DE102011005292A1 - Acoustic transducer for generating and receiving sound waves, has converting device, which is arranged for converting electrical signal into movement of movable element along moving direction - Google Patents

Abstract

The acoustic transducer has a movable element (1) for generating sound waves, where the element is movable by the sound waves. A converting device is arranged for converting an electrical signal into a movement of the movable element along a moving direction. The converting device converts a forward movement along a direction of movement of the movable element into an electrical signal. A medium is provided for increasing the bending stiffness of the movable element. An independent claim is also included for a method of manufacturing a movable element for an acoustic transducer.

Description

The invention relates to an acoustic transducer for generating and / or receiving sound waves according to claims 1, 9 or 13 and to a method for producing a movable element for an acoustic transducer according to claim 18.

Acoustic transducers in the form of loudspeakers are known from the prior art, which have movable elements (loudspeaker membranes) which are set in vibration to generate sound waves. A loudspeaker, which has a movable element in the form of a flat loudspeaker diaphragm is z. B. from the US 5,701,359 known.

The problem underlying the invention is to provide an acoustic transducer with the best possible conversion quality.

This problem is solved by the acoustic transducer having the features according to claim 1, by the acoustic transducer having the features according to claim 9, by the acoustic transducer having the features of claim 13 and by the method according to claim 18. Further developments of the invention are specified in the dependent claims.

• – mindestens einem zum Erzeugen von Schallwellen oder durch Schallwellen bewegbaren Element;
• – Umsetzmitteln zum Umsetzen eines elektrischen Signals in eine Bewegung des bewegbaren Elementes entlang einer Bewegungsrichtung und/oder zum Umsetzen einer entlang einer Bewegungsrichtung gerichteten Bewegung des bewegbaren Elementes in ein elektrisches Signal; und
• – Mitteln zum Erhöhen der Biegesteifigkeit des bewegbaren Elementes.

Thereafter, an acoustic transducer for generating and / or receiving sound waves is provided with

• - At least one for generating sound waves or by sound waves movable element;
• Conversion means for converting an electrical signal into a movement of the movable element along a direction of movement and / or for converting a direction of movement of the movable element into an electrical signal; and
• - means for increasing the flexural rigidity of the movable element.

For example, the means for increasing the bending stiffness comprise a reinforcement of a subsection of the movable element, so that the movable element in this subsection has an increased thickness compared to sections of the movable element outside the reinforced subregion, viewed in the direction of movement of the movable element.

In particular, the movable element is a substantially planar element (eg, a planar membrane), wherein the means for increasing the flexural rigidity increase the thickness of this planar element in sections, in order to realize an increased flexural rigidity of the movable element. The reinforcement is in particular in the form of one or more struts, d. H. Elevations of the surface of the movable element, which in particular face the Umsetzmitteln formed, so that the flexural rigidity of the movable member under load in the direction of movement (i.e., in a flat formed movable member perpendicular to its main extension plane) increases. The reinforcement of the movable element is effected in particular by separately manufactured structures which are then connected to the movable element. However, it is also possible that the reinforcement is formed integrally with the movable member.

According to another embodiment of the invention, the movable member has a base body, wherein the means for increasing the flexural rigidity form an edge which surrounds the base body and forms an outer circumference of the movable element, which protrudes at an angle from the base body. As a result of the edge projecting at an angle from the main body, the movable element has an increased thickness in the direction of movement in this region, so that the flexural rigidity of the movable element increases in this direction and in particular in the edge region.

The movable element is in particular, as already indicated above, flat. This means that the movable element (in particular its base body) extends along one surface (main extension surface) and thus has a greater extent along this surface than perpendicular to this surface; z. For example, the extent of the movable element along the main extension surface is at least three times greater than the extension perpendicular to the main extension surface. For example, the movable element is at least substantially planar. However, it is also conceivable that the movable element has a curvature (see below), d. H. extends along a curved surface.

In particular, the main body extends along a main plane of extension, ie it has a much greater extent along a plane (at least three times greater) than perpendicular to this plane. The edge thus runs in particular at an angle to this main extension plane of the main body. The fact that the edge protrudes "angled" from the base body, also includes the case that the edge and the base body are connected to each other via a curvature, ie the edge bent (bent) protrudes from the base body. Such a curvature between the base body and the edge has the particular advantage that reflections of acoustic waves in the movable element at the edge are reduced or completely be avoided. The edge of the movable element is in particular inward, ie in the direction of the conversion means and thus of a listener (if the acoustic transducer is designed in the form of a loudspeaker) or a speaker (if the acoustic transducer is designed in the form of a microphone), from the main body.

In particular, the movable element has a layer structure which has at least one inner layer and two outer layers, which are each arranged on opposite sides of the inner layer in a direction perpendicular to the inner layer. In other words, the inner layer is between the two outer layers. For example, the inner layer is formed from a rigid foam (for example Rohacell) and the two outer layers each comprise a fiber-reinforced material (in particular a carbon fiber-reinforced material). Of course, a plurality of inner layers and also a plurality of outer layers may be provided.

In particular, the outer layers are dimensioned so that they each project beyond the circumference of the inner layer (ie have a larger area than the inner layer) along the outer plane of the inner layer along its outer circumferential plane, the protruding portions of the outer layers thus run and connected to each other, that they form the angle projecting from the base edge. The edge of the movable element is thus formed only by the two outer layers, wherein the inner layer extends in particular only to the edge, but not into the edge. For example, the inner sides of the protruding portions of the outer layers are integrally connected to one another, for example adhesively bonded or welded. The "inner sides" of the protruding portions are those sides of the protruding portions that join the sides of the outer layers facing the inner layer.

According to a further variant of the invention, a surface of the movable element facing away from the conversion means (i.e., the outside of the movable element which faces a user when the acoustic transducer is used as intended) may be provided with an elastic coating. By way of example, the elastic coating is an elastic plastic (in particular a synthetic resin) or another rubber material. The elastic coating is used in particular for damping resonant breakdowns on the surface of the movable element.

According to another embodiment of the invention, the means for increasing the bending stiffness comprise a curved configuration of the movable element, wherein the movable element (in particular a body surrounded by a protruding edge) is arched at least approximately in the manner of a segment of a spherical surface. For example, the movable element embodied as a segment of a spherical surface has a side edge running approximately rectangularly (in plan view), i. H. the edge has two mutually parallel edge portions. For example, the movable element is rectangular in plan view, wherein the longer sides have a length of about 30 cm and the shorter sides of about 20 cm, and wherein the movable element z. B. has such a curvature that the center of the movable element has an offset of at least about 0.5 mm, in particular of 1 mm, relative to the outer edge of the movable element.

For example, the movable element is formed as a segment of a surface of a sphere having a radius of at least 300 m. Such a movable element can produce (for example in the low-frequency range, in particular below 300 Hz) at least approximately spherical wave fronts (principle of the breathing sphere).

According to another variant of the invention, the conversion means comprise at least one coil and the means for increasing the flexural rigidity comprise at least one stiffening layer, via which the coil is connected to the movable element. For example, the coil is arranged in or on a holder which is fastened via the stiffening layer to the movable element.

• – mindestens einem zum Erzeugen von Schallwellen oder durch Schallwellen bewegbaren Element;
• – Umsetzmitteln zum Umsetzen eines elektrischen Signals in eine Bewegung des bewegbaren Elementes entlang einer Bewegungsrichtung und/oder zum Umsetzen einer entlang einer Bewegungsrichtung gerichteten Bewegung des bewegbaren Elementes in ein elektrisches Signal, wobei
• – die Umsetzmittel mindestens vier Spulen aufweisen, die jeweils entlang einer parallel zur Bewegungsrichtung orientierten Erstreckungsebene verlaufen und die so hintereinander angeordnet sind, dass sie zumindest teilweise entlang einer Richtung senkrecht zu ihren Erstreckungsebenen überlappen.

According to a further aspect, the invention relates to an acoustic transducer for generating and / or receiving sound waves, with

• - At least one for generating sound waves or by sound waves movable element;
• - Conversion means for converting an electrical signal into a movement of the movable member along a direction of movement and / or for converting a direction of movement directed movement of the movable member into an electrical signal, wherein
• - The conversion means comprise at least four coils, each extending along a plane oriented parallel to the direction of extension plane and which are arranged one behind the other so that they overlap at least partially along a direction perpendicular to their extension planes.

The coils are thus each wound around an axis which extends perpendicular to the direction of movement of the movable element, wherein the coils are arranged, for example, one behind the other so that their respective axes coincide. The converter thus has a plurality of coil layers, whereby the filling factor and thus a special efficiency of the conversion means (the drive for driving the movable element) is achieved.

In particular, the coils form a first coil group comprising at least two coils connected in series and a second coil group comprising at least two coils likewise connected in series, wherein the first and the second coil group are connected in parallel to one another and connected to one another via a transverse contact. With this circuit of the coils, a lower DC resistance and a lower impedance can be produced compared with a simple series connection of the four coils (and also in comparison with an arrangement having only two coils). For example, each two adjacent coils form a coil group. Of course, it is also possible that more than four coils are used, wherein in particular an even number of coils is provided. For example, eight, twelve, sixteen or twenty-four coils are used.

According to another embodiment of the invention, the acoustic transducer has a first carrier and a second carrier connected to the first carrier, wherein each of two carriers are arranged on each carrier. In particular, the first and the second carrier are a printed circuit board, on each of which on one side (that is to say on the front and rear side of the printed circuit board) a coil in the form of a wound conductor track is formed.

By way of example, this conductor track is formed from copper (or another electrically conductive material) (for example printed or etched), wherein in particular a track width of 0.2 mm may be provided at a thickness of at least 35 μm. Of course, the conductor may also have other dimensions, eg. B. a width of less than 0.2 mm. In particular, the coil arrangement has a total conductor track length of at least 15 meters. The circuit boards are in particular made of a fiber-reinforced plastic.

The connection of the two carriers is z. B. cohesively, for example via an adhesive. It is also possible that the first and the second carrier are connected to one another via a connecting element, wherein it is in the connecting element z. B. to another circuit board (but in particular itself has no traces), with which the first and the second carrier are connected in particular cohesively.

• – einem bewegbaren Element;
• – Umsetzmitteln zum Umsetzen eines elektrischen Signals in eine Bewegung des bewegbaren Elementes entlang einer Bewegungsrichtung und/oder zum Umsetzen einer entlang einer Bewegungsrichtung gerichteten Bewegung des bewegbaren Elementes in ein elektrisches Signal;
• – einen Rahmen, der das bewegbare Element zumindest abschnittsweise umgibt; sowie
• – Schallabsorptionsmitteln zur Vermeidung eines akustischen Kurzschlusses, wobei die Schallabsorptionsmittel entlang zumindest eines Abschnitts eines äußeren Umfanges des bewegbaren Elementes zwischen dem bewegbaren Element und dem Rahmen verlaufen, wobei die Schallabsorptionsmittel an dem bewegbaren Element lediglich anliegen und nicht über Verbindungsmittel mit diesem verbunden sind.

A third aspect of the invention relates to an acoustic transducer for generating and / or receiving sound waves, with the invention

• A movable element;
• Conversion means for converting an electrical signal into a movement of the movable element along a direction of movement and / or for converting a direction of movement of the movable element into an electrical signal;
• A frame surrounding the movable element at least in sections; such as
• Sound absorbing means for preventing an acoustic short circuit, wherein the sound absorbing means extend along at least a portion of an outer periphery of the movable member between the movable member and the frame, wherein the sound absorbing means are applied to the movable member only and not connected via connecting means therewith.

By virtue of the fact that the sound absorption means only abut the movable element and are not connected to it by means of connection means, d. H. In particular, not materially fixed (about an adhesive as a connecting means) are fixed to this, the highest possible mobility of the movable element is possible.

By way of example, the sound absorbing means comprise a film which is arranged on a side facing the transfer means (that is to say a rear side) of the movable element. Here, it is conceivable that the film is indeed firmly bonded to the frame (for example, adhered to the frame), but at the back of the movable element only rests and is held for example only on adhesion forces between the film and the movable member.

For example, a film with a thickness of 7 .mu.m to 15 .mu.m is used, wherein as a material in particular a plastic, such as polyethylene, comes into question. In particular, the foil is configured to also extend in a frame-like manner (i.e., as a strip) along the frame of the acoustic transducer. By using a film that is as thin as possible, spring forces on the movable element are avoided or at least reduced as much as possible.

It is also possible to use, instead of a foil, a sound absorber which is similar to the foil described above, fixed on the frame, on the rear side of the movable one Element, however, only rests, but has a thickness which decreases from the frame to the movable member. For example, a first portion of the sound absorbing means via which it is fixed to the frame has a thickness in the mm range (eg, at least 0.5 mm) and a second portion over which the sound absorbing means rests on the movable member Thickness in the μm range (eg less than 10 μm).

Such a sound absorbing means may be formed in one piece; z. B. by a single layer of material whose thickness decreases from the frame to the movable element. However, it is also conceivable that it is formed of several components. For example, in order to form such a sound absorption medium, the above-described film is combined in the region of the frame with a material layer which is more rigid than that of the film.

As a result, the film extending beyond the frame to the movable element is stabilized, so that pushing away and detaching the film (held only by adhesion to the movable element) from the movable element by an air flow flowing between the outer edge of the movable element and the frame counteracted. At the same time, since the sound absorbing means is applied to the movable member only, spring forces on the movable member are avoided as much as possible.

The frame of the acoustic transducer is in particular formed of a plastic, for example Parapan.

The invention relates, as already mentioned above, in particular an acoustic transducer in the form of a loudspeaker. In this case, the speaker may well have more of the previously described acoustic transducer, d. H. in particular a plurality of movable elements, which can be moved in each case via Umsetzmittel in motion.

• – Erzeugen eines Schichtaufbaus, der mindestens eine innere Schicht und an einander in einer Richtung senkrecht zu der inneren Schicht gegenüberliegende Seiten der inneren Schicht angeordnete Außenschichten umfasst, derart, dass die Außenschichten jeweils mit einem entlang ihres äußeren Umfanges verlaufenden Abschnitts über den Umfang der inneren Schicht überstehen,
• – Abwinkeln oder Abbiegen der überstehenden Abschnitte der Außenschichten; und
• – Verbinden der überstehenden Abschnitte der Außenschichten miteinander.

The invention also relates to a method for producing a movable element for an acoustic transducer, which is designed, in particular, as described above, with the steps:

• Producing a layer structure comprising at least one inner layer and outer layers disposed opposite each other in a direction perpendicular to the inner layer, such that the outer layers each have a portion extending along their outer circumference around the circumference of the inner layer survive,
• - bending or bending the protruding portions of the outer layers; and
• - Connecting the protruding portions of the outer layers together.

The bending or bending of the protruding portions of the outer layers takes place in particular by impressing the layer structure in a correspondingly shaped receptacle, that is, the receptacle is dimensioned so that the protruding portions of the outer layers are bent, the remaining area (the main body) of the layer structure, however Not. It is also conceivable that the layer structure is at least partially produced only in the recording. For example, one of the outer layers is first pressed into the receptacle and then arranged the inner layer and the other outer layer in the receptacle.

Of course, it is also conceivable that the layer structure is already completed before insertion into the receptacle, d. H. the inner layer is connected to the two outer layers. In addition, it is also possible that the protruding portions of the outer layers are already connected to each other before their bending or bending, z. Example, the protruding portions of the outer layers are connected to each other before inserting the layer structure in a receptacle.

For example, arranging (impressing) the layer structure or layers of the layer structure in the receptacle takes place via a suitably designed tool. For example, this tool is designed in the form of a stamp, wherein z. B. between the edge of the punch and the inside (facing the layer structure) of the particular frame-like receptacle is a distance which is greater than the thickness of the two adjacent portions of the outer layers.

The receptacle is in particular also shaped so that the layer structure receives a curvature in the manner of a segment of a spherical surface. That is, by the impressions of the layer structure in the recording or the individual layers of the layer structure successively a curvature is imposed on the layer structure and thus the movable element.

The bonding of the sections of the outer layers to one another takes place, in particular, by way of gluing and / or welding, wherein the connection also takes place in particular under the influence of temperature.

The invention is explained in more detail below with reference to embodiments with reference to the figures. Show it:

1A a sectional view of a movable element of an acoustic transducer according to a first embodiment of the invention;

1B a partial region of the movable element 1A in perspective view;

2 a movable element of an acoustic transducer according to a second embodiment of the invention;

3 a movable element of an acoustic transducer according to a third embodiment of the invention;

4 a section of an acoustic transducer according to a fourth embodiment of the invention;

5 a coil arrangement of an acoustic transducer according to the invention;

6 the coil assembly 5 in a perspective exploded view;

7 schematically the wiring of the coil assembly of the 5 and 6 ;

8th an equivalent circuit diagram of the circuit 7 :

9A . 9B schematic sectional views of an acoustic transducer according to another embodiment of the invention; and

10 a schematic sectional view of an acoustic transducer according to another embodiment of the invention.

This in 1 In sectional view shown movable element in the form of a rigid diaphragm plate 1 has a layer structure (sandwich construction). The layer structure comprises an inner, in particular made of a rigid foam layer 11 on, being on an inner side of the inner layer 11 , which in the acoustic transducer facing means (not shown) for moving the membrane plate, a first outer layer in the form of a carbon fiber reinforced layer 12 and on another side of the inner layer 11 , which faces away from the conversion means in the acoustic transducer, a second outer layer 13 , which is also formed of a carbon fiber reinforced material extend. Of course, other materials for the layers 11 to 13 be used. The thickness of the rigid foam layer 11 in particular is significantly larger (at least three times larger) than the thickness of the outer layers 12 . 13 ,

The outer layers 12 . 13 each stand with a section 121 . 131 along its outer periphery over the rigid foam layer 11 over, ie, they each have a larger area than the rigid foam layer 11 , The protruding sections 121 . 131 are each opposite the hard foam protective layer 11 and their respective ones on the rigid foam protective layer 11 adjacent partial areas, curved. The rigid foam layer 11 and those on the hard foam protective layer 11 adjoining subregions of the outer layers 12 . 13 form a body 10 the membrane plate 1 , with the protruding sections 121 . 131 from this body protrude at an angle and an outer edge 14 the membrane plate 1 form. In particular, the sections 121 . 131 curved so that they are at least approximately perpendicular to the main body of the membrane plate 1 run.

The section 131 the outer layer 13 in the acoustic transducer, a listener facing the outside of the membrane plate 1 forms, before the bending on the hard foam protective layer 11 the membrane plate 1 over than the section 121 the (inner) outer layer 12 , This allows the sections 121 . 131 after being bent over, they overlap one another, with their inner sides facing each other in particular being connected to one another in a material-locking manner (for example via an adhesive or by welding). The two interconnected sections of the sections 121 . 132 make the angled from the main body 10 the membrane plate 1 protruding stabilizing edge 14 , By the protruding edge 14 learns in particular the edge region of the membrane plate 1 a stiffening and allows even with relatively thin design of the membrane plate 1 the highest possible bending stiffness.

Another way of designing the outer edge 24 the membrane plate 1 shows 2 after which the through the sections 121 . 131 the outer layers 12 . 13 formed edge 14 over a flattened curvature 141 the main body 10 the membrane plate 1 followed.

3 shows a further possibility of designing a movable element of an acoustic transducer according to the invention. After that, in turn, this has as a membrane plate 1 formed movable member to a curvature, so that the center of the membrane plate has an offset h (in the intended direction of movement of the membrane plate, ie perpendicular to the main plane of extension of the membrane plate) relative to the position of the edge 14 the membrane plate 1 having. The domed membrane plate 1 In particular, it is arranged in the acoustic transducer so that it is curved outwards (towards a listener).

For example, the membrane plate 1 formed as a segment of a spherical surface, while still in plan view, ie in perpendicular to Main extension plane of the membrane plate, at least approximately rectangular may be formed. The domed membrane plate has a like with reference to 1 and 2 described, from a basic body 10 angular protruding edge 14 in order to stabilize in particular the edge region of the membrane plate.

Furthermore, the membrane plate of the 3 by a layer structure analogous to the 1 and 2 be formed. Of course, the invention is not fixed to this layer structure, but it is also conceivable that, for example, consisting of more or fewer layers layer structure or even a single layer of material for the production of the membrane plate 1 is used. In this context, it is pointed out that even when a single material layer is used, an edge projecting from a main body of the membrane plate can be formed, for example by forming a reinforcing structure in the edge region, or by bending the material layer at the edge.

4 relates to a further embodiment of the invention, according to which the acoustic transducer according to the invention comprise conversion means for moving the movable element, the plurality of voice coils 2 include. The voice coils 2 of which in 4 One shown is in or on a T-shaped holder 21 arranged, which has a parallel to the membrane plate 1 extending section 211 with the membrane plate 1 connected is. Between one of the voice coil 2 facing (inner) side of the membrane plate 1 There are two reinforcing layers 41 . 42 (Stiffening layers) to the flexural rigidity of the membrane plate 1 in the field of voice coils 2 to increase. By way of example, the stiffening layers are fabric materials or fiber-reinforced materials which in particular are materially bonded to the membrane plate 1 or the bobbin holder 21 are connected. The drive of a membrane plate via such a voice coil, possible embodiments of the membrane plate and the construction of an acoustic transducer with a membrane plate (ie, a flat, rigid membrane) are in the international patent application PCT / EP 2010/063240 described 09.09.2010, in so far on the PCT / EP 2010/063240 express reference is made.

The 5 (Sectional view) and 6 (perspective exploded view) show a possible coil structure of the acoustic transducer according to the invention. Thereafter, converter means of the converter, which serve to move the movable element, comprise a plurality of coil arrangements, each of which, as in FIG 5 represented, at least four coils 2a . 2 B . 2c and 2d comprise, wherein the axis of the coils each perpendicular to the direction of movement of the movable element (not shown) extends. In other words, the coils each extend along a plane which is oriented along the direction of movement of the movable element, that is, perpendicular to the main plane of extension of the movable element, the z. B. according to the 1 and 2 may be formed as a membrane plate.

The coil arrangement comprises a first and a second carrier in the form of a first and a second printed circuit board 31 . 32 , each with two coils 2a . 2 B respectively. 2c . 2d are arranged on the first and the second circuit board. Here, in each case, a coil is located on one side of the printed circuit board, wherein the coils can be connected to one another, for example via plated-through holes in the printed circuit board. The spools 2a to 2d are in the form of on the circuit boards 31 . 32 produced conductor tracks produced.

Between the circuit boards 31 . 32 there is a connection element 33 , which may also be formed, for example, in the form of a printed circuit board, via which the two circuit boards 31 . 32 connected to each other. The connection is made in particular by the fact that both the first circuit board 31 as well as the second circuit board 32 each with one side of the connecting element 33 are connected cohesively.

7 illustrates a variant of the wiring of the coils 2a to 2d from the 5 and 6 , After that form the on the first circuit board 31 arranged coils 2a and 2 B a first coil group and those on the second circuit board 32 arranged coils 2c and 2d a second coil group.

The spools 2a . 2 B the first coil group and the coils 2c . 2d The second coil group are each connected in series, but the two coil groups parallel to each other, such as the equivalent circuit in 8th can be seen. In addition, the two coil groups are over a transverse contact 300 connected with each other. About connections 201 . 201 The coil assembly are each connected to an amplifier for driving the acoustic transducer. The cross contact 300 is in 7 by a connection of the coils 2 B and 2c realized, with an output side (the connection 201 turned away) of the coil 2c with an input side (the connection 201 facing) of the coil 2 B connected is.

The 9A and 9B relate to a further embodiment of an acoustic transducer according to the invention 100 , This converter in turn has a flat membrane plate 1 as a movable element, in particular by a protruding edge 14 is reinforced and z. B. according to the 1 and 2 is trained. However, this design of the membrane plate is not absolutely necessary, but it is also conceivable that the film 6 with a conventional, ie not reinforced in the edge region, membrane plate is used.

The worthier points the acoustic transducer 100 a frame 5 on top of the membrane plate 1 at least partially surrounds. At the frame 5 can still another frame 51 be placed on a listener facing side of the frame 5 extends and z. B. serves as a decorative element. The additional frame 51 can be a separate part. However, it is of course also conceivable that the frame 5 and the front frame 51 are integrally formed.

Furthermore, the converter has 100 Sound absorber in the form of a line along the edge 14 the membrane plate 1 and between the edge 14 and the frame 5 extending film 6 on. The foil 6 serves to avoid an acoustic short circuit; ie through the film 6 should be avoided that a gap between the movable element (the edge 14 ) and the frame 5 . 51 acoustic waves caused by a backward movement of the membrane plate 1 (away from the listener) arise, move forward (in the direction of the listener) and interfere with the sound emitted in the direction of the listener.

The foil 6 is arranged so that it has a first section 61 on a back side of the membrane plate 1 merely rests, but is not connected to this connection means. That is, the section 61 in particular not cohesively with the membrane plate 1 connected is. A second section 62 the surrounding foil 6 is, however, cohesively (for example via an adhesive) with an inside of the frame 6 connected.

The membrane 6 is formed in particular of a material having a relatively high adhesion to the material of the outside of the membrane plate 1 on which the film 6 rests, shows, so that even with a movement of the membrane plate 1 the section 61 as stable as possible at the back of the membrane plate 1 is applied. 9B shows a front position of the membrane, wherein the section 61 also safe at the back of the membrane plate 1 rests and thus a gap between the membrane plate and the frame 5 . 51 acoustically sealed.

It should be noted that elements of the different embodiments can of course also be used in combination with each other. For example, the coil arrangement of 5 and 6 along with the acoustic transducer of the 9A . 9B be used.

10 represents a modification of the embodiment of 9A and 9B Here are the sound absorbers of a combination of a film 6 with a thicker and thus more rigid material layer 7 formed, which is the material layer 7 at one of the frame 5 opposite side of the film 6 to about a lower (the membrane plate 1 facing) edge of the frame 5 extends. Thus, they have the foil 6 and the material situation 7 formed sound absorber a thicker and more rigid first section, which is attached to the frame 5 is fixed, and a thinner and less rigid second portion attached to the membrane plate 1 rests.

The material situation 7 that z. B. from a (eg., At least 0.5 mm, in particular about 1 mm thick) foam fleece is formed stabilizes the film 6 and in particular prevents that at the back of the membrane plate 1 overlying section 61 the film through one through the gap between the frame 5 and the edge 14 the membrane plate 1 incoming airflow L from the membrane plate 1 is pushed away and separates from her.

The material situation 7 can be right on the frame 5 or over the foil 6 on the frame 5 In particular, they are like the foil 6 in an upper area of the frame 5 connected to this. The material situation 7 can be similar to the foil along the entire circumference of the frame 5 run. However, it is also conceivable that they only cover part of the scope of the frame 5 Has a plurality of spaced apart pieces of parts, which at different portions of the frame 5 are arranged.

LIST OF REFERENCE NUMBERS

1

diaphragm plate

2, 2a-d

Kitchen sink

5

frame

6

foil

7

material layer

10

body

11

Rigid foam layer

12, 13

outer layer

14

edge

21

holder

31, 32

circuit board

33

connecting element

41, 42

reinforcing layer

51

front frame

61

first foil section

62

second film section

121, 131

overhanging section

141

curvature

201, 202

connection

211

section

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5701359 [0002]
• EP 2010/063240 [0057, 0057]

Claims (20)

Acoustic transducer for generating and / or receiving sound waves, comprising - at least one element capable of generating sound waves or sound waves ( 1 ); - conversion means for converting an electrical signal into a movement of the movable element ( 1 ) along a direction of movement and / or for converting a direction of movement directed movement of the movable element ( 1 in an electrical signal; and means for increasing the bending stiffness of the movable element ( 1 ). Acoustic transducer according to claim 1, characterized in that the movable element ( 1 ) is formed flat. Acoustic transducer according to claim 1 or 2, characterized in that the means for increasing the bending stiffness reinforcing a portion of the movable element ( 1 ), so that the movable element ( 1 ) in this section a - in the direction of movement of the movable element ( 1 ) - increased thickness compared to sections of the movable element ( 1 ) outside the reinforced section. Acoustic transducer according to one of the preceding claims, characterized in that the movable element ( 1 ) a basic body ( 10 ) and the means for increasing the flexural rigidity of a basic body ( 10 ) and an outer circumference of the movable element ( 1 ) forming edge ( 14 ), which from the body ( 10 ) protrudes at an angle. Acoustic transducer according to claim 4, characterized in that the movable element ( 1 ) is formed by a layer structure, the at least one inner layer ( 11 ) and in a direction perpendicular to the inner layer (FIG. 11 ) opposite sides of the inner layer ( 11 ) outer layers ( 12 . 13 ), wherein the outer layers ( 12 . 13 ) each with a portion extending along its outer circumference ( 121 . 131 ) over the circumference of the inner layer ( 11 ) and the protruding sections ( 121 . 131 ) of the outer layers ( 12 . 13 ) are so connected and connected to each other that they from the main body ( 10 ) angled protruding edge ( 14 ) train. Acoustic transducer according to one of the preceding claims, characterized in that a surface facing away from the conversion means of the movable element ( 1 ) is provided with an elastic coating. Acoustic transducer according to one of the preceding claims, characterized in that the means for increasing the flexural rigidity comprise a curved configuration of the movable element ( 1 ), wherein the movable element ( 1 ) is arched at least approximately in the manner of a segment of a spherical surface. Acoustic transducer according to one of the preceding claims, characterized in that the conversion means comprise at least one coil ( 2 ) and the means for increasing the bending stiffness at least one stiffening layer ( 41 . 42 ), over which the coil ( 2 ) with the movable element ( 1 ) connected is. Acoustic transducer for generating and / or receiving sound waves, in particular according to one of the preceding claims, having - at least one element capable of generating sound waves or sound waves ( 1 ); Conversion means for converting an electrical signal into a movement of the movable element along a movement direction and / or for converting a movement of the movable element directed along a movement direction into an electrical signal, wherein the conversion means comprises at least four coils 2a -D) each extending along an extension plane oriented parallel to the direction of movement and arranged one behind the other such that they at least partially overlap along a direction perpendicular to their planes of extent. Acoustic transducer according to claim 9, characterized in that the coils ( 2a D) a first coil group of at least two coils connected in series ( 2a . 2 B ) and a second coil group of at least two coils also connected in series form, wherein the first and the second coil group connected in parallel to each other and via a transverse contact ( 300 ) are interconnected. Acoustic transducer according to claim 9 or 10, characterized by a first carrier ( 31 ) and a second carrier connected to the first carrier ( 32 ), with each carrier ( 31 . 32 ) are each arranged two of the coils. Acoustic transducer according to claim 11, characterized in that the first and second supports ( 31 . 32 ) via a connecting element ( 33 ) are interconnected. Acoustic transducer for generating and / or receiving sound waves, in particular according to one of the preceding claims, having - at least one element capable of generating sound waves or sound waves ( 1 ); - conversion means for converting an electrical signal into a movement of the movable element ( 1 ) along a direction of movement and / or for converting a direction of movement directed movement of the movable member into an electrical signal; - a frame ( 5 ) which at least partially surrounds the movable element; and sound absorption means for preventing an acoustic short circuit, wherein the sound absorption means along at least a portion of an outer periphery of the movable element ( 1 ) between the movable element ( 1 ) and the frame ( 5 ), wherein the sound absorbing means on the movable element ( 1 ) are only present and not connected via connecting means with this. Acoustic transducer according to claim 13, characterized in that the sound absorbing means comprises a foil ( 6 ), which on a side facing away from the transfer means of the movable element ( 1 ) is arranged. Acoustic transducer according to claim 14, characterized in that the foil ( 6 ) cohesively on the frame ( 15 ). Acoustic transducer according to claim 14 or 15, characterized in that the film ( 6 ) like a frame along the outer periphery of the movable element ( 1 ). Acoustic transducer according to one of Claims 13 to 16, characterized in that the sound-absorbing means are provided with a first section on the frame ( 5 ) and with a second section on the movable element ( 1 ), wherein the first portion of the sound absorbing means has a higher bending stiffness and / or a greater thickness than the second portion. Method for producing a movable element for an acoustic transducer, in particular according to one of the preceding claims, comprising the steps: - producing a layer structure comprising at least one inner layer ( 11 ) and outer layers disposed on each other in a direction perpendicular to the inner layer opposite sides of the inner layer ( 12 . 13 ), such that the outer layers ( 12 . 13 ) each having a portion extending along its outer circumference ( 121 . 131 ) over the circumference of the inner layer ( 11 ), - angling or bending the projecting sections ( 121 . 131 ) of the outer layers ( 12 . 13 ); and - connecting the projecting sections ( 121 . 131 ) of the outer layers ( 12 . 13 ) together. A method according to claim 18, characterized in that the bending or bending of the projecting portions ( 121 . 131 ) of the outer layers ( 12 . 13 ) By impressing the layer structure in a suitably designed recording done. A method according to claim 19, characterized in that the receptacle is shaped so that the layer structure receives a curvature in the manner of a segment of a spherical surface.

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