
   • ∘ die Anordnung der unterschiedlich langen Biegewandler erfolgt entsprechend den vorhandenem Platzes so, dass die Flächenausnutzung der durch die Bewegungsebene und die äußeren Abmessungen des Biegewandlersystems gebildeten Fläche maximal ist
   • ∘ und die Bewegungsebene gegenüber der Längsachse 106 der umgebenden Geometrie in zumindest einem Winkel geneigt ist
2. 2. kurze Biegewandler sind im Bereich der Öffnungen angeordnet,
3. 3. lange Biegewandler sind zentral/mittig/dort wo Platz ist angeordnet
4. 4. Das Biegewandlersystem ist um eine Querachse der umgebenden Geometrie verkippt.
   4.1. Der Winkel der Bewegungsebene 10 gegenüber der Längsachse 106 der umgebenden Geometrie liegt zwischen 90° und 180°, bevorzugt 150° und 170° besonders bevorzugt 160 °.
5. 5. In Ausführungsbeispielen ist das Biegewandlersystem um eine Längsachse und/oder um eine Hochachse der umgebenden Geometrie verkippt
   5.1. Vergleichbare Winkel zu 5.1
6. 6. In Ausführungsbeispielen sind die kürzeren Biegewandler, die im Bereich der Öffnung angeordnet sind einseitig eingespannt. Wohingegen die langen Biegewandler beidseitig eingespannt sind
   • 6.1. Einseitige Einspannung möglich bei Biegewandlern, die kürzer sind als in etwa2000 µm
   • 6.2. Beidseitige Einspannung möglich bei Biegewandlern, die länger sind als in etwa 1000 µm
   • 6.3. Im Biegewandlersystem sind beliebige Kombinationen aus ein- und beidseitig eingespannten Biegewandlern möglich, Zielstellung ist immer hoher Schalldruck bei gleichzeitig breitem Frequenzbereich
7. 7. Ein Bauelement, dass ein Biegewandlersystem mit den vorstehend genannten Merkmalen aufweist, kann darüber hinaus auch weitere Einrichtungen enthalten:
   • zur fluiddynamischen Dämpfung
   • zur Signalverarbeitung
   • zur Drahtlosen Kommunikation
   • zur Spannungstransformation
   • Sensoren
   • Software
   • zur Speicherung von Daten
   • zur Versorgung mit Energie
8. 8. Ein Kopfhörer enthält zumindest ein Bauelement mit einem Biegewandlersystem mit vorherstehend genannten Merkmalen, wobei:
   • 8.1. Äußere Abmessungen des Kopfhörer entsprechen nahezu den inneren Abmessungen des Gehörgangs
   • 8.2. Kopfhörer ist so ausgebildet, dass das Bauelement im Gehörgang angeordnet ist, wenn ein Nutzer den Kopfhörer eingesetzt hat
   • 8.3. Kopfhörer ist so ausgebildet, dass der den Gehörgang nahezu verschließt
   • 8.4. oder Kopfhörer ist so ausgebildet, dass seine äußeren Abmessungen nicht den äußeren Abmessungen des Gehörganges eines Nutzer entspricht und deshalb aber in großen Stückzahlen kostengünstig hergestellt werden kann

Further possible exemplary embodiments according to the invention are described below. In summary, a bending transducer 3, 4 and 5 or a bending transducer system 1 and / or 2 comprising several such bending transducers 3, 4 and 5 or a component 100, 100 ', 100 "comprising several such bending transducer systems 1 and / or 2 - the example in can be built into a hearing aid - understood as:

1. 1. Bending transducer system
   • ∘ with external dimensions that are adapted to a surrounding geometry and the surrounding geometry has a longitudinal axis that corresponds approximately to the direction of sound
   • ∘ contains bending transducers of different lengths, consisting of deformable elements that are arranged in cavities and connected to a substrate
   • ∘ the deformation of the deformable element takes place transversely to the lateral direction in a substrate plane (in plane)
   • ∘ contains a large number of deformable elements whose respective directions of movement form a common plane of movement in the plane of the substrate
   • ∘ the deformable elements have different lengths and thus realize maximum deflections that differ from one another.
   • ∘ The bending transducers of different lengths are arranged according to the available space in such a way that the surface utilization of the area formed by the plane of movement and the external dimensions of the bending transducer system is maximum
   • ∘ and the plane of movement is inclined at least at an angle with respect to the longitudinal axis 106 of the surrounding geometry
2. 2. short bending transducers are arranged in the area of the openings,
3. 3. Long bending transducers are arranged centrally / in the middle / where there is space
4. 4. The bending transducer system is tilted about a transverse axis of the surrounding geometry.
   4.1. The angle of the plane of movement 10 with respect to the longitudinal axis 106 of the surrounding geometry is between 90 ° and 180 °, preferably 150 ° and 170 °, particularly preferably 160 °.
5. 5. In exemplary embodiments, the bending transducer system is tilted about a longitudinal axis and / or about a vertical axis of the surrounding geometry
   5.1. Comparable angles to 5.1
6. 6. In exemplary embodiments, the shorter bending transducers which are arranged in the area of the opening are clamped on one side. Whereas the long bending transducers are clamped on both sides
   • 6.1. One-sided clamping is possible with bending transducers that are shorter than about 2000 µm
   • 6.2. Clamping on both sides is possible with bending transducers that are longer than about 1000 µm
   • 6.3. In the bending transducer system, any combination of bending transducers clamped on one and both sides is possible; the aim is always high sound pressure with a wide frequency range
7. 7. A component that has a bending transducer system with the features mentioned above can also contain other devices:
   • for fluid dynamic damping
   • for signal processing
   • for wireless communication
   • for stress transformation
   • Sensors
   • software
   • for storing data
   • for the supply of energy
8. 8. Headphones contain at least one component with a bending transducer system with the aforementioned features, wherein:
   • 8.1. The external dimensions of the headphones almost correspond to the internal dimensions of the ear canal
   • 8.2. Headphones are designed so that the component is arranged in the ear canal when a user has inserted the headphones
   • 8.3. Headphones are designed so that they almost close off the ear canal
   • 8.4. or headphones are designed so that their external dimensions do not correspond to the external dimensions of the ear canal of a user and can therefore be manufactured cost-effectively in large numbers

Furthermore, an arrangement of the bending transducer system as a sound transducer system is left to the person skilled in the art. The technical teaching taken up here reveals to the person skilled in the art features of how a large number of bending transducers must be arranged in order to obtain a high acoustic quality with a simultaneously wide frequency range in a limited, predefined installation space.

In addition, the person skilled in the art can learn from technical lessons how a plane of movement that is formed by a plurality of directions of movement and can be inclined with respect to a longitudinal axis and / or transverse axis and / or vertical axis of the space surrounding the sound transducer system.

• zur fluiddynamischen Dämpfung
• zur Signalverarbeitung
• zur Drahtlosen Kommunikation
• zur Spannungstransformation
• zur Speicherung von Daten
• zur Versorgung mit Energie

Predefined spaces are, for example, the geometric dimensions due to the ear canal, other sensors or system technology:

• for fluid dynamic damping
• for signal processing
• for wireless communication
• for stress transformation
• for storing data
• for the supply of energy

Short bending transducers of a bending transducer system should advantageously be arranged where there is little space available and / or in the area of the openings that connect the cavities with the environment. These openings are located in the area of the outer limits of the bending transducer system. In contrast, long bending transducers are mainly arranged centrally in the bending transducer system. This has the advantage of making optimal use of the available space in order to achieve a high packing density of the individual bending transducers in order to increase the sound pressure level. In addition, longer bending transducers allow lower resonance frequencies due to their lower rigidity. Short bending transducers are characterized by a comparatively high degree of rigidity, which enables high resonance frequencies. If these bending transducers are arranged in the area of the openings that connect the cavities to the environment, resonances can be avoided and the sound quality can thus be improved.

Advantages of a tilted arrangement in a tube-like space, for example an ear canal.

The ear canal is approximately a cylinder with the dimensions L X D = 25 mm X 0.7 mm (Wiki).

The transversal acoustic resonance of the closed auditory canal (λ / 2) is accordingly at U _T ≈ 235 kHz, the corresponding longitudinal resonance at U _L ≈ 6.6 kHz. A headphone membrane in "normal, ie radial" orientation is provided by the longitudinal mode U _L ≈ 6.6 kHz is excited and thus generates an undesirable, audible additional resonance.

As a first approximation, a headphone membrane in an "axial" position is only excited by the transverse mode at U _T ≈ 235 kHz. That is much better, because acoustically completely irrelevant!

Of course, the size of the bending transducer system (analogous to the membrane) should be chosen so that the low natural frequencies of the membrane do not interfere. So it shouldn't be too big. At an inclination of 60 °, the first natural frequency of an ideal membrane is approx. 2 X 6.6 kHz = 13.2 kHz. For everything we know about the "real headphone" that's OK.

Due to the tilted arrangement of the bending transducer system, a larger base area of the bending transducer system can be arranged in the available space, on which in turn longer or more bending transducers can be arranged. By using a larger number of bending transducers, higher sound pressures can be achieved.

Another advantage is that openings can be optimally arranged in the direction of the sound direction given by the external dimensions. For example shows Figure 8 vertically arranged openings which are then arranged almost in the direction of sound when the component is tilted in the ear canal.

The application thus describes a further development with regard to the optimization of the sound quantity (sound pressure level) and sound quality that can be produced by the component in a specific environment.

High integration requirements relate to the adaptation to the existing installation space in general as well as to the system design from several components. For example, in ultra-mobile end devices (e.g. hearables smartwatches), in particular the energy storage device and any other HMI components (tactile surfaces, displays) that may be present are subject to narrow limits in terms of the installation space design (cylindrical / cuboid or flat / plate-shaped). In order to still achieve a minimization of the installation space, it is necessary to adapt the sound transducer to the remaining installation space and thus enable a high volume of sound.

In addition, aspects of sound quality should not be neglected when designing the systems (ultra-mobile, such as hearables or wearables in general). Specifically, a specific design of the sound transducer groups can be used to generate sound that is adapted to the geometric conditions in terms of sound radiation. The main drivers are frequency-dependent effects, and disturbing resonances can occur particularly at high frequencies.

With the present invention, both the sound quality and the sound quality can be improved significantly.

The principle of the bending transducer according to the invention is based on the NED (nanoscopic electrostatic drive) and is in WO 2012/095185 A1 described. NED is a new kind of MEMS (micro electromechanical system) actuator principle. The basic principle is that a silicon bar moves laterally in a plane, the substrate plane, which is defined by a silicon disk or a wafer. The silicon bar, which is connected to the substrate in a cavity, interacts with a volume flow. Furthermore, the component comprises an electronic circuit which is arranged in a layer of the layer stack, the electronic circuit being connected to the electromechanical bending transducer and which is designed to deflect the bending transducer based on an electrical signal. <b><u> Tag List</u></b> 1 First bending transducer system 2 Second bending transducer system 3 The first bending transducer has a first length 4th The second bending transducer has a second length 5 The third bending transducer has a third length 6th Direction of movement of the first bending transducer 7th Direction of movement of the second bending transducer 8th Direction of movement of the third bending transducer 9 Substrate level 10 Level of motion 11 cavity 12 Angle between the plane of movement and the longitudinal axis 13 openings 14th Restraint 15th Edge of the cavity 16 Volume flow 17th Edge of the cavity 18th Lid wafer 19th Handling wafer 20th Device wafer 21st ASIC 22nd Common substrate layer 30th auricle 31 Ear canal 32 eardrum 100 Component 100 ' Section from a component 101 External geometry of an ultra-mobile device, for example a housing 102 Length of the component 103 Width of the component 104 Thickness of the component 105 A transverse axis of the ultra-mobile device 106 Longitudinal axis of the ultra-mobile device 107 Vertical axis of the ultra-mobile device 108 Angle α

Claims (15)

Acoustic bending transducer system (1, 2) with
a plurality of bending transducers (3, 4, 5) which are designed in such a way that deformable elements (3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3 ' ₂ ) the bending transducers (3, 4, 5) oscillate coplanar in a common flat layer (10), the bending transducers (3, 4, 5) having different resonance frequencies and different dimensions of the deformable elements (3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3' ₂ ) along a common longitudinal axis that is transverse to a direction of vibration of the deformable elements (3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3' ₂ ). Acoustic bending transducer system (1, 2) according to Claim 1, with one or more cavities (11) in which the bending transducers (3, 4, 5) are arranged, and openings (13; 13 ₁ , 13 ' ₁ , 13 " ₁ ) through which a fluidic volume flow (16), which interacts with the plurality of bending transducers (3, 4, 5), can pass. Acoustic bending transducer system (1, 2) according to claim 1 or 2, wherein the deformable element (3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3' ₂ ) at least one bending transducer (3, 4, 5) is electrostatically, piezoelectrically, or thermomechanically deformable. Acoustic bending transducer system (1, 2) according to one of the preceding claims, wherein
at least a first subset of at least one first bending transducer (5) each has a deformable element clamped on one side, and / or at least a second subset of at least one second bending transducer (3, 4) each has a deformable element (3 ₁ , 3 ₂ , 3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3' ₂ ). Acoustic bending transducer system (1, 2) according to claim 4, wherein the at least first subset of at least one first bending transducer (5) has on average a higher resonance frequency than the at least second subset of at least one second bending transducer (3, 4) or vice versa. Acoustic bending transducer system (1, 2) according to claim 4 or 5, wherein the at least first subset of at least one first bending transducer (5) has a shorter length on average than the at least second subset of at least one second bending transducer (3, 4). Acoustic bending transducer system (1, 2) according to one of the preceding claims, wherein
each bending transducer (3, 4, 5) adjoins at least one cavity (11) and each cavity (11) is accessible via at least one opening (13; 13 ₁ , 13 ' ₁ , 13 " ₁ ) for the fluidic volume flow (16) to pass through is. Acoustic bending transducer system (1, 2) according to one of the preceding claims, wherein
the external dimension of the bending transducer system (1, 2) along the common longitudinal axis is between 750 μm and 2000 μm and particularly preferably between 850 μm and 1250 μm. Acoustic bending transducer system (1, 2) according to one of the preceding claims, wherein
an outer surface of the bending transducer system (1, 2), coplanar to the common planar layer, describes an oval elongated along the common longitudinal axis, an elongated rectangle along the common longitudinal axis or a polygon elongated along the common longitudinal axis. Acoustic bending transducer system (1, 2) according to one of the preceding claims, wherein
the bending transducers (3, 4, 5) are divided into groups of one or more bending transducers (3, 4, 5), with the several bending transducers (3, 4, 5) along in groups with several bending transducers (3, 4, 5) the common longitudinal axis are arranged one behind the other,
and / or, where
in groups with several bending transducers (3, 4, 5) the several bending transducers (3, 4, 5) are arranged next to one another in the common flat layer (10) transversely to the common longitudinal axis. Acoustic device with: an acoustic bending transducer system (1, 2) with at least one bending transducer (3, 4, 5) of at least one deformable element (3 ₁ , 3 ₂ , 4 ₁ ; 3 ₂ , 3 ₄ , 4 ₂ ; 3 ₁ , 3 ₂ , 3 ' ₁ , 3' ₂ ) which is arranged in a cavity (11), and an opening (13; 13 ₁ , 13 ' ₁ , 13 " ₁ ) through which a fluidic volume flow (16) interacting with a movement of the bending transducer (3, 4, 5) in the cavity (11) passes, and a housing (101) adapted to be inserted in a passage, wherein the bending transducer system is held in the housing (101) in such a way that the fluidic volume flow (16) can be aligned obliquely to a longitudinal axis of the aisle in a state in which the housing (101) is inserted into the aisle. Acoustic device according to claim 11, wherein the acoustic bending transducer system (1, 2) is designed according to one of claims 1 to 10, wherein the fluidic volume flow (16) is in the plane of the common flat layer (10) longitudinal axis of the bending transducer system (1, 2) runs. Acoustic device according to claim 11 or 12, wherein
the bending transducer system (1, 2) is held in the housing (101) in such a way that the fluidic volume flow (16) of the acoustic device is at an angle between 5 ° and 80 °, between 10 ° and 40 °, or between 15 ° and 30 ° ° inclined relative to the longitudinal axis of the passage through the openings (13; 13 ₁ , 13 ' ₁ , 13 " ₁ ) of the bending transducer system (1, 2) passes. Acoustic device according to one of the preceding claims 11 to 13, wherein
the acoustic bending transducer system (1, 2) can receive and / or emit an acoustic signal via the fluidic volume flow (16) passing through the openings (13; 13 ₁ , 13 ' ₁ , 13 " ₁ ). Acoustic device according to one of the preceding claims 11 to 14, further comprising: a control unit for controlling the individual bending transducers (3, 4, 5) of the bending transducer system (1, 2) and a power source for operating the acoustic device.

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