Electrodynamic exciter and electrodynamic transducer

Abstract

The invention relates to an electrodynamic exciter and an electrodynamic transducer. Disclosed is an electric exciter designed to be connected to a sound emitting structure and comprising a voice coil arrangement having at least one voice coil and a magnetic circuit system, the magnetic circuit system comprising an annular peripheral magnetic circuit system part and a central magnetic circuit system part, the voice coil arrangement being between the annular peripheral magnetic circuit system part and the central magnetic circuit system part. Further, the electric exciter includes a spring device coupling the peripheral magnetic circuit system portion to the central magnetic circuit system portion and allowing relative movement between the peripheral magnetic circuit system portion and the central magnetic circuit system portion in an offset direction parallel to the voice coil axis. The central magnetic circuit system portion comprises a central magnet and at least one plate adjoining the central magnet in an offset direction, where the at least one plate comprises a collar on its outer edge facing away from the central magnet. In addition, an electrodynamic transducer having such an electrodynamic exciter is disclosed.

Description

Technical Field

[0001] The invention relates to an electrodynamic exciter, which is designed to be connected to a sound-generating structure and comprises a voice coil device having at least one voice coil and a magnetic circuit system having an annular peripheral magnetic circuit system part and a central magnetic circuit system part, between which the voice coil device is located. The at least one voice coil has a magnetizer in the shape of an annulus extending around the voice coil axis in the annulus part, and the magnetic circuit system is designed to generate a magnetic field transverse to the magnetizer in the annulus part. In addition, the electrodynamic exciter comprises a spring device, which couples the peripheral magnetic circuit system part to the central magnetic circuit system part and allows relative movement between the peripheral magnetic circuit system part and the central magnetic circuit system part in an offset direction parallel to the voice coil axis. The central magnetic circuit system part comprises a central magnet and at least one plate adjacent to the central magnet in the offset direction. In addition, the invention relates to an electrodynamic transducer, which comprises a sound-generating structure and an electrodynamic exciter of the above type connected to the sound-generating structure. Background Art

[0002] Electrodynamic exciters and electrodynamic transducers of the above type are generally known in the prior art. Typically, the central magnetic circuit system part comprises a central magnet and a first plate or top plate adjoining the central magnet above in the offset direction and a second plate or bottom plate adjoining the central magnet below in the offset direction to guide the magnetic flux generated by the central magnet. Typically, the plates are simply cut or stamped out of a sheet, which is easy to produce, but this leads to some disadvantages:

[0003] Firstly, the magnetic flux density and magnetic resistance of the airgap in which at least one voice coil is arranged are inversely proportional to the height of the at least one plate, which also means that the magnetic flux density and magnetic resistance are inversely proportional to the mass of the at least one plate. Since the central magnetic circuit system part is usually the moving magnet part, this also means that the magnetic flux density and magnetic resistance affect the oscillation behavior of the central magnetic circuit system part. In other words, reducing the magnetic flux density and magnetic resistance leads to an increase in the mass of the central magnetic circuit system part and, therefore, to a deterioration of the high frequency response of the electrodynamic exciter in its application and to an undesirable reduction in the resonant frequency.

[0004] Secondly, it should be noted that the magnetic resistance or reluctance acts as a kind of "magnetic spring" because the magnetic circuit system tends to move to the position where the absolute value of the magnetic resistance or reluctance reaches a minimum. In turn, this also means that the height of at least one plate affects the idle position of the magnetic circuit system. In other words, moving the idle position by changing the height of at least one plate is again closely related to the changing mass of the moving central magnetic circuit system part.

[0005] Third, the height of at least one plate affects the maximum operating excursion. The thicker the plate, the higher the maximum operating excursion. In other words, increasing the maximum operating excursion again results in an increase in the mass of the central magnetic circuit system part and, therefore, in a deterioration in the high frequency response of the electrodynamic exciter.

[0006] Finally, the height of the at least one plate also influences the maximum overexcursion before further movement of the central magnetic circuit system part is mechanically blocked by another part of the electrodynamic exciter. This maximum overexcursion is not caused by normal operation, but by external excessive acceleration, for example when the electrodynamic exciter or a device in which the electrodynamic exciter is built falls to the ground. Excessive excursions may damage the electrodynamic exciter, in particular the spring device, which is usually quite filigree. In order to reduce the maximum overexcursion, it is conceivable to increase the height of the at least one plate, which again leads to an increase in the mass of the central magnetic circuit system part, as described above, and therefore to a deterioration of the high-frequency response of the electrodynamic exciter. Summary of the invention

[0007] Therefore, the object of the present invention is to overcome the disadvantages of the prior art and provide an improved electrodynamic exciter and an improved electrodynamic transducer. In particular, the above parameters of the electrodynamic exciter should keep the mass of the central magnetic circuit system part unchanged or substantially unchanged, thereby improving the design freedom of the electrodynamic exciter.

[0008] The problem of the invention is solved by an electrodynamic exciter as defined in the opening paragraph, wherein at least one plate comprises a collar on its outer edge (or respectively a raised edge region) which faces away from the central magnet in the deflection direction.

[0009] The problem of the invention is also solved by an electrodynamic (acoustic) transducer comprising a sound-emitting structure and an electrodynamic exciter of the above-described type connected to the sound-emitting structure. For example, the sound-emitting structure can be implemented as a diaphragm, a display screen or as a housing part of a device in which the electrodynamic exciter is built in. In the latter case, a device is formed, which comprises a housing and an electrodynamic exciter of the above-described type connected to the housing, wherein the housing forms the sound-emitting structure. In particular, the electrodynamic exciter can be mounted to the back side of the sound-emitting structure opposite to the sound-emitting surface of the sound-emitting structure, wherein the back side is oriented perpendicular to the voice coil axis.

[0010] By using the proposed measures, the disadvantages of the prior art are overcome. For example, the magnetic flux density and the magnetic resistance of the magnetic gap in which at least one voice coil is arranged are no longer inversely proportional to the mass of at least one plate, which contributes to the mass of the central magnetic circuit system part and affects the frequency response of the electrodynamic exciter. Advantageously, magnetic saturation of at least one plate can be avoided without significantly increasing its mass. In addition, the strength of the "magnetic spring", the maximum operating excursion (caused by the maximum nominal current flowing through at least one voice coil) and the maximum excessive excursion (caused by excessive external acceleration) are decoupled from the mass and oscillation behavior of the central magnetic circuit system or are less coupled to the mass and oscillation behavior of the central magnetic circuit system. Therefore, the collar solves many problems in the design of electrodynamic exciters in a synergistic manner and significantly improves the design freedom of electrodynamic exciters. In summary, at least the following parameters of the electrodynamic exciter are decoupled from the mass and oscillation behavior of the central magnetic circuit system or are less coupled to the mass and oscillation behavior of the central magnetic circuit system: magnetic flux density, magnetic resistance, magnetic spring, maximum operating excursion, maximum excessive excursion.

[0011] Typically, an "electric exciter" converts electrical energy into movement and force. The electric exciter together with the sound-emitting structure forms an "electric (acoustic) transducer". If the sound-emitting structure is a diaphragm, the electric exciter together with the diaphragm forms a "speaker". However, the sound-emitting structure can also have a more common shape and can, for example, also be a housing part of a device in which the electric exciter is built-in (for example, the device can be an in-ear transducer). Another special embodiment of the sound-emitting structure is a display screen. In this case, the electric exciter together with the display screen forms an "output device" (for both audio data and video data). Typically, the speaker, the electric transducer and the output device convert electrical energy into sound. Typically, the above-mentioned devices can also be intended to generate vibrations for tactile feedback.

[0012] In one embodiment, the voice coil device may be connected to the peripheral magnetic circuit system portion, and a magnetic gap may be formed between the voice coil device and the central magnetic circuit system portion. In another embodiment, the voice coil device may be connected to the central magnetic circuit system portion, and a magnetic gap may be formed between the voice coil device and the peripheral magnetic circuit system portion. In addition, the central magnetic circuit system portion or the peripheral magnetic circuit system portion may be mounted to the sound generating structure.

[0013] The force applied to the sound-emitting structure to produce the sound may be generated by the inertia of the part of the electrodynamic exciter that moves relative to the sound-emitting structure (action-reaction principle), or because the part of the electrodynamic exciter that moves relative to the sound-emitting structure is fixed to another part (for example, fixed to the housing of the device in which the electrodynamic exciter is built). Therefore, if the central magnetic circuit system part is mounted to the sound-emitting structure, the sound can be generated by the inertia of the moving peripheral magnetic circuit system part, or because the peripheral magnetic circuit system part is fixed to the other part. Vice versa, in the case where the peripheral magnetic circuit system part is mounted to the sound-emitting structure, this means that the sound can be generated by the inertia of the moving central magnetic circuit system part, or because the central magnetic circuit system part is fixed to the other part. In this case, it is advantageous if the part of the magnetic circuit system intended to be connected to the sound-emitting structure includes a flat mounting surface designed to be connected to the sound-emitting structure.

[0014] It should be noted that the sound can also be emitted from the back side of the sound-emitting structure. However, the back side usually faces the internal space of the device (e.g., a mobile phone) in which the electric exciter is built-in. Therefore, the sound-emitting structure can be considered to have a primary sound-emitting surface and an auxiliary sound-emitting surface (i.e., the back side). The sound waves emitted by the primary sound-emitting surface directly reach the user's ears, while the sound waves emitted by the auxiliary sound-emitting surface do not directly reach the user's ears, but only indirectly reach the user's ears via reflection or excitation (excitation) of other surfaces of the device housing in which the speaker or output device is built-in.

[0015] The springs of the spring device can each include an annular outer spring area connected to the peripheral magnetic circuit system part and a spring arm protruding inwardly and connected to the central magnetic circuit system part. However, the spring arms are not necessarily interconnected, but a pair of (a couple of) separate spring arms can also form a spring.

[0016] Often, in addition to the lateral fixation of the components of the magnetic circuit system and their spring function, the "spring arms" can also be used as dampers for the oscillating system. Therefore, the arms can also be seen and denoted as "damping arms" or "combined spring and damping arms". Often, by giving the arms different shapes and / or by making them of specific materials, different functions can be influenced. A spring arm is not necessarily a straight rod, but can be curved in its relaxed state.

[0017] In the context of the present disclosure, the term "annular" generally refers not only to circular rings, but also to other shapes, such as ellipses and polygons, in particular rectangles. In the case of polygons, it should also be noted that the straight sections of the polygon are not necessarily connected by sharp corners, but can also be connected by rounded corners. This definition relates to both the magnetic circuit system and the voice coil.

[0018] Furthermore, the term "annular" in the context of the peripheral magnetic circuit system part refers not only to a closed ring, but also to an annular arrangement of individual segments forming a ring as a whole. The segments may be in contact with each other, but may also be spaced apart from each other. This includes in particular straight segments forming straight sections of a polygon, wherein these segments may be connected or wherein the ends of the segments may be spaced apart from each other.

[0019] In one embodiment, the electric exciter may include a frame and / or a housing. The "frame" may hold multiple parts of the electric exciter together to form a subsystem, which may be the result of an intermediate step in the production process. For example, the frame may be directly connected to the magnetic circuit system (e.g., via an adhesive). The "housing" may be mounted to the frame and / or other parts of the electric exciter and may enclose the back cavity volume of the electric transducer, i.e., the air or gas compartment behind the sound-generating structure. In common designs, the housing may be hermetically sealed, respectively. However, depending on the circumstances, it may also include a small opening or a bass tube. In particular, the acoustic performance of the electric transducer may be affected by respectively changing the back cavity volume by providing openings in the housing.

[0020] It should be noted that deviations from the given numbers defined in the patent claims are unavoidable in reality due to technical tolerances, but in any case those patent claims should generally cover these deviations. Specifically, this means that the numbers defined in the patent claims are considered to include a range of + / -10% of the base value.

[0021] Further advantageous embodiments are disclosed in the claims and in the description as well as in the drawings.

[0022] Advantageously,

[0023] - the height of the collar may be in the range of 0.05 mm to 0.2 mm, the height of the collar being the extension of the collar in the offset direction; and / or

[0024] The width of the collar may be in the range of 0.2 mm to 0.6 mm, the width of the collar being half the difference between the outer dimension of the collar in a direction perpendicular to the circular path of the collar and the inner dimension of the collar in said direction.

[0025] In this way, the collar provides the above-mentioned advantages without significantly affecting the mass of the central magnet portion.

[0026] In another advantageous embodiment of the electrodynamic exciter,

[0027] - the height of the collar is in the range of 10% to 100% of the total height of the at least one plate, the height of the collar being the extension of the collar in the offset direction, the total height of the at least one plate being the extension of the at least one plate in the offset direction, and / or

[0028] - the width of the collar is in the range of 2% to 20% of the total width of the at least one plate, the width of the collar being half the difference between the outer dimension of the collar in a direction perpendicular to the annular path of the collar and the inner dimension of the collar in said direction, the total width of the at least one plate being the extension of the at least one plate in said direction perpendicular to the annular path, and / or

[0029] - the area of ​​the collar seen in a direction parallel to the voice coil axis is in the range of 5% to 80% (particularly in the range of 5% to 50% and more particularly in the range of 5% to 20%) of the total area of ​​the at least one plate seen in said direction.

[0030] In this way, the collar provides the above-mentioned advantages without significantly affecting the mass of the central magnet portion.

[0031] In one embodiment, the collar is continuous. In this way, the disclosed advantages are obtained over the entire at least one plate. However, in another embodiment, the collar can be discontinuous (i.e., the collar has gaps). In this way, the disclosed advantages are obtained only over a portion of at least one plate, however, with the advantage of reduced weight of the central magnetic circuit system portion and other advantages as appropriate.

[0032] In a very advantageous embodiment of the electrodynamic exciter, the collar is broken, wherein the arms of the spring device are arranged in the gap of the broken collar. Without taking measures, the central magnetic circuit system part could hit the spring device and damage the rather fragile spring arm at the maximum overexcursion caused by excessive external acceleration. However, by using the proposed measures, this potential risk can be avoided and the spring arm can be prevented from being damaged by the central magnetic circuit system part.

[0033] In a very advantageous embodiment of the electrodynamic exciter, the spring device comprises an annular outer spring region, which is connected to the peripheral magnetic circuit system part, and a spring arm, which projects inwards and is connected to the central magnetic circuit system part, wherein the annular outer spring region at least partially reaches over the collar. In this way, the spring arm can also be prevented from being damaged by the central magnetic circuit system part, because the central magnetic circuit system part hits the spring device at the relatively rigid annular outer spring region instead of at the relatively fragile spring arm in the event of an excessive deflection of the central magnetic circuit system part due to excessive external acceleration.

[0034] Typically, the plates and the peripheral magnetic circuit system parts can be made of soft iron. In this way, the magnetic flux can be guided in a useful way and the magnetic resistance can be kept small.

[0035] In various embodiments of the electrodynamic exciter,

[0036] - the plate can abut the central magnet from above, or

[0037] - the plate can abut the central magnet below, or

[0038] - The (first) plate can be adjacent to the central magnet at the top, and the central magnetic circuit system part can include another (second) plate, which is adjacent to the central magnet at the bottom in the offset direction and includes a ring on its outer edge (respectively a raised edge area) facing away from the central magnet.

[0039] The first two embodiments are advantageous in the case of an electrodynamic exciter with only one voice coil, whereas the third embodiment is advantageous in the case of an electrodynamic exciter with two voice coils, wherein the magnetic flux passes through two magnetic gaps and wherein the disclosed advantages can be provided twice by using two plates. It should also be noted that the above embodiments disclosed in the context of the (first) plate and the resulting advantages also relate to the collar of the second plate.

[0040] Advantageously, the average sound pressure level of the electric transducer or output device measured at a vertical distance of 10 cm from the sound emitting surface is at least 50 dB in the frequency range from 100 Hz to 15 kHz. "Average sound pressure level SPLAVG" generally refers to the integral of the sound pressure level SPL in a specific frequency range divided by the frequency range. In the above context, it specifically refers to the ratio of the sound pressure level SPL integrated in the frequency range from f = 100 Hz to f = 15 kHz to the frequency range from f = 100 Hz to f = 15 kHz. In more mathematical terms, this means:

[0041] BRIEF DESCRIPTION OF THE DRAWINGS

[0042] These and other aspects, features, details, utilities and advantages of the present invention will become more 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:

[0043] Figure 1 shows a cross-sectional view of an exemplary electrodynamic transducer;

[0044] Figure 2 Shown in Figure 1 An oblique cross-sectional view of an electrodynamic exciter used in an electrodynamic transducer;

[0045] Figure 3 Shows Figure 2 A detailed oblique cross-section of the electrodynamic exciter in the collar area;

[0046] Figure 4 Shows Figures 1 to 3 An oblique view of the top plate of the electrodynamic exciter depicted in;

[0047] Figure 5 similar Figure 3 , but with an enlarged collar;

[0048] Figure 6 Shows Figure 5 an oblique view of the top plate of the electrodynamic exciter depicted;

[0049] Figures 7 to 12 showing oblique cross-sectional views of electrodynamic exciters having plates with collars of various shapes;

[0050] Figures 13 to 16 Oblique views of the top plate showing broken collars of various shapes;

[0051] Fig.17 It shows that Fig.16 an oblique cross-sectional view of an electrodynamic exciter of the depicted panel; and

[0052] Fig.18 Shows Fig.17 Top view of the electric exciter.

[0053] Like reference numerals designate like or equivalent parts throughout the several views. DETAILED DESCRIPTION

[0054] 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 described in the specification and illustrated in the drawings. However, it will be appreciated by those skilled in the art that the embodiments may be practiced without such specific details. In other cases, well-known operations, components, and elements are not described in detail to avoid making the embodiments described in the specification unclear. It will be appreciated by those of ordinary skill in the art that the embodiments described and illustrated herein are non-limiting examples, and it will therefore be appreciated that the specific structural and functional details disclosed herein may be representative, and are not necessarily intended to limit the scope of the embodiments, which are limited only by the appended claims.

[0055] References throughout the specification to "various embodiments," "some embodiments," "one embodiment," or "an embodiment," etc., mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in at least one embodiment. Therefore, phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," etc., appearing in various places throughout the specification do not necessarily all refer to the same embodiment. In addition, in one or more embodiments, particular features, structures, or characteristics may be combined in any suitable manner. Therefore, particular features, structures, or characteristics illustrated or described in conjunction 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.

[0056] 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 expressly stated otherwise.

[0057] The terms "first", "second", etc. (if any) in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe a particular order or chronological order. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the invention described herein can, for example, operate in a sequence different from that illustrated or otherwise described herein. In addition, the terms "including", "having" and any variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article or device that includes a series of elements is not necessarily limited to these elements, but may include other elements that are not explicitly listed or inherent to the process, method, article or device.

[0058] All directional references (e.g., "plus," "minus," "up," "down," "upward," "downward," "left," "right," "leftward," "rightward," "front," "rear," "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, particularly as to position, orientation, or use of any aspect of the present disclosure. It should 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 operation in other orientations than those illustrated or otherwise described herein.

[0059] As used herein, the phrases "configured to," "configured for," and similar phrases indicate that the subject apparatus, device, or system is designed and / or constructed (e.g., through appropriate hardware, software, and / or components) to achieve one or more specific intended purposes, rather than that the subject apparatus, device, or system is capable of performing only those intended purposes.

[0060] Jointer references (e.g., "attach," "couple," "connect," etc.) should be interpreted broadly and may include intermediate members between the connection of elements and relative movement between elements. Therefore, a joint reference does not necessarily infer that two elements are directly connected and are in a fixed relationship with each other. It is intended that all content contained in the above description or shown in the accompanying drawings should be interpreted as merely exemplary and not restrictive. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims. However, the term "connect" in the present disclosure may specifically mean "direct connection" (without an intermediate portion), and the term "connection" in the present disclosure may specifically mean "direct or indirect connection" (with or without an intermediate portion).

[0061] All numbers expressing measurement and the like used in the description and claims are to be understood in any case as being modified by the term “about” or “substantially”, which especially means a deviation of ±10% from the reference value.

[0062] Figure 1 1 shows a cross-sectional view of an exemplary electrodynamic transducer 1, which includes an electrodynamic exciter 2a connected to a sound-generating structure 3. In addition, Figure 2 Shown in Figure 1 An oblique cross-sectional view of an electrodynamic exciter 2a used in the electrodynamic transducer 1, Figure 3 The region of the collars 14a, 14a' is shown. Figure 2 A detailed oblique cross-sectional view of the electrodynamic exciter 2a, and Figure 4 Shown in Figures 1 to 3 0047] An oblique view of the top plate 12a of the electrodynamic exciter 2a is depicted in FIG.

[0063] The electrodynamic exciter 2a includes a voice coil device 4 having two voice coils 5 and 6 and a magnetic circuit system 7a having an annular peripheral magnetic circuit system part 8a and a central magnetic circuit system part 9a, with the voice coil device 4 being provided between the annular peripheral magnetic circuit system part 8a and the central magnetic circuit system part 9a. The two voice coils 5 and 6 each have a ring-shaped magnetic conductor extending around the voice coil axis C in the ring part L, and the magnetic circuit system 7a is designed to generate a magnetic field B transverse to the conductor in the ring part L.

[0064] Specifically, the peripheral magnetic circuit system part 8a includes an annular ring body 10 or is formed by the annular ring body 10. In addition, the central magnetic circuit system part 9a includes a central magnet 11 and a first plate or top plate 12a (hereinafter referred to as "first plate 12a"), and a second plate or bottom plate 13a (hereinafter referred to as "second plate 13a"), the first plate 12a is adjacent to the central magnet 11 above in the offset direction, and the second plate 13a is adjacent to the central magnet 11 below in the offset direction. The first plate 12a and the second plate 13a each include a collar 14a, 14a' on its outer edge (respectively a raised edge area), and the collar 14a, 14a' faces away from the central magnet 11 in the offset direction. Therefore, the first plate 12a includes an upward-facing collar 14a on its outer edge, and the second plate 13a includes a downward-facing collar 14a' on its outer edge. Typically, the plates 12a, 13a and the peripheral magnetic circuit system part 8a can be made of soft iron.

[0065] In addition, the electrodynamic exciter 2a includes a spring device 15, which connects the peripheral magnetic circuit system part 8a to the central magnetic circuit system part 9a and allows relative movement between the peripheral magnetic circuit system part 8a and the central magnetic circuit system part 9a in an offset direction parallel to the voice coil axis C. Specifically, the spring device 15 includes a first spring or top spring 16 (hereinafter referred to as "first spring 16") arranged above the magnetic circuit system 7a and a second spring or bottom spring 17 (hereinafter referred to as "second spring 17") arranged below the magnetic circuit system 7a.

[0066] In this example, the springs 16, 17 each comprise an annular outer spring region 18 connected to the peripheral magnetic circuit system portion 8a and a spring arm 19 protruding inwardly and connected to the central magnetic circuit system portion 9a. Figures 1 to 3 The specific shapes of the springs 16 and 17 depicted in the drawings are merely exemplary, and springs of other shapes are also applicable. It should also be noted that the spring arms 19 are not necessarily interconnected, but a pair of separate spring arms 19 can form the first spring 16 and the second spring 17.

[0067] For example, the electrodynamic exciter 2a may be provided by a glue layer or an adhesive sheet ( Figure 1 1 (not shown) is connected to the sound emitting structure 3. To this end, the electrodynamic exciter 2a advantageously comprises a flat mounting surface, for example a flat mounting surface on the first spring 16, which is intended to be connected to the sound emitting structure 3. In particular, the sound emitting structure 3 has a sound emitting surface S and a back side opposite to the sound emitting surface S, wherein the electrodynamic exciter 2a is connected to the back side.

[0068] The sound-emitting structure 3 can be a passive structure, such as a part of the housing of a device in which the electrodynamic exciter 2a is built. However, the sound-emitting structure 3 itself can also have special functions. For example, if the sound-emitting structure 3 is implemented as a display screen, the electrodynamic exciter 2a forms an output device (for both audio data and video data) together with the display screen. In addition, the sound-emitting structure 3 can also be a diaphragm. In this case, the electrodynamic exciter 2a forms a loudspeaker together with the diaphragm.

[0069] Typically, a loudspeaker or electrodynamic transducer 1 (or output device) of the type disclosed above preferably produces an average sound pressure level of at least 50 dB_SPL in a frequency range of 100 Hz to 15 kHz, the average sound pressure level being measured at a vertical distance of 10 cm from the sound emitting surface. Specifically, the above average sound pressure level is measured at an electrical power of 1 W, more particularly at nominal impedance.

[0070] At this point, it should also be noted that Figure 1 The display screen of the sound-generating structure 3 in the embodiment of the present invention can be elastically connected to the housing of the device, of which the display screen is a part. In this case, the display screen can be regarded as the rigid diaphragm part of the diaphragm, wherein the display screen similar to the rigid diaphragm part mainly moves in a piston mode. Therefore, especially in this case, the boundary between the electrodynamic transducer 1 and the loudspeaker can be blurred with each other.

[0071] The force applied to the sound-generating structure 3 to generate sound can be provided by a portion of the electrodynamic exciter 2a that moves relative to the sound-generating structure 3 (which is Figure 1 This may be due to the inertia of the central magnetic circuit system part 9a in the sound generating structure, or because the part of the electric exciter 2a that moves relative to the sound generating structure 3 is fixed to another part (for example, fixed to the housing of the device in which the electric exciter 2a is built).

[0072] The connection between the sound-generating structure 3 and the electrodynamic exciter 2a is not necessarily made on the spring device 15 (here on the first spring 16), but can also be made on the annular ring body 10 or the intermediate part. In addition, the sound-generating structure 3 can also be connected to the central magnetic circuit system part 9a, which in turn causes the peripheral magnetic circuit system part 8a to move relative to the sound-generating structure 3. In other words, in this case, the role of the central magnetic circuit system part 9a and the peripheral magnetic circuit system part 8a changes.

[0073] In the context of the annular peripheral magnetic circuit system portion 8a, the term "annular" refers not only to a closed ring, but also to an annular device of individual segments forming a ring as a whole. For example, the annular peripheral magnetic circuit system portion 8a may include individual segments forming a ring as a whole. The segments may be in contact with each other, but they may also be spaced apart from each other. In particular, the annular peripheral magnetic circuit system portion 8a may include straight segments in which the corner areas are omitted.

[0074] Figures 1 to 4 An embodiment of the electrodynamic exciter 2a is shown with relatively small collars 14a, 14a'. However, this has no bonding features, and the collars 14b, 14b' may also be larger, as in Figure 5 and Figure 6 As shown in, Figure 5 A detailed oblique section view of another embodiment of an electrodynamic exciter 2b in the region of the collars 14b, 14b' is shown, and Figure 6 Shows Figure 5 0047] An oblique view of the top plate 12b of the electrodynamic exciter 2b depicted in FIG.

[0075] Specifically,

[0076] - the advantageous height h of the collars 14a..14b' c The advantageous height h of the collars 14a..14b' is in the range of 0.05 mm to 0.2 mm. c is the extension of the collar 14a..14b' in the offset direction; and / or

[0077] - the width w of the collar 14a..14b' c The width w of the collar 14a..14b' is in the range of 0.2 mm to 0.6 mm. c It is half of the difference between the outer dimension of the collar 14a..14b' in a direction perpendicular to the circular path AC of the collar 14a..14b' and the inner dimension of the collar 14a..14b' in said direction.

[0078] Alternatively or additionally, it is advantageous if:

[0079] - the height h of the collars 14a..14b' c At a total height h of the at least one plate 12a..13b p The total height h of the at least one plate 12a..13b is in the range of 10% to 100%. p is the extension of the at least one plate 12a..13b in the offset direction, and / or

[0080] - the width w of the collar 14a..14b' c The total width w of the at least one plate 12a..13b p The total width w of the at least one plate 12a..13b is in the range of 2% to 20%. p is the extension of the at least one plate 12a..13b in the direction perpendicular to the circular route AC, and / or

[0081] - The area of ​​the collar 14a..14b' seen in a direction parallel to the voice coil axis C is in the range of 5% to 80% (in particular, in the range of 5% to 50% and more particularly in the range of 5% to 20%) of the total area of ​​the at least one plate 12a..13b seen in said direction.

[0082] By using the collars 14a, 14a' at least the following parameters of the electrodynamic exciter 2a can be influenced without too much influencing the mass and the oscillating behavior of the central magnetic circuit system part 9a: flux density, magnetic resistance, magnetic spring, maximum operating deflection, maximum overdeflection.

[0083] For example, the height h of the collars 14a..14b' c Directly affects the flux density, magnetoresistance and reluctance. However, Figures 1 to 6 It can be imagined that the height h c It also has an impact on the maximum operating excursion (which is caused by the current flowing through the voice coil 5, 6), because the voice coil 5, 6 does not move away from the magnetic field B. Finally, the height h c The maximum over-excursion (which is caused by the external acceleration) is affected, i.e. the excursion until the movement of the moving part of the electrodynamic exciter 2a, 2b (which in the above example is the central magnetic circuit system part 9a, 9b) is blocked. Specifically, in the above example, the central magnetic circuit system part 9a, 9b hits the spring device 15 at the time of over-excursion. However, in other embodiments, the movement of the moving part of the electrodynamic exciter 2a, 2b can also be blocked by other parts, for example by a dedicated stopper.

[0084] Figures 7 to 12 Various oblique cross-sectional views of electrodynamic exciters 2c..2h having plates 12c..13h with collars 14c..14h' of various shapes are now shown. Specifically, Figure 7 An electrodynamic exciter 2c is shown having a plate 12c, 13c with a collar 14c, 14c' having a cross section in the shape of a semicircle, Figure 8 An electrodynamic exciter 2d is shown having plates 12d, 13d with collars 14d, 14d' having a triangular cross section, Fig. 9An electrodynamic exciter 2e is shown having plates 12e, 13e with collars 14e, 14e' having roundings, Fig.10 An electrodynamic exciter 2f is shown having a plate 12f, 13f with a collar 14f, 14f' having a square cross section and an inner groove, Fig.11 An electrodynamic exciter 2g is shown having a plate 12g, 13g with a collar 14g, 14g' having a chamfered square cross section and an inner groove, and Fig.12 An electrodynamic exciter 2h is shown with a plate 12h, 13h with a collar 14h, 14h' having a rounded square cross section and an inner groove. In general, the shape of the cross section of the collar 14c..14h' influences the magnetic flux. For example, the groove concentrates the magnetic flux and the rounded corners smooth the magnetic flux. By means of the proposed measures, the design of the collar 14c..14h' can be easily adapted to the requirements when designing the electrodynamic exciter 2g..2h.

[0085] exist Figures 1 to 6 In the example of , the collar 14a..14b' is continuous. This is why the disclosed advantages are obtained over the entire plate 12a..13b. However, this is not a necessary condition. In this context, Figures 13 to 16 A further example of a first plate 12i..12l with a broken collar 14i..14l is shown, which means that the collar 14i..14l has a gap G therein. In this way, the disclosed advantages are obtained only at a portion of the plate 12i..12l, however with the advantage of reduced weight of the plate 12i..12l and other advantages as the case may be.

[0086] In a very advantageous embodiment, the arms 19 of the spring device 15 are arranged in the gaps G of the disconnected collars 14i..14l. In this context, Fig.17 and Fig.18 Shows the use of Fig.16 Example of an electrodynamic exciter 21 with the plates 121, 131 depicted. By using the proposed measures, it is possible to prevent the spring arm 19 from being damaged by the central magnetic circuit system part 91 in the event that it reaches its maximum overexcursion caused by excessive external acceleration. Instead, the annular outer spring area 18 at least partially exceeds the collar 141, 141' and the central magnetic circuit system part 91 hits the relatively rigid annular outer spring area 18 when it reaches its maximum overexcursion. However, in another design, the central magnetic circuit system part 9a, 9l can hit another part of the electrodynamic exciter 2a..2l, such as a dedicated stop.

[0087] In the aforementioned example, the voice coil device 4 is connected to the peripheral magnetic circuit system portion 8a, 81, and a magnetic gap is formed between the voice coil device 4 and the central magnetic circuit system portion 9a, 91. However, this is not a necessary condition, and the voice coil device 4 may also be connected to the central magnetic circuit system portion 9a, 91, wherein a magnetic gap is formed between the voice coil device 4 and the peripheral magnetic circuit system portion 8a, 81. In this case, the roles of the central magnetic circuit system portion 9a, 91 and the peripheral magnetic circuit system portion 8a, 81 change as they move relative to each other.

[0088] Finally, it should be noted that, although in the aforementioned examples the electrodynamic exciter 2a..2l comprises a first plate and a second plate 13a..13l, in other embodiments the electrodynamic exciter 2a..2l may also comprise only a first plate 10a adjoining above or below the central magnet 11. This is advantageous if the disclosed advantages are required only on one of the top plate 12a..12l and the bottom plate 13a..13l, or if the voice coil arrangement 4 comprises only one voice coil 5 or 6.

[0089] It should also be noted that the cross-section of the collar 14a..14l' is independent of whether it is continuous or discontinuous. In particular, this means that Figures 1 to 12 The example shown can be used with Figures 13 to 16 The examples shown may be used in any combination.

[0090] In general, it should also be noted that the disclosed collars 14a..141' are not constrained by a specific shape of the electrodynamic exciter 2a..21, but various other shapes are possible. For example, the electrodynamic exciter 2a..21, instead of having a square footprint, may also have a generally polygonal shape or may be circular or elliptical. Polygonal shapes also include polygons with rounded corners. Furthermore, the disclosed collars 14a..141' are not constrained by a specific shape of the springs 16, 17 and the voice coils 5, 6. Rather, springs 16 and 17 having different shapes and numbers and voice coils 5, 6 having different shapes and numbers may also be used in the context of the disclosed collars 14a..141'.

[0091] Finally, it is noted that the scope of the present invention is defined by the appended claims, including known equivalents and unforeseeable equivalents at the time of filing this application. Although many embodiments of the present invention have been 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.

[0092] Reference numerals list

[0093] 1 Electric transducer

[0094] 2a..2l Electric exciter

[0095] 3 Sound structure

[0096] 4 Voice coil device

[0097] 5 First (upper) voice coil

[0098] 6 Second (lower) voice coil

[0099] 7a, 7l magnetic circuit system

[0100] 8a, 8l peripheral magnetic circuit system part

[0101] 9a, 9l Central magnetic circuit system

[0102] 10 Outer Ring

[0103] 11 Center magnet

[0104] 12a..12l First (top) plate

[0105] 13a..13l Second (bottom) plate

[0106] 14a..14l' ring

[0107] 15 Spring device

[0108] 16 First (upper) spring

[0109] 17 Second (lower) spring

[0110] 18 Outer spring area

[0111] 19 Spring Arm

[0112] h c Height of collar

[0113] h p Total height of the board

[0114] w c Width of collar

[0115] w p Total width of the board

[0116] AC ring loop

[0117] B Magnetic Field

[0118] C Voice coil axis

[0119] G Gland ring clearance

[0120] L Ring part

[0121] The S sound comes from the surface.

Claims

1. An electrodynamic exciter (2a..2l) designed to be connected to a sound-generating structure (3) and comprising: - a voice coil device (4) having at least one voice coil (5, 6) with a magnetic conductor in the form of a ring extending around a voice coil axis (C) in a ring portion (L), and - a magnetic circuit system (7a, 7l), the magnetic circuit system (7a, 7l) comprising an annular peripheral magnetic circuit system part (8a, 8l) and a central magnetic circuit system part (9a, 9l), the voice coil device (4) being between the annular peripheral magnetic circuit system part (8a, 8l) and the central magnetic circuit system part (9a, 9l), wherein the magnetic circuit system (7a, 7l) is designed to generate a magnetic field (B) transverse to the magnetic conductor in the annular part (L), and - spring means (15) coupling the peripheral magnetic circuit system part (8a, 81) to the central magnetic circuit system part (9a, 91) and allowing relative movement between the peripheral magnetic circuit system part (8a, 81) and the central magnetic circuit system part (9a, 91) in an offset direction parallel to the voice coil axis (C), - wherein the central magnetic circuit system part (9a, 9l) comprises a central magnet (11) and at least one plate (12a..13l) adjoining the central magnet (11) in the deflection direction, It is characterized in that - said at least one plate (12a..13l) comprises, on its outer edge, a collar (14a..14l'), said collar (14a..14l') facing away from said central magnet (11) in said deflection direction.

2. The electrodynamic exciter (2a..2l) according to claim 1, wherein: - the height (h) of the collar (14a..14l') c ) is in the range of 0.05 mm to 0.2 mm, the height (h c ) is the extension of the collar (14a..14l') in the offset direction; and / or - the width (w c ) is in the range of 0.2 mm to 0.6 mm, the width (w c ) is half of the difference between the outer dimension of the collar (14a..14l') in a direction perpendicular to the circular path (AC) of the collar (14a..14l') and the inner dimension of the collar (14a..14l') in the direction.

3. The electrodynamic exciter (2a..2l) according to claim 1, wherein: - the height (h) of the collar (14a..14l') c ) in the total height (h) of the at least one plate (12a..13l) p ) is within the range of 10% to 100%, the height (h c ) is the extension of the collar (14a..14l') in the offset direction, the total height (h p ) is the extension of said at least one plate (12a..13l) in said offset direction, and / or - the width (w c ) in the total width (w) of the at least one plate (12a..13l) p ) is in the range of 2% to 20%, the width (w c ) is half of the difference between the outer dimension of the collar (14a..14l') in a direction perpendicular to the circular path (AC) of the collar (14a..14l') and the inner dimension of the collar (14a..14l') in said direction, and the total width (w) of the at least one plate (12a..13l) is p ) is the extension of said at least one plate (12a..13l) in said direction perpendicular to said circular route (AC), and / or The area of ​​the collar (14a..14l') seen in a direction parallel to the voice coil axis (C) lies in the range 5% to 80% of the total area of ​​the at least one plate (12a..13l) seen in said direction.

4. The electrodynamic exciter (2a..2l) according to claim 1, wherein: The collars (14a..141') are continuous or discontinuous.

5. The electrodynamic exciter (2a..2l) according to claim 1, wherein The collar (14a..14l') is broken and wherein the arms (19) of the spring device (15) are arranged in the gaps (G) of the broken collars (14a..14l').

6. The electrodynamic exciter (2a..21) according to claim 1, wherein: The spring device (15) comprises an annular outer spring area (18) connected to the peripheral magnetic circuit system part (8a, 8l) and a spring arm (19) protruding inwardly and connected to the central magnetic circuit system part (9a, 9l), wherein the annular outer spring area (18) at least partially protrudes beyond the collar (14a..14l').

7. The electrodynamic exciter (2a..21) according to claim 1, wherein: - the voice coil device (4) is connected to the peripheral magnetic circuit system part (8a, 8l), and a magnetic gap is formed between the voice coil device (4) and the central magnetic circuit system part (9a, 9l), or - the voice coil device (4) is connected to the central magnetic circuit system part (9a, 91), and a magnetic gap is formed between the voice coil device (4) and the peripheral magnetic circuit system part (8a, 81).

8. The electrodynamic exciter (2a..21) according to claim 1, wherein The plates (12a..13l) and the peripheral magnetic circuit system parts (8a, 8l) are made of soft iron.

9. The electrodynamic exciter (2a..21) according to claim 1, wherein: - the plate (10a) adjoins the central magnet (11) at the top, or - the plate (10b) abuts the central magnet (11) below, or - the plate (10a) adjoins the central magnet (11) at the top, and wherein the central magnetic circuit system part (9a, 9l) comprises another plate (10b), which adjoins the central magnet (11) at the bottom in the offset direction and comprises a collar (14a'..14l') on its outer edge facing away from the central magnet (11).

10. An electrodynamic transducer (1) comprising a sound emitting structure (3) and an electrodynamic exciter (2a..21) according to claim 1, the electrodynamic exciter (2a..21) being connected to the sound emitting structure (3).

11. The electrodynamic transducer (1) according to claim 10, wherein: The average sound pressure level of the electrodynamic transducer (1) measured at a vertical distance of 10 cm from the sound emitting surface (S) of the sound emitting structure (3) is at least 50 dB_SPL in the frequency range of 100 Hz to 15 kHz.

12. The electrodynamic transducer (1) according to claim 10 or 11, wherein: The sound-generating structure (3) is implemented as a diaphragm, a display screen or a housing part of a device in which the electrodynamic exciter (2a..2l) is built.

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