Electroacoustic transducer device

Abstract

An electro-acoustic transducer device includes a hollow disc substantially defining a propagation axis, the hollow disc including a pair of plate-like members extending substantially perpendicularly to the propagation axis, each of the plate-like members being provided with a central sound port arranged about the propagation axis, and a peripheral enclosure joining the pair of plate-like members at their respective outer edge portions, thereby defining a resonant cavity between the pair of plate-like members, wherein an annular opening about the propagation axis is formed between the central sound ports of the plate-like members to enable access to the resonant cavity.

Description

[0001] Cross-reference

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 380,802, filed October 25, 2022, each of which is assigned to its assignee and is expressly incorporated herein by reference in its entirety. Technical Field

[0003] This application pertains to the field of electroacoustic transducers. In some embodiments, exemplary transducers include small piezoelectric sound-generating components with an extended output frequency range. Background Technology

[0004] Acoustic transducers play a crucial role in converting electrical signals into sound signals, and have become an indispensable component of modern multimedia devices. They are found in free-field sound devices, such as integrated or standalone speakers, or pressure-field sound devices, such as wearable headphones. As portable multimedia devices continue to seek to reduce their form factor, minimizing the size of sound-producing components while maintaining / improving their output capabilities to ensure sound quality has become a challenge.

[0005] Various types of sound-generating devices exist (e.g., electromagnetic, microelectromechanical systems (MEMS) types), each exhibiting different performance characteristics. For example, MEMS transducers offer advantages over traditional voice coil loudspeakers, including high consistency, low power consumption, and small size. MEMS transducers typically incorporate solid-state materials suitable for integrated manufacturing (e.g., piezoelectric materials) into miniature functional structures (e.g., suspended silicon structures with thin-film piezoelectric actuators); they can also be adaptively configured as planar or three-dimensional structures. Improving memory devices typically involves increasing memory cell density, improving read / write speeds, enhancing reliability, increasing data retention, reducing power consumption, or lowering manufacturing costs, among other things. Various operating conditions for memory devices can be adjusted by fine-tuning some parameters within the memory device to improve yield, performance, or reliability.

[0006] MEMS transducers in planar configurations are advantageous for reducing size, typically using acoustic actuators (e.g., piezoelectric plates) coupled to vibrating and sound-generating components (e.g., elastic / resonant diaphragms). However, the vibrating components in planar structures can sometimes restrict the deformation of the acoustic actuators, reducing the overall amplitude of the deformation displacement. This affects audio output quality and limits the acoustic performance of the electroacoustic transducer. On the other hand, while three-dimensional configurations generally decouple the actuators and vibrating components, the overall stability is often reduced due to the need for additional transmission components, which can easily introduce unstable modes affecting output sound quality. This arrangement may also make the transducer device more prone to drop failure or structural instability, resulting in lower reliability. SUMMARY

[0007] The present disclosure relates to an electro-acoustic transducer device comprising: a hollow disc defining a substantially defined propagation axis, the hollow disc comprising: a pair of plate-like members extending substantially perpendicular to the propagation axis, each of the plate-like members being provided with a central sound port arranged about the propagation axis, and a peripheral enclosure joining the pair of plate-like members at their respective outer edge portions thereby defining a resonance cavity between the pair of plate-like members; wherein an annular opening about the propagation axis is formed between the central sound ports of the plate-like members to enable access to the resonance cavity.

[0008] The present disclosure further relates to an electro-acoustic transducer device comprising: a first transducer component comprising a hollow disc defining a resonance cavity, wherein the hollow disc substantially defines a first propagation axis, the hollow disc comprising an active transducer unit provided with a central sound port arranged about the first propagation axis and enabling access to the resonance cavity; and a second transducer component arranged on the active transducer unit and substantially defining a second propagation axis, wherein the first propagation axis and the second propagation axis are substantially coaxially aligned. BRIEF DESCRIPTION OF DRAWINGS

[0009] In order that the manner in which the above-recited features of the present disclosure can be understood in detail, a brief description of the several views is provided below.

[0010] Figure 1 An exploded view of components of an exemplary electro-acoustic transducer device according to some embodiments of the present disclosure is depicted.

[0011] Figure 2 An isometric view and a partial cutaway magnified view of an exemplary transducer component for an electro-acoustic transducer device according to some embodiments of the present disclosure is depicted.

[0012] Figure 3 Various assembly configurations of an exemplary transducer component for an electro-acoustic transducer device according to some embodiments of the present disclosure is depicted.

[0013] Figure 4 Various assembly configurations of an exemplary transducer component for an electro-acoustic transducer device according to some embodiments of the present disclosure is depicted.

[0014] Figure 5 Various assembly configurations of an exemplary transducer component for an electro-acoustic transducer device according to some embodiments of the present disclosure is depicted.

[0015] Figure 6 Various complex transducer integration configurations of some electro-acoustic transducer devices according to the present disclosure is depicted.

[0016] Figure 7 Plan and cross-sectional views of an exemplary transducer component for an electro-acoustic transducer device are depicted in accordance with some embodiments of the present disclosure.

[0017] Figure 8 Plan and cross-sectional views of a transducer coupling arrangement for an electro-acoustic transducer device are depicted in accordance with some embodiments of the present disclosure.

[0018] Figure 9 Plan and cross-sectional views of a transducer coupling arrangement for an electro-acoustic transducer device are shown in accordance with some embodiments of the present disclosure.

[0019] Figure 10 Output versus frequency plots reflecting performance enhancements of example transducer components in accordance with the present application are shown.

[0020] Figure 11 Output versus frequency plots corresponding to various configurations of a pair of plate-like members defining different resonant chamber heights are shown.

[0021] Figure 12 Output versus frequency plots corresponding to various plate thickness (t) configurations of a pair of plate-like members defining a resonant chamber are shown.

[0022] Figure 13 Exemplary structural arrangements of a transducer component for an electro-acoustic transducer device are depicted in accordance with embodiments of the present disclosure.

[0023] Figure 14 Exemplary structural arrangements of a transducer component for an electro-acoustic transducer device are depicted in accordance with embodiments of the present disclosure.

[0024] Figure 15 Exemplary structural arrangements of a transducer component for an electro-acoustic transducer device are depicted in accordance with embodiments of the present disclosure.

[0025] Figure 16 Cross-sectional views of a composite acoustic transducer component for an electro-acoustic transducer device are depicted in accordance with embodiments of the present disclosure.

[0026] Figure 17 Schematic output versus frequency plots showing enhanced output performance of a composite acoustic transducer component for an electro-acoustic transducer device in accordance with embodiments of the present disclosure are shown.

[0027] Figure 18 Various views of a MEMS transducer component for an electro-acoustic transducer device are depicted in accordance with embodiments of the present disclosure.

[0028] Figure 19Multiple views of a MEMS transducer cell for an integrated passive circuit component of an electro-acoustic transducer device are depicted in accordance with an embodiment of the present disclosure. DETAILED DESCRIPTION

[0029] The present disclosure will now be described more fully with reference to the accompanying drawings, in which example arrangements of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as limited to the example arrangements set forth herein. Rather, these example arrangements are provided so that this disclosure will be thorough and complete, and fully convey the scope of the disclosure to those skilled in the art. Like reference numerals refer to like elements throughout.

[0030] The terminology used herein is for the purpose of describing particular example arrangements only and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," or "includes" and / or "including" when used herein, specify the presence of stated features, regions, integers, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0031] As used herein, the term "substrate" generally refers to a base material or construction upon which additional materials are formed. In some examples, at the micro-component level, a substrate can refer to a semiconductor substrate, a base semiconductor layer on a support structure, a metal electrode, or a semiconductor substrate having one or more layers, structures, or regions formed thereon. The substrate can be a conventional silicon substrate or other bulk substrate including a layer of semiconductor material. At the macro-encapsulation level, a substrate can refer to a component that provides structural support and signal connections for other functional device components, such as a printed circuit board (PCB).

[0032] As used herein, the term "configuring" refers to the size, shape, material composition, material distribution, orientation, and arrangement of one or more structures, and at least one device structure and device that facilitates operation of the one or more structures in a predetermined manner.

[0033] As used herein, the terms “longitudinal,” “vertical,” “lateral,” and “horizontal” are defined with reference to a major plane of a substrate (e.g., base material, base structure, base structure, etc.). In which or on which one or more structures and / or features are formed, and are not necessarily defined by the earth’s gravitational field. A “lateral” or “horizontal” direction is a direction substantially parallel to the major plane of the substrate, while a “longitudinal” or “vertical” direction is a direction substantially perpendicular to or transverse to the major plane of the substrate. The major plane of the substrate is defined by a surface of the substrate having a relatively large area compared to other surfaces of the substrate. In some examples, the major plane is shown as horizontal in the drawings of the present disclosure.

[0034] Spatially relative terms, such as “under,” “below,” “lower,” “bottom,” “over,” “upper,” “top,” “front,” “back,” “left,” “right,” and the like, can be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. Unless otherwise specified, the spatially relative terms are intended to encompass different orientations of the materials in addition to the orientation depicted in the figures. For example, if a component is described as “under” or “below” another component, then the component can be oriented above or below the other component, depending on the context. Thus, the term “under” can include above, below, and lateral orientations, depending on the context, which will be apparent to a person of ordinary skill in the art. The terms “first,” “second,” “third,” “fourth,” etc. are used herein to describe various elements, regions, layers, sections, and / or parts that can be used in one embodiment. Such terms are not necessarily intended to connote priority or order of creation, but to distinguish different components. The terms “first,” “second,” “third,” “fourth,” etc. are used herein to describe various elements, regions, layers, sections, and / or parts that can be used in one embodiment. Such terms are not necessarily intended to connote priority or order of creation, but to distinguish different components.

[0035] As used herein, the terms “connected” and “connected” refer to operational coupling or linking. Components that are connected can be directly coupled to one another or indirectly coupled, such as through another set of components.

[0036] As used herein, the terms “substantially” and “essentially” refer to a considerable degree or extent. When used in connection with an event or circumstance, these terms can refer to the event or circumstance occurring exactly as well as the event or circumstance occurring very close to, for example, considering typical tolerance levels of manufacture, the operation described herein. For example, “substantially all” generally refers to at least 90%, at least 95%, at least 99%, and at least 99.9%.

[0037] As used herein, the terms “electrically conductive” and “electrical conductivity” refer to the ability to transport electrical current. Electrically conductive materials generally correspond to those materials that exhibit little or no resistance to the flow of electrical current. One measure of electrical conductivity is Siemens per meter (“S m-1”). Generally, electrically conductive materials are materials that have an electrical conductivity greater than about 104S m-1, such as at least about 105S m-1or at least about 106S m-1. The electrical conductivity of a material can sometimes vary with temperature. Unless otherwise specified, the electrical conductivity of a material is defined at room temperature.

[0038] As used herein, "about" or "approximately" with respect to a numerical value of a particular parameter includes the numerical value and numerical values that are within an acceptable tolerance range of the particular parameter as understood by one of ordinary skill in the art. For example, "about" or "approximately" with respect to a numerical value can include additional numerical values that are within 90.0% to 110.0% of the numerical value, such as numerical values that are within 95.0% to 105.0% of the numerical value, within 97.5% to 102.5% of the numerical value, within 99.0% to 101.0% of the numerical value, within 99.5% to 100.5% of the numerical value, within 99.5% to 100.5% of the numerical value, or within 99.9% to 100.1% of the numerical value.

[0039] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure.

[0040] Figure 1 An exploded view depicting components of an exemplary electro-acoustic transducer device in accordance with some embodiments of the present disclosure is illustrated. For example, the illustrated transducer device 10 is in the form of an in-ear headphone. From left to right of the exemplary illustration, the transducer device 10 is provided with a first housing member (e.g., front housing member) 100-1 for connecting to an auricle of a user; a first transducer component (e.g., high frequency acoustic unit) 110; a second transducer component (e.g., low frequency acoustic unit) 120; and a second housing member (e.g., rear housing member) 100-2. The first housing member 100-1 can be provided with a protruding earbud member (e.g., shown in an inclined / angled arrangement in embodiments) that defines a front chamber for connecting to an ear canal of a user. The second housing member 100-2 can form a rear chamber for housing additional device components, such as a Bluetooth module for a wireless headphone arrangement or a signal cable component for a wired configuration.

[0041] In the exemplary arrangement, each of the first and second transducer components 110, 120 includes a substantially planar configuration. For example, the first transducer component 110 includes a generally disc-shaped body having a relatively thin profile (e.g., a high radius-to-thickness ratio) and a central region that is hollow. Further, a propagation axis (e.g., axis A) of acoustic output is defined as a planar body that is substantially perpendicular to the illustrated central aperture and passing through the central aperture. Further, the planar body of the exemplary first transducer component 110 is substantially geometrically symmetric with respect to the aforementioned propagation axis (e.g., axis A).

[0042] The exemplary second transducer component 120 includes a generally cylindrical disk body having a relatively thick profile. The propagation axis of the second transducer component is also defined as being substantially normal to its disk body through its central region. As shown in the illustrated arrangement, the propagation axes of the first and second transducer components 110, 120 are arranged in substantially coaxial alignment (e.g., collectively shown in the figure as "axis A"). In some arrangements, the disk-like plate bodies of the aforementioned transducer components have substantial geometric symmetry (e.g., the circular planar profile of the illustrated embodiment has a high degree of symmetry with respect to the propagation axis A). Thus, the aforementioned propagation axes substantially pass through the respective geometric centers of the transducer components 110, 120. However, perfect geometric symmetry is not mandatory. In some cases (e.g., the exemplary first transducer component 110), while the central acoustic resonant portion of the transducer component (e.g., the portion surrounding its central aperture; indicated in the figure below and corresponding description for purposes of clarity of the drawing) has a higher degree of geometric symmetry, the outer peripheral portion (e.g., the edge portion) need not do so (e.g., the edge portion can have a locally asymmetric notch structure as can be seen). Figure 1

[0043] The aforementioned first and second transducer components 110, 120 can include different types of sound emitting units having different operating principles and performance characteristics. For example, in some arrangements, the first transducer component 110 can include a piezoelectric acoustic unit specialized for higher range of output spectrum. Conversely, the second transducer component 120 can be a MEMS type acoustic unit configured for mid-frequency output, a coil type acoustic unit specialized for low frequency range output, or a balanced armature. In particular, small form factors of the transducer components can be achieved by modern semiconductor manufacturing techniques, e.g., using piezoelectric or MEMS type acoustic units. In the illustrated example, the higher frequency first transducer component 110 is arranged closer to the wearer's eardrum, while the lower frequency second transducer component 120 is arranged farther away from the wearer's eardrum.

[0044] It is noted that while the illustrated embodiments are exemplified as a micro-insert earphone device, the configurations of the present disclosure can be used in other applications, such as a headset, a mobile phone, a laptop speaker, or even a standalone sound emitting apparatus having various sizes suitable for the specifications of particular applications.

[0045] Figure 2 Exemplary isometric and partially cut-away magnified views of exemplary transducer components for an electro-acoustic transducer device are depicted in accordance with some embodiments of the present disclosure. For example, Figure 2 An isometric view of an electro-acoustic transducer device 20 and a partial cut-away view of exemplary transducer components thereof are illustrated.

[0046] ​The exemplary electro-acoustic transducer device 20 includes a hollow disc that substantially defines a propagation axis A. For example, while not having perfect geometric symmetry, the hollow disc of the exemplary transducer device 20 has a substantially circular planar shape with a hole formed in a central region thereof such that an imaginary line A (e.g., an acoustic output / propagation axis) passing through the central hole substantially coincides with a geometric symmetry axis of the hollow disc. In some embodiments, the transducer device 20 can correspond to the first transducer component 110 shown in FIG. 1. Figure 1

[0047] The hollow disc of the transducer device 20 is composed of a pair of plate-like members including a pair of resonant plates 212-1, 212-2 that extend substantially in a direction perpendicular to the propagation axis A.

[0048] In the illustrated example, the plate-like members have a circular planar profile in their entirety, the geometric center of which conveniently defines the propagation axis. However, other planar profiles can be employed for different application requirements. For example, in some applications, a convex polygonal shape can be used. It should be noted that perfect geometric symmetry is not mandatory.

[0049] In some implementations, each of the resonant plates 212-1, 212-2 has a central sound port O that is formed around the propagation axis A. The hollow disc of the transducer device 20 further includes a peripheral enclosure (e.g., an annular gasket 216) that engages the pair of resonant plates 212-1, 212-2 at their respective outer edge portions, thereby forming a resonant cavity between the pair of plate-like members. Thus, a ring-shaped opening R is formed between the central sound ports O of the plate-like members around the propagation axis to provide a path for access to the resonant cavity. From an external perspective through the aforementioned central sound ports O, the ring-shaped opening R resembles a slit having an annular profile that allows fluid communication into the resonant cavity defined between the pair of resonant plates 212-1, 212-2.

[0050] In some implementations, at least one of the pair of plate-like members described above is an active sound producing member. In some implementations, the active sound producing member can include a piezoelectric member attached to the resonant plate. For example, the exemplary transducer device 20 is shown as having a pair of active sound producing members. Figure 2

[0051] ​​In some embodiments, each active sound producing member has a plate-like structure (e.g., resonant plate 212-1, 212-2) as described above, and further includes a piezoelectric member 214-1 (or 214-2) also having a disc-like shape with a central hole formed therein corresponding to the central sound port O described above. The aforementioned resonant plates 212-1, 212-2 will act as an acoustic resonant membrane, which can be driven by the aforementioned piezoelectric members 214-1, 214-2 also in plate-like shape upon application of a voltage, thereby constituting a unimorph structure for generating sound output. In some embodiments, a pair of piezoelectric members can be provided on the resonant plate of each active sound producing member, one on each plane of the plate-like member, thereby constituting a bimorph structure to enhance sound driving performance.

[0052] The resonant plates 214-1, 214-2 can include a piezoelectric material that exhibits piezoelectric behavior, which can be driven to expand or contract (and thus vibrate) by the application of a voltage. Exemplary materials can include piezoelectric ceramics such as lead zirconate titanate (PZT), barium titanate, and lead titanate, gallium nitride, zinc oxide. Organic polymers such as PVDF, or ferroelectric materials with perovskite structure (e.g., BaTiO3[BT], (Bi1 / 2Na1 / 2)TiO3[BNT], (Bi1 / 2K1 / 2)TiO3[BKT], KNbO3[KN], (K,Na)NbO3[KNN]) can also be suitable. The resonant plates can include an elastic material that can be driven to vibrate. Suitable materials for the resonant plates can include metals / alloys that can withstand a stamping or impact forming process.

[0053] In the illustrated example, the exemplary transducer device 20 includes a hollow disc shape substantially defining a propagation axis A. The exemplary hollow disc shape includes a pair of resonant plates 212-1, 212-2, each extending substantially in a direction perpendicular to the propagation axis A. In addition, each of the resonant plates 212-1, 212-2 has a central sound port O disposed about the propagation axis A. The hollow disc shape of the transducer device 20 further includes a peripheral guard structure (e.g., annular gasket 216) that engages the outer edge portions of the pair of resonant plates 212-1, 212-2, thereby defining a resonant cavity between the pair of plate-like members. At the same time, an annular opening R about the propagation axis A is formed between the central sound ports O of the resonant plates 212-1, 212-2, providing a path into and out of the resonant cavity. The exemplary transducer device 20 further includes a pair of active sound producing members. Each of the active sound producing members includes a drive member (e.g., piezoelectric member 214-1, 214-2) attached to a plate-like member 212-1, 212-2.

[0054] Figure 3Various exemplary assembly configurations for exemplary transducer components of an electro-acoustic transducer device in accordance with some embodiments of the present disclosure are depicted. For example, Figure 3 Exemplary structural configurations suitable for electro-acoustic transducer devices 30 in a flat panel layout are shown.

[0055] In some embodiments, the hollow disc of the transducer device 30 is substantially comprised of a pair of substantially planar panel members. Of the pair of panel members of the exemplary transducer device 30, at least one is an active sound producing member 310, which is substantially comprised of a resonant panel 312-1 and a drive member 314. In some arrangements, both the drive member 314 and the resonant panel 312-1 have a substantially annular planar profile. In some arrangements, the resonant panel 312-1 has an outer diameter that is larger than the outer diameter of the drive member 314. In some arrangements, the drive member 314 and the resonant panel 312-1 are substantially concentrically coupled to each other.

[0056] In some arrangements, an annular gasket 316 can be disposed between the pair of resonant panels 312-1, 312-2 to collectively form a resonant cavity. The resonant cavity can be made to function for a desired operating frequency range by adjusting the thickness of the annular gasket 316. Accordingly, the outer surface of the annular gasket 316 at least partially forms the perimeter enclosure of the aforementioned hollow disc. For example, the outer circumferential surface of the exemplary annular gasket 316 can (at least partially) constitute the side / lateral surface of the substantially planar hollow disc of the transducer device 30. The perimeter of the aforementioned components can be structurally coupled by means of gluing (e.g., epoxy) or welding (e.g., laser welding). It is noted that while the illustrated examples exhibit a high degree of geometric symmetry (e.g., concentric circles), this can not be a strict requirement in some practical applications.

[0057] The number and location of drive members (e.g., piezoelectric members 314) can take on various different arrangements depending on performance or other application requirements. For example, for higher performance requirements, a dual drive member configuration (as shown by the pair of drive members 314a / 314b / 314c) can be used. In this case, the drive members (e.g., members 314a / 314b / 314c) can reside within or outside of the resonant cavity. Further, the thickness of the aforementioned annular gaskets (e.g., gaskets 316a / 316b / 316c) can be correspondingly adjusted to accommodate the placement of the pair of drive members. On the other hand, for budget or size conscious embodiments, a single drive member arrangement (as shown by the single drive member arrangements 314d / 314e) can be used.

[0058] Figure 4 Various exemplary assembly configurations for exemplary transducer components of an electro-acoustic transducer device in accordance with some embodiments of the present disclosure are depicted. For example, Figure 4Various exemplary structural configurations of the hollow disk of the electroacoustic transducer device 40 when employing a bowl-shaped architecture are shown.

[0059] In some arrangements, the resonant plate 412 of the plate-like member has a raised edge portion, which can be used to replace the need for structurally separate gasket members (e.g., replacing the use of the annular gasket 316 as described above).

[0060] Similar to the preceding description, both the exemplary resonant plate 412 and the driving member (e.g., a piezoelectric member) 414 comprise substantially annular planar profiles. In some embodiments, the outer diameter of the resonant plate 412 is larger than the outer diameter of the driving member 414. In some embodiments, the driving member 414 and the resonant plate 412 are coupled to each other substantially concentrically. In some embodiments, the ratio between the inner diameter Din of the resonant plate and its outer diameter Dout is in the range of 1:10 to 1:3.

[0061] The aforementioned inner opening diameter Din can be configured to accommodate additional sound-generating components arranged axially (e.g., Figure 1 The second transducer component 120 shown is an example. For instance, a smaller aperture (e.g., a 1:10 ratio) may support better sound output performance in higher frequency ranges, but may limit the output characteristics of complementary additional transducers (e.g., low-frequency devices). Conversely, a wider aperture may improve lower frequency output at the expense of high-frequency range performance. In some embodiments, the ratio between the inner diameter Din of the resonant plate and its outer diameter Dout is approximately 1:5. In some applications (e.g., wearable devices such as headphones), the outer diameter Dout of the resonant plate may be approximately 10 mm.

[0062] In this figure, the resonant plate 412 includes a generally flat central well portion 412W and a base portion 412B arranged opposite to the central well portion 412W; an annular lip portion 412L rises from the central well portion 412W along the propagation axis A, and an edge portion 412R surrounds the periphery of the annular lip portion 412L. In some embodiments, a drive member 414 is coupled to the base portion 412B of the resonant plate 412, so that after assembly, the drive member 414 will be located outside the resonant cavity. In some embodiments, the edge portion 412R of the resonant plate 412 will at least partially form the peripheral enclosure structure of the hollow disk after assembly. The individual peripheries (e.g., at the edge portion 412R) of a pair of resonant plates (e.g., the aforementioned resonant plate 412) can be structurally bonded by gluing (e.g., epoxy resin) or welding (e.g., laser welding).

[0063] Figure 4The bottom row shows various exemplary implementations of bowl-shaped plate members. The left-most example employs a mirror-symmetric arrangement. Two bowl-shaped active sound radiating members are coupled to each other at their respective edge portions. In this case, the individual drive members (e.g., piezoelectric layers) of the active sound radiating members are disposed outside the resonant cavity defined between the pair of bowl-shaped resonant plates. The middle example utilizes a combination of bowl-shaped resonant plates and flat plate members. For example, the illustrated bowl-shaped active plate members (active sound radiating members) are coupled to plate members at their respective edge portions, and the drive components are disposed outside the resonant cavity. The right-most example demonstrates an asymmetric arrangement in which only one bowl-shaped active sound radiating member is used in combination with a passive bowl-shaped plate member, thereby providing a budget-oriented transducer option.

[0064] Figure 5 Various exemplary assembly configurations of exemplary transducer components for an electroacoustic transducer device in accordance with some embodiments of the present disclosure are depicted. For example, Figure 5 Exemplary coupling schemes between the hollow disc members of the electroacoustic transducer device 50 are shown.

[0065] The hollow disc of the electroacoustic transducer device 50 employs a combination of bowl-shaped plate members (e.g., component 512-1) and flat plate members (e.g., component 512-2).

[0066] In the present example, the component 512-2 constitutes an active sound radiating member. The structural coupling between the components 512-1, 512-2 can be achieved using various suitable joining methods. For example, Figure 5 The first illustration in the bottom row on the far left shows a structural configuration suitable for welding (e.g., laser welding). In this arrangement, the edge portion of the component 512-1 can remain flat and have the same overall diameter as the component 512-2. Thus, the above-described arrangement can facilitate the implementation of a laser welding process at the edge around the joint interface R of the components 512-1, 512-2.

[0067] In the second illustration, the edge portion of the component 512-1 is provided with a raised extension E that extends perpendicularly from the flat edge portion (in the direction of axis A). In this case, the component 512-1 will have a slightly larger outer diameter than the component 512-2. The aforementioned raised extension E can facilitate alignment and positioning with the component 512-2. An adhesive (e.g., epoxy glue) can be applied around the edge of the aforementioned raised extension E, thereby establishing the structural coupling between the components 512-1, 512-2.

[0068] In the third illustration from the left, component 512-1 has a larger outer diameter than component 512-2. Furthermore, component 512-1 has a higher, protruding extension E', long enough to be stamped against component 512-2 on its edge, thereby establishing a structural coupling between components 512-1 and 512-2. In this arrangement, the physical connection between components 512-1 and 512-2 can be achieved without the application of additional bonding agents such as adhesives.

[0069] The rightmost illustration shows that component 512-2 has an outer diameter larger than that of component 512-1. In this example, component 512-2 has an edge extension E” that is wide enough to abut against the edge of component 512-1 after being post-stamped, thereby achieving structural coupling between the components.

[0070] Figure 6 Various complex transducer integration configurations of some electroacoustic transducer devices according to this disclosure are described.

[0071] In some implementations, only one active sound-generating component (e.g.) may be used. Figure 6 The single active sound-emitting member 610 used in the configurations (a), (b), (c), and (d) shown on the left. Furthermore, in some embodiments, one of a pair of plate-like members that jointly define the resonant cavity can be integrally formed as part of the transducer housing (e.g., housing member 600). For example, as shown in configurations (a)-(d), the housing member 600 is provided with an inner partition wall on which cavities are arranged to define the aforementioned resonant cavity. Furthermore, the reduced thickness of the inner partition wall toward the central axis of the housing member (e.g., axis A) (e.g., a stepped structure, for example) can be integrally formed as a transducer plate-like member (e.g., the first plate-like member previously described). Therefore, the active sound-emitting member 610 shown in this example can be positioned on the opposite side of the aforementioned inner partition wall (i.e., opposite to the thinner wall region and extending into the resonant cavity), thereby structurally and functionally forming the first transducer component in a multi-transducer device (e.g., as shown in the example). Figure 1 The first transducer component 110 shown.

[0072] In some implementations, a pair of active acoustic components (e.g., components 610a, 610b) may be used to enhance acoustic output performance (e.g., Figure 6 (As shown in (e), (f), (g), and (h) on the right). In this case, a pair of active sound-generating members 610a and 610b can be disposed on each side of the aforementioned inner partition wall, wherein a gap is maintained between them to form a spatial volume for defining the aforementioned resonant cavity. Thus, the first transducer device in the plurality of transducer devices (e.g., such as...) Figure 1The first transducer component 110) is shown to be formed.

[0073] In the illustrated embodiment, the transducer housing (e.g., the housing member 600) is further configured to accommodate additional transducer devices. For example, additional transducer devices comprising different types of acoustic transducers can also be integrated therein. For example, the additional transducer devices can be coil-type sound generators that perform well in the lower frequency spectrum of sound output. In some embodiments, the additional transducer devices can be MEMS-type acoustic units (e.g., member 1620) that are integrated on the active sound generating member (e.g., member 1610) in the manner shown. This will be further described below in relation to Figure 16 Figure 16

[0074] The propagation axis A of the additional transducer device (e.g., member 620) is coaxially arranged along the propagation axis of the first transducer device (e.g., member 610). The central sound port (not specifically shown) of the first transducer member (the active sound generating member 610, which is disposed towards the output opening end of the housing member 600, not specifically shown) in the present example of a plurality of integrated transducer devices is configured to output a mixed sound signal from the two integrated transducer components 610, 620.

[0075] Figure 7 Plan and cross-sectional views of exemplary transducer components for electro-acoustic transducer devices in accordance with some embodiments of the present disclosure are depicted. For example, Figure 7 Exemplary transducer components 70, 70' are shown with additional sound channel designs for enhanced acoustic coupling performance (e.g., when combined with a second transducer component 620 as shown). Figure 6

[0076] In both of the illustrated examples, both have peripheral acoustic ports Op that are circumferentially arranged around the periphery (e.g., edge portion) of the exemplary transducer components 70 / 70'.

[0077] Taking the transducer component 70 as an example, it employs a ring-shaped gasket configuration. In addition to the aforementioned central sound port Oc, it also has a plurality of peripheral acoustic ports Op that are formed along the circular peripheral region of the ring-shaped gasket 716. A pair of plate members 712a, 712b are respectively disposed on the front and back sides thereof, sandwiching the aforementioned ring-shaped gasket 716 (similar to the sandwiching manner depicted in Figure 3

[0078] ​​​​In the illustrated example, the peripheral acoustic ports Op are arranged in a substantially equidistant, substantially symmetrical manner around the propagation axis A. It is noted that other placement patterns can be used in actual applications, depending on the specific application requirements. In some arrangements, the peripheral acoustic ports Op have a circular profile and are dimensioned smaller than the central acoustic port Oc.

[0079] By way of example, the transducer component 70' employs a bowl-shaped configuration. A plate-like member 712a' having a larger radius is coupled to a bowl-shaped plate-like member 712b' to form a resonant cavity (similar to the form described in Figure 5

[0080] In the illustrated example, the acoustic ports Op' are arranged in a substantially equidistant, substantially symmetrical manner around the propagation axis A. It is noted that other placement patterns can be used in actual applications, depending on the specific application requirements. In some arrangements, the peripheral acoustic ports Op' have a circular profile and are dimensioned smaller than the central acoustic port Oc'.

[0081] When coupled with a second transducer component (e.g., in a coaxial arrangement as shown in Figure 6 the low-frequency acoustic unit 620), the low-range output signal from the aforementioned second transducer component can be transmitted through the peripheral acoustic ports Op / Op' around the high-frequency transducer component (e.g., transducer 70 / 70') to surround the high-frequency signal emanating from the center, thereby enabling the production of different auditory perceptions with acoustic depth and smooth transition from bass to treble.

[0082] Figure 8 Plan and cross-sectional views of a transducer coupling arrangement for an electroacoustic transducer device are depicted in accordance with some embodiments of the present disclosure. For example, Figure 8 Exemplary arrangements are shown in which the peripheral acoustic ports Op are formed using external mounting mechanisms (e.g., retaining rings 800 / 800' / 800") outside of a piezoelectric transducer component (e.g., component 810 / 810' / 810").

[0083] For applications with more stringent spatial requirements (e.g., earbuds / insert earphones), smaller mounting brackets (e.g., retaining rings 800 / 800' / 800") sized to fit into a user's ear canal can be used. For example, a circular ring-type mounting bracket with a suitably small diameter can be provided to accommodate a miniaturized piezoelectric transducer (e.g., component 810) in accordance with the present disclosure. The piezoelectric transducer component 810 can be structurally similar to the previous examples (e.g., component 810' in FIG. 8B). Figures 2-5 ​The holding ring 800 can be a separate component, or can be integrated with the housing member (e.g., as shown in FIG. 6B). In some embodiments, the holding ring 800 can be a separate component that is attached to the housing member (e.g., as shown in FIG. 6C). In some embodiments, the holding ring 800 can be integrated with the housing member (e.g., as shown in FIG. 6D). Figure 6 The holding ring 800 can be a separate component, or can be integrated with the housing member (e.g., as shown in FIG. 6B). In some embodiments, the holding ring 800 can be a separate component that is attached to the housing member (e.g., as shown in FIG. 6C). In some embodiments, the holding ring 800 can be integrated with the housing member (e.g., as shown in FIG. 6D).

[0084] The central hollow region of the holding ring 800 can be slightly smaller in size than the diameter of the piezoelectric transducer component 810, so as to establish a mechanical interface for holding. In some arrangements, the piezoelectric transducer component 810 can take on a bowl-type configuration (e.g., as shown in FIG. 8A), with a stepped profile at the bottom configured to fit into the central hollow region of the holding ring 800, so as to establish a larger coupling interface. Figure 4 The central hollow region of the holding ring 800 can be slightly smaller in size than the diameter of the piezoelectric transducer component 810, so as to establish a mechanical interface for holding. In some arrangements, the piezoelectric transducer component 810 can take on a bowl-type configuration (e.g., as shown in FIG. 8A), with a stepped profile at the bottom configured to fit into the central hollow region of the holding ring 800, so as to establish a larger coupling interface.

[0085] In addition to the central hollow region, additional peripheral acoustic ports (e.g., ports Op) can be integrally provided on the holding ring. For example, a plurality of peripheral acoustic ports Op can be provided in the thicker edge portion of the holding ring 800'. In this example, the placement of the peripheral acoustic ports Op is projected to be outside the circumference of the piezoelectric transducer 810', so as to prevent interference with the low frequency signal output (e.g., from the second transducer unit, such as the low frequency output of the component 620 shown in FIG. 6B). Figure 6

[0086] Similarly, a plurality of peripheral acoustic ports Op are circumferentially arranged along the peripheral region of the exemplary holding ring 800", and are further provided outward and partially through the thicker edge portion thereof. It should be noted that the specific number, shape, location of the peripheral acoustic ports Op depend on the actual application requirements, and should not be limited to the exemplary configuration shown in the present figure.

[0087] Figure 9 Plan and cross-sectional views of a transducer coupling arrangement for an electro-acoustic transducer device, in accordance with some embodiments of the present disclosure, are depicted. For example, Figure 9 Exemplary mounting mechanisms (e.g., holding members 900 / 900') for simultaneously accommodating one or more piezoelectric transducer components (e.g., components 910 / 910-1 / 910-2 / 910-3), in accordance with the present disclosure, are shown.

[0088] For applications with larger size and / or higher output requirements (e.g., wearable devices such as ear muff headphones, or even stationary devices such as speaker units), larger mounting brackets (holding members 900 / 900') with multiple mounting slots can be used. For example, a disc-type holding member 900 with multiple holding slots S can be employed to simultaneously accommodate one or more miniaturized piezoelectric transducers (e.g., components 910, 910-1, 910-2, 910-3). The piezoelectric transducers 910 can be comparable in structural design to those described in the previous examples (e.g., Figures 2-5 ​). On the other hand, the holding member 900 can be a separate component or an integrated structure integrated on the housing member (e.g., as shown in the inner partition wall of the housing member 600). Figure 6

[0089] Due to the small form factor nature of the piezoelectric transducers 910, 910-1, 910-2, 910-3, the simultaneous integration of multiple holding slots S in the holding member 900 / 900' can flexibly enable the selection of transducer units in terms of quantity and / or placement to meet a wide range of application requirements. For example, a single centrally placed transducer 910 on the holding member 900 provides a more cost-effective setup for larger size applications. Conversely, for larger applications that require higher output capability, multiple transducer configurations (e.g., transducers 910-1, 910-2, and 910-3) can be simultaneously employed on the support member 900' to meet higher performance requirements with minimal hardware changes.

[0090] Figure 10 An output versus frequency plot reflecting the performance enhancement of an example transducer component according to the present application is shown. In particular, the resonant cavity formed in the hollow body of the acoustic transducer component (e.g., as shown in the device 20 of Figure 2 the present disclosure enables the acoustic transducer component to produce a double peak (i.e., in addition to the wave peak produced by structural resonance, another wave peak produced by air resonance) in the output sound pressure level (SPL) along the output frequency band.

[0091] The additional area obtained between the double peaks presents an extended output frequency range at higher pressure levels, which can significantly improve the transducer performance with minimal increase in the size of the component, as compared to the conventional single-layer piezoelectric sheet design (whose output plot is shown by the solid line).

[0092] Again taking the electroacoustic transducer 20 of Figure 2 the piezoelectric unit of which is driven by an electrical signal input due to the inverse piezoelectric effect to produce sound. The resonant cavity formed by the separate arrangement of the pair of plate-like members 212-1, 212-2 (e.g., by an annular gasket such as the gasket 216, or by an annular slot in a bowl-type configuration as shown in Figure 4 , or by a housing compartment structure as shown in Figure 6 ), in which additional resonance is facilitated by squeezing the air in the cavity, so that an SPL boost can be obtained in its extended frequency band. Thus, the output sound pressure level can obtain an increase in continuous bandwidth range throughout the frequency response. In some embodiments, the optimized frequency bandwidth is approximately in the range of 1 kHz to 40 kHz.

[0093] Figure 11 ​Output vs. frequency plots are shown corresponding to various configurations of a pair of plate members defining a resonant cavity of different heights (ha).

[0094] In some embodiments, the separation distance ha between the pair of plate members (e.g., members 212-1, 212-2) substantially corresponds to the thickness of the annular spacer (e.g., spacer 216). As shown, Figure 11 As shown, the frequencies at the first peak region fs correspond to the resonant frequency of the hardware structure of the transducer device. On the other hand, the frequencies at the second peak region fc correspond to the resonant frequency of the resonant cavity between the resonant plates (plate members). The separation distance ha between the resonant plates can be adjusted to tune the frequency of the second peak. For example, an increase in the separation distance ha between the plate structures can correspond to a lower frequency of the second peak. In some embodiments, the outer diameter of the plate structures is on the order of 1 centimeter. Through extensive exploration by the inventor, the ratio of the cavity height ha to the outer diameter Dout of the resonant plates can be in the range of 1% to 5%.

[0095] Figure 12 Output vs. frequency plots are shown corresponding to various plate thickness t configurations of a pair of plate members defining a resonant cavity. For example, Figure 9 Output vs. frequency plots are shown corresponding to various plate thickness configurations of a pair of plate members (e.g., members 212-1, 212-2) defining a resonant cavity of different heights.

[0096] As shown, Figure 12 As shown in the upper right corner, each resonant plate has a thickness t. Similar to Figure 11 As shown, the frequencies at the first peak region (higher frequency peak) correspond to the resonant frequency of the hardware structure of the transducer device fs. On the other hand, the frequencies at the second peak region (lower frequency peak) correspond to the resonant frequency of the resonant cavity formed between the resonant plates (plate members) fc. Adjustments in the thickness of the resonant plates (plate members) will affect the frequencies of both the first peak (i.e., the structural resonance peak) and the second peak (i.e., the cavity resonance peak). For example, a decrease in the plate thickness will simultaneously shift both the first and second peaks to a lower frequency range.

[0097] Optimization of the thickness of the resonant plates needs to take into account several important factors, including those related to the feasibility of mass production. Through extensive exploration by the inventor, the ratio of the thickness t of the resonant plates to the outer diameter Dout can be in the range of 0.5% to 5%. In some embodiments, the thickness of the hollow body of the electro-acoustic transducer component according to the various aspects of the disclosure is only about 2 to 3 times the thickness of a conventional single-layer piezoelectric plate design.

[0098] Figure 13 Exemplary structural arrangements for a transducer component of an electro-acoustic transducer device according to embodiments of the disclosure are depicted. For example, Figure 13A plan view and a corresponding cross-sectional view of an example transducer device 130 are shown.

[0099] An example electro-acoustic transducer device 130 includes a circular hollow disc body with a hole formed in a central region thereof. The hollow disc body of the illustrated transducer device 130 includes a pair of plate-like members 1312-1, 1312-2 arranged in parallel and kept separated from each other (e.g., by an annular spacer, not specifically marked in the figure) so as to define a resonance cavity therebetween. Each of the plate-like members 1312-1, 1312-2 is provided with a central sound port O. Accordingly, an annular opening enabling access to the above-mentioned resonance cavity is formed between the central sound ports O of the pair of plate-like members 1312-1, 1312-2, respectively.

[0100] In the illustrated implementation, both plate-like members 1312-1, 1312-2 have an active sound producing member. For example, each of the plate-like members 1312-1, 1312-2 has a driving member 1314-1 / 1314-2 (e.g., a piezoelectric layer, arranged outside the resonance cavity) attached thereto. One (or more) electrically conductive traces 1322, passing through both the aforementioned driving member 1314 and plate member 1312, are provided to transmit electrical signals. The electrically conductive traces 1322 can include planar signal conducting structures that are advantageous for reducing form factor and device reliability. For example, the electrically conductive traces 1322 can be a pattern of electrically conductive traces provided on a flexible printed circuit (FPC) member, or by a suitable method such as electroplating or physical vapor deposition (PVD) techniques.

[0101] In the current illustration, electrical contacts 1318 are arranged between the electrically conductive traces 1322 and the transducer components 1312, 1314 to enable signal connection. An electrically conductive layer (e.g., layer 1324) is provided on a flat surface of the driving member 1314-1 / 1314-2. A protective layer (e.g., passivation layer 1326) can be further formed on the aforementioned electrically conductive layer 1324.

[0102] Figure 14 Example structural arrangements for transducer components of an electro-acoustic transducer device, in accordance with embodiments of the present disclosure, are depicted. For example, Figure 14 Signal path arrangements for different transducer configurations (a) and (b), in accordance with the present disclosure, are schematically shown.

[0103] Configuration (a) shows a single-layer piezoelectric sheet arrangement that uses a flat-panel single-layer piezoelectric sheet 1410a with a single driving layer (e.g., piezoelectric layer 1414). A signal routing structure 1422 is disposed on the top surface (exposed) of the aforementioned single-layer piezoelectric sheet 1410a to enable signal transmission to the piezoelectric layer 1414. The signal routing structure 1422 can include a thin and flexible flexible printed circuit unit. In some embodiments, one or more discrete circuit elements, such as capacitors and / or resistors, can be disposed on the signal routing structure 1422. For example, in the illustrated configuration (a), a resistor 1430 in the piezoelectric audio preamplifier circuit can be integrated on the aforementioned signal routing structure 1422. Integrating passive / parasitic components (e.g., resistor 1430) on the signal routing structure 1422 can help improve the stability of the preamplifier power supply and reduce the heat generation of the preamplifier IC.

[0104] After the single-layer piezoelectric sheet 1410a is coupled with the annular gasket 1416 and the second plate-like member (not specifically labeled), the transducer component with the embedded resonance chamber C is formed. In the illustrated example, a passive circuit element (e.g., resistor 1430) is arranged on the anchored end of the signal routing structure 1422 that is disposed above the aforementioned annular gasket 1416. The signal routing structure 1422 can further extend away from the single-layer piezoelectric sheet 1410a to connect other circuit elements (not specifically shown in the figure) of the transducer device.

[0105] Configuration (b) shows a double-layer piezoelectric sheet arrangement that uses a flat-panel double-layer piezoelectric sheet 1410b with a pair of oppositely disposed driving layers (e.g., piezoelectric layers 1414-1, 1414-2). A pair of oppositely disposed signal routing structures 1422-1, 1422-2 are arranged on the (exposed) top side and (enclosed) bottom side of the aforementioned double-layer piezoelectric sheet 1410b to enable signal transmission to the piezoelectric layers 1414-1, 1414-2. The signal routing structures 1422-1 / 1422-2 can be similar to those described in the previous example. In some embodiments, side openings Os can be provided at selected locations of the annular gasket 1416' to enable the signal routing structure 1422-2 to pass from the side of the resonance chamber C'.

[0106] Figure 15 Exemplary structural arrangements for a transducer component of an electroacoustic transducer device are depicted in accordance with embodiments of the present disclosure. For example, Figure 15 An exemplary multi-chamber architecture suitable for use in a transducer component 150 is schematically illustrated in accordance with some embodiments of the present disclosure.

[0107] Figure 15An exemplary transducer assembly 1510-1 is shown schematically, which incorporates a dual-layer, dual-chamber arrangement that can enable further tuning to extend the output bandwidth of the transducer device. By way of example, a pair of active sound radiating members 1510-1, 1510-2 are coupled together by a pair of annular spacers 1516-1, 1516-2 and an intermediate plate member (not specifically labeled) to form a transducer assembly having a pair of stacked, coaxially arranged multi-resonance cavities Cl, C2 about a propagation axis A.

[0108] The resonant cavities Cl, C2 coupled in series along the propagation axis A can enable a level of tuning. For example, by adjusting the thickness of the annular spacers 1516-1 / 1516-2 and / or the thickness of the active sound radiating members 1510-1 / 1510-2, the output bandwidth and characteristics of the transducer assembly can be further optimized. In some embodiments, active sound radiating members having resonant plates of different materials can be used to further extend the tunability of the transducer device.

[0109] Figure 16 A cross-sectional view of a composite acoustic transducer assembly for an electroacoustic transducer device is shown in accordance with an embodiment of the present disclosure. For example, Figure 16 A composite acoustic transducer assembly 160 is shown that uses a vertical integration architecture of coaxially configured active / driven transducer (piezoelectric) unit 1610 and a passive (MEMS) amplification unit 1620.

[0110] The active transducer unit 1610 (e.g., first transducer assembly) can include a hollow disc transducer member as previously described. For example, the active transducer unit 1610 can include a circular hollow disc body having a central region formed with a hole. The hollow disc body of the transducer unit 1610 includes a pair of plate members (not specifically labeled) arranged in parallel and held apart from each other by an annular spacer (not specifically labeled) to define a resonant cavity Cl. Each plate member is provided with a central sound port. Thus, a ring-shaped opening is formed between the central sound ports of the plate members that can allow access to the resonant cavity Cl. In addition, the central region of the active transducer unit 1610 is free and not subject to physical obstruction (e.g., materially structured connection / attachment with other device components).

[0111] In addition, both plate members of the active transducer unit 1610 include active sound radiating members having respective drive members (disposed outside the resonant cavity, not specifically labeled in the figure) attached thereto. A pair of conductive wires are provided to transmit electrical signals to the transducer assembly. In addition, electrical contacts are disposed between the conductive wires and the transducer assembly to enable signal connection.

[0112] The passive amplification unit 1620 (e.g., a second transducer component) can include a MEMS structure compatible with micro-fabrication techniques of semiconductor manufacturing processes. The passive amplification unit 1620 can have a second propagation axis arranged substantially aligned with the propagation axis of the active transducer unit 1610. In the illustrated example, the passive amplification unit 1620 is arranged on one of the resonant plates of the active transducer unit 1610 to facilitate further acoustic excitation and thus improve the output performance of the device. The passive amplification unit 1620 includes a base portion 1621 interfacing with the active transducer unit 1610. In some embodiments, the base portion 1621 can include a circuit board layer.

[0113] A semiconductor material layer (e.g., layer 1622) is further disposed on the base portion 1621 and projects over the central sound port of the active transducer unit 1610. The semiconductor material layer can include a drive portion 1622a secured to the base portion 1621, a spring portion 1622s extending from the drive portion 1622a, and a resonant membrane portion 1622m suspended by the spring portion 1622s and aligned over the central sound port. In some embodiments, the semiconductor layer can be made of a silicon substrate. The cantilever structure formed by the semiconductor layer 1622 projecting over the central sound port can define an additional resonant cavity C2 between the passive amplification unit 1620 and the active transducer unit 1610.

[0114] A drive component 1623 is arranged on the drive portion 1622a of the semiconductor layer and configured to apply a driving force to cause vibration of the resonant membrane portion 1622m through the spring portion 1622s upon receiving an electrical signal (e.g., a voltage). In some embodiments, the drive component 1623 includes a MEMS actuator comparable to the piezoelectric layer previously described. A conductive layer (e.g., an electrode layer) 1624 can be further disposed on the drive component 1623.

[0115] In the illustrated arrangement, the drive component 1623 (and the conductive layer 1624) extends laterally just proximate to the spring portion 1622s of the semiconductor layer. That is, the spring portion 1622s and the resonant membrane portion 1622m are substantially free from additional material covering. As a result, the resonant membrane portion 1622m and the spring portion 1622s can have a thinner thickness than the cantilevered drive portion 1622a of the semiconductor layer. Such an arrangement can ensure better freedom of vibration for the resonant membrane portion 1622m and further enhance the acoustic performance of the device.

[0116] A packaging cover 1625 can be further disposed on the base portion 1621 to provide shielding for the underlying delicate transducer components. The packaging cover 1625 is further configured with a central opening aligned with the resonant membrane portion 1622m / central sound port of the composite acoustic transducer components.

[0117] Figure 17 A schematic output vs. frequency plot is shown, which illustrates the enhanced output performance of a composite acoustic transducer component for an electro-acoustic transducer device according to embodiments of the present disclosure.

[0118] For example, Figure 17 A schematic output vs. frequency plot is shown for a composite acoustic transducer component 170. The composite acoustic transducer component 170 includes a vertically integrated active transducer unit (e.g., sound emitting plate member / active transducer unit 1710) configured to provide a base excitation and a passive amplification unit (MEMS amplifier 1720) configured to generate an enhanced acoustic pressure. In some embodiments, the active transducer unit can utilize a hollow disc transducer member (e.g., ceramic / piezoelectric transducer) as previously described. In some embodiments, the passive component can be a MEMS structure compatible with micro-processing techniques of semiconductor manufacturing processes.

[0119] Similar to the previous example, the active transducer unit 1710 and the passive amplification unit 1720 are in a coaxial configuration. In addition, an additional resonance cavity C2 is formed between the active transducer unit 1710 and the passive amplification unit 1720. The vertical integration of the active and passive units further ensures the formation of the resonance cavity C2, which is configured to induce an enhanced resonance effect (similar to the double-plate transducer structure previously described in embodiments of the present disclosure). At the same time, the lower resonant frequency of the MEMS transducer and the higher resonant frequency of the active transducer unit 1710 are expected to produce a superimposed acoustic pressure effect, thereby satisfying the working requirements of a large frequency bandwidth. For example, the passive amplification unit 1720 can generate a base acoustic pressure when energized; due to the active transducer unit 1710 being further excited by the passive amplification unit 1720, the acoustic pressure of additional frequencies (e.g., the total output Of integrated from the output O1710 and the output O1720) can be increased, thereby increasing the continuous bandwidth of high acoustic pressure in the overall frequency response. Figure 15

[0120] In addition, different speaker geometries can be manufactured through micro-fabrication techniques of semiconductor processes. When coupled with the application of piezoelectric materials, the integration of active elements (e.g., actuators) and passive elements (e.g., diaphragms and springs) can be achieved on a single wafer. In addition, the design flexibility, spring stiffness (e.g., spring constant), and diaphragm mass (e.g., mass) provided by micro-fabrication techniques can be adjusted according to the needs of the frequency band of the speaker application.

[0121] Figure 18 Various views of a MEMS transducer component for an electro-acoustic transducer device according to embodiments of the present disclosure are shown. For example, Figure 18 ​Plan and cross-sectional views showing a schematic layout arrangement of an exemplary MEMS transducer component 180, as well as a schematic view thereof in operation, are provided.

[0122] From the center to the peripheral region, the exemplary MEMS transducer component 180 includes a resonant membrane portion 1822m (having a mass m), a spring portion 1822s, which can be formed by a semiconductor material (e.g., silicon) patterned made (e.g., by photolithography techniques), and a drive portion 1822a in a cantilever configuration, which surrounds and supports the aforementioned spring portion 1822s and resonant membrane portion (resonant membrane portion) 1822m.

[0123] A drive component (e.g., a piezoelectric actuation layer) is arranged above the drive portion 1822a and is configured to apply a drive force to induce vibration of the resonant membrane portion 1822m through the spring portion 1822s upon receiving an electrical signal. The drive member extends laterally just proximate to the spring portion 1822s, such that the spring portion 1822s and resonant membrane portion 1822m are substantially free from additional material coverage.

[0124] Through microfabrication techniques of semiconductor processes, MEMS structures of different geometries can be fabricated. For example, through the design flexibility offered by microfabrication techniques, the spring stiffness (k) and membrane mass (m) can be fine-tuned to meet the frequency band requirements of a particular application.

[0125] Figure 19 Multiple views of a MEMS transducer unit for an integrated passive circuit component of an electro-acoustic transducer device, in accordance with embodiments of the present disclosure, are shown. For example, Figure 19 Schematic plan and cross-sectional layout views of an exemplary MEMS transducer device 190 are shown. Due to the high level of integration between the MEMS device and the integrated circuit components, peripheral circuit components (e.g., integrated resistor 1911, integrated capacitor 1912, and integrated inductor 1913) can be disposed at a peripheral location of the MEMS device (e.g., transducer unit 1920) located on the same chip surface, thereby improving the utilization of valuable space on the chip. Thus, the MEMS device 1920 and the associated circuit components 1911, 1912, and 1913 can be integrated on the same chip. The MEMS device 1920 can include a cantilever structure as depicted in the previous examples, which can be fabricated through semiconductor processes (photolithography, dry / wet etching, deposition, etc.). On the other hand, support circuit elements (e.g., filters) that can be constructed to function as functional circuit elements can be arranged on the surface of the MEMS device (or, at least a portion of the filter structure can be embedded in the MEMS structure).

[0126] The support circuit elements can include primarily passive elements, such as resistors, capacitors, and inductors. They can also be fabricated through semiconductor processes (photolithography, dry / wet etching, deposition). For example, resistors can be implemented by using an upper electrode deposition, lift-off, or etching process to create a wound resistor. Likewise, capacitors can be fabricated by using an upper electrode deposition, lift-off, or etching process to make a interdigital capacitor, or form a parallel plate capacitor with a lower electrode. Similarly, inductors can be created by using a top electrode deposition and etching process to form a toroidal coil inductor.

[0127] Accordingly, one aspect of the present disclosure provides an electro-acoustic transducer apparatus comprising: a hollow disc defining a propagation axis, the hollow disc comprising: a pair of plate members extending substantially perpendicular to the propagation axis, each of the plate members being provided with a central sound port arranged about the propagation axis, and a peripheral surround joining the pair of plate members at their respective outer edge portions thereby defining a resonant cavity between the pair of plate members; wherein an annular opening about the propagation axis is formed between the central sound ports of the plate members to enable access to the resonant cavity.

[0128] In some embodiments, at least one of the plate members comprises an active sound generating member.

[0129] In some embodiments, the active sound generating member comprises a piezoelectric member attached to a resonant plate.

[0130] In some embodiments, the piezoelectric member is located within the resonant cavity when assembled.

[0131] In some embodiments, the active sound generating member comprises a single layer piezoelectric sheet.

[0132] In some embodiments, the piezoelectric member and the resonant plate each have a substantially annular planform.

[0133] In some embodiments, the resonant plate has an outer diameter that is greater than an outer diameter of the piezoelectric member.

[0134] In some embodiments, the piezoelectric member and the resonant plate are substantially concentrically coupled to each other.

[0135] In some embodiments, the resonant plate has a ratio between its inner diameter and its outer diameter in the range of 1 : 10 to 1 : 3.

[0136] In some embodiments, the resonant plate comprises a substantially flat central well portion, a base portion disposed opposite the central well portion, an annular lip portion raised from the central well portion in the direction of the propagation axis, and a rim portion surrounding a periphery of the annular lip portion.

[0137] In some embodiments, the piezoelectric member is coupled to the base portion of the resonant plate, wherein, when assembled, the piezoelectric member is located outside the resonant cavity.

[0138] In some embodiments, when assembled, the edge portion of the resonant plate at least partially forms the perimeter enclosure of the hollow disc.

[0139] In some embodiments, further comprising an annular gasket disposed between the pair of plate-like members, which collectively form the resonant cavity, wherein an outer surface of the annular gasket at least partially forms the perimeter enclosure of the hollow disc.

[0140] In some embodiments, only one of the pair of plate-like members is an active sound producing member; wherein the other of the pair of plate-like members integrally forms a portion of a transducer housing.

[0141] In some embodiments, the transducer housing is further configured to house an additional active sound producing member, wherein a propagation axis of the additional active sound producing member is coaxially arranged along the propagation axis of the electro-acoustic transducer device.

[0142] In some embodiments, both of the pair of plate-like members are active sound producing members; wherein the perimeter enclosure integrally forms a portion of a transducer housing configured to house the electro-acoustic transducer device.

[0143] In some embodiments, the resonant cavity is configured to produce a double peak in output sound pressure level (SPL) in an output frequency band of the electro-acoustic transducer device.

[0144] In some embodiments, a separation distance between the pair of plate-like members defines a height of the resonant cavity, wherein a ratio of the height of the resonant plate to its outer diameter is in a range of 1% to 5%.

[0145] In some embodiments, the resonant plate has a first thickness, wherein a ratio of the first thickness of the resonant plate to its outer diameter is in a range of 0.5% to 5%.

[0146] Another aspect of the present disclosure provides an electro-acoustic transducer device, comprising: a first transducer component comprising a hollow disc defining a resonant cavity, wherein the hollow disc substantially defines a first propagation axis, the hollow disc comprising an active transducer unit provided with a central sound port arranged about the first propagation axis and capable of accessing the resonant cavity; and a second transducer component arranged on the active transducer unit and substantially defining a second propagation axis, wherein the first propagation axis and the second propagation axis are substantially coaxially aligned.

[0147] In some embodiments, a central region around the central sound port of the active transducer unit is free of physical obstructions.

[0148] In some embodiments, the second transducer component includes a drive portion connected around the central sound port of the active transducer unit, a spring portion extending from the drive portion, and a resonant membrane portion suspended by the spring portion above a projection of the central sound port, wherein a thickness of the drive portion is greater than a thickness of the resonant membrane portion.

[0149] The description herein is presented to enable any person skilled in the art to make or use the application. Various modifications to the application will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the scope of the application. Thus, the present application is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electro-acoustic transducer apparatus, comprising: a hollow disc body having a disc-shaped main body with an interior void forming a resonance cavity, wherein opposite surfaces of a central region of the hollow disc body are each provided with a central sound port, the hollow disc body comprising a pair of plate members arranged in parallel, wherein at least one of the plate members is an active sound producing member, the active sound producing member comprising a resonant plate; wherein the opposite central sound ports form annular openings between them, the two annular openings forming a passage through the hollow disc body and defining a path into and out of the resonance cavity within the hollow disc body.

2. The apparatus of claim 1, wherein each of the central sound ports is provided in a respective central region of each of the plate members.

3. The apparatus of claim 2, further comprising a peripheral enclosure joining the pair of plate members at their respective outer edge portions, thereby defining the resonance cavity between the pair of plate members.

4. The apparatus of claim 2, wherein, the hollow disc body defining a propagation axis, wherein the plate members extend perpendicular to the propagation axis, wherein the central sound ports surround the propagation axis.

5. The apparatus of claim 1, wherein, the active sound producing member further comprising a piezoelectric member attached to the resonant plate.

6. The apparatus of claim 5, wherein, the piezoelectric member is located within the resonance cavity.

7. The apparatus of claim 1, wherein the active sound producing member comprises a single layer piezoelectric sheet.

8. The apparatus of claim 5, wherein, the piezoelectric member and the resonant plate each have an annular planar profile; wherein an outer diameter of the resonant plate is greater than an outer diameter of the piezoelectric member; and wherein the piezoelectric member and the resonant plate are coupled concentrically to each other.

9. The apparatus of claim 8, wherein a ratio between an inner diameter of the resonant plate and its outer diameter is in a range of 1:10 to 1:

3.

10. The apparatus of claim 8, wherein the resonant plate comprises a flat central well, a base portion disposed opposite the central well, an annular lip portion raised from the central well, and an edge portion surrounding a periphery of the annular lip portion.

11. The apparatus of claim 10, wherein the piezoelectric member is coupled to the base portion of the resonant plate, wherein the piezoelectric member is located outside the resonance cavity.

12. The apparatus of claim 10, wherein the edge portion of the resonant plate at least partially forms the peripheral enclosure of the hollow disc body.

13. The apparatus of claim 3, further comprising an annular gasket disposed between the pair of plate members, which collectively form the resonance cavity, wherein, an outer surface of the annular gasket at least partially forms the peripheral enclosure of the hollow disc body.

14. The apparatus of claim 4, wherein the other of the pair of plate members integrally forms a portion of a transducer housing.

15. The apparatus of claim 14, wherein the transducer housing is further configured to house an additional sound producing member, wherein a propagation axis of the additional sound producing member is coaxially arranged along the propagation axis of the electro-acoustic transducer apparatus.

16. The apparatus of claim 4, further comprising an additional sound radiating member disposed on the active sound radiating member, the additional sound radiating member defining a second propagation axis, and the second propagation axis is coaxially aligned with the propagation axis of the hollow disc body.

17. The apparatus of claim 16, wherein a central region of the active sound radiating member around the central sound receiving port is suspended and free of physical obstruction.

18. The apparatus of claim 1, wherein both of the pair of plate-like members are active sound radiating members; wherein the peripheral enclosure structure of the hollow disc body is integrally formed as a portion of a transducer housing configured to house the electro-acoustic transducer device.

19. The apparatus of claim 1, wherein the resonant cavity is configured to produce a bimodal output sound pressure level (SPL) in an output frequency band of the electro-acoustic transducer device.

20. The apparatus of claim 19, wherein a separation distance between the pair of plate-like members defines a height of the resonant cavity, wherein a ratio of the height of the resonant plate to its outer diameter is in a range of 1% to 5%.

21. The apparatus of claim 19, wherein the resonant plate has a first thickness, wherein a ratio of the first thickness of the resonant plate to its outer diameter is in a range of 0.5% to 5%.

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