Method of manufacturing a voice coil, electrodynamic actuator, electrodynamic transducer and loudspeaker

Abstract

The invention relates to a method of manufacturing a voice coil, an electrodynamic actuator, an electrodynamic transducer and a loudspeaker. A method of manufacturing a voice coil (1a..1d) is disclosed, wherein windings (4a..4g) are arranged one above the other in a first section (B1) and next to each other in a second section (B2) when viewed in a cross-sectional plane (D). In a first step, in the second section (B2), a first winding (4a, 4a') and a second winding (4b) of the windings (4a..4g) are arranged above each other but offset laterally relative to each other. In a second step, in the second section (B2), the first winding (4a, 4a') is moved to the height position of the second winding (4b) by pressing and / or folding. Furthermore, an electrodynamic actuator (17a..17c) comprising a voice coil (1a..1d) of the aforementioned kind is disclosed. Finally, an electrodynamic transducer (32a..32b), a loudspeaker (21) and an output device comprising such an electrodynamic actuator (17a..17c) are disclosed.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a voice coil having an electrical conductor in the form of a ring or winding extending along a circumferential line around the voice coil axis. Furthermore, the present invention relates to an electrodynamic actuator designed to be connected to the back side of a plate-like structure or diaphragm, the back side being opposite to the sound-generating surface of the plate-like structure or diaphragm, and comprising at least one voice coil of the type described above and a magnet system designed to generate a magnetic field transverse to the electrical conductor in the annular segment of the voice coil. Furthermore, the present invention relates to a loudspeaker comprising an electrodynamic actuator of the type described above and a diaphragm fixed to the at least one voice coil and the magnet system. Furthermore, the present invention relates to an electrodynamic (acoustic) transducer comprising a plate-like structure having a sound-generating surface and a back side opposite to the sound-generating surface. The electrodynamic transducer further comprises an electrodynamic actuator of the type described above, the electrodynamic actuator being connected to the plate-like structure on the back side. In particular, the plate-like structure can be implemented as a display. In this way, the electric actuator together with the display forms an output device (for both audio and data). Background Art

[0002] Voice coils and methods for producing them are generally known. Typically, a wire is wound so that it has a spiral path and forms a voice coil. Within an electrodynamic actuator, the voice coil is arranged in a magnetic field so that when an electric current flows through the electrical conductor, a force acts on the voice coil. The movement of the voice coil relative to the magnet system caused by the force is converted into sound in an electrodynamic transducer or loudspeaker of the type mentioned above, as is generally known. Spatial limitations, especially in mobile handheld devices, can lead to problems when it comes to achieving a specific output power and sound quality in a restricted volume. The freedom of design is particularly limited by the voice coil, since it cannot be formed into any conceivable form according to the prior art. Summary of the Invention

[0003] The object of the present invention is therefore to overcome the disadvantages of the prior art and to provide a better method for manufacturing a voice coil, a better electrodynamic actuator, a better loudspeaker, a better electrodynamic transducer, and a better output device. In particular, the design freedom is to be improved so that a specific output power and sound quality can be achieved even within problematic space constraints.

[0004] The problem of the invention is solved by the method disclosed in the opening paragraph, wherein different windings in a first section of the circumferential line are arranged one above the other when viewed in a sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, wherein the different windings in a second section of the circumferential line are arranged next to each other when viewed in the sectional plane, and wherein the method comprises the following steps:

[0005] - in a first step, in a second section, arranging a first winding and a second winding of the windings above each other but offset to the side with respect to each other, and

[0006] a) in a second step, in a second section, the first winding is pressed to the height of the second winding, or

[0007] b) in a second step, in a second section, folding the first winding to the height of the second winding, or

[0008] c) In a second step, in a second section, the first winding is moved to the height of the second winding by means of a combined folding and pressing.

[0009] As a result, when viewed in a cross-sectional plane including the voice coil axis, the first winding and the second winding are located at the same height position or in the same plane disposed perpendicularly to the voice coil axis after the second step.

[0010] Furthermore, the problem of the invention is solved by an electric actuator as defined in the opening paragraph, wherein the different windings of the electrical conductor in a first segment of the circumferential line are arranged one above the other when viewed in a sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, and wherein said different windings of the electrical conductor in a second segment of the circumferential line are arranged next to each other when viewed in said sectional plane.

[0011] In particular, a voice coil of an electrodynamic actuator is manufactured by the method disclosed above.

[0012] Furthermore, the problem of the invention is solved by a loudspeaker comprising an electrodynamic actuator of the above-mentioned kind and a diaphragm fixed to a voice coil and magnet system.

[0013] Still further, the problem of the invention is solved by an electrodynamic (acoustic) transducer comprising a plate-like structure having a sound-emitting surface and a back side opposite the sound-emitting surface, and comprising an electrodynamic actuator of the type described above being connected to the back side. Advantageously, at least one voice coil or magnet system of the electrodynamic actuator comprises a flat mounting surface intended to be connected to the back side of the plate-like structure, which is opposite the sound-emitting surface of the plate-like structure, wherein the back side is oriented perpendicular to the voice coil axis. In particular, the plate-like structure can be implemented as a display. In this way, the electrodynamic actuator and the display together form an output device (for both audio and data).

[0014] Typically, when viewed in said sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, in the first segment, more different windings can be arranged one above the other than in the second segment, and in the second segment, more different windings can be arranged next to each other than in the first segment.

[0015] The proposed measures make it possible to manufacture voice coils with varying height profiles and to incorporate recesses similar to cutouts and holes. This alleviates problematic space and design constraints. Even within these constraints, a specific output power and sound quality can be achieved. In particular, the proposed measures offer the advantage that parts of the electrodynamic actuator itself or parts of the device in which it is integrated can be brought locally within the range of motion of the voice coil. This generally increases the assembly density of the electrodynamic actuator and the device in which it is integrated, compared to the prior art.

[0016] The proposed measures are particularly applicable to "micro" electrodynamic actuators. The proposed measures are also applicable to loudspeakers in general, and in particular to micro loudspeakers, whose diaphragm area is less than 600 mm 2 and / or its back cavity volume is 200mm 3 to 2cm 3 Such microspeakers are used in all kinds of mobile devices, such as mobile phones, mobile music devices, laptops and / or headphones. It should be noted at this point that a microspeaker does not necessarily include its own back volume, but can use the space of the device in which the speaker is built as the back volume. This means that the speaker does not have to include its own (closed) housing, but can only include an (open) frame. The back volume of the device in which such a speaker is built is typically less than 10 cm 3 .

[0017] In general, an "electric actuator" converts electrical power into movement and force. Together with the diaphragm, the electric actuator forms a "speaker." Together with the panel, the electric actuator forms an "electric (acoustic) transducer." A specific embodiment of a panel is a display. In this case, the electric actuator and the display together form an "output device" (for both audio and data). In general, the speaker, the electric transducer, and the output device convert electrical power into sound.

[0018] It should be noted that sound can also be emitted from the back side of the plate-like structure and the diaphragm. However, this back side usually faces the interior space of the device (e.g., a mobile phone) in which the speaker or output device is built. Therefore, the plate-like structure or diaphragm can be considered to have a primary sound-emitting surface and a secondary sound-emitting surface (i.e., the back side). The sound waves emitted by the primary sound-emitting surface reach the user's ears directly, while the sound waves emitted by the secondary sound-emitting surface do not reach the user's ears directly, but are only indirectly reflected or excited by other surfaces of the housing of the device in which the speaker or output device is built.

[0019] The electrodynamic acoustic transducer may comprise a frame and / or a housing.The magnet system and / or the voice coil may be connected to the housing or frame or may be part of the housing or frame.

[0020] The "frame" is typically the component that holds the diaphragm, voice coil, and magnet system together. Typically, the frame is directly attached to the diaphragm and magnet system (e.g., with the aid of adhesive), while the voice coil is attached to the diaphragm. Thus, the frame is fixed relative to the magnet system. Normally, the frame forms a subsystem with the diaphragm, voice coil, and magnet system as an intermediate step in the production process.

[0021] The "housing" is usually mounted to the frame and / or the diaphragm and encloses the back volume of the transducer, i.e. the air or gas compartment behind the diaphragm. The housing is therefore fixedly arranged relative to the magnet system. In common designs, the housing can be hermetically sealed (respectively airtight). However, depending on the specific circumstances, it can also include small openings or a bass tube. Among other things, the acoustic performance of the transducer can be influenced by varying the back volume by correspondingly arranging openings in the housing.

[0022] Advantageously, the first segment or multiple first segments can relate to at least 50% of the circumferential line in total, and the second segment or multiple second segments can relate to at most 50% of the circumferential line in total. In particular, the first segment or multiple first segments can relate to at least 60% of the circumferential line in total, and the second segment or multiple second segments can relate to at most 40% of the circumferential line in total. In another preferred embodiment, the first segment or multiple first segments can relate to at least 70% of the circumferential line in total, and the second segment or multiple second segments can relate to at most 30% of the circumferential line in total. If there is more than one segment at all, then "total" in the above context refers to "all segments together". For example, there can be four first segments and four second segments. Therefore, "total" in this example refers to "all four first segments together" and "all four second segments together". In another preferred embodiment, a single first segment relates to at least 20% of the circumferential line, and a single second segment relates to at most 20% of the circumferential line. In another preferred embodiment, a single first segment covers at least 40% of the circumference, and a single second segment covers at most 40% of the circumference. In general, the first segment is typically larger than (or at least equal to) the second segment, which facilitates uniform generation of the Lorentz force and, therefore, uniform movement of the voice coil with a low tendency to wobble. This is particularly true if it is not possible to distribute the first and second segments uniformly or symmetrically along the circumference.

[0023] Typically, the conductor may have a circular or rectangular cross section. Advantageously, the diameter of the electrical conductor of the voice coil of the "micro" electrodynamic actuator is ≤ 110 μm. Depending on the circumstances, the electrical conductor may also comprise an (electrically insulating) coating on the metal core.

[0024] For example, the electrical conductor of the voice coil may be made of copper, aluminum, and any copper or aluminum alloy.

[0025] Typically, the windings can be formed by winding an electrical conductor. In this case, the wire is wound, wherein, in the first step as defined above, in the second section, the different windings are arranged above each other but offset to the side relative to each other.

[0026] In another advantageous embodiment, the winding can be formed by cutting, stamping or etching a metal sheet or foil and can be

[0027] -) interconnection by welding or soldering, and / or

[0028] -) Fold on top of each other.

[0029] It should be noted that folding the electrical conductors on top of each other is different from coiling the electrical conductors. In the above context, "folding on top of each other" means bending the (flat) electrical conductors by 180° so as to form a flat structure again. "Coiling" means continuously bending the electrical conductors so as to form a circular voice coil or making bends <180° in the same direction so as to form a polygonal voice coil. Generally, the electrical conductors can be folded by hand, by machine, or by a combination of the two. It should also be noted that "folding on top of each other" in the above context should not be confused with the folding in steps b) and c), where "folding" generally involves or means a bending angle of about 90°.

[0030] Specifically, the method for manufacturing a voice coil may include the following steps:

[0031] i) cutting electrical conductors from metal foil;

[0032] ii) forming an insulating layer on an electrical conductor;

[0033] iii) a stack of windings made of electrical conductors by:

[0034] - stacking individual windings (individual sheets of electrical conductors) and electrically connecting the stacked individual windings, and / or

[0035] - folded electrical conductors;

[0036] iv) applying adhesive between the windings of the stack, and

[0037] v) Forming the winding in the second section or in accordance with the process steps of any of the cases a) to c) in the second section.

[0038] Thanks to the above measures, voice coils of virtually any shape can be manufactured by cutting out corresponding sheets of metal foil. In particular, polygonal structures can form very sharp corners. In contrast, this is impossible when winding wire or foil to form a polygonal voice coil, as the corners require very large radii. Since the magnet system is designed simultaneously with the voice coil, the proposed measures also significantly increase the manufacturing possibilities of the magnet system. This is particularly advantageous if the polygonal magnet system consists of multiple monolinear magnets, as the magnetic field lines traverse approximately the entire length of the voice coil's electrical conductor, based on the sharp corner radii. This means that the sound pressure level relative to the current flowing through the voice coil is very high; in other words, the efficiency of the electrodynamic acoustic transducer is very high. Furthermore, these voice coils can be manufactured with very low tolerances, allowing for a very small air gap between the magnet system and the voice coil. Consequently, the efficiency of the electrodynamic actuator is further improved.

[0039] Furthermore, the proposed approach provides a voice coil with a high density of electrical conductors. Preferably, the fill factor, as a proportion of all windings or conductive layers over the voice coil volume, is >80%. Other solutions, such as voice coils with voice coil wire, offer much lower fill factors, thereby reducing the voice coil's power-to-weight ratio. In other words, in this embodiment, the proposed electrodynamic actuator delivers more acoustic power for the same weight. Furthermore, the low weight of the voice coil also substantially impacts the sound quality of the electrodynamic acoustic transducer.

[0040] For example, the metal foil used for the electrical conductor of the voice coil can be made of copper, aluminum, and any copper or aluminum alloy. Preferably, the thickness of the conductive layer is 10 μm to 30 μm. This allows the desired number of turns to be provided within the desired height of the voice coil. The thickness of the insulating layer is preferably 1 μm to 5 μm. In this way, the electrical strength is high enough to withstand the voltage difference between the conductive layers, and the mechanical stability is high enough to withstand the forces applied to the voice coil during use, neither of which substantially reduces the favorable power-to-weight ratio of the voice coil. From this point of view, metal seems to be the most useful for the production of voice coils. However, the proposed method is generally applicable to conductive foils. Therefore, if a material different from metal is provided but with comparable or better conductivity, the term "metal foil" can be replaced in spirit by the term "conductive foil" throughout this document.

[0041] It should be noted that steps i) through v) do not necessarily imply a specific order of production steps. For example, when the conductive layers are connected to each other with the aid of an adhesive, step ii) can occur implicitly, without the need to form an insulating layer on the electrical conductor in a separate step. It should also be noted that mechanically connecting the conductive layers with the aid of an adhesive in step iv) does not necessarily follow the step of electrically connecting the stacked individual windings in step iii), but rather, electrical connection can follow mechanical connection. In this context, it should also be noted that mechanical connection means substantial connection of the windings or conductive layers, particularly substantial connection over an area greater than 50% of the area between two windings or conductive layers. Strictly speaking, electrical connection is also a mechanical connection, but it generally does not substantially enhance the stability of the layer construction. Step v) (forming the winding in the second section or, depending on the process step in any of cases a) through c), can involve sequentially forming a single winding of a plurality of windings or forming the plurality of windings in a single step. In a highly advantageous embodiment, forming the plurality of windings in a single step is performed after steps i) through iv). In particular, step v) can be performed with the aid of a mold. For example, after the adhesive has been applied, the winding stack is placed in a mold, and the two mold parts are then pressed against each other to give the winding stack the desired shape. In other words, the mold has a negative form of the voice coil. The adhesive can also be applied by simply filling the mold with adhesive and pressing out the excess. However, it is also possible to form the winding stack between two pressing plates.

[0042] It should also be noted that the stacking of individual windings and the electrical connection of the stacked individual windings, as well as the folding of electrical conductors to form a stack of conductive layers from electrical conductors, can be used in any desired combination. Thus, the stack of windings or conductive layers can be composed of only unfolded individual sheets of electrical conductors, only folded individual sheets of electrical conductors (or even only one folded sheet), or a mixture of unfolded and folded individual sheets of electrical conductors.

[0043] The "conductive layer" is the flat winding, and therefore the layer of the voice coil, that is capable of conducting a considerable level of current. In the present invention, the conductive layer is made of metal. It should be noted that the term "stack of conductive layers" does not exclude the presence of other layers between the conductive layers, particularly "insulating layers," "passivation layers," and / or "adhesive layers."

[0044] The "insulating layer" is a layer of the voice coil that can withstand a significant level of voltage without conducting a significant level of current. Examples of materials that can be used to construct the insulating layer are plastic materials, ceramics, and oxides. The insulating layer can include layers of a single insulating material, layers of different insulating materials (such as those mentioned previously), or one or more layers comprising a mixture of materials.

[0045] A "passivation layer" is a protective layer over a conductive layer. It can be formed by oxidizing the metal of the conductive layer. Thus, a passivation layer can include a metal oxide. Typically, a passivation layer has insulating properties. In this case, the passivation layer is part of the insulating layer. The formation of a passivation layer is optional, and the insulating layer can also be constructed without a passivation layer.

[0046] An "adhesive layer" is a layer that mechanically connects two adjacent layers by bonding. The adhesive layer also typically has insulating properties. In this case, the adhesive layer is also part of the insulating layer. Therefore, the insulating layer may typically include a passivation layer and / or an adhesive layer. The adhesive layer can be made of glue (particularly liquid glue), which is applied to the conductive layer or the passivation layer on the conductive layer, for example, by spraying, pad printing, or roller coating. The liquid glue can also be applied to the gap between the two conductive layers or the passivation layer. This glue is then drawn into the gap by capillary action. The liquid glue can include anaerobic or thermosetting adhesives, two-component adhesives, and hot melt adhesives (e.g., epoxy resins, acrylic acid). The viscosity of the adhesive can be less than 1000 mPas. In some embodiments, the viscosity of the adhesive is less than 500 mPas or even less than 50 mPas. The adhesive layer can also be formed by a plastic foil, particularly a single-sided or double-sided adhesive foil or a thermosetting adhesive film or a hot melt adhesive film, which is applied to the conductive layer or the passivation layer.

[0047] The "cutting" of the electrical conductors from the metal foil can occur in a variety of ways. For example, a laser, a water jet, plasma cutting, photoetching, a knife, or a punch can be used to perform the cutting step. Furthermore, the metal foil can be cut piece by piece, or multiple layers can be cut in a single step. In the latter case, the layers can be interconnected (mechanically and / or electrically) or not. Thus, other layers besides the conductive layer, in particular the insulating layer, the passivation layer, and / or the adhesive layer, can be cut at the same time.

[0048] Further advantageous embodiments are disclosed in the claims and the description as well as in the drawings.

[0049] In an advantageous embodiment, the electrical conductor is made of or comprises aluminum and is hardened and annealed in the folded or bent region. Folds in the electrical conductor can lead to an increase in electrical resistance in the region of the fold, which can affect the acoustic performance of the electric actuator. This increase in resistance can be compensated by increasing the width of the electrical conductor in the region of the fold line. In turn, a larger cross-sectional area is provided through which the current flows, thereby reducing the resistance. However, if aluminum is used for the electrical conductor, it can be hardened and locally annealed in the region of the fold, which also reduces the resistance. In this way, the width of the electrical conductor in the region of the fold line does not need to be increased, since as a result of the fold there is hardly any increase in resistance. The laser used for cutting and / or welding, in particular the same laser, can be used to harden and anneal the electrical conductor in the bent region.

[0050] In a further advantageous embodiment, a first of the windings performs a lateral movement (or at least a lateral movement component) transverse to the voice coil axis in the second section during one of steps a) to c).

[0051] In particular,

[0052] A first of the windings may project outwardly away from the voice coil axis before performing one of steps a) to c) and may perform an inward lateral movement transverse to the voice coil axis in the second segment during said one of steps a) to c), or

[0053] - A first of the windings may project inwardly towards the voice coil axis before performing one of steps a) to c) and during said one of steps a) to c) may perform an outward lateral movement transverse to the voice coil axis in the second segment.

[0054] Typically, the protrusion helps to avoid or at least limit stretching of the first winding in the second section, since the first winding is longer there than the second winding before deformation. In particular, the length of the first winding in the unbent state in the second section can be equal to its length in the bent state.

[0055] In yet another embodiment, when viewed in said cross-sectional plane perpendicular to the circumferential line and with the voice coil axis indicating the height direction, all windings in the first section of the circumferential line can be arranged one above the other. In this way, a voice coil is obtained that looks like a single-layer voice coil in the first section.

[0056] Advantageously,

[0057] - the first parts of the windings in the second section of the circumferential line may be arranged next to each other when viewed in said cross-sectional plane perpendicular to the circumferential line, and

[0058] The remaining second parts of the windings in the second section of the circumferential line may be arranged one above the other when viewed in said sectional plane.

[0059] In this way, a shallow recess or a recess having a low height compared to the overall height of the voice coil can be produced.

[0060] Advantageously, a dashed line, arranged in the cross-sectional plane perpendicular to the circumference and oriented perpendicular to the voice coil axis, indicates the width direction, wherein the conductor width is the same in the first and second segments. This achieves uniform conductivity of the conductor along the circumference. In this case, the voice coil is wider in the second segment than in the first segment.

[0061] Advantageously, the imaginary line indicates the width direction, wherein the width of the conductor in the first segment is greater than the width of the conductor in the second segment. In this way, the width of the conductor in the second segment is reduced to reduce the overall width of the voice coil in the second segment.

[0062] In a particularly advantageous embodiment, the imaginary line indicates the width direction, wherein the total width of the winding is the same in the first and second segments. Thus, the width of the voice coil is the same in the first and second segments. In other words, in this embodiment, a voice coil with a uniform width along the circumference is achieved.

[0063] In one embodiment, exactly two of the windings are arranged adjacent to each other at a specific height level in the second section. This makes manufacturing the voice coil in the second section less complicated. In another embodiment, more than two of the windings are arranged adjacent to each other at a specific height level in the second section. This allows for forming a deep recess in the voice coil.

[0064] Advantageously, the average sound pressure level of the loudspeaker or electrodynamic transducer (or output device) measured at an orthogonal distance of 10 cm from the sound emitting surface in the frequency range from 100 Hz to 15 kHz is at least 50 dB_SPL. AVG ” generally refers to the sound pressure level SPL in a specific frequency range divided by the integral of the frequency range. In the above context, in detail, it refers to the ratio between the sound pressure level SPL integrated in the frequency range from f = 100 Hz to f = 15 kHz and the frequency range from f = 100 Hz to f = 15 kHz. In particular, the above average sound pressure level is measured with an electric power of 1 W, more particularly with a nominal impedance. The unit “dB_SPL” generally indicates the sound pressure level relative to the audible threshold (20 μPa). BRIEF DESCRIPTION OF THE DRAWINGS

[0065] These and other aspects, features, details, utilities, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claims, and the accompanying drawings, which illustrate features according to exemplary embodiments of the present invention, and in which:

[0066] Figure 1 An angled view of a voice coil with a recess is shown;

[0067] Figure 2 shows a cross section through the voice coil in the first segment;

[0068] Figure 3 shows a cross section through the voice coil in the second segment;

[0069] Figure 4 In a detailed angled view from below, two windings of the voice coil in the second section are shown in an unbent state;

[0070] Figure 5 Shown Figure 4 The two windings are in a bent state;

[0071] Figure 6 Shown Figure 5 A bottom view of the two windings with an attached pressing tool;

[0072] Figure 7 Shown in top view Figures 4 to 6 The first winding;

[0073] Figure 8 Shown in top view Figures 4 to 6 The second winding;

[0074] Figure 9 Similar to Figure 4, but the second winding protrudes outward in the unbent state;

[0075] Figure 10 Shown in top view Figure 9 The first winding;

[0076] Figure 11 Shown in top view Figure 9 The second winding;

[0077] Figure 12 shows, in angled view, a plurality of windings being welded by a laser beam to form a voice coil;

[0078] Figure 13 shows a top view of the electrical conductor before being bent along a fold line to form a voice coil;

[0079] Figure 14 shows how the winding stack can be pressed with the aid of a die;

[0080] Figure 15 shows how the winding stack can be pressed with the aid of a pressure plate;

[0081] Figure 16 shows how the winding stack looks after the pressing step according to the first embodiment;

[0082] Figure 17 shows how the winding stack looks after the pressing step according to the second embodiment;

[0083] Figure 18 An angled view of a voice coil with a hole-like recess is shown;

[0084] Figure 19 An example of a loudspeaker having an electrodynamic actuator with a voice coil of the disclosed kind is shown in exploded view;

[0085] Figure 20 The cross-sectional view shows Figure 19 speakers;

[0086] Figure 21 Shown from below in an angled view Figure 19 The speaker's voice coil, arm arrangement, and frame;

[0087] Figure 22 a cross-sectional view showing a first example of an electrodynamic transducer; and

[0088] Figure 23 A cross-sectional view of a second example of an electrodynamic transducer having a movable part and a fixed part of a magnet system is shown.

[0089] Throughout the several views, the same reference numerals refer to the same or equivalent parts. DETAILED DESCRIPTION

[0090] Various embodiments are described herein for various devices. Many specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the drawings. However, it will be understood by those skilled in the art that these embodiments can be practiced without such specific details. In other cases, well-known operations, components, and parts are not described in detail so as not to confuse the embodiments described in the invention. It will be understood by those of ordinary skill in the art that the embodiments described and illustrated herein are non-limiting examples, and therefore it will be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments, which are limited only by the appended claims.

[0091] References throughout this specification to "various embodiments," "some embodiments," "one embodiment," or "an embodiment," etc., mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, phrases such as "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" appearing throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with features, structures, or characteristics of one or more other embodiments without limitation, as long as such combination is not illogical or non-functional.

[0092] It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise.

[0093] The terms "first," "second," and the like in the specification and claims are used to distinguish similar elements and are not necessarily used to describe a particular order or chronological sequence. It is to be understood that the terms so used are interchangeable where appropriate, such that the embodiments of the invention described herein are, for example, capable of operating in other orders than those illustrated or otherwise described herein. Moreover, the terms "comprising," "having," and any variations thereof are intended to cover non-exclusive inclusions such that a process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements that are not explicitly listed or that are inherent to such a process, method, article, or apparatus.

[0094] All directional references (e.g., "positive," "negative," "up," "down," "upward," "downward," "left," "right," "leftward," "rightward," "front," "back," "top," "bottom," "above," "below," "above," "below," "vertical," "horizontal," "clockwise," and "counterclockwise") are used for identification purposes only to aid the reader in understanding the present disclosure and are not intended to be limiting, especially with respect to the position, orientation, or use of any aspect of the present disclosure. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in orientations other than those illustrated or otherwise described herein.

[0095] As used herein, the phrases "configured to," "configured to," and similar phrases indicate that a subject device, apparatus, or system is designed and / or constructed (e.g., through appropriate hardware, software, and / or components) to meet one or more specific purposes, rather than that the subject device, apparatus, or system is capable of performing only that objective purpose.

[0096] Connective references (e.g., "attached," "coupled," "connected," etc.) are to be interpreted broadly and may include intermediate members between the connection of components and relative movement between components. Thus, connective references do not necessarily imply that two components are directly connected and / or in fixed relation to each other. All matter contained in the above description and shown in the accompanying drawings is to be interpreted as illustrative only and not limiting. Changes may be made in detail or structure without departing from the spirit of the invention as defined in the appended claims.

[0097] All numbers expressing measurement results and the like used in the present description and claims are to be understood as being modified in all instances by the term "about" or "substantially", which particularly refers to a deviation of 10% from the reference value.

[0098] Figure 1 An angled view of a voice coil 1a is shown, which has an electrical conductor in the form of a ring or winding extending in annular segments along a circumferential line C around a voice coil axis A. When viewed in a sectional plane D perpendicular to the circumferential line C, in a first segment B1 of the circumferential line C, the different windings of the electrical conductor are arranged one above the other, with the voice coil axis A indicating the height direction. Further on, when viewed in said sectional plane D, in a second segment B2 of the circumferential line C, the different windings of the electrical conductor are arranged next to each other. In the first segment B1 of the circumferential line C, the voice coil 1a has a standard height segment 2, while in the second segment B2 of the circumferential line C, the voice coil 1a has a recess 3a.

[0099] Figure 2 and Figure 3The arrangement of the electrical conductors is shown in more detail. Specifically, Figure 2 shows a cross section through the voice coil 1a in a first segment B1 of the circumferential line C, Figure 3 A section through the voice coil 1 a is shown in a second segment B2 of the circumferential line C. Both sections are perpendicular to the circumferential line C in said segments B1 , B2.

[0100] In this example, the voice coil 1a has seven windings 4a..4g. Figure 2 In the first section B1 shown, these windings are arranged one above the other. In the second section B2, some of the windings 4a to 4g are arranged adjacent to one another. Specifically, windings 4a to 4d, which were arranged one above the other in the first section B1, are arranged in two planes in the second section B2. More specifically, winding 4b is arranged adjacent to winding 4a, and winding 4d is arranged adjacent to winding 4c. Thus, the height h1 of the voice coil 1a in the first section B1 is greater than the height h2 of the voice coil 1a in the second section B2, with the voice coil axis A indicating the height direction. Consequently, this arrangement of windings 4a to 4g forms a recess 3a in the voice coil 1a.

[0101] Between the windings 4a..4g there is an insulating adhesive 5, by means of which firstly the windings 4a..4g are fixed to each other to improve the mechanical stability of the voice coil 1a and secondly the windings 4a..4g are insulated from each other so that the current must flow through the annular electrical conductor.

[0102] Voice coil 1a has some more special characteristics:

[0103] - When viewed in said sectional plane D perpendicular to the circumferential line C and when the voice coil axis A indicates the height direction, in the first segment B1, more different windings 4a..4g are arranged one above the other than in the second segment B2, and in the second segment B2, more different windings 4a..4g are arranged next to each other than in the first segment B1 (correspondingly, a recess 3a is formed in the voice coil 1a).

[0104] - when viewed in said sectional plane D perpendicular to the circumferential line C and when the voice coil axis A indicates the height direction, all windings 4a..4g in the first segment B1 of the circumferential line C are arranged one above the other (correspondingly, a single-layer voice coil is formed in the first segment B1).

[0105] - when viewed in said sectional plane D perpendicular to the circumferential line C, the first parts of the windings 4a..4g in the second segment B2 of the circumferential line C are arranged next to each other, and - when viewed in said sectional plane D, the remaining second parts of the windings 4a..4g in the second segment B2 of the circumferential line C are arranged one above the other (correspondingly, the depth of the recess 3a is smaller than the depth when all the windings 4a..4g are arranged next to each other in the second segment B2).

[0106] - Exactly two windings 4a, 4a', 4b of said windings 4a..4g are arranged next to each other at a certain height level (correspondingly, it is easy to manufacture the voice coil 1a in the second section B2).

[0107] - the width w1 of the conductor in the first segment B1 is greater than the width w2 of the conductor in the second segment B2, wherein the dashed line arranged in said cross-sectional plane D perpendicular to the circumferential line C and oriented perpendicular to the voice coil axis A indicates the width direction (correspondingly, the width w2 of the electrical conductor in the second segment B2 is reduced in view of its width w1 in the first segment B1 in order to reduce the overall width of the voice coil 1a in the second segment B2).

[0108] - the total width w1 of the windings 4a..4g is the same in the first section B1 and the second section B2 (therefore, the voice coil 1a has equal voice coil width in the first section B1 and the second section B2).

[0109] The electrical conductor has a rectangular cross section.

[0110] It should be noted that the above-mentioned features and combinations thereof are not mandatory, but the voice coil 1 a may be different from the above-mentioned features and combinations thereof.

[0111] For example:

[0112] - When viewed in said sectional plane D, the windings 4a..4g in the first segment B1 may be arranged next to each other so as to form a multi-layer voice coil in the first segment B1.

[0113] - Each of the windings 4a..4g in the second section B2 may have a neighboring winding 4a..4g arranged next to it at a certain height level, so that the recess 3a may be very deep.

[0114] More than two of the windings 4a..4g are arranged next to each other at a certain height level in the second section B2 so that the recess 3a can be formed deeper.

[0115] The widths w1, w2 of the electrical conductor may be the same in the first section B1 and the second section B2 so that the cross section of the electrical conductor does not decrease in the second section B2. Consequently, the electrical resistance of the electrical conductor does not increase in the second section B2 either.

[0116] The overall width w1 of the windings 4a..4g may be different in the first section B1 and the second section B2.

[0117] The electrical conductors may have different cross-sections, for example a circular cross-section.

[0118] Generally, it is advantageous if the first segment B1 or the plurality of first segments B1 together cover at least 50% of the circumference line C, and the second segment B2 or the plurality of second segments B2 together cover at most 50% of the circumference line C. In particular, the first segment B1 or the plurality of first segments B1 together may cover at least 60% of the circumference line C, and the second segment B2 or the plurality of second segments B2 together may cover at most 40% of the circumference line C. In another preferred embodiment, the first segment B1 or the plurality of first segments B1 together may cover at least 70% of the circumference line C, and the second segment B2 or the plurality of second segments B2 together may cover at most 30% of the circumference line C. In another preferred embodiment, a single first segment B1 covers at least 20% of the circumference line C, and a single second segment B2 covers at most 20% of the circumference line C. In yet another preferred embodiment, a single first segment B1 covers at least 40% of the circumference line C, and a single second segment B2 covers at most 40% of the circumference line C. The above measures contribute to a proper function of the voice coil 1 a , since the second segment B2 remains small relative to the first segment B1 , and accordingly the overall resistance of the voice coil 1 a remains low and provides for a uniform operation in terms of voice coil movement.

[0119] Typically, the second section B2 (case a) can be formed by, in a first step, arranging the first winding 4a and the second winding 4b of the windings 4a..4g in the second section B2 to be above each other but offset to the side relative to each other, and by, in a second step, pressing the first winding 4a to the height position of the second winding 4b in the second section B2.

[0120] In this context, Figures 4 to 6 Two windings 4a, 4b of the windings 4a..4g are shown in different states and from an angle view from below. Figure 7 and Figure 8The windings 4a, 4b are shown in a top view. As can be seen, the second winding 4b in the second section B2 has a cutout and is smaller than the second winding in the first section B1. The same is true for the first winding 4a, but its cutout is arranged mirror-symmetrically with respect to the cutout of the second winding 4b (see in particular). Figure 7 and Figure 8 ). Figure 4 The arrangement in a first step is shown, wherein in the second section B2 the windings 4a, 4b are arranged above each other but offset to the side with respect to each other. Figure 5 The arrangement after the second step is shown in a state in which, in the second section B2 , the first winding 4 a has been pressed to the height of the second winding 4 b . Figure 6 An example is depicted in which this second step is performed by a tool 6 , for example a press ram, which is pressed onto the first winding 4 a and deforms it in the second section B2 .

[0121] As a result, after the pressing step, when viewed in a cross-sectional plane including the voice coil axis A, the first winding 4 a and the second winding 4 b are located at the same height position or in the same plane arranged perpendicular to the voice coil axis A.

[0122] Although pressing the first winding 4a to the height of the second winding 4b is an advantageous method for forming the voice coil 1a in the second segment B2, this is not the only possibility. The voice coil 1a in the second segment B2 can also be formed by folding the first winding 4a' to the height of the second winding 4b (case b).

[0123] In this context, Figure 9 Two windings 4a', 4b of the windings 4a..4g are shown in a first state and from an angled view from below. Figure 10 and Figure 11 The windings 4a', 4b are shown in a top view. As can be seen, the second winding 4b in the second section B2 again has a cutout and is smaller than the second winding in the first section B1. The same is true for the first winding 4a', but its cutout is not only arranged in a mirror-symmetrical manner with respect to the cutout of the second winding 4b, but is also arranged in a mirror-symmetrical manner with respect to the cutout of the second winding 4b. Figures 4 to 8 The embodiment shown, on the contrary, projects outwards away from the voice coil axis A. In a second step, the first winding 4a' is folded to the height of the second winding 4b. This means that the first winding 4a' performs a rotational movement in the second section B2 (see Figure 9 In other words, the first winding is twisted there.

[0124] Accordingly, during the second step, the first winding 4a' performs a lateral movement in the second segment B2, transverse to the voice coil axis A. More specifically, the first winding 4a' also performs a vertical movement. Thus, the movement of the first winding 4a' has both a lateral and a vertical movement component. Specifically, during the folding step, the first winding performs an inward lateral movement in the second segment B2, transverse to the voice coil axis A.

[0125] As a result, after this folding step, when viewed in a cross-sectional plane including the voice coil axis A, the first winding 4a and the second winding 4b are located at the same height position or in the same plane arranged perpendicularly to the voice coil axis A.

[0126] exist Figures 9 to 11 In the embodiment shown, the first winding 4 a ′ projects outwardly away from the voice coil axis A before the folding step is performed, and during the folding step performs an inward lateral movement transverse to the voice coil axis A. Alternatively, the first winding 4 a ′ may also project inwardly toward the voice coil axis A before the folding step is performed, and during the folding step performs an outward lateral movement transverse to the voice coil axis A.

[0127] Figures 9 to 11 The shape of the first winding 4a' shown is not limited to folding, but can also be pressed vertically then laterally, laterally then vertically or in a direction with a combined laterally and vertical component. In this variant, there is no folding movement, but only a translational deformation.

[0128] Thirdly, a combined folding and pressing movement of the first windings 4a, 4a' is possible, usually in a second step, so that the first windings 4a, 4a' are moved to the height position of the second winding 4b (case c).

[0129] In all cases (folded and / or pressed), the protrusion of the first winding 4a' helps to avoid or at least limit the stretching of the first winding 4a' in the second section B2, because the first winding 4a' is longer there than the second winding 4b. In particular, the length of the first winding 4a' in the unbent state in the second section B2 can be equal to its length in the bent state.

[0130] It should also be noted that the press movement does not have to be Figure 6 The deformation of the first winding 4a, 4a' can be performed by a kind of pulling movement using a hook, rather than by a punch-like tool 6 as shown. However, in the context of the present disclosure, this pulling movement is considered to be a pressing movement on the first winding 4a, 4a', because a compressive force acts between the first winding 4a, 4a' and the hook, and not a tensile force at that time.

[0131] exist Figures 4 to 11In the example shown, the windings 4a..4g are preferably formed by cutting, stamping or etching a metal sheet or foil. In particular, laser cutting can be used for this process step. In a first embodiment, the individual windings 4a..4g can be formed as Figure 12 As shown, the interconnection is carried out by welding or soldering, wherein in this example only four windings 4a..4d are interconnected. In particular, laser welding or ultrasonic welding can be used for this task.

[0132] In detail, Figure 12 The four windings 4a..4d are shown welded by the laser beam L of the laser 7. In this way, a joint 8 is formed so that the electrical conductor formed by the four windings 4a..4d and the joint 8 has a semi-helical shape. At the end of the electrical conductor are two terminals T1, T2, which are used to connect the voice coil 1b to the amplifier of the audio signal source. It should be noted that Figure 12 Intended to illustrate the welding process and for simplicity, the voice coil 1b has no recess 3a. Alternatively, the electrical conductor can be considered as a stack of windings 4a..4g, wherein the recess 3a is formed later (see in this context Figures 14 to 17 ).

[0133] In another embodiment, the shape of the electrical conductor 9 in the initial state can be most easily interpreted as a shape that resembles a square wave signal. It can be formed by bending the initially straight electrical conductor 9 or again by cutting, punching or etching a metal sheet or foil. In the next step, the pre-winding formed by the electrical conductor 9 is folded on top of each other in a zigzag manner (or like Leporello) along the folding lines F1..F6, as shown in FIG. Figure 13 As depicted. Thus, the electrical conductor 9 is again half-helical at the end. Again, the electrical conductor 9 has a terminal, at Figure 13 Moreover, in this example, the electrical conductor 9 has an optional arcuate segment G which allows the voice coil to move along the voice coil axis A when the voice coil is built into the electrodynamic actuator and when the first terminal T1 is fixed.

[0134] In this context, it should be noted that the terminals T1, T2 of the voice coil 1b are not fixed terminals but moving terminals and should be connected to flexible conductors when the voice coil 1b is built into an electrodynamic actuator. Alternatively, the first winding 4a and the last winding 4b may have extensions of those flexible segments forming the electrical conductor 9.

[0135] In the above example, the windings 4a..4g are formed by a relatively complex production method, which in particular allows the manufacture of voice coils 1a, 1b of any desired shape (even with sharp corners). However, the windings 4a..4g can also be formed by winding the electrical conductor 9.

[0136] It should be noted that in all examples, the windings 4a..4g may be provided with a passivation or insulation layer to prevent short circuits between the windings 4a..4g. This passivation or insulation layer is applied before the windings 4a..4g are interconnected by means of the insulating adhesive 5. If the passivation or insulation layer is sufficiently strong, then in principle, the adhesive 5 does not need to have excellent insulating properties. However, it is clear that the insulation between the windings 4a..4g is achieved by both the passivation or insulation layer and the adhesive 5. Therefore, the appropriate insulating properties of the adhesive 5 improve the overall insulation properties between the windings 4a..4g.

[0137] In all embodiments, the electrical conductor 9 can be made of or comprise aluminum or copper. In the case of aluminum, the electrical conductor 9 is advantageously hardened and annealed in the folded or bent areas. Folds in the electrical conductor 9 can lead to increased electrical resistance in these folded areas, which can affect the acoustic performance of the electric actuator. This increased resistance can be compensated by increasing the width of the electrical conductor 9 in the area of ​​the folds F1 to F6. This, in turn, provides a larger cross-sectional area for current flow, thereby reducing resistance. However, if aluminum is used for the electrical conductor, it can be hardened and locally annealed in the folded areas, which also reduces resistance. In this way, the width of the electrical conductor 9 in the area of ​​the folds F1 to F6 does not need to be increased, as the folding results in little increase in resistance. The same laser 7 used for cutting and / or welding, in particular the same laser, can be used to harden and anneal the electrical conductor 9 in the bent areas.

[0138] As already mentioned, Figure 12 and Figure 13 The example does not show the formation of recesses 3a in the voice coils 1a, 1b. In principle, this can be done sequentially for a plurality of windings 4a..4g as in Figures 4 to 11 The steps outlined in the example shown are followed by forming a Figure 12 and Figure 13 3a. This can be accomplished with the voice coils 1a, 1b outlined in the example of FIG. However, in a more preferred embodiment, the stack of windings 4a, 4g is first formed, and then the plurality of windings 4a, 4g are deformed to form the recess 3a in a single process step. For example, the tool 6 can press the plurality of windings 4a, 4g into shape in a single process step.

[0139] In particular, the production method of the voice coil 1a, 1b may include the following steps:

[0140] i) cutting the electrical conductor 9 from the metal foil;

[0141] ii) forming an insulating layer on the electrical conductor 9;

[0142] iii) Making a stack of windings 4a..4g from electrical conductors 9 by:

[0143] - stacking of windings 4a..4g (individual sheets of electrical conductors 9) and electrically connecting the stacked individual windings 4a..4g (see Figure 12 ), and / or

[0144] - Folded electrical conductor 9 (see Figure 13 );

[0145] iv) applying adhesive 5 between the windings 4a..4g of the stack, and

[0146] v) The windings 4a..4g are formed in the second section B2 or in accordance with the process steps of any of the cases a) to c) in the second section B2.

[0147] In particular, step v) can be accomplished by Figure 14 The mold shown is carried out. In detail, Figure 14 The stack 10 of windings 4a..4g, a lower mold part 11, and an upper mold part 12 are shown. Advantageously, after adhesive 5 has been applied, the stack 10 of windings 4a..4g is placed into recess 13 in lower mold part 11, and the two mold parts 11 and 12 are then pressed against each other to give the stack 10 of windings 4a..4g the desired shape. To form recess 3a in voice coils 1a, 1b, upper mold part 12 has protrusion 14a. In other words, mold parts 11 and 12 have a negative form of voice coils 1a, 1b. Application of adhesive 5 can also be accomplished by simply filling recess 13 in lower mold part 11 with adhesive 5 and pressing out the excess using upper mold part 12.

[0148] exist Figure 15 In another embodiment illustrated, the stack 10 of windings 4a to 4g is pressed between a lower pressing plate 15 and an upper pressing plate 16. Similar to the above embodiment, it is advantageous to place the stack 10 of windings 4a to 4g onto the lower pressing plate 15 after the adhesive 5 has been applied, and then to press the two pressing plates 15 and 16 against each other to give the desired shape to the stack 10 of windings 4a to 4g. To form the recess 3a in the voice coils 1a and 1b, the upper pressing plate 16 has a protrusion or ridge 14b.

[0149] By using Figure 14 and Figure 15 In the two exemplary embodiments, however, a plurality of windings 4a . . . 4g are formed in a single process step, so that the voice coils 1a , 1b can be manufactured very efficiently there and in a short time.

[0150] It should be noted that although Figure 14and 15 A linear pressing movement is shown (case a), but it is also possible to rotate or fold the first winding 4a' in the stack 10 in the second segment B2 (e.g. by using Figures 9 to 11 The illustrated example discloses) (case b), or a combined pressing and folding movement. It is also possible to press the third part of the tool ( Figure 14 and 15 (not shown) causes the first winding 4a' in the stack 10 to bend transversely in the second section B2.

[0151] Figure 16 and Figure 17 The pressing step is shown in more detail. In particular, the stack 10a, 10b of the windings 4a..4g is shown after the pressing tool 6 has been moved downwards. Depending on the material, the windings 4a..4g are more exactly like in Figure 16 The laminate 10a is deformed as in FIG. 1 , or more precisely as in FIG. Figure 17 Of course, mixed deformations are also possible.

[0152] Figure 18 As shown by the voice coil 1c, the recess 3b is not necessarily a cutout or groove (as Figure 1 Instead of the recess 3a in the embodiment of the present invention, the recess 3b can also have the shape of a hole. In this case, there can be a pin-shaped or rod-shaped tool part, which is moved into the region of the recess 3b during the pressing step. It is also possible to first form the two halves of the voice coil 1a, each half having a shape similar to Figure 1 The recess 3a shown in FIG. 3a is then put together to obtain a Figure 18 The shape shown.

[0153] Figure 19 and Figure 20 An example of the electric actuator 17 a is now shown. Figure 19 shows an exploded view of the electric actuator 17a, Figure 20 A cross-sectional view of the electric actuator 17a is shown.

[0154] Typically, the electric actuator 17a is designed to be connected to the back side of the plate-like structure or diaphragm, which is opposite to the sound-generating surface S of the plate-like structure or diaphragm. Figure 19 and Figure 20 In the example shown, the electric actuator 17a is connected to the back of the diaphragm 18. The diaphragm 18 in this example includes a flexible diaphragm portion 19 and a rigid diaphragm portion 20 in the form of a plate. However, the flexible diaphragm portion 19 is only optional and can be omitted. The electric actuator 17a forms a loudspeaker 21 together with the diaphragm 18. Therefore, in principle, Figure 19 shows an exploded view of the loudspeaker 21, Figure 20A cross-sectional view of the loudspeaker 21 is shown.

[0155] The electric actuator 17a includes a voice coil 1d, which can be designed as disclosed above. Furthermore, the electric actuator 17a includes a magnet system 22, which in this example includes a central magnet 23 and an outer magnet 24, as well as a central top plate 25 made of soft iron, an outer top plate 26 made of soft iron, and a bottom plate 27 made of soft iron. The central magnet 23 is mounted to the bottom plate 27 and the central top plate 25, and the outer magnet 24 is mounted to the bottom plate 27 and the outer top plate 26. The magnet system 22 is generally designed to generate a magnetic field M in the annular segment that is transverse to the longitudinal direction of the electrical conductor 9 of the voice coil 1d.

[0156] Furthermore, the electrodynamic actuator 17 a comprises an arm arrangement 28 which generally comprises a plurality of arms (or legs or levers) connecting the voice coil 1 d and the magnet system 22 and allowing relative movement between the voice coil 1 d and said magnet system 22 along an excursion direction E parallel to the voice coil axis A. In this example, the arm arrangement 28 comprises two arm sub-arrangements 29 a, 29 b, each having two arms.

[0157] Finally, the electrodynamic actuator 17a comprises a frame 30 to which the diaphragm 18 (in detail, its flexible diaphragm portion 19), the external magnet 24, the external top plate 26, and the bottom plate 20 are mounted. However, the frame 30 can be shaped differently than depicted and can hold together a different set of components. For example, it can be connected only to the external magnet 24 or the external top plate 26. It should also be noted that the arm arrangement 28 does not necessarily have to directly connect the voice coil 1d and the magnet system 22, but can also connect them (indirectly), for example via the frame 30.

[0158] Figure 21 The voice coil 1d, arm arrangement 28 and frame 30 are shown separated from the rest of the loudspeaker 21 in an angled view from below. Figure 21 It is shown in detail that the voice coil 1d in this embodiment has two recesses 3c, 3d.

[0159] In general, voice coils 1a..1d can have any number of recesses 3a..3d having any desired shape. For example, the corners of voice coils 1a..1d can be raised, while the longitudinal sides can be lowered, or vice versa. Furthermore, recesses 3a..3d can be longer or shorter, can have the shape of a rectangular depression or hole in side view, or can be shaped in another manner. For example, recesses 3a..3d can have the shape of a triangular or circular depression or hole in side view, etc.

[0160] exist Figures 19 to 21In the example shown, the electric actuator 17a is connected to the diaphragm 18, thereby forming the speaker 21. However, this is not a necessary condition, and the electric actuators 17b, 17c may also be connected to the diaphragm 18. Figure 22 and Figure 23 A plate-like structure 31 is shown. Thus, electrodynamic transducers 32a and 32b are formed. Specifically, the plate-like structure 31 includes a sound-generating surface S and a back surface opposite the sound-generating surface S. The electrodynamic actuators 17b and 17c are connected to the back surface of the plate-like structure. To this end, the voice coil 1d or the magnet system 22 includes a flat mounting surface intended to be connected to the back surface of the plate-like structure 31, wherein the back surface is oriented perpendicular to the voice coil axis A.

[0161] Figure 22 A first example of such an electrodynamic transducer 32a is shown. In fact, the electrodynamic actuator 17b looks very much like the electrodynamic actuator 17a used for the loudspeaker 21. In contrast to this, the magnet system 22 is not connected to the plate-like structure 31 but is free to move relative to the voice coil 1d. Figure 22 In the example shown in FIG. 3 , the frame 30 is omitted. However, the electric transducer 32 a may include the frame 30 depending on the specific circumstances.

[0162] Figure 23 An example of an electric transducer 32b is shown, which is similar to Figure 22 The main difference is that the magnet system 22 comprises a fixed part 33 and a movable part 34. In this example, the fixed part 33 is formed by an outer ring 35 made of soft iron, while the movable part 34 is formed by the center magnet 23, the center top plate 25, and the bottom plate 27. Another difference is that the arm arrangement 29a, 29b is arranged inside the voice coil 1d and is connected to the movable part 34 of the magnet system 22. As a result, the movable part 34 can move freely relative to the voice coil 1d.

[0163] Typically, as described, the electric actuators 17b, 17c together with the plate-like structure 31 form the electric transducers 32a, 32b. For example, the plate-like structure can be a passive structure, such as part of the housing of the device in which the electric actuators 17b, 17c are built. However, the plate-like structure itself can also have a special function. For example, if the plate-like structure 31 is implemented as a display, the electric actuators 17b, 17c together with the display form an output device (for both audio and video data).

[0164] In contrast to the diaphragm 18, the plate-like structure 31 does not have a dedicated flexible part in the sense of the present disclosure as the diaphragm 18 has. Therefore, there is no extreme separation of deflection and piston movement, as is the case with the flexible diaphragm part 19 (deflection) and the rigid diaphragm part 20 (piston movement). Instead, the sound is generated via the deflection of the entire plate-like structure 31. Moreover, when a plate-like structure 31 is used, the voice coil 1d or the magnet system 22 (or at least a part thereof) is connected to the plate-like structure 31 or is arranged fixedly relative to the plate-like structure 31. The force applied to the plate-like structure 31 can be provided by the part of the electric actuator 17b, 17c that moves relative to the plate-like structure 31 (in the embodiment of the present invention). Figure 22 In the case of the magnet system 22, Figure 23 In this case, it is caused by the inertia of the movable part 34 of the magnet system 22, or because the part of the electric actuator 17b, 17c that moves relative to the plate structure 31 is fixed to another part (for example, to the housing of the device in which the electric actuator 17b, 17c is built).

[0165] It should also be noted that when the electric actuators 17b, 17c are connected to the back of the plate-like structure 31, the arm arrangement 28 can be regarded as a spring arrangement, while when the electric actuator 17a is connected to the back of the diaphragm 18, the arm arrangement can be regarded as a suspension system.

[0166] Typically, in the frequency range from 100 Hz to 15 kHz, the loudspeaker 21 or the electrodynamic transducer 32 a, 32 b (or output device) of the type disclosed above generates an average sound pressure level of at least 50 dB_SPL, measured at a normal distance of 10 cm from the sound emitting surface S. In particular, the above average sound pressure level is measured at an electrical power of 1 W, more particularly at a nominal impedance.

[0167] It should be noted that the present invention is not limited to the embodiments and exemplary working examples mentioned above. Further developments, modifications and combinations are also within the scope of the present patent claims and belong to those skilled in the art based on the above disclosure. Therefore, the techniques and structures described and illustrated herein should be understood to be illustrative and exemplary, rather than limiting the scope of the invention. The scope of the present invention is defined by the appended claims and includes equivalents and unforeseeable equivalents known at the time of filing this application. Although many embodiments of the present invention are described above with a certain degree of particularity, those skilled in the art may make various changes to the disclosed embodiments without departing from the spirit or scope of the present disclosure.

[0168] It should also be noted that the drawings are not necessarily drawn to scale and that parts depicted may actually be larger or smaller.

[0169] Label list

[0170] 1a..1d Voice Coil

[0171] 2 standard height segments of the voice coil

[0172] 3a..3d Recesses in the voice coil

[0173] 4a..4g Winding

[0174] 5 Insulation adhesive

[0175] 6 Tools

[0176] 7 Laser

[0177] 8 Fusion welding joints

[0178] 9 Electrical conductors

[0179] 10, 10a, 10b winding stack

[0180] 11 Lower mold part

[0181] 12 Upper mold part

[0182] 13 grooves

[0183] 14a, 14b protrusions

[0184] 15 Lower pressure plate

[0185] 16 Upper pressure plate

[0186] 17a..17c Electric actuator

[0187] 18 diaphragms

[0188] 19 Flexible diaphragm part

[0189] 20 Rigid diaphragm section

[0190] 21 speakers

[0191] 22 Magnet System

[0192] 23 center magnet

[0193] 24 External magnets

[0194] 25 center top plate

[0195] 26 External top plate

[0196] 27 bottom plate

[0197] 28-arm arrangement

[0198] 29a, 29b arm layout

[0199] 30 frames

[0200] 31 Plate structure

[0201] 32a, 32b Electric transducer

[0202] 33 Fixed part of the magnet system

[0203] 34 Movable part of the magnet system

[0204] 35 Outer Ring

[0205] A Voice coil axis

[0206] B1 first segment

[0207] B2 Second segment

[0208] C Circumference

[0209] D Section plane

[0210] E offset direction

[0211] F1..F6 Fold Line

[0212] G

[0213] L laser beam

[0214] M magnetic field

[0215] S Sounding surface

[0216] T1, T2 terminal

[0217] h1, h2: Height of the voice coil

[0218] w1, w2 width of the conductor.

Claims

1. A method of manufacturing a voice coil having an electrical conductor in the form of a ring or winding extending along a circumferential line around a voice coil axis, - in, When viewed in a cross-sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, the different windings in a first section of the circumferential line are arranged one above the other, and - wherein the different windings in the second section of the circumferential line are arranged next to each other when viewed in the cross-sectional plane, thereby forming a recess in the voice coil, The method comprises the following steps: - in a first step, in said second section, arranging a first winding and a second winding of said windings above each other but offset to the side with respect to each other, and a) in a second step, in the second section, pressing the first winding to the height of the second winding, or b) in a second step, folding the first winding to the height of the second winding in the second section, or c) In a second step, in the second section, the first winding is moved to the height of the second winding by means of a combined folding and pressing.

2. The method according to claim 1, characterized in that The winding is formed by winding the electrical conductor.

3. The method according to claim 1, wherein The windings are formed by cutting, stamping or etching a metal sheet or foil which: -) interconnection by welding or brazing, and / or -) Fold on top of each other.

4. The method according to claim 1, wherein The electrical conductor is made of or comprises aluminum and is hardened and annealed in the folded or bent regions.

5. The method according to claim 1, wherein During one of steps a) to c), the first of the windings performs a lateral movement transverse to the voice coil axis in the second section.

6. The method according to claim 1, wherein - a first of the windings projects outwardly away from the voice coil axis before performing one of steps a) to c), and during said one of steps a) to c), performs an inward lateral movement transverse to the voice coil axis in the second segment, or - a first of the windings protrudes inwardly towards the voice coil axis before performing one of steps a) to c), and during said one of steps a) to c), performs an outward lateral movement transverse to the voice coil axis in the second segment.

7. The method according to claim 1, characterized in that The following steps are involved: i) cutting the electrical conductor from the metal foil; ii) forming an insulating layer on the electrical conductor; iii) forming a stack of windings from said electrical conductors by: - stacking individual windings and electrically connecting the stacked individual windings, and / or - folding the electrical conductor; iv) applying adhesive between said windings of said stack, and v) forming the winding in the second section or in the second section according to a process step of any one of steps a) to c).

8. The method according to claim 1, characterized in that A plurality of windings are formed in a single process step according to steps a) to c).

9. An electric actuator, the electric actuator being designed to be connected to a back surface of a plate-like structure or a diaphragm, the back surface being opposite to a sound-generating surface of the plate-like structure or the diaphragm, and comprising: - at least one voice coil having, in an annular segment, an electrical conductor in the form of a ring or winding extending along a circumferential line around a voice coil axis, and in particular the at least one voice coil being manufactured by a method according to any one of claims 1 to 8, and - a magnet system designed to generate a magnetic field transverse to the conductor in an annular segment of the at least one voice coil, - wherein the different windings of the electrical conductor in a first section of the circumferential line are arranged one above the other when viewed in a cross-sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, and - wherein the different windings of the electrical conductor in the second section of the circumferential line are arranged next to each other when viewed in the cross-sectional plane.

10. The electric actuator according to claim 9, wherein The first segment or the plurality of first segments together relate to at least 50% of the circumferential line, and the second segment or the plurality of second segments together relate to at most 50% of the circumferential line.

11. The electric actuator according to claim 9, wherein: The conductor has a circular cross section or a rectangular cross section.

12. The electric actuator according to claim 9, wherein: When viewed in the sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, in the first segment, more different windings are arranged one above the other than in the second segment, and in the second segment, more different windings are arranged next to each other than in the first segment.

13. The electric actuator according to claim 9, wherein: When viewed in the cross-sectional plane perpendicular to the circumferential line and when the voice coil axis indicates the height direction, all windings in the first section of the circumferential line are arranged one above the other.

14. The electric actuator according to claim 9, wherein - the first parts of the windings in the second section of the circumferential line are arranged next to each other when viewed in the cross-sectional plane perpendicular to the circumferential line, and - the remaining second parts of the windings in the second section of the circumferential line are arranged one above the other when viewed in the cross-sectional plane.

15. The electric actuator according to claim 9, wherein: A dotted line disposed in the cross-sectional plane perpendicular to the circumferential line and oriented perpendicular to the voice coil axis indicates a width direction, and the width of the conductor is the same in the first segment and in the second segment.

16. The electric actuator according to claim 9, wherein: A dotted line disposed in the cross-sectional plane perpendicular to the circumferential line and oriented perpendicular to the voice coil axis indicates a width direction, and the width of the conductor in the first segment is greater than the width of the conductor in the second segment.

17. The electric actuator according to claim 9, wherein: A dashed line disposed in the cross-sectional plane perpendicular to the circumferential line and oriented perpendicular to the voice coil axis indicates a width direction, and the total width of the winding is the same in the first segment and in the second segment.

18. The electric actuator according to claim 9, wherein: Exactly two of the windings are disposed next to each other at a specific height level in the second section, or more than two of the windings are disposed next to each other at a specific height level in the second section, so that the recess is formed deeper.

19. The electric actuator according to claim 9, wherein: The at least one voice coil or the magnet system comprises a flat mounting surface intended to be connected to a back side of the panel-like structure, opposite to a sound-emitting surface of the panel-like structure, wherein the back side is oriented perpendicular to the voice coil axis.

20. A speaker, characterized in that The electric actuator and diaphragm according to claim 9, wherein the diaphragm is fixed to the at least one voice coil and to the magnet system.

21. An electrodynamic transducer comprising a plate-like structure having a sound-generating surface and a back surface opposite to the sound-generating surface, and comprising an electrodynamic actuator connected to the back surface, wherein: The electric actuator is designed according to claim 9.

22. The electric transducer according to claim 21, wherein The average sound pressure level of the electrodynamic transducer measured at a normal distance of 10 cm from the sound-emitting surface in the frequency range from 100 Hz to 15 kHz is at least 50 dB_SPL.

23. An output device, characterized in that: The plate-like structure in the electric transducer according to claim 21 is implemented as a display, and the electric actuator is connected to a back surface of the display.

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