Electroacoustic transducer diaphragm with integrated structural features and related systems and methods

Abstract

The present invention relates to an electroacoustic transducer diaphragm with integrated structural features and related systems and methods. The present invention provides an electroacoustic transducer having an acoustic diaphragm and a voice coil. The diaphragm defines a first major surface. A flange extends from the diaphragm in a direction opposite to the first major surface. The voice coil has a first plurality of windings positioned adjacent to the acoustic diaphragm and a second plurality of windings positioned distal to the acoustic diaphragm. The flange overlaps the first plurality of windings. The flange and the winding can be adhesively joined to each other to form a lap joint. The lap joint can transfer force from the voice coil to the diaphragm.

Description

[0001] This application is a divisional application of the invention patent application with application number 201910741922.0, application date August 13, 2019, and invention name “Electroacoustic transducer diaphragm with integrated structural feature parts and related systems and methods”. Technical Field

[0002] The present application and related subject matter (collectively, the "disclosure") generally relate to electroacoustic transducers, and related systems and methods. Background Art

[0003] An electronic device may include one or more electroacoustic transducers to produce sound. Given size constraints, some electronic devices incorporate electroacoustic transducers configured as so-called "microspeakers." Examples of microspeakers include speaker transducers found in earphones, headphones, smartphones, or other similar compact electronic devices (such as, for example, wearable electronic devices, portable timekeeping devices, or tablets, notebooks, or laptops). Summary of the invention

[0004] In some aspects, the concepts disclosed herein relate generally to electroacoustic transducers, and more particularly, but not exclusively, to loudspeaker transducers. More particularly, but not exclusively, the present disclosure relates to loudspeakers including diaphragms having integrated structural features, such as, for example, a base adapted to interface with a movable portion of an electric driver (e.g., a voice coil). As another illustrative example, the disclosed loudspeaker diaphragms may include one or more supplemental reinforcements to modify the break-off frequency mode of the diaphragm.

[0005] Some disclosed transducers include diaphragms with integrated structural features that improve the physical robustness of the transducer. For example, some disclosed structures are adapted to improve the physical connection to the drive element. Likewise, some disclosed structural features may improve the physical robustness of the transducer and / or mitigate manufacturing defects. Such structural features may modify the break-off frequency, for example, by moving the break-off frequency mode outside the audible frequency band. Thus, compared to existing electro-acoustic transducers, some disclosed electro-acoustic transducers may be driven with greater excursions and with greater force than conventional electro-acoustic transducers, thereby providing improved fidelity and greater playback.

[0006] According to a first aspect, an electroacoustic transducer includes an acoustic diaphragm defining a first major surface and an opposing second major surface. A base extends laterally from the second major surface. The acoustic diaphragm and the base form a unitary structure. The electroacoustic transducer also includes a drive element. The base and the drive element are positioned to overlap and align with each other.

[0007] The pedestal may define an outer surface, and the voice coil may define a corresponding inner surface.The electro-acoustic transducer may further include an adhesively bonded lap joint between the outer surface of the pedestal and the inner surface of the voice coil.

[0008] The pedestal may define an inner surface, and the voice coil may define a corresponding outer surface.The electro-acoustic transducer may further include an adhesively bonded lap joint between the inner surface of the pedestal and the outer surface of the voice coil.

[0009] The drive element may have a plurality of layers of conductive filaments. The overlapping alignment between the drive element and the base may include an overlapping relationship between the base and the plurality of layers of conductive filaments. In some cases, the drive element extends from a proximal end positioned adjacent to the acoustic diaphragm to a distal end spaced apart from the acoustic diaphragm. The plurality of layers in overlapping relationship with the base may include a first plurality of layers positioned adjacent to the proximal end of the drive element. The drive element may also include a second plurality of layers of conductive filaments.

[0010] The voice coil of some disclosed electroacoustic transducers may extend longitudinally from a proximal end positioned adjacent the acoustic diaphragm to a distal end spaced from the acoustic diaphragm.The overlapping alignment between the voice coil and the pedestal may include an overlapping relationship between the pedestal and the proximal end of the voice coil.

[0011] The overlay registration between the voice coil and the base may also include an adhesive bond between the base and the voice coil.

[0012] According to another aspect, an electroacoustic transducer includes an acoustic diaphragm defining a first major surface and an opposing second major surface. Each of the first major surface and the opposing second major surface defines a corresponding major axis and a minor axis. Each corresponding major axis is longer than the corresponding minor axis. The electroacoustic transducer includes a base extending laterally from the second major surface, and a driving element. The electroacoustic transducer also includes a bonded lap joint between the driving element and the base.

[0013] The acoustic diaphragm and the base may form a one-piece construction.

[0014] The acoustic diaphragm may define an outer perimeter.The base may extend from the second major surface at a location adjacent the outer perimeter.

[0015] The acoustic diaphragm may define an outer perimeter, and the lap joint may be positioned inboard of the outer perimeter.

[0016] The electroacoustic transducer may further include a reinforcement member extending from the first major surface and along the acoustic diaphragm toward the outer periphery. Such reinforcement member may be integrally formed with the diaphragm. Such reinforcement member may include an elongated rib having a longitudinal axis and defining a cross-sectional area. The cross-sectional area may taper along the longitudinal axis and toward the outer periphery. The reinforcement member may modify the fracture frequency mode of the diaphragm.

[0017] According to yet another aspect, an electroacoustic transducer may include an acoustic diaphragm defining a first major surface and a flange extending opposite the first major surface. The voice coil has a first plurality of windings positioned adjacent to the acoustic diaphragm and a second plurality of windings positioned distally of the acoustic diaphragm. The flange overlaps the first plurality of windings.

[0018] The electro-acoustic transducer may include an adhesive bond between the flange and the first plurality of windings.

[0019] The first plurality of windings may have fewer windings than the second plurality of windings such that the first plurality of windings is thinner than the second plurality of windings.

[0020] The first major surface can define a major axis and a minor axis.

[0021] The electro-acoustic transducer may further include a transducer base and a surrounding member extending from the base to the acoustic diaphragm. The acoustic diaphragm may further define a protrusion extending from the first major surface at a location adjacent to the surrounding member.

[0022] The present invention also discloses associated methods, as well as audio instruments and audio accessories incorporating the disclosed electroacoustic transducer.

[0023] The foregoing and other features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Referring to the drawings, wherein like numerals refer to like parts throughout the several views and the specification, various aspects of the disclosed principles are illustrated by way of example and not by way of limitation.

[0025] Figure 1 Aspects of an electroacoustic transducer are shown.

[0026] Figure 2 Aspects of another electroacoustic transducer having a diaphragm including one or more integrated structural features are shown.

[0027] Figure 3 An exploded view of the diaphragm and drive member assembly is shown.

[0028] Figure 4 Schematically shows Figure 2 Detail of the electroacoustic transducer shown within the dashed line "IV".

[0029] Figure 5 Shows Figure 4 Various aspects of the diaphragm are shown in .

[0030] Fig. 6A Schematically shows Figure 4 Aspects of the drive elements shown in .

[0031] Figure 6B Schematically shows Figure 4 Aspects of another configuration of a drive element are shown in .

[0032] Figure 7 Schematically shows Figure 4An alternative arrangement of the diaphragm and drive assembly is shown in FIG.

[0033] Figures 8 to 10 Other alternative configurations of diaphragms and drive assemblies are shown.

[0034] Fig.11 Shown along Figure 2 A cross-sectional view taken along section line XI-XI in FIG.

[0035] Fig.12 A top plan view of a diaphragm having an integrated reinforcement member extending from an upper major surface is shown. Fig. 9 In FIG. 1 , an upper major surface is shown, and aspects of the base extending below an opposing lower major surface are prominently shown.

[0036] Fig.13 Shows Fig.12 The diaphragm shown in FIG. 1 is a cross-sectional view taken along the left side of the section line XIII-XIII and the section line XIIIa-XIIIa.

[0037] Fig.14 An intermediate configuration during an overmolding process is schematically shown.A portion of the diaphragm has integrated structural features that inhibit excess material flow and thus reduce the formation of so-called "flash".

[0038] Fig.15 Shown is an assembly with an acoustic box Figure 2 Aspects of the electroacoustic transducer shown in .

[0039] Fig.16 A block diagram illustrating aspects of an audio instrument is shown. DETAILED DESCRIPTION

[0040] Various principles related to electroacoustic transducers, and related systems and methods are described below. For example, some disclosed principles relate to structural features of electroacoustic transducers that change the structural robustness of the transducer diaphragm compared to existing diaphragms. That is, the description of a specific combination of specific transducers, instruments, devices or system configurations and method actions herein is only a specific example of the envisioned transducer, instrument, component, system and method selected as a convenient illustrative example of the disclosed principles. One or more disclosed principles can be combined in various other combinations to achieve any of the various corresponding desired characteristics. Therefore, after studying the present disclosure, a person of ordinary skill in the art will recognize that transducers, instruments, components, systems and methods having properties different from those specific examples discussed herein can embody one or more principles disclosed herein and can be used in applications not described in detail herein. Such alternative embodiments also fall within the scope of the present disclosure.

[0041] I. Overview

[0042] Some disclosed electroacoustic transducers incorporate one or more selected structural features suitable for use in microspeakers. For example, such structural features may provide improved structural robustness, audio fidelity, long-term reliability, or other enhancements to the microspeaker compared to existing electroacoustic transducers. Such structural features may include one or more protrusions from one or both major surfaces of the diaphragm. Similarly, such structural features may include one or more grooves, channels, conduits, holes, or other recesses formed on one or both major surfaces.

[0043] II. Electroacoustic transducer

[0044] See also Figure 1 , an electroacoustic transducer 10 may have an acoustic radiator (e.g., diaphragm) 12 physically coupled to an electrically driven element 14. The acoustic radiator defines a first major surface 12a and an opposing major surface 12b, both of which extend into and out of the page, as shown in FIG. Figure 1 Depicted.

[0045] The drive element 14 may include a bobbin or other member combined with one or more windings of, for example, a conductive filament. In one aspect, the drive element is formed as a layered construction, wherein each layer has a corresponding winding. In another aspect, the drive element does not include a bobbin, but is formed from layered windings of filaments. The drive element 14 may have an annular or elongated shape to produce a cross-section, such as Figure 1 The conductive wire (e.g., copper-clad aluminum) is sometimes referred to as "voice coil wire." Such a bobbin is sometimes referred to in the art as a "voice coil former" or "former," and the one or more windings are sometimes referred to in the art as a "voice coil" or "coil."

[0046] The voice coil former (or the voice coil when the former is omitted) may be physically attached (e.g., bonded) to the major surface 12b of the acoustic diaphragm 12. For example, the first end of the voice coil 14 may be chemically or otherwise physically bonded to the second major surface 12b of the acoustic diaphragm 12. The bond may provide a platform for transmitting mechanical forces and mechanical stability to the diaphragm 12. Such mechanical forces may be generated between the voice coil and the surrounding magnets.

[0047] For example, the drive element 14 may be positioned in a gap between one or more permanent magnets 16a, 16b (e.g., NdFeB magnets) such that the member 14 is immersed in a static magnetic field generated by the one or more magnets. An electric current may pass through a coil and induce a corresponding magnetic field. The induced magnetic field from the coil may interact with the static magnetic field of the magnets 16a, 16b to cause the coil, and therefore the diaphragm 12 to which the drive element 14 is attached, to move.

[0048] As the current varies in strength and direction, the magnitude of the magnetic force urging the electric drive element 14 may vary in magnitude and direction, thereby causing the electric drive element to reciprocate, for example, as a piston. Such reciprocating motion is depicted by the double-ended arrow covering the drive element 14. In addition, a physical connection 13 between the drive element 14 and the acoustic diaphragm 12 may transmit the reciprocating piston movement of the drive element to the diaphragm. When the corresponding current or voltage potential is alternating, for example, at audible frequencies, the voice coil 14 (and diaphragm 12) can move, for example, a reciprocating piston moves and radiates sound.

[0049] The transducer module 10 has a frame 17 and a suspension system 15 that supports and couples an acoustic diaphragm 12 to the frame. The diaphragm 12 can be hard (or rigid) and lightweight. Ideally, the diaphragm 12 exhibits perfect piston motion. The diaphragm (sometimes referred to as a cone or dome, for example, corresponding to its selected shape) can be formed of aluminum, paper, plastic, composite materials, or other materials that provide high stiffness, low mass, and can be appropriately shaped during manufacturing.

[0050] The suspension system 15 generally provides a restoring force to the diaphragm 12 after an excursion driven by the interaction of the magnetic field from the driven voice coil member 14 and one or more magnets 16a, 16b. Such a restoring force may return the diaphragm 12 to a neutral position, such as Figure 1 As shown. The suspension system 15 can maintain the voice coil within a desired position range relative to one or more magnets 16a, 16b. For example, the suspension 15 can provide controlled axial movement (e.g., piston movement) along an axis Z that is transverse to the diaphragm 12, while largely preventing lateral movement or tilting, which can cause the drive element 14 to strike other motor components, such as, for example, one or more magnets 16a, 16b or a member attached to one of the magnets. As used herein, references to "magnets" refer to magnets or magnet assemblies. The magnet assembly, in turn, may include a magnet physically coupled to, for example, another member or coating. For example, a steel plate or other magnetic conductor may be attached to a magnet to form a magnet assembly.

[0051] The elasticity of the suspension 15 can be selected (e.g., location-dependent stiffness) to match the force and flexure characteristics of the motor system (e.g., voice coil and magnets 16a, 16b). The exemplary suspension system 15 includes a surround extending outward from the outer periphery 15a of the diaphragm 12. The surround can be formed of a polyurethane foam material, a silicone material, or other flexible material. In some cases, the surround can be compressed into a desired shape by heat and pressure applied to the material in the mold or mold.

[0052] The connection 13 between the drive element 14 and the diaphragm 12 may involve attaching the edge 14a of the drive element to the second major surface 12b, for example, a flat area defined by the second major surface 12b. However, such a bond may be relatively weak, in large part due to the relatively small contact area between the edge 14a of the drive element and the second major surface 12b of the diaphragm. Therefore, a chamfer 13a may be formed to strengthen the connection 13.

[0053] However, chamfer 13a occupies a limited volume other than driven element 14 and diaphragm 12, and many commercially desirable electronic devices are quite small. Therefore, other components (e.g., permanent magnet 16a) may be complementarily contoured to prevent interference between chamfer 13a and magnet 16a during deflection of diaphragm 12. Figure 1 As shown, the top surface 18 of the magnet 16a has a chamfer 18a contoured corresponding to the chamfer 13a to prevent interference of the chamfer with the magnet 16a during "downward" diaphragm deflection. In some cases, forming such a chamfer 18a may require secondary machining or other processing.

[0054] In addition, the speaker diaphragm 12 may flex or resonate when driven with sufficient force and / or at certain, for example, resonant frequencies. Such flexure or resonance is sometimes referred to in the art as "fracture" and may occur at certain "fracture mode" frequencies. Such fracture flexure or resonance may reduce the fidelity of the speaker and reduce the reliability of the connector 13. Therefore, given the limitations of its physical size and structural features (e.g., the connector 13), the design of the connector 13 may be limited. Figure 1 The output levels achievable by the microspeakers are shown.

[0055] See now Figure 2 The improved electroacoustic transducer may have a diaphragm 22 defining a first major surface 22a and an opposing second major surface 22b. Figure 1 Like the transducer shown, Figure 2 The illustrated transducer may include a drive element 24 (e.g., a voice coil member) physically coupled to a diaphragm 22, and the drive element 24 may have a voice coil immersed in a static magnetic field, for example, associated with magnets 26a, 26b. Figure 1 As shown, the diaphragm 22 may be coupled to the frame via the suspension system 15 .

[0056] However, with Figure 1 Unlike the transducers in the embodiment of the present invention, a base 23 (or flange) may extend from the second major surface 22b of the diaphragm 22. The base 23 may be suitable for overlapping the diaphragm 22 with the movable driving element 24. Some one-piece diaphragm / base components are formed using an injection molding process. The injection molding process can provide flexibility and form a variety of integrated structural features in the one-piece acoustic diaphragm. Some representative structural features are described in detail below.

[0057] Figure 3 The exploded view in the figure shows the Figure 2 Various aspects of the lap joint between the diaphragm 32 and the drive element 34 are shown similarly. Figure 3 In the embodiment of the present invention, the diaphragm 32 and the base 33 form an integral structure. The base 33 extends from the second main surface 32b to the distal side 36 and defines a recessed inner area 35. The driving element 34 defines a shoulder 37 and a proximal end face 38. The shear surface 39 extends from the shoulder 37 to the proximal end face 38. The base 33 and the driving element 34 can be aligned and positioned to overlap each other so that the proximal end face 38 of the driven element 34 can be received in the recessed inner area 35 of the base 33. Such alignment between the diaphragm and the driving element can facilitate the assembly of the electroacoustic transducer, such as by aligning the diaphragm and the driving element relative to each other. Similarly, such alignment can improve the concentricity of the components and improve the audio fidelity of the resulting loudspeaker transducer. For example, when the diaphragm is driven by offset, the properly aligned driver and diaphragm can maintain a high degree of piston motion. It should be noted that although a shoulder 37 is shown, the wall defining the shear surface 39 may extend longitudinally uninterrupted to the distal end of the drive element 34 , thereby eliminating the shoulder 37 .

[0058] Additional aspects of the connection between the diaphragm and the drive element are described below. For example, Figure 4 Shows Figure 2 Detail shown in dashed circle "IV" in FIG. As shown, the base 23 can extend from a proximal end of the second major surface 22b of the diaphragm 22 adjacent to (e.g., integrally formed with) to define an integral diaphragm and base configuration. The distal region of the base 23 can (but need not) define a contour that is complementary shaped relative to a corresponding proximal end of a drive element 24 (sometimes also referred to as a driver). The base 23 and the drive element 24 can be positioned in an overlapping alignment with each other, and the lap joint 25 can include an adhesive 21 that spans a gap between the base 23 and the driver 24.

[0059] For example, by referring to Figure 5 , Fig. 6A and Figure 6B , the distal region of the base 23 may define a stepped region, and the proximal region of the driver 24 may define a complementary stepped region. For example, a portion of the base 23 may be recessed from the distal end face 41 to define a shoulder 43. The inwardly facing (e.g., relative to the inner magnet 26a) shear face 42 may span the distance from the distal end face 41 to the shoulder 43. Similarly, the driver element 24 may define a proximal side 52 and a shoulder 54. The outwardly facing shear face 55 may span the distance from the proximal end face 52 to the shoulder 54. When joined to form Figure 4When the lap joint 25 is shown, the proximal side surface 52 of the driver 24 can be positioned opposite the shoulder 43 of the base 24. Similarly, the shear face 42 of the base can be positioned opposite the shear face 55 of the driver 24. And, the distal end surface 41 of the base 23 can be positioned opposite the shoulder 54 of the driver 24.

[0060] Adhesive 21( Figure 4 ) For example, a heat-sensitive adhesive, a curable epoxy resin or another suitable adhesive material can fill the gap between the faces and shoulders of the base and the driver to form a lap joint 25. This lap joint can bond the base 23 to the driver 24.

[0061] Fig. 6A and Figure 6B Shows Figure 2 The cross-sectional view of the Fig. 6A As shown, the bobbin 51 may support one or more windings of conductive filaments. Fig. 6A and Figure 6B 6, the driver 24, 24' is shown having a first winding region 53 and a second winding region 56. The first winding region 53 extends from the proximal end face 52 of the driver 24 to the opposite distal end of the driver. In contrast, the second winding region 56 extends from the shoulder 54 of the driver 24 to the opposite distal end, thereby exposing an area of ​​the first winding region 53 to define a shear surface 55. The first winding region 53 can have any possible number of windings. The second winding region 56 can have any selected number of windings, including zero windings. The drive element 24 of FIG. 6 includes a bobbin (or coil former) 51, and Fig. 6A The drive element 24' in the embodiment omits the bobbin 51. Fig. 6A In the embodiment, the windings forming the coil form a laminated construction having sufficient rigidity so that no bobbin is required.

[0062] Alternative arrangements of the diaphragm 22, the base 23 and the drive element 24 are also possible. Figure 4 and Figure 5 The base 23 in FIG. 4 is shown as defining an inwardly facing shear surface 42, but the base 23b ( Figure 7 ) may define an outwardly facing shear surface. Similarly, drive element 24a ( Figure 7 ) may define inwardly facing shear surfaces to form an alternative lap joint 25b in an alternative arrangement 60.

[0063] Figures 8 to 10 Other possible arrangements are shown. Figure 8 In the embodiment, the base 23b is repositioned relative to the diaphragm 22 (with Figure 4 and Figure 5 More specifically, Figure 8The base 23b in the membrane is adjacent to the outer peripheral edge 15a of the diaphragm 22 and extends downward. Fig. 9 A similar position of the base 23c is shown. Fig. 9 As shown, the base 23 ( Figure 5 and Figure 8 ) has been omitted from the lap joint 25c. Fig. 9 In the embodiment, the lap joint 25c is adhesively engaged with the corresponding outwardly facing shear surface of the drive element 24c between the inwardly facing shear surface of the base 23c. The shear surface of the base 23c is not defined by a recessed area formed on the base, but is defined by the inwardly facing major surface of the base 23c.

[0064] exist Fig.10 In the embodiment of the present invention, the base 23d is positioned inboard of the outer periphery 15a of the diaphragm 22, and the shear surface of the base 23d is the outwardly facing major surface of the base (although the shear surface can be positioned on the inwardly facing major surface of the base 23d, such as Fig. 9 See also Fig.10 , the lap joint 25d between the drive element 24d and the base 23d is still created by the overlapping relationship between the base and the drive element 24d. However, the drive element 24d is positioned outside the base 23d and is shown as being generally coextensive with the outer peripheral edge 15a of the diaphragm 22. As a matter of design choice, the drive element 24d may be positioned inside this edge 15a or may extend outwardly from the edge 15a. Fig.10 In the embodiment, the outwardly facing major surface of the base 23d is adhered to the inwardly facing surface of the drive element 24d.

[0065] like Fig. 9 As shown, the drive element may optionally include a winding region 28c positioned outboard of the inwardly facing shear surface of the base 23c so as to define a stepped proximal end (relative to the diaphragm 22) for the drive element 24c. For example, the winding region 28c may include an additional winding layer compared to the region 24c. The lap joint 25c may optionally include an adhesive in the gap between the optional winding region 28c and the base 23c. Fig.10 As shown, the drive element 24d may optionally include a winding region 28d positioned inboard of the outwardly facing shear surface of the base 23d so as to define a stepped proximal end (relative to the diaphragm 22) for the drive element 24d. The winding region 28d may include additional winding layers compared to the region 24d. Of course, either drive element 24c, 24d may optionally include a winding region extending outwardly from the outer peripheral edge 15a. Also, either or both of the drive elements 24c, 24d may include or omit a bobbin, as described in conjunction with FIGS. 6 and 7. Fig. 6AIn any case, the lap joint as described above can place the adhesive bond between the base and the corresponding driver primarily or completely in shear, and can increase the surface area available for the adhesive bond between the diaphragm and the driver (e.g., the voice coil, the voice coil former, or both), as compared to the previous edge bond 13 (with or without the reinforcing chamfer 13a), as described above. Figure 1 By increasing the strength of the joint between the driver element and the diaphragm, the voice coil can reliably apply an increased force to the diaphragm compared to the force applied to the diaphragm 12 via the edge bond 13.

[0066] In addition, the lap joint can reduce or eliminate the need to create an adhesive chamfer 13a in the edge bond 13 between the voice coil (or frame) and the diaphragm. Without or at least with a smaller chamfer, more space can be used for other components (e.g., magnets 26a, 26b). By providing additional packaging volume for, for example, magnets, acoustic performance can be increased and less secondary machining or other machining operations are required, such as on the magnets to accommodate conventional chamfers. For example, in Figure 2 In the embodiment, the top surface 27a of the magnet 26a has a raw edge 27b that does not require a bevel to avoid interference with the lap joint 25, unlike the magnet 16a which requires a bevel 18a to avoid interference with the chamfer 13a of the joint 13 ( Figure 1 ).

[0067] like Fig.11 As shown, placing the drive element 24 between the inner magnet 26a and the outer magnet 26b can leave an air gap 71 between the drive element and the outer magnet, and an air gap 72 between the drive element and the inner magnet 26a. Fig.11 In the embodiment, the drive element 24 is shown as having a bobbin 51 as shown in FIG6 , so that the air gap 72 is positioned between the bobbin 51 and the inner magnet 26a. However, in an operational embodiment, each winding region 53, 56 has two winding layers, and the bobbin 51 is omitted, such as Fig. 6A Other embodiments have any selected number of winding layers.

[0068] Using this configuration ( Fig. 6A ), the air gap 72 may extend between the winding region 53 and the inner magnet 26a. Fig. 6A With each configuration of drive elements 24, 24' shown, a shear face of the base extending from the diaphragm may be positioned in overlapping relation with a portion 55 of the winding region 53. An adhesive material (eg, glue) may physically couple the overlapping faces of the base and drive element to form a lap joint.

[0069] Design choices can be made between various alternative lap joints between the drive element and the integrated diaphragm and base. Such design choices can be selected to provide a suitable compromise between the bond strength of the corresponding lap joints, the dynamics that can be generated by the interaction between the magnetic flux generated by the winding regions 53, 56 and the magnets 26a, 26b, and the overall available packaging volume (e.g., compared to the volume occupied by the various components of the electroacoustic transducer).

[0070] In other respects, Figure 2 The electroacoustic transducer 20 is similar to Figure 1 The transducer 10 shown. For example, each transducer 10, 20 has a frame (or base) 17 and a suspension system including a surround 15 suspending the corresponding diaphragm 12, 22 from the base 17. For example, the surround 15 may overlap and be connected to the peripheral area 15a of the corresponding diaphragm 12, 22. The transducers 10, 20 may define a rear area 19 partially defined by each corresponding second major surface 12b, 22b. Similarly, each transducer 10, 20 may emit sound to a surrounding front area 18 partially defined by each corresponding first major surface 12a, 22a. Some electronic devices acoustically couple such microspeakers to one or more open areas suitable for improving radiated sound, such as an acoustic cavity 30 ( Fig.15 ) of the nature of the

[0071] The voice coil / seat assembly 23, 24 may have a cross-sectional shape corresponding to the shape of the major surface of the diaphragm 22. For example, when viewed in plan from above (or below), the diaphragm 22 may have a substantially circular shape (e.g., as shown in FIG. Figure 3 ), a straight line (e.g., Fig.11 Similarly, the voice coil (or voice coil former) may have a substantially circular, rectilinear, oval, racetrack, or other cross-sectional shape. In other cases, the cross-sectional shape of the voice coil former may differ from the shape of the diaphragm when viewed in plan view from above (or below).

[0072] Generally speaking, the diameter or major axis of a non-circular microspeaker diaphragm (e.g. Fig.12 The y-axis in the figure may measure, for example, between about 3 mm and about 75 mm, such as between about 15 mm and about 65 mm, for example between about 20 mm and about 50 mm. The minor axis (e.g., Fig.12 The coil may be disposed along a longitudinal axis (e.g., Figure 2 The z-axis in the figure) measures between about 0.5 mm and about 3 mm (e.g., between about 1.0 mm and about 1.5 mm).

[0073] Generally speaking, the diaphragm 22 can be defined from a first major surface 22a (eg Fig.12 The reinforcing element 92 shown), the second major surface 22b (as shown Figure 2 as shown) or both (as shown Fig.13 The diaphragm may include one or more protrusions or other features (e.g., grooves, holes, etc.) extending from the first major surface 22a (as shown). Each such feature may be formed as an integral structure with the corresponding diaphragm. Similarly, the diaphragm may define grooves or other depressions (or holes) in one or more areas of the first major surface 22a, the second major surface 22b, or both.

[0074] Such protrusions or grooves can be integrated into the diaphragm using, for example, injection molding or other forming processes. The integrated features can provide Figure 1 One or more corresponding beneficial effects lacking from the illustrated diaphragm 12, for example, as described above. For example, one or more holes (not shown) may extend through the diaphragm 22, extending from the first major surface to the second major surface, and allow gas pressure to equalize on the diaphragm 22.

[0075] See now Fig.12 , which describes other examples of structural features that can be formed with the diaphragm as a unitary construction. Fig.12 As shown, the diaphragm 90 may include one or more reinforcing elements 92, such as thickened areas, ribs, or struts. For example, such reinforcing elements 92 may be incorporated into the diaphragm at selected areas to modify the resonant bending frequency (sometimes referred to as the breakaway frequency) of the diaphragm, which may reduce the fidelity of the loudspeaker transducer. The resonant bending frequency of the diaphragm 90 may depend on the geometry of the diaphragm, the material properties of the material used to form the diaphragm, and how the diaphragm is supported (e.g., by a surround 94 covering the outer periphery of the diaphragm) and the base / drive element assembly 96 (e.g., as described above with respect to FIG. 1 ). Figures 2 to 8 described above).

[0076] exist Fig.12 , acoustic diaphragm 90 defines an outer peripheral region 98 extending outside of base / drive element assembly 96. At opposite end regions (e.g., along major axis y), diaphragm 90 defines respective cantilever regions extending from the exterior of the base to the outer periphery (e.g., below surround 94). Stiffeners 92 extend along each cantilever region toward outer periphery 98. In some (e.g., injection molded) diaphragms, the stiffeners are integrally formed with the cantilever regions.

[0077] exist Fig.12 In the embodiment, the reinforcement member is an elongated rib having a longitudinal axis. The rib defines a cross-sectional area that tapers along the longitudinal axis and toward the outer periphery 98. Fig.13 As shown, the cross-sectional area of ​​the exemplary ribs is longitudinal (e.g., along the y-axis) and along the z-axis ( Figure 2) tapers. Incorporating such a reinforcement 92 into the diaphragm 90 can change the fracture frequency mode of the diaphragm 90, for example by reinforcing (e.g., strengthening) an area that is subject to flexure or buckling. However, even without incorporating Fig.12 The reinforcement member 92 shown, the integrated base 96 (or Figure 2 The base 23 in the diaphragm 22 can also modify the stiffness of the diaphragm 22. Also, the bases 23b, 23c, 23d ( Figure 8 , Fig. 9 and Fig.10 ) can eliminate or reduce Fig.12 The size of the outer peripheral area 98 shown in FIG. Figure 2 Such an arrangement may modify the bending stiffness of the diaphragm and may modify its fracture frequency compared to the diaphragm shown.

[0078] Some acoustic diaphragms described herein may include overmolded layers of material. Fig.14 An example of such a diaphragm is shown. Fig.14 A temporary configuration 110 is shown during an overmolding process applied to a diaphragm 112 having an integrated structural feature, such as a pillar (or protrusion) 113, as disclosed herein. A supply source 114 of siloxane 5 may be injected into an overmolding mold 115, and the siloxane may flow through and partially encapsulate a portion of the surround 15 and the diaphragm. The mold 115 may define opposing jaws that contact the diaphragm 112 at a position between the surround 15 and the pillar 113. However, some siloxane 5 may flow between the jaws and the diaphragm 112 (e.g., as the mold wears over time). This unintentional deposition of material (e.g., siloxane) produced by the overmolding process is sometimes referred to in the art as "flash evaporation." The protrusion 113 may inhibit the flow of siloxane 5 through the protrusion, and may reduce the extent of flash evaporation produced by the overmolding process. Alternatively, the protrusion 113 may be "crushed" into the surface of the diaphragm 112 by the mold 115. According to another aspect, grooves or other depressions in one or more areas of the diaphragm (eg, in addition to or opposite to protrusions 113) can receive inadvertent deposits of adhesive or other materials applied to the diaphragm.

[0079] See now Fig.15 , speaker module 20( Figure 2 ) is positioned in an acoustic box 1. The acoustic box 1 may be a stand-alone device, such as a conventional bookshelf speaker or a smart speaker. Alternatively, the acoustic box 1 may constitute a defined area within the housing of a smaller portable device such as, for example, a smart phone. In other alternative embodiments, the acoustic box may constitute part of a smart watch, in-ear headphones, on-ear headphones, or over-ear headphones.

[0080] In either case, Fig.15 The acoustic enclosure 1 in comprises a housing 2 defining an open interior region 3. A loudspeaker diaphragm 22 or more generally an acoustic radiator is positioned in the open interior region 3 and defines a first major surface 22a and an opposing second major surface 22b. Fig.15 In the embodiment, the open interior region 3 defines an acoustic cavity 30 adjacent to the first major surface 22a and an acoustically sealed acoustic cavity 19 adjacent to the second major surface 22b. Fig.15 , the acoustic cavity 30 and the acoustically sealed acoustic cavity 19 are at least partially defined by the first major surface 22a and the second major surface 22b, respectively.

[0081] The housing 2 also defines an acoustic port 6 from the acoustic cavity 30 to the surrounding environment 7. The port 6 and the diaphragm 22 may be arranged in a so-called "side-firing" arrangement, such as in Fig.15 That is, the cross-section (or mouth) of the port 6 may be oriented transversely relative to the major surfaces 22a, 22b of the diaphragm 22. For example, in Fig.15 , the port 6 is oriented so that a vector normal to the port mouth extends normal to a vector normal to the speaker diaphragm 22 .

[0082] Although the illustrated acoustic port 6 has a cover 8 or other protective barrier to inhibit dirt, water or other debris from penetrating into the acoustic cavity 18, some acoustic ports have no obvious cover. Fig.15 Rather than defining a single aperture as in , the housing 2 can define a perforated wall (not shown) extending across the mouth of the port 6 .

[0083] Although Fig.15 , the acoustic port 6 is generally illustrated as a hole defined by the housing wall, but in some cases, the acoustic port 6 includes an acoustic duct or channel extending from the acoustic cavity 18 to the outer surface 2a of the housing 2 or other shell. For example, the aesthetics or other design constraints of the electronic device may cause the acoustic cavity 18 to be spaced apart from the outer surface 2a of the housing or other shell. Therefore, a duct or other acoustic channel (not shown) may extend from the acoustic cavity 18 to the outer surface to acoustically connect the acoustic cavity 18 to the surrounding environment 7. Although not shown, such a duct may have an internal baffle to define a circuitous path from a proximal end adjacent to the acoustic cavity 30 to a distal end adjacent to the outer surface 2a.

[0084] Although a side-firing arrangement is shown, some disclosed speaker enclosures are arranged for so-called direct-firing. A direct-firing enclosure directs a major surface of the speaker diaphragm toward an opening in the enclosure. Even with a direct-firing arrangement, the diaphragm may be spaced from the outer surface of the enclosure and acoustically coupled to the external environment through ports and / or channels (e.g., circuit channels). A mesh or other covering may extend over the diaphragm or ports for aesthetic or reliability reasons (e.g., to inhibit the intrusion of debris).

[0085] And, although not in Figure 2 or Fig.15 As shown in , the speaker transducer and / or acoustic enclosure may include other circuits (e.g., application specific integrated circuits (ASICs)) or electrical devices (e.g., capacitors, inductors, and / or amplifiers) to condition and / or drive the electrical signal through the voice coil. Such circuits may form part of the computing environment or audio equipment described herein.

[0086] See now Fig.16 , electronic devices incorporating the disclosed electro-acoustic transducers are described with reference to specific examples of audio instruments. Electronic devices represent only one possible class of computing environments that can incorporate the disclosed electro-acoustic transducers, as described herein. However, the electronic device is briefly described in conjunction with a particular audio instrument 130 to illustrate an example of a system that incorporates and benefits from the disclosed electro-acoustic transducers.

[0087] like Fig.16 As shown, the audio instrument 130 or other electronic device in its most basic form may include a processor 134, a memory 135, and a speaker or other electro-acoustic transducer 137, as well as associated circuitry (e.g., signal buses, which are shown for clarity). Fig.16 The memory 135 may store instructions that, when executed by the processor 134, cause the circuit in the audio instrument 130 to drive the electroacoustic transducer 137 to emit sound over the selected frequency bandwidth. Fig.15 As shown, the audio instrument 130 may have a implanted acoustic cavity positioned adjacent to the electroacoustic transducer.

[0088] Fig.16 The audio device 130 schematically shown in the figure also includes a communication connection 136 for establishing communication with another computing environment. Similarly, the audio device 130 includes an audio acquisition module 131, which has a microphone transducer 132 that converts incident sound into an electrical signal, and a signal conditioning module 133 that adjusts (e.g., samples, filters and / or otherwise adjusts) the electrical signal emitted by the microphone. In addition, the memory 135 can store other instructions that, when executed by the processor, cause the audio device 130 to perform any of a variety of tasks similar to general computing environments, such as distributed computing environments, network-connected computing environments, and stand-alone computing environments.

[0089] The audio instrument may take the form of a portable media device adapted for use with a variety of accessory devices.

[0090] The accessory device may take the form of a wearable device such as, for example, a smart watch, in-ear earbuds, on-ear headphones, and over-ear headphones. The accessory device may include one or more electroacoustic transducers as described herein.

[0091] IX. Other Implementation Schemes

[0092] The previous description is provided to enable those skilled in the art to make or use the disclosed principles. Embodiments other than those described in detail above are conceived based on the principles disclosed herein and any attendant changes in the configuration of the corresponding structures described herein, without departing from the essence or scope of the present disclosure.

[0093] The above examples generally relate to "small" electroacoustic transducers and related systems and methods. However, microspeakers operate on principles similar to larger electroacoustic transducers. Therefore, the concepts disclosed herein can be incorporated into electroacoustic transducers other than microspeakers.

[0094] In addition, various modifications to the examples described herein will be apparent to those skilled in the art. For example, some disclosed pedestals formed in a speaker diaphragm may replace a separate coil former (or bobbin). In such an embodiment, the pedestal may serve as a bobbin or other frame to which the voice coil winding is applied when the coil is constructed. With such an assembly, a separate adhesive layer 21 may be eliminated, for example by joining the pedestal and voice coil wire simultaneously with forming the coil winding (e.g., using a resin covering the coil wire).

[0095] Direction and other related references (e.g., up, down, top, bottom, left, right, backward, forward, etc.) may be used to help discuss the drawings and principles of this article, but are not intended to be limiting. For example, certain terms such as "upward", "downward", "upper", "lower", "horizontal", "vertical", "left", "right", etc. may be used. These terms are used to provide some clarity when dealing with relative relationships, especially with respect to the illustrated embodiments, where applicable. However, such terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, an "upper" surface can simply become a "lower" surface by flipping the object. Nevertheless, it is still the same surface and the object remains unchanged. As used herein, "and / or" means "and" or "or", as well as "and" and "or". In addition, for all purposes, all patents and non-patent literature cited herein are hereby incorporated by reference in their entirety.

[0096] Furthermore, it should be understood by those of ordinary skill in the art that the exemplary embodiments disclosed herein may be adapted to various configurations and / or uses without departing from the principles disclosed herein. Applying the principles disclosed herein, a wide variety of damping acoustic boxes and related methods and systems may be provided. For example, the principles described above in conjunction with any particular example may be combined with the principles described in conjunction with another example described herein. Therefore, all structural and functional equivalents of the features and method measures of the various embodiments described throughout the present disclosure that are known or later become known to those of ordinary skill in the art are intended to be covered by the principles described herein and the features claimed for protection. Accordingly, neither the claims nor this detailed description should be construed in a limiting sense, and after reviewing the present disclosure, those of ordinary skill in the art will understand the wide variety of audio instruments and related methods and systems that can be designed under the concepts disclosed and claimed for protection.

[0097] Furthermore, nothing disclosed herein is intended to be made available to the public regardless of whether such disclosure is explicitly recited in the claims. To assist the Patent Office and any reader of any patent that issues in this application in interpreting the appended claims or claims otherwise presented during the prosecution of this or any continuation of a patent application, applicants wish to note that they are not intended to invoke any claimed features under or otherwise construed under 35 U.S.C. §112(f) unless the words "means for" or "step for" are expressly used in a particular claim.

[0098] The appended claims are not intended to be limited to the embodiments shown herein, but rather are intended to have the full scope consistent with the language claims, wherein reference to features in the singular (such as by use of the articles "a" or "an") are not intended to mean "one and only one," but rather "one or more," unless specifically noted. Furthermore, in view of the many possible embodiments to which the disclosed principles may be applied, I reserve the right to claim any and all combinations of the features and techniques described herein as would be understood by one of ordinary skill in the art, including, for example, all those within the scope and spirit of the following claims.

Claims

1. An electroacoustic transducer, comprising: An integrated component, comprising: an acoustic diaphragm and a base integrally formed with the acoustic diaphragm, the acoustic diaphragm defining a first major surface and an opposing second major surface, wherein each of the first major surface and the opposing second major surface defines a corresponding major axis and a minor axis, each corresponding major axis being longer than the corresponding minor axis, wherein the base extends laterally from the second major surface, the acoustic diaphragm defining an outer perimeter; and a reinforcement member integrally formed with the acoustic diaphragm and extending from the first major surface and along the acoustic diaphragm toward the outer periphery, the reinforcement member comprising an elongated rib having a longitudinal axis and defining a cross-sectional area, wherein the cross-sectional area tapers along the longitudinal axis and toward the outer periphery; A drive element; and A bonded lap joint couples the drive element to the base of the unitary member. 2 . The electroacoustic transducer of claim 1 , wherein the pedestal extends from the second major surface at a position adjacent to the outer periphery.

3. The electroacoustic transducer of claim 1, wherein the acoustic diaphragm defines a cantilever region, and the reinforcement is integrally formed with the cantilever region.

4. The electroacoustic transducer of claim 1, wherein the reinforcement modifies a break-off frequency mode of the diaphragm.

5. The electroacoustic transducer of claim 1, wherein the drive element comprises a coil having a first plurality of windings positioned adjacent the acoustic diaphragm and a second plurality of windings positioned distally of the acoustic diaphragm.

6. An electronic device comprising: Acoustic box; as well as An electroacoustic transducer, wherein the electroacoustic transducer is disposed in the acoustic box, and the electroacoustic transducer comprises: A unitary component comprising an acoustic diaphragm and a base integrally formed with the acoustic diaphragm, the acoustic diaphragm defining a first major surface and an opposing second major surface, wherein each of the first major surface and the opposing second major surface defines a corresponding major axis and a minor axis, each corresponding major axis being longer than the corresponding minor axis, wherein the base extends laterally from the second major surface, wherein: The acoustic diaphragm defines an outer perimeter, The one-piece member further includes a reinforcement member extending from the first major surface and along the acoustic diaphragm toward the outer periphery, The reinforcement member includes an elongated rib having a longitudinal axis and defining a cross-sectional area, and The cross-sectional area tapers along the longitudinal axis and toward the outer periphery; A drive element; and A bonded lap joint couples the drive element to the base of the unitary member.

7. The electronic device of claim 6, wherein the base extends from the second major surface at a location adjacent the outer perimeter.

8. The electronic device of claim 6, wherein the reinforcement is formed integrally with the acoustic diaphragm.

9. The electronic device of claim 6, wherein the stiffener modifies a fracture frequency mode of the diaphragm.

10. The electronic device of claim 6, wherein the drive element comprises a coil having a first plurality of windings positioned adjacent to the acoustic diaphragm and a second plurality of windings positioned distally of the acoustic diaphragm.

11. The electronic device according to claim 6, wherein the electronic device is an independent electronic device, and wherein the acoustic box forms a housing of the independent electronic device.

12. The electronic device of claim 11, wherein the electronic device comprises a wearable electronic device.

13. A method of operating an electronic device, the method comprising: providing an electric current to a driving element of an electroacoustic transducer, the electroacoustic transducer comprising a unitary component including an acoustic diaphragm and a base integrally formed with the acoustic diaphragm, the acoustic diaphragm defining a first major surface and an opposing second major surface, wherein each of the first major surface and the opposing second major surface defines a corresponding major axis and a minor axis, each respective major axis being longer than the corresponding minor axis, wherein the base extends laterally from the second major surface, wherein the acoustic diaphragm defines an outer perimeter; forming a reinforcement member integrally with the acoustic diaphragm, wherein the reinforcement member extends from the first major surface and along the acoustic diaphragm toward the outer periphery, the reinforcement member comprising an elongated rib having a longitudinal axis and defining a cross-sectional area, wherein the cross-sectional area tapers along the longitudinal axis and toward the outer periphery; as well as Movement of the acoustic diaphragm is driven using the drive element, wherein the drive element is coupled to the base via a bonded lap joint.

14. The method of claim 13, wherein the drive element comprises a voice coil, and wherein providing the current to the drive element comprises passing current through windings of the voice coil.

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