Loudspeaker and loudspeaker method

Abstract

To provide a compact, lightweight and inexpensive loudspeaker capable of securing rigidity along a direction orthogonal to a preferential direction of motion.SOLUTION: The loudspeaker 1 includes a coil 301C, a center core 301A around which the coil is wound, and an outer core 301B installed at a side of the coil and separated from the center core to define a gap. A ferromagnetic circuit forming with the coil a fixed operating unit, a magnet 302 installed in the gap and movable inside the gap along a movement direction according to a magnetic field generated by the coil, a radiator operatively coupled to the magnet and forming with the magnet a movable operating unit, and a guide system comprising a flexible portion 60 connected to the movable operating unit and to the fixed operating unit, the flexible portion having a plurality of deformable joints and rigid connecting portions, the joints being interposed between the rigid connecting portions so as to guide the magnet along the movement direction by elastically deforming the flexible portion.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a loudspeaker and a method for amplifying sound. [Background technology]

[0002] Generally speaking, loudspeakers comprise electromechanical conversion systems that convert variable electrical signals into mechanical movements of the radiators to generate sound waves, these conversion systems having magnetic elements integrated with the fixed part of the sound diffuser and magnetic elements connected to the radiators for moving them, in particular the movable magnetic elements moving under the action of the magnetic field generated by the integrated magnetic elements.

[0003] In this context, there are two types of electromechanical transduction systems. In the more common systems known as "moving coil" systems, the integrated magnetic element is a permanent magnet and the moving magnetic element is a coil. The coil is excited by the electrical signal to be transduced and moves in response to interaction with the magnetic field generated by the permanent magnet. An example of a moving coil system is described in patent document US 5,014,323 A. Alternatively, in what are known as "moving magnet" systems, the integrated magnetic element is a fixed coil and the moving magnetic element is a magnet. The fixed coil is excited by an electrical signal and the moving magnet moves in response to the magnetic field generated by the coil. An example of a moving magnet system is described in patent document EP 2 550 724 in the name of the applicant.

[0004] In loudspeakers, the linear motion of the components needs to be guided to ensure that the motion is fixed as precisely as possible along the direction perpendicular to the direction of motion. Furthermore, it is preferable that the "compliance" is higher along the direction of motion than along the direction perpendicular to it. For this purpose, loudspeakers are equipped with a centering (or guide) system.

[0005] Patent document US Pat. No. 5,014,323 A describes a moving coil system with a centering system called a spider, but such a centering system tends to break down easily and requires frequent repairs.

[0006] Patent document 102022000026061 in the name of the applicant describes a moving magnet or moving coil system with a guide system between the moving and fixed parts of the loudspeaker. The guide system consists of an element that closes on itself to form a ring, and the element is configured to roll between the components as the components move relative to each other. However, this guide system can generate noise. In practice, a particularly strong need is to obtain the quietest possible movement, especially in loudspeakers of the moving magnet type.

[0007] Patent document EP 4207809 A1 in the name of the applicant discloses a moving magnet loudspeaker with a guide system comprising a plurality of retaining bands configured to allow movement along a single axis and prevent lateral displacement. In particular, each retaining band comprises a plurality of flat portions connected to one another by angled portions. During movement of the magnet, the flat portions bend and the resulting deformation is accommodated by the angled positions.

[0008] To facilitate such bending, the flat portion is provided with a plurality of triangular cutouts, while the angled portion is not provided with such cutouts and is therefore relatively stiffer. However, a guide system based on a retaining band does not provide sufficient stiffness in the lateral direction because the flat portion itself deforms not only along the intended direction of movement of the magnet as it bends, but also deforms laterally, thereby reducing the system's ability to effectively restrict undesired degrees of freedom.

[0009] Additionally, with moving magnet loudspeakers, it is important that the loudspeaker be compact, lightweight, and relatively inexpensive to manufacture. Summary of the Invention

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a loudspeaker and method for amplifying sound that overcomes the above-mentioned drawbacks of the prior art.

[0011] In particular, it is an object of the present invention to provide a loudspeaker and method that ensures a high degree of stiffness along a direction perpendicular to the preferred direction of movement.

[0012] A further object of the present invention is to provide a loudspeaker that is compact, lightweight and inexpensive.

[0013] These objects are fully achieved by the loudspeaker and loudspeaker method of the present disclosure, as characterized in the appended claims.

[0014] The loudspeaker includes a coil configured to generate a magnetic field along a longitudinal axis.

[0015] The loudspeaker comprises a ferromagnetic circuit, the ferromagnetic circuit including a central core, a coil wound around the central core, and in particular, the coil having a plurality of windings wound around a longitudinal axis and surrounding the central core, the central core being coincident with the longitudinal axis.

[0016] The ferromagnetic circuit includes an outer core that flanks the coil and at least partially surrounds the coil.

[0017] The outer core is separated from the central core to form a gap.

[0018] Preferably, the coil and the ferromagnetic circuit constitute a fixed working unit.

[0019] The loudspeaker includes a magnet. The magnet is disposed in the gap and is movable within the gap along the direction of movement in response to a magnetic field generated by the coil. In particular, the gap extends along the direction of movement. Therefore, the magnet moves within the gap along the direction of movement.

[0020] In one embodiment, the direction of movement and the longitudinal axis are parallel or coincident with each other, or the direction of movement and the longitudinal axis are perpendicular to each other. Thus, the direction of the magnet and the longitudinal axis around which the coil is wound may be parallel or perpendicular to each other.

[0021] The loudspeaker includes a radiator operatively coupled to a magnet such that movement of the magnet along the direction of movement corresponds to vibration of the radiator along the direction of movement, generating pressure waves. In particular, when the direction of movement of the coil and the longitudinal axis are parallel to or coincident with each other, the vibration of the radiator is parallel to (or along) the longitudinal axis.

[0022] Preferably, the magnet and the radiator form a movable working unit.

[0023] The loudspeaker comprises a guide system configured to move the magnet along a direction of movement, in other words, the guide system is configured to constrain (guide) longitudinal (reciprocating) movement.

[0024] In particular, the guide system comprises flexible parts, which constitute compliant mechanisms. The term compliant mechanism is used to mean a mechanical system whose movement is caused by elastic deformation of the mechanism itself. A compliant mechanism is configured to be flexible at certain points (hereinafter referred to as deformable joints) and to maintain its rigidity at other parts (hereinafter referred to as rigid connections).

[0025] The flexible portion is connected to the movable working unit at a first connection region and to the fixed working unit at a second connection region.

[0026] The flexible section has a number of deformable joints and a number of rigid connecting sections, where the deformable joints are more flexible than the rigid connecting sections, i.e., the joints deform to allow the rigid connecting sections to move relative to each other.

[0027] Preferably, the deformable joint is an area of ​​the flexible portion that is thinner than the rigid connecting portion.

[0028] The deformable joint is interposed between the rigid connecting portions (or vice versa) and guides the magnet along the direction of movement by elastic deformation of the flexible portion, the deformable joint being configured to deform in response to movement of the magnet along the direction of movement.

[0029] In this way, the flexible portion controls and guides the movement of the mobile working unit relative to the fixed working unit. When the magnet of the mobile working unit moves, the deformable joint deforms and the rigid connecting portions remain unbent and move relative to each other along the direction of movement, allowing the mobile working unit to move longitudinally. The flexible portion prevents (i.e., is configured to prevent) the mobile working unit (particularly the magnet) from moving along a direction perpendicular to the direction of movement.

[0030] Therefore, a compliant mechanism is composed of a combination of flexible parts (joints) and rigid parts (connecting parts) to realize motion transmission through elastic deformation.

[0031] Unlike the guide system disclosed in patent document EP 4207809 A1 filed in the name of the same applicant, the flexible part according to the invention does not operate by bending, as is the case with the retaining band of EP 4207809 A1, but only by tension and compression between the rigid connecting parts.

[0032] In response to the movement of the magnet, the rigid connecting portions remain substantially undeformed (i.e., do not bend), so that the mutual distances between all internal points of each rigid connecting portion remain unchanged during the movement of the magnet. In other words, the rigid connecting portions of the flexible member behave as rigid bodies. In contrast, in EP 4 207 809 A1, the flat portions are deformed by bending, so that the mutual distances between points of the flat portions change during the movement of the magnet.

[0033] Preferably, one or more of the plurality of rigid connection portions extend along a direction transverse to the direction of movement, in other words, the rigid connection portion extends in a direction that prevents movement, i.e., laterally to the direction of movement.

[0034] In particular, the rigid connection portions have a main extension transverse to the direction of movement. More specifically, each rigid connection portion extends transverse to the direction of movement between a first end and a second end, and the deformable joints may be located at the ends of the rigid connection portions. The main extension of the rigid connection portions may be substantially equal to the extension of the magnets along the same direction.

[0035] More specifically, the rigid connection portions have a width defined along a first lateral direction, the first lateral direction being perpendicular to the direction of movement, and the rigid connection portions have a depth defined along a second lateral direction, the second lateral direction being perpendicular to both the direction of movement and the first lateral direction. For each rigid connection portion, the width is greater than the depth. In particular, the width of the rigid connection portions is substantially equal to (or comparable to) the overall width of the loudspeaker. The loudspeaker has a lateral dimension or width defined along the first lateral direction, and the width of the rigid connection portions is substantially equal to (or comparable to) the lateral dimension or width of the loudspeaker.

[0036] Preferably, the compliant mechanism is made from a homogenous material, ie the joints and rigid portions are made from the same material.

[0037] The flexible part therefore makes it possible to obtain precise movements without friction and mechanical backlash, and is in fact quieter compared to solutions with elements that roll or slide between the components.

[0038] In one embodiment, the loudspeaker comprises a plurality of magnets. In particular, the plurality of magnets comprises said magnet. Each of the plurality of magnets is movable along a respective movement direction parallel to the longitudinal axis. Each of the plurality of magnets is disposed in a gap. In other words, the loudspeaker comprises a plurality of gaps, each magnet disposed in a respective gap. The plurality of magnets are connected to a radiator and, together with the radiator, define a movable working unit of the loudspeaker.

[0039] For each magnet of the plurality of magnets, the guide system comprises a flexible portion connected to the magnet at a first connection region and connected to the fixed working unit at a second connection region, each flexible portion configured to guide the magnet of the plurality of magnets along a respective direction of movement.

[0040] The flexible portions may be connected to one another (directly or indirectly).

[0041] In one embodiment, the flexible portion is monolithic, in other words, the flexible portion is formed as one piece.

[0042] Preferably, the flexible part is made from a plastic / polymer material, or in any case from a polymer material that can withstand the cyclic stresses due to deformation. Preferably, the flexible part is made from an acetal resin.

[0043] The flexible portion may be injection molded or cut by laser, water, numerical control, or other methods.

[0044] In one example, the plurality of rigid connection portions have a corresponding plurality of rigid bodies, i.e., each rigid connection portion defines a rigid body, which may be elongated along a main direction, preferably transverse to the direction of movement of the magnet.

[0045] The rigid bodies are configured to remain substantially undeformed when a force is applied. In other words, the rigid bodies are substantially non-deformable when a force is applied. The rigid bodies are connected to each other by one deformable joint of a plurality of deformable joints. The joint is configured to bend or flex when a force is applied. When the magnet moves along the movement direction, the deformable joint is configured to deform, while the rigid bodies maintain their shape.

[0046] In one example, the first connection region includes an upper connection region and a lower connection region.

[0047] In one embodiment, with respect to a plane dividing the loudspeaker in half transversely to the direction of movement, the upper connection region is located in a first half-space and the lower connection region is located in a second half-space (opposite the first half-space), the upper and lower connection regions being arranged on opposite sides of the loudspeaker with respect to said transverse plane.

[0048] In particular, with respect to a plane dividing the loudspeaker laterally, the upper and lower connection areas are arranged in an asymmetrical manner relative to said plane.

[0049] In particular, the upper and lower connection regions are spaced apart along the longitudinal axis and / or transverse to the direction of movement and are located at different heights along the direction of movement.

[0050] The plurality of joints may include a first joint located proximate the upper connection region. The plurality of joints may include a second joint located proximate the lower connection region. The plurality of joints may include a third joint. The third joint may be located proximate the second connection region.

[0051] The plurality of joints may include a fourth joint and a fifth joint.

[0052] The plurality of rigid connection portions may comprise a first rigid connection portion, a second rigid connection portion, and a third rigid connection portion.

[0053] The first rigid connection portion may extend transversely to the direction of movement between the first joint and the fourth joint, and the second rigid connection portion may extend transversely to the direction of movement between the second joint and the fifth joint.

[0054] A third rigid connection portion may be interposed between the first rigid connection portion and the second rigid connection portion. The third rigid connection portion is connected to the first rigid connection portion at a fourth joint. The third rigid connection portion is connected to the second rigid connection portion at a fifth joint. The third rigid connection portion is connected to the fixed working unit of the loudspeaker by a second connection point.

[0055] Thus, the flexible portion deforms at the first joint, the second joint, the third joint, the fourth joint, and the fifth joint, but remains unbent at the first rigid connection portion, the second rigid connection portion, and the third rigid connection portion.

[0056] It should be noted that the term connection may refer to any means of attaching two elements to one another, for example the connection may be a mechanical connection (pressure or form coupling) or an adhesive connection.

[0057] In particular, the flexible portion has a width, which is defined perpendicular to the direction of movement by an upper connection region and a lower connection region. The flexible portion has a depth, which is defined perpendicular to the direction of movement and the width. Preferably, the width of the flexible portion is greater than its depth. In other words, the flexible portion extends primarily to the upper connection region and the lower connection region.

[0058] More specifically, the length to depth ratio is greater than 2. Preferably, the length to depth ratio is less than 12.

[0059] Thus, the greater the depth, the greater the stiffness of the flexible segment along the axis of deployment of the depth of the flexible segment, thus minimizing twisting of the flexible segment towards or away from the axis of movement.

[0060] In practice, it is preferable to have high stiffness of motion of the magnet along a direction perpendicular to the direction of movement.

[0061] Additionally or alternatively, it should be noted that where there are multiple flexible segments, they are preferably connected to one another directly or indirectly to obtain stiffness for movement towards and away from the longitudinal axis, in particular the flexible segments are connected to one another directly or indirectly to form a polygon, more particularly a quadrilateral.

[0062] For example, flexible portions may be connected to one another (directly or indirectly) to form a polygon of flexible portions, the polygon lying in a plane perpendicular to the direction of movement, and the polygon formed by the flexible portions may constitute an object that may be stiff along a direction perpendicular to the direction of movement and movable along the direction of movement.

[0063] It should also be noted that in a rest state (when no force is applied to the magnet), the first and second rigid connection regions are arranged parallel to each other. Preferably, the third rigid connection region has a parallelepiped shape.

[0064] In one embodiment, the joints (and rigid connection portions) are configured to create a kinematic mechanism that approximates a linear watt guide. In other words, the flexible portion constitutes a linear watt guide. In a linear watt guide, the upper connection point and the first joint coincide, and the lower connection point and the second joint coincide. In this case, the joints are not configured to deform and rotate like pins around the upper and lower connection regions. In a linear watt guide, the first rigid connection region is pivoted at the upper connection point so that it can rotate like a rigid body around the upper connection point, and the second rigid connection region is pivoted at the lower connection point so that it can rotate like a rigid body around the lower connection point.

[0065] The third rigid connection region is connected to the first rigid connection region and the second rigid connection region by a fourth joint and a fifth joint, respectively, in which the fourth joint and the fifth joint do not deform but rotate like a pin.

[0066] When the magnet moves, the upper and lower connection regions move in response to the movement of the magnet (the connection regions are directly or indirectly connected to the magnet), thereby causing the first, second and third rigid connection portions to move via joints (pins in the case of a linear watt guide) that allow them to move.The rigid connection portions are connected to the fixed working unit of the loudspeaker by the second connection point via the joints and the first and second rigid connection points, so that the magnet fixed to the deformable part is constrained to move only along the movement direction and is prevented from moving along an axis perpendicular to the movement direction.

[0067] In one example, the third rigid connection portion is connected to the outer core of the ferromagnetic circuit at the second connection region, and preferably, relative to the second connection region, the third rigid connection portion can freely rotate about an axis passing through the second connection region.

[0068] In one embodiment, the third rigid connection portion comprises a plurality of arms, each extending transversely to the direction of movement (and to the longitudinal axis, if the direction of movement and the longitudinal axis are perpendicular to each other). In particular, the arms are configured to allow the third rigid connection region to deform along the direction of movement in response to movement of the magnet along the direction of movement.

[0069] In particular, the plurality of arms includes a first arm and a second arm, each arm extending between two ends, the first arm and the second arm being connected to each other at their ends, and the arms being arranged parallel to each other.

[0070] The third rigid connection region may include a plurality of slits that allow the third rigid connection region to deform when subjected to a force applied to the third rigid connection region along the direction of movement. The slits may extend in a direction transverse to the direction of movement.

[0071] In one embodiment, the first arm includes a sixth joint, a seventh joint, and a fourth rigid connection portion disposed between the sixth and seventh joints, and the second arm includes an eighth joint, a ninth joint, and a fifth rigid connection portion disposed between the eighth and ninth joints.

[0072] The first arm and the second arm are configured to deform at the sixth joint, the seventh joint, the eighth joint and the ninth joint in response to the magnet moving along the movement direction.

[0073] In one embodiment, the guide device includes a support structure configured to connect the magnet to the flexible portion. The support structure is configured to move along the movement direction in response to the magnet moving along the movement direction. In particular, the support structure is connected to the flexible portion at a first connection region (in particular an upper connection region or a lower connection region) and is connected to the first and second rigid connection portions of the flexible portion.

[0074] In one embodiment, the support structure comprises a housing, and the magnet is mounted to the housing of the support structure, such that the structure and magnet move together.

[0075] In another embodiment, the support structure may include one or more corner elements, each configured to connect a pair of magnets together. In particular, the corner elements are interposed between the magnets, connecting them to form a polygon (or a rectangle, if there are four magnets).

[0076] Each magnet has a first extent, the first extent being transverse to the direction of movement. Each magnet has the first extent between a first end and a second end, and each corner element is configured to connect an end (first or second) of a magnet to an end (first or second) of an adjacent magnet.

[0077] Each corner element is configured to connect a pair of flexible portions together, and in particular, corner elements are interposed between and connect multiple flexible portions to form a polygon of flexible portions (or a quadrilateral, if there are four flexible portions).

[0078] In particular, each corner element is configured to connect a first connection region (in particular an upper connection region) of a flexible portion to a connection region (in particular a lower connection region) of an adjacent flexible portion.

[0079] In one embodiment, the support structure is configured to connect the magnet to the first and second rigid connection regions of the flexible portion (at the first connection point, i.e., the upper or lower connection point).

[0080] The loudspeaker may comprise an actuation part configured to connect the magnet to the radiator so that movement of the magnet along the direction of movement corresponds to movement of the radiator along the same direction (or orientation) or preferably along the opposite direction (or orientation).

[0081] In particular, the actuating part may be connected to the magnet by a support structure, for this purpose the actuating part may be connected to the magnet by a corner element.

[0082] In one embodiment, the loudspeaker comprises a plurality of working portions, and corner elements may be interposed between the working portions to form a polygon for the working portions (particularly, since there are four working portions, the working portions form a quadrilateral).

[0083] The present disclosure also provides a linear actuator. The linear actuator includes a coil configured to generate a magnetic field along a longitudinal axis. The linear actuator includes a ferromagnetic circuit. The ferromagnetic circuit includes a central core around which a coil is wound. The ferromagnetic circuit includes an outer core disposed on a side of the coil and at least partially surrounding the coil. The outer core is separated from the inner core to form a gap. The coil and ferromagnetic circuit constitute a stationary working unit. The linear actuator includes a magnet disposed in the gap and movable within the gap along a direction of movement in response to a magnetic field generated by the coil. The magnet constitutes a movable working unit. The gap extends along the direction of movement.

[0084] The loudspeaker comprises a guide system configured to move the magnet along a movement direction, the guide system including a flexible portion that constitutes a compliant mechanism.

[0085] The flexible portion is connected to the movable working unit at a first connection region and to the fixed working unit at a second connection region, and the flexible portion has a plurality of deformable joints and a plurality of rigid connecting portions, and the deformable joints are interposed between the rigid connecting portions to guide the magnet along the movement direction by elastic deformation of the flexible portion.

[0086] Generally speaking, the flexible portion may be made according to one or more of the features described herein.

[0087] The present disclosure also provides a method for sound reinforcement, the method including the steps of providing a coil and a ferromagnetic circuit, the ferromagnetic circuit including a central core around which the coil is wound and an outer core disposed on a side of and at least partially surrounding the coil, the outer core being separated from the central core to define a gap, the coil and the ferromagnetic circuit forming a fixed working unit.

[0088] The method includes providing a magnet disposed in the gap and a radiator operably coupled to the magnet, the magnet and radiator comprising a movable working unit.

[0089] The method includes generating a magnetic field along a longitudinal axis via a coil and moving a magnet within a gap along a direction of movement in response to the generated magnetic field. The method includes vibrating a radiator along the direction of movement in response to the movement of the magnet to generate pressure waves. The gap extends along the direction of movement.

[0090] The method includes guiding movement of a magnet along a movement direction via a guide system, the guide system including a flexible portion constituting a compliant mechanism, the flexible portion being connected to a movable working unit at a first connection region and to a fixed working unit at a second connection region, the flexible portion having a plurality of deformable joints and a plurality of rigid connection portions, the deformable joints being interposed between the rigid connection portions.

[0091] The step of guiding the magnet along the direction of movement is performed by the flexible part by elastic deformation of the flexible part.

[0092] In one example, the step of providing a magnet includes providing a plurality of magnets including the magnet, each magnet connected to a radiator and together with the radiator defining a movable working unit, and for each magnet of the plurality of magnets, the guide system comprises a flexible portion connected to the respective magnet at a first connection point, and the method includes the step of moving each magnet along a respective movement direction, and the step of guiding includes the step of guiding the movement of the respective magnet along the movement direction via the respective flexible portion.

[0093] In one example, the first connection region includes an upper connection region and a lower connection region, the plurality of joints includes a first joint, a second joint, a third joint, a fourth joint, and a fifth joint, and the plurality of rigid connection portions includes a first rigid connection portion, a second rigid connection portion, and a third rigid connection portion.

[0094] The first joint is located adjacent to the upper connection region, the second joint is located adjacent to the lower connection region, and the third joint is located adjacent to the second connection region. The first rigid connection portion extends transversely to the direction of movement between the first joint and the fourth joint, and the second rigid connection portion extends transversely to the direction of movement between the second joint and the fifth joint.

[0095] The third rigid connection part is connected to the first rigid connection part at a fourth joint and to the second rigid connection part at a fifth joint, and the third rigid connection part is connected to the fixed working unit of the loudspeaker by the second connection point.

[0096] In one embodiment, the third rigid connection portion includes a plurality of arms, each extending transversely to the direction of movement, the plurality of arms including a first arm and a second arm connected to each other at respective ends, the first arm including a sixth joint, a seventh joint, and a fourth rigid connection portion interposed between the sixth joint and the seventh joint.

[0097] The second arm includes an eighth joint, a ninth joint, and a fifth rigid connecting portion interposed between the eighth joint and the ninth joint.

[0098] In one example, the second connection region comprises a pair of connection regions. The third joint comprises a pair of joints, and the pair of connection regions is interposed between the joints of the pair of joints. The third rigid connection portion comprises a central portion connected to the fixed operating unit of the loudspeaker within the pair of connection regions and movable relative to the first arm and the second arm by deforming the pair of joints. In particular, in the guiding step, the first arm and the second arm deform at the sixth joint, the seventh joint, the eighth joint, and the ninth joint, and the central portion deforms at the pair of joints in response to movement of the magnet along the movement direction.

[0099] In one example, the guide device includes a support structure configured to connect the magnet to the first rigid connection portion and the second rigid connection portion, and in the guiding step, the support structure moves along the movement direction in response to the magnet moving along the movement direction. [Brief explanation of the drawings]

[0100] This and other features will become more apparent from the following description of preferred embodiments, illustrated by way of non-limiting example in the accompanying drawings, in which: [Figures 1A-1D] 1 illustrates a flexible portion according to one or more features described herein. [Figure 2] 1 illustrates a loudspeaker according to one or more features described in the present disclosure. [Figure 3A-3G] 3 illustrates the loudspeaker of FIG. 2 according to one or more features described in this disclosure. [Figure 4A-4B] 1 illustrates a ferromagnetic circuit and coil according to one or more features described herein. [Figure 5] 3 illustrates an exploded view of the loudspeaker of FIG. 2 according to one or more features described in this disclosure. [Figures 6A-6B] 1 illustrates a loudspeaker according to one or more features described in the present disclosure. [Figure 6C] 1 illustrates a magnet of a loudspeaker according to one or more features described herein. [Figures 7A-7D] 10 illustrates possible variations of a flexible portion in accordance with one or more features described herein. DETAILED DESCRIPTION OF THE INVENTION

[0101] The number 1 in the figure indicates a loudspeaker.

[0102] The loudspeaker 1 comprises a coil 301C configured to generate a magnetic field along a longitudinal axis X. In particular, the coil 301C is wound around the longitudinal axis X. The loudspeaker 1 comprises a ferromagnetic circuit including a central core 301A. The central core 301A has a central portion 301Aa extending along the longitudinal axis X and around which the coil 301C is wound. The central core 301A has lateral portions 301Ab. The lateral portions 301Ab of the central core 301A are arranged opposite the central portion 301Aa and surrounding the coil 301C. The ferromagnetic circuit includes an outer core 301B located on a side of the coil 301C and at least partially surrounding the coil 301C.

[0103] In particular, central portion 301Aa of central core 301A is aligned with longitudinal axis X, and lateral portions 301Ab of central core 301A surround coil 301C and are at least partially disposed about longitudinal axis X. Outer core 301B may be spaced apart from central core 301A along longitudinal axis X or may be spaced apart from central core 301A along a transverse axis perpendicular to longitudinal axis X.

[0104] The outer core 301B is separated from the central core 301A to define a gap T; more specifically, the outer core 301B is separated from a lateral portion 301Ab of the central core 301A to define a gap T.

[0105] In the embodiment shown in FIG. 2 for illustrative purposes only, outer core 301B is separated from central core 301A along a lateral direction perpendicular to longitudinal axis X.

[0106] In the embodiment shown for illustrative purposes only in FIGS. 6A and 6B, outer core 301B is separated from central core 301A along a longitudinal direction defined by longitudinal axis X.

[0107] The central core 301A may be divided into a first half shell and a second half shell, which are aligned with each other along the longitudinal axis X.

[0108] 6A and 6B, one of the first and second half shells defines the outer core 301B of the other of the first and second half shells (or vice versa), and is therefore separated from the other of the first and second half shells (or vice versa) to define a gap T.

[0109] 6A and 6B, the loudspeaker 1 includes an additional coil 301C, such that the coil 301C is wound around the central core 301A of the first half shell and the additional coil 301C is wound around the central core 301A of the second half shell. The two half shells are separated from each other to define a gap T.

[0110] In one example, the two half shells together with the side portions 301Ab of the central core 301A define a recess that constitutes a region having high magnetic permeability.

[0111] The loudspeaker 1 comprises one magnet 302 or multiple magnets 302 .

[0112] For example, as shown in Figures 6A and 6B, loudspeaker 1 comprises only one magnet 302 located within gap T between the first and second half shells. Magnet 302 extends along a plane perpendicular to the longitudinal axis. Magnet 302 is interposed between coil 301C and additional coil 301C along longitudinal axis X. Magnet 302 is configured to move within gap T along movement direction M. In the example of Figures 6A and 6B, movement direction M is perpendicular to longitudinal axis X.

[0113] For example, as shown in Figure 2, the loudspeaker 1 includes a plurality of magnets 302. In particular, the plurality of magnets 302 are disposed in a gap T defined by a central core 301A and an outer core 301B. In this case, the gap T extends along a direction parallel to the longitudinal axis X. The magnets 302 extend along a plane perpendicular to the longitudinal axis X. In this case, the movement direction M of the magnets 302 is parallel to the longitudinal axis X.

[0114] The coil 301C may comprise a plurality of straight sections connected to one another by curved sections. The straight sections of the coil 301C are opposite each other and arranged symmetrically about the longitudinal axis X to define a quadrilateral. The outer core 301B comprises a plurality of outer sections, preferably the outer sections of the outer core 301B are separated from one another. If the loudspeaker 1 comprises a plurality of magnets 302, these are arranged relative to one another to form a quadrilateral within the gap between the straight sections of the coil 301C and the outer sections of the outer core 301B.

[0115] In particular, in embodiments in which the direction of movement M is parallel to the longitudinal axis X, each magnet 302 has a first face extending along a plane parallel to the longitudinal axis X and opposite a second face, the first and second faces lying in a plane parallel to the longitudinal axis X, and the first and second faces having opposite polarities. In this manner, when the magnets 302 positioned in the gap T are traversed along their longitudinal direction by the alternating magnetic field generated by the coil 301C, each magnet 302 reciprocates along the direction of movement M parallel to the longitudinal direction.

[0116] In particular, in embodiments in which the direction of movement M is perpendicular to the longitudinal axis X, each magnet 302 extends along a plane perpendicular to the longitudinal axis X and has a first face opposite a second face, the first and second faces lying in a plane parallel to the longitudinal axis X, the first and second faces each having a first section 302A and a second section 302B, the first section 302A of the first face lying on the second section 302A of the second face and the second section 302B of the first face lying on the first section 302A of the second face, and the first section 302A and second section 302B of each face having opposite polarities. The magnets 302 may also be considered as a pair of magnets 302, each having a first section 302A (defining a first face) and a second section 302B (defining a second face), the first section 302A and the second section 302B having opposite polarities. The two magnets 302 of the pair are aligned with each other along the direction of movement M, with the first section 302A of the first magnet 302 aligned with the second section 302B of the second magnet 302, and the second section 302B of the first magnet 302 aligned with the first section 302A of the second magnet 302 along the direction of movement. Thus, the polarization of the first magnet 302 of the pair is oriented orthogonal to the direction of movement and opposite the polarization of the second magnet 302 of the pair.

[0117] In this way, when one magnet 302 (or a pair of magnets 302) placed in the gap T is traversed along the longitudinal direction by the alternating magnetic field generated by the coil 301C and the additional coil 301C, the magnet 302 moves back and forth along a movement direction M perpendicular to the longitudinal direction.

[0118] The loudspeaker 1 comprises a radiator operatively coupled to a magnet 302 or magnets 302, which moves along a direction of movement M to generate pressure waves.

[0119] The loudspeaker 1 comprises a guide system comprising a plurality of flexible sections 60. Each flexible section 60 comprises a first upper connection region 60a', a second lower connection region 60a'', and a second connection region 60b. Each flexible section 60 comprises a plurality of joints and a plurality of rigid connection sections.

[0120] In one embodiment, each flexible portion 60 includes a first joint 601, a second joint 602, a third joint 603, a fourth joint 604, a fifth joint 605, a first rigid connection portion 611, a second rigid connection portion 612 and a third rigid connection portion 613.

[0121] The first rigid connection portion 611 extends transversely to the movement direction M between the first joint 601 and the fourth joint 604, and the second rigid connection portion 612 extends transversely to the movement direction M between the fifth joint 605 and the second joint 602. The third rigid connection portion 613 is interposed between the first rigid connection portion 611 and the second rigid connection portion 612, and in particular, the third rigid connection portion 613 is connected to the first rigid connection portion 611 at the fourth joint 604 and to the second rigid connection portion 612 at the fifth joint 605. The first joint 601 is located adjacent to the upper connection region 60a', and the second joint 602 is located adjacent to the lower connection region 60a''. The third joint 603 is located adjacent to the second connection region 60b.

[0122] The flexible portion 60 is connected to the magnet 302 at an upper connection region 60a' and a lower connection region 60a''. Thus, the first rigid connection region 611 is connected to the magnet 302 by the upper connection region 60a' and the second rigid connection region 612 is connected to the magnet 302 by the lower connection region 60a''. The third rigid connection region 613 is connected to the outer core 301B of the ferromagnetic circuit at a second connection point 60b.

[0123] In particular, each magnet 302 extends between a first end and a second end along an axis perpendicular to the direction of movement M. Thus, each flexible portion 60 is connected to the magnet 302 at the first end and the second end of the magnet 302.

[0124] In the embodiment shown in FIG. 1C for illustrative purposes only, the third rigid connection portion 613 comprises a first arm 613′, a second arm 613″ and a central portion 613′″, each extending transversely to the direction of movement M and arranged parallel to one another, with the central portion 613′″ being interposed between the first arm 613′ and the second arm 613″. The first arm 613′ comprises a sixth joint 606, a seventh joint 607 and a fourth rigid connection portion 614 interposed between the sixth joint 606 and the seventh joint 607. The second arm 613″ comprises an eighth joint 608, a ninth joint 609 and a fifth rigid connection portion 615 interposed between the eighth joint 608 and the ninth joint 609. The third joint 603 includes a pair of joints 603′ and 603″, and the second connection region 60b includes a pair of connection regions 60b′ and 60b″, with the pair of connection regions 60b′ and 60b″ interposed between the pair of joints 603′ and 603″. The central portion 613′″ is connected to the first arm 613′ and the second arm 613″ at the pair of joints 603′ and 603″, and is connected to the outer core 301B at the pair of connection regions 60b′ and 60b″. In one example, the second connection region 60b includes an additional connection region 60b′″. The third rigid connection portion includes one slit or multiple slits. The slits are interposed between the first arm 613′ and the central portion 613′″ and between the second arm 613″ and the central portion 613′″.

[0125] The flexible portion 60 is configured to deform at a plurality of joints about a corresponding plurality of deformation axes D. The deformation axes D of the joints are shown, for example, in Figure 7. Figure 7 also shows possible embodiments of the flexible portion 60 that differ substantially in the ratio of the depth P to the width L.

[0126] In the embodiment shown by way of example only in Figure 2, each flexible portion 60 is connected to one magnet 302 of the plurality of magnets. In the embodiment shown by way of example only in Figures 6A and 6B, each flexible portion 60 is connected to a magnet 302. Generally speaking, the flexible portion 60 is connected to the plurality of magnets 302 or to said one magnet 302 by a support structure 62 configured to move along the movement direction M. The support structure 62 is connected to the flexible portion 60 at an upper connection region 60a' and a lower connection region 60a''.

[0127] In the embodiment shown by way of example only in FIGS. 6A and 6B , the support structure 62 comprises a first support member 621 and a second support member 622. The first support member 621 and the second support member 622 are U-shaped, i.e., they each comprise a pair of lateral elements and a transverse element interposed between the lateral elements to define a U-shape. The lateral elements extend along parallel planes, and the transverse elements extend along a plane transverse to the plane along which the lateral elements extend. The lateral elements are connected to the flexible portion 60. The transverse elements of the first support member 621 and the second support member 622 together define a housing configured to accommodate the magnet 302. Thus, the support structure 62 moves in unison with the magnet 302 and transfers that movement to the flexible portion 60, which deforms at multiple joints.

[0128] 2, the support structure 62 comprises a plurality of corner elements 630. Each corner element 630 is configured to connect a pair of magnets 302 to each other and to connect the magnets 302 to the flexible portions 60. In particular, each corner element 630 is configured to connect two adjacent flexible portions 60 at an upper connection region 60a' and a lower connection region 60a''. In this manner, the plurality of magnets 302 form a quadrilateral, and the plurality of flexible portions 60 form a quadrilateral surrounding the magnets 302.

[0129] An outer portion of outer core 301B is interposed between magnet 302 and flexible portion 60, to which flexible portion 60 is connected by second connection point 60b. When magnet 302 moves along movement direction M in response to the magnetic field generated by coil 301C, corner element 630 moves integrally with magnet 302, and flexible portion 60 deforms at multiple joints.

[0130] Figures 1B and 1D show simplified depictions of the flexible portion 60 of Figures 1A and 1C, respectively. In particular, note that the flexible portion 60 of Figures 1A and 1C can be approximated to the flexible portion 60 of Figures 1B and 1D, respectively, with the deformable joints replaced by pins around which the flexible portion 60 rotates in accordance with the relative movement of the rigid connecting portions.

[0131] In one embodiment, the loudspeaker 1 comprises a plurality of actuating portions 401 configured to connect the magnets 302 to the radiators, such that movement of the magnets 302 corresponds to movement of the radiators along the same direction but in the opposite sense. In particular, the support structure 62 (particularly the corner elements 630) connects each actuating portion 401 to a respective magnet 302. Each actuating portion 401 may comprise a thin plate 402 embedded in the actuating portion 401 and configured to increase its rigidity. The thin plate 402 may be a punched plate.

[0132] For a more detailed description of the actuating portion 401, reference is made to patent document 102021000032906 in the name of the applicant, which is incorporated herein by reference.

[0133] The loudspeaker 1 comprises a first half shell 7a and a second half shell 7b, between which the coil 301C (and the additional coil 301C), a ferromagnetic circuit and one magnet 302 (out of the plurality of magnets 302) are housed. [Prior art documents] [Patent documents]

[0134] [Patent Document 1] US5014323A [Patent Document 2] EP2550724 [Patent Document 3] 102022000026061 [Patent Document 4] EP4207809A1 [Explanation of symbols]

[0135] 1. Loudspeaker X Longitudinal Axis 301A central core 301Aa Central part of 301A 301Ab Outer part of 301A 301B outer core 301C coil 302 Magnet 302A First Section 302B Second Section 401 Working Parts 402 Thin plate 60 Flexible part 60a First connection area 60a' Upper connection area 60a'' lower connection area 60b Second connection area 60b', 60b'' Pair of connection areas 60b''' Additional second connection area 601 First Joint 602 Second Joint 603 Third Joint 603', 603'' Pair of joints 604 Fourth Joint 605 5th Joint 606 6th Joint 607 7th Joint 608 8th Joint 609 9th Joint 611 First Rigid Connection Region 612 Second Rigid Connection Region 613 Third Rigid Connection Region 614 Fourth Rigid Connection Region 615 Fifth Rigid Connection Region 62 Support member 621 first support member 622 second support member 630 Corner Elements 7a, 7b half shell

Claims

1. A loudspeaker, a coil configured to generate a magnetic field along a longitudinal axis; a ferromagnetic circuit, a central core having a coil wound therearound; a ferromagnetic circuit including an outer core disposed on a side of the coil and at least partially surrounding the coil, the outer core being separated from the central core to define a gap, the coil and the ferromagnetic circuit forming a fixed working unit; a magnet located in the gap and movable within the gap along a direction of movement in response to the magnetic field generated by the coil, the gap extending along the direction of movement; a radiator operatively coupled to said magnet, wherein movement of said magnet along each direction of movement corresponds to vibration of said radiator, generating pressure waves, said magnet and said radiator constituting a movable working unit; a guide system configured to move said magnet along said direction of movement, The guide system includes a flexible portion constituting a compliant mechanism connected to the movable operating unit at a first connection region and connected to the fixed operating unit at a second connection region, the flexible portion having a plurality of deformable joints and a plurality of rigid connecting portions, the deformable joints being interposed between the rigid connecting portions so as to guide the magnet along the movement direction by elastically deforming the flexible portion.

2. A plurality of magnets are provided, - said plurality of magnets comprises said magnet, - each magnet of said plurality of magnets is movable along a respective direction of movement and is connected to said radiator and defines, together with said radiator, said movable working unit of said loudspeaker; 2. The loudspeaker of claim 1, wherein for each magnet of the plurality of magnets, the guide system comprises a flexible portion connected to the respective magnet at the first connection region and connected to the fixed working unit at the second connection region, the flexible portion being configured to guide the magnet of the plurality of magnets along a respective direction of movement.

3. 3. A loudspeaker as claimed in claim 1 or 2, wherein the flexible portion is made of acetal resin.

4. 3. The loudspeaker of claim 1, wherein the plurality of joints are configured to form a mechanism that approximates a Watt linear rail.

5. - said first connection region comprises an upper connection region and a lower connection region; - the plurality of joints comprises a first joint, a second joint, a third joint, a fourth joint and a fifth joint; - said plurality of rigid connection portions comprises a first rigid connection portion, a second rigid connection portion and a third rigid connection portion; - the first joint is located adjacent to the upper connection area, the second joint is located adjacent to the lower connection area, and the third joint is located adjacent to the second connection area; - said first rigid connection portion extends transversely to said direction of movement between said first joint and said fourth joint, and said second rigid connection portion extends transversely to said direction of movement between said second joint and said fifth joint; - A loudspeaker as described in claim 1 or 2, wherein the third rigid connection part is connected to the first rigid connection part at the fourth joint and to the second rigid connection part at the fifth joint, and the third rigid connection part is connected to the fixed working unit of the loudspeaker by a second connection point.

6. 6. The loudspeaker of claim 5, wherein the flexible portion has a width defined by the upper connection region and the lower connection region perpendicular to the direction of movement, and a depth defined perpendicular to the direction of movement and the width, the ratio of the width to the depth being greater than 2.

7. 7. The loudspeaker of claim 6, wherein the ratio of said width to said depth is less than 12.

8. 6. The loudspeaker of claim 5, wherein the third rigid connection portion comprises a plurality of arms, each of the plurality of arms extending transversely to the direction of movement so as to enable the third rigid connection region to deform along the direction of movement in response to movement of the magnet along the direction of movement.

9. the plurality of arms include a first arm and a second arm connected to each other at respective ends; said first arm comprises a sixth joint, a seventh joint and a fourth rigid connection portion interposed between said sixth joint and said seventh joint; the second arm comprises an eighth joint, a ninth joint and a fifth rigid connection portion interposed between the eighth and ninth joints; 9. The loudspeaker of claim 8, wherein the first arm and the second arm are configured to deform at the sixth joint, the seventh joint, the eighth joint, and the ninth joint in response to the magnet moving along the movement direction.

10. - said second connection area comprises a pair of connection areas, - the third joint comprises a pair of joints, the pair of connection regions being interposed between the joints of the pair of joints; - The loudspeaker described in claim 9, wherein the third rigid connection portion has a central portion connected to the fixed operating unit of the loudspeaker at the pair of connection regions and movable relative to the first arm and the second arm by deforming the pair of joints.

11. 6. The loudspeaker of claim 5, wherein the guide device includes a support structure configured to connect the magnet to the first rigid connection portion and the second rigid connection portion, the support structure being movable along the movement direction in response to the magnet moving along the movement direction.

12. 12. The loudspeaker of claim 11, comprising an actuating portion configured to connect the magnet to the radiator, such that movement of the magnet along the direction of movement corresponds to movement of the radiator in the opposite direction, the actuating portion being connected to the magnet by the support structure.

13. 1. A linear actuator, comprising: a coil configured to generate a magnetic field along a longitudinal axis; a ferromagnetic circuit, a central core around which the coil is wound; a ferromagnetic circuit including an outer core located to a side of the coil and at least partially surrounding the coil, the outer core being separated from the central core to define a gap, the coil and the ferromagnetic circuit forming a fixed working unit; a magnet disposed in the gap and movable within the gap along a direction of movement in response to the magnetic field generated by the coil, the gap extending along the direction of movement (M), the magnet constituting a movable working unit; a guide system configured to move said magnet along said direction of movement, The guide system includes a flexible portion constituting a compliant mechanism connected to the movable operating unit at a first connection region and connected to the fixed operating unit at a second connection region, the flexible portion having a plurality of deformable joints and a plurality of rigid connection portions, the deformable joints being interposed between the rigid connection portions and elastically deforming the flexible portion to guide the magnet along the movement direction of the linear actuator.

14. A sound reinforcement method, comprising: a coil and a ferromagnetic circuit, a central core around which the coil is wound; providing a ferromagnetic circuit including an outer core located to a side of the coil and at least partially surrounding the coil, the outer core being separated from the core to define a gap, the coil and the ferromagnetic circuit forming a fixed working unit; - providing a magnet located in the gap and a radiator operably coupled to the magnet, the magnet and the radiator forming a mobile working unit; - generating a magnetic field along the longitudinal axis via said coil; - moving the magnet in the gap along the direction of movement in response to the generated magnetic field; - causing the radiator to oscillate along the direction of movement in response to the movement of the magnet, thereby generating pressure waves; - guiding the movement of said magnet along said direction of movement via a guide system, a flexible portion constituting a compliant mechanism, the flexible portion having a plurality of deformable joints and a plurality of rigid connection portions, the deformable joints being interposed between the rigid connection portions; and a sound reinforcement method, the step of guiding the magnet along the movement direction being performed by the flexible portion through elastic deformation of the flexible portion.

15. the step of providing a magnet includes providing a plurality of magnets; - said plurality of magnets comprises said magnet, - each magnet of said plurality of magnets is movable along a respective direction of movement and is connected to said radiator and defines, together with said radiator, said movable working unit of said loudspeaker; - for each magnet of said plurality of magnets, said guide system comprises a flexible part connected to said magnet at said first connection area and connected to said fixed working unit at said second connection area; 15. The method of claim 14, wherein the method includes moving each magnet along a respective direction of movement, and wherein the guiding step includes guiding movement of each magnet along the direction of movement via a respective flexible portion.

16. - said first connection region comprises an upper connection region and a lower connection region; - the plurality of joints comprises a first joint, a second joint, a third joint, a fourth joint and a fifth joint; - said plurality of rigid connection portions comprises a first rigid connection portion, a second rigid connection portion, and a third rigid connection portion; - the first joint is located adjacent to the upper connection area, the second joint is located adjacent to the lower connection area, and the third joint is located adjacent to the second connection area; - said first rigid connection portion extends transversely to said direction of movement between said first joint and said fourth joint, and said second rigid connection portion extends transversely to said direction of movement between said second joint and said fifth joint; The method according to claim 14 or 15, wherein the third rigid connection part is connected to the first rigid connection part at the fourth joint and to the second rigid connection part at the fifth joint, and the third rigid connection part is connected to the fixed working unit of the loudspeaker by a second connection point.

17. - said third rigid connection part comprises a plurality of arms, each of said plurality of arms extending transversely to said direction of movement, said plurality of arms comprising a first arm and a second arm connected to each other at their respective ends; - said first arm comprises a sixth joint, a seventh joint and a fourth rigid connection part (614) interposed between said sixth joint and said seventh joint; the second arm comprises an eighth joint, a ninth joint and a fifth rigid connection portion interposed between the eighth and ninth joints; - said second connection area comprises a pair of connection areas, - the third joint comprises a pair of joints, the pair of connection regions being interposed between the joints of the pair of joints; the third rigid connection part comprises a central part connected to the fixed working unit of the loudspeaker at the pair of connection regions and movable relative to the first arm and the second arm by deforming the pair of joints; 17. The method of claim 16, wherein in the guiding step, the first arm and the second arm deform at the sixth joint, the seventh joint, the eighth joint (608), and the ninth joint, and the central portion deforms at the pair of joints in response to the magnet moving along the movement direction.

18. 17. The method of claim 16, wherein the guiding device includes a support structure configured to connect the magnet to the first rigid connection portion and the second rigid connection portion, and wherein in the guiding step, the support structure moves along the movement direction in response to the magnet moving along the movement direction.

19. 2. The loudspeaker of claim 1, wherein the rigid connecting portion has a main extension along a lateral direction, the lateral direction being transverse to the direction of movement, and the guide system is configured to prevent the magnet from moving along the lateral direction.

20. - the rigid connection of the flexible part, a width defined along a first lateral direction, the first lateral direction being perpendicular to the direction of movement of the magnet; and a depth defined along a second lateral direction, the second lateral direction being perpendicular to the direction of movement of the magnet and the first lateral direction; - the loudspeaker has a lateral dimension defined along the first lateral direction; 20. The loudspeaker of claim 19, wherein the width of the rigid connecting portion is substantially equal to the lateral dimension of the loudspeaker.

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