WO2011029872A1

WO2011029872A1 - Arrangement for displacing a displaceable element, acoustic transducer, and displaceable element for an acoustic transducer

Info

Publication number: WO2011029872A1
Application number: PCT/EP2010/063240
Authority: WO
Inventors: Werner Eymann; Andreas MÜLLER
Original assignee: Cicada Technologies Gbr
Priority date: 2009-09-09
Filing date: 2010-09-09
Publication date: 2011-03-17
Also published as: DE102009040982A1

Abstract

The invention relates to an arrangement for displacing a displaceable element, having - converting means (3) for converting an electrical signal into a displacement of the displaceable element (21-23) along a displacement direction (R) and/or for converting a displacement aligned along a displacement direction (R) of the displaceable element (21-23) into an electrical signal, wherein - the converting means comprise a coil (7) that can be connected to the displaceable element and a device for generating a magnetic field, with which the coil (7) interacts. According to the invention, the coil (7) is wound so that it extends substantially along a plane oriented parallel to the displacement direction. The invention further relates to an acoustic transducer for generating and/or receiving sound waves, having a displaceable element supported and designed to be flexurally rigid, such that when the displaceable element is displaced by means of the converting means or under the effect of sound waves on the displaceable element, no bending vibration of the displaceable element occurs.

Description

Arrangement for moving a movable element, acoustic transducer and movable element for an acoustic transducer

The invention relates to an arrangement for moving a movable element according to claim 1, an acoustic transducer for generating and / or receiving sound waves according to claim 29 and acoustic transducer according to claims 39 and 52. Furthermore, the invention relates to a movable element for an acoustic Converter according to claim 47.

From the prior art electrodynamic drives are known which have to move an element via a coil-magnet combination. For example, acoustic transducers (e.g., loudspeakers) are known that use an electrodynamic drive to move a diaphragm.

The problem underlying the invention is to provide the most efficient drive for moving a movable element, which is particularly suitable for moving planar movable elements. Furthermore, the invention is based on the problem to provide an acoustic transducer, which provides the best possible conversion quality and has the highest possible efficiency.

These problems are solved by the movable member moving device according to claim 1, the acoustic wave generating and / or receiving acoustic transducers according to claims 29, 39 and 52, and the movable transducer element according to claim 47. Further developments of the invention are specified in the dependent claims.

Thereafter, an arrangement for moving a movable member is provided with - 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 a coil connectable to the movable member and a device for generating a magnetic field, with which cooperates the coil (when current flows through the coil), wherein

- The coil is wound so that it extends substantially along a plane oriented parallel to the direction of movement.

The coil is thus not cylindrically wound like a voice coil known from conventional loudspeaker construction, but along a plane and extends in particular flat. However, this does not necessarily mean that the coil has to be wound in one layer, but several windings can be provided on top of each other, i. the coil may well have a certain thickness perpendicular to the plane along which it extends mainly (main plane of extension), but this thickness is small compared to the dimensions of the coil along the main extension plane. By orienting the coil parallel to the direction of movement it is e.g. possible to move larger areas of a movable element over the coil. For example, the coil can be used to move a (in particular flat) diaphragm of a loudspeaker, i. the arrangement according to the invention is used as a loudspeaker drive. However, the arrangement according to the invention is not limited to use as a loudspeaker drive. Rather, other applications are conceivable, e.g. as a linear adjuster (for example for adjusting a table top) or as a drive of a cooling device, which has a movable element which is moved to produce a cooling air movement over the arrangement according to the invention.

Moreover, it is possible to align the coil (the coil windings) substantially completely parallel to the magnetic field generated by the conversion means, whereby wobble coils that in a cylindrically wound coil due to the inevitably oblique orientation of the coil windings (or at least some of the coil windings) for Magnetic field can occur, can be avoided. This plays a role in particular when using the arrangement according to the invention as a loudspeaker drive. In one embodiment of the invention, the coil (the coil winding) has a first and a second longitudinally extending portion, wherein the first and the second portion spaced and in particular also parallel to each other, wherein the means for generating a magnetic field is formed so that the of their generated magnetic field passes through the first section in a first direction and the second section in a second direction opposite to the first direction.

The first and second sections are interconnected and, in particular, represent two sections of electrical conductor. In addition, they are arranged to flow in opposite directions from a current flowing through the coil. However, since the magnetic fields (or the areas of a magnetic field) acting on the first and the second portion, respectively, are directed opposite to each other, the coil experiences a force parallel to its Haupterstre- ckungssebene when it is flowed through by a current.

The device for generating a magnetic field comprises, for example, at least one permanent magnet and / or one electromagnet, which generates a stationary magnetic field, so that the magnetic field generated by current flow through the coil in the region of the coil interacts with the magnetic field of the magnet and movement of the coil and so that the movable element is generated relative to the magnet.

For generating a magnetic field passing through the first portion of the coil in one direction and the second portion in an opposite direction, the device for generating a magnetic field, e.g. a first and a second longitudinally extending permanent magnet, the poles of each extending along its longitudinal direction, that the transition region between the poles also extends along the longitudinal direction, wherein the permanent magnets are arranged so that the two poles of the first permanent magnet along a direction transverse to Longitudinal direction each opposite to an oppositely poled pole of the second permanent magnet.

By way of example, the permanent magnets are bar magnets whose poles each extend along the longitudinal axis and over the entire length of the respective bar magnet. It is, as mentioned above, of course, also possible to use an electromagnet instead of at least one of the permanent magnets, wherein the longitudinal direction of the electromagnet is determined in particular by the longitudinal direction of its core. In particular, the magnets are to be arranged relative to the movable element such that one pole (eg the north pole) of the first permanent magnet faces the movable element, while the pole of the second permanent magnet facing the movable element has opposite polarity (eg south pole). However, the invention is not limited to the exclusive use of such bar magnets. Other magnets (in particular a plurality of magnets) may also be provided which are used in place of the bar magnets to generate the described magnetic field (which passes through the two coil sections in opposite directions).

The first and second permanent magnets may also each include a first pole piece extending along the first pole of the respective permanent magnet and a second pole piece extending along the second pole of the respective permanent magnet. For example, the pole piece extends transversely to the longitudinal extension direction of the respective permanent magnet beyond the permanent magnet.

The first section of the coil runs, in particular, in the magnetic field formed by the first pole of the first permanent magnet and the opposite first pole of the second permanent magnet, while the second section of the coil extends in the second pole of the first permanent magnet and the opposite polarity Pol formed magnetic field of the second permanent magnet. Of course, it is also conceivable that no pole shoes are used, wherein the geometry of the magnetic field is adjusted by the geometry of the permanent magnet itself.

For example, the first and the second portion of the coil each extend in a gap between a pole piece (and / or a pole) of the first permanent magnet and a pole piece (and / or a pole) of the second permanent magnet, wherein the magnetic field between the pole pieces and / or In particular, the pole is substantially homogeneous and the main extension plane of the coil is perpendicular to the magnetic field between the pole shoes or poles. The device for generating the magnetic field thus has no core around which the coil is wound. According to a further embodiment, the coil (in plan view) is rectangular, wherein the longer sides of the coil form the first and the second section. However, the rectangular shape is not mandatory, but the coil can in principle also have a deviating from the rectangular shape geometry, eg circular or elliptical. In addition, the coil may be arranged in or on a bobbin holder. For example, the coil holder is designed in the form of a printed circuit board on which the coil is arranged. Here it is conceivable that the coil has conductor tracks which are arranged on the printed circuit board (for example vapor-deposited or printed). However, it is also possible that the coil comprises a wound electrical conductor which is placed on the circuit board and fixed to it.

According to a development, the coil holder has a first section (eg in the form of the printed circuit board mentioned), or in which the coil is arranged, and a second section which extends at least approximately perpendicular to the first section and which is connectable to the movable element , on, ie the bobbin holder is designed substantially T-shaped. The first and second portions of the bobbin holder are e.g. initially formed as separate elements which are connected to each other (in particular by material bonding, for example by soldering or gluing). More specifically, the bobbin holder is connected to the movable member (e.g., in the form of a flat speaker diaphragm) via the second portion.

The bobbin holder is, for. B. in one piece and / or as rigid as possible, e.g. Carboniferous (about carbon fiber reinforced) material manufactured. The coil is e.g. wound from baked enamel wire and may, as mentioned, embedded in the coil holder (such as welded or cast) or arranged in a recess of the coil holder. The embedding of the coil in or on a rigid material counteracts bending of the coil during operation of the acoustic transducer, so that frequency deviations, internal friction, radiation direction errors and thus efficiency and quality losses of the acoustic transducer can be reduced or avoided.

According to another embodiment of the invention, the arrangement comprises a fastening element, via which the coil holder is connected to the device for generating a magnetic field, for example by material bonding. In particular, the fastening element is designed such that it impedes movement of the bobbin holder and thus the bobbin in the direction of movement (ie along the main direction of extension of the bobbin) as little as possible (at least in a predefinable deflection region), but at the same time counteracts a movement transverse to the main extension direction of the bobbin , ie acts as a centering element. At the same time, as mentioned, the bobbin holder can be connected to the movable element (eg flat loudspeaker membrane), wherein the Storage of the movable element, for example, exclusively on the bobbin holder takes place (see below).

For centering the bobbin holder between the permanent magnets (or the pole shoes of the permanent magnets), a first portion of the fastener with the first pole piece (or the first permanent magnet, if no pole piece is provided) and the bobbin holder and a second portion of the fastener with the second Pole (or permanent magnet) and the coil holder to be connected, wherein the first and the second portion at least approximately symmetrically with respect to the (in particular along a main extension plane extending ne and formed, for example in the form of a circuit board) coil holder.

The fastener is e.g. an elongate element (in particular a wire) passing through an opening of the coil holder and having a first end on the first permanent magnet (or a pole piece of the first permanent magnet) and a second end with the second permanent magnet (or a pole piece of the second Permanent magnet) is connected. Here, the portions of the fastener between the bobbin holder and the respective permanent magnet (or pole piece) are oriented, in particular, approximately equally long and at the same angle to the bobbin holder (i.e., to the plane along which the bobbin extends).

According to another variant, the fastening element is a circular, flat element with a recess in the form of a circular sector, wherein the planar element is oriented transversely to the plane along which the coil extends, and is inserted with a portion in a slot of the coil holder, that the radially extending, the recess bounding sides of the flat element extending symmetrically to the coil holder. These sides of the planar element thus enter into the slot of the bobbin holder at the same angle. For example, the flat element is made of a flexible material, e.g. a tissue formed.

The invention also relates to an acoustic transducer for generating and / or receiving sound waves, comprising an arrangement according to any one of the preceding claims and a movable element coupled to the coil so as to be set in motion for generating sound waves via the conversion means or via the conversion means, a movement of the movable element into an electrical signal can be implemented. The coil is in particular connected via fastening means with the movable element, wherein this connection can be made in particular indirectly, for example via an already mentioned coil holder on which or in which the coil is arranged. In principle, it is also conceivable for the coil to be arranged stationarily on a mounting device (for example a frame or a rear wall) of the transducer and the device for generating a magnetic field (eg in the form of permanent magnets and / or electromagnets) on the movable element are.

As already mentioned above, it is possible for the coil to be substantially single-layered, whereby its inductance is lower compared to multilayer coils. Lower inductance leads to lower resonance (self-oscillation) of the coil and thereby to increased efficiency in the transformation of electrical into acoustic energy. In one example, the coil is wound from a wire of a maximum of 5 m. Furthermore, the coil may be arranged so that only small deflections of the movable element occur such that the coil does not substantially move out of a homogeneous region of the stationary magnetic field.

In another embodiment of the invention, means for dissipating heat are arranged in the region of the coil, for example in the form of a ferrofluid. The arrangement of a ferrofluid is made possible, in particular, by a planar design of the movable element, since no displacement of the ferrofluid occurs due to the relatively small deflections of the movable element that occur. A good heat dissipation from the coil can also be achieved by the material of the bobbin holder and / or by a chimney effect of a recess of the bobbin holder, in which the coil is arranged.

The ferrofluid moves independently in the range of the strongest magnetic forces (strongest field lines) and is characterized in particular by the fact that it is fluid due to the selected grain size without carrier solution.

In addition, the coil may be disposed relative to the magnetic field generating device so that no friction occurs between the coil and the device (e.g., a permanent magnet).

In particular, the acoustic transducer has a plurality of devices for generating a magnetic field, wherein these devices each at least one with associated coil is associated with the movable element, that is, there are a plurality of coils. For example, a device for generating a magnetic field (eg, a permanent magnet or electromagnet) may also be assigned to a plurality of coils. The plurality of coils are in particular arranged in a grid, wherein the number of coils (and the associated devices for generating a magnetic field) depends in particular on the size of the movable element. The coils are operated in parallel, for example, but also a series connection of at least some of the coils is conceivable. Several, arranged at different locations of the movable element support coils in particular allow a possible bending vibration-free moving the movable element. At the same time tilting of the movable element can be prevented by the arrangement of several magnet coil combinations. The movable element is formed, for example, flat (approximately in the form of a plate), ie it extends, for example, substantially along a main plane of extension, wherein the direction of its smallest extension is perpendicular to this main extension plane. In particular, the coil is oriented so that its main extension plane is perpendicular to the movable element. The fact that the movable element is formed "flat", does not necessarily mean that it extends plan (ie along a plane), but it may well be at least partially curved (see below).

A transducer having such a planar movable element can for example be integrated in a wall, a piece of furniture or an electronic device (eg television or mobile phone) or arranged on these elements. Also, such a movable element could serve as a projection surface for the image of a projector. In another example, the converter according to the invention is integrated in a picture display device (in particular in the form of a display of an electronic device), wherein a transparent front screen of the picture display device simultaneously forms the movable element of the converter. For example, the movable element here is small, in particular with side lengths that do not exceed 10 cm or 15 cm, respectively. For example, the movable element (in plan view) is rectangular, for example with the dimensions of at least 60 cm x at least 60 cm (in particular 60 x 60 cm). In In another variant, the movable element is rectangular with side lengths of up to 40 cm or 60 cm, in particular 60 x 40 cm, formed.

For example, the movable member has a thickness (i.e., an extent perpendicular to its main plane of extension) of less than 2 cm, more preferably less than 5 mm, or more preferably less than 3 mm. However, a rectangular shape of the movable element is of course not mandatory, but in principle any shapes are conceivable, depending in particular on the intended application of the transducer, for example, the movable element may also have an elongated shape or at least partially spherical in shape ,

In contrast to conventional cone-shaped membranes, a large effective area can be realized in a simple way with a movably configured planar element, so that a comparatively high sound pressure can be generated with a small deflection (stroke) of the movable element.

In particular, when using a flat movable element, a coil which is conventional in comparison with coils (measured in the direction of movement of the movable element) can be used. This is possible because a larger amount of air can be moved across the larger effective area of the planar movable member than with a circular conventional loudspeaker, so that a comparable sound pressure (i.e., volume) can be generated with less displacement of the movable member. Lower deflections, in turn, allow the use of one (or more) shorter coils.

It is also conceivable that the coil is operated by induction. For example, for this purpose, an electrical line can be arranged in the region of the coil, for example on a wall, when the acoustic transducer is attached to a wall.

In particular, the movable element is moreover arranged and arranged such that it predominantly or exclusively excites parallel sound waves. In particular, flat sound waves are generated, which can provide a distortion-free sound image, for example, compared to the waves excited by conventional point loudspeakers (eg cone speakers). In particular, the predominant excitation of plane sound waves by the rigid design of the movable element and its (as free) mobility (ie in particular by its storage, the example on a connection of the edge of the movable element with a frame omitted (see below)).

In addition, the wave amplitude (i.e., the volume) of planar sound waves decreases less than sound waves generated by a spotlight.

According to a further embodiment of the invention, the movable element is mounted so that the entire movable element is movable along an excitation direction and thus can be displaced into a piston-like movement via the conversion means or by sound action.

For example, the movable element is formed flat and stored so that the entire movable element, including its entire edge region, in a direction perpendicular to its main extension plane movable and thus via the Umsetzmittel or by sound action in a piston-like movement perpendicular to the main extension plane is displaceable. The edge of the movable element, i. the outer contour of the sides of the movable element extending along the main plane of extension is also movable perpendicular to the main plane of extension and not e.g. fixed to a mounting device of the transducer. For example, there is no connection of the edge region of the movable element to a mounting device or any other element of the transducer and the transducer is also to be mounted so that the edge region is freely movable.

Thus, storage of the (planar) movable element along the side edge (i.e., a bead) is dispensed with, so that there is no connection via fastening means between the edge of the movable element and a frame surrounding the movable element.

However, it is possible for a device to be provided in the edge region of the movable element which closes a gap between the movable element and a mounting device (eg in the form of a frame) of the acoustic transducer but which perpendicularly moves the edge region of the movable element not obstructed to its main extension plane. For example, a sound absorption means for avoiding an acoustic short circuit is arranged between the edge of the movable element and the movable element at least partially surrounding the frame movable element and / or the frame but only rests and is not connected via fastening means to the movable member and the frame. In one variant, the sound absorption medium comprises at least one porous absorber and / or at least one closed-pore nonwoven fabric. It should be noted that the configuration according to which the side edge of the movable element is not mounted on the frame, but can only be realized by a membrane drive, and independently of the flat design of the coil of the conversion means, for example, with a conventional loudspeaker drive. A frame or other component of the acoustic transducer of the movable element may also have attachment structures for securing the movable element to a wall. In particular rearward sound can be dissipated by means of a wall attachment, wherein the wall itself is hardly excitable by the sound and thus disturbances due to the sound dissipation are as far as possible avoided.

The formulation according to which the sound absorbing means abuts on the "movable element" also includes the possibility that the sound absorbing means abut indirectly on the movable element, i.e. the movable element is connected to further structures against which the sound absorbing means abuts.

Furthermore, the movable element can be mounted so that after deflection of the movable element only a negligible restoring force occurs. This will e.g. a ringing of the movable element, e.g. occurs in a membrane of a conventional speaker and thus unwanted sound generation, avoided.

The mounting of the movable element is in particular designed such that although a movement perpendicular to the main extension plane is possible for sound generation or sound recording, it is counteracted to move the movable element in a direction parallel to its main extension plane. Examples of the realization of such storage will be explained below.

According to another variant of the invention, the movable element is mounted so that different areas of the movable element are movable in phase, but with different rather deflection. For example, the movable element is pivotally coupled to a support device (eg in the form of a frame) of the acoustic transducer. Thus, the movable element for generating sound can be a Swivel axis wing-like back and forth. This can in particular - in the embodiment of the transducer as a loudspeaker - cause a particularly spatial sound impression. For example, the movable element is rectangular in plan view, wherein one of the sides of the rectangle is hingedly coupled to the support means. For example, a hinge (eg, integral) is provided which extends between the movable member and the support means over at least a portion of the length of said side of the movable member. It should be noted, however, that this variant of the invention is not limited to the rectangular design of the movable element, but the movable member may also have a basically any contour, for example, circular or oval, with a portion of the contour hinged to the Holder device is coupled. In another embodiment of the invention, the acoustic transducer has a first (eg planar) movable element, which is pivotally coupled to a mounting device, and a second movable element, which is completely linear along an excitation direction, ie piston-like, movably mounted. For example, the two movable elements are mounted so that they extend in a rest position in a common plane. In a variant, the movable elements are mounted on a common frame.

According to a further variant, two movable elements are provided, which are each pivotally connected to a mounting device, and which are arranged on mutually opposite sides of a linear (piston-like) movable element.

According to another embodiment, a plurality of movable, in particular flat trained, elements are provided which are mounted independently movable. For example, each of these movable elements is mounted so that it is linearly movable. However, a combination of a plurality of pivotally mounted movable elements with a plurality of linearly movably mounted movable elements is also conceivable. The movement of the movable element excited by the conversion means or triggered by the action of sound is effected, in particular, in a forward direction and in a direction opposite to the forward direction, depending on the mounting of the movable element. Direction oriented reverse direction, ie, for example, linear along a forward and backward direction or with pivotable mounting of the movable member in a forward direction of rotation and an opposite reverse direction of rotation. The acoustic transducer has, for example, deflection means which deflect at least a part of the sound waves generated by the movement of the movable element in the backward or reverse direction.

In particular, by moving the movable element, first sound waves are generated, which propagate along a forward propagation direction perpendicular to the movable element or, in the case of pivotable mounting of the movable element, approximately perpendicular to the movable element in the rest position relative to a planar configuration of the movable element. In addition, second sound waves are generated, which propagate along a reverse propagation direction opposite to the forward propagation direction. For example, the deflection means are designed to cover at least part of the second sound waves in the direction of the first sound waves, i. in Forward propagation direction, divert.

According to this variant of the converter, e.g. A loudspeaker can be created which redirects the sound radiated to the "back", ie in a direction away from the listener, at least partially towards the front, ie towards the listener.This at least partial utilization of the sound emitted to the rear can for example result in improved efficiency of the speaker.

In one embodiment, the deflection means have at least one opening in a frame and / or a housing of the acoustic transducer. In particular, the acoustic transducer is designed such that the sound waves propagating in the rearward propagation direction emerge from the frame and / or the housing in such a way that they overlap substantially in the correct phase with the sound waves excited in the forward propagation direction.

In addition, the acoustic transducer may also comprise means for wirelessly receiving the electrical signal to be converted to sound waves via the conversion means and the movable element. According to a second aspect of the invention, there is provided an acoustic transducer for generating and / or receiving sound waves, comprising

- An element for generating sound waves or by sound waves movable element; and - Conversion means for converting an electrical signal into a movement of the movable member and / or for converting a movement of the movable member into an electrical signal, wherein

- The conversion means are arranged and the movable member is mounted and rigidly formed such that upon movement of the movable member via the Umsetzmittel or upon the action of sound waves on the movable member substantially no bending vibrations of the movable member occur.

In other words, it is avoided that the movable element vibrates in itself, i. that different areas of the movable element move relative to each other. Rather, the entire movable element is moved closed, i. all sections of the movable element are moved simultaneously and in phase. The in-phase movement of all sections of the movable element makes it possible to realize an acoustic transducer (for example in the form of an area loudspeaker) which provides a particularly distortion-free sound image.

At the same time, the acoustic transducer has a particularly high efficiency by avoiding bending vibrations, d. H. that z. B. a greater part of the energy used to move the movable element of the transducer energy is used to generate sound waves. This is particularly due to the fact that a mutual movement of different portions of the movable element, i. "Partialschwingungen" of the movable element, is avoided, so that a large amount of air can be moved in phase or that the movable element can be moved by a large amount of air.Moreover, by avoiding bending vibrations destructive interference of sound waves through The partial oscillations occurring in a conventional loudspeaker diaphragm also change with frequency, so that the partially destructive interference of the sound waves produced with the partial oscillations leads to a frequency-dependent volume of an acoustic signal reproduced by the diaphragm be avoided with the transducer according to the invention.

In particular, a "rigid" (rigid) movable element is a movable element to understand that when excited by the Umsetzmittel or in case of sound from the outside at best performs negligible bending vibrations whose amplitude is so low and / or their frequencies outside the interest Range (in particular the audible range of 15 - 20,000 Hz), so that they have an influence on the sound conversion. In particular, the natural frequencies of the movable element are outside the audible range.

In one example, the movable element comprises a material or is formed from such a material, which has a modulus of elasticity of at least 30 GPa, in particular of at least 60 or in particular of at least 100 GPa. For example, the material has a modulus of elasticity of approximately 130 GPa. As a material for the movable element is for example glass, plastic, metal and / or a fiber-reinforced material in question. Further examples will be explained below.

In particular, the movable element is arranged (eg stored) and formed so rigid that bending vibrations of the movable element are avoided when it is moved at a frequency of 5,000 Hz, that is, when it is excited to oscillations of this frequency or sound waves of this frequency on the movable element act. Furthermore, the movable element can be designed so that bending vibrations are avoided over a large part or over the entire audible frequency range, for example over a frequency range between 100 and 15,000 Hz. As a measure of the flexural rigidity of the movable element is in particular the product of modulus of elasticity E of the material of the movable element and its area moment of inertia I (relative to a direction perpendicular to the main extension plane of the movable element) understood. For example, the movable element has a flexural rigidity (with respect to a direction perpendicular to its main plane of extent) of at least 100 Nm ² , in particular of at least 300 Nm ² or of at least 500 Nm ² .

In particular, the movable element has a rough or porous surface and comprises, for example, an electrically non-conductive material, a fiber-reinforced material, carbon, a rigid foam (eg Rohacell) and / or a lignin. By way of example, the movable element is realized in the form of a layer structure comprising at least one layer of rigid foam and at least one layer of a carbon fiber reinforced material. However, it is also possible to provide more than two layers of rigid foam and carbon fiber-reinforced material, the layers being arranged alternately in particular. It is also possible that the movable element has at least one raised area, in particular in the form of a strut, which increase the flexural rigidity of the movable element. For example, the area runs along a (in particular straight) line. The raised area can be formed integrally with the movable element (eg by embossing and / or bending forming). However, it is also conceivable that by material structures (eg made of carbon, balsa wood, metal, etc.), which are connected to the movable element (in particular cohesively, for example by gluing). In addition, it can also be provided that the movable element has a curvature, which increases its flexural rigidity. It is conceivable here that the movable element is bent along at least one straight line, ie has at least one curvature line. However, it is also possible that the entire movable element is curved, that is formed as a segment of a spherical surface.

It should be noted that the acoustic transducer of the second aspect of the invention can also be combined with the embodiments described above in relation to the first aspect of the invention, in particular the movable element and / or its mounting and / or the conversion means, without the coil the conversion agent must necessarily extend along a plane parallel to the direction of movement.

In a third aspect, the invention relates to an acoustic transducer, in particular as described above, with

- An element for generating sound waves or by sound waves movable element;

- Conversion means of an electrical signal in a movement of the movable member and / or for converting a movement of the movable member into an electrical signal; and

- means for supporting the movable element, via which it is movably mounted on a holder device of the acoustic transducer, wherein

- The movable element is pivotally coupled via the means for supporting with the support means or the means for supporting the movable member spaced apart to an outer periphery of the movable member are arranged, so that the entire movable member is linearly movable.

Accordingly, the movable element is pivotally (rotatably) coupled to the support device about a pivot axis, so that the entire movable element about the Swivel axis can be pivoted. The pivot axis extends in particular along a portion of an outer circumference of the movable element. In particular, the movable element is designed to be sufficiently rigid, so that during a pivoting movement or a linear movement of the movable element, this essentially performs no bending oscillations.

In particular, the movable element is formed flat and the means for supporting the movable element are e.g. formed in the form of a hinge which pivotally couples a (narrow) side of the movable member to the support means of the transducer.

According to another variant, the means for storing are arranged at a distance from an outer contour (edge) of the (areally configured) movable element. This is in particular such that the entire edge or at least a portion of the edge of the movable element is movable in the sound generation direction (i.e., perpendicular to the main extension plane of the planar movable element).

According to a further variant of the invention, the means for supporting the movable element comprise a device for exerting a magnetic force, via which the movable element is mounted on the mounting device. The mounting device is z. Example, a frame which surrounds the movable element with a portion and in particular spaced from the movable element, wherein another, for example web-like portion of the frame is used for mounting of the movable element. By way of example, other components of the acoustic transducer are also arranged on this frame (or on structures connected to the frame), e.g. B. a device (such as a permanent magnet) for generating a magnetic field that belongs to the conversion means. In addition, the mounting device may also have structures over which the transducer attached, eg suspended on a wall can be. The means for supporting the movable member by magnetic force include, for. Example, a first magnetic element which is arranged on one of the support means facing side of the movable element, and at least a second (eg attached to the support means) magnetic element which cooperates with the first magnetic element and thus the storage of the movable element Be acts. In particular, the magnetic elements are designed and arranged such that a movement of the movable element transversely to its main extension plane is possible, however, a movement in one direction along the main extension direction is counteracted.

As already described above, the conversion means comprise at least one device for generating a magnetic field and at least one coil connected to the movable element and cooperating with the device for generating a magnetic field. In another embodiment of the second variant of the invention, the device for generating a magnetic field and the coil are simultaneously part of the means for supporting the movable element, so that the movable element is supported by the magnetic field generated by the device for generating a magnetic field and the coil becomes. Examples of this embodiment have already been discussed above for a coil oriented along a surface.

For example, in addition to the device for generating a magnetic field and the coil or a plurality of devices and corresponding to a plurality of coils, no further elements for supporting the movable element are provided, d. h., The movable member is supported solely by the magnetic field generated by the magnetic field generating device and by the coil. For example, the device for generating a magnetic field, for. B. a permanent magnet, mounted on the support means of the acoustic transducer, in particular connected to the support means.

However, the means for supporting the movable element need not necessarily be designed for magnetic storage. For example, the means for storing may also include mechanical structures for supporting the movable element, e.g. a guide mechanism that allows movement of the movable member in the sound generation direction, however, counteracts a movement transversely to the sound generation direction. It is also possible that the magnetic and mechanical bearings are used in combination.

The invention also includes a loudspeaker or a microphone (or a combination of both) with an acoustic transducer as described above.

Furthermore, the invention relates to a movable element for an acoustic transducer, in particular as described above, for generating and / or receiving sound waves having a layer structure having at least a first and a second layer, wherein the first layer is more rigid than the second Location is and the second layer has a higher (mechanical) damping factor than the first layer, ie mechanical vibrations are attenuated by the second layer more than by the first layer. For example, the first layer comprises a fiber-reinforced material (in particular a carbon fiber-reinforced material) (or is formed from such a material) and the second layer of a rigid foam, in particular Rohacell. In particular, the layer structure has a plurality of alternating first and second layers, for example a plurality of alternating layers of a fiber-reinforced material and a rigid foam.

In another aspect of the invention, the movable element comprises a first material, which need not necessarily be formed as a layer, and a second material, which is also not necessarily designed as a layer. The first material is more rigid than the second material, while the second material has a higher damping constant than the first material.

However, it is also conceivable that the movable element of the acoustic transducer has no layer structure, but only consists of a single layer. For example, this layer may be a solid foam, e.g. a carbon foam and / or a metal foam (in particular a nickel foam) or consist of such (or any other) solid foam. This embodiment of the movable element is particularly suitable for small dimensions of the movable element, e.g. with a movable element with an area of up to 10 cm x 10 cm. Movable elements that are planar and formed with such small areas are particularly suitable when using the acoustic transducer in portable devices such. a mobile phone or an MP3 player.

Furthermore, the invention relates to an arrangement for moving a movable element of an acoustic transducer, with a coil that is wound so that it extends substantially flat. For example, the coil is formed as already described above; For example, the coil is embedded or arranged in a coil holder, wherein the coil holder in particular has a fiber-reinforced (eg carbon fiber reinforced) material. The invention is explained in more detail below with reference to embodiments with reference to the figures. Show it: Fig. 1 is a plan view of an acoustic transducer according to a first embodiment of the invention;

FIGS. 2 to 5 are views of an acoustic transducer according to FIG. 1;

6 is a perspective view of an acoustic transducer according to a second embodiment of the invention;

Fig. 7 is a perspective view of a movable member of an acoustic transducer according to a third embodiment of the invention;

Fig. 8 shows a cross section of a movable element according to Figure 7 with a

Layer structure according to an embodiment of the invention; 9 shows schematically an embodiment of the arrangement according to the invention;

Fig. 10 shows schematically a further embodiment of the invention

Arrangement; Fig. 1 1 A, 1 1 B further views of the arrangement of Figure 10;

12A, 12B show a first embodiment of fastening elements for a connection of a bobbin holder with pole pieces of an arrangement according to the invention; FIGS. 13A, 13B show a second embodiment of the fastening elements;

14 shows a third embodiment of the fastening elements;

FIGS. 15A-15E variants of a sound absorption medium;

Fig. 16 plate-shaped movable elements with struts; and

Fig. 17 is a formed as a segment of a spherical surface movable element. FIG. 1 shows schematically an inventive acoustic transducer in the form of a loudspeaker 1. The loudspeaker 1 has three movable elements arranged adjacent to one another in the form of movably mounted, rectangular plates 21-23. The Plates 21-23 each replace a diaphragm of a conventional loudspeaker and are moved in response to an electrical signal carrying acoustic information. By moving the plates 21-23 sound waves are excited so that the acoustic information transmitted by the electrical signal becomes audible.

The plates 21-23 are in particular so rigid that they do not perform bending vibrations when they are moved to generate sound in order to achieve a trouble-free reproduction of the acoustic signal as possible. For moving the plates 21 to 23, an arrangement 10 according to the invention is provided for moving 10, the conversion means in the form of a plurality of magnet coil combinations 3 is provided, which transmits the electrical signal transmitted to the conversion means in a reciprocating movement of the plates 21 to 23 implement. The magnet coil combinations 3 are arranged on a rear side of the plates 21 to 23, which faces away from the listener when the loudspeaker 1 is in operation.

One of the plates (plate 22) is centered between the two other plates 21, 23 and supported so as to extend completely, including its edge, in a direction perpendicular to its main plane of extent (along which the front and back facing the listener in use) the remote from the listener rear of the plate 22 extends) piston-like manner when it is excited via the magnet coil combinations 3.

The coils of the magnet-coil combinations 3 are wound so as to each extend along a main plane of extension which is oriented parallel to the direction of movement of the plate 22 produced (i.e., perpendicular to the plate 22).

On the other hand, the two lateral plates 21, 23 are each pivotably connected to a holding device (not shown in FIG. 1) via a side 21 1, 231 facing the middle plate 22. The remaining three narrow, perpendicular to the front and back of the plates 21, 23 extending sides of the outer plates 21, 23, however, are freely movable, so that the plates 21, 23 at excitation by the magnet coil combinations 3 each one at least approximately along the central plate 22 facing side 21 1, 231 extending axis of rotation are pivoted and each perform a wing-like pivoting movement about these axes of rotation. The middle plate 22 is, in order to allow a linear, piston-like reciprocating movement of the entire plate 2 perpendicular to its main extension, not connected via its edge region or with another area fixed to the mounting device of the speaker. The storage of the middle plate 22 is via means for storage, which are positioned at a distance from the edge of the plate 22. According to the embodiment of Figure 1, arranged on the plate 22 magnetic coil combinations 3 at the same time also means for supporting the plate, the plate 22 is stored in particular exclusively on the magnetic field generated by the magnetic coil combinations 3 arranged on it , This support on the one hand allows the freedom of movement of the plate 22 in a direction perpendicular to its main plane of extent and at the same time counteracts slippage of the plate in a direction parallel to its main extension plane.

Although the externa ßeren plates 21, 23 are to a certain extent also supported by the magnetic field of each arranged in their area magnet coil combinations 3, but they are additionally connected via a pivot bearing with the support means, as described above.

The middle plate 22 is particularly designed and stored so that it serves for exciting high-frequency sound waves as the two externa ßeren plates 21, 23, d. H. the middle plate 22 serves as a tweeter of the loudspeaker 1, while the outer plates 21, 23 realize middle and woofers of the loudspeaker. The middle plate 22 also has a small area than the two externa ßeren, pivotally mounted plates 21, 23. In a (not shown) variant, the externa ßeren plates are stored so that they like the middle plate a piston-like movement (and no Swivel movement). For this purpose, it is sufficient, for example, if in each case two coils are arranged in the region of the outer plates. The coils are in particular arranged one behind the other so that they extend in a common plane. This plane is parallel to two opposite sides of the respective plate and approximately centrally with respect to the other two sides of the respective plate.

FIGS. 2 to 5 show further views of a loudspeaker 1 according to FIG. 1, wherein the loudspeaker is shown in a perspective view in each case. FIG. 3 shows a section through the loudspeaker of FIG. 2. FIG. 5 shows a partially transparent representation for the purpose of illustrating the loudspeaker 1. The in Figs. 2 to 5 shown speaker corresponds to the number of magnet coil combinations, the speaker of FIG. 1st

According to e.g. 3, the loudspeaker 1 has a support device comprising a frame 4 surrounding the plates 21-23. The frame 4 is arranged at a distance from the frame 4 facing sides of the plates 21-23, so that these sides of the plates are not fixed to the frame 4, but are mounted freely movable. Between the frame 4 facing sides of the plates 21-23 and an inner periphery of the frame 4 facing the plates 21-23 there is thus a gap (e.g., air-filled) extending, in particular, along the entire inner circumference of the frame.

The storage of the plates 21 -23 is carried out, as already explained above, via the hinge-like connection of the externa ßeren plates 21 -23 with the support means (eg, connected to the frame 4 web), on the magnetic field of the magnet coil combinations. 3 for exciting a movement of the plates 21-23 and / or via a connection of the coils of the magnet-coil combinations 3 with the respective plate. An enlarged view of one of the coil-magnet combinations 3, of which the permanent magnets 61, 62 are part, is shown in FIG. 4.

The magnet-coil combinations 3 each comprise a device for generating a magnetic field in the form of first and second longitudinally extended permanent magnets 61, 62, which run parallel to the plate 21. The permanent magnets 61, 62 each have a first and a second pole piece 61 1, 612 and 621, 622 for distributing the magnetic field generated by the magnets, wherein the first pole pieces 61 1, 621 each arranged on one side of the associated permanent magnet are, which faces the plate 21. The second pole pieces 612, 622 are arranged on the sides of the magnets 61, 62 facing away from the plates 21. The permanent magnets 61, 62 are arranged such that their respective poles 613, 614 or 623, 624 extend along their longitudinal axis and over their entire length, ie one pole 613, 623 in each case faces the plate 21, while the other pole 614, 624 of the plate 21 are turned away. The coils 7 of the magnet coil combinations 3 are each arranged in a gap 51 between the permanent magnets 61, 62 and the pole shoes so that a first section 71 of the coil 7 (which, as shown, quite sections of several Wiek- the pole (61) facing in the region of the upper (ie the plate 21 facing) and the poles 613, 623 extends, while a second portion 72 in the region of the lower (ie the plate 21 facing away) pole pieces 612, 622 and / or poles 614, 624.

The permanent magnets 61, 62 are further arranged such that the poles (i.e., the upper and lower poles) opposite each other transversely to the longitudinal direction of the magnets 61, 62 each have an opposite polarity, e.g. The upper pole 613 of the first magnet 61 is the north pole, while the upper pole 623 of the second magnet is the south pole (or vice versa). Accordingly, the lower poles 614, 624 are polar oppositely to each other. Since the current through the first portion 71 of the coil 7 is directed opposite to the current in the second portion, the coil 7 undergoes a current perpendicular to the magnetic field generated by the magnets 61, 62 and thus a movement in a current flow through the coil Direction perpendicular to the plate 21st

The magnets 61, 62 and the pole shoes are also arranged parallel to one another, that the upper and lower poles and pole shoes each opposite to a direction transverse to the main extension plane of the coil and in the region of the first and second portions 71, 72 of the coil 7 at least approximately homogeneous magnetic field is created. This magnetic field extends at least approximately parallel to the plate 21.

The coil 7 is located in a recess 81 of a T-shaped coil holder 8, i. the coil holder 8 has a first portion 82 in which the recess 81 is located, and a second portion 83 which is perpendicular to the first portion 82 and approximately parallel to the movable plate 21 on.

The bobbin holder 8 is connected via its second portion 83 with the plate 21, wherein this compound is produced for example via an adhesive. The movement of the coil 7 produced by current flowing through the coil 7 is passed through the connection of the coil holder 8 with the plate 21 thereto, so that the plate 21 relative to a holding device, with which the magnets 61, 62 are connected, in a Pivoting movement is offset. This pivotal movement, as mentioned, generates sound waves, whereby the acoustic information of the electric signal flowing through the coil 7 becomes audible. In an analogous way, those in the range of the two their plates 22, 23 arranged magnetic coil combinations, the plates 22, 23 in motion.

It is understood that the invention is not limited to a certain number of movable plates and / or magnet-coil combinations. Thus, for the reproduction (or recording) of acoustic information, for example, only a movable plate can be used, which is not stored for example over its edge, but only on the magnet coil combinations. Furthermore, z. B. also conceivable that a single plate is used for the speaker, which is pivotally coupled at one of its narrow sides with a mounting device to allow a wing-like movement of the plate. Such an example is shown in FIG. Here, a loudspeaker 1 according to the invention comprises a substantially rectangular plate 21. The plate 21 is hingedly coupled at one of its longer sides 21 1 to a mounting device so that the plate 21 can be excited to oscillate about an axis of rotation approximately parallel to the side 21 1. The excitation of the plate 21 is carried out as in the embodiment described above on not shown in Figure 6 magnetic coil combinations.

FIG. 7 schematically shows a movable element of an acoustic transducer according to the invention in the form of a rectangular plate 21. On the plate two coils 7 are arranged, which are each located in a coil holder 8, as described above, for example. has already been described with reference to FIG. The bobbin holders 8 are arranged parallel to a pair of opposite sides of the plate 21 and spaced from the sides of the plate 21 (eg, centered with respect to at least one of the sides of the plate 21), with each first portion 82 of the bobbin holders 8 being vertical is aligned with the main plane of extension of the plate 21. The second portion 83 of the coil holder 8, which is perpendicular to the first, approximately rectangular portion 82, is respectively parallel to the main plane of extension of the plate 21 oriented embedded in the plate 21; see. Fig. 8.

In the present example, the plate 21 has an area of about 380 mm x 280 mm and the bobbin holders 8 have a length L of the longer sides of the bobbin holder section 82 (which run parallel to the main extension direction of the plate 21) of about 150 mm. The length of the shorter sides of the coil holder section 82, ie, the height H of this coil holder section 82 measured from the surface of the plate 21, is about 5, for example mm. Furthermore, the coil holder 8 with their respective first portion 82 with a distance A of about 15 mm to the externa ßeren, perpendicular to the bobbins 8 edges of the plate 21 and a distance B of 40 mm to each other on a line parallel to the longer Side of the plate 21 may be arranged. Of course, the above numerical values are only examples. The invention is not limited to specific dimensions of the plate or to a particular arrangement of the coil holder.

FIG. 8 schematically shows the section through the plate 21 of FIG. 7 in the region of one of the coil holders 8 (along the line X-X). The layer structure has five plane-parallel layers 91, 92, 93, 94, 95, wherein the layers 91, 93, 95 consist of a hard foam, in particular Rohacell, and two further layers 92, 94 of a carbon fiber reinforced plastic (CFRP). The rigid foam layers 91, 93, 95 are arranged alternately with the CFK layers 92, 94, so that the rigid foam layer 93 is arranged in the middle of the layer structure, then followed by a CFK layer 92, 94 on both sides and the two rigid foam layers 91, 95 form the two outermost layers of the layer structure.

With the plate 21 of the coil holder 8 is connected by the fact that its second portion 83 is embedded parallel to the main extension plane in the layer structure. In particular, at least a portion of the second portion 83 is in one of the layers 91-95, e.g. embedded in one of the CFRP layers 92, 94, with, for example, the first portion 82 of the bobbin holder 8 extending through at least one of the layers 91-95 (e.g., through the rigid foam layer 91), i. with a portion in the interior of the plate 21 runs. The remaining first portion 82 protrudes from the plate 21 and is perpendicular to the surface of the plate 21 aligned.

In one embodiment of the invention, the two CFRP layers 92, 94 and the two externa ßeren hard foam layers 91, 95 each have the same thickness, wherein the thickness of the rigid foam layers 91, 95 different (eg larger) may be of the Thickness of the CFRP layers 92, 94 (eg 0.2 mm for the CFRP layers and 1, 0 mm for the rigid foam layers). The middle rigid foam layer 93 may in turn have a different (eg greater) thickness from the outer layers; Eg 2 mm, the total thickness D of the layer structure with the layers 91-95 then, for example, about 5 mm. Embodiments of the invention are not limited to five layers and the above-described arrangement and dimensions of the rigid foam layers and CFK layers, but there are also more or less layers conceivable, for example, with other layered material arrangements. The functional principle of the arrangement 10 according to the invention for moving a movable element (not shown) will be explained again with reference to FIG. The arrangement 10 comprises two permanent magnets 61, 61, each having a first pole 613, 623 and a second pole 614, 624. It is also possible that in each case at least two magnets are used instead of a single magnet 61, 62, wherein one pole of one magnet forms the first pole 613 or 623 and one pole of the other magnet forms the second pole 623, 624, eg bar magnets which are arranged transversely to conductor sections 71, 72 (see below) of the coil. Accordingly, at least four magnets would be used.

It is also conceivable that instead of at least one of the magnets 61, 62 several (shorter) magnets are provided, which are arranged along the conductor sections one behind the other and each have a first pole in the region of a first conductor portion 71 and a second pole in the region of the second conductor portion 72 have.

Furthermore, the arrangement 10 comprises a coil 7 which cooperates with the magnetic field of the magnets 61, 62 such that, when current flows through the coil, a movement of the coil along a direction of movement R is generated.

The coil is wound so that it extends (its windings) along a Haupterstre- ckungsebene, which is oriented parallel to the direction of movement R. More specifically, the coil 7 has a first portion 71 and a second portion 72, each passing through a gap between the poles 613, 623 and 614, 624, so that on the portion 71, the magnetic field generated by the poles 613, 623 and on the section 72, the (substantially homogeneous) magnetic field generated by the poles 614, 624 acts.

The poles 613, 623 and 614, 624 lying opposite to one another in a direction perpendicular to the main plane of extent of the coil 7 have in each case opposite polarity, the first pole 613 of the first magnet 61 being the north pole and the first pole 623 of the second magnet 62 the South pole of the magnet is. As a result, the magnetic fields that passed through the sections 71, 72 of the coil are directed opposite to each other, so that, since the current through the sections 71, 72 runs opposite, a force in the direction R occurs. In reverse current direction, a force would arise in the opposite direction. FIG. 10 likewise shows an arrangement according to the invention, the two permanent magnets 61, 62 being in the form of bar magnets and each having a pole piece 61 1, 612 or 61, 622 on the side to be moved and turned (not shown) (abut on this). This arrangement corresponds in principle to the arrangement 10 from FIG. 4. It should be noted that at least one of the permanent magnets 61, 61 can also be replaced by an electromagnet.

Figures 1 1 A and 1 1 B show an arrangement similar to FIG. 10 in section and in perspective view, wherein a arranged on a coil holder 8 coil between the magnets 61, 62 is shown.

FIGS. 12 to 14 relate to embodiments of a fastening element via which the coil holder 8 is connected to pole shoes of the arrangement according to the invention, wherein the fastening element (or fastening elements) is designed such that it controls the movement of the coil holder in the drive direction (ie parallel to the main element). ckungsebene the coil 7) restrict as little as possible, counteract a movement transverse thereto (ie to the pole pieces or the permanent magnets to), ie Ensure centering of the coil in the gap between the pole shoes. In order to realize the most constant possible distance between the pole shoes 61 1, 621, there are spacers 150 between the pole shoes, which are connected to the mutually facing surfaces of the pole shoes.

According to FIGS. 12A (top view) and 12B (section through coil holder along its main extension plane), two fastening elements are each provided in the form of a bent (in particular damped) wire 101, 102 (eg of steel), each having an opening 84, 85 in the coil holder 8 (designed as a circuit board) pass through. The wires 101, 102 are each bent at about 90 °, so that it each has two sections 101 1, 1012 and 1021, 1022, which are oriented at about 45 ° to the coil holder 8 and also at least approximately the same length, ie are arranged symmetrically with respect to the coil holder. The ends of the sections 101 1, 1012 and 1021, 1022 are respectively fixed to a surface of a pole piece 61 1, 621 of the magnets 61, 62, in particular to an edge of the surface or another reference point, which defines a defined arrangement of the wires 100, 101 allows. The wires are designed so that they each have a restoring force perpendicular to the main Generate plane of extension of the coil (or the bobbin holder), so that the coil (in the current-carrying state) in a swinging motion parallel to its Haupterstre- ckung level as centered between the pole pieces and / or the magnet is performed. At the same time, the wires of the oscillatory movement of the coil act as little as possible.

Of course, other bending angles than 90 ° or other lengths of the wires are conceivable. An example of longer length wires is shown in phantom in FIG. 12A. A further embodiment of a fastening element is shown in FIGS. 13A (top view) and 13B (section along the coil holder 8). Here are two fasteners in the form of two circular, flat pieces of fabric 103, 104 are provided, each having a recess 1031 and 1041. The pieces of fabric 103, 104 are respectively inserted into a slot 86, 87 of the bobbin holder 8, such that the sides 1032, 1033 and 1042, 1043 bounding the recesses 1031, 1041 are symmetrical to the bobbin holder 8, i. One half of the pieces of fabric 103, 104 is located on one side of the bobbin holder 8 and the other half on the other side of the bobbin holder. The pieces of fabric are each fixed to surfaces of the pole pieces (for example, materially bonded).

According to the variant of FIG. 14, two at least approximately rectangular pieces of tissue 105, 106 may be used as fastening elements, each extending along the pole pieces (or the magnets 61, 62, if there are no pole pieces). One of the longitudinal sides 1051, 1061 of the pieces of fabric 105, 106 is respectively connected to the bobbin holder 8, while an area (which extends along the other longitudinal sides 1052, 1062, for example, along the other longitudinal sides 1052, 1062) is connected to the pole piece. Specifically, the tissue pieces 105, 106 are arranged to hold the coil holder 8 centered between the magnets 61, 62 while being flexible enough to minimize movement of the coil (and thus the coil holder) when current flows along the main plane of extension of the coil possible to obstruct.

FIGS. 15A to 15E relate to an acoustic transducer in the form of a loudspeaker 1, which has a membrane in the form of a plate-like movable element 21. The membrane plate 21 is driven in particular by means of conversion means, which have at least one coil (not shown) extending along a plane, for example as described with reference to FIG. 4. Furthermore, the plate 21, also as described above, be formed as rigid as possible, so that bending vibrations of the plate are avoided as possible.

The side edge (peripheral edge) 21 1 of the plate 21 is not connected as in a conventional speaker via a bead with a frame 4, but is freely movable relative to the frame and in particular mounted only on the drive. Nevertheless, there is at least in sections between the side edge 21 1 and the frame 4, a sound absorbing means, the an acoustic short circuit, i. an air movement between a rear side (i.e., the side facing the speaker drive) and the front of the plate 21, counteracts. According to the variant of Figure 15A, the sound absorbing means comprises a porous absorber 160 (e.g., in the form of insulating wool) lying in a groove 41 disposed in a portion 42 of the frame 4 engaging behind the plate 21. From the side edge 21 1 of the plate 21 is a web 21 1 1 in the direction of the groove 41, wherein one end of the web 21 1 1 rests against the porous absorber. The absorber 160 is not fixed by fastening means, but rests only on the web 21 1 1 and the frame portion 42, so that an unobstructed movement of the membrane plate 21 is possible.

A modification is shown in FIG. 15B, according to which the porous absorber 160, while also located in a groove 41 of the frame 4, the side edge 21 1 of the plate 21, however, has no web. Instead, the side edge 21 1 is located directly on the absorber 160.

According to FIG. 15C, instead of a porous absorber, a closed-pored element 170 (in particular in the form of a fleece) is provided, which is connected (eg glued) to a first and a spaced second section on a side of the frame 4 facing the plate 21 , A projecting from the side edge 21 1 of the plate 21 web 21 1 1 presses between its connected to the frame 4 sections against the element 170, so that between the side edge 21 1 and the frame 4, a seal is formed. Alternatively, as shown in FIG. 15D, the member 170 may be fixed to the frame 4 with one portion while abutting with another portion on the side edge 21 1 of the plate 21. It is also conceivable that the sound absorption means, as shown in Fig. 15E, has a (in particular highly elastic) sealing tube 180, which rests on the one hand on the back of the plate 21 and on the other hand on a plate 42 engaging behind the plate portion of the frame 4.

FIG. 16 shows differently shaped plate-like movable elements 21, which each have raised portions in the form of struts 300, which increase the flexural strength of the plate.

The first row of figures relates to circular movable elements 21, each having differently designed struts 300, wherein the bending strength of the movable element increases from left to right. According to the first variant (left illustration) a plurality of radial struts 300 are provided. However, other types of braces are also conceivable, e.g. concentric (third figure from the left) or combinations of the struts shown in the first series of figures.

The two lower rows of figures of Fig. 16 relate to other geometries of the movable element and each show differently configured struts 300 (e.g., meandering or cross-shaped), again increasing the flexural strength from left to right.

Figure 17 shows a curved movable element 24 which is formed as a segment of a spherical surface. The curvature of the movable element 24, i. the radius of the underlying ball is chosen according to the bending strength requirements of the movable element, e.g. a radius of curvature of at least 300 m is used.

It should be noted that elements of the exemplary embodiments explained with reference to the figures can of course also be used in combination with one another. For example, the fasteners of FIGS. 12-14 could be used with the magnet-coil combination of FIG. LIST OF REFERENCE NUMBERS

1 speaker

3 magnet-coil combination

4 frames

7 coil

8 bobbin holders

10 arrangement

21,22,23 plate

24 spherical surface segment

41 groove

42 section frame

51 slot

61.62 permanent magnet

71 first section

72 second section

81 recess

82 first section

83 second part

84 opening

86, 87 slot

91.93,95 hard foam layer

92, 94 carbon fiber layer

101, 102 wire

103, 104 fabric element

105, 106 piece of tissue

150 spacers

160 porous absorber

170 closed porous element

180 sealing hose

211,231 page

300 bracing

611,621 first pole piece

612, 622 second pole piece

613,623 first pole 614, 624 second pole

1011, 1021 first section wire

1012, 1022 second section wire

1031, 1041 recess

1032, 1042 first page

1033, 1043 second page

1051, 1061 longitudinal side

2111 footbridge

A, B distance

D total thickness

H height

L length

R movement direction

Claims

claims

1 . Arrangement for moving a movable element, with

- Umsetzmitteln (3) for converting an electrical signal into a movement of the movable element (21 -23) along a direction of movement (R) and / or for converting along a direction of movement (R) directed movement of the movable element (21 -23) in an electrical signal, with

- The conversion means comprise a coil connectable to the movable element (7) and a device for generating a magnetic field, with which the coil (7) cooperates, characterized in that the coil (7) is wound so that they are substantially along extending parallel to the direction of movement (R) oriented plane.

2. Arrangement according to claim 1, characterized in that the coil (7) extends substantially flat.

3. Arrangement according to claim 1 or 2, characterized in that

- The coil (7) has a first and a second longitudinally extending portion (71, 72) which are spaced from each other, and

- The device for generating a magnetic field is formed so that the magnetic field generated by the first portion (71) in a first direction and the second portion (72) in a second, opposite to the first direction

Interspersed direction.

4. Arrangement according to claim 3, characterized in that

- The device for generating a magnetic field having a first and a second, longitudinally extended permanent or electromagnets (61, 62), the poles

(613, 614, 623, 624) extend along the longitudinal direction of the respective permanent or electromagnet (61, 62) so that the transition region between the poles also extends along the longitudinal direction, wherein

- The permanent or electromagnets (61, 62) are arranged so that the two poles (613, 614) of the first permanent or electromagnet (61) along a

Direction transverse to the direction of longitudinal extension of the permanent magnet or electromagnet in each case opposite to a pole opposite polarity (623, 624) of the second permanent magnet or electromagnet.

5. Arrangement according to one of claims 4 or 5, characterized in that the first and the second permanent or electromagnets (61, 62) each have a first pole piece (61 1, 621) extending along the first pole (613, 623) of the respective permanent or electromagnet (61, 62), and a second pole piece (612, 622) extending respectively along the second pole (614, 624) of the respective permanent or electromagnet (61, 62).

6. Arrangement according to claim 4 or 5, characterized in that the first portion (71) of the coil (7) in the first pole (613) of the first permanent or electromagnet (61) and the oppositely poled first pole (623 ) of the second permanent magnet or electromagnet (62) and the second section (72) of the coil (7) in which the second pole (614) of the first permanent or electromagnet (61) and the oppositely poled second pole (6) 624) of the second permanent magnet or electromagnet (62) formed magnetic field.

7. Arrangement according to one of claims 3 to 6, characterized in that the coil (7) is rectangular, wherein the longer sides of the first and the second portion (71, 72) form.

8. Arrangement according to one of the preceding claims, characterized in that the coil (7) is arranged in or on a bobbin holder (8).

9. Arrangement according to claim 8, characterized by a fastening element (101 - 106) via which the coil holder (8) is connected to the device for generating a magnetic field.

10. Arrangement according to claim 9 as far as referring back to one of claims 5 or 6, characterized in that the coil holder (8) between the pole pieces (61 1, 621, 612, 622) is arranged and a first portion (101 1, 1021) the fastening element (101, 102) is connected to the first pole piece (61 1) and the coil holder (8) and a second portion (1012, 1022) of the fastening element is connected to the second pole piece (621) and the coil holder (8), wherein the first and second portions (101 1, 1021, 1012, 1022) of the fastener (101, 102) extend at least approximately symmetrically with respect to the bobbin holder (8).

1 1. Arrangement according to claim 10, characterized in that the fastening element (101, 102) is an elongated element which passes through an opening (84) of the spool. lenhalters (8) and is connected to a first end to the first pole piece (61 1) and with a second end to the second pole piece (621).

12. Arrangement according to claim 10, characterized in that the fastening element is a circular, flat element (103, 104) with a recess (1031, FIG.

1041) is in the form of a circular sector, wherein the planar element is oriented transversely to the plane along which the coil (7) extends and is inserted with a portion into a slot (86, 87) of the bobbin holder (8) the radially extending sides (1032, 1033, 1042, 1043) delimiting the recess (1031, 1041) of the planar element (103, 104) extend at least approximately symmetrically with respect to the coil holder (8).

13. Arrangement according to one of claims 8 to 12, characterized in that the coil holder (8) has a first portion (82) on or in which the coil (7) is arranged, and a second portion (83), at least extends approximately perpendicular to the first portion (82) and which is connectable to the movable member (21 - 23) has.

14. Acoustic transducer for generating and / or receiving sound waves, with an arrangement according to one of the preceding claims and a movable

Element which is coupled to the coil (7), so that it can be set in motion to generate sound waves via the conversion means or via the conversion means, a movement of the movable element is convertible into an electrical signal.

15. Acoustic transducer according to claim 14, characterized by a plurality of devices (3) for generating a magnetic field, wherein these devices each associated with at least one of the movable element (21 -23) coupled to the coil (7).

16. Acoustic transducer according to claim 14 or 15, characterized in that the movable element (21 -23) is formed flat.

17. Acoustic transducer according to one of claims 14 to 16, characterized in that the movable element (21-23) is mounted and designed so that all areas of the movable element (21-23) move substantially simultaneously and substantially in phase ,

18. Acoustic transducer according to one of claims 14 to 17, characterized in that the movable element (21 -23) is mounted so that the entire moving bare element (21-23) can be moved linearly along an excitation direction and thus displaced into a piston-like movement via the conversion means (3) or by sound action.

19. Acoustic transducer according to claim 17 or 18, characterized in that the movable member (21 -23) is mounted so that the entire movable member, including its entire edge region, is movable in a direction perpendicular to its main extension plane.

20. Acoustic transducer according to claim 19, characterized in that between the edge of the movable element and the movable element at least partially circumferential frame, a sound absorbing means is arranged, which, however, only applied to the movable member and / or the frame and not via fastening means the movable element and the frame is connected.

21. Acoustic transducer according to one of claims 14 to 17, characterized in that the movable element (21-23) is mounted so that different areas of the movable element are movable in phase but with different deflection.

22. Acoustic transducer according to claim 21, characterized in that the movable element (21-23) is pivotally coupled to a mounting device of the acoustic transducer.

23. Acoustic transducer according to claim 21 or 22, characterized in that the movable element (21, 23) is flat and in plan view rectangular, circular or oval and is connected via one of its sides (21 1, 231) pivotally connected to the mounting device ,

24. Acoustic transducer according to one of claims 21 to 23, characterized by a further movable element (22) which is mounted so that the entire further movable element (22) is linearly movable.

25. Acoustic transducer according to any one of claims 14 to 24, characterized by a plurality of movable elements (21-23) which are mounted and formed so that they are independently movable.

26. Acoustic transducer according to one of claims 13 to 25, characterized in that

upon movement of the movable element (21-23), first sound waves that propagate in a forward propagation direction and second sound waves that propagate in a reverse propagation direction opposite to the forward propagation direction are excited; and

- The acoustic transducer comprises deflection means which deflect at least a portion of the second sound waves from the Rückwärtsausbreitungsrichtung.

27. Acoustic transducer according to claim 26, characterized in that the deflection means deflect at least a portion of the second sound waves in Vorwärtsausbreitungsrichtung so that they overlap at least with a portion of the first sound waves in phase.

28. Acoustic transducer according to claim 26 or 27, characterized by a frame (4) and / or a housing, wherein the deflection means has at least one opening in the frame (4) and / or the housing for deriving the second sound waves.

29. Acoustic transducer for generating and / or receiving sound waves, in particular according to one of claims 14 to 27, with

a member (21-23) movable to generate sound waves or sound waves; and

- Conversion means (3) for converting an electrical signal into a movement of the movable member (21 -23) and / or for converting a movement of the movable element (21 -23) into an electrical signal, characterized in that the conversion means are arranged and the movable member is supported and rigidly formed so as to avoid bending vibrations of the movable member upon movement of the movable member (21-23) through the conversion means or upon action of sound waves on the movable member (21-23).

30. Acoustic transducer according to claim 29, characterized in that the movable member (21 -23) is arranged and formed so rigid that bending vibrations of the movable member (21 -23) are avoided when it moves at a frequency of 5000 Hz becomes.

31. Acoustic transducer according to claim 29 or 30, characterized in that the movable element (21-23) is arranged and made rigid in such a way that bending vibrations of the movable element (21-23) are avoided, if at a frequency between 100 and 15,000 Hz is moved.

32. Acoustic transducer according to one of claims 29 to 31, characterized in that the movable element (21 -23) is formed flat.

33. Acoustic transducer according to one of claims 29 to 32, marked thereby, that the movable element (21-23) comprises a fiber-reinforced material, carbon, a rigid foam, in particular Rohacell, and / or lignin.

34. Acoustic transducer according to one of claims 29 to 33, characterized in that the movable element (21-23) has a layer structure.

35. Acoustic transducer according to one of claims 29 to 34, characterized by

- A layer structure having at least a first and a second layer (91-95), wherein

the first layer (92, 94) is more rigid than the second layer (91, 93, 95); and - the second layer (91, 93, 95) has a higher attenuation factor than the first layer

(92, 94).

36. Acoustic transducer according to claim 35, characterized in that the first layer comprises a fiber-reinforced material and the second layer comprises a rigid foam.

37. Acoustic transducer according to one of claims 29 to 36, characterized in that the movable element has at least one raised portion (300), in particular in the form of a strut, which increases the flexural rigidity of the movable element.

38. Acoustic transducer according to one of claims 29 to 37, characterized in that the movable element has at least one curvature.

39. Acoustic transducer for generating and / or receiving sound waves, in particular according to one of claims 14 to 38, with

a member (21-23) movable to generate sound waves or sound waves; - conversion means (3) for converting an electrical signal into a movement of the movable element and / or for converting a movement of the movable element into an electrical signal; and

- means for supporting the movable element, via which it is movably mounted on a holder device of the acoustic transducer, characterized in that the movable element (21-23) is coupled via the means for storing such pivotally connected to the mounting device that the Whole movable member (21 - 23) can be pivoted about a pivot axis, or the movable member (21-23) is mounted on the means for supporting so spaced apart to an outer periphery of the movable member that the entire movable member is linearly movable.

40. Acoustic transducer according to claim 39, characterized in that the movable element is mounted exclusively on the spaced apart from an externa ßeren circumference means for storing.

41. Acoustic transducer according to claim 39 or 40, characterized in that the means for supporting the movable member (21-23) by magnetic force on the support means store.

42. Acoustic transducer according to claim 41, characterized in that the means for moving the movable element at least one device (61, 62) for

Generating a magnetic field and at least one coil (7) connected to the movable element (21-23) and cooperating with the magnetic field generating device (61, 62), the magnetic field generating device (61, 62) Coil (7) are simultaneously part of the means for supporting the movable element, so that the movable element (21-23) is supported by the magnetic field generated by the magnetic field generating device (61, 62) and the coil (7). is produced.

43. Acoustic transducer according to claim 42, characterized in that the movable element (21-23) is supported solely by the magnetic field generated by the magnetic field generating device (61, 62) and by the coil (7) becomes.

44. Acoustic transducer according to claim 42 or 43, characterized in that the device (61, 62) for generating a magnetic field is mounted on the mounting device.

45. Acoustic transducer according to one of claims 39 to 44, characterized in that the movable element is formed of a material having a modulus of elasticity of at least 30 GPa, in particular of at least 100 GPa.

46. loudspeaker or microphone with an acoustic transducer according to any one of claims to 14-44.

47. A movable element for an acoustic transducer, in particular for an acoustic transducer according to one of claims 14 to 45, characterized by

- A layer structure having at least a first and a second layer (91-95), wherein

the first layer (92, 94) is more rigid than the second layer (91, 93, 95); and

- The second layer (91, 93, 95) has a higher damping factor than the first layer.

48. A movable member according to claim 47, characterized in that the first layer of a fiber-reinforced material, in particular a carbon fiber reinforced material, and the second layer of a rigid foam, in particular Rohacell having.

49. A movable element according to claim 47 or 48, characterized in that the layer structure comprises a plurality of alternately arranged first and second layers.

50. A movable element for an acoustic transducer, in particular for an acoustic transducer according to one of claims 1 to 45, characterized in that it is formed of a solid foam, in particular a carbon or a metal foam.

51. An acoustic transducer for generating and / or receiving sound waves with an element (21-23) movable to generate sound waves or by sound waves and formed according to any one of claims 47 to 50.

52. Acoustic transducer for generating and / or receiving sound waves, in particular according to one of claims 14 to 44 or 50, with a member (21-23) movable to generate sound waves or sound waves; and

- conversion means (3) for converting an electrical signal into a movement of the movable element (21-23) and / or for converting a movement of the movable element (21-23) into an electrical signal, characterized in that the movable element (21 23) and has a flexural rigidity with respect to a direction perpendicular to its main extension plane of at least 100 Nm ² , in particular of at least 300 Nm ² , and / or a material having a modulus of elasticity of at least 30 GPa, in particular of at least 60 GPa , having.